WorldWideScience

Sample records for bacteria-associated chemical cues

  1. Coordinated sensor cueing for chemical plume detection

    Science.gov (United States)

    Abraham, Nathan J.; Jensenius, Andrea M.; Watkins, Adam S.; Hawthorne, R. Chad; Stepnitz, Brian J.

    2011-05-01

    This paper describes an organic data fusion and sensor cueing approach for Chemical, Biological, Radiological, and Nuclear (CBRN) sensors. The Joint Warning and Reporting Network (JWARN) uses a hardware component referred to as the JWARN Component Interface Device (JCID). The Edgewood Chemical and Biological Center has developed a small footprint and open architecture solution for the JCID capability called JCID-on-a-Chip (JoaC). The JoaC program aims to reduce the cost and complexity of the JCID by shrinking the necessary functionality down to a small single board computer. This effort focused on development of a fusion and cueing algorithm organic to the JoaC hardware. By embedding this capability in the JoaC, sensors have the ability to receive and process cues from other sensors without the use of a complex and costly centralized infrastructure. Additionally, the JoaC software is hardware agnostic, as evidenced by its drop-in inclusion in two different system-on-a-chip platforms including Windows CE and LINUX environments. In this effort, a partnership between JPM-CA, JHU/APL, and the Edgewood Chemical and Biological Center (ECBC), the authors implemented and demonstrated a new algorithm for cooperative detection and localization of a chemical agent plume. This experiment used a pair of mobile Joint Services Lightweight Standoff Chemical Agent Detector (JSLSCAD) units which were controlled by fusion and cueing algorithms hosted on a JoaC. The algorithms embedded in the JoaC enabled the two sensor systems to perform cross cueing and cooperatively form a higher fidelity estimate of chemical releases by combining sensor readings. Additionally, each JSLSCAD had the ability to focus its search on smaller regions than those required by a single sensor system by using the cross cue information from the other sensor.

  2. Note: Reaction of bacteria associated with fish spoilage to chemical and physical stress

    NARCIS (Netherlands)

    Kirby, R.; Silva, da M.; Capell, C.; Vaz-Pires, P.; Luten, J.B.

    2001-01-01

    A cocktail made up of six bacteria isolated from fish was subjected to various heats (30 °C and 60 °C, 20 s) and chemical preservative stresses, alone and in combination. The chemical preservatives tested were potassium sorbate (PS, 1Œ trisodium phosphate (TSP, 10€and tetrasodium pyrophosphate (TSPP

  3. Note: Reaction of bacteria associated with fish spoilage to chemical and physical stress

    NARCIS (Netherlands)

    Kirby, R.; Silva, da M.; Capell, C.; Vaz-Pires, P.; Luten, J.B.

    2001-01-01

    A cocktail made up of six bacteria isolated from fish was subjected to various heats (30 °C and 60 °C, 20 s) and chemical preservative stresses, alone and in combination. The chemical preservatives tested were potassium sorbate (PS, 1Œ trisodium phosphate (TSP, 10€and tetrasodium pyrophosphate

  4. Keeping eyes peeled: guppies exposed to chemical alarm cue are more responsive to ambiguous visual cues

    OpenAIRE

    Stephenson, Jessica Frances

    2016-01-01

    Abstract Information received from the visual and chemical senses is qualitatively different. For prey species in aquatic environments, visual cues are spatially and temporally reliable but risky as the prey and predator must often be in close proximity. Chemical cues, by contrast, can be distorted by currents or linger and thus provide less reliable spatial and temporal information, but can be detected from a safe distance. Chemical cues are therefore often the first detected and may provide...

  5. Sustainable biodegradation of phenolic endocrine-disrupting chemicals by Phragmites australis-rhizosphere bacteria association.

    Science.gov (United States)

    Toyama, T; Ojima, T; Tanaka, Y; Mori, K; Morikawa, M

    2013-01-01

    The efficacy of two rhizobacteria (Sphingobium fuliginis TIK1 and Sphingobium sp. IT4) of Phragmites australis for the sustainable treatment of water polluted with phenolic endocrine-disrupting chemicals (EDCs) was investigated. Strains TIK1 and IT4 have recently been isolated from Phragmites rhizosphere and shown to degrade various 4-alkylphenols-TIK1 via phenolic ring hydroxylation and meta-cleavage and IT4 via ipso-hydroxylation. The two strains also degraded bisphenol A (BPA), bisphenol B, bisphenol E, bisphenol F, bisphenol P and bisphenol S (BPS). Thus, strains TIK1 and IT4 have wide degradation spectra for phenolic EDCs. The two strains utilized Phragmites root extracts as a sole carbon source and sustainably colonized Phragmites roots, where they degraded phenolic EDCs. In sequencing batch reactor experiments using Phragmites in association with TIK1 or IT4, both associations repeatedly removed phenolic EDCs from polluted secondary effluent water (BPA, BPS, 4-tert-butylphenol, 4-tert-octylphenol and 4-nonylphenol) from polluted secondary effluent water. The results suggest that hydroponic systems using Phragmites-TIK and Phragmites-IT4 associations would be useful for sustainable treatment of polluted waters containing various phenolic EDCs.

  6. Stream grazers determine their crawling direction on the basis of chemical and particulate microalgal cues.

    Science.gov (United States)

    Katano, Izumi; Doi, Hideyuki

    2014-01-01

    This study aimed to determine the association between herbivore behavior and cues from producers. We used stream grazer Glossosoma larvae and determined their crawling direction in relation to chemical and visual cues from microalgae. The experimental treatments included control (no cue), particulate (chemical and particulate cues), and dissolved (chemical cue) cues from microalgae. The experimental water samples were randomly placed into either arm of a Y-shaped channel, and the crawling direction of the grazers was determined. Although the grazers crawled toward the arm containing either particulate or dissolved cues, they preferred the arm with particulate cues. This suggested that grazers responded well to both particulate (i.e., drifting algal cells) and chemical (algal smell) cues, and that particulate cues were more important for foraging. In natural habitats, grazers detect cues from producers and change their behaviors to maintain a balance between top-down and bottom-up cues.

  7. Homing orientation in salamanders: A mechanism involving chemical cues

    Science.gov (United States)

    Madison, D. M.

    1972-01-01

    A detailed description is given of experiments made to determine the senses and chemical cues used by salamanders for homing orientation. Sensory impairment and cue manipulative techniques were used in the investigation. All experiments were carried out at night. Results show that sense impaired animals did not home as readily as those who were blind but retained their sensory mechanism. This fact suggests that the olfactory mechanism is necessary for homing in the salamander. It was determined that after the impaired salamander regenerated its sensory mechanism it too returned home. It was concluded that homing ability in salamanders is direction independent, distant dependent, and vision independent.

  8. Marine chemical ecology: chemical signals and cues structure marine populations, communities, and ecosystems.

    Science.gov (United States)

    Hay, Mark E

    2009-01-01

    Chemical cues constitute much of the language of life in the sea. Our understanding of biotic interactions and their effects on marine ecosystems will advance more rapidly if this language is studied and understood. Here, I review how chemical cues regulate critical aspects of the behavior of marine organisms from bacteria to phytoplankton to benthic invertebrates and water column fishes. These chemically mediated interactions strongly affect population structure, community organization, and ecosystem function. Chemical cues determine foraging strategies, feeding choices, commensal associations, selection of mates and habitats, competitive interactions, and transfer of energy and nutrients within and among ecosystems. In numerous cases, the indirect effects of chemical signals on behavior have as much or more effect on community structure and function as the direct effects of consumers and pathogens. Chemical cues are critical for understanding marine systems, but their omnipresence and impact are inadequately recognized.

  9. Chemical cues mediate species recognition in field crickets

    Directory of Open Access Journals (Sweden)

    Frances eTyler

    2015-05-01

    Full Text Available Cuticular hydrocarbons (CHCs are important in mate choice in many insects, and may be used for species recognition if CHC profiles differ between potentially hybridizing species. In the sibling field cricket species Gryllus campestris and G. bimaculatus, females of G. bimaculatus are tolerant towards G. campestris males and can mate with them. However, G. campestris females are highly aggressive towards heterospecific G. bimaculatus males, and matings between them never happen. We examined whether cricket females might use CHCs to determine the species identity of their potential mates. We firstly analyzed the cuticular chemical profile by gas chromatography and mass spectrometry to assess the potential of CHCs to be used for species recognition in these crickets. We then manipulated females’ ability to detect chemical cues by carrying out chemical ablation of the antennae, and measured changes in aggressive responses to heterospecific males. We show that there are significant interspecies differences in CHC expression for both sexes, and that females with chemically ablated antennae reduce aggressive behavior towards heterospecific males. Our findings support the prediction that cuticular semiochemicals can play a key role in reproductive isolation between closely related insect species.

  10. Behavioral responses of zebrafish depend on the type of threatening chemical cues.

    Science.gov (United States)

    Abreu, Murilo S; Giacomini, Ana Cristina V; Gusso, Darlan; Koakoski, Gessi; Oliveira, Thiago A; Marqueze, Alessandra; Barreto, Rodrigo Egydio; Barcellos, Leonardo J G

    2016-12-01

    In fish, defensive reactions are induced by different chemical cues that emanate from sense-related stresses [physical, chemical, and visual (visual contact with predator)] or food stresses (acute fasting and chronic food restriction). Using a shuttle box with a two-chamber unmixed laminar flow that allowed fish to remain or flee from a chemical cue, we showed that the avoidance response depended on the type of the chemical cue. We show that zebrafish (Danio rerio) retreated from water conditioned with chemical cues released by chemically or physically stressed fish and acutely fasted fish, but not from water with cues from fish experiencing visual contact with predatory fish or fish suffering from chronic food restriction. Our data reinforced the hypothesis that fish use a combination of information and the context of the situation to determine their evasion strategy.

  11. Mianserin affects alarm reaction to conspecific chemical alarm cues in Nile tilapia.

    Science.gov (United States)

    Barreto, Rodrigo Egydio

    2017-02-01

    In this study, I show that mianserin, a chemical with serotonin and adrenoceptor antagonist activities, increases fish vulnerability to a potential predator threat, when prey fish must deal with this threat based on conspecific chemical alarm cues. For that, I evaluated whether mianserin, diluted in the water, influences the behavioral responses of Nile tilapia (Oreochromis niloticus) to conspecific skin extract (chemical alarm cues). I found that, while mianserin did not abolished antipredator responses, this drug mitigates some components of this defensive reaction. Thus, a potential decrease in serotonin and adrenergic activities reduces the ability of dealing with predators when perceiving conspecific chemical alarm cues.

  12. The effect of physical and chemical cues on hepatocellular function and morphology.

    Science.gov (United States)

    Abdellatef, Shimaa A; Ohi, Akihiko; Nabatame, Toshihide; Taniguchi, Akiyoshi

    2014-03-11

    Physical topographical features and/or chemical stimuli to the extracellular matrix (ECM) provide essential cues that manipulate cell functions. From the physical point of view, contoured nanostructures are very important for cell behavior in general, and for cellular functions. From the chemical point of view, ECM proteins containing an RGD sequence are known to alter cell functions. In this study, the influence of integrated physical and chemical cues on a liver cell line (HepG2) was investigated. To mimic the physical cues provided by the ECM, amorphous TiO2 nanogratings with specific dimensional and geometrical characteristics (nanogratings 90 nm wide and 150 nm apart) were fabricated. To mimic the chemical cues provided by the ECM, the TiO2 inorganic film was modified by immobilization of the RGD motif. The hepatic cell line morphological and functional changes induced by simultaneously combining these diversified cues were investigated, including cellular alignment and the expression of different functional proteins. The combination of nanopatterns and surface modification with RGD induced cellular alignment and expression of functional proteins, indicating that physical and chemical cues are important factors for optimizing hepatocyte function.

  13. Anemonefishes rely on visual and chemical cues to correctly identify conspecifics

    Science.gov (United States)

    Johnston, Nicole K.; Dixson, Danielle L.

    2017-09-01

    Organisms rely on sensory cues to interpret their environment and make important life-history decisions. Accurate recognition is of particular importance in diverse reef environments. Most evidence on the use of sensory cues focuses on those used in predator avoidance or habitat recognition, with little information on their role in conspecific recognition. Yet conspecific recognition is essential for life-history decisions including settlement, mate choice, and dominance interactions. Using a sensory manipulated tank and a two-chamber choice flume, anemonefish conspecific response was measured in the presence and absence of chemical and/or visual cues. Experiments were then repeated in the presence or absence of two heterospecific species to evaluate whether a heterospecific fish altered the conspecific response. Anemonefishes responded to both the visual and chemical cues of conspecifics, but relied on the combination of the two cues to recognize conspecifics inside the sensory manipulated tank. These results contrast previous studies focusing on predator detection where anemonefishes were found to compensate for the loss of one sensory cue (chemical) by utilizing a second cue (visual). This lack of sensory compensation may impact the ability of anemonefishes to acclimate to changing reef environments in the future.

  14. Natural populations of shipworm larvae are attracted to wood by waterborne chemical cues.

    Directory of Open Access Journals (Sweden)

    Gunilla B Toth

    Full Text Available The life cycle of many sessile marine invertebrates includes a dispersive planktonic larval stage whose ability to find a suitable habitat in which to settle and transform into benthic adults is crucial to maximize fitness. To facilitate this process, invertebrate larvae commonly respond to habitat-related chemical cues to guide the search for an appropriate environment. Furthermore, small-scale hydrodynamic conditions affect dispersal of chemical cues, as well as swimming behavior of invertebrate larvae and encounter with potential habitats. Shipworms within the family Teredinidae are dependent on terrestrially derived wood in order to complete their life cycle, but very little is known about the cues and processes that promote settlement. We investigated the potential for remote detection of settling substrate via waterborne chemical cues in teredinid larvae through a combination of empirical field and laboratory flume experiments. Natural populations of teredinid larvae were significantly more abundant close to wooden structures enclosed in plankton net compared to empty control nets, clearly showing that shipworm larvae can sense and respond to chemical cues associated with suitable settling substrate in the field. However, the flume experiments, using ecologically relevant flow velocities, showed that the boundary layer around experimental wooden panels was thin and that the mean flow velocity exceeded larval swimming velocity approximately 5 mm (≈ 25 larval body lengths from the panel surface. Therefore, we conclude that the scope for remote detection of waterborne cues is limited and that the likely explanation for the higher abundance of shipworm larvae associated with the wooden panels in the field is a response to a cue during or after attachment on, or very near, the substrate. Waterborne cues probably guide the larva in its decision to remain attached and settle, or to detach and continue swimming and drifting until the next

  15. Parasite Lost: Chemical and Visual Cues Used by Pseudacteon in Search of Azteca instabilis.

    Science.gov (United States)

    Mathis, Kaitlyn A; Philpott, Stacy M; Moreira, Rayane F

    2011-05-01

    An undescribed species of phorid fly (genus: Pseudacteon) parasitizes the ant Azteca instabilis F Smith, by first locating these ants through the use of both chemical and visual cues. Experiments were performed in Chiapas, Mexico to examine a) the anatomical source of phorid attractants, b) the specific chemicals produced that attract phorids, and c) the nature of the visual cues used by phorids to locate the ants. We determined that phorid-attracting chemicals were present within the dorsal section of the abdomen, the location of the pygidial gland. Further experiments indicate that a pygidial gland compound, 1-acetyl-2-methylcyclopentane, is at least partially responsible for attracting phorid flies to their host. Finally, although visual cues such as movement were important for host location, size and color of objects did not influence the frequency with which phorids attacked moving targets.

  16. Donor life stage influences juvenile American eel Anguilla rostrata attraction to conspecific chemical cues

    Science.gov (United States)

    Galbraith, Heather S.; Blakeslee, Carrie J.; Schmucker, Andrew K.; Johnson, Nicholas; Hansen, Michael J.; Li, Weiming

    2017-01-01

    The present study investigated the potential role of conspecific chemical cues in inland juvenile American eel Anguilla rostrata migrations by assessing glass eel and 1 year old elver affinities to elver washings, and elver affinity to adult yellow eel washings. In two-choice maze assays, glass eels were attracted to elver washings, but elvers were neither attracted to nor repulsed by multiple concentrations of elver washings or to yellow eel washings. These results suggest that A. rostrata responses to chemical cues may be life-stage dependent and that glass eels moving inland may use the odour of the previous year class as information to guide migration. The role of chemical cues and olfaction in eel migrations warrants further investigation as a potential restoration tool.

  17. Ontogenetic shift in response to prey-derived chemical cues in prairie rattlesnakes Crotalus viridis viridis

    Institute of Scientific and Technical Information of China (English)

    Anthony J.SAVIOLA; David CHISZAR; Stephen P.MACKESSY

    2012-01-01

    Snakes often have specialized diets that undergo a shift from one prey type to another depending on the life stage of the snake.Crotalus viridis viridis (prairie rattlesnake) takes different prey at different life stages,and neonates typically prey on ectotherms,while adults feed almost entirely on small endotherms.We hypothesized that elevated rates of tongue flicking to chemical stimuli should correlate with particular prey consumed,and that this response shifts from one prey type to another as individuals age.To examine if an ontogenetic shift in response to chemical cues occurred,we recorded the rate of tongue flicking for 25 neonate,20 subadult,and 20 adult (average SVL=280.9,552,789.5 mm,respectively) wild-caught C.v.viridis to chemical stimuli presented on a cotton-tipped applicator; water-soluble cues from two ectotherms (prairie lizard,Sceloporus undulatus,and house gecko,Hemidactylusfrenatus),two endotherms (deer mouse,Peromyscus maniculatus and lab mouse,Mus musculus),and water controls were used.Neonates tongue flicked significantly more to chemical cues of their common prey,S.undulatus,than to all other chemical cues; however,the response to this lizard's chemical cues decreased in adult rattlesnakes.Subadults tongue flicked with a higher rate of tongue flicking to both S.undulatus and P.maniculatus than to all other treatments,and adults tongue flicked significantly more to P.maniculatus than to all other chemical cues.In addition,all three sub-classes demonstrated a greater response for natural prey chemical cues over chemical stimuli of prey not encountered in the wild (M.musculus and H.frenatus).This shift in chemosensory response correlated with the previously described ontogenetic shifts in C.v.viridis diet.Because many vipers show a similar ontogenetic shift in diet and venom composition,we suggest that this shift in prey cue discrimination is likely a general phenomenon among viperid snakes.

  18. Chemical cues released by an alien invasive aquatic gastropod drive its invasion success.

    Directory of Open Access Journals (Sweden)

    Jacqueline L Raw

    Full Text Available BACKGROUND: Chemical cues provide aquatic organisms with sensory information that guides behavioural responses and thus interactions among themselves, each other and the environment. Chemical cues are considered important for predator avoidance, foraging, larval settlement and broadcast spawning in aquatic environments. However, the significance of their role as drivers of direct interactions between heterospecifics has been largely overlooked. METHODOLOGY/PRINCIPAL FINDINGS: A video camera and a demarcated arena were used in situ to record behavioural responses of three native gastropod species, Assiminea cf. capensis, Melanoides tuberculata and Coriandria durbanensis, exposed to treatments representing chemical cues released by a non-native invasive gastropod, Tarebia granifera. The responses were measured quantitatively as displacement and orientation of movement at locations in St Lucia Estuary, within the iSimangaliso Wetland Park, a UNESCO World Heritage Site on the east coast of South Africa. All native gastropods exhibited a negative taxis response to chemical cues released by T. granifera, while T. granifera individuals responded randomly to conspecifics. Displacement was measured relative to the source of the extract, the number of steps taken were determined with path analysis and orientation was determined from the mean (±95% CIs turning angles, with significant negative turning angles representing negative taxis. Responses to treatments corresponding to the environment and conspecifics were random and undirected, indicating kinesis. CONCLUSION/SIGNIFICANCE: This study presents evidence for interactions driven by chemical cues between a non-native invasive gastropod and several gastropods native to South Africa. The results indicate that chemical cues can facilitate invasion success as the behavioural response of native gastropods is to move away allowing additional food and space resources to become available to T. granifera.

  19. The herbicide atrazine induces hyperactivity and compromises tadpole detection of predator chemical cues.

    Science.gov (United States)

    Ehrsam, Mackenzie; Knutie, Sarah A; Rohr, Jason R

    2016-09-01

    The ability to detect chemical cues is often critical for freshwater organisms to avoid predation and find food and mates. In particular, reduced activity and avoidance of chemical cues signaling predation risk are generally adaptive behaviors that reduce prey encounter rates with predators. The present study examined the effects of the common herbicide atrazine on the ability of Cuban tree frog (Osteopilus septentrionalis) tadpoles to detect and respond to chemical cues from larval dragonfly (Libellulidae sp.) predators. Tadpoles exposed to an estimated environmental concentration of atrazine (calculated using US Environmental Protection Agency software; measured concentration, 178 μg/L) were significantly hyperactive relative to those exposed to solvent control. In addition, control tadpoles significantly avoided predator chemical cues, but tadpoles exposed to atrazine did not. These results are consistent with previous studies that have demonstrated that ecologically relevant concentrations of atrazine can induce hyperactivity and impair the olfactory abilities of other freshwater vertebrates. The authors call for additional studies examining the role of chemical contaminants in disrupting chemical communication and the quantification of subsequent impacts on the fitness and population dynamics of wildlife. Environ Toxicol Chem 2016;35:2239-2244. © 2016 SETAC.

  20. Predators marked with chemical cues from one prey have increased attack success on another prey species

    NARCIS (Netherlands)

    van Maanen, R.; Broufas, G.; de Jong, P.; Aguilar-Fenollosa, E.; Revynthi, A.; Sabelis, M.W.; Janssen, A.

    2015-01-01

    1. To reduce the risk of being eaten by predators, prey alter their morphology or behaviour. This response can be tuned to the current danger if chemical or other cues associated with predators inform the prey about the risks involved. 2. It is well known that various prey species discriminate

  1. Significance of chemical recognition cues is context dependent in ants

    DEFF Research Database (Denmark)

    Bos, N.; Guerrieri, F.J.; d'Ettorre, P.

    2010-01-01

    Recognition of group members is of fundamental importance in social animals, allowing individuals to protect resources against intruders and parasites, as well as ensuring social cohesion within the group. In ants and other social insects, social recognition relies on multicomponent chemical...... been suggested that associative learning might play a role in nestmate recognition. We investigated whether Camponotus aethiops ants can associate a complete cuticular hydrocarbon profile, consisting of about 40 compounds, with a food reward and whether the new association, developed in an appetitive...... context, affects aggression against non-nestmates carrying the hydrocarbon profile associated with food. Individual ant workers were able to associate the non-nestmate chemical profile with food. However, conditioned ants were still aggressive when encountering a non-nestmate carrying the odour profile...

  2. Responses of Eastern red-backed salamanders (Plethodon cinereus) to chemical cues of prey presented in soluble and volatile forms.

    Science.gov (United States)

    Telfer, A C; Laberge, F

    2013-04-10

    Terrestrial salamanders are able to detect prey items using chemical cues, but the nature of the cues involved is uncertain. This study aimed to tease apart the roles of the soluble and volatile components of prey cues detected by Eastern red-backed salamanders (Plethodon cinereus), assuming the likelihood that these different components are respectively detected by the vomeronasal (accessory) and main olfactory organs. Wild-caught salamanders were exposed to control or soluble and volatile cricket cues in two different behavioural assays conducted in the laboratory. The first series of assays focused on localized presentation of soluble cues on the substrate, and the second on point sources of volatile cues delivered through plastic tubes. Room temperature was varied across experiments. Salamanders increased chemoinvestigation of the substrate via nosetapping when soluble prey cues were distributed non-uniformly on the substrate. In the warmer of two temperatures tested, salamanders additionally showed a spatial preference for location of soluble cue deposition. Attraction to a point source of volatile cues was not evident when examining the responses of salamanders grouped together; however, investigation of the volatile point source was significantly correlated with side preference only when both soluble cues and a volatile point source were present. The latter suggests that a subset of salamanders were attracted to the point source of volatile cues in the presence of soluble cues on the substrate. This study indicates that soluble prey cues alone are sufficient to trigger salamander foraging behaviour, and that temperature influences this foraging response. It supports the notion that the vomeronasal system plays an important role in prey detection, but suggests that volatile cues are also investigated by some salamanders when soluble prey cues have been detected.

  3. The relative importance of prey-borne and predator-borne chemical cues for inducible antipredator responses in tadpoles.

    Science.gov (United States)

    Hettyey, Attila; Tóth, Zoltán; Thonhauser, Kerstin E; Frommen, Joachim G; Penn, Dustin J; Van Buskirk, Josh

    2015-11-01

    Chemical cues that evoke anti-predator developmental changes have received considerable attention, but it is not known to what extent prey use information from the smell of predators and from cues released through digestion. We conducted an experiment to determine the importance of various types of cues for the adjustment of anti-predator defences. We exposed tadpoles (common frog, Rana temporaria) to water originating from predators (caged dragonfly larvae, Aeshna cyanea) that were fed different types and quantities of prey outside of tadpole-rearing containers. Variation among treatments in the magnitude of morphological and behavioural responses was highly consistent. Our results demonstrate that tadpoles can assess the threat posed by predators through digestion-released, prey-borne cues and continually released predator-borne cues. These cues may play an important role in the fine-tuning of anti-predator responses and significantly affect the outcome of interactions between predators and prey in aquatic ecosystems. There has been much confusion regards terminology used in the literature, and therefore we also propose a more precise and consistent binomial nomenclature based on the timing of chemical cue release (stress-, attack-, capture-, digestion- or continually released cues) and the origin of cues (prey-borne or predator-borne cues). We hope that this new nomenclature will improve comparisons among studies on this topic.

  4. Orientation of larval and juvenile horseshoe crabs Limulus polyphemus to visual cues: Effects of chemical odors

    Directory of Open Access Journals (Sweden)

    Julie M. MEDINA, Richard A. TANKERSLEY

    2010-10-01

    Full Text Available Adult horseshoe crabs Limulus polyphemus have long served as models for the study of vision in marine arthropods. Yet, little is known about the ability of early life history stages to detect and respond to visual cues. We examined the visually directed movements of larvae and first stage juveniles to horizons containing dark visual targets of different sizes. The study tested the hypotheses that (1 larval and juvenile crabs can detect and respond to visual targets and (2 the direction of orientation varies with the presence of chemical cues associated with settlement habitats. Orientation of larval and juvenile crabs to rectangles subtending angles from 30-330o was tested in a circular arena containing water that either lacked estuarine chemical cues (offshore water or contained odors from aquatic vegetation or known predators. In the absence of chemical odors, larvae oriented toward and juveniles moved away from dark horizons subtending angles > 60°. When placed in water containing chemical odors from potential nursery habitats, including the seagrasses Halodule wrightii and Syringodium filiforme, crabs reversed their direction of orientation relative to their responses in offshore water. Odors from two known predators, the mummichug Fundulus grandis and blue crab Callinectes sapidus, had no affect on the orientation of larvae. Yet, juveniles responded to both odors by moving toward the visual target. Results support the hypothesis that the visual orientation of larval and juvenile horseshoe crabs changes upon exposure to habitat and predator cues and that the direction of the response undergoes an ontogenetic shift following metamorphosis [Current Zoology 56 (5: 618–633, 2010].

  5. Possible environmental chemical cues affecting behaviour of the mangrove gastropod Cerithidea decollata

    Science.gov (United States)

    Lazzeri, Anna Marta

    2017-03-01

    The Indo-West Pacific mangrove gastropod Cerithidea decollata feeds on the ground at low tide and climbs the trees (Avicennia marina) two hours before the arrival of water, settling well above the level that the incoming tide will reach at high tide (from 0 to 80 cm, depending on the tidal phase). In addition, it has been shown that these snails climb twice as high when translocated to lower shore sites (dominated by Rhizophora mucronata), where C. decollata is missing and the high water can reach 1.6 m instead of about 80 cm as within the snail home environment. The study assesses the possible role of chemical cues in the afore-mentioned behaviours. The hypothesis that snails may foresee the periodical tide level variation thanks to airborne chemical cues, possibly released by trees or sediments, has been rejected. On the other hand, airborne chemical cues released by R. mucronata may play a role in inducing snails translocated to low shore sites to climb much higher than control, allowing them to avoid submersion.

  6. Effects of predator chemical cues and behavioral biorhythms on foraging activity of terrestrial salamanders.

    Science.gov (United States)

    Maerz, J C; Panebianco, N L; Madison, D M

    2001-07-01

    Red-backed salamanders, Plethodon cinereus, show a variety of alarm responses to chemical cues from eastern garter snakes, Thamnophis sirtalis. We measured the foraging activity of red-backed salamanders exposed to water soiled by a garter snake (fed P. cinereus) or to unsoiled water. Salamanders exposed to snake-soiled water showed less foraging activity than salamanders exposed to unsoiled water; therefore, predators could have nonlethal effects on salamander populations. Our results also show additional factors influenced salamander foraging activity. Salamander foraging activity and responsiveness to chemical cues do not appear to have been affected by sex or food deprivation. Salamander foraging activity does appear to have been influenced by activity biorhythms. Foraging activity of animals in both treatments showed a bimodal periodicity that is consistent with natural activity patterns controlled by internal biorhythms. Exposure to snake-soiled water significantly reduced foraging activity during periods of peak foraging activity, but had a subtler effect on foraging activity during natural lulls in activity. We suggest that both activity biorhythms and exposure to chemical cues are important factors affecting salamander foraging behavior.

  7. The mandible opening response: quantifying aggression elicited by chemical cues in ants

    DEFF Research Database (Denmark)

    Guerrieri, Fernando J; d'Ettorre, Patrizia

    2008-01-01

    Social insects have evolved efficient recognition systems guaranteeing social cohesion and protection from enemies. To defend their territories and threaten non-nestmate intruders, ants open their mandibles as a first aggressive display. Albeit chemical cues play a major role in discrimination......) was recorded as the aggressive response. In all assayed species, MOR significantly differed among stimuli, being weakest towards nestmate odour and strongest towards odours originating from ants of a different genus. We thus introduce here a new procedure suitable for studying the chemical basis of aggression...

  8. Female sea lamprey shift orientation toward a conspecific chemical cue to escape a sensory trap

    Science.gov (United States)

    Brant, Cory O.; Johnson, Nicholas; Li, Ke; Buchinger, Tyler J.; Li, Weiming

    2016-01-01

    The sensory trap model of signal evolution hypothesizes that signalers adapt to exploit a cue used by the receiver in another context. Although exploitation of receiver biases can result in conflict between the sexes, deceptive signaling systems that are mutually beneficial drive the evolution of stable communication systems. However, female responses in the nonsexual and sexual contexts may become uncoupled if costs are associated with exhibiting a similar response to a trait in both contexts. Male sea lamprey (Petromyzon marinus) signal with a mating pheromone, 3-keto petromyzonol sulfate (3kPZS), which may be a match to a juvenile cue used by females during migration. Upstream movement of migratory lampreys is partially guided by 3kPZS, but females only move toward 3kPZS with proximal accuracy during spawning. Here, we use in-stream behavioral assays paired with gonad histology to document the transition of female preference for juvenile- and male-released 3kPZS that coincides with the functional shift of 3kPZS as a migratory cue to a mating pheromone. Females became increasingly biased toward the source of synthesized 3kPZS as their maturation progressed into the reproductive phase, at which point, a preference for juvenile odor (also containing 3kPZS naturally) ceased to exist. Uncoupling of female responses during migration and spawning makes the 3kPZS communication system a reliable means of synchronizing mate search. The present study offers a rare example of a transition in female responses to a chemical cue between nonsexual and sexual contexts, provides insights into the origins of stable communication signaling systems.

  9. An evaluation of silver-stage American Eel conspecific chemical cueing during outmigration

    Science.gov (United States)

    Schmucker, Andrew K.; Johnson, Nicholas S.; Galbraith, Heather S.; Li, Weiming

    2017-01-01

    American Eel Anguilla rostrata abundance has declined in recent decades, in part because sexually maturing, silver-stage adults, outmigrating from freshwater to oceanic spawning grounds, encounter migratory blockades or perish when passing through active hydroelectric turbines. To help improve downstream passage effectiveness and increase survival rates, the role of silver-stage American Eel conspecific chemical cueing during outmigration was investigated using a new type of bioassay. Inside a laboratory flume, downstream-swimming eels were exposed to both live (putative attractant) and dead (putative repellent) conspecific washings to determine whether their trajectory of downstream movement, level of activity, or time spent inside targeted areas of the arena changed after exposure. Silver eels were not attracted to or repulsed by either odor, as none of five scoring metrics indicated a behavioral response. Results did not support the hypothesis that conspecific chemical cueing is a mechanism for downstream migration coordination or danger avoidance; however responses may not have been readily apparent in this type of assay. Fisheries managers may opt to focus future research on more feasible restoration efforts using alternate experimental designs to remedy this ecological issue.

  10. Discrimination of conspecific sex and reproductive condition using chemical cues in axolotls ( Ambystoma mexicanum).

    Science.gov (United States)

    Park, D; McGuire, J M; Majchrzak, A L; Ziobro, J M; Eisthen, H L

    2004-05-01

    Chemosensory cues play an important role in the daily lives of salamanders, mediating foraging, conspecific recognition, and territorial advertising. We investigated the behavioral effects of conspecific whole-body odorants in axolotls, Ambystoma mexicanum, a salamander species that is fully aquatic. We found that males increased general activity when exposed to female odorants, but that activity levels in females were not affected by conspecific odorants. Although males showed no difference in courtship displays across testing conditions, females performed courtship displays only in response to male odorants. We also found that electro-olfactogram responses from the olfactory and vomeronasal epithelia were larger in response to whole-body odorants from the opposite sex than from the same sex. In males, odorants from gravid and recently spawned females evoked different electro-olfactogram responses at some locations in the olfactory and vomeronasal epithelia; in general, however, few consistent differences between the olfactory and vomeronasal epithelia were observed. Finally, post hoc analyses indicate that experience with opposite-sex conspecifics affects some behavioral and electrophysiological responses. Overall, our data indicate that chemical cues from conspecifics affect general activity and courtship behavior in axolotls, and that both the olfactory and vomeronasal systems may be involved in discriminating the sex and reproductive condition of conspecifics.

  11. Foraging and ingestive behaviors of whale sharks, Rhincodon typus, in response to chemical stimulus cues.

    Science.gov (United States)

    Dove, Alistair D M

    2015-02-01

    Whale sharks, Rhincodon typus, display a number of behaviors that suggest these animals can locate food from afar, as well as identify and discriminate between food items. However, their intractably large size and relative rarity in the field has so far prevented direct studies of their behavior and sensory capability. A small population of aquarium-held whale sharks facilitated direct studies of behavior in response to chemical stimulus plumes. Whale sharks were exposed to plumes composed of either homogenized krill or simple aqueous solutions of dimethyl sulfide (DMS), which is associated with krill aggregations and is used by several pelagic species as a food-finding stimulus. Whale sharks exhibited pronounced ingestive and search behaviors when exposed to both types of stimuli, compared to control trials. Ingestive behaviors included open mouth swimming and active surface feeding (gulping). These behaviors were stronger and more prevalent in response to krill homogenate plumes than to DMS plumes. Both chemical stimuli also increased visitation rate, and krill homogenate plumes additionally affected swimming speed. Whale sharks use chemosensory cues of multiple types to locate and identify palatable food, suggesting that chemical stimuli can help direct long-range movements and allow discrimination of different food items. There appears to be a hierarchy of responses: krill metabolites directly associated with food produced more frequent and intense feeding responses relative to DMS, which is indirectly associated with krill. DMS is used to find food by a number of pelagic species and may be an important signaling molecule in pelagic food webs.

  12. Behavioural responses of Odontophrynus americanus tadpoles (Anura: Leptodactylidae to fish chemical cues

    Directory of Open Access Journals (Sweden)

    Scarabotti, Pablo A.

    2007-02-01

    Full Text Available Las larvas de muchas especies de anfibios viven en ambientes con vegetación y de aguas turbias, donde la visibilidad es muy limitada. En estos ambientes, la utilización de señales químicas para la detección de depredadores podría ser más confiable que la utilización de señales visuales. Las larvas de Odontophrynus americanus habitan en las lagunas del valle aluvial del río Paraná Medio, Argentina, donde normalmente se dan condiciones de baja visibilidad. La hipótesis de este trabajo fue que los renacuajos de esta especie pueden detectar a los depredadores y responder subsecuentemente con conducta antipredador ante la percepción de señales químicas de los depredadores. En el presente trabajo se llevaron a cabo tres experimentos de laboratorio para evaluar si los renacuajos de O. americanus responden conductualmente al estímulo químico del pez Astyanax fasciatus. Las respuestas conductuales fueron evaluadas observando cambios en actividad, utilización de refugio y distribución espacial de los renacuajos. En presencia del estímulo químico del pez, los renacuajos redujeron su actividad en un 27%, incrementaron cinco veces la utilización de refugios, pero no exhibieron una respuesta de elusión espacial al estímulo del depredador. Las respuestas conductuales de los renacuajos de esta especie podrían reducir las probabilidades de encuentro y ataque por parte de los depredadores. Many amphibian larvae live in turbid and vegetated habitats with very limited visibility. In these habitats, the use of chemical cues for predator detection may be more reliable than visual ones. Odontophrynus americanus tadpoles inhabit floodplain ponds of the middle Paraná River, Argentina, where they frequently encounter low visibility conditions. We hypothesize that tadpoles of this species can detect predators and subsequently respond with antipredator behaviour by means of chemical cues from predators. In the present work, we ran three separate

  13. Encoding physico-chemical cues in synthetic hydrogels by triple helix assembly of collagen mimetic peptides

    Science.gov (United States)

    Stahl, Patrick

    The ECM is a complex natural system evolved to promote proliferation and differentiation of cells during tissue development. In order to create synthetic biomaterials for studying cell-scaffold interactions and ultimately for engineering tissues, scientists strive to recapitulate many characteristics of ECM by developing hydrogels that contain mechanical cues and biochemical signals such as adhesion moieties and cell growth factors. While synthetic hydrogels bypass limitations of naturally-derived materials (e.g. transfer of pathogens), nature provides inspiration to enhance the functionality of synthetic hydrogels through biomimetic approaches. The collagen triple helix is the basis for the supramolecular structure of collagen in the ECM, and its adaptation in collagen mimetic peptides (CMPs) has provided hybridization mechanisms that can be employed in the formation and functionalization of synthetic hydrogels. The aim of this dissertation is to develop novel poly(ethylene glycol) (PEG)-based hydrogels that employ CMP triple helix assembly as a non-covalent yet target-specific tool to encode physical and chemical cues into the hydrogel with spatial control. We demonstrate that multi-arm PEG functionalized with CMPs form hydrogels supported by physical crosslinks mediated by CMP triple helix. Particle tracking microrheology shows that these physical crosslinks are sensitive to temperature as well as addition of exogenous CMPs that can disrupt crosslinks by competing for triple helix formation. This physical crosslink disruption enables the modulation of bulk hydrogel elasticity and the introduction of local stiffness gradients in PEG-CMP hydrogels. We also present photopolymerized PEG diacrylate (PEGDA) hydrogels displaying CMPs that can be further conjugated to CMPs with bioactive moieties via triple helix hybridization. Encoding these hydrogels with cell-adhesive CMPs induces cell spreading and proliferation. We further demonstrate generation of gradients and

  14. Multi-Modal Homing in Sea Turtles: Modeling Dual Use of Geomagnetic and Chemical Cues in Island-Finding.

    Science.gov (United States)

    Endres, Courtney S; Putman, Nathan F; Ernst, David A; Kurth, Jessica A; Lohmann, Catherine M F; Lohmann, Kenneth J

    2016-01-01

    Sea turtles are capable of navigating across large expanses of ocean to arrive at remote islands for nesting, but how they do so has remained enigmatic. An interesting example involves green turtles (Chelonia mydas) that nest on Ascension Island, a tiny land mass located approximately 2000 km from the turtles' foraging grounds along the coast of Brazil. Sensory cues that turtles are known to detect, and which might hypothetically be used to help locate Ascension Island, include the geomagnetic field, airborne odorants, and waterborne odorants. One possibility is that turtles use magnetic cues to arrive in the vicinity of the island, then use chemical cues to pinpoint its location. As a first step toward investigating this hypothesis, we used oceanic, atmospheric, and geomagnetic models to assess whether magnetic and chemical cues might plausibly be used by turtles to locate Ascension Island. Results suggest that waterborne and airborne odorants alone are insufficient to guide turtles from Brazil to Ascension, but might permit localization of the island once turtles arrive in its vicinity. By contrast, magnetic cues might lead turtles into the vicinity of the island, but would not typically permit its localization because the field shifts gradually over time. Simulations reveal, however, that the sequential use of magnetic and chemical cues can potentially provide a robust navigational strategy for locating Ascension Island. Specifically, one strategy that appears viable is following a magnetic isoline into the vicinity of Ascension Island until an odor plume emanating from the island is encountered, after which turtles might either: (1) initiate a search strategy; or (2) follow the plume to its island source. These findings are consistent with the hypothesis that sea turtles, and perhaps other marine animals, use a multi-modal navigational strategy for locating remote islands.

  15. Multi-modal homing in sea turtles: modeling dual use of geomagnetic and chemical cues in island-finding

    Directory of Open Access Journals (Sweden)

    Courtney S Endres

    2016-02-01

    Full Text Available Sea turtles are capable of navigating across large expanses of ocean to arrive at remote islands for nesting, but how they do so has remained enigmatic. An interesting example involves green turtles (Chelonia mydas that nest on Ascension Island, a tiny land mass located approximately 2000 km from the turtles' foraging grounds along the coast of Brazil. Sensory cues that turtles are known to detect, and which might hypothetically be used to help locate Ascension Island, include the geomagnetic field, airborne odorants, and waterborne odorants. One possibility is that turtles use magnetic cues to arrive in the vicinity of the island, then use chemical cues to pinpoint its location. As a first step toward investigating this hypothesis, we used oceanic, atmospheric, and geomagnetic models to assess whether magnetic and chemical cues might plausibly be used by turtles to locate Ascension Island. Results suggest that waterborne and airborne odorants alone are insufficient to guide turtles from Brazil to Ascension, but might permit localization of the island once turtles arrive in its vicinity. By contrast, magnetic cues might lead turtles into the vicinity of the island, but would not typically permit its localization because the field shifts gradually over time. Simulations reveal, however, that the sequential use of magnetic and chemical cues can potentially provide a robust navigational strategy for locating Ascension Island. Specifically, one strategy that appears viable is following a magnetic isoline into the vicinity of Ascension Island until an odor plume emanating from the island is encountered, after which turtles might either: (1 initiate a search strategy; or (2 follow the plume to its island source. These findings are consistent with the hypothesis that sea turtles, and perhaps other marine animals, use a multi-modal navigational strategy for locating remote islands.

  16. Discrimination of familiarity and sex from chemical cues in the dung by wild southern white rhinoceros.

    Science.gov (United States)

    Cinková, Ivana; Policht, Richard

    2015-01-01

    Communication in rhinos is primarily mediated by the vocal and olfactory signals as they have relatively poor eyesight. White rhinos are the most social of all the rhinoceros species, they defecate at common dungheaps and the adult bulls use dung and urine to mark their territory. Chemical communication may therefore be particularly important in the social interactions of white rhinos, and its knowledge could be very helpful in their management and conservation. However, no studies have investigated up until now the olfactory discrimination in any rhinoceros species in the wild. We have experimentally studied the reactions of the wild southern white rhinos (Ceratotherium simum) to the dung of familiar and unfamiliar adult females and adult territorial males. We registered the number of sniffing events, the duration of sniffing and the latency of the vigilance posture from the onset of sniffing. The dung of unfamiliar rhinos was sniffed longer than that of familiar rhinos. The rhinos showed a shorter latency of vigilance posture to the familiar dung of males than that of females. For unfamiliar dung, they displayed a shorter latency of vigilance posture to female than male dung. Our results indicate that the rhinos are able to discriminate the familiarity and sex of conspecifics from the smell of their dung. Olfactory cues could therefore play an important role in the social relationships and spatial organization of the southern white rhinoceros.

  17. Bacteria associated with Amblyomma cajennense tick eggs

    Directory of Open Access Journals (Sweden)

    Erik Machado-Ferreira

    2015-01-01

    Full Text Available AbstractTicks represent a large group of pathogen vectors that blood feed on a diversity of hosts. In the Americas, the Ixodidae ticks Amblyomma cajennense are responsible for severe impact on livestock and public health. In the present work, we present the isolation and molecular identification of a group of culturable bacteria associated with A. cajennense eggs from females sampled in distinct geographical sites in southeastern Brazil. Additional comparative analysis of the culturable bacteria from Anocentor nitens, Rhipicephalus sanguineus and Ixodes scapularis tick eggs were also performed. 16S rRNA gene sequence analyses identified 17 different bacterial types identified as Serratia marcescens, Stenotrophomonas maltophilia, Pseudomonas fluorescens, Enterobacter spp., Micrococcus luteus, Ochrobactrum anthropi, Bacillus cereus and Staphylococcus spp., distributed in 12 phylogroups. Staphylococcus spp., especially S. sciuri,was the most prevalent bacteria associated with A. cajennenseeggs, occurring in 65% of the samples and also frequently observed infecting A. nitens eggs. S. maltophilia, S. marcescens and B. cereus occurred infecting eggs derived from specific sampling sites, but in all cases rising almost as pure cultures from infected A. cajennense eggs. The potential role of these bacterial associations is discussed and they possibly represent new targets for biological control strategies of ticks and tick borne diseases.

  18. Hyphae colonizing bacteria associated with Penicillium bilaii

    DEFF Research Database (Denmark)

    Ghodsalavi, Behnoushsadat

    shown that mycorrhizal helper bacteria presenting in mycorrhizal fungi could stimulate fungal growth, promote establishment of root-fungus symbiosis and enhance plant production. But it is unknown if the comparable relationship exist between the non-mycorrhizal fungus P. bilaii and its hyphae associated...... bacteria. In the current PhD thesis, we assumed that hyphae-associated microbiome of P. bilaii might harbor helper bacteria with ability to improve fungal growth and P solubilization performance. Therefore, we aimed to isolate bacteria associated with the P. bilaii hyphae and identify the fungal growth...... stimulating bacteria with the perspective of promoting efficiency of Jumpstart in soil – plant system. For this purpose, most of the work within the current project was carried out by development of suitable model systems by mimicking the natural soil habitat to reach to the reliable performance in soil...

  19. Anthropogenic chemical cues can alter the swimming behaviour of juvenile stages of a temperate fish.

    Science.gov (United States)

    Díaz-Gil, Carlos; Cotgrove, Lucy; Smee, Sarah Louise; Simón-Otegui, David; Hinz, Hilmar; Grau, Amalia; Palmer, Miquel; Catalán, Ignacio A

    2017-04-01

    Human pressure on coastal areas is affecting essential ecosystems including fish nursery habitats. Among these anthropogenic uses, the seasonal increment in the pressure due to leisure activities such as coastal tourism and yachting is an important environmental stressor in many coastal zones. These pressures may elicit understudied impacts due to, for example, sunscreens or other seasonal pollutants. The island of Majorca, northwest Mediterranean Sea, experiences one of the highest number of tourist visits per capita in the world, thus the surrounding coastal habitat is subject to high anthropogenic seasonal stress. Studies on early stages of fishes have observed responses to coastal chemical cues for the selection or avoidance of habitats. However, the potential interferences of human impacts on these signals are largely unknown. A choice chamber was used to determine water type preference and behaviour in naïve settled juvenile gilt-head sea bream (Sparus aurata), a temperate species of commercial interest. Fish were tested individually for behavioural changes with respect to water types from potential beneficial habitats, such as seawater with extract of the endemic seagrass Posidonia oceanica, anthropogenically influenced habitats such as water extracted from a commercial and recreational harbour and seawater mixed with sunscreen at concentrations observed in coastal waters. Using a Bayesian approach, we investigated a) water type preference; b) mean speed; and c) variance in the movement (as an indicator of burst swimming activity, or "sprint" behaviour) as behavioural descriptors with respect to water type. Fish spent similar percentage of time in treatment and control water types. However, movement descriptors showed that fish in sunscreen water moved slower (98.43% probability of being slower) and performed fewer sprints (90.1% probability of having less burst in speed) compared to control water. Less evident increases in sprints were observed in harbour

  20. Volatile chemical cues guide host location and host selection by parasitic plants

    Science.gov (United States)

    Justin B. Runyon; Mark C. Mescher; Consuelo M. De Moraes

    2006-01-01

    The importance of plant volatiles in mediating interactions between plant species is much debated. Here, we demonstrate that the parasitic plant Cuscuta pentagona (dodder) uses volatile cues for host location. Cuscuta pentagona seedlings exhibit directed growth toward nearby tomato plants (Lycopersicon esculentum...

  1. Karrikins Identified in Biochars Indicate Post-Fire Chemical Cues Can Influence Community Diversity and Plant Development

    Science.gov (United States)

    Kochanek, Jitka; Flematti, Gavin R.

    2016-01-01

    Background Karrikins are smoke-derived compounds that provide strong chemical cues to stimulate seed germination and seedling growth. The recent discovery in Arabidopsis that the karrikin perception system may be present throughout angiosperms implies a fundamental plant function. Here, we identify the most potent karrikin, karrikinolide (KAR1), in biochars and determine its role in species unique plant responses. Methods Biochars were prepared by three distinct commercial-scale pyrolysis technologies using systematically selected source material and their chemical properties, including karrikinolide, were quantified. Dose-response assays determined the effects of biochar on seed germination for two model species that require karrikinolide to break dormancy (Solanum orbiculatum, Brassica tourneforttii) and on seedling growth using two species that display plasticity to karrikins, biochar and phytotoxins (Lactuca sativa, Lycopersicon esculentum). Multivariate analysis examined relationships between biochar properties and the plant phenotype. Findings and Conclusions Results showed that karrikin abundant biochars stimulated dormant seed germination and seedling growth via mechanisms analogous to post-fire chemical cues. The individual species response was associated with its sensitivity to karrikinolide and inhibitory compounds within the biochars. These findings are critical for understanding why biochar influences community composition and plant physiology uniquely for different species and reaffirms that future pyrolysis technologies promise by-products that concomitantly sequester carbon and enhance plant growth for ecological and broader plant related applications. PMID:27536995

  2. Divergent chemical cues elicit seed collecting by ants in an obligate multi-species mutualism in lowland Amazonia.

    Science.gov (United States)

    Youngsteadt, Elsa; Guerra Bustios, Patricia; Schal, Coby

    2010-12-30

    In lowland Amazonian rainforests, specific ants collect seeds of several plant species and cultivate them in arboreal carton nests, forming species-specific symbioses called ant-gardens (AGs). In this obligate mutualism, ants depend on the plants for nest stability and the plants depend on ant nests for substrate and nutrients. AG ants and plants are abundant, dominant members of lowland Amazonian ecosystems, but the cues ants use to recognize the seeds are poorly understood. To address the chemical basis of the ant-seed interaction, we surveyed seed chemistry in nine AG species and eight non-AG congeners. We detected seven phenolic and terpenoid volatiles common to seeds of all or most of the AG species, but a blend of the shared compounds was not attractive to the AG ant Camponotus femoratus. We also analyzed seeds of three AG species (Anthurium gracile, Codonanthe uleana, and Peperomia macrostachya) using behavior-guided fractionation. At least one chromatographic fraction of each seed extract elicited retrieval behavior in C. femoratus, but the active fractions of the three plant species differed in polarity and chemical composition, indicating that shared compounds alone did not explain seed-carrying behavior. We suggest that the various AG seed species must elicit seed-carrying with different chemical cues.

  3. Divergent chemical cues elicit seed collecting by ants in an obligate multi-species mutualism in lowland Amazonia.

    Directory of Open Access Journals (Sweden)

    Elsa Youngsteadt

    Full Text Available In lowland Amazonian rainforests, specific ants collect seeds of several plant species and cultivate them in arboreal carton nests, forming species-specific symbioses called ant-gardens (AGs. In this obligate mutualism, ants depend on the plants for nest stability and the plants depend on ant nests for substrate and nutrients. AG ants and plants are abundant, dominant members of lowland Amazonian ecosystems, but the cues ants use to recognize the seeds are poorly understood. To address the chemical basis of the ant-seed interaction, we surveyed seed chemistry in nine AG species and eight non-AG congeners. We detected seven phenolic and terpenoid volatiles common to seeds of all or most of the AG species, but a blend of the shared compounds was not attractive to the AG ant Camponotus femoratus. We also analyzed seeds of three AG species (Anthurium gracile, Codonanthe uleana, and Peperomia macrostachya using behavior-guided fractionation. At least one chromatographic fraction of each seed extract elicited retrieval behavior in C. femoratus, but the active fractions of the three plant species differed in polarity and chemical composition, indicating that shared compounds alone did not explain seed-carrying behavior. We suggest that the various AG seed species must elicit seed-carrying with different chemical cues.

  4. Chemical Cues Influence Pupation Behavior of Drosophila simulans and Drosophila buzzatii in Nature and in the Laboratory

    Science.gov (United States)

    Beltramí, Marcial; Medina-Muñoz, María Cristina; Del Pino, Francisco; Ferveur, Jean-Francois; Godoy-Herrera, Raúl

    2012-01-01

    In the wild, larvae of several species of Drosophila develop in heterogeneous and rapidly changing environments sharing resources as food and space. In this scenario, sensory systems contribute to detect, localize and recognize congeners and heterospecifics, and provide information about the availability of food and chemical features of environments where animals live. We investigated the behavior of D. simulans and D. buzzatii larvae to chemicals emitted by conspecific and heterospecific larvae. Our goal was to understand the role of these substances in the selection of pupation sites in the two species that cohabit within decaying prickly pear fruits (Opuntia ficus-indica). In these breeding sites, larvae of D. simulans and D. buzzatii detect larvae of the other species changing their pupation site preferences. Larvae of the two species pupated in the part of the fruit containing no or few heterospecifics, and spent a longer time in/on spots marked by conspecifics rather than heterospecifics. In contrast, larvae of the two species reared in isolation from conspecifics pupated randomly over the substrate and spent a similar amount of time on spots marked by conspecifics and by heterospecifics. Our results indicate that early chemically-based experience with conspecific larvae is critical for the selection of the pupation sites in D. simulans and D. buzzatii, and that pupation site preferences of Drosophila larvae depend on species-specific chemical cues. These preferences can be modulate by the presence of larvae of the same or another species. PMID:22737236

  5. Chemical cues influence pupation behavior of Drosophila simulans and Drosophila buzzatii in nature and in the laboratory.

    Directory of Open Access Journals (Sweden)

    Marcial Beltramí

    Full Text Available In the wild, larvae of several species of Drosophila develop in heterogeneous and rapidly changing environments sharing resources as food and space. In this scenario, sensory systems contribute to detect, localize and recognize congeners and heterospecifics, and provide information about the availability of food and chemical features of environments where animals live. We investigated the behavior of D. simulans and D. buzzatii larvae to chemicals emitted by conspecific and heterospecific larvae. Our goal was to understand the role of these substances in the selection of pupation sites in the two species that cohabit within decaying prickly pear fruits (Opuntia ficus-indica. In these breeding sites, larvae of D. simulans and D. buzzatii detect larvae of the other species changing their pupation site preferences. Larvae of the two species pupated in the part of the fruit containing no or few heterospecifics, and spent a longer time in/on spots marked by conspecifics rather than heterospecifics. In contrast, larvae of the two species reared in isolation from conspecifics pupated randomly over the substrate and spent a similar amount of time on spots marked by conspecifics and by heterospecifics. Our results indicate that early chemically-based experience with conspecific larvae is critical for the selection of the pupation sites in D. simulans and D. buzzatii, and that pupation site preferences of Drosophila larvae depend on species-specific chemical cues. These preferences can be modulate by the presence of larvae of the same or another species.

  6. Chemical cues influence pupation behavior of Drosophila simulans and Drosophila buzzatii in nature and in the laboratory.

    Science.gov (United States)

    Beltramí, Marcial; Medina-Muñoz, María Cristina; Del Pino, Francisco; Ferveur, Jean-Francois; Godoy-Herrera, Raúl

    2012-01-01

    In the wild, larvae of several species of Drosophila develop in heterogeneous and rapidly changing environments sharing resources as food and space. In this scenario, sensory systems contribute to detect, localize and recognize congeners and heterospecifics, and provide information about the availability of food and chemical features of environments where animals live. We investigated the behavior of D. simulans and D. buzzatii larvae to chemicals emitted by conspecific and heterospecific larvae. Our goal was to understand the role of these substances in the selection of pupation sites in the two species that cohabit within decaying prickly pear fruits (Opuntia ficus-indica). In these breeding sites, larvae of D. simulans and D. buzzatii detect larvae of the other species changing their pupation site preferences. Larvae of the two species pupated in the part of the fruit containing no or few heterospecifics, and spent a longer time in/on spots marked by conspecifics rather than heterospecifics. In contrast, larvae of the two species reared in isolation from conspecifics pupated randomly over the substrate and spent a similar amount of time on spots marked by conspecifics and by heterospecifics. Our results indicate that early chemically-based experience with conspecific larvae is critical for the selection of the pupation sites in D. simulans and D. buzzatii, and that pupation site preferences of Drosophila larvae depend on species-specific chemical cues. These preferences can be modulate by the presence of larvae of the same or another species.

  7. Following of conspecific and avoidance of predator chemical cues by pine snakes (Pituophis melanoleucus).

    Science.gov (United States)

    Burger, J

    1989-03-01

    The ability of hatchling pine snakes (Pituophis melanoleucus) to follow or avoid the chemical trails of conspecifics and a king snake (Lampropeltis getulus) on paper substrates was investigated inY-maze experiments. Hatchlings entered the arm with the adult conspecific trail and avoided the arm containing the king snake trail at a frequency much greater than that due to chance. The data support the hypotheses that pine snakes follow the chemical trails of adult conspecifics and avoid the chemical trails of a predator.

  8. Effect of chemical cues on the foraging and tunneling behavior of Formosan subterranean termites (Isoptera: Rhinotermitidae)

    Science.gov (United States)

    Wood rot fungi can cause directional tunneling, aggregation behavior and increased wood consumption by subterranean termites. Because vanillin and guaiacol are byproducts of lignin degradation, these chemicals were tested as potential attractants to Formosan subterranean termites, Coptotermes formo...

  9. Strong differences in chemical recognition cues between two closely related species of ants from the genus Lasius (Hymenoptera: Formicidae).

    Science.gov (United States)

    Morrison, W R; Witte, V

    2011-11-01

    Cuticular hydrocarbons (CHCs) are increasingly recognized as important to insects and are used for constructing taxonomies. However, multiple parameters affect the expression of CHCs besides a genetic component. We propose that selection may act differently on the expression of CHCs, depending on the evolutionary context. To explore the influence of selection, the CHCs of two closely related ant species, Lasius niger and Lasius platythorax, were studied in a multidisciplinary approach. We characterized (i) CHCs and (ii) niches (through baiting, activity observations and foraging analysis). The species were distinct in both measures, although to a varying degree. Although they showed moderate niche partitioning along diet and environmental preferences, chemical differences were unexpectedly pronounced. This may be explained by divergent selection on mate recognition cues or by other influences on CHCs. Such striking chemical differences among closely related species may not be the rule and suggest that taxonomies based on CHCs should be interpreted cautiously; though, they remain useful tools for differentiating among cryptic species. © 2011 The Authors. Journal of Evolutionary Biology © 2011 European Society For Evolutionary Biology.

  10. Chemical cues for host location by the chestnut gall wasp, Dryocosmus kuriphilus.

    Science.gov (United States)

    Germinara, Giacinto S; De Cristofaro, Antonio; Rotundo, Giuseppe

    2011-01-01

    Dryocosmus kuriphilus is one of the most damaging pests of Castanea spp. Behavioral, chemical, and electrophysiological investigations were employed to examine the role of plant volatiles for host location by this thelytokuos cynipid. Y-tube olfactometer bioassays showed that adult wasps are significantly attracted by C. sativa twigs with at least 1-hr-old mechanical damage. Odors of undamaged host seedlings, intact twigs, and twigs with a fresh mechanical damage were not attractive. Wasps were repelled by plant materials of the non-host Prunus laurocerasus. Fourteen compounds, mainly general green leaf volatiles, were identified in the head-space of attractive host plant twigs by gas chromatography coupled to mass spectrometry. All compounds elicited dose-dependent antennal responses in adult wasps. A synthetic blend comprising all identified compounds in the same ratio as in the attractive host source induced significant positive responses in Y-tube olfactometer bioassays. The study gives a basis for future identification of host plant attractants that could contribute to semiochemical-based monitoring and management practices of this pest.

  11. Facultative slave-making ants Formica sanguinea label their slaves with own recognition cues instead of employing the strategy of chemical mimicry.

    Science.gov (United States)

    Włodarczyk, Tomasz; Szczepaniak, Lech

    2017-01-01

    Slave-making ant species use the host workforce to ensure normal colony functioning. Slaves are robbed as pupae from their natal nest and after eclosion, assume the parasite colony as their own. A possible factor promoting the successful integration of slaves into a foreign colony is congruence with the slave-makers in terms of cuticular hydrocarbons, which are known to play the role of recognition cues in social insects. Such an adaptation is observed in the obligate slave-making ant species, which are chemically adjusted to their slaves. To date, however, no reports have been available on facultative slave-making species, which represent an earlier stage of the evolution of slavery. Such an example is Formica sanguinea, which exploit F. fusca colonies as their main source of a slave workforce. Our results show that F. sanguinea ants have a distinct cuticular hydrocarbon profile, which contains compounds not present in free-living F. fusca ants from potential target nests. Moreover, enslaved F. fusca ants acquire hydrocarbons from their slave-making nestmates to such an extent that they become chemically differentiated from free-living, conspecific ants. Our study shows that F. sanguinea ants promote their own recognition cues in their slaves, rather than employing the strategy of chemical mimicry. Possible reasons why F. sanguinea is not chemically well adjusted to its main host species are discussed in this paper. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Long-term exposure to elevated carbon dioxide does not alter activity levels of a coral reef fish in response to predator chemical cues.

    Science.gov (United States)

    Sundin, Josefin; Amcoff, Mirjam; Mateos-González, Fernando; Raby, Graham D; Jutfelt, Fredrik; Clark, Timothy D

    2017-01-01

    Levels of dissolved carbon dioxide (CO2) projected to occur in the world's oceans in the near future have been reported to increase swimming activity and impair predator recognition in coral reef fishes. These behavioral alterations would be expected to have dramatic effects on survival and community dynamics in marine ecosystems in the future. To investigate the universality and replicability of these observations, we used juvenile spiny chromis damselfish (Acanthochromis polyacanthus) to examine the effects of long-term CO2 exposure on routine activity and the behavioral response to the chemical cues of a predator (Cephalopholis urodeta). Commencing at ~3-20 days post-hatch, juvenile damselfish were exposed to present-day CO2 levels (~420 μatm) or to levels forecasted for the year 2100 (~1000 μatm) for 3 months of their development. Thereafter, we assessed routine activity before and after injections of seawater (sham injection, control) or seawater-containing predator chemical cues. There was no effect of CO2 treatment on routine activity levels before or after the injections. All fish decreased their swimming activity following the predator cue injection but not following the sham injection, regardless of CO2 treatment. Our results corroborate findings from a growing number of studies reporting limited or no behavioral responses of fishes to elevated CO2. Alarmingly, it has been reported that levels of dissolved carbon dioxide (CO2) forecasted for the year 2100 cause coral reef fishes to be attracted to the chemical cues of predators. However, most studies have exposed the fish to CO2 for very short periods before behavioral testing. Using long-term acclimation to elevated CO2 and automated tracking software, we found that fish exposed to elevated CO2 showed the same behavioral patterns as control fish exposed to present-day CO2 levels. Specifically, activity levels were the same between groups, and fish acclimated to elevated CO2 decreased their swimming

  13. Polarizing cues.

    Science.gov (United States)

    Nicholson, Stephen P

    2012-01-01

    People categorize themselves and others, creating ingroup and outgroup distinctions. In American politics, parties constitute the in- and outgroups, and party leaders hold sway in articulating party positions. A party leader's endorsement of a policy can be persuasive, inducing co-partisans to take the same position. In contrast, a party leader's endorsement may polarize opinion, inducing out-party identifiers to take a contrary position. Using survey experiments from the 2008 presidential election, I examine whether in- and out-party candidate cues—John McCain and Barack Obama—affected partisan opinion. The results indicate that in-party leader cues do not persuade but that out-party leader cues polarize. This finding holds in an experiment featuring President Bush in which his endorsement did not persuade Republicans but it polarized Democrats. Lastly, I compare the effect of party leader cues to party label cues. The results suggest that politicians, not parties, function as polarizing cues.

  14. Antibacterial and biofilm inhibitory activities of bacteria associated with polychaetes

    Directory of Open Access Journals (Sweden)

    Chellamnadar Vaikundavasagom Sunjaiy Shankar

    2015-06-01

    Full Text Available Objective: To study the antibacterial and antibiofilm activities expressed by epibiotic bacteria associated with the polychaetes Platynereis dumerilii and Syllis sp. Methods: A total of 32 cultivable bacterial strains were isolated from the two polychaete species. The crude extracts were tested for antibacterial activity and biofilm inhibitory activity against pathogenic and biofilm-forming bacterial strains. Extracts of the strains which showed strong activity were analyzed by thin-layer chromatography (TLC and the bacterial strains were identified based on 16S rRNA gene sequencing. Results: Extracts of 13 bacterial strains showed inhibitory activity against pathogenic and biofilm-forming bacteria. The crude extracts also affected the synthesis of extracellular polymeric substances and cell surface hydrophobicity of the Alteromonas sp. isolated from marine biofilm. The adhesion of Alteromonas sp. on glass surface showed significant variation between surface-associated bacterial crude extract treatment and control groups. Among the 13 bacteria, two strains PA8 and PA19 were further analyzed for bioactive fractions. Thinlayer chromatography indicated the presence of a single active fraction in the crude extract of both the bacterial strains. The epibiotic bacterial strains P8 and P19 were identified as Exiguobacterium sp. and Actinobacterium sp. respectively based on 16S rRNA gene sequencing. Conclusions: The present study indicates that bacteria associated with marine invertebrates inhabiting the coastal waters could be used as a potential source for the isolation of bioactive metabolites.

  15. Antibacterial and bioiflm inhibitory activities of bacteria associated with polychaetes

    Institute of Scientific and Technical Information of China (English)

    Sathianeson Satheesh; Nadarajan Viju

    2015-01-01

    Objective:To study the antibacterial and antibiofilm activities expressed by epibiotic bacteria associated with the polychaetes Platynereis dumerilii and Syllis sp. Methods:A total of 32 cultivable bacterial strains were isolated from the two polychaete species. The crude extracts were tested for antibacterial activity and biofilm inhibitory activity against pathogenic and biofilm-forming bacterial strains. Extracts of the strains which showed strong activity were analyzed by thin-layer chromatography (TLC) and the bacterial strains were identified based on 16S rRNA gene sequencing. Results:Extracts of 13 bacterial strains showed inhibitory activity against pathogenic and biofilm-forming bacteria. The crude extracts also affected the synthesis of extracellular polymeric substances and cell surface hydrophobicity of the Alteromonas sp. isolated from marine biofilm. The adhesion of Alteromonas sp. on glass surface showed significant variation between surface-associated bacterial crude extract treatment and control groups. Among the 13 bacteria, two strains PA8 and PA19 were further analyzed for bioactive fractions. Thin-layer chromatography indicated the presence of a single active fraction in the crude extract of both the bacterial strains. The epibiotic bacterial strains P8 and P19 were identified as Exiguobacterium sp. and Actinobacterium sp. respectively based on 16S rRNA gene sequencing. Conclusions:The present study indicates that bacteria associated with marine invertebrates inhabiting the coastal waters could be used as a potential source for the isolation of bioactive metabolites.

  16. Structural complexity of chemical recognition cues affects the perception of group membership in the ants Linephithema humile and Aphaenogaster cockerelli.

    Science.gov (United States)

    Greene, Michael J; Gordon, Deborah M

    2007-03-01

    Hydrocarbon profiles on the cuticle of social insects act as multi-component recognition cues used to identify membership in a species, a colony or, within colonies, cues about its reproductive status or task group. To examine the role of structural complexity in ant hydrocarbon recognition cues, we studied the species recognition response of two ant species, Linepithema humile and Aphaenogaster cockerelli, and the recognition of conspecifics by L. humile. The cuticular hydrocarbons of ants are composed of molecules of varying chain lengths from three structural classes, n-alkanes, methyl-branched alkanes and n-alkenes. We employed species recognition bioassays that measured the aggressive response of both species of ants to mixtures of hydrocarbon classes, single structural classes of hydrocarbons (n-alkanes, methyl-branched alkanes and n-alkenes), and controls. The results showed that a combination of at least two hydrocarbon structural classes was necessary to elicit an aggressive species recognition response. Moreover, no single class of hydrocarbons was more important than the others in eliciting a response. Similarly, in the recognition of conspecifics, Linepithema humile did not respond to a mixture of n-alkane cuticular hydrocarbons presented alone, but supplementation of nestmate hydrocarbon profiles with the n-alkanes did elicit high levels of aggression. Thus both L. humile and A. cockerelli required mixtures of hydrocarbons of different structural classes to recognize species and colony membership. It appears that information on species and colony membership is not in isolated components of the profile, but instead in the mixture of structural classes found in cuticular hydrocarbon profiles.

  17. Tests for attraction to prey and predator avoidance by chemical cues in spiders of the beech forest floor

    Directory of Open Access Journals (Sweden)

    Wetter, Melissa B.

    2012-07-01

    Full Text Available Spiders leave draglines, faeces and other secretions behind when traveling through their microhabitat. The presence of these secretions may unintentionally inform other animals, prey as well as predators, about a recent and possible current predation risk or food availability. For a wolf spider, other spiders including smaller conspecifics, form a substantial part of their prey, and larger wolf spiders, again including conspecifics, are potential predators. We tested two hypotheses: that large wolf spiders may locate patches of potential spider prey through the presence of silk threads and/or other secretions; and that prey spiders may use secretions from large wolf spiders to avoid patches with high predation risk. We used large (subadult or adult Pardosa saltans to provide predator cues and mixed dwarf spiders or small (juvenile P. saltans to provide prey cues. Subadult wolf spiders were significantly attracted to litter contaminated by dwarf spiders or small conspecifics after 6 hours but no longer after 24 hours. In contrast, neither dwarf spiders nor small P. saltans showed significant avoidance of substrate contaminated by adult P. saltans. However, small P. saltans showed different activity patterns on the two substrates. The results indicate that wolf spiders are able to increase the efficiency of foraging by searching preferentially in patches with the presence of intraguild prey. The lack of a clear patch selection response of the prey in spite of a modified activity pattern may possibly be associated with the vertical stratification of the beech litter habitat: the reduced volume of spaces in the deeper layers could make downward rather than horizontal movement a fast and safe tactic against a large predator that cannot enter these spaces.

  18. Chemical Cues Influence Pupation Behavior of Drosophila simulans and Drosophila buzzatii in Nature and in the Laboratory.

    OpenAIRE

    Marcial Beltramí; María Cristina Medina-Muñoz; Francisco Del Pino; Jean-Francois Ferveur; Raúl Godoy-Herrera

    2012-01-01

    International audience; In the wild, larvae of several species of Drosophila develop in heterogeneous and rapidly changing environments sharing resources as food and space. In this scenario, sensory systems contribute to detect, localize and recognize congeners and heterospecifics, and provide information about the availability of food and chemical features of environments where animals live. We investigated the behavior of D. simulans and D. buzzatii larvae to chemicals emitted by conspecifi...

  19. Chemical Cues which Include Amino Acids Mediate Species-Specific Feeding Behavior in Invasive Filter-Feeding Bigheaded Carps.

    Science.gov (United States)

    Claus, Aaron W; Sorensen, Peter W

    2017-03-15

    This study tested whether and how dissolved chemicals might assist food recognition in two filter-feeding fishes, the silver (Hypophthalmichthys molitrix) and the bighead carp (H. nobilis). These species evolved in Asia, are now invasive in the Mississippi River, and feed voraciously on microparticles including plankton. The food habits and biology of these carps are broadly similar to many filter-feeding fish, none of whose chemical ecology has been examined. We conducted five experiments. First, we demonstrated that buccal-pharngeal pumping (BPP), a behavior in which fish pump water into their buccal cavities, is responsible for sampling food: BPP activity in both silver and bighead carps was low and increased nearly 25-fold after exposure to a filtrate of a planktonic food mixture (P < 0.01) and over 35-fold when planktonic food was added (P < 0.001). Next, we showed that of nine food filtrates, the one containing chemicals released by spirulina, a type of cyanobacterium, was the most potent planktonic component for both species. The potency of filtrates varied between species in ways that reflected their different chemical compositions. While L-amino acids could explain about half of the activity of food filtrate, other unknown chemical stimuli were also implicated. Finally, occlusion experiments showed the olfactory sense has a very important, but not exclusive, role in bigheaded carp feeding behaviors and this might be exploited in both their control and culture.

  20. Interactions with combined chemical cues inform harvester ant foragers' decisions to leave the nest in search of food.

    Science.gov (United States)

    Greene, Michael J; Pinter-Wollman, Noa; Gordon, Deborah M

    2013-01-01

    Social insect colonies operate without central control or any global assessment of what needs to be done by workers. Colony organization arises from the responses of individuals to local cues. Red harvester ants (Pogonomyrmex barbatus) regulate foraging using interactions between returning and outgoing foragers. The rate at which foragers return with seeds, a measure of food availability, sets the rate at which outgoing foragers leave the nest on foraging trips. We used mimics to test whether outgoing foragers inside the nest respond to the odor of food, oleic acid, the odor of the forager itself, cuticular hydrocarbons, or a combination of both with increased foraging activity. We compared foraging activity, the rate at which foragers passed a line on a trail, before and after the addition of mimics. The combination of both odors, those of food and of foragers, is required to stimulate foraging. The addition of blank mimics, mimics coated with food odor alone, or mimics coated with forager odor alone did not increase foraging activity. We compared the rates at which foragers inside the nest interacted with other ants, blank mimics, and mimics coated with a combination of food and forager odor. Foragers inside the nest interacted more with mimics coated with combined forager/seed odors than with blank mimics, and these interactions had the same effect as those with other foragers. Outgoing foragers inside the nest entrance are stimulated to leave the nest in search of food by interacting with foragers returning with seeds. By using the combined odors of forager cuticular hydrocarbons and of seeds, the colony captures precise information, on the timescale of seconds, about the current availability of food.

  1. Interactions with combined chemical cues inform harvester ant foragers' decisions to leave the nest in search of food.

    Directory of Open Access Journals (Sweden)

    Michael J Greene

    Full Text Available Social insect colonies operate without central control or any global assessment of what needs to be done by workers. Colony organization arises from the responses of individuals to local cues. Red harvester ants (Pogonomyrmex barbatus regulate foraging using interactions between returning and outgoing foragers. The rate at which foragers return with seeds, a measure of food availability, sets the rate at which outgoing foragers leave the nest on foraging trips. We used mimics to test whether outgoing foragers inside the nest respond to the odor of food, oleic acid, the odor of the forager itself, cuticular hydrocarbons, or a combination of both with increased foraging activity. We compared foraging activity, the rate at which foragers passed a line on a trail, before and after the addition of mimics. The combination of both odors, those of food and of foragers, is required to stimulate foraging. The addition of blank mimics, mimics coated with food odor alone, or mimics coated with forager odor alone did not increase foraging activity. We compared the rates at which foragers inside the nest interacted with other ants, blank mimics, and mimics coated with a combination of food and forager odor. Foragers inside the nest interacted more with mimics coated with combined forager/seed odors than with blank mimics, and these interactions had the same effect as those with other foragers. Outgoing foragers inside the nest entrance are stimulated to leave the nest in search of food by interacting with foragers returning with seeds. By using the combined odors of forager cuticular hydrocarbons and of seeds, the colony captures precise information, on the timescale of seconds, about the current availability of food.

  2. Response to prey chemical cues by hatchling pine snakes (Pituophis melanoleucus): Effects of incubation temperature and experience.

    Science.gov (United States)

    Burger, J

    1991-06-01

    The ability of hatchling pine snakes (Pituophis melanoleucus) to select and follow or avoid chemical odors of prey (mice,Mus musculus) on a shavings and paper substrate was investigated in Y-maze experiments, as a function of incubation temperature and experience. Incubation temperature affected behavior in the maze, and the maze choices of naive snakes, but not of snakes that had already eaten a mouse. The data indicate that snakes that have eaten, preferentially enter the arm bearing chemical stimuli from mice, whereas those that have not eaten show no preference.

  3. Potential use of Bacillus thuringiensis bacteriocins to control antibiotic-resistant bacteria associated with mastitis in dairy goats.

    Science.gov (United States)

    Gutiérrez-Chávez, A J; Martínez-Ortega, E A; Valencia-Posadas, M; León-Galván, M F; de la Fuente-Salcido, N M; Bideshi, D K; Barboza-Corona, J E

    2016-01-01

    Mastitis caused by microbial infections in dairy goats reduces milk yield, modifies milk composition, and potentially contributes to morbidity in herds and consumers of dairy products. Microorganisms associated with mastitis in dairy goats are commonly controlled with antibiotics, but it is known that continued use of these chemical agents promotes antibiotic resistance among bacterial populations. Recently, it has been shown that bacteriocins of Bacillus thuringiensis inhibit growth of food-borne pathogens and also bacteria associated with bovine mastitis. However, there is no report on their ability to inhibit microorganisms linked to mastitis in dairy goats. In this study, using 16S rDNA and ITS regions of rDNA, we identified nine bacterial isolates and an encapsulated yeast associated with mastitis in dairy goats. Enterococcus durans, Brevibacillus sp., and Staphylococcus epidermidis 2 were resistant to, respectively, 75, ~67, ~42, and ~42 % of the antibiotics screened. In addition, 60 % of the bacterial isolates were resistant to penicillin, ampicillin, vancomycin, and dicloxacillin. Importantly, 60 % of the isolates were inhibited by the bacteriocins, but S. epidermidis 1, Enterobacter sp., Escherichia vulneris, and Cryptococcus neoformans were not susceptible to these antimicrobial peptides. Using Brevibacillus sp. and Staphylococcus chromogenes as indicator bacteria, we show that peptides of ~10 kDa that correspond to the molecular mass of bacteriocins used in this study are responsible for the inhibitory activity. Our results demonstrate that multiple antibiotic-resistant bacteria associated with subclinical mastitis in dairy goats from Guanajuato, Mexico, are susceptible to bacteriocins produced by B. thuringiensis.

  4. Phosphate-solubilizing bacteria associated with runner bean rhizosphere

    Directory of Open Access Journals (Sweden)

    Mihalache Gabriela

    2015-01-01

    Full Text Available Soil microorganisms, especially rhizobacteria, play a key role in soil phosphorus (P dynamics and the subsequent availability of phosphate to plants. Utilization of phosphate-solubilizing bacteria as biofertilizers instead of synthetic chemicals is known to improve plant growth through the supply of plant nutrients, and may help to sustain environmental health and soil productivity. The main purpose of this study was to identify new phosphate-solubilizing bacteria isolated from runner bean rhizosphere. Ten out of 25 isolated bacterial strains solubilized Ca3(PO42 in qualitative and quantitative P-solubilization. The strain that exhibited the highest potential to solubilize Ca3(PO42, was selected for further determination of the mechanisms involved in the process. The medium pH was measured, organic acids released in the culture medium were identified by HPLC analysis, and the acid and alkaline phosphatase activities were determined. Our results showed that strain R7 solubilized phosphorous through the production of various organic acids such as lactic, isocitric, tartaric and pyruvic acids, and that it can be used as a potential biofertilizer.

  5. Chemotaxis signaling systems in model beneficial plant-bacteria associations.

    Science.gov (United States)

    Scharf, Birgit E; Hynes, Michael F; Alexandre, Gladys M

    2016-04-01

    Beneficial plant-microbe associations play critical roles in plant health. Bacterial chemotaxis provides a competitive advantage to motile flagellated bacteria in colonization of plant root surfaces, which is a prerequisite for the establishment of beneficial associations. Chemotaxis signaling enables motile soil bacteria to sense and respond to gradients of chemical compounds released by plant roots. This process allows bacteria to actively swim towards plant roots and is thus critical for competitive root surface colonization. The complete genome sequences of several plant-associated bacterial species indicate the presence of multiple chemotaxis systems and a large number of chemoreceptors. Further, most soil bacteria are motile and capable of chemotaxis, and chemotaxis-encoding genes are enriched in the bacteria found in the rhizosphere compared to the bulk soil. This review compares the architecture and diversity of chemotaxis signaling systems in model beneficial plant-associated bacteria and discusses their relevance to the rhizosphere lifestyle. While it is unclear how controlling chemotaxis via multiple parallel chemotaxis systems provides a competitive advantage to certain bacterial species, the presence of a larger number of chemoreceptors is likely to contribute to the ability of motile bacteria to survive in the soil and to compete for root surface colonization.

  6. Cues of maternal condition influence offspring selfishness.

    Directory of Open Access Journals (Sweden)

    Janine W Y Wong

    Full Text Available The evolution of parent-offspring communication was mostly studied from the perspective of parents responding to begging signals conveying information about offspring condition. Parents should respond to begging because of the differential fitness returns obtained from their investment in offspring that differ in condition. For analogous reasons, offspring should adjust their behavior to cues/signals of parental condition: parents that differ in condition pay differential costs of care and, hence, should provide different amounts of food. In this study, we experimentally tested in the European earwig (Forficula auricularia if cues of maternal condition affect offspring behavior in terms of sibling cannibalism. We experimentally manipulated female condition by providing them with different amounts of food, kept nymph condition constant, allowed for nymph exposure to chemical maternal cues over extended time, quantified nymph survival (deaths being due to cannibalism and extracted and analyzed the females' cuticular hydrocarbons (CHC. Nymph survival was significantly affected by chemical cues of maternal condition, and this effect depended on the timing of breeding. Cues of poor maternal condition enhanced nymph survival in early broods, but reduced nymph survival in late broods, and vice versa for cues of good condition. Furthermore, female condition affected the quantitative composition of their CHC profile which in turn predicted nymph survival patterns. Thus, earwig offspring are sensitive to chemical cues of maternal condition and nymphs from early and late broods show opposite reactions to the same chemical cues. Together with former evidence on maternal sensitivities to condition-dependent nymph chemical cues, our study shows context-dependent reciprocal information exchange about condition between earwig mothers and their offspring, potentially mediated by cuticular hydrocarbons.

  7. Cues of Maternal Condition Influence Offspring Selfishness

    Science.gov (United States)

    Wong, Janine W. Y.; Lucas, Christophe; Kölliker, Mathias

    2014-01-01

    The evolution of parent-offspring communication was mostly studied from the perspective of parents responding to begging signals conveying information about offspring condition. Parents should respond to begging because of the differential fitness returns obtained from their investment in offspring that differ in condition. For analogous reasons, offspring should adjust their behavior to cues/signals of parental condition: parents that differ in condition pay differential costs of care and, hence, should provide different amounts of food. In this study, we experimentally tested in the European earwig (Forficula auricularia) if cues of maternal condition affect offspring behavior in terms of sibling cannibalism. We experimentally manipulated female condition by providing them with different amounts of food, kept nymph condition constant, allowed for nymph exposure to chemical maternal cues over extended time, quantified nymph survival (deaths being due to cannibalism) and extracted and analyzed the females’ cuticular hydrocarbons (CHC). Nymph survival was significantly affected by chemical cues of maternal condition, and this effect depended on the timing of breeding. Cues of poor maternal condition enhanced nymph survival in early broods, but reduced nymph survival in late broods, and vice versa for cues of good condition. Furthermore, female condition affected the quantitative composition of their CHC profile which in turn predicted nymph survival patterns. Thus, earwig offspring are sensitive to chemical cues of maternal condition and nymphs from early and late broods show opposite reactions to the same chemical cues. Together with former evidence on maternal sensitivities to condition-dependent nymph chemical cues, our study shows context-dependent reciprocal information exchange about condition between earwig mothers and their offspring, potentially mediated by cuticular hydrocarbons. PMID:24498046

  8. Blood cues induce antipredator behavior in Nile tilapia conspecifics.

    Directory of Open Access Journals (Sweden)

    Rodrigo Egydio Barreto

    Full Text Available In this study, we show that the fish Nile tilapia displays an antipredator response to chemical cues present in the blood of conspecifics. This is the first report of alarm response induced by blood-borne chemical cues in fish. There is a body of evidence showing that chemical cues from epidermal 'club' cells elicit an alarm reaction in fish. However, the chemical cues of these 'club' cells are restricted to certain species of fish. Thus, as a parsimonious explanation, we assume that an alarm response to blood cues is a generalized response among animals because it occurs in mammals, birds and protostomian animals. Moreover, our results suggest that researchers must use caution when studying chemically induced alarm reactions because it is difficult to separate club cell cues from traces of blood.

  9. Multiple approaches to enhance the cultivability of bacteria associated with the marine sponge Haliclona (gellius) sp

    NARCIS (Netherlands)

    Sipkema, D.; Schippers, K.J.; Maalcke, W.J.; Yang, Y.; Salim, S.; Blanch, H.W.

    2011-01-01

    Three methods were examined to cultivate bacteria associated with the marine sponge Haliclona (gellius) sp.: agar plate cultures, liquid cultures, and floating filter cultures. A variety of oligotrophic media were employed, including media with aqueous and organic sponge extracts, bacterial signal m

  10. Pectic Enzyme Activities of Bacteria Associated with Rotted Onions (Allium cepa)

    OpenAIRE

    Obi, Samuel K. C.; Umezurike, Gabriel M.

    1981-01-01

    The aerobic bacteria associated with soft rot in onions (Allium cepa) were isolated and identified as a Vibrio sp., Micrococcus epidermidis, Pseudomonas cepacia, an Acinetobacter sp., a Xanthomonas sp., Bacillus polymyxa, and Bacillus megaterium. With the cup-plate assay method, no pectin hydrolase could be detected from any of these isolates when they were cultured in pectin medium, but lyase and pectinesterases were detectable. Onion tissue cultures showed pectin hydrolase activity for P. c...

  11. Population of Aerobic Heterotrophic Nitrogen-Fixing Bacteria Associated with Wetland and Dryland Rice

    OpenAIRE

    Barraquio, W.L.; de Guzman, M. R.; Barrion, M.; Watanabe, I.

    1982-01-01

    Nitrogen-fixing activity and populations of nitrogen-fixing bacteria associated with two varieties of rice grown in dryland and wetland conditions were measured at various growth stages during the dry season. Acetylene reduction activities were measured both in the field and for the hydroponically grown rice, which was transferred from the field to water culture 1 day before assay. The activities measured by both methods were higher in wetland than in dryland rice. The population of nitrogen-...

  12. Illumina sequencing-based community analysis of bacteria associated with different bryophytes collected from Tibet, China.

    Science.gov (United States)

    Tang, Jing Yan; Ma, Jing; Li, Xue Dong; Li, Yan Hong

    2016-11-16

    Previous studies on the bacteria associated with the bryophytes showed that there were abundant bacteria inhabited in/on these hosts. However, the type of bacteria and whether these discriminate between different bryophytes based on a particular factor remains largely unknown. This study was designed to analyze the biodiversity and community of the bacteria associated with ten liverworts and ten mosses using Illumina-sequencing techniques based on bacterial 16S rRNA gene. A total of 125,762 high quality sequences and 437 OTUs were obtained from twenty bryophytes. Generally, there were no obvious differences between the richness of bacteria associated with liverworts and mosses; however, the diversity was significantly higher in liverworts than in mosses. The taxonomic analyses showed that there were abundant bacteria inhabited with each bryophyte and those primarily detected in all samples were within the phyla Proteobacteria, Actinobacteria, Acidobacteria, Bacteroidetes, Armatimonadetes and Planctomycetes. In addition, bacteria assigned to Chloroflexi, Fibrobacteres, Gemmatimonadetes, Chlamydiae, group of TM6 and WCHB1-60 also appeared in part of the bryophytes. The assigned bacteria included those adapted to aquatic, anaerobic and even extreme drought environments, which is consistent with the bryophyte transition from aquatic to terrestrial conditions. Of them, approximately 10 recognized genera were shared by all the samples in a higher proportion, such as Burkholderia, Novosphingobium, Mucilaginibacter, Sorangium, Frankia, Frondihatitans, Haliangium, Rhizobacter, Granulicella and Hafnia, and 11 unclassified genera were also detected in all samples, which exhibited that large amounts of unclassified bacteria could interact with the bryophytes. The Heatmap and Principle Coordinate Analyses showed that bacteria associated with six mosses displayed a higher community similarity. Notably, the bacteria associated with another four mosses exhibited higher similarity

  13. A metagenomic assessment of the bacteria associated with Lucilia sericata and Lucilia cuprina (Diptera: Calliphoridae).

    Science.gov (United States)

    Singh, Baneshwar; Crippen, Tawni L; Zheng, Longyu; Fields, Andrew T; Yu, Ziniu; Ma, Qun; Wood, Thomas K; Dowd, Scot E; Flores, Micah; Tomberlin, Jeffery K; Tarone, Aaron M

    2015-01-01

    Lucilia Robineau-Desvoidy (Diptera: Calliphoridae) is a blow fly genus of forensic, medical, veterinary, and agricultural importance. This genus is also famous because of its beneficial uses in maggot debridement therapy (MDT). Although the genus is of considerable economic importance, our knowledge about microbes associated with these flies and how these bacteria are horizontally and trans-generationally transmitted is limited. In this study, we characterized bacteria associated with different life stages of Lucilia sericata (Meigen) and Lucilia cuprina (Wiedemann) and in the salivary gland of L. sericata by using 16S rDNA 454 pyrosequencing. Bacteria associated with the salivary gland of L. sericata were also characterized using light and transmission electron microscopy (TEM). Results from this study suggest that the majority of bacteria associated with these flies belong to phyla Proteobacteria, Firmicutes, and Bacteroidetes, and most bacteria are maintained intragenerationally, with a considerable degree of turnover from generation to generation. In both species, second-generation eggs exhibited the highest bacterial phylum diversity (20 % genetic distance) than other life stages. The Lucilia sister species shared the majority of their classified genera. Of the shared bacterial genera, Providencia, Ignatzschineria, Lactobacillus, Lactococcus, Vagococcus, Morganella, and Myroides were present at relatively high abundances. Lactobacillus, Proteus, Diaphorobacter, and Morganella were the dominant bacterial genera associated with a survey of the salivary gland of L. sericata. TEM analysis showed a sparse distribution of both Gram-positive and Gram-negative bacteria in the salivary gland of L. sericata. There was more evidence for horizontal transmission of bacteria than there was for trans-generational inheritance. Several pathogenic genera were either amplified or reduced by the larval feeding on decomposing liver as a resource. Overall, this study provides

  14. Metabarcoding of Bacteria Associated with the Acute Oak Decline Syndrome in England

    Directory of Open Access Journals (Sweden)

    Melanie Sapp

    2016-04-01

    Full Text Available Outbreaks of acute oak decline (AOD have been documented in England from 2006. Both species of native oaks (Quercus robur and Quercus petraea are affected. To complement isolation efforts for identification of putative causative biotic agents and increase our understanding of bacteria associated with oak tissue, five sites in England were chosen for this study. Samples of outer bark, inner bark, sapwood and heartwood were taken from healthy oak and trees with symptoms at varying stages of the syndrome. Furthermore, larval galleries attributed to infestation with Agrilus biguttatus were included. After DNA extraction and amplification of the V3–V5 fragment of the bacterial 16S rRNA genes by pyrosequencing, the dataset was analyzed to identify patterns in bacterial communities in oak tissue samples with and without AOD symptoms at each site. The composition of bacterial communities differed greatly according to the site from which the samples were obtained. Within each site, the composition of the bacteria associated with symptomatic tissue varied between advanced stages of the syndrome and healthy tissue. Key players in healthy and symptomatic tissue were identified and included members of the Gammaproteobacteria related to Pseudomonas sp. or Brenneria goodwinii and members of the Firmicutes.

  15. A statistical approach to identify candidate cues for nestmate recognition

    DEFF Research Database (Denmark)

    van Zweden, Jelle; Pontieri, Luigi; Pedersen, Jes Søe

    2014-01-01

    on its cuticle. In this study we use previous results of this species to searchfor nestmate recognition cues (NMR cues) in two other species of ants, Camponotusaethiops, and Monomorium pharaonis. Employing chemical distances and observedaggression between colonies, we first ask which type of data...

  16. Cue conflicts in context

    DEFF Research Database (Denmark)

    Boeg Thomsen, Ditte; Poulsen, Mads

    2015-01-01

    When learning their first language, children develop strategies for assigning semantic roles to sentence structures, depending on morphosyntactic cues such as case and word order. Traditionally, comprehension experiments have presented transitive clauses in isolation, and crosslinguistically...

  17. Cue conflicts in context

    DEFF Research Database (Denmark)

    Boeg Thomsen, Ditte; Poulsen, Mads

    2015-01-01

    When learning their first language, children develop strategies for assigning semantic roles to sentence structures, depending on morphosyntactic cues such as case and word order. Traditionally, comprehension experiments have presented transitive clauses in isolation, and crosslinguistically...... in discourse-pragmatically felicitous contexts. Our results extend previous findings of preschoolers’ sensitivity to discourse-contextual cues in sentence comprehension (Hurewitz, 2001; Song & Fisher, 2005) to the basic task of assigning agent and patient roles....

  18. Hyphae colonizing bacteria associated with Penicillium bilaii

    DEFF Research Database (Denmark)

    Ghodsalavi, Behnoushsadat

    bacteria. In the current PhD thesis, we assumed that hyphae-associated microbiome of P. bilaii might harbor helper bacteria with ability to improve fungal growth and P solubilization performance. Therefore, we aimed to isolate bacteria associated with the P. bilaii hyphae and identify the fungal growth...... microscopy. Furthermore, the hyphae-associated microbiome of P. bilaii was characterized comprehensively by 16S rRNA gene-targeted amplicon sequencing. Comparison between amplicon sequencing of the 16S rRNA genes from soil bacterial community and hyphae associated bacterial microbiom indicated...... interactions between the fungus and bacteria could be considered as a promising tool to obtain reliable results after applying the bio-fertilizers in the soil system in combination with plants....

  19. Diversity and antimicrobial potential of culturable heterotrophic bacteria associated with the endemic marine sponge Arenosclera brasiliensis

    Directory of Open Access Journals (Sweden)

    Cintia P.J. Rua

    2014-06-01

    Full Text Available Marine sponges are the oldest Metazoa, very often presenting a complex microbial consortium. Such is the case of the marine sponge Arenosclera brasiliensis, endemic to Rio de Janeiro State, Brazil. In this investigation we characterized the diversity of some of the culturable heterotrophic bacteria living in association with A. brasiliensis and determined their antimicrobial activity. The genera Endozoicomonas (N = 32, Bacillus (N = 26, Shewanella (N = 17, Pseudovibrio (N = 12, and Ruegeria (N = 8 were dominant among the recovered isolates, corresponding to 97% of all isolates. Approximately one third of the isolates living in association with A. brasiliensis produced antibiotics that inhibited the growth of Bacillus subtilis, suggesting that bacteria associated with this sponge play a role in its health.

  20. Challenging synergistic activity of poplar-bacteria association for the Cd phytostabilization.

    Science.gov (United States)

    C, Cocozza; D, Trupiano; G, Lustrato; G, Alfano; D, Vitullo; A, Falasca; T, Lomaglio; V, De Felice; G, Lima; G, Ranalli; S, Scippa; R, Tognetti

    2015-12-01

    The synergistic activity between plants and microorganisms may contribute to the implementation of proactive management strategies in the stabilization of contaminated sites, although heavy metals, such as cadmium (Cd), are potentially toxic to them. The aim of this study was to evaluate the degree of tolerance to Cd contamination (supplying twice 40 mg kg(-1) of Cd) in poplar cuttings [clone I-214, P. × euramericana (Dode) Guinier] inoculated or not with two concentrations of Serratia marcescens strain (1 × 10(7) CFU/g and 2 × 10(7) CFU/g of potting mix). The response of the plant-bacteria system to excess Cd was investigated with special reference to the structural traits of plants and the functional efficiency of bacteria. Bacterial colonization and substrate components were previously assessed in order to define the best solution for formulating the experimental plant growth media. The tested plant-bacteria association, especially when bacteria were provided in double concentration, stimulated specific tolerance mechanisms to Cd through the promotion of the poplar growth. Inoculated plants produced larger leaves and increased stem diameter, while roots grew longer and wider in Cd-treated plants. The effect of bacterial inoculum on plant growth traits and metal partitioning in plant organs was assessed in order to define the potential of this poplar clone to be a suitable candidate for phytostabilization of Cd-contaminated soil. The final effect of the inoculation with bacteria, which alleviated the metal load and Cd phytotoxicity due to their bioaccumulation ability, suggests promising phytostabilization potential of these plant-bacteria associations.

  1. Reactivity to nicotine cues over repeated cue reactivity sessions

    Science.gov (United States)

    LaRowe, Steven D.; Saladin, Michael E.; Carpenter, Matthew J.; Upadhyaya, Himanshu P.

    2009-01-01

    The present study investigated whether reactivity to nicotine-related cues would attenuate across four experimental sessions held one week apart. Participants were nineteen non-treatment seeking, nicotine-dependent males. Cue reactivity sessions were performed in an outpatient research center using in vivo cues consisting of standardized smoking-related paraphernalia (e.g., cigarettes) and neutral comparison paraphernalia (e.g., pencils). Craving ratings were collected before and after both cue presentations while physiological measures (heart rate, skin conductance) were collected before and during the cue presentations. Although craving levels decreased across sessions, smoking-related cues consistently evoked significantly greater increases in craving relative to neutral cues over all four experimental sessions. Skin conductance was higher in response to smoking cues, though this effect was not as robust as that observed for craving. Results suggest that, under the described experimental parameters, craving can be reliably elicited over repeated cue reactivity sessions. PMID:17537583

  2. Reactivity to nicotine cues over repeated cue reactivity sessions.

    Science.gov (United States)

    LaRowe, Steven D; Saladin, Michael E; Carpenter, Matthew J; Upadhyaya, Himanshu P

    2007-12-01

    The present study investigated whether reactivity to nicotine-related cues would attenuate across four experimental sessions held 1 week apart. Participants were nineteen non-treatment seeking, nicotine-dependent males. Cue reactivity sessions were performed in an outpatient research center using in vivo cues consisting of standardized smoking-related paraphernalia (e.g., cigarettes) and neutral comparison paraphernalia (e.g., pencils). Craving ratings were collected before and after both cue presentations while physiological measures (heart rate, skin conductance) were collected before and during the cue presentations. Although craving levels decreased across sessions, smoking-related cues consistently evoked significantly greater increases in craving relative to neutral cues over all four experimental sessions. Skin conductance was higher in response to smoking cues, though this effect was not as robust as that observed for craving. Results suggest that, under the described experimental parameters, craving can be reliably elicited over repeated cue reactivity sessions.

  3. Cues and expressions

    Directory of Open Access Journals (Sweden)

    Thorbjörg Hróarsdóttir

    2005-02-01

    Full Text Available A number of European languages have undergone a change from object-verb to verb-object order. We focus on the change in English and Icelandic, showing that while the structural change was the same, it took place at different times and different ways in the two languages, triggered by different E-language changes. As seen from the English viewpoint, low-level facts of inflection morphology may express the relevant cue for parameters, and so the loss of inflection may lead to a grammar change. This analysis does not carry over to Icelandic, as the loss of OV there took place despite rich case morphology. We aim to show how this can be explained within a cue-style approach, arguing for a universal set of cues. However, the relevant cue may be expressed differently among languages: While it may have been expressed through morphology in English, it as expressed through information structure in Icelandic. In both cases, external effects led to fewer expressions of the relevant (universal cue and a grammar change took place.

  4. Biophysical Cueing and Vascular Endothelial Cell Behavior

    Directory of Open Access Journals (Sweden)

    Joshua A. Wood

    2010-03-01

    Full Text Available Human vascular endothelial cells (VEC line the vessels of the body and are critical for the maintenance of vessel integrity and trafficking of biochemical cues. They are fundamental structural elements and are central to the signaling environment. Alterations in the normal functioning of the VEC population are associated with a number of vascular disorders among which are some of the leading causes of death in both the United States and abroad. VECs attach to their underlying stromal elements through a specialization of the extracellular matrix, the basement membrane. The basement membrane provides signaling cues to the VEC through its chemical constituents, by serving as a reservoir for cytoactive factors and through its intrinsic biophysical properties. This specialized matrix is composed of a topographically rich 3D felt-like network of fibers and pores on the nano (1–100 nm and submicron (100–1,000 nm size scale. The basement membrane provides biophysical cues to the overlying VECs through its intrinsic topography as well as through its local compliance (relative stiffness. These biophysical cues modulate VEC adhesion, migration, proliferation, differentiation, and the cytoskeletal signaling network of the individual cells. This review focuses on the impact of biophysical cues on VEC behaviors and demonstrates the need for their consideration in future vascular studies and the design of improved prosthetics.

  5. Composition: Cue Wheel

    DEFF Research Database (Denmark)

    Bergstrøm-Nielsen, Carl

    2014-01-01

    Cue Rondo is an open composition to be realised by improvising musicians. See more about my composition practise in the entry "Composition - General Introduction". This work is licensed under a Creative Commons "by-nc" License. You may for non-commercial purposes use and distribute it, performance...

  6. Diversity of pigmented Gram-positive bacteria associated with marine macroalgae from Antarctica.

    Science.gov (United States)

    Leiva, Sergio; Alvarado, Pamela; Huang, Ying; Wang, Jian; Garrido, Ignacio

    2015-12-01

    Little is known about the diversity and roles of Gram-positive and pigmented bacteria in Antarctic environments, especially those associated with marine macroorganisms. This work is the first study about the diversity and antimicrobial activity of culturable pigmented Gram-positive bacteria associated with marine Antarctic macroalgae. A total of 31 pigmented Gram-positive strains were isolated from the surface of six species of macroalgae collected in the King George Island, South Shetland Islands. On the basis of 16S rRNA gene sequence similarities ≥99%, 18 phylotypes were defined, which were clustered into 11 genera of Actinobacteria (Agrococcus, Arthrobacter, Brachybacterium, Citricoccus, Kocuria, Labedella, Microbacterium, Micrococcus, Rhodococcus, Salinibacterium and Sanguibacter) and one genus of the Firmicutes (Staphylococcus). It was found that five isolates displayed antimicrobial activity against a set of macroalgae-associated bacteria. The active isolates were phylogenetically related to Agrococcus baldri, Brachybacterium rhamnosum, Citricoccus zhacaiensis and Kocuria palustris. The results indicate that a diverse community of pigmented Gram-positive bacteria is associated with Antartic macroalgae and suggest its potential as a promising source of antimicrobial and pigmented natural compounds. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  7. Isolation and selection of plant growth-promoting bacteria associated with sugarcane

    Directory of Open Access Journals (Sweden)

    Ariana Alves Rodrigues

    2016-06-01

    Full Text Available Microorganisms play a vital role in maintaining soil fertility and plant health. They can act as biofertilizers and increase the resistance to biotic and abiotic stress. This study aimed at isolating and characterizing plant growth-promoting bacteria associated with sugarcane, as well as assessing their ability to promote plant growth. Endophytic bacteria from leaf, stem, root and rhizosphere were isolated from the RB 867515 commercial sugarcane variety and screened for indole acetic acid (IAA production, ability to solubilize phosphate, fix nitrogen and produce hydrogen cyanide (HCN, ammonia and the enzymes pectinase, cellulase and chitinase. A total of 136 bacteria were isolated, with 83 of them presenting some plant growth mechanism: 47 % phosphate solubilizers, 26 % nitrogen fixers and 57 % producing IAA, 0.7 % HCN and chitinase, 45 % ammonia, 30 % cellulose and 8 % pectinase. The seven best isolates were tested for their ability to promote plant growth in maize. The isolates tested for plant growth promotion belong to the Enterobacteriaceae family and the Klebsiella, Enterobacter and Pantoea genera. Five isolates promoted plant growth in greenhouse experiments, showing potential as biofertilizers.

  8. Antibacterial activity of moxifloxacin on bacteria associated with periodontitis within a biofilm.

    Science.gov (United States)

    Tsaousoglou, Phoebus; Nietzsche, Sandor; Cachovan, Georg; Sculean, Anton; Eick, Sigrun

    2014-02-01

    The activity of moxifloxacin was compared with ofloxacin and doxycycline against bacteria associated with periodontitis within a biofilm (single strain and mixed population) in vitro. MICs and minimal bactericidal concentrations (MBCs) of moxifloxacin, ofloxacin and doxycyline were determined against single strains and mixed populations in a planktonic state. Single-species biofilms of two Porphyromonas gingivalis and two Aggregatibacter actinomycetemcomitans strains and a multispecies biofilm consisting of 12 species were formed for 3 days. The minimal biofilm eradication concentrations (MBECs) were determined after exposing the biofilms to the antibacterials (0.002-512 µg ml(-1)) for 18 h, addition of nutrient broth for 3 days and subsequent subcultivation. Photographs were taken using confocal laser-scanning microscopy and scanning electron microscopy. The MICs and MBCs did not differ between ofloxacin and moxifloxacin against A. actinomycetemcomitans, whilst moxifloxacin was more active than the other tested antibacterials against anaerobes and the mixed population. The single-species biofilms were eradicated by moderate concentrations of the antibacterials, and the lowest MBECs were always found for moxifloxacin (2-8 µg ml(-1)). MBECs against the multispecies biofilms were 128, >512 and >512 µg ml(-1) for moxifloxacin, ofloxacin and doxycycline, respectively. In summary, moxifloxacin in a topical formulation may have potential as an adjunct to mechanical removal of the biofilms.

  9. Genetic diversity of bacteria associated with the hindgut of the terrestrial crustacean Porcellio scaber (Crustacea: Isopoda).

    Science.gov (United States)

    Kostanjsek, Rok; Strus, Jasna; Avgustin, Gorazd

    2002-06-01

    Molecular approaches were used to examine the genetic diversity of bacteria associated with the gut wall of the terrestrial isopod Porcellio scaber and to determine whether an autochthonous microflora exists in the P. scaber hindgut. 16S ribosomal genes were amplified from the total DNA isolated from thoroughly washed papillate regions of the hindgut, where the highest concentrations of bacteria are commonly found. The amplified genes were cloned, sequenced and phylogenetically analysed. The results implied an unexpectedly large diversity of microflora associated with the cuticle of the hindgut. Almost half of the retrieved sequences were found to be less than 80% homologous with any of the known sequences available at DNA data banks. Most of these sequences were clustered in one of three groups, and were clearly distant from the sequences of other bacterial taxa, indicating that they could represent novel bacterial species or even genera. More than two thirds of the sequences were found to be phylogenetically related to sequences from bacteria typically isolated from human and animal intestines, e.g. streptococci, enterococci, and members of the genus Bacteroides. The majority of the remaining sequences were most closely related to typical soil bacteria, e.g. bacilli and pseudomonads. The facts that a large proportion of the retrieved sequences was related to the sequences of bacteria, which are autochthonous to intestinal ecosystems, and that bacteria, specifically attached to the cuticular spines, were observed, indicate that truly autochthonous bacteria may well be present in the hindgut of P. scaber.

  10. Endosymbiotic Bacteria Associated with the Mealy Bug, Rhizoecus amorphophalli (Hemiptera: Pseudococcidae).

    Science.gov (United States)

    Sreerag, Ravikumar Sreekala; Jayaprakas, C A; Ragesh, L; Kumar, Sasidharan Nishanth

    2014-01-01

    The mealy bug, Rhizoecus amorphophalli, is a menace to the aroid farmers due to the intensive infestation on stored tubers. Spraying of pesticides was able to control this pest but it always left a chance for fungal growth. Bacterial endosymbionts associated with the insects provide several benefits to their host. Since such endosymbionts play a vital role even in the physiology of their host, revealing the types of bacteria associated with mealy bug will give basic information, which may throw light on the management of this noxious pest. The present study is the first to identify bacterial endosymbionts associated with R. amorphophalli employing phenotypic characterization and 16S rDNA sequencing. Three culturable bacteria, namely, Bacillus subtilis, Staphylococcus gallinarum, and Staphylococcus saprophyticus, were isolated from R. amorphophalli. Moreover, the antibiotic susceptibility tests against the isolated bacteria showed that all the isolates were susceptible to the three antibiotics tested, except cephalexin. Recently, endosymbionts are used as effective biocontrol agents (BCAs) and the present study will stand as a connecting link in identification and effective utilization of these endosymbionts as BCAs for management of R. amorphophalli.

  11. Pectic Enzyme Activities of Bacteria Associated with Rotted Onions (Allium cepa).

    Science.gov (United States)

    Obi, S K; Umezurike, G M

    1981-10-01

    The aerobic bacteria associated with soft rot in onions (Allium cepa) were isolated and identified as a Vibrio sp., Micrococcus epidermidis, Pseudomonas cepacia, an Acinetobacter sp., a Xanthomonas sp., Bacillus polymyxa, and Bacillus megaterium. With the cup-plate assay method, no pectin hydrolase could be detected from any of these isolates when they were cultured in pectin medium, but lyase and pectinesterases were detectable. Onion tissue cultures showed pectin hydrolase activity for P. cepacia and B. polymyxa and lyase and pectinesterase activities for all of the isolates, usually at higher levels of activity than those of the pectin medium culture filtrates. In both culture media, Vibrio sp. showed the highest lyase and pectinesterase activities. In the viscometric test, all of the isolates achieved at least a 50% decrease in viscosity for lyase enzyme, with M. epidermidis and Vibrio sp. recording viscosity decreases as high as 83%. The ability to cause soft rot in onion bulbs was demonstrated by P. cepacia and Xanthomonas sp. Benzoic acid at a concentration of 0.8 mg/ml caused total suppression of enzyme production, whereas sodium benzoate at this concentration reduced pectinesterase production by 71% and lyase production by 72%. The possible use of these preservatives in the control of soft rot in onions is noted.

  12. Bacteria associated with an encrusting sponge (Terpios hoshinota) and the corals partially covered by the sponge.

    Science.gov (United States)

    Tang, Sen-Lin; Hong, Mei-Jhu; Liao, Ming-Hui; Jane, Wann-Neng; Chiang, Pei-Wen; Chen, Chung-Bin; Chen, Chaolun A

    2011-05-01

    Terpios hoshinota, a dark encrusting sponge, is known to be a competitor for space in coral reef environments, and facilitates the death of corals. Although numerous cyanobacteria have been detected in the sponge, little is known of the sponge-associated bacterial community. This study examined the sponge-associated bacterial community and the difference between the bacterial communities in the sponge and the coral partially covered by the sponge by analysis of 16S rRNA gene sequences of samples isolated from the sponge covering the corals Favia complanata, Isopora palifera, Millepora sp., Montipora efflorescens and Porites lutea. The sponge-associated bacterial community was mainly (61-98%) composed of cyanobacteria, with approximately 15% of these alphaproteobacteria and gammaproteobacteria, although the proportions varied in different sponge samples. The dominant cyanobacteria group was an isolated group closely related to Prochloron sp. The comparison of the bacterial communities isolated from sponge-free and the sponge-covered P. lutea showed that covering by the sponge caused changes in the coral-associated bacterial communities, with the presence of bacteria similar to those detected in black-band disease, suggesting the sponge might benefit from the presence of bacteria associated with unhealthy coral, particularly in the parts of the coral closest to the margin of the sponge.

  13. Bacteria associated with Artemia spp. along the salinity gradient of the solar salterns at Eilat (Israel).

    Science.gov (United States)

    Tkavc, Rok; Ausec, Luka; Oren, Aharon; Gunde-Cimerman, Nina

    2011-08-01

    The crustacean genus Artemia naturally inhabits various saline and hypersaline environments and is the most frequently laboratory-hatched animal for live feed in mari- and aquaculture. Because of its high economic importance, Artemia-bacteria interactions were so far studied mostly in laboratory strains. In this study, we focused our attention on the Artemia-associated microbiota in its natural environment in the solar salterns of Eilat, Israel. We applied a culture-independent method (clone libraries) to investigate the bacterial community structure associated with Artemia in five evaporation ponds with salinities from slightly above seawater (5%) to the point of saturation (32%), in two different developmental stages: in nauplii and in the intestine of adult animals. Bacteria found in naupliar and adult stages were classified within the Proteobacteria, Bacteroidetes, Firmicutes, Actinobacteria and Cyanobacteria. The halophilic proteobacterial genera Halomonas spp. and Salinivibrio spp. dominated the Artemia microbiota in both stages in all ponds. We also analysed a clone library of entire adult animals, revealing a novel bacterial phylogenetic lineage. This is the first molecular study of bacteria associated with two developmental stages of Artemia along a salinity gradient.

  14. Predominant bacteria associated with red snapper from the Northern Gulf of Mexico.

    Science.gov (United States)

    Arias, Covadonga R; Koenders, Kevin; Larsen, Andrea M

    2013-12-01

    Since the Deepwater Horizon oil spill in 2010, anecdotal observations of Red Snapper Lutjanus campechanus from the northern Gulf of Mexico exhibiting unusual external lesions have been reported. Two opportunistic bacterial fish pathogens, Vibrio vulnificus and Photobacterium damselae, were recovered from the fish and were deemed responsible for the abnormalities. However, the culturable microbiota of healthy Red Snapper has not yet been characterized. We analyzed the heterotrophic bacteria associated with healthy Red Snapper caught off the Louisiana coast. In total, 179 isolates from 60 fish were recovered from skin and mucus, and 43 isolates were obtained from anterior kidney. All isolates were identified by 16S ribosomal RNA gene sequencing. The Proteobacteria was the predominant phylum in both external and internal samples, followed by the Firmicutes and the Actinobacteria. Within the Proteobacteria, most isolates were members of the genera Vibrio and Photobacterium, and V. natriegens and P. damselae were the predominant species. The results of this study suggest that both Vibrio spp. and Photobacterium spp. are associated with the normal microbiota of healthy Red Snapper. Thus, the opportunistic fish pathogens recovered in previous studies cannot be deemed lesion-forming until Koch's postulates are fulfilled.

  15. Isolation and identification of bacteria associated with the surfaces of several algal species

    Institute of Scientific and Technical Information of China (English)

    WANG Zifeng; XIAO Tian; PANG Shaojun; LIU Min; YUE Haidong

    2009-01-01

    We conducted this study to assess the diversity of bacteria associated with the surfaces of algae based on 16S rDNA sequence analyses. Twelve strains of bacteria were obtained from the surfaces of the following four species of algae: Gracilaria textorii, Ulva pertusa, Laminaria japonica, and Polysiphonia urceolata. The isolated strains of bacteria can be divided into two groups: Halomonas and Vibrio, in physiology, biochemical characteristics and 16S rDNA sequence analyses. The phylogenetic tree constructed based on 16S rDNA sequences of the isolates shows four obvious clusters, Halomonas venusta, Vibrio tasmaniensis, Vibrio lentus, and Vibrio splendidus. Isolates from the surface of P. Urceolata are more abundant and diverse, of which strains P9 and P28 have a 16S rDNA sequence very similar (97.5%-99.8%) to that of V. Splendidus. On the contrary, the isolates from the surfaces of G. Textorii, U. Pertusa and L. Japonica are quite simple and distribute on different branches of the phylogenetic tree. In overall, the results of this study indicate that the genetic relationships among the isolates are quite close and display a certain level of host species specificity, and alga-associated bacteria species are algal species specific.

  16. Bacteria Associated With Piezodorus guildinii (Hemiptera: Pentatomidae), With Special Reference to Those Transmitted by Feeding.

    Science.gov (United States)

    Husseneder, Claudia; Park, Jong-Seok; Howells, Andrea; Tikhe, Chinmay V; Davis, Jeffrey A

    2017-02-01

    The redbanded stink bug, Piezodorus guildinii (Westwood) (Hemiptera: Heteroptera: Pentatomidae), is a rapidly growing pest damaging southern US agriculture. Pentatomid stink bugs are known to vector bacterial, fungal, and viral plant diseases. However, bacteria associated with redbanded stink bugs and their vector potential have not yet been assessed. In this study, we 1) cultured and identified bacteria transmitted by feeding of redbanded stink bug and 2) described bacteria from guts of redbanded stink bug individuals using next-generation sequencing of 16S rRNA genes. Nineteen bacteria transmitted by feeding of redbanded stink bug on soybean agar were isolated and identified via Sanger sequencing of near full length 16S RNA genes. The transmitted bacteria belonged to at least a dozen species in eight genera and included potential plant pathogens (Phaseolibacter flectens), plant beneficials (Bacillus atropheus), and possible insect beneficials (Acinetobacter sp. and Citrobacter farmeri). A total of 284,448 reads were captured from Illumina MiSeq sequencing of the uncultured gut bacteria community. Fifty-one putative bacteria species (74% of the estimated total species richness) were identified via matches to NCBI databases. The bacteria metagenome contained potential plant and insect pathogens (Erwinia persicina, E. rhaponici, Brenneria nigrifluens, Ralstonia picketti, and Serratia marcescens) and beneficials (Pantoea dispersa, Klebsiella oxytoca, Clostridium butyricum, and Citrobacter farmeri). © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  17. Isolation and characterization of beneficial bacteria associated with citrus roots in Florida.

    Science.gov (United States)

    Trivedi, Pankaj; Spann, Timothy; Wang, Nian

    2011-08-01

    Cultivable diversity of bacteria associated with citrus was investigated as part of a larger study to understand the roles of beneficial bacteria and utilize them to increase the productive capacity and sustainability of agro-ecosystems. Citrus roots from Huanglongbing (HLB) diseased symptomatic and asymptomatic citrus were used in this study. A total of 227 and 125 morphologically distinct colonies were isolated and characterized from HLB asymptomatic and symptomatic trees, respectively. We observed that the frequency of bacterial isolates possessing various plant beneficial properties was significantly higher in the asymptomatic samples. A total of 39 bacterial isolates showing a minimum of five beneficial traits related to mineral nutrition [phosphate (P) solubilization, siderophore production, nitrogen (N) fixation], development [indole acetic acid (IAA) synthesis], health [production of antibiotic and lytic enzymes (chitinase)], induction of systemic resistance [salicylic acid (SA) production], stress relief [production of 1-amino-cyclopropane-1-carboxylate deaminase] and production of quorum sensing [N-acyl homoserine lactones] signals were characterized. A bioassay using ethidium monoazide (EMA)-qPCR was developed to select bacteria antagonistic to Candidatus Liberibacter asiaticus. Using the modified EMA-qPCR assay, we found six bacterial isolates showing maximum similarity to Paenibacillus validus, Lysinibacillus fusiformis, Bacillus licheniformis, Pseudomonas putida, Microbacterium oleivorans, and Serratia plymutica could significantly reduce the population of viable Ca. L. asiaticus in HLB symptomatic leaf samples. In conclusion, we have isolated and characterized multiple beneficial bacterial strains from citrus roots which have the potential to enhance plant growth and suppress diseases.

  18. Detection of viruses and atypical bacteria associated with acute respiratory infection of children in Hubei, China.

    Science.gov (United States)

    Wu, Zegang; Li, Yan; Gu, Jian; Zheng, Hongyun; Tong, Yongqing; Wu, Qing

    2014-02-01

    Acute respiratory infection is the major cause of disease and death in children, particularly in developing countries. However, the spectrum of pathogenic viruses and atypical bacteria that exist in many of these countries remains incompletely characterized. The aim of this study was to examine the spectrum of pathogenic viruses and atypical bacteria associated with acute respiratory infection in children under the age of 16. A total of 10 435 serum sera specimens were collected from hospitalized children presenting with acute respiratory infection symptoms. Indirect immunofluorescence assays were performed to detect immunoglobulin M antibodies against nine common pathogens: mycoplasma pneumonia, influenza virus B, respiratory syncytial virus, parainfluenza virus, adenovirus, influenza virus A, legionella pneumophila, coxiella burnetii and chamydophila pneumonia. Of the 10 435 specimens examined, 7046 tested positive for at least one pathogen. Among all of the tested pathogens, mycoplasma pneumonia had the highest detection rate (56.9%). Influenza virus A and influenza virus B epidemics occurred during both winter and summer. The detection rate of respiratory syncytial virus and adenovirus was higher in spring. Cases of mixed infection were more complex: 4136 specimens (39.6%) tested positive for ≥2 pathogens. There were statistically significant difference in detection rates of mycoplasma pneumonia, influenza virus B, respiratory syncytial virus, parainfluenza virus, adenovirus, influenza virus A, legionella pneumophila and chamydophila pneumonia among different age groups (P virus B and respiratory syncytial virus. The detection rates for each pathogen displayed specific seasonal and age group variations. © 2013 The Authors. Respirology © 2013 Asian Pacific Society of Respirology.

  19. Helmets: conventional to cueing

    Science.gov (United States)

    Sedillo, Michael R.; Dixon, Sharon A.

    2003-09-01

    Aviation helmets have always served as an interface between technology and flyers. The functional evolution of helmets continued with the advent of radio when helmets were modified to accept communication components and later, oxygen masks. As development matured, interest in safety increased as evident in more robust designs. Designing helmets became a balance between adding new capabilities and reducing the helmet's weight. As the research community better defined acceptable limits of weight-tolerances with tools such as the "Knox Box" criteria, system developers added and subtracted technologies while remaining within these limits. With most helmet-mounted technologies being independent of each other, the level of precision in mounting these technologies was not as significant a concern as it is today. The attachment of new components was acceptable as long as the components served their purpose. However this independent concept has become obsolete with the dawn of modern helmet mounted displays. These complex systems are interrelated and demand precision in their attachment to the helmet. The helmets' role now extends beyond serving as a means to mount the technologies to the head, but is now instrumental in critical visual alignment of complex night vision and missile cueing technologies. These new technologies demand a level of helmet fit and component alignment previously not seen in past helmet designs. This paper presents some of the design, integration and logistical issues gleaned during the development of the Joint Helmet Mounted Cueing System (JHMCS) to include the application of head-track technologies in forensic investigations.

  20. Cue reactivity towards shopping cues in female participants.

    Science.gov (United States)

    Starcke, Katrin; Schlereth, Berenike; Domass, Debora; Schöler, Tobias; Brand, Matthias

    2013-03-01

    Background and aims It is currently under debate whether pathological buying can be considered as a behavioural addiction. Addictions have often been investigated with cue-reactivity paradigms to assess subjective, physiological and neural craving reactions. The current study aims at testing whether cue reactivity towards shopping cues is related to pathological buying tendencies. Methods A sample of 66 non-clinical female participants rated shopping related pictures concerning valence, arousal, and subjective craving. In a subgroup of 26 participants, electrodermal reactions towards those pictures were additionally assessed. Furthermore, all participants were screened concerning pathological buying tendencies and baseline craving for shopping. Results Results indicate a relationship between the subjective ratings of the shopping cues and pathological buying tendencies, even if baseline craving for shopping was controlled for. Electrodermal reactions were partly related to the subjective ratings of the cues. Conclusions Cue reactivity may be a potential correlate of pathological buying tendencies. Thus, pathological buying may be accompanied by craving reactions towards shopping cues. Results support the assumption that pathological buying can be considered as a behavioural addiction. From a methodological point of view, results support the view that the cue-reactivity paradigm is suited for the investigation of craving reactions in pathological buying and future studies should implement this paradigm in clinical samples.

  1. Perception of aircraft Deviation Cues

    Science.gov (United States)

    Martin, Lynne; Azuma, Ronald; Fox, Jason; Verma, Savita; Lozito, Sandra

    2005-01-01

    To begin to address the need for new displays, required by a future airspace concept to support new roles that will be assigned to flight crews, a study of potentially informative display cues was undertaken. Two cues were tested on a simple plan display - aircraft trajectory and flight corridor. Of particular interest was the speed and accuracy with which participants could detect an aircraft deviating outside its flight corridor. Presence of the trajectory cue significantly reduced participant reaction time to a deviation while the flight corridor cue did not. Although non-significant, the flight corridor cue seemed to have a relationship with the accuracy of participants judgments rather than their speed. As this is the second of a series of studies, these issues will be addressed further in future studies.

  2. SURFACE-PROPERTIES OF CATHETERS, STENTS AND BACTERIA ASSOCIATED WITH URINARY-TRACT INFECTIONS

    NARCIS (Netherlands)

    REID, G; BUSSCHER, HJ; MITTELMAN, MW; MCINTYRE, S

    1995-01-01

    Applications of surface and physico-chemical techniques to the clinical setting, in particular related to the urogenital tract, have been sporadic, often concentrating on aspects of biocompatibility and interactions of blood cells with materials. In an era where billions of such devices are

  3. A study on bacteria associated with the intestinal tract of farmed yellow seahorse, Hippocampus kuda (Bleeker, 1852): Characterization and extracellular enzymes

    Digital Repository Service at National Institute of Oceanography (India)

    Tanu; Deobagkar, D.D.; Khandeparker, R.; Sreepada, R.A.; Sanaye, S.V.; Pawar, H.B.

    The microenvironment of bacteria associated with the gastrointestinal tract of an animal influences the host in many ways, including the metabolism of several nutrients. Isolation, molecular characterization and enzymatic activities of culturable...

  4. CHEMICALS

    CERN Document Server

    Medical Service

    2002-01-01

    It is reminded that all persons who use chemicals must inform CERN's Chemistry Service (TIS-GS-GC) and the CERN Medical Service (TIS-ME). Information concerning their toxicity or other hazards as well as the necessary individual and collective protection measures will be provided by these two services. Users must be in possession of a material safety data sheet (MSDS) for each chemical used. These can be obtained by one of several means : the manufacturer of the chemical (legally obliged to supply an MSDS for each chemical delivered) ; CERN's Chemistry Service of the General Safety Group of TIS ; for chemicals and gases available in the CERN Stores the MSDS has been made available via EDH either in pdf format or else via a link to the supplier's web site. Training courses in chemical safety are available for registration via HR-TD. CERN Medical Service : TIS-ME :73186 or service.medical@cern.ch Chemistry Service : TIS-GS-GC : 78546

  5. Effects of mosquitofish (Gambusia affinis cues on wood frog (Lithobates sylvaticus tadpole activity

    Directory of Open Access Journals (Sweden)

    Katherine F. Buttermore

    2011-06-01

    Full Text Available We examined the changes in activity of wood frog (Lithobates sylvaticus tadpoles exposed to combinations of visual, chemical, and mechanical cues of the invasive mosquitofish (Gambusia affinis. We also examined whether the responses of the tadpoles to the predator cues were influenced by the short-term accumulation of chemical cues in the experimental container. In our experiment, the activity of wood frog (L. sylvaticus tadpoles was not affected by the presence of various cues from mosquitofish. Our experiment demonstrated that the repeated use of trial water can influence the activity level of tadpoles, regardless of the predator cue treatment used. Tadpoles in the first trial tended to be less active than tadpoles in subsequent trials. This effect does not appear to be mediated by the accumulation of predator cues since there was no significant interaction term. Our results suggest that short-term accumulation of predator chemical cues do not affect the behavior of wood frog tadpoles: however, our results suggest that the repeated use of the same water in consecutive trials may affect tadpole behavior, perhaps through the accumulation of conspecific chemical cues.

  6. Antimicrobial Potential of Bacteria Associated with Marine Sea Slugs from North Sulawesi, Indonesia

    Directory of Open Access Journals (Sweden)

    Nils Böhringer

    2017-06-01

    Full Text Available Nudibranchia, marine soft-bodied organisms, developed, due to the absence of a protective shell, different strategies to protect themselves against putative predators and fouling organisms. One strategy is to use chemical weapons to distract predators, as well as pathogenic microorganisms. Hence, these gastropods take advantage of the incorporation of chemical molecules. Thereby the original source of these natural products varies; it might be the food source, de novo synthesis from the sea slug, or biosynthesis by associated bacteria. These bioactive molecules applied by the slugs can become important drug leads for future medicinal drugs. To test the potential of the associated bacteria, the latter were isolated from their hosts, brought into culture and extracts were prepared and tested for antimicrobial activities. From 49 isolated bacterial strains 35 showed antibiotic activity. The most promising extracts were chosen for further testing against relevant pathogens. In that way three strains showing activity against methicillin resistant Staphylococcus aureus and one strain with activity against enterohemorrhagic Escherichia coli, respectively, were identified. The obtained results indicate that the sea slug associated microbiome is a promising source for bacterial strains, which hold the potential for the biotechnological production of antibiotics.

  7. Airborne bacteria associated with corrosion of mild steel 1010 and aluminum alloy 1100.

    Science.gov (United States)

    Rajasekar, Aruliah; Xiao, Wang; Sethuraman, Manivannan; Parthipan, Punniyakotti; Elumalai, Punniyakotti

    2017-03-01

    A novel approach to measure the contribution of airborne bacteria on corrosion effects of mild steel (MS) and aluminum alloy (AA) as a function of their exposure period, and the atmospheric chemical composition was investigated at an urban industrial coastal site, Singapore. The 16S rRNA and phylogenetic analyses showed that Firmicutes are the predominant bacteria detected in AA and MS samples. The dominant bacterial groups identified were Bacillaceae, Staphylococcaceae, and Paenibacillaceae. The growth and proliferation of these bacteria could be due to the presence of humidity and chemical pollutants in the atmosphere, leading to corrosion. Weight loss showed stronger corrosion resistance of AA (1.37 mg/cm(2)) than MS (26.13 mg/cm(2)) over the exposure period of 150 days. The higher corrosion rate could be a result of simultaneous action of pollutants and bacterial exopolysaccharides on the metal surfaces. This study demonstrates the significant involvement of airborne bacteria on atmospheric corrosion of engineering materials.

  8. Evaluation of multimodal ground cues

    DEFF Research Database (Denmark)

    Nordahl, Rolf; Lecuyer, Anatole; Serafin, Stefania

    2012-01-01

    This chapter presents an array of results on the perception of ground surfaces via multiple sensory modalities,with special attention to non visual perceptual cues, notably those arising from audition and haptics, as well as interactions between them. It also reviews approaches to combining synth...... synthetic multimodal cues, from vision, haptics, and audition, in order to realize virtual experiences of walking on simulated ground surfaces or other features....

  9. Surface properties of catheters, stents and bacteria associated with urinary tract infections

    Science.gov (United States)

    Reid, Gregor; Busscher, Henk J.; Sharma, Sunaina; Mittelman, Marc W.; McIntyre, Stewart

    Applications of surface and physico-chemical techniques to the clinical setting, in particular related to the urogenital tract, have been sporadic, often concentrating on aspects of biocompatibility and interactions of blood cells with materials. In an era where billions of such devices are implanted annually, it is important to utilize such techniques to improve our understanding of material-host interactions. In an effort to encourage further such interactive investigations, this review will illustrate some practical biomedical examples where utilization of sophisticated surface-science techniques has provided valuable insight into interfacial events between host components, micro-organisms and material surfaces. Techniques to reduce bacterial infection and encrustations will be discussed, and suggestions given for future lines of enquiry.

  10. Odour cues from suitors' nests determine mating success in a fish

    National Research Council Canada - National Science Library

    Lehtonen, Topi K; Kvarnemo, Charlotta

    2015-01-01

    .... Here, using the sand goby Pomatoschistus minutus, a small fish with paternal egg care, we investigated the possibility that 'extrinsic' chemical cues in the males' nests could also have a significant...

  11. Plant growth-promoting bacteria associated with nitrogen fertilization at topdressing in popcorn agronomic performance

    Directory of Open Access Journals (Sweden)

    Leandro Teodoski Spolaor

    2016-03-01

    Full Text Available ABSTRACT The use of plant growth-promoting bacteria is a promising alternative with low environmental impact to increase the efficiency of use of chemical fertilizers, ensuring high yield with better cost-effective ratio. In maize crops, several studies have demonstrated an increased yield when Azospirillum-based inoculants are used. In the case of popcorn, there are no available studies related to use of inoculation and its response on yield parameters. Thus, the aim of this study was to evaluate the field performance of popcorn when inoculated with the commercial product Masterfix L (A. brasilense Ab-V5 and A. brasilense Ab-V6 and the non-commercial inoculant UEL (A. brasilense Ab-V5 + Rhizobium sp. 53GRM1 associated with nitrogen fertilization. The trials were conducted in Londrina and Maringá, Paraná State, Brazil, in a randomized block design with four replications, in a split plot design with the inoculation treatments located in the plots (uninoculated, Masterfix L, and UEL and the different N rates located in the subplots where ammonium sulphate was applied in the topdressing at the V6 stage (0, 50, 100, and 150 kg∙ha–1. The variance analysis showed significant effects (p < 0.05 of inoculation (Londrina environment and N rates (both environments only for grain yield. There was no inoculation effect in the grain yield when inoculants were applied together with N-fertilization at topdressing. In the absence of N-fertilization at topdressing, the inoculants Masterfix L. and UEL promoted higher grain yield as compared to the uninoculated plants, with resulting increases of 13.21 and 26.61% in yield, respectively.

  12. Optimal assessment of multiple cues

    NARCIS (Netherlands)

    Fawcett, TW; Johnstone, RA

    2003-01-01

    In a wide range of contexts from mate choice to foraging, animals are required to discriminate between alternative options on the basis of multiple cues. How should they best assess such complex multicomponent stimuli? Here, we construct a model to investigate this problem, focusing on a simple case

  13. Behavioral Cues of Interpersonal Warmth

    Science.gov (United States)

    Bayes, Marjorie A.

    1972-01-01

    The results of this study suggest, first, that interpersonal warmth does seem to be a personality dimension which can be reliably judged and, second, that it was possible to define and demonstrate the relevance of a number of behavioral cues for warmth. (Author)

  14. Optimal cue integration in ants.

    Science.gov (United States)

    Wystrach, Antoine; Mangan, Michael; Webb, Barbara

    2015-10-07

    In situations with redundant or competing sensory information, humans have been shown to perform cue integration, weighting different cues according to their certainty in a quantifiably optimal manner. Ants have been shown to merge the directional information available from their path integration (PI) and visual memory, but as yet it is not clear that they do so in a way that reflects the relative certainty of the cues. In this study, we manipulate the variance of the PI home vector by allowing ants (Cataglyphis velox) to run different distances and testing their directional choice when the PI vector direction is put in competition with visual memory. Ants show progressively stronger weighting of their PI direction as PI length increases. The weighting is quantitatively predicted by modelling the expected directional variance of home vectors of different lengths and assuming optimal cue integration. However, a subsequent experiment suggests ants may not actually compute an internal estimate of the PI certainty, but are using the PI home vector length as a proxy. © 2015 The Author(s).

  15. Effects of Spatial Cueing on Representational Momentum

    Science.gov (United States)

    Hubbard, Timothy L.; Kumar, Anuradha Mohan; Carp, Charlotte L.

    2009-01-01

    Effects of a spatial cue on representational momentum were examined. If a cue was present during or after target motion and indicated the location at which the target would vanish or had vanished, forward displacement of that target decreased. The decrease in forward displacement was larger when cues were present after target motion than when cues…

  16. When Symbolic Spatial Cues Go before Numbers

    Science.gov (United States)

    Herrera, Amparo; Macizo, Pedro

    2011-01-01

    This work explores the effect of spatial cueing on number processing. Participants performed a parity judgment task. However, shortly before the target number, a cue (arrow pointing to left, arrow pointing to right or a cross) was centrally presented. In Experiment 1, in which responses were lateralized, the cue direction modulated the interaction…

  17. Cue salience influences the use of height cues in reorientation in pigeons (Columba livia).

    Science.gov (United States)

    Du, Yu; Mahdi, Nuha; Paul, Breanne; Spetch, Marcia L

    2016-07-01

    Although orienting ability has been examined with numerous types of cues, most research has focused only on cues from the horizontal plane. The current study investigated pigeons' use of wall height, a vertical cue, in an open-field task and compared it with their use of horizontal cues. Pigeons were trained to locate food in 2 diagonal corners of a rectangular enclosure with 2 opposite high walls as height cues. Before each trial, pigeons were rotated to disorient them. In training, pigeons could use either the horizontal cues from the rectangular enclosure or the height information from the walls to locate the food. In testing, the apparatus was modified to provide (a) horizontal cues only, (b) height cues only, and (c) both height and horizontal cues in conflict. In Experiment 1 the lower and high walls, respectively, were 40 and 80 cm, whereas in Experiment 2 they were made more perceptually salient by shortening them to 20 and 40 cm. Pigeons accurately located the goal corners with horizontal cues alone in both experiments, but they searched accurately with height cues alone only in Experiment 2. When the height cues conflicted with horizontal cues, pigeons preferred the horizontal cues over the height cues in Experiment 1 but not in Experiment 2, suggesting that perceptual salience influences the relative weighting of cues. (PsycINFO Database Record

  18. Similarity and differentiation between bacteria associated with skin of salamanders (Plethodon jordani) and free-living assemblages.

    Science.gov (United States)

    Fitzpatrick, Benjamin M; Allison, Amanda L

    2014-06-01

    All animals and plants have intimate associations with microbes. Opinion has shifted from viewing microbes primarily as pathogens to the idea that healthy animals and plants carry specialized communities of coevolving microorganisms. However, the generality of this proposition is unknown because surveys rarely compare host-associated microbes with samples from relevant microhabitats. Symbiotic communities might be assembled from local environments with little evolutionary specialization. We evaluated the specificity of bacteria associated with salamander skin in comparison with surfaces in their immediate environments using 16S rRNA sequences. Host-associated and free-living samples were significantly different. However, relative abundances were strongly correlated; the most abundant taxa on salamander skin were also most abundant on moist debris on the forest floor. Thus, although bacterial assemblages on salamander skin are statistically differentiated from those on inanimate surfaces, they are not entirely 'distinct'. Candidate salamander specialists were few in number and occurred at low relative abundances. Within some OTUs, differences in allele frequency suggested genetic specialization at finer levels. Although host-associated and free-living assemblages were similar, a range of more or less specialized symbiotes was evident and bacteria on salamander skin were often specific genotypes of OTUs commonly found on other moist surfaces in the environment.

  19. Case study of the relationship between fungi and bacteria associated with high-molecular-weight polycyclic aromatic hydrocarbon degradation.

    Science.gov (United States)

    Wang, Shuozhi; Nomura, Nobuhiko; Nakajima, Toshiaki; Uchiyama, Hiroo

    2012-05-01

    Although bacteria play dominant roles in microbial bioremediation, few of them have been reported that were capable of utilizing high-molecular-weight (HMW) organic pollutants as their sole sources of carbon and energy. However, many soil fungi can metabolize those of pollutants, although they rarely complete mineralization. In this paper, we investigated the dynamic relationship between fungi and bacteria associated with degradation of HMW-polycyclic aromatic hydrocarbons (PAHs). Artificial fungal-bacterial mixed cultures were constructed to simulate the environment of actual polluted sites. Four bacterial strains and seven fungal strains were isolated that related to the removal of phenanthrene, fluoranthene and pyrene in the soil. Furthermore, these strains were used to create mixed culture of bacteria (Bact-mix), mixed culture of fungi (Fung-mix), fungal-bacterial co-cultures (Fung-Bact), respectively. The maximal pyrene removal rate (67%, 28days) was observed in the Fung-Bact, compared with cultures of Fung-mix (39%) and Bact-mix (56%). The same tendency was also indicated in the degradation of phenanthrene and fluoranthene. In addition, a dynamic relationship during the degradation process between fungi and bacteria was monitored through using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) method.

  20. Identification of bacteria associated with underground parts of Crocus sativus by 16S rRNA gene targeted metagenomic approach.

    Science.gov (United States)

    Ambardar, Sheetal; Sangwan, Naseer; Manjula, A; Rajendhran, J; Gunasekaran, P; Lal, Rup; Vakhlu, Jyoti

    2014-10-01

    Saffron (Crocus sativus L), an autumn-flowering perennial sterile plant, reproduces vegetatively by underground corms. Saffron has biannual corm-root cycle that makes it an interesting candidate to study microbial dynamics in its rhizosphere and cormosphere (area under influence of corm). Culture independent 16S rRNA gene metagenomic study of rhizosphere and cormosphere of Saffron during flowering stage revealed presence of 22 genera but none of the genus was common in all the three samples. Bulk soil bacterial community was represented by 13 genera with Acidobacteria being dominant. In rhizosphere, out of eight different genera identified, Pseudomonas was the most dominant genus. Cormosphere bacteria comprised of six different genera, dominated by the genus Pantoea. This study revealed that the bacterial composition of all the three samples is significantly different (P < 0.05) from each other. This is the first report on the identification of bacteria associated with rhizosphere, cormosphere and bulk soil of Saffron, using cultivation independent 16S rRNA gene targeted metagenomic approach.

  1. Diversity and antagonistic potential of bacteria associated with bryophytes from nutrient-poor habitats of the Baltic Sea Coast.

    Science.gov (United States)

    Opelt, Katja; Berg, Gabriele

    2004-11-01

    Very little is known about the interaction of bryophytes with bacteria. Therefore, we analyzed bacteria associated with three bryophyte species, Tortula ruralis, Aulacomnium palustre, and Sphagnum rubellum, which represent typical moss species of three nutrient-poor plant communities at the southern Baltic Sea coast in Germany. By use of two cultivation-independent techniques, denaturing gradient gel electrophoresis and single-strand conformation polymorphism analysis of the 16S ribosomal DNA, a high degree of moss specificity was found for associated bacterial communities. This specificity could be further evidenced by a cultivation-dependent approach for the following parameters: (i) plate counts of bacteria on R2A medium, (ii) proportion of antagonistic isolates, (iii) antagonistic activity as well as spectrum against pathogens, and (iv) diversity and richness of antagonistic isolates. The proportion of isolates with antagonistic activity against the pathogenic model fungus Verticillium dahliae was highest for S. rubellum (31%), followed by A. palustre (17%) and T. ruralis (5%). A high percentage (99%) of moss-associated antagonistic bacteria produced antifungal compounds. The high recovery of antagonistic isolates strongly suggests that bryophytes represent an ecological niche which harbors a diverse and hitherto largely uncharacterized microbial population with yet unknown and untapped potential biotechnological applications, e.g., for biological control of plant pathogens.

  2. Bacteria-associated haemophagocytic syndrome and septic pulmonary embolism caused by Burkholderia cepacia complex in a woman with chronic granulomatous disease.

    Science.gov (United States)

    Hisano, Michi; Sugawara, Kana; Tatsuzawa, Osamu; Kitagawa, Michihiro; Murashima, Atsuko; Yamaguchi, Koushi

    2007-05-01

    Chronic granulomatous disease (CGD) is a primary immunodeficiency characterized by recurrent infections with certain types of bacteria and fungi. Presented herein is the case of a 29 year old woman with CGD who suffered from bacteria-associated haemophagocytic syndrome and a septic pulmonary embolism following a uterine infection and sepsis, caused by Burkholderia cepacia complex.

  3. Effects of biodegradable plastics on the predominant culturable bacteria associated with soil aggregate formation and stability after 9 months of incubation in natural soil

    Science.gov (United States)

    An in vitro study of the effects of biodegradable plastics on the predominant soil aggregating bacteria associated to soil aggregate formation and stability after 9 months of incubation in soil. Caesar-TonThat TC, Fukui R*, Caesar AJ., Lartey, RT, and Gaskin, JF. USDA-Agricultural Research Service, ...

  4. Protist-bacteria associations: Gammaproteobacteria and Alphaproteobacteria are prevalent as digestion-resistant bacteria in ciliated protozoa

    Directory of Open Access Journals (Sweden)

    Jun eGong

    2016-04-01

    Full Text Available Protistan bacterivory, a microbial process involving ingestion and digestion, is ecologically important in the microbial loop in aquatic and terrestrial ecosystems. While bacterial resistance to protistan ingestion are relatively well understood, little is known about protistan digestion in which some ingested bacteria could not be digested in cells of major protistan grazers in the natural environment. Here we report the phylogenetic identities of digestion-resistant bacteria (DRB that could survive starvation and form relatively stable associations with 11 marine and one freshwater ciliate species. Using clone library and sequencing of 16S rRNA genes, we found that the protistan predators could host a high diversity of DRB, most of which represented novel bacterial taxa that have not been cultivated. The localization inside host cells, quantity, and viability of these bacteria were checked using fluorescence in situ hybridization. The DRB were affiliated with Actinobacteria, Bacteroidetes, Firmicutes, Parcubacteria (OD1, Planctomycetes, and Proteobacteria, with Gammaproteobacteria and Alphaproteobacteria being the most frequently occurring classes. The dominance of Gamma- and Alphaproteobacteria corresponds well to a previous study of Global Ocean Sampling metagenomic data showing the widespread types of bacterial type VI and IV secretion systems (T6SS and T4SS in these two taxa, suggesting a putatively significant role of secretion systems in promoting marine protist-bacteria associations. In the DRB assemblages, opportunistic bacteria such as Alteromonadaceae, Pseudoalteromonadaceae and Vibrionaceae often presented with high proportions, indicating these bacteria could evade protistan grazing thus persist and accumulate in the community, which, however, contrasts with the well-known rarity of these bacteria in nature. This begs the question whether viral lysis is significant in killing these indigestible bacteria in microbial communities

  5. Pyrosequencing 16S rRNA genes of bacteria associated with wild tiger mosquito Aedes albopictus: a pilot study

    Directory of Open Access Journals (Sweden)

    Guillaume eMinard

    2014-05-01

    Full Text Available The Asian tiger mosquito Aedes (Stegomya albopictus is an invasive species that has spread across the world in the last two decades, showing a great capacity to adapt to contrasting climates and environments. While demonstrated in many insects, the contribution of bacterial symbionts in Aedes ecology is a challenging aspect that needs to be investigated however. Some bacterial species have already been identified in Ae. albopictus using classical methods, but a more accurate survey of mosquito-associated bacterial diversity is needed to decipher the potential biological functions of bacterial symbionts in mediating or constraining insect adaptation. We surveyed the bacteria associated with field populations of Ae. albopictus from Madagascar by pyrosequencing 16S rRNA gene amplicons. Different aspects of amplicon preparation and sequencing depth were tested to optimise the breadth of bacterial diversity identified. The results revealed that all mosquitoes collected from different sites have a bacterial microbiota dominated by a single taxon, Wolbachia pipientis, which accounted for about 99% of all 98,520 sequences obtained. Ae. albopictus is known to harbour two Wolbachia strains, wAlbA and wAlbB, and quantitative PCR was used to estimate the relative densities, i.e. the bacteria-to-host gene ratios, of the strains in individual mosquitoes. Relative densities were between 6.25 × 100.01 and 5.47 × 100.1 for wAlbA and between 2.03 × 100.1 and 1.4 × 101 for wAlbB. Apart from Wolbachia, a total of 32 bacterial taxa were identified at the genus level using the different in method variations. Diversity index values were low and probably underestimated the true diversity due to the high abundance of Wolbachia sequences vastly outnumbering sequences from other taxa. Further studies should implement alternative strategies to specifically discard from analysis any sequences from Wolbachia, the dominant endosymbiotic bacterium in Ae. albopictus from

  6. Earthworms Use Odor Cues to Locate and Feed on Microorganisms in Soil

    OpenAIRE

    Lara Zirbes; Mark Mescher; Véronique Vrancken; Jean-Paul Wathelet; Verheggen, François J.; Philippe Thonart; Eric Haubruge

    2011-01-01

    Earthworms are key components of temperate soil ecosystems but key aspects of their ecology remain unexamined. Here we elucidate the role of olfactory cues in earthworm attraction to food sources and document specific chemical cues that attract Eisenia fetida to the soil fungi Geotrichum candidum. Fungi and other microorganisms are major sources of volatile emissions in soil ecosystems as well as primary food sources for earthworms, suggesting the likelihood that earthworms might profitably u...

  7. Surface Flow from Visual Cues

    OpenAIRE

    Petit, Benjamin,; Letouzey, Antoine; Boyer, Edmond; Franco, Jean-Sébastien

    2011-01-01

    International audience; In this paper we study the estimation of dense, instantaneous 3D motion fields over a non-rigidly moving surface observed by multi-camera systems. The motivation arises from multi-camera applications that require motion information, for arbitrary subjects, in order to perform tasks such as surface tracking or segmentation. To this aim, we present a novel framework that allows to efficiently compute dense 3D displacement fields using low level visual cues and geometric con...

  8. Thin Layer Sensory Cues Affect Antarctic Krill Swimming Kinematics

    Science.gov (United States)

    True, A. C.; Webster, D. R.; Weissburg, M. J.; Yen, J.

    2013-11-01

    A Bickley jet (laminar, planar free jet) is employed in a recirculating flume system to replicate thin shear and phytoplankton layers for krill behavioral assays. Planar laser-induced fluorescence (LIF) and particle image velocimetry (PIV) measurements quantify the spatiotemporal structure of the chemical and free shear layers, respectively, ensuring a close match to in situ hydrodynamic and biochemical conditions. Path kinematics from digitized trajectories of free-swimming Euphausia superba examine the effects of hydrodynamic sensory cues (deformation rate) and bloom level phytoplankton patches (~1000 cells/mL, Tetraselamis spp.) on krill behavior (body orientation, swimming modes and kinematics, path fracticality). Krill morphology is finely tuned for receiving and deciphering both hydrodynamic and chemical information that is vital for basic life processes such as schooling behaviors, predator/prey, and mate interactions. Changes in individual krill behavior in response to ecologically-relevant sensory cues have the potential to produce population-scale phenomena with significant ecological implications. Krill are a vital trophic link between primary producers (phytoplankton) and larger animals (seabirds, whales, fish, penguins, seals) as well as the subjects of a valuable commercial fishery in the Southern Ocean; thus quantifying krill behavioral responses to relevant sensory cues is an important step towards accurately modeling Antarctic ecosystems.

  9. Beyond magic traits: Multimodal mating cues in Heliconius butterflies.

    Science.gov (United States)

    Mérot, Claire; Frérot, Brigitte; Leppik, Ene; Joron, Mathieu

    2015-11-01

    Species coexistence involves the evolution of reproductive barriers opposing gene flow. Heliconius butterflies display colorful patterns affecting mate choice and survival through warning signaling and mimicry. These patterns are called "magic traits" for speciation because divergent natural selection may promote mimicry shifts in pattern whose role as mating cue facilitates reproductive isolation. By contrast, between comimetic species, natural selection promotes pattern convergence. We addressed whether visual convergence interferes with reproductive isolation by testing for sexual isolation between two closely related species with similar patterns, H. timareta thelxinoe and H. melpomene amaryllis. Experiments with models confirmed visual attraction based on wing phenotype, leading to indiscriminate approach. Nevertheless, mate choice experiments showed assortative mating. Monitoring male behavior toward live females revealed asymmetry in male preference, H. melpomene males courting both species equally while H. timareta males strongly preferred conspecifics. Experiments with hybrid males suggested an important genetic component for such asymmetry. Behavioral observations support a key role for short-distance cues in determining male choice in H. timareta. Scents extracts from wings and genitalia revealed interspecific divergence in chemical signatures, and hybrid female scent composition was significantly associated with courtship intensity by H. timareta males, providing candidate chemical mating cues involved in sexual isolation. © 2015 The Author(s). Evolution © 2015 The Society for the Study of Evolution.

  10. Cueing the Virtual Storyteller: Analysis of cue phrase usage in fairy tales

    NARCIS (Netherlands)

    Penning, Manon; Theune, Mariët; Busemann, S.

    2007-01-01

    An existing taxonomy of Dutch cue phrases, designed for use in story generation, was validated by analysing cue phrase usage in a corpus of classical fairy tales. The analysis led to some adaptations of the original taxonomy.

  11. Cue Integration With Categories: Weighting Acoustic Cues in Speech Using Unsupervised Learning and Distributional Statistics

    National Research Council Canada - National Science Library

    Toscano, Joseph C; McMurray, Bob

    2010-01-01

    .... We show that a cue-weighting metric in which cues receive weight as a function of their reliability at distinguishing phonological categories provides a good fit to the perceptual data obtained...

  12. Stress as a Normal Cue in the Symbiotic Environment.

    Science.gov (United States)

    Schwartzman, Julia A; Ruby, Edward G

    2016-05-01

    All multicellular hosts form associations with groups of microorganisms. These microbial communities can be taxonomically diverse and dynamic, and their persistence is due to robust, and sometimes coevolved, host-microbe and microbe-microbe interactions. Chemical and physical sources of stress are prominently situated in this molecular exchange, as cues for cellular responses in symbiotic microbes. Stress in the symbiotic environment may arise from three sources: host tissues, microbe-induced immune responses, or other microbes in the host environment. The responses of microbes to these stresses can be general or highly specialized, and collectively may contribute to the stability of the symbiotic system. In this review, we highlight recent work that emphasizes the role of stress as a cue in the symbiotic environment of plants and animals.

  13. Use of olfactory cues by newly metamorphosed wood frogs (Lithobates sylvaticus) during emigration

    Science.gov (United States)

    Zydlewski, Joseph; Popescu, Viorel D.; Brodie, Bekka S.; Hunter, Malcom L.

    2012-01-01

    Juvenile amphibians are capable of long-distance upland movements, yet cues used for orientation during upland movements are poorly understood. We used newly metamorphosed Wood Frogs (Lithobates sylvaticus) to investigate: (1) the existence of innate (i.e., inherited) directionality, and (2) the use of olfactory cues, specifically forested wetland and natal pond cues during emigration. In a circular arena experiment, animals with assumed innate directionality did not orient in the expected direction (suggested by previous studies) when deprived of visual and olfactory cues. This suggests that juvenile Wood Frogs most likely rely on proximate cues for orientation. Animals reared in semi-natural conditions (1500 l cattle tanks) showed a strong avoidance of forested wetland cues in two different experimental settings, although they had not been previously exposed to such cues. This finding is contrary to known habitat use by adult Wood Frogs during summer. Juvenile Wood Frogs were indifferent to the chemical signature of natal pond (cattle tank) water. Our findings suggest that management strategies for forest amphibians should consider key habitat features that potentially influence the orientation of juveniles during emigration movements, as well as adult behavior.

  14. Geographic and Temporal Variation in Moth Chemical Communication

    Science.gov (United States)

    Unlike acoustic and visual communication, chemical communication cues have not been viewed in the background of a chemically noisy habitat. Species with similar chemical cues may not only directly interfere with each other's communication channels, but the presence and abundance of other species may...

  15. Cueing for freezing of gait: a need for 3-dimensional cues?

    NARCIS (Netherlands)

    Snijders, A.H.; Jeene, P.; Nijkrake, M.J.; Abdo, W.F.; Bloem, B.R.

    2012-01-01

    Visual cues can ameliorate freezing of gait, an incapacitating symptom frequently seen in patients with parkinsonism. Here, we describe a patient with severe freezing of gait, who responded well to 3-dimensional cues, but not to 2-dimensional visual cues. We discuss the potential implications of

  16. Cue-switch costs in task-switching: cue priming or control processes?

    Science.gov (United States)

    Grange, James A; Houghton, George

    2010-09-01

    In the explicitly cued task-switching paradigm, two cues per task allow separation of costs associated with switching cues from costs of switching tasks. Whilst task-switch costs have become controversial, cue-switch costs are robust. The processes that contribute to cue-switch costs are under-specified in the literature: they could reflect perceptual priming of cue properties, or priming of control processes that form relevant working memory (WM) representations of task demands. Across two experiments we manipulated cue-transparency in an attention-switching design to test the contrasting hypotheses of cue-switch costs, and show that such costs emerge from control processes of establishing relevant WM representations, rather than perceptual priming of the cue itself. When the cues were maximally transparent, cue-switch costs were eradicated. We discuss the results in terms of recent theories of cue encoding, and provide a formal definition of cue-transparency in switching designs and its relation to WM representations that guide task performance.

  17. Female-borne cues affecting Psyttalia concolor (Hymenoptera: Braconidae) male behavior during courtship and mating

    Institute of Scientific and Technical Information of China (English)

    Angelo Canale; Giovanni Benelli; Andrea Lucchi

    2013-01-01

    Knowledge of the mechanisms that regulate courtship and mating behavior in Psyttalia concolor (Szépligeti)-a koinobiont endophagous solitary parasitoid of the olive fruit fly,Bactrocera oleae (Rossi),and of other fruit flies-is essential to its mass rearing and management.Augmentative releases ofP.concolor for olive fruit fly control started in the Mediterranean areas in the 1950s and still continue with limited success.We determined the influence of visual and chemical cues on courtship and mating behavior of this braconid and the possible effect of the mating status of males and females in the perception of these cues.Our results suggest that integration of visual and chemical stimuli are fundamental for mate location and courtship.Indeed,the optimal response of the male was achieved when physical and chemical cues were simultaneously presented and vision and olfaction worked synergistically.

  18. Chemical Sensory Mechanisms of Insects%昆虫的化学感觉机理

    Institute of Scientific and Technical Information of China (English)

    娄永根; 程家安

    2001-01-01

    Insects possess two kinds of chemical sensory organ,olfactoryorgan and gustatory organ,by which they can perceive chemical cues in the circumstance and subsequently make a series of corresponding behavioral responses.From perceiving chemical cues to making behavioral responses,it involves in information coding,proceeding and integration to chemical cues at various level in insect nerve system.New pest control methods will be developed with the elucidation of insect chemical sensory mechanisms.

  19. Wax On, Wax Off: Nest Soil Facilitates Indirect Transfer of Recognition Cues between Ant Nestmates

    DEFF Research Database (Denmark)

    Bos, Nick; Grinsted, Lena; Holman, Luke

    2011-01-01

    Social animals use recognition cues to discriminate between group members and non-members. These recognition cues may be conceptualized as a label, which is compared to a neural representation of acceptable cue combinations termed the template. In ants and other social insects, the label consists...... of a waxy layer of colony-specific hydrocarbons on the body surface. Genetic and environmental differences between colony members may confound recognition and social cohesion, so many species perform behaviors that homogenize the odor label, such as mouth-to-mouth feeding and allogrooming. Here, we test...... for another mechanism of cue exchange: indirect transfer of cuticular hydrocarbons via the nest material. Using a combination of chemical analysis and behavioral experiments with Camponotus aethiops ants, we show that nest soil indirectly transfers hydrocarbons between ants and affects recognition behavior...

  20. Guiding Attention by Cooperative Cues

    Institute of Scientific and Technical Information of China (English)

    KangWoo Lee

    2008-01-01

    A common assumption in visual attention is based on the rationale of "limited capacity of information pro-ceasing". From this view point there is little consideration of how different information channels or modules are cooperating because cells in processing stages are forced to compete for the limited resource. To examine the mechanism behind the cooperative behavior of information channels, a computational model of selective attention is implemented based on two hypotheses. Unlike the traditional view of visual attention, the cooperative behavior is assumed to be a dynamic integration process between the bottom-up and top-down information. Furthermore, top-down information is assumed to provide a contextual cue during selection process and to guide the attentional allocation among many bottom-up candidates. The result from a series of simulation with still and video images showed some interesting properties that could not be explained by the competitive aspect of selective attention alone.

  1. How rats combine temporal cues.

    Science.gov (United States)

    Guilhardi, Paulo; Keen, Richard; MacInnis, Mika L M; Church, Russell M

    2005-05-31

    The procedures for classical and operant conditioning, and for many timing procedures, involve the delivery of reinforcers that may be related to the time of previous reinforcers and responses, and to the time of onsets and terminations of stimuli. The behavior resulting from such procedures can be described as bouts of responding that occur in some pattern at some rate. A packet theory of timing and conditioning is described that accounts for such behavior under a wide range of procedures. Applications include the food searching by rats in Skinner boxes under conditions of fixed and random reinforcement, brief and sustained stimuli, and several response-food contingencies. The approach is used to describe how multiple cues from reinforcers and stimuli combine to determine the rate and pattern of response bouts.

  2. Children's recognition of emotions from vocal cues

    NARCIS (Netherlands)

    Sauter, D.A.; Panattoni, C.; Happé, F.

    2013-01-01

    Emotional cues contain important information about the intentions and feelings of others. Despite a wealth of research into children's understanding of facial signals of emotions, little research has investigated the developmental trajectory of interpreting affective cues in the voice. In this study

  3. Dylan Pritchett, Storyteller. Cue Sheet for Students.

    Science.gov (United States)

    Evans, Karen L. B.

    Designed to be used before and after attending a storytelling performance by Dylan Pritchett, this cue sheet presents information about the performance and suggests activities that can be done with classmates, friends, or family members. The cue sheet discusses where and why people tell stories, what makes a story good for telling, what makes a…

  4. Cross-Cultural Nonverbal Cue Immersive Training

    Science.gov (United States)

    2008-12-01

    Global Assessment Orlando, Florida, 32809 + University of Central Florida Orlando, Florida, 32816 ++ Army Research Institute...technologies incorporating mixed reality training may be used to promote social cooperative learning. 1. INTRODUCTION As a global community...communicated either consciously or unconsciously through various forms of nonverbal cues such as body posture and facial expressions. Nonverbal cues

  5. Perceived predation risk as a function of predator dietary cues in terrestrial salamanders.

    Science.gov (United States)

    Murray; Jenkins

    1999-01-01

    Prey often avoid predator chemical cues, and in aquatic systems, prey may even appraise predation risk via cues associated with the predator's diet. However, this relationship has not been shown for terrestrial predator-prey systems, where the proximity of predators and prey, and the intensity of predator chemical cues in the environment, may be less than in aquatic systems. In the laboratory, we tested behavioural responses (avoidance, habituation and activity) of terrestrial red-backed salamanders, Plethodon cinereus, to chemical cues from garter snakes, Thamnophis sirtalis, fed either red-backed salamanders or earthworms (Lumbricus spp.). We placed salamanders in arenas lined with paper towels pretreated with snake chemicals, and monitored salamander movements during 120 min. Salamanders avoided substrates preconditioned by earthworm-fed (avoidanceX+/-SE=91.1+/-2.5%, N=25) and salamander-fed (95.2+/-2.5%, N=25) snakes, when tested against untreated substrate (control). Salamanders avoided cues from salamander-fed snakes more strongly (75.2+/-5.5%, N=25) than earthworm-fed snakes when subjected to both treatments simultaneously, implying that salamanders were sensitive to predator diet. Salamanders tended to avoid snake substrate more strongly during the last 60 min of a trial, but activity patterns were similar between salamanders exposed exclusively to control substrate versus those subject to snake cues. In another experiment, salamanders failed to avoid cues from dead conspecifics, suggesting that the stronger avoidance of salamander-fed snakes in the previous experiment was not directly due to chemical cues emitted by predator-killed salamanders. Salamanders also did not discriminate between cues from a salamander-fed snake versus a salamander-fed snake that was recently switched (i.e. <14 days) to an earthworm diet. Our results imply that terrestrial salamanders are sensitive to perceived predation risk via by-products of predator diet, and that snake

  6. Kin-informative recognition cues in ants

    DEFF Research Database (Denmark)

    Nehring, Volker; Evison, Sophie E F; Santorelli, Lorenzo A

    2011-01-01

    behaviour is thought to be rare in one of the classic examples of cooperation--social insect colonies--because the colony-level costs of individual selfishness select against cues that would allow workers to recognize their closest relatives. In accord with this, previous studies of wasps and ants have...... found little or no kin information in recognition cues. Here, we test the hypothesis that social insects do not have kin-informative recognition cues by investigating the recognition cues and relatedness of workers from four colonies of the ant Acromyrmex octospinosus. Contrary to the theoretical...... prediction, we show that the cuticular hydrocarbons of ant workers in all four colonies are informative enough to allow full-sisters to be distinguished from half-sisters with a high accuracy. These results contradict the hypothesis of non-heritable recognition cues and suggest that there is more potential...

  7. The Extracellular Environment's Effect on Cellular Processes: An In Vitro Study of Mechanical and Chemical Cues on Human Mesenchymal Stem Cells and C17.2 Neural Stem Cells

    Science.gov (United States)

    Casey, Meghan E.

    Stem cells are widely used in the area of tissue engineering. The ability of cells to interact with materials on the nano- and micro- level is important in the success of the biomaterial. It is well-known that cells respond to their micro- and nano-environments through a process termed chemo-mechanotransduction. It is important to establish standard protocols for cellular experiments, as chemical modifications to maintenance environments can alter long-term research results. In this work, the effects of different media compositions on human mesenchymal stem cells (hMSCs) throughout normal in vitro maintenance are investigated. Changes in RNA regulation, protein expression and proliferation are studied via quantitative polymerase chain reaction (qPCR), immunocytochemistry (ICC) and cell counts, respectively. Morphological differences are also observed throughout the experiment. Results of this study illustrate the dynamic response of hMSC maintenance to differences in growth medium and passage number. These experiments highlight the effect growth medium has on in vitro experiments and the need of consistent protocols in hMSC research. A substantial opportunity exists in neuronal research to develop a material platform that allows for both the proliferation and differentiation of stem cells into neurons and the ability to quantify the secretome of neuronal cells. Anodic aluminum oxide (AAO) membranes are fabricated in a two-step anodization procedure where voltage is varied to control the pore size and morphology of the membranes. C17.2 neural stem cells are differentiated on the membranes via serum-withdrawal. Cellular growth is characterized by scanning electron microscopy (SEM), ICC and qPCR. ImageJ software is used to obtain phenotypic cell counts and neurite outgrowth lengths. Results indicate a highly tunable correlation between AAO nanopore sizes and differentiated cell populations. By selecting AAO membranes with specific pore size ranges, control of neuronal

  8. Action experience changes attention to kinematic cues

    Directory of Open Access Journals (Sweden)

    Courtney eFilippi

    2016-02-01

    Full Text Available The current study used remote corneal reflection eye-tracking to examine the relationship between motor experience and action anticipation in 13-month-old infants. To measure online anticipation of actions infants watched videos where the actor’s hand provided kinematic information (in its orientation about the type of object that the actor was going to reach for. The actor’s hand orientation either matched the orientation of a rod (congruent cue or did not match the orientation of the rod (incongruent cue. To examine relations between motor experience and action anticipation, we used a 2 (reach first vs. observe first x 2 (congruent kinematic cue vs. incongruent kinematic cue between-subjects design. We show that 13-month-old infants in the observe first condition spontaneously generate rapid online visual predictions to congruent hand orientation cues and do not visually anticipate when presented incongruent cues. We further demonstrate that the speed that these infants generate predictions to congruent motor cues is correlated with their own ability to pre-shape their hands. Finally, we demonstrate that following reaching experience, infants generate rapid predictions to both congruent and incongruent hand shape cues—suggesting that short-term experience changes attention to kinematics.

  9. Divergent pro-inflammatory profile of human dendritic cells in response to commensal and pathogenic bacteria associated with the airway microbiota

    DEFF Research Database (Denmark)

    Larsen, Jeppe Madura; Steen-Jensen, Daniel Bisgaard; Laursen, Janne Marie

    2012-01-01

    Recent studies using culture-independent methods have characterized the human airway microbiota and report microbial communities distinct from other body sites. Changes in these airway bacterial communities appear to be associated with inflammatory lung disease, yet the pro-inflammatory properties...... differences in DC stimulating properties of bacteria associated with the airway microbiota....... of individual bacterial species are unknown. In this study, we compared the immune stimulatory capacity on human monocyte-derived dendritic cells (DCs) of selected airway commensal and pathogenic bacteria predominantly associated with lungs of asthma or COPD patients (pathogenic Haemophillus spp. and Moraxella...

  10. Cue-Specific Reactivity in Experienced Gamblers

    OpenAIRE

    2009-01-01

    To examine whether gambling cue reactivity is cue-specific, 47 scratch-off lottery players and 47 horse race gamblers were presented with video clips of their preferred and non-preferred modes of gambling, and two control stimuli including an exciting car race and a mental stressor task while heart rates, excitement, and urge to gamble were being measured. Heart rates for both groups of gamblers were highest to the mental stressor and did not differ in response to the other three cues. Excite...

  11. Chemosensory responses to chemical and visual stimuli in five species of colubrid snakes

    Directory of Open Access Journals (Sweden)

    Anthony J. Saviola

    2012-07-01

    Full Text Available Snakes utilize chemical and visual stimuli during predation, however the emphasis on these cues and which cues are used to initiate predation varies among species. For example, rattlesnakes using the ambush strategy rely on chemical cues to locate an ambush station, then visual and thermal cues to initiate envenomating strikes, then chemical cues again to track prey. By contrast, many natricine snakes use chemical cues to initiate predation, increasing the rate of tongue flicking regardless of whether visual cues are present. The present study examined the individual and interactive effects of chemical and visual stimuli of prey on the predatory behavior of five snake taxa representing three feeding guilds. Bull snakes (Pituophis catenifer, Eastern Corn snakes (Pantherophis guttatus, and Midland Rat snakes (Scotophis spiloides have a diet primarily consisting of mammals; Western Fox snakes (Mintonius vulpina prey primarily on bird eggs; and Common Kingsnakes (Lampropeltis getula prey equally on mammals and reptiles. Three patterns of response to chemical and visual stimuli of the test prey (Mus musculus were observed. Mammal specialists responded to chemical cues. Fox snakes responded to visual cues, but not to chemical cues. Kingsnakes exhibited increased rates of tongue flicking in response to both chemical and visual stimuli. This study suggests correlations between the evolution of prey preference, foraging ecology and the utilization of chemical or visual stimuli by snakes.

  12. Sensory cues employed for the acquisition of familiarity-dependent recognition of a shoal of conspecifics by climbing perch (Anabas testudineus Bloch).

    Science.gov (United States)

    Binoy, V V; Kasturirangan, Rajesh; Sinha, Anindya

    2015-06-01

    In this study we showed that a freshwater fish, the climbing perch (Anabas testudineus) is incapable of using chemical communication but employs visual cues to acquire familiarity and distinguish a familiar group of conspecifics from an unfamiliar one. Moreover, the isolation of olfactory signals from visual cues did not affect the recognition and preference for a familiar shoal in this species.

  13. Sensory cues employed for the acquisition of familiarity-dependent recognition of a shoal of conspecifics by climbing perch (Anabas testudineus Bloch)

    Indian Academy of Sciences (India)

    VV Binoy; Rajesh Kasturirangan; Anindya Sinha

    2015-06-01

    In this study we showed that a freshwater fish, the climbing perch (Anabas testudineus) is incapable of using chemical communication but employs visual cues to acquire familiarity and distinguish a familiar group of conspecifics from an unfamiliar one. Moreover, the isolation of olfactory signals from visual cues did not affect the recognition and preference for a familiar shoal in this species.

  14. Effect of Plant Growth Promoting Bacteria Associated with Halophytic Weed (Psoralea corylifolia L) on Germination and Seedling Growth of Wheat Under Saline Conditions.

    Science.gov (United States)

    Sorty, Ajay M; Meena, Kamlesh K; Choudhary, Khushboo; Bitla, Utkarsh M; Minhas, P S; Krishnani, K K

    2016-11-01

    Halotolerant bacteria associated with Psoralea corylifolia L., a luxuriantly growing annual weed in salinity-affected semi-arid regions of western Maharashtra, India were evaluated for their plant growth-promoting activity in wheat. A total of 79 bacteria associated with different parts viz., root, shoot and nodule endophytes, rhizosphere, rhizoplane, and leaf epiphytes, were isolated and grouped based on their habitat. Twelve bacteria isolated for their potential in plant growth promotion were further selected for in vitro studies. Molecular identification showed the presence of the genera Bacillus, Pantoea, Marinobacterium, Acinetobacter, Enterobacter, Pseudomonas, Rhizobium, and Sinorhizobium (LC027447-53; LC027455; LC027457, LC027459, and LC128410). The phylogenetic studies along with carbon source utilization profiles using the Biolog® indicated the presence of novel species and the in planta studies revealed promising results under salinity stress. Whereas the nodule endophytes had minute plant growth-promoting (PGP) activity, the cell free culture filtrates of these strains enhanced seed germination of wheat (Triticum aestivum L). The maximum vigor index was monitored in isolate Y7 (Enterobacter sp strain NIASMVII). Indole acetic acid (IAA) production by the isolates ranged between 0.22 and 25.58 μg mL(-1). This signifies the need of exploration of their individual metabolites for developing next-generation bio-inoculants through co-inoculation with other compatible microbes. This study has potential in utilization of the weed-associated microbiome in terms of alleviation of salinity stress in crop plants.

  15. Nipping cue reactivity in the bud: baclofen prevents limbic activation elicited by subliminal drug cues.

    Science.gov (United States)

    Young, Kimberly A; Franklin, Teresa R; Roberts, David C S; Jagannathan, Kanchana; Suh, Jesse J; Wetherill, Reagan R; Wang, Ze; Kampman, Kyle M; O'Brien, Charles P; Childress, Anna Rose

    2014-04-02

    Relapse is a widely recognized and difficult to treat feature of the addictions. Substantial evidence implicates cue-triggered activation of the mesolimbic dopamine system as an important contributing factor. Even drug cues presented outside of conscious awareness (i.e., subliminally) produce robust activation within this circuitry, indicating the sensitivity and vulnerability of the brain to potentially problematic reward signals. Because pharmacological agents that prevent these early cue-induced responses could play an important role in relapse prevention, we examined whether baclofen-a GABAB receptor agonist that reduces mesolimbic dopamine release and conditioned drug responses in laboratory animals-could inhibit mesolimbic activation elicited by subliminal cocaine cues in cocaine-dependent individuals. Twenty cocaine-dependent participants were randomized to receive baclofen (60 mg/d; 20 mg t.i.d.) or placebo. Event-related BOLD fMRI and a backward-masking paradigm were used to examine the effects of baclofen on subliminal cocaine (vs neutral) cues. Sexual and aversive cues were included to examine specificity. We observed that baclofen-treated participants displayed significantly less activation in response to subliminal cocaine (vs neutral) cues, but not sexual or aversive (vs neutral) cues, than placebo-treated participants in a large interconnected bilateral cluster spanning the ventral striatum, ventral pallidum, amygdala, midbrain, and orbitofrontal cortex (voxel threshold p baclofen may inhibit the earliest type of drug cue-induced motivational processing-that which occurs outside of awareness-before it evolves into a less manageable state.

  16. Gender differences in craving and cue reactivity to smoking and negative affect/stress cues.

    Science.gov (United States)

    Saladin, Michael E; Gray, Kevin M; Carpenter, Matthew J; LaRowe, Steven D; DeSantis, Stacia M; Upadhyaya, Himanshu P

    2012-01-01

    There is evidence that women may be less successful when attempting to quit smoking than men. One potential contributory cause of this gender difference is differential craving and stress reactivity to smoking- and negative affect/stress-related cues. The present human laboratory study investigated the effects of gender on reactivity to smoking and negative affect/stress cues by exposing nicotine dependent women (n = 37) and men (n = 53) smokers to two active cue types, each with an associated control cue: (1) in vivo smoking cues and in vivo neutral control cues, and (2) imagery-based negative affect/stress script and a neutral/relaxing control script. Both before and after each cue/script, participants provided subjective reports of smoking-related craving and affective reactions. Heart rate (HR) and skin conductance (SC) responses were also measured. Results indicated that participants reported greater craving and SC in response to smoking versus neutral cues and greater subjective stress in response to the negative affect/stress versus neutral/relaxing script. With respect to gender differences, women evidenced greater craving, stress and arousal ratings and lower valence ratings (greater negative emotion) in response to the negative affect/stressful script. While there were no gender differences in responses to smoking cues, women trended towards higher arousal ratings. Implications of the findings for treatment and tobacco-related morbidity and mortality are discussed.

  17. Perception of health from facial cues

    Science.gov (United States)

    Henderson, Audrey J.; Holzleitner, Iris J.; Talamas, Sean N.

    2016-01-01

    Impressions of health are integral to social interactions, yet poorly understood. A review of the literature reveals multiple facial characteristics that potentially act as cues to health judgements. The cues vary in their stability across time: structural shape cues including symmetry and sexual dimorphism alter slowly across the lifespan and have been found to have weak links to actual health, but show inconsistent effects on perceived health. Facial adiposity changes over a medium time course and is associated with both perceived and actual health. Skin colour alters over a short time and has strong effects on perceived health, yet links to health outcomes have barely been evaluated. Reviewing suggested an additional influence of demeanour as a perceptual cue to health. We, therefore, investigated the association of health judgements with multiple facial cues measured objectively from two-dimensional and three-dimensional facial images. We found evidence for independent contributions of face shape and skin colour cues to perceived health. Our empirical findings: (i) reinforce the role of skin yellowness; (ii) demonstrate the utility of global face shape measures of adiposity; and (iii) emphasize the role of affect in facial images with nominally neutral expression in impressions of health. PMID:27069057

  18. Spontaneous Hedonic Reactions to Social Media Cues.

    Science.gov (United States)

    van Koningsbruggen, Guido M; Hartmann, Tilo; Eden, Allison; Veling, Harm

    2017-05-01

    Why is it so difficult to resist the desire to use social media? One possibility is that frequent social media users possess strong and spontaneous hedonic reactions to social media cues, which, in turn, makes it difficult to resist social media temptations. In two studies (total N = 200), we investigated less-frequent and frequent social media users' spontaneous hedonic reactions to social media cues using the Affect Misattribution Procedure-an implicit measure of affective reactions. Results demonstrated that frequent social media users showed more favorable affective reactions in response to social media (vs. control) cues, whereas less-frequent social media users' affective reactions did not differ between social media and control cues (Studies 1 and 2). Moreover, the spontaneous hedonic reactions to social media (vs. control) cues were related to self-reported cravings to use social media and partially accounted for the link between social media use and social media cravings (Study 2). These findings suggest that frequent social media users' spontaneous hedonic reactions in response to social media cues might contribute to their difficulties in resisting desires to use social media.

  19. Earthworms use odor cues to locate and feed on microorganisms in soil.

    Directory of Open Access Journals (Sweden)

    Lara Zirbes

    Full Text Available Earthworms are key components of temperate soil ecosystems but key aspects of their ecology remain unexamined. Here we elucidate the role of olfactory cues in earthworm attraction to food sources and document specific chemical cues that attract Eisenia fetida to the soil fungi Geotrichum candidum. Fungi and other microorganisms are major sources of volatile emissions in soil ecosystems as well as primary food sources for earthworms, suggesting the likelihood that earthworms might profitably use olfactory cues to guide foraging behavior. Moreover, previous studies have documented earthworm movement toward microbial food sources. But, the specific olfactory cues responsible for earthworm attraction have not previously been identified. Using olfactometer assays combined with chemical analyses (GC-MS, we documented the attraction of E. fetida individuals to filtrate derived from G. candidum colonies and to two individual compounds tested in isolation: ethyl pentanoate and ethyl hexanoate. Attraction at a distance was observed when barriers prevented the worms from reaching the target stimuli, confirming the role of volatile cues. These findings enhance our understanding of the mechanisms underlying key trophic interactions in soil ecosystems and have potential implications for the extraction and collection of earthworms in vermiculture and other applied activities.

  20. Earthworms use odor cues to locate and feed on microorganisms in soil.

    Science.gov (United States)

    Zirbes, Lara; Mescher, Mark; Vrancken, Véronique; Wathelet, Jean-Paul; Verheggen, François J; Thonart, Philippe; Haubruge, Eric

    2011-01-01

    Earthworms are key components of temperate soil ecosystems but key aspects of their ecology remain unexamined. Here we elucidate the role of olfactory cues in earthworm attraction to food sources and document specific chemical cues that attract Eisenia fetida to the soil fungi Geotrichum candidum. Fungi and other microorganisms are major sources of volatile emissions in soil ecosystems as well as primary food sources for earthworms, suggesting the likelihood that earthworms might profitably use olfactory cues to guide foraging behavior. Moreover, previous studies have documented earthworm movement toward microbial food sources. But, the specific olfactory cues responsible for earthworm attraction have not previously been identified. Using olfactometer assays combined with chemical analyses (GC-MS), we documented the attraction of E. fetida individuals to filtrate derived from G. candidum colonies and to two individual compounds tested in isolation: ethyl pentanoate and ethyl hexanoate. Attraction at a distance was observed when barriers prevented the worms from reaching the target stimuli, confirming the role of volatile cues. These findings enhance our understanding of the mechanisms underlying key trophic interactions in soil ecosystems and have potential implications for the extraction and collection of earthworms in vermiculture and other applied activities.

  1. Smelling wrong: hormonal contraception in lemurs alters critical female odour cues

    Science.gov (United States)

    Crawford, Jeremy Chase; Boulet, Marylène; Drea, Christine M.

    2011-01-01

    Animals, including humans, use olfaction to assess potential social and sexual partners. Although hormones modulate olfactory cues, we know little about whether contraception affects semiochemical signals and, ultimately, mate choice. We examined the effects of a common contraceptive, medroxyprogesterone acetate (MPA), on the olfactory cues of female ring-tailed lemurs (Lemur catta), and the behavioural response these cues generated in male conspecifics. The genital odorants of contracepted females were dramatically altered, falling well outside the range of normal female variation: MPA decreased the richness and modified the relative abundances of volatile chemicals expressed in labial secretions. Comparisons between treatment groups revealed several indicator compounds that could reliably signal female reproductive status to conspecifics. MPA also changed a female's individual chemical ‘signature’, while minimizing her chemical distinctiveness relative to other contracepted females. Most remarkably, MPA degraded the chemical patterns that encode honest information about genetic constitution, including individual diversity (heterozygosity) and pairwise relatedness to conspecifics. Lastly, males preferentially investigated the odorants of intact over contracepted females, clearly distinguishing those with immediate reproductive potential. By altering the olfactory cues that signal fertility, individuality, genetic quality and relatedness, contraceptives may disrupt intraspecific interactions in primates, including those relevant to kin recognition and mate choice. PMID:20667870

  2. Direct and Indirect Cues to Knowledge States during Word Learning

    Science.gov (United States)

    Saylor, Megan M.; Carroll, C. Brooke

    2009-01-01

    The present study investigated three-year-olds' sensitivity to direct and indirect cues to others' knowledge states for word learning purposes. Children were given either direct, physical cues to knowledge or indirect, verbal cues to knowledge. Preschoolers revealed a better ability to learn words from a speaker following direct, physical cues to…

  3. Cross-modal cueing in audiovisual spatial attention

    DEFF Research Database (Denmark)

    Blurton, Steven Paul; Greenlee, Mark W.; Gondan, Matthias

    2015-01-01

    effects have been reported for endogenous visual cues while exogenous cues seem to be mostly ineffective. In three experiments, we investigated cueing effects on the processing of audiovisual signals. In Experiment 1 we used endogenous cues to investigate their effect on the detection of auditory, visual......Visual processing is most effective at the location of our attentional focus. It has long been known that various spatial cues can direct visuospatial attention and influence the detection of auditory targets. Cross-modal cueing, however, seems to depend on the type of the visual cue: facilitation...... the possibility that cue-target contingencies were responsible for the difference between Experiment 1 and 2. In all experiments we investigated if a response time model can explain the data and tested whether the observed cueing effects were modality-dependent. The results observed with endogenous cues imply...

  4. An Eye Tracking Comparison of External Pointing Cues and Internal Continuous Cues in Learning with Complex Animations

    Science.gov (United States)

    Boucheix, Jean-Michel; Lowe, Richard K.

    2010-01-01

    Two experiments used eye tracking to investigate a novel cueing approach for directing learner attention to low salience, high relevance aspects of a complex animation. In the first experiment, comprehension of a piano mechanism animation containing spreading-colour cues was compared with comprehension obtained with arrow cues or no cues. Eye…

  5. An Eye Tracking Comparison of External Pointing Cues and Internal Continuous Cues in Learning with Complex Animations

    Science.gov (United States)

    Boucheix, Jean-Michel; Lowe, Richard K.

    2010-01-01

    Two experiments used eye tracking to investigate a novel cueing approach for directing learner attention to low salience, high relevance aspects of a complex animation. In the first experiment, comprehension of a piano mechanism animation containing spreading-colour cues was compared with comprehension obtained with arrow cues or no cues. Eye…

  6. Cuticular hydrocarbons as potential kin recognition cues in a subsocial spider

    DEFF Research Database (Denmark)

    Grinsted, Lena; Bilde, Trine; D'Ettorre, Patrizia

    2011-01-01

    In animal societies, recognition of group members and relatives is an important trait for the evolution and maintenance of social behavior. In eusocial insects, nest mate recognition is based on cuticular hydrocarbons and allows colony members to reject competitors and parasites. The study...... cuticular hydrocarbons candidates for kin recognition cues. Our behavioral assays indicate that spiderlings can discriminate between cuticular cues from kin and nonkin: In a choice set-up, spiderlings more often chose to reside near cuticular chemical extracts of siblings compared with nonsiblings...

  7. In situ identification and quantification of protein-hydrolyzing ruminal bacteria associated with the digestion of barley and corn grain.

    Science.gov (United States)

    Xia, Yun; Kong, Yunhong; Huang, Heping; Yang, Hee Eun; Forster, Robert; McAllister, Tim A

    2016-12-01

    In this study, BODIPY FL DQ™ casein staining combined with fluorescence in situ hybridization (FISH) was used to detect and identify protein-hydrolyzing bacteria within biofilms that produced active cell-surface-associated serine- and metallo-proteases during the ruminal digestion of barley and corn grain in cows fed barley-based diets at 2 different levels. A doublet coccoid bacterial morphotype associated with barley and corn grain particles fluoresced after BODIPY FL DQ™ casein staining. Bacteria with this morphotype accounted for 3%-10% of the total bacteria attached to surface of cereal grain particles, possibly indicative of an important role in the hydrolysis of the protein matrix within the endosperm. However, the identity of these predominant proteolytic bacteria could not be determined using FISH. Quantitative FISH revealed that known proteolytic species, Prevotella ruminicola, Ruminobacter amylophilus, and Butyrivibrio fibrisolvens, were attached to particles of various cultivars of barley grain and corn, confirming their role in the proteolysis of cereal grains. Differences in chemical composition among different barley cultivars did not affect the composition of proteolytic bacterial populations. However, the concentrate level in the basal diet did have an impact on the relative abundance of proteolytic bacteria and thus possibly their overall contribution to the proteolysis of cereal grains.

  8. Deciphering faces: quantifiable visual cues to weight.

    Science.gov (United States)

    Coetzee, Vinet; Chen, Jingying; Perrett, David I; Stephen, Ian D

    2010-01-01

    Body weight plays a crucial role in mate choice, as weight is related to both attractiveness and health. People are quite accurate at judging weight in faces, but the cues used to make these judgments have not been defined. This study consisted of two parts. First, we wanted to identify quantifiable facial cues that are related to body weight, as defined by body mass index (BMI). Second, we wanted to test whether people use these cues to judge weight. In study 1, we recruited two groups of Caucasian and two groups of African participants, determined their BMI and measured their 2-D facial images for: width-to-height ratio, perimeter-to-area ratio, and cheek-to-jaw-width ratio. All three measures were significantly related to BMI in males, while the width-to-height and cheek-to-jaw-width ratios were significantly related to BMI in females. In study 2, these images were rated for perceived weight by Caucasian observers. We showed that these observers use all three cues to judge weight in African and Caucasian faces of both sexes. These three facial cues, width-to-height ratio, perimeter-to-area ratio, and cheek-to-jaw-width ratio, are therefore not only related to actual weight but provide a basis for perceptual attributes as well.

  9. Enhancing Manual Scan Registration Using Audio Cues

    Science.gov (United States)

    Ntsoko, T.; Sithole, G.

    2014-04-01

    Indoor mapping and modelling requires that acquired data be processed by editing, fusing, formatting the data, amongst other operations. Currently the manual interaction the user has with the point cloud (data) while processing it is visual. Visual interaction does have limitations, however. One way of dealing with these limitations is to augment audio in point cloud processing. Audio augmentation entails associating points of interest in the point cloud with audio objects. In coarse scan registration, reverberation, intensity and frequency audio cues were exploited to help the user estimate depth and occupancy of space of points of interest. Depth estimations were made reliably well when intensity and frequency were both used as depth cues. Coarse changes of depth could be estimated in this manner. The depth between surfaces can therefore be estimated with the aid of the audio objects. Sound reflections of an audio object provided reliable information of the object surroundings in some instances. For a point/area of interest in the point cloud, these reflections can be used to determine the unseen events around that point/area of interest. Other processing techniques could benefit from this while other information is estimated using other audio cues like binaural cues and Head Related Transfer Functions. These other cues could be used in position estimations of audio objects to aid in problems such as indoor navigation problems.

  10. Word segmentation with universal prosodic cues.

    Science.gov (United States)

    Endress, Ansgar D; Hauser, Marc D

    2010-09-01

    When listening to speech from one's native language, words seem to be well separated from one another, like beads on a string. When listening to a foreign language, in contrast, words seem almost impossible to extract, as if there was only one bead on the same string. This contrast reveals that there are language-specific cues to segmentation. The puzzle, however, is that infants must be endowed with a language-independent mechanism for segmentation, as they ultimately solve the segmentation problem for any native language. Here, we approach the acquisition problem by asking whether there are language-independent cues to segmentation that might be available to even adult learners who have already acquired a native language. We show that adult learners recognize words in connected speech when only prosodic cues to word-boundaries are given from languages unfamiliar to the participants. In both artificial and natural speech, adult English speakers, with no prior exposure to the test languages, readily recognized words in natural languages with critically different prosodic patterns, including French, Turkish and Hungarian. We suggest that, even though languages differ in their sound structures, they carry universal prosodic characteristics. Further, these language-invariant prosodic cues provide a universally accessible mechanism for finding words in connected speech. These cues may enable infants to start acquiring words in any language even before they are fine-tuned to the sound structure of their native language.

  11. Stingless bees use terpenes as olfactory cues to find resin sources.

    Science.gov (United States)

    Leonhardt, S D; Zeilhofer, S; Blüthgen, N; Schmitt, Thomas

    2010-09-01

    Insects largely rely on olfactory cues when seeking and judging information on nests, partners, or resources. Bees are known to use volatile compounds-besides visual cues-to find flowers suitable for pollen and nectar collection. Tropical stingless bees additionally collect large amounts of plant resins for nest construction, nest maintenance, nest defense, and to derive chemical constituents for their cuticular profiles. We here demonstrate that stingless bees of Borneo also use olfactory cues to find tree resins. They rely on volatile mono- and sesquiterpenes to locate or recognize known resin sources. Moreover, by modifying resin extracts, we found that stingless bees do not use the entire resin bouquet but relative proportions of several terpenes. In doing so, the bees are able to learn specific tree resin profiles and distinguish between tree species and partly even tree individuals.

  12. Bacteria Associated to Plants Naturally Selected in a Historical PCB Polluted Soil Show Potential to Sustain Natural Attenuation

    Directory of Open Access Journals (Sweden)

    Lorenzo Vergani

    2017-07-01

    Full Text Available The exploitation of the association between plants and microorganisms is a promising approach able to boost natural attenuation processes for soil clean-up in vast polluted areas characterized by mixed chemical contamination. We aimed to explore the selection of root-associated bacterial communities driven by different plant species spontaneously established in abandoned agricultural soils within a historical polluted site in north Italy. The site is highly contaminated by chlorinated persistent organic pollutants, mainly constituted by polychlorobiphenyls (PCBs, together with heavy metals and metalloids, in variable concentrations and uneven distribution. The overall structure of the non-vegetated and root-associated soil fractions bacterial communities was described by high-throughput sequencing of the 16S rRNA gene, and a collection of 165 rhizobacterial isolates able to use biphenyl as unique carbon source was assayed for plant growth promotion (PGP traits and bioremediation potential. The results showed that the recruitment of specific bacterial communities in the root-associated soil fractions was driven by both soil fractions and plant species, explaining 21 and 18% of the total bacterial microbiome variation, respectively. PCR-based detection in the soil metagenome of bacterial bphA gene, encoding for the biphenyl dioxygenase α subunit, indicated that the soil in the site possesses metabolic traits linked to PCB degradation. Biphenyl-utilizing bacteria isolated from the rhizosphere of the three different plant species showed low phylogenetic diversity and well represented functional traits, in terms of PGP and bioremediation potential. On average, 72% of the strains harbored the bphA gene and/or displayed catechol 2,3-dioxygenase activity, involved in aromatic ring cleavage. PGP traits, including 1-aminocyclopropane-1-carboxylic acid deaminase activity potentially associated to plant stress tolerance induction, were widely distributed

  13. Bacteria Associated to Plants Naturally Selected in a Historical PCB Polluted Soil Show Potential to Sustain Natural Attenuation.

    Science.gov (United States)

    Vergani, Lorenzo; Mapelli, Francesca; Marasco, Ramona; Crotti, Elena; Fusi, Marco; Di Guardo, Antonio; Armiraglio, Stefano; Daffonchio, Daniele; Borin, Sara

    2017-01-01

    The exploitation of the association between plants and microorganisms is a promising approach able to boost natural attenuation processes for soil clean-up in vast polluted areas characterized by mixed chemical contamination. We aimed to explore the selection of root-associated bacterial communities driven by different plant species spontaneously established in abandoned agricultural soils within a historical polluted site in north Italy. The site is highly contaminated by chlorinated persistent organic pollutants, mainly constituted by polychlorobiphenyls (PCBs), together with heavy metals and metalloids, in variable concentrations and uneven distribution. The overall structure of the non-vegetated and root-associated soil fractions bacterial communities was described by high-throughput sequencing of the 16S rRNA gene, and a collection of 165 rhizobacterial isolates able to use biphenyl as unique carbon source was assayed for plant growth promotion (PGP) traits and bioremediation potential. The results showed that the recruitment of specific bacterial communities in the root-associated soil fractions was driven by both soil fractions and plant species, explaining 21 and 18% of the total bacterial microbiome variation, respectively. PCR-based detection in the soil metagenome of bacterial bphA gene, encoding for the biphenyl dioxygenase α subunit, indicated that the soil in the site possesses metabolic traits linked to PCB degradation. Biphenyl-utilizing bacteria isolated from the rhizosphere of the three different plant species showed low phylogenetic diversity and well represented functional traits, in terms of PGP and bioremediation potential. On average, 72% of the strains harbored the bphA gene and/or displayed catechol 2,3-dioxygenase activity, involved in aromatic ring cleavage. PGP traits, including 1-aminocyclopropane-1-carboxylic acid deaminase activity potentially associated to plant stress tolerance induction, were widely distributed among the isolates

  14. Bacteria Associated to Plants Naturally Selected in a Historical PCB Polluted Soil Show Potential to Sustain Natural Attenuation

    KAUST Repository

    Vergani, Lorenzo

    2017-07-25

    The exploitation of the association between plants and microorganisms is a promising approach able to boost natural attenuation processes for soil clean-up in vast polluted areas characterized by mixed chemical contamination. We aimed to explore the selection of root-associated bacterial communities driven by different plant species spontaneously established in abandoned agricultural soils within a historical polluted site in north Italy. The site is highly contaminated by chlorinated persistent organic pollutants, mainly constituted by polychlorobiphenyls (PCBs), together with heavy metals and metalloids, in variable concentrations and uneven distribution. The overall structure of the non-vegetated and root-associated soil fractions bacterial communities was described by high-throughput sequencing of the 16S rRNA gene, and a collection of 165 rhizobacterial isolates able to use biphenyl as unique carbon source was assayed for plant growth promotion (PGP) traits and bioremediation potential. The results showed that the recruitment of specific bacterial communities in the root-associated soil fractions was driven by both soil fractions and plant species, explaining 21 and 18% of the total bacterial microbiome variation, respectively. PCR-based detection in the soil metagenome of bacterial bphA gene, encoding for the biphenyl dioxygenase α subunit, indicated that the soil in the site possesses metabolic traits linked to PCB degradation. Biphenyl-utilizing bacteria isolated from the rhizosphere of the three different plant species showed low phylogenetic diversity and well represented functional traits, in terms of PGP and bioremediation potential. On average, 72% of the strains harbored the bphA gene and/or displayed catechol 2,3-dioxygenase activity, involved in aromatic ring cleavage. PGP traits, including 1-aminocyclopropane-1-carboxylic acid deaminase activity potentially associated to plant stress tolerance induction, were widely distributed among the isolates

  15. Defocus cue and saliency preserving video compression

    Science.gov (United States)

    Khanna, Meera Thapar; Chaudhury, Santanu; Lall, Brejesh

    2016-11-01

    There are monocular depth cues present in images or videos that aid in depth perception in two-dimensional images or videos. Our objective is to preserve the defocus depth cue present in the videos along with the salient regions during compression application. A method is provided for opportunistic bit allocation during the video compression using visual saliency information comprising both the image features, such as color and contrast, and the defocus-based depth cue. The method is divided into two steps: saliency computation followed by compression. A nonlinear method is used to combine pure and defocus saliency maps to form the final saliency map. Then quantization values are assigned on the basis of these saliency values over a frame. The experimental results show that the proposed scheme yields good results over standard H.264 compression as well as pure and defocus saliency methods.

  16. Consumer attention to product health cues

    DEFF Research Database (Denmark)

    Orquin, Jacob Lund

    Purpose As part of a larger project aiming at improving healthy food choice among consumers, four studies were carried out to identify packaging cues that communicate product healthfulness. Methods Study 1 was an eye tracking experiment using a 5x3 group mixed design where the stimuli (five...... was a 2x2 group mixed design manipulating health claims (absent, present) and taste claims (absent, present). Study 4 was a four-group between-subjects design manipulating food labels (a national organic label, EU organic label, a national keyhole label [indicating product healthfulness], a combination...... of all labels). Results The only elements operating as health cues were the nutrition label and the organic label. The information cues used during purchase evaluation were the product category name and the nutrition label. Results also revealed that the probability a consumer will read the nutrition...

  17. Perceptions of Sexual Orientation From Minimal Cues.

    Science.gov (United States)

    Rule, Nicholas O

    2017-01-01

    People derive considerable amounts of information about each other from minimal nonverbal cues. Apart from characteristics typically regarded as obvious when encountering another person (e.g., age, race, and sex), perceivers can identify many other qualities about a person that are typically rather subtle. One such feature is sexual orientation. Here, I review the literature documenting the accurate perception of sexual orientation from nonverbal cues related to one's adornment, acoustics, actions, and appearance. In addition to chronicling studies that have demonstrated how people express and extract sexual orientation in each of these domains, I discuss some of the basic cognitive and perceptual processes that support these judgments, including how cues to sexual orientation manifest in behavioral (e.g., clothing choices) and structural (e.g., facial morphology) signals. Finally, I attend to boundary conditions in the accurate perception of sexual orientation, such as the states, traits, and group memberships that moderate individuals' ability to reliably decipher others' sexual orientation.

  18. Attention to health cues on product packages

    DEFF Research Database (Denmark)

    Orquin, Jacob Lund; Scholderer, Joachim

    2011-01-01

    attention was measured by means of eye-tracking. Task (free viewing, product healthfulness evaluation, and purchase likelihood evaluation) and product (five different yoghurt products) were varied in a mixed within-between subjects design. The free viewing condition served as a baseline against which...... increases or decreases in attention during product healthfulness evaluation and purchase likelihood evaluation were assessed. The analysis revealed that the only element operating as a health cue during product healthfulness evaluation was the nutrition label. The information cues used during purchase...... likelihood evaluation were the name of the product category and the nutrition label. Taken together, the results suggest that the only information element that consumers consistently utilize as a health cue is the nutrition label and that only a limited amount of attention is devoted to read nutrition labels...

  19. Calcifying algae maintain settlement cues to larval abalone following algal exposure to extreme ocean acidification.

    Science.gov (United States)

    O'Leary, Jennifer K; Barry, James P; Gabrielson, Paul W; Rogers-Bennett, Laura; Potts, Donald C; Palumbi, Stephen R; Micheli, Fiorenza

    2017-07-18

    Ocean acidification (OA) increasingly threatens marine systems, and is especially harmful to calcifying organisms. One important question is whether OA will alter species interactions. Crustose coralline algae (CCA) provide space and chemical cues for larval settlement. CCA have shown strongly negative responses to OA in previous studies, including disruption of settlement cues to corals. In California, CCA provide cues for seven species of harvested, threatened, and endangered abalone. We exposed four common CCA genera and a crustose calcifying red algae, Peyssonnelia (collectively CCRA) from California to three pCO2 levels ranging from 419-2,013 µatm for four months. We then evaluated abalone (Haliotis rufescens) settlement under ambient conditions among the CCRA and non-algal controls that had been previously exposed to the pCO2 treatments. Abalone settlement and metamorphosis increased from 11% in the absence of CCRA to 45-69% when CCRA were present, with minor variation among CCRA genera. Though all CCRA genera reduced growth during exposure to increased pCO2, abalone settlement was unaffected by prior CCRA exposure to increased pCO2. Thus, we find no impacts of OA exposure history on CCRA provision of settlement cues. Additionally, there appears to be functional redundancy in genera of CCRA providing cues to abalone, which may further buffer OA effects.

  20. Cognitive Cues are More Compelling than Facial Cues in Determining Adults' Reactions towards Young Children

    Directory of Open Access Journals (Sweden)

    Carlos Hernández Blasi

    2015-04-01

    Full Text Available Previous research has demonstrated the significant influence that both children's facial features (Lorenz, 1943 and children's cognitive expressions (Bjorklund, Hernández Blasi, and Periss, 2010 have on adults' perception of young children. However, until now, these two types of cues have been studied independently. The present study contrasted these two types of cues simultaneously in a group of college students. To this purpose, we designed five experimental conditions (Consistent, Inconsistent, Mature-Face, Immature-Face, and Faces-Only in which we varied the presentation of a series of mature and immature vignettes (including two previously studied types of thinking: natural thinking and supernatural thinking associated with a series of more mature and less mature children's faces. Performance in these conditions was contrasted with data from a Vignettes-Only condition taken from Bjorklund et al. (2010. Results indicated that cognitive cues were more powerful than facial cues in determining adults' perceptions of young children. From an evolutionary developmental perspective, we suggest that facial cues are more relevant to adults during infancy than during the preschool period, when, with the development of spoken language, the verbalized expressions of children's thoughts become the principal cues influencing adults' perceptions, with facial cues playing a more secondary role.

  1. Vowel identification by cochlear implant users: Contributions of duration cues and dynamic spectral cues.

    Science.gov (United States)

    Donaldson, Gail S; Rogers, Catherine L; Johnson, Lindsay B; Oh, Soo Hee

    2015-07-01

    A recent study from our laboratory assessed vowel identification in cochlear implant (CI) users, using full /dVd/ syllables and partial (center- and edges-only) syllables with duration cues neutralized [Donaldson, Rogers, Cardenas, Russell, and Hanna (2013). J. Acoust. Soc. Am. 134, 3021-3028]. CI users' poorer performance for partial syllables as compared to full syllables, and for edges-only syllables as compared to center-only syllables, led to the hypotheses (1) that CI users may rely strongly on vowel duration cues; and (2) that CI users have more limited access to dynamic spectral cues than steady-state spectral cues. The present study tested those hypotheses. Ten CI users and ten young normal hearing (YNH) listeners heard full /dVd/ syllables and modified (center- and edges-only) syllables in which vowel duration cues were either preserved or eliminated. The presence of duration cues significantly improved vowel identification scores in four CI users, suggesting a strong reliance on duration cues. Duration effects were absent for the other CI users and the YNH listeners. On average, CI users and YNH listeners demonstrated similar performance for center-only stimuli and edges-only stimuli having the same total duration of vowel information. However, three CI users demonstrated significantly poorer performance for the edges-only stimuli, indicating apparent deficits of dynamic spectral processing.

  2. Disentangling attention from action in the emotional spatial cueing task.

    Science.gov (United States)

    Mulckhuyse, Manon; Crombez, Geert

    2014-01-01

    In the emotional spatial cueing task, a peripheral cue--either emotional or non-emotional--is presented before target onset. A stronger cue validity effect with an emotional relative to a non-emotional cue (i.e., more efficient responding to validly cued targets relative to invalidly cued targets) is taken as an indication of emotional modulation of attentional processes. However, results from previous emotional spatial cueing studies are not consistent. Some studies find an effect at the validly cued location (shorter reaction times compared to a non-emotional cue), whereas other studies find an effect at the invalidly cued location (longer reaction times compared to a non-emotional cue). In the current paper, we explore which parameters affect emotional modulation of the cue validity effect in the spatial cueing task. Results from five experiments in healthy volunteers led to the conclusion that a threatening spatial cue did not affect attention processes but rather indicate that motor processes are affected. A possible mechanism might be that a strong aversive cue stimulus decreases reaction times by means of stronger action preparation. Consequently, in case of a spatially congruent response with the peripheral cue, a stronger cue validity effect could be obtained due to stronger response priming. The implications for future research are discussed.

  3. Neural mechanisms of cue-approach training.

    Science.gov (United States)

    Bakkour, Akram; Lewis-Peacock, Jarrod A; Poldrack, Russell A; Schonberg, Tom

    2017-05-01

    Biasing choices may prove a useful way to implement behavior change. Previous work has shown that a simple training task (the cue-approach task), which does not rely on external reinforcement, can robustly influence choice behavior by biasing choice toward items that were targeted during training. In the current study, we replicate previous behavioral findings and explore the neural mechanisms underlying the shift in preferences following cue-approach training. Given recent successes in the development and application of machine learning techniques to task-based fMRI data, which have advanced understanding of the neural substrates of cognition, we sought to leverage the power of these techniques to better understand neural changes during cue-approach training that subsequently led to a shift in choice behavior. Contrary to our expectations, we found that machine learning techniques applied to fMRI data during non-reinforced training were unsuccessful in elucidating the neural mechanism underlying the behavioral effect. However, univariate analyses during training revealed that the relationship between BOLD and choices for Go items increases as training progresses compared to choices of NoGo items primarily in lateral prefrontal cortical areas. This new imaging finding suggests that preferences are shifted via differential engagement of task control networks that interact with value networks during cue-approach training. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Visual Cues and Listening Effort: Individual Variability

    Science.gov (United States)

    Picou, Erin M.; Ricketts, Todd A; Hornsby, Benjamin W. Y.

    2011-01-01

    Purpose: To investigate the effect of visual cues on listening effort as well as whether predictive variables such as working memory capacity (WMC) and lipreading ability affect the magnitude of listening effort. Method: Twenty participants with normal hearing were tested using a paired-associates recall task in 2 conditions (quiet and noise) and…

  5. Exam Question Sequencing Effects and Context Cues

    Science.gov (United States)

    Davis, Doris Bitler

    2017-01-01

    Providing two or more versions of multiple-choice exams has long been a popular strategy for reducing the opportunity for students to engage in academic dishonesty. While the results of studies comparing exam scores under different question-order conditions have been inconclusive, the potential importance of contextual cues to aid student recall…

  6. Development of cue integration in human navigation.

    Science.gov (United States)

    Nardini, Marko; Jones, Peter; Bedford, Rachael; Braddick, Oliver

    2008-05-06

    Mammalian navigation depends both on visual landmarks and on self-generated (e.g., vestibular and proprioceptive) cues that signal the organism's own movement [1-5]. When these conflict, landmarks can either reset estimates of self-motion or be integrated with them [6-9]. We asked how humans combine these information sources and whether children, who use both from a young age [10-12], combine them as adults do. Participants attempted to return an object to its original place in an arena when given either visual landmarks only, nonvisual self-motion information only, or both. Adults, but not 4- to 5-year-olds or 7- to 8-year-olds, reduced their response variance when both information sources were available. In an additional "conflict" condition that measured relative reliance on landmarks and self-motion, we predicted behavior under two models: integration (weighted averaging) of the cues and alternation between them. Adults' behavior was predicted by integration, in which the cues were weighted nearly optimally to reduce variance, whereas children's behavior was predicted by alternation. These results suggest that development of individual spatial-representational systems precedes development of the capacity to combine these within a common reference frame. Humans can integrate spatial cues nearly optimally to navigate, but this ability depends on an extended developmental process.

  7. Cue-specific reactivity in experienced gamblers.

    Science.gov (United States)

    Wulfert, Edelgard; Maxson, Julie; Jardin, Bianca

    2009-12-01

    To examine whether gambling cue reactivity is cue-specific, 47 scratch-off lottery players and 47 horse race gamblers were presented with video clips of their preferred and nonpreferred modes of gambling, and two control stimuli including an exciting car race and a mental stressor task while heart rates, excitement, and urge to gamble were being measured. Heart rates for both groups of gamblers were highest to the mental stressor and did not differ in response to the other three cues. Excitement for both groups was highest in response to the action cues (horse race and car chase). Urge to gamble was significantly higher for each group to their preferred mode of gambling. A post hoc exploratory analysis comparing social gamblers (n = 54) and probable pathological gamblers (n = 40) revealed a similar pattern of responses. However, pathological gamblers reported overall significantly higher urges to gamble than social gamblers. As urges have been shown to play a pivotal role in addictive behaviors and relapse, the current findings may have implications for the development of gambling problems and relapse after successful treatment. Copyright 2009 APA

  8. Spontaneous hedonic reactions to social media cues

    NARCIS (Netherlands)

    Koningsbruggen, G.M. van; Hartmann, T.; Eden, A.; Veling, H.P.

    2017-01-01

    Why is it so difficult to resist the desire to use social media? One possibility is that frequent social media users possess strong and spontaneous hedonic reactions to social media cues, which, in turn, makes it difficult to resist social media temptations. In two studies (total N = 200), we

  9. Spontaneous hedonic reactions to social media cues

    NARCIS (Netherlands)

    Koningsbruggen, G.M. van; Hartmann, T.; Eden, A.; Veling, H.P.

    2017-01-01

    Why is it so difficult to resist the desire to use social media? One possibility is that frequent social media users possess strong and spontaneous hedonic reactions to social media cues, which, in turn, makes it difficult to resist social media temptations. In two studies (total N = 200), we invest

  10. Use of chemosensory cues as repellents for sea lamprey: Potential directions for population management

    Science.gov (United States)

    Imre, I.; Brown, G.E.; Bergstedt, R.A.; McDonald, R.

    2010-01-01

    Sea lamprey invaded the Great Lakes in the early 20th century and caused an abrupt decline in the population densities of several native fish species. The integrated management of this invasive species is composed of chemical (lampricide) applications, low-head barrier dams, adult trapping and sterile male release. Recently, there has been an increased emphasis on the development of control methods alternative to lampricide applications. We propose as an alternative-control method the use of chemosensory cues as repellents for sea lamprey population management. Based on the available evidence at this time, we suggest that injury-released chemical alarm cues show promise as repellents for sea lamprey and further research should be directed at determining whether sea lamprey show an avoidance response to these types of chemosensory cues. From a management perspective, these chemosensory cues could be used to restrict sea lamprey access to spawning grounds. Repellents could also be used together with attractants like sex pheromones to manipulate sea lamprey behavior, similar to the "push-pull" strategies utilized with insect pests. ?? 2010 Elsevier B.V.

  11. Baby on board: olfactory cues indicate pregnancy and fetal sex in a non-human primate

    Science.gov (United States)

    Crawford, Jeremy Chase; Drea, Christine M.

    2015-01-01

    Olfactory cues play an integral, albeit underappreciated, role in mediating vertebrate social and reproductive behaviour. These cues fluctuate with the signaller's hormonal condition, coincident with and informative about relevant aspects of its reproductive state, such as pubertal onset, change in season and, in females, timing of ovulation. Although pregnancy dramatically alters a female's endocrine profiles, which can be further influenced by fetal sex, the relationship between gestation and olfactory cues is poorly understood. We therefore examined the effects of pregnancy and fetal sex on volatile genital secretions in the ring-tailed lemur (Lemur catta), a strepsirrhine primate possessing complex olfactory mechanisms of reproductive signalling. While pregnant, dams altered and dampened their expression of volatile chemicals, with compound richness being particularly reduced in dams bearing sons. These changes were comparable in magnitude with other, published chemical differences among lemurs that are salient to conspecifics. Such olfactory ‘signatures’ of pregnancy may help guide social interactions, potentially promoting mother–infant recognition, reducing intragroup conflict or counteracting behavioural mechanisms of paternity confusion; cues that also advertise fetal sex may additionally facilitate differential sex allocation. PMID:25716086

  12. The (unclear effects of invalid retro-cues.

    Directory of Open Access Journals (Sweden)

    Marcel eGressmann

    2016-03-01

    Full Text Available Studies with the retro-cue paradigm have shown that validly cueing objects in visual working memory long after encoding can still benefit performance on subsequent change detection tasks. With regard to the effects of invalid cues, the literature is less clear. Some studies reported costs, others did not. We here revisit two recent studies that made interesting suggestions concerning invalid retro-cues: One study suggested that costs only occur for larger set sizes, and another study suggested that inclusion of invalid retro-cues diminishes the retro-cue benefit. New data from one experiment and a reanalysis of published data are provided to address these conclusions. The new data clearly show costs (and benefits that were independent of set size, and the reanalysis suggests no influence of the inclusion of invalid retro-cues on the retro-cue benefit. Thus, previous interpretations may be taken with some caution at present.

  13. Cue-induced craving in patients with cocaine use disorder predicts cognitive control deficits toward cocaine cues.

    Science.gov (United States)

    DiGirolamo, Gregory J; Smelson, David; Guevremont, Nathan

    2015-08-01

    Cue-induced craving is a clinically important aspect of cocaine addiction influencing ongoing use and sobriety. However, little is known about the relationship between cue-induced craving and cognitive control toward cocaine cues. While studies suggest that cocaine users have an attentional bias toward cocaine cues, the present study extends this research by testing if cocaine use disorder patients (CDPs) can control their eye movements toward cocaine cues and whether their response varied by cue-induced craving intensity. Thirty CDPs underwent a cue exposure procedure to dichotomize them into high and low craving groups followed by a modified antisaccade task in which subjects were asked to control their eye movements toward either a cocaine or neutral drug cue by looking away from the suddenly presented cue. The relationship between breakdowns in cognitive control (as measured by eye errors) and cue-induced craving (changes in self-reported craving following cocaine cue exposure) was investigated. CDPs overall made significantly more errors toward cocaine cues compared to neutral cues, with higher cravers making significantly more errors than lower cravers even though they did not differ significantly in addiction severity, impulsivity, anxiety, or depression levels. Cue-induced craving was the only specific and significant predictor of subsequent errors toward cocaine cues. Cue-induced craving directly and specifically relates to breakdowns of cognitive control toward cocaine cues in CDPs, with higher cravers being more susceptible. Hence, it may be useful identifying high cravers and target treatment toward curbing craving to decrease the likelihood of a subsequent breakdown in control. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Responsiveness of Nigerian Students to Pictorial Depth Cues.

    Science.gov (United States)

    Evans, G. S.; Seddon, G. M.

    1978-01-01

    Three groups of Nigerian high school and college students were tested for response to four pictorial depth cues. Students had more difficulty with cues concerning the relative size of objects and the foreshortening of straight lines than with cues involving overlap of lines and distortion of the angles between lines. (Author/JEG)

  15. Binaural weighting of pinna cues in human sound localization

    NARCIS (Netherlands)

    Hofman, P.M.; Opstal, A.J. van

    2003-01-01

    Human sound localization relies on binaural difference cues for sound-source azimuth and pinna-related spectral shape cues for sound elevation. Although the interaural timing and level difference cues are weighted to produce a percept of sound azimuth, much less is known about binaural mechanisms un

  16. Configural Effect in Multiple-Cue Probability Learning

    Science.gov (United States)

    Edgell, Stephen E.; Castellan, N. John, Jr.

    1973-01-01

    In a nonmetric multiple-cue probability learning task involving 2 binary cue dimensions, it was found that Ss can learn to use configural or pattern information (a) when only the configural information is relevant, and in addition to the configural information, one or both of the cue dimensions are relevant. (Author/RK)

  17. Effects of Typographical Cues on Reading and Recall of Text.

    Science.gov (United States)

    Lorch, Robert F., Jr.; And Others

    1995-01-01

    Effects of typographical cues on text memory were investigated in 2 experiments involving 204 college students. Findings demonstrated that effects of typographical cues on memory were mediated by effects on attention during reading. Typographical cues appeared to increase attention only to the signaled content, resulting in better memory. (SLD)

  18. Bacterial Diversity and Bioprospecting for Cold-Active Hydrolytic Enzymes from Culturable Bacteria Associated with Sediment from Nella Fjord, Eastern Antarctica

    Directory of Open Access Journals (Sweden)

    Bo Chen

    2011-01-01

    Full Text Available The diversity and cold-active hydrolytic enzymes of culturable bacteria associated with sandy sediment from Nella Fjord, Eastern Antarctica (69°22′6″ S, 76°21′45″ E was investigated. A total of 33 aerobic heterotrophic bacterial strains were isolated at 4 °C. These bacterial isolates could be sorted into 18 phylotypes based on the 16S rRNA gene sequence belonging to four phyla, namely Alphaproteobacteria, Gammaproteobacteria, Bacteroidetes and Actinobacteria. Only seven isolates were psychrophilic, 15 isolates were moderately psychrophilic, and 11 isolates were psychrotolerant. More than 72% of the isolates required sodium chloride to grow. Esterase, b-glucosidase and proteases activities at 4 °C were detected in more than 45% of the strains while approximately 21%, 15% and 12% of the strains possessed lipase, amylase and chitinase, respectively. These results indicate that a relatively high culturable bacterial diversity is present within marine sediment of Nella Fjord and it could serve as an ideal candidate region for bioprospecting.

  19. Bacterial diversity and bioprospecting for cold-active hydrolytic enzymes from culturable bacteria associated with sediment from Nella Fjord, Eastern Antarctica.

    Science.gov (United States)

    Yu, Yong; Li, Hui-Rong; Zeng, Yin-Xin; Chen, Bo

    2011-01-31

    The diversity and cold-active hydrolytic enzymes of culturable bacteria associated with sandy sediment from Nella Fjord, Eastern Antarctica (69°22'6″ S, 76°21'45″ E) was investigated. A total of 33 aerobic heterotrophic bacterial strains were isolated at 4 °C. These bacterial isolates could be sorted into 18 phylotypes based on the 16S rRNA gene sequence belonging to four phyla, namely Alphaproteobacteria, Gammaproteobacteria, Bacteroidetes and Actinobacteria. Only seven isolates were psychrophilic, 15 isolates were moderately psychrophilic, and 11 isolates were psychrotolerant. More than 72% of the isolates required sodium chloride to grow. Esterase, β-glucosidase and proteases activities at 4 °C were detected in more than 45% of the strains while approximately 21%, 15% and 12% of the strains possessed lipase, amylase and chitinase, respectively. These results indicate that a relatively high culturable bacterial diversity is present within marine sediment of Nella Fjord and it could serve as an ideal candidate region for bioprospecting.

  20. Rapid detection and quantification of tyrosine decarboxylase gene (tdc) and its expression in gram-positive bacteria associated with fermented foods using PCR-based methods.

    Science.gov (United States)

    Torriani, Sandra; Gatto, Veronica; Sembeni, Silvia; Tofalo, Rosanna; Suzzi, Giovanna; Belletti, Nicoletta; Gardini, Fausto; Bover-Cid, Sara

    2008-01-01

    In this study, PCR-based procedures were developed to detect the occurrence and quantify the expression of the tyrosine decarboxylase gene (tdc) in gram-positive bacteria associated with fermented foods. Consensus primers were used in conventional and reverse transcription PCR to analyze a collection of 87 pure cultures of lactic acid bacteria and staphylococci. All enterococci, Staphylococcus epidermidis, Lactobacillus brevis, Lactobacillus curvatus, and Lactobacillus fermentum strains and 1 of 10 Staphylococcus xylosus strains produced amplification products with the primers DEC5 and DEC3 in accordance with results of the screening plate method and with previously reported result obtained with high-performance liquid chromatography. No amplicons were obtained for tyramine-negative strains, confirming the high specificity of these new primers. A novel quantitative real-time PCR assay was successfully applied to quantify tdc and its transcript in pure cultures and in meat and meat products. This assay allowed estimation of the influence of different variables (pH, temperature, and NaCl concentration) on the tdc expression of the tyraminogenic strain Enterococcus faecalis EF37 after 72 h of growth in M17 medium. Data obtained suggest that stressful conditions could induce greater tyrosine decarboxylase activity. The culture-independent PCR procedures developed here may be used for reliable and fast detection and quantification of bacterial tyraminogenic activity without the limitations of conventional techniques.

  1. Divergent pro-inflammatory profile of human dendritic cells in response to commensal and pathogenic bacteria associated with the airway microbiota.

    Science.gov (United States)

    Larsen, Jeppe Madura; Steen-Jensen, Daniel Bisgaard; Laursen, Janne Marie; Søndergaard, Jonas Nørskov; Musavian, Hanieh Sadat; Butt, Tariq Mahmood; Brix, Susanne

    2012-01-01

    Recent studies using culture-independent methods have characterized the human airway microbiota and report microbial communities distinct from other body sites. Changes in these airway bacterial communities appear to be associated with inflammatory lung disease, yet the pro-inflammatory properties of individual bacterial species are unknown. In this study, we compared the immune stimulatory capacity on human monocyte-derived dendritic cells (DCs) of selected airway commensal and pathogenic bacteria predominantly associated with lungs of asthma or COPD patients (pathogenic Haemophillus spp. and Moraxella spp.), healthy lungs (commensal Prevotella spp.) or both (commensal Veillonella spp. and Actinomyces spp.). All bacteria were found to induce activation of DCs as demonstrated by similar induction of CD83, CD40 and CD86 surface expression. However, asthma and COPD-associated pathogenic bacteria provoked a 3-5 fold higher production of IL-23, IL-12p70 and IL-10 cytokines compared to the commensal bacteria. Based on the differential cytokine production profiles, the studied airway bacteria could be segregated into three groups (Haemophilus spp. and Moraxella spp. vs. Prevotella spp. and Veillonella spp. vs. Actinomyces spp.) reflecting their pro-inflammatory effects on DCs. Co-culture experiments found that Prevotella spp. were able to reduce Haemophillus influenzae-induced IL-12p70 in DCs, whereas no effect was observed on IL-23 and IL-10 production. This study demonstrates intrinsic differences in DC stimulating properties of bacteria associated with the airway microbiota.

  2. Divergent pro-inflammatory profile of human dendritic cells in response to commensal and pathogenic bacteria associated with the airway microbiota.

    Directory of Open Access Journals (Sweden)

    Jeppe Madura Larsen

    Full Text Available Recent studies using culture-independent methods have characterized the human airway microbiota and report microbial communities distinct from other body sites. Changes in these airway bacterial communities appear to be associated with inflammatory lung disease, yet the pro-inflammatory properties of individual bacterial species are unknown. In this study, we compared the immune stimulatory capacity on human monocyte-derived dendritic cells (DCs of selected airway commensal and pathogenic bacteria predominantly associated with lungs of asthma or COPD patients (pathogenic Haemophillus spp. and Moraxella spp., healthy lungs (commensal Prevotella spp. or both (commensal Veillonella spp. and Actinomyces spp.. All bacteria were found to induce activation of DCs as demonstrated by similar induction of CD83, CD40 and CD86 surface expression. However, asthma and COPD-associated pathogenic bacteria provoked a 3-5 fold higher production of IL-23, IL-12p70 and IL-10 cytokines compared to the commensal bacteria. Based on the differential cytokine production profiles, the studied airway bacteria could be segregated into three groups (Haemophilus spp. and Moraxella spp. vs. Prevotella spp. and Veillonella spp. vs. Actinomyces spp. reflecting their pro-inflammatory effects on DCs. Co-culture experiments found that Prevotella spp. were able to reduce Haemophillus influenzae-induced IL-12p70 in DCs, whereas no effect was observed on IL-23 and IL-10 production. This study demonstrates intrinsic differences in DC stimulating properties of bacteria associated with the airway microbiota.

  3. Evidence for partial overlap of male olfactory cues in lampreys

    Science.gov (United States)

    Buchinger, Tyler J.; Li, Ke; Huertas, Mar; Baker, Cindy F.; Jia, Liang; Hayes, Michael C.; Li, Weiming; Johnson, Nicholas S.

    2016-01-01

    Animals rely on a mosaic of complex information to find and evaluate mates. Pheromones, often comprised of multiple components, are considered to be particularly important for species-recognition in many species. While the evolution of species-specific pheromone blends is well-described in many insects, very few vertebrate pheromones have been studied in a macro-evolutionary context. Here, we report a phylogenetic comparison of multi-component male odours that guide reproduction in lampreys. Chemical profiling of sexually mature males from eleven species of lamprey, representing six of ten genera and two of three families, indicated the chemical profiles of sexually mature male odours are partially shared among species. Behavioural assays conducted with four species sympatric in the Laurentian Great Lakes indicated asymmetric female responses to heterospecific odours, where Petromyzon marinus were attracted to male odour collected from all species tested but other species generally preferred only the odour of conspecifics. Electro-olfactogram recordings from P. marinusindicated that although P. marinus exhibited behavioural responses to odours from males of all species, at least some of the compounds that elicited olfactory responses were different in conspecific male odours compared to heterospecific male odours. We conclude that some of the compounds released by sexually mature males are shared among species and elicit olfactory and behavioural responses in P. marinus, and suggest that our results provide evidence for partial overlap of male olfactory cues among lampreys. Further characterization of the chemical identities of odour components is needed to confirm shared pheromones among species.

  4. Introspective responses to cues and motivation to reduce cigarette smoking influence state and behavioral responses to cue exposure.

    Science.gov (United States)

    Veilleux, Jennifer C; Skinner, Kayla D

    2016-09-01

    In the current study, we aimed to extend smoking cue-reactivity research by evaluating delay discounting as an outcome of cigarette cue exposure. We also separated introspection in response to cues (e.g., self-reporting craving and affect) from cue exposure alone, to determine if introspection changes behavioral responses to cigarette cues. Finally, we included measures of quit motivation and resistance to smoking to assess motivational influences on cue exposure. Smokers were invited to participate in an online cue-reactivity study. Participants were randomly assigned to view smoking images or neutral images, and were randomized to respond to cues with either craving and affect questions (e.g., introspection) or filler questions. Following cue exposure, participants completed a delay discounting task and then reported state affect, craving, and resistance to smoking, as well as an assessment of quit motivation. We found that after controlling for trait impulsivity, participants who introspected on craving and affect showed higher delay discounting, irrespective of cue type, but we found no effect of response condition on subsequent craving (e.g., craving reactivity). We also found that motivation to quit interacted with experimental conditions to predict state craving and state resistance to smoking. Although asking about craving during cue exposure did not increase later craving, it resulted in greater delaying of discounted rewards. Overall, our findings suggest the need to further assess the implications of introspection and motivation on behavioral outcomes of cue exposure.

  5. Cued in: advances and opportunities in freshwater chemical ecology.

    Science.gov (United States)

    Burks, Romi L; Lodge, David M

    2002-10-01

    We focus this mini-review on how naturally occurring chemical cues mediate ecological interactions, especially interspecific competition and predation in freshwater communities. Although freshwater chemical ecology lags behind terrestrial and marine chemical ecology, we identify recent progress toward: (1) identifying the chemical composition of cues important in food web interactions, e.g., specific glucosinolates, benzyl succinoates, and lignoids as deterrents to herbivory on freshwater macrophytes; (2) employing a nonreductionist approach that tests for emergent responses to suites of multiple chemical cues, e.g., trade-offs in snail refuge-seeking behavior in the presence of chemical cues from both fish and crayfish; (3) investigating how abiotic forces, such as hydrodynamics, impact chemical communication across a broad spatial and temporal scale, e.g., drift responses of mayfly nymphs to whole-stream additions of trout cue; and (4) quantifying the importance of genetic variability, e.g., how chemical cues change selective pressures of local environments. The questions of interest in freshwater chemical ecology cross taxonomic boundaries; traverse broad spatial and temporal scales; demonstrate nonlinear, unpredictable results; and necessitate a multidisciplinary approach for adequate understanding.

  6. Cleaning MEG artifacts using external cues.

    Science.gov (United States)

    Tal, I; Abeles, M

    2013-07-15

    Using EEG, ECoG, MEG, and microelectrodes to record brain activity is prone to multiple artifacts. The main power line (mains line), video equipment, mechanical vibrations and activities outside the brain are the most common sources of artifacts. MEG amplitudes are low, and even small artifacts distort recordings. In this study, we show how these artifacts can be efficiently removed by recording external cues during MEG recordings. These external cues are subsequently used to register the precise times or spectra of the artifacts. The results indicate that these procedures preserve both the spectra and the time domain wave-shapes of the neuromagnetic signal, while successfully reducing the contribution of the artifacts to the target signals without reducing the rank of the data.

  7. Social traits modulate attention to affiliative cues

    Directory of Open Access Journals (Sweden)

    Sarah R. Moore

    2014-06-01

    Full Text Available Neurobehavioral models of personality suggest that the salience assigned to particular classes of stimuli vary as a function of traits that reflect both the activity of neurobiological encoding and relevant social experience. In turn, this joint influence modulates the extent that salience influences attentional processes, and hence learning about and responding to those stimuli. Applying this model to the domain of social valuation, we assessed the differential effects on attentional guidance by affiliative cues of (i a higher-order temperament trait (Social Closeness, and (ii attachment style in a sample of 57 women. Attention to affiliative pictures paired with either incentive or neutral pictures was assessed using camera eye-tracking. Trait social closeness and attachment avoidance interacted to modulate fixation frequency on affiliative but not on incentive pictures, suggesting that both traits influence the salience assigned to affiliative cues specifically.

  8. Social traits modulate attention to affiliative cues.

    Science.gov (United States)

    Moore, Sarah R; Fu, Yu; Depue, Richard A

    2014-01-01

    Neurobehavioral models of personality suggest that the salience assigned to particular classes of stimuli vary as a function of traits that reflect both the activity of neurobiological encoding and relevant social experience. In turn, this joint influence modulates the extent that salience influences attentional processes, and hence learning about and responding to those stimuli. Applying this model to the domain of social valuation, we assessed the differential effects on attentional guidance by affiliative cues of (i) a higher-order temperament trait (Social Closeness), and (ii) attachment style in a sample of 57 women. Attention to affiliative pictures paired with either incentive or neutral pictures was assessed using camera eye-tracking. Trait social closeness and attachment avoidance interacted to modulate fixation frequency on affiliative but not on incentive pictures, suggesting that both traits influence the salience assigned to affiliative cues specifically.

  9. Cue-Based Feeding in the NICU.

    Science.gov (United States)

    Whetten, Cynthia H

    In NICU settings, caring for neonates born as early as 23 weeks gestation presents unique challenges for caregivers. Traditionally, preterm infants who are learning to orally feed take a predetermined volume of breast milk or formula at scheduled intervals, regardless of their individual ability to coordinate each feeding. Evidence suggests that this volume-driven feeding model should be replaced with a more individualized, developmentally appropriate practice. Evidence from the literature suggests that preterm infants fed via cue-based feeding reach full oral feeding status faster than their volume-feeding counterparts and have shorter lengths of stay in the hospital. Changing practice to infant-driven or cue-based feedings in the hospital setting requires staff education, documentation, and team-based communication.

  10. Teaching hand-washing with pictorial cues

    Directory of Open Access Journals (Sweden)

    Timo Saloviita

    2016-01-01

    Full Text Available Applied behavior analysis has been shown to be an effective means to teach daily living skills to individuals with intellectual disability. In the present study pictorial cues based on task analysis, system of least prompts, and social reinforcement were used to teach a man with mild intellectual disability to wash his hands correctly. An ABAB reversal design was used with follow-up after two weeks. The results show a rapid increase in hand-washing skills.

  11. Pilot Cueing Synergies for Degraded Visual Environments

    Science.gov (United States)

    2016-02-19

    The authors would like to express their sincere gratitude to the following people for their contributions to this project. Without the assistance of...condition is termed brownout. Recent empirical evidence indicates there is a potential benefit to supplementing visual displays and symbology with tactile...compatibility, benefit , or conflict when used in DVE. Methods Eight test pilots evaluated aural and tactile cueing configurations in combination

  12. Habitat selection, facilitation, and biotic settlement cues affect distribution and performance of coral recruits in French Polynesia.

    Science.gov (United States)

    Price, Nichole

    2010-07-01

    Habitat selection can determine the distribution and performance of individuals if the precision with which sites are chosen corresponds with exposure to risks or resources. Contrastingly, facilitation can allow persistence of individuals arriving by chance and potentially maladapted to local abiotic conditions. For marine organisms, selection of a permanent attachment site at the end of their larval stage or the presence of a facilitator can be a critical determinant of recruitment success. In coral reef ecosystems, it is well known that settling planula larvae of reef-building corals use coarse environmental cues (i.e., light) for habitat selection. Although laboratory studies suggest that larvae can also use precise biotic cues produced by crustose coralline algae (CCA) to select attachment sites, the ecological consequences of biotic cues for corals are poorly understood in situ. In a field experiment exploring the relative importance of biotic cues and variability in habitat quality to recruitment of hard corals, pocilloporid and acroporid corals recruited more frequently to one species of CCA, Titanoderma prototypum, and significantly less so to other species of CCA; these results are consistent with laboratory assays from other studies. The provision of the biotic cue accurately predicted coral recruitment rates across habitats of varying quality. At the scale of CCA, corals attached to the "preferred" CCA experienced increased survivorship while recruits attached elsewhere had lower colony growth and survivorship. For reef-building corals, the behavioral selection of habitat using chemical cues both reduces the risk of incidental mortality and indicates the presence of a facilitator.

  13. Heat, sight and scent: multiple cues influence foraging site selection by an ambush-foraging snake Hoplocephalus bungaroides (Elapidae

    Directory of Open Access Journals (Sweden)

    Weiguo DU, Jonathan K. WEBB, Richard SHINE

    2009-08-01

    Full Text Available Most mobile organisms respond to multiple cues when selecting habitat types, and laboratory experiments that manipulate only single cues may fail to reveal the true complexity of habitat-selection behaviour. In south-eastern Australia, broad-headed snakes Hoplocephalus bungaroides (Elapidae lie in wait under sun-warmed rocks to ambush velvet geckos Oedura leseuerii (Gekkonidae. Previous laboratory work has shown that both the geckos and the snakes actively select hotter rather than colder rocks, and that the snakes actively select rocks scented by geckos. We manipulated rock temperature and the presence of two types of cues from geckos (chemical and visual information to clarify the causal basis for foraging site selection by the juveniles of this snake. When given a choice between cold lizard-scented rocks and hot unscented rocks, our captive snakes gave a higher priority to lizard scent than to temperature. The snakes also selected shelter-sites that provided visual as well as scent cues from lizards, rather than shelter-sites with scent cues alone. Thus, although broad-headed snakes show a direct preference for hotter rather than colder rocks in the laboratory, their choice of foraging site in the field may also be influenced by the presence of scent cues from prey. Our laboratory results suggest that habitat selection by broad-headed snakes may be more complex than has been suggested by previous single-factor laboratory trials[Current Zoology 55(4: 266–271, 2009].

  14. Smoking Cues, Argument Strength, and Perceived Effectiveness of Antismoking PSAs

    Science.gov (United States)

    Cappella, Joseph. N.; Lerman, Caryn; Strasser, Andrew A.

    2011-01-01

    Introduction: The study examines the effectiveness of antismoking public service announcements (PSAs) among adult smokers as a function of smoking cues and the argument strength of the PSAs. Consistent with the previous cue-reactivity studies, smoking cues are defined as one of the following visual scenes: (a) objects associated with smoking, (b) holding or handling cigarettes, and (c) actual smoking behaviors. Argument strength indicates smoker's judgments of perceived strength and persuasiveness of the arguments extracted from the PSAs. Methods: Data were collected through a web-based experiment of a random sample of general population of smokers (n = 566 adults aged 19 years or older). Each participant was shown 4 PSAs randomly selected from a set of 60. Data were analyzed using multilevel modeling to assess the effects of smoking cues and argument strength. Effectiveness measures include perceived persuasiveness, transportation, valenced thought, negative emotion, and smoking-related thoughts. Results: Argument strength is a significant predictor of outcome variables. Although there were no significant main effects of smoking cues on any outcome variables, smoking cues were found to interact with argument strength such that the association between argument strength and outcome variables became weaker for PSAs in the smoking cue condition compared with those in the no-cue condition. Conclusions: The interaction between smoking cues and argument strength suggests that smoking cues in antismoking PSAs undermine a significant part of what makes PSAs effective—their arguments against smoking. In designing antismoking messages, the inclusion of smoking cues should be weighed carefully. PMID:21330273

  15. Use of explicit memory cues following parietal lobe lesions.

    Science.gov (United States)

    Dobbins, Ian G; Jaeger, Antonio; Studer, Bettina; Simons, Jon S

    2012-11-01

    The putative role of the lateral parietal lobe in episodic memory has recently become a topic of considerable debate, owing primarily to its consistent activation for studied materials during functional magnetic resonance imaging studies of recognition. Here we examined the performance of patients with parietal lobe lesions using an explicit memory cueing task in which probabilistic cues ("Likely Old" or "Likely New"; 75% validity) preceded the majority of verbal recognition memory probes. Without cues, patients and control participants did not differ in accuracy. However, group differences emerged during the "Likely New" cue condition with controls responding more accurately than parietal patients when these cues were valid (preceding new materials) and trending towards less accuracy when these cues were invalid (preceding old materials). Both effects suggest insufficient integration of external cues into memory judgments on the part of the parietal patients whose cued performance largely resembled performance in the complete absence of cues. Comparison of the parietal patients to a patient group with frontal lobe lesions suggested the pattern was specific to parietal and adjacent area lesions. Overall, the data indicate that parietal lobe patients fail to appropriately incorporate external cues of novelty into recognition attributions. This finding supports a role for the lateral parietal lobe in the adaptive biasing of memory judgments through the integration of external cues and internal memory evidence. We outline the importance of such adaptive biasing through consideration of basic signal detection predictions regarding maximum possible accuracy with and without informative environmental cues. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. Viewpoint-independent contextual cueing effect

    Directory of Open Access Journals (Sweden)

    taiga etsuchiai

    2012-06-01

    Full Text Available We usually perceive things in our surroundings as unchanged despite viewpoint changes caused by self-motion. The visual system therefore must have a function to process objects independently of viewpoint. In this study, we examined whether viewpoint-independent spatial layout can be obtained implicitly. For this purpose, we used a contextual cueing effect, a learning effect of spatial layout in visual search displays known to be an implicit effect. We compared the transfer of the contextual cueing effect between cases with and without self-motion by using visual search displays for 3D objects, which changed according to the participant’s assumed location for viewing the stimuli. The contextual cueing effect was obtained with self-motion but disappeared when the display changed without self-motion. This indicates that there is an implicit learning effect in spatial coordinates and suggests that the spatial representation of object layouts or scenes can be obtained and updated implicitly. We also showed that binocular disparity play an important role in the layout representations.

  17. Children Use Wealth Cues to Evaluate Others.

    Directory of Open Access Journals (Sweden)

    Kristin Shutts

    Full Text Available Wealth differences between individuals are ubiquitous in modern society, and often serve as the basis for biased social evaluations among adults. The present research probed whether children use cues that are commonly associated with wealth differences in society to guide their consideration of others. In Study 1, 4-5-year-old participants from diverse racial backgrounds expressed preferences for children who were paired with high-wealth cues; White children in Study 1 also matched high-wealth stimuli with White faces. Study 2 conceptually replicated the preference effect from Study 1, and showed that young children (4-6 years also use material wealth indicators to guide their inferences about people's relative standing in other domains (i.e., competence and popularity. Study 3 revealed that children (5-9 years use a broad range of wealth cues to guide their evaluations of, and actions toward, unfamiliar people. Further, biased responses were not attenuated among children whose families were lower in socioeconomic status. Often overlooked by those who study children's attitudes and stereotypes, social class markers appear to influence evaluations, inferences, and behavior early in development.

  18. Children Use Wealth Cues to Evaluate Others.

    Science.gov (United States)

    Shutts, Kristin; Brey, Elizabeth L; Dornbusch, Leah A; Slywotzky, Nina; Olson, Kristina R

    2016-01-01

    Wealth differences between individuals are ubiquitous in modern society, and often serve as the basis for biased social evaluations among adults. The present research probed whether children use cues that are commonly associated with wealth differences in society to guide their consideration of others. In Study 1, 4-5-year-old participants from diverse racial backgrounds expressed preferences for children who were paired with high-wealth cues; White children in Study 1 also matched high-wealth stimuli with White faces. Study 2 conceptually replicated the preference effect from Study 1, and showed that young children (4-6 years) also use material wealth indicators to guide their inferences about people's relative standing in other domains (i.e., competence and popularity). Study 3 revealed that children (5-9 years) use a broad range of wealth cues to guide their evaluations of, and actions toward, unfamiliar people. Further, biased responses were not attenuated among children whose families were lower in socioeconomic status. Often overlooked by those who study children's attitudes and stereotypes, social class markers appear to influence evaluations, inferences, and behavior early in development.

  19. Visual cues in ice hockey goaltending.

    Science.gov (United States)

    Salmela, J H; Fiorito, P

    1979-03-01

    The effect of both the availability and the quality of visual cues preceding stick-puck contact was investigated for an ice hockey goaltending task. Thirty-four young (15.8 years) goaltenders observed filmed sequences of a hockey player approaching the net and directing a shot to one of the four corners. The film sequences were edited so that 2, 4 or 8 images were occluded prior to the impact of the stick with the puck, reflecting durations of 1/12, 1/6, 1/3 of a second, respectively. The subjects' performances for both the wrist and the slap shot were measured as well as the level of response confidence in both the horizontal and vertical planes. The results indicated that performance precision was aided by the increased availability of pre-shot visual cues. It was also evident that the wrist shot provided more cues for the goaltender than did the slap shot. Performances were found to be superior in the horizontal as compared to the vertical plane. In all dimensions, the subjects' perceptions of their success closely followed the actual performance patterns. It appeared that information that could facilitate anticipation in this goaltending task was both available and useable during the period that precedes the shot.

  20. Multiple cue use and integration in pigeons (Columba livia).

    Science.gov (United States)

    Legge, Eric L G; Madan, Christopher R; Spetch, Marcia L; Ludvig, Elliot A

    2016-05-01

    Encoding multiple cues can improve the accuracy and reliability of navigation and goal localization. Problems may arise, however, if one cue is displaced and provides information which conflicts with other cues. Here we investigated how pigeons cope with cue conflict by training them to locate a goal relative to two landmarks and then varying the amount of conflict between the landmarks. When the amount of conflict was small, pigeons tended to integrate both cues in their search patterns. When the amount of conflict was large, however, pigeons used information from both cues independently. This context-dependent strategy for resolving spatial cue conflict agrees with Bayes optimal calculations for using information from multiple sources.

  1. Disentangling environmental and heritable nestmate recognition cues in a carpenter ant.

    Science.gov (United States)

    van Zweden, Jelle S; Dreier, Stephanie; d'Ettorre, Patrizia

    2009-02-01

    Discriminating between group members and strangers is a key feature of social life. Nestmate recognition is very effective in social insects and is manifested by aggression and rejection of alien individuals, which are prohibited to enter the nest. Nestmate recognition is based on the quantitative variation in cuticular hydrocarbons, which can include heritable cues from the workers, as well as acquired cues from the environment or queen-derived cues. We tracked the profile of six colonies of the ant Camponotus aethiops for a year under homogeneous laboratory conditions. We performed chemical and behavioral analyses. We show that nestmate recognition was not impaired by constant environment, even though cuticular hydrocarbon profiles changed over time and were slightly converging among colonies. Linear hydrocarbons increased over time, especially in queenless colonies, but appeared to have weak diagnostic power between colonies. The presence of a queen had little influence on nestmate discrimination abilities. Our results suggest that heritable cues of workers are the dominant factor influencing nestmate discrimination in these carpenter ants and highlight the importance of colony kin structure for the evolution of eusociality.

  2. Antimicrobial and anti-biofilm effect of Bac8c on major bacteria associated with dental caries and Streptococcus mutans biofilms.

    Science.gov (United States)

    Ding, Yonglin; Wang, Wei; Fan, Meng; Tong, Zhongchun; Kuang, Rong; Jiang, WenKai; Ni, Longxing

    2014-02-01

    Dental caries is a common oral bacterial infectious disease. Its prevention and treatment requires control of the causative pathogens within dental plaque, especially Streptococcus mutans (S. mutans). Antimicrobial peptides (AMPs), one of the promising substitutes for conventional antibiotics, have been widely tested and used for controlling bacterial infections. The present study focuses on evaluating the potential of the novel AMPs cyclic bactenecin and its derivatives against bacteria associated with dental caries. The results indicate that Bac8c displayed highest activity against the bacteria tested, whereas both cyclic and linear bactenecin had weak antimicrobial activity. The cytotoxicity assay showed that Bac8c did not cause detectable toxicity at concentrations of 32-128μg/ml for 5min or 32-64μg/ml for 60min. S. mutans and Lactobacillus fermenti treated with Bac8c showed variable effects on bacterial structure via scanning electron microscopy and transmission electron microscopy. There appeared to be a large amount of extracellular debris and obvious holes on the cell surface, as well as loss of cell wall and nucleoid condensation. The BioFlux system was employed to generate S. mutans biofilms under a controlled flow, which more closely resemble the formation process of natural biofilms. Bac8c remarkably reduced the viability of cells in biofilms formed in the BioFlux system. This phenomenon was further analyzed and verified by real-time PCR results of a significant suppression of the genes involved in S. mutans biofilm formation. Taken together, this study suggests that Bac8c has a potential clinical application in preventing and treating dental caries. Copyright © 2013 Elsevier Inc. All rights reserved.

  3. Mate choice: from sexual cues to cognitive adaptations.

    Science.gov (United States)

    Miller, G F

    1997-01-01

    Evolutionary psychologists have successfully combined sexual selection theory and empirical research to compile lists of sexual attractiveness cues used in human mate choice. But a list of inputs is not the same as a normative or descriptive model of a psychological adaptation. We need to shift from cataloguing sexual cues to modelling cognitive adaptations for mate choice. This theoretical chapter addresses how to make this transition in three parts. The introduction discusses four general problems with cue cataloguing as an evolutionary psychology research strategy: animals' promiscuous flexibility of cue use; cue use being marginal to cognition; cue use being marginal to the hard game-theoretical aspects of mate choice; and cue use being uninformative about the exact adaptive functions of mate choice. The middle section develops six critiques of current mate choice research: the obsession with sex difference; the over-emphasis on physical rather than behavioural cues; the assumption of weighted linear models of cue integration; the avoidance of game-theoretical problems of mutual choice and assortative mating; the neglect of co-evolution between mate choice heuristics and the cues that they select; and the failure to understand that mate choice is only worth doing if potential mates show significant genetic variance. The conclusion outlines a new normative and descriptive framework for mate choice, centred on the use of brutally efficient search heuristics that exploit the informational structure of human genotypes, phenotypes and populations to make good mate choices.

  4. Laboratory-based, cue-elicited craving and cue reactivity as predictors of naturally occurring smoking behavior.

    Science.gov (United States)

    Carpenter, Matthew J; Saladin, Michael E; DeSantis, Stacia; Gray, Kevin M; LaRowe, Steven D; Upadhyaya, Himanshu P

    2009-01-01

    Cigarette craving, one hallmark sign of nicotine dependence, is often measured in laboratory settings using cue reactivity methods. How lab measures of cue reactivity relate to real world smoking behavior is unclear, particularly among non-treatment seeking smokers. Within a larger study of hormonal effects on cue reactivity (N=78), we examined the predictive relationship of cue reactivity to smoking, each measured in several ways. Results indicated that cue-evoked craving in response to stressful imagery, and to a lesser extent, in vivo smoking cues, significantly predicted smoking behavior during the week following testing. However, this predictive relationship was absent upon controlling for reactivity to neutral cues. Nicotine dependence may moderate the relationship between cue reactivity and actual smoking, such that this predictive relationship is less robust among highly dependent smokers than among smokers low in nicotine dependence. The question of whether cue-elicited craving predicts smoking among smokers not in treatment is best answered with a qualified yes, depending on how craving is manipulated and measured. Our findings highlight important methodological and theoretical considerations for cue reactivity research.

  5. Consumer attention to product health cues

    DEFF Research Database (Denmark)

    Orquin, Jacob Lund

    Purpose As part of a larger project aiming at improving healthy food choice among consumers, four studies were carried out to identify packaging cues that communicate product healthfulness. Methods Study 1 was an eye tracking experiment using a 5x3 group mixed design where the stimuli (five...... healthfulness and purchase likelihood. Study 2 used a 3x2x2 group mixed design manipulating product images (control images, health-related images, exercise-related images), brand (control brand, health association brand), and color scheme (control color scheme, green health-association color scheme). Study 3...

  6. Visual cues to female physical attractiveness.

    OpenAIRE

    Tovée, M.J.; Maisey, D S; Emery, J. L.; Cornelissen, P L

    1999-01-01

    Evolutionary psychology suggests that a woman's sexual attractiveness is based on cues of health and reproductive potential. In recent years, research has focused on the ratio of the width of the waist to the width of the hips (the waist-to-hip ratio (WHR). A low WHR (i.e. a curvaceous body) is believed to correspond to the optimal fat distribution for high fertility, and so this shape should be highly attractive. In this paper we present evidence that weight scaled for height (the body mass ...

  7. Low-Level Flight Simulation: Vertical Cues

    Science.gov (United States)

    1983-09-01

    The ASPT visual s’ester Soiftware autoematic’ally droips the’m freim the scene- at altitudes above 2000 fe’et AGI.) In an attempt to make the cue’s...8217 vertical (V) field of view. The ASPT has a - 15’ view o er the nose. - 370 over the left side, and - 15’ over the right side. (The aircraft field of...simulation, the ASPT /F-16 provided several instructional features that were used in this study. A video display of the HUD (Figures 1 and 21 and forward

  8. Human Perception of Ambiguous Inertial Motion Cues

    Science.gov (United States)

    Zhang, Guan-Lu

    2010-01-01

    Human daily activities on Earth involve motions that elicit both tilt and translation components of the head (i.e. gazing and locomotion). With otolith cues alone, tilt and translation can be ambiguous since both motions can potentially displace the otolithic membrane by the same magnitude and direction. Transitions between gravity environments (i.e. Earth, microgravity and lunar) have demonstrated to alter the functions of the vestibular system and exacerbate the ambiguity between tilt and translational motion cues. Symptoms of motion sickness and spatial disorientation can impair human performances during critical mission phases. Specifically, Space Shuttle landing records show that particular cases of tilt-translation illusions have impaired the performance of seasoned commanders. This sensorimotor condition is one of many operational risks that may have dire implications on future human space exploration missions. The neural strategy with which the human central nervous system distinguishes ambiguous inertial motion cues remains the subject of intense research. A prevailing theory in the neuroscience field proposes that the human brain is able to formulate a neural internal model of ambiguous motion cues such that tilt and translation components can be perceptually decomposed in order to elicit the appropriate bodily response. The present work uses this theory, known as the GIF resolution hypothesis, as the framework for experimental hypothesis. Specifically, two novel motion paradigms are employed to validate the neural capacity of ambiguous inertial motion decomposition in ground-based human subjects. The experimental setup involves the Tilt-Translation Sled at Neuroscience Laboratory of NASA JSC. This two degree-of-freedom motion system is able to tilt subjects in the pitch plane and translate the subject along the fore-aft axis. Perception data will be gathered through subject verbal reports. Preliminary analysis of perceptual data does not indicate that

  9. Materialistic Cues Boosts Personal Relative Deprivation

    Directory of Open Access Journals (Sweden)

    Hong Zhang

    2016-08-01

    Full Text Available Three studies investigated whether exposure to materialistic cues would increase perceptions of personal relative deprivation and related emotional reactions. In Study 1, individuals who were surveyed in front of a luxury store reported higher levels of personal relative deprivation than those surveyed in front of an ordinary building. In Study 2, participants who viewed pictures of luxurious goods experienced greater personal relative deprivation than those viewed pictures of neutral scenes. Study 3 replicated the results from Study 2, with a larger sample size and a more refined assessment of relative deprivation. Implications of these findings for future studies on relative deprivation and materialism are discussed.

  10. Materialistic Cues Boosts Personal Relative Deprivation.

    Science.gov (United States)

    Zhang, Hong; Zhang, Wen

    2016-01-01

    Three studies investigated whether exposure to materialistic cues would increase perceptions of personal relative deprivation and related emotional reactions. In Study 1, individuals who were surveyed in front of a luxury store reported higher levels of personal relative deprivation than those surveyed in front of an ordinary building. In Study 2, participants who viewed pictures of luxurious goods experienced greater personal relative deprivation than those viewed pictures of neutral scenes. Study 3 replicated the results from Study 2, with a larger sample size and a more refined assessment of relative deprivation. Implications of these findings for future studies on relative deprivation and materialism are discussed.

  11. An auditory cue-depreciation effect.

    Science.gov (United States)

    Gibson, J M; Watkins, M J

    1991-01-01

    An experiment is reported in which subjects first heard a list of words and then tried to identify these same words from degraded utterances. Paralleling previous findings in the visual modality, the probability of identifying a given utterance was reduced when the utterance was immediately preceded by other, more degraded, utterances of the same word. A second experiment replicated this "cue-depreciation effect" and in addition found the effect to be weakened, if not eliminated, when the target word was not included in the initial list or when the test was delayed by two days.

  12. Consumer Involvement and Knowledge Influence on Wine Choice Cue Utilisation

    DEFF Research Database (Denmark)

    Bruwer, Johan; Chrysochou, Polymeros; Lesschaeve, Isabelle

    2017-01-01

    Purpose The purpose of this paper is to examine the utilisation of product choice cues in a retail environment and the impact of consumer involvement on this utilisation. It further investigates the impact of product knowledge on product choice cue utilisation and its moderating role on the impact...... of consumer involvement. Design/methodology/approach The case of wine as an exemplary product category is considered, given the importance and variability of choice cues that have been found to affect product choice. Analysis is conducted on survey data from a sample of wine consumers in Ontario, Canada....... Product choice cues are grouped into extrinsic, intrinsic and marketing mix. The importance of how these cues are influenced from different dimensions of consumer involvement is illustrated. Findings The results show that product knowledge has a positive impact on intrinsic product cue utilisation...

  13. Reactivity to alcohol cues: isolating the role of perceived availability.

    Science.gov (United States)

    MacKillop, James; Lisman, Stephen A

    2005-08-01

    Perceived availability of a substance has been proposed to play a role in cue reactivity by both traditional classical conditioning models and S. T. Tiffany's (1990) cognitive processing model (CPM) of substance use. This study investigated the role of availability information on alcohol cue reactivity. Subjects were 134 heavy drinkers in a 2 x 2 between-subjects design, crossing cues (alcohol vs. neutral) and availability information (availability vs. unavailability). The results indicated significant main effects for cue type, with alcohol cues eliciting greater reactivity on multiple measures, and an interaction effect on the Alcohol Urge Questionnaire (M. J. Bohn, D. D. Krahn, & B. B. Staehler, 1995), such that exposure to alcohol cues in conjunction with unavailability information elicited a greater urge. This was largely a result of changes in self-reported craving and was interpreted as consistent with the CPM. Alternative methodologies and limitations are discussed.

  14. Specific cue reactivity on computer game-related cues in excessive gamers.

    Science.gov (United States)

    Thalemann, R; Wölfling, K; Grüsser, S M

    2007-06-01

    It has been posited that excessive computer game playing behavior, referred to as computer game addiction, meets criteria that have been internationally established to define drug addiction. Nevertheless, there have been no psychophysiological investigations of the underlying mechanisms available to support the characterization of excessive computer gaming as behavioral addiction. To investigate whether excessive computer gaming parallels learning processes in development and maintenance (which are assumed to underlie drug addiction), the authors obtained a psychophysiological assessment of the (learned) emotional processing of computer game-relevant and -irrelevant cues. For this purpose, electroencephalographic recordings in excessive and casual computer game players were conducted. Significant between-group differences in event-related potentials evoked by computer game related-cues were found at parietal regions and point to an increased emotional processing of these cues in excessive pathological players compared with casual players. These results are in concordance with the suggestion that addiction is characterized and maintained through sensitization of the mesolimbic dopaminergic system along with incentive salience of specific addiction-associated cues.

  15. Pheromonal and behavioral cues trigger male-to-female aggression in Drosophila.

    Science.gov (United States)

    Fernández, María de la Paz; Chan, Yick-Bun; Yew, Joanne Y; Billeter, Jean-Christophe; Dreisewerd, Klaus; Levine, Joel D; Kravitz, Edward A

    2010-11-23

    Appropriate displays of aggression rely on the ability to recognize potential competitors. As in most species, Drosophila males fight with other males and do not attack females. In insects, sex recognition is strongly dependent on chemosensory communication, mediated by cuticular hydrocarbons acting as pheromones. While the roles of chemical and other sensory cues in stimulating male to female courtship have been well characterized in Drosophila, the signals that elicit aggression remain unclear. Here we show that when female pheromones or behavior are masculinized, males recognize females as competitors and switch from courtship to aggression. To masculinize female pheromones, a transgene carrying dsRNA for the sex determination factor transformer (traIR) was targeted to the pheromone producing cells, the oenocytes. Shortly after copulation males attacked these females, indicating that pheromonal cues can override other sensory cues. Surprisingly, masculinization of female behavior by targeting traIR to the nervous system in an otherwise normal female also was sufficient to trigger male aggression. Simultaneous masculinization of both pheromones and behavior induced a complete switch in the normal male response to a female. Control males now fought rather than copulated with these females. In a reciprocal experiment, feminization of the oenocytes and nervous system in males by expression of transformer (traF) elicited high levels of courtship and little or no aggression from control males. Finally, when confronted with flies devoid of pheromones, control males attacked male but not female opponents, suggesting that aggression is not a default behavior in the absence of pheromonal cues. Thus, our results show that masculinization of either pheromones or behavior in females is sufficient to trigger male-to-female aggression. Moreover, by manipulating both the pheromonal profile and the fighting patterns displayed by the opponent, male behavioral responses towards

  16. Pheromonal and behavioral cues trigger male-to-female aggression in Drosophila.

    Directory of Open Access Journals (Sweden)

    María de la Paz Fernández

    Full Text Available Appropriate displays of aggression rely on the ability to recognize potential competitors. As in most species, Drosophila males fight with other males and do not attack females. In insects, sex recognition is strongly dependent on chemosensory communication, mediated by cuticular hydrocarbons acting as pheromones. While the roles of chemical and other sensory cues in stimulating male to female courtship have been well characterized in Drosophila, the signals that elicit aggression remain unclear. Here we show that when female pheromones or behavior are masculinized, males recognize females as competitors and switch from courtship to aggression. To masculinize female pheromones, a transgene carrying dsRNA for the sex determination factor transformer (traIR was targeted to the pheromone producing cells, the oenocytes. Shortly after copulation males attacked these females, indicating that pheromonal cues can override other sensory cues. Surprisingly, masculinization of female behavior by targeting traIR to the nervous system in an otherwise normal female also was sufficient to trigger male aggression. Simultaneous masculinization of both pheromones and behavior induced a complete switch in the normal male response to a female. Control males now fought rather than copulated with these females. In a reciprocal experiment, feminization of the oenocytes and nervous system in males by expression of transformer (traF elicited high levels of courtship and little or no aggression from control males. Finally, when confronted with flies devoid of pheromones, control males attacked male but not female opponents, suggesting that aggression is not a default behavior in the absence of pheromonal cues. Thus, our results show that masculinization of either pheromones or behavior in females is sufficient to trigger male-to-female aggression. Moreover, by manipulating both the pheromonal profile and the fighting patterns displayed by the opponent, male behavioral

  17. Subliminal Cues While Teaching: HCI Technique for Enhanced Learning

    OpenAIRE

    Pierre Chalfoun; Claude Frasson

    2011-01-01

    This paper presents results from an empirical study conducted with a subliminal teaching technique aimed at enhancing learner's performance in Intelligent Systems through the use of physiological sensors. This technique uses carefully designed subliminal cues (positive) and miscues (negative) and projects them under the learner's perceptual visual threshold. A positive cue, called answer cue, is a hint aiming to enhance the learner's inductive reasoning abilities and projected in a way to hel...

  18. Population dynamics of bacteria associated with different strains of the pine wood nematode Bursaphelenchus xylophilus after inoculation in maritime pine (Pinus pinaster).

    Science.gov (United States)

    Roriz, Mariana; Santos, Carla; Vasconcelos, Marta W

    2011-08-01

    For a long time it was thought that Bursaphelenchus xylophilus was the only agent of the pine wilt disease. Recently, it was discovered that there are bacteria associated with the nematodes that contribute to the pathogenesis of this disease, mainly through the release of toxins that promote the death of the pines. Among the species most commonly found, are bacteria belonging to the Bacillus, Pantoea, Pseudomonas and Xanthomonas genera. The main objective of this work was to study the effect of inoculation of maritime pine (Pinus pinaster) with four different nematode isolates, in the bacterial population of nematodes and trees, at different stages of disease progression. The monitoring of progression of disease symptoms was also recorded. Also, the identification of bacteria isolated from the xylem of trees and the surface of nematodes was performed by classical identification methods, by the API20E identification system and by sequencing of bacterial DNA. The results showed that for the symptoms progression, the most striking difference was observed for the pines inoculated with the avirulent isolate, C14-5, which led to a slower and less severe aggravation of symptoms than in pines inoculated with the virulent isolates. In general, it was found that bacterial population, inside the tree, increased with disease progression. A superior bacterial quantity was isolated from pines inoculated with the nematode isolates HF and 20, and, comparatively, few bacteria were isolated from pines inoculated with the avirulent isolate. The identification system API20E was insufficient in the identification of bacterial species; Enterobacter cloacae species was identified in 79% of the isolated bacterial colonies and seven of these colonies could not be identified by this method. Molecular identification methods, through bacterial DNA sequencing, allowed a more reliable identification: eleven different bacterial species within the Bacillus, Citrobacter, Enterobacter, Escherichia

  19. Strategy selection in cue-based decision making.

    Science.gov (United States)

    Bryant, David J

    2014-06-01

    People can make use of a range of heuristic and rational, compensatory strategies to perform a multiple-cue judgment task. It has been proposed that people are sensitive to the amount of cognitive effort required to employ decision strategies. Experiment 1 employed a dual-task methodology to investigate whether participants' preference for heuristic versus compensatory decision strategies can be altered by increasing the cognitive demands of the task. As indicated by participants' decision times, a secondary task interfered more with the performance of a heuristic than compensatory decision strategy but did not affect the proportions of participants using either type of strategy. A stimulus set effect suggested that the conjunction of cue salience and cue validity might play a determining role in strategy selection. The results of Experiment 2 indicated that when a perceptually salient cue was also the most valid, the majority of participants preferred a single-cue heuristic strategy. Overall, the results contradict the view that heuristics are more likely to be adopted when a task is made more cognitively demanding. It is argued that people employ 2 learning processes during training, one an associative learning process in which cue-outcome associations are developed by sampling multiple cues, and another that involves the sequential examination of single cues to serve as a basis for a single-cue heuristic.

  20. Cross-language differences in cue use for speech segmentation.

    Science.gov (United States)

    Tyler, Michael D; Cutler, Anne

    2009-07-01

    Two artificial-language learning experiments directly compared English, French, and Dutch listeners' use of suprasegmental cues for continuous-speech segmentation. In both experiments, listeners heard unbroken sequences of consonant-vowel syllables, composed of recurring three- and four-syllable "words." These words were demarcated by (a) no cue other than transitional probabilities induced by their recurrence, (b) a consistent left-edge cue, or (c) a consistent right-edge cue. Experiment 1 examined a vowel lengthening cue. All three listener groups benefited from this cue in right-edge position; none benefited from it in left-edge position. Experiment 2 examined a pitch-movement cue. English listeners used this cue in left-edge position, French listeners used it in right-edge position, and Dutch listeners used it in both positions. These findings are interpreted as evidence of both language-universal and language-specific effects. Final lengthening is a language-universal effect expressing a more general (non-linguistic) mechanism. Pitch movement expresses prominence which has characteristically different placements across languages: typically at right edges in French, but at left edges in English and Dutch. Finally, stress realization in English versus Dutch encourages greater attention to suprasegmental variation by Dutch than by English listeners, allowing Dutch listeners to benefit from an informative pitch-movement cue even in an uncharacteristic position.

  1. Cross-modal cueing in audiovisual spatial attention

    DEFF Research Database (Denmark)

    Blurton, Steven Paul; Greenlee, Mark W.; Gondan, Matthias

    2015-01-01

    Visual processing is most effective at the location of our attentional focus. It has long been known that various spatial cues can direct visuospatial attention and influence the detection of auditory targets. Cross-modal cueing, however, seems to depend on the type of the visual cue: facilitation...... that the perception of multisensory signals is modulated by a single, supramodal system operating in a top-down manner (Experiment 1). In contrast, bottom-up control of attention, as observed in the exogenous cueing task of Experiment 2, mainly exerts its influence through modality-specific subsystems. Experiment 3...

  2. Retro-dimension-cue benefit in visual working memory

    Science.gov (United States)

    Ye, Chaoxiong; Hu, Zhonghua; Ristaniemi, Tapani; Gendron, Maria; Liu, Qiang

    2016-01-01

    In visual working memory (VWM) tasks, participants’ performance can be improved by a retro-object-cue. However, previous studies have not investigated whether participants’ performance can also be improved by a retro-dimension-cue. Three experiments investigated this issue. We used a recall task with a retro-dimension-cue in all experiments. In Experiment 1, we found benefits from retro-dimension-cues compared to neutral cues. This retro-dimension-cue benefit is reflected in an increased probability of reporting the target, but not in the probability of reporting the non-target, as well as increased precision with which this item is remembered. Experiment 2 replicated the retro-dimension-cue benefit and showed that the length of the blank interval after the cue disappeared did not influence recall performance. Experiment 3 replicated the results of Experiment 2 with a lower memory load. Our studies provide evidence that there is a robust retro-dimension-cue benefit in VWM. Participants can use internal attention to flexibly allocate cognitive resources to a particular dimension of memory representations. The results also support the feature-based storing hypothesis. PMID:27774983

  3. Attention to health cues on product packages

    DEFF Research Database (Denmark)

    Orquin, Jacob Lund; Scholderer, Joachim

    2011-01-01

    The objectives of the study were (a) to examine which information and design elements on dairy product packages operate as cues in consumer evaluations of product healthfulness, and (b) to measure the degree to which consumers voluntarily attend to these elements during product choice. Visual att...... during purchase likelihood evaluations. The study also revealed that the probability that a consumer will read the nutrition label during the purchase decision process is associated with gender, body mass index and health motivation.......The objectives of the study were (a) to examine which information and design elements on dairy product packages operate as cues in consumer evaluations of product healthfulness, and (b) to measure the degree to which consumers voluntarily attend to these elements during product choice. Visual...... attention was measured by means of eye-tracking. Task (free viewing, product healthfulness evaluation, and purchase likelihood evaluation) and product (five different yoghurt products) were varied in a mixed within-between subjects design. The free viewing condition served as a baseline against which...

  4. Magnetic information calibrates celestial cues during migration.

    Science.gov (United States)

    Sandberg; Bäckman; Moore; Lõhmus

    2000-10-01

    Migratory birds use celestial and geomagnetic directional information to orient on their way between breeding and wintering areas. Cue-conflict experiments involving these two orientation cue systems have shown that directional information can be transferred from one system to the other by calibration. We designed experiments with four species of North American songbirds to: (1) examine whether these species calibrate orientation information from one system to the other; and (2) determine whether there are species-specific differences in calibration. Migratory orientation was recorded with two different techniques, cage tests and free-flight release tests, during autumn migration. Cage tests at dusk in the local geomagnetic field revealed species-specific differences: red-eyed vireo, Vireo olivaceus, and northern waterthrush, Seiurus noveboracensis, selected seasonally appropriate southerly directions whereas indigo bunting, Passerina cyanea, and grey catbird, Dumetella carolinensis, oriented towards the sunset direction. When tested in deflected magnetic fields, vireos and waterthrushes responded by shifting their orientation according to the deflection of the magnetic field, but buntings and catbirds failed to show any response to the treatment. In release tests, all four species showed that they had recalibrated their star compass on the basis of the magnetic field they had just experienced in the cage tests. Since release tests were done in the local geomagnetic field it seems clear that once the migratory direction is determined, most likely during the twilight period, the birds use their recalibrated star compass for orientation at departure. Copyright 2000 The Association for the Study of Animal Behaviour.

  5. Interpreting prosodic cues in discourse context

    Science.gov (United States)

    Brown, Meredith; Salverda, Anne Pier; Gunlogson, Christine; Tanenhaus, Michael K.

    2014-01-01

    Two visual-world experiments investigated whether and how quickly discourse-based expectations about the prosodic realization of spoken words modulate interpretation of acoustic-prosodic cues. Experiment 1 replicated effects of segmental lengthening on activation of onset-embedded words (e.g. pumpkin) using resynthetic manipulation of duration and fundamental frequency (F0). In Experiment 2, the same materials were preceded by instructions establishing information-structural differences between competing lexical alternatives (i.e. repeated vs. newly-assigned thematic roles) in critical instructions. Eye-movements generated upon hearing the critical target word revealed a significant interaction between information structure and target-word realization: Segmental lengthening and pitch excursion elicited more fixations to the onset-embedded competitor when the target word remained in the same thematic role, but not when its thematic role changed. These results suggest that information structure modulates the interpretation of acoustic-prosodic cues by influencing expectations about fine-grained acoustic-phonetic properties of the unfolding utterance. PMID:25599081

  6. Haven't a Cue? Mapping the CUE Space as an Aid to HRA Modeling

    Energy Technology Data Exchange (ETDEWEB)

    David I Gertman; Ronald L Boring; Jacques Hugo; William Phoenix

    2012-06-01

    Advances in automation present a new modeling environment for the human reliability analysis (HRA) practitioner. Many, if not most, current day HRA methods have their origin in characterizing and quantifying human performance in analog environments where mode awareness and system status indications are potentially less comprehensive, but simpler to comprehend at a glance when compared to advanced presentation systems. The introduction of highly complex automation has the potential to lead to: decreased levels of situation awareness caused by the need for increased monitoring; confusion regarding the often non-obvious causes of automation failures, and emergent system dependencies that formerly may have been uncharacterized. Understanding the relation of incoming cues available to operators during plant upset conditions, in conjunction with operating procedures, yields insight into understanding the nature of the expected operator response in this control room environment. Static systems methods such as fault trees do not contain the appropriate temporal information or necessarily specify the relationship among cues leading to operator response. In this paper, we do not attempt to replace standard performance shaping factors commonly used in HRA nor offer a new HRA method, existing methods may suffice. In this paper we strive to enhance current understanding of the basis for operator response through a technique that can be used during the qualitative portion of the HRA analysis process. The CUE map is a means to visualize the relationship among salient cues in the control room that help influence operator response, show how the cognitive map of the operator changes as information is gained or lost, and is applicable to existing as well as advanced hybrid plants and small modular reactor designs. A brief application involving loss of condensate is presented and advantages and limitations of the modeling approach and use of the CUE map are discussed.

  7. Sight or smell? Behavioural and heart rate responses in subordinate rainbow trout exposed to cues from dominant fish.

    Science.gov (United States)

    Höjesjö, Johan; Axelsson, Michael; Dahy, Ronja; Gustavsson, Lena; Johnsson, Jörgen I

    2015-01-01

    Many animals, including fish, can utilize both vision and the chemical senses in intra-specific communication. However, the relative influence of these sensory modalities on behavioral and physiological responses in social interactions is not well understood. The aim of this study was therefore to investigate the relative effects of visual and chemical stimuli from dominant individuals on the behavioral and physiological responses of subordinate rainbow trout (Oncorhynchus mykiss). External electrodes were used to detect ECG signals from free-swimming fish. This method allowed the simultaneous recording of behavioral and physiological responses, and possible sex differences in these responses were also investigated. The results suggest that, in this context, visual cues are more important than chemical cues in settling the social hierarchy in rainbow trout because a combination of chemical and visual exposure generally yielded a response in focal fish that was similar to the response elicited by visual exposure alone. Both activity and physiological responses were most pronounced during the first ten seconds after exposure, with subordinate fish moving closer to the dominant, accompanied by a strong bradycardic response. Furthermore, females acted more boldly and moved closer to the dominant fish than males, but here the effect of the modes was additive, with a stronger effect of the combined visual and chemical exposure. Overall, the extra information furnished to the fish in the form of chemical cues did not change either the behavioral or the physiological response. This result suggests that visual cues are more important than chemically mediated ones for social communication and individual recognition in rainbow trout.

  8. Sight or smell? Behavioural and heart rate responses in subordinate rainbow trout exposed to cues from dominant fish

    Directory of Open Access Journals (Sweden)

    Johan Höjesjö

    2015-08-01

    Full Text Available Many animals, including fish, can utilize both vision and the chemical senses in intra-specific communication. However, the relative influence of these sensory modalities on behavioral and physiological responses in social interactions is not well understood. The aim of this study was therefore to investigate the relative effects of visual and chemical stimuli from dominant individuals on the behavioral and physiological responses of subordinate rainbow trout (Oncorhynchus mykiss. External electrodes were used to detect ECG signals from free-swimming fish. This method allowed the simultaneous recording of behavioral and physiological responses, and possible sex differences in these responses were also investigated. The results suggest that, in this context, visual cues are more important than chemical cues in settling the social hierarchy in rainbow trout because a combination of chemical and visual exposure generally yielded a response in focal fish that was similar to the response elicited by visual exposure alone. Both activity and physiological responses were most pronounced during the first ten seconds after exposure, with subordinate fish moving closer to the dominant, accompanied by a strong bradycardic response. Furthermore, females acted more boldly and moved closer to the dominant fish than males, but here the effect of the modes was additive, with a stronger effect of the combined visual and chemical exposure. Overall, the extra information furnished to the fish in the form of chemical cues did not change either the behavioral or the physiological response. This result suggests that visual cues are more important than chemically mediated ones for social communication and individual recognition in rainbow trout.

  9. Preconditioning of Spatial and Auditory Cues: Roles of the Hippocampus, Frontal Cortex, and Cue-Directed Attention

    Directory of Open Access Journals (Sweden)

    Andrew C. Talk

    2016-12-01

    Full Text Available Loss of function of the hippocampus or frontal cortex is associated with reduced performance on memory tasks, in which subjects are incidentally exposed to cues at specific places in the environment and are subsequently asked to recollect the location at which the cue was experienced. Here, we examined the roles of the rodent hippocampus and frontal cortex in cue-directed attention during encoding of memory for the location of a single incidentally experienced cue. During a spatial sensory preconditioning task, rats explored an elevated platform while an auditory cue was incidentally presented at one corner. The opposite corner acted as an unpaired control location. The rats demonstrated recollection of location by avoiding the paired corner after the auditory cue was in turn paired with shock. Damage to either the dorsal hippocampus or the frontal cortex impaired this memory ability. However, we also found that hippocampal lesions enhanced attention directed towards the cue during the encoding phase, while frontal cortical lesions reduced cue-directed attention. These results suggest that the deficit in spatial sensory preconditioning caused by frontal cortical damage may be mediated by inattention to the location of cues during the latent encoding phase, while deficits following hippocampal damage must be related to other mechanisms such as generation of neural plasticity.

  10. Feasibility of Using Virtual Reality to Assess Nicotine Cue Reactivity during Treatment

    Science.gov (United States)

    Kaganoff, Eili; Bordnick, Patrick S.; Carter, Brian Lee

    2012-01-01

    Cue reactivity assessments have been widely used to assess craving and attention to cues among cigarette smokers. Cue reactivity has the potential to offer insights into treatment decisions; however, the use of cue reactivity in treatment studies has been limited. This study assessed the feasibility of using a virtual reality-based cue reactivity…

  11. Feasibility of Using Virtual Reality to Assess Nicotine Cue Reactivity during Treatment

    Science.gov (United States)

    Kaganoff, Eili; Bordnick, Patrick S.; Carter, Brian Lee

    2012-01-01

    Cue reactivity assessments have been widely used to assess craving and attention to cues among cigarette smokers. Cue reactivity has the potential to offer insights into treatment decisions; however, the use of cue reactivity in treatment studies has been limited. This study assessed the feasibility of using a virtual reality-based cue reactivity…

  12. The Effects of Pain Cues on the Behavior of High and Low Aggressive Boys

    Science.gov (United States)

    Dubanoski, Richard A.; Kong, Colleen

    1977-01-01

    To investigate effects of pain cues on behavior, responses of high and low aggressive boys were followed either by pain cues or by nonpain cues. Overall, pain cues facilitated the rate of responding more than nonpain cues. More responses were made by high aggressive boys than by low aggressive boys. (Author)

  13. Evolution of environmental cues for phenotypic plasticity.

    Science.gov (United States)

    Chevin, Luis-Miguel; Lande, Russell

    2015-10-01

    Phenotypically plastic characters may respond to multiple variables in their environment, but the evolutionary consequences of this phenomenon have rarely been addressed theoretically. We model the evolution of linear reaction norms in response to several correlated environmental variables, in a population undergoing stationary environmental fluctuations. At evolutionary equilibrium, the linear combination of environmental variables that acts as a developmental cue for the plastic trait is the multivariate best linear predictor of changes in the optimum. However, the reaction norm with respect to any single environmental variable may exhibit nonintuitive patterns. Apparently maladaptive, or hyperadaptive plasticity can evolve with respect to single environmental variables, and costs of plasticity may increase, rather than reduce, plasticity in response to some variables. We also find conditions for the evolution of an indirect environmental indicator that affects expression of a plastic phenotype, despite not influencing natural selection on it.

  14. UV induced visual cues in grasses

    Science.gov (United States)

    Baby, Sabulal; Johnson, Anil John; Govindan, Balaji; Lukose, Sujith; Gopakumar, Bhaskaran; Koshy, Konnath Chacko

    2013-01-01

    Grasses are traditionally considered as wind pollinated, however, field observations confirmed frequent insect visits to grass flowers, suggesting insect pollination. Fruit and seed predators inflict heavy losses to cereals and millets during their growth, maturation and storage. The actual factors guiding insects and predators to grass flowers, fruits and seeds are not clear. Here, we report attractive blue fluorescence emissions on grass floral parts such as glumes, lemma, palea, lodicules, staminal filaments, pollens and fruits in ultraviolet (UV) 366 nm, whereas the stigmatic portions were not blue, but red fluorescent. We characterized the blue fluorescent constituent in grass reproductive structures as ferulic acid (FA). Fluorescence spectra of blue-emitting grass floral, seed extracts and isolated FA on excitation at 366 nm showed their emissions at 420–460 nm. We propose these FA-based blue fluorescence emissions in grass reproductive structures as visual cues that attract pollinators, predators and even pests towards them. PMID:24061408

  15. Specific genomic cues regulate Cajal body assembly.

    Science.gov (United States)

    Sawyer, Iain A; Hager, Gordon L; Dundr, Miroslav

    2016-10-07

    The assembly of specialized sub-nuclear microenvironments known as nuclear bodies (NBs) is important for promoting efficient nuclear function. In particular, the Cajal body (CB), a prominent NB that facilitates spliceosomal snRNP biogenesis, assembles in response to genomic cues. Here, we detail the factors that regulate CB assembly and structural maintenance. These include the importance of transcription at nucleating gene loci, the grouping of these genes on human chromosomes 1, 6 and 17, as well as cell cycle and biochemical regulation of CB protein function. We also speculate on the correlation between CB formation and RNA splicing levels in neurons and cancer. The timing and location of these specific molecular events is critical to CB assembly and its contribution to genome function. However, further work is required to explore the emerging biophysical characteristics of CB assembly and the impact upon subsequent genome reorganization.

  16. Emoticons: Visual Cues for Computer-Mediated Communication.

    Science.gov (United States)

    Rezabeck, Landra L.; Cochenour, John J.

    Emoticons are visual cues formed from ordinary typographical symbols that when read sideways represent feelings or emotions. Because the use of electronic mail eliminates the visual cues such as head nodding, facial expressions, posture, and eye contact found in face-to-face conversation, electronic mail users often incorporate emoticons as visual…

  17. Boosting Vocabulary Learning by Verbal Cueing During Sleep.

    Science.gov (United States)

    Schreiner, Thomas; Rasch, Björn

    2015-11-01

    Reactivating memories during sleep by re-exposure to associated memory cues (e.g., odors or sounds) improves memory consolidation. Here, we tested for the first time whether verbal cueing during sleep can improve vocabulary learning. We cued prior learned Dutch words either during non-rapid eye movement sleep (NonREM) or during active or passive waking. Re-exposure to Dutch words during sleep improved later memory for the German translation of the cued words when compared with uncued words. Recall of uncued words was similar to an additional group receiving no verbal cues during sleep. Furthermore, verbal cueing failed to improve memory during active and passive waking. High-density electroencephalographic recordings revealed that successful verbal cueing during NonREM sleep is associated with a pronounced frontal negativity in event-related potentials, a higher frequency of frontal slow waves as well as a cueing-related increase in right frontal and left parietal oscillatory theta power. Our results indicate that verbal cues presented during NonREM sleep reactivate associated memories, and facilitate later recall of foreign vocabulary without impairing ongoing consolidation processes. Likewise, our oscillatory analysis suggests that both sleep-specific slow waves as well as theta oscillations (typically associated with successful memory encoding during wakefulness) might be involved in strengthening memories by cueing during sleep.

  18. Investigating Cue Competition in Contextual Cuing of Visual Search

    Science.gov (United States)

    Beesley, T.; Shanks, David R.

    2012-01-01

    A fundamental principle of learning is that predictive cues or signals compete with each other to gain control over behavior. Associative and propositional reasoning theories of learning provide radically different accounts of cue competition. Propositional accounts predict that under conditions that do not afford or warrant the use of higher…

  19. Children's Recognition of Emotions from Vocal Cues

    Science.gov (United States)

    Sauter, Disa A.; Panattoni, Charlotte; Happe, Francesca

    2013-01-01

    Emotional cues contain important information about the intentions and feelings of others. Despite a wealth of research into children's understanding of facial signals of emotions, little research has investigated the developmental trajectory of interpreting affective cues in the voice. In this study, 48 children ranging between 5 and 10 years…

  20. Cue Representation and Situational Awareness in Task Analysis

    Science.gov (United States)

    Carl, Diana R.

    2009-01-01

    Task analysis in human performance technology is used to determine how human performance can be well supported with training, job aids, environmental changes, and other interventions. Early work by Miller (1953) and Gilbert (1969, 1974) addressed cue processing in task execution and recommended cue descriptions in task analysis. Modern task…

  1. Menstrual cycle and cue reactivity in women smokers.

    Science.gov (United States)

    Gray, Kevin M; DeSantis, Stacia M; Carpenter, Matthew J; Saladin, Michael E; LaRowe, Steven D; Upadhyaya, Himanshu P

    2010-02-01

    Emerging research suggests potential effects of the menstrual cycle on various aspects of smoking behavior in women, but results to date have been mixed. The present study sought to explore the influence of menstrual cycle phase on reactivity to smoking in vivo and stressful imagery cues in a sample of non-treatment-seeking women smokers. Via a within-subjects design, nicotine-dependent women (N = 37) participated in a series of four cue reactivity sessions, each during a distinct biologically verified phase of the menstrual cycle (early follicular [EF], mid-follicular [MF], mid-luteal [ML], and late luteal [LL]). Subjective (Questionnaire of Smoking Urges-Brief; QSU-B) and physiological (skin conductance and heart rate) measures of craving and reactivity were collected and compared across phases. Subjective reactive craving (QSU-B) to smoking in vivo cues varied significantly across the menstrual cycle (p = .02) and was higher in both EF and MF phases versus ML and LL phases, but this finding was not sustained when controlling for reactivity to neutral cues. Heart rate reactivity to stressful imagery cues (p = .01) and skin conductance reactivity to smoking in vivo cues (p = .05) varied significantly across the menstrual cycle upon controlling for reactivity to neutral cues, with highest reactivity during the MF phase. Menstrual cycle phase may have an effect on reactivity to smoking-related and stressful cues among women smokers. These findings contribute to an expanding literature, suggesting menstrual cycle effects on smoking behaviors in women.

  2. Isolation of Binocular Cues for Motion in Depth

    Directory of Open Access Journals (Sweden)

    Satoshi Shioiri

    2011-05-01

    Full Text Available There are two binocular cues of motion in depth: the interocular velocity difference (IOVD and changing disparity over time (CDOT. Psychophysical evidence for the contribution to perceiving motion in depth has been accumulated for both of the two cues, using techniques to isolate each cue. However, no study estimated seriously how reliably each cue is isolated in the techniques. In this study, we apply a model of motion in depth to estimate how each type of stimuli isolates each of IOVD and CDOT cues. The model consists of the motion energy and the disparity energy detectors as subunits and adds their outputs to built the IOVD and CDOT detectors. Simulations show that some, but not all of stimuli used in the literature are appropriate for isolating cues. The temporally uncorrelated randomdot stereogram isolates CDOT cue and the binocularly uncorrelated randomdot kinematogram isolates IOVD cues. However, temporally anticorreated version of randomdot stereogram has influence of reverse motion components of IOVD and binocularly anticorreated version of randomdot kinematogram has influence of reverse motion components of CDOT. Gratings with opposite orientation between the eyes are also good for isolation of IOVD. We performed psychophysical experiments to examine the plausibility of the model prediction.

  3. Comprehending Conflicting Science-Related Texts: Graphs as Plausibility Cues

    Science.gov (United States)

    Isberner, Maj-Britt; Richter, Tobias; Maier, Johanna; Knuth-Herzig, Katja; Horz, Holger; Schnotz, Wolfgang

    2013-01-01

    When reading conflicting science-related texts, readers may attend to cues which allow them to assess plausibility. One such plausibility cue is the use of graphs in the texts, which are regarded as typical of "hard science." The goal of our study was to investigate the effects of the presence of graphs on the perceived plausibility and…

  4. Inhibition of return is unimpressed by emotional cues

    NARCIS (Netherlands)

    Lange, W.G.; Heuer, K.; Reinecke, A.; Becker, E.S.; Rinck, M.

    2008-01-01

    of return (IOR) is a phenomenon observed when a target unexpectedly appears in the place of a preceding cue: With long cue-target stimulus onset asynchronies, reaction times are longer than for targets that appear in an alternative location. Cognitive theories of anxiety suppose that the IOR effect

  5. Altered Brain Reactivity to Game Cues After Gaming Experience.

    Science.gov (United States)

    Ahn, Hyeon Min; Chung, Hwan Jun; Kim, Sang Hee

    2015-08-01

    Individuals who play Internet games excessively show elevated brain reactivity to game-related cues. This study attempted to test whether this elevated cue reactivity observed in game players is a result of repeated exposure to Internet games. Healthy young adults without a history of excessively playing Internet games were recruited, and they were instructed to play an online Internet game for 2 hours/day for five consecutive weekdays. Two control groups were used: the drama group, which viewed a fantasy TV drama, and the no-exposure group, which received no systematic exposure. All participants performed a cue reactivity task with game, drama, and neutral cues in the brain scanner, both before and after the exposure sessions. The game group showed an increased reactivity to game cues in the right ventrolateral prefrontal cortex (VLPFC). The degree of VLPFC activation increase was positively correlated with the self-reported increase in desire for the game. The drama group showed an increased cue reactivity in response to the presentation of drama cues in the caudate, posterior cingulate, and precuneus. The results indicate that exposure to either Internet games or TV dramas elevates the reactivity to visual cues associated with the particular exposure. The exact elevation patterns, however, appear to differ depending on the type of media experienced. How changes in each of the regions contribute to the progression to pathological craving warrants a future longitudinal study.

  6. Influence of smoking cues in movies on craving among smokers

    NARCIS (Netherlands)

    Lochbühler, K.C.; Engels, R.C.M.E.; Scholte, R.H.J.

    2009-01-01

    Aims - Research has shown that smoking-related cues are important triggers for craving. The objective of the present study was to test whether smoking cues in movies also function as triggers to evoke craving. To accomplish this, we conducted a pilot study in which we examined smokers' reactivity to

  7. Impact of DCS-facilitated cue exposure therapy on brain activation to cocaine cues in cocaine dependence.

    Science.gov (United States)

    Prisciandaro, James J; Myrick, Hugh; Henderson, Scott; McRae-Clark, Aimee L; Santa Ana, Elizabeth J; Saladin, Michael E; Brady, Kathleen T

    2013-09-01

    The development of addiction is marked by a pathological associative learning process that imbues incentive salience to stimuli associated with drug use. Recent efforts to treat addiction have targeted this learning process using cue exposure therapy augmented with d-cycloserine (DCS), a glutamatergic agent hypothesized to enhance extinction learning. To better understand the impact of DCS-facilitated extinction on neural reactivity to drug cues, the present study reports fMRI findings from a randomized, double-blind, placebo-controlled trial of DCS-facilitated cue exposure for cocaine dependence. Twenty-five participants completed two MRI sessions (before and after intervention), with a cocaine-cue reactivity fMRI task. The intervention consisted of 50mg of DCS or placebo, combined with two sessions of cocaine cue exposure and skills training. Participants demonstrated cocaine cue activation in a variety of brain regions at baseline. From the pre- to post-study scan, participants experienced decreased activation to cues in a number of regions (e.g., accumbens, caudate, frontal poles). Unexpectedly, placebo participants experienced decreases in activation to cues in the left angular and middle temporal gyri and the lateral occipital cortex, while DCS participants did not. Three trials of DCS-facilitated cue exposure therapy for cocaine dependence have found that DCS either increases or does not significantly impact response to cocaine cues. The present study adds to this literature by demonstrating that DCS may prevent extinction to cocaine cues in temporal and occipital brain regions. Although consistent with past research, results from the present study should be considered preliminary until replicated in larger samples. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  8. Speaker's voice as a memory cue.

    Science.gov (United States)

    Campeanu, Sandra; Craik, Fergus I M; Alain, Claude

    2015-02-01

    Speaker's voice occupies a central role as the cornerstone of auditory social interaction. Here, we review the evidence suggesting that speaker's voice constitutes an integral context cue in auditory memory. Investigation into the nature of voice representation as a memory cue is essential to understanding auditory memory and the neural correlates which underlie it. Evidence from behavioral and electrophysiological studies suggest that while specific voice reinstatement (i.e., same speaker) often appears to facilitate word memory even without attention to voice at study, the presence of a partial benefit of similar voices between study and test is less clear. In terms of explicit memory experiments utilizing unfamiliar voices, encoding methods appear to play a pivotal role. Voice congruency effects have been found when voice is specifically attended at study (i.e., when relatively shallow, perceptual encoding takes place). These behavioral findings coincide with neural indices of memory performance such as the parietal old/new recollection effect and the late right frontal effect. The former distinguishes between correctly identified old words and correctly identified new words, and reflects voice congruency only when voice is attended at study. Characterization of the latter likely depends upon voice memory, rather than word memory. There is also evidence to suggest that voice effects can be found in implicit memory paradigms. However, the presence of voice effects appears to depend greatly on the task employed. Using a word identification task, perceptual similarity between study and test conditions is, like for explicit memory tests, crucial. In addition, the type of noise employed appears to have a differential effect. While voice effects have been observed when white noise is used at both study and test, using multi-talker babble does not confer the same results. In terms of neuroimaging research modulations, characterization of an implicit memory effect

  9. Detecting natural occlusion boundaries using local cues

    Science.gov (United States)

    DiMattina, Christopher; Fox, Sean A.; Lewicki, Michael S.

    2012-01-01

    Occlusion boundaries and junctions provide important cues for inferring three-dimensional scene organization from two-dimensional images. Although several investigators in machine vision have developed algorithms for detecting occlusions and other edges in natural images, relatively few psychophysics or neurophysiology studies have investigated what features are used by the visual system to detect natural occlusions. In this study, we addressed this question using a psychophysical experiment where subjects discriminated image patches containing occlusions from patches containing surfaces. Image patches were drawn from a novel occlusion database containing labeled occlusion boundaries and textured surfaces in a variety of natural scenes. Consistent with related previous work, we found that relatively large image patches were needed to attain reliable performance, suggesting that human subjects integrate complex information over a large spatial region to detect natural occlusions. By defining machine observers using a set of previously studied features measured from natural occlusions and surfaces, we demonstrate that simple features defined at the spatial scale of the image patch are insufficient to account for human performance in the task. To define machine observers using a more biologically plausible multiscale feature set, we trained standard linear and neural network classifiers on the rectified outputs of a Gabor filter bank applied to the image patches. We found that simple linear classifiers could not match human performance, while a neural network classifier combining filter information across location and spatial scale compared well. These results demonstrate the importance of combining a variety of cues defined at multiple spatial scales for detecting natural occlusions. PMID:23255731

  10. Distinguishing Reconfiguration and Compound-cue Retrieval in Task Switching

    Directory of Open Access Journals (Sweden)

    Gordon D Logan

    2010-10-01

    Full Text Available Many researchers claim that task switching requires reconfiguration of the cognitive system. Others claim that task switching involves cue-based memory retrieval processes and not reconfiguration. We evaluate these competing claims by developing both reconfiguration and cue-based memory models in a common theoretical framework and by fitting the models to' target functions', which show how performance on individual target stimuli varies depending on the task subjects perform on the targets. Our analyses show that the process of compound-cue retrieval – using the task cue and the target as joint retrieval cues to select a response from memory – is sufficient to explain target functions for parity and magnitude judgments of digits and that reconfiguration does not seem to add anything to the explanation. We address the generality of this conclusion and speculate about the conditions under which reconfiguration may be necessary for task switching.

  11. D-cycloserine and cocaine cue reactivity: preliminary findings.

    Science.gov (United States)

    Price, Kimber L; McRae-Clark, Aimee L; Saladin, Michael E; Maria, Megan M Moran-Santa; DeSantis, Stacia M; Back, Sudie E; Brady, Kathleen T

    2009-01-01

    D-cycloserine (DCS), a partial glutamate N-methyl-D-aspartic acid (NMDA) receptor agonist, enhances extinction of conditioned fear responding in rodents and facilitates exposure-based learning in humans with anxiety disorders. This preliminary study investigates DCS pretreatment on response to cocaine cues in cocaine-dependent subjects. Ten cocaine-dependent subjects were randomly assigned to receive either 50 mg DCS or matching placebo two hours before each of two 1-hour cocaine cue exposure sessions one day apart. HR and craving ratings were obtained before and during cue exposure sessions. There was a trend towards increased craving to cocaine cues in cocaine-dependent individuals after administration of DCS. The administration of DCS prior to cue exposure sessions may facilitate response activation. While facilitation of extinction-based learning by DCS may have therapeutic potential for cocaine dependence, this drug may exhibit a different profile in cocaine-dependent individuals as compared to those with anxiety disorders.

  12. Identity cues and dementia in nursing home intervention.

    Science.gov (United States)

    Vézina, Aline; Robichaud, Line; Voyer, Philippe; Pelletier, Daniel

    2011-01-01

    This study examines the identity cues that family caregivers and healthcare personnel use with seniors living with dementia and living in nursing homes. The identity cues represent biographical knowledge used to stimulate the dementia sufferer, trigger signals and incite interaction. Our grounded approach hinges on three objectives: to identify and categorize identity cues; to document their uses; and to gain a better understanding of their effectiveness. We interviewed nine family caregivers and 12 healthcare workers. Qualitative data indicates that the participants use identity cues that evoke seniors' sociological, relational and individual characteristics. These identity cues play a central role in communication and constitute important information that the family caregivers can share with healthcare personnel. They sustain memory, facilitate care and reinforce seniors' self-value. These results help to define identity, foster a greater role for family caregivers, and constitute a sound basis for the implementation of personalized interventions.

  13. Contextual Cueing Effect in Spatial Layout Defined by Binocular Disparity

    Science.gov (United States)

    Zhao, Guang; Zhuang, Qian; Ma, Jie; Tu, Shen; Liu, Qiang; Sun, Hong-jin

    2017-01-01

    Repeated visual context induces higher search efficiency, revealing a contextual cueing effect, which depends on the association between the target and its visual context. In this study, participants performed a visual search task where search items were presented with depth information defined by binocular disparity. When the 3-dimensional (3D) configurations were repeated over blocks, the contextual cueing effect was obtained (Experiment 1). When depth information was in chaos over repeated configurations, visual search was not facilitated and the contextual cueing effect largely crippled (Experiment 2). However, when we made the search items within a tiny random displacement in the 2-dimentional (2D) plane but maintained the depth information constant, the contextual cueing was preserved (Experiment 3). We concluded that the contextual cueing effect was robust in the context provided by 3D space with stereoscopic information, and more importantly, the visual system prioritized stereoscopic information in learning of spatial information when depth information was available. PMID:28912739

  14. Conditioned learning in alcohol dependence: implications for cue exposure treatment.

    Science.gov (United States)

    Drummond, D C; Cooper, T; Glautier, S P

    1990-06-01

    A review of the literature pertinent to cue exposure treatment in alcohol dependence is presented. Psychological models of relapse, based on conditioning and social learning theories, are critically evaluated. In particular, attention is drawn to the potential implications for cue exposure research and treatment of an interaction between Pavlovian and operant conditioning, problems with the application of the concepts of arousal and craving and the importance of a systems model to understand physiological responses. It is concluded that no study has so far demonstrated a link between conditioned responses to alcohol-related cues and relapse, an assumption on which cue exposure treatment is based. Further, the evidence for the effectiveness of cue exposure as a treatment is lacking. Promising research directions are identified.

  15. Olfactory Cues, Visual Cues, and Semiochemical Diversity Interact During Host Location by Invasive Forest Beetles.

    Science.gov (United States)

    Kerr, Jessica L; Kelly, Dave; Bader, Martin K-F; Brockerhoff, Eckehard G

    2017-01-01

    Plant-feeding insects use visual and olfactory cues (shape, color, plant volatiles) for host location, but the relative importance of different cues and interactions with non-host-plant volatiles in ecosystems of varying plant biodiversity is unclear for most species. We studied invasive bark beetles and wood borers associated with pine trees to characterize interactions among color, host and non-host volatiles, by employing traps that mimic tree trunks. Cross-vane flight intercept traps (black, green, red, white, yellow, clear) and black funnel traps were used with and without attractants (α-pinene + ethanol), repellents (non-host green leaf volatiles, 'GLV'), and attractant/repellent combinations in four pine forests in New Zealand. We trapped 274,594 Hylurgus ligniperda, 7842 Hylastes ater, and 16,301 Arhopalus ferus. Trap color, attractant, and color × attractant effects were highly significant. Overall, black and red traps had the highest catches, irrespective of the presence of attractants. Alpha-pinene plus ethanol increased trap catch of H. ligniperda 200-fold but only 6-fold for H. ater and 2-fold for A. ferus. Green leaf volatiles had a substantial repellent effect on trap catch of H. ligniperda but less on H. ater and A. ferus. Attack by H. ligniperda was halved when logs were treated with GLV, and a similar effect was observed when logs were placed among broadleaved understory shrubs emitting GLV. Overall, H. ligniperda was most strongly affected by the olfactory cues used, whereas H. ater and A. ferus were more strongly affected by visual cues. Collectively, the results support the semiochemical diversity hypothesis, indicating that non-host plant volatiles from diverse plant communities or artificial dispensers can contribute to resistance against herbivores by partly disrupting host location.

  16. Acupuncture inhibits cue-induced heroin craving and brain activation

    Institute of Scientific and Technical Information of China (English)

    Xinghui Cai; Xiaoge Song; Chuanfu Li; Chunsheng Xu; Xiliang Li; Qi Lu

    2012-01-01

    Previous research using functional MRI has shown that specific brain regions associated with drug dependence and cue-elicited heroin craving are activated by environmental cues.Craving is an important trigger of heroin relapse,and acupuncture may inhibit craving.In this study,we performed functional MRI in heroin addicts and control subjects.We compared differences in brain activation between the two groups during heroin cue exposure,heroin cue exposure plus acupuncture at the Zusanli point(ST36)without twirling of the needle,and heroin cue exposure plus acupuncture at the Zusanli point with twirling of the needle.Heroin cue exposure elicited significant activation in craving-related brain regions mainly in the frontal lobes and callosal gyri.Acupuncture without twirling did not significantly affect the range of brain activation induced by heroin cue exposure,but significantly changed the extent of the activation in the heroin addicts group.Acupuncture at the Zusanli.point with twirling of the needle significantly decreased both the range and extent of activation induced by heroin cue exposure compared with heroin cue exposure plus acupuncture without twirling of the needle.These experimental findings indicate that presentation of heroin cues can induce activation in craving-related brain regions,which are involved in reward,learning and memory,cognition and emotion.Acupuncture at the Zusanli point can rapidly suppress the activation of specific brain regions related to craving,supporting its potential as an intervention for drug craving.

  17. Arrow-Elicited Cueing Effects at Short Intervals: Rapid Attentional Orienting or Cue-Target Stimulus Conflict?

    Science.gov (United States)

    Green, Jessica J.; Woldorff, Marty G.

    2012-01-01

    The observation of cueing effects (faster responses for cued than uncued targets) rapidly following centrally-presented arrows has led to the suggestion that arrows trigger rapid automatic shifts of spatial attention. However, these effects have primarily been observed during easy target-detection tasks when both cue and target remain on the…

  18. The influence of social and symbolic cues on observers' gaze behaviour.

    Science.gov (United States)

    Hermens, Frouke; Walker, Robin

    2016-08-01

    Research has shown that social and symbolic cues presented in isolation and at fixation have strong effects on observers, but it is unclear how cues compare when they are presented away from fixation and embedded in natural scenes. We here compare the effects of two types of social cue (gaze and pointing gestures) and one type of symbolic cue (arrow signs) on eye movements of observers under two viewing conditions (free viewing vs. a memory task). The results suggest that social cues are looked at more quickly, for longer and more frequently than the symbolic arrow cues. An analysis of saccades initiated from the cue suggests that the pointing cue leads to stronger cueing than the gaze and the arrow cue. While the task had only a weak influence on gaze orienting to the cues, stronger cue following was found for free viewing compared to the memory task.

  19. Paternal signature in kin recognition cues of a social insect: concealed in juveniles, revealed in adults.

    Science.gov (United States)

    Wong, Janine W Y; Meunier, Joël; Lucas, Christophe; Kölliker, Mathias

    2014-10-22

    Kin recognition is a key mechanism to direct social behaviours towards related individuals or avoid inbreeding depression. In insects, recognition is generally mediated by cuticular hydrocarbon (CHC) compounds, which are partly inherited from parents. However, in social insects, potential nepotistic conflicts between group members from different patrilines are predicted to select against the expression of patriline-specific signatures in CHC profiles. Whereas this key prediction in the evolution of insect signalling received empirical support in eusocial insects, it remains unclear whether it can be generalized beyond eusociality to less-derived forms of social life. Here, we addressed this issue by manipulating the number of fathers siring clutches tended by females of the European earwig, Forficula auricularia, analysing the CHC profiles of the resulting juvenile and adult offspring, and using discriminant analysis to estimate the information content of CHC with respect to the maternal and paternal origin of individuals. As predicted, if paternally inherited cues are concealed during family life, increases in mating number had no effect on information content of CHC profiles among earwig juveniles, but significantly decreased the one among adult offspring. We suggest that age-dependent expression of patriline-specific cues evolved to limit the risks of nepotism as family-living juveniles and favour sibling-mating avoidance as group-living adults. These results highlight the role of parental care and social life in the evolution of chemical communication and recognition cues.

  20. Extinction of drug cue reactivity in methamphetamine-dependent individuals.

    Science.gov (United States)

    Price, Kimber L; Saladin, Michael E; Baker, Nathaniel L; Tolliver, Bryan K; DeSantis, Stacia M; McRae-Clark, Aimee L; Brady, Kathleen T

    2010-09-01

    Conditioned responses to drug-related environmental cues (such as craving) play a critical role in relapse to drug use. Animal models demonstrate that repeated exposure to drug-associated cues in the absence of drug administration leads to the extinction of conditioned responses, but the few existing clinical trials focused on extinction of conditioned responses to drug-related cues in drug-dependent individuals show equivocal results. The current study examined drug-related cue reactivity and response extinction in a laboratory setting in methamphetamine-dependent individuals. Methamphetamine cue-elicited craving was extinguished during two sessions of repeated (3) within-session exposures to multi-modal (picture, video, and in-vivo) cues, with no evidence of spontaneous recovery between sessions. A trend was noted for a greater attenuation of response in participants with longer (4-7 day) inter-session intervals. These results indicate that extinction of drug cue conditioned responding occurs in methamphetamine-dependent individuals, offering promise for the development of extinction- based treatment strategies. 2010 Elsevier Ltd. All rights reserved.

  1. Modelling the interplay of multiple cues in prosodic focus marking

    Directory of Open Access Journals (Sweden)

    Anja Arnhold

    2017-03-01

    Full Text Available Focus marking is an important function of prosody in many languages. While many phonological accounts concentrate on fundamental frequency (F0, studies have established several additional cues to information structure. However, the relationship between these cues is rarely investigated. We simultaneously analyzed five prosodic cues to focus—F0 range, word duration, intensity, voice quality, the location of the F0 maximum, and the occurrence of pauses—in a set of 947 simple Subject Verb Object (SVO sentences uttered by 17 native speakers of Finnish. Using random forest and generalized additive mixed modelling, we investigated the systematicity of prosodic focus marking, the importance of each cue as a predictor, and their functional shape. Results indicated a highly consistent differentiation between narrow focus and givenness, marked by at least F0 range, word duration, intensity, and the location of the F0 maximum, with F0 range being the most important predictor. No cue had a linear relationship with focus condition. To account for the simultaneous significance of several predictors, we argue that these findings support treating multiple prosodic cues to focus in Finnish as correlates of prosodic phrasing. Thus, we suggest that prosodic phrasing, having multiple functions, is also marked with multiple cues to enhance communicative efficiency.

  2. Sex ratio strategies and the evolution of cue use.

    Science.gov (United States)

    Moore, Jamie C; Zavodna, Monika; Compton, Stephen G; Gilmartin, Philip M

    2005-06-22

    Quantitative tests of sex allocation theory have often indicated that organism strategies deviate from model predictions. In pollinating fig wasps, Lipporrhopalum tentacularis, whole fig (brood) sex ratios are generally more female-biased than predicted by local mate competition (LMC) theory where females (foundresses) use density as a cue to assess potential LMC. We use microsatellite markers to investigate foundress sex ratios in L. tentacularis and show that they actually use their clutch size as a cue, with strategies closely approximating the predictions of a new model we develop of these conditions. We then provide evidence that the use of clutch size as a cue is common among species experiencing LMC, and given the other predictions of our model argue that this is because their ecologies mean it provides sufficiently accurate information about potential LMC that the use of other more costly cues has not evolved. We further argue that the use of these more costly cues by other species is due to the effect that ecological differences have on cue accuracy. This implies that deviations from earlier theoretical predictions often indicate that the cues used to assess environmental conditions differ from those assumed by models, rather than limits on the ability of natural selection to produce "perfect" organisms.

  3. Extinction of Drug Cue Reactivity in Methamphetamine-Dependent Individuals

    Science.gov (United States)

    Price, Kimber L.; Saladin, Michael E.; Baker, Nathaniel L.; Tolliver, Bryan K.; DeSantis, Stacia M.; McRae-Clark, Aimee L.; Brady, Kathleen T.

    2010-01-01

    Conditioned responses to drug-related environmental cues (such as craving) play a critical role in relapse to drug use. Animal models demonstrate that repeated exposure to drug-associated cues in the absence of drug administration leads to the extinction of conditioned responses, but the few existing clinical trials focused on extinction of conditioned responses to drug-related cues in drug-dependent individuals show equivocal results. The current study examined drug-related cue reactivity and response extinction in a laboratory setting in methamphetamine-dependent individuals. Methamphetamine cue-elicited craving was extinguished during two sessions of repeated (3) within-session exposures to multi-modal (picture, video, and in-vivo) cues, with no evidence of spontaneous recovery between sessions. A trend was noted for a greater attenuation of response in participants with longer (4-7 day) inter-session intervals. These results indicate that extinction of drug-cue conditioned responding occurs in methamphetamine-dependent individuals, offering promise for the development of extinction- based treatment strategies. PMID:20538262

  4. Effect of pictorial depth cues, binocular disparity cues and motion parallax depth cues on lightness perception in three-dimensional virtual scenes.

    Directory of Open Access Journals (Sweden)

    Michiteru Kitazaki

    Full Text Available BACKGROUND: Surface lightness perception is affected by scene interpretation. There is some experimental evidence that perceived lightness under bi-ocular viewing conditions is different from perceived lightness in actual scenes but there are also reports that viewing conditions have little or no effect on perceived color. We investigated how mixes of depth cues affect perception of lightness in three-dimensional rendered scenes containing strong gradients of illumination in depth. METHODOLOGY/PRINCIPAL FINDINGS: Observers viewed a virtual room (4 m width x 5 m height x 17.5 m depth with checkerboard walls and floor. In four conditions, the room was presented with or without binocular disparity (BD depth cues and with or without motion parallax (MP depth cues. In all conditions, observers were asked to adjust the luminance of a comparison surface to match the lightness of test surfaces placed at seven different depths (8.5-17.5 m in the scene. We estimated lightness versus depth profiles in all four depth cue conditions. Even when observers had only pictorial depth cues (no MP, no BD, they partially but significantly discounted the illumination gradient in judging lightness. Adding either MP or BD led to significantly greater discounting and both cues together produced the greatest discounting. The effects of MP and BD were approximately additive. BD had greater influence at near distances than far. CONCLUSIONS/SIGNIFICANCE: These results suggest the surface lightness perception is modulated by three-dimensional perception/interpretation using pictorial, binocular-disparity, and motion-parallax cues additively. We propose a two-stage (2D and 3D processing model for lightness perception.

  5. Functional Significance Of Ultraviolet Feeding Cues In Wild Turkeys.

    Science.gov (United States)

    Werner, Scott J; Buchholz, Richard; Tupper, Shelagh K; Pettit, Susan E; Ellis, Jeremy W

    2013-10-25

    WERNER, S. J., R. BUCHHOLZ, S. K. TUPPER, S. E. PETTIT AND J. W. ELLIS. Functional significance of ultraviolet feeding cues in wild turkeys. PHYSIOL BEHAV 00:000-000, 2013.- Most birds are able to sense ultraviolet (UV) visual signals. Ultraviolet wavelengths are used for plumage signaling and sexual selection among birds. The aim of our study was to determine if UV cues are also used for the process of food selection in wild turkeys (Meleagris gallopavo). We used avoidance conditioning to test the hypothesis that UV feeding cues can be used functionally for foraging behavior in wild turkeys. Female turkeys exhibited no avoidance of untreated food and 75-98% avoidance of food treated with an UV-absorbent, postingestive repellent (0.5-4% anthraquinone; wt/wt) during repellent exposure. Male turkeys exhibited 78-99% avoidance of food treated with 0.5-4% anthraquinone. Female and male turkeys that consumed more than 200mg and 100mg of anthraquinone, respectively, subsequently avoided food treated only with an UV-absorbent cue. In contrast, unconditioned females consumed 58% more food treated with the UV-absorbent cue than untreated food. Thus, wild turkeys do not prefer foods associated with UV wavelengths regardless of feeding experience. We also observed 1) a weak negative correlation between body condition and intestinal parasite infection and 2) moderate, positive correlations between consumption of food treated with the conditioned UV cue and intestinal parasite infection among male turkeys. The UV feeding cue was used to maintain food avoidance during the four days subsequent to postingestive conditioning. Moreover, the consequences of consuming food treated with the postingestive, UV-absorbent repellent were necessary for conditioned avoidance of the UV-absorbent cue. These findings suggest functional significance of UV feeding cues for avian foraging behavior, the implications of which will enable subsequent investigations regarding the sensory physiology and

  6. Polymeric Nerve Conduits with Contact Guidance Cues Used in Nerve Repair

    Institute of Scientific and Technical Information of China (English)

    G DAI; X NIU; J YIN

    2016-01-01

    In the modern life, the nerve injury frequently happens due to mechanical, chemical or thermal accidents. In the trivial injuries, the peripheral nerves can regenerate on their own; however, in most of the cases the clinical treatments are required, where relatively large nerve injury gaps are formed. Currently, the nerve repair can be accomplished by direct suture when the injury gap is not too large;while the autologous nerve graft working as the gold standard of peripheral nerve injury treatment for nerve injuries with larger gaps. However, the direct suture is limited by heavy tension at the suture sites, and the autologous nerve graft also has the drawbacks of donor site morbidity and insufifcient donor tissue. Recently, artiifcial nerve conduits have been developed as an alternative for clinical nerve repair to overcome the limitations associated with the above treatments. In order to further improve the efifciency of nerve conduits, various guidance cues are incorporated, including physical cues, biochemical signals, as well as support cells. First, this paper reviewed the contact guidance cues applied in nerve conduits, such as lumen ifllers, multi-channels and micro-patterns on the inner surface. Then, the paper focused on the polymeric nerve conduits with micro inner grooves. The polymeric nerve conduits were fabricated using the phase inversion-based ifber spinning techniques. The smart spinneret with grooved die was designed in the spinning platform, while different spinning conditions, including flow rates, air-gap distances, and polymer concentrations, were adjusted to investigate the inlfuence of fabrication conditions on the geometry of nerve conduits. The inner groove size in the nerve conduits can be precisely controlled in our hollow ifber spinning process, which can work as the efifcient contact guidance cue for nerve regeneration.

  7. Effects of biophysical and biochemical cues on human corneal epithelial cell behavior

    Science.gov (United States)

    Tocce, Elizabeth J.

    2011-12-01

    Recent advances in the design of biomaterials aim at mimicking the natural biophysical and biochemical components found in a tissue's extracellular environment (ECM). Of particular interest in this work is mimicking the specialized ECM of the human corneal epithelium called the basement membrane (BM) and understanding how corneal epithelial cells (HCECs) respond to biophysical and biochemical cues. To this end, well defined topographic features with dimension of the BM (20 to 200 nm) were fabricated to support controlled cell interactions with biochemical motifs (e.g., adhesive peptide ligands) found in the BM. Here, features of 30 to 70 nm that represent the smallest features found in the BM were used to demonstrate that the smallest features that HCECs can recognize are 30 and 45 nm, depending on the soluble environment. In addition, HCECs demonstrate contact guidance on the smallest BM features (30 to 70 nm) and on the largest BM features (200 nm), but differs from contact guidance on micron-scale features, suggesting that BM scale topography scale is an influential factor in regulating HCEC behavior. To study the simultaneous presentation of biophysical and biochemical cues, topographic features are coated with thin films using a layer-by-layer deposition of covalently reacting polymers, poly(ethylene imine) and poly(2-vinyl-4,4-dimethylazlactone (PEI/PVDMA). The films are functionalized with the bioactive peptide argenine-glycine-aspartic acid (RGD) to control cell-substrate interactions. We demonstrate that PEI/PVDMA films can be functionalized with monotonically increasing densities of ROD to control HCEC attachment and proliferation. In addition PEI/PVDMA films functionalized with RGD were used to demonstrate that HCEC response to topographic cues is dependent on the scale of the topography, the surface chemical composition and the soluble environment. Results from these studies will advance the understanding of how BM-relevant biophysical and biochemical

  8. Habitat selection, facilitation, and biotic settlement cues affect distribution and performance of coral recruits in French Polynesia

    Science.gov (United States)

    2010-01-01

    Habitat selection can determine the distribution and performance of individuals if the precision with which sites are chosen corresponds with exposure to risks or resources. Contrastingly, facilitation can allow persistence of individuals arriving by chance and potentially maladapted to local abiotic conditions. For marine organisms, selection of a permanent attachment site at the end of their larval stage or the presence of a facilitator can be a critical determinant of recruitment success. In coral reef ecosystems, it is well known that settling planula larvae of reef-building corals use coarse environmental cues (i.e., light) for habitat selection. Although laboratory studies suggest that larvae can also use precise biotic cues produced by crustose coralline algae (CCA) to select attachment sites, the ecological consequences of biotic cues for corals are poorly understood in situ. In a field experiment exploring the relative importance of biotic cues and variability in habitat quality to recruitment of hard corals, pocilloporid and acroporid corals recruited more frequently to one species of CCA, Titanoderma prototypum, and significantly less so to other species of CCA; these results are consistent with laboratory assays from other studies. The provision of the biotic cue accurately predicted coral recruitment rates across habitats of varying quality. At the scale of CCA, corals attached to the “preferred” CCA experienced increased survivorship while recruits attached elsewhere had lower colony growth and survivorship. For reef-building corals, the behavioral selection of habitat using chemical cues both reduces the risk of incidental mortality and indicates the presence of a facilitator. PMID:20169452

  9. Probabilistic Tracking of Objects with Adaptive Cue Fusion Mechanism

    Institute of Scientific and Technical Information of China (English)

    ZHANG Bo; TIAN Wei-feng; JIN Zhi-hua

    2007-01-01

    A tracking method based on adaptive multiple cue fusion mechanism was presented, where particle filter is used to integrate color and edge cues. The fusion mechanism assigns different weights to two cues according to their importance, thus improving the robustness and reliability of the tracking algorithm. Moreover, a multi-part color model is also invoked to deal with the confliction among similar objects. The experimental results on two real image sequences show the tracking algorithm with adaptive fusion mechanism performs well in the presence of complex scenarios such as head rotation, scale change and multiple person occlusions.

  10. Designing auditory cues for Parkinson's disease gait rehabilitation.

    Science.gov (United States)

    Cancela, Jorge; Moreno, Eugenio M; Arredondo, Maria T; Bonato, Paolo

    2014-01-01

    Recent works have proved that Parkinson's disease (PD) patients can be largely benefit by performing rehabilitation exercises based on audio cueing and music therapy. Specially, gait can benefit from repetitive sessions of exercises using auditory cues. Nevertheless, all the experiments are based on the use of a metronome as auditory stimuli. Within this work, Human-Computer Interaction methodologies have been used to design new cues that could benefit the long-term engagement of PD patients in these repetitive routines. The study has been also extended to commercial music and musical pieces by analyzing features and characteristics that could benefit the engagement of PD patients to rehabilitation tasks.

  11. Spatial Hearing with Incongruent Visual or Auditory Room Cues

    DEFF Research Database (Denmark)

    Gil Carvajal, Juan Camilo; Cubick, Jens; Santurette, Sébastien;

    2016-01-01

    whether a mismatch between playback and recording room reduces perceived distance, azimuthal direction, and compactness of the auditory image, and whether this is mostly due to incongruent auditory cues or to expectations generated from the visual impression of the room. Perceived distance ratings...... decreased significantly when collected in a more reverberant environment than the recording room, whereas azimuthal direction and compactness remained room independent. Moreover, modifying visual room-related cues had no effect on these three attributes, while incongruent auditory room-related cues between...

  12. Facial, Olfactory, and Vocal Cues to Female Reproductive Value

    Directory of Open Access Journals (Sweden)

    Susanne Röder

    2013-04-01

    Full Text Available Facial, olfactory, and vocal cues may advertise women's fertility. However, most of the evidence for this proposal has come from studies of changes in young adult women's attractiveness over the menstrual cycle. By contrast with this emphasis on changes in attractiveness over the menstrual cycle, possible changes in women's attractiveness over their lifespan have received little attention. The present study investigated men's ratings of young girls' (11–15 years old, adult women's (19–30 years old and circum-menopausal women's (50–65 years old facial, body odor, and vocal attractiveness and femininity. Faces and voices, but not body odors, of young girls and adult women were perceived to be significantly more attractive and feminine than those of circum-menopausal women. These data suggest that facial and vocal cues may be cues to women's reproductive value, but that body odor cues do not necessarily advertise this information.

  13. Memory for incidentally perceived social cues: Effects on person judgment.

    Science.gov (United States)

    Pawling, Ralph; Kirkham, Alexander J; Tipper, Steven P; Over, Harriet

    2017-02-01

    Dynamic face cues can be very salient, as when observing sudden shifts of gaze to a new location, or a change of expression from happy to angry. These highly salient social cues influence judgments of another person during the course of an interaction. However, other dynamic cues, such as pupil dilation, are much more subtle, affecting judgments of another person even without awareness. We asked whether such subtle, incidentally perceived, dynamic cues could be encoded in to memory and retrieved at a later time. The current study demonstrates that in some circumstances changes in pupil size in another person are indeed encoded into memory and influence judgments of that individual at a later time. Furthermore, these judgments interact with the perceived trustworthiness of the individual and the nature of the social context. The effect is somewhat variable, however, possibly reflecting individual differences and the inherent ambiguity of pupil dilation/constriction. © 2016 The British Psychological Society.

  14. Acoustic cues identifying phonetic transitions for speech segmentation

    CSIR Research Space (South Africa)

    Van Niekerk, DR

    2008-11-01

    Full Text Available The quality of corpus-based text-to-speech (TTS) systems depends strongly on the consistency of boundary placements during phonetic alignments. Expert human transcribers use visually represented acoustic cues in order to consistently place...

  15. Norwegian Retroflexion − Licensing by Cue or Prosody?

    Directory of Open Access Journals (Sweden)

    Silke Hamann

    2004-01-01

    Full Text Available This article deals with the class of retroflex segments in Norwegian. The question is handled whether the phonotactic restrictions on retroflexes to occur mainly only in coda position cannot be better described in terms of the availability of the retroflex cues in post-vocalic position instead of refering to their syllable-position. The latter approach, the so-called prosodic licensing (Lombardi 1995, is shown to be insufficient in cases of retroflexion across word-boundaries, where retroflexes appear in onset-position. The so-called lincensing by cue-approach (Steriade 1995, on the other hand, is shown to be able to cover all the instances of retroflex occurrences: retroflexes in Norwegian occur only when a vowel precedes, which enhances their strong transitional cues from vowel to retroflex. In addition to this, licensing by cue can account for the progressive assimilation of retroflexion also found in Norwegian.

  16. Cue Combination of Conflicting Color and Luminance Edges

    Directory of Open Access Journals (Sweden)

    Rebecca J Sharman

    2015-12-01

    Full Text Available Abrupt changes in the color or luminance of a visual image potentially indicate object boundaries. Here, we consider how these cues to the visual “edge” location are combined when they conflict. We measured the extent to which localization of a compound edge can be predicted from a simple maximum likelihood estimation model using the reliability of chromatic (L−M and luminance signals alone. Maximum likelihood estimation accurately predicted the pattern of results across a range of contrasts. Predictions consistently overestimated the relative influence of the luminance cue; although L−M is often considered a poor cue for localization, it was used more than expected. This need not indicate that the visual system is suboptimal but that its priors about which cue is more useful are not flat. This may be because, although strong changes in chromaticity typically represent object boundaries, changes in luminance can be caused by either a boundary or a shadow.

  17. Cue Combination of Conflicting Color and Luminance Edges.

    Science.gov (United States)

    Sharman, Rebecca J; McGraw, Paul V; Peirce, Jonathan W

    2015-12-01

    Abrupt changes in the color or luminance of a visual image potentially indicate object boundaries. Here, we consider how these cues to the visual "edge" location are combined when they conflict. We measured the extent to which localization of a compound edge can be predicted from a simple maximum likelihood estimation model using the reliability of chromatic (L-M) and luminance signals alone. Maximum likelihood estimation accurately predicted the pattern of results across a range of contrasts. Predictions consistently overestimated the relative influence of the luminance cue; although L-M is often considered a poor cue for localization, it was used more than expected. This need not indicate that the visual system is suboptimal but that its priors about which cue is more useful are not flat. This may be because, although strong changes in chromaticity typically represent object boundaries, changes in luminance can be caused by either a boundary or a shadow.

  18. Augmented Reality Cues and Elderly Driver Hazard Perception

    Science.gov (United States)

    Schall, Mark C.; Rusch, Michelle L.; Lee, John D.; Dawson, Jeffrey D.; Thomas, Geb; Aksan, Nazan; Rizzo, Matthew

    2013-01-01

    Objective Evaluate the effectiveness of augmented reality (AR) cues in improving driving safety in elderly drivers who are at increased crash risk due to cognitive impairments. Background Cognitively challenging driving environments pose a particular crash risk for elderly drivers. AR cueing is a promising technology to mitigate risk by directing driver attention to roadway hazards. This study investigates whether AR cues improve or interfere with hazard perception in elderly drivers with age-related cognitive decline. Methods Twenty elderly (Mean= 73 years, SD= 5 years), licensed drivers with a range of cognitive abilities measured by a speed of processing (SOP) composite participated in a one-hour drive in an interactive, fixed-base driving simulator. Each participant drove through six, straight, six-mile-long rural roadway scenarios following a lead vehicle. AR cues directed attention to potential roadside hazards in three of the scenarios, and the other three were uncued (baseline) drives. Effects of AR cueing were evaluated with respect to: 1) detection of hazardous target objects, 2) interference with detecting nonhazardous secondary objects, and 3) impairment in maintaining safe distance behind a lead vehicle. Results AR cueing improved the detection of hazardous target objects of low visibility. AR cues did not interfere with detection of nonhazardous secondary objects and did not impair ability to maintain safe distance behind a lead vehicle. SOP capacity did not moderate those effects. Conclusion AR cues show promise for improving elderly driver safety by increasing hazard detection likelihood without interfering with other driving tasks such as maintaining safe headway. PMID:23829037

  19. Female hummingbirds do not relocate rewards using colour cues

    OpenAIRE

    Tello Ramos, Maria Cristina; Hurly, T. Andrew; Healy, Susan D.

    2014-01-01

    This research was supported by CONACYT (The Mexican National Council for Science and Technology) grant number: 310717, the University of Lethbridge and the Natural Sciences and Engineering Research Council of Canada (grant number: RGPIN 121496-2003) and the University of St Andrew's Russell Trust Award. Males generally outperform females in spatial tasks. This difference in spatial performance may reflect differences in cue preference because males often use both spatial cues 9distance and...

  20. Segmentation cues in conversational speech: robust semantics and fragile phonotactics.

    Science.gov (United States)

    White, Laurence; Mattys, Sven L; Wiget, Lukas

    2012-01-01

    Multiple cues influence listeners' segmentation of connected speech into words, but most previous studies have used stimuli elicited in careful readings rather than natural conversation. Discerning word boundaries in conversational speech may differ from the laboratory setting. In particular, a speaker's articulatory effort - hyperarticulation vs. hypoarticulation (H&H) - may vary according to communicative demands, suggesting a compensatory relationship whereby acoustic-phonetic cues are attenuated when other information sources strongly guide segmentation. We examined how listeners' interpretation of segmentation cues is affected by speech style (spontaneous conversation vs. read), using cross-modal identity priming. To elicit spontaneous stimuli, we used a map task in which speakers discussed routes around stylized landmarks. These landmarks were two-word phrases in which the strength of potential segmentation cues - semantic likelihood and cross-boundary diphone phonotactics - was systematically varied. Landmark-carrying utterances were transcribed and later re-recorded as read speech. Independent of speech style, we found an interaction between cue valence (favorable/unfavorable) and cue type (phonotactics/semantics). Thus, there was an effect of semantic plausibility, but no effect of cross-boundary phonotactics, indicating that the importance of phonotactic segmentation may have been overstated in studies where lexical information was artificially suppressed. These patterns were unaffected by whether the stimuli were elicited in a spontaneous or read context, even though the difference in speech styles was evident in a main effect. Durational analyses suggested speaker-driven cue trade-offs congruent with an H&H account, but these modulations did not impact on listener behavior. We conclude that previous research exploiting read speech is reliable in indicating the primacy of lexically based cues in the segmentation of natural conversational speech.

  1. Deceptive body movements reverse spatial cueing in soccer.

    Directory of Open Access Journals (Sweden)

    Michael J Wright

    Full Text Available The purpose of the experiments was to analyse the spatial cueing effects of the movements of soccer players executing normal and deceptive (step-over turns with the ball. Stimuli comprised normal resolution or point-light video clips of soccer players dribbling a football towards the observer then turning right or left with the ball. Clips were curtailed before or on the turn (-160, -80, 0 or +80 ms to examine the time course of direction prediction and spatial cueing effects. Participants were divided into higher-skilled (HS and lower-skilled (LS groups according to soccer experience. In experiment 1, accuracy on full video clips was higher than on point-light but results followed the same overall pattern. Both HS and LS groups correctly identified direction on normal moves at all occlusion levels. For deceptive moves, LS participants were significantly worse than chance and HS participants were somewhat more accurate but nevertheless substantially impaired. In experiment 2, point-light clips were used to cue a lateral target. HS and LS groups showed faster reaction times to targets that were congruent with the direction of normal turns, and to targets incongruent with the direction of deceptive turns. The reversed cueing by deceptive moves coincided with earlier kinematic events than cueing by normal moves. It is concluded that the body kinematics of soccer players generate spatial cueing effects when viewed from an opponent's perspective. This could create a reaction time advantage when anticipating the direction of a normal move. A deceptive move is designed to turn this cueing advantage into a disadvantage. Acting on the basis of advance information, the presence of deceptive moves primes responses in the wrong direction, which may be only partly mitigated by delaying a response until veridical cues emerge.

  2. Menstrual cycle and cue reactivity in women smokers

    Science.gov (United States)

    DeSantis, Stacia M.; Carpenter, Matthew J.; Saladin, Michael E.; LaRowe, Steven D.; Upadhyaya, Himanshu P.

    2010-01-01

    Introduction: Emerging research suggests potential effects of the menstrual cycle on various aspects of smoking behavior in women, but results to date have been mixed. The present study sought to explore the influence of menstrual cycle phase on reactivity to smoking in vivo and stressful imagery cues in a sample of non–treatment-seeking women smokers. Methods: Via a within-subjects design, nicotine-dependent women (N = 37) participated in a series of four cue reactivity sessions, each during a distinct biologically verified phase of the menstrual cycle (early follicular [EF], mid-follicular [MF], mid-luteal [ML], and late luteal [LL]). Subjective (Questionnaire of Smoking Urges–Brief; QSU-B) and physiological (skin conductance and heart rate) measures of craving and reactivity were collected and compared across phases. Results: Subjective reactive craving (QSU-B) to smoking in vivo cues varied significantly across the menstrual cycle (p = .02) and was higher in both EF and MF phases versus ML and LL phases, but this finding was not sustained when controlling for reactivity to neutral cues. Heart rate reactivity to stressful imagery cues (p = .01) and skin conductance reactivity to smoking in vivo cues (p = .05) varied significantly across the menstrual cycle upon controlling for reactivity to neutral cues, with highest reactivity during the MF phase. Discussion: Menstrual cycle phase may have an effect on reactivity to smoking-related and stressful cues among women smokers. These findings contribute to an expanding literature, suggesting menstrual cycle effects on smoking behaviors in women. PMID:19996146

  3. Segmentation cues in conversational speech: Robust semantics and fragile phonotactics

    Directory of Open Access Journals (Sweden)

    Laurence eWhite

    2012-10-01

    Full Text Available Multiple cues influence listeners’ segmentation of connected speech into words, but most previous studies have used stimuli elicited in careful readings rather than natural conversation. Discerning word boundaries in conversational speech may differ from the laboratory setting. In particular, a speaker’s articulatory effort – hyperarticulation vs hypoarticulation (H&H – may vary according to communicative demands, suggesting a compensatory relationship whereby acoustic-phonetic cues are attenuated when other information sources strongly guide segmentation. We examined how listeners’ interpretation of segmentation cues is affected by speech style (spontaneous conversation vs read, using cross-modal identity priming. To elicit spontaneous stimuli, we used a map task in which speakers discussed routes around stylised landmarks. These landmarks were two-word phrases in which the strength of potential segmentation cues – semantic likelihood and cross-boundary diphone phonotactics – was systematically varied. Landmark-carrying utterances were transcribed and later re-recorded as read speech.Independent of speech style, we found an interaction between cue valence (favourable/unfavourable and cue type (phonotactics/semantics. Thus, there was an effect of semantic plausibility, but no effect of cross-boundary phonotactics, indicating that the importance of phonotactic segmentation may have been overstated in studies where lexical information was artificially suppressed. These patterns were unaffected by whether the stimuli were elicited in a spontaneous or read context, even though the difference in speech styles was evident in a main effect. Durational analyses suggested speaker-driven cue trade-offs congruent with an H&H account, but these modulations did not impact on listener behaviour. We conclude that previous research exploiting read speech is reliable in indicating the primacy of lexically-based cues in the segmentation of natural

  4. Meals and snacks: Children's characterizations of food and eating cues.

    Science.gov (United States)

    Marx, Jenna M; Hoffmann, Debra A; Musher-Eizenman, Dara R

    2016-02-01

    This study examined preschoolers' and their parents' categorizations of eating episodes based on cues used for defining these occasions (i.e., time, portion size, preparation, content, and emotion) as a meal or snack. Thirty-four children aged 4 to 6 saw pictorial representations of each cue, along with a short verbal description, and were asked to place the picture in one of three boxes: "meal", "snack", or "either meal or snack". One parent per child (85% mothers, Mean age = 35.1 years) separately categorized the same items in an online survey. Results illustrated which cues play a role in how parents and children categorize eating occasions as meals or snacks. Parents used 24 of the 32 cue-related items to distinguish between eating occasions as a meal or a snack, while children used only four. Parents and preschoolers were consistent in using cartoon character packaging to indicate a snack, and also used several of the same content cues. The current study highlights the various cues used to categorize an eating occasion, and the unhealthy character of snacks, as participants associated some unhealthy foods and very few healthy foods with snacks. Future research should focus on the role of parents, the home environment, and advertising media in shaping children's characterizations of eating occasions towards development of healthy eating habits and away from problematic eating behaviors that may persist later in life.

  5. Examining the durability of incidentally learned trust from gaze cues.

    Science.gov (United States)

    Strachan, James W A; Tipper, Steven P

    2017-10-01

    In everyday interactions we find our attention follows the eye gaze of faces around us. As this cueing is so powerful and difficult to inhibit, gaze can therefore be used to facilitate or disrupt visual processing of the environment, and when we experience this we infer information about the trustworthiness of the cueing face. However, to date no studies have investigated how long these impressions last. To explore this we used a gaze-cueing paradigm where faces consistently demonstrated either valid or invalid cueing behaviours. Previous experiments show that valid faces are subsequently rated as more trustworthy than invalid faces. We replicate this effect (Experiment 1) and then include a brief interference task in Experiment 2 between gaze cueing and trustworthiness rating, which weakens but does not completely eliminate the effect. In Experiment 3, we explore whether greater familiarity with the faces improves the durability of trust learning and find that the effect is more resilient with familiar faces. Finally, in Experiment 4, we push this further and show that evidence of trust learning can be seen up to an hour after cueing has ended. Taken together, our results suggest that incidentally learned trust can be durable, especially for faces that deceive.

  6. Transferrable Learning of Multisensory Cues in Flight Simulation

    Directory of Open Access Journals (Sweden)

    Georg F Meyer

    2011-10-01

    Full Text Available Flight simulators which provide visual, auditory, and kinematic (physical motion cues are increasingly used for pilot training. We have previously shown that kinematic cues, but not auditory cues, representing aircraft motion improve target tracking performance for novice ‘pilots’ in a simulated flying task (Meyer et al IMRF 2010. Here we explore the effect of learning on task performance. Our subjects were first tested on a target tracking task in a helicopter flight simulation. They were then trained in a simulator-simulator, which provided full audio, simplified visuals, but not kinematic signals to test whether learning of auditory cues is possible. After training we evaluated flight performance in the full simulator again. We show that after 2 hours training auditory cues are used by our participants as efficiently as kinematic cues to improve target tracking performance. The performance improvement relative to a condition where no audio signals are presented is robust if the sound environment used during training is replaced by a very different audio signal that is modulated in amplitude and pitch in the same way as the training signal. This shows that training is not signal specific but that our participants learn to extract transferrable information on sound pitch and amplitude to improve their flying performance.

  7. Eating by example. Effects of environmental cues on dietary decisions.

    Science.gov (United States)

    Prinsen, Sosja; de Ridder, Denise T D; de Vet, Emely

    2013-11-01

    The present studies examined the role of environmental cues in steering people's dietary decisions in response to food temptations. Based on the notion that people show a tendency to conform to eating standards derived from the eating behavior of others, it was hypothesized that communication of other people's dietary decisions through environmental cues affect whether and what people eat. Conformity to environmental cues about food intake was assessed in a local bakery (Study 1, N=144) and a lab setting (Study 2, N=65). Participants were unobtrusively presented with a bowl of individually wrapped chocolates. The presence of empty wrappers was manipulated, to indicate whether others who had been in the same situation had or had not eaten. Conformity to environmental cues about food choice was assessed in Study 3 (N=90). Participants were required to choose between a healthy and an unhealthy snack. Food wrappers indicated whether previous participants had chosen the healthy or the unhealthy snack. As expected, participants were more likely to take chocolates in the presence of an environmental cue that others did too. Also, participants were more likely to choose a snack that was consistent with the choice of others. Together, these findings support our main hypothesis that environmental cues steer people's decisions concerning food intake and food choice. Moreover, the results suggest that only small changes in the environment may support healthy eating behavior. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Smoking-Cue Induced Brain Activation In Adolescent Light Smokers

    Science.gov (United States)

    Rubinstein, Mark L.; Luks, Tracy L.; Moscicki, Anna-Barbara; Dryden, Wendy; Rait, Michelle A.; Simpson, Gregory V.

    2010-01-01

    Purpose Using fMRI, we examined whether or not adolescents with low levels of nicotine exposure (light smokers) display neural activation in areas shown to be involved with addiction in response to smoking-related stimuli. Design/Setting/Participants Twelve adolescent light smokers (aged 13 to17, smoked 1 to 5 cigarettes per day) and 12 non-smokers (ages 13 to 17, never smoked a cigarette) from the San Francisco Bay Area underwent fMRI scanning. During scanning they viewed blocks of photographic smoking and control cues. Smoking cues consisted of pictures of people smoking cigarettes and smoking-related objects such as lighters and ashtrays. Neutral cues consisted of everyday objects and people engaged in everyday activities. Findings For smokers, smoking cues elicited greater activation than neutral cues in the mesolimbic reward circuit (left anterior cingulate (T=7.88, pbrain regions seen in adult and heavy teen smokers suggests that even at low levels of smoking, adolescents exhibit heightened reactivity to smoking cues. This paper adds to the existing literature suggesting that nicotine dependence may begin with exposure to low levels of nicotine, underscoring the need for early intervention among adolescent smokers. PMID:21185518

  9. Acoustic cues in the perception of second language speech sounds

    Science.gov (United States)

    Bogacka, Anna A.

    2001-05-01

    The experiment examined to what acoustic cues Polish learners of English pay attention when distinguishing between English high vowels. Predictions concerned the influence of Polish vowel system (no duration differences and only one vowel in the high back vowel region), salience of duration cues and L1 orthography. Thirty-seven Polish subjects and a control group of English native speakers identified stimuli from heed-hid and who'd-hood continua varying in spectral and duration steps. Identification scores by spectral and duration steps, and F1/F2 plots of identifications, were given as well as fundamental frequency variation comments. English subjects strongly relied on spectral cues (typical categorical perception) and almost did not react to temporal cues. Polish subjects relied strongly on temporal cues for both continua, but showed a reversed pattern of identification of who'd-hood contrast. Their reliance on spectral cues was weak and had a reversed pattern for heed-hid contrast. The results were interpreted with reference to the speech learning model [Flege (1995)], perceptual assimilation model [Best (1995)] and ontogeny phylogeny model [Major (2001)].

  10. Spectral information as an orientation cue in dung beetles

    Science.gov (United States)

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

    2015-01-01

    During the day, a non-uniform distribution of long and short wavelength light generates a colour gradient across the sky. This gradient could be used as a compass cue, particularly by animals such as dung beetles that rely primarily on celestial cues for orientation. Here, we tested if dung beetles can use spectral cues for orientation by presenting them with monochromatic (green and UV) light spots in an indoor arena. Beetles kept their original bearing when presented with a single light cue, green or UV, or when presented with both light cues set 180° apart. When either the UV or the green light was turned off after the beetles had set their bearing in the presence of both cues, they were still able to maintain their original bearing to the remaining light. However, if the beetles were presented with two identical green light spots set 180° apart, their ability to maintain their original bearing was impaired. In summary, our data show that ball-rolling beetles could potentially use the celestial chromatic gradient as a reference for orientation. PMID:26538537

  11. What makes words special? Words as unmotivated cues.

    Science.gov (United States)

    Edmiston, Pierce; Lupyan, Gary

    2015-10-01

    Verbal labels, such as the words "dog" and "guitar," activate conceptual knowledge more effectively than corresponding environmental sounds, such as a dog bark or a guitar strum, even though both are unambiguous cues to the categories of dogs and guitars (Lupyan & Thompson-Schill, 2012). We hypothesize that this advantage of labels emerges because word-forms, unlike other cues, do not vary in a motivated way with their referent. The sound of a guitar cannot help but inform a listener to the type of guitar making it (electric, acoustic, etc.). The word "guitar" on the other hand, can leave the type of guitar unspecified. We argue that as a result, labels gain the ability to cue a more abstract mental representation, promoting efficient processing of category members. In contrast, environmental sounds activate representations that are more tightly linked to the specific cause of the sound. Our results show that upon hearing environmental sounds such as a dog bark or guitar strum, people cannot help but activate a particular instance of a category, in a particular state, at a particular time, as measured by patterns of response times on cue-picture matching tasks (Exps. 1-2) and eye-movements in a task where the cues are task-irrelevant (Exp. 3). In comparison, labels activate concepts in a more abstract, decontextualized way-a difference that we argue can be explained by labels acting as "unmotivated cues".

  12. The impact of early reflections on binaural cues.

    Science.gov (United States)

    Gourévitch, Boris; Brette, Romain

    2012-07-01

    Animals live in cluttered auditory environments, where sounds arrive at the two ears through several paths. Reflections make sound localization difficult, and it is thought that the auditory system deals with this issue by isolating the first wavefront and suppressing later signals. However, in many situations, reflections arrive too early to be suppressed, for example, reflections from the ground in small animals. This paper examines the implications of these early reflections on binaural cues to sound localization, using realistic models of reflecting surfaces and a spherical model of diffraction by the head. The fusion of direct and reflected signals at each ear results in interference patterns in binaural cues as a function of frequency. These cues are maximally modified at frequencies related to the delay between direct and reflected signals, and therefore to the spatial location of the sound source. Thus, natural binaural cues differ from anechoic cues. In particular, the range of interaural time differences is substantially larger than in anechoic environments. Reflections may potentially contribute binaural cues to distance and polar angle when the properties of the reflecting surface are known and stable, for example, for reflections on the ground.

  13. Subliminal Cues While Teaching: HCI Technique for Enhanced Learning

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    Pierre Chalfoun

    2011-01-01

    Full Text Available This paper presents results from an empirical study conducted with a subliminal teaching technique aimed at enhancing learner's performance in Intelligent Systems through the use of physiological sensors. This technique uses carefully designed subliminal cues (positive and miscues (negative and projects them under the learner's perceptual visual threshold. A positive cue, called answer cue, is a hint aiming to enhance the learner's inductive reasoning abilities and projected in a way to help them figure out the solution faster but more importantly better. A negative cue, called miscue, is also used and aims at obviously at the opposite (distract the learner or lead them to the wrong conclusion. The latest obtained results showed that only subliminal cues, not miscues, could significantly increase learner performance and intuition in a logic-based problem-solving task. Nonintrusive physiological sensors (EEG for recording brainwaves, blood volume pressure to compute heart rate and skin response to record skin conductivity were used to record affective and cerebral responses throughout the experiment. The descriptive analysis, combined with the physiological data, provides compelling evidence for the positive impact of answer cues on reasoning and intuitive decision making in a logic-based problem-solving paradigm.

  14. Lexical distributional cues, but not situational cues, are readily used to learn abstract locative verb-structure associations.

    Science.gov (United States)

    Twomey, Katherine E; Chang, Franklin; Ambridge, Ben

    2016-08-01

    Children must learn the structural biases of locative verbs in order to avoid making overgeneralisation errors (e.g., (∗)I filled water into the glass). It is thought that they use linguistic and situational information to learn verb classes that encode structural biases. In addition to situational cues, we examined whether children and adults could use the lexical distribution of nouns in the post-verbal noun phrase of transitive utterances to assign novel verbs to locative classes. In Experiment 1, children and adults used lexical distributional cues to assign verb classes, but were unable to use situational cues appropriately. In Experiment 2, adults generalised distributionally-learned classes to novel verb arguments, demonstrating that distributional information can cue abstract verb classes. Taken together, these studies show that human language learners can use a lexical distributional mechanism that is similar to that used by computational linguistic systems that use large unlabelled corpora to learn verb meaning.

  15. Trust in haptic assistance: weighting visual and haptic cues based on error history.

    Science.gov (United States)

    Gibo, Tricia L; Mugge, Winfred; Abbink, David A

    2017-08-01

    To effectively interpret and interact with the world, humans weight redundant estimates from different sensory cues to form one coherent, integrated estimate. Recent advancements in physical assistance systems, where guiding forces are computed by an intelligent agent, enable the presentation of augmented cues. It is unknown, however, if cue weighting can be extended to augmented cues. Previous research has shown that cue weighting is determined by the reliability (inversely related to uncertainty) of cues within a trial, yet augmented cues may also be affected by errors that vary over trials. In this study, we investigate whether people can learn to appropriately weight a haptic cue from an intelligent assistance system based on its error history. Subjects held a haptic device and reached to a hidden target using a visual (Gaussian distributed dots) and haptic (force channel) cue. The error of the augmented haptic cue varied from trial to trial based on a Gaussian distribution. Subjects learned to estimate the target location by weighting the visual and augmented haptic cues based on their perceptual uncertainty and experienced errors. With both cues available, subjects were able to find the target with an improved or equal performance compared to what was possible with one cue alone. Our results show that the brain can learn to reweight augmented cues from intelligent agents, akin to previous observations of the reweighting of naturally occurring cues. In addition, these results suggest that the weighting of a cue is not only affected by its within-trial reliability but also the history of errors.

  16. Computer-Mediated Impression Formation: A Test of the Sticky Cues Model Using Facebook

    Science.gov (United States)

    Van Der Heide, Brandon Lee

    2009-01-01

    This research offers a model of online impression formation that explains how different impression-bearing cues may carry more or less informational value. This research considers the possibility that impression-bearing cues have greater informational value when those cues are distinctive and are task-relevant. This research refers to such cues as…

  17. Employing an Internal Wavemaker to Simulate Sensory Cues in the Plankton

    Science.gov (United States)

    True, A. C.; Webster, D. R.; Weissburg, M. J.; Yen, J.

    2012-11-01

    Internal waves are a ubiquitous feature in many coastal marine ecosystems and as such are important features to consider in the spatiotemporal dynamics of thin planktonic layers. Oscillations of the pycnocline in stratified waters due to internal wave propagation generate fluxes of quantities, such as fluid momentum, thermal energy, and chemical concentration. These fields compose a set of hydrodynamic and thermochemical sensory cues that are fundamental to many planktonic life processes, including prey and predator detection, mate-tracking, habitat partitioning, nutrient and waste transport processes, and chemical communications. Thus, we expect that internal waves generate sensory cues in the water column, influence many fundamental biological processes, and broadly affect spatiotemporal productivity dynamics through unique biophysical coupling over a wide range of relevant scales. We constructed an internal wave generator facility to mimic characteristics that plankton observe in situ. Simultaneous particle image velocimetry (PIV) and laser-induced fluorescence (LIF) are employed on internal waves generated in a two-layer stratification to quantify wave-induced scalar fluxes. Difficulties inherent in scaling down in situ conditions for laboratory-scale behavioral assays are discussed in the context of accurately matching spatiotemporal scales from a planktonic point of view. Finally, the results are interpreted in the context of zooplankton sensory ecology.

  18. Informative Cues Facilitate Saccadic Localization in Blindsight Monkeys.

    Science.gov (United States)

    Yoshida, Masatoshi; Hafed, Ziad M; Isa, Tadashi

    2017-01-01

    Patients with damage to the primary visual cortex (V1) demonstrate residual visual performance during laboratory tasks despite denying having a conscious percept. The mechanisms behind such performance, often called blindsight, are not fully understood, but the use of surgically-induced unilateral V1 lesions in macaque monkeys provides a useful animal model for exploring such mechanisms. For example, V1-lesioned monkeys localize stimuli in a forced-choice condition while at the same time failing to report awareness of identical stimuli in a yes-no detection condition, similar to human patients. Moreover, residual cognitive processes, including saliency-guided eye movements, bottom-up attention with peripheral non-informative cues, and spatial short-term memory, have all been demonstrated in these animals. Here we examined whether post-lesion residual visuomotor processing can be modulated by top-down task knowledge. We tested two V1-lesioned monkeys with a visually guided saccade task in which we provided an informative foveal pre-cue about upcoming target location. Our monkeys fixated while we presented a leftward or rightward arrow (serving as a pre-cue) superimposed on the fixation point (FP). After various cue-target onset asynchronies (CTOAs), a saccadic target (of variable contrast across trials) was presented either in the affected (contra-lesional) or seeing (ipsi-lesional) hemifield. Critically, target location was in the same hemifield that the arrow pre-cue pointed towards in 80% of the trials (valid-cue trials), making the cue highly useful for task performance. In both monkeys, correct saccade reaction times were shorter during valid than invalid trials. Moreover, in one monkey, the ratio of correct saccades towards the affected hemifield was higher during valid than invalid trials. We replicated both reaction time and correct ratio effects in the same monkey using a symbolic color cue. These results suggest that V1-lesion monkeys can use informative

  19. Informative Cues Facilitate Saccadic Localization in Blindsight Monkeys

    Science.gov (United States)

    Yoshida, Masatoshi; Hafed, Ziad M.; Isa, Tadashi

    2017-01-01

    Patients with damage to the primary visual cortex (V1) demonstrate residual visual performance during laboratory tasks despite denying having a conscious percept. The mechanisms behind such performance, often called blindsight, are not fully understood, but the use of surgically-induced unilateral V1 lesions in macaque monkeys provides a useful animal model for exploring such mechanisms. For example, V1-lesioned monkeys localize stimuli in a forced-choice condition while at the same time failing to report awareness of identical stimuli in a yes-no detection condition, similar to human patients. Moreover, residual cognitive processes, including saliency-guided eye movements, bottom-up attention with peripheral non-informative cues, and spatial short-term memory, have all been demonstrated in these animals. Here we examined whether post-lesion residual visuomotor processing can be modulated by top-down task knowledge. We tested two V1-lesioned monkeys with a visually guided saccade task in which we provided an informative foveal pre-cue about upcoming target location. Our monkeys fixated while we presented a leftward or rightward arrow (serving as a pre-cue) superimposed on the fixation point (FP). After various cue-target onset asynchronies (CTOAs), a saccadic target (of variable contrast across trials) was presented either in the affected (contra-lesional) or seeing (ipsi-lesional) hemifield. Critically, target location was in the same hemifield that the arrow pre-cue pointed towards in 80% of the trials (valid-cue trials), making the cue highly useful for task performance. In both monkeys, correct saccade reaction times were shorter during valid than invalid trials. Moreover, in one monkey, the ratio of correct saccades towards the affected hemifield was higher during valid than invalid trials. We replicated both reaction time and correct ratio effects in the same monkey using a symbolic color cue. These results suggest that V1-lesion monkeys can use informative

  20. Feasibility of Using Virtual Reality to Assess Nicotine Cue Reactivity During Treatment.

    Science.gov (United States)

    Kaganoff, Eili; Bordnick, Patrick S; Carter, Brian Lee

    2012-03-01

    Cue reactivity assessments have been widely used to assess craving and attention to cues among cigarette smokers. Cue reactivity has the potential to offer insights into treatment decisions; however, the use of cue reactivity in treatment studies has been limited. This study assessed the feasibility of using a virtual reality-based cue reactivity assessment approach (VR-NCRAS) during treatment. In a clinical smoking cessation treatment study, 46 treatment-seeking nicotine-dependent adult smokers were assessed for cue reactivity at baseline, Week 4, and Week 10 of treatment. Measures of cue reactivity included subjective craving and attention to cues after exposure to two neutral and two smoking cue environments. Overall, feasibility of using VR-NCRAS was demonstrated and these findings support the use of the cue reactivity assessment during treatment, which can inform treatment decisions.

  1. Impact of External Cue Validity on Driving Performance in Parkinson's Disease

    Directory of Open Access Journals (Sweden)

    Karen Scally

    2011-01-01

    Full Text Available This study sought to investigate the impact of external cue validity on simulated driving performance in 19 Parkinson's disease (PD patients and 19 healthy age-matched controls. Braking points and distance between deceleration point and braking point were analysed for red traffic signals preceded either by Valid Cues (correctly predicting signal, Invalid Cues (incorrectly predicting signal, and No Cues. Results showed that PD drivers braked significantly later and travelled significantly further between deceleration and braking points compared with controls for Invalid and No-Cue conditions. No significant group differences were observed for driving performance in response to Valid Cues. The benefit of Valid Cues relative to Invalid Cues and No Cues was significantly greater for PD drivers compared with controls. Trail Making Test (B-A scores correlated with driving performance for PDs only. These results highlight the importance of external cues and higher cognitive functioning for driving performance in mild to moderate PD.

  2. Chemical ecology of marine plankton.

    Science.gov (United States)

    Schwartz, Emily R; Poulin, Remington X; Mojib, Nazia; Kubanek, Julia

    2016-07-28

    Covering: January 2013 to online publication December 2014This review summarizes recent research in the chemical ecology of marine pelagic ecosystems, and aims to provide a comprehensive overview of advances in the field in the time period covered. In order to highlight the role of chemical cues and toxins in plankton ecology this review has been organized by ecological interaction types starting with intraspecific interactions, then interspecific interactions (including facilitation and mutualism, host-parasite, allelopathy, and predator-prey), and finally community and ecosystem-wide interactions.

  3. The Effects of Cues on Neurons in the Basal Ganglia in Parkinson’s Disease

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    Sridevi V. Sarma

    2012-07-01

    Full Text Available Visual cues open a unique window to the understanding of Parkinson’s disease (PD. These cues can temporarily but dramatically improve PD motor symptoms. Although details are unclear, cues are believed to suppress pathological basal ganglia (BG activity through activation of corticostriatal pathways. In this study, we investigated human BG neurophysiology under different cued conditions. We evaluated bursting, 10-30Hz oscillations (OSCs, and directional tuning (DT dynamics in the subthalamic nucleus activity while 7 patients executed a two-step motor task. In the first step (predicted +cue, the patient moved to a target when prompted by a visual go cue that appeared 100% of the time. Here, the timing of the cue is predictable and the cue serves an external trigger to execute a motor plan. In the second step, the cue appeared randomly 50% of the time, and the patient had to move to the same target as in the first step. When it appeared (unpredicted +cue, the motor plan was to be triggered by the cue, but its timing was not predictable. When the cue failed to appear (unpredicted -cue, the motor plan was triggered by the absence of the visual cue. We found that during predicted +cue and unpredicted -cue trials, OSCs significantly decreased and DT significantly increased above baseline, though these modulations occurred an average of 640 milliseconds later in unpredicted -cue trials. Movement and reaction times were comparable in these trials. During unpredicted +cue trials, OSCs and DT failed to modulate though bursting significantly decreased after movement. Correspondingly, movement performance deteriorated. These findings suggest that during motor planning either a predictably timed external cue or an internally generated cue (generated by the absence of a cue trigger the execution of a motor plan in premotor cortex, whose increased activation then suppresses pathological activity in STN through direct pathways, leading to motor facilitation in

  4. Related assemblages of sulphate-reducing bacteria associated with ultradeep gold mines of South Africa and deep basalt aquifers of Washington State.

    Science.gov (United States)

    Baker, Brett J; Moser, Duane P; MacGregor, Barbara J; Fishbain, Susan; Wagner, Michael; Fry, Norman K; Jackson, Brad; Speolstra, Nico; Loos, Steffen; Takai, Ken; Lollar, Barbara Sherwood; Fredrickson, Jim; Balkwill, David; Onstott, Tullis C; Wimpee, Charles F; Stahl, David A

    2003-04-01

    We characterized the diversity of sulphate-reducing bacteria (SRB) associated with South African gold mine boreholes and deep aquifer systems in Washington State, USA. Sterile cartridges filled with crushed country rock were installed on two hydrologically isolated and chemically distinct sites at depths of 3.2 and 2.7 km below the land surface (kmbls) to allow development of biofilms. Enrichments of sulphate-reducing chemolithotrophic (H2) and organotrophic (lactate) bacteria were established from each site under both meso- and thermophilic conditions. Dissimilatory sulphite reductase (Dsr) and 16S ribosomal RNA (rRNA) genes amplified from DNA extracted from the cartridges were most closely related to the Gram-positive species Desulfotomaculum thermosapovorans and Desulfotomaculum geothermicum, or affiliated with a novel deeply branching clade. The dsr sequences recovered from the Washington State deep aquifer systems affiliated closely with the South African sequences, suggesting that Gram-positive sulphate-reducing bacteria are widely distributed in the deep subsurface.

  5. How each prosodic boundary cue matters: evidence from german infants.

    Science.gov (United States)

    Wellmann, Caroline; Holzgrefe, Julia; Truckenbrodt, Hubert; Wartenburger, Isabell; Höhle, Barbara

    2012-01-01

    Previous studies have revealed that infants aged 6-10 months are able to use the acoustic correlates of major prosodic boundaries, that is, pitch change, preboundary lengthening, and pause, for the segmentation of the continuous speech signal. Moreover, investigations with American-English- and Dutch-learning infants suggest that processing prosodic boundary markings involves a weighting of these cues. This weighting seems to develop with increasing exposure to the native language and to underlie crosslinguistic variation. In the following, we report the results of four experiments using the headturn preference procedure to explore the perception of prosodic boundary cues in German infants. We presented 8-month-old infants with a sequence of names in two different prosodic groupings, with or without boundary markers. Infants discriminated both sequences when the boundary was marked by all three cues (Experiment 1) and when it was marked by a pitch change and preboundary lengthening in combination (Experiment 2). The presence of a pitch change (Experiment 3) or preboundary lengthening (Experiment 4) as single cues did not lead to a successful discrimination. Our results indicate that pause is not a necessary cue for German infants. Pitch change and preboundary lengthening in combination, but not as single cues, are sufficient. Hence, by 8 months infants only rely on a convergence of boundary markers. Comparisons with adults' performance on the same stimulus materials suggest that the pattern observed with the 8-month-olds is already consistent with that of adults. We discuss our findings with respect to crosslinguistic variation and the development of a language-specific prosodic cue weighting.

  6. How each prosodic boundary cue matters: Evidence from German infants

    Directory of Open Access Journals (Sweden)

    Caroline eWellmann

    2012-12-01

    Full Text Available Previous studies have revealed that infants aged six to ten months are able to use the acoustic correlates of major prosodic boundaries, that is, pitch change, preboundary lengthening, and pause, for the segmentation of the continuous speech signal. Moreover, investigations with American-English- and Dutch-learning infants suggest that processing prosodic boundary markings involves a weighting of these cues. This weighting seems to develop with increasing exposure to the native language and to underlie crosslinguistic variation. In the following, we report the results of four experiments using the headturn preference procedure to explore the perception of prosodic boundary cues in German infants. We presented eight-month-old infants with a sequence of names in two different prosodic groupings, with or without boundary markers. Infants discriminated both sequences when the boundary was marked by all three cues (Experiment 1 and when it was marked by a pitch change and preboundary lengthening in combination (Experiment 2. The presence of a pitch change (Experiment 3 or preboundary lengthening (Experiment 4 as single cues did not lead to a successful discrimination. Our results indicate that pause is not a necessary cue for German infants. Pitch and preboundary lengthening in combination, but not as single cues, are sufficient. Hence, by eight months infants only rely on a convergence of boundary markers. Comparisons with adults’ performance on the same stimulus materials suggest that the pattern observed with the eight-month-olds is already consistent with that of adults. We discuss our findings with respect to crosslinguistic variation and the development of a language-specific prosodic cue weighting.

  7. European starlings unriddle the ambiguous-cue problem

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    Marco eVasconcelos

    2014-08-01

    Full Text Available The ambiguous-cue problem is deceptively simple. It involves two concurrently trained simultaneous discriminations (known as PA and NA trials, but only three stimuli. Stimulus A is common to both discriminations, but serves as non-reinforced stimulus (S- on PA trials and as reinforced stimulus (S+ on NA trials. Typically, animals’ accuracy is lower on PA trials—the ambiguous-cue effect. We conducted two experiments with European starlings (Sturnus vulgaris using Urcuioli and Michalek’s [2007, Psychon B Rev 14, 658-662] experimental manipulations as a springboard to test the predictions of two of the most important theoretical accounts of the effect: the interfering cue hypothesis and value transfer theory. Both experiments included two groups of birds, one trained with a regular ambiguous-cue problem (Group Continuous and another trained with partial reinforcement on PA trials (Group PA-Partial. The experiments differed only in the number of sessions (18 vs. 36 and daily trials (360 vs. 60. As previously observed, we found faster acquisition on NA trials than on PA trials in both experiments, but by the end of training PA performance was surprisingly high, such that no ambiguous-cue effect was present in Group Continuous of either experiment. The effect was still present in both PA-Partial groups, but to a smaller degree than expected. These findings are inconsistent with the literature, in particular with the results of Urcuioli and Michalek with pigeons, and question the aforementioned theoretical accounts as complete explanations of the ambiguous-cue effect. In our view, to achieve such high levels of accuracy on PA trials, starlings must have attended to configural (i.e., contextual cues, thus differentiating stimulus A when presented on PA trials from stimulus A when presented on NA trials. A post hoc simulation of a reinforcement-based configural model supported our assertion.

  8. Sink or swim: a test of tadpole behavioral responses to predator cues and potential alarm pheromones from skin secretions.

    Science.gov (United States)

    Maag, Nino; Gehrer, Lukas; Woodhams, Douglas C

    2012-11-01

    Chemical signaling is a vital mode of communication for most organisms, including larval amphibians. However, few studies have determined the identity or source of chemical compounds signaling amphibian defensive behaviors, in particular, whether alarm pheromones can be actively secreted from tadpoles signaling danger to conspecifics. Here we exposed tadpoles of the common toad Bufo bufo and common frog Rana temporaria to known cues signaling predation risk and to potential alarm pheromones. In both species, an immediate reduction in swimming activity extending over an hour was caused by chemical cues from the predator Aeshna cyanea (dragonfly larvae) that had been feeding on conspecific tadpoles. However, B. bufo tadpoles did not detectably alter their behavior upon exposure to potential alarm pheromones, neither to their own skin secretions, nor to the abundant predator-defense peptide bradykinin. Thus, chemicals signaling active predation had a stronger effect than general alarm secretions of other common toad tadpoles. This species may invest in a defensive strategy alternative to communication by alarm pheromones, given that Bufonidae are toxic to some predators and not known to produce defensive skin peptides. Comparative behavioral physiology of amphibian alarm responses may elucidate functional trade-offs in pheromone production and the evolution of chemical communication.

  9. Visual and Olfactory Floral Cues of Campanula (Campanulaceae and Their Significance for Host Recognition by an Oligolectic Bee Pollinator.

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    Paulo Milet-Pinheiro

    Full Text Available Oligolectic bees collect pollen from a few plants within a genus or family to rear their offspring, and are known to rely on visual and olfactory floral cues to recognize host plants. However, studies investigating whether oligolectic bees recognize distinct host plants by using shared floral cues are scarce. In the present study, we investigated in a comparative approach the visual and olfactory floral cues of six Campanula species, of which only Campanula lactiflora has never been reported as a pollen source of the oligolectic bee Ch. rapunculi. We hypothesized that the flowers of Campanula species visited by Ch. rapunculi share visual (i.e. color and/or olfactory cues (scents that give them a host-specific signature. To test this hypothesis, floral color and scent were studied by spectrophotometric and chemical analyses, respectively. Additionally, we performed bioassays within a flight cage to test the innate color preference of Ch. rapunculi. Our results show that Campanula flowers reflect the light predominantly in the UV-blue/blue bee-color space and that Ch. rapunculi displays a strong innate preference for these two colors. Furthermore, we recorded spiroacetals in the floral scent of all Campanula species, but Ca. lactiflora. Spiroacetals, rarely found as floral scent constituents but quite common among Campanula species, were recently shown to play a key function for host-flower recognition by Ch. rapunculi. We conclude that Campanula species share some visual and olfactory floral cues, and that neurological adaptations (i.e. vision and olfaction of Ch. rapunculi innately drive their foraging flights toward host flowers. The significance of our findings for the evolution of pollen diet breadth in bees is discussed.

  10. Synthetic predator cues impair immune function and make the biological pesticide Bti more lethal for vector mosquitoes.

    Science.gov (United States)

    Op De Beeck, Lin; Janssens, Lizanne; Stoks, Robby

    2016-03-01

    The control of vector mosquitoes is one of the biggest challenges facing humankind with the use of chemical pesticides often leading to environmental impact and the evolution of resistance. Although to a lesser extent, this also holds for Bacillus thuringiensis israelensis (Bti), the most widely used biological pesticide to control mosquito populations. This raises the need for the development of integrated pest management strategies that allow the reduction of Bti concentrations without loss of the mosquito control efficiency. To this end, we tested in a laboratory experiment the combined effects of larval exposure to a sublethal Bti concentration and predation risk cues on life history and physiology of larval and adult Culex pipiens mosquitoes. Besides natural predator kairomones and prey alarm cues, we also tested synthetic kairomones of Notonecta predators. Neither Bti nor predation risk cues affected mortality, yet when both stressors were combined mortality increased on average by 133% compared to the treatment with only predation risk cues. This synergistic interaction was also present when Bti was combined with synthetic kairomones. This was further reflected in changes of the composite index of population performance, which suggested lowered per capita growth rates in mosquitoes exposed to Bti but only when Bti was combined with synthetic kairomones. Furthermore, predation risk cues shortened larval development time, reduced mass at metamorphosis in males, and had an immunosuppressive effect in larval and adult mosquitoes which may affect the mosquito vector competence. We provide the first demonstration that synthetic kairomones may generate similar effects on prey as natural kairomones. The identified immunosuppressive effect of synthetic kairomones and the novel lethal synergism type between a biological pesticide and synthetic predator kairomones provide an important proof of principle illustrating the potential of this combination for integrated

  11. Modeling the Development of Audiovisual Cue Integration in Speech Perception

    Science.gov (United States)

    Getz, Laura M.; Nordeen, Elke R.; Vrabic, Sarah C.; Toscano, Joseph C.

    2017-01-01

    Adult speech perception is generally enhanced when information is provided from multiple modalities. In contrast, infants do not appear to benefit from combining auditory and visual speech information early in development. This is true despite the fact that both modalities are important to speech comprehension even at early stages of language acquisition. How then do listeners learn how to process auditory and visual information as part of a unified signal? In the auditory domain, statistical learning processes provide an excellent mechanism for acquiring phonological categories. Is this also true for the more complex problem of acquiring audiovisual correspondences, which require the learner to integrate information from multiple modalities? In this paper, we present simulations using Gaussian mixture models (GMMs) that learn cue weights and combine cues on the basis of their distributional statistics. First, we simulate the developmental process of acquiring phonological categories from auditory and visual cues, asking whether simple statistical learning approaches are sufficient for learning multi-modal representations. Second, we use this time course information to explain audiovisual speech perception in adult perceivers, including cases where auditory and visual input are mismatched. Overall, we find that domain-general statistical learning techniques allow us to model the developmental trajectory of audiovisual cue integration in speech, and in turn, allow us to better understand the mechanisms that give rise to unified percepts based on multiple cues. PMID:28335558

  12. Brain activation to cocaine cues and motivation/treatment status.

    Science.gov (United States)

    Prisciandaro, James J; McRae-Clark, Aimee L; Myrick, Hugh; Henderson, Scott; Brady, Kathleen T

    2014-03-01

    Motivation to change is believed to be a key factor in therapeutic success in substance use disorders; however, the neurobiological mechanisms through which motivation to change impacts decreased substance use remain unclear. Existing research is conflicting, with some investigations supporting decreased and others reporting increased frontal activation to drug cues in individuals seeking treatment for substance use disorders. The present study investigated the relationship between motivation to change cocaine use and cue-elicited brain activity in cocaine-dependent individuals using two conceptualizations of 'motivation to change': (1) current treatment status (i.e. currently receiving versus not receiving outpatient treatment for cocaine dependence) and (2) self-reported motivation to change substance use, using the Stages of Change Readiness and Treatment Eagerness Scale. Thirty-eight cocaine-dependent individuals (14 currently in treatment) completed a diagnostic assessment and an fMRI cocaine cue-reactivity task. Whole-brain analyses demonstrated that both treatment-seeking and motivated participants had lower activation to cocaine cues in a wide variety of brain regions in the frontal, occipital, temporal and cingulate cortices relative to non-treatment-seeking and less motivated participants. Future research is needed to explain the mechanism by which treatment and/or motivation impacts neural cue reactivity, as such work could potentially aid in the development of more effective therapeutic techniques for substance-dependent patients.

  13. Cues of fatigue: effects of sleep deprivation on facial appearance.

    Science.gov (United States)

    Sundelin, Tina; Lekander, Mats; Kecklund, Göran; Van Someren, Eus J W; Olsson, Andreas; Axelsson, John

    2013-09-01

    To investigate the facial cues by which one recognizes that someone is sleep deprived versus not sleep deprived. Experimental laboratory study. Karolinska Institutet, Stockholm, Sweden. Forty observers (20 women, mean age 25 ± 5 y) rated 20 facial photographs with respect to fatigue, 10 facial cues, and sadness. The stimulus material consisted of 10 individuals (five women) photographed at 14:30 after normal sleep and after 31 h of sleep deprivation following a night with 5 h of sleep. Ratings of fatigue, fatigue-related cues, and sadness in facial photographs. The faces of sleep deprived individuals were perceived as having more hanging eyelids, redder eyes, more swollen eyes, darker circles under the eyes, paler skin, more wrinkles/fine lines, and more droopy corners of the mouth (effects ranging from b = +3 ± 1 to b = +15 ± 1 mm on 100-mm visual analog scales, P sleep deprivation (P sleep deprivation, nor associated with judgements of fatigue. In addition, sleep-deprived individuals looked sadder than after normal sleep, and sadness was related to looking fatigued (P sleep deprivation affects features relating to the eyes, mouth, and skin, and that these features function as cues of sleep loss to other people. Because these facial regions are important in the communication between humans, facial cues of sleep deprivation and fatigue may carry social consequences for the sleep deprived individual in everyday life.

  14. Does acute tobacco smoking prevent cue-induced craving?

    Science.gov (United States)

    Schlagintweit, Hera E; Barrett, Sean P

    2016-05-01

    Smoking cessation aids appear to be limited in their ability to prevent craving triggered by exposure to smoking-associated stimuli; however, the extent to which cue-induced cravings persist following denicotinized or nicotine-containing tobacco smoking is not known. Thirty (17 male) ⩾12-hour abstinent dependent smokers completed two sessions during which they smoked a nicotine-containing or denicotinized cigarette. Instructions regarding the nicotine content of the cigarette varied across sessions, and all participants were exposed to a neutral cue followed by a smoking cue after cigarette consumption. Craving was assessed before and after cigarette consumption and cue exposure. Reduced intentions to smoke were associated with both nicotine expectancy (pcraving was uniquely associated with nicotine administration (pcraving regardless of nicotine expectancy or administration (p-valuesappear to contribute to craving reduction associated with acute tobacco smoking, neither smoking-related nicotine administration nor expectation prevents increases in craving following exposure to smoking-associated stimuli. These findings suggest that cue-induced craving may be resistant to various pharmacological and psychological interventions. © The Author(s) 2016.

  15. Overshadowing depends on cue and reinforcement sensitivity but not schizotypy.

    Science.gov (United States)

    Pickett, Clare; Cassaday, Helen J; Bibby, Peter A

    2017-03-15

    There is evidence for impaired selective learning mechanisms in individuals high in schizotypy. Overshadowing provides a direct test of selective learning based on cue salience and has previously been reported to be impaired in relation to schizotypy scores. The present study tested for overshadowing using food allergy and Lego construction task variants. Both variants used the same number of conditioned stimulus (CS) cues and the same number of learning trials. CS cues were trained in compound pairs or in isolation and overshadowing was subsequently tested on trials followed by negative versus positive outcomes. Participants also completed the O-LIFE to measure schizotypy and BIS-BAS scales to measure reinforcement sensitivity. Learning was demonstrated for both cue variants; however overshadowing emerged only in the Lego variant and only on the trials followed by the negative outcome. Contrary to expectations, there was no evidence for any relationship between overshadowing and O-LIFE scores. However, there was evidence of a positive relationship between overshadowing and BAS-Drive as well as a negative relationship with BIS-Anxiety, for the trials followed by the positive outcome in the food allergy variant. These results suggest that the development of overshadowing depends on cue and reinforcement sensitivity, but not necessarily on schizotypy.

  16. Alcohol cues impair learning inhibitory signals in beer drinkers

    Science.gov (United States)

    Laude, Jennifer R.; Fillmore, Mark T.

    2015-01-01

    Background Models of drug addiction emphasize the reciprocal influence of incentive-motivational properties of drug-related cues and poor impulse control resulting in drug use. Recent studies have shown that alcohol-related cues can impair response inhibition. What is unknown is whether these cues also disrupt learning of inhibitory associations. Methods Participants performed a Conditioned Inhibition (CI) task and were required to learn that a neutral image was a conditioned inhibitor when presented in the context of either an alcohol image intended to draw their attention away from the to-be-trained inhibitor, or a control condition in which the alcohol image was absent. After training, subjects in each condition rated the likelihood that the neutral image would signal the outcome. Eye tracking was used to verify that attention to the neutral image was in fact reduced when the alcohol image was present. Results Compared with controls those trained in the alcohol image condition reported a greater likelihood that the presence of the inhibitor would be followed by the outcome and thus were less able to acquire CI. Measures of eye-tracking verified that attention to the alcohol cue was associated with this maladaptive behavior. Conclusions When alcohol cues are present, there is a reduced ability to learn that such information is irrelevant to an outcome, and this impairs ones’ ability to inhibit perseveration of a response. This has implications for persistence of a drinking episode. PMID:25872597

  17. G-cueing microcontroller (a microprocessor application in simulators)

    Science.gov (United States)

    Horattas, C. G.

    1980-01-01

    A g cueing microcontroller is described which consists of a tandem pair of microprocessors, dedicated to the task of simulating pilot sensed cues caused by gravity effects. This task includes execution of a g cueing model which drives actuators that alter the configuration of the pilot's seat. The g cueing microcontroller receives acceleration commands from the aerodynamics model in the main computer and creates the stimuli that produce physical acceleration effects of the aircraft seat on the pilots anatomy. One of the two microprocessors is a fixed instruction processor that performs all control and interface functions. The other, a specially designed bipolar bit slice microprocessor, is a microprogrammable processor dedicated to all arithmetic operations. The two processors communicate with each other by a shared memory. The g cueing microcontroller contains its own dedicated I/O conversion modules for interface with the seat actuators and controls, and a DMA controller for interfacing with the simulation computer. Any application which can be microcoded within the available memory, the available real time and the available I/O channels, could be implemented in the same controller.

  18. Isolation and characterization of endophytic plant growth-promoting (PGPB) or stress homeostasis-regulating (PSHB) bacteria associated to the halophyte Prosopis strombulifera.

    Science.gov (United States)

    Sgroy, Verónica; Cassán, Fabricio; Masciarelli, Oscar; Del Papa, María Florencia; Lagares, Antonio; Luna, Virginia

    2009-11-01

    This study was designed to isolate and characterize endophytic bacteria from halophyte Prosopis strombulifera grown under extreme salinity and to evaluate in vitro the bacterial mechanisms related to plant growth promotion or stress homeostasis regulation. Isolates obtained from P. strombulifera were compared genotypically by BOX-polymerase chain reaction, grouped according to similarity, and identified by amplification and partial sequences of 16S DNAr. Isolates were grown until exponential growth phase to evaluate the atmospheric nitrogen fixation, phosphate solubilization, siderophores, and phytohormones, such as indole-3-acetic acid, zeatin, gibberellic acid and abscisic acid production, as well as antifungal, protease, and 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity. A total of 29 endophytic strains were grouped into seven according to similarity. All bacteria were able to grow and to produce some phytohormone in chemically defined medium with or without addition of a nitrogen source. Only one was able to produce siderophores, and none of them solubilized phosphate. ACC deaminase activity was positive for six strains. Antifungal and protease activity were confirmed for two of them. In this work, we discuss the possible implications of these bacterial mechanisms on the plant growth promotion or homeostasis regulation in natural conditions.

  19. Comparing the relative importance of water-borne cues and direct grazing for the induction of defenses in the brown seaweed Fucus vesiculosus.

    Science.gov (United States)

    Flöthe, Carla R; John, Uwe; Molis, Markus

    2014-01-01

    Some seaweed species have been shown to release water-borne cues after herbivore attack, for example, to attract natural enemies of the herbivore. These cues may also be sensed by neighboring seaweeds and used to adjust their defenses in anticipation of a possible herbivore attack. Several studies indicated information transfer between seaweed individuals in the past, including the brown seaweed Fucus vesiculosus. Previous work showed induction of defenses in F. vesiculosus in response to water-borne cues released by isopod-grazed conspecifics. In contrast, another study on induced responses after exposure to cues from isopod-grazed neighbors using the same seaweed species yielded contradictory results. This study reassessed the ability of F. vesiculosus individuals to sense water-borne cues released by isopod-grazed neighbors in a series of experiments that monitored F. vesiculosus palatability in response to direct grazing by Idotea baltica and water-borne cues from isopod-grazed neighbors relative to unmanipulated seaweed pieces. Two-choice feeding assays were conducted with both fresh and reconstituted seaweed pieces. Direct grazing by I. baltica induced a chemical defense in F. vesiculosus, confirming results of previous studies. In contrast, evidence for increased herbivore resistance in seaweed pieces that were located downstream of isopod-grazed F. vesiculosus could not be provided. The lack of defense induction in response to grazing of conspecific neighbors may be explained by the environmental conditions and the scattered distribution of F. vesiculosus individuals in the intertidal zone of Helgoland, which may render resource investment in the emission and/or response to water-borne cues at this site unprofitable.

  20. Comparing the relative importance of water-borne cues and direct grazing for the induction of defenses in the brown seaweed Fucus vesiculosus.

    Directory of Open Access Journals (Sweden)

    Carla R Flöthe

    Full Text Available Some seaweed species have been shown to release water-borne cues after herbivore attack, for example, to attract natural enemies of the herbivore. These cues may also be sensed by neighboring seaweeds and used to adjust their defenses in anticipation of a possible herbivore attack. Several studies indicated information transfer between seaweed individuals in the past, including the brown seaweed Fucus vesiculosus. Previous work showed induction of defenses in F. vesiculosus in response to water-borne cues released by isopod-grazed conspecifics. In contrast, another study on induced responses after exposure to cues from isopod-grazed neighbors using the same seaweed species yielded contradictory results. This study reassessed the ability of F. vesiculosus individuals to sense water-borne cues released by isopod-grazed neighbors in a series of experiments that monitored F. vesiculosus palatability in response to direct grazing by Idotea baltica and water-borne cues from isopod-grazed neighbors relative to unmanipulated seaweed pieces. Two-choice feeding assays were conducted with both fresh and reconstituted seaweed pieces. Direct grazing by I. baltica induced a chemical defense in F. vesiculosus, confirming results of previous studies. In contrast, evidence for increased herbivore resistance in seaweed pieces that were located downstream of isopod-grazed F. vesiculosus could not be provided. The lack of defense induction in response to grazing of conspecific neighbors may be explained by the environmental conditions and the scattered distribution of F. vesiculosus individuals in the intertidal zone of Helgoland, which may render resource investment in the emission and/or response to water-borne cues at this site unprofitable.

  1. Smoker reactivity to cues: effects on craving and on smoking behavior.

    Science.gov (United States)

    Shiffman, Saul; Dunbar, Michael; Kirchner, Thomas; Li, Xiaoxue; Tindle, Hilary; Anderson, Stewart; Scholl, Sarah

    2013-02-01

    We assessed craving and smoking in response to smoking-relevant cues. Two hundred seven daily smokers viewed images related to 1 of 6 cue sets (cigarettes, positive and negative affect, alcohol, smoking prohibitions, and neutral cues) in separate sessions. Compared with neutral cues, cigarette cues significantly increased craving, and positive affect cues significantly decreased craving. When subjects were then allowed to smoke during continuing cue exposure, cues did not affect the likelihood of smoking or the amount smoked (number of cigarettes, number of puffs, puff time, or increased carbon monoxide). However, craving intensity predicted likelihood of smoking, latency to smoke, and amount smoked, with craving increases after cue exposure making significant independent contributions. Some craving effects were curvilinear, suggesting that they are subject to thresholds and might not be observed under some circumstances.

  2. Smoker Reactivity to Cues: Effects on Craving and on Smoking behavior

    Science.gov (United States)

    Shiffman, Saul; Dunbar, Michael; Kirchner, Thomas; Li, Xiaoxue; Tindle, Hilary; Anderson, Stewart; Scholl, Sarah

    2013-01-01

    We assessed craving and smoking in response to smoking-relevant cues. 207 daily smokers viewed images related to one of six cue sets (cigarettes, positive and negative affect, alcohol, smoking prohibitions, and neutral cues) in separate sessions. Compared to neutral cues, cigarette cues significantly increased craving, and positive affect cues significantly decreased craving. When subjects were then allowed to smoke during continuing cue exposure, cues did not affect the likelihood of smoking or the amount smoked (number of cigarettes, number of puffs, puff time, or increased carbon monoxide). However, craving intensity predicted likelihood of smoking, latency to smoke, and amount smoked, with craving increases after cue exposure making significant independent contributions. Some craving effects were curvilinear, suggesting that they are subject to thresholds and might not be observed under some circumstances. PMID:22708884

  3. Sequential modulation of cue use in the task switching paradigm

    Directory of Open Access Journals (Sweden)

    Mike eWendt

    2012-08-01

    Full Text Available In task switching studies, pre-cuing of the upcoming task improves performance, indicating preparatory activation of the upcoming task set and/or inhibition of the previous task set. To further investigate cue-based task preparation, the authors presented both valid and invalid task cues in a task switching experiment involving three tasks. Consistent with previous findings, a validity effect in terms of higher reaction times on invalidly compared to validly cued tasks was obtained. However, this validity effect was reduced following invalidly cued trials, suggesting dynamic adjustment in terms of decreased cue-based preparation after being misled. Performance was particularly impaired when the current task was the one that was invalidly cued on the preceding trial. This finding may reflect either particular reluctance to prepare or persisting inhibition of the erroneously prepared task set from the pre-trial.

  4. Sequential Modulation of Cue Use in the Task Switching Paradigm

    Science.gov (United States)

    Wendt, Mike; Luna-Rodriguez, Aquiles; Reisenauer, Renate; Jacobsen, Thomas; Dreisbach, Gesine

    2012-01-01

    In task switching studies, pre-cuing of the upcoming task improves performance, indicating preparatory activation of the upcoming task-set, and/or inhibition of the previous task-set. To further investigate cue-based task preparation, the authors presented both valid and invalid task cues in a task switching experiment involving three tasks. Consistent with previous findings, a validity effect in terms of higher reaction times on invalidly compared to validly cued tasks was obtained. However, this validity effect was reduced following invalidly cued trials, suggesting dynamic adjustment in terms of decreased cue-based preparation after being misled. Performance was particularly impaired when the current task was the one that was invalidly cued on the preceding trial. This finding may reflect either particular reluctance to prepare or persisting inhibition of the erroneously prepared task-set from the pre-trial. PMID:22908004

  5. Value transfer contributes to ambiguous-cue discrimination learning.

    Science.gov (United States)

    Urcuioli, Peter J; Michalek, Sarah

    2007-08-01

    Pigeons learned two concurrent simultaneous discriminations in which the S- for one served as the S+ for the other. When all correct choices were reinforced, accuracy on the former (positive vs. ambiguous-cue or PA) discrimination was lower than on the latter (negative vs. ambiguous-cue or NA) discrimination. When correct choices on the PA discrimination were intermittently reinforced, however, pigeons chose the S- more often than the S+ on those trials. By contrast, intermittently reinforcing correct choices on the NA discrimination did not affect NA-trial accuracy but yielded higher PA-trial accuracy relative to continuous reinforcement. Together with a separate preference assessment, these results indicate that value transfer, in which some of the positive value accrued by an S+ transfers to its companion S-, contributes to ambiguous-cue performances.

  6. Cue integration and the perception of action in intentional binding

    DEFF Research Database (Denmark)

    Wolpe, Noham; Haggard, Patrick; Siebner, Hartwig R

    2013-01-01

    'Intentional binding' describes the perceived temporal attraction between a voluntary action and its sensory consequence. Binding has been used in health and disease as an indirect measure of awareness of action or agency, that is, the sense that one controls one's own actions. It has been proposed...... that binding results from cue integration, in which a voluntary action provides information about the timing of its consequences or vice versa. The perception of the timing of either event is then a weighted average, determined according to the reliability of each of these two cues. Here we tested...... the contribution of cue integration to the perception of action and its sensory effect in binding, that is, action and tone binding, by manipulating the sensory reliability of the outcome tone. As predicted, when tone reliability was reduced, action binding was diminished and tone binding was increased. However...

  7. Children use nonverbal cues to make inferences about social power.

    Science.gov (United States)

    Brey, Elizabeth; Shutts, Kristin

    2015-01-01

    Four studies (N = 192) tested whether young children use nonverbal information to make inferences about differences in social power. Five- and six-year-old children were able to determine which of two adults was "in charge" in dynamic videotaped conversations (Study 1) and in static photographs (Study 4) using only nonverbal cues. Younger children (3-4 years) were not successful in Study 1 or Study 4. Removing irrelevant linguistic information from conversations did not improve the performance of 3- to 4-year-old children (Study 3), but including relevant linguistic cues did (Study 2). Thus, at least by 5 years of age, children show sensitivity to some of the same nonverbal cues adults use to determine other people's social roles.

  8. A strategic account of the cue-depreciation effect.

    Science.gov (United States)

    Thapar, A; Greene, R L

    1995-12-01

    A word fragment is less likely to be completed if it is presented incrementally (R______P, R____R _ P, R_I__R_P, R_I__R O P) than if it is presented all at once (e.g., R_I__R O P). This phenomenon is known as the cue-depreciation effect. The present study examined the role of strategies in this phenomenon. The magnitude of the cue-depreciation effect was increased when subjects were asked to adopt a passive generation approach to word fragment completion. The current study investigated an extension of Bruner and Potter's (1964) early hypothesis-generation account of the cue-depreciation effect. Findings demonstrated the influence of completion strategies for a general theory of fragment completion.

  9. Smoking, food, and alcohol cues on subsequent behavior: a qualitative systematic review.

    Science.gov (United States)

    Veilleux, Jennifer C; Skinner, Kayla D

    2015-03-01

    Although craving is a frequent phenomenon in addictive behaviors, and laboratory paradigms have robustly established that presentation of cues can elicit self-reported craving responses, extant work has not established whether cue exposure influences subsequent behavior. We systematically review extant literature assessing the effects of cue exposure to smoking, food, and alcohol cues on behavioral outcomes framed by three questions: (1) Is there value in distinguishing between the effects of cue exposure on behavior from the responses to cues (e.g., self-reported craving) predicting behavior?; (2) What are the effect of cues on behavior beyond lapse, such as broadly considering both target-syntonic (e.g., do cigarette cues predict smoking-related behaviors) and target-dystonic behaviors (e.g., do cigarette cues predict other outcomes besides smoking)?; (3) What are the lessons to be learned from examining cue exposure studies across smoking, food and alcohol domains? Evidence generally indicates an effect of cue exposure on both target-syntonic and target-dystonic behavior, and that self-report cue-reactivity predicts immediate target-syntonic outcomes. Effects of smoking, food and alcohol cues on behavior are compared to elucidate generalizations about the effects of cue exposure as well as methodological differences that may serve the study of craving in the future. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Motor Training: Comparison of Visual and Auditory Coded Proprioceptive Cues

    Directory of Open Access Journals (Sweden)

    Philip Jepson

    2012-05-01

    Full Text Available Self-perception of body posture and movement is achieved through multi-sensory integration, particularly the utilisation of vision, and proprioceptive information derived from muscles and joints. Disruption to these processes can occur following a neurological accident, such as stroke, leading to sensory and physical impairment. Rehabilitation can be helped through use of augmented visual and auditory biofeedback to stimulate neuro-plasticity, but the effective design and application of feedback, particularly in the auditory domain, is non-trivial. Simple auditory feedback was tested by comparing the stepping accuracy of normal subjects when given a visual spatial target (step length and an auditory temporal target (step duration. A baseline measurement of step length and duration was taken using optical motion capture. Subjects (n=20 took 20 ‘training’ steps (baseline ±25% using either an auditory target (950 Hz tone, bell-shaped gain envelope or visual target (spot marked on the floor and were then asked to replicate the target step (length or duration corresponding to training with all feedback removed. Visual cues (mean percentage error=11.5%; SD ± 7.0%; auditory cues (mean percentage error = 12.9%; SD ± 11.8%. Visual cues elicit a high degree of accuracy both in training and follow-up un-cued tasks; despite the novelty of the auditory cues present for subjects, the mean accuracy of subjects approached that for visual cues, and initial results suggest a limited amount of practice using auditory cues can improve performance.

  11. Diversity and Bioactivity of Marine Bacteria Associated with the Sponges Candidaspongia flabellata and Rhopaloeides odorabile from the Great Barrier Reef in Australia

    Directory of Open Access Journals (Sweden)

    Candice M. Brinkmann

    2017-09-01

    Full Text Available Sponges and their associated microbial communities have sparked much interest in recent decades due on the abundant production of chemically diverse metabolites that in nature serve as functional compounds required by the marine sponge host. These compounds were found to carry therapeutic importance for medicinal applications. In the presented study, 123 bacterial isolates from the culture collection of the Australian Institute of Marine Science (AIMS previously isolated from two different sponge species, namely Candidaspongia flabellata and Rhopaloeides odorabile, originating from different locations on the Great Barrier Reef in Queensland, Australia, were thus studied for their bioactivity. The symbiotic bacterial isolates were first identified using 16S rRNA gene analysis and they were found to belong to five different dominating classes of Domain Bacteria, namely Alphaproteobacteria, Gammaproteobacteria, Flavobacteria, Bacilli and Actinobacteria. Following their taxonomical categorization, the isolates were screened for their antimicrobial activity against human pathogenic microbial reference strains: Escherichia coli (ATCC® BAA-196™, E. coli (ATCC® 13706™, E. coli (ATCC® 25922™, Klebsiella pneumoniae (ATCC® BAA-1705™, Enterococcus faecalis (ATCC® 51575™, Bacillus subtilis (ATCC® 19659™, Staphylococcus aureus (ATCC® 29247™, Candida albicans (ATCC® 10231™ and Aspergillus niger (ATCC® 16888™. Over 50% of the isolates displayed antimicrobial activity against one or more of the reference strains tested. The subset of these bioactive bacterial isolates was further investigated to identify their biosynthetic genes such as polyketide synthase (PKS type I and non-ribosomal peptide synthetase (NRPS genes. This was done using polymerase chain reaction (PCR with degenerate primers that have been previously used to amplify PKS-I and NRPS genes. These specific genes have been reported to be possibly involved in bacterial

  12. Design and Implementation of a Cueing Wideband Digital EW Receiver

    Institute of Scientific and Technical Information of China (English)

    ZHU Jun; TANG Bin; WU Wei; JIANG Zong-ming; ZHANG Chang-ju; YIN Mao-wei; DEN Ming-yi; DU Dong-ping

    2006-01-01

    A cueing wideband digital Electronic Warfare (EW) receiver is presented. The proposed receiver, which is to measure the instantaneous frequency and bandwidth of the intercept short-duration pulse radar signals that cue and match the corresponding ones, meets the requirements of good sensitivity and dynamic range for EW and can save hardware resources greatly as well. In addition, real-time signal processing, which is the main bottleneck for covering a wide instantaneous frequency band for EW receiver, is better solved in the proposed design structure. The highly efficient implementation and good parameter estimation algorithms are proposed as well. Theoretical analysis and experimental results show that this structure is feasible.

  13. Two Predictions of a Compound Cue Model of Priming

    OpenAIRE

    Walenski, Matthew

    2003-01-01

    This paper examines two predictions of the compound cue model of priming (Ratcliff and McKoon, 1988). While this model has been used to provide an account of a wide range of priming effects, it may not actually predict priming in these or other circumstances. In order to predict priming effects, the compound cue model relies on an assumption that all items have the same number of associates. This assumption may be true in only a restricted number of cases. This paper demonstrates that when th...

  14. Cues That Language Users Exploit to Segment Speech

    Institute of Scientific and Technical Information of China (English)

    陈冰茹

    2015-01-01

    <正>The capability to segment words from fluent speech is an important step for learning and acquiring a language(Jusczyk,1999).Therefore,a number of researches and studies have focused on various cues that language learners exploit to locate word boundaries.During the half century,it has been discussed that there are mainly four crucial cues can be used by listeners to segment words in speech.Particularly,they are:(1)Prosody(Echols et al.1997;Jusczyk et al.1996):(2)Statistical and distributional regularities(Brent et al.1996;Saffran et al.1996);(3)Phonotactics(Brent et al.1996;Myers et al.1996);

  15. CONSUMER EVALUATIONS OF BEAUTIFICATION PRODUCTS: EFFECTS OF EXTRINSIC CUES

    Directory of Open Access Journals (Sweden)

    Md. Humayun Kabir Chowdhury

    2006-01-01

    Full Text Available This study investigates the influence of extrinsic cues, i.e. brand image, perceived price, perceived quality, and perceived country of origin on consumers' evaluative judgments for beautification products. Multi-item measures were used for data collection. Resultsrevealed that three extrinsic cues: brand image, perceived quality, and perceived country of origin have positive and significant influence on consumers' brand evaluation of beautification brands. Only perceived price has shown no such influence on consumers' brand evaluation. Finally, unanswered questions and future researchdirections are presented.

  16. Cue-Reactive Altered State of Consciousness Mediates the Relationship Between Problem-Gambling Severity and Cue-Reactive Urge in Poker-Machine Gamblers.

    Science.gov (United States)

    Tricker, Christopher; Rock, Adam J; Clark, Gavin I

    2016-06-01

    In order to enhance our understanding of the nature of poker-machine problem-gambling, a community sample of 37 poker-machine gamblers (M age = 32 years, M PGSI = 5; PGSI = Problem Gambling Severity Index) were assessed for urge to gamble (responses on a visual analogue scale) and altered state of consciousness (assessed by the Altered State of Awareness dimension of the Phenomenology of Consciousness Inventory) at baseline, after a neutral cue, and after a gambling cue. It was found that (a) problem-gambling severity (PGSI score) predicted increase in urge (from neutral cue to gambling cue, controlling for baseline; sr (2) = .19, p = .006) and increase in altered state of consciousness (from neutral cue to gambling cue, controlling for baseline; sr (2) = .57, p gambling cue) mediated the relationship between problem-gambling severity and increase in urge (from neutral cue to gambling cue; κ(2) = .40, 99 % CI [.08, .71]). These findings suggest that cue-reactive altered state of consciousness is an important component of cue-reactive urge in poker-machine problem-gamblers.

  17. The Power Cues%权力线索

    Institute of Scientific and Technical Information of China (English)

    魏秋江

    2012-01-01

    权力线索指人们判断权力所依赖的各种信息,其能预测人们的思维和行为。除以视觉刺激和听觉刺激的形式直接影响人们的权力感知外,权力线索也可利用人们对其在空间和数字上的心理表征,间接影响人们的权力判断。各种权力线索的具体效应仍存争议。学者已开始关注现有线索去伪存真、分类和标准化等问题,还从生理视角对其加以验证,并探求新的权力线索。%Power cues are the internal and external stimuli that people utilize to judge the power of others and themselves. Recognizing people's power is the basic interaction in social and organizational life, which reduces the likelihood of conflicts within and between the groups and effectively assigns resources. Recognizing power also important to self - reinforcing and self - definition. Power cues are not only the statement of targets' power, but also can be used to predict people's minds and behaviors. Generally speaking, there are two kinds of encoding, visual and auditory, for the input information. The visual encoding includes appearance, such as the formation of face, behaviors, especially non - verbal behaviors, which always come out without consciousness but indicate peoples' power more exactly. The auditory encoding includes several parameters of sound, such as formant dispersion (Dr) , fundamental frequency ( F0 ) , variation in F0 , intensity, and utterance duration. Some kinds of messages are different, such as semantic content, via both ways, which connect with power based on higher level of cognition. In these three viewpoints, more cues are needed to be explored. Surprisingly, there is another odd factor, i.e. , gender. Research related to it reveals a diversity of results. So gender is more of a moderator than a definite power cue, which calls for more attention to the interaction effect. Besides, the mental representation of power, which involves mental simulation of space

  18. Social learning of predators in the dark: understanding the role of visual, chemical and mechanical information.

    Science.gov (United States)

    Manassa, R P; McCormick, M I; Chivers, D P; Ferrari, M C O

    2013-08-22

    The ability of prey to observe and learn to recognize potential predators from the behaviour of nearby individuals can dramatically increase survival and, not surprisingly, is widespread across animal taxa. A range of sensory modalities are available for this learning, with visual and chemical cues being well-established modes of transmission in aquatic systems. The use of other sensory cues in mediating social learning in fishes, including mechano-sensory cues, remains unexplored. Here, we examine the role of different sensory cues in social learning of predator recognition, using juvenile damselfish (Amphiprion percula). Specifically, we show that a predator-naive observer can socially learn to recognize a novel predator when paired with a predator-experienced conspecific in total darkness. Furthermore, this study demonstrates that when threatened, individuals release chemical cues (known as disturbance cues) into the water. These cues induce an anti-predator response in nearby individuals; however, they do not facilitate learnt recognition of the predator. As such, another sensory modality, probably mechano-sensory in origin, is responsible for information transfer in the dark. This study highlights the diversity of sensory cues used by coral reef fishes in a social learning context.

  19. Patterns in Clam Excurrent Siphon Velocity According to External Environmental Cues

    Science.gov (United States)

    Webster, D. R.; Delavan, S. K.

    2010-11-01

    This study attempts to determine the patterns and/or randomness of the excurrent velocity of actively feeding clams, Mercenaria mercenaria. We hypothesize that clams alter their feeding current velocity patterns or randomness according to external cues in the environment such as hydrodynamic characteristics, density of the clam patch, and presence of predators in the upstream flow. A PIV system measured vector fields for two-dimensional planes that bisect the clam excurrent siphons, and time records were extracted at the siphon exit position. Fractal and lacunarity analysis of the jet velocity time records revealed that clams alter their jet excurrent velocity unsteadiness according to the horizontal crossflow velocity. The results also reveal that the effect of clam patch density on the feeding activity was dependent on the size of the organism. This size/density dependent relationship suggests that predation by blue crabs dominates the system since larger clams are no longer susceptible to blue crab predation, whereas clams of all sizes are susceptible to whelk predation. Finally, clams increase the randomness of their excurrent jet velocity values when predator cues are located in the upstream flume flow. This suggests that the presence of predators elicits clam behavior that promotes the mixing and dilution of their chemical metabolites.

  20. Attraction of female grapevine moth to common and specific olfactory cues from 2 host plants.

    Science.gov (United States)

    Tasin, Marco; Bäckman, Anna-Carin; Anfora, Gianfranco; Carlin, Silvia; Ioriatti, Claudio; Witzgall, Peter

    2010-01-01

    In herbivorous insects with more than 1 host plant, attraction to host odor could conceptually be mediated by common compounds, by specific compounds released by each plant or by combinations of common and specific compounds. We have compared the attraction of female grapevine moth, Lobesia botrana, with specific and common (shared) odors from 2 different plants: a wild host (Daphne gnidium) and a recently colonized host (Vitis vinifera). Odor blends eliciting female attraction to V. vinifera have previously been identified. In this study, olfactory cues from D. gnidium were identified by electroantennographic detection and chemical analysis. The attraction of mated females to synthetic odor blends was then tested in a wind tunnel bioassay. Female attraction was elicited by a blend of compounds released by both from D. gnidium and V. vinifera and by 2 blends with the compounds released specifically from each host. However, more complete odor blends of the 2 plants elicited stronger attraction. The common compounds in combination with the specific compounds of D. gnidium were the most attractive blend. This blend was tested with the common compounds presented both in the ratio emitted by D. gnidium and by V. vinifera, but there was no difference in female attraction. Our findings suggest that specific as well as common plant odor cues play a role in L. botrana host recognition and that there is plasticity in attraction to partial blends. The results are discussed in relation to mechanisms behind host odor recognition and the evolution of insect-plant associations.

  1. Chemical Emergencies

    Science.gov (United States)

    When a hazardous chemical has been released, it may harm people's health. Chemical releases can be unintentional, as in the case of an ... the case of a terrorist attack with a chemical weapon. Some hazardous chemicals have been developed by ...

  2. Visual Cues of Object Properties Differentially Affect Anticipatory Planning of Digit Forces and Placement.

    Science.gov (United States)

    Lee-Miller, Trevor; Marneweck, Michelle; Santello, Marco; Gordon, Andrew M

    2016-01-01

    Studies on anticipatory planning of object manipulation showed initial task failure (i.e., object roll) when visual object shape cues are incongruent with other visual cues, such as weight distribution/density (e.g., symmetrically shaped object with an asymmetrical density). This suggests that shape cues override density cues. However, these studies typically only measured forces, with digit placement constrained. Recent evidence suggests that when digit placement is unconstrained, subjects modulate digit forces and placement. Thus, unconstrained digit placement might be modulated on initial trials (since it is an explicit process), but not forces (since it is an implicit process). We tested whether shape and density cues would differentially influence anticipatory planning of digit placement and forces during initial trials of a two-digit object manipulation task. Furthermore, we tested whether shape cues would override density cues when cues are incongruent. Subjects grasped and lifted an object with the aim of preventing roll. In Experiment 1, the object was symmetrically shaped, but with asymmetrical density (incongruent cues). In Experiment 2, the object was asymmetrical in shape and density (congruent cues). In Experiment 3, the object was asymmetrically shaped, but with symmetrical density (incongruent cues). Results showed differential modulation of digit placement and forces (modulation of load force but not placement), but only when shape and density cues were congruent. When shape and density cues were incongruent, we found collinear digit placement and symmetrical force sharing. This suggests that congruent and incongruent shape and density cues differentially influence anticipatory planning of digit forces and placement. Furthermore, shape cues do not always override density cues. A continuum of visual cues, such as those alluding to shape and density, need to be integrated.

  3. Food and drug cues activate similar brain regions: a meta-analysis of functional MRI studies.

    Science.gov (United States)

    Tang, D W; Fellows, L K; Small, D M; Dagher, A

    2012-06-06

    In healthy individuals, food cues can trigger hunger and feeding behavior. Likewise, smoking cues can trigger craving and relapse in smokers. Brain imaging studies report that structures involved in appetitive behaviors and reward, notably the insula, striatum, amygdala and orbital frontal cortex, tend to be activated by both visual food and smoking cues. Here, by carrying out a meta-analysis of human neuro-imaging studies, we investigate the neural network activated by: 1) food versus neutral cues (14 studies, 142 foci) 2) smoking versus neutral cues (15 studies, 176 foci) 3) smoking versus neutral cues when correlated with craving scores (7 studies, 108 foci). PubMed was used to identify cue-reactivity imaging studies that compared brain response to visual food or smoking cues to neutral cues. Fourteen articles were identified for the food meta-analysis and fifteen articles were identified for the smoking meta-analysis. Six articles were identified for the smoking cue correlated with craving analysis. Meta-analyses were carried out using activation likelihood estimation. Food cues were associated with increased blood oxygen level dependent (BOLD) response in the left amygdala, bilateral insula, bilateral orbital frontal cortex, and striatum. Smoking cues were associated with increased BOLD signal in the same areas, with the exception of the insula. However, the smoking meta-analysis of brain maps correlating cue-reactivity with subjective craving did identify the insula, suggesting that insula activation is only found when craving levels are high. The brain areas identified here are involved in learning, memory and motivation, and their cue-induced activity is an index of the incentive salience of the cues. Using meta-analytic techniques to combine a series of studies, we found that food and smoking cues activate comparable brain networks. There is significant overlap in brain regions responding to conditioned cues associated with natural and drug rewards.

  4. Evidence for greater cue reactivity among low-dependent vs. high-dependent smokers.

    Science.gov (United States)

    Watson, Noreen L; Carpenter, Matthew J; Saladin, Michael E; Gray, Kevin M; Upadhyaya, Himanshu P

    2010-07-01

    Cue reactivity paradigms are well-established laboratory procedures used to examine subjective craving in response to substance-related cues. For smokers, the relationship between nicotine dependence and cue reactivity has not been clearly established. The main aim of the present study was to further examine this relationship. Participants (N=90) were between the ages 18-40 and smoked > or =10 cigarettes per day. Average nicotine dependence (Fagerström Test for Nicotine Dependence; FTND) at baseline was 4.9 (SD=2.1). Participants completed four cue reactivity sessions consisting of two in vivo cues (smoking and neutral) and two affective imagery cues (stressful and relaxed), all counterbalanced. Craving in response to cues was assessed following each cue exposure using the Questionnaire of Smoking Urges-Brief (QSU-B). Differential cue reactivity was operationally defined as the difference in QSU scores between the smoking and neutral cues, and between the stressful and relaxed cues. Nicotine dependence was significantly and negatively associated with differential cue reactivity scores in regard to hedonic craving (QSU factor 1) for both in vivo and imagery cues, such that those who had low FTND scores demonstrated greater differential cue reactivity than those with higher FTND scores (beta=-.082; p=.037; beta=-.101; p=.023, respectively). Similar trends were found for the Total QSU and for negative reinforcement craving (QSU factor 2), but did not reach statistical significance. Under partially sated conditions, less dependent smokers may be more differentially cue reactive to smoking cues as compared to heavily dependent smokers. These findings offer methodological and interpretative implications for cue reactivity studies. 2010 Elsevier Ltd. All rights reserved.

  5. Evidence for greater cue reactivity among low dependent vs. high dependent smokers

    Science.gov (United States)

    Watson, Noreen L.; Carpenter, Matthew J.; Saladin, Michael E.; Gray, Kevin M.; Upadhyaya, Himanshu P.

    2010-01-01

    Introduction Cue reactivity paradigms are well-established laboratory procedures used to examine subjective craving in response to substance-related cues. For smokers, the relationship between nicotine dependence and cue reactivity has not been clearly established. The main aim of the present study was to further examine this relationship. Methods Participants (N=90) were between the ages 18–40 and smoked ≥10 cigarettes per day. Average nicotine dependence (Fagerström Test for Nicotine Dependence; FTND) at baseline was 4.9 (SD=2.1). Participants completed four cue reactivity sessions consisting of two in vivo cues (smoking, neutral) and two affective imagery cues (stressful, relaxed), all counterbalanced. Craving in response to cues was assessed following each cue exposure using the Questionnaire of Smoking Urges—Brief (QSU-B). Differential cue reactivity was operationally defined as the difference in QSU scores between the smoking and neutral cues, and between the stressful and relaxed cues. Results Nicotine dependence was significantly and negatively associated with differential cue reactivity scores in regards to hedonic craving (QSU factor 1) for both in vivo and imagery cues, such that those who had low FTND scores demonstrated greater differential cue reactivity than those with higher FTND scores (β = −.082; p = .037; β = −.101; p = .023, respectively). Similar trends were found for the total QSU and for negative reinforcement craving (QSU factor 2), but did not reach statistical significance. Discussion Under partially sated conditions, less dependent smokers may be more differentially cue reactive to smoking cues as compared to heavily dependent smokers. These findings offer methodological and interpretative implications for cue reactivity studies. PMID:20206451

  6. Cuticular Hydrocarbons as Potential Close Range Recognition Cues in Orchid Bees.

    Science.gov (United States)

    Pokorny, Tamara; Ramírez, Santiago R; Weber, Marjorie Gail; Eltz, Thomas

    2015-12-01

    Male Neotropical orchid bees collect volatile chemicals from their environment and compose species-specific volatile signals, which are subsequently exposed during courtship display. These perfumes are hypothesized to serve as attractants and may play a role in female mate choice. Here, we investigated the potential of cuticular hydrocarbons as additional recognition cues. The cuticular hydrocarbons of males of 35 species belonging to four of the five extant euglossine bee genera consisted of aliphatic hydrocarbons ranging in chain lengths between 21 and 37 C-atoms in distinct compositions, especially between sympatric species of similar coloring and size, for all but one case. Cleptoparasitic Exaerete spp. had divergent profiles, with major compounds predominantly constituted by longer hydrocarbon chains (>30 C-atoms), which may represent an adaptation to the parasitic life history ("chemical insignificance"). Phylogenetic comparative analyses imply that the chemical profiles exhibited by Exaerete spp. are evolutionarily divergent from the rest of the group. Female hydrocarbon profiles were not identical to male profiles in the investigated species, with either partial or complete separation between sexes in multivariate analyses. Sexually dimorphic hydrocarbon profiles are assumed to be the basis for sex recognition in a number of insects, and thus may supplement the acquired perfume phenotypes in chemical information transfer. Overall, cuticular hydrocarbons meet the requirements to function as intraspecific and intersexual close range recognition signals; behavioral experiments are needed to determine their potential involvement in mate recognition.

  7. Overtraining and the use of feature and geometric cues for reorientation.

    Science.gov (United States)

    Sturz, Bradley R; Gaskin, Katherine A; Bodily, Kent D

    2013-03-01

    Using a dynamic three-dimensional virtual environment task, we investigated the influence of overtraining of feature and geometric cues on preferential spatial cue use. We trained two groups of human participants to respond to feature and geometric cues in separate enclosures before placing these cues in conflict on a critical test trial. All participants learned to respond to rewarded features located along the principal axis of a rectangular search space and to rewarded geometric cues of a rectangular search space in separate training phases followed by a single test trial. During the test trial, we situated the rewarded features in the unrewarded geometric corners and the unrewarded features in rewarded geometric corners. For one group, participants were overtrained with feature cues compared to geometric cues before experiencing the conflict test; whereas, for another group, participants were overtrained with geometric cues compared to feature cues before experiencing the conflict test. Although both groups learned to respond to both feature and geometric cues at an equivalent rate and to an equivalent level of terminal accuracy, testing results revealed no difference between the groups with respect to their preference for feature or geometric cues. Despite a lack of influence of overtraining on spatial cue preference, participants showed an overall preference for feature cues. We discuss the results with respect to implications for theoretical accounts of spatial learning.

  8. Does predictability matter? Effects of cue predictability on neurocognitive mechanisms underlying Prospective Memory

    Directory of Open Access Journals (Sweden)

    Giorgia eCona

    2015-04-01

    Full Text Available Prospective memory (PM represents the ability to successfully realize intentions when the appropriate moment or cue occurs. In this study, we used event-related potentials (ERPs to explore the impact of cue predictability on the cognitive and neural mechanisms supporting PM. Participants performed an ongoing task and, simultaneously, had to remember to execute a pre-specified action when they encountered the PM cues. The occurrence of the PM cues was predictable (being signalled by a warning cue for some participants and was completely unpredictable for others. In the predictable cue condition, the behavioural and ERP correlates of strategic monitoring were observed mainly in the ongoing trials wherein the PM cue was expected. In the unpredictable cue condition they were instead shown throughout the whole PM block. This pattern of results suggests that, in the predictable cue condition, participants engaged monitoring only when subjected to a context wherein the PM cue was expected, and disengaged monitoring when the PM cue was not expected. Conversely, participants in the unpredictable cue condition distributed their resources for strategic monitoring in more continuous manner. The findings of this study support the most recent views – the ‘Dynamic Multiprocess Framework’ and the ‘Attention to Delayed Intention’ (AtoDI model – confirming that strategic monitoring is a flexible mechanism that is recruited mainly when a PM cue is expected and that may interact with bottom-up spontaneous processes.

  9. Looking for cues - infant communication of hunger and satiation during milk feeding.

    Science.gov (United States)

    Shloim, N; Vereijken, C M J L; Blundell, P; Hetherington, M M

    2017-01-01

    It is known that duration of breastfeeding and responsive feeding are associated with decreased risk of obesity. It is however, not clear whether breastfed infants signal more to mothers to facilitate responsive feeding, compared to formula fed, nor what communication cues are important during the feeding interaction. The present study aimed to explore feeding cues in milk-fed infants and to examine if such cues vary by mode of feeding. Twenty-seven mothers and infants were filmed while breastfeeding or formula feeding. Infants' age ranged from 3 to 22 weeks. Feeding cues were identified using a validated list of communication cues (NCAST). The frequency of each cue during the beginning, middle, and end of the meal was recorded. There were 22 feeding cues identified during the feeds, with significantly more frequent disengagement cues expressed than engagement cues. Significantly more frequent feeding cues were observed at the beginning than at the end of the meal showing that cue frequency changes with satiation. Breastfeeding infants exhibited more engagement and disengagement cues than formula fed infants. Supporting mothers to identify engagement and disengagement cues during a milk feed may promote more responsive feeding-strategies that can be acquired by mothers using different modes of feeding.

  10. The role of different cues in the brain mechanism on visual spatial attention

    Institute of Scientific and Technical Information of China (English)

    SONG Weiqun; LUO Yuejia; CHI Song; JI Xunming; LING Feng; ZHAO Lun; WANG Maobin; SHI Jiannong

    2006-01-01

    The visual spatial attention mechanism in the brain was studied in 16 young subjects through the visual search paradigm of precue-target by the event-related potential (ERP) technique, with the attentive ranges cued by different scales of Chinese character and region cues. The results showed that the response time for Chinese character cues was much longer than that for region cues especially for small region cues. With the exterior interferences, the target stimuli recognition under region cues was much quicker than that under Chinese character cues. Compared with that under region cues, targets under Chinese character cues could lead to increase of the posterior P1,decrease of the N1 and increase of the P2. It should also be noted that the differences between region cues and Chinese character cues were affected by the interference types. Under exterior interferences, no significant difference was found between region cues and Chinese character cues; however, it was not the case under the interior interferences. Considering the difference between the exterior interferences and the interior interferences, we could conclude that with the increase of difficulty in target recognition there was obvious difference in the consumption of anterior frontal resources by target stimuli under the two kinds of cues.

  11. Cross-language differences in cue use for speech segmentation

    NARCIS (Netherlands)

    Tyler, M.D.; Cutler, A.

    2009-01-01

    Two artificial-language learning experiments directly compared English, French, and Dutch listeners' use of suprasegmental cues for continuous-speech segmentation. In both experiments, listeners heard unbroken sequences of consonant-vowel syllables, composed of recurring three- and four-syllable "wo

  12. Acoustic cues to lexical segmentation: a study of resynthesized speech.

    Science.gov (United States)

    Spitzer, Stephanie M; Liss, Julie M; Mattys, Sven L

    2007-12-01

    It has been posited that the role of prosody in lexical segmentation is elevated when the speech signal is degraded or unreliable. Using predictions from Cutler and Norris' [J. Exp. Psychol. Hum. Percept. Perform. 14, 113-121 (1988)] metrical segmentation strategy hypothesis as a framework, this investigation examined how individual suprasegmental and segmental cues to syllabic stress contribute differentially to the recognition of strong and weak syllables for the purpose of lexical segmentation. Syllabic contrastivity was reduced in resynthesized phrases by systematically (i) flattening the fundamental frequency (F0) contours, (ii) equalizing vowel durations, (iii) weakening strong vowels, (iv) combining the two suprasegmental cues, i.e., F0 and duration, and (v) combining the manipulation of all cues. Results indicated that, despite similar decrements in overall intelligibility, F0 flattening and the weakening of strong vowels had a greater impact on lexical segmentation than did equalizing vowel duration. Both combined-cue conditions resulted in greater decrements in intelligibility, but with no additional negative impact on lexical segmentation. The results support the notion of F0 variation and vowel quality as primary conduits for stress-based segmentation and suggest that the effectiveness of stress-based segmentation with degraded speech must be investigated relative to the suprasegmental and segmental impoverishments occasioned by each particular degradation.

  13. Effects of Cueing and Modeling Variables in Teacher Training Systems.

    Science.gov (United States)

    Orme, Michael E. J.

    Theoretical considerations suggest that the differential effectiveness of teaching models and associated feedback procedures stems from their distinctive cueing properties. This led to the development of three treatment conditions which may be labeled "rating" (rehearsal of key discriminations), "observation" vicarious reinforcement), and "direct…

  14. Person Perception: Family Structure as a Cue for Stereotyping.

    Science.gov (United States)

    Bryan, Linda R.; And Others

    1986-01-01

    Compared perceptions of stepparents and stepchildren to perceptions of other adults and children. Results indicated family structure is a cue by which stereotypes are formed. The categories of stepparent and stepchild, in particular, appeared to lend themselves to more negative stereotyping. (Author/ABL)

  15. Developmental differences in the brain response to unhealthy food cues

    NARCIS (Netherlands)

    Meer, van Floor; Laan, van der Laura N.; Charbonnier, Lisette; Viergever, Max A.; Adan, Roger A.H.; Smeets, Paul A.M.

    2016-01-01

    Background: Food cues are omnipresent and may trigger overconsumption. In the past 2 decades, the prevalence of childhood obesity has increased dramatically. Because children’s brains are still developing, especially in areas important for inhibition, children may be more susceptible than adults to

  16. Children Use Different Cues to Guide Noun and Verb Extensions

    Science.gov (United States)

    Childers, Jane B.; Heard, M. Elaine; Ring, Kolette; Pai, Anushka; Sallquist, Julie

    2012-01-01

    Learning new words involves decoding both how a word fits the current situation and how it could be used in new situations. Three studies explore how two types of cues--sentence structure and the availability of multiple instances--affect children's extensions of nouns and verbs. In each study, 2.5-year-olds heard nouns, verbs, or no new word…

  17. Social and Linguistic Cues Facilitate Children's Register Comprehension

    Science.gov (United States)

    Wagner, Laura; Vega-Mendoza, Mariana; Van Horn, Suzanne

    2014-01-01

    Speakers must command different linguistic registers to index various social-discourse elements, including the identity of the addressee. Previous work found that English-learning children could link registers to appropriate addressees by 5 years. Two experiments found that better cues to the linguistic form or to the social meaning of register…

  18. Plant surface cues prime Ustilago maydis for biotrophic development.

    Directory of Open Access Journals (Sweden)

    Daniel Lanver

    2014-07-01

    Full Text Available Infection-related development of phytopathogenic fungi is initiated by sensing and responding to plant surface cues. This response can result in the formation of specialized infection structures, so-called appressoria. To unravel the program inducing filaments and appressoria in the biotrophic smut fungus Ustilago maydis, we exposed cells to a hydrophobic surface and the cutin monomer 16-hydroxy hexadecanoic acid. Genome-wide transcriptional profiling at the pre-penetration stage documented dramatic transcriptional changes in almost 20% of the genes. Comparisons with the U. maydis sho1 msb2 double mutant, lacking two putative sensors for plant surface cues, revealed that these plasma membrane receptors regulate a small subset of the surface cue-induced genes comprising mainly secreted proteins including potential plant cell wall degrading enzymes. Targeted gene deletion analysis ascribed a role to up-regulated GH51 and GH62 arabinofuranosidases during plant penetration. Among the sho1/msb2-dependently expressed genes were several secreted effectors that are essential for virulence. Our data also demonstrate specific effects on two transcription factors that redirect the transcriptional regulatory network towards appressorium formation and plant penetration. This shows that plant surface cues prime U. maydis for biotrophic development.

  19. Color matters: color as trustworthiness cue in web sites

    NARCIS (Netherlands)

    Alberts, Wouter A.; van der Geest, Thea

    2011-01-01

    Purpose: In today's increasingly technological world, the first impression of an orgnization is often based on a user's judgment of the corporate Web site's trustworthiness. This study investigates whether color as a Web site element can serve as a trustworthiness cue. In addition, the context of

  20. The Effects of Attention Cueing on Visualizers' Multimedia Learning

    Science.gov (United States)

    Yang, Hui-Yu

    2016-01-01

    The present study examines how various types of attention cueing and cognitive preference affect learners' comprehension of a cardiovascular system and cognitive load. EFL learners were randomly assigned to one of four conditions: non-signal, static-blood-signal, static-blood-static-arrow-signal, and animation-signal. The results indicated that…

  1. Reinforcing Visual Grouping Cues to Communicate Complex Informational Structure.

    Science.gov (United States)

    Bae, Juhee; Watson, Benjamin

    2014-12-01

    In his book Multimedia Learning [7], Richard Mayer asserts that viewers learn best from imagery that provides them with cues to help them organize new information into the correct knowledge structures. Designers have long been exploiting the Gestalt laws of visual grouping to deliver viewers those cues using visual hierarchy, often communicating structures much more complex than the simple organizations studied in psychological research. Unfortunately, designers are largely practical in their work, and have not paused to build a complex theory of structural communication. If we are to build a tool to help novices create effective and well structured visuals, we need a better understanding of how to create them. Our work takes a first step toward addressing this lack, studying how five of the many grouping cues (proximity, color similarity, common region, connectivity, and alignment) can be effectively combined to communicate structured text and imagery from real world examples. To measure the effectiveness of this structural communication, we applied a digital version of card sorting, a method widely used in anthropology and cognitive science to extract cognitive structures. We then used tree edit distance to measure the difference between perceived and communicated structures. Our most significant findings are: 1) with careful design, complex structure can be communicated clearly; 2) communicating complex structure is best done with multiple reinforcing grouping cues; 3) common region (use of containers such as boxes) is particularly effective at communicating structure; and 4) alignment is a weak structural communicator.

  2. Landscape mapping MAV using single image perspective cues

    CSIR Research Space (South Africa)

    Tekane, YC

    2015-01-01

    Full Text Available in order to do mapping, our method does require a 3 D model. Instead, our method first classifies the type of site the MAV is in, and the uses vision algorithms based on perspective cues to estimate the landscape location and the do mapping. We tested our...

  3. Eating by Example: Effects of Environmental Cues on Dietary Decisions

    NARCIS (Netherlands)

    Prinsen, S.|info:eu-repo/dai/nl/369408217; de Ridder, D.T.D.|info:eu-repo/dai/nl/070706174; De Vet, E.|info:eu-repo/dai/nl/290924197

    2013-01-01

    Objective: The present studies examined the role of environmental cues in steering people’s dietary decisions in response to food temptations. Based on the notion that people show a tendency to conform to eating standards derived from the eating behavior of others, it was hypothesized that communica

  4. Eating by example. Effects of environmental cues on dietary decisions

    NARCIS (Netherlands)

    Prinsen, S.; Ridder, de D.T.D.; Vet, de E.W.M.L.

    2013-01-01

    Objective: The present studies examined the role of environmental cues in steering people’s dietary decisions in response to food temptations. Based on the notion that people show a tendency to conform to eating standards derived from the eating behavior of others, it was hypothesized that communica

  5. Poor Metacomprehension Accuracy as a Result of Inappropriate Cue Use

    Science.gov (United States)

    Thiede, Keith W.; Griffin, Thomas D.; Wiley, Jennifer; Anderson, Mary C. M.

    2010-01-01

    Two studies attempt to determine the causes of poor metacomprehension accuracy and then, in turn, to identify interventions that circumvent these difficulties to support effective comprehension monitoring performance. The first study explored the cues that both at-risk and typical college readers use as a basis for their metacomprehension…

  6. Effects of smoking cues in movies on immediate smoking behavior

    NARCIS (Netherlands)

    Lochbuehler, K.; Peters, M.; Scholte, R.H.J.; Engels, R.C.M.E.

    2010-01-01

    Introduction: The objective of this study was to investigate the effect of smoking cues in movies on immediate smoking behavior. We tested whether smokers who are confronted with smoking characters in a movie smoke more cigarettes while watching than those confronted with non-smoking characters and

  7. Visual Discrimination Learning with Variable Irrelevant Cues in Autistic Children.

    Science.gov (United States)

    Miyashita, Teruko

    1985-01-01

    Ten autistic children and 10 normal nursery school children, matched for mean developmental age, were presented with figure stimuli and had variable irrelevant cues in two-choice simultaneous discrimination learning. Performance of the autistic group did not vary as a function of irrelevant variability, a result attributed to poor performance of…

  8. Plant surface cues prime Ustilago maydis for biotrophic development.

    Science.gov (United States)

    Lanver, Daniel; Berndt, Patrick; Tollot, Marie; Naik, Vikram; Vranes, Miroslav; Warmann, Tobias; Münch, Karin; Rössel, Nicole; Kahmann, Regine

    2014-07-01

    Infection-related development of phytopathogenic fungi is initiated by sensing and responding to plant surface cues. This response can result in the formation of specialized infection structures, so-called appressoria. To unravel the program inducing filaments and appressoria in the biotrophic smut fungus Ustilago maydis, we exposed cells to a hydrophobic surface and the cutin monomer 16-hydroxy hexadecanoic acid. Genome-wide transcriptional profiling at the pre-penetration stage documented dramatic transcriptional changes in almost 20% of the genes. Comparisons with the U. maydis sho1 msb2 double mutant, lacking two putative sensors for plant surface cues, revealed that these plasma membrane receptors regulate a small subset of the surface cue-induced genes comprising mainly secreted proteins including potential plant cell wall degrading enzymes. Targeted gene deletion analysis ascribed a role to up-regulated GH51 and GH62 arabinofuranosidases during plant penetration. Among the sho1/msb2-dependently expressed genes were several secreted effectors that are essential for virulence. Our data also demonstrate specific effects on two transcription factors that redirect the transcriptional regulatory network towards appressorium formation and plant penetration. This shows that plant surface cues prime U. maydis for biotrophic development.

  9. Use of acoustic cues by children with cochlear implants

    NARCIS (Netherlands)

    Giezen, M.R.; Escudero, P.; Baker, A.

    2010-01-01

    Purpose: This study examined the use of different acoustic cues in auditory perception of consonant and vowel contrasts by profoundly deaf children with a cochlear implant (CI) in comparison to age-matched children and young adults with normal hearing. Method: A speech sound categorization task in

  10. Responsiveness to child feeding cues: an observational scale

    Science.gov (United States)

    Mismatched caregiver responsiveness to child hunger and satiety cues, is thought to contribute to obesity in infancy and beyond. Assessment of this proposition, however, has been limited by a lack of reliable and valid measures. This research evaluated the interrater reliability of a new observation...

  11. Development of the responsiveness to child feeding cues scale

    Science.gov (United States)

    Parent–child feeding interactions during the first 2 years of life are thought to shape child appetite and obesity risk, but remain poorly studied. This research was designed to develop and assess the Responsiveness to Child Feeding Cues Scale, an observational measure of caregiver responsiveness to...

  12. Learning to Decode Nonverbal Cues in Cross-Cultural Interactions

    Science.gov (United States)

    2009-06-01

    tactile / haptic communication (via touch), paralanguage (auditory utterances that affect meaning), silence, olfaction, and chronemics (time and...and eyes. Spatial communication focuses on the space between us and others. Tactile communication describes the physical contact between people...his subordinate (body communication) and touches him ( tactile communication) in a meeting. Finally, nonverbal cues may be used to mean

  13. Integration of pragmatic and phonetic cues in spoken word recognition.

    Science.gov (United States)

    Rohde, Hannah; Ettlinger, Marc

    2012-07-01

    Although previous research has established that multiple top-down factors guide the identification of words during speech processing, the ultimate range of information sources that listeners integrate from different levels of linguistic structure is still unknown. In a set of experiments, we investigate whether comprehenders can integrate information from the 2 most disparate domains: pragmatic inference and phonetic perception. Using contexts that trigger pragmatic expectations regarding upcoming coreference (expectations for either he or she), we test listeners' identification of phonetic category boundaries (using acoustically ambiguous words on the /hi/∼/∫i/ continuum). The results indicate that, in addition to phonetic cues, word recognition also reflects pragmatic inference. These findings are consistent with evidence for top-down contextual effects from lexical, syntactic, and semantic cues, but they extend this previous work by testing cues at the pragmatic level and by eliminating a statistical-frequency confound that might otherwise explain the previously reported results. We conclude by exploring the time course of this interaction and discussing how different models of cue integration could be adapted to account for our results. 2012 APA, all rights reserved

  14. Looking the part: social status cues shape race perception.

    Science.gov (United States)

    Freeman, Jonathan B; Penner, Andrew M; Saperstein, Aliya; Scheutz, Matthias; Ambady, Nalini

    2011-01-01

    It is commonly believed that race is perceived through another's facial features, such as skin color. In the present research, we demonstrate that cues to social status that often surround a face systematically change the perception of its race. Participants categorized the race of faces that varied along White-Black morph continua and that were presented with high-status or low-status attire. Low-status attire increased the likelihood of categorization as Black, whereas high-status attire increased the likelihood of categorization as White; and this influence grew stronger as race became more ambiguous (Experiment 1). When faces with high-status attire were categorized as Black or faces with low-status attire were categorized as White, participants' hand movements nevertheless revealed a simultaneous attraction to select the other race-category response (stereotypically tied to the status cue) before arriving at a final categorization. Further, this attraction effect grew as race became more ambiguous (Experiment 2). Computational simulations then demonstrated that these effects may be accounted for by a neurally plausible person categorization system, in which contextual cues come to trigger stereotypes that in turn influence race perception. Together, the findings show how stereotypes interact with physical cues to shape person categorization, and suggest that social and contextual factors guide the perception of race.

  15. Binaural cues provide for a release from informational masking.

    Science.gov (United States)

    Tolnai, Sandra; Dolležal, Lena-Vanessa; Klump, Georg M

    2015-10-01

    Informational masking (IM) describes the insensitivity of detecting a change in sound features in a complex acoustical environment when such a change could easily be detected in the absence of distracting sounds. IM occurs because of the similarity between deviant sound and distracting sounds (so-called similarity-based IM) and/or stimulus uncertainty stemming from trial-to-trial variability (so-called uncertainty-based IM). IM can be abolished if similarity-based or uncertainty-based IM are minimized. Here, we modulated similarity-based IM using binaural cues. Standard/deviant tones and distracting tones were presented sequentially, and level-increment thresholds were measured. Deviant tones differed from standard tones by a higher sound level. Distracting tones covered a wide range of levels. Standard/deviant tones and distracting tones were characterized by their interaural time difference (ITD), interaural level difference (ILD), or both ITD and ILD. The larger the ITD or ILD was, the better similarity-based IM was overcome. If both interaural differences were applied to standard/deviant tones, the release from IM was larger than when either interaural difference was used. The results show that binaural cues are potent cues to abolish similarity-based IM and that the auditory system makes use of multiple available cues. (c) 2015 APA, all rights reserved).

  16. Modeling the utility of binaural cues for underwater sound localization.

    Science.gov (United States)

    Schneider, Jennifer N; Lloyd, David R; Banks, Patchouly N; Mercado, Eduardo

    2014-06-01

    The binaural cues used by terrestrial animals for sound localization in azimuth may not always suffice for accurate sound localization underwater. The purpose of this research was to examine the theoretical limits of interaural timing and level differences available underwater using computational and physical models. A paired-hydrophone system was used to record sounds transmitted underwater and recordings were analyzed using neural networks calibrated to reflect the auditory capabilities of terrestrial mammals. Estimates of source direction based on temporal differences were most accurate for frequencies between 0.5 and 1.75 kHz, with greater resolution toward the midline (2°), and lower resolution toward the periphery (9°). Level cues also changed systematically with source azimuth, even at lower frequencies than expected from theoretical calculations, suggesting that binaural mechanical coupling (e.g., through bone conduction) might, in principle, facilitate underwater sound localization. Overall, the relatively limited ability of the model to estimate source position using temporal and level difference cues underwater suggests that animals such as whales may use additional cues to accurately localize conspecifics and predators at long distances. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Skeletal images as visual cues in graph visualization

    NARCIS (Netherlands)

    Herman, I.; Marshall, M.S.; Melançon, G.; Duke, D.J.; Delest, M.; Domenger, J.-P.

    1998-01-01

    The problem of graph layout and drawing is fundamental to many aproaches to the visualization of relational information structures. As the data set grows, the visualization problem is compounded by the need to reconcile the user's need for orientation cues with the danger of information overload. Pu

  18. Effects of smoking cues in movies on immediate smoking behavior

    NARCIS (Netherlands)

    Lochbuehler, K.; Peters, M.; Scholte, R.H.J.; Engels, R.C.M.E.

    2010-01-01

    Introduction: The objective of this study was to investigate the effect of smoking cues in movies on immediate smoking behavior. We tested whether smokers who are confronted with smoking characters in a movie smoke more cigarettes while watching than those confronted with non-smoking characters and

  19. Effects of smoking cues in movies on immediate smoking behavior

    NARCIS (Netherlands)

    Lochbühler, K.C.; Peters, P.M.; Scholte, R.H.J.; Engels, R.C.M.E.

    2010-01-01

    The objective of this study was to investigate the effect of smoking cues in movies on immediate smoking behavior. We tested whether smokers who are confronted with smoking characters in a movie smoke more cigarettes while watching than those confronted with non-smoking characters and whether this e

  20. Facilitation of motor imagery through movement-related cueing

    NARCIS (Netherlands)

    Heremans, Elke; Helsen, Werner F.; De Poel, Harjo J.; Alaerts, Kaat; Meyns, Pieter; Feys, Peter

    2009-01-01

    In the past few years, the use of motor imagery as an adjunct to other forms of training has been studied extensively. However, very little attention has been paid to how imagery could be used to greatest effect. it is well known that the provision of external cues has a beneficial effect on motor s

  1. Role of cues and contexts on drug-seeking behaviour

    Science.gov (United States)

    Perry, Christina J; Zbukvic, Isabel; Kim, Jee Hyun; Lawrence, Andrew J

    2014-01-01

    Environmental stimuli are powerful mediators of craving and relapse in substance-abuse disorders. This review examined how animal models have been used to investigate the cognitive mechanisms through which cues are able to affect drug-seeking behaviour. We address how animal models can describe the way drug-associated cues come to facilitate the development and persistence of drug taking, as well as how these cues are critical to the tendency to relapse that characterizes substance-abuse disorders. Drug-associated cues acquire properties of conditioned reinforcement, incentive motivation and discriminative control, which allow them to influence drug-seeking behaviour. Using these models, researchers have been able to investigate the pharmacology subserving the behavioural impact of environmental stimuli, some of which we highlight. Subsequently, we examine whether the impact of drug-associated stimuli can be attenuated via a process of extinction, and how this question is addressed in the laboratory. We discuss how preclinical research has been translated into behavioural therapies targeting substance abuse, as well as highlight potential developments to therapies that might produce more enduring changes in behaviour. Linked Articles This article is part of a themed section on Animal Models in Psychiatry Research. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2014.171.issue-20 PMID:24749941

  2. Conditioned craving cues elicit an automatic approach tendency

    NARCIS (Netherlands)

    D. van Gucht; D. Vansteenwegen; O. Van den Bergh; T. Beckers

    2008-01-01

    In two experiments, we used a Pavlovian differential conditioning procedure to induce craving for chocolate. As a result of repeated pairing with chocolate intake, initially neutral cues came to elicit an automatic approach tendency in a speeded stimulus-response compatibility reaction time task. Th

  3. Using Implicit Instructional Cues to Influence False Memory Induction

    Science.gov (United States)

    Cirelli, Laura K.; Dickinson, Joël; Poirier, Marie

    2015-01-01

    Previous research has shown that explicit cues specific to the encoding process (endogenous) or characteristic of the stimuli themselves (exogenous) can be used to direct a reader's attentional resources towards either relational or item-specific information. By directing attention to relational information (and therefore away from item-specific…

  4. Auditory gist: recognition of very short sounds from timbre cues.

    Science.gov (United States)

    Suied, Clara; Agus, Trevor R; Thorpe, Simon J; Mesgarani, Nima; Pressnitzer, Daniel

    2014-03-01

    Sounds such as the voice or musical instruments can be recognized on the basis of timbre alone. Here, sound recognition was investigated with severely reduced timbre cues. Short snippets of naturally recorded sounds were extracted from a large corpus. Listeners were asked to report a target category (e.g., sung voices) among other sounds (e.g., musical instruments). All sound categories covered the same pitch range, so the task had to be solved on timbre cues alone. The minimum duration for which performance was above chance was found to be short, on the order of a few milliseconds, with the best performance for voice targets. Performance was independent of pitch and was maintained when stimuli contained less than a full waveform cycle. Recognition was not generally better when the sound snippets were time-aligned with the sound onset compared to when they were extracted with a random starting time. Finally, performance did not depend on feedback or training, suggesting that the cues used by listeners in the artificial gating task were similar to those relevant for longer, more familiar sounds. The results show that timbre cues for sound recognition are available at a variety of time scales, including very short ones.

  5. Social and Linguistic Cues Facilitate Children's Register Comprehension

    Science.gov (United States)

    Wagner, Laura; Vega-Mendoza, Mariana; Van Horn, Suzanne

    2014-01-01

    Speakers must command different linguistic registers to index various social-discourse elements, including the identity of the addressee. Previous work found that English-learning children could link registers to appropriate addressees by 5 years. Two experiments found that better cues to the linguistic form or to the social meaning of register…

  6. Compound Cue Processing in Linearly and Nonlinearly Separable Environments

    Science.gov (United States)

    Hoffrage, Ulrich; Garcia-Retamero, Rocio; Czienskowski, Uwe

    2008-01-01

    Take-the-best (TTB) is a fast and frugal heuristic for paired comparison that has been proposed as a model of bounded rationality. This heuristic has been criticized for not taking compound cues into account to predict a criterion, although such an approach is sometimes required to make accurate predictions. By means of computer simulations, it is…

  7. The relationship between perceived stress and cue sensitivity for alcohol.

    NARCIS (Netherlands)

    Snelleman, M.; Schoenmakers, T.M.; Mheen, D. van de

    2014-01-01

    Previous research has shown that cue sensitivity and stress affect the risk for relapse in alcohol-dependent patients. Theoretically, a link between the two can be expected. However, a clear overview of the interplay of these factors is not yet available. The purpose of this review was to examine th

  8. Skeletal images as visual cues in graph visualization

    NARCIS (Netherlands)

    I. Herman (Ivan); M.S. Marshall (Scott); G. Melançon; D.J. Duke; M. Delest; J.-P. Domenger

    1998-01-01

    textabstractThe problem of graph layout and drawing is fundamental to many aproaches to the visualization of relational information structures. As the data set grows, the visualization problem is compounded by the need to reconcile the user's need for orientation cues with the danger of information

  9. Conditioned craving cues elicit an automatic approach tendency

    NARCIS (Netherlands)

    van Gucht, D.; Vansteenwegen, D.; Van den Bergh, O.; Beckers, T.

    2008-01-01

    In two experiments, we used a Pavlovian differential conditioning procedure to induce craving for chocolate. As a result of repeated pairing with chocolate intake, initially neutral cues came to elicit an automatic approach tendency in a speeded stimulus-response compatibility reaction time task.

  10. Aging affects postural tracking of complex visual motion cues.

    Science.gov (United States)

    Sotirakis, H; Kyvelidou, A; Mademli, L; Stergiou, N; Hatzitaki, V

    2016-09-01

    Postural tracking of visual motion cues improves perception-action coupling in aging, yet the nature of the visual cues to be tracked is critical for the efficacy of such a paradigm. We investigated how well healthy older (72.45 ± 4.72 years) and young (22.98 ± 2.9 years) adults can follow with their gaze and posture horizontally moving visual target cues of different degree of complexity. Participants tracked continuously for 120 s the motion of a visual target (dot) that oscillated in three different patterns: a simple periodic (simulated by a sine), a more complex (simulated by the Lorenz attractor that is deterministic displaying mathematical chaos) and an ultra-complex random (simulated by surrogating the Lorenz attractor) pattern. The degree of coupling between performance (posture and gaze) and the target motion was quantified in the spectral coherence, gain, phase and cross-approximate entropy (cross-ApEn) between signals. Sway-target coherence decreased as a function of target complexity and was lower for the older compared to the young participants when tracking the chaotic target. On the other hand, gaze-target coherence was not affected by either target complexity or age. Yet, a lower cross-ApEn value when tracking the chaotic stimulus motion revealed a more synchronous gaze-target relationship for both age groups. Results suggest limitations in online visuo-motor processing of complex motion cues and a less efficient exploitation of the body sway dynamics with age. Complex visual motion cues may provide a suitable training stimulus to improve visuo-motor integration and restore sway variability in older adults.

  11. Mechanisms of Choice Behavior Shift Using Cue-approach Training

    Directory of Open Access Journals (Sweden)

    Akram eBakkour

    2016-03-01

    Full Text Available Cue-approach training has been shown to effectively shift choices for snack food items by associating a cued button-press motor response to particular food items. Furthermore, attention is biased toward previously cued items, even when the cued item is not chosen for real consumption during a choice phase. However, the exact mechanism by which preferences shift during cue-approach training is not entirely clear. In three experiments, we shed light on the possible underlying mechanisms at play during this novel paradigm: 1 Uncued, wholly predictable motor responses paired with particular food items were not sufficient to elicit a preference shift; 2 Cueing motor responses early – concurrently with food item onset – and thus eliminating the need for heightened top-down attention to the food stimulus in preparation for a motor response also eliminated the shift in food preferences. This finding reinforces our hypothesis that heightened attention at behaviorally relevant points in time is key to changing choice behavior in the cue-approach task; 3 Crucially, indicating choice using eye movements rather than manual button presses preserves the effect, thus demonstrating that the shift in preferences is not governed by a learned motor response but more likely via modulation of subjective value in higher associative regions, consistent with previous neuroimaging results. Cue-approach training drives attention at behaviorally relevant points in time to modulate the subjective value of individual items, providing a mechanism for behavior change that does not rely on external reinforcement and that holds great promise for developing real world behavioral interventions.

  12. The contribution of dynamic visual cues to audiovisual speech perception.

    Science.gov (United States)

    Jaekl, Philip; Pesquita, Ana; Alsius, Agnes; Munhall, Kevin; Soto-Faraco, Salvador

    2015-08-01

    Seeing a speaker's facial gestures can significantly improve speech comprehension, especially in noisy environments. However, the nature of the visual information from the speaker's facial movements that is relevant for this enhancement is still unclear. Like auditory speech signals, visual speech signals unfold over time and contain both dynamic configural information and luminance-defined local motion cues; two information sources that are thought to engage anatomically and functionally separate visual systems. Whereas, some past studies have highlighted the importance of local, luminance-defined motion cues in audiovisual speech perception, the contribution of dynamic configural information signalling changes in form over time has not yet been assessed. We therefore attempted to single out the contribution of dynamic configural information to audiovisual speech processing. To this aim, we measured word identification performance in noise using unimodal auditory stimuli, and with audiovisual stimuli. In the audiovisual condition, speaking faces were presented as point light displays achieved via motion capture of the original talker. Point light displays could be isoluminant, to minimise the contribution of effective luminance-defined local motion information, or with added luminance contrast, allowing the combined effect of dynamic configural cues and local motion cues. Audiovisual enhancement was found in both the isoluminant and contrast-based luminance conditions compared to an auditory-only condition, demonstrating, for the first time the specific contribution of dynamic configural cues to audiovisual speech improvement. These findings imply that globally processed changes in a speaker's facial shape contribute significantly towards the perception of articulatory gestures and the analysis of audiovisual speech. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Augmented reality cues and elderly driver hazard perception.

    Science.gov (United States)

    Schall, Mark C; Rusch, Michelle L; Lee, John D; Dawson, Jeffrey D; Thomas, Geb; Aksan, Nazan; Rizzo, Matthew

    2013-06-01

    The aim of this study was to evaluate the effectiveness of augmented reality (AR) cues in improving driving safety among elderly drivers who are at increased crash risk because of cognitive impairments. Cognitively challenging driving environments pose a particular crash risk for elderly drivers. AR cuing is a promising technology to mitigate risk by directing driver attention to roadway hazards. We investigate whether AR cues improve or interfere with hazard perception in elderly drivers with age-related cognitive decline. A total of 20 elderly (M = 73 years, SD = 5) licensed drivers with a range of cognitive abilities measured by a speed-of-processing (SOP) composite participated in a 1-hr drive in an interactive, fixed-base driving simulator. Each participant drove through six straight, 6-mile-long, rural roadway scenarios following a lead vehicle. AR cues directed attention to potential roadside hazards in three of the scenarios, and the other three were uncued (baseline) drives. Effects of AR cuing were evaluated with respect to (a) detection of hazardous target objects, (b) interference with detecting nonhazardous secondary objects, and (c) impairment in maintaining safe distance behind a lead vehicle. AR cuing improved the detection of hazardous target objects of low visibility. AR cues did not interfere with detection of nonhazardous secondary objects and did not impair ability to maintain safe distance behind a lead vehicle. SOP capacity did not moderate those effects. AR cues show promise for improving elderly driver safety by increasing hazard detection likelihood without interfering with other driving tasks, such as maintaining safe headway.

  14. Out of sight, out of mind: racial retrieval cues increase the accessibility of social justice concepts.

    Science.gov (United States)

    Salter, Phia S; Kelley, Nicholas J; Molina, Ludwin E; Thai, Luyen T

    2017-01-16

    Photographs provide critical retrieval cues for personal remembering, but few studies have considered this phenomenon at the collective level. In this research, we examined the psychological consequences of visual attention to the presence (or absence) of racially charged retrieval cues within American racial segregation photographs. We hypothesised that attention to racial retrieval cues embedded in historical photographs would increase social justice concept accessibility. In Study 1, we recorded gaze patterns with an eye-tracker among participants viewing images that contained racial retrieval cues or were digitally manipulated to remove them. In Study 2, we manipulated participants' gaze behaviour by either directing visual attention toward racial retrieval cues, away from racial retrieval cues, or directing attention within photographs where racial retrieval cues were missing. Across Studies 1 and 2, visual attention to racial retrieval cues in photographs documenting historical segregation predicted social justice concept accessibility.

  15. The effect of monocular depth cues on the detection of moving objects by moving observers

    National Research Council Canada - National Science Library

    Royden, Constance S; Parsons, Daniel; Travatello, Joshua

    2016-01-01

    ... and thus is an ambiguous cue. We tested whether the addition of information about the distance of objects from the observer, in the form of monocular depth cues, aided detection of moving objects...

  16. Rhizosphere chemical dialogues: plant-microbe interactions

    Energy Technology Data Exchange (ETDEWEB)

    Badri, D.V.; van der Lelie, D.; Weir, T. L.; Vivanco, J. M.

    2009-12-01

    Every organism on earth relies on associations with its neighbors to sustain life. For example, plants form associations with neighboring plants, microflora, and microfauna, while humans maintain symbiotic associations with intestinal microbial flora, which is indispensable for nutrient assimilation and development of the innate immune system. Most of these associations are facilitated by chemical cues exchanged between the host and the symbionts. In the rhizosphere, which includes plant roots and the surrounding area of soil influenced by the roots, plants exude chemicals to effectively communicate with their neighboring soil organisms. Here we review the current literature pertaining to the chemical communication that exists between plants and microorganisms and the biological processes they sustain.

  17. Enhanced neurite outgrowth of PC-12 cells on graphene-monolayer-coated substrates as biomimetic cues

    Science.gov (United States)

    Lee, Jong Ho; Shin, Yong Cheol; Jin, Oh Seong; Han, Dong-Wook; Kang, Seok Hee; Hong, Suck Won; Kim, Jong Man

    2012-11-01

    Neurons are electrically excitable cells that transmit and process information in the nervous system. Recently, the differentiation of human neural stem cells to neurons has been shown to be enhanced on graphene substrates, and differentiated neurons have been shown to be able to still carry electrical signals when stimulated by graphene electrodes. Graphene films grown by using chemical vapor deposition were transferred onto glass coverslips by using the scooping method and were then coated with fetal bovine serum for a neuronal cell culture. The graphene substrates as biomimetic cues have been shown to enhance the neurite outgrowth of PC-12 cells. Our findings suggest that graphene has a unique surface property that can promote neuronal cells, which should open tremendous opportunities in neuroscience, neural engineering and regenerative medicine.

  18. Olfactory cues from different plant species in host selection by female pea moths.

    Science.gov (United States)

    Thöming, Gunda; Norli, Hans Ragnar

    2015-03-01

    In herbivorous insects specialized on few plant species, attraction to host odor may be mediated by volatiles common to all host species, by specific compounds, or combinations of both. The pea moth Cydia nigricana is an important pest of the pea. Volatile signatures of four host plant species were studied to identify compounds involved in pea moth host selection and to improve previously reported attractive volatile blends. P. sativum and alternative Fabaceae host species were compared regarding female attraction, oviposition, and larval performance. Pea moth females were strongly attracted to the sweet pea Lathyrus odoratus, but larval performance on that species was moderate. Chemical analyses of sweet pea odor and electrophysiological responses of moth antennae led to identification of seven sweet-pea-specific compounds and ten compounds common to all tested host species. Blends of these specific and common cues were highly attractive to mated pea moth females in wind tunnel and field experiments.

  19. Cues from the reef: olfactory preferences of a symbiotically luminous cardinalfish

    Science.gov (United States)

    Gould, Alison L.; Harii, Saki; Dunlap, Paul V.

    2015-06-01

    The symbiotically luminous, reef-dwelling cardinalfish, Siphamia tubifer (Perciformes: Apogonidae), exhibits daily site fidelity, homing behavior, and a preference for the long-spined urchin, Diadema setosum, as its daytime host. The fish acquires its symbiont during larval development and releases large numbers of the bacteria with its feces daily at a host urchin. To examine the role of olfaction in site fidelity and homing by S. tubifer, juvenile and adult fish were tested in a two-channel choice flume for their olfactory preferences. Neither juveniles nor adults showed a preference for seawater conditioned by D. setosum. Juvenile fish, but not adults, preferred seawater conditioned by conspecific fish versus unconditioned seawater. Both juveniles and adults preferred seawater conditioned by their luminous symbiont and also preferred home site water to foreign reef water. These results suggest that S. tubifer uses chemical cues for homing and possibly settlement and symbiont acquisition, but not for host urchin recognition.

  20. Perceptual scaling of visual and inertial cues: Effects of field of view, image size, depth cues, and degree of freedom

    NARCIS (Netherlands)

    Correia Grácio, B.J.; Bos, J.E.; Paassen, M.M. van; Mulder, M.

    2014-01-01

    In the field of motion-based simulation, it was found that a visual amplitude equal to the inertial amplitude does not always provide the best perceived match between visual and inertial motion. This result is thought to be caused by the "quality" of the motion cues delivered by the simulator motion

  1. The neural correlates of social attention: automatic orienting to social and nonsocial cues.

    Science.gov (United States)

    Greene, Deanna J; Mooshagian, Eric; Kaplan, Jonas T; Zaidel, Eran; Iacoboni, Marco

    2009-07-01

    Previous evidence suggests that directional social cues (e.g., eye gaze) cause automatic shifts in attention toward gaze direction. It has been proposed that automatic attentional orienting driven by social cues (social orienting) involves a different neural network from automatic orienting driven by nonsocial cues. However, previous neuroimaging studies on social orienting have only compared gaze cues to symbolic cues, which typically engage top-down mechanisms. Therefore, we directly compared the neural activity involved in social orienting to that involved in purely automatic nonsocial orienting. Twenty participants performed a spatial cueing task consisting of social (gaze) cues and automatic nonsocial (peripheral squares) cues presented at short and long stimulus (cue-to-target) onset asynchronies (SOA), while undergoing fMRI. Behaviorally, a facilitation effect was found for both cue types at the short SOA, while an inhibitory effect (inhibition of return: IOR) was found only for nonsocial cues at the long SOA. Imaging results demonstrated that social and nonsocial cues recruited a largely overlapping fronto-parietal network. In addition, social cueing evoked greater activity in occipito-temporal regions at both SOAs, while nonsocial cueing recruited greater subcortical activity, but only for the long SOA (when IOR was found). A control experiment, including central arrow cues, confirmed that the occipito-temporal activity was at least in part due to the social nature of the cue and not simply to the location of presentation (central vs. peripheral). These results suggest an evolutionary trajectory for automatic orienting, from predominantly subcortical mechanisms for nonsocial orienting to predominantly cortical mechanisms for social orienting.

  2. Influence of Dietary Experience on the Induction of Preference of Adult Moths and Larvae for a New Olfactory Cue.

    Directory of Open Access Journals (Sweden)

    Christophe Petit

    Full Text Available In Lepidoptera, host plant selection is first conditioned by oviposition site preference of adult females followed by feeding site preference of larvae. Dietary experience to plant volatile cues can induce larval and adult host plant preference. We investigated how the parent's and self-experience induce host preference in adult females and larvae of three lepidopteran stem borer species with different host plant ranges, namely the polyphagous Sesamia nonagrioides, the oligophagous Busseola fusca and the monophagous Busseola nairobica, and whether this induction can be linked to a neurophysiological phenotypic plasticity. The three species were conditioned to artificial diet enriched with vanillin from the neonate larvae to the adult stage during two generations. Thereafter, two-choice tests on both larvae and adults using a Y-tube olfactometer and electrophysiological (electroantennography [EAG] recordings experiments on adults were carried out. In the polyphagous species, the induction of preference for a new olfactory cue (vanillin by females and 3rd instar larvae was determined by parents' and self-experiences, without any modification of the sensitivity of the females antennae. No preference induction was found in the oligophagous and monophagous species. Our results suggest that lepidopteran stem borers may acquire preferences for new olfactory cues from the larval to the adult stage as described by Hopkins' host selection principle (HHSP, neo-Hopkins' principle, and the concept of 'chemical legacy.'

  3. Reef ecology. Chemically mediated behavior of recruiting corals and fishes: a tipping point that may limit reef recovery.

    Science.gov (United States)

    Dixson, Danielle L; Abrego, David; Hay, Mark E

    2014-08-22

    Coral reefs are in global decline, converting from dominance by coral to dominance by seaweed. Once seaweeds become abundant, coral recovery is suppressed unless herbivores return to remove seaweeds, and corals then recruit. Variance in the recovery of fishes and corals is not well understood. We show that juveniles of both corals and fishes are repelled by chemical cues from fished, seaweed-dominated reefs but attracted to cues from coral-dominated areas where fishing is prohibited. Chemical cues of specific seaweeds from degraded reefs repulsed recruits, and cues from specific corals that are typical of healthy reefs attracted recruits. Juveniles were present at but behaviorally avoided recruiting to degraded reefs dominated by seaweeds. For recovery, degraded reefs may need to be managed to produce cues that attract, rather than repel, recruiting corals and fishes.

  4. Suprasegmental lexical stress cues in visual speech can guide spoken-word recognition

    NARCIS (Netherlands)

    Jesse, A.; McQueen, J.M.

    2014-01-01

    Visual cues to the individual segments of speech and to sentence prosody guide speech recognition. The present study tested whether visual suprasegmental cues to the stress patterns of words can also constrain recognition. Dutch listeners use acoustic suprasegmental cues to lexical stress (changes i

  5. Two-Year-Olds Are Vigilant of Others' Non-Verbal Cues to Credibility

    Science.gov (United States)

    Birch, Susan A. J.; Akmal, Nazanin; Frampton, Kristen L.

    2010-01-01

    Data from three experiments provide the first evidence that children, at least as young as age two, are vigilant of others' non-verbal cues to credibility, and flexibly use these cues to facilitate learning. Experiment 1 revealed that 2- and 3-year-olds prefer to learn about objects from someone who appears, through non-verbal cues, to be…

  6. Direct effects of food cues seen during TV viewing on energy intake in young women

    NARCIS (Netherlands)

    Nee, R.L. van; Larsen, J.K.; Fisher, J.O.

    2016-01-01

    Few studies have examined direct effects of food cues presented within television (TV) programs on eating behavior in adults. This research experimentally determined whether exposure to food cues in TV programs affects energy intake during TV viewing among young women, independently from food cues p

  7. An electronic knot in the handkerchief : "Content free cueing" and the maintenance of attentive control

    NARCIS (Netherlands)

    Manly, T; Davison, B; Gaynord, B; Greenfield, E; Parr, A; Ridgeway, [No Value; Robertson, IH

    2004-01-01

    Rapid changes in consumer technology mean that many of us now carry a range of automated cueing devices. The value of organisers and pagers in cueing specific to-be-remembered items, particularly for people with memory deficits, is clear. Here we investigate whether cueing can serve a more general p

  8. Emotional and informational patient cues: the impact of nurses' responses on recall.

    NARCIS (Netherlands)

    Jansen, J.; Weert, J.C.M. van; Groot, J. de; Dulmen, S. van; Heeren, T.J.; Bensing, J.M.

    2010-01-01

    OBJECTIVE: To investigate older cancer patients' informational and emotional cues, how nurses respond to these cues and the effect of cues and responses on patients' information recall. METHODS: 105 cancer patients (aged >/=65 years) completed a recall questionnaire after an educational session prec

  9. The effect of self-control on attentional bias for alcohol cues in male heavy drinkers.

    NARCIS (Netherlands)

    Teunissen, H.A.; Spijkerman, R.; Schoenmakers, T.M.; Vohs, K.D.; Engels, R.C.M.

    2012-01-01

    Attentional bias for alcohol cues increases craving and subsequent alcohol consumption. Override processes can be used to disengage attention from alcohol cues. This requires self-control and implies that depletion of self-control would impair the ability to disengage attention from alcohol cues. Th

  10. The Effect of Self-Control on Attentional Bias for Alcohol Cues in Male Heavy Drinkers

    NARCIS (Netherlands)

    Teunissen, H.A.; Spijkerman, R.; Schoenmakers, T.M.; Vohs, K.D.; Engels, R.C.M.E.

    2012-01-01

    Attentional bias for alcohol cues increases craving and subsequent alcohol consumption. Override processes can be used to disengage attention from alcohol cues. This requires self-control and implies that depletion of self-control would impair the ability to disengage attention from alcohol cues. Th

  11. Haptic Cues Used for Outdoor Wayfinding by Individuals with Visual Impairments

    Science.gov (United States)

    Koutsoklenis, Athanasios; Papadopoulos, Konstantinos

    2014-01-01

    Introduction: The study presented here examines which haptic cues individuals with visual impairments use more frequently and determines which of these cues are deemed by these individuals to be the most important for way-finding in urban environments. It also investigates the ways in which these haptic cues are used by individuals with visual…

  12. Selecting a Response in Task Switching: Testing a Model of Compound Cue Retrieval

    Science.gov (United States)

    Schneider, Darryl W.; Logan, Gordon D.

    2009-01-01

    How can a task-appropriate response be selected for an ambiguous target stimulus in task-switching situations? One answer is to use compound cue retrieval, whereby stimuli serve as joint retrieval cues to select a response from long-term memory. In the present study, the authors tested how well a model of compound cue retrieval could account for a…

  13. Haptic Cues Used for Outdoor Wayfinding by Individuals with Visual Impairments

    Science.gov (United States)

    Koutsoklenis, Athanasios; Papadopoulos, Konstantinos

    2014-01-01

    Introduction: The study presented here examines which haptic cues individuals with visual impairments use more frequently and determines which of these cues are deemed by these individuals to be the most important for way-finding in urban environments. It also investigates the ways in which these haptic cues are used by individuals with visual…

  14. Two faces of anonymity : Paradoxical effects of cues to identity in CMC

    NARCIS (Netherlands)

    Tanis, M; Postmes, T.

    2007-01-01

    This paper presents two experimental studies investigating the effects of presenting cues that provide information about the interactors - called cues to identity - in computer mediated communications (CMCs). Study I shows that even though cues to identity affected interpersonal evaluations, in maki

  15. Emotions in primary care: are there cultural differences in the expression of cues and concerns?

    NARCIS (Netherlands)

    Schouten, B.C.; Schinkel, S.

    2015-01-01

    OBJECTIVE: This study compared native-Dutch and Turkish-Dutch patients' expressions of emotional cues/concerns and GPs' responses to these cues/concerns. Relations between patient's cues/concerns and GPs' perceptions of the patient's health complaint were examined too. METHODS: 82 audiotaped encount

  16. The Effect of Varied Visual Cueing Strategies in Facilitating Student Achievement on Different Educational Objectives.

    Science.gov (United States)

    Jennings, Thomas; Dwyer, Francis M.

    The effectiveness of elaborate visual cueing and reduced step size (i.e., increasing the number of visual cues) in facilitating student achievement on different instructional tasks was examined. The hypothesis proposed that instructional treatments utilizing reduced step size and elaborate visual cueing alone and in combination would be superior…

  17. Craving and startle modification during in vivo exposure to food cues.

    Science.gov (United States)

    Hawk, Larry W; Baschnagel, Joseph S; Ashare, Rebecca L; Epstein, Leonard H

    2004-12-01

    Food craving and reactivity to food cues are related to food intake. Research has shown that both startle magnitude and prepulse inhibition of startle may be useful indices of cue reactivity and drug craving. The goal of this study was to assess the utility of these paradigms for the study of food craving in food-deprived participants. Twenty-nine non-smoking, food-deprived undergraduate participants were exposed to a counterbalanced series of food, cigarette, and neutral cues. During each 4.5-min cue, nine startle probes (102-dB white noise) were presented, and a prepulse (20-ms noise 8 dB above background) preceded 2/3 of the probes by 60 or 120 ms. Subjects were divided into those high and low in food-craving on the basis of subjective craving to food cues. Responses to food cues were compared to smoking cues to control for attention and arousal. Both probe-alone startle magnitude and percent prepulse inhibition were significantly reduced during the food cue compared to the smoking cue among high food cravers, but not low food cravers. These processes seemed to be independent, as cue-induced changes in prepulse inhibition were uncorrelated with cue effects on probe-alone startle magnitude. Both probe-alone startle magnitude and prepulse inhibition are sensitive to cue-induced craving for food, but appear to assess separate processes. Startle methodologies may prove useful in understanding basic processes that regulate food intake.

  18. Dual-Processes in Learning and Judgment: Evidence from the Multiple Cue Probability Learning Paradigm

    Science.gov (United States)

    Rolison, Jonathan J.; Evans, Jonathan St. B. T.; Dennis, Ian; Walsh, Clare R.

    2012-01-01

    Multiple cue probability learning (MCPL) involves learning to predict a criterion based on a set of novel cues when feedback is provided in response to each judgment made. But to what extent does MCPL require controlled attention and explicit hypothesis testing? The results of two experiments show that this depends on cue polarity. Learning about…

  19. Direct effects of food cues seen during TV viewing on energy intake in young women

    NARCIS (Netherlands)

    Nee, R.L. van; Larsen, J.K.; Fisher, J.O.

    2016-01-01

    Few studies have examined direct effects of food cues presented within television (TV) programs on eating behavior in adults. This research experimentally determined whether exposure to food cues in TV programs affects energy intake during TV viewing among young women, independently from food cues p

  20. Direct effects of food cues seen during TV viewing on energy intake in young women

    NARCIS (Netherlands)

    Nee, R.L. van; Larsen, J.K.; Fisher, J.O.

    2016-01-01

    Few studies have examined direct effects of food cues presented within television (TV) programs on eating behavior in adults. This research experimentally determined whether exposure to food cues in TV programs affects energy intake during TV viewing among young women, independently from food cues

  1. Effort responses to suboptimal reward cues are related to striatal dopaminergic functioning

    NARCIS (Netherlands)

    Pas, P.; Custers, R.; Bijleveld, E.H.; Vink, M.

    2014-01-01

    Reward cues have been found to increase the investment of effort in tasks even when cues are presented suboptimally (i.e. very briefly), making them hard to consciously detect. Such effort responses to suboptimal reward cues are assumed to rely mainly on the mesolimbic dopamine system, including the

  2. Development and Implementation of Discrete Polymeric Microstructural Cues for Applications in Cardiac Tissue Engineering

    Science.gov (United States)

    Pinney, James Richardson

    Chronic fibrosis caused by acute myocardial infarction (MI) leads to increased morbidity and mortality due to cardiac dysfunction. Despite care in the acute setting of MI, subsequent development of scar tissue and a lack of treatments for this maladaptive response lead to a poor prognosis. This has increased burdens on the cost of healthcare due to chronic disability. Here a novel therapeutic strategy that aims to mitigate myocardial fibrosis by utilizing injectable polymeric microstructural cues to attenuate the fibrotic response and improve functional outcomes is presented. Additionally, applications of integrated chemical functionalizations into discrete, micro-scale polymer structures are discussed in the realm of tissue engineering in order to impart enhancements in in vivo localization, three-dimensional manipulation and drug delivery. Polymeric microstructures, termed "microrods" and "microcubes", were fabricated using photolithographic techniques and studied in three-dimensional culture models of the fibrotic environment and by direct injection into the infarct zone of adult Sprague-Dawley rats. In vitro gene expression and functional and histological results were analyzed, showing a dose-dependent down-regulation fibrotic indicators and improvement in cardiac function. Furthermore, iron oxide nanoparticles and functionalized fluorocarbons were incorporated into the polymeric microdevices to promote in situ visualization by magnetic resonance imaging as well as to facilitate the manipulation and alignment of microstructural cues in a tissue-realistic environment. Lastly, successful encapsulation of native MGF peptide within microrods is demonstrated with release over two weeks as a proof of concept in the ability to locally deliver myogenic or supportive pharmacotherapeutics to the injured myocardium. This work demonstrates the efficacy and versatility of discrete microtopographical cues to attenuate the fibrotic response after MI and suggests a novel

  3. OCCURRENCE OF PATHOGENIC BACTERIA ASSOCIATED WITH ...

    African Journals Online (AJOL)

    USER

    carriers of microbial and other health hazards (Yagoub. 2009, Adebayo ... swirled in 10 ml distilled water (Emikpe et al., 2011). The stock .... two fish farms are of good quality because the aerobic plate count ... and Technology 25: 607-625. 148 ...

  4. Coryneform bacteria associated with canine otitis externa

    DEFF Research Database (Denmark)

    Aalbæk, Bent; Bemis, David A.; Schjærff, Mette

    2010-01-01

    of coryneform bacteria was 16% among 55 cases of canine otitis externa examined at the Danish hospital during 2007. In contrast, detectable levels of coryneform bacteria were not demonstrated in samples from the acustic meatus of 35 dogs with apparently healthy ears, attending the hospital during the same year......This study aims to investigate the occurrence of coryneform bacteria in canine otitis externa. A combined case series and case-control study was carried out to improve the current knowledge on frequency and clinical significance of coryneform bacteria in samples from canine otitis externa. A total...... of 16 cases of otitis externa with involvement of coryneform bacteria were recorded at two referral veterinary hospitals in Denmark and the US, respectively. Coryneform bacteria were identified by partial 16S rRNA gene sequencing. Corynebacterium auriscanis was the most common coryneform species (10...

  5. Coryneform bacteria associated with canine otitis externa.

    Science.gov (United States)

    Aalbæk, Bent; Bemis, David A; Schjærff, Mette; Kania, Stephen A; Frank, Linda A; Guardabassi, Luca

    2010-10-26

    This study aims to investigate the occurrence of coryneform bacteria in canine otitis externa. A combined case series and case-control study was carried out to improve the current knowledge on frequency and clinical significance of coryneform bacteria in samples from canine otitis externa. A total of 16 cases of otitis externa with involvement of coryneform bacteria were recorded at two referral veterinary hospitals in Denmark and the US, respectively. Coryneform bacteria were identified by partial 16S rRNA gene sequencing. Corynebacterium auriscanis was the most common coryneform species (10 cases). Small colony variants of this species were also observed. Other coryneform isolates were identified as Corynebacterium amycolatum (3 cases), Corynebacterium freneyi (2 cases) and an Arcanobacterium-like species (1 case). The coryneform bacteria were in all cases isolated together with other bacteria, mainly Staphylococcus pseudintermedius alone (n=5) or in combination with Malassezia pachydermatis (n=5). Some coryneform isolates displayed resistance to fusidic acid or enrofloxacin, two antimicrobial agents commonly used for the treatment of otitis externa in dogs. The frequency of isolation of coryneform bacteria was 16% among 55 cases of canine otitis externa examined at the Danish hospital during 2007. In contrast, detectable levels of coryneform bacteria were not demonstrated in samples from the acustic meatus of 35 dogs with apparently healthy ears, attending the hospital during the same year. On basis of the current knowledge, these coryneform bacteria should be regarded as potential secondary pathogens able to proliferate in the environment of an inflamed ear canal.

  6. Roles of olfactory cues, visual cues, and mating status in orientation of Diaphorina citri Kuwayama (Hemiptera: Psyllidae) to four different host plants.

    Science.gov (United States)

    Wenninger, Erik J; Stelinski, Lukasz L; Hall, David G

    2009-02-01

    Diaphorina citri Kuwayama (Hemiptera: Psyllidae) is an important worldwide pest of citrus that vectors bacteria (Candidatus Liberibacter spp.) responsible for huanglongbing (citrus greening disease). We examined the behavioral responses of mated and unmated D. citri of both sexes to odors from host plants in a Y-tube olfactometer, with and without visual cues. The host plants tested were 'Duncan' grapefruit (Citrus paradisi Macfayden), sour orange (Citrus aurantium L.), navel orange (C. sinensis L.), and Murraya paniculata L. Jack. Responses varied by plant species, psyllid sex and mating status, and the presence of a visual cue. Evidence of attraction generally was stronger in females and in mated individuals of both sexes relative to virgins. The presence of a visual cue typically enhanced attractiveness of olfactory cues; in no case did unmated individuals show evidence of attraction to host plant odors in the absence of avisual cue. In the absence of visual cues, mated females and males showed evidence of attraction only to odors from sour orange and navel orange, respectively. Psyllids exhibited anemotactic responses when assayed with plant odors alone but showed strong evidence of attraction only when olfactory and visual cues were combined, suggesting that olfactory cues facilitate orientation to host plants but may be insufficient alone. Antennal responses to citrus volatiles were confirmed by electroantennogram. The results reported here provide evidence that D. citri uses olfactory and visual cues in orientation to host plants and suggest the possibility of using plant volatiles in monitoring and management of this pest.

  7. 16s rDNA文库法分析番石榴果实蝇共生菌组成%Composition of symbiotic bacteria associated with Bactrocera correcta analyzed by 16s rDNA libraries

    Institute of Scientific and Technical Information of China (English)

    戴阳; 李志红; 柳丽君; 吴佳教; 邓裕亮

    2012-01-01

    [Objective] The composition of symbiotic bacteria associated with Guava fruit fly, Bacirocera correcta (Bezzi), was investigated to provide the basis for further study on physiological function of the symbionts and co-evolution between bacteria and the host. [Method] 16s rDNA libraries of laboratory population for B. correcta were constructed, and BLAST analysis of bacterial composition and abundance was carried out in this study. [Result] The dominant symbionts in B. correcta male adults were Pseudomonas aeruginosa and Lactococcus lactis, while symbiotic bacteria in female adults were Enterobacter bacteria. [Conclusion] Various bacteria are present in the Guava fruit fly, B. correcta.%[目的]探索分析番石榴果实蝇[ Bactrocera correcta (Bezzi)]的共生菌组成,为进一步探索共生菌的生理功能以及与宿主的协同进化关系奠定基础.[方法]构建番石榴果实蝇室内种群共生菌的16s rDNA文库,BLAST分析其共生菌的组成以及丰度.[结果]室内雄虫共生菌主要为Pseudomonas aeruginosa和Lactococcus lactis,雌虫共生菌主要为Enterobacter属的细菌.[结论]本研究结果证明番石榴果实蝇存在多种共生菌.

  8. Effects of cue frequency and repetition on prospective memory: an ERP investigation.

    Science.gov (United States)

    Wilson, Jennifer; Cutmore, Tim R H; Wang, Ya; Chan, Raymond C K; Shum, David H K

    2013-11-01

    Prospective memory involves the formation and completion of delayed intentions and is essential for independent living. In this study (n = 33), event-related potentials (ERPs) were used to systematically evaluate the effects of PM cue frequency (10% versus 30%) and PM cue repetition (high versus low) on ERP modulations. PM cues elicited prospective positivity and frontal positivity but not N300, perhaps due to the semantic nature of the task. Results of this study revealed an interesting interaction between PM cue frequency and PM cue repetition for prospective positivity and frontal positivity, highlighting the importance of taking both factors into account when designing future studies.

  9. Facial Cues to Perceived Height Influence Leadership Choices in Simulated War and Peace Contexts

    Directory of Open Access Journals (Sweden)

    Daniel E. Re

    2013-01-01

    Full Text Available Body size and other signs of physical prowess are associated with leadership hierarchies in many social species. Here we (1 assess whether facial cues associated with perceived height and masculinity have different effects on leadership judgments in simulated wartime and peacetime contexts and (2 test how facial cues associated with perceived height and masculinity influence dominance perceptions. Results indicate that cues associated with perceived height and masculinity in potential leaders' faces are valued more in a wartime (vs. peacetime context. Furthermore, increasing cues of apparent height and masculinity in faces increased perceived dominance. Together, these findings suggest that facial cues of physical stature contribute to establishing leadership hierarchies in humans.

  10. Mixed Messages: Illusory Durations Induced by Cue Combination

    Directory of Open Access Journals (Sweden)

    Craig Aaen-Stockdale

    2012-05-01

    Full Text Available Pairing a visual stimulus with a concurrent auditory stimulus of subtly longer or shorter duration expands or contracts the duration of that visual stimulus, even when the observer is asked to ignore the irrelevant auditory component. Here we map out this relationship and find a roughly linear relationship between perceived duration of the visual component and the duration of the irrelevant auditory component. Beyond this ‘window of integration’ the obligatory combination of cues breaks down rather suddenly, at durations 0.2 log units longer or shorter than baseline. Conversely, a visual duration has virtually no effect on the perceived duration of a concurrently presented auditory duration. A model is presented based on obligatory combination of visual and auditory cues within a window defined by the respective JNDs of vision and audition.

  11. Microfluidic device with dual mechanical cues for cell migration investigation.

    Science.gov (United States)

    Tsai, Chin-Hsiung; Kuo, Po-Ling

    2013-01-01

    Cell migration plays an important role in numerous physiological and pathological conditions, such as angiogenesis, wound healing and cancer metastasis. Understanding the fundamental mechanisms of cell migration is crucial to develop strategies for disease treatment and regenerative medicine. Several biomechanical cues have been well studied about their effects on guiding cell migration. However, the effects of dual or multiple cues on cell migration are barely addressed. In this work, we developed a microfluidic-based device to study the combinatory effects of osmotic and stiffness gradient on cell migration. Computer simulation and experimental validation showed that the device was capable of providing stable osmotic and stiffness gradient to cultured cells at the same time. Preliminary results suggest that our device has a valuable potential in studying cell migration in complex conditions which better recapitulate the complex environmental conditions in vivo.

  12. Increasing hand washing compliance with a simple visual cue.

    Science.gov (United States)

    Ford, Eric W; Boyer, Brian T; Menachemi, Nir; Huerta, Timothy R

    2014-10-01

    We tested the efficacy of a simple, visual cue to increase hand washing with soap and water. Automated towel dispensers in 8 public bathrooms were set to present a towel either with or without activation by users. We set the 2 modes to operate alternately for 10 weeks. Wireless sensors were used to record entry into bathrooms. Towel and soap consumption rates were checked weekly. There were 97,351 hand-washing opportunities across all restrooms. Towel use was 22.6% higher (P=.05) and soap use was 13.3% higher (P=.003) when the dispenser presented the towel without user activation than when activation was required. Results showed that a visual cue can increase hand-washing compliance in public facilities.

  13. Cues and economy in the acquisition of verb movement

    Directory of Open Access Journals (Sweden)

    Kristine Bentzen

    2005-02-01

    Full Text Available In this paper we will discuss how economy principles interact with cues in the input in bilingual first language acquisition. We will look at the acquisition of verb placement in a child acquiring English and Norwegian simultaneously. Based on data from this child, it will be argued that when faced with ambiguous cues with respect to the verb movement parameter, children do not necessarily adopt the default, less marked setting. Rather, they may opt for a setting which yields an overall consistent grammar, even when this grammar contains operations that are more costly than those used in the target language. We will suggest that economy in acquisition may involve consistency in a grammar in correlation with economy in the more traditional sense within minimalism, where moving an element in general is considered more costly than not moving it (Chomsky 1995.

  14. Durable spatiotemporal surveillance of Caenorhabditis elegans response to environmental cues

    Science.gov (United States)

    Kopito, Ronen B; Levine, Erel

    2016-01-01

    Animal response to changes in environmental cues is a complex dynamical process that occurs at diverse molecular and cellular levels. To gain a quantitative understanding of such processes, it is desirable to observe many individuals, subjected to repeatable and well defined environmental cues over long time periods. Here we present WormSpa, a microfluidic system where worms are individually confined in optimized chambers. We show that worms in WormSpa are neither stressed nor starved, and in particular exhibit pumping and egg-laying behaviors equivalent to those of freely behaving worms. We demonstrate the applicability of WormSpa for studying stress response and physiological processes. WormSpa is simple to make and easy to operate, and its design is modular, making it straightforward to incorporate available microfluidic technologies. We expect that WormSpa would open novel avenues of research, hitherto impossible or impractical. PMID:24336777

  15. The avian head induces cues for sound localization in elevation.

    Directory of Open Access Journals (Sweden)

    Hans A Schnyder

    Full Text Available Accurate sound source localization in three-dimensional space is essential for an animal's orientation and survival. While the horizontal position can be determined by interaural time and intensity differences, localization in elevation was thought to require external structures that modify sound before it reaches the tympanum. Here we show that in birds even without external structures like pinnae or feather ruffs, the simple shape of their head induces sound modifications that depend on the elevation of the source. Based on a model of localization errors, we show that these cues are sufficient to locate sounds in the vertical plane. These results suggest that the head of all birds induces acoustic cues for sound localization in the vertical plane, even in the absence of external ears.

  16. The avian head induces cues for sound localization in elevation.

    Science.gov (United States)

    Schnyder, Hans A; Vanderelst, Dieter; Bartenstein, Sophia; Firzlaff, Uwe; Luksch, Harald

    2014-01-01

    Accurate sound source localization in three-dimensional space is essential for an animal's orientation and survival. While the horizontal position can be determined by interaural time and intensity differences, localization in elevation was thought to require external structures that modify sound before it reaches the tympanum. Here we show that in birds even without external structures like pinnae or feather ruffs, the simple shape of their head induces sound modifications that depend on the elevation of the source. Based on a model of localization errors, we show that these cues are sufficient to locate sounds in the vertical plane. These results suggest that the head of all birds induces acoustic cues for sound localization in the vertical plane, even in the absence of external ears.

  17. Interpretation bias in responses to ambiguous cues in pain patients.

    Science.gov (United States)

    Pincus, T; Pearce, S; McClelland, A; Farley, S; Vogel, S

    1994-05-01

    Pain patients and control subjects responses to ambiguous cues were compared in two separate investigations. In the first, pain patients, control subjects and physiotherapists were asked to produce a list of spontaneous associations to ambiguous cues (such as terminal and growth). To control for mood effects the experiment was repeated with three more groups: Pain patients, osteopaths and a control group. Measures of anxiety and depression were incorporated in the analysis. Results indicate that pain patients systematically produce more pain related associations than the other groups, and that this effect is independent of anxiety and depression levels. The discussion concentrates on the implications of these findings both for the theory of pain processing and for clinical interventions.

  18. The Influence of Visual Cues on Sound Externalization

    DEFF Research Database (Denmark)

    Carvajal, Juan Camilo Gil; Santurette, Sébastien; Cubick, Jens;

    Background: The externalization of virtual sounds reproduced via binaural headphone-based auralization systems has been reported to be less robust when the listening environment differs from the room in which binaural room impulse responses (BRIRs) were recorded. It has been debated whether...... this is due to incongruent auditory cues between the recording and playback room during sound reproduction or to an expectation effect from the visual impression of the room. This study investigated the influence of a priori acoustic and visual knowledge of the playback room on sound externalization...... the more reverberant the listening environment was. While the visual impression of the playback room did not affect perceived distance, visual cues helped resolve localization ambiguities and improved compactness perception....

  19. In monkeys making value-based decisions, amygdala neurons are sensitive to cue value as distinct from cue salience.

    Science.gov (United States)

    Leathers, Marvin L; Olson, Carl R

    2017-04-01

    Neurons in the lateral intraparietal (LIP) area of macaque monkey parietal cortex respond to cues predicting rewards and penalties of variable size in a manner that depends on the motivational salience of the predicted outcome (strong for both large reward and large penalty) rather than on its value (positive for large reward and negative for large penalty). This finding suggests that LIP mediates the capture of attention by salient events and does not encode value in the service of value-based decision making. It leaves open the question whether neurons elsewhere in the brain encode value in the identical task. To resolve this issue, we recorded neuronal activity in the amygdala in the context of the task employed in the LIP study. We found that responses to reward-predicting cues were similar between areas, with the majority of reward-sensitive neurons responding more strongly to cues that predicted large reward than to those that predicted small reward. Responses to penalty-predicting cues were, however, markedly different. In the amygdala, unlike LIP, few neurons were sensitive to penalty size, few penalty-sensitive neurons favored large over small penalty, and the dependence of firing rate on penalty size was negatively correlated with its dependence on reward size. These results indicate that amygdala neurons encoded cue value under circumstances in which LIP neurons exhibited sensitivity to motivational salience. However, the representation of negative value, as reflected in sensitivity to penalty size, was weaker than the representation of positive value, as reflected in sensitivity to reward size.NEW & NOTEWORTHY This is the first study to characterize amygdala neuronal responses to cues predicting rewards and penalties of variable size in monkeys making value-based choices. Manipulating reward and penalty size allowed distinguishing activity dependent on motivational salience from activity dependent on value. This approach revealed in a previous study

  20. Cue utilisation and quality perception with regard to branded beef

    DEFF Research Database (Denmark)

    Bredahl, Lone

    2004-01-01

    Consumers' quality perception is based on individual evaluative judgments. Meat is a food category where consumers' quality perception is particularly difficult, among other things because meat is mostly sold unbranded. Through interviews with buyers of branded beef steaks, the study investigates...... the presence of a brand, the correspondence between expected and experienced quality remains moderate. Product familiarity seems to influence the quality perception process as well, with low familiarity consumers relying significantly more on the brand as a quality cue....

  1. Improved curveball hitting through the enhancement of visual cues.

    OpenAIRE

    Osborne, K; Rudrud, E; Zezoney, F

    1990-01-01

    This study investigated the effectiveness of using visual cues to highlight the seams of baseballs to improve the hitting of curveballs. Five undergraduate varsity baseball team candidates served as subjects. Behavior change was assessed through an alternating treatments design involving unmarked balls and two treatment conditions that included baseballs with 1/4-in. and 1/8-in. orange stripes marking the seams of the baseballs. Results indicated that subjects hit a greater percentage of mark...

  2. Incidental rewarding cues influence economic decision-making in obesity

    Directory of Open Access Journals (Sweden)

    Jakob eSimmank

    2015-10-01

    Full Text Available Recent research suggests that obesity is linked to prominent alterations in learning and decision-making. This general difference may also underlie the preference for immediately consumable, highly palatable but unhealthy and high-calorie foods. Such poor food-related inter-temporal decision-making can explain weight gain; however, it is not yet clear whether this deficit can be generalized to other domains of inter-temporal decision-making, for example financial decisions. Further, little is known about the stability of decision-making behavior in obesity, especially in the presence of rewarding cues. To answer these questions, obese and lean participants (n=52 completed two sessions of a novel priming paradigm including a computerized monetary delay discounting task. In the first session, general differences between groups in financial delay discounting were measured. In the second session, we tested the general stability of discounting rates. Additionally, participants were primed by affective visual cues of different contextual categories before the financial decision. We found that the obese group showed stronger discounting of future monetary rewards than the lean group, but groups did not differ in their general stability between sessions nor in their sensitivity towards changes in reward magnitude. In the obese group, a fast decrease of subjective value over time was directly related to a higher tendency for opportunistic eating. Obese in contrast to lean people were primed by the affective cues, showing a sex-specific pattern of priming direction. Our findings demonstrate that environments rich of cues, aiming at inducing unhealthy consumer decisions, can be highly detrimental for obese people. It also underscores that obesity is not merely a medical condition but has a strong cognitive component, meaning that current dietary and medical treatment strategies may fall too short.

  3. Behavioral sensitivity to broadband binaural localization cues in the ferret.

    Science.gov (United States)

    Keating, Peter; Nodal, Fernando R; Gananandan, Kohilan; Schulz, Andreas L; King, Andrew J

    2013-08-01

    Although the ferret has become an important model species for studying both fundamental and clinical aspects of spatial hearing, previous behavioral work has focused on studies of sound localization and spatial release from masking in the free field. This makes it difficult to tease apart the role played by different spatial cues. In humans and other species, interaural time differences (ITDs) and interaural level differences (ILDs) play a critical role in sound localization in the azimuthal plane and also facilitate sound source separation in noisy environments. In this study, we used a range of broadband noise stimuli presented via customized earphones to measure ITD and ILD sensitivity in the ferret. Our behavioral data show that ferrets are extremely sensitive to changes in either binaural cue, with levels of performance approximating that found in humans. The measured thresholds were relatively stable despite extensive and prolonged (>16 weeks) testing on ITD and ILD tasks with broadband stimuli. For both cues, sensitivity was reduced at shorter durations. In addition, subtle effects of changing the stimulus envelope were observed on ITD, but not ILD, thresholds. Sensitivity to these cues also differed in other ways. Whereas ILD sensitivity was unaffected by changes in average binaural level or interaural correlation, the same manipulations produced much larger effects on ITD sensitivity, with thresholds declining when either of these parameters was reduced. The binaural sensitivity measured in this study can largely account for the ability of ferrets to localize broadband stimuli in the azimuthal plane. Our results are also broadly consistent with data from humans and confirm the ferret as an excellent experimental model for studying spatial hearing.

  4. On how the brain decodes vocal cues about speaker confidence.

    Science.gov (United States)

    Jiang, Xiaoming; Pell, Marc D

    2015-05-01

    In speech communication, listeners must accurately decode vocal cues that refer to the speaker's mental state, such as their confidence or 'feeling of knowing'. However, the time course and neural mechanisms associated with online inferences about speaker confidence are unclear. Here, we used event-related potentials (ERPs) to examine the temporal neural dynamics underlying a listener's ability to infer speaker confidence from vocal cues during speech processing. We recorded listeners' real-time brain responses while they evaluated statements wherein the speaker's tone of voice conveyed one of three levels of confidence (confident, close-to-confident, unconfident) or were spoken in a neutral manner. Neural responses time-locked to event onset show that the perceived level of speaker confidence could be differentiated at distinct time points during speech processing: unconfident expressions elicited a weaker P2 than all other expressions of confidence (or neutral-intending utterances), whereas close-to-confident expressions elicited a reduced negative response in the 330-500 msec and 550-740 msec time window. Neutral-intending expressions, which were also perceived as relatively confident, elicited a more delayed, larger sustained positivity than all other expressions in the 980-1270 msec window for this task. These findings provide the first piece of evidence of how quickly the brain responds to vocal cues signifying the extent of a speaker's confidence during online speech comprehension; first, a rough dissociation between unconfident and confident voices occurs as early as 200 msec after speech onset. At a later stage, further differentiation of the exact level of speaker confidence (i.e., close-to-confident, very confident) is evaluated via an inferential system to determine the speaker's meaning under current task settings. These findings extend three-stage models of how vocal emotion cues are processed in speech comprehension (e.g., Schirmer & Kotz, 2006) by

  5. Cues and control in Expert-Client Dialogues

    CERN Document Server

    Whittaker, S; Whittaker, Steve; Stenton, Phil

    1995-01-01

    We conducted an empirical analysis into the relation between control and discourse structure. We applied control criteria to four dialogues and identified 3 levels of discourse structure. We investigated the mechanism for changing control between these structures and found that utterance type and not cue words predicted shifts of control. Participants used certain types of signals when discourse goals were proceeding successfully but resorted to interruptions when they were not.

  6. Acoustic and Perceptual Cues to Contrastive Stress in Dysarthria

    Science.gov (United States)

    Patel, Rupal; Campellone, Pamela

    2009-01-01

    Purpose: In this study, the authors sought to understand acoustic and perceptual cues to contrastive stress in speakers with dysarthria (DYS) and healthy controls (HC). Method: The production experiment examined the ability of 12 DYS (9 male, 3 female; M = 39 years of age) and 12 age- and gender-matched HC (9 male, 3 female; M = 37.5 years of age)…

  7. Cue utilisation and quality perception with regard to branded beef

    DEFF Research Database (Denmark)

    Bredahl, Lone

    2004-01-01

    Consumers' quality perception is based on individual evaluative judgments. Meat is a food category where consumers' quality perception is particularly difficult, among other things because meat is mostly sold unbranded. Through interviews with buyers of branded beef steaks, the study investigates...... the presence of a brand, the correspondence between expected and experienced quality remains moderate. Product familiarity seems to influence the quality perception process as well, with low familiarity consumers relying significantly more on the brand as a quality cue....

  8. The scent of supercolonies: the discovery, synthesis and behavioural verification of ant colony recognition cues

    Directory of Open Access Journals (Sweden)

    Sulc Robert

    2009-10-01

    Full Text Available Abstract Background Ants form highly social and cooperative colonies that compete, and often fight, against other such colonies, both intra- and interspecifically. Some invasive ants take sociality to an extreme, forming geographically massive 'supercolonies' across thousands of kilometres. The success of social insects generally, as well as invasive ants in particular, stems from the sophisticated mechanisms used to accurately and precisely distinguish colonymates from non-colonymates. Surprisingly, however, the specific chemicals used for this recognition are virtually undescribed. Results Here, we report the discovery, chemical synthesis and behavioural testing of the colonymate recognition cues used by the widespread and invasive Argentine ant (Linepithema humile. By synthesizing pure versions of these chemicals in the laboratory and testing them in behavioural assays, we show that these compounds trigger aggression among normally amicable nestmates, but control hydrocarbons do not. Furthermore, behavioural testing across multiple different supercolonies reveals that the reaction to individual compounds varies from colony to colony -- the expected reaction to true colony recognition labels. Our results also show that both quantitative and qualitative changes to cuticular hydrocarbon profiles can trigger aggression among nestmates. These data point the way for the development of new environmentally-friendly control strategies based on the species-specific manipulation of aggressive behaviour. Conclusion Overall, our findings reveal the identity of specific chemicals used for colonymate recognition by the invasive Argentine ants. Although the particular chemicals used by other ants may differ, the patterns reported here are likely to be true for ants generally. As almost all invasive ants display widespread unicoloniality in their introduced ranges, our findings are particularly relevant for our understanding of the biology of these damaging

  9. Alcohol-cue exposure effects on craving and attentional bias in underage college-student drinkers.

    Science.gov (United States)

    Ramirez, Jason J; Monti, Peter M; Colwill, Ruth M

    2015-06-01

    The effect of alcohol-cue exposure on eliciting craving has been well documented, and numerous theoretical models assert that craving is a clinically significant construct central to the motivation and maintenance of alcohol-seeking behavior. Furthermore, some theories propose a relationship between craving and attention, such that cue-induced increases in craving bias attention toward alcohol cues, which, in turn, perpetuates craving. This study examined the extent to which alcohol cues induce craving and bias attention toward alcohol cues among underage college-student drinkers. We designed within-subject cue-reactivity and visual-probe tasks to assess in vivo alcohol-cue exposure effects on craving and attentional bias on 39 undergraduate college drinkers (ages 18-20). Participants expressed greater subjective craving to drink alcohol following in vivo cue exposure to a commonly consumed beer compared with water exposure. Furthermore, following alcohol-cue exposure, participants exhibited greater attentional biases toward alcohol cues as measured by a visual-probe task. In addition to the cue-exposure effects on craving and attentional bias, within-subject differences in craving across sessions marginally predicted within-subject differences in attentional bias. Implications for both theory and practice are discussed. (PsycINFO Database Record

  10. Measurement and modeling of depth cue combination: in defense of weak fusion.

    Science.gov (United States)

    Landy, M S; Maloney, L T; Johnston, E B; Young, M

    1995-02-01

    Various visual cues provide information about depth and shape in a scene. When several of these cues are simultaneously available in a single location in the scene, the visual system attempts to combine them. In this paper, we discuss three key issues relevant to the experimental analysis of depth cue combination in human vision: cue promotion, dynamic weighting of cues, and robustness of cue combination. We review recent psychophysical studies of human depth cue combination in light of these issues. We organize the discussion and review as the development of a model of the depth cue combination process termed modified weak fusion (MWF). We relate the MWF framework to Bayesian theories of cue combination. We argue that the MWF model is consistent with previous experimental results and is a parsimonious summary of these results. While the MWF model is motivated by normative considerations, it is primarily intended to guide experimental analysis of depth cue combination in human vision. We describe experimental methods, analogous to perturbation analysis, that permit us to analyze depth cue combination in novel ways. In particular these methods allow us to investigate the key issues we have raised. We summarize recent experimental tests of the MWF framework that use these methods.

  11. Cue integration vs. exemplar-based reasoning in multi-attribute decisions from memory

    Directory of Open Access Journals (Sweden)

    Arndt Broeder

    2010-08-01

    Full Text Available Inferences about target variables can be achieved by deliberate integration of probabilistic cues or by retrieving similar cue-patterns (exemplars from memory. In tasks with cue information presented in on-screen displays, rule-based strategies tend to dominate unless the abstraction of cue-target relations is unfeasible. This dominance has also been demonstrated --- surprisingly --- in experiments that demanded the retrieval of cue values from memory (M. Persson and J. Rieskamp, 2009. In three modified replications involving a fictitious disease, binary cue values were represented either by alternative symptoms (e.g., fever vs. hypothermia or by symptom presence vs. absence (e.g., fever vs. no fever. The former representation might hinder cue abstraction. The cues were predictive of the severity of the disease, and participants had to infer in each trial who of two patients was sicker. Both experiments replicated the rule-dominance with present-absent cues but yielded higher percentages of exemplar-based strategies with alternative cues. The experiments demonstrate that a change in cue representation may induce a dramatic shift from rule-based to exemplar-based reasoning in formally identical tasks.

  12. Children’s identification of familiar songs from pitch and timing cues

    Directory of Open Access Journals (Sweden)

    Anna eVolkova

    2014-08-01

    Full Text Available The goal of the present study was to ascertain whether children with normal hearing and prelingually deaf children with cochlear implants could use pitch or timing cues alone or in combination to identify familiar songs. Children 4-7 years of age were required to identify the theme songs of familiar TV shows in a simple task with excerpts that preserved (1 the relative pitch and timing cues of the melody but not the original instrumentation, (2 the timing cues only (rhythm, meter, and tempo, and (3 the relative pitch cues only (pitch contour and intervals. Children with normal hearing performed at high levels and comparably across the three conditions. The performance of child implant users was well above chance levels when both pitch and timing cues were available, marginally above chance with timing cues only, and at chance with pitch cues only. This is the first demonstration that children can identify familiar songs from monotonic versions—timing cues but no pitch cues—and from isochronous versions—pitch cues but no timing cues. The study also indicates that, in the context of a very simple task, young implant users readily identify songs from melodic versions that preserve pitch and timing cues.

  13. When to approach novel prey cues? Social learning strategies in frog-eating bats.

    Science.gov (United States)

    Jones, Patricia L; Ryan, Michael J; Flores, Victoria; Page, Rachel A

    2013-12-01

    Animals can use different sources of information when making decisions. Foraging animals often have access to both self-acquired and socially acquired information about prey. The fringe-lipped bat, Trachops cirrhosus, hunts frogs by approaching the calls that frogs produce to attract mates. We examined how the reliability of self-acquired prey cues affects social learning of novel prey cues. We trained bats to associate an artificial acoustic cue (mobile phone ringtone) with food rewards. Bats were assigned to treatments in which the trained cue was either an unreliable indicator of reward (rewarded 50% of the presentations) or a reliable indicator (rewarded 100% of the presentations), and they were exposed to a conspecific tutor foraging on a reliable (rewarded 100%) novel cue or to the novel cue with no tutor. Bats whose trained cue was unreliable and who had a tutor were significantly more likely to preferentially approach the novel cue when compared with bats whose trained cue was reliable, and to bats that had no tutor. Reliability of self-acquired prey cues therefore affects social learning of novel prey cues by frog-eating bats. Examining when animals use social information to learn about novel prey is key to understanding the social transmission of foraging innovations.

  14. Pavlovian conditioning to hedonic food cues in overweight and lean individuals.

    Science.gov (United States)

    Meyer, Monica D; Risbrough, Victoria B; Liang, June; Boutelle, Kerri N

    2015-04-01

    Obese individuals develop heightened reactivity to environmental cues associated with hedonic foods through Pavlovian conditioning. This study examined differences between overweight (n = 16) and lean (n = 17) 18-26 year-olds in their acquisition of a swallowing response to visual cues paired with chocolate milk, tasteless water and no taste stimulus. We hypothesized that, compared to lean participants, overweight participants would demonstrate a heightened conditioned swallowing response to the visual cue paired with chocolate milk as well as a resistance to extinction of this response. Results showed that overweight participants swallowed more in response to the visual cue previously paired with chocolate than the cue previously paired with tasteless water (t(15) = -3.057, p = .008) while lean participants showed no cue discrimination (t(16) = -1.027, p = .320). The results evaluating the extinction hypothesis could not be evaluated, as the lean participants did not acquire a conditioned response. In evaluating the conditioned swallow response of overweight participants only, results indicated that there was not a significant decrease in swallowing to cues paired with chocolate milk or water, but overall, overweight participants swallowed more to cues paired with chocolate than cues paired with water. These are the first results to show differential acquisition of Pavlovian conditioned responding in overweight individuals compared to lean individuals, as well as differential conditioning to cues paired with hedonic food stimuli compared to cues paired with neutral stimuli.

  15. Dynamic perspective cues enhance depth perception from motion parallax.

    Science.gov (United States)

    Buckthought, Athena; Yoonessi, Ahmad; Baker, Curtis L

    2017-01-01

    Motion parallax, the perception of depth resulting from an observer's self-movement, has almost always been studied with random dot textures in simplified orthographic rendering. Here we examine depth from motion parallax in more naturalistic conditions using textures with an overall 1/f spectrum and dynamic perspective rendering. We compared depth perception for orthographic and perspective rendering, using textures composed of two types of elements: random dots and Gabor micropatterns. Relative texture motion (shearing) with square wave corrugation patterns was synchronized to horizontal head movement. Four observers performed a two-alternative forced choice depth ordering task with monocular viewing, in which they reported which part of the texture appeared in front of the other. For both textures, depth perception was better with dynamic perspective than with orthographic rendering, particularly at larger depths. Depth ordering performance with naturalistic 1/f textures was slightly lower than with the random dots; however, with depth-related size scaling of the micropatterns, performance was comparable to that with random dots. We also examined the effects of removing each of the three cues that distinguish dynamic perspective from orthographic rendering: (a) small vertical displacements, (b) lateral gradients of speed across the corrugations, and (c) speed differences in rendered near versus far surfaces. Removal of any of the three cues impaired performance. In conclusion, depth ordering performance is enhanced by all of the dynamic perspective cues but not by using more naturalistic 1/f textures.

  16. Spectral segmentation via midlevel cues integrating geodesic and intensity.

    Science.gov (United States)

    Lu, Huchuan; Zhang, Ruixuan; Li, Shifeng; Li, Xuelong

    2013-12-01

    Image segmentation still remains as a challenge in image processing and pattern recognition when involving complex natural scenes. In this paper, we present a new affinity model for spectral segmentation based on midlevel cues. In contrast to most existing methods that operate directly on low-level cues, we first oversegment the image into superpixel images and then integrate the geodesic line edge and intensity cue to form the similarity matrix W so that it more accurately describes the similarity between data. The geodesic line edge could avoid strong boundary and represent the true boundary between two superpixels while the mean red green blue vector could describe the intensity of superpixels better. As far as we know, this is a totally new kind of affinity model to represent superpixels. Based on this model, we use the spectral clustering in the superpixel level and then achieve the image segmentation in the pixel level. The experimental results show that the proposed method performs steadily and well on various natural images. The evaluation comparisons also prove that our method achieves comparable accuracy and significantly performs better than most state-of-the-art algorithms.

  17. Uncovering gender discrimination cues in a realistic setting.

    Science.gov (United States)

    Dupuis-Roy, Nicolas; Fortin, Isabelle; Fiset, Daniel; Gosselin, Frédéric

    2009-02-10

    Which face cues do we use for gender discrimination? Few studies have tried to answer this question and the few that have tried typically used only a small set of grayscale stimuli, often distorted and presented a large number of times. Here, we reassessed the importance of facial cues for gender discrimination in a more realistic setting. We applied Bubbles-a technique that minimizes bias toward specific facial features and does not necessitate the distortion of stimuli-to a set of 300 color photographs of Caucasian faces, each presented only once to 30 participants. Results show that the region of the eyes and the eyebrows-probably in the light-dark channel-is the most important facial cue for accurate gender discrimination; and that the mouth region is driving fast correct responses (but not fast incorrect responses)-the gender discrimination information in the mouth region is concentrated in the red-green color channel. Together, these results suggest that, when color is informative in the mouth region, humans use it and respond rapidly; and, when it's not informative, they have to rely on the more robust but more sluggish luminance information in the eye-eyebrow region.

  18. Social performance cues induce behavioral flexibility in humans

    Directory of Open Access Journals (Sweden)

    Ulf eToelch

    2011-07-01

    Full Text Available Behavioral flexibility allows individuals to react to environmental changes, but changing established behavior carries costs, with unknown benefits. Individuals may thus modify their behavioral flexibility according to the prevailing circumstances. Social information provided by the performance level of others provides one possible cue to assess the potential benefits of changing behavior, since out-performance in similar circumstances indicates that novel behaviors (innovations are potentially useful. We demonstrate that social performance cues, in the form of previous players’ scores in a problem-solving computer game, influence behavioral flexibility. Participants viewed only performance indicators, not the innovative behavior of others. While performance cues (high, low, or no scores had little effect on innovation discovery rates, participants that viewed high scores increased their utilization of innovations, allowing them to exploit the virtual environment more effectively than players viewing low or no scores. Perceived conspecific performance can thus shape human decisions to adopt novel traits, even when the traits employed cannot be copied. This simple mechanism, social performance feedback, could be a driver of both the facultative adoption of innovations and cumulative cultural evolution, processes critical to human success.

  19. Role of gravitational versus egocentric cues for human spatial orientation.

    Science.gov (United States)

    Bury, Nils; Bock, Otmar

    2016-04-01

    Our perception of the vertical depends on allocentric information about the visual surrounds, egocentric information about the own body axis and gravicentric information about the pull of gravity. Previous work has documented that some individuals rely strongly on allocentric information, while others do not, and the present work scrutinizes the existence of yet another dichotomy: We hypothesize that in the absence of allocentric cues, some individuals rely strongly on gravicentric information, while others do not. Twenty-four participants were tested at three angles of body pitch (0° = upright, -90° = supine, -110° = head down) after eliminating visual orientation cues. When asked to adjust a rotating tree '…such that the tree looks right,' nine persons set the tree consistently parallel to gravity, eight consistently parallel to their longitudinal axis and seven switched between these two references; responses mid-between gravity and body axis were rare. The outcome was similar when tactile cues were masked by body vibration, as well as when participants were asked to adjust the tree '… such that leaves are at the top and roots are at the bottom'; the incidence of gravicentric responses increased with the instruction to set the tree '… such that leaves are at the top and roots are at the bottom in space, irrespective of your own position.' We conclude that the perceived vertical can be anchored in gravicentric or in egocentric space, depending on instructions and individual preference.

  20. Geometric cue for protein localization in a bacterium

    Science.gov (United States)

    Lecuyer, Sigolene; Ramamurthi, Kumaran; Stone, Howard; Losick, Richard

    2009-03-01

    Proteins in bacteria deploy to particular places, but the cues for localization are frequently mysterious. We present evidence that the membrane protein SpoVM recognizes a geometric cue in Bacillus subtilis. In vivo experiments show that SpoVM localizes to a particular patch of the inner membrane in sporulating Bacillus subtilis bacteria, namely the convex surface of the developing spore. Our in vitro experiments support the hypothesis that this localization is driven by geometry rather than biochemical recognition. When purified SpoVM is incubated with polydisperse micrometer-sized DOPC vesicles, we observe that the protein preferentially adsorbs on smaller vesicles, of diameter similar to the size of the bacterial spore (˜ 1 μm). Using fluorescent GFP-tagged SpoVM, we quantify the amount of adsorbed protein by confocal microscopy. Our results, when interpreted using existing protein adsorption models, suggest the existence of a cooperative adsorption mechanism for high enough membrane curvature, which involves the formation of small clusters of proteins. Membrane curvature could be a general cue for protein localization in bacteria.

  1. Nicotine craving: ERPs correlates after VR exposure to smoking cues.

    Science.gov (United States)

    Gamito, Pedro; Oliveira, Jorge; Baptista, André; Morais, Diogo; Lopes, Paulo; Saraiva, Tomaz; Rosa, Pedro; Santos, Nuno; Soares, Fábio; Sottomayor, Catarina; Barata, Filipa

    2012-01-01

    Even though it is diminishing in Europe, smoking is still a serious health problem. The craving of Nicotine is one of the hardest behaviours to tackle when a smoking cessation programme is implemented. Following on previous work [1], which aimed at evaluating the possibility of inducing smoking craving in smokers using a VR platform, the present study was devised to assess the role of craving in cognitive processing through event related potentials (ERP). From an initial sample of 89 university students (smokers and non-smokers), which was randomly exposed to VR smoking cues and VR non-smoking cue scenarios, a subsample of 13 smokers and non-smokers was drawn. This subsample (M = 23.08; SD = 4.39), which had previously been immersed in the VR smoking cues environment, was presented to a rapid (1 sec) serial of smoking and neutral images. Data on brain activity was recorded through an EEG during this task to further estimate ERPs. When compared to non-smokers, smokers showed higher frontal activation when watching smoking related images.

  2. Spatiotemporal control of cardiac anisotropy using dynamic nanotopographic cues.

    Science.gov (United States)

    Mengsteab, Paulos Y; Uto, Koichiro; Smith, Alec S T; Frankel, Sam; Fisher, Elliot; Nawas, Zeid; Macadangdang, Jesse; Ebara, Mitsuhiro; Kim, Deok-Ho

    2016-04-01

    Coordinated extracellular matrix spatiotemporal reorganization helps regulate cellular differentiation, maturation, and function in vivo, and is therefore vital for the correct formation, maintenance, and healing of complex anatomic structures. In order to evaluate the potential for cultured cells to respond to dynamic changes in their in vitro microenvironment, as they do in vivo, the collective behavior of primary cardiac muscle cells cultured on nanofabricated substrates with controllable anisotropic topographies was studied. A thermally induced shape memory polymer (SMP) was employed to assess the effects of a 90° transition in substrate pattern orientation on the contractile direction and structural organization of cardiomyocyte sheets. Cardiomyocyte sheets cultured on SMPs exhibited anisotropic contractions before shape transition. 48 h after heat-induced shape transition, the direction of cardiomyocyte contraction reoriented significantly and exhibited a bimodal distribution, with peaks at ∼45 and -45° (P < 0.001). Immunocytochemical analysis highlighted the significant structural changes that the cells underwent in response to the shift in underlying topography. The presented results demonstrate that initial anisotropic nanotopographic cues do not permanently determine the organizational fate or contractile properties of cardiomyocytes in culture. Given the importance of surface cues in regulating primary and stem cell development, investigation of such tunable nanotopographies may have important implications for advancing cellular maturation and performance in vitro, as well as improving our understanding of cellular development in response to dynamic biophysical cues.

  3. Location and acoustic scale cues in concurrent speech recognition.

    Science.gov (United States)

    Ives, D Timothy; Vestergaard, Martin D; Kistler, Doris J; Patterson, Roy D

    2010-06-01

    Location and acoustic scale cues have both been shown to have an effect on the recognition of speech in multi-speaker environments. This study examines the interaction of these variables. Subjects were presented with concurrent triplets of syllables from a target voice and a distracting voice, and asked to recognize a specific target syllable. The task was made more or less difficult by changing (a) the location of the distracting speaker, (b) the scale difference between the two speakers, and/or (c) the relative level of the two speakers. Scale differences were produced by changing the vocal tract length and glottal pulse rate during syllable synthesis: 32 acoustic scale differences were used. Location cues were produced by convolving head-related transfer functions with the stimulus. The angle between the target speaker and the distracter was 0 degrees, 4 degrees, 8 degrees, 16 degrees, or 32 degrees on the 0 degrees horizontal plane. The relative level of the target to the distracter was 0 or -6 dB. The results show that location and scale difference interact, and the interaction is greatest when one of these cues is small. Increasing either the acoustic scale or the angle between target and distracter speakers quickly elevates performance to ceiling levels.

  4. Cue validity probability influences neural processing of targets.

    Science.gov (United States)

    Arjona, Antonio; Escudero, Miguel; Gómez, Carlos M

    2016-09-01

    The neural bases of the so-called Spatial Cueing Effect in a visuo-auditory version of the Central Cue Posneŕs Paradigm (CCPP) are analyzed by means of behavioral patterns (Reaction Times and Errors) and Event-Related Potentials (ERPs), namely the Contingent Negative Variation (CNV), N1, P2a, P2p, P3a, P3b and Negative Slow Wave (NSW). The present version consisted of three types of trial blocks with different validity/invalidity proportions: 50% valid - 50% invalid trials, 68% valid - 32% invalid trials and 86% valid - 14% invalid trials. Thus, ERPs can be analyzed as the proportion of valid trials per block increases. Behavioral (Reaction Times and Incorrect responses) and ERP (lateralized component of CNV, P2a, P3b and NSW) results showed a spatial cueing effect as the proportion of valid trials per block increased. Results suggest a brain activity modulation related to sensory-motor attention and working memory updating, in order to adapt to external unpredictable contingencies.

  5. Impulsive reactions to food-cues predict subsequent food craving.

    Science.gov (United States)

    Meule, Adrian; Lutz, Annika P C; Vögele, Claus; Kübler, Andrea

    2014-01-01

    Low inhibitory control has been associated with overeating and addictive behaviors. Inhibitory control can modulate cue-elicited craving in social or alcohol-dependent drinkers, and trait impulsivity may also play a role in food-cue reactivity. The current study investigated food-cue affected response inhibition and its relationship to food craving using a stop-signal task with pictures of food and neutral stimuli. Participants responded slower to food pictures as compared to neutral pictures. Reaction times in response to food pictures positively predicted scores on the Food Cravings Questionnaire - State (FCQ-S) after the task and particularly scores on its hunger subscale. Lower inhibitory performance in response to food pictures predicted higher FCQ-S scores and particularly those related to a desire for food and lack of control over consumption. Task performance was unrelated to current dieting or other measures of habitual eating behaviors. Results support models on interactive effects of top-down inhibitory control processes and bottom-up hedonic signals in the self-regulation of eating behavior, such that low inhibitory control specifically in response to appetitive stimuli is associated with increased craving, which may ultimately result in overeating.

  6. Deep Fusion of Multiple Semantic Cues for Complex Event Recognition.

    Science.gov (United States)

    Zhang, Xishan; Zhang, Hanwang; Zhang, Yongdong; Yang, Yang; Wang, Meng; Luan, Huanbo; Li, Jintao; Chua, Tat-Seng

    2016-03-01

    We present a deep learning strategy to fuse multiple semantic cues for complex event recognition. In particular, we tackle the recognition task by answering how to jointly analyze human actions (who is doing what), objects (what), and scenes (where). First, each type of semantic features (e.g., human action trajectories) is fed into a corresponding multi-layer feature abstraction pathway, followed by a fusion layer connecting all the different pathways. Second, the correlations of how the semantic cues interacting with each other are learned in an unsupervised cross-modality autoencoder fashion. Finally, by fine-tuning a large-margin objective deployed on this deep architecture, we are able to answer the question on how the semantic cues of who, what, and where compose a complex event. As compared with the traditional feature fusion methods (e.g., various early or late strategies), our method jointly learns the essential higher level features that are most effective for fusion and recognition. We perform extensive experiments on two real-world complex event video benchmarks, MED'11 and CCV, and demonstrate that our method outperforms the best published results by 21% and 11%, respectively, on an event recognition task.

  7. Great cormorants ( Phalacrocorax carbo) can detect auditory cues while diving

    Science.gov (United States)

    Hansen, Kirstin Anderson; Maxwell, Alyssa; Siebert, Ursula; Larsen, Ole Næsbye; Wahlberg, Magnus

    2017-06-01

    In-air hearing in birds has been thoroughly investigated. Sound provides birds with auditory information for species and individual recognition from their complex vocalizations, as well as cues while foraging and for avoiding predators. Some 10% of existing species of birds obtain their food under the water surface. Whether some of these birds make use of acoustic cues while underwater is unknown. An interesting species in this respect is the great cormorant ( Phalacrocorax carbo), being one of the most effective marine predators and relying on the aquatic environment for food year round. Here, its underwater hearing abilities were investigated using psychophysics, where the bird learned to detect the presence or absence of a tone while submerged. The greatest sensitivity was found at 2 kHz, with an underwater hearing threshold of 71 dB re 1 μPa rms. The great cormorant is better at hearing underwater than expected, and the hearing thresholds are comparable to seals and toothed whales in the frequency band 1-4 kHz. This opens up the possibility of cormorants and other aquatic birds having special adaptations for underwater hearing and making use of underwater acoustic cues from, e.g., conspecifics, their surroundings, as well as prey and predators.

  8. Generating physical symptoms from visual cues: An experimental study.

    Science.gov (United States)

    Ogden, Jane; Zoukas, Serafim

    2009-12-01

    This experimental study explored whether the physical symptoms of cold, pain and itchiness could be generated by visual cues, whether they varied in the ease with which they could be generated and whether they were related to negative affect. Participants were randomly allocated by group to watch one of three videos relating to cold (e.g. ice, snow, wind), pain (e.g. sporting injuries, tattoos) or itchiness (e.g. head lice, scratching). They then rated their self-reported symptoms of cold, pain and itchiness as well as their negative affect (depression and anxiety). The researcher recorded their observed behaviour relating to these symptoms. The results showed that the interventions were successful and that all three symptoms could be generated by the visual cues in terms of both self-report and observed behaviour. In addition, the pain video generated higher levels of anxiety and depression than the other two videos. Further, the degree of itchiness was related to the degree of anxiety. This symptom onset process also showed variability between symptoms with self-reported cold symptoms being greater than either pain or itchy symptoms. The results show that physical symptoms can be generated by visual cues indicating that psychological factors are not only involved in symptom perception but also in symptom onset.

  9. Susceptibility to distraction by social cues in borderline personality disorder.

    Science.gov (United States)

    Krause-Utz, Annegret; Elzinga, Bernet M; Oei, Nicole Y L; Spinhoven, Philip; Bohus, Martin; Schmahl, Christian

    2014-01-01

    Individuals with borderline personality disorder (BPD) are highly sensitive to social rejection and show alterations in social perception. Increased susceptibility to social cues in patients with BPD might interfere with executive functions that play an important role in goal-directed behavior. The aim of this study was to investigate the influence of task-irrelevant (neutral vs. negatively arousing) social cues on working memory performance in BPD patients compared to healthy controls (HC). 28 unmedicated female BPD patients and 28 female HC (matched for age and education) performed a Sternberg item recognition task, while being distracted by neutral versus negatively arousing pictures from the International Affective Picture System (interpersonal scenes) and the Karolinska Directed Emotional Faces Set (faces). Additionally, self-ratings of aversive inner tension were assessed and correlated with task performance. Compared to HC, BPD patients showed significantly impaired accuracy after distraction by negatively arousing stimuli (both scenes and faces) and neutral faces (but not neutral scenes). Significant negative correlations between overall accuracy and self-reported aversive inner tension were observed in BPD patients. Findings of the present study suggest increased susceptibility to distracting (negatively arousing) social cues in individuals with BPD, which might interfere with cognitive functioning. © 2013 S. Karger AG, Basel.

  10. Brain response to prosodic boundary cues depends on boundary position

    Directory of Open Access Journals (Sweden)

    Julia eHolzgrefe

    2013-07-01

    Full Text Available Prosodic information is crucial for spoken language comprehension and especially for syntactic parsing, because prosodic cues guide the hearer’s syntactic analysis. The time course and mechanisms of this interplay of prosody and syntax are not yet well understood. In particular, there is an ongoing debate whether local prosodic cues are taken into account automatically or whether they are processed in relation to the global prosodic context in which they appear. The present study explores whether the perception of a prosodic boundary is affected by its position within an utterance. In an event-related potential (ERP study we tested if the brain response evoked by the prosodic boundary differs when the boundary occurs early in a list of three names connected by conjunctions (i.e., after the first name as compared to later in the utterance (i.e., after the second name. A closure positive shift (CPS — marking the processing of a prosodic phrase boundary — was elicited only for stimuli with a late boundary, but not for stimuli with an early boundary. This result is further evidence for an immediate integration of prosodic information into the parsing of an utterance. In addition, it shows that the processing of prosodic boundary cues depends on the previously processed information from the preceding prosodic context.

  11. The human startle reflex and alcohol cue reactivity: effects of early versus late abstinence.

    Science.gov (United States)

    Saladin, Michael E; Drobes, David J; Coffey, Scott F; Libet, Julian M

    2002-06-01

    This study investigated the human eyeblink startle reflex as a measure of alcohol cue reactivity. Alcohol-dependent participants early (n = 36) and late (n = 34) in abstinence received presentations of alcohol and water cues. Consistent with previous research, greater salivation and higher ratings of urge to drink occurred in response to the alcohol cues. Differential salivary and urge responding to alcohol versus water cues did not vary as a function of abstinence duration. Of special interest was the finding that startle response magnitudes were relatively elevated to alcohol cues, but only in individuals early in abstinence. Affective ratings of alcohol cues suggested that alcohol cues were perceived as aversive. Methodological and theoretical implications of the findings are discussed.

  12. Are computers effective lie detectors? A meta-analysis of linguistic cues to deception.

    Science.gov (United States)

    Hauch, Valerie; Blandón-Gitlin, Iris; Masip, Jaume; Sporer, Siegfried L

    2015-11-01

    This meta-analysis investigates linguistic cues to deception and whether these cues can be detected with computer programs. We integrated operational definitions for 79 cues from 44 studies where software had been used to identify linguistic deception cues. These cues were allocated to six research questions. As expected, the meta-analyses demonstrated that, relative to truth-tellers, liars experienced greater cognitive load, expressed more negative emotions, distanced themselves more from events, expressed fewer sensory-perceptual words, and referred less often to cognitive processes. However, liars were not more uncertain than truth-tellers. These effects were moderated by event type, involvement, emotional valence, intensity of interaction, motivation, and other moderators. Although the overall effect size was small, theory-driven predictions for certain cues received support. These findings not only further our knowledge about the usefulness of linguistic cues to detect deception with computers in applied settings but also elucidate the relationship between language and deception.

  13. Effects of d-amphetamine and smoking abstinence on cue-induced cigarette craving.

    Science.gov (United States)

    Alsene, Karen M; Mahler, Stephen V; de Wit, Harriet

    2005-08-01

    In this study, the authors investigated the effects of the indirect dopamine agonist d-amphetamine (AMPH) on cue-induced cigarette craving in smokers. Abstinent or nonabstinent cigarette smokers (N=21) rated their cravings for cigarettes and for food (control) after pretreatment with AMPH (15 mg) or placebo and before and after viewing blocks of smoking-related, food-related, and neutral pictures. Before the cues were presented, AMPH increased cigarette craving and decreased food craving. Smoking and food cues increased craving for cigarettes and for food, respectively. AMPH also further increased cigarette craving (and decreased food craving) after cue presentation, but it did so regardless of cue type (food or smoking). Smoking abstinence markedly increased craving regardless of cue presentation or drug condition. These results suggest that both AMPH and smoking abstinence can increase cigarette craving, but they do not appear to specifically affect responses to conditioned smoking-related cues. ((c) 2005 APA, all rights reserved).

  14. Selectivity in associative learning: A cognitive stage framework for blocking and cue competition phenomena

    Directory of Open Access Journals (Sweden)

    Yannick eBoddez

    2014-11-01

    Full Text Available Blocking is the most important phenomenon in the history of associative learning theory: For over 40 years, blocking has inspired a whole generation of learning models. Blocking is part of a family of effects that are typically termed cue competition effects. Common amongst all cue competition effects is that a cue-outcome relation is poorly learned or poorly expressed because the cue is trained in the presence of an alternative predictor or cause of the outcome. We provide an overview of the cognitive processes involved in cue competition effects in humans and propose a stage framework that brings these processes together. The framework contends that the behavioral display of cue competition is cognitively construed following three stages that include (1 an encoding stage, (2 a retention stage, and (3 a performance stage. We argue that the stage framework supports a comprehensive understanding of cue competition effects.

  15. Food cue reactivity and craving predict eating and weight gain: a meta-analytic review.

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    Boswell, Rebecca G; Kober, Hedy

    2016-02-01

    According to learning-based models of behavior, food cue reactivity and craving are conditioned responses that lead to increased eating and subsequent weight gain. However, evidence supporting this relationship has been mixed. We conducted a quantitative meta-analysis to assess the predictive effects of food cue reactivity and craving on eating and weight-related outcomes. Across 69 reported statistics from 45 published reports representing 3,292 participants, we found an overall medium effect of food cue reactivity and craving on outcomes (r = 0.33, p food cues (e.g. pictures and videos) were associated with a similar effect size to real food exposure and a stronger effect size than olfactory cues. Overall, the present findings suggest that food cue reactivity, cue-induced craving and tonic craving systematically and prospectively predict food-related outcomes. These results have theoretical, methodological, public health and clinical implications.

  16. Detection vs. selection: integration of genetic, epigenetic and environmental cues in fluctuating environments.

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    McNamara, John M; Dall, Sasha R X; Hammerstein, Peter; Leimar, Olof

    2016-10-01

    There are many inputs during development that influence an organism's fit to current or upcoming environments. These include genetic effects, transgenerational epigenetic influences, environmental cues and developmental noise, which are rarely investigated in the same formal framework. We study an analytically tractable evolutionary model, in which cues are integrated to determine mature phenotypes in fluctuating environments. Environmental cues received during development and by the mother as an adult act as detection-based (individually observed) cues. The mother's phenotype and a quantitative genetic effect act as selection-based cues (they correlate with environmental states after selection). We specify when such cues are complementary and tend to be used together, and when using the most informative cue will predominate. Thus, we extend recent analyses of the evolutionary implications of subsets of these effects by providing a general diagnosis of the conditions under which detection and selection-based influences on development are likely to evolve and coexist.

  17. Cue integration in categorical tasks: insights from audio-visual speech perception.

    Directory of Open Access Journals (Sweden)

    Vikranth Rao Bejjanki

    Full Text Available Previous cue integration studies have examined continuous perceptual dimensions (e.g., size and have shown that human cue integration is well described by a normative model in which cues are weighted in proportion to their sensory reliability, as estimated from single-cue performance. However, this normative model may not be applicable to categorical perceptual dimensions (e.g., phonemes. In tasks defined over categorical perceptual dimensions, optimal cue weights should depend not only on the sensory variance affecting the perception of each cue but also on the environmental variance inherent in each task-relevant category. Here, we present a computational and experimental investigation of cue integration in a categorical audio-visual (articulatory speech perception task. Our results show that human performance during audio-visual phonemic labeling is qualitatively consistent with the behavior of a Bayes-optimal observer. Specifically, we show that the participants in our task are sensitive, on a trial-by-trial basis, to the sensory uncertainty associated with the auditory and visual cues, during phonemic categorization. In addition, we show that while sensory uncertainty is a significant factor in determining cue weights, it is not the only one and participants' performance is consistent with an optimal model in which environmental, within category variability also plays a role in determining cue weights. Furthermore, we show that in our task, the sensory variability affecting the visual modality during cue-combination is not well estimated from single-cue performance, but can be estimated from multi-cue performance. The findings and computational principles described here represent a principled first step towards characterizing the mechanisms underlying human cue integration in categorical tasks.

  18. Environment size and the use of feature and geometric cues for reorientation.

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    Sturz, Bradley R; Kelly, Debbie M

    2013-02-01

    We tested associative-based accounts of orientation by investigating the influence of environment size on the use of feature and geometric cues for reorientation. Two groups of participants were trained in dynamic three-dimensional virtual rectangular environments that differed in size to find a distinctly colored bin located at one of the four corners. Subsequently, we probed the reliance on feature and geometric cues for reorientation during test trials by presenting six trial types: Small Geometry Only, Large Geometry Only, Small Cue Conflict, Large Cue Conflict, Small Distal, and Large Distal. During Geometry Only test trials, all bins were black; thus, all distinctive featural information was removed leaving only geometric cues. For Cue Conflict test trials, all colored bins were shifted counter-clockwise one corner; thus, the geometric cues from the trained corner and the trained color were in direct conflict. During Distal test trials, the bin in the geometrically incorrect corner farthest from the trained corner was colored the same as during training; the remaining three bins were black. Thus, only this distant feature cue could be used to determine the location of the goal bin. Results suggested that geometric cues were used across changes in environment size, featural cues exerted greater influence when in conflict with geometric cues, and the far featural cue was used to disambiguate the correct from the rotationally equivalent location. In short, both feature and geometric cues were used for reorientation, and environment size influenced the relative use of feature and geometric cues. Collectively, our results provide evidence against associative-based accounts of orientation. Copyright © 2012 Elsevier B.V. All rights reserved.

  19. Effect of training and familiarity on responsiveness to human cues in domestic dogs (Canis familiaris).

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    Cunningham, Clare L; Ramos, Mari F

    2014-05-01

    Domestic dogs (Canis familiaris) seem to possess an evolved competency to follow human-given cues, often out-performing their wild progenitor the wolf (Canis lupus) on cue-following tasks. However, domestication may not be solely responsible for the socio-cognitive skills of dogs, with ontogenetic experience also playing a role. This research evaluated the effects of intensive training on cue-following behaviour using an unreinforced object-choice paradigm. The responses of dogs that were trained to competitive levels were compared to those of pet dogs with only basic training, and dogs living in an animal shelter that demonstrated no or only rudimentary following of basic commands. Using a cue-following task where three types of cues were presented by familiar and unfamiliar human partners, the number of cues followed by each training group were recorded. All dogs found cues where gesture was combined with a congruent head and eye movement easier to follow than either gesture or eye gaze alone. Whether the cue-giver was familiar or not had a significant effect on number of cues followed in homed dogs, and the performance of shelter dogs was comparable to the other groups when faced with an unfamiliar cue-giver. Contrary to predictions, level of training did not improve performance on the cue-following task. This work does provide support for the presence of an evolved adaptation to exploit social cues provided by humans that can be augmented by familiarity with the cue giver. However, additional joint activity as experienced in an intensive training regime does not seem to increase accuracy in following human-given cues.

  20. Cue reactivity is associated with duration and severity of alcohol dependence: an FMRI study.

    Directory of Open Access Journals (Sweden)

    Zsuzsika Sjoerds

    Full Text Available INTRODUCTION: With the progression of substance dependence, drug cue-related brain activation is thought to shift from motivational towards habit pathways. However, a direct association between cue-induced brain activation and dependence duration has not yet been shown. We therefore examined the relationship between alcohol cue-reactivity in the brain, cue-induced subjective craving and alcohol dependence duration and severity. Since alcohol dependence is highly comorbid with depression/anxiety, which may modulate brain responses to alcohol cues, we also examined the relation between comorbid depression/anxiety and cue-reactivity. METHODS: We compared 30 alcohol dependent patients with 15 healthy controls and 15 depression/anxiety patients during a visual alcohol cue-reactivity task using functional magnetic resonance imaging blood oxygenated level-dependent responses and subjective craving as outcomes. Within the alcohol dependent group we correlated cue-reactivity with alcohol dependence severity and duration, with cue-induced craving and with depression/anxiety levels. RESULTS: Alcohol dependent patients showed greater cue-reactivity in motivational brain pathways and stronger subjective craving than depression/anxiety patients and healthy controls. Depression/anxiety was not associated with cue-reactivity, but depression severity in alcohol dependent patients was positively associated with craving. Within alcohol dependence, longer duration of alcohol dependence was associated with stronger cue-related activation of the posterior putamen, a structure involved in habits, whereas higher alcohol dependence severity was associated with lower cue-reactivity in the anterior putamen, an area implicated in goal-directed behavior preceding habit formation. CONCLUSION: Cue-reactivity in alcohol dependence is not modulated by comorbid depression or anxiety. More importantly, the current data confirm the hypothesis of a ventral to dorsal striatal shift