Attractive Cues Research Articles

Nest Gasses as a Potential Attraction Cue for Biting Flying Insects and Other Ectoparasites of Cavity Nesting Birds

The presence of nestlings and other nest dwelling living beings in nests built in cavities alter the composition of gases inside the cavity. This different concentration of gases could be used by some parasites as a cue to localize their hosts. Here, we explored the temporal variation in the concentration and isotopic signature of carbon dioxide (CO2) and methane (CH4) inside nest boxes of blue tits Cyanistes caeruleus during the nestling period (days 3, 8, 13, 20 and 21 post-hatching) as well as several variables potentially affecting such variation. Finally, we checked whether difference in gases concentration affects the number of different types of parasites affecting nestlings. Concentration of gases and isotopic signature were significantly different between nest cavities and the forest during the nestling period. CO2 concentration was higher while CH4 was lower inside nests than in forest air. We expect that the abundance of those parasites seeking actively for nests (blackflies, biting midges and blowflies) could be related with differences in gases concentrations if they use these differences as a cue for host location. In this respect, abundance of biting midges were related positively with differences in CO2 between nest and forest at day 20 of nestling age indicating that these mosquitoes can use concentrations of that gas to find their host. In addition, we found a positive relationship between blackflies and differences in CH4 concentration. However, concentration of this gas inside nests may be related with bacterial activity and therefore this relationship may be due to an effect of bacteria on blackflies and not to the effect of gas as a blackfly attractant to nests. Other relationships between difference on gases concentration and mites were found but due to the way these parasites use to reach nests (i.e.: transported by adult birds) we discard the possibility that they use that difference as a cue for host location. Brood size was also related with mite and flea abundances and relative humidity with flea abundance. In addition, the condition of blue tit females was negative and significantly related with the abundance of blowfly pupae.

Cortical distribution of GABAergic interneurons is determined by migration time and brain size

Cortical interneurons (CINs) originate in the ganglionic eminences (GEs) and migrate tangentially to the cortex guided by different attractive and repulsive cues. Once inside the cortex, the cellular and molecular mechanisms determining the migration of CINs along the rostrocaudal axis are less well understood. Here, we investigated the cortical distribution of CINs originating in the medial and caudal GEs at different time points. Using molecular and genetic labeling, we showed that, in the mouse, early- and late-born CINs (E12 versus E15) are differentially distributed along the rostrocaudal axis. Specifically, late-born CINs are preferentially enriched in cortical areas closer to their respective sites of origin in the medial or caudal GE. Surprisingly, our in vitro experiments failed to show a preferential migration pattern along the rostrocaudal axis for medial- or caudal-born CINs. Moreover, in utero transplantation experiments suggested that the rostrocaudal dispersion of CINs depends on the developmental stage of the host brain and is limited by the migration time and the increasing size of the developing brain. These data suggest that the embryonic expansion of the cortex contributes to the rostrocaudal distribution of CINs.

Integrating Chemistry and Mechanics: The Forces Driving Axon Growth.

The brain is our most complex organ. During development, neurons extend axons, which may grow over long distances along well-defined pathways to connect to distant targets. Our current understanding of axon pathfinding is largely based on chemical signaling by attractive and repulsive guidance cues. These cues instruct motile growth cones, the leading tips of growing axons, where to turn and where to stop. However, it is not chemical signals that cause motion-motion is driven by forces. Yet our current understanding of the mechanical regulation of axon growth is very limited. In this review, I discuss the origin of the cellular forces controlling axon growth and pathfinding, and how mechanical signals encountered by growing axons may be integrated with chemical signals. This mechanochemical cross talk is an important but often overlooked aspect of cell motility that has major implications for many physiological and pathological processes involving neuronal growth.

Fertility as a cue for attractiveness in homo- and heterosexual men

According to the sexual strategy theory (SST), men pursue short-term mating strategies to enhance their reproductive fitness. To do so, heterosexual men search for women who signal high reproductive value through multiple fertility cues. We hypothesize that, due to an interplay of mating strategies derived from a person's biological sex and the sexual orientation of a person (which develops independently of biological sex), not only heterosexual but also homosexual men should find high fertility more attractive in others. Accordingly, in Study 1 (N = 124), we found that hetero- as well as homosexual men rated the physical attractiveness of a female stimulus person to be greater when she was portrayed to be of high (versus low) fertility. Interestingly, in Study 2 (N = 224), we found that only homosexual-, but not heterosexual men perceived a male stimulus to be less attractive when information was provided that pointed at his low (versus high) fertility and when no information was given. We discuss these findings against the background of evolved adaptive mating motives in humans. Overall, the present results indicate that fertility appears to be an important cue for perceived physical attractiveness for both hetero- and homosexual men.

Herbivore-induced plant volatiles from red spider mite, Oligonychus coffeae infested tea plants as attractant cues for the predatory mite, Neoseiulus longispinosus

Abstract Gas chromatographic studies revealed qualitative and quantitative variations in the volatile profiles of red spider mite (Oligonychus coffeae) infested and uninfested tea leaves. So further studies were conducted in laboratory using ‘Y’-tube olfactometer to determine whether the odours of O. coffeae induced plant volatiles from tea leaves are detectable cues for the attraction of the predatory mite, Neoseiulus longispinosus preying on red spider mite. Alpha farnesene, Beta ocimene and Linalool were found only in the volatiles from infested tea leaves. When predatory mites starved for 0 to 10 h were introduced into the experimental set up with four leaves each with 100 prey mites against uninfested tea leaves, the predatory mites which starved for 6 and 10 h showed significant preference to volatiles from infested tea leaves. Four leaves each with 12 prey mites did not show significant attraction of predatory mites over uninfested leaves. But predatory mites were significantly attracted to infested leaves when more numbers of prey mites were presented. There was no significant variation in attraction when mechanically damaged or previously infested tea leaves were presented against normal leaves. Preference was most significant to four leaves each with 100 prey mites when supplied against clean air. Results of this study deserve importance as data base for further determination of the feasibility of manipulating volatile info-chemicals as attractants for N. longispinosus in tea plantation.

Exposure of cane toad hatchlings to older conspecifics suppresses chemosensory food tracking behaviour and increases risk of predation post-exposure.

Attempts to control invasive species using species-specific pheromones need to incorporate an understanding of interactive effects among those pathways. The larvae of invasive cane toads (Rhinella marina) utilise chemical cues to repulse, attract or suppress conspecific larvae. We can exploit these effects to reduce toad abundance, but the effects of each cue may not be additive. That is, exposure to one type of cue may lessen the impact of exposure to another cue. To assess this possibility, we exposed toad larvae to combinations of cues. Tadpoles that had been exposed to the suppression cue during larval development exhibited no response to the attraction cue, resulting in lower capture rates in attractant-baited traps. Suppression, however, did not affect a tadpole’s response to the alarm cue, and exposure to the alarm cue during tadpole development did not affect response to the attraction cue. Tadpoles exposed to the suppression cue were smaller than control tadpoles at 10 days post-exposure, and consequently were more vulnerable to gape-limited invertebrate predators. Our results demonstrate that the responses by toad tadpoles to chemical cues interact in important ways, and are not simply additive when combined. Control efforts need to incorporate an understanding of such interactions if we are to most effectively use chemical-communication pathways to control invasive amphibians.

RhoJ integrates attractive and repulsive cues in directional migration of endothelial cells.

During angiogenesis, VEGF acts as an attractive cue for endothelial cells (ECs), while Sema3E mediates repulsive cues. Here, we show that the small GTPase RhoJ integrates these opposing signals in directional EC migration. In the GTP-bound state, RhoJ interacts with the cytoplasmic domain of PlexinD1. Upon Sema3E stimulation, RhoJ released from PlexinD1 induces cell contraction. PlexinD1-bound RhoJ further facilitates Sema3E-induced PlexinD1-VEGFR2 association, VEGFR2 transphosphorylation at Y1214, and p38 MAPK activation, leading to reverse EC migration. Upon VEGF stimulation, RhoJ is required for the formation of the holoreceptor complex comprising VEGFR2, PlexinD1, and neuropilin-1, thereby preventing degradation of internalized VEGFR2, prolonging downstream signal transductions via PLCγ, Erk, and Akt, and promoting forward EC migration. After conversion to the GDP-bound state, RhoJ shifts from PlexinD1 to VEGFR2, which then terminates the VEGFR2 signals. RhoJ deficiency in ECs efficiently suppressed aberrant angiogenesis in ischemic retina. These findings suggest that distinct Rho GTPases may act as context-dependent integrators of chemotactic cues in directional cell migration and may serve as candidate therapeutic targets to manipulate cell motility in disease or tissue regeneration.

The influence of attractiveness and convenience cues on food appeal in adults with and without ADHD

ObjectivePrevious research on adults with ADHD revealed high rates of overweight and obesity, as well as unhealthy diet habits. Other studies demonstrated that social-affective contexts can influence food choice. This study examines the sensitivity of adults with ADHD to cues of food attractiveness and convenience, for healthy and unhealthy foods. MethodOne hundred and seventy-two university students with (n = 59) and without (n = 113) ADHD, aged 19–40, participated in the study. Participants rated the level of appeal of 32 pictures of healthy and unhealthy foods, which varied in the degree of attractiveness and convenience. ResultsThe findings reveal a higher level of appeal of attractive food items compared to non-attractive ones (p < .001), as well as of convenient compared to non-convenient food items (p = .005). Type of diagnostic group did not have an effect on the level of appeal. ConclusionIncreasing the attractiveness and convenience of food items increased the level of appeal for both students with and without ADHD. These findings emphasize the importance of environmental health intervention to potentially reduce abnormal eating pattern in the ADHD adult population, which may contribute in preventing the reported higher risk of obesity in this population.

The Mutex Watershed and its Objective: Efficient, Parameter-Free Graph Partitioning.

Image partitioning, or segmentation without semantics, is the task of decomposing an image into distinct segments, or equivalently to detect closed contours. Most prior work either requires seeds, one per segment; or a threshold; or formulates the task as multicut / correlation clustering, an NP-hard problem. Here, we propose an efficient algorithm for graph partitioning, the "Mutex Watershed". Unlike seeded watershed, the algorithm can accommodate not only attractive but also repulsive cues, allowing it to find a previously unspecified number of segments without the need for explicit seeds or a tunable threshold. We also prove that this simple algorithm solves to global optimality an objective function that is intimately related to the multicut / correlation clustering integer linear programming formulation. The algorithm is deterministic, very simple to implement, and has empirically linearithmic complexity. When presented with short-range attractive and long-range repulsive cues from a deep neural network, the Mutex Watershed gives the best results currently known for the competitive ISBI 2012 EM segmentation benchmark.

Sign-tracking behavior is sensitive to outcome devaluation in a devaluation context-dependent manner: implications for analyzing habitual behavior.

Motivationally attractive cues can draw in behavior in a phenomenon termed incentive salience. Incentive cue attraction is an important model for animal models of drug seeking and relapse. One question of interest is the extent to which the pursuit of motivationally attractive cues is related to the value of the paired outcome or can become unrelated and habitual. We studied this question using a sign-tracking (ST) paradigm in rats, in which a lever stimulus preceding food reward comes to elicit conditioned lever-interaction behavior. We asked whether reinforcer devaluation by means of conditioned taste aversion, a classic test of habitual behavior, can modify ST to incentive cues, and whether this depends upon the manner in which reinforcer devaluation takes place. In contrast to several recent reports, we conclude that ST is indeed sensitive to reinforcer devaluation. However, this effect depends critically upon the congruence between the context in which taste aversion is learned and the context in which it is tested. When the taste aversion successfully transfers to the testing context, outcome value strongly influences ST behavior, both when the outcome is withheld (in extinction) and when animals can learn from outcome feedback (reacquisition). When taste aversion does not transfer to the testing context, ST remains high. In total, the extent to which ST persists after outcome devaluation is closely related to the extent to which that outcome is truly devalued in the task context. We believe this effect of context on devaluation can reconcile contradictory findings about the flexibility/inflexibility of ST. We discuss this literature and relate our findings to the study of habits generally.

Inositol 1,4,5-Trisphosphate Receptor Type 3 Regulates Neuronal Growth Cone Sensitivity to Guidance Signals.

SummaryDuring neurodevelopment, the growth cone deciphers directional information from extracellular guidance cues presented as shallow concentration gradients via signal amplification. However, it remains unclear how the growth cone controls this amplification process during its navigation through an environment in which basal cue concentrations vary widely. Here, we identified inositol 1,4,5-trisphosphate (IP3) receptor type 3 as a regulator of axonal sensitivity to guidance cues in vitro and in vivo. Growth cones lacking the type 3 subunit are hypersensitive to nerve growth factor (NGF), an IP3-dependent attractive cue, and incapable of turning toward normal concentration ranges of NGF to which wild-type growth cones respond. This is due to globally, but not asymmetrically, activated Ca2+ signaling in the hypersensitive growth cones. Remarkably, lower NGF concentrations can polarize growth cones for turning if IP3 receptor type 3 is deficient. These data suggest a subtype-specific IP3 receptor function in sensitivity adjustment during axon navigation.

Evolution, developmental expression and function of odorant receptors in insects.

Animals rely on their chemosensory system to discriminate among a very large number of attractive or repulsive chemical cues in the environment, which is essential to respond with proper action. The olfactory sensory systems in insects share significant similarities with those of vertebrates, although they also exhibit dramatic differences, such as the molecular nature of the odorant receptors (ORs): insect ORs function as heteromeric ion channels with a common Orco subunit, unlike the G-protein-coupled olfactory receptors found in vertebrates. Remarkable progress has recently been made in understanding the evolution, development and function of insect odorant receptor neurons (ORNs). These studies have uncovered the diversity of olfactory sensory systems among insect species, including in eusocial insects that rely extensively on olfactory sensing of pheromones for social communication. However, further studies, notably functional analyses, are needed to improve our understanding of the origins of the Orco-OR system, the mechanisms of ORN fate determination, and the extraordinary diversity of behavioral responses to chemical cues.

Cues of pregnancy decrease female physical attractiveness for males

To increase their reproductive success, ancestral males must show preferences for fertile females. Gravid females are infertile, and, thus, should be less preferred by males compared with non-gravid females. We investigated this idea by manipulating salient cues of pregnancy with a sample of Slovak females who were rated by males. Physical attractiveness of putatively pregnant females was lower compared with non-gravid females. In line with the idea that pursuing short-term and long-term relationships creates different costs to males, physical attractiveness of putatively pregnant females was lower for short-term compared with long-term possible relationship. Older males and uncommitted males rated females as more attractive compared with younger and committed males. Our results suggest that putatively pregnant females are less attractive due to the costs of selecting an infertile partner, or due to male unwillingness to invest in biologically unrelated children.

Mating behaviour of the leucosiid crabPyrhila pisum(De Haan, 1841)

AbstractMating behaviour of the leucosiid crabPyrhila pisumwas studied in the laboratory and tidal flats in Japan. Most males actively approached females. Males started guarding females without any courtship behaviour (pre-copulatory guarding). Males began copulation within several minutes. The copulation continued for about 1–2 h, following which males began post-copulatory guarding. This guarding lasted from almost 0 to over 3 days, but its duration was generally much longer than that prior to copulation. Release of guarding was not linked to ovulation by females. Long-term rearing experiments revealed that both sexes ofP. pisumcould copulate multiple times with various mates. Developmental stages of the embryos recorded from copulating ovigerous females widely varied; their timing of copulation may not be fixed. In the tidal flat, wandering males frequently contacted with other individuals, but without distinguishing single males, single females and pairs ofP. pisum, orHemigrapsus takanoi. MaleP. pisumcannot recognize female conspecifics, and they approach their mates relying only on vision, without using any attractive cues from females. In cases in which males encountered pairing crabs, they successfully stole the females when the guardians were smaller than the challengers, suggesting that effectiveness of guarding depends on male size. Among the mating pairs, males tended to be larger than females, and the tendency of size-assortative mating was weak or absent. Therefore, the mating behaviour ofP. pisumis not elaborate, although their guarding behaviour may contribute to improve success to some degree.

An odorant receptor from Anopheles gambiae that demonstrates enantioselectivity to the plant volatile, linalool.

Insects express chemical receptors within sensory neurons that are activated by specific cues in the environment, thereby influencing the acquisition of critical resources. A significant gap in our current understanding of insect chemical ecology is defining the molecular mechanisms that underlie sensitivity to plant-emitted volatiles. Linalool is a commonly-occurring monoterpene that has various effects on insect behavior, either acting as an attractant or a repellent, and existing in nature as one of two possible stereoisomers, (R)-(–)-linalool and (S)-(+)-linalool. In this study, we have used a cell-based functional assay to identify linalool and structurally-related compounds as ligands of Odorant receptor 29, a labellum-expressed receptor in the malaria vector mosquito, Anopheles gambiae (AgamOr29). While (R)-(–)-linalool activates AgamOr29, a mixture of the (R) and (S) stereoisomers activates the receptor with higher potency, implying enantiomeric selectivity. Orthologs of Or29 are present in the genomes of Anophelines within the Cellia subgenus. The conservation of this receptor across Anopheline lineages suggests that this ecologically important compound might serve as an attraction cue for nectar-seeking mosquitoes. Moreover, the characterization of a mosquito terpene receptor could serve as a foundation for future ligand-receptor studies of plant volatiles and for the discovery of compounds that can be integrated into push-pull vector control strategies.

Acoustic deterrents to manage fish populations

Finding effective ways to direct native fish away from anthropogenic hazards and limit the spread of invasive species, without physical intervention, harming non-target fishes or interrupting aquatic commerce is a major challenge for fisheries management. One option is to target fish sensory systems to manipulate behavior using attractive or repulsive cues. Many, if not all species of fish, use sound as part of their behavioral repertoire and display varying degrees of phonotaxis. Sound has inherent advantages over other sensory stimuli such as light or odor as underwater sound attenuates slowly, is highly directional and is unimpeded by low light or water turbidity. This review details the use of acoustics to deter and guide fish movements for a wide variety of fishes, before critically assessing the benefits and limitations of the technology. No single method of fish deterrence is a “one size fits all”, and therefore this review will assist both managers and researchers attempting to use acoustic deterrents for different fish orders.

Impression formation on online dating sites: Effects of language errors in profile texts on perceptions of profile owners’ attractiveness

This article presents two experimental studies investigating the impact of language errors in online dating profiles on impression formation. A first study examined whether language errors have a negative effect on perceptions of attraction and dating intention and whether this effect is moderated by the presence of visual information, that is, the profile picture. This 2 (Language Errors/No Language Errors) × 2 (Visible/Blurred Picture) experiment revealed that language errors negatively affect perceptions of social and romantic attraction and that a visible picture on a profile positively affects perceptions of physical attraction. Study 2 focused on mechanical, rule-based, and informal language errors, which can each be attributed to different personality traits. Mechanical and rule-based errors lead to lower scores on, respectively, perceived attentiveness and intelligence, which in turn lead to lower attraction and dating intention scores. These results highlight the importance of error-free language use as a cue for attractiveness.

Promotion of Axon Growth by the Secreted End of a Transcription Factor

Axon growth is regulated externally by attractive and repulsive cues generated in the environment. In addition, intrinsic pathways govern axon development, although the extent to which axons themselves can influence their own growth is unknown. We find that dorsal root ganglion (DRG) axons secrete a factor supporting axon growth and identify it as the C terminus of the ER stress-induced transcription factor CREB3L2, which is generated by site 2 protease (S2P) cleavage in sensory neurons. S2P and CREB3L2 knockdown or inhibition of axonal S2P interfere with the growth of axons, and C-terminal CREB3L2 is sufficient to rescue these effects. C-terminal CREB3L2 forms a complex with Shh and stabilizes its association with the Patched-1 receptor on developing axons. Our results reveal a neuron-intrinsic pathway downstream of S2P that promotes axon growth.

Are attractive reviewers more persuasive? Examining the role of physical attractiveness in online reviews

PurposeWhile online reviews are of paramount importance in brand evaluations and purchase decisions, the impact of a reviewer’s attractiveness is not well understood. To bridge that gap, this paper aims to explore how physical attractiveness cues through profile photos influence customers’ brand evaluations.Design/methodology/approachThe first study assesses the impact of attractiveness and review valence on brand evaluations. The authors used an experimental design and tested the model with an ANCOVA. Study 2 examines the impact of attractiveness in the context of multiple reviews and tests attractiveness heuristic as the underlying mechanism.FindingsThe findings indicate that when an attractive (vs less-attractive) reviewer writes a positive review, brand evaluations are enhanced. However, such an effect does not occur with a negative review. With multiple reviews varying in valence, cognitive load activates the use of an attractiveness heuristic when a positive review is written by an attractive (vs less-attractive) reviewer, thus leading to enhanced brand evaluations.Originality/valueThese findings highlight the presence of the attractiveness halo effect in online reviews and offer important implications to social media marketers. While previous studies have largely focused on review characteristics (e.g. star ratings, strength of the argument, etc.), this study focuses on reviewer characteristics (i.e. attractiveness) and cognitive biases associated with online brand evaluations.

Attractiveness is positively related to World Cup performance in male, but not female, biathletes

AbstractWhole-organism performance capacity is thought to play a key role in sexual selection, through its impacts on both intrasexual competition and intersexual mate choice. Based on data from elite sports, several studies have reported a positive association between facial attractiveness and athletic performance in humans, leading to claims that facial correlates of sporting prowess in men reveal heritable or nonheritable mate quality. However, for most of the sports studied (soccer, ice hockey, American football, and cycling), it is not possible to separate individual performance from team performance. Here, using photographs of athletes who compete annually in a multi-event World Cup, we examine the relationship between facial attractiveness and individual career-best performance metrics in the biathlon, a multidisciplinary sport that combines target shooting and cross-country skiing. Unlike all previous studies, which considered only male athletes, we report relationships for both sportsmen and sportswomen. As predicted by evolutionary arguments, we found that male biathletes were judged more attractive if (unknown to the raters) they had achieved a higher peak performance (World Cup points score) in their career, whereas there was no significant relationship for female biathletes. Our findings show that elite male athletes display visible, attractive cues that reliably reflect their athletic performance.