Striking Behavior Research Articles

Characterization of a rapid avoidance behavior in Manduca sexta larvae in response to noxious stimuli.

This study focuses on the nociceptive responses observed in the tobacco hornworm (Manduca sexta). While prior investigations have described the sensory neurons and muscle activation patterns associated with the 'strike' behavior, there remains a gap in our understanding of the alternative 'withdrawal' movement, wherein the animal bends its head and thorax away from the stimulus. Our results show that stimulus location determines which nocifensive behavior is elicited. Interestingly, stimulation of specific mid-body segments could result in either withdrawal or strike, indicating a decision process rather than a hard-wired circuit. The withdrawal behavior was characterized using high-speed videography and electromyography. The results show that withdrawal in Manduca is driven by contralateral ventral muscles, followed by an increase in ipsilateral muscle activation just before the bending stops. Dorsal muscles are co-activated throughout the movement. Although both withdrawal and strike behaviors involve sequential activation of lateral muscles, these behaviors involve different muscle groups. This discovery provides a novel model system to investigate the context-dependence and decision-making processes triggered by stressful or noxious stimuli.

Confinement in the Transverse Field Ising Model on the Heavy Hex Lattice.

Inspired by a recent quantum computing experiment [Y. Kim etal., Nature (London), 618, 500-5 (2023)NATUAS0028-083610.1038/s41586-023-06096-3], we study the emergence of confinement in the transverse field Ising model on a decorated hexagonal lattice. Using an infinite tensor network state optimized with belief propagation we show how a quench from a broken symmetry state leads to striking nonthermal behavior underpinned by persistent oscillations and saturation of the entanglement entropy. We explain this phenomenon by constructing a minimal model based on the confinement of elementary excitations. Our model is in excellent agreement with our numerical results. For quenches to larger values of the transverse field and/or from nonsymmetry broken states, our numerical results display the expected signatures of thermalization: a linear growth of entanglement entropy in time, propagation of correlations, and the saturation of observables to their thermal averages. These results provide a physical explanation for the unexpected classical simulability of the quantum dynamics.

Optimal polarization and susceptibility profiles of a half-filled open magnetoelectric Fermi-Hubbard optical dimer

Magnetoelectric materials, such as thin films and magnetoelectric antennae, exhibit tunable magnetic polarization using external electric field and electric polarization using external magnetic field at room temperature by introducing strain, for instance. A more straightforward method to optimize magnetoelectric effect is by adjusting the applied electromagnetic fields in systems modeled by the Fermi-Hubbard dimer. In this study, direct and converse magnetoelectric effects are theoretically observed in an open Fermi-Hubbard dimer by tuning the external electromagnetic fields. Results show that an external magnetic field can enhance the electric polarization and susceptibility of the dimer particles without the necessity of mechanical strain. Conversely, gradients in an external electric field modulate the magnetic polarization and susceptibility. This striking behavior in the Fermi-Hubbard dimer can serve as a physical model for developing quantum control of complex materials such as in biosensors, biomedical processes, and energy harvesting.

Responses to prey chemical cues in wild-caught, adult gopher snakes (Pituophis catenifer).

Surface chemical cues from prey elicit elevated levels of tongue-flicking and striking behavior in many species of snakes and lizards. These responses are mediated by the vomeronasal system, and they may even occur in the absence of other sensory cues. How individuals of a species respond to prey chemical cues can reflect developmental, ecological, and evolutionary processes. Our focus in this study was ecologically based, and involved testing whether levels of chemosensory responding reflect the putative relative intake of prey types in nature. We tested 11 wild-caught adult gopher snakes (Pituophis catenifer) for their chemosensory responses, namely tongue flicking, in response to surface chemicals of natural prey items (rodent and bird) and to two control stimuli (distilled water and hexane). On average the snakes had significantly higher rates of tongue flicking toward prey cues than to control stimuli (p = .001). Responses to rodent and bird surface chemicals did not significantly differ from each other (p = .35). Tongue-flick responses to rodent surface chemicals were significantly higher than to both water and hexane (ps < .01), while responses to bird surface chemicals were significantly higher than to water (p < .05) but not to hexane (p = .12). (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Anomalous scalings of fluctuations of the area swept by a Brownian particle trapped in a [formula omitted] potential

We study the fluctuations of the area A=∫0Tx(t)dt under a one-dimensional Brownian motion x(t) in a trapping potential ∼|x|, at long times T→∞. We find that typical fluctuations of A follow a Gaussian distribution with a variance that grows linearly in time (at large T), as do all higher cumulants of the distribution. However, large deviations of A are not described by the “usual” scaling (i.e., the large deviations principle), and are instead described by two different anomalous scaling behaviors: Moderately-large deviations of A, obey the anomalous scaling PA;T∼e−T1/3fA/T2/3 while very large deviations behave as PA;T∼e−TΨA/T2. We find the associated rate functions f and Ψ exactly. Each of the two functions contains a singularity, which we interpret as dynamical phase transitions of the first and third order, respectively. We uncover the origin of these striking behaviors by characterizing the most likely scenario(s) for the system to reach a given atypical value of A. We extend our analysis by studying the absolute area B=∫0T|x(t)|dt and also by generalizing to higher spatial dimension, focusing on the particular case of three dimensions.

Observation of Energetic Electron Near the Electron Diffusion Region of Magnetic Reconnection

AbstractMagnetic reconnection can effectively convert magnetic energy into plasma energy, and accelerate electrons. In this article, the electrons with energies up to 150 keV are observed in the separatrix region and near the electron diffusion region (EDR) detected by the Magnetospheric Multiscale mission in the magnetotail. Combined with the electron pitch‐angle distribution, the electrons in these two regions have a striking behavior: the low‐energy electrons (&lt;∼10 keV) move mainly toward the X‐line, while the energetic electrons (69–139 keV) move mainly away from the X‐line. In the EDR, the energy of electrons can reach up to 10 keV and there is a notable enhancement in the flux of electrons in the direction perpendicular to the magnetic field, which implies the presence of acceleration processes occurring in the EDR, leading to the energization of electrons. Furthermore, the energy spectrum of non‐thermal electron with energies above 6 keV shows a power law distribution in this event, suggesting the occurrence of multiple acceleration processes rather than a single energization mechanism. These findings underscore the EDR's role as a crucial region for electron acceleration during magnetic reconnection. The study provides essential clues about the mechanisms driving electron acceleration, contributing to our understanding of space weather phenomena and the broader dynamics of plasma physics in space environments.

What determines mate choices? Heterospecific mating in Sympetrum dragonflies

Abstract Heterospecific interactions are an important phenomenon of animal epigamic behaviour; however, they remain understudied within important groups, such as insects. Dragonflies are an ideal group for research on interspecific mating and possible hybridisation as they are easily identifiable, large insects, with a conspicuous mating process, often striking territorial behaviour and several mating systems. Using the genus Sympetrum as the model group, we examined heterospecific mating at three different levels. In the field, we identified whether species identity, time and weather affected heterospecific mating frequency. One important part of heterospecific mating is whether the process is completed. For dragonflies, this means that flying in tandem is followed by successful copulation, gamete fusion and oviposition (which comprise mating completeness). In a mesocosm experiment, we determined mating completeness (tandems, copulation, oviposition) of hetero‐ and homospecific pairs and the possible role of species density in heterospecific mating. In the laboratory, we compared the viability of the offspring from heterospecific pairs with different epigamous behaviour. We found heterospecific mating to be a relatively common phenomenon unaffected by environmental variables, that was primarily influenced by species identity, temporal distribution and abundance of dragonfly species. Consequently, the presence of counterparts of other species is the main predictor of the frequency of heterospecific mating. The probability of completed epigamic behaviour (copulation and subsequent oviposition) connected with gamete fusion is lower in heterospecific mating. Generally, based on our results we can assume that successful heterospecific mating (leading to gamete fusion) occurs in closely related species (e.g., Sympetrum striolatum and Sympetrum vulgatum). However, as pre‐copulatory barriers are not strongly developed in some dragonfly groups, less closely related species (e.g., Sympetrum sanguineum and S. striolatum) also may mate. This phenomenon requires further study as it may present a threat to the survival of some species in the context of changing environmental conditions, including climate change.

A 3-year observation on analyzing cloud-to-ground lightning in Peninsular Malaysia using graph theory

Malaysia has a high amount of lightning events due to its geographical location and tropical climate, leading to substantial destruction of electrical systems and human injuries. Despite numerous studies connecting lightning activity with environmental factors, few had explored the multi-year correlation between strike patterns and times. The present study proposed a new approach employing graph theory to express Cloud-to-Ground Lightning (CGL) strike data. Using data mapping and vertex matrices, this technique visualizes CGL behavior, offering insights into lightning characteristics. The relationship between the CGL strike data across three years (2013, 2014, and 2015) was studied by using simple matching coefficient technique. Results indicate a robust positive correlation between directed graphs created across these years, suggesting consistent CGL strike behaviors in certain regions at Malaysia. The proposed method, in the form of directed edges, reduces the complexity of computation hence making it a promising integration to existing lightning prediction systems.

Universal Conductance Fluctuations in a MnBi2Te4 Thin Film.

Quantum coherence of electrons can produce striking behaviors in mesoscopic conductors. Although magnetic order can also strongly affect transport, the combination of coherence and magnetic order has been largely unexplored. Here, we examine quantum coherence-driven universal conductance fluctuations in the antiferromagnetic, canted antiferromagnetic, and ferromagnetic phases of a thin film of the topological material MnBi2Te4. In each magnetic phase, we extract a charge carrier phase coherence length of about 100 nm. The conductance magnetofingerprint is repeatable when sweeping applied magnetic field within one magnetic phase. Surprisingly, in the antiferromagnetic and canted antiferromagnetic phases, but not in the ferromagnetic phase, the magnetofingerprint depends on the direction of the field sweep. To explain our observations, we suggest that conductance fluctuation measurements are sensitive to the motion and nucleation of magnetic domain walls in MnBi2Te4.

A 9 Month Hubble Space Telescope Near-UV Survey of M87. I. Light and Color Curves of 94 Novae, and a Redetermination of the Nova Rate* * This paper is respectfully dedicated to Jay Gallagher and the late Art Code, who first characterized the striking ultraviolet behavior of a nova a half-century ago.

M87 has been monitored with a cadence of 5 days over a span of 9 months through the near-ultraviolet (NUV; F275W) and optical (F606W) filters of the Wide Field Camera 3 (WFC3) of the Hubble Space Telescope. This unprecedented dataset yields the NUV and optical light and color curves of 94 M87 novae, characterizing the outburst and decline properties of the largest extragalactic nova dataset in the literature (after M31 and M81). We test and confirm nova modelers’ prediction that recurrent novae cannot erupt more frequently than once every 45 days, show that there are zero rapidly recurring novae in the central ∼1/3 of M87 with recurrence times <130 days, demonstrate that novae closely follow the K-band light of M87 to within a few arcsecs of the galaxy nucleus, show that nova NUV light curves are as heterogeneous as their optical counterparts, and usually peak 5–30 days after visible light maximum, determine our observations’ annual detection completeness to be 71%–77%, and measure the rate R nova of nova eruptions in M87 as yr−1. The corresponding luminosity-specific classical nova rate for this galaxy is . These rates confirm that ground-based observations of extragalactic novae miss most faint, fast novae and those near the centers of galaxies. An annual M87 nova rate of 300 or more seems inescapable. A luminosity-specific nova rate of ∼7–10/yr/1010 L ⊙,K in all types of galaxies is indicated by the data available in 2023.

Measuring response functions of active materials from data

From flocks of birds to biomolecular assemblies, systems in which many individual components independently consume energy to perform mechanical work exhibit a wide array of striking behaviors. Methods to quantify the dynamics of these so-called active systems generally aim to extract important length or time scales from experimental fields. Because such methods focus on extracting scalar values, they do not wring maximal information from experimental data. We introduce a method to overcome these limitations. We extend the framework of correlation functions by taking into account the internal headings of displacement fields. The functions we construct represent the material response to specific types of active perturbation within the system. Utilizing these response functions we query the material response of disparate active systems composed of actin filaments and myosin motors, from model fluids to living cells. We show we can extract critical length scales from the turbulent flows of an active nematic, anticipate contractility in an active gel, distinguish viscous from viscoelastic dissipation, and even differentiate modes of contractility in living cells. These examples underscore the vast utility of this method which measures response functions from experimental observations of complex active systems.

Bacterial bioconvection confers context-dependent growth benefits and is robust under varying metabolic and genetic conditions.

Microbes often respond to environmental cues by adopting collective behaviors-like biofilms or swarming-that benefit the population. During "bioconvection," microbes gather in dense groups and plume downward through fluid environments, driving flow and mixing on the scale of millions of cells. Though bioconvection was observed a century ago, the effects of differing physical and chemical inputs and its potential selective advantages for different species of microbes remain largely unexplored. In Bacillus subtilis, vertical oxygen gradients that originate from air-liquid interfaces create cell-density inversions that drive bioconvection. Here, we develop Escherichia coli as a complementary model for the study of bioconvection. In the context of a still fluid, we found that motile and chemotactic genotypes of both E. coli and B. subtilis bioconvect and show increased growth compared to immotile or non-chemotactic genotypes, whereas in a well-mixed fluid, there is no growth advantage to motility or chemotaxis. We found that fluid depth, cell concentration, and carbon availability affect the emergence and timing of bioconvective patterns. Also, whereas B. subtilis requires oxygen gradients to bioconvect, E. coli deficient in aerotaxis (Δaer) or energy-taxis (Δtsr) still bioconvects, as do cultures that lack an air-liquid interface. Thus, in two distantly related microbes, bioconvection may confer context-dependent growth benefits, and E. coli bioconvection is robustly elicited by multiple types of chemotaxis. These results greatly expand the set of physical and metabolic conditions in which this striking collective behavior can be expected and demonstrate its potential to be a generic force for behavioral selection across ecological contexts. IMPORTANCE Individual microorganisms frequently move in response to gradients in their fluid environment, with corresponding metabolic benefits. At a population level, such movements can create density variations in a fluid that couple to gravity and drive large-scale convection and mixing called bioconvection. In this work, we provide evidence that this collective behavior confers a selective benefit on two distantly related species of bacteria. We develop new methods for quantifying this behavior and show that bioconvection in Escherichia coli is surprisingly robust to changes in cell concentration, fluid depth, interface conditions, metabolic sensing, and carbon availability. These results greatly expand the set of conditions known to elicit this collective behavior and indicate its potential to be a selective pressure across ecological contexts.

Symmetric group fixed quotients of polynomial rings

Given a representation of a finite group G over some commutative base ring k, the cofixed space is the largest quotient of the representation on which the group acts trivially. If G acts by k-algebra automorphisms, then the cofixed space is a module over the ring of G-invariants. When the order of G is not invertible in the base ring, little is known about this module structure. We study the cofixed space in the case that G is the symmetric group on n letters acting on a polynomial ring by permuting its variables. When k has characteristic 0, the cofixed space is isomorphic to an ideal of the ring of symmetric polynomials in n variables. Localizing k at a prime integer p while letting n vary reveals striking behavior in these ideals. As n grows, the ideals stay stable in a sense, then jump in complexity each time n reaches a multiple of p.

Thermoluminescent glow curve of Gd1-xRExAlO3 (RE=Dy or Pr) beta irradiated phosphors

Phosphors composed of Gd1-xRExAlO3 (0≤x ≤ 5 RE = Dy or Pr) stoichiometries were synthesized using the reverse coprecipitation pathway. The thermoluminescent responses of all phosphors were studied under beta radiation exposure. Doping the gadolinium aluminate host improved the thermoluminescent response of the phosphors, with the phosphors composed of Gd0.99Dy0.01AlO3 and Gd0.95Pr0.05AlO3 being the most sensitive. The Dy3+ ions produced a higher improvement of the thermoluminescent signal than the Pr3+ ions. Additionally, a proportional relationship between the similarity of the atomic numbers of the dopant and replaced ions and the sensitivity to thermoluminescence was confirmed. Besides, a slight shift of the thermoluminescent peaks toward lower temperatures was detected for doped phosphors. In the repeatability tests applied to the phosphor composed of Gd0.99Dy0.01AlO3, an anomalous increase in sensitization was observed. The observed sensitization was associated with the formation of electron trap clusters resulting from the continuous exposure to beta radiation. Furthermore, another sensitization phenomenon was detected in the phosphor with Gd0.95Pr0.05AlO3 stoichiometry when it was heated at low temperatures. The aforementioned striking behavior was related to quasi-continuous distributions of electron traps and the tunneling effect. In regard to linearity, the phosphor composed of Gd0.99Dy0.01AlO3 exhibited a linear response with the dose across the entire range of beta doses. However, the response of the Gd0.95Pr0.05AlO3 phosphor lost linearity beyond 26.4 Gy of beta dose. The results obtained through the use of the Tmax-Tstop method and deconvolutions suggested an enhancement in the efficiency of the thermoluminescent mechanisms due to the incorporation of activators.

Valley conductance and reflection probabilities in substrate-induced graphene superlattice

We study the transport properties of mass-less and spin-less Dirac fermions in a substrate-induced graphene super-lattice. The tight binding model for the super-lattice gives the energy band structure and we classify the topological regions (trivial and non-trivial) depending on the topological order parameter. The transfer matrix approach is used to compute the probabilities of the reflection and transmission in terms of structural parameters and we investigate the valley-switching phenomenon for all values of incident electron energies (E). We observe that the Dirac fermions with valley degree of freedom sometimes completely and other times partially reflect and transmit to the other valley under some specific values of structure parameters suggesting that we have a finite value of switching probability (≤100%) for all values of E. Moreover, the conductance exhibits striking behaviour, showing a peak at each Dirac point, which merges and subsequently vanishes depending on the structure parameters.

Behavioral diversity and biomechanical determinants of the outcome of a fish predator–prey interaction

AbstractPredator–prey interactions are ubiquitous and under strong selection because of the consequences experienced by both predator and prey if they lose the interaction. Biomechanics and behavior play important roles in the outcome of these interactions, but many studies focus on the prey, restrict the range of behaviors considered, and the role of prey boldness in the outcome is not understood. We used high‐speed video to test for effects of multiple measures of performance and kinematics of both the predator and prey, and boldness of prey on the outcome of interactions between Pike Cichlids (Crenicichla sp.) and Guppies (Poecilia reticulata). We found high variation in the behaviors employed during the predator–prey interactions, including in suction versus raptorial feeding, strike accuracy, and guppy responsiveness. We also found that predators moving relatively slower and prey moving relatively faster were more successful at consuming the prey and evading the predator, respectively. Prey that reacted farther from the predator was more likely to escape predation, but boldness of the prey did not affect the interaction. Our work suggests that a high level of variation in predator–prey interactions is widespread, even when strike and escape behaviors are stereotyped. We also showed that what both the predator and the prey do during an interaction are important in determining the outcome.

An investigation into the impact resistance of bio‐inspired laminates with interlayer hybrid unidirectional/woven carbon fibers

AbstractThis study investigates the rapid mandible strike behavior of trap‐jaw ants (Odontomachus monticola), a highly aggressive species of terrestrial social organisms. An impact‐resistant gradient waviness structure is discovered in the mandibles of trap‐jaw ants. The gradient waviness structure is incorporated into the fiber laminates to enhance their impact resistance and damage tolerance. Bioinspired interlayer hybrid laminates with both unidirectional and woven arrangements were fabricated using the mold press forming technique. The impact resistance and damage tolerance of the bionic laminates are investigated through low‐velocity impact, ultrasonic C‐scanning, and compression after impact tests. The results indicate that hybrid laminates play a key role in limiting damage propagation and improving energy dissipation capacity. The hybrid configuration effectively mitigates crack propagation, enhances load‐bearing capacity, and improves residual compressive strength. Bionic laminates offer an efficient solution for enhancing damage tolerance against through‐the‐thickness loads.Highlights An impact‐resistant gradient waviness structure is discovered in trap‐jaw ants. Bioinspired interlayer hybrid laminate is fabricated by mold pressing. The hybrid laminate restrict damage propagation and improve residual strength. Bionic laminate offer an efficient solution for enhancing damage tolerance.

Compendium of medically important snakes, venom activity and clinical presentations in Ghana.

Snake bite envenoming (SBE) is one neglected tropical disease that has not received the needed attention. The sequelae of burdensome disability and mortality impact the socioeconomic life of communities adversely with little documentation of SBE in health facility records in Ghana. This study details SBE and snake distribution, habits/habitats, type of venom expressed and clinical manifestations. We conducted a structured thematic desk review of peer reviewed papers, books and reports from repositories including PubMed, World Health Organization (WHO) and Women's & Children's Hospital (WCH) Clinical Toxinology Resources using bibliographic software EndNote and search engine Google Scholar with the following key words; snakes, medical importance, snake bites, venom and venom type, envenomation, symptoms and signs, vaccines, venom expenditure, strike behaviour and venom-metering + Ghana, West Africa, Africa, World. We also reviewed data from the District Health Information Management System (DHIMS) of the Ghana Health Service (GHS). Outcome variables were organized as follows: common name (s), species, habitat/habit, species-specific toxin, clinical manifestation, antivenom availability, WHO category. Snake bites and SBE were grouped by the activity of the expressed venom into neurotoxic, cardiotoxic, haemorrhagic, cytotoxic, myotoxic, nephrotoxic and procoagulants. Neurotoxic snake bites were largely due to elapids. Expressed venoms with cardiotoxic, haemorrhagic, nephrotoxic and procoagulant activities principally belonged to the family Viperidae. Snakes with venoms showing myotoxic activity were largely alien to Ghana and the West African sub-region. Venoms showing cytotoxic activity are expressed by a wide range of snakes though more prevalent among the Viperidae family. Snakes with neurotoxic and haemorrhagic venom activities are prevalent across all the agro-ecological zones in Ghana. Understanding the characteristics of snakes and their venoms is useful in the management of SBE. The distribution of snakes by their expressed venoms across the agro-ecological zones is also instructive to species identification and diagnosis of SBE.

Zebrafish larvae use stimulus intensity and contrast to estimate distance to prey

The ability to determine the distance to objects is an important feature of most visual systems, but little is known about the neuronal mechanisms for distance estimation. Larval zebrafish execute different visual behaviors depending on distance; at medium distances, they converge their eyes and approach, but when the prey is close enough, they execute a strike and suck the prey into their mouths. To study distance estimation, we developed a head-fixed strike assay. We found that we could evoke strike behavior in head-fixed larvae and quantify head movements to classify the behavior as a strike. Strikes were dependent on distance to prey, allowing us to use them to study distance estimation. Light intensity is rapidly attenuated as it travels through water, so we hypothesized that larvae could use intensity as a distance cue. We found that increasing stimulus intensity could cause larvae to strike at prey that would normally be out of range, and decreasing the intensity could lower the strike rate even for very proximal stimuli. In addition, stimulus contrast is a key parameter, and this could allow larvae to estimate distance over the range of natural illumination. Finally, we presented prey in the binocular vs. monocular visual field and found that monocular prey did evoke strikes, although the binocular input produced more. These results suggest that strike behavior is optimally evoked by bright UV dots in the binocular zone with minimal UV background light and provide a foundation to study the neuronal mechanisms of distance estimation.

The Fastest Microrobot Pitcher: Design Exploration for a Throwing Microrobot

Mantis shrimp are distinguished by their high-speed striking appendages, which achieve tip speeds on the order of tens of meters per second underwater in order to break open the shells of their prey. To better understand the mechanics by which mantis shrimp achieve these speeds, prior research has designed and modeled a striking microrobot to mimic the mantis shrimp's high speed appendage's striking behavior. Here, we utilize a similar mantis shrimp mechanism for small-scale throwing. After adapting the mechanism for projectiles, we describe improvements to the throwing speed via a process of modeling and experimental validation of key components. This work explores the inclusion of a passive joint on the throwing arm and different projectile carriage designs. The current device achieves throwing speeds of over 10 m/s for a 65 mg ball bearing, making it the fastest microrobot “pitcher” demonstrated to date. Keywords: Nano/Micro Robots, Mechanism Design, Throwing, Impulsive Mechanisms