scholarly journals Nanotube Formation: A Rapid Form of “Alarm Signaling”?

2016 ◽  
Vol 38 (5) ◽  
pp. 1066-1072 ◽  
Author(s):  
Zuyi Weng ◽  
Bodi Zhang ◽  
Irene Tsilioni ◽  
Theoharis C. Theoharides
Keyword(s):  
Alarm Signaling

Age-dependent fitness costs of alarm signaling in aphids

2003 ◽  
Vol 81 (5) ◽  
pp. 757-762 ◽  
Author(s):  
Edward B Mondor ◽  
Bernard D Roitberg
Keyword(s):  
Alarm Pheromone ◽  
Fourth Instar ◽  
Fitness Cost ◽  
Fitness Costs ◽  
Alarm Signal ◽  
Offspring Production ◽  
Direct Fitness ◽  
Alarm Signaling ◽  
Pea Aphids ◽  
Age Dependent

For an alarm signal to evolve, the benefits to the signaler must outweigh the costs of sending the signal. Research has largely focused on the benefits of alarm signaling, and the costs to an organism of sending an alarm signal are not well known. When attacked by a predator, aphids secrete cornicle droplets, containing an alarm pheromone, for individual protection and to warn clonemates. As aphid alarm pheromone is synthesized de novo in a feedback loop with juvenile hormone, we hypothesized that the secretion of cornicle droplets may result in a direct fitness cost to the emitter. We show that the secretion of a single cornicle droplet by pre-reproductive (third- and fourth-instar) pea aphids, Acyrthosiphon pisum, directly altered the timing and number of offspring produced. Third-instar pea aphids delayed offspring production but produced more offspring overall than non-secreting aphids, demonstrating a life-history shift but no significant fitness cost of droplet secretion. Fourth-instar pea aphids also delayed offspring production but produced the same number of offspring as non-secretors, resulting in a direct fitness cost of droplet secretion. Offspring production by adult, reproductive pea aphids that secreted a cornicle droplet did not differ from that of non-secretors. Thus, the fitness costs of secreting cornicle droplets containing an alarm signal are age-dependent.

scholarly journals Collision Prevention Algorithm for Fishing Vessels Using mmWAVE Communication

2020 ◽  
Vol 8 (2) ◽  
pp. 115 ◽  
Author(s):  
Myoung-Ki Lee ◽  
Young-Soo Park
Keyword(s):  
Communication Technology ◽  
Continuous Monitoring ◽  
Wireless Access ◽  
False Alarms ◽  
Maritime Traffic ◽  
Fishing Vessels ◽  
Dangerous Situation ◽  
Alarm Signaling ◽  
Collision Prevention

This study leveraged the millimeter wireless access in vehicular environments (mmWAVE) communication technology to reflect the maneuvering characteristics of small fishing vessels and constructed a collision prevention algorithm that can be applied relatively easily. The algorithm was verified through simulation and actual ship experiments. The algorithm had four components: detection of vessels within three miles; identification of dangerous vessels by applying the time to the closest point of approach (TCPA) and distance at the closest point of approach (DCPA) criteria; continuous monitoring of maritime traffic risk; and incremental alarm signaling. The simulations and experiments confirmed that the alarm was generated incrementally in accordance with the distance to a dangerous situation, with no false alarms. Thus, the proposed algorithm offers potential to enhance the safety of small fishing vessels.

scholarly journals Multimodal alarm behavior in urban and rural gray squirrels studied by means of observation and a mechanical robot

2010 ◽  
Vol 56 (3) ◽  
pp. 313-326 ◽  
Author(s):  
Sarah R. Partan ◽  
Andrew G. Fulmer ◽  
Maya A. M. Gounard ◽  
Jake E. Redmond
Keyword(s):  
Communication Systems ◽  
Sensory Modality ◽  
Multimodal Communication ◽  
Visual Signals ◽  
Urban Habitats ◽  
Multimodal Signals ◽  
Alarm Behavior ◽  
Alarm Signaling ◽  
Interesting Possibility ◽  
Multimodal Enhancement

Abstract Urbanization of animal habitats has the potential to affect the natural communication systems of any species able to survive in the changed environment. Urban animals such as squirrels use multiple signal channels to communicate, but it is unknown how urbanization has affected these behaviors. Multimodal communication, involving more than one sensory modality, can be studied by use of biomimetic mechanical animal models that are designed to simulate the multimodal signals and be presented to animal subjects in the field. In this way the responses to the various signal components can be compared and contrasted to determine whether the multimodal signal is made up of redundant or nonredundant components. In this study, we presented wild gray squirrels in relatively urban and relatively rural habitats in Western Massachusetts with a biomimetic squirrel model that produced tail flags and alarm barks in a variety of combinations. We found that the squirrels responded to each unimodal component on its own, the bark and tail flag, but they responded most to the complete multimodal signal, containing both the acoustic and the moving visual components, providing evidence that in this context the signal components are redundant and that their combination elicits multimodal enhancement. We expanded on the results of Partan et al. (2009) by providing data on signaling behavior in the presence and absence of conspecifics, suggesting that alarm signaling is more likely if conspecifics are present. We found that the squirrels were more active in the urban habitats and that they responded more to tail flagging in the urban habitats as compared to the rural ones, suggesting the interesting possibility of a multimodal shift from reliance on audio to visual signals in noisier more crowded urban habitats.

Pea aphid, Acyrthosiphon pisum, cornicle ontogeny as an adaptation to differential predation risk

2002 ◽  
Vol 80 (12) ◽  
pp. 2131-2136 ◽  
Author(s):  
Edward B Mondor ◽  
Bernard D Roitberg
Keyword(s):  
Alarm Pheromone ◽  
Acyrthosiphon Pisum ◽  
Harmonia Axyridis ◽  
Inclusive Fitness ◽  
Pea Aphid ◽  
Body Parts ◽  
Anatomical Structures ◽  
Alarm Signaling ◽  
Risk Of Predation ◽  
Pea Aphids

Aphids possess unique anatomical structures called cornicles through which a defensive secretion containing alarm pheromone is often emitted when a predator attacks an aphid. The levels of alarm pheromone in cornicle droplets from the pea aphid, Acyrthosiphon pisum (Harris), vary considerably during development; however, it is not clear how the length of the cornicle changes during ontogeny. The length of the cornicle relative to the lengths of other body structures may have profound effects on aphid defense and alarm signal diffusion. Using previously published morphological measurements of pea aphids and observing interactions between pea aphids and multicolored Asian ladybird beetles, Harmonia axyridis Pallas, it was observed that pea aphid cornicles elongate proportionally more than other body parts during the first four instars, when alarm-pheromone levels have peaked, than during the fifth (adult) instar, when pheromone levels decline. Pea aphids also are more likely to emit cornicle droplets and daub them onto a predator when the cornicles are undergoing such rapid growth. We suggest that because of a high risk of predation, rapid cornicle growth in juveniles has evolved both for individual defense and for the inclusive fitness benefits of alarm signaling.

scholarly journals Elimination of HSV-2 infected cells is mediated predominantly by paracrine effects of tissue-resident T cell derived cytokines

2019 ◽  
Author(s):  
Pavitra Roychoudhury ◽  
David A Swan ◽  
Elizabeth Duke ◽  
Lawrence Corey ◽  
Jia Zhu ◽  
...  
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
T Cell ◽  
Lesion Size ◽  
Viral Kinetics ◽  
Paracrine Effects ◽  
Alarm Signaling ◽  
Infected Cells ◽  
Simplex Virus ◽  
Herpes Simplex Virus 2

AbstractThe mechanisms underlying rapid elimination of herpes simplex virus-2 (HSV-2) in the human genital tract despite low tissue-resident CD8+ T-cell density (TRM) are unknown. We analyzed shedding episodes during chronic HSV-2 infection: viral clearance always occurred within 24 hours of detection even if viral load exceeded 107HSV DNA copies; surges in granzyme B and interferon-γoccurred within the early hours after reactivation. We next developed a mathematical model of an HSV-2 genital ulcer to integrate mechanistic observations of TRMin situproliferation, trafficking, cytolytic effects and cytokine alarm signaling from murine studies with viral kinetics, histopathology and lesion size data from humans. A sufficiently high density of HSV-2 specific TRMpredicted rapid contact-mediated elimination of infected cells. At lower TRMdensities, TRMmust initiate a rapidly diffusing, polyfunctional cytokine response in order to eliminate of a majority of infected cells and eradicate briskly spreading HSV-2 infection.One Sentence SummaryControl of herpes simplex virus-2 is primarily mediated by rapidly diffusing cytokines secreted by tissue-resident T cells.

On-Line Tracking and Monitoring of Rolling Element Bearing Faults

2014 ◽  
Author(s):  
S. Chatterton ◽  
P. Borghesani ◽  
P. Pennacchi ◽  
A. Vania
Keyword(s):  
Real Time ◽  
Damage Index ◽  
Vibration Signal ◽  
Operating Conditions ◽  
Rolling Element Bearing ◽  
Simple Task ◽  
Alarm Signaling ◽  
Rolling Element ◽  
On Line ◽  
Element Bearing

Diagnostics of rolling element bearings is usually performed by the analysis of vibration signal using suitable signal analysis tools, such as the most used and simplest method, Envelope Analysis. This method is based on the identification of bearing damage frequency components in the so-called Square Envelope Spectrum. If the assessment of the bearing health is quite a simple task, the on-line monitoring and the real-time evaluation of the trend of a suitable damage index is a complex task to be performed in an automatic way. The damage index must be robust against variations of system operating conditions and external vibration sources to avoid misleading results. The damage index should be also simple to be evaluated in the case of real-time applications. In the paper, the case of a rolling element bearing in which the defect develops until a permanent failure is described as well as the algorithm implemented for alarm signaling.

Joint tail and vocal alarm signals of gray squirrels (Sciurus carolinensis)

Behaviour ◽  
2014 ◽  
Vol 151 (10) ◽  
pp. 1433-1452 ◽  
Author(s):  
Thaddeus R. McRae ◽  
Steven M. Green
Keyword(s):  
Physical Appearance ◽  
Ground Squirrels ◽  
Sciurus Carolinensis ◽  
Gray Squirrel ◽  
Signaling System ◽  
Statistical Index ◽  
Natural Manner ◽  
Alarm Signals ◽  
Alarm Signaling ◽  
Presence And Absence

Threat-specific vocalizations have been observed in primates and ground squirrels, but their contemporaneous usage with visible signals has not been experimentally analyzed for association with threat type. Here we examine the eastern gray squirrel, an arboreal squirrel that uses both vocal and tail signals as alarms. Squirrels were presented with cat and hawk models simulating natural terrestrial or aerial predator attacks and also with control objects that do not resemble predators but approach in a similar manner. Individuals responded with tail signals (twitches and flags) and vocalizations (kuks, quaas and moans), but only flags and moans are associated with predator type. Moans were elicited primarily by aerial stimuli and flags by terrestrial stimuli. Eastern gray squirrels use an alarm-signaling system in which signals in each modality potentially are associated with particular attributes of a threat or may be general alarms. Terrestrially-approaching stimuli yielded vocal and tail alarm signals regardless of whether the stimulus resembled a predator. With aerially-approaching stimuli, however, quaas were used more often when the stimulus resembled an aerial predator than when it did not. An approaching object’s physical appearance may therefore affect squirrels’ responses to aerial, but not terrestrial, objects. When the stimuli resembled real predators approaching in the natural manner (terrestrially or aerially), both tail flags and vocal moans were associated with predator type, so we also considered moans and flags together. The presence and absence of moans and flags in an alarm signaling bout yields a higher statistical index of predictive association as to whether the threat is aerial or terrestrial than does either component alone.

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