Sex Differences and Seasonal Trade-Offs in Response to Injured and Non-Injured Conspecifics in Red-Spotted Newts, Notophthalmus viridescens

Injured prey often release alarm chemicals that induce antipredator behaviors in conspecifics. Injured or killed prey most likely release a wide array of chemicals in addition to alarm substances, such as sexual pheromones, which could enhance or compromise antipredator responses. Thus, damage-release cues provide an excellent opportunity to examine the influence of seasonally fluctuating sexual pheromones on antipredator behaviors. We used a series of laboratory and field experiments and meta-analysis to examine seasonal changes and sex differences in the response of red-spot-ted newts, Notophthalmus viridescens, to the odor of non-injured conspecifics and conspecific tissue extracts, the latter of which presumably contain pheromones of non-injured conspecifics combined with alarm chemicals signaling predation. During the peak of the breeding season, males were attracted to females and multiple males, but did not avoid tissue extracts from either sex. As the breeding season waned, male attraction to females and males decreased, while avoidance of alarm extracts from both sexes concurrently increased. In contrast to male behavior, females were indifferent to both sexes during the breeding season, and showed significant avoidance only of female extract. As the breeding season progressed, females displayed no change in response to treatments. Male and female responses to female rinse and extract differed significantly, but their response to male treatments did not. During the non-breeding season, both males and females were indifferent to the odor of conspecifics and avoided conspecific tissue extracts, with the magnitude of male avoidance greater than that of female avoidance, suggesting sex differences in response to alarm cues in both the breed-ing and non-breeding seasons. In general, both male and female response to conspecific odor and tissue extracts covaried positively, suggesting that social pheromones can be detected within conspecific macerates and com-promise alarm-chemical avoidance. Many of the sex differences in both seasons are likely explained by selection pressures imposed on males to intensely mate search during the breeding season, suggesting that the mating system of newts directly influences predation threat during reproductive activity and may have significant indirect consequences on risk during the non-breeding season

On Temporal Variation and Conflicting Selection Pressures: A Test of Theory Using Newts

Most studies that examine conflicting selection pressures hold resources and risks constant, despite their ubiquitous fluctuation. Since little is known about the consequences of neglecting this variation, we examined the temporal response of male red-spotted newts, Notophthalmus viridescens, to conflicting female pheromones and damage-release alarm chemicals signaling predation. After a single exposure in both the laboratory and field, males were attracted to female odor and avoided conspecific alarm chemicals. Response to these combined cues depended on time after exposure, with males initially avoiding, and then being attracted to, the cue combination. This response shift was due to the resource and risk declining at different rates, and female odor accelerating male recovery from antipredator behavior. In the laboratory, males suppressed activity when exposed to alarm chemicals alone but increased their activity when female odor was added. Iterative exposures through the breeding season revealed that, as male mate search activity declined, male avoidance of alarm chemicals increased, but alarm chemical production appeared unchanged. Thawing dates differed between ponds of the same and different populations, which offset levels of mate search activity and consequently alarm chemical avoidance. As a result, simultaneous pond surveys made it appear as though there was geographic variation in reproductive and predator-avoidance behaviors. However, when thawing dates were aligned, the time courses of reproductive and predator-avoidance behaviors for the ponds coincided, demonstrating that observed site differences were predominantly due to different behavioral onsets, which would have gone overlooked had the larger temporal scale not been considered. These results indicate that temporal variation can be easily mistaken for geographic variation in behavior, increasing the potential for data interpretation errors. These studies underscore the importance of considering temporal variation when examining conflicting selection pressures

Behavioural Responses by Red-Backed Salamanders to Conspecific and Heterospecific Cues

Chemical cues released from injured prey are thought to indicate the proximity of a predator or predation event, and therefore, an area of elevated predation risk. Prey often avoid chemical cues released from injured heterospecifics, but there is little evidence to determine whether this is due to homologous cues among phylogenetically related species, or avoidance of injured syntopic species that experience predation from the same predators. The purpose of this study was to examine the response of terrestrial red-backed salamanders (Plethodon cinereus) to chemical cues from non-injured and injured members of their prey guild that vary in their relatedness to P cinereus. In the laboratory, P. cinereus avoided chemical cues from injured conspecifics, injured and non-injured slimy salamanders (P glutinosus), and injured confamilial dusky salamanders (Desmognathus ochrophaeus). Red-backed salamanders did not avoid rinses from non-injured conspecifics and dusky salamanders, or cues from injured and non-injured earthworms (Lumbricus sp.), a more distantly related prey guild member. These results cannot be fully explained by either phylogenetic relatedness (among plethodontid salamanders) or prey guild membership alone. We suggest that a combination of these factors, and perhaps others, likely influenced the evolution of heterospecific alarm cue avoidance in the red-backed salamander

The Ontogeny of Chemically-Mediated Antipredator Behaviours in Newts (Notophthalmus viridescens): Responses to Injured and Non-Injured Conspecifics

Responses to alarm chemicals from injured prey may influence predation risk and foraging success of receivers and senders, while learning can influence the strength of these responses. Thus, it is important to know when in ontogeny prey produce and detect alarm substances and how learning shapes their response, but surprisingly little is known about either of these topics. We assessed when in the life of red-spotted newts, Notophthalmus viridescens, alarm chemicals are produced and detected by comparing adult versus eft (terrestrial juveniles) and larval responses to rinses and tissue extracts from individuals in each life-history stage. To evaluate the influence of experience in larvae exposed to conspecific alarm substances and rinses from adults known to cannibalize larvae, we compared the response of naive larvae, which had no prior experience with alarm chemicals or predators, to experienced larvae, which were likely to have experienced alarm chemicals and predators in their native pond. Larvae were indifferent to larval rinses and extracts, but reduced their activity in response to adult rinses and extracts. There was no difference between responses of recently hatched naive and experienced larvae, indicating that larvae exhibit innate antipredator behaviors in response to adult odour. Adults were indifferent to all larval treatments and adult rinse, but avoided adult extract. Since neither adults nor larvae responded to larval extract, larvae did not appear to possess alarm chemicals, and consequently, we were unable to assess the influence of experience on alarm substance response in larvae. Adults and efts were indifferent to rinses, but avoided extracts from conspecifics of both life-history stages. Together, these results demonstrate that red-spotted newts do not produce alarm chemicals until late in larval development, but can respond to predation-related chemical cues soon after hatching

To Avoid or Not to Avoid? Factors Influencing the Discrimination or Predator Diet Cues by a Terrestrial Salamander

Many prey species use chemical cues deposited by predators to assess predation risk, and some prey are capable of discriminating among predator chemical traces based on the predator’s recent diet. Here we test the influence of genetic relatedness (degree of genetic similarity between prey) and ecological relatedness (degree of refuge and trophic overlap between syntopic prey) on the evolution of predator-diet discrimination by red-backed salamanders, Plethodon cinereus. In experiment 1, we examined whether red-backed salamanders from Binghamton University (Binghamton, New York, U.S.A.) would differentially respond to chemical traces from garter snakes (Thamnophis sirtalis) fed conspecific P. cinereus from four populations belonging to three phylogenetic groups: Group II from Mountain Lake, Virginia, Group III from Binghamton University, New York, Group III from Hawk Mountain, Pennsylvania, and Group IV from Cherry Springs, Pennsylvania, U.S.A. The test salamanders only avoided chemical traces from garter snakes fed salamanders from the two Group III sites, although the response to the Group III-Hawk Mountain treatment was intermediate to that for the Group III-Binghamton University treatment and the Group II and IV treatments. In experiment 2, we examined whether red-backed salamanders collected from two subpopulations, syntopic or allotopic with two-lined salamanders, Eurycea bislineata, vary in their response to chemical cues from garter snakes foraging on two-lined salamanders. Only red-backed salamanders syntopic with E. bislineata avoided chemical traces from garter snakes fed E. bislineata. These results suggest that both genetic and ecological relatedness play a role in the evolution of predator-diet discrimination in red-backed salamanders

It\u27s All Fun and Games Until Someone Gets Hurt: An Analysis of Trampoline Injuries in the Pennsylvania Trauma System

Introduction: It is well known that trampolines can be a particular source of danger, especially in children. We sought to examine the profile of those patients with trampoline injuries. We hypothesized there would be certain injury patterns predicative of trampoline injuries. Methods: All patients submitted to Pennsylvania Trauma Outcome Study (PTOS) database from 2016-2018 were analyzed. Trampoline injury was determined by ICD10 activity code. Injury patterns in the form of abbreviated injury scale (AIS) body regions were examined in the trampoline injured patients. Patient demographics and clinical variables were compared between those with trampoline injury versus those without. Results: There were 107 patients from 2016-2018 in PTOS who had a trampoline injury. All of these patients were discharged alive and had a blunt mechanism of injury. Of the 107 patients, the most common injury type was injury to the extremities (90/107 patients [84.1%]) with 54 (50.5%) patients having upper extremity injury and 36 (33.6%) patients having lower extremity injury. 10 (9.35%) patients had injury to the spine and 5 (4.67%) had head injury. Those with trampoline injuries were significantly younger (mean age: 13.0 vs. 48.6) and more likely to be white or of Hispanic ethnicity. Almost half of the patients injured (49.5%) were under 10 years of age. Patients with trampoline injuries had significantly lower injury severity scores and significantly higher Shock Index (Table 1). Conclusions: The majority of patients with trampoline injuries had injury to an extremity and were pediatric patients. These results help better understand the demographic, physiologic and anatomic patterns surrounding trampoline injuries. Current government standards recommend that no child under age 6 should use a full-sized trampoline; however, based off of the study results, we advise that this age be increased to 10

QuickCough: An instrumentational proximal airway clearance technique (ACT) for select patients with Neuromuscular Disease (NMD)

Patients with neuromuscular disease (NMD) requiring tracheostomy and mechanical ventilation secondary to respiratory failure encounter increased difficulty in removing pulmonary secretions from the airways. To combat issues associated with current treatment modalities for insufficient cough efficacy (cost, poor mobility, discomfort, lack of evidence), we have developed an instrumentational proximal airway clearance technique (ACT) which augments a manual proximal ACT developed by a client with NMD. QuickCough is a 3D-printed PLA attachment to the tracheostomy apparatus which has demonstrated its ability to facilitate pressure changes necessary to increase patient’s peak cough flow (PCF) by providing a stronger exsufflation for the patient. QuickCough meets client needs by providing a machine-washable, inexpensive method of facilitating secretion expulsion without the use of bulky equipment in-transit. This novel instrumentational augmentation of a manual ACT was designed using the engineering design process discussed in The University of Akron’s biomedical engineering design course 4800:470. Future work ought to focus on development of an automated procedure to allow application of QuickCough in cases of global paralysis or insufficient home-care