Evidence of learning walks related to scorpion home burrow navigation

The Navigation by Chemotextural Familiarity Hypothesis (NCFH) suggests that scorpions use their midventral pectines to gather chemical and textural information near their burrows and use this information as they subsequently return home. For NCFH to be viable, animals must somehow acquire home-directed ″tastes″ of the substrate, such as through path integration (PI) and/or learning walks. We conducted laboratory behavioral trials using desert grassland scorpions (Paruroctonus utahensis). Animals reliably formed burrows in small mounds of sand we provided in the middle of circular, sand lined behavioral arenas. We processed overnight infrared video recordings with a MATLAB script that tracked animal movements at 1-2 s intervals. In all, we analyzed the movements of 23 animals, representing nearly 1500 hours of video recording. We found that once animals established their home burrows, they immediately made one to several short, looping excursions away from and back to their burrows before walking greater distances. We also observed similar excursions when animals made burrows in level sand in the middle of the arena (i.e., no mound provided). These putative learning walks, together with recently reported PI in scorpions, may provide the crucial home-directed information requisite for NCFH.

Towards the development of a chemical lure to improve the management of invading rat populations

<p>Introduced species, such as Rattus norvegicus and Rattus rattus,have contributed to the extinction of many native animals and plants in New Zealand(NZ). Current strategies exist to monitor, manage and eradicate pest species. However, these haven’t always been completely successful and tools to detect small or invading densities remain to be developed. One possible new method to address this problem is the application of chemical attractants (lures). Recently, a major urinary protein (MUP) has been shown in male miceto act as a sexual attractant. MUPs modulate the release of volatile attractants and have potential to act as attractants themselves. Our aim was to determine if a similar MUP(s) and associated volatiles are present in the urine of rats, with the prospect of creating a chemical lure to use in rat detection and eradication. Using Gas Chromatography/Mass Spectrometry, potential volatiles in rat urine have been identified. Analysis of rat urine by gel electrophoresis has shown MUPs present in both sexes. A 22.4 kDa MUP in Rattus norvegicushas been synthesised and expressed in E.coliusing recombinant DNA technology. Preliminary steps have been made towards the production of a MUP based on ship rat DNA sequence. Future behavioral trials are needed to investigate whether the synthesised protein, in the presence or absence of the urinary-derived volatiles, is a sexual attractant.</p>

Towards the development of a chemical lure to improve the management of invading rat populations

<p>Introduced species, such as Rattus norvegicus and Rattus rattus,have contributed to the extinction of many native animals and plants in New Zealand(NZ). Current strategies exist to monitor, manage and eradicate pest species. However, these haven’t always been completely successful and tools to detect small or invading densities remain to be developed. One possible new method to address this problem is the application of chemical attractants (lures). Recently, a major urinary protein (MUP) has been shown in male miceto act as a sexual attractant. MUPs modulate the release of volatile attractants and have potential to act as attractants themselves. Our aim was to determine if a similar MUP(s) and associated volatiles are present in the urine of rats, with the prospect of creating a chemical lure to use in rat detection and eradication. Using Gas Chromatography/Mass Spectrometry, potential volatiles in rat urine have been identified. Analysis of rat urine by gel electrophoresis has shown MUPs present in both sexes. A 22.4 kDa MUP in Rattus norvegicushas been synthesised and expressed in E.coliusing recombinant DNA technology. Preliminary steps have been made towards the production of a MUP based on ship rat DNA sequence. Future behavioral trials are needed to investigate whether the synthesised protein, in the presence or absence of the urinary-derived volatiles, is a sexual attractant.</p>

Long-term Exposure to Predation Threat Can Modulate the Expression of Sexually Selected Traits in Male Guppy (Poecilia reticulata)

The expression of sexual traits can be affected by different environmental factors among which predation may be particularly important life-history traits. This study investigated the effects of predation risk on courtship behavior, growth and sexual color patterns in male guppy (Poecilia reticulata). In the study, juvenile male guppies were randomly assigned to two treatments, namely T1 (predation threat) and T2 (no predation threat). The courtship performances were visually observed and recorded, while color patterns and morphological traits were measured by using the ImageJ software from the captured photos. The courtship behavioral trials revealed that predation threatened males performed significantly lower number of sigmoid displays than those of no-predation group. Further, the predation scared group had significantly shorter standard length, body area and a reduced number and area of orange spots than their counter group. However, the predation threat did not affect significantly the gonopodial thrusts, and black and iridescent color components (spot number and area). The reduction of costly traits (e.g. behavior, color patterns and body size) is common anti-predator response which presumably reduces predation risks. Male guppies are probably using this form of defence in response to the increased predation risk. The overall result suggests that growth and sexually selected trait expression are sensitive to predation risk and thereby aid in our understanding to predict the evolution of phenotypic variation in natural systems.

The dear enemy effect drives conspecific aggressiveness in an Azteca-Cecropia system

Territoriality is costly, and the accurate identification of intruders and the decision to perform aggressive responses are key behavioral traits in social animals. We studied aggression among individuals belonging to close and distant nests of the plant-ant Azteca muelleri, which lives in stems of the pioneer tree Cecropia glaziovii. More specifically, we aim to investigate if the DE (dear-enemy effect—less aggression towards neighbors than strangers) or NN (nasty-neighbor effect—less aggression to strangers than neighbors) effects or even none of them apply for this iconic Azteca-Cecropia system. We further checked if ant aggression towards conspecifics is related to cuticular hydrocarbon profiles (CHCs), which provide chemical cues for nestmate recognition. Therefore, we sampled 46 nests of A. muelleri in three Brazilian Atlantic forest fragments and performed behavioral trials within and between sites. Consistently with the DE effect, we found higher aggression levels in ‘between sites’ versus ‘within sites’ treatments as well as a positive effect of spatial distance on ant aggressiveness. We found no effect of the overall dissimilarities on CHC blend on ant aggressiveness, but of one CHC class, the methylated alkanes. Overall, we provide key insights on nest-mate recognition in obligatory ant-plant mutualisms.

Physical Activity and Exercise Interventions in Cancer Survivors

The field of exercise oncology has developed such that it is clear that people affected by cancer should be encouraged to be physically active from the point of diagnosis; indeed, this is now a key component of the survivorship care package in many countries. However, there are still gaps in the evidence. The majority of evidence for the benefits of exercise after cancer comes from breast, prostate, and colorectal cancer patients, usually without metastatic disease. Trials have usually been rated as low to moderate in quality, and although double-blinding will always be an issue in behavioral trials, there is a need to approach exercise studies with the rigor applied to drug trials if it is to be considered an adjuvant cancer therapy. Additionally, there are still gaps around the most appropriate types of exercise for specific cancer sites and how best to implement exercise as part of cancer care, balancing interventions that are likely to reach a large number of patients (e.g., remote, digital) versus those that may have greater benefit (e.g., supervised, face to face). Finally, while observational data are strongly supportive of higher self-reported postdiagnosis physical activity being associated with lower all-cause and cancer-specific mortality, and possibly recurrence, definitive trial data does not yet exist (although a number of trials are underway). Until survival data are generated, caution should be used in how the benefits of exercise are presented to cancer patients, with a focus on the large number of outcomes that have been robustly demonstrated to improve in response to intervention.

Underrepresentation of Adults and Older Adults With Disabilities in Behavioral Clinical Trials: A Scoping Review

A lack of evidence-based interventions for people aging with long-term physical disabilities exists. To examine the exclusion of people with disabilities in behavioral clinical trials, a scoping review was conducted. ClinicalTrials.gov was searched for interventional behavioral studies from the United States completed from 2008–2018, with results focused on adults (18–64) and older adults (65+). In total, 158 clinical trials were included. In 129 articles, health conditions were excluded 697 times. Seventy-one clinical trials excluded at least one health condition with strong justification, 11 with poor justification, and 115 without justification. There is strong evidence that people with disabilities are excluded from behavioral clinical trials, often without justification. To help close this gap, our presentation will discuss how translational research strategies, focused on adapting existing EB behavioral trials, can be used to increase the availability of interventions that address the needs of individuals aging with and into long-term disabilities. Part of a symposium sponsored by the Lifelong Disabilities Interest Group.

Comparative Lipidomics of Different Yeast Species Associated to Drosophila suzukii

Yeasts constitute a dietary source for the spotted wing drosophila (SWD) and produce compounds that attract these flies. The study of the chemical composition of the yeast communities associated with SWD should therefore help to understand the relationship between the biology of the insect and the yeast’s metabolism. In the present study, the lipidome of five yeast species isolated from grapes infested by SWD (three Hanseniaspora uvarum strains, Candida sp., Issatchenkia terricola, Metschnikowia pulcherrima and Saccharomycopsis vini) and a laboratory strain of Saccharomyces cerevisiae was explored using an untargeted approach. Additionally, the lipid profile of two species, S. cerevisiae and H. uvarum, which were reported to elicit different responses on SWD flies based on feeding and behavioral trials, was compared with a chemical enrichment approach. Overall, 171 lipids were annotated. The yeast species could be distinguished from each other based on their lipid profile, except for the three strains of H. uvarum, which were very similar to each other. The chemical enrichment analysis emphasized diversities between S. cerevisiae and H. uvarum, that could not be detected based on their global lipid profile. The information concerning differences between species in their lipidome may be of interest to future entomological studies concerning the yeast-insect interaction and could help to explain the responses of SWD to diverse yeast species.

Imperfect transparency and camouflage in glass frogs

Camouflage patterns prevent detection and/or recognition by matching the background, disrupting edges, or mimicking particular background features. In variable habitats, however, a single pattern cannot match all available sites all of the time, and efficacy may therefore be reduced. Active color change provides an alternative where coloration can be altered to match local conditions, but again efficacy may be limited by the speed of change and range of patterns available. Transparency, on the other hand, creates high-fidelity camouflage that changes instantaneously to match any substrate but is potentially compromised in terrestrial environments where image distortion may be more obvious than in water. Glass frogs are one example of terrestrial transparency and are well known for their transparent ventral skin through which their bones, intestines, and beating hearts can be seen. However, sparse dorsal pigmentation means that these frogs are better described as translucent. To investigate whether this imperfect transparency acts as camouflage, we used in situ behavioral trials, visual modeling, and laboratory psychophysics. We found that the perceived luminance of the frogs changed depending on the immediate background, lowering detectability and increasing survival when compared to opaque frogs. Moreover, this change was greatest for the legs, which surround the body at rest and create a diffuse transition from background to frog luminance rather than a sharp, highly salient edge. This passive change in luminance, without significant modification of hue, suggests a camouflage strategy, “edge diffusion,” distinct from both transparency and active color change.