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1. Defensive structures influence fighting outcomes

   https://doi.org/10.1111/1365-2435.13730  

   Emberts, Zachary; Wiens, John J.; Auer, ed., Sonya (December 2020, Functional Ecology)

   Abstract In many animal species, individuals engage in fights with conspecifics over access to limited resources (e.g. mates, food, or shelter). Most theory about these intraspecific fights assumes that damage has an important role in determining the contest winner. Thus, defensive structures that reduce the amount of damage an individual accrues during intraspecific competition should provide a fighting advantage.Examples of such damage‐reducing structures include the dermal shields of goats, the dorsal osteoderms of crocodiles, and the armoured telsons of mantis shrimps. Although numerous studies have identified these defensive structures, no study has investigated whether they influence the outcomes of intraspecific fights.Here we investigated whether inhibiting damage by enhancing an individual's armour influenced fighting behaviour and success in the giant mesquite bug,Thasus neocalifornicus(Insecta: Hemiptera: Coreidae).We found that experimentally manipulated individuals (i.e. those provided with additional armour) were 1.6 times more likely to win a fight when compared to the control. These results demonstrate that damage, and damage‐reducing structures, can influence fighting success.The implications of these results are twofold. First, our results experimentally support a fundamental assumption of most theoretical fighting models: that damage is a fighting cost that can influence contest outcomes. Second, these results highlight the importance of an individual's defensive capacity, and why defence should not be ignored. A freePlain Language Summarycan be found within the Supporting Information of this article. 

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2. Multiple convergent hypothalamus–brainstem circuits drive defensive behavior

   https://doi.org/10.1038/s41593-020-0655-1  

   Lovett-Barron, Matthew; Chen, Ritchie; Bradbury, Susanna; Andalman, Aaron S.; Wagle, Mahendra; Guo, Su; Deisseroth, Karl (August 2020, Nature Neuroscience)

   null (Ed.)
3. Fundamental Defensive Programming Practicec with Secure Coding Modules

   Yang, Jeong; Lodgher, Akhtar (January 2019, International Conference on Security and Management)

   While many vulnerabilities are often related to computing and network systems, there has been a growing number of vulnerabilities and attacks in software systems. They are generally caused by careless software design and implementations, and not putting sufficient effort into eliminating defects and flaws in the software itself. When it comes to building reliable and secure software, it is critical that security must be considered throughout the software development process. This paper presents a series of modules that are designed to introduce security concepts in beginners programming courses. The modules have been developed to teach the fundamental concepts of defensive programming from the freshman year, to ensure that the programming concepts are taught to beginning programmers from a security perspective. These modules are intended to build a strong cybersecurity foundation, which will then be enhanced further in the advanced courses, such as Secure Applications Programming and Secure Software Engineering courses. Both instructors and students can practice defensive programming with these modules in their classroom. The study plans to evaluate the teaching effectiveness of the modules associated with the Model-Eliciting Activity (MEA), an evidence-based teaching and learning methodology. 

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4. Warmer nights offer no respite for a defensive mutualism

   https://doi.org/10.1111/1365-2656.13238  

   Higashi, Clesson H. V.; Barton, Brandon T.; Oliver, Kerry M.; Behmer, ed., Spencer (May 2020, Journal of Animal Ecology)

   Abstract Ecologically relevant symbioses are widespread in terrestrial arthropods but based on recent findings these specialized interactions are likely to be especially vulnerable to climate warming. Importantly, empirical data and climate models indicate that warming is occurring asynchronously, with night‐time temperatures increasing faster than daytime temperatures. Daytime (DTW) and night‐time warming (NTW) may impact ectothermic animals and their interactions differently as DTW results in greater daily temperature variation and moves organisms nearer to their thermal limits, while NTW avoids thermal limits and may relieve constraints of cooler night‐time temperatures; a nuance that has largely been ignored in the literature.In laboratory experiments, we investigated how the timing of warming influences a widespread defensive mutualism involving the pea aphidAcyrthosiphon pisum, and its heritable symbiont,Hamiltonella defensa, which protects against an important natural enemy, the parasitic waspAphidius ervi.Three aphid sublines were experimentally created from single aphid genotype susceptible toA. ervi: one line infected with a highly protectiveH. defensastrain, one infected with a moderately protective strain and one without any facultative symbiont. We examined aphid fitness in the presence and absence of parasitoids and when exposed to an average 2.5°C increase occurring across three warming scenarios (night‐time vs. daytime vs. uniform) relative to no‐warming controls.An increase of 2.5°C, as predicted to occur by the IPCC before 2100, was sufficient to disable the aphid defensive mutualism regardless of the timing of warming; a surprising result given that the daily maxima for control and NTW scenarios were identical. We also found that warming negatively impacted (a) symbiont‐mediated interactions between host and parasitoid more than symbiont‐free ones; (b) species interactions (host–parasitoid) more than each participant independently and (c) aphids more than parasitoids even though higher trophic levels are generally predicted to be more affected by warming.Here we show that 2.5°C warming, regardless of timing, negatively impacted a common microbe‐mediated defensive mutualism. While this was a laboratory‐based study, results suggest that temperature increases predicted in the near‐term may disrupt the many ecological symbioses present in terrestrial ecosystems. 

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5. An observation of a potentially novel defensive behavior against pesticides: Messor oertzeni build a defensive wall against ant traps in the field (preliminary note)

   PRETENDS EAGLE, TJ: RODRIGUEZ (October 2021, Bulletin of insectology)

   In the course of conducting honey bee experiments on the Greek Island of Lesbos we took the opportunity to observe the reactions of ants, Messor oertzeni Forel (Hymenoptera Formicidae Myrmicinae), to a baited ant trap placed in its main foraging path (active ingredient: sodium cacodylate). Each trap had three entrances and we tested five nests. For 14 days we observed the nests and photographs were taken daily to document our observations. Following a baseline condition in which none of the three entrances were open, one entrance was open. Several days later the entrance we opened was turned 90 degrees away from the main foraging trail and a second entrance was opened and placed in the same orientation as the first entrance (i.e., in the main foraging path). Our observations revealed that for four of the five ant colonies, the ants built a barrier around the opened entrance preventing other ants from entering the trap. The materials they used to bar the entrance was composed of twigs, pebbles and soil. We believe that the apparent ability of ants to avoid the effects of an insecticide by baring the entrance to a bait trap is a novel finding and should be replicated under more controlled conditions. 

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