Search results for " defence"

Zinc Adsorption by Activated Carbon Prepared from Lignocellulosic Waste Biomass

2019

Sawdust was used as a precursor for the production of biomass-based activated carbon. Carbonization and activation are single-stage processes, and steam was used as a physical activation agent at 800 &deg

Failing to Provide Public Goods: Why the Afghan Army Did Not Fight

2022

The theory of public goods is mainly about the difficulty in paying for them. Our question here is this: Why might public goods not be provided, even if funding is available? We use the Afghan Army as our case study. We explore this issue using a simple model of a public good that can be provided through collective action and peer pressure, by modeling the self-organization of a group (the Afghan Army) as a mechanism design problem. We consider two kinds of transfer subsidies from an external entity such as the U.S. government. One is a Pigouvian subsidy that simply pays the salaries, rewarding individuals who provide effort. The second is an output/resource multiplier (the provision of mil…

Intra- and inter-specific social selection of vigilance and defense phenotypes in breeding colonies of lesser kestrels and jackdaws

2012

Testing the effectiveness of pyrazine defences against spiders

2020

Insects live in a dangerous world and may fall prey to a wide variety of predators, encompassing multiple taxa. As a result, selection may favour defences that are effective against multiple predator types, or target-specific defences that can reduce predation risk from particular groups of predators. Given the variation in sensory systems and hunting tactics, in particular between vertebrate and invertebrate predators, it is not always clear whether defences, such as chemical defences, that are effective against one group will be so against another. Despite this, the majority of research to date has focused on the role of a single predator species when considering the evolution of defended…

Parasite avoidance behaviours in aquatic environments

2018

Parasites, including macroparasites, protists, fungi, bacteria and viruses, can impose a heavy burden upon host animals. However, hosts are not without defences. One aspect of host defence, behavioural avoidance, has been studied in the terrestrial realm for over 50 years, but was first reported from the aquatic environment approximately 20 years ago. Evidence has mounted on the importance of parasite avoidance behaviours and it is increasingly apparent that there are core similarities in the function and benefit of this defence mechanism between terrestrial and aquatic systems. However, there are also stark differences driven by the unique biotic and abiotic characteristics of terrestrial …

Not just the sum of its parts : Geographic variation and nonadditive effects of pyrazines in the chemical defence of an aposematic moth

2022

Chemical defences often vary within and between populations both in quantity and quality, which is puzzling if prey survival is dependent on the strength of the defence. We investigated the within- and between-population variability in chemical defence of the wood tiger moth (Arctia plantaginis). The major components of its defences, SBMP (2-sec-butyl-3-methoxypyrazine) and IBMP (2-isobutyl-3-methoxypyrazine), are volatiles that deter bird attacks. We hypothesized that (1) variation in the chemical defences of male wood tiger moths reflects the local predation pressure; (2) observed differences in quantity and quality of defence among populations have a genetic basis; and (3) increasing con…

Supporting Cyber Resilience with Semantic Wiki

2016

Cyber resilient organizations, their functions and computing infrastructures, should be tolerant towards rapid and unexpected changes in the environment. Information security is an organization-wide common mission; whose success strongly depends on efficient knowledge sharing. For this purpose, semantic wikis have proved their strength as a flexible collaboration and knowledge sharing platforms. However, there has not been notable academic research on how semantic wikis could be used as information security management platform in organizations for improved cyber resilience. In this paper, we propose to use semantic wiki as an agile information security management platform. More precisely, t…

The hyperspectral and smartphone technology in CBRNE countermeasures and defence

2016

Caused by industrial and military use as well as other sources of chemical, biological, radiological, nuclear and high-yield explosive (CBRNE) materials, the global threat of weapons of mass destruction (WMDs) remains in spite of such weapons being internationally prohibited. With these materials, industrial and transportation accidents are likely in all countries and can also be triggered by natural disasters, such as in Fukushima in 2011. In addition, governments cannot fully control the manufacturing and usage of WMDs, as extreme terrorists have access to as well as the knowledge and motivation to use such materials. Due to multiple large-scale risks, the countering of CBRNE threats requ…

Immunolocalization of an antimicrobial peptide in Ciona intestinalis (Tunicata ) tunic

2009

The price of safety: food deprivation in early life influences the efficacy of chemical defence in an aposematic moth

2018

Aposematism is the combination of a primary signal with a secondary defence that predators must learn to associate with one another. However, variation in the level of defence, both within and between species, is very common. As secondary defences influence individual fitness, this variation in quality and quantity requires an evolutionary explanation, particularly as it may or may not correlate with variation in primary signals. The costs of defence production are expected to play a considerable role in generating this variation, yet studies of the cost of chemical defence have focused on species that sequester their defences, while studies in species that produce them de novo are scarce. …