Search results for "SEMAT"

Iisalmi

How do startups develop internet-of-things systems : a multiple exploratory case study

2019

Internet-of-Things applications are not only the new opportunity for digital businesses but also a major driving force for the modification and creation of software systems in all industries and businesses. Compared to other types of software-intensive products, the development of Internet-of-Things applications lacks a systematic approach and guidelines. This paper aims at understanding the methodological commonalities among startups who are developing Internet-of-Things products. Using the SEMAT Essence framework, we captured common team compositions, common types of Minimum Viable Products and common way of working in early stage Internet-of-Things startups. We found that startups includ…

Ground-level predation on artificial caterpillars indicates no enemy-free time for lepidopteran larvae

2017

Lepidoptera is one of the most diverse orders of insects, their larvae are very abundant in many habitats, and frequent prey of various predators. To decrease predation risk, caterpillars developed several means of defence, among them timing their activity to avoid predators (seeking enemy-free time). Although the enemy-free time hypothesis is often invoked to explain caterpillar behaviour, empirical evidence for it is scarce. We tested whether such enemy-free time exists in a temperate forest by comparing predation pressure on artificial caterpillars during day and night on the ground in forest fragments in Denmark. We found a high predation rate, 23.9% d(-1), and higher predation rate at …

Mimicry between unequally defended prey can be parasitic: evidence for quasi-Batesian mimicry

2010

The nature of signal mimicry between defended prey (known as Mullerian mimicry) is controversial. Some authors assert that it is always mutualistic and beneficial, whilst others speculate that less well defended prey may be parasitic and degrade the protection of their better defended co-mimics (quasi-Batesian mimicry). Using great tits (Parus major) as predators of artificial prey, we show that mimicry between unequally defended co-mimics is not mutualistic, and can be parasitic and quasi-Batesian. We presented a fixed abundance of a highly defended model and a moderately defended dimorphic (mimic and distinct non-mimetic) species, and varied the relative frequency of the two forms of the …

THE EFFECT OF ALTERNATIVE PREY ON THE DYNAMICS OF IMPERFECT BATESIAN AND MÜLLERIAN MIMICRIES

2004

Both Batesian and Müllerian mimicries are considered classical evidence of natural selection where predation pressure has, at times, created a striking similarity between unrelated prey species. Batesian mimicry, in which palatable mimics resemble unpalatable aposematic species, is parasitic and only beneficial to the mimics. By contrast, in classical Müllerian mimicry the cost of predators' avoidance learning is shared between similar unpalatable co-mimics, and therefore mimicry benefits all parties. Recent studies using mathematical modeling have questioned the dynamics of Müllerian mimicry, suggesting that fitness benefits should be calculated in a way similar to Batesian mimicry; that i…

Prey community structure affects how predators select for Müllerian mimicry

2012

Müllerian mimicry describes the close resemblance between aposematic prey species; it is thought to be beneficial because sharing a warning signal decreases the mortality caused by sampling by inexperienced predators learning to avoid the signal. It has been hypothesized that selection for mimicry is strongest in multi-species prey communities where predators are more prone to misidentify the prey than in simple communities. In this study, wild great tits ( Parus major ) foraged from either simple (few prey appearances) or complex (several prey appearances) artificial prey communities where a specific model prey was always present. Owing to slower learning, the model did suffer higher mort…

Paradox lost: variable colour-pattern geometry is associated with differences in movement in aposematic frogs

2014

Aposematic signal variation is a paradox: predators are better at learning and retaining the association between conspicuousness and unprofitability when signal variation is low. Movement patterns and variable colour patterns are linked in non-aposematic species: striped patterns generate illusions of altered speed and direction when moving linearly, affecting predators' tracking ability; blotched patterns benefit instead from unpredictable pauses and random movement. We tested whether the extensive colour-pattern variation in an aposematic frog is linked to movement, and found that individuals moving directionally and faster have more elongated patterns than individuals moving randomly and…

Investigating Müllerian mimicry: predator learning and variation in prey defences

2006

Inexperienced predators are assumed to select for similarity of warning signals in aposematic species (Mullerian mimicry) when learning to avoid them. Recent theoretical work predicts that if co-mimic species have unequal defences, predators attack them according to their average unpalatability and mimicry may not be beneficial for the better defended co-mimic. In this study, we tested in a laboratory environment whether a uniform warning signal is superior to a variable one in promoting predator learning, and simultaneously whether co-mimics are preyed upon according to their average unpalatability. There was an interaction of signal variation and unpalatability but inexperienced birds did…

Autonomous maritime ecosystem : digital concepts and business case : results from the JYU TJTSM54 course on advanced topics on systems development

2019

Convergent evolution of aposematic coloration in Neotropical poison frogs: a molecular phylogenetic perspective

2003

Submitted by Guilherme Lemeszenski (guilherme@nead.unesp.br) on 2014-02-26T17:17:10Z No. of bitstreams: 1 WOS000186417800006.pdf: 196897 bytes, checksum: cbe901a47807d22aec173ee8cc011a64 (MD5) Made available in DSpace on 2014-02-26T17:17:10Z (GMT). No. of bitstreams: 1 WOS000186417800006.pdf: 196897 bytes, checksum: cbe901a47807d22aec173ee8cc011a64 (MD5) Previous issue date: 2003-01-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T13:59:12Z No. of bitstreams: 1 WOS000186417800006.pdf: 196897 bytes, checksum: cbe901a47807d22aec173ee8cc011a64 (MD5) Made available in DSpace on 2014-05-20T13:59:12Z (GMT). No. of bitstreams: 1 WOS000186417800006.pdf: 196…