Search results for "mekanismit"

Defense against predators incurs high reproductive costs for the aposematic moth Arctia plantaginis

2020

Abstract To understand how variation in warning displays evolves and is maintained, we need to understand not only how perceivers of these traits select color and toxicity but also the sources of the genetic and phenotypic variation exposed to selection by them. We studied these aspects in the wood tiger moth Arctia plantaginis, which has two locally co-occurring male color morphs in Europe: yellow and white. When threatened, both morphs produce defensive secretions from their abdomen and from thoracic glands. Abdominal fluid has shown to be more important against invertebrate predators than avian predators, and the defensive secretion of the yellow morph is more effective against ants. Her…

Nanoscale etching of III-V semiconductors in acidic hydrogen peroxide solution: GaAs and InP, a striking contrast in surface chemistry

2019

In this study of nanoscale etching for state-of-the-art device technology, the importance of surface chemistry, in particular the nature of the surface oxide, is demonstrated for two III-V materials. Striking differences in etching kinetics were found for GaAs and InP in sulphuric and hydrochloric acidic solutions containing hydrogen peroxide. Under similar conditions, etching of GaAs was much faster, while the dependence of the etch rate on pH, and on H2O2 and acid concentrations also differed markedly for the two semiconductors. Surface analysis techniques provided information on the product layer present after etching: strongly non-stoichiometric porous (hydr)oxides on GaAs and a thin st…

Best Practices in Constant pH MD Simulations: Accuracy and Sampling

2022

Various approaches have been proposed to include the effect of pH in molecular dynamics (MD) simulations. Among these, the λ-dynamics approach proposed by Brooks and co-workers [Kong, X.; Brooks III, C. L. J. Chem. Phys.1996, 105, 2414−2423] can be performed with little computational overhead and hfor each typeence be used to routinely perform MD simulations at microsecond time scales, as shown in the accompanying paper [Aho, N. et al. J. Chem. Theory Comput.2022, DOI: 10.1021/acs.jctc.2c00516]. At such time scales, however, the accuracy of the molecular mechanics force field and the parametrization becomes critical. Here, we address these issues and provide the community with guidelines on…

Mechanistic Explanations and Deliberate Misrepresentations

2020

The philosophy of mechanisms has developed rapidly during the last 30 years. As mechanisms-based explanations (MBEs) are often seen as an alternative to nomological, law-based explanations, MBEs could be relevant in IS. We begin by offering a short history of mechanistic philosophy and set out to clarify the contemporary landscape. We then suggest that mechanistic models provide an alternative to variance and process models in IS. Finally, we highlight how MBEs typically contain deliberate misrepresentations. Although MBEs have recently been advocated as critical realist (CR) accounts in IS, idealizations (deliberate misrepresentations) seem to violate some fundamental tenets of CR and rese…

How customer knowledge affects exploration : generating, guiding, and gatekeeping

2021

The importance of understanding customers in order to sustain the long-term success of the company has been claimed by academics and practitioners for decades, to the point that the claim has turned into a truism. And still, the role of customer knowledge in organizational renewal, especially via explorative new product development (NPD), remains ambiguous. While existing literature generally emphasizes the value of customer knowledge, critics argue that a strong customer focus can also de-motivate and misguide exploration. This study adds clarity to our understanding of this tension by drawing from an intensive analysis of the corporate archives of a rapidly growing high-tech company. The …

Can warning signals be honest? : wing colouration and the strength of chemical defence in the female wood tiger moth (Parasemia plataginis)

2016

The warning displays of aposematic organisms signal to predators that they possess a secondary defence and are unprofitable. Within species variation exists in the strength of the signal and defence. As natural selection is expected to favour higher levels of defence, variation in such traits requires explanation. One hypothesis is that the strength of primary and secondary defences are correlated as they reflect the condition of the signaller. This study explores if variation in individual conspicuousness is an honest signal of the level of defence in the wood tiger moth (Parasemia plantaginis). P. plantaginis has conspicuous hind wing warning colouration, which in females varies from yell…

Systeemisen lastensuojelun toimintamallin ydinelementit : Kuvaus asiakastason ydinelementeistä, tavoitteista ja toimintamekanismeista

2019

Tämä työpaperi kuvaa suomalaisen systeemisen lastensuojelun toimintamallin keskeiset ydinelementit, tavoitteet ja toimintamekanismit. Kuvaus on kirjoitettu tutkijoiden vetämän työpajaprosessin pohjalta, missä tutkijat kutsuivat mallin kansalliseen kehittämiseen ja levittämiseen osallistuneita avainhenkilöitä työstämään yhteistä käsitystä mallin keskeisimmistä ominaisuuksista. Tutkijavetoisen prosessin tavoitteena on ollut kirkastaa ja konkretisoida systeemistä lastensuojelun toimintamallia. Tällä tavoin mallin nykyiset ja uudet käyttäjät voivat paremmin arvioida, miten erilaiset paikalliset ratkaisut suhtautuvat tässä työpaperissa esitettyyn mallin peruskuvaukseen. Työpaperin kuvaus keskitt…

Common and separable behavioral and neural mechanisms underlie the generalization of fear and disgust

2021

Generalization represents the transfer of a conditioned responses to stimuli that resemble the conditioned stimulus (CS). Previous studies on generalization of defensive avoidance responses have primarily focused on fear and have neglected disgust generalization, which represents a key pathological mechanism in some anxiety disorders. In the present study we examined common and distinct mechanisms of fear and disgust generalization by means of a fear or disgust multi-CS conditioning and generalization paradigm with concomitant event-related potential (ERPs) acquisition in n = 62 subjects. We demonstrate that compared to fear, disgust-relevant generalized stimuli (GS) elicited larger expecta…

Henkilökohtaisen informaation salaamisesta, paljastamisesta ja defenssimekanismeista

1997

Mucin induces CRISPR-Cas defense in an opportunistic pathogen

2022

It is unknown what circumstances promote particular bacterial defenses against bacterial viruses (phages). Almeida & Hoikkala et al. show that mucin, derived from mucus, greatly accelerates CRISPR-Cas defenses against phage in an opportunistic pathogen. Parasitism by bacteriophages has led to the evolution of a variety of defense mechanisms in their host bacteria. However, it is unclear what factors lead to specific defenses being deployed upon phage infection. To explore this question, we co-evolved the bacterial fish pathogen Flavobacterium columnare and its virulent phage V156 in presence and absence of a eukaryotic host signal (mucin) for sixteen weeks. The presence of mucin leads to a …