Search results for "sietokyky"

Experimental approaches for testing if tolerance curves are useful for predicting fitness in fluctuating environments

2017

Most experimental studies on adaptation to stressful environments are performed under conditions that are rather constant and rarely ecologically relevant. Fluctuations in natural environmental conditions are ubiquitous and include for example variation in intensity and duration of temperature, droughts, parasite loads, and availability of nutrients, predators and competitors. The frequency and amplitude of many of these fluctuations are expected to increase with climate change. Tolerance curves are often used to describe fitness components across environmental gradients. Such curves can be obtained by assessing performance in a range of constant environmental conditions. In this perspectiv…

Epigenetic and Genetic Contributions to Adaptation in Chlamydomonas

2017

Epigenetic modifications, such as DNA methylation or histone modifications, can be transmitted between cellular or organismal generations. However, there are no experiments measuring their role in adaptation, so here we use experimental evolution to investigate how epigenetic variation can contribute to adaptation. We manipulated DNA methylation and histone acetylation in the unicellular green alga Chlamydomonas reinhardtii both genetically and chemically to change the amount of epigenetic variation generated or transmitted in adapting populations in three different environments (salt stress, phosphate starvation, and high CO2) for two hundred asexual generations. We find that reducing the …

Prolonged diapause has sex-specific fertility and fitness costs

2019

AbstractDiapause in seasonal environments allows insects to survive adverse seasons. However, individuals can sometimes enter a prolonged diapause for more than a year, and also skip favourable seasons, which can bring additional costs through e.g. loss of metabolic resources. At the same time, prolonged diapause can be beneficial if it allows individuals to have a risk-spreading strategy to skip potentially suboptimal breeding seasons. We studied if prolonged diapause (2-year diapause) negatively affects the fertility and fitness of female and male Colorado potato beetles (Leptinotarsa decemlineata) compared to control (1-year diapause) beetles. We also tested the parental effects on the s…

Cold water reduces the severity of parasite-inflicted damage : support for wintertime recuperation in aquatic hosts

2019

The reduction in host fitness caused by parasite infections (virulence) depends on infection intensity and the degree of damage caused per parasite. Environmental conditions can shape both virulence components, but in contrast to infection intensity, environmental impacts on per-parasite damage are poorly understood. Here, we studied the effect of ambient temperature on per-parasite damage, which is jointly determined by the ability of parasites to induce harm (per-parasite pathogenicity) and the ability of hosts to limit damage (tolerance). We experimentally exposed two salmonid species, Atlantic salmon (Salmo salar) and sea trout (Salmo trutta), to replicated genotypes of the eye fluke Di…

Negative associations between parasite avoidance, resistance and tolerance predict host health in salmonid fish populations

2020

Genetic variation in defence against parasite infections is fundamental for host–parasite evolution. The overall level of defence of a host individual or population includes mechanisms that reduce parasite exposure (avoidance), establishment (resistance) or pathogenicity (tolerance). However, how these traits operate and evolve in concert is not well understood. Here, we investigated genetic variation in and associations between avoidance, resistance and tolerance in a natural host–parasite system. Replicated populations of Atlantic salmon ( Salmo salar ) and sea trout (an anadromous form of brown trout, Salmo trutta ) were raised under common garden conditions and infected with the eye fl…

Starvation resistance and tissue-specific gene expression of stress-related genes in a naturally inbred ant population

2016

Starvation is one of the most common and severe stressors in nature. Not only does it lead to death if not alleviated, it also forces the starved individual to allocate resources only to the most essential processes. This creates energetic trade-offs which can lead to many secondary challenges for the individual. These energetic trade-offs could be exacerbated in inbred individuals, which have been suggested to have a less efficient metabolism. Here, we studied the effect of inbreeding on starvation resistance in a natural population of Formica exsecta ants, with a focus on survival and tissue-specific expression of stress, metabolism and immunity-related genes. Starvation led to large tis…

Social Service Entrepreneurship As a Context for Entrepreneurial Activity

2014

The Promise of Pop-Up Entrepreneurship Towards Temporality And Ambidexterity On Entrepreneuring

2014

Effects of bioheapleaching technology utilizing metal mine emissions on fish in boreal freshwaters

2018

Emissions from metal mining activities are known to deteriorate the quality of aquatic habitats and impair the condition and reproductive potential of fish. Metal extraction by biomining methods has been considered to cause fewer emissions, but for example in Finland, the impacts of a bioheapleaching technology utilizing metal mine on the local freshwaters have been substantial. In this thesis, the impacts of the bioheapleaching mine emissions on three native fish species, brown trout (Salmo trutta) European perch (Perca fluviatilis) and whitefish (Coregonus lavaretus pallasi), were investigated. Manganese and sulphate concentrations have been elevated in the mining impacted waters, and in …

Jatkuvuuden hallinta IT-palveluliiketoiminnassa : case Tieto Oyj

2012

Yhteiskunnan tietoteknistymisen jatkuessa vakaille IT-palveluille on yhä enemmän kysyntää. IT-palvelutoimittajien rooli asiakasyritysten liiketoiminnassa kasvaa, koska liiketoimintaprosessit ovat yhä riippuvaisempia tietojärjestelmistä ja muusta IT-infrastruktuurista. Samanaikaisesti IT-infrastruktuuri kehittyy kompleksisempaan suuntaan, siksi jatkuvuuden hallinnalla, häiriöiden sietokyvyllä ja toipumiskyvyllä on elintärkeä rooli liiketoiminnan ylläpitämisessä. Kaikkia häiriötilanteita ei voi estää, mutta riskien vaikuttavuutta liiketoimintaan voidaan vähentää varautumisen avulla, tällöin puhutaan organisationaalisen häiriönsietokyvyn kasvattamisesta. Häiriötilanteisiin varautumisen lisäksi…