Search results for "Lust"

TNT:n ja RDX:n määrittäminen HPLC:lla ja menetelmän validointi

2009

Vertaissuhteet, hyvinvointi ja kouluviihtyvyys peruskoulun alakoulusta yläkouluun siirryttäessä

2009

Tutkimuksen tarkoituksena oli tarkastella oppilaiden vertaissuhteita, hyvinvointia ja kouluviihtyvyyttä, niissä tapahtuvia muutoksia oppilaiden siirtyessä alakoulusta yläkouluun sekä vertaissuhteiden yhteyttä hyvinvointiin ja kouluviihtyvyyteen. Tutkimukseen osallistuneet oppilaat (N=142, 88 tyttöä, 54 poikaa) täyttivät kyselylomakkeen kaksi kertaa: 6. luokalla (kevät 2008) ja siirryttyään 7. luokalle (syksy 2008). Oppilaiden vertaissuhteet kaverisuhteiden laadun osalta, itsetunto ja kouluviihtyvyys olivat hyviä niin ala- kuin yläkoulussa, minkä lisäksi yksinäisyyttä ja masennusoireita ei juuri havaittu. Kiusaamista kuitenkin havaittiin sekä ala- että yläkoulussa, niin että alakoulussa kius…

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. …

Multimodal Aposematic Defenses Through the Predation Sequence

2021

Aposematic organisms warn predators of their unprofitability using a combination of defenses, including visual warning signals, startling sounds, noxious odors, or aversive tastes. Using multiple lines of defense can help prey avoid predators by stimulating multiple senses and/or by acting at different stages of predation. We tested the efficacy of three lines of defense (color, smell, taste) during the predation sequence of aposematic wood tiger moths (Arctia plantaginis) using blue tit (Cyanistes caeruleus) predators. Moths with two hindwing phenotypes (genotypes: WW/Wy = white, yy = yellow) were manipulated to have defense fluid with aversive smell (methoxypyrazines), body tissues with a…

Multiple modalities in insect warning displays have additive effects against wild avian predators

2019

Allocation to different components of defence has been suggested as an explanation for the existence of multiple aposematic morphs in a single population. We tested whether there are trade-offs between warning colouration and chemical defence or whether these have an additive effect when combined, using blue tits (Cyanistes caeruleus) as predators and the polymorphic wood tiger moth (Arctia plantaginis) as prey. We used artificial edible models (with and without the moths’ defensive fluids) with paper wings whose colour and pattern properties matched those of real moths. When the models were presented sans defensive fluids or when the fluids were presented without colour cues, we detected n…

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…

Weak warning signals can persist in the absence of gene flow

2019

Aposematic organisms couple conspicuous warning signals with a secondary defense to deter predators from attacking. Novel signals of aposematic prey are expected to be selected against due to positive frequency-dependent selection. How, then, can novel phenotypes persist after they arise, and why do so many aposematic species exhibit intrapopulation signal variability? Using a polytypic poison frog (Dendrobates tinctorius), we explored the forces of selection on variable aposematic signals using 2 phenotypically distinct (white, yellow) populations. Contrary to expectations, local phenotype was not always better protected compared to novel phenotypes in either population; in the white popul…

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…

Asento vai lepo : komppanianpäälliköiden, kouluttajien ja varusmiesten näkemyksiä puolustusvoimien liikuntakoulutuksesta

1999

Effectiveness of a kindergarten-based intervention to increase vegetable intake and reduce food neophobia amongst 1-year-old children: a cluster rand…

2021

Background: Children’s first years of life are crucial to their future health. Studies show that a varied diet with a high intake of vegetables is positive in several domains of health. The present low vegetable intake amongst children is, therefore, a concern. Food neophobia is a common barrier to vegetable intake in children. As most Norwegian children attend kindergarten from an early age, kindergartens could contribute to the prevention of food neophobia and the promotion of vegetable intake. Objective: The aim of this study was to assess the effect of a cluster randomised trial amongst 1-year-old children in kindergarten to reduce food neophobia and promote healthy eating. Methods: Kin…