1,168 research outputs found
Lectio prĂŠcursoria: "They Look Me in the Eyes and I Smile and Then We Know: The Interaction of Finnish Roma and East European Roma in Finland
A lectio prĂŠcursoria is a short presentation read out loud by a doctoral candidate at the start of a public thesis examination in Finland. It introduces the key points or central argument of the thesis in a way that should make the ensuing discussion between the examinee and the examiner apprehensible to the audience, many of whom may be unfamiliar with the candidateâs research or even anthropological research in general
Stability analysis of a distributed parameter model for the growth of micro-organisms
AbstractA distributed parameter system for the growth of micro-organisms in a chemostat is considered. The growth rate depends on the internal concentration in the cells of one essential nutritient and a partial differential equation describing the situation where different cells have different growth rates is studied
Living with IT: Uses and Interpretations of Computers in the Home and Family Context
Having a computer and Internet connection at home is becoming increasingly common. In order to get a richer and fuller understanding of the impact of IT on life in the information society, the use and interpretations of computers need to be studied also outside the world of work and organizations. The paper reports on how a group of 50 families (183 people) live with information technology in their home. The focus is on the process of making the computer a part of the home and family life, going from the moment the new computer enters the home up until one year has passed. The IT-families field trial in Loviisa, a town in the southeast part of Finland, is used as a source of empirical data. The paper describes how participants start using their computer and Internet connection for leisure, entertainment, games, but also for banking, shopping and communication. The purpose of the paper is to explore what âIT in the homeâ means to participants: how they use and interpret the technology in various situations, what kind of physical and mental positions the computer takes on in the home and the minds of family members, and how the technology affects the nature of daily life in the home
Spatial ecology of a specialist insect herbivore : the leaf-mining moth Tischeria ekebladella on the pedunculate oak Quercus robur
Herbivorous insects comprise a major part of terrestrial biodiversity, and their interactions with their host plants and natural enemies are of vast ecological importance. A large body of research demonstrates that the ecology and evolution of these insects may be affected by trophic interactions, by abiotic influences, and by intraspecific processes, but so far research on these individual aspects has rarely been combined. This thesis uses the leaf-mining moth Tischeria ekebladella and the pedunculate oak (Quercus robur) as a case study to assess how spatial variation in trophic interactions and the physical distribution of host trees jointly affect the distribution, dynamics and evolution of a host-specific herbivore.
With respect to habitat quality, Tischeria ekebladella experiences abundant variation at several spatial scales. Most of this variation occurs at small scales notably among leaves and shoots within individual trees. While hypothetically this could cause moths to evolve an ability to select leaves and shoots of high quality, I did not find any coupling between female preference and offspring performance. Based on my studies on temporal variation in resource quality I therefore propose that unpredictable temporal changes in the relative rankings of individual resource units may render it difficult for females to predict the fate of their developing offspring.
With respect to intraspecific processes, my results suggest that limited moth dispersal in relation to the spatial distribution of oak trees plays a key role in determining the regional distribution of Tischeria ekebladella. The distribution of the moth is aggregated at the landscape level, where local leaf miner populations are less likely to be present where oaks are scarce. A modelling exercise based on empirical dispersal estimates revealed that the moth population on Wattkast an island in south-western Finland is spatially structured overall, but that the relative importance of local and regional processes on tree-specific moth dynamics varies drastically across the landscape.
To conclude, my work in the oak-Tischeria ekebladella system demonstrates that the local abundance and regional distribution of a herbivore may be more strongly influenced by the spatial location of host trees than by their relative quality. Hence, it reveals the importance of considering spatial context in the study of herbivorous insects, and forms a bridge between the classical fields of plant-insect interactions and spatial ecology.De vÀxtÀtande insekterna utgör en artrik grupp av stor ekologisk och ekonomisk betydelse. Utbredningen av vÀxtÀtare har omvÀxlande ansetts avspegla rumslig variation i vÀrdvÀxtkvalitet, utbredning av naturliga fiender eller yttre miljöfaktorer. Under senare Är har ekologisk forskning dock visat att en art kan upptrÀda pÄ vissa lokaler och saknas pÄ andra utan nÀmnvÀrd variation i ovannÀmnda faktorer detta p.g.a. begrÀnsningar i artens spridningsförmÄga och begrÀnsad livslÀngd hos lokala bestÄnd. Trots detta har den relativa betydelsen av livsmiljöns kvalitet och rumsliga utbredning sÀllan beaktats i studier av vÀxtÀtande insekter. I min avhandling undersöker jag hur vÀrdvÀxtens kvalitet och utbredning pÄverkar utbredning, bestÄndsfluktuationer och evolution hos den större ekpannluggmalen (Tischeria ekebladella), en art som Àr specialiserad pÄ ek, Quercus robur.
I min avhandling pÄvisar jag att enskilda ekar ur ekpannluggmalens perspektiv ter sig som mosaiker av blad och skott av varierande kvalitet, medan skillnaderna i bladkvalitet mellan olika trÀdindivider Àr förhÄllandevis smÄ. Trots att malarnas resursval kan ha viktiga konsekvenser för avkommans livsduglighet förmÄr ÀgglÀggande malhonor inte urskilja de blad och skott som Àr bÀst för larvernas överlevnad. En möjlig förklaring Àr att ett adaptivt resursval Àr omöjligt i en situation dÀr den relativa kvaliteten hos olika resursenheter varierar oförutsÀgbart i tid.
Mina resultat tyder pÄ att rumsliga mönster i ekpannluggmalens utbredning till stor del beror pÄ malarnas begrÀnsade spridningsförmÄga. Arten förekommer med en lÀgre frekvens pÄ isolerade ekar Àn pÄ trÀd i större ekbestÄnd. En populationsmodell för malbestÄndet pÄ ön Wattkast i Korpo visar att graden av vÀxelverkan mellan malar pÄ olika trÀd kraftigt varierar med ekarnas avstÄnd frÄn varandra.
Sammanfattningsvis bygger mitt arbete med ekpannluggmalen en bro mellan tidigare forskningstraditioner som Ä ena sidan fokuserat pÄ den lokala vÀxelverkan mellan vÀrdtrÀd och vÀxtÀtare och Ä andra sidan pÄ rumsliga processer. Mina resultat visar att utbredningen av vÀxtÀtande insekter inte nödvÀndigtvis avspeglar rumsliga mönster i livsmiljöns kvalitet, och att vÀrdvÀxtens utbredning har viktiga konsekvenser för insekternas rumsliga populationsstruktur. Var vÀrdvÀxten finns pÄverkar dÀrigenom det ekologiska och evolutiva samspelet mellan vÀxtÀtande insekter, vÀrdvÀxter och naturliga fiender
âRebuilding Ties That Existed Long Agoâ : Experiences of Finnish Roma during Missionary Work in Estonia
This article analyses Finnish Roma experiences of interaction with Roma in Estonia, in the period after the historic fall of the Iron Curtain in 1989 through to the present. The research data rely on semi-structured interviews and informal conversations, as well as indirect observations of Finnish Roma missionising activities. The results show that Roma identity was seen as a unifying factor and a source of a feeling of belonging, but not as the major factor driving mission. The driving force of the mission stems from the urge to evangelise, inherent in how Pentecostal teaching is lived and directed. This study contributes to the understanding of the interplay of ethnic identity and spirituality in Roma communities in the context of missionising, as well as the role of missionising for the missionaries themselves.Peer reviewe
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Antagonistic interaction networks are structured independently of latitude and host guild
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Inequalities for numerical invariants of sets of matrices
We prove three inequalities relating some invariants of sets of matrices,
such as the joint spectral radius. One of the inequalities, in which proof we
use geometric invariant theory, has the generalized spectral radius theorem of
Berger and Wang as an immediate corollary.Comment: 10 pages. Results and presentation slightly improve
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Changes in oak (Quercus robur) photosynthesis after winter moth (Operophtera brumata) herbivory are not explained by changes in chemical or structural leaf traits
Insect herbivores have the potential to change both physical and chemical traits of their host plant. Although the impacts of herbivores on their hosts have been widely studied, experiments assessing changes in multiple leaf traits or functions simultaneously are still rare. We experimentally tested whether herbivory by winter moth (Operophtera brumata) caterpillars and mechanical leaf wounding changed leaf mass per area, leaf area, leaf carbon and nitrogen content, and the concentrations of 27 polyphenol compounds on oak (Quercus robur) leaves. To investigate how potential changes in the studied traits affect leaf functioning, we related the traits to the rates of leaf photosynthesis and respiration. Overall, we did not detect any clear effects of herbivory or mechanical leaf damage on the chemical or physical leaf traits, despite clear effect of herbivory on photosynthesis. Rather, the trait variation was primarily driven by variation between individual trees. Only leaf nitrogen content and a subset of the studied polyphenol compounds correlated with photosynthesis and leaf respiration. Our results suggest that in our study system, abiotic conditions related to the growth location, variation between tree individuals, and seasonal trends in plant physiology are more important than herbivory in determining the distribution and composition of leaf chemical and structural traits
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