Drivers of inter-year variability of plant production and decomposers across contrasting island ecosystems

Despite the likely importance of inter-year dynamics of plant production and consumer biota for driving community- and ecosystem-level processes, very few studies have explored how and why these dynamics vary across contrasting ecosystems. We utilized a well characterized system of 30 lake islands in the boreal forest zone of northern Sweden across which soil fertility and productivity vary considerably, with larger islands being more fertile and productive than smaller ones. In this system we assessed the inter-year dynamics of several measures of plant production and the soil microbial community (primary consumers in the decomposer food web) for each of 9 years, and soil microfaunal groups (secondary and tertiary consumers) for each of 6 of those years. We found that for measures of plant production and each of the three consumer trophic levels, inter-year dynamics were strongly affected by island size. Further, many variables were strongly affected by island size (and thus bottom-up regulation by soil fertility and resources) for some years but none in others, most likely due to inter-year variation in climatic conditions. For each of the plant and microbial variables for which we had 9 years of data, we also determined the inter-year coefficient of variation (CV), an inverse measure of stability. We found that CVs of some measures of plant productivity were greater on large islands while those of other measures were greater on smaller islands; CVs of microbial variables were unresponsive to island7 size. We also found that the effects of island size on the temporal dynamics of some variables were related to inter-year variability of macroclimatic variables. As such, our results show that the inter year dynamics of both plant productivity and decomposer biota across each of three trophic levels, as well as the inter-year stability of plant productivity, differs greatly across contrasting ecosystems, with potentially important but largely overlooked implications for community and ecosystem processes

Bilingualism and Performance on Two Widely Used Developmental Neuropsychological Test Batteries

Peer reviewe

4-aminobutyrate aminotrasferase (ABAT): genetic and pharmacological evidence for an involvement in gastro esophageal reflux disease

Extent: 9p.Gastro-esophageal reflux disease (GERD) is partly caused by genetic factors. The underlying susceptibility genes are currently unknown, with the exception of COL3A1. We used three independent GERD patient cohorts to identify GERD susceptibility genes. Thirty-six families, demonstrating dominant transmission of GERD were subjected to whole genome microsatellite genotyping and linkage analysis. Five linked regions were identified. Two families shared a linked region (LOD 3.9 and 2.0) on chromosome 16. We used two additional independent GERD patient cohorts, one consisting of 219 trios (affected child with parents) and the other an adult GERD case control cohort consisting of 256 cases and 485 controls, to validate individual genes in the linked region through association analysis. Sixty six single nucleotide polymorphism (SNP) markers distributed over the nine genes present in the linked region were genotyped in the independent GERD trio cohort. Transmission disequilibrium test analysis followed by multiple testing adjustments revealed a significant genetic association for one SNP located in an intron of the gene 4-aminobutyrate aminotransferase (ABAT) (Padj = 0.027). This association did not replicate in the adult case-control cohort, possibly due to the differences in ethnicity between the cohorts. Finally, using the selective ABAT inhibitor vigabatrin (c-vinyl GABA) in a dog study, we were able to show a reduction of transient lower esophageal sphincter relaxations (TLESRs) by 57.3611.4 % (p = 0.007) and the reflux events from 3.160.4 to 0.860.4 (p = 0.007). Our results demonstrate the direct involvement of ABAT in pathways affecting lower esophageal sphincter (LES) control and identifies ABAT as a genetic risk factor for GERD.Johan Jirholt, Bengt Åsling, Paul Hammond, Geoffrey Davidson, Mikael Knutsson, Anna Walentinsson, Jörgen M. Jensen, Anders Lehmann, Lars Agreus and Maria Lagerström-Ferme

Linkages of nitrogen and phosphorus availability to ecosystem processes and succession in forests of northern Sweden and New Zealand

Initially after catastrophic disturbance ecosystems undergo a build-up phase but in the long term absence of catastrophic disturbance ecosystems can enter a phase of decline called ecosystem retrogression. It is characterised by reduced productivity, decomposition rates and rates of nutrient cycling as a consequence of nutrient limitation. Over the course of long-term soil development, phosphorus (P) availability decreases due to leaching and chemical immobilisation, leading to increased soil N: P ratios during retrogression. In contrast, nitrogen (N) is continuously supplied to natural ecosystems through biological N2 fixation, though late successional plant species can have a negative effect on N availability during retrogression, reinforcing N limitation. I studied variation in supply and availability of N and P throughout a 5000 year retrogressive chronosequence in which the soil N: P ratio increases, and investigated how it affected the nutrient status of soil microbes and plants. I found that total N increases considerably during retrogression as a consequence of increased N2 fixation. Total P did not change across the chronosequence but labile mineral P declined in the retrogressive stage and this was connected to decreased soil microbial activity. Plant nutrient status showed diverging trends between trees and dwarf shrubs across the chronosequence, indicating increasing resource partitioning as retrogression proceeds. Variation in leaf traits was due to shifting species composition rather than within species changes. I also studied factors influencing the availability of N and P during the build-up phase of succession as affected by an important extrinsic driver, i.e., herbivory. Herbivory of a N2 fixing shrub had considerable negative effects on the nutrient status of not only its own growth and nutrient status, but also that of neighbouring non-fixing plants and soil processes. These studies in combination have demonstrated how changing availability of nutrients during succession, both in the build-up phase and the retrogressive phase, can be driven by biological processes such as N2 fixation and species effects on carbon (C) quality and, how this in turn leads to differences in the relative success of coexisting plant species in the community. As such, these results demonstrate the dynamic and variable nature of nutrient limitation and the processes leading to it

Gymnasieelevers argumentation i ämnet naturkunskap : kunskap, värderingar och perspektiv

En del av syftet med ämnet naturkunskap i den svenska gymnasieskolan är att ge eleverna en slags naturvetenskaplig allmänbildning eller scientific literacy, som grund för diskussion och ställningstaganden i aktuella samhällsfrågor. Att undervisa naturkunskap med utgångspunkt i samhällsfrågor med naturvetenskapligt innehåll (SNI) är en metod där argumentation och diskussion får ta mycket plats i klassrummet. Studier visar dock att många lärare känner att diskussionen sker på bekostnad av kursens naturvetenskapliga innehåll och en omfattande studie visar att elever baserar sina argument på värderingar i högre grad än kunskap. Den här studien undersöker elevers argumentation och vad den baseras på för att öka kunskapen om hur argumentation och diskussion kan användas i undervisningen på ett bra sätt. Eleverna instruerades att argumentera för och emot en SNI som de själva valde. Deras skriftliga argument analyserades sedan med avseende på perspektiv (biologiskt, ekonomiskt eller socialt perspektiv) och grund (kunskap, värdering eller personlig erfarenhet). Resultaten visade att en övervägande majoritet av argumenten baserades på kunskap, en mindre del på värderingar och ytterst få på personlig erfarenhet. Det perspektiv som flest argument utgick ifrån var biologiskt, men det varierade mellan ämnena. En slutsats är att hur elever argumenterar är i hög grad beroende av hur den lärarledda diskussionen i klassrummet ser ut, vilka typer av argument som tas upp där och hur de värderas. Som lärare är det alltså viktigt att ha klart för sig vad bra argumentation är och föregå med gott exempel för eleverna

Experimentell studie om ett nytt latent värmelagringssystem

Heating and cooling accounts for the majority of the world’s energy consumption and yet, almost 70 % ends up as waste heat. In a world with constantly growing energy demand, viable thermal energy storage technologies (TES) are increasingly needed. Latent heat thermal energy storage (LHTES) can contribute significantly to a more efficient use of waste heat and energy resources, overcoming the challenges of supply mismatching with demand. The city of Espoo aims to develop Kera area to a smart city ecosystem and Lux-Turrim5G project is paving the ground for this sustainable growth. The mission is to develop a 5G network based on smart poles and a low-temperature district heating (DH) network for efficient use of waste heat. The smart poles accumulate low-grade waste heat, and a network of them might offer potential for heat recovery and recycling through DH or LHTES. Within this context, this thesis firstly investigates waste heat streams from different sectors and their recycling possibilities through LHTES. Secondly, this thesis experimentally investigates the performance of a medium-low and medium temperature pilot LHTES system for utilization of waste heat. The focus is set on power ranges and temperature ranges that are relevant for smart poles, DH and low-temperature DH networks to suit the interests of the LuxTurrim5G project. The investigated pilot LHTES employs different innovative 3D-printed heat exchangers (HE), designed to possess a large heat transfer area, yet have a lightweight structure. The tested phase change materials (PCMs) are characterized by two different temperature ranges to suit waste heat of different grade. As a novel part, biocarbon (BC) additives are investigated for thermal performance enhancement in lightweight storage elements. The experimental analysis focuses on how these elements (HE structure, PCM and additives) affect the power, duration and storage capacity of the LHTES. It was found that the heaviest HE structure provided the highest heat transfer rates regardless the PCM. The most lightweight HE structure provided lowest heat transfer rates but allowed using larger amount of storage medium. Finally, it was found that 1 wt-% BC additives could compensate for the loss in thermal conductivity of the lightweight structure by increasing charging power of the configuration by 32% and reducing charging time by 33%. Finally, a conceptual LHTES system is proposed of scaling up the pilot system by a modular design and integrating it to a smart city bus stop in Kera area. Using decanoic acid with 1 wt-% BC as PCM, a modular system of already 10 elements enable heat storage capacity of 1.2 kWh, enough to heat a floor for 6 hours or a bench for 15 hours. To simultaneously achieve waste heat recycling, the system is suggested to use excess heat from DH substations and consequently, serve as a buffer for DH.Uppvärmning och nedkylning står för majoriteten av världens energikonsumtion, varav 70% resulterar i spillvärme. I en värld där energibehovet ökar konstant är det allt viktigare med termisk energilagring. Latenta värmelagringssystem kan bidra betydligt till en mer effektiv användning av spillvärme och energiresurser och kan därmed lösa de utmaningar som uppstår när utbud inte sammanfaller med efterfrågan. Esbo stad planerar att utveckla Kera område till ett ”smart city” ekosystem och LuxTurrim5G projektet banar väg för denna hållbara utveckling. Målet är att utveckla ett 5G nätverk baserat på ”smart poles” och ett lågtempererat fjärrvärmesystem för effektiv användning av spillvärme. Smart poles avger låggradig spillvärme, och ett nätverk av dem kan potentiellt erbjuda återvinningsmöjligheter genom lågtempererade fjärrvärmesystem. Till att börja med granskar denna avhandling spillvärmeströmmar från olika sektorer samt deras återvinningsmöjligheter genom latenta värmelagringssystem. Därpå granskas prestandan av ett latent värmelagringssystem experimentellt. Värmelagringssystemet i fråga är av medel- och medellåg temperatur, för avseendet av spillvärme. Fokusen är satt på kraft- och temperaturomfattningar som är relevanta för smart poles, fjärrvärme och lågtempererat fjärrvärme, för att motsvara de intressen som finns i LuxTurrim5G projektet. Det granskade värmelagringssystemet använder sig av olika innovativa 3D-printade värmeväxlare som är designade att inneha stor värmeöverföringsyta och samtidigt ha lätt struktur. Fasändringsmaterialen som testas är karakteriserade av två temperaturklasser för att lämpa sig för spillvärme av olika grad. Bio-kol som tillsatsmedel undersöks för förbättring av termisk prestanda i lättviktiga värmeväxlare. Den experimentella delen undersöker hur systemets effekt, varaktighet och kapacitet ändras beroende på värmeväxlarens struktur, fasändringsmaterialet och tillsatsmedlet. Resultaten påvisade att den tyngsta värmeväxlaren resulterade i högsta värmeöverföringshastigheten oberoende av fasändringsmaterial. Den lättviktiga värmeväxlaren resulterade i lägsta värmeöverföringshastigheten, men tillät användning av en större mängd värmelagringsmedium. Till sist konstaterades att tillsatsen av 1 mass-% bio-kol kunde kompensera förlusterna i termiska konduktiviteten av den lättviktiga värmeväxlaren genom att öka laddningseffekten med 32% och minska laddningstiden med 33%. Slutligen föreslår arbetet ett koncept där det latenta värmelagringssystemet skalas upp i en modulär design och integreras i en smart city busshållplats i Kera område. Genom att använda dekansyra med 1 mass-% bio-kol som fasändringsmaterial, kan redan ett system med 10 modulära element erbjuda värmelagringskapacitet på 1.2 kWh, tillräckligt för att värma upp ett golv i 6 timmar och en bänk i 15 timmar. För att samtidigt uppnå återvinning av spillvärme, föreslås att systemet använder överlopps värme från fjärrvärmesystemens distributionsstationer och kan därmed även fungera som en buffert för fjärrvärmesystemet

To promote children’s participation : A study of some children’s librarians’ approach on children’s participation in the activities of public libraries.

The objective of this thesis is to explore the prerequisites for children’s participation in the activities of the public library as expressed by six children’s librarians. Qualitative semi-structured interviews were carried out to investigate how the librarians interpreted the concept of participation and viewed power issues between children and adults. Further, difficulties and possibilities experienced in working with children’s participation and manifestations of children’s participation in everyday library work were also investigated. The theoretic framework of the thesis was based on childhood theory together with concepts drawn from Gallagher on childhood and power relationships in work involving children’s participation. The results reveal that participation is viewed as a complex and problematical concept. The informants interpretations vary from participation as passive observers to involvement, at least to the extent of being asked to participate in the planning of activities at libraries. Although aware of the imbalance of power between adults and children, the informants described difficulties in allowing children to take control. A lack of time was found to be the greatest hinder in working with participation. Time, they argue, is required in order to create security, to build relationships and to be able to reflect on participation processes. The most common manifestation of children’s participation is the use of children’s suggestions for buying library materials. However, we conclude that children are in fact participative in that they have access to libraries guided by a child perspective. Children are listened to and respected by the children’s librarians although there is still much that can be done to improve the extent of children’s participation in everyday library work.Program: Bibliotekari

Intresset för volontär tandvård bland blivande tandläkare och tandhygienister : en enkätstudie

Många människor i utvecklingsländer lever dagligen med tandvärk och har aldrig besökt en tandläkare. Tandläkare och tandhygienister som arbetar som volontärer åker iväg för att hjälpa till, skänka glädje och hopp till dessa människor. Syftet med denna studie var att undersöka om det fanns tandläkar- och tandhygieniststudenter som ville arbeta ideellt som volontär inom tandvården i utvecklingsländer efter avslutade studier. Studien genomfördes som en enkätundersökning där enkäterna sändes ut till alla (n= 367) som studerar sitt sista år på tandläkar- och tandhygienistprogrammet i Sverige. Resultatet visade att lite mer än hälften, 106 av 204 respondenter önskade arbeta ideellt som volontär i utvecklingsländer efter avslutade studier. Endast ett fåtal hade någon erfarenhet av ideellt arbete sedan tidigare och den största anledningen till att studenterna ville arbeta som volontärer i utvecklingsländer var viljan att hjälpa till. Det fanns ingen skillnad i svaren beroende på könsfördelning och yrkesgruppering. Slutsatsen med studien är att cirka hälften av de tillfrågade tandläkar - och tandhygieniststudenterna önskade att arbeta ideellt som volontär i utvecklingsländer

Raising Language Awareness Using Digital Media : Methods for Revealing Linguistic Stereotyping

Whether we are aware of it or not, language is at the heart of the mechanisms leading to stereotyping and inequality. It is one of the major factors that we evaluate when we meet others, and it has long been demonstrated that individuals are judged in terms of intellect and other character traits on the basis of their language output (e.g. Cavallaro & Chin 2009). We also adapt our own language to fit underlying norms and preconceived social stereotypes when we communicate with others. In this way, we help to shape individuals through the way we treat them linguistically, and social identity expressed through language is consequently something that is renegotiated during every meeting between humans (Crawford 1995). An awareness of such mechanisms is especially important for teachers. In most language courses aimed at student teachers of various levels, students are given a theoretical overview of research on aspects related to identity (gender, ethnicity, social class etc.) and language. But however well intended, there is a real danger that research focussed on identifying differences also strengthens stereotypes. Further, there is a risk that such theoretical knowledge remains just that; creating the link between so-called factual knowledge – for example, theoretical frameworks and previous studies – and internalized knowledge, applicable in our everyday lives, is especially challenging. This is particularly true in the domain of language, where metalinguistic knowledge ideally should be translated into professional language practice, a key skill for anyone working with human interaction. The Chapter explores  preliminary experiments conducted in 2011 where we were able to use digital media in order manipulate identity variables such as gender, and describes the aim of the current project - to further develop and explore experiential pedagogic approaches aimed at raising sociolinguistic language awareness about conceived identity-related phenomena in language, and to systematically test the effects of these methods. The project thereby combines the fields of sociolinguistics, social psychology and digital humanities in an innovative way with the objective to produce tested methods for exposing and combatting linguistic stereotyping. RAVEC-RAVEAtt öka medvetenheten genom virtuella upplevelser - Utveckling av metoder för att belysa språkliga stereotyper med hjälp av digitala medier. Diarienummer 721-2014-197