Solving the puzzle of mobile learning adoption

The dissertation seeks to explore how to improve users‘ adoption of mobile learning in current education systems. Considering the difference between basic and tertiary education in China, the research consists of two separate but interrelated parts, which focus on the use of mobile learning in basic and tertiary education contexts, respectively. In the dissertation, two adoption frameworks are developed based on previous studies. The frameworks are then evaluated using different technologies. Concerning mobile learning use in basic education settings, case study methodology is utilized. A leading provider of mobile learning services and products in China, Noah Ltd., is investigated. Multiple sources of evidence are collected to test the framework. Regarding mobile learning adoption in tertiary education contexts, survey research methodology is utilized. Based on 209 useful responses, the framework is evaluated using structural equation modelling technology. Four proposed determinants of intention to use are evaluated, which are perceived ease of use, perceived near-term usefulness, perceived ong-term usefulness and personal innovativeness. The dissertation provides a number of new insights for both researchers and practitioners. In particular, the dissertation specifies a practical solution to deal with the disruptive effects of mobile learning in basic education, which keeps the use of mobile learning away from the schools across such as European countries. A list of new and innovative mobile learning technologies is systematically introduced as well. Further, the research identifies several key factors driving mobile learning adoption in tertiary education settings. In theory, the dissertation suggests that since the technology acceptance model is initiated in work-oriented innovations by testing employees, it is not necessarily the best model for studying educational innovations. The results also suggest that perceived longterm usefulness for educational systems should be as important as perceived usefulness for utilitarian systems, and perceived enjoyment for hedonic systems. A classification based on the nature of systems purpose (utilitarian, hedonic or educational) would contribute to a better understanding of the essence of IT innovation adoption.

Työmatkaliikkumissuunnitelma Turun yliopistolliselle keskussairaalalle

Tämän työn tavoitteena on luoda Turun yliopistolliselle keskussairaalalle kestävän kehityksen mukainen työmatkaliikkumissuunnitelma, jonka avulla lisätään kestävien liikkumismuotojen käyttöä, kustannusnäkökulma huomioon ottaen. Lisäksi tavoitteena on ratkaista nykyisen pysäköintijärjestelyn ongelmia. Työn teoriaosuudessa on esitetty kestävän liikkumisen, työssä hyödynnettävän kustannuslaskennan ja liikkumissuunnitelman luomisen vaiheiden periaatteet. Empiriaosuudessa rakennettava liikkumissuunnitelma perustuu näihin teorioihin. Työn keskeisenä tutkimusmenetelmänä on käytetty Webropol-pohjaista kyselyä, jolla tutkittiin työmatkaliikkumisen nykytilaa. Lisäksi kyselyllä tutkittiin työntekijöiden mielipiteitä mahdollisista kehitystoimenpiteistä. Työntekijöiden vuosittaisista työmatkakilometreistä 16,9 miljoonaa kuljettiin yksityisautolla, mikä on noin 65 % kaikista työmatkakilometreistä. Yksityisautoilu aiheuttaa kulkumuodoista suurimmat päästöt kaikissa päästöluokissa. Pysäköinnin kustannuksia tutkittaessa havaittiin, että pysäköintioikeuden hinta on alhainen verrattuna parkkihallin rakennus- ja ylläpitokustannuksiin. Eri liikkumistapoja vertailtaessa havaittiin, että nykytilanteessa yksityisautoilu on lyhyillä työmatkoilla edullisempi kulkumuoto kuin julkinen liikenne. Toteutettavuus-vaikuttavuus-suhde huomioon ottaen, parhaimmat työmatkaliikkumisen kehitystoimenpiteet ovat osittain kustannettu työsuhdematkalippu työntekijöille, lukittavien pyörätelineiden sijoittaminen työpaikan välittömään läheisyyteen, kävely- ja pyöräreittien parempi talvikunnossapito, työnantajan kustantama vuosittainen polkupyörähuolto ja pysäköintioikeuden hinnankorotus. Toimenpiteiden jälkeen yksityisautoilu on kaikilla työmatkan pituuksilla kallein liikkumismuoto.

Evaluation of the throughfall and stemflow nutrient contents in mixed and pure plantations of Acacia mangium, Pseudosamenea guachapele and Eucalyptus grandis

The interception of the rainfall by the forest canopy has great relevance to the nutrient geochemistry cycle in low fertility tropical soils under native or cultivated forests. However, little is known about the modification of the rainfall water quality and hydrological balance after interception by the canopies of eucalyptus under pure and mixed plantations with leguminous species, in Brazil. Samples of rainfall (RF), throughfall (TF) and stemflow (SF) were collected and analyzed in pure plantations of mangium (nitrogen fixing tree -NFT), guachapele (NFT) and eucalyptus (non-nitrogen fixing tree -NNFT) and in a mixed stand of guachapele and eucalyptus in Seropédica, State of Rio de Janeiro, Brazil. Nine stemflow collectors (in selected trees) and nine pluviometers were randomly disposed under each stand and three pluviometers were used to measure the incident rainfall during 5.5 months. Mangium conveyed 33.4% of the total rainfall for its stem. An estimative based on corrections for the average annual precipitation (1213 mm) indicated that the rainfall's contribution to the nutrient input (kg ha-1) was about 8.42; 0.95; 19.04; 6.74; 4.72 and 8.71 kg ha-1 of N-NH4+, P, K+, Ca+2, Mg+2 and Na+, respectively. Throughfall provided the largest contributions compared to the stemflow nutrient input. The largest inputs of N-NH4+ (15.03 kg ha-1) and K+ (179.43 kg ha-1) were observed under the guachapele crown. Large amounts of Na+ denote a high influence of the sea. Mangium was the most adapted species to water competitiveness. Comparatively to pure stand of eucalyptus, the mixed plantation intensifies the N, Ca and Mg leaching by the canopy, while the inputs of K and P were lower under these plantations.

DPS-Like Peroxide Resistance Protein: Structural and Functional Studies on a Versatile Nanocontainer

Oxidative stress is a constant threat to almost all organisms. It damages a number of biomolecules and leads to the disruption of many crucial cellular functions. It is caused by reactive oxygen species (ROS), such as hydrogen peroxide (H2O₂), superoxide (•O₂ -), and hydroxyl radical (•OH). The most harmful of these compounds is •OH, which is only formed in cells in the presence of redox-cycling transition metals, such as iron and copper. Bacteria have developed a number of mechanisms to cope with ROS. One of the most widespread means employed by bacteria is the DNA-binding proteins from starved cells (Dps). Dps proteins protect the cells by binding and oxidizing Fe2+, thus greatly reducing the production of •OH. The oxidized iron is stored inside the protein as an iron core. In addition, Dps proteins bind directly to DNA forming a protective coating that shields DNA from harmful agents. Moreover, Dps proteins have been found to elicit other protective functions in cells and to participate in bacterial virulence. Dps proteins are of special importance to Streptococci owing to the lack of catalase in this genus of bacteria.This study was focused on structural and functional characterization of streptococcal Dpslike peroxide resistance (Dpr) proteins. Initially, crystal structures of Streptococcus pyogenes Dpr were determined. The data confirmed the presence of a di-metal ferroxidase center (FOC) in Dpr proteins and revealed the presence of a novel N-terminal helix as well as a surface metal-binding site. The crystal structures of Streptococcus suis Dpr complexed with transition metals demonstrated the metal specificity of the FOC. Solution binding studies also indicated the presence of a di-metal FOC. These results suggested a possible role for Dpr in the detoxification of various metals. Iron was found to mineralize inside the protein as ferrihydrite based on X-ray absorption spectroscopy data. The iron core was found to exhibit clear superparamagnetic behaviour using magnetic and Mössbauer measurements. The results from this study are expected to further increase our understanding on the binding, oxidation, and mineralization of iron and other metals in Dpr proteins. In particular, the structural and magnetic properties of the iron core can form a basis for potential new applications in nanotechnology. From the streptococcal viewpoint, the results would help in understanding better the complicated picture of bacterial pathogenesis. Dpr proteins may also provide a novel target for drug design due to their tight involvement in bacterial virulence.

Litter fall production and decomposition in a fragment of secondary Atlantic Forest of São Paulo, sp, southeastern Brazil

Litter fall consists of all organic material deposited on the forest floor, being of extremely important for the structure and maintenance of the ecosystem through nutrient cycling. This study aimed to evaluate the production and decomposition of litter fall in a secondary Atlantic forest fragment of secondary Atlantic Forest, at the Guarapiranga Ecological Park, in São Paulo, SP. The litter samples were taken monthly from May 2012 to May 2013. To assess the contribution of litter fall forty collectors were installed randomly within an area of 0.5 ha. The collected material was sent to the laboratory to be dried at 65 °C for 72 hours, being subsequently separated into fractions of leaves, twigs, reproductive parts and miscellaneous, and weighed to obtain the dry biomass. Litterbags were placed and tied close to the collectors to estimate the decomposition rate in order to evaluate the loss of dry biomass at 30, 60, 90, 120 and 150 days. After collection, the material was sent to the laboratory to be dried and weighed again. Total litter fall throughout the year reached 5.7 Mg.ha-1.yr-1 and the major amount of the material was collected from September till March. Leaves had the major contribution for total litter fall (72%), followed by twigs (14%), reproductive parts (11%) and miscellaneous (3%). Reproductive parts had a peak during the wet season. Positive correlation was observed between total litter and precipitation, temperature and radiation (r = 0.66, p<0.05; r = 0.76, p<0.05; r = 0.58, p<0.05, respectively). The multiple regression showed that precipitation and radiation contributed significantly to litter fall production. Decomposition rate was in the interval expected for secondary tropical forest and was correlated to rainfall. It was concluded that this fragment of secondary forest showed a seasonality effect driven mainly by precipitation and radiation, both important components of foliage renewal for the plant community and that decomposition was in an intermediate rate.

Essays on Business and Leadership Ethics

As this is a dissertation, an academic thesis, it is important to define the objectives of my research, even if ex post facto, explicitly: - To define, develop and study the concept of business and leadership ethics. - To empirically study the phenomena associated with business and leadership from an ethical perspective. - To create a new framework for the development of responsible business. - To create an “acid test” for my body of works, i.e. a test and an evaluation on how well my research and ideas hold up under academic philosophical reflection. The utilitarian reasoning had the most support when the actors justified their actions regarding economic benefit. (=instrumental good). Duty and benefit were often mixed up in people’s speech. Their meaning contents were blurred and the argumentation lines created by the actors were broken. This can be interpreted in a way that supports Frankena’s mixed deontological philosophy as a frame of reference. Deontologica reasoning was used e.g. in describing the personnel management processes of a company. Virtue ethics is a favourable starting point for studying management and leadership ethics. All the actors studied could name virtues for their operations, towards which to aspire to. They also named professional practices already in use that they considered to be virtuous. Finally, I wish to state that normative ethics is an important branch of philosophical ethics, if also very important in applied ethics especially. From the normative standpoint, the results of this dissertation want to lead nations, communities and individuals towards the virtues of democratic leadership and sustainable economic development.

Turun seudun turvallisen ja kestävän liikkumisen suunnitelma

Turun seudun turvallisen ja kestävän liikkumisen suunnitelma on laadittu seudun kuntien ja Varsinais-Suomen ELY-keskuksen yhteistyönä. Suunnitelmassa on selvitetty liikenneturvallisuuden, liikkumisen, toimintaympäristön ja liikennejärjestelmän nykytilaa sekä kartoitettu liikenneturvallisuusongelmia erilaisten analyysien ja kyselyiden avulla. Nykytila-analyysin pohjalta on asetettu liikenneturvallisuustyön visio ja tavoitteet sekä määritetty toimenpide-ehdotukset. Tavoitteisiin pääsemistä tukevat liikenneympäristön parantamistoimenpiteiden ohjelma, liikkumisen ohjauksen toimintaohjelma sekä hallintokuntien liikenneturvallisuustyön toimenpiteistä kootut toimintasuunnitelmat. Onnettomuusanalyysin perusteella liikenneturvallisuuden tila oli Turun seudulla hieman koko Suomen keskiarvoa heikompi. Seudulla tapahtui vuosina 2001-2010 henkilövahinkoon johtaneita onnettomuuksia keskimäärin 132 / 100 000 asukasta, kun vastaava luku oli 126 koko maan osalta. Kuolemaan johtaneita onnettomuuksia tapahtui seudulla vähemmän, mutta loukkaantumiseen johtaneita onnettomuuksia koko maan keskiarvoa enemmän. Onnettomuuksissa kuoli tai loukkaantui koko maan keskiarvoa enemmän jalankulkijoita ja polkupyöräilijöitä. Lukumäärällisesti eniten onnettomuuksia tapahtui 18–19-vuotiaille, mutta henkilövahinkoon johtaneita onnettomuuksia tapahtui selvästi eniten 15–16-vuotiaille. Seudulla tapahtuneista liikenneonnettomuuksista aiheutui vuosittain keskimäärin 127,2 miljoonan euron kustannukset, josta kuntien osuus oli vuosittain noin 22,3 miljoonaa euroa. Asukkaille suunnatun kyselyn mukaan sekä työmatkat että lyhyet vapaa-ajan matkat tehtiin useimmiten henkilöautolla. Koululaisia pidettiin turvattomimpana tienkäyttäjäryhmänä, ja kävelyä sekä pyöräilyä turvattomimpina kulkutapoina. Välinpitämättömyyttä pidettiin merkittävimpänä syynä erilaisiin liikennerikkomuksiin ja tärkeimmäksi kehittämistarpeeksi nousi liikennekäyttäytyminen. Yhdyskuntarakenteen ja toimintaympäristön analyysin perusteella seudulla on hyvät edellytykset kestävien kulkumuotojen kuten joukkoliikenteen houkuttelevuuden lisäämiselle sekä kävelyn ja pyöräilyn verkoston kehittämiselle. Onnettomuusanalyysin ja valtakunnallisten tavoitteiden pohjalta Turun seudulle asetettiin liikenneturvallisuustyön tavoitteet. Tavoitelaskelman mukaan liikennekuolemien ja loukkaantuneiden määrä tulee puolittaa vuosien 2006-2010 keskiarvosta vuoteen 2020 mennessä. Tavoitteen mukaan liikenteessä kuolee enintään 6 (lähtötaso 12) ja loukkaantuu 236 (lähtötaso 471) vuonna 2020. Vaikutusarvion perusteella voidaan arvioida päästävän tavoitteeseen suunnitelmakauden aikana. Tavoitteiden saavuttaminen on kuitenkin haasteellista ja edellyttää tehokasta yhteistyötä eri tahojen välillä. Tavoitteeseen tulee pyrkiä laajaa keinovalikoimaa käyttäen. Suunnitelmatyön aikana aktivoitiin kuntien turvallisen ja kestävän liikkumisen ryhmät, joiden toiminnan tueksi laadittiin toimintasuunnitelmat sekä vuosikello työn eri vaiheista. Ryhmät vastaavat suunnitelman toteuttamisesta, toteutumisen seurannasta ja tarvittaessa päivittämisestä.

Modeling and Control of the Power Conversion Unit in a Solid Oxide Fuel Cell Environment

In this doctoral thesis, a power conversion unit for a 10 kWsolid oxide fuel cell is modeled, and a suitable control system is designed. The need for research was identified based on an observation that there was no information available about the characteristics of the solid oxide fuel cell from the perspective of power electronics and the control system, and suitable control methods had not previously been studied in the literature. In addition, because of the digital implementation of the control system, the inherent characteristics of the digital system had to be taken into account in the characteristics of the solid oxide fuel cell (SOFC). The characteristics of the solid oxide fuel cell as well the methods for the modeling and control of the DC/DC converter and the grid converter are studied by a literature survey. Based on the survey, the characteristics of the SOFC as an electrical power source are identified, and a solution to the interfacing of the SOFC in distributed generation is proposed. A mathematical model of the power conversion unit is provided, and the control design for the DC/DC converter and the grid converter is made based on the proposed interfacing solution. The limit cycling phenomenon is identified as a source of low-frequency current ripple, which is found to be insignificant when connected to a grid-tied converter. A method to mitigate a second harmonic originating from the grid interface is proposed, and practical considerations of the operation with the solid oxide fuel cell plant are presented. At the theoretical level, the thesis discusses and summarizes the methods to successfully derive a model for a DC/DC converter, a grid converter, and a power conversion unit. The results of this doctoral thesis can also be used in other applications, and the models and methods can be adopted to similar applications such as photovoltaic systems. When comparing the results with the objectives of the doctoral thesis, we may conclude that the objectives set for the work are met. In this doctoral thesis, theoretical and practical guidelines are presented for the successful control design to connect a SOFC-based distributed generation plant to the utility grid.

Disturbance and ecosystem functioning : the role of changes in benthic biological traits

Rapid changes in biodiversity are occurring globally, as a consequence of anthropogenic disturbance. This has raised concerns, since biodiversity is known to significantly contribute to ecosystem functions and services. Marine benthic communities participate in numerous functions provided by soft-sedimentary ecosystems. Eutrophication-induced oxygen deficiency is a growing threat against infaunal communities, both in open sea areas and in coastal zones. There is thus a need to understand how such disturbance affects benthic communities, and what is lost in terms of ecosystem functioning if benthic communities are harmed. In this thesis, the status of benthic biodiversity was assessed for the open Baltic Sea, a system severely affected by broad-scale hypoxia. Long-term monitoring data made it possible to establish quantitative biodiversity baselines against which change could be compared. The findings show that benthic biodiversity is currently severely impaired in large areas of the open Baltic Sea, from the Bornholm Basin to the Gulf of Finland. The observed reduction in biodiversity indicates that benthic communities are structurally and functionally impoverished in several of the sub-basins due to the hypoxic stress. A more detailed examination of disturbance impacts (through field studies and -experiments) on benthic communities in coastal areas showed that changes in benthic community structure and function took place well before species were lost from the system. The degradation of benthic community structure and function was directed by the type of disturbance, and its specific temporal and spatial characteristics. The observed shifts in benthic trait composition were primarily the result of reductions in species’ abundances, or of changes in demographic characteristics, such as the loss of large, adult bivalves. Reduction in community functions was expressed as declines in the benthic bioturbation potential and in secondary biomass production. The benthic communities and their degradation accounted for a substantial proportion of the changes observed in ecosystem multifunctionality. Individual ecosystem functions (i.e. measures of sediment ecosystem metabolism, elemental cycling, biomass production, organic matter transformation and physical structuring) were observed to differ in their response to increasing hypoxic disturbance. Interestingly, the results suggested that an impairment of ecosystem functioning could be detected at an earlier stage if multiple functions were considered. Importantly, the findings indicate that even small-scale hypoxic disturbance can reduce the buffering capacity of sedimentary ecosystem, and increase the susceptibility of the system towards further stress. Although the results of the individual papers are context-dependent, their combined outcome implies that healthy benthic communities are important for sustaining overall ecosystem functioning as well as ecosystem resilience in the Baltic Sea.

Development of a three-dimensional nonlinear viscoelastic constitutive model of solid propellant

A three dimensional nonlinear viscoelastic constitutive model for the solid propellant is developed. In their earlier work, the authors have developed an isotropic constitutive model and verified it for one dimensional case. In the present work, the validity of the model is extended to three-dimensional cases. Large deformation, dewetting and cyclic loading effects are treated as the main sources of nonlinear behavior of the solid propellant. Viscoelastic dewetting criteria is used and the softening of the solid propellant due to dewetting is treated by the modulus decrease. The nonlinearities during cyclic loading are accounted for by the functions of the octahedral shear strain measure. The constitutive equation is implemented into a finite element code for the analysis of propellant grains. A commercial finite element package ‘ABAQUS’ is used for the analysis and the model is introduced into the code through a user subroutine. The model is evaluated with different loading conditions and the predicted values are in good agreement with the measured ones. The resulting model applied to analyze a solid propellant grain for the thermal cycling load.

Interpreting marine benthic ecosystem functioning in coastal waters: validating the biological trait concept

Coastal areas harbour high biodiversity, but are simultaneously affected by rapid degradations of species and habitats due to human interactions. Such alterations also affect the functioning of the ecosystem, which is primarily governed by the characteristics or traits expressed by the organisms present. Marine benthic fauna is nvolved in numerous functions such as organic matter transformation and transport, secondary production, oxygen transport as well as nutrient cycling. Approaches utilising the variety of faunal traits to assess benthic community functioning have rapidly increased and shown the need for further development of the concept. In this thesis, I applied biological trait analysis that allows for assessments of a multitude of categorical traits and thus evaluation of multiple functional aspects simultaneously. I determined the functional trait structure, diversity and variability of coastal zoobenthic communities in the Baltic Sea. The measures were related to recruitment processes, habitat heterogeneity, large-scale environmental and taxonomic gradients as well as anthropogenic impacts. The studies comprised spatial scales from metres to thousands of kilometres, and temporal scales spanning one season as well as a decade. The benthic functional structure was found to vary within and between seagrass landscape microhabitats and four different habitats within a coastal bay, in papers I and II respectively. Expressions of trait categories varied within habitats, while the density of individuals was found to drive the functional differences between habitats. The findings in paper III unveiled high trait richness of Finnish coastal benthos (25 traits and 102 cateogries) although this differed between areas high and low in salinity and human pressure. In paper IV, the natural reduction in taxonomic richness across the Baltic Sea led to an overall reduction in function. However, functional richness in terms of number of trait categories remained comparatively high at low taxon richness. Changes in number of taxa within trait categories were also subtle and some individual categories were maintained or even increased. The temporal analysis in papers I and III highlighted generalities in trait expressions and dominant trait categories in a seagrass landscape as well as a “type organism” for the northern Baltic Sea. Some initial findings were made in all four papers on the role of common and rare species and traits for benthic community functioning. The findings show that common and rare species may not always express the same trait categories in relation to each other. Rare species in general did not express unique functional properties. In order to advance the understanding of the approach, I also assessed some issues concerning the limitations of the concept. This was conducted by evaluating the link between trait category and taxonomic richness using especially univariate measures. My results also show the need to collaborate nationally and internationally on safeguarding the utility of taxonomic and trait data. The findings also highlight the importance of including functional trait information into current efforts in marine spatial planning and biomonitoring.

Social networks and networking facilitating internationalization: Experiences of two Finnish fashion companies

Background: Fashion is a dynamic and creative industry where larger retailers are enjoying international success. Small businesses however are struggling in the face of international expansion, as they lack the necessary resources and managerial know-how. The Finnish fashion industry has neither been able to develop the industry environment to support small and micro firms nor has Finland relevant finance or public domains, such as, seen in other Nordic countries. Networking has been recognized to facilitate organizational growth and international expansion in industries such as manufacturing and high technology. It has enabled smaller companies to gain resources, knowledge and experiences otherwise unattainable. Objective: The purpose of this study was to explore how networking has been utilized in the Finnish fashion industry. Particularly social relationships and networks are examined, as they emphasize the importance of individuals. Exploration on the past actions should also provide insight how networks and networking could be utilized and developed in the future. Main findings: It was discovered that the Finnish fashion industry (social) network is rather dense. This was mainly due to the small size of the Finnish market. In the early years of the establishment of the company, close contacts seemed to be utilized. As a company expands and extends its business, the relationships tended to move towards more utilitarian in nature. However, in some cases, the long term relationships had also affectionate features, such as trust and commitment. International networking was found to have positive impact on business opportunities. Participation to events, such as trade shows, was perceived as one of the best ways to meet new international contacts and to develop ones network. Active networking in the Finnish market, however, created both domestic and international opportunities. Furthermore, cooperation and open communication were discovered to facilitate innovation and projects. The public sector seemed to lack the interest in supporting the fashion industry according to the interviewees. The major issues for the fashion industry still concerned, among others, funding, administrative guidance and public support for developing the industry as a whole.

Itse tehty moderni. Gramofoni, polkupyörä ja valokuvaus suomalaisten elämässä 1880-luvulta 1940-luvulle

Tässä tutkimuksessa tarkastellaan aineellista modernia ja materiaalisen kulttuurin muutosta Suomessa 1880-luvulta 1940-luvulle tutkimalla sitä, miten kolme kansainvälistä teknologiaa, gramofoni, polkupyörä ja valokuvaus, otettiin Suomessa käyttöön ja millaisia paikallisia ilmiöitä niiden ympärille kehittyi. Tutkimus koostuu johdanto- ja yhteenveto-osan lisäksi kuudesta artikkelista, joissa käsitellään seuraavia alateemoja: itse tehtyjä polkupyöriä, käyntikorttikuvien käyttöä maalaiskodeissa, maaseudun pyöräilyä ja sen muistelemista, vuoden 1929 gramofonikuumetta, valokuvausta teknisenä harrastuksena sekä maalaisia gramofonin käytön tapoja. Tutkimuksen lähteinä on käytetty laajoja muistitietoaineistoja, sanoma- ja aikakauslehtiaineistoja, arkistoaineistoja, aikalaiskirjallisuutta ja museoesineitä. Lähteistä on etsitty mikrohistoriallista lukutapaa noudattaen johtolankoja gramofoniin, polkupyörään ja valokuvaukseen liittyneihin käytäntöihin. Esitän, että muistitietolähteet, muiden lähteiden kanssa ristiinluettuina, antavat hyvän mahdollisuuden sellaisten arjen käytäntöjen tarkasteluun, joiden tutkiminen muiden lähteiden perusteella olisi vaikeaa tai mahdotonta. Tutkimuksessa käytetyistä teoreettisista kehyksistä niin teknologian sosiaalinen rakentuminen, arjen historia, materiaaliseen kulttuuriin liittyvä teoriapohja, kulutuskulttuurin tutkimus kuin käytäntöteoriatkin kannustavat tarkastelemaan sitä, miten käyttäjien toiminta muokkaa ja määrittää teknologiaa. Näiden teoriasuuntausten pohjalta olen tätä tutkimusta varten kehittänyt itse tehdyn modernin ja kansankeksinnön käsitteet, jotka tarkentavat katseen ajallisesti ja paikallisesti tyypillisiin teknologian muokkauksen ja määrittelyn tapoihin sekä paikalliseen teknologiseen kekseliäisyyteen. Itse tehdyn modernin käsite auttaa hahmottamaan materiaalisia muutoksia ja pysyvyyksiä ajanjaksolla 1800-luvun lopulta toiseen maailmansotaan. Suomalaiset muovasivat omanlaisensa modernin, jossa uutuudet ja muutokset sulautuivat osaksi sitkeinä jatkuvia ja hitaasti muuttuvia maalaisyhteiskunnan toimintatapoja ja muokkasivat niitä vähitellen. Itse tehty moderni sekoitti omavaraisuutta ja kulutuskulttuuria, käsillä tekemiseen perustuvaa taitavuutta ja kursseilla sekä koulutuksessa saavutettua teknistä tietoa, paikallisia aineksia ja kansainvälisiä vaikutteita. Puhumalla kansanomaisista keksinnöistä olen halunnut korostaa tällaisten yhdistelmien mahdollisuutta ruohonjuuritasolla ja massatuotettujen laitteiden sovittamista osaksi pitkälti itse tehtyä ja omavaraista esinemaailmaa.

Elementos minerais em folhas de espécies arbóreas de Mata Atlântica e Mata de Restinga, na Ilha do Cardoso, SP

(Elementos minerais em folhas de espécies arbóreas de Mata Atlântica e Mata de Restinga, na Ilha do Cardoso, SP). Os teores de macro e micronutrientes, Na e Al foram determinados no compartimento das folhas, representado pelas espécies arbóreas mais importantes ocorrentes em áreas cobertas com Mata Atântica e Mata de Restinga, na Ilha do Cardoso (25º12'S e 48º01'W), São Paulo, como parte de um estudo sobre ciclagem de nutrientes. Utilizaram-se, em cada área, as 10 espécies com maiores índices de valor de importância, cujas folhas compuseram amostras mistas, realizando-se duas coletas (jun/93 e dez/93). Todos os elementos analisados apresentaram concentrações mais elevadas nas folhas coletadas na Mata Atlântica, com exceção de B e Na. A concentração da maioria dos elementos minerais foi mais alta nas folhas vivas do que na serapilheira foliar produzida em cada ambiente, sendo evidenciadas estratégias de economia de nutrientes, em ambas as formações vegetais, porém mais acentuadas na Mata de Restinga, indicando sua alta eficiência na utilização de um pequeno estoque de nutrientes.

Litterfall and litter nutrient content in two Brazilian Tropical Forests

Litterfall and transfer of nutrients was estimated in two tropical coastal forests of Brazil - the Atlantic and the Restinga Forests at Cardoso Island, São Paulo. Samples were collected monthly, from June 1990 to May 1991, using thirty 0.25 m2 traps. There were significant differences in litter production between the Atlantic Forest (6.3 t.ha-1.year-1) and the Restinga Forest (3.9 t.ha-1.year-1). Litterfall was continuous throughout the year with maximum in the beginning of the rainy season in both sites. The annual return of mineral elements through litter in the Atlantic Forest was (kg.ha-1): 101.8 N, 3.8 P, 20.3 K, 60.0 Ca, 18.0 Mg, and 14.6 S and in the Restinga Forest was: 27.5 N, 1.0 P, 6.5 K, 30.0 Ca, 10.9 Mg, and 6.6 S. The return, although small, is relevant due to the low fertility of the soils in those ecosystems, especially in Restinga. The Restinga Forest seems to be an ecosystem well adapted to oligotrophic conditions, lying among those presenting higher nutrient use efficiency.