Articles from TUHAT CRIS


Kokoelma sisältää TUHAT-tutkimustietojäjestelmän kautta tallennetut Open Access-artikkelit.

Helsingin yliopiston tutkijat voivat rinnakkaistallentaa tutkimusjulkaisujansa HELDAan liittämällä kokotekstin julkaisuun TUHAT-tutkimustietojärjestelmässä. (Toimintaohje tutkijalle)

This collection contains Open Access articles deposited from the University of Helsinki TUHAT CRIS

Recent Submissions

  • Castagnoli, Emmanuelle; Mikkola, Raimo; Salo, Johanna; Andersson, Maria A; Sistonen, Esko; Vornanen-Winqvist, Camilla; Viljanen, Martti; Salkinoja-Salonen, Mirja Sinikka (2015)
    Suuren toimistokiinteistön työtiloista (11 kpl) mitattiin sisäilman mikrobilaskeumien lajistoa ja resistenssejä homeeenesto kemikaaleille, toksiineja tuottavia mikrobeja pölyissä ja rakenneavausnäytteissä; sisäpölyn toksisuutta ja sisäilmasta tiivistetyn veden toksisuutta, sekä monitoroitiin sisäilman 24/7 hengitettäviä hiukkasia (PM2.5, PM10), ilman painetta, lämpötilaa, suhteellista kosteutta sekä formaldehydiä, hiilidioksidia ja VOC aineita. Tavoitteena oli saada mittaustietoa niistä tekijöistä jotka ovat yhteydessä hyvinvointihaittaan. Tulokset osoittivat, että jokainen tutkittu, ongelmainen huone oli yksilöllinen mikrobiston, toksisuuksien, kemiallisten ja fysikaalisten parametrien suhteen, ja että useat 24/7 mitatut parametrit osoittivat viikkorytmiin, vuorokauden aikaan, tunti- tai jopa minuuttirytmiin kytkettyä syklisyyttä.
  • Kaasalainen, Ulla; Heinrichs, Jochen; Krings, Michael; Myllys, Leena; Grabenhorst, Heinrich; Rikkinen, Jouko; Schmidt, Alexander R. (Public Library of Science, 2015)
    One of the most important issues in molecular dating studies concerns the incorporation of reliable fossil taxa into the phylogenies reconstructed from DNA sequence variation in extant taxa. Lichens are symbiotic associations between fungi and algae and/or cyanobacteria. Several lichen fossils have been used as minimum age constraints in recent studies concerning the diversification of the Ascomycota. Recent evolutionary studies of Lecanoromycetes, an almost exclusively lichen-forming class in the Ascomycota, have utilized the Eocene amber inclusion Alectoria succinic as a minimum age constraint. However, a re-investigation of the type material revealed that this inclusion in fact represents poorly preserved plant remains, most probably of a root. Consequently, this fossil cannot be used as evidence of the presence of the genus Alectoria (Parmeliaceae, Lecanorales) or any other lichens in the Paleogene. However, newly discovered inclusions from Paleogene Baltic and Bitterfeld amber verify that alectorioid morphologies in lichens were in existence by the Paleogene. The new fossils represent either a lineage within the alectorioid group or belong to the genus Oropogon.
  • Alam, Syed Ariful (2012)
    Oats are a good source of protein and dietary fibre, especially β-glucan. Due to the health benefits of β-glucan, oats have gained popularity in snack food formulations. The literature review deals with oats and its components, removal of lipids and fractionation of oat products. The particular emphasis of the literature review was given to studies on the effects of different oat fractions and extrusion process variables on the properties of oat-containing extrudates. The aim of this study was to find out how different oat fractions and extrusion process variables (screw speed, water content and feed rate) affect the physical and chemical properties of the extrudates. The measured physical properties were expansion, hardness and water content. Extrusion trials were carried out by using defatted oat endosperm flour (EF) as the main ingredient. Whole grain oat flour (WF) was used as a reference. To improve the nutritional quality, defatted oat protein concentrate (PC) and defatted oat bran concentrate (OBC) were added to EF. The oat fractions were defatted by supercritical carbon dioxide (SC-CO2). Pregelatinised corn starch (CS) and waxy corn starch (WS) were added in some trials to increase the expansion of the extrudates. A co-rotating twin-screw extruder was used for the extrusion. Different process variables were: water content of the mass (16, 18 and 20%), screw speed (240, 370 and 500 rpm) and feed rate (68, 76 and 84 g/min). The temperature profile of the extruder barrel was held constant in all of the trials: 40, 70, 70, 100, 110, 130 and 130 °C (sections 1–6 and die). Screw speed had significant effect on the expansion and hardness. Expansion increased and hardness decreased with increasing screw speed. Water content of the mass affected all the response variables in WF extrudates and all but not hardness and torque in EF extrudates. Increased water content of mass decreased the expansion and hardness in WF extrudates. Feed rate did not have significant effect on the physical properties. When using EF, more expanded and less hard extrudates compared to the WF were obtained. Addition of PC or OBC (10%) decreased the expansion and increased the hardness. Mixing of EF with corn starch (CS or WS; 30%) gave less hard and more expanded extrudates compared to pure EF. The highest expansion was achieved by the addition of WS. Even addition of OBC (20%) in a presence of WS (30%) gave highly expanded and less hard extrudates with high β-glucan content 7.4% (dry weight). Decreasing the particle size of OBC (by ultra-fine milling) or the molecular weight of β-glucan (by enzymatic hydrolysis) did not affect the physical properties of the extrudates even though small decrease in hardness was observed in the trial with enzyme-hydrolysed OBC. The results showed that defatted oat fractions can successfully be used in extrusion when mixed with corn starch. Screw speed had the most profound effect on the physical properties of the oat-containing extrudates followed by the water content of mass.
  • Niemelä, Kati Marianne (SAGE PUBLICATIONS LTD., 2015)
    The prevailing attitude to the national churches in the Nordic countries has often been described as ‘believing in belonging’. Based on a longitudinal survey data, this article argues that this notion no longer applies to the younger generation, often referred to as Generation Y. Instead, they are challenging traditional reasons for belonging to national churches. The number of church-leavers has been unusually high in Finland since the beginning of the 21st century, the vast majority of them young adults. These same young adults were confirmed in the church only a few years earlier. This study aims to understand why such a high number of young people leave the Evangelical Lutheran Church soon after confirmation. The study shows that for Generation Y, the Church-leaving process is linked to personal beliefs and values. They leave the Church because they do not find it to be in line with their own beliefs. Tradition and culture alone are not enough to keep them as members.
  • Fagerholm, Fabian; Ikonen, Marko; Kettunen, Petri; Münch, Jürgen; Roto, Virpi; Abrahamsson, Pekka (ELSEVIER BV, 2015)
    Context: Companies increasingly strive to adapt to market and ecosystem changes in real time. Gauging and understanding team performance in such changing environments present a major challenge. Objective: This paper aims to understand how software developers experience the continuous adaptation of performance in a modern, highly volatile environment using Lean and Agile software development methodology. This understanding can be used as a basis for guiding formation and maintenance of high-performing teams, to inform performance improvement initiatives, and to improve working conditions for software developers. Method: A qualitative multiple-case study using thematic interviews was conducted with 16 experienced practitioners in five organisations. Results: We generated a grounded theory, Performance Alignment Work, showing how software developers experience performance. We found 33 major categories of performance factors and relationships between the factors. A cross-case comparison revealed similarities and differences between different kinds and different sizes of organisations. Conclusions: Based on our study, software teams are engaged in a constant cycle of interpreting their own performance and negotiating its alignment with other stakeholders. While differences across organisational sizes exist, a common set of performance experiences is present despite differences in context variables. Enhancing performance experiences requires integration of soft factors, such as communication, team spirit, team identity, and values, into the overall development process. Our findings suggest a view of software development and software team performance that centres around behavioural and social sciences.
  • Kreutz, Andreas; Aakala, Tuomas; Grenfell, Russell; Kuuluvainen, Timo (Finnish Society of Forest Science, 2015)
    Development of species composition during succession is well studied in natural boreal forests, but empirical assessments of how within-stand spatial structure develops in late-successional stages are few. Here, we quantified spatial patterns in three unmanaged stands consisting of Picea abies (L.) Karst. and Betula pubescens Ehrh. and Betula pendula Roth (hereafter Betula spp.) in northern boreal Fennoscandia. We conducted a comprehensive analysis of small-scale spatial point patterns in three fully mapped 1.2-ha sample plots, representing different forest developmental stages: mid-successional, late-successional and old-growth forest. We used several variants of Ripley’s K-function to analyze the spatial point patterns along the successional gradient. Univariate analyses showed that mature trees of both species were either randomly distributed or clumped. P. abies saplings were clumped, and Betula spp. saplings occurred in a random or clumped manner. In the bivariate analyses, saplings were more likely to be found in the surroundings of mature trees of the same species, but occurred independent of the individuals of other tree species. Mature trees showed interspecific repulsion. Only modest differences occurred in the univariate patterns between the three successional stages, but in the bivariate analyses the most evident patterns, i.e. intraspecific attraction and interspecific repulsion, were stronger in the older successional stages. Overall, the studied stands appear structured as species-specific mosaics. These mosaics, along with mixed species composition, seem to be maintained by species self-replacement, which contrasts with findings from earlier studies.
  • Gel'man, Vladimir (Russian Analytical Digest, 2015)
    Idäntutkimus-lehden 1/2015 pääkirjoitus
  • Lehtisaari, Katja (SAGE PUBLICATIONS LTD., 2015)
  • Ahonen, Pertti Pellervo (ResearchGate, 2015)
    The purpose of this article is an examination informed by neo-institutional political and related research on two foremost aspects of institutionalization, performance and legitimation. Political research published by scholars of the extended Baltic region by late May r 2013 comprises the study topic. The article considers political research in four selected subfields: general political science, international relations/world politics, public policy, and public administration/public management. The results indicate that Denmark and Norway are “great powers” in the region, with a strong presence in strongly legitimate publication arenas of political research. Looking further at the performance suggested by publications and citations to these, Sweden and Finland stand out no less than Denmark and Norway, and Estonia and Lithuania also receive visibility. Examining performance with the bibliometric “h” index suggests that “size matters”, which accentuates German achievements, although Norway, Denmark and Sweden continue to stand out despite their relatively small population size.
  • Mikkonen, Kirsi S.; Parikka, Kirsti; Suuronen, Jussi-Petteri; Ghafar, Abdul; Serimaa, Ritva; Tenkanen, Maija (RSC Publishing, 2014)
  • Suuronen, Jussi-Petteri; Matusewicz, Michal; Olin, Markus; Serimaa, Ritva (ELSEVIER BV, 2014)
  • University of Helsinki, Aleksanteri Institute; Palonkorpi, Mikko; (Ministry for Foreign Affairs of Finland, 2015)