University of Lapland

About: University of Lapland is a education organization based out in Rovaniemi, Finland. It is known for research contribution in the topics: Arctic & Indigenous. The organization has 665 authors who have published 1870 publications receiving 39129 citations. The organization is also known as: University of Rovaniemi & Lapin yliopisto.

Effects of ultraviolet (UV) exclusion on the seasonal concentration of photosynthetic and UV-screening pigments in Scots pine needles

Abstract: The effects of ultraviolet (UV) radiation on the photosynthetic and UV-screening pigments in needles of Scots pine (Pinus sylvestris L.) saplings were studied in a UV-exclusion field chamber experiment in northern Finland (67°N) during 2001–2002. The chambers held filters that excluded both UVB and UVA, only UVB, transmitted all UV, or lacked filters. Analyses of control needles (no filter and polyethene filter) showed that the first changes to occur in spring (end of April) was an abrupt increase in the epoxidation state (EPS) of the xanthophyll cycle pigments, likely in relation with the beginning of the photosynthetic activity. The concentration of chlorophyll, lutein, neoxanthin, α-carotene, β-carotene, and the size of the xanthophyll cycle pool (violaxanthin+antheraxanthin+zeaxanthin=VAZ) changed only later when needles reached their summer photosynthesis state. Exclusion of UV radiation significantly affected the xanthophyll cycle but not the other photosynthetic pigments analysed. Interestingly, the effects on xanthophylls were dependent on the sampling date. Under UVA/B-exclusion, the EPS was increased and VAZ pool size was unchanged in April, whereas EPS remained unchanged and the VAZ pool size was reduced in May and June. The existence of two sustained and active antenna modes during winter and summer could be an explanation for the specific UV-exclusion effect in the different season. A high-performance liquid chromatography analysis of soluble phenolics showed that the exclusion of UVA/B radiation caused a significant effect on five compounds out of 46 studied, without affecting the concentration of the total soluble phenolics. Under UVA/B-exclusion, the concentration of three of them (secoisolariciresinol-glucopyranoside, two unknown) was reduced while the concentration of dicoumaroyl-astragalin and pinosylvin monomethylether was increased compared with both controls separately. In general, the exclusion of UVA/B caused a stronger effect than the exclusion of UVB on both photosynthetic and UV screening pigments. The effects of UV radiation on xanthophyll cycle pigments were season-specific and detectable only under stressful spring conditions (freezing temperatures and high irradiance due to snow reflection). The effect on the xanthophyll cycle could be a direct consequence of UV treatments, or an indirect consequence of the changed flavonoid composition, or a combination of both.

No Pain, No Gain? Teachers' Implementing ICT in Instruction.

Abstract: Purpose – The purpose of this paper is to investigate the differences between 99 Finnish primary and secondary teachers in their frequency and nature of information and communication technology (ICT) use, levels of ICT implementation, functional uses and perceived values about educational use of ICT.Design/methodology/approach – The data were collected with an online questionnaire and analyzed with expectancy‐value theory as a theoretical background.Findings – Teachers use ICT mostly for administrative tasks. Teachers' methods of utilizing student‐centred approaches in their teaching, proficiency levels in relation to ICT, and their self‐reported stage of ICT integration into teaching strongly depend on how much ICT teachers use in their teaching activities. Primary teachers value utilizing ICT in teaching more positively than secondary teachers even though secondary teachers reported being more active in the use of ICT in various functional uses. Pedagogical thinking in educational institutes has not adv...