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Institution

University of Turku

EducationTurku, Finland
About: University of Turku is a education organization based out in Turku, Finland. It is known for research contribution in the topics: Population & Galaxy. The organization has 16296 authors who have published 45124 publications receiving 1505428 citations. The organization is also known as: Turun yliopisto & Åbo universitet.


Papers
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Journal ArticleDOI
TL;DR: A clear but detailed view of the chemical ecology of tannins and the methodology used to study them is given, and a new method to estimate the oxidative activity of all types of tANNins and other phenolics that might cause oxidative stress to herbivores is introduced.
Abstract: Summary 1. Tannins are one of the most studied groups of plant secondary metabolites in research related to chemical ecology. They are traditionally thought to form an important factor of plant defence against herbivorous insects. 2. For a long time, tannins’ anti-herbivore activity was thought to derive from their protein precipitation capacity that rendered plant tissues non-nutritious and unpalatable for herbivores. Recent evidence suggests that tannin activity cannot be explained quite this simply, as tannin oxidation should also be taken into account as a defence mechanism for plants. 3. Tannins show very high variability in their structures with several hundred unique molecules detected in plants. These molecules are unevenly distributed in the plant kingdom and only very seldom—if ever—do two plant species share the same tannin pool. In many cases tannin composition varies even within organs of the same plant species and individual. Still, the overall tannin composition of many plant species is as of yet unknown. 4. Chemical ecology of tannins is challenging due to its multi-disciplinary nature. To facilitate research on tannins, we must provide ecologists and chemists with methodological and collaborative alternatives that enable the true and holistic investigation of all important questions that may arise from the field. So far this has not been possible with the tannin oxidation hypothesis, since simple and widely usable methods have not been available. 5. The aim of this review is to give a clear but detailed view of the chemical ecology of tannins and the methodology used to study them. In addition, we introduce a new method to estimate the oxidative activity of all types of tannins and other phenolics that might cause oxidative stress to herbivores. Hopefully our arguments and method will lead to clear changes in the approaches we take to tannins and their exciting biological activities, and we will witness a new era of flourishing and productive research in the chemical ecology of tannins.

418 citations

Journal ArticleDOI
TL;DR: By dating the branching events, it is inferred that Nymphalidae originated in the Cretaceous at 90 Ma, but that the ancestors of 10–12 lineages survived the end-Cretaceous catastrophe in the Neotropical and Oriental regions.
Abstract: The butterfly family Nymphalidae contains some of the most important non-drosophilid insect model systems for evolutionary and ecological studies, yet the evolutionary history of the group has remained shrouded in mystery. We have inferred a robust phylogenetic hypothesis based on sequences of 10 genes and 235 morphological characters for exemplars of 400 of the 540 valid nymphalid genera representing all major lineages of the family. By dating the branching events, we infer that Nymphalidae originated in the Cretaceous at 90 Ma, but that the ancestors of 10–12 lineages survived the end-Cretaceous catastrophe in the Neotropical and Oriental regions. Patterns of diversification suggest extinction of lineages at the Cretaceous/Tertiary boundary (65 Ma) and subsequent elevated speciation rates in the Tertiary.

417 citations

Journal ArticleDOI
TL;DR: While intakes of energy and nutrients have changed favourably in Finnish young adults between 1980 and 2001 with regard to the risk of CVD, they are still far from recommended levels.
Abstract: Objective To assess nutrient intakes relevant in the prevention of cardiovascular diseases (CVD) among young adults in Finland and to find past and present determinants of quality of diet. Design Prospective study, 21 years of follow-up. Setting The Cardiovascular Risk in Young Finns Study, Finland. Subjects At baseline in 1980: 3569 children aged 3-18 y participated (83% of those invited), and every second of them (1780) were selected to the dietary study. At follow-ups in 1986 and 2001: 1200 and 1037 of the original sample, respectively, participated. Methods Food consumption was assessed using 48-h dietary recall. Intakes in 2001 were compared with those obtained in 1980 and 1986. Nutrients selected for further examination were those implicated in the risk of CVD: saturated, monounsaturated, polyunsaturated and n-3 fatty acids, fibre and salt. An index describing the quality of adulthood diet was constructed. Multivariate logistic regression was used to identify independent childhood and adulthood determinants of the quality index. Results The average intakes showed substantial changes since 1980. Intakes of fat and saturated fat had decreased, while the consumption of vegetables and fruit had increased. However, a great disparity was present between the recommended levels and actual intakes for many of the nutrients, particularly salt, saturated fat and fibre. Intake of fat and consumption of vegetables in childhood and physical activity in adulthood were important health behavioural determinants of the cardiovascular quality of the adult diet. Socio-demographic factors, including education of the subject and their parents, had no significant associations with diet. Conclusions While intakes of energy and nutrients have changed favourably in Finnish young adults between 1980 and 2001 with regard to the risk of CVD, they are still far from recommended levels. Childhood diet is a significant determinant of adult diet even after 21 y. Sponsorship This study was supported by the Academy of Finland (grant 77841) and Juho Vainio Foundation.

417 citations

Journal ArticleDOI
TL;DR: It is shown that PROTON GRADIENT REGULATION5 (PGR5)–dependent regulation of electron transfer and proton motive force is crucial for protection of PSI against photodamage, which occurred particularly during the high light phases of fluctuating light cycles.
Abstract: In nature, plants are challenged by constantly changing light conditions. To reveal the molecular mechanisms behind acclimation to sometimes drastic and frequent changes in light intensity, we grew Arabidopsis thaliana under fluctuating light conditions, in which the low light periods were repeatedly interrupted with high light peaks. Such conditions had only marginal effect on photosystem II but induced damage to photosystem I (PSI), the damage being most severe during the early developmental stages. We showed that PROTON GRADIENT REGULATION5 (PGR5)–dependent regulation of electron transfer and proton motive force is crucial for protection of PSI against photodamage, which occurred particularly during the high light phases of fluctuating light cycles. Contrary to PGR5, the NAD(P)H dehydrogenase complex, which mediates cyclic electron flow around PSI, did not contribute to acclimation of the photosynthetic apparatus, particularly PSI, to rapidly changing light intensities. Likewise, the Arabidopsis pgr5 mutant exhibited a significantly higher mortality rate compared with the wild type under outdoor field conditions. This shows not only that regulation of PSI under natural growth conditions is crucial but also the importance of PGR5 in PSI protection.

417 citations

Journal ArticleDOI
TL;DR: Serum metabolite profiles were compared between sample series drawn from children who progressed to type 1 diabetes and controls who remained nondiabetic and permanently autoantibody negative, finding that autoimmunity may be a relatively late response to the early metabolic disturbances.
Abstract: The risk determinants of type 1 diabetes, initiators of autoimmune response, mechanisms regulating progress toward β cell failure, and factors determining time of presentation of clinical diabetes are poorly understood. We investigated changes in the serum metabolome prospectively in children who later progressed to type 1 diabetes. Serum metabolite profiles were compared between sample series drawn from 56 children who progressed to type 1 diabetes and 73 controls who remained nondiabetic and permanently autoantibody negative. Individuals who developed diabetes had reduced serum levels of succinic acid and phosphatidylcholine (PC) at birth, reduced levels of triglycerides and antioxidant ether phospholipids throughout the follow up, and increased levels of proinflammatory lysoPCs several months before seroconversion to autoantibody positivity. The lipid changes were not attributable to HLA-associated genetic risk. The appearance of insulin and glutamic acid decarboxylase autoantibodies was preceded by diminished ketoleucine and elevated glutamic acid. The metabolic profile was partially normalized after the seroconversion. Autoimmunity may thus be a relatively late response to the early metabolic disturbances. Recognition of these preautoimmune alterations may aid in studies of disease pathogenesis and may open a time window for novel type 1 diabetes prevention strategies.

416 citations


Authors

Showing all 16461 results

NameH-indexPapersCitations
Kari Alitalo174817114231
Mika Kivimäki1661515141468
Jaakko Kaprio1631532126320
Veikko Salomaa162843135046
Markus W. Büchler148154593574
Eugene C. Butcher14644672849
Steven Williams144137586712
Terho Lehtimäki1421304106981
Olli T. Raitakari1421232103487
Pim Cuijpers13698269370
Jeroen J. Bax132130674992
Sten Orrenius13044757445
Aarno Palotie12971189975
Stefan W. Hell12757765937
Carlos López-Otín12649483933
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Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
2023102
2022290
20212,673
20202,688
20192,407
20182,189