| 1. |
- Divakar, Pradeep K., et al.
(author)
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Evolution of complex symbiotic relationships in a morphologically derived family of lichen-forming fungi
- 2015
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In: New Phytologist. - : Wiley. - 0028-646X .- 1469-8137. ; 208:4, s. 1217-1226
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Journal article (peer-reviewed)abstract
- We studied the evolutionary history of the Parmeliaceae (Lecanoromycetes, Ascomycota), one of the largest families of lichen-forming fungi with complex and variable morphologies, also including several lichenicolous fungi. We assembled a six-locus data set including nuclear, mitochondrial and low-copy protein-coding genes from 293 operational taxonomic units (OTUs). The lichenicolous lifestyle originated independently three times in lichenized ancestors within Parmeliaceae, and a new generic name is introduced for one of these fungi. In all cases, the independent origins occurred c. 24 million yr ago. Further, we show that the Paleocene, Eocene and Oligocene were key periods when diversification of major lineages within Parmeliaceae occurred, with subsequent radiations occurring primarily during the Oligocene and Miocene. Our phylogenetic hypothesis supports the independent origin of lichenicolous fungi associated with climatic shifts at the Oligocene-Miocene boundary. Moreover, diversification bursts at different times may be crucial factors driving the diversification of Parmeliaceae. Additionally, our study provides novel insight into evolutionary relationships in this large and diverse family of lichen-forming ascomycetes.
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| 2. |
- Jansen, Willemijn J, et al.
(author)
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Prevalence Estimates of Amyloid Abnormality Across the Alzheimer Disease Clinical Spectrum.
- 2022
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In: JAMA neurology. - : American Medical Association (AMA). - 2168-6157 .- 2168-6149. ; 79:3, s. 228-243
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Journal article (peer-reviewed)abstract
- One characteristic histopathological event in Alzheimer disease (AD) is cerebral amyloid aggregation, which can be detected by biomarkers in cerebrospinal fluid (CSF) and on positron emission tomography (PET) scans. Prevalence estimates of amyloid pathology are important for health care planning and clinical trial design.To estimate the prevalence of amyloid abnormality in persons with normal cognition, subjective cognitive decline, mild cognitive impairment, or clinical AD dementia and to examine the potential implications of cutoff methods, biomarker modality (CSF or PET), age, sex, APOE genotype, educational level, geographical region, and dementia severity for these estimates.This cross-sectional, individual-participant pooled study included participants from 85 Amyloid Biomarker Study cohorts. Data collection was performed from January 1, 2013, to December 31, 2020. Participants had normal cognition, subjective cognitive decline, mild cognitive impairment, or clinical AD dementia. Normal cognition and subjective cognitive decline were defined by normal scores on cognitive tests, with the presence of cognitive complaints defining subjective cognitive decline. Mild cognitive impairment and clinical AD dementia were diagnosed according to published criteria.Alzheimer disease biomarkers detected on PET or in CSF.Amyloid measurements were dichotomized as normal or abnormal using cohort-provided cutoffs for CSF or PET or by visual reading for PET. Adjusted data-driven cutoffs for abnormal amyloid were calculated using gaussian mixture modeling. Prevalence of amyloid abnormality was estimated according to age, sex, cognitive status, biomarker modality, APOE carrier status, educational level, geographical location, and dementia severity using generalized estimating equations.Among the 19097 participants (mean [SD] age, 69.1 [9.8] years; 10148 women [53.1%]) included, 10139 (53.1%) underwent an amyloid PET scan and 8958 (46.9%) had an amyloid CSF measurement. Using cohort-provided cutoffs, amyloid abnormality prevalences were similar to 2015 estimates for individuals without dementia and were similar across PET- and CSF-based estimates (24%; 95% CI, 21%-28%) in participants with normal cognition, 27% (95% CI, 21%-33%) in participants with subjective cognitive decline, and 51% (95% CI, 46%-56%) in participants with mild cognitive impairment, whereas for clinical AD dementia the estimates were higher for PET than CSF (87% vs 79%; mean difference, 8%; 95% CI, 0%-16%; P=.04). Gaussian mixture modeling-based cutoffs for amyloid measures on PET scans were similar to cohort-provided cutoffs and were not adjusted. Adjusted CSF cutoffs resulted in a 10% higher amyloid abnormality prevalence than PET-based estimates in persons with normal cognition (mean difference, 9%; 95% CI, 3%-15%; P=.004), subjective cognitive decline (9%; 95% CI, 3%-15%; P=.005), and mild cognitive impairment (10%; 95% CI, 3%-17%; P=.004), whereas the estimates were comparable in persons with clinical AD dementia (mean difference, 4%; 95% CI, -2% to 9%; P=.18).This study found that CSF-based estimates using adjusted data-driven cutoffs were up to 10% higher than PET-based estimates in people without dementia, whereas the results were similar among people with dementia. This finding suggests that preclinical and prodromal AD may be more prevalent than previously estimated, which has important implications for clinical trial recruitment strategies and health care planning policies.
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| 3. |
- Mattsson, Niklas, 1979, et al.
(author)
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Cerebrospinal Fluid Microglial Markers in Alzheimer's Disease: Elevated Chitotriosidase Activity but Lack of Diagnostic Utility
- 2011
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In: NeuroMolecular Medicine. - : Springer Science and Business Media LLC. - 1535-1084 .- 1559-1174. ; 13:2, s. 151-159
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Journal article (peer-reviewed)abstract
- Activated microglial cells, which are the resident macrophages of the central nervous system, surround amyloid beta-plaques in Alzheimer's disease (AD) brains. Inflammation including microglial activation may contribute in AD pathogenesis, and biomarkers for this process may thus be of value to study AD pathogenesis and might facilitate development of therapies targeting these cells. We therefore examined cerebrospinal fluid (CSF) biomarkers in patients with AD, other dementias, mild cognitive impairment and in healthy controls. Samples were analyzed for markers with known association to macrophage activity, including chitotriosidase, YKL-40 (CHI3L1, HC gp-39) and chemokine CC motif ligand 2 (CCL2, MCP1). Patients with AD had higher chitotriosidase activity than controls and patients with stable mild cognitive impairment, consistent with the presence of activated microglial cells in AD brains, but with large overlaps between groups. CCL2 and YKL-40 concentrations did not differ among groups. Microglial markers are unlikely to be useful for AD diagnosis, but might be useful for identification of distinct subgroups of patients, and for the development and implementation of drugs targeting microglial pathology.
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| 4. |
- Prade, Thomas, et al.
(author)
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Vall som biogassubstrat : utvärdering av skördesystemets och odlingsintensitetens påverkan på biogasutbytet
- 2014
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Reports (other academic/artistic)abstract
- I ett fältförsök på marginalmark odlades och skördades olika vallblandningar som biogassubstrat. Syftet med studien var att (a) undersöka biomassa- och metanavkastningen för de olika vallblandningarna och (b) analysera spridningen av metanpotentialbestämningarnas resultat för att undersöka möjligheter till minskning av analyskostnaderna genom annan provtagnings- och provberedningsstrategi. En gödslad kommersiell vall gav med 8,1 ton ts/ha den högsta biomassaavkastningen vid två skördar per år. Vid bara en skörd per år var det den gödslade kommersiella vallen och den befintliga vegetationen som gav högst biomassaavkastning. Metanpotentialsskillnaderna mellan vallblandningarna var ganska små vid samma skördetidpunkt. Däremot ökar den specifika metanpotentialen (liter metan per kg VS) med två skördar per år. Beräkningarna visade att antalet analyser för metanpotentialbestämningen kan reduceras betydligt när samlingsprover används i analyserna. På detta sätt minskar man variationen inom leden, vilket bidrar till att skillnader mellan olika behandlingar enklare kan upptäckas.
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| 5. |
- Amato, M, et al.
(author)
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Literature review on STEM education
- 2019
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In: Do Well Science. - Breslavia : Società Dante Alighieri. - 9788394521301 ; , s. 15-27
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Book chapter (other academic/artistic)
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| 6. |
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| 7. |
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| 8. |
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| 9. |
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| 10. |
- Articus, Kristina, et al.
(author)
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Phylogenetic studies in Usnea.
- 2000
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In: The Fourth IAL Symposium Progress and Problems in Lichenology at the Turn of the Millenium, Abstracts: 100. Barcelona..
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Conference paper (other academic/artistic)
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| 11. |
- Articus, Kristina, 1971-
(author)
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Phylogenetic Studies in Usnea (Parmeliaceae) and Allied Genera
- 2004
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Doctoral thesis (other academic/artistic)abstract
- This thesis deals with the phylogeny of the lichen genus Usnea (Parmeliaceae, Ascomycetes). The relationships and the morphological variation among Usnea species has been studied, as well as the relationship of Usnea to allied genera. Two species, U. florida and U. subfloridana, which earlier were regarded to form two separate species have been synonymized. In an analysis based on sequence data these two taxa formed a monophyletic group of intermixed specimens. Usnea florida and U. subfloridana have earlier been regarded to form a species pair, but the species pairs concept cannot be applied in this case. The morphological characters traditionally used for species recognition of a number of European Usnea species have been analyzed regarding their reliability. The evolution and distribution of the morphological characters was studied in relation to a phylogeny based on sequence data. Most characters proved to be homoplastic in relation to the phylogeny. Few characters were consistent in a clade, and the same character could be inconsistent in another clade. Therefore a combination of several characters is recommended for species recognition. The relationship of Neuropogon to Usnea was investigated based on sequence data. Neuropogon showed to be closely related to Usnea subg. Usnea. The subgenera Eumitria and Dolichousnea formed the sister group to the clade comprising subg. Usnea and Neuropogon. Usnea is paraphyletic in this investigation. Eumitria is treated as a genus and the subgenus Dolichousnea is elevated to generic rank. The position of Usnea, Neuropogon, Eumitria, and Dolichousnea in the family Parmeliaceae was investigated based on a phylogeny obtained by sequence data. Protousnea probably forms the sister group to the clade of Usnea, Neuropogon, Eumitria, and Dolichousnea. Several monophyletic groups in the family Parmeliaceae were identified.
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| 12. |
- Articus, Kristina, et al.
(author)
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Ribosomal DNA and beta-tubulin data do not support the separation of the lichens Usnea florida and U-subfloridana as distinct species
- 2002
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In: Mycological Research. - 0953-7562 .- 1469-8102. ; 106, s. 412-418
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Journal article (peer-reviewed)abstract
- The lichens Usnea florida and U. subfloridana have since long been recognised as distinct species. They show many similarities in morphology, but have different reproductive strategies. Usnea florida is always provided with many apothecia and produces no specialised asexual propagules. Usnea subfloridana has soralia, isidiomorphs and occasionally apothecia. Phylogenetic analyses based on continuous sequences of the ITS and LSU regions of the nuclear ribosomal DNA and the gene coding for beta-tubulin, show that specimens of the two species form one monophyletic group of intermixed specimens, and not two groups corresponding to morphology, which Would have been expected if two species were at hand. The 'species pair' concept in lichenology is discussed. Other Usnea species included in the study are: U. articulata, U. barbata, U. ceratina, U. filipendula. U. hirta, U. rigida and U. wasmuthii.
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| 13. |
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| 14. |
- Arup, Ulf, et al.
(author)
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High performance thin layer chromatography (HPTLC), an improved technique for screening lichen substances.
- 1993
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In: The Lichenologist. - : Cambridge University Press (CUP). - 0024-2829 .- 1096-1135. ; 25, s. 61-71
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Journal article (peer-reviewed)abstract
- High performance thin layer chromatography (HPTLC) is a method that can be used for screening lichen substances. It is as simple to use as standard TLC, but has many advantages: It is more sensitive, it is possible to run more samples in a shorter period of time, and the amount of solvent used is much smaller. The material needed and the methods used are described in detail. Horizontal chromatogram development was used. Since two of the solvents used in system B have been substituted, and since the properties of the HPTLC plates are slightly different, our results are not entirely in accordance with the standardized TLC method. A revised table for the identification of 69 lichen substances (obtained from 62 taxa) is accordingly presented.
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| 15. |
- Arup, Ulf, et al.
(author)
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Professor Ingvar Kärnfelt - a birthday tribute
- 2009
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In: The Lichenologist. - Cambridge : Cambridge University Press. - 0024-2829 .- 1096-1135. ; 41:5, s. 453-456
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Journal article (other academic/artistic)abstract
- On 19 July 2009 Ingvar Kärnefelt celebrated his 65th birthday. This could have meant that we, his former students, would be celebrating him in his retirement from his position as head of the Biological Museums at Lund University. We are grateful that this is not the case, as Ingvar will carry on, probably for at least one or two more years. Instead, we celebrate Ingvar because he is the main reason for all of us having studied lichenology in Lund. This special issue of The Lichenologist is dedicated to him as a birthday tribute in honour of his long and fruitful lichenological career. The main authors of all the papers in this issue are former students of Ingvar. For several of us he has not only acted as supervisor but later also as the director of the Botanical Museum where we meet him in our daily work.
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| 16. |
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| 17. |
- Arup, Ulf, et al.
(author)
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The sister group relation of Parmeliaceae (Lecanorales, Ascomycota)
- 2007
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In: Mycologia. - : Informa UK Limited. - 0027-5514 .- 1557-2536. ; 99:1, s. 42-49
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Journal article (peer-reviewed)abstract
- The family Parmeliaceae (Lecanorales, Ascomycota) is possibly the largest, best known and most thoroughly studied lichen family within its order. Despite this fact the relationship between Parmeliaceae and other groups in Lecanorales is still poorly known. The aim of the present study is to contribute to finding the sister group of Parmeliaceae as an aid in future studies on the phylogeny and character evolution of the group. We do this by sampling all potential relatives to the Parmeliaceae that we have identified, i.e. Cypsoplaca, Japewia, Mycoblastus, Protoparmelia, and Tephromela, a good representation of the major groups within the Parmeliaceae s. lat. and a good representation of other taxa in the core Lecanorales. We use molecular data from two genes, the large subunit of the nuclear ribosomal RNA gene (nrLSU) and the small subunit of the mitochondrial ribosomal RNA gene (mrSSU), and a Bayesian analysis of the combined data. The results show that the closest relatives to Parmeliaceae are the two genera Protoparmelia and Gypsoplaca, which are crustose lichens. Parmeliaceae in our sense is a well supported group, including also the family segregates Alectoriaceae, Hypogymniaceae, Usneaceae and Anziaceae.
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| 18. |
- Brinkmalm, Gunnar, et al.
(author)
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An online nano-LC-ESI-FTICR-MS method for comprehensive characterization of endogenous fragments from amyloid β and amyloid precursor protein in human and cat cerebrospinal fluid.
- 2012
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In: Journal of mass spectrometry : JMS. - : Wiley. - 1096-9888 .- 1076-5174. ; 47:5, s. 591-603
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Journal article (peer-reviewed)abstract
- Amyloid precursor protein (APP) is the precursor protein to amyloid β (Aβ), the main constituent of senile plaques in Alzheimer's disease (AD). Endogenous Aβ peptides reflect the APP processing, and greater knowledge of different APP degradation pathways is important to understand the mechanism underlying AD pathology. When one analyzes longer Aβ peptides by low-energy collision-induced dissociation tandem mass spectrometry (MS/MS), mainly long b-fragments are observed, limiting the possibility to determine variations such as amino acid variants or post-translational modifications (PTMs) within the N-terminal half of the peptide. However, by using electron capture dissociation (ECD), we obtained a more comprehensive sequence coverage for several APP/Aβ peptide species, thus enabling a deeper characterization of possible variants and PTMs. Abnormal APP/Aβ processing has also been described in the lysosomal storage disease Niemann-Pick type C and the major large animal used for studying this disease is cat. By ECD MS/MS, a substitution of Asp7 → Glu in cat Aβ was identified. Further, sialylated core 1 like O-glycans at Tyr10, recently discovered in human Aβ (a previously unknown glycosylation type), were identified also in cat cerebrospinal fluid (CSF). It is therefore likely that this unusual type of glycosylation is common for (at least) species belonging to the magnorder Boreoeutheria. We here describe a detailed characterization of endogenous APP/Aβ peptide species in CSF by using an online top-down MS-based method.
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| 19. |
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| 20. |
- Ceken, Fatma, et al.
(author)
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The use of the theory of conceptual profiles to assess learning outcome
- 2016
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In: Electronic Proceedings of the ESERA 2015 Conference<em></em>. - Helsinki : University of Helsinki. - 9789515115416 ; , s. 2716-2721
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Conference paper (peer-reviewed)abstract
- The Swedish Schools Inspectorate (2012) made an evaluation of the quality in science teaching in year 1–3 in the Swedish compulsory school. Large differences were found among the 30 schools studied. Often teaching only consisted of mediating facts or experiments made by the teacher. The students rarely got an opportunity to learn through systematic investigations. Less than 60% of the lessons observed involved activities were the students to large extent met scientific methods. Also, good examples were found in schools were the teachers consciously let the students make hypotheses about what will happen in an experiment. In many schools the teacher use readymade teaching packages. Generally, they consist of instructions for how series of lessons with different themes may be planned and performed by using the material included. Some of the packages also include education of the teachers. According to the School Inspectorate teachers without education in science claim that with help of the packages they have been able to teach in all areas of school science. Teachers sometime use the packages as inspiration, but chose other methods for their teaching. The purpose of this study was to examine how students in primary school use concepts and to study their conceptual development during two sequences of lessons, primarily based on the student’s own documentations. Written diaries and reports of the students were analysed in order to construct their conceptual profiles and to follow their development. The assessment of the performances in relation to the knowledge requirement evaluated students ability to discuss simple questions concerning chemical processes, plan simple experiments and formulate simple question. The study shows that observations, discussions, and written documentation of simple experiments promotes conceptual development.
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| 21. |
- Crespo, Ana, et al.
(author)
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Phylogenetic generic classification of parmelioid lichens (Parmeliaceae,Ascomycota) based on molecular, morphological and chemical evidence.
- 2010
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In: Taxon. - : John Wiley & Sons. - 0040-0262 .- 1996-8175. ; 59:6, s. 1735-1753
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Journal article (peer-reviewed)abstract
- Parmelioid lichens are a diverse and ubiquitous group of foliose lichens. Generic delimitation in parmelioid lichens has been in a state of flux since the late 1960s with the segregation of the large, heterogeneous genus Parmelia into numerous smaller genera. Recent molecular phylogenetic studies have demonstrated that some of these new genera were monophyletic, some were not, and others, previously believed to be unrelated, fell within single monophyletic groups, indicating the need for a revision of the generic delimitations. This study aims to give an overview of current knowledge of the major clades of all parmelioid lichens. For this, we assembled a dataset of 762 specimens, including 31 of 33 currently accepted parmelioid genera (and 63 of 84 accepted genera of Parmeliaceae). We performed maximum likelihood and Bayesian analyses of combined datasets including two, three and four loci. Based on these phylogenies and the correlation of morphological and chemical characters that characterize monophyletic groups, we accept 27 genera within nine main clades. We re-circumscribe several genera and reduce Parmelaria to synonymy with Parmotrema. Emodomelanelia Divakar & A. Crespo is described as a new genus (type: E. masonii). Nipponoparmelia (Kurok.) K.H. Moon, Y. Ohmura & Kashiw. ex A. Crespo & al. is elevated to generic rank and 15 new combinations are proposed (in the genera Flavoparmelia, Parmotrema, Myelochroa, Melanelixia and Nipponoparmelia). A short discussion of the accepted genera is provided and remaining challenges and areas requiring additional taxon sampling are identified.
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| 22. |
- Crespo, Ana, et al.
(author)
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Testing morphology-based hypotheses of phylogenetic relationships in Parmeliaceae (Ascomycota) using three ribosomal markers and the nuclear RPB1 gene
- 2007
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In: Molecular Phylogenetics and Evolution. - : Elsevier BV. - 1055-7903 .- 1095-9513. ; 44:2, s. 812-824
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Journal article (peer-reviewed)abstract
- Parmeliaceae is the largest family of lichen-forming fungi with more than 2000 species and includes taxa with different growth forms. Morphology was widely employed to distinguish groups within this large, cosmopolitan family. In this study we test these morphology-based groupings using DNA sequence data from three nuclear and one mitochondrial marker from 1.20 taxa that include 59 genera and represent the morphological and chemical diversity in this lineage. Parmeliaceae is strongly supported as monophyletic and six well-supported main clades can be distinguished within the family. The relationships among them remain unresolved. The clades largely agree with the morphology-based groupings and only the placement of four of the genera studied is rejected by molecular data, while four other genera belong to clades previously unrecognised. The classification of these previously misplaced genera, however, has already been questioned by some authors based on morphological evidence. These results support morphological characters as important for the identification of monophyletic clades within Parmeliaceae.
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| 23. |
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| 24. |
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| 25. |
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| 26. |
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| 27. |
- Joshi, Peter K, et al.
(author)
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Directional dominance on stature and cognition in diverse human populations
- 2015
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In: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 523:7561, s. 459-462
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Journal article (peer-reviewed)abstract
- Homozygosity has long been associated with rare, often devastating, Mendelian disorders, and Darwin was one of the first to recognize that inbreeding reduces evolutionary fitness. However, the effect of the more distant parental relatedness that is common in modern human populations is less well understood. Genomic data now allow us to investigate the effects of homozygosity on traits of public health importance by observing contiguous homozygous segments (runs of homozygosity), which are inferred to be homozygous along their complete length. Given the low levels of genome-wide homozygosity prevalent in most human populations, information is required on very large numbers of people to provide sufficient power. Here we use runs of homozygosity to study 16 health-related quantitative traits in 354,224 individuals from 102 cohorts, and find statistically significant associations between summed runs of homozygosity and four complex traits: height, forced expiratory lung volume in one second, general cognitive ability and educational attainment (P < 1 × 10(-300), 2.1 × 10(-6), 2.5 × 10(-10) and 1.8 × 10(-10), respectively). In each case, increased homozygosity was associated with decreased trait value, equivalent to the offspring of first cousins being 1.2 cm shorter and having 10 months' less education. Similar effect sizes were found across four continental groups and populations with different degrees of genome-wide homozygosity, providing evidence that homozygosity, rather than confounding, directly contributes to phenotypic variance. Contrary to earlier reports in substantially smaller samples, no evidence was seen of an influence of genome-wide homozygosity on blood pressure and low density lipoprotein cholesterol, or ten other cardio-metabolic traits. Since directional dominance is predicted for traits under directional evolutionary selection, this study provides evidence that increased stature and cognitive function have been positively selected in human evolution, whereas many important risk factors for late-onset complex diseases may not have been.
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| 28. |
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| 29. |
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| 30. |
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| 31. |
- Kärnefelt, Ingvar, et al.
(author)
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The lichen genera Arctocetraria, Cetraria and Cetrariella (Parmeliaceae) and their presumed evolutionary affinities.
- 1993
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In: Bryologist. - 1938-4378. ; 96:3, s. 394-404
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Journal article (peer-reviewed)abstract
- A circumscription of the lichen genus Cetraria Ach. s.s., presently comprising 15 species, is made. The genus is characterized by oblong, citriform conidia as well as characters of the ascus: a small axial body and a distinct amyloid ring structure in the tholus (the region between the ocular chamber and the outer membranes in the apex of the ascus). All fertile species of Coelocaulon Link are incorporated into Cetraria, based upon the similarities in ascus structures and conidia. Two new combinations are made: Cetraria crespoae (Barreno & Vázquez) Kärnef. and C. steppae (Sav.) Kärnef. Two new genera, Arctocetraria Kärnef & Thell and Cetrariella Kärnef. & Thell are described, each of which differs in ascus structure from Cetraria. The new combinations Arctocetraria andrejevii (Oxn.) Kärnef. & Thell, A. nigricascens (Nyl. in Kihim.) Kärnef. & Thell, Cetrariella delisei (Schaer.) Kärnef. & Thell, and C. fastigiata (Nyl.) Kärnef. & Thell are made. Two additional species, earlier presumed to belong to Cetraria in the rather strict sense, are transferred to Tuckermannopsis Gyeln., mainly because of similarities in the ascus structure; the new combinations Tuckermannopsis inermis (Nyl.) Kärnef. and T. subalpina (Imsh.) Kärnef. are made to reflect this change. The presumed evolutionary affinities of all of these taxa are discussed.
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| 32. |
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| 33. |
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| 34. |
- Lättman, Håkan, et al.
(author)
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At what age becomes Cliostomum corrugatum adult?
- 2006
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Conference paper (other academic/artistic)abstract
- The objective was to investigate at what the age specimen of Cliostomum corrugatum become fertile in order to estimate the time span between the meiosis events. The species has its main distribution in Europe but has also been found on the west coast of British Columbia and is red listed, e.g., in Sweden (nearly threatened), Denmark, Germany and England. In the province of Östergötland, southern Sweden it is most frequent on old Quercus robur trees in open oak forest or meadows. I may also be found on other deciduous trees as Ulmus and Fraxinus species. It is mainly groving on the flat terminal parts of the rough bark of the tree trunks and not on the sides of the cracks. Cliostomum corrugatum does not grow on young oak trees. The smallest tree trunk diameter with Cliostomum corrugatum was is 0.65 m, a tree of at least 100 years of age. On two localities in Östergötland all oaks were studied and the size of the trees and the size of the largest thallus of Cliostomum corrugatum were recorded. Out of this data the size of how small a tree can possibly be for hosting Cliostomum corrugatum. This estimate was compared with the size of the smallest thalli with apothecia and the size of trees on which these appeared. With knowledge of the peripheral secondary growth of oaks it was possible to estimate the age of the youngest fertile Cliostomum corrugatum to about 30 years. Thus, equal to the time span between two meiosis events.
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| 35. |
- Lättman, Håkan, et al.
(author)
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Changes in the distributions of epiphytic lichens in southern Sweden using a new statistical method
- 2009
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In: Nordic Journal of Botany. - : Wiley. - 0107-055X .- 1756-1051. ; 27:5, s. 413-418
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Journal article (peer-reviewed)abstract
- Past studies on changes in species distribution have mainly been based on analysis of range boundaries. In contrast, the method used here evaluates shifts in species geographic centroids within a predefined area. We used presence/absence data on epiphytic lichens collected 1986 and 2003 from 64 sites in southern Sweden. A centroid was calculated each year, for each lichen species and substrate. The distance of centroid movement was evaluated in a permutation procedure. In total, 56 lichen species on 22 tree species were involved in the analyses, yielding 30 cases that had sufficient sample sizes both years to be evaluated. Out of these, three exhibited a significant movement of their centroid. The shift of lichen centroids of Hypogymnia physodes (L.) Nyl. and Vulpicida pinastri (Scop.) J.-E. Mattsson andamp; M. J. Lai on the tree species Juniperus communis L. was 50 and 151 km with the direction 27 degrees and 48 degrees, respectively. For Hypogymnia physodes on Pinus sylvestris L., corresponding values were 41 km and 30 degrees. The northnortheast shifts of these species in Sweden could be a response to a warming climate.
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| 36. |
- Lättman, Håkan, et al.
(author)
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Estimating the dispersal capacity of the rare lichen Cliostomum corrugatum
- 2009
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In: Biological Conservation. - : Elsevier BV. - 0006-3207 .- 1873-2917. ; 142:8, s. 1870-1878
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Research review (peer-reviewed)abstract
- The objective of this study was to estimate the dispersal rate in an organism assumed to be confined totree stands with unbroken continuity. We used the lichen-forming ascomycete Cliostomum corrugatum,which is largely confined to old oak stands. Five populations, with pairwise distances ranging from 6.5to 83 km, were sampled in Östergötland, south-eastern Sweden. DNA sequence data from an intron inthe small subunit nuclear ribosomal RNA gene was obtained from 85 samples. Nearly all molecular variance(99.6%) was found within populations and there were no signs of isolation-by-distance. The absolutenumber of immigrants per population per generation (estimated to 30 years), inferred by BayesianMCMC, was found to be between 1 and 5. Altogether, evidence suggests abundant gene flow in the historyof our sample. A simulation procedure demonstrated that we cannot know whether effective dispersal isongoing or if it ceased at the time when oaks started to decrease dramatically around 400 years BP. However,a scenario where effective dispersal ceased already at the time when the postglacial reinvasion ofoak had reached the region around 6000 years BP is unlikely. Vegetation history suggests that the habitatof C. corrugatum was patchily distributed in the landscape since the early Holocene. Combined with thehigh dispersal rate estimate, this suggests that the species has been successful at frequently crossing distancesof at least several kilometres and possibly that it has primarily been limited by the availability ofhabitat rather than by dispersal.
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| 37. |
- Lättman, Håkan, et al.
(author)
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Generation time estimated to be 25-30 years in Cliostomum cossugatum (Ach.) Fr.
- 2009
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In: The Lichenologist. - : Britich Lichen Society. - 0024-2829 .- 1096-1135. ; 41:5, s. 557-559
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Journal article (other academic/artistic)abstract
- Knowledge of spore to spore generation time is extremely important for several reasons. As it is the shortest generation time, it indicates the maximum nucleotide substitution rate over time and provides a rate limit for the evolution of a species. In population genetics most calculations involving time use ‘generations’ as the unit of measurement and in order to convert these ‘generations’ into ‘years’, knowledge of generation time is needed but rarely available. Knowledge of generation time may also be essential for conservation purposes and assessments of migration history. This knowledge also makes it possible to estimate both the age of a population and also to determine to what extent a population represents the genetic diversity of a species (Rosenberg & Nordborg 2002). In this paper we present a method for assessing generation length for lichens using Cliostomum corrugatum (Ach.) Fr. as an example. This lichen was selected for investigation because it is restricted to forests with long temporal continuity (Lättman et al. 2009) and information on generation time is essential to estimate the rate of dispersal at the landscape level.
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| 38. |
- Lättman, Håkan, et al.
(author)
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Genetic variation in the SSU intron and the dispersal and migration history in Sweden of Cliostomum corrugatum
- 2006
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Conference paper (other academic/artistic)abstract
- The aim with this study is to determine genetic variation, dispersal potential and the migration history to Sweden since the last glaciation of the rare lichen Cliostomum corrugatum, a crustose epiphytic lichen with a grey greenish thallus,conspicuous light yellow to light brown apothecia and black pycnidia. Collections were made in January and February in 2005 at five sites in Östergötland, Sweden. The most frequent common habitat for Cliostomum corrugatumis on Quercus and sometimes also on other deciduous trees for example Ulmus and Fraxinus. On the tree trunk it is the rough bark it prefers and the flat terminal parts of the bark structure and not on the sides of the cracks. The main distribution of Cliostomum corrugatum is in Europe but a satellite population has been found on the west coast of North American in British Columbia. It is red listed in Sweden, with the status near threatened. Three sequences SSUintron, IGS and ITS were studied and the two latter appear to lack genetic variation. A total of 85 sequences with a length of 614 base pairs were studied of a rRNA SSU intron. Eleven haplotypes were detected, two was common 46 and 30 in numbers respectively and was present on all five localities the other nine were detected only once each. The two common haplotypes are in the centre of a rooted net work and the rare in the periphery. Cliostomum corrugatum does not seem to have problem with its dispersal. The limiting factor seems to be the occurrence big oaks. In the studied area the smallest tree trunk diameter that Cliostomum corrugatum was found on is 0,65 metre. The tree with the largest diameter in the research area is 1,65 metre. A tree that is 0,65 metre in diameter is at least 100 years old. Oaks of this age are scarce and this is one of the reasons for the rareness of Cliostomum corrugatum. When Cliostomum corrugatum colonized Sweden after the last ice age, all eleven haplotypes may already have existed. However, it is possible, that some haplotypes evolved after the migration to Östergötland.
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| 39. |
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| 40. |
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| 41. |
- Lättman, Håkan, 1958-, et al.
(author)
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Regional gradients in occurrence and size of the epiphytic lichen : Hypogymnia physodes (L.) Nyl. in southern Sweden
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Other publication (other academic/artistic)abstract
- Background: Despite their omnipresence throughout the world, the demography of lichens is poorly documented and understood. Contributing to this lack of understanding are the small propagules involved, the difficulty of separating individuals and asexual reproduction strategies. Aim: In the present study we searched for possible regional gradients in thallus size distribution and abundance of the common epiphytic lichen Hypogymnia physodes. We expected the species to display large-scale spatial gradients as it had been previously shown to decrease in presence in the southernmost part of Sweden. More specifically the aim was to examine whether the gradients in occurrence and diameter of thallus correspond. Methods: The lichen was sampled on 66 sites in southern Sweden. Initial analyses were done by rotating the reference system of investigated sites around the origin to search for the angle that would result in the largest explanatory power of models fitted to data. Two models were used: one based on presence/absence data and the other on the diameter of the thalli. Results: Presence/absence data showed an increased occurrence of H. physodes with the strongest directional gradient at 15° (north-north-east) and an increase of thallus diameter with the strongest directional gradient at 304° (west-north-west). Conclusions: As the gradients identified in thallus size and occurrence were almost perpendicular, it seems that the processes governing growth and establishment/death do not co vary.
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| 42. |
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| 43. |
- Lättman, Håkan, 1958-
(author)
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Studies on spatial and temporal distributions of epiphytic lichens
- 2012
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Doctoral thesis (other academic/artistic)abstract
- Lichens are an important group of organisms in terms of environmental issues, conservation biology and biodiversity, principally due to their sensitivity to changes in their environment. Therefore it is important that we develop our understanding of the factors that affect lichen distribution. In this thesis, both spatial and temporal distributions of epiphytic lichens at different scales have been studied in southern Sweden.Generation time of the red-listed lichen Cliostomum corrugatum was examined using Bjärka-Säby as the study site. The results showed that the average age of an individual of C. corrugatum is 25–30 years at the onset of spore production.The rarity of C. corrugatum was also examined. DNA analysis of an intron from 85 samples, collected at five sites in Östergötland, yielded 11 haplotypes. Results from coalescent analysis, mantel test and AMOVA indicated that C. corrugatum have a high ability to disperse. The study concluded that its rarity is most likely connected with the low amount of available habitat, old Quercus robur.The changes in the distribution of epiphytic lichens in southern Sweden, between 1986 and 2003, were also compared. For each year a centroid was calculated on all combinations of tree and lichen species. The three significant cases showed that the centroid movement pointed toward a north-east or north-north-east direction.Finally differences in species richness and cover of lichens on large Q. robur were examined between urban and rural environment. The results demonstrated that species number and percent cover was significantly higher on oaks standing rural compared to oaks standing urban. Effects of urban sprawl showed a decline in species richness and cover with increasing age of the surrounding buildings.
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| 44. |
- Lönn, Mikael, et al.
(author)
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Results and Comparison of Different Complementary Assessment Methods of Science Learning Outcome
- 2015
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In: Conference proceedings. New perspectives in science education, 4<sup>th</sup> ed.. - : Libreriauniversitaria.it. - 9788862926003 ; , s. -5
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Conference paper (peer-reviewed)abstract
- To assess the quality of different aspects of the learning outcomes in relation to knowledge requirements as results of teaching several assessment methods have to be used. For most teachers it is also obvious that students differ in their ability to demonstrate the learning outcome depending on the assessment method used. In order to compare different assessment methods of the learning outcome of pre-school teacher students’ different types of tasks were evaluated and compared in order to identify the potential of each method to give the students fair chances of showing their skills. Thus, assessments based on multiple choice questionnaires of different types, long answer questions, practical laboratory experiments, experiment construction and the students ability to evaluate experiment plans were compared. Having Swedish as mother tongue also was included as an explanatory variable since we suspected that some of the assessment methods in reality rather evaluates the linguistic skills in interpreting texts rather than evaluating the content knowledge of the subject. The results for each student when different methods were used were compared in order to evaluate if some of the methods for assessment gave similar results or if the methods induced differences in the results for the same student. We use ordination techniques to assess and visualize main trends in the data and linear models and classification trees to evaluate specific associations. There is correlation between results from several assessment methods, there are positive correlation between combinations of results from long answers, experiment and experiment construction, meaning students who showed good results with one method did so also with the others - but in some comparisons like long answer questions and multiple choice questions good results were independent of each other. There was a negative effect of having a non-Swedish mother tongue on the results in multiple choice questionnaires, but a positive effect of a non-Swedish mother tongue on the combined scores on experimental construction and experiment. Linear models show that good achievements in experimental construction are explained by high summed scores of Doll´s criteria, the four R’s richness, recursion, relations, and rigor.
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| 45. |
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| 48. |
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| 49. |
- Mattsson, Jan-Eric, 1949-, et al.
(author)
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Aim: To practise scientific methods. Result: Personal development
- 2014
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In: Ebook proceedings of the ESERA 2013 Conference. - Nicosia, Cypern : European Science Education Research Association. - 9789963700776 ; , s. 2410-2417
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Conference paper (peer-reviewed)abstract
- Field work in a teacher training program was focussed on the collection and presentation of data showing changes in the environment depending on variable factors. The observations should be possible to use as models for studies performed by children at school. The instructions were sparse and many of the observations from the first visit to the sites were impossible to repeat. The first four observations were made during autumn every month while the last was made in late spring sixteen months later. After this the students wrote short reflections on their impressions and experiences during the last visit compared to the earlier ones. These were analysed in order to reveal the impact on the students. Most of the students were very uncertain about what to do the first time. Almost none of them complained about this afterwards. Many were astonished over their own incapability of understanding or declared their lack of understanding general ideas. Many students wrote about strong emotions when returning to a familiar site that appeared to have changed and described how this created a strong attachment to the site. What was more surprising was that some students experienced their own development, in some cases towards becoming a teacher but also on a more private or personal level. They not only recognized themselves as the inexperienced student from the first visit and what was achieved later. They also realized how the relation between themselves and the site had a chronological development in accordance with their own development. The simple activity of field observations in combination with personal reflection created complicated processes beneficial for the student.Thus, we achieved and observed unexpected results together with what was expected.
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| 50. |
- Mattsson, Jan-Eric, 1949-, et al.
(author)
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Art studies as tools for understanding observations in science
- 2017
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In: Conference proceedings New perspectives in science education. - Limena : Libreriauniversitaria.it. - 9788862928472 ; , s. 513-516
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Conference paper (peer-reviewed)abstract
- Observations are fundamental in science as they has to include cognitive activities based on the perceived sensations. These activities have to be transformed to written or spoken language. In order to practice and visualize these processes we present a method based on Roland Barthes concepts studium and punctum. About 60 students aiming at becoming primary school teachers (years 4–6) were followed during a period of the first two years of their education. The results on all course examinations during these years (n=17) were compared to the quality of two reflective texts. One from the end of the first year on the impression of art works by David Hockney or Bill Viola, another of experiences from field sites used at the beginning of their studies. They wrote reflections on their experiences including observations and their personal and professional development during their teacher training. The texts where analysed by using the 4 R’s of Doll’s. Results of VARK tests assessing the learning style of the students from the beginning of their education were used. The choice of science courses can be shown to be correlated to different factors depending of the selection of these but there was no general pattern behind the choice of science. Training of observation in different contexts and reflections on these in relation to personal development seem to promote better professional understanding.
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