26 research outputs found

    Morphology of the transverse ligament of the atlas and the alar ligaments in the silver fox (Vulpes vulpes var)

    Get PDF
    Background Recent new anatomical and histological features of craniocervical junction in dogs and cats were described providing evidence of differences between the carnivore species. No information on these structures in foxes exists. Results Two parts of the alar ligaments were found. A longer one aroused from dens of axis to the internal (medial) surface of the occipital condyles and was called apical part. A shorter part originated from the entire length of the lateral edge of the dens of axis and terminated on the internal wall of the vertebral foramen of atlas and thus was called the lateral part. The transverse ligament of the atlas was widened in the mid region, above the dens of axis, and thickened at enthesis. Periosteal fibrocartilage was detected in the transverse ligament of the atlas at the enthesis, and sesamoid fibrocartilage was present on periphery in the middle of the ligament. Conclusions The craniocervical junction in foxes differs in part from other carnivores such as dogs and cats but resembles that of mesaticephalic dogs. The sesamoid and periosteal fibrocartilage supports the transverse ligament of the atlas whereas the alar ligaments have no cartilage

    Infraspecific Variation of Huperzine A and B in Icelandic Huperzia selago Complex

    Get PDF
    Publisher's version (útgefin grein)The alkaloids huperzine A and huperzine B were originally isolated from the Chinese club moss Huperzia serrata. They are known inhibitors of acetylcholinesterase, and especially huperzine A shows pharmaceutical potential for the treatment of Alzheimerʼs disease. Its supply heavily relies on natural plant sources belonging to the genus Huperzia, which shows considerable interspecific huperzine A variations. Furthermore, taxonomic controversy remains in this genus, particularly in the Huperzia selago group. With focus on Icelandic H. selago taxa, we aimed to explore the relatedness of Huperzia species using multi-locus phylogenetic analysis, and to investigate correlations between huperzine A contents, morphotypes, and genotypes. Phylogenetic analysis was performed with five chloroplastic loci (the intergenic spacer between the photosystem II protein D1 gene and the tRNA-His gene, maturase K, ribulose-1,5-bisphosphate carboxylase/oxygenase large subunit, tRNA-Leu, and the intergenic spacer region between tRNA-Leu and tRNA-Phe). Huperzine A and huperzine B contents were determined using an HPLC-UV method. The phylogenetic analysis suggests that previously proposed Huperzia appressa and Huperzia arctica should not be considered species, but rather subspecies of H. selago. Three genotypes of Icelandic H. selago were identified and presented in a haplotype networking diagram. A significantly (p < 0.05) higher amount of huperzine A was found in H. selago genotype 3 (264 – 679 µg/g) than genotype 1 (20 – 180 µg/g), where the former shows a typical green and reflexed “selago” morphotype. The huperzine A content in genotype 3 is comparable to Chinese H. serrata and a good alternative huperzine A source. Genotype 2 contains multiple morphotypes with a broad huperzine A content (113 – 599 µg/g). The content of huperzine B in Icelandic taxa (6 – 13 µg/g) is much lower than that in Chinese H. serrata (79 – 207 µg/g).The People Programme (Marie Curie Actions) of the European Unionʼs Seventh Framework Programme FP7/2007–2013 (grant number 606895) and the Icelandic Research Fund (grant number 152604051) are acknowledged for financial support. This study was also funded from the Bergthora and Thorsteinn Scheving Thorsteinsson Fund.Peer Reviewe

    Non-native vascular flora of the Arctic : Taxonomic richness, distribution and pathways

    Get PDF
    We present a comprehensive list of non-native vascular plants known from the Arctic, explore their geographic distribution, analyze the extent of naturalization and invasion among 23 subregions of the Arctic, and examine pathways of introductions. The presence of 341 non-native taxa in the Arctic was confirmed, of which 188 are naturalized in at least one of the 23 regions. A small number of taxa (11) are considered invasive; these plants are known from just three regions. In several Arctic regions there are no naturalized non-native taxa recorded and the majority of Arctic regions have a low number of naturalized taxa. Analyses of the non-native vascular plant flora identified two main biogeographic clusters within the Arctic: American and Asiatic. Among all pathways, seed contamination and transport by vehicles have contributed the most to non-native plant introduction in the Arctic.Peer reviewe

    Invasion of a Legume Ecosystem Engineer in a Cold Biome Alters Plant Biodiversity

    Get PDF
    Plant ecosystem engineers are widely used to combat land degradation. However, the ability of those plants to modulate limiting abiotic and biotic resources of other species can cause damage to ecosystems in which they become invasive. Here, we use Lupinus nootkatensis as example to estimate and project the hazardous potential of nitrogen fixing herbaceous plants in a sub-polar oceanic climate. L. nootkatensis was introduced to Iceland in the 1940s to address erosion problems and foster reforestation, but subsequently became a high-latitude invader. In a local field survey, we quantified the impact of L. nootkatensis invasion at three different cover levels (0, 10–50, and 51–100%) upon native plant diversity, richness, and community composition of heath-, wood-, and grasslands using a pairwise comparison design and comparisons of means. Afterward, we scaled impacts up to the ecosystem and landscape level by relating occurrences of L. nootkatensis to environmental and human-mediated variables across Iceland using a species distribution model. Plant diversity was significantly deteriorated under high lupine cover levels of the heath- and woodland, but not in the grassland. Plant species richness of the most diverse habitat, the heathland, linearly decreased with lupine cover level. The abundance of small rosettes, cushion plants, orchids, and small woody long-lived plants of the heath declined with invader presence, while the abundance of late successional species and widespread nitrophilous ruderals in wood- and grasslands increased. Distribution modeling revealed 13.3% of Iceland’s land surface area to be suitable lupine habitat. Until 2061–2080, this area will more than double and expand significantly into the Central Highlands due to human mediation and increasingly favorable climatic conditions. Species-rich habitats showed a loss of plant species diversity and richness as well as a change in community composition even in low lupine cover classes. The future increase of suitable lupine habitat might lead to the displacement of cold-adapted native plant species and will certainly challenge conservation as well as restoration of ecosystems in the cold climate of Iceland, but also elsewhere. Lupine invasion speeds up succession, which may be additive with climate change effects, and accelerates ecological change in cold biomes

    Nordic LifeWatch cooperation, final report: A joint initiative from Denmark, Iceland, Finland, Norway and Sweden

    Get PDF
    The main goal of the present report is to outline the possibilities for an enhanced cooperation between the Nordic countries within eScience and biodiversity. LifeWatch is one of several ESFRI projects which aim to establish eInfrastructures and databases in the field of biodiversity and ecosystem research. Similarities between Nordic countries are extensive in relation to a number of biodiversity related issues. Most species in Nordic countries are common, and frequently the same challenges concerning biodiversity and ecosystem services are addressed in the different countries. The present report has been developed by establishing a Nordic LifeWatch network with delegates from each of the Nordic countries. The report has been written jointly by the delegates, and the work was organized by establishing working groups with the following themes: strategic issues, technical development, legal framework and communication. Written during two workshops, Skype meetings and emailing, the following main issues are discussed in the present report: * Scientific needs for improved access to biodiversity data and advanced eScience research infrastructure in the Nordic countries. * Future challenges and priorities facing the international biodiversity research community. * Scientific potential of openly accessible biodiversity and environmental data for individual researchers and institutions. * Spin-off effects of open access for the general public. * Internationally standardized Nordic metadata inventory. * Legal framework and challenges associated with environmental-, climate-, and biodiversity data sharing, communication, training and scientific needs. * Finally, some strategic steps towards realizing a Nordic LifeWatch construction and operational phase are discussed. Easy access to open data on biodiversity and the environment is crucial for many researchers and research institutions, as well as environmental administration. Easy access to data from different fields of science creates an environment for new scientific ideas to emerge. This potential of generating new, interdisciplinary approaches to pre-existing problems is one of the key features of open-access data platforms that unify diverse data sources. Interdisciplinary elements, access to data over larger gradients, compatible eSystems and eTools to handle large amounts of data are extremely important and, if further developed, represent significant steps towards analysis of biological effects of climate change, human impact and development of operational ecosystem service assessment techniques. It is concluded that significant benefits regarding both scientific potential, technical developments and financial investments can be obtained by constructing a common Nordic LifeWatch eInfrastructure. Several steps concerning organizing and funding of a future Nordic LifeWatch are discussed, and an action plan towards 2020 is suggested. To analyze the potential for future Nordic LifeWatch in detail, our main conclusion is to arrange a Nordic LifeWatch conference as soon as possible. This conference should involve Nordic research councils, scientists and relevant stakeholders. The national delegates from the participating countries in the Nordic LifeWatch project are prepared to present details from the report and developments so far as a basis for further development of Nordic LifeWatch. The present work is financed by NordForsk and in-kind contributions from participating institutions

    Non-native species in the vascular flora of highlands and mountains of Iceland

    No full text
    The highlands and mountains of Iceland are one of the largest remaining wilderness areas in Europe. This study aimed to provide comprehensive and up-to-date data on non-native plant species in these areas and to answer the following questions: (1) How many non-native vascular plant species inhabit highland and mountainous environments in Iceland? (2) Do temporal trends in the immigration of alien species to Iceland differ between highland and lowland areas? (3) Does the incidence of alien species in the disturbed and undisturbed areas within Icelandic highlands differ? (4) Does the spread of non-native species in Iceland proceed from lowlands to highlands? and (5) Can we detect hot-spots in the distribution of non-native taxa within the highlands? Overall, 16 non-native vascular plant species were detected, including 11 casuals and 5 naturalized taxa (1 invasive). Results showed that temporal trends in alien species immigration to highland and lowland areas are similar, but it is clear that the process of colonization of highland areas is still in its initial phase. Non-native plants tended to occur close to man-made infrastructure and buildings including huts, shelters, roads etc. Analysis of spatio-temporal patterns showed that the spread within highland areas is a second step in non-native plant colonization in Iceland. Several statically significant hot spots of alien plant occurrences were identified using the Getis-Ord Gi* statistic and these were linked to human disturbance. This research suggests that human-mediated dispersal is the main driving force increasing the risk of invasion in Iceland’s highlands and mountain areas

    Identifying and ascribing the relative significance of introduction pathways for non-native plants into Iceland

    No full text
    The study is aimed at identifying pathways frequently used by non-native plant species, assessing their relative significance and development in time. Pathways were defined following NOBANIS framework (Madsen et al., 2014). Species assessments were based on HARMONIA scheme (Branquart, 2007). Four categories of environmental hazards were assessed plus two additional categories summarizing impacts on health and economy. Temporal development of pathways was assessed using cumulative per annum taxa records. To quantify the activity of investigated pathways over time an index (δ10) showing the number of new species introduced during the period of 10 years was calculated. The study shows that horticulture, landscaping and agriculture can be pointed out as pathways of concern in Iceland. A set of species of concern is also proposed. Two plant taxa are included in A list (high risk species): Anthriscus sylvestis and Lupinus nootkatensis. Three taxa are placed in B list (watch list): Heracleum mantegazzianum, Heracleum persicum and Pinus contorta. Results of the present study are compared with similar studies carried out in Denmark, Scandinavia and Baltic countries. Different measures to prevent introductions of new and potentially dangerous non-native species are also discussed including selection of good practices that may significantly reduce the threat from non-native species used in agriculture and horticulture

    Anopheles analysis

    No full text
    <p>The is a demonstration of how you can upload workflows</p
    corecore