0000000000206993
AUTHOR
Tommi Nyman
Evolutionary transitions in broad tapeworms (Cestoda: Diphyllobothriidea) revealed by mitogenome and nuclear ribosomal operon phylogenetics
Abstract Broad tapeworms (Diphyllobothriidea) are parasites whose adults are capable of infecting a wide range of freshwater, marine and terrestrial tetrapods including humans. Previous works examining the evolution of habitat and host use in this group have been hampered by the lack of a well-resolved phylogeny. In order to produce a robust phylogenetic framework for diphyllobothriideans, we sequenced the complete mitochondrial genome of 13 representatives, carefully chosen to cover the major clades, and two outgroup species representing the Spathebothriidea and Haplobothriidea. In addition, complementary data from the nuclear ribosomal operon was sequenced for 10 representative taxa. Mito…
Search for an excess of events with an identical flavour lepton pair and significant missing transverse momentum in root s=7 TeV proton-proton collisions with the ATLAS detector
Results are presented of a search for supersymmetric particles decaying into final states with significant missing transverse momentum and exactly two identical flavour leptons (e or mu) of opposite charge in sqrt{s}=7 TeV collisions at the Large Hadron Collider. This channel is particularly sensitive to supersymmetric particle cascade decays producing flavour correlated lepton pairs. Flavour uncorrelated backgrounds are subtracted using a sample of opposite flavour lepton pair events. Observation of an excess beyond Standard Model expectations following this subtraction procedure would offer one of the best routes to measuring the masses of supersymmetric particles. In a data sample corres…
Imprints of latitude, host taxon, and decay stage on fungus-associated arthropod communities
Interactions among fungi and insects involve hundreds of thousands of species. While insect communities on plants have formed some of the classic model systems in ecology, fungus-based communities and the forces structuring them remain poorly studied by comparison. We characterize the arthropod communities associated with fruiting bodies of eight mycorrhizal basidiomycete fungus species from three different orders along a 1200-km latitudinal gradient in northern Europe. We hypothesized that, matching the pattern seen for most insect taxa on plants, we would observe a general decrease in fungal-associated species with latitude. Against this backdrop, we expected local communities to be struc…
DNA barcoding reveals different cestode helminth species in northern European marine and freshwater ringed seals
Three subspecies of the ringed seal (Pusa hispida) are found in northeastern Europe: P. h. botnica in the Baltic Sea, P. h saimensis in Lake Saimaa in Finland, and P. h. ladogensis in Lake Ladoga in Russia. We investigated the poorly-known cestode helminth communities of these closely related but ecologically divergent subspecies using COI barcode data. Our results show that, while cestodes from the Baltic Sea represent Schistocephalus solidus, all worms from the two lakes are identified as Ligula intestinalis, a species that has previously not been reported from seals. The observed shift in cestode communities appears to be driven by differential availability of intermediate fish host spec…
Biologian kenttäopetus yliopistoissa: yhteistyöllä uuteen nousuun
Kenttäkurssit ovat keskeinen osa biologian ja lähitieteiden opetusta yliopistoissa. Luonnossa tapahtuva opetus kehittää sekä ymmärrystä tieteenalan teoreettisista perusteista että ammatillisia käytännön taitoja. Kenttäkursseilla omat havainnot muodostuvat oppimisen perustaksi muiden oppimistapojen rinnalla. Vaikka kenttäopetuksen tarpeellisuudesta ollaan yksimielisiä, kenttäkursseja uhkaavat yliopistojen rahoituksen väheneminen ja tutkimusasemaverkoston karsiminen. Tässä kirjoituksessa pohdimme, kuinka uhkista huolimatta kenttäopetuksen määrää, laatua ja kustannustehokkuutta voidaan lisätä yliopistojen ja niiden tutkimusasemien välisellä yhteistyöllä. nonPeerReviewed