Search results for "laji"
showing 10 items of 410 documents
Risk factors for Lyme disease : A scale-dependent effect of host species diversity and a consistent negative effect of host phylogenetic diversity
2021
Biodiversity can influence disease risk. One example of a diversity-disease relationship is the dilution effect, which suggests higher host species diversity (often indexed by species richness) reduces disease risk. While numerous studies support the dilution effect, its generality remains controversial. Most studies of diversity-disease relationships have overlooked the potential importance of phylogenetic diversity. Furthermore, most studies have tested diversity-disease relationships at one spatial scale, even though such relationships are likely scale dependent. Using Lyme disease as a model system, we investigated the effects of host species richness and phylogenetic relatedness on the…
Adaptation and ecological speciation in seasonally varying environments at high latitudes: Drosophila virilis group
2022
Living in high latitudes and altitudes sets specific requirements on species’ ability to forecast seasonal changes and to respond to them in an appropriate way. Adaptation into diverse environmental conditions can also lead to ecological speciation through habitat isolation or by inducing changes in traits that influence assortative mating. In this review, we explain how the unique time-measuring systems of Drosophila virilis group species have enabled the species to occupy high latitudes and how the traits involved in species reproduction and survival exhibit strong linkage with latitudinally varying photoperiodic and climatic conditions. We also describe variation in reproductive barriers…
Sequencing, De Novo Assembly and Annotation of the Colorado Potato Beetle, Leptinotarsa decemlineata, Transcriptome
2012
Background. The Colorado potato beetle (Leptinotarsa decemlineata) is a major pest and a serious threat to potato cultivation throughout the northern hemisphere. Despite its high importance for invasion biology, phenology and pest management, little is known about L. decemlineata from a genomic perspective. We subjected European L. decemlineata adult and larval transcriptome samples to 454-FLX massively-parallel DNA sequencing to characterize a basal set of genes from this species. We created a combined assembly of the adult and larval datasets including the publicly available midgut larval Roche 454 reads and provided basic annotation. We were particularly interested in diapause-specific g…
Differences in parasite community composition support ecological differentiation in a freshwater gadoid fish
2022
Several northern freshwater fishes have gone through rapid adaptive radiation after the last glacial period, resulting in new species or intraspecific morphs with distinct life histories. Parasite infections can promote adaptive radiations and spatiotemporal differences in patterns of infections can potentially reveal incipient or ongoing speciation processes. We investigated intraspecific differentiation in a freshwater gadoid fish, burbot (Lota lota), by exploring differences in parasite infections between two potential life-history morphs in Lake Konnevesi, Central-Finland, one reproducing species characteristically in shallow littoral waters in February and the other possibly in deep pr…
Titmice are a better indicator of bird density in Northern European than in Western European forests
2022
Publisher Copyright: © 2022 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd. Population sizes of many birds are declining alarmingly and methods for estimating fluctuations in species’ abundances at a large spatial scale are needed. The possibility to derive indicators from the tendency of specific species to co-occur with others has been overlooked. Here, we tested whether the abundance of resident titmice can act as a general ecological indicator of forest bird density in European forests. Titmice species are easily identifiable and have a wide distribution, which makes them potentially useful ecological indicators. Migratory birds often use information on the densit…
Contrasting responses of vascular plants and bryophytes to present and past connectivity in unmanaged grasslands
2022
AbstractThe area of semi-natural grasslands has decreased dramatically causing many grassland specialist species to persist in small habitat fragments. Furthermore, ecological communities once shaped by disturbances related to traditional agriculture now face the impacts of modern agriculture and urbanization. Many of the species have become endangered due to the combined effects of habitat destruction and degradation. We studied the responses of vascular plants and bryophytes to present and past connectivity in semi-natural grasslands, while accounting for the effects of local environmental conditions. We conducted vegetation surveys in 33 fragmented, unmanaged dry grasslands in Southwest …
Kognitīvās funkcijas normatīvi veseliem bērniem, bērniem ar CSWS sindromu un citiem epilepsijas traucējumiem
2021
Šajā darbā ir apskatītas kognitīvās funkcijas, kurās ietilpst atmiņa, uzmanība, uztvere, vadības funkcijas un valoda, kā arī plašāk apskatīta epilepsija, tās ārstēšana, CSWS sindroms (epilepsija ar nepārtrauktiem smailajiem viļņiem miega laikā), kā arī epilepsijas saistība ar kognitīvajām funkcijām un UDHS (uzmanības deficīta un hiperaktivitātes sindroms). Šī pētījuma mērķis un uzdevums ir izprast un izzināt, vai bērniem ar CSWS sindromu un citiem epilepsijas traucējumiem vizuālās uzmanības, vizuālās un verbālās darba atmiņas, uztveres, vadības un motoro funkciju līmeņi tiek prognozēti zemāki, vai būs izteiktākas uzvedības problēmas, īpaši agresivitāte un hiperaktivitāte, kā arī, vai būs iz…
Automatic image-based identification and biomass estimation of invertebrates
2020
1. Understanding how biological communities respond to environmental changes is a key challenge in ecology and ecosystem management. The apparent decline of insect populations necessitates more biomonitoring but the time-consuming sorting and expert-based identification of taxa pose strong limitations on how many insect samples can be processed. In turn, this affects the scale of efforts to map and monitor invertebrate diversity altogether. Given recent advances in computer vision, we propose to enhance the standard human expert-based identification approach involving manual sorting and identification with an automatic image-based technology. 2. We describe a robot-enabled image-based ident…
"Todella hyvä uutinen!" : Facebookin uutisten saateteksti tekstilajina
2017
Tässä tutkielmassa tarkastelen Facebookissa jaettujen uutisten saatetekstejä. Aihe on ajankohtainen ja tärkeä, sillä uutisia seurataan yhä useammin sosiaalisen median palvelujen kautta. Sosiaalisessa mediassa uutisen otsikon, uutiskuvan ja ingressin lisäksi lukijaa lähestytään uutiseen liitettävän saatetekstin kautta. Saatetekstillä onkin paljon merkitystä siinä, päätyykö lukija avaamaan uutista. Saateteksti myös antaa lukijalle tietyn näkökulman aiheesta ja ohjaa täten lukijan ajattelua sekä uutisen ympärille kehittyvää keskustelua. Tarkoituksenani oli selvittää tutkielmassani, millaisen tekstilajin Facebookin uutisten saatetekstit muodostavat. Tutkielman lähtökohtana onkin tekstilajianaly…
Parasites in sympatric populations of native and invasive freshwater bivalves
2021
An increasing threat to local, native freshwater mussels (Unionida)—an ecologically important but globally alarmingly declining group— is the invasion by exotic bivalves. The Enemy Release Hypothesis predicts that introduced species should benefit from enemy-mediated competition because they are less likely to be harmed by natural enemies, such as parasites, than their native competitors. We investigated within-site differences in parasitism between sympatric native (tot. five spp.) and invasive (tot. three spp.) bivalves in eight northern European waterbodies, which harboured totally 15 parasite taxa. In paired comparisons using within-site averages, the mean number of parasite species in …