Search results for "geeni"
showing 10 items of 247 documents
Optogenetic Control of Bacterial Expression by Red Light
2022
In optogenetics, as in nature, sensory photoreceptors serve to control cellular processes by light. Bacteriophytochrome (BphP) photoreceptors sense red and far-red light via a biliverdin chromophore and, in response, cycle between the spectroscopically, structurally, and functionally distinct Pr and Pfr states. BphPs commonly belong to two-component systems that control the phosphorylation of cognate response regulators and downstream gene expression through histidine kinase modules. We recently demonstrated that the paradigm BphP from Deinococcus radiodurans exclusively acts as a phosphatase but that its photosensory module can control the histidine kinase activity of homologous receptors.…
Grouping facilitates avoidance of parasites by fish
2013
Background. Parasite distribution is often highly heterogeneous, and intensity of infection depends, among other things, on how well hosts can avoid areas with a high concentration of parasites. We studied the role of fish behaviour in avoiding microhabitats with a high infection risk using Oncorhynchus mykiss and cercariae of Diplostomum pseudospathaceum as a model. Spatial distribution of parasites in experimental tanks was highly heterogeneous. We hypothesized that fish in groups are better at recognizing a parasitized area and avoiding it than solitary fish. Methods. Number of fish, either solitary or in groups of 5, was recorded in different compartments of a shuttle tank where fish co…
Heterogeneity of traditional and digital media use among older adults : A six-country comparison
2021
The concept of aged heterogeneity has been associated with older adults' ability to adapt to the digital age without a systematic empirical analysis. We analyse retired adults' (aged 62 or more) use of traditional media and their digital equivalents in six countries. First, we ask whether heterogeneity in traditional and digital media use increases with age. Second, we study to what extent gender is related to this heterogeneity, and third, the country differences in the heterogeneity of media use in later life. We analyse the 2018 data (N = 5865) of the ‘Older audiences in the digital media environment’ survey using zero-inflated negative binomial models. The results provide partial suppor…
Plasma cell-free DNA in diagnostic KRAS mutation testing
2015
Epidermaalisen kasvutekijän reseptorin (EGFR) monoklonaalisia vasta-aineita (mAb) käytetään apuna metastaattisen kolorektaalisyövän (mCRC) hoidossa. Aktivoivat mutaatiot KRAS- ja NRAS-onkogeeneissä tekevät syöpäsolut vastustuskykyisiksi anti-EGFR-vasta-aineille, ja tästä syystä tuumorit tulee genotyypittää ennen hoidon aloittamista. Kudosbiopsian ottaminen on kuitenkin invasiivinen toimenpide, eikä näyte välttämättä edusta kattavasti syövän kaikkien solupopulaatioiden geneettisiä muutoksia. Verenkierron solunulkoisen DNA:n (cfDNA) on havaittu sisältävän maligneista soluista lähtöisin olevia onkogeenisiä mutaatioita, ja se voi olla hyvä vaihtoehtoinen tuumoriperäisen DNA:n lähde. Kehitimme j…
Repeated exposure of fluazinam fungicides affects gene expression profiles yet carries no costs on a nontarget pest
2021
Fungicides are used to control pathogenic fungi of crop species, but they have also been shown to alter behavioral, life history and fitness related traits of non-target insects. Here, we tested the fungicide effects on feeding behavior, survival and physiology of the non-target pest insect, the Colorado potato beetle (Leptinotarsa decemlineata). Feeding behavior was studied by a choice test of adult beetles, which were allowed to choose between a control and a fungicide (fluazinam) treated potato leaf. Larval survival was recorded after 24-hour and 72-hour exposure to control and fungicide-treated leaves with two different concentrations. The adults did not show fungicide avoidance behavio…
Carbon’s Three-Center-Four-Electron Tetrel Bond, Treated Experimentally
2018
Tetrel bonding is the noncovalent interaction of group IV elements with electron donors. It is a weak, directional interaction that resembles hydrogen and halogen bonding yet remains barely explored. Herein, we present an experimental investigation of the carbon-centered, three-center, four-electron tetrel bond, [N−C− N]+ , formed by capturing a carbenium ion with a bidentate Lewis base. NMRspectroscopic, titration-calorimetric, and reaction-kinetic evidence for the existence and structure of this species is reported. The studied interaction is by far the strongest tetrel bond reported so far and is discussed in comparison with the analogous halogen bond. The necessity of the involvement of…
Photosensitive Alternative Splicing of the Circadian Clock Gene timeless Is Population Specific in a Cold-Adapted Fly, Drosophila montana.
2018
To function properly, organisms must adjust their physiology, behavior and metabolism in response to a suite of varying environmental conditions. One of the central regulators of these changes is organisms' internal circadian clock, and recent evidence has suggested that the clock genes are also important in the regulation of seasonal adjustments. In particular, thermosensitive splicing of the core clock gene <i>timeless</i> in a cosmopolitan fly, <i>Drosophila melanogaster</i> , has implicated this gene to be involved in thermal adaptation. To further investigate this link we examined the splicing of <i>timeless</i> in a northern malt fly species, <i&…
Sex-specific responses to cold in a very cold-tolerant, northern Drosophila species
2021
Funding: This work was supported by Academy of Finland projects 268214 and 322980 to MK and a NERC (UK) grant NE/P000592/1 to MGR. Organisms can plastically alter resource allocation in response to changing environmental factors. For example, in harsh conditions, organisms are expected to shift investment from reproduction toward survival; however, the factors and mechanisms that govern the magnitude of such shifts are relatively poorly studied. Here we compared the impact of cold on males and females of the highly cold-tolerant species Drosophila montana at the phenotypic and transcriptomic levels. Although both sexes showed similar changes in cold tolerance and gene expression in response…
Excretion and measurement of corticosterone and testosterone metabolites in bank voles (Myodes glareolus)
2017
The bank vole is a commonly used model species in behavioral and ecophysiological studies. Thus, presenting a validated method for noninvasive monitoring of corticosterone and testosterone secretion is of high relevance. Here, we evaluated the effect of time of day and an ACTH challenge test on measured fecal corticosterone (FCM) and testosterone (FTM) metabolites in both sexes. Furthermore, we performed radiometabolism experiments for both steroids and sexes to study metabolism and excretion of 3H-corticosterone and 3H-testosterone. FCM and FTM were analysed with a 5α-pregnane-3β,11β,21-triol-20-one enzyme immunoassay (EIA) and a testosterone (measuring 17β-hydroxyandrostanes) EIA, respect…
Polygenic Risk Scores and Physical Activity
2020
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