42 research outputs found

    Effects of cold acclimation and dsRNA injections on Gs1l gene splicing in Drosophila montana

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    Alternative splicing, in which one gene produce multiple transcripts, may influence how adaptive genes respond to specific environments. A newly produced transcriptome of Drosophila montana shows the Gs1-like (Gs1l) gene to express multiple splice variants and to be down regulated in cold acclimated flies with increased cold tolerance. Gs1l's effect on cold tolerance was further tested by injecting cold acclimated and non-acclimated flies from two distantly located northern and southern fly populations with double stranded RNA (dsRNA) targeting Gs1l. While both populations had similar cold acclimation responses, dsRNA injections only effected the northern population. The nature of splicing expression was then investigated in the northern population by confirming which Gs1l variants are present, by comparing the expression of different gene regions and by predicting the protein structures of splices using homology modelling. We find different splices of Gs1l not only appear to have independent impacts on cold acclimation but also elicit different effects in populations originating from two very different environments. Also, at the protein level, Gs1l appears homologous to the human HDHD1A protein and some splices might produce functionally different proteins though this needs to be verified in future studies by measuring the particular protein levels. Taken together, Gs1l appears to be an interesting new candidate to test how splicing influences adaptations

    Standards of conduct and reporting in evidence syntheses that could inform environmental policy and management decisions

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    Accurate, unbiased and concise synthesis of available evidence following clear methodology and transparent report‑ ing is necessary to support effective environmental policy and management decisions. Without this, less reliable and/ or less objective reviews of evidence could inform decision making, leading to ineffective, resource wasteful inter‑ ventions with potential for unintended consequences. We evaluated the reliability of over 1000 evidence syntheses (reviews and overviews) published between 2018 and 2020 that provide evidence on the impacts of human activities or effectiveness of interventions relevant to environmental management. The syntheses are drawn from the Col‑ laboration for Environmental Evidence Database of Evidence Reviews (CEEDER), an online, freely available evidence service for evidence users that assesses the reliability of evidence syntheses using a series of published criteria. We found that the majority of syntheses have problems with transparency, replicability and potential for bias. Overall, our results suggest that most recently published evidence syntheses are of low reliability to inform decision making. Reviews that followed guidance and reporting standards for evidence synthesis had improved assessment ratings, but there remains substantial variation in the standard of reviews amongst even these. Furthermore, the term ‘system‑ atic review’, which implies conformity with a methodological standard, was frequently misused. A major objective of the CEEDER project is to improve the reliability of the global body of environmental evidence reviews. To this end we outline freely available online resources to help improve review conduct and reporting. We call on authors, editors and peer reviewers to use these resources to ensure more reliable syntheses in the future

    Aalto-1, multi-payload CubeSat: design, integration and launch

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    The design, integration, testing, and launch of the first Finnish satellite Aalto-1 is briefly presented in this paper. Aalto-1, a three-unit CubeSat, launched into Sun-synchronous polar orbit at an altitude of approximately 500 km, is operational since June 2017. It carries three experimental payloads: Aalto Spectral Imager (AaSI), Radiation Monitor (RADMON), and Electrostatic Plasma Brake (EPB). AaSI is a hyperspectral imager in visible and near-infrared (NIR) wavelength bands, RADMON is an energetic particle detector and EPB is a de-orbiting technology demonstration payload. The platform was designed to accommodate multiple payloads while ensuring sufficient data, power, radio, mechanical and electrical interfaces. The design strategy of platform and payload subsystems consists of in-house development and commercial subsystems. The CubeSat Assembly, Integration & Test (AIT) followed Flatsat -- Engineering-Qualification Model (EQM) -- Flight Model (FM) model philosophy for qualification and acceptance.The paper briefly describes the design approach of platform and payload subsystems, their integration and test campaigns, and spacecraft launch. The paper also describes the ground segment & services that were developed by the Aalto-1 team.</p

    FORESAIL-1 cubesat mission to measure radiation belt losses and demonstrate de-orbiting

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    Abstract Today, the near-Earth space is facing a paradigm change as the number of new spacecraft is literally sky-rocketing. Increasing numbers of small satellites threaten the sustainable use of space, as without removal, space debris will eventually make certain critical orbits unusable. A central factor affecting small spacecraft health and leading to debris is the radiation environment, which is unpredictable due to an incomplete understanding of the near-Earth radiation environment itself and its variability driven by the solar wind and outer magnetosphere. This paper presents the FORESAIL-1 nanosatellite mission, having two scientific and one technological objectives. The first scientific objective is to measure the energy and flux of energetic particle loss to the atmosphere with a representative energy and pitch angle resolution over a wide range of magnetic local times. To pave the way to novel model - in situ data comparisons, we also show preliminary results on precipitating electron fluxes obtained with the new global hybrid-Vlasov simulation Vlasiator. The second scientific objective of the FORESAIL-1 mission is to measure energetic neutral atoms (ENAs) of solar origin. The solar ENA flux has the potential to contribute importantly to the knowledge of solar eruption energy budget estimations. The technological objective is to demonstrate a satellite de-orbiting technology, and for the first time, make an orbit manoeuvre with a propellantless nanosatellite. FORESAIL-1 will demonstrate the potential for nanosatellites to make important scientific contributions as well as promote the sustainable utilisation of space by using a cost-efficient de-orbiting technology.Peer reviewe

    Sex-specific responses to cold in a very cold-tolerant, northern Drosophila species.

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    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 to cold treatment, indicating that the majority of changes are concordant between the sexes, we identified a clear reduction in sexually dimorphic gene expression, suggesting that preparing for the colder season involves reducing investment in sex-specific traits. This reduction was larger in males than females, as expected if male sexual traits are more condition-dependent than female traits, as predicted by theory. Gene expression changes were primarily associated with shifts in metabolic profile, which likely play a role in increasing cold tolerance. Finally, we found that the expression of immune genes was reduced following cold treatment, suggesting that reduced investment in costly immune function may be important in helping flies survive colder periods

    Biotransformation of Dimethylarsinic Acid in Mouse, Hamster and Man

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    THE METABOLISM OF DIMETHYLARSINIC ACID (DMA) A COMMON PESTICIDE AND THE MAIN METABOLITE OF INORGANIC ARSENIC IN MAMMALS, HAS BEEN STUDIED IN MICE, HAMSTERS AND MAN. MICE AND HAMSTERS WERE ADMINISTERED A SINGLE DOSE OF 74AS-DMA (40 MG AS/KG BODY WEIGHT) ORALLY, WHILE A HUMAN SUBJECT INGESTED DMA CORRESPONDING TO 0.1 MG AS/KG BODY WEIGHT. ION EXCHANGE CHROMATOGRAPHY, PAPER ELECTROPHORESIS, THIN LAYER CHROMA- TOGRAPHY AS WELL AS ARSINE GENERATION - GAS CHROMATOGRAPHY COMBINED WITH ATOMIC ABSORPTION SPECTROPHOTOMETRY OR MASS SPECTROMETRY WERE USED TO CHARACTERIZE THE ARSENIC METABOLITES IN URINE AND FECES COLLECTED OVER 48 HOURS AFTER TREATMENT. IN MICE AND HAMSTERS 3.5% AND 6.4% OF THE DOSE, RESPECTIVELY, WERE EXCRETED IN URINE IN THE FORM OF TRIMETHYLARSINE OXIDE (TMAO). NO TMAO WAS FOUND IN FECES. A DMA-COMPLEX WAS DETECTED IN URINE AND FECES. IT AMOUNTED TO ABOUT 13% OF THE DOSE IN MICE AND 15% IN HAMSTERS. ABOUT 80-85% OF THE DOSE WAS ELIMINATED IN URINE AND FECES IN THE FORM OF UNMETABOLIZED DMA. NO DEMETHYLATION OF DMA TO INORGANIC ARSENIC WAS OBSERVED. IN MAN, ABOUT 4% OF THE DOSE WAS EXCRETED IN AS TMAO AND ABOUT 80% AS DMA. KEY WORDS DIMETHYLARSINIC ACID, BIOTRANSFORMATION, MOUSE, HAMSTER, MAN, URINE, TRIMETHYLARSINE OXIDE.NA-NOT AVAILABL
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