Relativistic electron fluxes and dose rate variations observed on the international space station

The paper presents observations of relativistic electron precipitations (REP) on the International Space Station (ISS) obtained by three Bulgarian-built instruments flown in 2001 and 2008–2010. The first data are from the Liulin-E094 instrument flown in May–August 2001 inside the US laboratory module of the ISS. Next the time profiles of the REP-generated daily fluences and the absorbed doses at the orbit of ISS during the period February 2008–August 2010 are analyzed in dependence of the daily Ap index and compared with the daily relativistic electron fluence with energies of more than 2 MeV measured by the GOES. The REP in April 2010 being the second largest in GOES history (with a >2 MeV electron fluence event) is specially studied

Factors affecting the global distribution of Hydrilla verticillata

Hydrilla verticillata (Hydrocharitaceae) is a submerged freshwater flowering plant within the monotypic genus. Over the geological periods, fossils of this family and genus have shown distinct diversifications between warm and cool fluctuations with more adaptations occurring in warmer periods and suppressions during severely cold paleoclimate changes. Recently, H. verticillata has shown a wide range of adaptive plasticity, allowing successful proliferation into non-native regions, whilst also undergoing unexplained disappearance from its native localities, and this phenomenon has stimulated this inquiry. Against this somewhat complex background, particular interest for this investigation has been focussed on an understanding of which aspects of climate change have contributed towards global adaptations and distribution patterns of H. verticillata. Whilst it is recognised that some of these changes are natural, other aggravating impacts are due to anthropogenic influences. Identifying the appropriate combinations of these climatic factors (temperature, rainfall, photoperiod), in concert with environmental (water level, CO2, salinity, eutrophication), geographical (altitude, latitude) and other factors (UV-B) are necessary precursors for instituting appropriate management strategies. In this respect, control measures are needed in non-native regions and restoration of this plant in native habitats are essential for its ecologically balanced global distribution. © 2021 European Weed Research Societ