61 research outputs found
Geography and history education in Estonia: processes, policies and practices in an ethnically divided society from the late 1980s to the early 2000s
This article studies processes, policies and practices for geography and
history education in Estonia. The analysis covers the societal
transformation period in an ethnically divided society from the 1980s to
the early 2000s characterized by Estonia’s disintegration from the
Soviet Union towards the integration to the European Union and NATO.
Geography and history education curricula, textbooks and related
policies and practices promoted a particular national time-space by
supporting the belongingness of Estonia into Europe, rejecting
connections towards Russia and suggesting a division between ethnic
Estonians and ethnically non-Estonian residents of Estonia. In geography
and history textbooks, the Russian-speaking population, comprising then
almost a third of the entire population of Estonia, was divided into
non-loyal, semi-loyal and loyal groups of whom only the latter could be
integrated in the Estonian time-space. The formal education policies for
geography and history supported Estonia’s disintegration from the
Soviet past and pawed way to integration to the western political and
economic structures. However, challenging market and sensitive cultural
contexts created peculiar, alternative and sometimes opposing local
practices in geography and history education.</p
Ribosome engineering reveals the importance of 5S rRNA autonomy for ribosome assembly
5S rRNA is an indispensable component of cytoplasmic ribosomes in all species. The functions of 5S rRNA and the reasons for its evolutionary preservation as an independent molecule remain unclear. Here we used ribosome engineering to investigate whether 5S rRNA autonomy is critical for ribosome function and cell survival. By linking circularly permutated 5S rRNA with 23S rRNA we generated a bacterial strain devoid of free 5S rRNA. Viability of the engineered cells demonstrates that autonomous 5S rRNA is dispensable for cell growth under standard conditions and is unlikely to have essential functions outside the ribosome. The fully assembled ribosomes carrying 23S-5S rRNA are highly active in translation. However, the engineered cells accumulate aberrant 50S subunits unable to form stable 70S ribosomes. Cryo-EM analysis revealed a malformed peptidyl transferase center in the misassembled 50S subunits. Our results argue that the autonomy of 5S rRNA is preserved due to its role in ribosome biogenesis
The role of calcium ions in toxic cell injury.
Calcium ions have been increasingly implicated as a mediator of the mechanisms generating lethal cell injury under a variety of pathologic circumstances. An overview of the various roles suggested for such alterations in cellular calcium homeostasis is presented. The central role of plasma membrane damage in the genesis of irreversible cell injury is used to divide the postulated roles for calcium ions into two major mechanisms. On the one hand, calcium ions have been proposed as mediators of the functional consequences of plasma membrane injury. An influx of extracellular calcium ions across a damaged permeability barrier and down a steep concentration gradient may convert potentially reversible injury into irreversible injury. On the other hand, alterations in intracellular calcium homeostasis are postulated to participate in the mechanisms generating potentially lethal plasma membrane injury. The release of calcium stores sequestered within intracellular organelles raises the cytosolic concentration of free calcium, a process that may activate, in turn, a number of membrane-disruptive processes. The data supporting these two distinct actions of calcium are reviewed and discussed
A global threats overview for Numeniini populations: synthesising expert knowledge for a group of declining migratory birds
The Numeniini is a tribe of thirteen wader species (Scolopacidae, Charadriiformes) of which seven are near-threatened or globally threatened, including two critically endangered. To help inform conservation management and policy responses, we present the results of an expert assessment of the threats that members of this taxonomic group face across migratory flyways. Most threats are increasing in intensity, particularly in non-breeding areas, where habitat loss resulting from residential and commercial development, aquaculture, mining, transport, disturbance, problematic invasive species, pollution and climate change were regarded as having the greatest detrimental impact. Fewer threats (mining, disturbance, problematic native species and climate change) were identified as widely affecting breeding areas. Numeniini populations face the greatest number of non-breeding threats in the East Asian-Australasian Flyway, especially those associated with coastal reclamation; related threats were also identified across the Central and Atlantic Americas, and East Atlantic flyways. Threats on the breeding grounds were greatest in Central and Atlantic Americas, East Atlantic and West Asian flyways. Three priority actions were associated with monitoring and research: to monitor breeding population trends (which for species breeding in remote areas may best be achieved through surveys at key non-breeding sites), to deploy tracking technologies to identify migratory connectivity, and to monitor land-cover change across breeding and non-breeding areas. Two priority actions were focused on conservation and policy responses: to identify and effectively protect key non-breeding sites across all flyways (particularly in the East Asian - Australasian Flyway), and to implement successful conservation interventions at a sufficient scale across human-dominated landscapes for species’ recovery to be achieved. If implemented urgently, these measures in combination have the potential to alter the current population declines of many Numeniini species and provide a template for the conservation of other groups of threatened species
Status of Biodiversity in the Baltic Sea
The brackish Baltic Sea hosts species of various origins and environmental tolerances. These immigrated to the sea 10,000 to 15,000 years ago or have been introduced to the area over the relatively recent history of the system. The Baltic Sea has only one known endemic species. While information on some abiotic parameters extends back as long as five centuries and first quantitative snapshot data on biota (on exploited fish populations) originate generally from the same time, international coordination of research began in the early twentieth century. Continuous, annual Baltic Sea-wide long-term datasets on several organism groups (plankton, benthos, fish) are generally available since the mid-1950s. Based on a variety of available data sources (published papers, reports, grey literature, unpublished data), the Baltic Sea, incl. Kattegat, hosts altogether at least 6,065 species, including at least 1,700 phytoplankton, 442 phytobenthos, at least 1,199 zooplankton, at least 569 meiozoobenthos, 1,476 macrozoobenthos, at least 380 vertebrate parasites, about 200 fish, 3 seal, and 83 bird species. In general, but not in all organism groups, high sub-regional total species richness is associated with elevated salinity. Although in comparison with fully marine areas the Baltic Sea supports fewer species, several facets of the system's diversity remain underexplored to this day, such as micro-organisms, foraminiferans, meiobenthos and parasites. In the future, climate change and its interactions with multiple anthropogenic forcings are likely to have major impacts on the Baltic biodiversity
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Variations in accelerometry measured physical activity and sedentary time across Europe – harmonized analyses of 47,497 children and adolescents
Funder: Ministero delle Politiche Agricole Alimentari e Forestali; doi: http://dx.doi.org/10.13039/501100005401Funder: ZonMw; doi: http://dx.doi.org/10.13039/501100001826Funder: The Research Council of Norway, Division for Society and Health.Abstract: Background: Levels of physical activity and variation in physical activity and sedentary time by place and person in European children and adolescents are largely unknown. The objective of the study was to assess the variations in objectively measured physical activity and sedentary time in children and adolescents across Europe. Methods: Six databases were systematically searched to identify pan-European and national data sets on physical activity and sedentary time assessed by the same accelerometer in children (2 to 9.9 years) and adolescents (≥10 to 18 years). We harmonized individual-level data by reprocessing hip-worn raw accelerometer data files from 30 different studies conducted between 1997 and 2014, representing 47,497 individuals (2–18 years) from 18 different European countries. Results: Overall, a maximum of 29% (95% CI: 25, 33) of children and 29% (95% CI: 25, 32) of adolescents were categorized as sufficiently physically active. We observed substantial country- and region-specific differences in physical activity and sedentary time, with lower physical activity levels and prevalence estimates in Southern European countries. Boys were more active and less sedentary in all age-categories. The onset of age-related lowering or leveling-off of physical activity and increase in sedentary time seems to become apparent at around 6 to 7 years of age. Conclusions: Two third of European children and adolescents are not sufficiently active. Our findings suggest substantial gender-, country- and region-specific differences in physical activity. These results should encourage policymakers, governments, and local and national stakeholders to take action to facilitate an increase in the physical activity levels of young people across Europe
Variations in accelerometry measured physical activity and sedentary time across Europe - harmonized analyses of 47,497 children and adolescents
Background: Levels of physical activity and variation in physical activity and sedentary time by place and person in
European children and adolescents are largely unknown. The objective of the study was to assess the variations in
objectively measured physical activity and sedentary time in children and adolescents across Europe.
Methods: Six databases were systematically searched to identify pan-European and national data sets on physical
activity and sedentary time assessed by the same accelerometer in children (2 to 9.9 years) and adolescents (≥10 to
18 years). We harmonized individual-level data by reprocessing hip-worn raw accelerometer data files from 30
different studies conducted between 1997 and 2014, representing 47,497 individuals (2–18 years) from 18 different
European countries.
Results: Overall, a maximum of 29% (95% CI: 25, 33) of children and 29% (95% CI: 25, 32) of adolescents were
categorized as sufficiently physically active. We observed substantial country- and region-specific differences in
physical activity and sedentary time, with lower physical activity levels and prevalence estimates in Southern
European countries. Boys were more active and less sedentary in all age-categories. The onset of age-related
lowering or leveling-off of physical activity and increase in sedentary time seems to become apparent at around 6
to 7 years of age. Conclusions: Two third of European children and adolescents are not sufficiently active. Our findings suggest
substantial gender-, country- and region-specific differences in physical activity. These results should encourage
policymakers, governments, and local and national stakeholders to take action to facilitate an increase in the
physical activity levels of young people across Europe.peer-reviewe
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