Determination of oxygen tension in the subcutaneous tissue of cosmonauts during the Salyut-6 mission

A polarographic technique was used to measure the oxygen tension in subcutaneous tissue of the forearm of a cosmonaut prior to, after, and on the fourth day of a space mission performed by Salut-6. A drop in the oxygen exchange rate in the peripheral tissues during weightlessness was observed. The mechanisms of this change are studied, taking into consideration the blood distribution in the organism and microcirculation disorders reflected by a decreased blood flow rate in arterial-venous junctions

Enacting Productive Dialogue: Addressing the Challenge that Non-Human Cognition Poses to Collaborations Between Enactivism and Heideggerian Phenomenology

This chapter uses one particular proposal for interdisciplinary collaboration – in this case, between early Heideggerian phenomenology and enactivist cognitive science – as an example of how such partnerships may confront and negotiate tensions between the perspectives they bring together. The discussion begins by summarising some of the intersections that render Heideggerian and enactivist thought promising interlocutors for each other. It then moves on to explore how Heideggerian enactivism could respond to the challenge of reconciling the significant differences in the ways that each discourse seeks to apply the structures it claims to uncover

Investigation of cooling properties of the gaseous medium of a space station

An investigation of cooling properties of the gaseous medium was performed in the biosatellite Kosmos-936 as well as in the orbital complexes Soyuz-28/Salyut-6 and Soyuz-30/Salyut-6 with the aid of an especially constructed electric dynamic catathermometer. In this instrument current was measured which was necessary to keep a steady settled temperature of the sensing device. The investigation was performed because of the disturbed heat exhange of the human body caused by lack of natural convection in weightlessness. The instrument also enabled objective estimation of the temperature of the cosmonaut's ody in six optionally selected regions. The results obtained by means of the catathermometer will also enable defining the appropriate hygienic conditions of the gaseous medium of space stations

Multiscale Drivers of Water Chemistry of Boreal Lakes and Streams

The variability in surface water chemistry within and between aquatic ecosystems is regulated by many factors operating at several spatial and temporal scales. The importance of geographic, regional-, and local-scale factors as drivers of the natural variability of three water chemistry variables representing buffering capacity and the importance of weathering (acid neutralizing capacity, ANC), nutrient concentration (total phosphorus, TP), and importance of allochthonous inputs (total organic carbon, TOC) were studied in boreal streams and lakes using a method of variance decomposition. Partial redundancy analysis (pRDA) of ANC, TP, and TOC and 38 environmental variables in 361 lakes and 390 streams showed the importance of the interaction between geographic position and regional-scale variables. Geographic position and regional-scale factors combined explained 15.3% (streams) and 10.6% (lakes) of the variation in ANC, TP, and TOC. The unique variance explained by geographic, regional, and local-scale variables alone was <10%. The largest amount of variance was explained by the pure effect of regional-scale variables (9.9% for streams and 7.8% for lakes), followed by local-scale variables (2.9% and 5.8%) and geographic position (1.8% and 3.7%). The combined effect of geographic position, regional-, and local-scale variables accounted for between 30.3% (lakes) and 39.9% (streams) of the variance in surface water chemistry. These findings lend support to the conjecture that lakes and streams are intimately linked to their catchments and have important implications regarding conservation and restoration (management) endeavors

Effective monitoring of freshwater fish

Freshwater ecosystems constitute only a small fraction of the planet’s water resources, yet support much of its diversity, with freshwater fish accounting for more species than birds, mammals, amphibians, or reptiles. Fresh waters are, however, particularly vulnerable to anthropogenic impacts, including habitat loss, climate and land use change, nutrient enrichment, and biological invasions. This environmental degradation, combined with unprecedented rates of biodiversity change, highlights the importance of robust and replicable programmes to monitor freshwater fish assemblages. Such monitoring programmes can have diverse aims, including confirming the presence of a single species (e.g. early detection of alien species), tracking changes in the abundance of threatened species, or documenting long-term temporal changes in entire communities. Irrespective of their motivation, monitoring programmes are only fit for purpose if they have clearly articulated aims and collect data that can meet those aims. This review, therefore, highlights the importance of identifying the key aims in monitoring programmes, and outlines the different methods of sampling freshwater fish that can be used to meet these aims. We emphasise that investigators must address issues around sampling design, statistical power, species’ detectability, taxonomy, and ethics in their monitoring programmes. Additionally, programmes must ensure that high-quality monitoring data are properly curated and deposited in repositories that will endure. Through fostering improved practice in freshwater fish monitoring, this review aims to help programmes improve understanding of the processes that shape the Earth's freshwater ecosystems, and help protect these systems in face of rapid environmental change

Drivers and stressors of freshwater biodiversity patterns across different ecosystems and scales : a review

The present review with focus on the last decade (2000-2010) aims to (i) collecting the major hypotheses explaining freshwater biodiversity patterns, (ii) identifying the main stressors affecting freshwater biodiversity, and (iii) revealing information gaps regarding ecosystem types, organism groups, spatial and temporal scales to highlight research needs to better propose sound conservation measures. The comparative analysis addresses six organism groups ranging from microorganisms to fish in basins, rivers, lakes, wetlands, ponds and groundwater. Short-term studies at ecoregion and catchment scale focusing on invertebrates, macrophytes and fish in Palaearctic and Nearctic regions dominated. The most frequent hypotheses tested were the landscape filter concept, the species-area relationship, the metacommunity concept. Dominating natural drivers were area, heterogeneity and disturbance. Land use, eutrophication and habitat destruction were identified as most important stressors. Generally, freshwater biodiversity declined in response to these stressors in contrast to increasing biodiversity determined by natural drivers across all ecosystems. Preferred organism groups were fish and invertebrates, most frequently studied in rivers, in contrast to smaller organisms (e.g. bacteria) and, e.g. groundwater being underrepresented. Hypotheses originating from the last century are still tested in freshwater research, while novel concepts are either missing or untested. Protection of freshwater biodiversity is the ultimate challenge since it supports valuable ecosystems services ensuring perpetuation of mankind. For that, comprehensive large-scale studies with holistic approaches are urgently needed

Local habitat is a strong determinant of spatial and temporal patterns of macrophyte diversity and composition in boreal lakes

Macrophyte species and trait assemblages from 104 minimally disturbed boreal forest lakes, covering broad environmental and geographic gradients were analysed to identify associations with environmental variables at different spatial scales: geographic context (GEO) and catchment (CATCH) and lake (LOCAL) characteristics.Constrained ordination and variation partitioning were used to quantify variation in species (canonical correspondence analysis [CCA] and pCCA) and trait (redundancy analysis [RDA] and pRDA) compositions that could be explained by environmental variables, and to rank the main environmental factors associated with spatial and temporal patterns.Diversity and assemblage composition correlated with spatial context and variables related to the length of the growing season, catchment forest type and with lake characteristics such as ecosystem size, lake productivity and alkalinity.Variation partitioning showed that lake characteristics alone explained 53% (species) and 73.5% (traits) of the variability in macrophyte assemblages. Contrary to predictions, the shared variance component between latitude and catchment forest type (GEO&CATCH 0.05, paired t-test). Ordination showed that among-year variability in macrophyte assemblage composition was also negligible (0.3%) compared to the variability explained by GEO, CATCH and LOCAL variables. Combined, these findings indicate low species turnover in the boreal lakes of our study.Responses of macrophyte species and trait assemblages and the TMI index were predictable and significantly correlated with lake characteristics associated with nutrient enrichment (Chl a, nutrients) and alkalinity supporting their use in monitoring eutrophication of boreal lakes