Friluftsliv explored: An environmental and outdoor teaching approach for knowledge, emotions and quality of life

Friluftsliv explored doesn’t only include nature knowledge, techniques in the outdoors and outdoor pedagogics but also covers ecology, human ecology, geography, environmental and societal questions, history, health, biology, craft and lots of practical activities -both for urban and rural friluftsliv. In this translation to English of the revised fifth edition of the Swedish book there are many activities and the text is suitable for the modern day. Friluftsliv embraces the feeling around the campfire, paddling along winding rivers and walking towards the distant blue mountains. But, it is also to whittle a stick, to remember your waterproofs and to find your way home. Knowledge emerges when you combine imagination with facts and the glint in your eyes, using all our outdoor environments: forests, water, the coast, mountains and the nature close at hand. Emotion is to swim in crystal clear water far out in the archipelago and to see the clouds gliding across the sky. But also, to be able to present other sides of yourself, to be fascinated by your own body, the struggling ant and the sight of frost on trees. Quality of life is to experience friluftsliv – as it happens!

Bridge Abutment Protection against Scouring for Unsteady Flow Conditions

The bridge abutment is one of the main parts of a bridge and significantly contributes to bridge stability. This study experimentally investigated the effect of the unsteadiness characteristics of hydrographs on the scouring phenomenon around the bridge abutment under clear water conditions. The ability of the permeable and impermeable spur dikes and their distances from the abutment at its upstream on the control of scouring around the bridge abutment was also investigated. The experimental observations imply that the effect of unsteady flow on the scouring process is relatively similar to the steady flow conditions. The results showed that the base time of hydrographs, the type of spur dikes, and the distance of spur dikes from the bridge abutment were the dominant parameters among the considered parameters in this study on the scouring process around the abutment. The results also revealed that the impermeable spur dike was able to completely eliminate scouring around the bridge abutment for two distances of 2L and 3L (where L is the abutment length) for both steady and unsteady flow conditions.

The front runner in roll waves produced by local disturbances

Roll waves produced by a local disturbance comprise a group of shock waves with steep fronts. We used a robust and accurate numerical scheme to capture the steep fronts in a shallow-water hydraulic model of the waves. Our simulations of the waves in clear water revealed the existence of a front runner with an exceedingly large amplitude – much greater than those of all other shock waves in the wave group. The trailing waves at the back remained periodic. Waves were produced continuously within the group due to nonlinear instability. The celerity depended on the wave amplitude. Over time, the instability produced an increasing number of shock waves in an ever-expanding wave group. We conducted simulations for three types of local disturbances of very different duration over a range of amplitudes. We interpreted the simulation results for the front runner and the trailing waves, guided by an analytical solution and the laboratory data available for the smaller waves in the trailing end of the wave group.

Mapping of Malaria Receptivity Areas in Buton Regency, Southeast Sulawesi Province

Malaria is an acute and chronic infectious disease caused by Plasmodium infection that attacks erythrocytes and is characterized by the discovery of asexual forms in the blood with symptoms of fever, chills, anemia and enlarged spleen. Buton Regency is a district with an Annual Parasite Incidence (API) that is less than 1 per 1000 population for 4 consecutive years and is a low endemic area. This study aims to determine the level of receptivity of malaria transmission areas in Buton Regency, Southeast Sulawesi Province. This type of research is descriptive observational with a cross sectional study approach. The results showed that there were 3 species of Anopheles identified in adult mosquitoes, namely An.Minimus, An.Indifinitus and An.Kochi. Habitat Index (HI) of Anopheles vector, sp > 1, breeding places for Anopheles vector wallows, rivers, ditches, ponds, rivers, swamps and rice fields with the characteristics of the presence of temporary and clear water, moss and mud, with a pH of 6 on a scale 6-6.5 and zero salinity. Vector confirmation by PCR is negative for all species. It was concluded that the level of malaria receptivity in Buton Regency, especially in the Village of Face Jaya, was at a moderate receptivity level.

Lake browning impacts community structure and essential fatty acid content of littoral invertebrates in boreal lakes

Many lakes in the northern hemisphere are browning due to increasing concentrations of terrestrial dissolved organic carbon (DOC). The consequences of lake browning to littoral invertebrates, however, are not fully understood. We analyzed community structure and fatty acid (FA) profiles of littoral invertebrates in humic (DOC-rich) and clear-water lakes in Eastern Finland. We found higher abundance of chironomids (Diptera: Chironomidae) in humic compared to clear-water lakes, whereas stoneflies (Plecoptera) and mayflies (Ephemeroptera: Baetidae) were more abundant in clear-water lakes. Taxon explained 65% of the differences in the FA composition of littoral invertebrates. However, the proportion and content of polyunsaturated FAs of several taxa were significantly higher in clear-water lakes compared to humic lakes. Our results reveal differences in both community structure and nutritional quality of littoral invertebrates for fish between humic and clear-water lakes.

Fulvic acid isolation and characterisation from water of a Ramsar Lake Mansar, J&K, India

The present study was undertaken with the aim to understand the chemical properties of aquatic fulvic acid in a clear water Lake Mansar. Along with that, the physical and chemical environment of the lake was also analysed. Fulvic acid was isolated from the water of Lake Mansar following IHSS recommended methodology and was subjected to characterisation, viz. elemental analysis, H-NMR and FTIR spectroscopy. The yield of fulvic acid from water of Lake Mansar was 0.22 mg/L that was far less than coloured aquatic systems. Elemental analysis revealed per cent carbon, hydrogen, nitrogen and oxygen content to be 53.6%, 5.04%, 6.3% and 35.06%, respectively. H-NMR and FTIR spectra revealed the presence of various functional groups like aliphatic, hydroxyl, amide, quinones, ketones, carbonyl, cellulose, etc. Based on the present studies, it was concluded that the origin of humic material in Lake Mansar is mostly from algae and non-vascular plants that have undergone less degree of humification.