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Vendace populations on the life table: between-lake variation and the association between early life and mature survival and growth
Get PDFThe vital rates related to reproduction and survival dictate the resistance and persistence of a population under perturbations. Freshwater fishes perform high levels of phenotypic plasticity thus these rates may differ widely between populations and temporally within a population. Knowledge of their ranges enables understanding the scope of population persistence and predicting the effects of environmental stressors. Time series of vendace (Coregonus albula) catch samples from 22 lakes were applied to estimate the lake-specific average length-at-age and survival in mature age groups (mS). Assuming an age-at-maturity of 2 yr and a constant length–fecundity relationship, survival from spawning to age 1 (firstS) and 2 (premS, prematurity survival) were estimated using a life table assuming a stable state. The average length at age 2 yr (L2) varied two-fold between populations, 200 mm, and the estimated fecundity approximately eight-fold. Also, mS varied considerably, 0.2% per 2 yr, being highest in populations with low L2 and fecundity combined with low mS. The range of firstS estimate was even higher, 0.01–2%. This high between-lake variability seems to occur especially after hatching during the first summer. Its level is set by the factors external to the population, e.g., the abundance of key predators. Persistence with low early life survival is possible because of the wide scope of compensation in the size- and fecundity-at-age and mS. Early life survival is expected to decrease due to climate change while the compensation has its limits, increasing the risk of local extinctions.202
Optimization of ultrasound assisted extraction of the Sea buckthorn leaves, characterization of the phenolic compounds, and determination of bioactive properties of the extracts
Get PDFea buckthorn leaves are known to be rich in antioxidants and phenolic compounds. However, non-proper processing methods can result in a decrease of the beneficial properties. To address this, response surface methodology (RSM) was used in the modelling and optimizing of the ultrasound assisted extraction of the sea buckthorn leaves to obtain high yields of total phenolics content in the extract. The alike obtained extracts were subjected under investigations of bioactivities such as the antioxidant activities (FRAP and ORAC), antibacterial properties against Staphylococcus aureus and Escherichia coli and anti-inflammatory characteristics. The results indicated that the extracts obtained under the optimal process conditions of 30 min, continuous pulse, and solid to liquid ratio of 0.2 showed antioxidant activity, and antibacterial activity against both Gram+ and Gram– bacteria at a moderate level. The extracts are rich in polyphenolic compounds, such as ellagic acid and flavonoids. The in vitro anti-inflammatory tests with THP-1 promonocyte model indicated that the sea buckthorn leaf extract obtained by ultrasound assisted extraction has powerful anti-inflammatory properties. These results prove that the ultrasound assisted extraction of sea buckthorn leaves provides a good source of phenolic compounds that have versatile bioactive properties and can generally be regarded as health promoting food compounds.202
Divergent apparent temperature sensitivity of forest-floor respiration across a managed boreal forest landscape
No full text202
Valuable biochemicals of the future : The outlook for bio-based value-added chemicals and their growing markets
Get PDFBio-based value-added chemicals are chemical compounds derived from biomass that can be used for a wide range of industrial applications. They account for about 7% of the EU bio-based industrial market. Bio-based industry refers to production from biomass, excluding the food and beverage industry. This report describes the different groups of chemical compounds from forest, agricultural and aquatic biomass and their applications in different product groups. The report focuses on biochemicals that can be extracted from biomass by different extraction methods and highlights studies on their suitability for different applications. The aim is to outline a future vision for the use of biochemicals by 2050.
Global megatrends such as climate change, geopolitical tensions, security of supply, loss of biodiversity, population growth will influence the potential for biomass production at regional and global level. Given limited resources, industry needs to make more efficient use of the biomass produced. The limits of the earth's carrying capacity are being reached earlier every year and therefore there is a high and growing demand for biomass-based products. Bio-based solutions offer an alternative to fossil-based products, the production of which is problematic due to greenhouse gas emissions, environmental chemicalization and the depletion of fossil reserves. When replacing fossil products with bio-based solutions, the environmental benefits must be clearly demonstrated, for example through life-cycle assessment.
Cascade processing of different biomasses produces a wide range of fractions for industrial use. For example, hot water extraction can be used to separate phenolic compounds such as condensed tannins, stilbenes and flavonoids, which have applications in leather tanning, winemaking, building materials, flocculants and coagulants, adhesives, pharmaceuticals, food supplements and cosmetics. Hemicellulose can be used to produce a wide range of sugars for further processing into bioproducts and as a carbon source for fermentation. Commercial biochemical products based on novel materials are among the products with belong to the low volume but high unite price. In the future, the high demand for bio-based products will increase the production and availability of bio-based alternatives. The most important growing category of bio-chemicals are the basic industrial chemicals, the so-called platform chemicals, which can be tailored to specific applications.202
