Activin B, a member of the transforming growth factor-β superfamily, is ubiquitously expressed in diverse tissues and is a regulator of reproduction, embryonic development, and adult tissue homeostasis. We aimed to determine whether activin B is involved in skeletal muscle injury and if selective inhibition of activin B would provide a regenerative benefit. The local introduction of activin B into normal skeletal muscle increased the expression of inflammatory and muscle atrophy genes TWEAK, TNFα, GDF3 and TRIM63, by 2-, 10-, 10-, and 4-fold, respectively. The data indicate a sensitive response of skeletal muscle to activin B. Six hours after cardiotoxin-induced skeletal muscle damage, circulating activin B protein expression in serum increased by 9-fold and InhβB gene expression increased by 30-fold in muscle. After cardiotoxin-induced skeletal muscle damage, activin B protein expression in muscle was significantly increased at 48- and 120-hours by 1.5 and 2-fold, respectively. Muscle histopathological features showed that activin B antibody–treated mice displayed a reduction in necrotic debris, with a concomitant reduction in intramyocellular space at 9-days after injury. Activin B treated C2C12 myoblasts also displayed a dose-dependent reduction in active myogenesis. Furthermore, the increased presence of activin B early in muscle injury impedes muscle repair and remodeling. In summary, acute muscle injury leads to increases in activin B levels and when selectively neutralized with a monoclonal antibody, there is augmented skeletal muscle repair.

År 2012 publicerades en sammanfattande syntesrapport från Energimyndigheten (2012). Rapporten fann bevis på att grotuttaget låg på ca 14 TWh/år. Rapporten visar också att Sveriges skogar kan hantera upp till 24 TWh/ år utan att orsaka allvarliga konsekvenser på omgivningen eller nästkommande generationer av träd. Studien beräknade grotens potentiella uttag utifrån insamlade analyser av markkemi, tekniska verktyg och uppskattningar. Dagens rapporter angående ämnet estimerar potentialen till ungefär densamma med en liten höjning till ca 27-30 TWh/år. Detta har satts i relation till hur olika hyggeslagrings tekniker påverkar det möjliga uttaget av grot tillsammans med hur kemin i marken påverkar trädens tillväxt och omgivningen. Grotuttaget gick ner till ca 8-9 TWh/år från år 2012 till 2019, från 14 TWh/år. Eftersom skogsägarna i Sydsverige är privatbrukare och behöver gå runt ekonomiskt för att kunna fortsätta sina verksamheter leder detta till att grotuttaget följer kostnadseffektiviteten av grot i sverige. I framtiden uppskattas det att grotuttaget kan öka drastiskt. Beroende på hur utvecklingen sker kan det verkliga uttaget skilja stort med många påverkande faktorer som t.ex. kostnadseffektivitet och utveckling av andra energikällor. / In 2012 a synthesis report was published by ”Energimyndigheten (2012)”. The report states that forest residues used as bioenergy represents around 14 TWh/year. The report also shows that Swedish forests can manage an outtake of up to 24 TWh/year without suffering from serious consequences, -on the plantation grounds or for, the next coming generation of trees. The study calculated the potential residue of forest outtake from collected analysis of soil chemistry, technical tools and estimations. Recent reports on forest residue outlet estimates a potential of about the same as 2012 with a slight rise to approximately 27-30 TWh/year. This has been put into relation of how different logging storage techniques affect the trees growth, the plantation grounds and the surroundings. The forest residue outlet went down to between 8-9 TWh/year from 2012-2019. This is because the main part of the forests in southern Sweden belongs to private owners and who experienced a decreasing economy to sell their residue. That leads to a problem, where the actual forest residue outlet is heavily dependent on the cost efficiency of forest residues. In the future it is estimated that the forest residue outlet can increase drastically. Depending on how the development proceed, the future outlet of forest residues may differ greatly depending on the future cost efficiency and how other energy sources develop and progress.