High-solid digestion - A comparison of completely stirred and plug-flow reactor systems.

High-solid digestion (HSD) for biogas production is a resource-efficient and sustainable method to treat organic wastes with high total solids content and obtain renewable energy and an organic fertiliser, using a lower dilution rate than in the more common wet digestion process. This study examined the effect of reactor type on the performance of an HSD process, comparing plug-flow (PFR) type reactors developed for continuous HSD processes, and completely stirred-tank reactors (CSTRs) commonly used for wet digestion. The HSD process was operated in thermophilic conditions (52 °C), with a mixture of household waste, garden waste and agricultural residues (total solids content 27-28 %).

The motives and experiences of donor-conceived persons requesting the identity of their sperm donors.

Research Question: What are the motives and experiences of donor-conceived persons (DCP) who search for and receive information about their identity-release sperm donor?

Design: A qualitative interview study with 29 individuals (21 women, seven men, one non-binary) who were consecutively recruited after having requested information about their sperm donor at five Swedish University hospitals. All participants were conceived after donor insemination to heterosexual couples within an identity-release donation programme. Individual semi-structured interviews were conducted face-to-face or via telephone between September 2016 and November 2019, and transcribed audio recordings were analysed using reflexive thematic analysis.

Potential biomarkers for southern African hunter-gatherer arrow poisons applied to ethno-historical and archaeological samples.

The detection of complex poison recipes applied to ancient hunting weapons has the potential to provide important insights into traditional pharmacological knowledge systems. Yet, recipes comprising many ingredients can be challenging to decipher, especially in older samples that have undergone biodegradation. We present the results of our attempt to analyze samples of poison collected from nineteenth and twentieth century arrowheads from southern Africa, and from a 1000-year-old archaeological bone point.

Improved bioenergy value of residual rice straw by increased lipid levels from upregulation of fatty acid biosynthesis.

Background: Rice (Oryza sativa) straw is a common waste product that represents a considerable amount of bound energy. This energy can be used for biogas production, but the rate and level of methane produced from rice straw is still low. To investigate the potential for an increased biogas production from rice straw, we have here utilized WRINKLED1 (WRI1), a plant AP2/ERF transcription factor, to increase triacylglycerol (TAG) biosynthesis in rice plants.