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Naturliga metanutsläpp sker från våra våtmarker världen över. Metan produceras naturligt genom nedbrytning i de syrefria förhållanden som en våtmark erbjuder. För att bättre kunna modellera och skala upp hur mycker metan som faktiskt släpps ut från dessa våtmarker måste ytterligare förståelse skapas över varför metanutsläppen varierar så kraftigt både i tid och rum. Denna studie försöker öka först

Luminiscensdatering är en väletablerad dateringsmetod inom geologisk och arkeologisk forskning. Dock är användandet av luminiscensdatering, mer specifikt optiskt stimulerad luminiscens (OSL), fortfarande underrepresenterat inom norsk arkeologi. Denna studie ämnar utreda lämpligheten av denna dateringsmetod som ett användbart alternativ för utgrävningar av Stenålderslokaler på den norska kusten. De

Trimetallic nickel–iron–molybdenum oxides are excellent electrocatalysts for alkaline water electrolysis despite experiencing severe molybdenum dissolution. While the impact of molybdenum on fresh samples is well-understood, its substantial loss during operation without compromising performance presents a unique puzzle. Here, we show that the initial presence of molybdenum induces the formation of

Secondary organic aerosol (SOA) plays a significant role in climate change by altering the global atmospheric radiation budget. Biogenic volatile organic compounds (BVOCs) are major sources for the formation of SOA. Their relationship is critical to understand the continental biosphere-aerosol-cloud-climate (COBACC) feedback mechanism but receives less attention in previous studies. In this study,

The X-ray structures of dUTPase from equine infectious anaemia virus (EIAV) in unliganded and complexed forms have been determined to 1.9 and 2.0 A resolution, respectively. The structures were solved by molecular replacement using Escherichia coli dUTPase as search model. The exploitation of a relatively novel refinement approach for the initial model, combining maximum likelihood refinement with

Abstract in UndeterminedSoil microbes constitute an important control on nitrogen (N) turnover and retention in arctic ecosystems where N availability is the main constraint on primary production. Ectomycorrhizal (ECM) symbioses may facilitate plant competition for the specific N pools available in various arctic ecosystems. We report here our study on the N uptake patterns of coexisting plants an

Scots pine tree-ring width (TRW) data from Jamtland in the Central Scandinavian Mountains has been used to reconstruct summer temperatures back to 1630 BC. However, it was recently shown that this reconstruction was of limited spatial importance. In this paper, we aim to explain this limitation in the TRW data as a temperature proxy, as well as assess the temperature information from new maximum l

Effects of hydrogen bonding and the axial ligand interaction on the B800 band in two LH2 complexes Rhodopseudomonas (Rps.) acidophila and Rhodospirillum (Rs.) molischianum have been theo retically investigated by using density functional theory. The local electrostatic environment of the B800 bacteriochlorophyll is simulated as an atomic charge field consisting of the pigments in the protomer unit

Designing and developing a software product is a difficult process. The product must be usable and solve the correct problem. At the same time, the underlying code must be well written. Many projects fail to deliver or exceed their budget. This thesis explores a practical approach to software design and development that tries to adhere to both user centered design and agile development. The proces

The specific insertion of a divalent metal ion into tetrapyrrole macrocycles is catalyzed by a group of enzymes called chelatases. Distortion of the tetrapyrrole has been proposed to be an important component of the mechanism of metallation. We present the structures of two different inhibitor complexes: (1) N-methylmesoporphyrin (N-MeMP) with the His183Ala variant of Bacillus subtilis ferrochelat

Ribonucleotide reductases (RNRs) catalyze the reduction of ribonucleotides to deoxyribonucleotides, the building blocks for DNA synthesis, and are found in all but a few organisms. RNRs use radical chemistry to catalyze the reduction reaction. Despite RNR having evolved several mechanisms for generation of different kinds of essential radicals across a large evolutionary time frame, this initial r

Antibiotics are used to treat both humans and animals for both preventive and therapeutic purposes. The overreliance on and misuse of antibiotics has given rise to a stealth pandemic, known as antimicrobial resistance (AMR). Globally, they pose a significant threat to human, animal, and environmental health. Surveillance of antibiotic residues in the environment, especially in wastewater, for tack