Housing Aquaporins in Nanostructured Glass

Proteins are a group of biomolecules that perform versatile tasks, which in many cases are essential for life. The magnitude of their importance is perhaps expressed by the word protein itself, coined by the Swedish chemist J\uf6ns Jacob Berzelius in the summer of 1838. It is derived from the Greek word πρωτείος which means ‘primary’ or ‘of the highest importance’. By adding a different ending, Berzelius shaped the word protein which means ‘the most important building block in a thin thread’.The proteins of importance to this PhD thesis are aquaporins, whose primary function in nature is to sustain the osmotic balance across the cell membrane by transporting water. This transportation is highly energy efficient and selective compared to artificial processes, which renders aquaporins interesting from a water purification point of view. Many proteins, including aquaporins, are however not stable in non-native environments, which often results in protein degradation or aggregation upon use in synthetic environments. This is particularly prominent for membrane proteins, which need to be housed in an amphiphilic environment to function properly.This thesis explores aquaporin stabilization through different kinds of interactions with glass. Human Aquaporin 4 was either intercalated with a mesoporous silica substrate or covered in a thin layer of silica. In both cases, aquaporins were stabilized by a lipid bilayer that mimics its native cell membrane surroundings. This thesis also includes work on the first structural and functional characterization of Climbing Perch Aquaporin 1 and a synthesis method for producing uniform silica nanoparticles with accessible mesopores.Detailed characterization provided valuable information on different kinds of aquaporin-silica interactions. Aquaporins were, for instance, shown to extend into a porous silica substrate underneath a supported lipid bilayer. Furthermore, aquaporin secondary structure was preserved when stabilized by a silica shell. The findings in this thesis show that silica may be used as a biocompatible stabilization option for aquaporins, potentially paving the way for better aquaporin utilization in applications such as water purification

Anaerobic Digestion of Animal Manure and Influence of Organic Loading Rate and Temperature on Process Performance, Microbiology, and Methane Emission From Digestates

Biogas production from manure is of particular value in regard of lowering greenhouse gas emissions and enhancing nutrient re-circulation. However, the relatively low energy content and the characteristics of manure often result in low degradation efficiency, and the development of operating strategies is required to improve the biogas yield and the economic benefits. In this study, the potential to enhance the performance of two full-scale biogas plants operating with cattle manure, in mono-digestion or combined with poultry manure, was investigated. Four continuously fed laboratory-scale reactors were operated in sets of two, in which the temperature in one reactor in each set was increased from 37-42 degrees C to 52 degrees C. The potential to increase the capacity was thereafter assessed by increasing the organic loading rate (OLR), from ca 3 to 5 kg volatile solids (VS)/ m(3) and day. The processes were evaluated with both chemical and microbiological parameters, and in addition, the residual methane potential (RMP) was measured to evaluate the risk of increased methane emissions from the digestate. The results showed that both processes could be changed from mesophilic to themophilic temperature without major problems and with a similar shift in the microbial community profile to a typical thermophilic community, e.g., an increase in the relative abundance of the phylum Firmicutes. However, the temperature increase in the reactor co-digesting cattle and poultry manure caused a slight accumulation of fatty acids (2 g/l) and reduced the specific methane production, most likely due to ammonia inhibition (0.4-0.7 g NH3/l). Still, during operation at higher OLR, thermophilic as compared to mesophilic temperature slightly increased the methane yield and specific methane production, in both investigated processes. However, the higher OLR decreased the overall degree of degradation in all processes, and this showed a positive correlation with increased RMP values. Chemical analyses suggested that high RMP values (40-98 Nml gVS(-1)) were related to the degradation of cellulose, hemicellulose, and volatile fatty acid enriched in the digestate. Conclusively, increased temperature and load can increase the methane yield from manure but can result in less efficient degradation and increased risks for methane emissions during storage and handling of the digestate

Medborgarförslag. Ett effektivt verktyg i demokratins tjänst eller ett spel för gallerierna?

Uppsatsen behandlar medborgarförslag, en ansats från Sveriges regering för att fördjupa den svenska demokratin. Medborgarförslag infördes som en möjlighet i kommuner för att stödja den lokala demokratin och därmed minska politisk marginalisering och utanförskap, samt öka det politiska engagemanget i kommunen. Syftet med studien är att utreda om regeringens mål att öka och diversera det politiska deltagandet har uppfyllts. För att begränsa undersökningen utifrån uppsatsens omfång koncentreras undersökningen på de medborgarförslag som kom in till Lunds kommun under 2011. Genom en intervjubaserad frågeundersökning utreds vilka samhällsgrupper som lämnat förslag och hur den demografiska spridningen ser ut bland de engagerade medborgarna. Studien innefattar även en kvalitativ textanalys av offentliga dokument och relevant forskning gällande medborgarförslag och politiskt deltagande. Resultatet som framkommer av studien är att medborgarförslagen är ett användbart verktyg för att öka det politiska engagemanget och aktiverar flera medborgargrupper som inte har någon erfarenhet av politiskt deltagande. Avslutningsvis föreslås uppslag till diskussion och fortsatt forskning

Enabling Image Recognition on Constrained Devices Using Neural Network Pruning and a CycleGAN

Smart cameras are increasingly used in surveillance solutions in public spaces. Contemporary computer vision applications can be used to recognize events that require intervention by emergency services. Smart cameras can be mounted in locations where citizens feel particularly unsafe, e.g., pathways and underpasses with a history of incidents. One promising approach for smart cameras is edge AI, i.e., deploying AI technology on IoT devices. However, implementing resource-demanding technology such as image recognition using deep neural networks (DNN) on constrained devices is a substantial challenge. In this paper, we explore two approaches to reduce the need for compute in contemporary image recognition in an underpass. First, we showcase successful neural network pruning, i.e., we retain comparable classification accuracy with only 1.1% of the neurons remaining from the state-of-the-art DNN architecture. Second, we demonstrate how a CycleGAN can be used to transform out-of-distribution images to the operational design domain. We posit that both pruning and CycleGANs are promising enablers for efficient edge AI in smart cameras

Ассоциация полиморфизма генов ферментов биотрансформации и детоксикации ксенобиотиков с риском развития заболеваний у детей, перенесших перинатальные гипоксические поражения ЦНС

ПОЛИМОРФИЗМ ГЕНЕТИЧЕСКИЙФЕРМЕНТЫБИОТРАНСФОРМАЦИЯЛЕКАРСТВ ДЕТОКСИКАЦИЯ МЕТАБОЛИЧЕСКАЯКСЕНОБИОТИКИФАКТОРЫ РИСКАПЕРИНАТОЛОГИЯНЕРВНАЯ СИСТЕМА ЦЕНТРАЛЬНАЯ /повреждПЛОДА ГИПОКСИ

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

BackgroundRice (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. Two forms of Arabidopsis thaliana WRI1 were evaluated by transient expression and stable transformation of rice plants, and transgenic plants were analyzed both for TAG levels and biogas production from straw.ResultsBoth full-length AtWRI1, and a truncated form lacking the initial 141 amino acids (including the N-terminal AP2 domain), increased fatty acid and TAG levels in vegetative and reproductive tissues of Indica rice. The stimulatory effect of the truncated AtWRI1 was significantly lower than that of the full-length protein, suggesting a role for the deleted AP2 domain in WRI1 activity. Full-length AtWRI1 increased TAG levels also in Japonica rice, indicating a conserved effect of WRI1 in rice lipid biosynthesis. The bio-methane production from rice straw was 20% higher in transformants than in the wild type. Moreover, a higher producing rate and final yield of methane was obtained for rice straw compared with rice husks, suggesting positive links between methane production and a high amount of fatty acids.ConclusionsOur results suggest that heterologous WRI1 expression in transgenic plants can be used to improve the metabolic potential for bioenergy purposes, in particular methane production

Quantification of Normal Cell Fraction and Copy Number Neutral LOH in Clinical Lung Cancer Samples Using SNP Array Data

Technologies based on DNA microarrays have the potential to provide detailed information on genomic aberrations in tumor cells. In practice a major obstacle for quantitative detection of aberrations is the heterogeneity of clinical tumor tissue. Since tumor tissue invariably contains genetically normal stromal cells, this may lead to a failure to detect aberrations in the tumor cells.Using SNP array data from 44 non-small cell lung cancer samples we have developed a bioinformatic algorithm that accurately models the fractions of normal and tumor cells in clinical tumor samples. The proportion of normal cells in combination with SNP array data can be used to detect and quantify copy number neutral loss-of-heterozygosity (CNNLOH) in the tumor cells both in crude tumor tissue and in samples enriched for tumor cells by laser capture microdissection.Genome-wide quantitative analysis of CNNLOH using the CNNLOH Quantifier method can help to identify recurrent aberrations contributing to tumor development in clinical tumor samples. In addition, SNP-array based analysis of CNNLOH may become important for detection of aberrations that can be used for diagnostic and prognostic purposes

Conjugated Polymer for Voltage-Controlled Release of Molecules

2017-2018 > Academic research: refereed > Publication in refereed journal201805 bcrcpublished_fina