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Peatlands are ecosystems of global importance for biodiversity conservation. Peatlands are wetland ecosystems which provide a critical habitat for many rare and specialized species. Biodiversity maintains the provision of ecosystem services, which are the benefits people obtain from ecosystems. The loss of biodiversity and peatland degradation constitute global challenges. One of the main reasons why biodiversity loss and peatland degradation remain challenges is nested in the failure to account for the range of economic benefits of ecosystem services and biodiversity in relevant policy making. The role of peatlands in maintaining global biodiversity has often been underestimated in global, regional and local land use planning and conservation measures. This thesis undertakes a systematic literature review on the empirical economic valuation literature on peatland ecosystem services and biodiversity. The two main aims of this literature review are to synthesize the current state of knowledge on this phenomenon and analyse the role of biodiversity in the economic valuation of peatland ecosystem services by answering specific research questions. This systematic literature review employs the data of 23 peer-reviewed English language papers published between 2006 and June 2021. The studies were chosen for analysis based on a selected search strategy and screening process. The data analysis was undertaken using the qualitative data analysis software Atlas.ti which is a tool used to help organize analysed material with the help of descriptive codes. Based on the findings of this thesis, the inclusion of biodiversity in the economic valuation of peatland ecosystem services has become a standard procedure. This is showcased by the number of studies applying stated preference approaches. The sample included studies applying different valuation methods in order to value many ecosystem services. The studies including biodiversity in economic valuation often find that biodiversity conservation policies can be cost-effective, and that people are generally willing to pay for biodiversity conservation and would derive economic benefits from this. Biodiversity is included in the studies as different elements, mainly as a specific species or as a reference to wildlife. Biodiversity is also found to be closely related to cultural ecosystem services and their benefits. Many studies find that people value familiar peatland landscapes, and biodiversity plays an important part in defining that value. Some studies find that human activity plays an important role in maintaining biodiversity in semi-natural peatland landscapes. Hence, biodiversity conservation needs to be in some accordance with local interests. Biodiversity provided founding principles for policy making, but previously implemented practices, such as existing conservation measures and the extractive use of peatlands exerted much influence on final economic values. Moreover, biodiversity plays different roles in determining the objectives of the studies. Eight studies use biodiversity as the justification for conducting the economic analysis. Most studies include biodiversity as a study component among others under valuation. The portrayal of biodiversity influences the focus of the studies and how biodiversity contributes to the findings of the literature. The body of literature on the economic valuation of peatland ecosystem services remains small. The geographical distribution of the sample is skewed towards Europe and Southeast Asia. There is a notable upward trend in the number of studies which have been published in the last five years. The literature demonstrates that the economic valuation of peatland ecosystem services and the need to adopt sustainable peatland management with biodiversity conservation have become relevant and topical issues in policy making. There is a significant need to address the issue of peatland degradation and biodiversity loss by increasing awareness. Further research is needed to establish a more comprehensive understanding of the links between peatlands, ecosystem services and their values. In addition, future research could study how the provision of information and the contribution of biodiversity awareness and knowledge influence economic valuation.

Some flavonoids are thought to have antioxidant functions in plants, but this is still controversial because of a lack of in planta evidence. Methyl viologen (MV) sensitivity was assayed in sterile culture by growing seven day old Arabidopsis seedlings on 0.5x MS media supplemented with and without MV. Seedlings grew for 9 days after that, and then were photographed and root growth measured. We used several flavonoid deficient Arabidopsis transparent testa (tt) mutants and found they were hypersensitive to MV that produces reactive oxygen species (ROS) in chloroplasts and mitochondria. Flavonoids are transported into different compartments of the cell via a specific flavonoid transport system but no chloroplastic or mitochondrial transporters are currently known. To identify potential chloroplastic and mitochondrial transporters, knockout mutants of candidate MATE and ABC transporters have been screened for MV sensitivity. Flavonoids modulate auxin transport, which raises the possibility of passive effects through auxin during ROS sensitivity. To test whether auxin or the inhibitions of auxin transport have a role in protecting against ROS stress, MV sensitivity was assayed under exogenous treatment of artificial auxin (NAA) and an auxin transport inhibitor (NPA) during MV stress. From this study, we obtained data about the role of flavonoids and auxin in ROS signalling. The inhibition of auxin transport modulated MV sensitivity. We found that NAA had no effect or very modest effect. However, a protective effect of NPA was observed that helps against ROS formation, mimicking the effect of flavonoids. NPA induced more protection. One MATE transporter also gave the mimic of (tt) phenotype, however their role in the movement of flavonoids into or out of the chloroplast or mitochondria remains unclear, as they may be transporting some other protective agent that helps against oxidative stress. However, At1g54350 is a candidate for further testing.

Histamine and hypocretin/orexin are neuromodulators important for regulation of alertness and wakefulness. These systems project to major areas of the brain, are highly conserved among vertebrates and they significantly innervate each other. Different studies have indicated an interaction between the histaminergic and orexin systems, however the role of histamine in this interaction is still not well-established. The goal of this study was to examine possible changes in orexin neurons development and larvae behaviour, after genetic loss of histamine decarboxylase (hdc), the histamine-synthesizing enzyme. Using whole-mount in-situ hybridization and immunofluorescence staining we observed a significant reduction in the expression of the hcrt mRNA and the orexin A peptide in 6 dpf hdcKO zebrafish larvae. However, KO of hdc had no effect on startle response, dark flash response and sleeping behaviour of 6 dpf larvae. To further investigate the regulatory role of the histaminergic system, we employed treatment of hdcWT and KO larvae with ciproxifan, a histamine H3 receptor inverse agonist. Ciproxifan treatment increased darkness habituation in 7 dpf hdcWT and KO larvae but reduced the intensity of the dark flash response only on hdcWT larvae. Furthermore, ciproxifan treatment differentially affected the expression of the orexin A peptide in 7 dpf hdcWT and KO larvae but had no effect on the expression levels of the hcrt mRNA. Collectively, these findings suggest the significance of histaminergic signaling for normal development of orexin neurons and the implication of histamine in the execution of the dark flash response. Lastly, this study indicates the complex role of the histamine H3 receptor and the requirement of further studies for better characterization of its function.

Sensory systems display a topographical organization, and in the murine somatosensory system there is oneto-one correspondence between individual whiskers and individual cortical columns called barrels. Functional connectivity in the whisker-to-barrel system is formed prenatally and refined after birth, guided by both spontaneous and whisker-evoked activity. GABAergic connectivity emerges already prenatally and includes transient circuits, but the exact role of GABAergic signalling in early development is elusive. The neuronal, major chloride extruder, potassium-chloride cotransporter (KCC2) is heavily upregulated in the cortex during the first two postnatal weeks resulting in the emergence of hyperpolarizing inhibition. However, in cortical interneurons (INs) KCC2 expression can be detected already at the time of birth. The role of this early interneuronal KCC2 expression is unclear. The aim of this thesis was to study the role of KCC2 in the network activity of cortical INs during the perinatal period. Transgenic mice with conditional inactivation of Kcc2 gene, and expression of the calcium indicator GCaMP6f in GAD2+ neurons (INs) were used to image cortical Ca2+ activity. Transcranial widefield Ca2+ imaging in awake head-fixed mice was performed at the day of birth (P0) and showed that spontaneous, but not evoked, activity was significantly reduced in the knock-out animals. Moreover, immunostaining for the activity-induced transcription factor Egr1 showed that thalamic network activity was significantly decreased in the knock-out and heterozygous animals, suggesting involvement of subcortical areas in the decreased cortical activity. Additional experiments are needed to elucidate the role of other mechanisms contributing to the observed change in activity.

With the aggravation of global environmental problems and the reduction of finite reserved fossil fuels, seeking for alternative energy sources has become one of the priorities for the sustainable development of human society. Vascular plants save the biomass mainly as the form of xylem (also called as wood), which is now considered as an ideal environmental-friendly energy resource. Wood is now being used as renewable biofuels, Biomass composites to replace plastic and so on. The lateral meristem vascular cambium gives rise to xylem and phloem, contributes to the radial growth of plants. Dr. Mähönen’s group choose Arabidopsis root as a model to understand the growth dynamics of vascular cambium. Auxin is essential for various plant developmental processes. The transcription factor family AUXIN RESPONSE FACTOR (ARF) is an important component in auxin signaling pathway, among which AUXIN RESPONSE FACTOR5 (ARF5)/MONOPTEROS (MP) has been discovered to be essential in various plant developmental processes. The first part of my thesis work mainly focuses on analyzing the expression of ARFs during Arabidopsis root secondary development by using both histological reporter GUS and green fluorescent protein GFP. The second part is screening the secondary growth phenotype among the arf knock out mutants. As mp mutant fails to form primary root, artificial microRNA technique is applied to inhibit MP expression in transcriptional level, this construct was established in an XVE inducible system and driven by a broadly expressed promoter to specifically inhibit MP expression at the secondary development stage. I overexpressed amiMP in both wild type background and arf7,19 double mutant background. These three ARFs have strong expressions in cambium and they might function redundantly to regulate cambium activity. Our preliminary results suggest that ARFs function redundantly in regulating root secondary growth, ARF1 and ARF2 together are functional in regulating vascular pattern formation, and ARF16 can repress the root secondary growth and secondary xylem formation. MP is proved to regulate cambium activity and secondary xylem formation by controlling various auxin-response genes, ARF7 and ARF19 might also participate in this process.

In this master’s thesis project, I studied the association of lipid molecules phosphatidylinositol 4-phosphate (PI4P) and phosphatidylinositol 3-phosphate (PI3P) with autophagy in neurons. One of the aims of the study is to determine the level of basal autophagy in primary hippocampal neurons and to come up with a protocol for autophagosome observation without forcing radical changes in cell culture conditions. Other mammalian cells have extremely weak basal autophagy, but they increase it significantly in response to starvation, for example. However, neurons are extremely sensitive to any changes in their surroundings. They change their morphology, behaviour and biochemical properties, and often they simply do not survive. Therefore, the goal is a protocol for successful autophagy observation with minimal external influence. Despite the debate around basal autophagy in neurons, I observed high levels of basal autophagy in neuronal cells incubated in media without supplements. Also, my observations revealed that the inhibition of the last step of autophagosome processing with Bafilomycin A1, was enough to cause the massive accumulation of large autophagosomes. Results demonstrated that primary hippocampal neurons exhibit high levels of basal autophagy, suggesting that on the contrary to other mammalian cells neurons might not have enough potential to increase autophagy when it is induced pharmacologically or by stressful conditions. This would explain why autophagy induction is often claimed to be ineffective for neuronal cultures. The main goal is to observe and compare PI4P presence on autophagosomes in normal conditions and when autophagosome:lysosome fusion is inhibited with Bafilomycin A1. The side goal is to observe PI3P presence on autophagosomes as well. I transfected primary hippocampal neurons with fluorescent probes for PI4P or PI3P as well as for autophagosome-related protein LC3. Localization data was collected with live-cell imaging on a confocal microscope. As expected, PI3P was not detected on autophagosomes located in soma. It is involved in the initial vesicle biogenesis in distal axons but not in later events taking place closer to the cell body. PI4P showed high degree of colocalization with LC3, indicating PI4P presence on autophagosomes, but only when the fusion was presumably inhibited by Bafilomycin A1. These results suggest that PI4P appears on autophagosomes either as a result of compensatory pathway, where autophagosomes fuse with late endosomes instead of lysosomes; or as a molecule normally involved in autophagosome:lysosome fusion. Literature supports the latter explanation, but it cannot be confirmed without further research. These results give an insight into PI4P role in neuronal autophagy and might be relevant for the future research of autophagy disruption and aggregate accumulation in neuronal diseases as a consequence of abnormal lipid signalling, lipid metabolism and transport.

This thesis investigates whether the antidepressant-like and plasticity-promoting effects of LSD depend on TrkB expression among parvalbumin-positive interneurons (PV+ INs). Given the pivotal role of PV+ INs in facilitating critical-period-like plasticity, both during development and under the influence of conventional antidepressants, we hypothesized they may be involved in mediating psychedelic-induced neuroplasticity. Our findings challenge prevailing hypotheses, suggesting that LSD's plasticity-promoting effects may not rely on PV+ INs. We found that LSD did not increase the spine density of PV+ INs among wildtype mice, nor affected the expression of parvalbumin in PV+ INs or the perineuronal nets (PNNs) that enwrap them. Unexpectedly, we found that LSD did have subtle effects on PV+ IN spine density and the expression of parvalbumin in a mouse model with reduced TrkB expression among PV+ INs, suggesting a possible kind of compensatory mechanism at play. Our results reveal the multifaceted nature of LSD's actions on plasticity, shedding light on its therapeutic potential and prompting further exploration into its underlying mechanisms.

While weeks of continuous treatment is required for conventional antidepressant drugs (e.g. fluoxetine) to bring their full therapeutic effects, a subanesthetic dose of ketamine alleviates the core symptoms of depression (anhedonia, depressed mood) and suicidal thinking within just few hours and the effects may last for days. Nitrous oxide (N2O, “laughing gas”), another NMDAR antagonist, has recently been shown to have similar rapid antidepressant effects in treatment-resistant depressed patients (Nagele et al. 2015). We previously found using naïve mice ketamine and N2O treatment to upregulate five mRNAs related to the MAPK pathway and synaptic plasticity, both implicated as being important in the action of rapid-acting antidepressants. In the current study, these shared mechanisms were further investigated in C57BL/6JHsd mice, using behavioral test batteries to study depressive-like behaviour and RT-qPCR for biochemical analyses. We first aimed to demonstrate behavioral differences between naïve mice and a chronic corticosterone-induced animal model of depression, and to use this model to investigate antidepressant-like effects of ketamine and N2O. According to the results, chronic corticosterone produced some behaviors typical of a depressive-like phenotype, namely significant worsening of coat state and decreased saccharin consumption in the saccharin preference test. Both ketamine and N2O exhibited antidepressant-like effects by reverting decreased saccharin preference. We then aimed to elucidate the effects of ketamine and N2O on five previously found shared mRNAs: Arc, Dusp1, Dusp5, Dusp6 and Nr4a1. N2O significantly upregulated all targets in the vmPFC, except Dusp5, two hours after beginning of N2O treatment. Neither ketamine nor sole chronic corticosterone produced any significant changes. The results of this study suggest that N2O is a potential candidate for rapid alleviation of depressive symptoms. We suggest that the action of rapid-acting antidepressants, more specifically N2O, is based on a homeostatic response of the brain to a presented challenge. Here this challenge would be cortical excitation previously been shown to be caused by N2O, which leads to activation of pathways such as MAPK and subsequent Arc, Dusp and Nr4a1 signaling. The level of expression of these markers would then depend on which phase this response is in and hence, the differences in time between treatment and brain sample dissection could be a reason for conflicting results to previous research. Future studies would benefit from detailed investigation of the chronic corticosterone-induced model due to its potential in controlling for behavioral variability, thus reducing the number of animals needed for preclinical research. Overall the preliminary findings of this study could be one of the first steps in the search for the mechanisms underlying the potential antidepressant effect of N2O, how these molecular markers are related to its action and how it differs from the action of ketamine.

Marine debris is a problem that also affects sea birds. Several bird species are known to utilise marine debris among their nest materials in different parts of the world. Debris in nests can cause entanglement and increase the risk of debris ingestion, and hazardous substances leaching from plastics can have negative effects on birds. There are also anecdotal observations of debris in the great cormorant (Phalacrocorax carbo sinensis) nests in the Gulf of Finland, however, systematic studies are lacking. In this Master’s thesis I examined the prevalence of debris in cormorant nests in the Gulf of Finland, focusing mainly on plastic debris. The study was carried out in four nesting islets, which were located in Kotka, Porvoo, Espoo and Kirkkonummi. The sampling took place in autumn 2021. 50 nests were randomly sampled on each nesting islet, and plastic debris in the nest was counted and classified according to their type, colour and origin. Plastic debris was further categorized in the laboratory according to their polymer type using Fourier Transform Infrared spectroscopy (FTIR). Debris from the nesting islets was also counted and classified according to their type, colour and origin. In total, 58% of the nests contained debris, but the prevalence of debris in the nests varied between the colonies; In Kirkkonummi debris was found in 92% of the nests while in Porvoo only 34% of the nests included debris. Plastics constituted great majority of nest debris (95%). Most common source for plastic debris was consumers, most common plastic type threadlike and polymer type polyethylene (PE). The number of debris in the nests was linked to the width and location of the nests: core nests contained more debris than periphery nests and the number of debris in the nest was positively correlated with the width of the nest. The amount of threadlike plastics in the nests was higher than that in the surrounding environment, indicating active selection by cormorants for threadlike debris types as nest material. Based on the results of this thesis, nest surveys could be a useful tool in evaluating the effectiveness of certain reduction measures aiming to tackle marine plastic pollution.

Gastrointestinal stromal tumours (GISTs) are rare mesenchymal neoplasms that arise from the interstitial cells of Cajal, the so-called pacemaker cells of the intestine. GISTs typically contain an oncogenic driver mutation either in the proto-oncogene KIT or platelet-derived growth factor receptor A (PDGFRA), which belong to the class III receptor tyrosine kinases. Patients with a high-risk or advanced disease are standardly treated with a tyrosine kinase inhibitor imatinib. Despite this molecularly targeted treatment, many patients experience disease relapse, after which the prognosis is poor. Personalised treatment is rarely offered to patients as a first-line treatment option, even though several targeted therapies have been approved for GIST. Increasing treatment personalisation could improve treatment outcomes, yet the lack of patient-specific research models for GIST hinders the research. Three-dimensional (3D) cell culture models are widely used in cancer research to study the molecular mechanisms underlying tumorigenesis. Their ability to mimic the tumour biology and microenvironment is superior compared to the traditional two-dimensional (2D) cell culture model. For several cancers, these cell culture models have also been researched as platforms for personalised treatment selection with promising results. This thesis project aimed to study UPM Biomedicals’ GrowDex-based 3D cell culture model as a potential platform for personalised treatment selection for GIST patients. GrowDex is a plant-derived hydrogel that resembles the extracellular matrix. Another aim of this project was to set up a Sanger sequencing protocol covering frequently mutated areas in GIST to facilitate the validation of this cell culture model through drug testing on patient samples. To assess the GrowDex microenvironment, the viability and proliferation of two GIST cell lines, GIST-T1 and GIST48 were monitored. Furthermore, the imatinib response of GIST-T1 in GrowDex was assessed and compared to the response in other cell culturing conditions. The Sanger sequencing protocol was optimised using the aforementioned cell lines and then applied to GIST patient samples. The results of this project demonstrated that GrowDex provides a suitable microenvironment for culturing GIST cells and supports their 3D growth. GIST-T1 cells were less sensitive to imatinib when cultured in GrowDex in comparison to the 2D culturing condition, which is likely explained by the 3D organisation of the cells. Finally, the Sanger sequencing protocol was used to uncover the KIT/PDGFRA mutation status of several GIST patient samples. In conclusion, these results provide important information for further development of this cell culture model with patient samples.