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The vagus nerve is the longest nerve of the autonomic nervous system. It innervates, among other organs, the stomach, the lungs and the heart, and it reaches several areas of the brain, including the locus coeruleus and the amygdala. The invasive stimulation of this nerve (vagus nerve stimulation, or VNS) is a currently used method for the treatment of refractory epilepsy and pharmaco-resistant depression (Englot et al. 2011; O’Reardon et al., 2006), but the impact that this technique might have on the brain physiology and functions is still under investigation. Various studies (Frangos et al., 2015; Yakunina et al., 2016; Hansen, 2019) have shown that VNS increases noradrenaline production in the brain, a neurotransmitter that is involved in several cognitive processes, such as sleep and mood control. Furthermore, in a study on patients with epilepsy, by Sun et al. in 2017, VNS appeared to have a clear effect on working memory and emotion-attention interaction. Nevertheless, VNS presents all the risks and potential complications that characterize invasive procedures requiring surgery. Therefore, research is now focusing on safer, non-invasive alternatives, such as transcutaneous vagus nerve stimulation (tVNS). This technique allows to stimulate the nerve through its sensory fibres, located in the cymba and tragus of the ear. The scope of the present study was to see whether tVNS would have the same effects on cognitive and affective functions as VNS. The sample for this single blind placebo-controlled study was composed of 30 healthy subjects between 18 and 45 years old. Exclusion criteria included a history of psychiatric, neurological or cardiovascular diseases. All subjects were asked to complete a computer-based task, the Executive Reaction Times-Test. Throughout the test the subjects alternately received an active or a placebo stimulation, and their brain activity was recorded for the whole duration of the test using a 64-channel EEG cap. The Executive-Reaction Times-Test was chosen for this study because it allows to test multiple executive functions simultaneously. The subjects were presented with a series of stimuli on a screen and were asked to react as fast and accurately as possible to “Go” signals, and to refrain from responding when “NoGo” signals appeared. The test started with a triangle pointing either up- or downwards, followed by a brief pause and a traffic light image. The traffic light showed either a red or a green light and included an emotional distractor in the form of a spider or a flower. The red and green lights were alternately used as “Go” or “NoGo” signals, and the rule changed at each test block. In order to complete the task, subjects needed to keep the image of the triangle in their working memory, stay focused on the stimuli and be ready to react or be able to inhibit any responses, thus several main executive functions are being tested: inhibitory control, working memory, attention and emotion-attention interaction. Active stimulation was delivered through clip electrodes that were attached to the tragus of the left ear, whereas placebo stimulation was delivered through clip electrodes that were attached to the left ear lobe. The subjects were not aware of the difference between the two locations. Only the data of 18 subjects was used for the results analysis, because of technical difficulties with the EEG data (some recordings were too noisy, some presented flat channels). The behavioural data was divided into reaction times and errors, which were separately analysed. The EEG data was used to extract the amplitudes of the ERP peaks N2 and P3. The former is a negative peak visible at 200-350ms; the latter is a positive peak visible at 300-500ms. Previous studies have shown the peaks to be associated with response conflict and inhibition (Falkenstein et al., 1999; Donkers et al., 2004; Smith et al., 2013). The behavioural data analysis did not show any significant effect of stimulation on reaction times or error amounts. The ERP analysis, instead, returned interesting results. We observed a main effect of stimulation (p=0.04) in “NoGo” conditions. There was a significant reduction in the N2P3 amplitude and the N2 amplitude in “NoGo” conditions, with active stimulation compared to placebo. These results seem to suggest that with tVNS, fewer cognitive resources are allocated to resolve the inhibitory task, without worsening the subjects’ performance. The lack of significance in the behavioural results might have been due to a ceiling effect, with the Executive Reaction Times-test being too easy for our sample. Overall, the number of errors was too low to conduct a reliable statistical analysis. Nevertheless, the effects we observed on brain physiology would suggest that further research is needed to explore the actual impact of tVNS on cognitive and affective functions.

The intensification of agriculture is one of the main drivers of biodiversity loss worldwide. One of the intensification shifts has occurred from cattle grazing on biodiversity-rich semi-natural grasslands to ceased grazing or grazing on cultivated species-poor grasslands. While the effect of different grazing pressure on biodiversity in semi-natural grasslands has been studied extensively, little is known of how current grazing regimes on cultivated grasslands affect biodiversity and ecosystem services in different farming systems. Here, we investigated how arthropod abundance and potential ecosystem services are related to varying grazing pressure on cultivated grasslands at conventional and organic farms with meat or dairy production. We sampled aerial arthropods with sticky tape traps in four land-use types within the farms. Relative arthropod abundance was derived from the tapes using an imagery analysis, and the numbers of pollinators and predators from 4 taxonomic groups were counted. The results showed no difference in the relative arthropod abundance in relation to grazing pressure, but there was weak evidence for higher predator abundance at low and high grazing pressure. The relative arthropod abundance showed a positive trend in organic farms. However, pollinator abundance was higher in conventional farms, and predator abundance did not differ between farming systems. Land-use type was related to the occurrence of predators and pollinators: both groups had the lowest abundance in farmyards compared to cultivated pastures, silage fields, and cereal crop fields. Predator numbers were also higher in silage fields than in the other land-use types. However, there was no significant interaction between land-use types and farming systems in their effect on the arthropod groups. The results suggest that grazing pressure on cultivated grasslands has a minor or negligible impact on arthropod abundance in the two commonest farming systems. However, the effect of farming systems on relative arthropod abundance might be obscured by low sample sizes, high abundance of only a few species, and other variables not included here, such as the use of manure or pesticides. In addition, pollinators included only two taxonomic groups, potentially leading to results not applicable to all pollinators. Consequently, more large-scale studies with higher sample sizes and the inclusion of arthropod diversity and data on the key on-farm practices and landscape structure are needed to disentangle the relationship between biodiversity and grazing on cultivated grasslands in Finland.

Ongoing climate warming has unprecedented impacts on glacial melt and associated fjord systems in Greenland. As the glaciers are shrinking, freshwater inflow to the sea is increasing resulting in increased nutrient supply by upwelling. In this study I examined environmental factors impacting marine primary productivity, biomass (chlorophyll a), phytoplankton abundance and species composition along a transect from the glacier front to the outer fjord in Godthåbsfjord, SW-Greenland, in August 2019. Gradients in nitrogen and phosphate concentrations were explained by glacial runoff and coastal water inflow while silicate concentration did not follow these patterns. The main variables explaining phytoplankton biomass distribution were nitrogen together with phosphate concentrations, salinity, and depth. Silicate limited waters were strongly dominated (≥ 90%) by the diatom Chaetoceros socialis, which had a strong influence on phytoplankton community response to environmental conditions. High dominance of C. socialis was also related to high species richness. Nitrogen depleted waters were usually related to relatively high abundances (9–46%) of mixotrophic Dinobryon balticum. Higher number of species and higher dominance of C. socialis was detected closer to the glacier. Phytoplankton abundance and biomass (chlorophyll a) were higher in the inner fjord region, whereas primary productivity had the opposite pattern (higher productivity in the outer fjord). This suggested that an autumn bloom was peaking in the inner fjord, whereas in the outer fjord the autumn bloom was still developing. Thus, glacial surface runoff and subglacial discharge contributed to higher phytoplankton abundance and chlorophyll a concentrations, whereas primary production was also dependent on other factors such as light availability and vertical mixing. Melting of Greenland Ice sheet is predicted to accelerate in the future. Thus, the upwelling effect might increase, leading to transitory increase in marine primary production. Increased surface runoff might increase silicate concentrations benefiting diatom species, although turbid runoff water will also decrease the primary productivity due to light limitation. Nevertheless, if marine-terminating glaciers retreat further and become land-terminating glaciers, lack of nutrient upwelling will lead to faster exhaustion of nitrogen in the upper water column and primary productivity will eventually decrease. Thus, global warming and retrieving of glaciers will change the productivity of the fjord and inevitably shape the rich and unique fjord ecosystems of the Arctic.

The heath vegetation in the Jauristunturit study area is highly affected by the reindeer fence that was built in the mid-1950s between Finland and Norway, to prevent summer grazing in the Norwegian side. In the study area, the Finnish and Norwegian pastures are used during different seasons, causing differences in reindeer grazing history, and with time differences in vegetation. Additionally, local topography also impacts the vegetation composition and structure creating variation in local vegetation patterns. My research questions are: How vegetation patterns differ between summer- and winter- grazed areas, and which plant functional groups have the most significant difference? How local topography affects vegetation patterns, and does the effect of topography differ between summer and winter pastures? The data was collected from five 400 m long transects that crossed the fence and had vegetation plots with 10-m intervals. The %-cover and height of each vascular plant, bryophyte, and lichen species were estimated from 0.25 m2 plots. Later, species data was grouped into functional groups and general linear models were used to analyze differences in cover, height, species number, biomass, and leaf-area indices between countries. Topography indices were calculated in GIS for each plot and analyzed with random forest models to find out the most important topography indices explaining vegetation patterns. The vegetation data was collected by four teams, and therefore, the comparability in the collected data between teams was analyzed. Significant vegetation differences were found in the ground layer, with higher cover and biomass of bryophytes on the Finnish side (mean biomass 168.2 vs. 65.2 g m-2). Reindeer lichens were more abundant on the Norwegian side (mean biomass 197.0 vs. 2.9 g m-2) which is visible in aerial and satellite images and in the field. Among vascular plants, evergreen dwarf shrubs had higher biomass and leaf area index on the Finnish side and dwarf birch had higher cover and height on the Norwegian side. Topography indices had a higher level of variance explained on the Norwegian side, and higher at the ground layer compared to vascular plants. Elevation had the greatest impact on vegetation, and after that, topography protection index for 50 m and depth to water stream network for 2 and 10 ha. The differences between data collectors were not considered to have a major impact on the results. The results indicate that there are significant differences in vegetation between summer- and winter-grazed areas, mainly in the ground layer, and most differences are caused by differences in reindeer grazing history, but also local topography has an impact.

Boreal mires are natural sources of methane and contribute considerably to the global methane budget. Therefore, in order to comprehend the overall impact that these ecosystems have on climate change, it is essential to understand the factors that influence processes involved in methane production and consumption. Factors affecting methane flux vary between different mires, but there is also great spatial and temporal variation in flux within mires. In previous studies, temperature and water table position have been shown to influence methane flux, but vegetation could aid in explaining the small-scale variation. Vegetation can indicate spatial variation in water table position, but also affect methane flux directly by the transportation of methane through plant tissues, and by providing substrate for microorganisms through primary production. Furthermore, redox potential is a poorly studied factor that can reflect if chemical conditions in peat are suitable for methane production or consumption, making it a useful tool in predicting methane flux. In this thesis, I seek to identify if small-scale spatial variation in the methane flux occurs within the studied mire area. In addition, I strive to identify important controllers of the observed spatiotemporal variation in methane flux, with a specific focus on the effect of vegetation properties and redox potential. Methane and carbon dioxide fluxes were measured with the closed chamber technique at a boreal fen in Sodankylä (67°22'06.6"N 26°39'16.0"E) during the growing season in 2019. Flux measurements were carried out at nine measurement plots belonging to three different vegetation types: flark, lawn and string. Coverage and height of plant functional groups were followed during the summer and continuous redox potential was measured for each plot. CH4 fluxes of different plots and vegetation types were compared to study the spatial variation in methane flux. Generalized additive models (GAM) were used to determine which variables are best to explain spatiotemporal variation in methane flux over the growing season. Mean methane flux during the summer was 0.94 ug CH4 m-2 s-1 which is in the same magnitude as observed in a previous study at the fen. Some small-scale spatial variation in the methane fluxes was observed at the study site, with strings having lower flux than flaks and lawns. However, overall the spatial variation was small, while temporal variation in methane flux over the growing season was considerable. The best model, that was a combination of vegetation, redox potential and environmental variables, and it explained 72 % of the observed variation in methane flux. Vascular plant variables were the most important variables in the model, whereas moss functional groups were of lesser importance. Redox potential in deeper peat layers was also important in the model, but redox potential closer to the surface was not found to be significant. Vegetation is an important controller of methane flux, and this information could potentially be used when predicting methane flux over larger areas by using remote sensing to map vegetation characteristics. Redox potential, on the other hand, is relatively easy to measure, and the result suggests that it could provide a useful tool for improving the predictions of methane flux.

With the growth and concentration of urban areas, methods for minimizing the impacts of fragmentation and habitat loss on biodiversity are needed. Spatial Conservation Prioritization (SCP) methods, which holistically assess the connectivity of urban areas, provide an effective tool for prioritizing conservation efforts, but producing these analyses require large amounts of high-quality data on e.g., the spatial distribution of biodiversity features in the area. An index-based approach is a simpler way to evaluate the ecological quality of single corridors, and could be a cheaper alternative to SCP methods, especially in cases where prior environmental data is limited or there is a frequent need for new analyses. In this study, I created an index-based method to evaluate the ecological quality and functionality of wildlife corridors. The three-step approach included a literature review on factors affecting the functionality of wildlife corridors as well as the building and testing of the index. The main objective in creating the index was to provide a tool that is easy to use and interpret, and that could be used in decision-making to minimize human impact on nature. The index is based on scientific literature and provides information on the ecological functionality of wildlife corridors in facilitating the dispersal of organisms. From the literature review I identified certain key elements of functionality for wildlife corridors. These elements included sufficient width of the corridor to form an undisturbed core habitat, the absence of barriers and disturbance within the corridor and the connectivity of the corridor habitat itself. When tested on fictitious example corridors, the index was able to differentiate wildlife corridors according to their ecological quality. To further test the index, it was applied on a real-world wildlife corridor located in Uusimaa as a case study. The index was found to be effective on evaluating the ecological functionality of wildlife corridors, but further development needs were also discovered. The most important next steps are to fine-tune the parameter values given to factors hindering dispersal (resistance values) based on an extended literature review, and systematic testing on real-world corridors to spot irregularities and possible mistakes. At its current state the index can be used to identify features that impede or promote the ecological functionality of the corridor, even without extensive prior inventories on the areas’ biodiversity features.

Spontaneous and voluntary movements of infants effectively reflect the developmental integrity of brain networks. When it comes to the research of motor development, the use of intelligent technology has shown to provide objective, automated, and scalable methods for movement assessment. In addition to intelligent technology, research on the usage of surveys – in this case parental surveys – has looked at the untapped potential that parental viewpoint. Guardians have a unique and holistic image of the child’s development, thus data from parental surveys could be used to further help us to assess infant’s development. For this study, I studied how the parents’ time estimate on the positions their child spends time in holds up against the machine-learning based data obtained with the smart jumpsuit. Using the data acquired from the smart jumpsuit during the recordings, we can see the amount of time the child spends in each position. Aim was to study the relationship between these variables and gain further understanding on the utilization of parental perspective in the assessment of motor development. Data was collected from 19 video recordings and videos were annotated with Anvil video annotation software for child’s posture and movements, and the annotations were used for training a machine learning-based classifier of the smart jumpsuit. Only data regarding postures was extracted for further analysis. Parental surveys were carried alongside of recordings. In the survey of parental estimate, we asked the parent to assess how much time the child spends in a specific posture. Positions which the survey focused on were prone, supine, side, sitting, crawling, and standing. Data from the recordings as well as data from parental surveys were visualized with radar plots. In addition, correlation was visualized in a linear regression. Positions which had both correlation of higher than 0.5 and a significant p-value were sitting (p < .001**), crawl posture (p < .05*), standing (p < .001**), and supine (p < .05*). Results suggested that parents were successfully assess the time spent in following postures: sitting, crawling, standing, and supine. This indicates that parents have a holistic understanding of their child’s motor development, and the knowledge could be useful in the overall assessment of development, especially when it comes to children with developmental delay. The parent’s ability to accurately assess a child’s motor development helps the parent support the child’s development.

The composition and dynamics of the early life gut microbiota plays a major role in establishing neonatal immunity and is suggested to have multiple impacts on the child’s long-term health. Meanwhile, the composition of the infant gut microbiome has been shown to be affected by the birth mode, infant health and diet. However, the characterization of the infant gut microbiome and its impact on the host’s health is still challenging as the contribution and importance of multiple co-factors on the early microbiome during infant growth is still poorly understood and characterized. The Health and Early-life microbiota (HELMi) is a cohort of more than 1000 healthy Finnish infants currently followed from birth to 4-5 years old. By now, the HELMi dataset comprises more than 400 whole genome shotgun metagenomes obtained from stool samples from 80 infants and parents, but also an in-depth characterization of the families’ lifestyle, environment, health and nutrition, allowing for a precise and cutting-edge characterization of the early gut microbiota. Based on the datasets from the HELMi, this project used Metaphlan3, Kraken and Braken to determine the best computational approach for the taxonomic profiling of the metagenomic reads. Then a PERMANOVA test was performed to evaluate and determine the factors significantly associated with the compositional microbiota variation within the infant gut metagenomes. This study first identified technical factors introducing bias in taxonomic profiling (e.g., DNA extraction batch), which served as confounders in the analysis of environmental and host variables. The investigation of these biological factors indicates that pre-natal and peri-natal variables such as the mode of delivery significantly impact the infant gut microbiota, while we did not identify any significant impact of breastfeeding habits and medication exposures in this study.

Wood development is a significant process with both financial as well as natural perspectives. Trees and wood are of highly significance in Finland where a huge part of the gross national income devises from the forestry area. Ecologically and commercially the Norway spruce (Picea abies) is one of the most common tree species in Europe. It covers about 30% of Finland's forest area. Norway spruce is frequently used in research to study many phenomena related specifically to the wood formation and lignification. The principal objective of my thesis work was to reveal an unknown step in the lignification process in developing xylem of Norway spruce, i.e. the initiation site(s) for lignification. To achieve this goal, the aim was to investigate the chemical identity of possible lignification initiation sites in the middle lamellae and cell corners of developing Norway spruce xylem, and to answer the question where in the cell wall soluble monolignols first emerge and lead to the start of lignin formation (polymerization). I was approaching this goal with immunolabeling technique for confocal microscopy and Raman spectroscopy to unravel this initiation site of lignification by using specific monoclonal antibodies for cell wall compounds and comparing the results with the initial lignin deposition sites. To detect the location/distribution of some important polysaccharides and lignin substructure for lignification initiation, monoclonal antibodies i.e. LM10, LM11, LM15, LM24 and antibody Dibenzodioxocin or DBD were applied for confocal microscopy and some monolignol specific spectra were applied for Raman microscopy. The xylan was detected by LM10 in secondary cell wall abundantly and few are in primary cell wall of Norway spruce. The LM11 against arabinoxylan was determined more in primary cell walls but less in secondary cell wall. The location of xyloglucan was identified in the middle lamellae, primary and secondary cell wall of Norway spruce by LM15. The LM24 against glycosylated xyloglucan was found in secondary cell walls, abundantly in cell corners but few in primary cell wall. The primary antibody Dibenzodioxocin or DBD for the lignin substructure revealed that these were present in the mature cells of secondary cell walls (S2 and S3 layers). The lignin substructures DBD were not found in youngest cells where secondary cell walls are absent. The developing xylem of Norway spruce was subjected Raman microscopy and which revealed the locations of cinnamyl alcohol, coniferyl alcohol and coniferyl aldehyde. The cinnamyl alcohol was abundantly found at cell corner and middle lamellae in most developing part of xylem. The coniferyl alcohol was determined only in developing xylem cell corners. The coniferyl aldehyde was observed at cell corners, middle lamella and primary cell walls of developing xylem. The coniferyl aldehyde was located more in mature cells than younger cells. So, the Confocal and Raman microscopy images revealed the possible bindings of monolignols to polysaccharide in young cell corners, cell wall layers and middle lamellae.

Tiivistelmä - Referat - Abstract To aim for a just and sustainable society, it is essential to consider how we manage cities and to reflect on the role of young people as agents for successful future generations. The school system must take on the responsibility of developing a sense of social justice amongst young people. However, few learning activities are established to promote learning about environmental and intergenerational justice issues, and are usually limited to a top-down approach based on STEM disciplines (Science, Technology, Engineering and Mathematics). In this work, I argue that education in sustainability needs to be opened to a relational approach that introduces new justice perspectives, becoming a driver for active citizenship and public participation. The thesis is based on ten workshops conducted in Kumpula, Helsinki, involving 197 students from two upper secondary schools. The novelty of this work consists in addressing a specific range of upper secondary school students (16 to 19) and combining cognitive and relational learning activities to elicit reflections on environmental justice. I used a learning activity based on a Role-play method to actively involve students in working with justice perceptions and nature-based solutions. The analysis is based on a mixed methods- approach where the statistical analysis (pretest-posttest) and qualitative content analysis support each other. The innovative integration of cognitive and relational learning contributed to a deeper knowledge of urban green space management. This approach elicited new recognition justice perspectives by enhancing the participants’ awareness of community values and needs, comprehending both humans and non-humans. After the learning activity, students were generally more willing to make their voice heard by policy makers and to participate in public discussions. Based on the findings, more resources and time would be needed to build a long-term project in order to assess the permanence of relational and cognitive learning and more widely the efficacy of this approach for transformative learning.