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The main motivator of this thesis was to discover the importance of Chaoborus in a eutrophic and dystrophic lake and evaluate suitable restoration methods to enhance the state of the study lake. The role of Chaoborus in the study lake, Lake Jouttenus, was studied with sampling of both the water column and the sediment, echo-surveys, and diet analyses of fish. The sampling was planned as comprehensive, and the sampling stations were distributed across the whole lake area to examine the density and distribution of Chaoborus. The deeper areas of the lake were emphasized more in sampling because Chaoborus tend to favor those areas. The Chaoborus density was calculated with stratified sampling, which gives a more precise mean density estimate than simple random sampling. In addition, fish were caught on four (4) study occasions to find out if they had included Chaoborus in their diets. The mean density of Chaoborus in Lake Jouttenus was a little lower than expected, only 271 individuals/m2 in areas ≥2 m depth. The highest density of larvae was found from mid-depths between 6.0-7.9 m in the sediment. Only the deepest areas (≥8 m depth) had limnetic Chaoborus and more limnetic than benthic larvae. The mean length of larvae was 8.4 mm in the sediment and 9.0 mm in the water column. The length distributions appeared to be unimodal. Echo-surveys confirmed that the larvae occurred in the water column only in the deepest area in the north of the lake where the hypolimnion had a low oxygen concentration below 4 m depth. The diet analyses showed that roach and perch had eaten Chaoborus but the number of Chaoborus was high only in the diet of roach in early July. In comparison with other studied lakes, the density of Chaoborus was the lowest in Lake Jouttenus. In addition, the mean length of benthic Chaoborus in Lake Jouttenus was lower than in the other studied humic lakes. The distribution of limnetic Chaoborus appeared as restricted to the deepest areas in the lake and elsewhere the larvae occurred only in the sediment. The slow growth of Chaoborus and their low mean density could be explained by the lack of an efficient refuge and probably also the lack of resources. The larvae were unable to reach the epilimnion and their prey safely at daytime and/or the amount and quality of food items for the larvae were poor. The darkness caused by humic substances and low oxygen concentration in the hypolimnion created a refuge for the limnetic larvae only in the deepest area of Lake Jouttenus. Roach and perch ate Chaoborus occasionally. However, mass removal of fish is not recommended as it would decrease the predation pressure by fish on Chaoborus and increase the risk of Chaoborus population growth at the deepest areas and enable their range to extend. Instead of mass removal of fish all methods that aim in reducing the humic substances in the water especially at the lake catchment area might enhance the state of the lake. The clarification of water would diminish the living conditions for Chaoborus in long-term and help with controlling the other troubling factors such as Gonyostomum semen blooms in the study lake.

Background and objectives: Since early adolescence, the bedtimes and wake-up times begin to delay gradually until the early adulthood. This so-called shift to eveningness reaches its maximum at around the age of 20, and it usually occurs earlier in girls than boys. Eveningness has been previously associated with depression, anxiety, sleep problems, somatic symptoms, and other health-related issues in adolescents and adults. The aim of this study is to examine the associations between adolescents’ chronotype and their physical and mental well-being. Methods: This study examined how the self-reported chronotype was associated with self-reported problems related to adolescents’ physical and mental well-being. The chronotypes were divided into 5 types: Definitive Morning-types, Moderate Morning-types, Intermediate-types, Moderate Evening-types, and Definitive Evening-types. The participants were 7th, 8th and 9th graders, and the sample consisted of 6522 students from 83 schools in Finland. Some of the data was gathered at three time points, some at two time points, and some at one time point during the academic year. The associations between chronotype and well-being variables were studied cross-sectionally and some of them also longitudinally. Results: The main findings were that eveningness was associated with difficulty concentrating in lessons, susceptibility to give up easily on difficult tasks, school burnout symptoms, feelings of nervousness and anxiety, excessive worrying, difficulty relaxing, irritability, restlessness, difficulty falling asleep, waking up at night, daytime tiredness, and low mood as compared to morningness. Eveningness was also associated with neck and shoulder pain, lower back pain, and headache, as well as pain in the head and lower back due to the use of digital devices. Eveningness was associated with decreased concentration in lessons and increased susceptibility to give up on difficult tasks across time. On the other hand, feeling lonely and not being accepted as part of the group were associated with morningness. Conclusions: In conclusion, the physical and mental health problems were emphasized among Evening-type adolescents, as compared to Morning-type adolescents. Since adolescents shift toward eveningness, the need for thorough management of sleep and circadian problems should be highlighted, in order to intervene and improve the mental and physical well-being of adolescents both at school and at home.

The motivation of this study was to find new treatment options for the rare cancer pseudomyxoma peritonei (PMP). PMP is a slowly progressing mucinous adenocarcinoma that originates from the appendix and disseminates into the peritoneum where the cancer cells secrete large amounts of MUC2, the main component of intestinal mucus, into the peritoneum. The disulfide isomerase AGR2 helps MUC2 with forming the correct intramolecular disulfide bonds prior secretion, and is essential to MUC2 protein production. The mucus build-up into the peritoneum causes stress on vital organs, and eventually death. Therefore, inhibiting MUC2 production in PMP cancer cells might slow down the disease progression significantly. MAPK/ERK and cAMP/PKA signaling pathways stimulate MUC2 production, and activating mutations in KRAS and GNAS of these pathways are common in PMP. The aim of this study was to elucidate how MUC2 and AGR2 affect each other’s expression levels, and how the MAPK/ERK pathway and the cAMP/PKA pathway targeting substances caffeine, theophylline, cromolyn, fudosteine, octreotide, and lanreotide, affect MUC2 expression in vitro. This study was conducted on human colorectal adenocarcinoma cell lines LS174T, LoVo, and HT29 that all produce large amounts of MUC2. In addition, LS174T and LoVo cell lines carry activating heterozygous mutations in their KRAS genes. MUC2 and AGR2 expression levels were measured on mRNA level with real-time quantitative reverse transcriptase polymerase chain reaction. The effects of MUC2 on AGR2 expression, and vice versa, were tested by silencing each at a time with the appropriate siRNA. MUC2 siRNA suppressed both MUC2 and AGR2 mRNA levels down to 50 % in LS174T cells and down to 40 % in LoVo cells in respect to their control groups. AGR2 siRNA suppressed AGR2 mRNA levels down to 50 % in LS174T cells and even down to 30 % in LoVo cells in respect to their control groups, while there were no statistically significant changes in MUC2 mRNA levels. Caffeine and theophylline inhibit phosphodiesterase of the cAMP/PKA signaling pathway, and in consequence, the hydrolysis of the secondary messenger cAMP, prolonging the activation of the pathway. Caffeine stimulated MUC2 production in LS174T and LoVo cells. In addition, AGR2 mRNA levels increased in LoVo cells, in which the fold change in MUC2 mRNA levels was much greater. Theophylline, a compound found in tea, and used for the treatment of asthma, did not affect MUC2 production. PMP cancer cells express protein S100P. Cromolyn is a pharmaceutical substance used for the treatment of asthma, and it inhibits S100P, and thereby S100P/RAGE signaling -dependent activation of MAPK/ERK pathway. Fudosteine, on the other hand, is a mucoactive pharmaceutical substance that lowers the production of MUC5AC, the main component of lung mucus. Since activating GNAS mutation stimulates the production of both MUC2 and MUC5AC in HT29 cells, the expression of both must be at least partially controlled by same mechanisms. In addition, Somatostatin analogues octreotide and lanreotide inhibit ERK1/2 of the MAPK/ERK pathway, as well as protein kinase A of the cAMP/PKA pathway, and hence cAMP production. However, none of these four tested pharmaceutical substances were able to inhibit MUC2 production in the cell lines used this study in vitro.

Kainate receptors (KARs) act as prominent regulators of neuronal excitability, network activity as well as neurotransmitter release in the developing brain. In the neonatal hippocampus the GluK1 subunit containing KARs take part in regulating the activity of the CA3 interneurons and hence the maintenance of early synchronous network oscillations, which are thought to be vital for developing connections. In the interneurons of the CA3 subfield this regulatory activity is likely performed through a noncanonical, G-protein mediated inhibition of a Ca2+ sensitive medium-duration afterhyperpolarizing current (ImAHP). As in various central neurons the ImAHP has been shown to be regulated by voltage-gated calcium channels (VGCCs) and as the activity of the voltage-gated calcium channels has been in turn shown to be modulated by G-protein coupled signaling of GluK1 KARs, we went on to investigate whether a direct link between GluK1 KARs and VGCCs could be detected in the CA3 stratum radiatum interneurons of neonatal hippocampus. Here we show that the pharmacological inhibition of GluK1 KARs does not affect the amplitude of Ca2+ influx through VGCCs in the CA3 stratum radiatum interneurons of acute hippocampal slices from neonatal mice. As G-protein mediated signaling has been shown to induce alterations in the voltage-dependence of the VGCC-mediated currents, we similarly investigated the effects of GluK1 inhibition on the current-voltage relationship of Ca2+ currents in CA3 interneurons during the first postnatal week as well as during the second postnatal week, since GluK1 subunit is known to undergo developmental changes in its expression during this time. No significant effect was however detected in either of the age groups. Although in our experiments the GluK1-KAR inhibition seemed to induce no statistically significant changes in the Ca2+ current amplitudes or in the voltage-dependence of VGCC-mediated currents in the CA3 interneurons, further, more specific studies should be encouraged to investigate the phenomenon in specific interneuron subtypes and in distinct calcium channel families.

Epileptic patients experience spontaneous recurrent seizures and interictal epileptiform discharges that lead to brain injuries, triggering neuroinflammation and waste product accumulation. Due to the detrimental effect of waste products on brain homeostasis, their removal from the central nervous system is (CNS) is crucial. Meningeal lymphatic vessels (mLVs) located in dura matter contribute to CNS clearance by the drainage of metabolites, waste products, and immune cells from subarachnoid space into cervical lymph nodes. Therefore, because of its role in brain homeostasis, the study of mLVs in different neurological conditions and diseases, including TLE, has gotten increased attention in the last decade. In this study, we sought to understand mLVs role in neuroinflammation and changes in rapid eye movement (REM) sleep stage during epilepsy. For this purpose, we induced mLVs ablation followed by kainic acid (KA) epilepsy model in mice. Shortly, animals were inoculated with AAV-VEGFR3-1-4 to induce mLVs ablation and subsequently challenged with KA to induce status epilepticus. Simultaneously, a control group of animals were injected with a sham AAV and later injection of KA. Afterward, spontaneous EEG activity was registered continuously, and data analysed to compare durations of REM sleep. Also, immunohistochemistry of brain samples was performed to investigate neuroinflammatory changes between experimental groups. Ex-vivo analyses of Iba1 and GFAP expression in brain tissue did not show statistically significant changes in neuroinflammation between experimental groups. However, we observed a trend towards lower expression of inflammatory markers in mLVs ablated animals. The analysis of REM sleep duration shows a progressive reduction of this sleep stage in both groups during the first recording period with a subsequent stabilization during the second one. Our data also indicate that mLVs ablated animals present prolonged REM sleep duration compared to the control group. Although this data contradicts our initial hypothesis it is consistent with the well-established negative correlation between neuroinflammation and REM sleep duration. Future studies should consider a deeper analysis of the glial cell profile for a better understanding of the effect of mLVs dysfunction on epileptic pathology. Moreover, the impact of mLVs ablation on REM sleep duration should be characterized in healthy animals.

Travel behavior change is crucial for sustainable energy transition in urban environments. Among various strategies, Light Rail Transit (LRT) is gaining popularity as a potent facilitator of modal shift. However, its effectiveness is not consistently superior to its alternative, Bus Rapid Transit (BRT). LRT is less cost-effective than BRT while it is more environmentally friendly, which maintains BRT as a feasible and popular means of sustainable transport. While no consensus has been reached, Helsinki, Finland, replaced an existing BRT with its first LRT, raising questions about the sustainability consequences of this change. This paper investigates the first effects of Helsinki’s LRT on travel behavior and its potential benefits over BRT, capturing the duration in which both modes were operational (October to December 2023). Addressing this area's lack of qualitative research, 20 semi-structured interviews are analyzed alongside supplementary quantitative data. The theory of social practice is employed as the theoretical framework, enabling an in-depth understanding of everyday traveling practices. This study aims to answer two questions: 1) What do residents using LRT consider to be the most important factors influencing travel behavior change and why? 2) What potential benefits might LRT exhibit compared to buses? The results show that service attributes such as convenience, frequency, and reliability play a crucial role in the modal choice of Helsinki residents participating in this study, while door-to-door travel time is the most significant factor. It also indicates that they have a more positive attitude toward LRT than BRT at the time of the study. The probable benefits of LRT—speed, reliability, and comfort—are identified as the root factors for LRT's better attractiveness than BRT. From the perspective of social practices, the elements of the practices of LRT, BRT, and cars are identified, and the relationships among them are systematically presented. Marking the initial impacts of LRT on travel behavior from the novel case of Helsinki, the findings offer valuable insights for future research.

Platelets originate from megakaryocytes and therefore contain the same receptors. This also applies to the extracellular vesicles (EVs) they release into the bloodstream. Glycoprotein VI (GPVI) is an activating collagen receptor on platelets. It plays an essential role in platelet biology by binding to collagen and activating platelets, leading to generation of EVs. Regulation of hemostasis involves shedding of GPVI from activated platelets, leading to a soluble fragment of GPVI. Soluble GPVI is used as a biomarker for diseases. According to current literature, GPVI is present on megakaryocyte-derived EVs but not on platelet-derived EVs (pEVs), as it is considered that activation of platelets leads to proteolytic cleavage of GPVI. Research on the presence of GPVI on pEVs is so far limited and the results are inconsistent. Based on alternate finding on the presence of GPVI on pEVs using proteomics (Palviainen et al. 2024), the aims of this project were to investigate the presence of GPVI on pEVs and to compare the presence of GPVI on megakaryocyte-derived EVs and pEVs. The presence of GPVI on pEVs was investigated by using multiple set of samples which could express GPVI differently. Platelets from platelet concentrate were isolated, activated, removed after activation and the samples were analysed with flow cytometry. Isolated pEVs were analysed with dot blot and western blot. To obtain megakaryocyte-derived EVs, K562 cell line was differentiated to megakaryocyte-like cells and EVs were isolated from cell conditioned media. The presence of GPVI on pEVs and megakaryocyte-derived EVs was compared with western blot. GPVI was found on pEVs. However, an expected difference in the presence of GPVI between pEVs from activated and unstimulated platelets was not observed. The results also indicated a higher amount of GPVI in megakaryocyte-derived EVs compared to pEVs, but further optimization of the methods used is required for more reliable results. GPVI, previously thought to exist only on megakaryocyte-derived EVs in the circulation or in soluble form cleaved from activated platelets, may actually be present on pEVs. Distinguishing the presence of GPVI between megakaryocyte-derived EVs and pEVs, is relevant when using the receptor as a biomarker. The results of this study are a foundation for further investigation of GPVI on pEVs to elucidate this exciting discrepancy.

Cities of the 21st century consume massive amounts of energy, and indoor climate control within the built environment is responsible for a large fraction of the total demand. With pressures to make buildings more environmentally friendly, new energy efficient technologies and designs are continually sought after. A green roof, or a living roof, is a structural design approach that can provide a variety of ecosystem services along with the reduction of building energy demands. It has been shown that green roofs are effective tools for reducing cooling energy demands in warm and sunny climates; however, in cold climates, where heat energy demands dominate, there is a lack of research and general uncertainty about how beneficial a green roof may be. This thesis, conducted during the winter of 2013-2014, focused on the thermal performance of green roofs in cold weather (winter) conditions. The aim of the study was to quantify the reduction in energy loss that a green roof achieves and to examine the thermal behaviour of each of the green roof layers. Extensive green roofs with hot boxes underneath were constructed in Lahti (southern Finland). Heat sensors were placed vertically through the bare and green roofs to measure linear heat transfer from the interior to the exterior. Heat transfer by conduction was assessed, and a steady state analysis was used to quantify heat flux values. Furthermore, a green roof thermal conductivity model was developed to estimate the thermal conductivity of each of the layers under various environmental conditions (changing moisture contents, frost depths, and during freezing and thawing periods). Monthly comparisons of the energy lost through the two roofing structures were quantified. My results showed that green roofs reduced the amount of energy loss through the surface compared to bare roofs throughout the winter season. The overall reduction in energy loss, due to the presence of green roofs, was on average, 32.6%. Layer analysis showed that thermal conductivity of each of the layers decreased when penetrated by frost. A frost depth that extended through the whole green roof yielded the highest thermal resistance for the green roof at 3.96 m2KW-1. Comparatively, the bare roof had a thermal resistance of 0.27 m2KW-1. During times of snow coverage, the snow acted as a good thermal insulator, reducing the relative benefits achieved from green roofs. During refreezing and thawing, the green roof experienced the lowest values of thermal resistance at 1.83 m2KW-1. These results can be used for quantifying possible heat loss reductions in similar climates using a similar green roof, and the layer analysis provides information of how to best design green roof components for thermal resistance.

Global surface temperature is increasing at an alarming rate. Local populations can cope with the change, if they have adaptive potential to face the new thermal regime. Hybridization with a closely related lineage is one potential source of adaptive genetic variability. My thesis aimed to investigate thermal adaptation by looking into thermal tolerance differences between two mound-building wood ants Formica polyctena and Formica aquilonia and their hybrids. The two parental species have distinct distributions: F. aquilonia can be found in Northern Europe while F. polyctena is distributed from Central Europe to Fennoscandia. The samples for this thesis were collected from a relatively small area in southern Finland and Åland Islands. Aim of my thesis was to clarify whether the two parental species have distinct thermal tolerances, which would reflect the differences in their distributions. I also tested whether hybrid individuals have wider thermal limits since they have alleles from both northern and southern parental species and could therefore show adaptive potential. I tested thermal tolerance differences with two temperature assays: heat-knockdown resistance and chill-coma recovery. I hypothesized that F. aquilonia would express more cold-tolerant thermal limits whereas F. polyctena would express more heat-tolerant limits. My results showed that the parental species differed in their thermal tolerance and expressed thermal limits which reflected their distribution. These results support the thermal adaptation hypothesis: parental species expressed thermal limits that reflected the thermal environment in their native habitat. The results also showed that hybrids could not combine the thermal tolerance of both parental species as they did not have wider thermal tolerance than parental species. Intriguingly, dry weight had a significant role in thermal tolerance, bigger ants coping better with higher temperatures. These results contribute to building up knowledge on the outcomes of hybridization and the potential that species possess in coping with the environmental change. Wood ants are keystone species in boreal forests and the findings of my thesis shed a light on the changes in population dynamics for these species in the face of global climate change.

Vaccines have proven to be one of the most effective methods of mitigating the effects of infectious diseases. One of the most prominent hurdles facing widespread vaccine delivery is the cost and added time attributed to cold chain logistics. That is that vaccines need to be kept constantly below a certain temperature to retain their effectiveness, which in many cases is as low as -80°C. Application of specific biopolymers is one method of enhancing vaccine thermostability, diminishing the need for such cold chains by preservation at lower temperatures. This enhanced vaccine formulation is achieved through a technique known as microencapsulation, in which an active agent, in this case the vaccine, is protected through storage in a thin film of polymeric material. This preserves vaccine efficacy until later use and release from the protective film upon vaccine delivery. In the following study, a naturally derived biopolymer was investigated for its cryopreserving properties with the aim of exceeding the current benchmark of preservation at ambient temperature for 72 hours. This involved evaluation of the formulation, referred to as our designed technology (DT) across different stress parameters (4°C, 22°C and 37°C) for differing periods of time, applicability to different vaccine systems (adenovirus, envelope virus and mRNA based) and finally efficacy in both in vitro and in vivo settings. The results demonstrate that adenovirus based vaccines are able to withstand the physical, pH and temperature alterations of diverse stress tests when protected by biopolymer microencapsulation both in vitro and in vivo. This suggests that microencapsulation with the naturally derived biopolymer is a strong method of preserving adenovirus vaccine stability at temperatures up to 37°C for up to three weeks. As such, naturally derived biopolymer microencapsulation stands to drastically reduce the cost of vaccines by mitigating the need for cold chain logistics through preservation at temperatures up to 37°C.