Browsing by Title
Now showing items 161-180 of 1112
-
(2021)Concern about global warming can lead to climate change anxiety, a form of anxiety characterized by excessive worry about the climate crisis and associated consequences on the natural world and human society. It has been suggested by previous research that humor can be used to manage feelings of anxiety. This study seeks to determine if this phenomenon can be applied specifically to climate change anxiety. The research combines a comprehensive literature review with an online survey that leveraged climate change themed internet memes as a proxy for humor to gather opinions about the intersections between these two topics. The survey data supplemented claims made by existing literature, indicating that climate change themed internet memes and humor in general can be useful coping mechanisms to mitigate feelings of climate anxiety. The survey was completed by 93 respondents; most of these participants were women, located in the US, and/or between the ages of 20 and 29. Results from the survey showed that people tend to feel best about their environmental anxiety when they are taking active steps to solve the problem. Conscious decisions such as reducing waste or participating in activist movements are easier to recognize and self-report than more passive coping skills. Reliance on humor was reported as a supplementary coping skill, but many respondents indicated that looking at humorous climate change themed memes did influence their feelings about climate change overall. The scope of this study was relatively small in scale, therefore the results presented in this thesis may not be indicative of broader social trends and likely require further research.
-
(2022)Climate change have widespread increasing negative health impacts on urban residents. The impacts vary in different temporal and spatial dimensions and include health impacts such as increases in heat related illnesses, respiratory issues, and vector-borne diseases. Vulnerability and exposure to those impacts depend on different interacting factors from city level systems to individual characteristics. Papers that study how cities’ moderating factors impact on different climate change induced health impacts are an important part for setting adaptation policies. Little is known how city systems and system factors (social and physical environment and policy and planning) moderate climate change induced health impacts in cities and their role in different vulnerability and exposure outcomes. With an analytical framework that utilizes systems approach and follows conceptual framework that considers city systems as moderating factors to different vulnerability and exposure outcomes, this thesis answers the questions: How are the city systems and system factors, and climate risk elements (vulnerability, exposure) related? And what are the different types of interactions that lead to vulnerability and exposure outcomes? The main data of this qualitative case study is collected with 18 expert pair-interviews. The experts are selected from four residential areas that represent different municipalities in Helsinki and Turku. The interviews are transcribed and coded with Atlas.ti. The findings of this study emphasize that moderating factors have an impact on different vulnerability and exposure outcomes. The results also show that adaptation measures that would consider cities moderating factors, would have a significant impact on reduced exposure and vulnerability to begin with. Identification of different city system, climate risk and health impact pathway synergies doesn’t promote better adaptation policies as such. Better understanding of efficient adaptation policies require further studies of the consequences resulting from the policy decisions in physical and social environment in the long run.
-
(2020)Static floating chamber (FC) measurements of CH₄ and CO₂ fluxes from northern boreal river Kitinen were analyzed for this thesis. Measurements were carried out in summer 2018. Spatiotemporal variability was measured in the fluxes by comparing three chamber measuring locations: the opposite river banks and the middle of the river. Mean CO₂ flux estimate was 0.83±0.54 μmol CO₂ m⁻² s⁻¹ (mean ± SD, n = 73), consistent with other estimates for similar systems, with a corresponding k₆₀₀ CO₂ gas transfer velocity estimate of 17±9 cm h⁻¹ . Nonlinear modelling of CO₂ flux was found useful for analyzing floating chamber data from a river. The mean CH₄ flux was 0.0084±0.0047 μmol CH₄ m⁻² s⁻¹ , slightly lower than the median for different river systems in literature. The flux estimates were compared with eddy covariance measurements (EC). FC measurements are expected to give larger results, but additionally chambers are known to overestimate fluxes in flowing water. The comparison yielded chamber fluxes 3.3 and 2.9 times the EC median values for CO₂ and CH₄ respectively. Fluxes were similar between the three locations, and they peaked in late July for both gases in all loca- tions. Some differences over the river cross-section were observed. Discharge was significantly correlated to fluxes in the middle of the river, which could be explained by inhomogeneous flow. On two measuring days in early August, the mid-river CO₂ fluxes were three times those observed near the banks. The difference was also measured in methane. No clear cause was determined, but measuring spatial variation in surface water gas concentrations and flow could clarify the causes of similar observations in further studies.
-
(2023)Tropical coral reefs are amongst the most biodiverse and productive ecosystems on Earth. In recent decades, coral reefs have suffered an unprecedented decline in habitat-forming hard coral cover due to anthropogenic stressors, with severe impacts on ecosystem functioning and the provision of ecosystem services. Some of the pressing issues that coral reefs are facing can be mitigated through active reef restoration, such as coral transplantation, which aims to increase the hard coral cover, biodiversity, and structural complexity of a reef site. Studies on the passive benefits that increase the natural recovery potential and resilience of coral reefs following active restoration efforts remain scarce. In collaboration with Indo Ocean Project, this study aimed to compare benthic recruitment patterns between three coral sites located within the Nusa Penida Marine Protected Area, Indonesia. The reef sites included a restoration site with gardened Acropora corals, a natural site, and a rubble site that could serve as a restoration site. The experiment was conducted using standardized settlement tiles to measure and observe various response variables as indicators for the natural recovery potential and resilience capacity of the reef. The sites were also surveyed for their benthic reef cover, structural complexity, and fish abundance and community composition. The research objective was to find out how benthic recruitment patterns differ between restoration and natural reef sites, and why. The results confirm that active coral reef restoration efforts induce co-benefits in the benthic environment through enhanced structural complexity, leading to subsequent increases in overall fish abundance and particularly the number of herbivorous fish, and thus to a lower density of turf algae. These are promising findings for the later development of the reef site. The results do not imply that restoration efforts directly translate into enhanced coral recruitment or increases in crustose coralline algae abundance. However, the plentiful supply of spats observed at the restoration site indicates that local coral recruitment can improve over time after the transplanted corals have healed from transplantation stress and become fecund. Finally, the current rubble area can be expected to function as a restoration area in the future, as it appears to be within the reach of coral recruits. This study demonstrates that active coral reef restoration can yield benefits for the whole benthic ecosystem, and thereby aid recovery and strengthen resilience at localized scales. Given the accelerated rate of coral reef degradation, regular monitoring of restoration success is crucial to avoid loss of information regarding the benefits of active coral reef restoration for the fragile benthic ecosystem.
-
(2024)Despite promises of economic growth and prosperity through international trade, a continued divergence in national incomes demonstrates the continuously rising inequality between countries of the Global North and South. While many studies have attributed factors such as availability of capital resources and political and economic institutions to the uneven economic development of countries over time, very little has been said about the role of historical relations and colonial legacies in this prevailing state of global (economic) inequality. This thesis aims to shed light at the impact of colonial legacies on economic inequality between countries based on a unique database on forest commodity trade between Germany and Cameroon from 1892 to 2022, derived from the German governments statistical office. The findings of the trade data analysis indicate major structural inequality starting from the period of German colonialism from 1892-1912. The imported forestry commodities benefitted the industrialization and development of the German economy, while the exported commodities mainly served the German community in Cameroon. After the German colonial period, a drastically declining export of forest products demonstrates the changing ownership structures of the colonial plantations into French and British hands as well as the role of political rivalries in the accessibility of colonial markets. From 1950 onwards, timber plank exports appeared as a new commodity, implying an emerging timber processing industry in Cameroon. However, the value of those exports did not exceed the log exports, suggesting the struggle of the local industry to establish itself. After market liberalization in the 1990s, a second attempt at establishing a plank industry succeeded, suggesting a strong role of foreign companies within the industry. Overall, albeit other sectors, such as oil and gas becoming Cameroon’s main export sector over time, the forestry sector clearly remained the dominant German import sector throughout time, suggesting a strong path dependency from colonial times. Through an additional analysis of tracing German financial actors presence through a historical network analysis approach, this thesis further aims to show how historically established structures facilitate the reproduction of colonial relations in economic flows, by arguing that first mover advantages of German companies, made possible through colonial occupation, allowed companies to establish and manifest their position in the forest industry, making it harder for local companies to enter the industry. Albeit the limited sample size, the findings suggest confirming this pattern, as several German financial actors remain in the Cameroonian forestry sector over time. These notably include one of the companies that was a signatory of the treaty establishing German colonial rule in 1884.
-
(2023)Both microplastics (MPs, size 0.1 to 5 mm) and pharmaceuticals and personal care products (PPCPs) are ubiquitous in aquatic environments globally. Polystyrene microplastic (PS-MP) and diclofenac (DCF) are among the most widespread and commonly occurring MPs and PPCPs in the environment. Exposure to these chemicals in single has been reported to cause oxidative stress, immobilization, changes in growth and reproduction and even mortality in Daphnia magna. Moreover, MPs have the ability to act as a vector for PPCPs, and several laboratory studies have reported that PS-MP is able to absorb DCF. However, the combined toxicity of MPs and PPCPs remains largely unknown, especially as is the case for the combined toxicity of PS-MP and DCF in D. magna. In this study, D. magna was exposed to PS-MP and DCF, both in single and combined, at a concentration of 0.5 mg/L each. The aim was to assess the combined toxicity of the two, and determine whether they had a synergistic, additive, or antagonistic effect in D. magna. Whole organism endpoints monitored included mortality, immobilization, and moulting. Physiological endpoints monitored focused on oxidative stress and antioxidant defence, including reactive oxygen species (ROS), superoxidase dismutase (SOD), catalase (CAT), and glutathione S-transferase (GST). The results indicated that both PS-MP and DCF in single were able to significantly alter D. magna antioxidant and biotransformation enzyme activities by inhibition of SOD and GST, while there were no observed impacts on the monitored whole organism endpoints or ROS and CAT. However, similar significant inhibition of SOD and GST was not observed in the combined exposure, which indicates that the combined toxicity of PS-MP and DCF in D. magna was most likely antagonistic. These results highlight that the combined toxicity of MPs and PPCPs is a complex topic that still needs further investigation to fully understand the complex interactions between MPs and PPCPs.
-
(2022)Diabetes mellitus is an incurable disease caused by dysfunctional insulin signaling. The brown adipose tissue (BAT) serves as a hotspot for both lipid and glucose consumption and is thus an attractive target for treating metabolic diseases. Newly surfacing evidence suggest that the endothelial cells (ECs) lining the inner layer of vessels might regulate the morphology and function of adipose tissues. Several studies, including our own, suggest that the vessel density is negatively affected by metabolic diseases. As the BAT is an important organ for systemic lipid and glucose metabolism, and as the effects of metabolic diseases on BAT vessels are not adequately explored, I wanted to investigate how the BAT vasculature changes upon early time points of type 1 (T1D) and 2 (T2D) diabetes in this thesis work. To this end, I used mouse models with chemically induced T1D and genetic T2D and characterized these models with immunohistochemical analyses and immunoassays. To explore the transcriptomic landscapes of ECs and adipose stem cells (ASCs), I analyzed scRNAseq data of BAT stromal vascular fractions (SVF), focusing on changes in gene expression and EC-ASC interactions at a transcriptomic level. Also, by using a publicly available single-cell RNA sequencing (scRNAseq) dataset, I compared BAT SVF gene expression to complement the data resulting from our experiments. The results from this work reveal differential angiogenic responses in the T1D and T2D mouse models and open new avenues of research into how these different pathways are activated and how we can take advantage of these differences to treat diseases. All in all, this work will support the efforts in developing better options for future diabetes prevention, diagnosis, and care.
-
(2021)Tiivistelmä – Referat – Abstract ROS or Reactive Oxygen Species can be found throughout all living organisms on the planet. Without ROS, processes, which are essential for the sustainment of most living organisms, such as respiration would not be possible. On the other hand, uncontrolled ROS generation can cause severe damage to the cellular structure. The family of ROS includes multiple compounds, which share a common trait of high chemical activity. ROS can be produced on demand by specific enzymes which are localized within cellular structures, such as membranes. One group of enzymes is called NADPH (Nicotinamide adenine dinucleotide phosphate) oxidases. These enzymes possess common structure which is composed of transmembrane region with multiple loop helixes and usually two or more terminal motifs, which are devised into regulatory EF-hand motifs and catalytic motifs. NADPH oxidases are essential ROS producers and can be found throughout most clades of living organism and are widely represented in different cellular compartments and distributed across different tissues in multicellular organisms. As an example, Nox family of NADPH oxidases can be found in human tissues and immune cells. Another common group of NADPH oxidases is respiratory burst oxidase homologues (RBOH) can be found in plants. Members of this group play important role in plant immune defense against pathogens. One example is AtRBOHD, which is expressed in Arabidopsis genus of plants. Upon activation, these enzymes are known to produce hydrogen peroxide (H2O2) as mean of antibacterial defense. These host defense mechanisms are known to be driven by different signaling molecules. It has been determined that in some examples of NADPH Oxidases, including Nox5 and RBOHD, the state of activation can be induced through the effects of Ca2+ ions. Moreover, it has been determined, that ROS-producing state of these NADPH oxidases is achieved through change of conformation. This change in conformation is attributed to the different modes of interaction of motifs of oxidases, which are dependent on concentration of bivalent cation Ca2+. Previous research regarding intramolecular interactions within specific NADPH oxidase- Nox5β has been performed by multiple research teams and different sources appear to contradict each other on the exact mode of interaction of Nox5β EF-hand upon presence of Ca2+. Therefore the exact interaction model of terminals of Nox5β is unclear. In addition, the effect of presence of Ca2+ on the interaction terminals in another representative of NADPH oxidases- AtRBOHD, which possess highly analogous molecular structure of catalytic C-terminus to Nox5β, has never been thoroughly studied, as well as interactive cross-compatibility of the C and N terminals from these two distinct species of NADPH oxidases. The objectives of this research are to analyze intramolecular interactions of N- and C- terminals in Arabidopsis RBOHD and Human Nox5β upon presence of ionic calcium, compare Ca2+-induced terminals interactions in said oxidases and to establish possible cross-compatibility of terminals in these two distinct NADPH oxidase species. Practical aspects of this research included cloning the C- and N- cytoplasmic regions of Nox5β and AtRBOHD into bacterial expression vectors utilizing the PIPE cloning method, heterologous production of epitope-tagged tails of NOX5β and RBOHD in E. Coli BL21 and finally in-vitro pull-down assays to analyse the interactions of the tails upon the presence of Ca2+ as well as interactive cross-compatibility of these tails. By utilizing methods mentioned above, this research has demonstrated that interactions of terminals motifs both in Nox5β and AtRBOHD are possible even in calcium-deprived environment, which was achieved through use calcium-binding agent (EDTA) and the effect of calcium on interactions of terminals both in RBOHD and Nox5β is very limited if not insignificant. This research has also demonstrated that the cross-compatible interactions between terminals of Nox5β and AtRBOHD are possible. Results of this research indicate a strong structural conservation within NADPH oxidases, which indicates similar intramolecular interaction mechanisms within two highly diverged species. These findings may prove to be useful as a background for the future research regarding ROS producing enzymes and evolutional conservation in structures of oxidases.
-
(2022)Agriculture is emitting ~6.2 Gt CO2-Eq. annually, which accounts for ~12 % of the total annual net anthropogenic greenhouse gas (GHG) emissions globally. Agriculture emits N2O and CH4, and it is responsible globally for ~79% of N2O emissions and ~40% CH4 emissions. These emissions are vital since N2O and CH4 are 273- and 27-times greater GHG than CO2, respectively. There are many different food production systems developed to reduce these emissions. One of the most promising systems is agroforestry. Agroforestry is a complex system where trees and/or shrubs are interacting with crops and/or animals. Agroforestry is an old practice which can provide plenty of advantages, e.g., increased yields, increased biodiversity, and increased carbon sequestration. Therefore, the interest towards it has been increasing in the last decades. In this master’s thesis the different maize production systems in Zambia were studied. The comparison was conducted between low-input maize monoculture where only external input was maize seed for sowing; high-input maize monoculture where mineral fertilizers and seeds for sowing were used; and maize-Faidherbia albida agroforestry system where only external input was maize seed for sowing. The goal of this master’s thesis was to find out, which production system is having the lowest climate change potential in the Central Province of Zambia. To conduct this study, Life Cycle Assessment (LCA) -method was used. Two cases were used in LCA, i.e., Case 1 with functional unit (FU) of 1000 kg d.m. maize grain, and Case 2 with FU of 3 ha maize field. Also, four sensitivity analyses were conducted. The result from this study indicates that agroforestry system had the lowest climate change potential in both cases, and in most of the sensitivity analyses. Only exception was found in the sensitivity analysis where above-ground biomass of F. albida was substituting hydropower. In this sensitivity analysis the monoculture without external inputs had the lowest climate change potential. Since the food production in Zambia must increase in the future to reduce the hunger, the high-input system or agroforestry system are more favourable options as they produce higher crop yields. When taking the climate change potential into account, according to the results of this thesis, the agroforestry system provides more benefits. The results of this thesis can provide new knowledge which could be used in the future decision-making processes. Yet, in the future studies, more complex agroforestry systems with more sustainability pillars should be considered to provide improved information for decision-making.
-
(2015)Suomesta tavataan kaksi majavalajia: alkuperäinen euroopanmajava (Castor fiber) ja vieraslaji amerikanmajava (Castor canadensis). Euroopanmajava metsästettiin sukupuuttoon 1800–luvulla ja viimeinen euroopanmajava ammuttiin tiettävästi Sallan Eniönjoesta vuonna 1868. Vuonna 1935 aloitettiin majavien uudelleenistutukset 17 Norjasta tuodulla euroopanmajavalla. Vuonna 1937 Suomen majavakantaa vahvistettiin seitsemällä Amerikasta tuodulla amerikanmajavalla. Tahallisesta vieraslajin tuomisesta ei kuitenkaan ollut kyse, vaan vasta vuonna 1973 todettiin Castor-suvun koostuvan kahdesta eri lajista. Alueilla, joille istutettiin molempia lajeja, on jäljellä ainoastaan amerikanmajava. Syyt ovat edelleen epäselviä. Molempien lajien kannat ovat edelleen keskittyneet alkuperäisten istutusalueiden läheisyyteen, ja amerikanmajavakanta on muutamia poikkeuksia lukuun ottamatta saanut kasvaa ilman euroopanmajavan kilpailun vaikutusta. Jos lajien elinympäristövaatimukset ovat samat, eivät lajit voi esiintyä rinnakkain. Näin ollen on tärkeää tuntea molempien lajien elinympäristön käyttö mahdollisemman tarkkaan aluekohtaisesti ja ennakoida, johtaako majavalajien kohtaaminen kahden lajin rauhaisaan yhteiseloon vai mahdollisesti euroopanmajavan häviämiseen läntisestä Suomesta. Tutkimuksen tarkoituksena oli vertailla lajien elinympäristön vaatimuksia ja sitä kautta tuoda lisätietoa euroopanmajavan suojeluun. Tutkimusalueeksi valikoitui keskinen Pirkanmaan alue, missä lajien välinen etäisyys on ainoastaan 11 kilometriä linnuntietä. Aineisto koostuu vuoden 2013 Luonnonvarakeskuksen koordinoimista valtakunnallisten majavalaskentojen pesätiedoista sekä erilaisista paikkatietoaineistoista. Elinympäristönkäytön mallin muuttujat on tuotettu CORINE Land Cover 2012 (CLC2012), vuoden 2011 Valtakunnallisen Metsien Inventoinnin (VMI) ja Maanmittauslaitoksen maastotietokannan digitaalisiin paikkatietoaineistojen avulla. Alueelle luotiin 60 satunnaispistettä, jotka kuvaavat tarjolla olevaa elinympäristöä. Lajien elinympäristöjen käyttöä analysoitiin kahden logistisen regressioanalyysimallin avulla, joista ensimmäisessä tarkastellaan ydinaluetta (50m) ja toisessa elinpiiriä (1km). Analyyseissä verrattiin lajeja keskenään sekä satunnaispisteisiin. Ennen regressioanalyysejä tarkasteltiin muuttujien kolineaarisuutta Variance Inflation Factor:in (VIF) avulla, jonka jälkeen tarkasteltiin aineiston yhteensopivuuttaa mallin kanssa Akaiken informaatiokriteerin (AIC) avulla. Pienin AIC ilmaisee parhaan mallin korkeimman selitysasteen ja mallin yksinkertaisuuden (parsimonisuuden) kompromissina. Ydinalueella ei havaittu merkitseviä eroja elinympäristön vaatimuksissa lajien välillä. Majavien elinympäristönkäyttö ei kuitenkaan ollut satunnaista. Kuusen tilavuudella oli positiivinen vaikutus euroopanmajavan esiintymiseen ja lehtipuiden tilavuudella oli positiivinen vaikutus amerikanmajavan esiintymiseen verrattuna tarjolla olevaan ympäristöön. Elinpiirianalyyseissä lajien välillä havaittiin merkitseviä eroja, joissa euroopanmajava esiintyi alueilla, missä kuusen tilavuus ja sekametsän osuus oli suurempi verrattuna amerikanmajavan elinpiiriin. Kasvavalla kuusen tilavuudella, sekametsän osuudella sekä vesistöjen määrällä oli positiivinen vaikutus euroopanmajavan esiintymiseen ja rakennetuilla alueilla negatiivinen vaikutus euroopanmajavan esiintymiseen verrattaessa tarjolla olevaan ympäristöön. Amerikanmajavan elinympäristön käyttö ei poikennut satunnaisesta. Tulokset saattavat heijastaa rantavyöhykkeen metsäsukkession eri vaiheita, mutta on huomattava, että lajien välillä oli merkittäviä eroja. Elinympäristön muuttujat selittivät huomattavasti enemmän euroopanmajavan esiintymistä alueella verrattuna amerikanmajavaan. Toisin sanoen euroopanmajavan elinympäristön vaatimukset ovat spesifimmät/tarkemmat/ominaisemmat. Tulosten avulla on mahdollista ennustaa niin amerikanmajavan leviämistä alueella kuin hyödyntää tietoja euroopanmajavalle tärkeiden elinympäristöjen suojelussa.
-
(2024)Anxiety disorder is the most common mental health disorder and often comorbid with sleep disturbances. However, anxiety disorder and its link to sleep features is not well-studied. In this study, we hypothesized that anxiety and depression can affect sleep architecture in different ways. Polysomnographic (PSG) recordings of 203 subjects from two different studies were analysed to characterize changes of electroencephalographic (EEG) activity between patient groups and healthy controls during sleep. Results show that sleep patterns and EEG spectral power densities in patients with anxiety and depression follow similar patterns when compared to healthy controls. Stage N1 sleep increased in all patient groups, while REM sleep decreased compared to healthy control group. Moreover, REM sleep duration increased, and REM latency decreased in all patient groups following the exclusion of individuals under antidepressant medication. In addition, decreased EEG delta (0.4-4 Hz) and increased EEG beta (15-32 Hz) power were seen in all patient groups. These results demonstrate that sleep quality (quantified as increased N1 sleep) in patients with anxiety and depression decreases and that both disorders affect sleep in a similar way. Observing specific sleep alterations as a whole could prove more efficient than solely analysing individual sleep parameters. The use of diagnostic EEG data provides new opportunities for sleep research with relatively large sample size while also taking into account age, antidepressant use, and comorbidity with depression.
-
Comparing soil carbon content in urban meadows and managed lawns in the Helsinki Metropolitan Area (2023)Promoting carbon sequestration and storage is an important part of climate change mitigation. Soils play a prominent role in this, as they contain the largest terrestrial carbon pools. Urban soils have been shown to contain significant amounts of carbon, and thus, urban green spaces have the potential to contribute to climate regulation through soil carbon sequestration and storage. Many green spaces in cities consist of managed lawns containing significant amounts of soil organic carbon, although management activities such as mowing can also be a source of carbon emissions. A low-maintenance alternative to lawns is urban meadows. The benefits in terms of soil carbon sequestration in urban meadows, however, are still poorly documented. This study aims to contribute to an increased understanding of the ecosystem services urban meadows provide, which is valuable in the planning of urban green infrastructure. I quantified soil organic carbon content in 140 urban meadows of different land use types in the Helsinki Metropolitan Area to determine their value in terms of carbon storage and to compare this with the soil carbon storage in highly managed urban lawns. The meadow types explored included valuable grasslands, which have special nature or cultural values, landscape meadows, road verge grasslands, and rocky outcrops. Soil samples were taken from a depth of 0–10 cm using a soil corer. The soil organic matter content and bulk density were measured. Existing data from the soils of city park lawns in Helsinki were used for comparison in the analysis. The soil organic carbon content in the different meadows, as well as in the lawns, was then analysed using land use type and site productivity as explanatory variables. Results show that park lawn soils have a significantly higher carbon density (kg C per square meter) than any of the meadow types. Out of the meadow sites, valuable grasslands had the highest carbon density. The higher carbon content in park lawn soils may be due to increased productivity due to frequent mowing, as well as the fact that these lawns were likely established on nutrient-rich soil. Interestingly, the highest %C was detected in rocky sites. However, the total carbon stocks of rocky sites are lower due to the soil cover being shallow and large portions of the sites not having soil cover at all. To answer the question of whether a lawn should be converted into a meadow in hopes of increasing carbon sequestration and storage, future studies should focus on meadows that were formerly lawns, and that had the same or similar initial conditions as a typical lawn.
-
(2023)While the effects of agricultural land use on biodiversity are beginning to unravel in Europe and North America, Africa remains poorly studied. Biodiversity in a broad sense provides ecosystem functioning and services, whose importance has become obvious to humankind in the quickly changing modern world. In Ghana, the practice of mango farming continues to grow in popularity due to suitable climate and potential source of livelihood. With increased demand and production of mango, natural habitats, namely savannahs, are being converted to plantations. The effects of such habitat conversion on local biodiversity are unknown for most taxa, thus providing an interesting study system for biodiversity research. Given the direct relation between functional diversity and ecosystem services, in this work I compare the taxonomic and functional diversity of ground-living spiders between mango orchards and savannah. I chose spiders (Arthropoda; Araneae) as model organisms as they critically contribute to several ecosystem services, such as biological pest control and nitrogen cycling, while being ubiquitous and abundant, thus easy to collect in the field. Spiders were captured with pitfall traps from six mango and four savannah areas in the Northern region of Ghana. A total of 424 individuals and 53 (morpho)species were identified and counted. Additionally, six morphological and four ecological traits were quantified for each (morpho)species. With these data, I calculated taxonomic richness and evenness, functional richness, dispersion, and evenness, and beta diversity of the different assemblages in the R environment. These metrics were then compared between spiders collected from mango orchards and savannah. Mango orchards showed lower taxonomic and functional evenness than savannah, contrary to all other alpha diversity measures. The two habitat types share many of the same diversity of ground-living spiders, but species and traits are distributed less evenly in mango orchards due to incomplete niche differentiation between species. Both taxonomic and functional beta diversity were significantly different between habitat types indicating that mango orchards sustain a similar richness of species as savannah, but the species composition is different. In conclusion, mango orchards have the potential to conserve some aspects of the original diversity, but species composition and the way species interact are substantially different. We should strive to find the best practices to produce mango without radically changing the natural biodiversity patterns.
-
(2022)Light is crucial for aquatic ecosystems, as photosynthesis supports the higher trophic levels. Light attenuates in water due to absorption and scattering by optically active substances (OAS), the main ones in coastal environments being chlorophyll-a (chl-a), particulate matter and coloured dissolved organic matter (CDOM). Light attenuation measurements are also important indicators of many environmental changes. Traditionally, Secchi depth has been used to monitor changes in light attenuation. However, Secchi depth (ZS) is a not an accurate estimate of light attenuation, and conversion to light attenuation coefficient (Kd) is needed to study light conditions as aquatic organisms observe them. Therefore, calibration between methods is important. In this study, light attenuation was estimated with Secchi disc, a light meter and light loggers to scrutinize the possibilities of autonomous measurements in this context. The aims of the study were 1) to compare three methods for estimating light attenuation and 2) to identify the environmental drivers affecting the relationships and accuracy of these methods, and 3) to assess the possibility of using conductivity as a proxy for light attenuation. The main hypotheses were that the differences in conversion between ZS and the two sensor-based methods in different concentrations of optically active substances can be explained by contribution of scattering to light attenuation, and that variation in different Kd-estimates is due to the different measurement spectra. The effect of three OASs (chl-a, particulate matter, CDOM) on differences among light attenuation estimates were quantified in Pohjanpitäjänlahti bay. Light attenuation was mainly controlled by CDOM, followed by particulate matter and chl-a. Conductivity was found to be a good proxy for light attenuation. However, there was a mixed signal if the differences among methods could be explained by OAS concentrations or conductivity, as the hypotheses were supported with one device pair but not with the other. Therefore, the differences among light measurement methods might stem from the characteristics of the devices or measurement errors. However, all the methods were found suitable for tracking changes in light attenuation and a summary table of the advantages and disadvantages of each method is presented to help choose a suitable method to estimate light attenuation e.g., in future studies or environmental monitoring.
-
(2012)Genome wide linkage and association methods are used to map genes affecting traits with genetic predisposition. In this thesis, I compare the methods suitable for quantitative trait mapping in complex, extended pedigrees. As a case study, gene-mapping study of musical aptitude is performed with these methods. Linkage analysis methods are developed for family studies. However, only a few methods are suitable for extended families with a quantitative trait. Three linkage programs were successfully applied for such data in this study. These programs are the SOLAR, JPSGCS and KELVIN. All of these three programs are based on different methods and thus, the same calculations are not repeated. SOLAR is based on the variance components method, JPSGCS on a graphical method and KELVIN on the Bayesian method. Association analysis is also difficult to implement for large pedigrees, because it is best suited for case-control data. Fortunately, methods are extended also for family-based studies. Here, a genomic control method was used to correct for the familial relationships. The method evaluates the relatedness from the whole genome data and the association tests are corrected for the relatedness rates. This method was implemented from the GenAbel program. As a case study, these methods were applied to a musical aptitude study. The musical aptitude is here understood as an ability to perceive the melody, harmony and rhythm of music, and to recognize structures in set of sounds. These abilities were tested with Carl Seashore s tests for pitch and time and Kai Karma's test for auditory structuring. The data consists of 107 pedigrees and 93 sporadic subjects, comprising in total of 915 individuals. Each family includes 2 - 50 individuals. These individuals were genotyped with a SNP chip for over 700,00 SNPs. The linkage analyses revealed several promising loci for the musical aptitude. The best result was located in 4q12 and it was found with all of the three linkage programs. Most of the other results could also be identified with multiple programs, but some differences also occurred. However, none of the findings could be discovered with association analysis, probably due to a too small sample size.
-
(2024)Immunotherapy, especially with PD-L1 and PD-1 blockers, has transformed the treatment landscape for melanoma, offering renewed hope to many. However, some patients respond well while others do not, which remains a critical challenge in immunotherapy. Peripheral blood mononuclear cells (PBMCs) play a key role in the immune system, making them good candidates for exploring the differences between good responders and bad responders. In this study, the pre-treatment PBMC profiles of melanoma patients receiving PD-1 blockers were investigated to uncover differences in the PBMC populations between good responders and bad responders. An extensive optimization process was undertaken to ensure the robustness and reproducibility of the PBMC cell suspension protocol. Single-cell RNA sequencing (scRNA-seq) was used to profile the cellular composition and gene expression patterns of the PBMCs. Chromium X microfluidics technology was used for more precise cell sorting and to obtain higher quality scRNA-seq data. After sequencing, computational techniques were applied to process the scRNA-seq data, identifying unique PBMC populations and differentially expressed genes through differential expression analysis and clustering. The analysis revealed distinct PBMC populations and demonstrated variations in cell type distributions, such as T cells, monocytes, and B cells, between good and bad responders. Multiple differentially expressed genes were identified not only in the combined scRNA-seq data but also within specific cell types. Notably, genes such as IL7R and IFI44L were predominantly upregulated in good responders, suggesting their potential roles as biomarkers for an effective immune response. Conversely, genes like CD83 were more highly expressed in bad responders, potentially indicating mechanisms of immune suppression. These findings highlight the complexity of immune interactions in response to PD-1 blockade and underscore the potential of scRNA-seq analysis of PBMCs to discover biomarkers for predicting treatment outcomes. Future studies are required to further refine cell suspension protocols and enhance data robustness. Additionally, larger cohort studies are needed to validate these findings and further clarify the cellular mechanisms influencing responses to PD-L1 blockade in melanoma, aiming to enhance the predictive power of liquid biopsies and refine immunotherapeutic strategies.
-
(2024)The protein kinase C (PKC) enzyme is a type of peripheral membrane protein that is classified as a member of the Ser/Thr kinases superfamily. Its function is to add phosphate groups to serine or threonine residues in other proteins. The multitude of functions that PKC performs, and consequently its involvement in a diverse array of diseases, is attributed to the complicated nature of the enzyme: it consists of 12 distinct isoforms, each exhibiting minor variations in catalytic activity. Out of them, eight have therapeutic potential and utilize diacylglycerol (DAG) as a secondary signalling molecule. The research in this thesis is to perform computational modelling that assists an experimental research program searching for selective activators for PKC. The particular project involves combining molecular modelling with insight from structural biology. In concrete terms, three pieces of scientific work are involved: 1) The investigation of the behaviour in the membrane of drug candidate molecules that emerge as new scaffolds is developed by the experimental medicinal chemistry team. 2) Predicting the structure of PKCα, PKCδ, and PKCϵ using AlphaFold2 and evaluating their stability using molecular dynamic simulation. 3) Combining the predicted structures with DAG-containing membranes to examine predicted protein binding to the membrane. According to the results, 15 candidates out of 21 exhibited comparable behaviour to the positive control in terms of their angle of penetration into the membrane leaflets. Turning to regulatory domain prediction, all three proteins’ C1 and C2 domains were predicted with high confidence scores. All predicted structures showed root mean square deviation (RMSD) and root mean square fluctuation (RMSF) within the normal range, and most of their secondary structures were stable during simulation. When combined with the membrane, the C2 domains showed stable interactions with the membrane, and C2 binding to the membrane completely triggers C1 to bind to the membrane; however, there were some instabilities between the C1 domain binding and the membrane. This study highlights promising PKC activators, demonstrating the utility of computational modelling for identifying potential therapeutic agents.
-
(2022)Ympäristökriisi on yksi aikamme suurimmista globaaleista ongelmista. Voimakkaana tekijänä kriisissä ovat ihmisten valinnat niin arjen kuluttamisessa kuin yleisessä käyttäytymisessä luontoa kohtaan. Ympäristömyönteinen käyttäytyminen kumpuaa luontoyhteydestä, jonka nähdään rappeutuneen nyky-yhteiskunnassamme. Tästä johtuen lisäämällä ihmisten luontoyhteyttä voisimme edistää heidän ympäristömyönteistä käyttäytymistään. Tämä tutkielma käsittelee luontoyhteyden ja ympäristömyönteisen käyttäytymisen välistä yhteyttä. Tavoitteena on hahmottaa, millä tavoin tämä yhteys muodostuu, jotta voimme lisätä ihmisten ympäristömyönteistä käyttäytymistä syvällä ja perusteellisella tasolla. Tutkielmassa pyritään vastaamaan tähän systemaattisen kirjallisuuskatsauksen keinoin perehtymällä aiempien tutkimusten aihepiireihin ja niiden teoreettiseen pohjaan koskien luontoyhteyden ja ympäristömyönteisen käyttäytymisen suhdetta. Katsauksessa löydettiin 38 kappaletta soveltuvia artikkeleita, joita analysoitiin luokittelemalla niitä seuraavin perustein: 1) millaisia yhteyksiä aiempi tutkimus on luonut luontoyhteyden ja ympäristömyönteisen käyttäytymisen välille, ja 2) mitä välittäviä muuttujia luontoyhteyden ja ympäristömyönteisen käyttäytymisen välillä on havaittu aiemmissa tutkimuksissa. Tutkimuksen mukaan aineistosta voidaan muodostaa kolme kategoriaa, jotka ovat: 1) CTN-PEB, 2) x-CTN-PEB, and 3) CTN-x-PEB. Tutkimuksessa syvennyttiin eniten kategoriaan numero kolme, jossa luontoyhteyden ja ympäristömyönteisen käyttäytymisen suhdetta selvitettiin erilaisten välittävien muuttujien avulla. Jatkotutkimusta kausaalisen yhteyden selvittämiseksi tarvitaan.
-
(2023)Deforestation is the main threat to biodiversity, ecological integrity and socio-ecological resilience of the of the Amazon biome, one of the most biodiverse places on Earth and home to at least 2 million people. A complex network of diverse protection strategies exists across the Amazon as key component of the global strategy to halt biodiversity loss. Biosphere reserves are a part of this network that aims to create spaces to learn how human communities can develop sustainably, while the protecting the environment, by implementing a zonation system with different degrees of protection We consider that it is necessary to produce relevant efficiency assessments on area-based conservation strategies in this region, and to understand how different protection strategies affect conservation outcomes. We used state-of-the-art matching methods to create a counterfactual deforestation avoidance measure of seven Biosphere reserves the western Amazon: Yasuní, Podocarpus-El Cóndor, Sumaco, Manu, BIOAY, Pilón Lajas and Beni. We obtained diverse efficiency results, some of the studied reserves avoiding large quantities of deforestation to reserves that were attracting deforestation. We found that more strictly protected zones were subjected to significatively lower relative pressure levels and did not have higher deforestation avoidance values. Representativity of the matched treatment area was also lower for these zones, meaning that the matching analysis was more difficult to perform in these areas. These research findings add to growing evidence about the important role of biosphere reserves in buffering against deforestation in one of the world’s most important biodiversity hotspots.
-
(2024)Korkeasaari Zoo has several large ruminants adapted to distinct climates and habitats. It is well known, that ensuring the possibility of the animals to live in captivity, that resemble their natural habitat, is important for their welfare. However, thermal environment of zoo-housed animals is not often studied, even though it can have major impact on animal welfare. Especially for cold-adapted species the shade availability during hot, sunny days is essential and therefore needs high attention. In my thesis, I monitored the shade use and behaviour of musk ox (Ovibos moschatus), yak (Bos grunniens), takin (Budorcas taxicolor), wisent (Bison bonasus), Przewalski’s wild horse (Equus przewalskii) and kulan (Equus hemionus kulan) in their enclosures in Korkeasaari zoo by using ZooMonitor application. Species were chosen by their different level of warm adaption for comparison. I found out the shade availability in each enclosure during different times of the day with aerial photographs. The purpose was to find out if there is a need to enhance the shaded areas to ensure animal welfare. Research questions were 1) How much shade is available in each enclosure? 2) Is shade use dependent on a) temperature b) time of the day? 3) Are less warm adapted species (musk ox, yak, takin) seeking shade more obviously than more warm adapted species (wisent, kulan, wild horse)? To analyse, behavioural space use data was assessed in the form of a heat map with aerial photographs to evaluate location preferences for each animal in each enclosure. Behaviour Budget reports were used to display the percent of time engaged in behaviours. In conclusion, musk ox has shade in their enclosure 43% in the morning, 18% in the noon and 36% in the afternoon. Its shade use is dependent on time. Yak, kulan and wild horse has shade 33% in the morning, 18% in the noon and 21% in the afternoon. Shade use of yak and kulan is dependent on temperature. Shade use of wild horse is dependent on time. Takin has shade 93% in the morning, 73% in the noon and 77% in the afternoon. Its shade use is dependent on temperature and time. Wisent has shade 57% in the morning, 43% in the noon and 14% in the afternoon. Its shade use is dependent on time. Less warm adapted species are seeking shade more frequently than more warm adapted species, but surprisingly kulan stronger than wisent and almost equally as yak. Combined, shaded areas are important for zoo-housed animals to thermoregulate. The least warm adapted musk ox needs more shaded areas as they are scarce in their enclosure. Providing more shaded areas increases the space available for the animals.
Now showing items 161-180 of 1112