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  • North, Ace (Helsingin yliopisto, 2010)
    Environmental variation is a fact of life for all the species on earth: for any population of any particular species, the local environmental conditions are liable to vary in both time and space. In today's world, anthropogenic activity is causing habitat loss and fragmentation for many species, which may profoundly alter the characteristics of environmental variation in remaining habitat. Previous research indicates that, as habitat is lost, the spatial configuration of remaining habitat will increasingly affect the dynamics by which populations are governed. Through the use of mathematical models, this thesis asks how environmental variation interacts with species properties to influence population dynamics, local adaptation, and dispersal evolution. More specifically, we couple continuous-time continuous-space stochastic population dynamic models to landscape models. We manipulate environmental variation via parameters such as mean patch size, patch density, and patch longevity. Among other findings, we show that a mixture of high and low quality habitat is commonly better for a population than uniformly mediocre habitat. This conclusion is justified by purely ecological arguments, yet the positive effects of landscape heterogeneity may be enhanced further by local adaptation, and by the evolution of short-ranged dispersal. The predicted evolutionary responses to environmental variation are complex, however, since they involve numerous conflicting factors. We discuss why the species that have high levels of local adaptation within their ranges may not be the same species that benefit from local adaptation during range expansion. We show how habitat loss can lead to either increased or decreased selection for dispersal depending on the type of habitat and the manner in which it is lost. To study the models, we develop a recent analytical method, Perturbation expansion, to enable the incorporation of environmental variation. Within this context, we use two methods to address evolutionary dynamics: Adaptive dynamics, which assumes mutations occur infrequently so that the ecological and evolutionary timescales can be separated, and via Genotype distributions, which assume mutations are more frequent. The two approaches generally lead to similar predictions yet, exceptionally, we show how the evolutionary response of dispersal behaviour to habitat turnover may qualitatively depend on the mutation rate.
  • Dadzie, Samuel K (2007)
    The thesis is about a one year follow-up ergonomic intervention study on the improvement of low back disorders, perceived health status and overall working ability, among various kitchen institutions in Finland, with the ultimate aim of meeting the requirements of workers’ capabilities by addressing their issues and the working environment; the match between personnel and equipments usage, work processes and environment. LBP is a typical MSD which may be characterised by periodic and protracted pains, stresses and strains around the low back often as a result of fitting workers in working environments whose design falls short of targeted ergonomic standards. Effective ergonomic changes can be attained by means of technical, administrative and socioeconomic procedures. Workers involvement in the planning and implementation of possible changes effects ergonomic efficiency. Individual physical attributes and habits ought to be taken into consideration to better understand and assess the effect of ergonomic intervention programs. Effective ergonomic approach is realised through a reduction in MSD (eg. LBP) cases and associated pain reduction, minimal absenteeism, perceived health improvement and hence, improved work ability. Linear mixed models was the main statistical analyses employed in modelling the mean changes in low back pain, as well as accounting for the covariances in the repeated measures. The statistical results revealed that, generally, there was an improvement in low back pain, reduced LBP sick leaves, among the intervention group compared to that of the control group. These differences, however, were often not, statistically, significant. Further, the intervention group excelled in their respective perception of health (in terms of aspects of quality of life). It is recommended that work organization be improved in the direction of elevated levels of WPFs, which are keys to job satisfaction and LBP recovery. Larger sample size is required in guaranteeing further and detailed analyses to deepen our understanding and appreciation of the interrelationships among many underlying constructs associated with MSDs, and their progression, for the effective evaluation of intervention program
  • Sutton, David (2003)
    Peacekeeping operations have grown in scope and frequency over the decades since the establishment of the Unite Nations (UN). In particular, the optimism attending the UN’s prospects of greater leadership in conflict resolution in a new season of openness following the end of the Cold War saw increasing UN involvement in varied and complex conflicts – many involving ethnic rivalries that have surfaced amid the turbulence of the formation of new states and the spread of democracy in the last decade. Unfortunately, few of these operations have been widely regarded as successful, and some have ended in absolute disaster. There is a continuing need to search for the factors which hinder success and to evaluate the compatibility of current peacekeeping methods and assumptions with conflicts in which those factors play a significant role. Thus, this paper begins by examining the design, function and doctrine of traditional peacekeeping missions, from which a definition of success is also established. The nature and particular difficulties of ethnicity and ethnic conflict are delineated and a key interaction between these and the current broad UN approach to conflict is explored. From this understanding, two UN missions – the United Nations Operation in Mozambique (ONUMOZ) and the United Nations Assistance Mission for Rwanda (UNAMIR) – are compared to determine whether a substantial ethnic component to a conflict may in fact emerge as a significant hindrance to successful peacekeeping operations given current methods and assumptions. The conclusion drawn is that the success of UN peacekeeping missions, which are designed to facilitate negotiated settlements with the consent of the parties involved, is seriously challenged when the conflict in question is characterized by significant ethnic animosity. It is suggested that UN planners should therefore intervene in ethnic conflict more circumspectly, and that more serious consideration should be given to more robust measures if a peacekeeping mission is undertaken.
  • Mujunen, Virpi (2004)
    In the social psychological research, language and identity may be seen as reciprocally related. As the abundance of sociolinguistic research has focused on how identity explains behaviour, the focus of this study was reversed, that is, how one´s identity is shaped by language. The goal of this study was two-fold, to find out about the relationship among objective ethnolinguistic vitality (EV), individual network of language contacts (INLC), and ethnolinguistic identity, as well as to find out about the importance of childhood language background to ethnolinguistic identity. Ethnolinguistic vitality construct developed by Giles, Bourhis and Taylor (1977), as well as the model by Allard and Landry (1986, 1992, 1994) were used as the theoretical framework for this study. According to the latter model, INLC acts as a link between the sociological level (EV) and the psychological level (identity). The sample consisted of 563 Swedish-speaking Finns, out of which 51% came from South Finland province and 49% from West Finland province. About 44% of the participants were males and 56% were females. The study was conducted using data collected in the fall 2000 for a research project “Swedish and Finnish as minority and as majority: Stereotypes, group identification and self-images” led by professors Karmela Liebkind and Anders Lange. The data was analyzed using mainly hierarchical regressional analysis. The results of this study supported earlier research according to which ethnolinguistic vitality has an effect on ethnolinguistic identity via individual network of language contacts. The objective vitality, in this case the language of community, allows these networks to expand, but it is these networks that have the effect on identity.
  • Mujunen, Virpi (2004)
    Sosiaalipsykologisessa tutkimuksessa kieli ja identiteetti nähdään usein olevan molemminpuolisessa vuorovaikutussuhteessa keskenään. Koska suuri osa aikaisemmasta tutkimuksesta on käsitellyt identiteetin vaikutusta käyttäytymiseen, tämän tutkimuksen tarkoitus oli päinvastainen eli selvittää, miten kieli vaikuttaa identiteettiin. Tutkimuksessa keskityttiin lähinnä kahteen kysymykseen: Ensinnäkin selvitettiin objektiivisen etnolingvistisen vitaliteetin, henkilökohtaisten kielikontaktiverkostoiden ja etnisen identiteetin välisiä suhteita. Toisaalta haluttiin saada selville mikä merkitys lapsuuden kielitaustalla on etniselle identiteetille. Viitekehyksenä näiden tekijöiden välisiä suhteita tarkasteltaessa oli Gilesin, Bourhisin ja Taylorin (1977) sekä Allardin ja Landryn (1986, 1992, 1994) esittämät etnolingvistisen vitaliteetin mallit. Jälkimmäisen mallin mukaan kielikontaktiverkostot toimivat välittäjinä sosiologisen ja psykologisen tason välillä. Tutkimuksen otos koostui 563 ruotsinsuomalaisesta, joista 51% oli Etelä-Suomen läänistä ja 49% Länsi-Suomen läänistä. Naisia tutkimukseen osallistuneista oli 56% ja vastaavasti miehiä 44%. Tutkimusaineistona käytettiin syksyllä 2000 professori Karmela Liebkindin ja professori Anders Langen johtamaa tutkimusta varten kerättyä aineistoa (”Suomalaiset ja ruotsalaiset vähemmistönä ja enemmistönä: Stereotypiat, ryhmäsamastuminen ja minä-käsitys”). Aineisto analysoitiin pääasiassa hierarkkisten regressioanalyysien avulla. Tutkimuksen tulokset tukivat aikaisempia tutkimuksia, joiden mukaan kielikontaktiverkostot toimivat välittäjinä etnolingvistisen vitaliteetin sekä identiteetin välillä. Objektiivinen vitaliteetti eli tässä tapauksessa kunnan kielisyysaste luo puitteet, joissa kielikontaktiverkostot voivat kehittyä. Nämä verkostot ovat kuitenkin niitä, jotka vaikuttavat etniseen identiteettiin. Samoin toisesta kysymyksestä saadut tulokset tukivat aiempaa tutkimusta eli lapsuuden kielitausta oli merkittävä etniselle identiteetille.
  • Penttinen, Heidi (2013)
    The main goal of the thesis was to investigate the effects of a 12-month supervised exercise intervention on breast cancer patients' QoL shortly after adjuvant treatment. The secondary aims were to assess the physical and psychological well-being of patients immediately after adjuvant treatment of the largest breast cancer survivor population intervention study (BREX) to date and the patients' willingness to participate in such a long intervention. In addition, the work aimed to further clarify the results of the intervention by analyzing the QoL changes of participants of the exercise study compared to those of normal follow-up patients. Patients: Of the 573 randomized patients (aged 35 to 68 years), 500 were included in the final analyses of the effects of exercise intervention: 263 in the exercise group and 237 in the control group. A total of 73 patients were excluded from the final analyses for various reasons: not meeting the inclusion criteria (36), declined for personal reasons (20), breast cancer recurrence (14), and new malignancy during the intervention (3). All 537 patients who met the inclusion criteria after the baseline visit and investigations were included in the baseline analysis. Patients of the additional study consisted of two separate patient groups: 237 control patients of the BREX study and 108 similar breast cancer patients (who met the same inclusion criteria and were treated according to the same guidelines as the patients in exercise study) participating in a follow-up study which did not contain any intervention. Methods: The EORTC QLQ-C30 and BR-23 questionnaires were used to evaluate QoL, FACIT-F for fatigue, and the Finnish modified version of Beck s 13-item depression scale (BDI). Physical fitness was assessed by a 2-km walking test and figure-8 running test, and physical activity (PA) by metabolic equivalent (MET) hours per week (MET-h/wk) based on data collected by a prospective two-week physical activity diary. Results: Of the eligible patients 78.3% participated in the study. At baseline, the global QoL of the study patients was lower than in the general population; 26% of them were rated as depressed, 20% as fatigued, and 82% suffered from menopausal symptoms, which seemed to impair QoL. Most scores from the EORTC QLQ-C30 improved significantly within both the exercise and control groups during 12 months, with no significant differences between groups. Participation in the exercise intervention study per se seemed not to improve the QoL of breast cancer survivors. At baseline, 62% of the walking test results were below the population average. Physical performance in walking tests correlated significantly to MET hours and to previous leisure-time physical activity. The amount of physical activity increased from baseline over a 12-month period in both groups; there were no significant differences between the groups. Neuromuscular performance improved significantly in the training group during 12 months. No significant effect of intervention was observed on cardiorespiratory fitness. However, the walk time improved significantly in both groups during the intervention. Already at baseline, PA improved QoL. After the 12-month follow-up there was a linear relationship between increased PA and improved QoL, irrespective of the intervention. There was a significant linear trend between higher physical activity and improved QoL and recovery from fatigue. No significant relationship was detected between physical activity and depression or between physical performance (figure-8 running or 2-km walking test) and QoL, fatigue or depression. Conclusions: Recruiting patients to the study succeeded excellently. With the exception of age limit and musculoskeletal disorders, the study population represents the general Finnish breast cancer population. At baseline, the QoL of the patients was impaired and the physical performance poor compared with the general population; in particular, depression and fatigue were related to impaired QoL. The study did not find evidence to support the superiority of the 12-month supervised vigorous aerobic exercise and home training over the control arm in improving physical activity and QoL of the patients. In contrast, both groups improved equally during the follow-up duration. Spontaneous recovery of QoL seems to be the most likely explanation for the observed results, at least when the intervention is timed to the rehabilitation period. Future exercise intervention studies targeting improvement of QoL should identify groups of patients that could benefit the most from an intervention and tailor the interventions to their specific needs.
  • Alam, Syed Ariful (Helsingfors universitet, 2012)
    Oats are a good source of protein and dietary fibre, especially ?-glucan. Due to the health benefits of ?-glucan, oats have gained popularity in snack food formulations. The literature review deals with oats and its components, removal of lipids and fractionation of oat products. The particular emphasis of the literature review was given to studies on the effects of different oat fractions and extrusion process variables on the properties of oat-containing extrudates. The aim of this study was to find out how different oat fractions and extrusion process variables (screw speed, water content and feed rate) affect the physical and chemical properties of the extrudates. The measured physical properties were expansion, hardness and water content. Extrusion trials were carried out by using defatted oat endosperm flour (EF) as the main ingredient. Whole grain oat flour (WF) was used as a reference. To improve the nutritional quality, defatted oat protein concentrate (PC) and defatted oat bran concentrate (OBC) were added to EF. The oat fractions were defatted by supercritical carbon dioxide (SC-CO2). Pregelatinised corn starch (CS) and waxy corn starch (WS) were added in some trials to increase the expansion of the extrudates. A co-rotating twin-screw extruder was used for the extrusion. Different process variables were: water content of the mass (16, 18 and 20%), screw speed (240, 370 and 500 rpm) and feed rate (68, 76 and 84 g/min). The temperature profile of the extruder barrel was held constant in all of the trials: 40, 70, 70, 100, 110, 130 and 130 °C (sections 1 6 and die). Screw speed had significant effect on the expansion and hardness. Expansion increased and hardness decreased with increasing screw speed. Water content of the mass affected all the response variables in WF extrudates and all but not hardness and torque in EF extrudates. Increased water content of mass decreased the expansion and hardness in WF extrudates. Feed rate did not have significant effect on the physical properties. When using EF, more expanded and less hard extrudates compared to the WF were obtained. Addition of PC or OBC (10%) decreased the expansion and increased the hardness. Mixing of EF with corn starch (CS or WS; 30%) gave less hard and more expanded extrudates compared to pure EF. The highest expansion was achieved by the addition of WS. Even addition of OBC (20%) in a presence of WS (30%) gave highly expanded and less hard extrudates with high ?-glucan content 7.4% (dry weight). Decreasing the particle size of OBC (by ultra-fine milling) or the molecular weight of ?-glucan (by enzymatic hydrolysis) did not affect the physical properties of the extrudates even though small decrease in hardness was observed in the trial with enzyme-hydrolysed OBC. The results showed that defatted oat fractions can successfully be used in extrusion when mixed with corn starch. Screw speed had the most profound effect on the physical properties of the oat-containing extrudates followed by the water content of mass.
  • Xiang, Xiaoqiang (Helsingin yliopisto, 2011)
    Bile acids are important steroid-derived molecules essential for fat absorption in the small intestine. They are produced in the liver and secreted into the bile. Bile acids are transported by bile flow to the small intestine, where they aid the digestion of lipids. Most bile acids are reabsorbed in the small intestine and return to the liver through the portal vein. The whole recycling process is referred to as the enterohepatic circulation, during which only a small amount of bile acids are removed from the body via faeces. The enterohepatic circulation of bile acids involves the delicate coordination of a number of bile acid transporters expressed in the liver and the small intestine. Organic anion transporting polypeptide 1B1 (OATP1B1), encoded by the solute carrier organic anion transporter family, member 1B1 (SLCO1B1) gene, mediates the sodium independent hepatocellular uptake of bile acids. Two common SNPs in the SLCO1B1 gene are well known to affect the transport activity of OATP1B1. Moreover, bile acid synthesis is an important elimination route for cholesterol. Cholesterol 7α-hydroxylase (CYP7A1) is the rate-limiting enzyme of bile acid production. The aim of this thesis was to investigate the effects of SLCO1B1 polymorphism on the fasting plasma levels of individual endogenous bile acids and a bile acid synthesis marker, and the pharmacokinetics of exogenously administered ursodeoxycholic acid (UDCA). Furthermore, the effects of CYP7A1 genetic polymorphism and gender on the fasting plasma concentrations of individual endogenous bile acids and the bile acid synthesis marker were evaluated. Firstly, a high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method for the determination of bile acids was developed (Study I). A retrospective study examined the effects of SLCO1B1 genetic polymorphism on the fasting plasma concentrations of individual bile acids and a bile acid synthesis marker in 65 healthy subjects (Study II). In another retrospective study with 143 healthy individuals, the effects of CYP7A1 genetic polymorphism and gender as well as SLCO1B1 polymorphism on the fasting plasma levels of individual bile acids and the bile acid synthesis marker were investigated (Study III). The effects of SLCO1B1 polymorphism on the pharmacokinetics of exogenously administered UDCA were evaluated in a prospective genotype panel study including 27 healthy volunteers (Study IV). A robust, sensitive and simple HPLC-MS/MS method was developed for the simultaneous determination of 16 individual bile acids in human plasma. The method validation parameters for all the analytes met the requirements of the FDA (Food and Drug Administration) bioanalytical guidelines. This HPLC-MS/MS method was applied in Studies II-IV. In Study II, the fasting plasma concentrations of several bile acids and the bile acid synthesis marker seemed to be affected by SLCO1B1 genetic polymorphism, but these findings were not replicated in Study III with a larger sample size. Moreover, SLCO1B1 polymorphism had no effect on the pharmacokinetic parameters of exogenously administered UDCA. Furthermore, no consistent association was observed between CYP7A1 genetic polymorphism and the fasting plasma concentrations of individual bile acids or the bile acid synthesis marker. In contrast, gender had a major effect on the fasting plasma concentrations of several bile acids and also total bile acids. In conclusion, gender, but not SLCO1B1 or CYP7A1 polymorphisms, has a major effect on the fasting plasma concentrations of individual bile acids. Moreover, the common genetic polymorphism of CYP7A1 is unlikely to influence the activity of CYP7A1 under normal physiological conditions. OATP1B1 does not play an important role in the in vivo disposition of exogenously administered UDCA.
  • Zou, Ling (Helsingfors universitet, 2009)
    Andean lupin (Lupinus mutabilis Sweet) is a potential oilseed crop, with a very high protein content (40–45%) and 15–20% oil content. It is valued as an alternative protein source for both human and animal consumption, and like several other lupin species, has a potential role in phytoremediation. Previous experience in central and southern Europe has shown the crop to have low and unstable yields with high sensitivity to heat and drought during the grain–filling stage. The species may therefore be more suitable for cool–temperate climates, as it comes from similar altitudes and latitudes as potato. Therefore, an experiment was set out to quantify the responses of Andean lupin to heat stress, using both gradually and suddenly rising temperatures during grain filling. In preliminary tests 60 accessions from 4 germplasm banks were screened for time to flowering and daylength sensitivity. For this experiment, 3 accessions were chosen, 478435, 457972, 457977, with vegetative phase durations of 44, 53, 64 days from sowing to first flower, respectively. Forty two plants of each accession were sown and reduced to 30 on the basis of uniformity. Plants were grown in a glasshouse with 22 °C, 18 h days and 18 °C, 6 h nights until about 25 days after flowering. Ten plants of each accession were subjected to one of the following treatments: control (continuing in the same glasshouse conditions), sudden heat stress (transferred to a growth chamber and subjected to 38 °C from 11:00 to 15:00) or gradual heat stress (transferred to a growth chamber and subjected to temperature increases of 4 °C day temperature and 2 °C night temperature, with the final two days at 38 °C from 11:00 to 15:00). The plants were returned to the glasshouse and when mature, the seeds were harvested and pooled into 3 replicates per accession and treatment for quality analysis. Seed protein, oil, soluble sugar, ash and moisture content were determined. Data were calculated on the basis of percentage of overall seed mass and also on a milligrams per seed basis in order to reflect the seed physiology at grain–filling stage. Sudden heat stress had greater effects on seed composition than gradual heat stress. When compared with control, sudden heat stress resulted in more loss of every component than gradual heat stress, on a per–seed basis, in all 3 accessions and the responses of the accessions to the sudden stress were not statistically different. Under sudden heat stress, mean seed weight declined by 70%, protein content by 70%, oil content by 85%, ash content by 50%, and soluble sugar content by 75%. The accessions responded differently, however, to the gradual heat stress. Accession 478435 experienced significantly greater reduction in seed weight, protein and ash content than accessions 457972 and 457977. Oil content per seed and soluble sugar content per seed were also lower in 478435 than in the other two cultivars, but the difference was not significant. On the flour basis, sudden heat stress increased ash content and decreased oil content and soluble sugar content significantly in all accessions. Accession 478435 had highest value in ash content at significant level. Under gradual stress, protein and ash content were increased while oil mass and soluble sugar mass were decreased. 478435 had significantly higher protein mass and ash mass in flour with respectively 57% and 5.1%, 457977 had significantly higher soluble sugar content with 112 mg/g. The results showed that heat stress can have a significant effect on the quantity and quality of seed yield in Andean lupin. While all tested accessions were severely susceptible to sudden heat stress, gradual stress identified differences between accessions, with one being much more susceptible than the other two. The most susceptible accession was the earliest to flower. Gradual heat stress allows better resolution than sudden heat stress when screening germplasm for heat tolerance.
  • Martinmäki, Vuokko (2014)
    There are large differences in hours of market work between OECD countries. It has bees argued that taxes do account much of these differences and substantial part of differences in labor supply between United States and Continental Europe can in fact be explained by differences in tax rates. However, there are differences between labor supply between Scandinavia and Continental Europe that do not support this assumption since labor supply in Scandinavia is higher than in Continental Europe despite higher tax rates on labor income. The gap in labor supply between Scandinavia and Continental Europe stems from the differences in government spending programs, in other words, use of the tax revenues. Aim of my thesis is to explore the part of the differences in hours of market work that can be explained by differences in taxation and by use of the tax revenues. First part of the paper is conducted by exploring articles and models already made about the subject. For motivation I start by presenting differences in hours worked across OECD countries and how this has changed over time. In this thesis I am going to survey how government spending policies on productive purposes affect the hours of work supplied in market sector. Two applications of government spending considered are subsidies on the price of market services and subsidies on child care. The main research question is why people in Scandinavia are working more than could be concluded purely based on labor income tax rates and can this be explained by subsidies on work. In order to explain the effects of income taxes and government spending programs on hours of market work, I present standard real business cycle model with home production. In this model households do not only allocate their time between leisure and work, but also home work. This model allows us to explore the substitution into and out of market activity which is caused by fiscal variables like taxation and transfers that are affected by state of economy. First I am going to present simple model with lump-sum transfers and then add some fiscal policy applications to the model. These applications are subsidies on the price of market services and subsidies on child care, which are forms of government spending on productive purposes and subsidies on market work. In the last part of my thesis I will simulate the models constructed. These simulations are done by using Finland as an object of interest. Result from my simulations yield that based on my models constructed, the subsidies on work can explain why people in Scandinavia work more than could be suspected based on tax rates. Based on result from my simulations I can argue that differences in labor income taxes are not a sufficient explanation for the differences in hours of market work between economies. It can be concluded that the government spending on subsidizing work through supporting family and market services do at least partly offset the effect of income taxes.
  • Laaksonen, Tommi J. (Helsingin yliopisto, 2001)
  • Harjuniemi, Aliisa (Helsingfors universitet, 2014)
    The Atlantic forest on the Eastern coast of Brazil is one of the world’s most endangered biotopes. Less than 12 % of the original forest remains due to agricultural and pasture expansion. In addition, many Atlantic forest restoration projects in the past have failed, largely because of inadequate silvicultural practices. Meanwhile, the growth rates of Eucalyptus and pine plantations have been increased 3 to 4 fold in Brazil over the last four decades by utilizing intensive silvicultural methods such as site preparation, fertilization, and weed control which in turn increases resource supply (nutrient, water and light). This study determines the effects of these same intensive silvicultural methods on Atlantic forest restoration regarding initial growth and carbon sequestering. Two parallel research sites were established in 2004 on latitudes 11°S and 23°S on the Eastern coast of Brazil to determine the effects of intensive silviculture, planting density and species composition on the development of 20 native tree species. This research focused on the Northern site (200 km North of Salvador, Bahia State) which has a typical tropical climate and soil type. The project has a 23 factorial design totalling 8 treatments, with the following factors: i) intensive and traditional treatments; ii) initial planting densities (3333 trees ha-1 and 1667 trees ha-1); and iii) species composition proportion (50:50 and 67:33 ratio of pioneer vs. late successional species). After 8 years from planting, survival and development of each species, aboveground biomass and leaf area index (LAI) were determined for all the treatments to compare the effects of the different factors. In summary, the main findings of this study are: 1) The more intensive management methods improved survival and the initial growth of tree species 2) Lower stand density (1667 trees ha-1) had the best response to the intensive management for LAI, stemwood production, and above ground carbon sequestration 3) Out of 20 species, 19 had significantly higher growth with intensive management, indicating that both pioneer and late successional species are constrained by the original site conditions. 4) Intensive management was essential, especially for non-pioneer species. 5) Under low intensity silviculture, the 67:33 ratio pioneers vs. non-pioneers with higher planting density (3333 trees ha-1) was the best option to obtain the highest stemwood volumes 8 years from planting, while the 50:50 ratio pioneers vs. non-pioneers with lower planting density (1667 tree ha-1) could be recommended under intensive silviculture. Conclusion: Intensive management methods have the potential to increase early restoration success by increasing biodiversity through enchancing survival and growth of non-pioneer species and accelerating the canopy closure. Intensive management methods increased the above ground carbon sequestered in 8 years, remarkably, up to 3-fold compared to traditional management, making it an attractive management option for carbon offsets.
  • Sirkiä, Saija (Helsingin yliopisto, 2010)
    The Capercaillie (Tetrao urogallus L.) is often used as a focal species for landscape ecological studies: the minimum size for its lekking area is 300 ha, and the annual home range for an individual may cover 30 80 km2. In Finland, Capercaillie populations have decreased by approximately 40 85%, with the declines likely to have started in the 1940s. Although the declines have partly stabilized from the 1990s onwards, it is obvious that the negative population trend was at least partly caused by changes in human land use. The aim of this thesis was to study the connections between human land use and Capercaillie populations in Finland, using several spatial and temporal scales. First, the effect of forest age structure on Capercaillie population trends was studied in 18 forestry board districts in Finland, during 1965 1988. Second, the abundances of Capercaillie and Moose (Alces alces L.) were compared in terms of several land-use variables on a scale of 50 × 50 km grids and in five regions in Finland. Third, the effects of forest cover and fine-grain forest fragmentation on Capercaillie lekking area persistence were studied in three study locations in Finland, on 1000 and 3000 m spatial scales surrounding the leks. The analyses considering lekking areas were performed with two definitions for forest: > 60 and > 152 m3ha 1 of timber volume. The results show that patterns and processes at large spatial scales strongly influence Capercaillie in Finland. In particular, in southwestern and eastern Finland, high forest cover and low human impact were found to be beneficial for this species. Forest cover (> 60 m3ha 1 of timber) surrounding the lekking sites positively affected lekking area persistence only at the larger landscape scale (3000 m radius). The effects of older forest classes were hard to assess due to scarcity of older forests in several study areas. Young and middle-aged forest classes were common in the vicinity of areas with high Capercaillie abundances especially in northern Finland. The increase in the amount of younger forest classes did not provide a good explanation for Capercaillie population decline in 1965 1988. In addition, there was no significant connection between mature forests (> 152 m3ha 1 of timber) and lekking area persistence in Finland. It seems that in present-day Finnish landscapes, area covered with old forest is either too scarce to efficiently explain the abundance of Capercaillie and the persistence of the lekking areas, or the effect of forest age is only important when considering smaller spatial scales than the ones studied in this thesis. In conclusion, larger spatial scales should be considered for assessing the future Capercaillie management. According to the proposed multi-level planning, the first priority should be to secure the large, regional-scale forest cover, and the second priority should be to maintain fine-grained, heterogeneous structure within the separate forest patches. A management unit covering hundreds of hectares, or even tens or hundreds of square kilometers, should be covered, which requires regional-level land-use planning and co-operation between forest owners.
  • Õkva, Kai (Helsingin yliopisto, 2012)
    Discussions on laboratory animal welfare issues often refer to the Three Rs replacement, reduction and refinement. Replacement means substituting living animals with non-sentient systems; reduction refers to using fewer animals and refinement causing less pain, suffering and distress to the animals or improving their welfare. This work is focusing on two R-s: reduction and refinement in mice. If one considers reduction as meaning obtaining trustworthy information from using fewer animals, then this can be achieved by improved research strategies, better experimental design and more sophisticated statistical analyses. One can reduce variation within the group by using isogenic inbred animals or by finding ways to reduce variation in outbred animals. One approach to achieve reduction in outbred animals is to include litter and individual features of the animals, e.g weight dynamics, in the statistical analyses. Since the elevated plus-maze (EPM) test is one of the most common tests to evaluate anxiety-like behaviour, it was used to assess the possible effects of litter and weight on the behaviour of outbred mice and the effects of environmental enrichment (EE) on the behaviour of inbred mice. As a research tool, the effects of acute or chronic administration of ethanol or acute therapy with the nitric oxide synthase (NOS) inhibitor L-NOARG were examined in outbred NIH/S mice. The administration of L-NOARG had no effect on the behaviour of mice after acute or chronic ethanol administration but attenuated the anxiogenic effect of ethanol withdrawal. The litter from which the mice had originated had a significant effect on their behaviour in the EPM test. The behavioural indices of mice, originating from different litters, tended to be above or below the mean of the corresponding drug-treatment group, irrespective of the drug treatment. Litter had a significant effect on the initial weight and also on the weight changes occurring during the adaptation period and ethanol inhalation. An approach to refinement, EE, has been introduced to create more natural species-specific living conditions for laboratory animals. At the same time, it has been claimed that EE can affect the results of behavioural studies and also increase variation. The effects of different types of EE and different time periods were studied in inbred C57BL/6J and BALB/c mice. The exposure of male C57BL/6J mice to the different types of EE objects in the form of cage furniture (CF) -nest box, corner and stairs- induced an anxiolytic-like effect in the EPM test and tended to increase the locomotor activity of mice. This apparent anxiolytic-like effect was most pronounced in the third week. The CF, in the form of modified Tapvei OY mouse stairs, produced an anxiolytic-like effect and increased the locomotor activity in female C57BL/6J mice, but not in BALB/c female mice. In conclusion, the NOS inhibitors may have effects on the behavioural changes caused by ethanol withdrawal. Information about the litter of outbred mice could and should be used in statistical analysis in order to reduce variation and the number of mice needed. In the EPM test, different CF items induced an anxiolytic-like effect in male and female C57BL/6J mice, but not in BALB/c female mice. This effect depended on the type of objects and was influenced by time. This anxiolytic like effect can be interpreted as refinement of the housing by improving animal welfare. The effects of CF should be considered in planning enrichment programs for housing institutions, in designing behavioural experiments and in analyzing the results obtained. Therefore the evaluation of CF could provide the valuable information and it is recommended that CF manufacturers collate and distribute the refinement results on the specific CF items they produce.