Psychological resources, their social antecedents, and association with well-being and health behaviour in early adulthood

The success of entering work life, young people s psychological resources and self-reported well-being were studied in a longitudinal setting from a life-span developmental-contextual perspective in early adulthood. The aim was to analyse how psychosocial characteristics in early childhood and adolescence predict successful entrance into work life, how this is associated with well-being, and to assess the level of psychological resources such as dispositional optimism, personal meaning of work and coping in early adulthood. The role of these and social support, in the relationship between regional factors (such as place of residence and migration), self-reported health and life satisfaction was studied. The association between a specific coping strategy, i.e. eating and drinking in a stressful situation and eating habits, was studied to demonstrate how coping is associated with health behaviour. Multivariate methods, including binary logistic regression analyses and ANOVA, were used for statistical analyses. The subjects were members of the Northern Finland 1966 Birth Cohort, which consists of all women and men born in 1966 in the two northernmost provinces of Finland (n= 12,058). The most recent follow-up, at the age of 31 years when 11,637 subjects were alive, took place in 1997-1998. The results show, first, that social resources in the childhood family and adolescence school achievement predict entrance into the labour market. Secondly, psychosocial resources were found to mediate the relationship between migration from rural to urban areas, and subjective well-being. Thirdly, psychological resources at entrance into the labour market were found to develop from early infancy on. They are, however, influenced later by work history. Fourthly, stress-related eating and drinking, as a way of coping, was found to be directly associated with unhealthy eating habits and alcohol use. Gender differences were found in psychosocial resources predicting, and being associated with success in entering the labour market. For men, the role of attitudinal and psychological factors seems to be especially important in entrance into work life and in the development of psychological resources. For women, academic attainment was more important for successfully entering work life, and lack of emotional social support was a risk factor for stress-related eating only among women. Stress-related eating and drinking habits were predicted by a long history of unemployment as well as a low level of education among both genders, but not excluding an academic degree among men. The results emphasize the role of childhood psychosocial factors in preventing long-term unemployment and in enhancing psychological well-being in early adulthood. Success in entering work life, in terms of continuous work history, plays a crucial role for well-being and the amount of psychological resources in early adulthood. The results emphasize the crucial role of enhancing psychological resources for promoting positive health behaviour and diminishing regional differences in subjective well-being.

Nicotine Dependence and Smoking Behaviour : A genetic and epidemiological study

The worldwide health burden caused by the tobacco epidemic highlights the importance of study-ing determinants of smoking behaviour and key factors sustaining nicotine dependence. Despite vast-ranging preventive efforts, smoking remains one of the most deleterious health behaviours, and its genetic and environmental factors warrant continuous investigation. The heritability of smoking behaviour and nicotine dependence has been suggested to be relatively high. Earlier smoking behaviour, nicotine dependence, socio-economic position and demographic factors have all been shown to be associated with smoking cessation. This thesis aimed to examine various aspects of smoking behaviour and nicotine dependence from an epidemiological and genetic per-spective. Data for Studies I and IV were obtained from the Older Finnish Twin Cohort, a postal health sur-vey conducted in 1975, 1981 and 1990 on same-sexed pairs and in 1996-1997 on male-female adult pairs. The number of ever-smoking participants was 8941 in Study I and 3069 in Study IV. Data for Studies II and III came from the Family Study of Cigarette Smoking - Vulnerability to Nicotine Addiction. This study is linked to the Older Finnish Twin Cohort with new data collec-tion during 2001-2006 that focused on smoking twin pairs and their family members. The meas-ures included intensive telephone interviews, blood samples and additional postal questionnaires. The numbers of ever-smoking participants was 1370 in Study II and 529 in Study III. Study I examined whether a genetic component underlies smoking behaviour among Finnish adults. Genetic factors were important in the amount smoked and smoking cessation, with about half of the phenotypic differences explained by genetic variance. A novel finding was that genetic influences on amount smoked and smoking cessation were largely independent of genetic influ-ences on age at initiation. This result has implications for defining phenotypes in the search for genes underlying smoking behaviour. Furthermore, even if smoking initiation is postponed to a later age, potential vulnerability to subsequent nicotine dependence cannot be completely inhib-ited. Study II investigated the effect of genetic and environmental factors on nicotine dependence, as measured by the novel multidimensional Nicotine Dependence Syndrome Scale (NDSS). This scale was validated in the Finnish data. The NDSS correlated highly with other established nico-tine dependence scales (FTND and DSM-IV), suggesting that this new scale would be a feasible and valid measure for identifying nicotine-dependent smokers among the ever-smoking popula-tion. About one-third of the phenotypic variation in nicotine dependence in this sample was ex-plained by genetic influences. Study III aimed at identifying chromosomal regions harbouring genes that influence smoking be-haviour and nicotine dependence. Linkage analysis of family data revealed that for smoker and nicotine dependence phenotypes as well as for co-morbidity between nicotine dependence and alcohol use signals on specific chromosome regions (chromosomes 2q33, 5q12, 5q34 7q21, 7q31, 10q25, 11p15, 20p13) exist. Results further support the hypothesis that smoking behaviour phe-notypes have a genetic background. Study IV examined associations of smoking behaviour, socio-economic position and transition of marital status with smoking cessation. Indicators of socio-economic position were important pre-dictors of smoking cessation even when adjusted for previous smoking behaviour. Getting married was associated with an increased probability of cessation in men, a finding confirmed among dis-cordant twin pairs. Thus, having a partner appears to have a positive impact on smoking cessation. In conclusion, nicotine dependence and smoking behaviour demonstrate significant genetic liabil-ity, but also substantial environmental influences among Finnish adults. Smoking initiation should be prevented or at least postponed to a later age. Although genetic factors are important in nicotine dependence and smoking behaviour, societal actions still have a primary role in tobacco control and smoking prevalence. Future studies should examine the complex interactions between genetic and environmental factors in nicotine dependence.

Effect of colostrum feeding method and presence of dam on the sleep, rest and sucking behaviour of newborn calves

"In rats, sucking milk reduces anxiety and promotes non-rapid eye movement (NREM) sleep, and in calves it induces resting but the effect on sleep is unknown. Here, we investigated how calves' sleep was affected by colostrum feeding methods. Forty-one calves were blocked by birth date and randomly allotted within blocks to the experimental treatments. Calves were housed for four days either with their dam (DAM) or individually with warm colostrum feeding (2 L four times a day) from either a teat bucket (TEAT) or an open bucket (BUCKET). DAM calves suckled their dam freely. Calves' sleeping and sucking behaviour was filmed continuously for 48 h at the ages of two and three days. Behavioural sleep (BS) was defined as calves resting at least 30 s with their head still and raised (non-rapid eye movement) or with their head against their body or the ground (rapid eye movement, REM). Latency from the end of colostrum feeding to the start of BS was recorded. We compared behaviour of TEAT calves with that of DAM and BUCKET calves using mixed models. Milk meal duration was significantly longer for TEAT calves than for BUCKET calves (mean +/- S.E.M.; 8.3 +/- 0.6 min vs. 5.2 +/- 0.6 min), but equal to that of DAM calves. We found no effect of feeding method on the duration of daily BS (12 h 59 min I h 38 min) but we found a tendency for the daily amount of NREM sleep; BUCKET calves had less NREM sleep per day than TEAT calves (6 h 18 min vs. 7 h 48 min, S.E.M. = 45 min) and also longer latencies from milk ingestion to BS (21.9 +/- 2.0 min vs. 16.2 +/- 2.0 min). DAM calves slept longer bouts than TEAT calves (10.8 +/- 1.0 min vs. 8.3 +/- 1.0 min) and less often (78 +/- 4 vs. 92 +/- 4). Sucking colostrum from a teat bucket compared with drinking from an open"

Rearing strategies of young dairy calves in relation to production, behaviour and welfare

Vasikoiden kasvatus yksilökarsinoissa, imemismahdollisuuden puute maitojuoton yhteydessä sekä pienet juomamäärät ovat tekijöitä, jotka mahdollisesti voivat vähentää vasikoiden hyvinvointia. Vasikoiden kasvatukseen etsitäänkin uusia tapoja, joissa eläinten käyttäytymistarpeet ja hyvinvointi otetaan entistä paremmin huomioon. Tässä väitöskirjassa vasikoiden kasvatusta on tarkasteltu sekä tuotannon että vasikoiden käyttäytymisen ja hyvinvoinnin kannalta. Väitöskirja koostuu kolmesta kokeesta, joista ensimmäisessä tutkittiin vasikoiden kasvatusta ryhmäkarsinoissa ulkona tai sisällä ja vasikoiden kasvatusta sisällä ryhmä- tai yksilökarsinoissa. Toisessa kokeessa vasikoiden annettiin imeä emiään rajoitetusti lypsyn jälkeen viiden tai kahdeksan viikon ajan ja kolmannessa selvitettiin vasikoiden veden juontia, kun vasikat saivat juomarehua vapaasti. Lisäksi kokeiden yhdistetystä aineistosta analysoitiin eri rehujen syöntimäärien suhdetta sekä rehujen vaikutusta kasvuun ennen ja jälkeen maidosta vieroituksen. Tutkimuksessa todettiin, että vasikoita voi ryhmässä kasvattaa kylmissä ja vaihtelevissa sääoloissa ulkona, kunhan ne hoidetaan ja ruokitaan erittäin huolellisesti. Kylmällä ilmalla vasikat saattavat kuitenkin syödä väkirehua vähemmän varsinkin, jos ruokailupaikka on ulkona ja makuualue sisällä. Ryhmässä kasvaneet vasikat aloittivat sekä kuivien rehujen syönnin että märehtimisen nuorempina kuin yksilökarsinassa kasvaneet. Ryhmissä esiintyvää käyttäytymisongelmaa, toisten vasikoiden imemistä, voidaan vähentää hoito- ja ruokintamenetelmillä. Annettaessa vasikoiden imeä emiään rajoitetusti lypsyn jälkeen vasikat oppivat imemään emiään hyvin nopeasti. Lypsytyö vaikeutui muutamien lehmien kohdalla, sillä ne pidättivät maitoa lypsettäessä. Saadessaan imeä rajoitetusti vasikat imivät suurehkoja maitomääriä kerrallaan. Vieroittaminen suurilta maitomääriltä viiden viikon iässä oli kuitenkin liian aikaista, koska vasikat eivät vielä syöneet riittävästi kuivia rehuja. Vieroitus emästä niin viiden kuin kahdeksankin viikon iässä aiheutti vasikoissa levottomuutta ja ääntelyn lisääntymistä. Saadessaan hapatettua juomarehua vapaasti vasikat joivat keskimäärin vain vähän vettä, olipa vesilähteenä avoin ämpäri tai vesinippa. Vasikoiden välillä oli suurta vaihtelua veden juontimäärissä. Viikkoa ennen maidosta vieroitusta vasikat joivat 0-3 l vettä päivässä. Vasikat joivat nipasta kerrallaan vähemmän vettä kuin ämpäristä, ja käyttivät enemmän aikaa päivässä veden juomiseen kuin vesiämpäristä juoneet vasikat. Suurin osa vasikoista joi vettä juomanipoista erikoisella tavalla esimerkiksi painamalla nippaa otsalla ja juomalla tippuvaa vettä. Vesinipat voivat olla siis vasikoille joko vaikeita tai epämukavia käyttää. Vasikoiden juoman maitomäärän lisääntyessä kasvu lisääntyy selvästi. Runsas maidon juominen vähentää kuitenkin kuivien rehujen syöntiä ja vieroitusvaiheessa kasvu voi hidastua. Vasikat olisikin tärkeää vieroittaa vähitellen, ettei muutoksia kasvuun tulisi. Syönti- ja kasvutulokset eivät aina anna oikeaa kuvaa kasvatusmenetelmien eroista eläinten hyvinvoinnin kannalta. Käyttäytyminen on herkkä hyvinvoinnin mittari ja se tulisikin aina huomioida eri kasvatusmenetelmiä arvioitaessa. .

Psychosocial processes of health behaviour change in a lifestyle intervention : Influences of gender, socioeconomic status and personality

Background: The onset of many chronic diseases such as type 2 diabetes can be delayed or prevented by changes in diet, physical activity and obesity. Known predictors of successful behaviour change include psychosocial factors such as selfefficacy, action and coping planning, and social support. However, gender and socioeconomic differences in these psychosocial mechanisms underlying health behaviour change have not been examined, despite well-documented sociodemographic differences in lifestyle-related mortality and morbidity. Additionally, although stable personality traits (such as dispositional optimism or pessimism and gender-role orientation: agency and communion) are related to health and health behaviour, to date they have rarely been studied in the context of health behaviour interventions. These personality traits might contribute to health behaviour change independently of the more modifiable domain-specific psychosocial factors, or indirectly through them, or moderated by them. The aims were to examine in an intervention setting: (1) whether changes (during the three-month intervention) in psychological determinants (self-efficacy beliefs, action planning and coping planning) predict changes in exercise and diet behaviours over three months and 12 months, (2) the universality assumption of behaviour change theories, i.e. whether preintervention levels and changes in psychosocial determinants are similar among genders and socioeconomic groups, and whether they predict changes in behaviour in a similar way in these groups, (3) whether the personality traits optimism, pessimism, agency and communion predict changes in abdominal obesity, and the nature of their interplay with modifiable and domain-specific psychosocial factors (self-efficacy and social support). Methods: Finnish men and women (N = 385) aged 50 65 years who were at an increased risk for type 2 diabetes were recruited from health care centres to participate in the GOod Ageing in Lahti Region (GOAL) Lifestyle Implementation Trial. The programme aimed to improve participants lifestyle (physical activity, eating) and decrease their overweight. The measurements of self-efficacy, planning, social support and dispositional optimism/pessimism were conducted pre-intervention at baseline (T1) and after the intensive phase of the intervention at three months (T2), and the measurements of exercise at T1, T2 and 12 months (T3) and healthy eating at T1 and T3. Waist circumference, an indicator of abdominal obesity, was measured at T1 and at oneyear (T3) and three-year (T4) follow-ups. Agency and communion were measured at T4 with the Personal Attributes Questionnaire (PAQ). Results: (1) Increases in self-efficacy and planning were associated with three-month increases in exercise (Study I). Moreover, both the post-intervention level and three-month increases (during the intervention) in self-efficacy in dealing with barriers predicted the 12-month increase in exercise, and a high postintervention level of coping plans predicted the 12-month decrease in dietary fat (Study II). One- and three-year waist circumference reductions were predicted by the initial three-month increase in self-efficacy (Studies III, IV). (2) Post-intervention at three months, women had formed more action plans for changing their exercise routines and received less social support for behaviour change than men had. The effects of adoption self-efficacy were similar but change in planning played a less significant role among men (Study I). Examining the effects of socioeconomic status (SES), psychosocial determinants at baseline and their changes during the intervention yielded largely similar results. Exercise barriers self-efficacy was enhanced slightly less among those with low SES. Psychosocial determinants predicted behaviour similarly across all SES groups (Study II). (3) Dispositional optimism and pessimism were unrelated to waist circumference change, directly or indirectly, and they did not influence changes in self-efficacy (Study III). Agency predicted 12-month waist circumference reduction among women. High communion coupled with high social support was associated with waist circumference reduction. However, the only significant predictor of three-year waist circumference reduction was an increase in health-related self-efficacy during the intervention (Study IV). Conclusions: Interventions should focus on improving participants self-efficacy early on in the intervention as well as prompting action and coping planning for health behaviour change. Such changes are likely to be similarly effective among intervention participants regardless of gender and educational level. Agentic orientation may operate via helping women to be less affected by the demands of the self-sacrificing female role and enabling them to assertively focus on their own goals. The earlier mixed results regarding the role of social support in behaviour change may be in part explained by personality traits such as communion.

Death, Destruction and Commemoration : Tracing ritual activities in Finnish Late Iron Age cemeteries (AD 550-1150)

The thesis is connected with death, memory and ancestor commemoration during the Merovingian Period, the Viking Age and the beginning of the Crusade Period (AD 550-1150) in Finland. During this time, cremation was the dominant burial rite. It was not until the end of the Viking Age that inhumation became more common but both cremations and inhumations are performed even at the same sites throughout the time. Three different burial types 1) cremation cemeteries below level ground, 2) inhumation burials and 3) water burials are discussed in five articles. I consider these burial forms from three different viewpoints; collectivity-individuality, visibility-invisibility and cremation-inhumation. The thesis also discusses the topics of memory, memorialisation and monument re-use, which have been neglected subjects in Finnish archaeology until now. Both cremation cemeteries below level ground and inhumation burials have been re-used during their time of usage, and on most occasions are situated in a landscape that is overlaid by other monuments as well. The main questions of the thesis are: What kinds of ritual behaviour can we detect in the burials during the period (AD 550-1150)? How did people perceive the moraine hills that functioned as burial places? What kind of re-use can be detected in the Iron Age cemeteries? Why have ancient sites and artefacts been re-used? This thesis shows that it is possible to claim that both artefact and site re-use is a much more widespread phenomenon than has previously been thought in Finnish archaeology. It is also a conscious and deliberate behaviour that can be related to an ancestor cult and commemoration of the dead. The funerary rituals during this time period show great variation and complex, both regionally and nationally. Not only have the dead been buried using elaborate rituals, they have also been mourned and commemorated in intricate ways that proves that death was not an end product, but the start of something new.

Phosphorus retention in forest soils and the functioning of buffer zones used in forestry

Phosphorus (P) retention properties of soils typical for boreal forest, i.e. podzolic soil and peat soils, vary significantly, but the range of this variation has not been sufficiently documented. To assess the usefulness of buffer zones used in forestry in removing P from the discharge by chemical sorption in soil, and to estimate the risk of P leaching after forestry operations, more data is needed on soil P retention properties. P retention properties of soils were studied at clear-cut areas, unharvested buffer zones adjoining the clear-cut and at peatland buffer zone areas. Desorption-sorption isotherms were determined for the humus layer, the mineral soil horizons E, B and C of the Podzol profile and for the surface layer peat (0-15 cm) and the subsurface layer peat (15-30 cm). The efficiency of buffer zones in retaining P was studied at six peatland buffer zone areas by adding P-containing solute in the inflow. A tracer study was conducted at one of the buffer zone areas to determine the allocation of the added P in soil and vegetation. Measured sorption or desorption rather than parameter values of fitted sorption equations described P desorption and sorption behaviour in soil. The highest P retention efficiency was in the B horizon and consequently, if contact occurred or was established between the soluble P in the water and the soil B horizon, the risk of P leaching was low. Humus layer was completely incapable of retaining P after clear-cutting. In the buffer zones, the decrease in P retention properties in the humus layer and the low amount of P sorbed by it indicated that the importance of the layer in the functioning of buffer zones is low. The peatland buffer zone areas were efficient in retaining soluble P from inflow. P sorption properties of the peat soil at the buffer zone areas varied largely but the contribution of P sorption in the peat was particularly important during high flow in spring, when the vegetation was not fully developed. Factors contributing to efficient P retention were large buffer size and low hydrological load whereas high hydrological load combined with the formation of preferential flow paths, especially during early spring or late autumn was disadvantageous. However, small buffer zone areas, too, may be efficient in reducing P load.

The decline of northern malaria and population dynamics of Plamodium vivax

Europe was declared malaria free in 1975. The disappearance of malaria has traditionally been attributed to numerous deliberate actions like vector control, the screening of houses, more efficient medication etc. Malaria, however, disappeared from many countries like Finland before any counter measures had even started. The aim of this thesis is to study the population ecology of P. vivax and its interaction with the human host and the vector. By finding the factors that attributed to the extinction of vivax malaria it might be possible to improve the modern strategy against P. vivax. The parasite was studied with data from Finland, which provides the longest time series (1749-2008) of malaria statistics in the world. The malaria vectors, Anopheles messeae and A. beklemishevi are still common species in the country. The eradication of vivax malaria is difficult because the parasite has a dormant stage that can cause a relapse long after a primary infection. It was now shown that P. vivax is able to detect the presence of a potential vector. A dormant stage is triggered even from a bite of an uninfected Anopheles mosquito. This optimizes the chances for the Plasmodium to reach a mosquito vector for sexual reproduction. The longevity of the dormant stage could be shown to be at least nine years. The parasite spends several years in its human host and the behaviour of the human carrier had a profound impact on the decline of the disease in Finland. Malaria spring epidemics could be explained by a previous warm summer. Neither annual nor summer mean temperature had any impact on the long term malaria trend. Malaria disappeared slowly from Finland without mosquito control. The sociological change from extended families to nuclear families led to decreased household size. The decreased household size correlated strongly with the decline of malaria. That led to an increased isolation of the subpopulations of P. vivax. Their habitat consisted of the bedrooms in which human carriers slept together with the overwintering vectors. The isolation of the parasite ultimately led to the extinction of vivax malaria. Metapopulation models adapted to local conditions should therefore be implemented as a tool for settlement planning and socio-economic development and become an integrated part of the fight against malaria.

Occurrence and properties of steryl ferulates and glycosides in wheat and rye

Cereal kernels are known to contain a number of minor components that possess beneficial health attributes. In this thesis rye and wheat were studied as sources of steryl ferulates and steryl glycosides and their behaviour in processing were evaluated. Further, enzymatic hydrolysis of these conjugates was studied, as well as the capacity of steryl ferulates to inhibit lipid oxidation at different temperatures. Steryl ferulates were shown to have a strong positive correlation with dietary fibre contents in milling fractions from the outer parts of the kernels obtained from a commercial scale mill. Highest contents of steryl ferulates were found in the bran in both cereals, with the content decreasing once moving towards the inner parts of the kernel. Variation in the contents of steryl ferulates was higher in wheat fractions than rye fractions. Steryl glycosides, on the other hand, had either negative or no correlation with dietary fibre, and the range of the steryl glycoside contents was much narrower than that of steryl ferulates in both cereals. There were significant differences in the sterol compositions of these steryl conjugates when compared with each other or with the total plant sterols in the corresponding fractions. Properties of steryl ferulates and steryl glycosides were evaluated after common processing methods and in enzymatic hydrolysis. Thermal and mechanical processing had only minor or no effects on the contents of steryl conjugates from rye and wheat bran. Enzymatic treatments on the other hand caused some changes, especially in the contents of glycosylated sterols. When steryl ferulates extracted from rye or wheat bran were subjected to enzymatic treatments by steryl esterase, significant differences in the rates of hydrolysis were observed between steryl ferulates from different sources with differing sterol compositions. Further, differences were also observed between enzymes from different sources. Steryl glycosides were shown to be hydrolysed by β-glucosidase (cellobiase) from A. niger, but less with β-glucosidases from other sources. Steryl ferulates showed good antioxidant activity at both moderate and high temperatures. In bulk and emulsion systems of methyl linoleate at 40°C steryl ferulates extracted from rye and wheat bran inhibited hydroperoxide formation much more effectively than synthetic steryl ferulates or those extracted from rice (γ-oryzanol), demonstrating that the sterol composition has an effect on the activity. At cooking (100°C) and frying temperatures (180°C) sitostanyl ferulate was shown to inhibit polymer formation significantly and, especially at 100°C, comparably to α-tocopherol. The rate of antioxidant degradation was slower for sitostanyl ferulate, showing higher heat stability than α-tocopherol. When evaluated as a mixture, no synergistic effect was observed between these two antioxidants. The data presented in this thesis provides information that may henceforth be applied when evaluating the intakes of steryl conjugates from cereal sources, as well as their possible influences as minor bioactive components. Wheat and rye both are good sources of steryl ferulates and steryl glycosides and, especially with steryl ferulates, what may be lost out to some other cereals on quantity is compensated with quality of the sterol composition.

Determinants of farmer retirement and farm succession in Finland

In the past decade, the Finnish agricultural sector has undergone rapid structural changes. The number of farms has decreased and the average farm size has increased when the number of farms transferred to new entrants has decreased. Part of the structural change in agriculture is manifested in early retirement programmes. In studying farmers exit behaviour in different countries, institutional differences, incentive programmes and constraints are found to matter. In Finland, farmers early retirement programmes were first introduced in 1974 and, during the last ten years, they have been carried out within the European Union framework for these programmes. The early retirement benefits are farmer specific and de-pend on the level of pension insurance the farmer has paid over his active farming years. In order to predict the future development of the agricultural sector, farmers have been frequently asked about their future plans and their plans for succession. However, the plans the farmers made for succession have been found to be time inconsistent. This study estimates the value of farmers stated succession plans in predicting revealed succession decisions. A stated succession plan exists when a farmer answers in a survey questionnaire that the farm is going to be transferred to a new entrant within a five-year period. The succession is revealed when the farm is transferred to a suc-cessor. Stated and revealed behaviour was estimated as a recursive Binomial Probit Model, which accounts for the censoring of the decision variables and controls for a potential correlation between the two equations. The results suggest that the succession plans, as stated by elderly farmers in the questionnaires, do not provide information that is significant and valuable in predicting true, com-pleted successions. Therefore, farmer exit should be analysed based on observed behaviour rather than on stated plans and intentions. As farm retirement plays a crucial role in determining the characteristics of structural change in agriculture, it is important to establish the factors which determine an exit from farming among eld-erly farmers and how off-farm income and income losses affect their exit choices. In this study, the observed choice of pension scheme by elderly farmers was analysed by a bivariate probit model. Despite some variations in significance and the effects of each factor, the ages of the farmer and spouse, the age and number of potential successors, farm size, income loss when retiring and the location of the farm together with the production line were found to be the most important determi-nants of early retirement and the transfer or closure of farms. Recently, the labour status of the spouse has been found to contribute significantly to individual retirement decisions. In this study, the effect of spousal retirement and economic incentives related to the timing of a farming couple s early retirement decision were analysed with a duration model. The results suggest that an expected pension in particular advances farm transfers. It was found that on farms operated by a couple, both early retirement and farm succession took place more often than on farms operated by a single person. However, the existence of a spouse delayed the timing of early retirement. Farming couples were found to co-ordinate their early retirement decisions when they both exit through agricultural retirement programmes, but such a co-ordination did not exist when one of the spouses retired under other pension schemes. Besides changes in the agricultural structure, the share and amount of off-farm income of a farm family s total income has also increased. In the study, the effect of off-farm income on farmers retirement decisions, in addition to other financial factors, was analysed. The unknown parameters were first estimated by a switching-type multivariate probit model and then by the simulated maxi-mum likelihood (SML) method, controlling for farmer specific fixed effects and serial correlation of the errors. The results suggest that elderly farmers off-farm income is a significant determinant in a farmer s choice to exit and close down the farm. However, off-farm income only has a short term effect on structural changes in agriculture since it does not significantly contribute to the timing of farm successions.

Polymerization of Ethene and Branched α-olefins with Group IV Metal Complexes Bearing Nitrogen- and Oxygen-Based Ligands

The commodity plastics that are used in our everyday lives are based on polyolefin resins and they find wide variety of applications in several areas. Most of the production is carried out in catalyzed low pressure processes. As a consequence polymerization of ethene and α-olefins has been one of the focus areas for catalyst research both in industry and academia. Enormous amount of effort have been dedicated to fine tune the processes and to obtain better control of the polymerization and to produce tailored polymer structures The literature review of the thesis concentrates on the use of Group IV metal complexes as catalysts for polymerization of ethene and branched α-olefins. More precisely the review is focused on the use of complexes bearing [O,O] and [O,N] type ligands which have gained considerable interest. Effects of the ligand framework as well as mechanical and fluxional behaviour of the complexes are discussed. The experimental part consists mainly of development of new Group IV metal complexes bearing [O,O] and [O,N] ligands and their use as catalysts precursors in ethene polymerization. Part of the experimental work deals with usage of high-throughput techniques in tailoring properties of new polymer materials which are synthesized using Group IV complexes as catalysts. It is known that the by changing the steric and electronic properties of the ligand framework it is possible to fine tune the catalyst and to gain control over the polymerization reaction. This is why in this thesis the complex structures were designed so that the ligand frameworks could be fairly easily modified. All together 14 complexes were synthesised and used as catalysts in ethene polymerizations. It was found that the ligand framework did have an impact within the studied catalyst families. The activities of the catalysts were affected by the changes in complex structure and also effects on the produced polymers were observed: molecular weights and molecular weight distributions were depended on the used catalyst structure. Some catalysts also produced bi- or multi-modal polymers. During last decade high-throughput techniques developed in pharmaceutical industries have been adopted into polyolefin research in order to speed-up and optimize the catalyst candidates. These methods can now be regarded as established method suitable for both academia and industry alike. These high-throughput techniques were used in tailoring poly(4-methyl-1-pentene) polymers which were synthesized using Group IV metal complexes as catalysts. This work done in this thesis represents the first successful example where the high-throughput synthesis techniques are combined with high-throughput mechanical testing techniques to speed-up the discovery process for new polymer materials.

The Population Consequences of Sex and Conflict

Natural selection generally operates at the level of the individual, or more specifically at the level of the gene. As a result, individual selection does not always favour traits which benefit the population or species as a whole. The spread of an individual gene may even act to the detriment of the organism in which it finds. Thus selection at the level of the individual can affect processes at the level of the organism, group or even at the level of the species. As most behaviours ultimately affect births, deaths and the distribution of individuals, it seems inevitable that behavioural decisions will have an impact on population dynamics and population densities. Behavioural decisions can often involve costs through allocation of energy into behavioural strategies, such as the investment into armaments involved in fighting over resources or increased mortality due to injury or increased predation risk. Similarly, behaviour may act o to benefit the population, in terms of higher survival and increased fecundity. Examples include increased investment through parental care, choosing a mate based on the nuptial gifts they may supply and choosing territories in the face of competition. Investigating the impact of behaviour on population ecology may seem like a trivial task, but it is likely to have important consequences at different levels. For example, antagonistic behaviour may occasionally become so extreme that it increases the risk of extinction, and such extinction risk may have important implications for conservation. As a corollary, any such behaviour may also act as a macroevolutionary force, weeding out populations with traits which, whilst beneficial to the individuals in the short term, ultimately result in population extinction. In this thesis, I examine how behaviours, specifically conflict and competition over a resource and aspects of behaviour involved in sexual selection, can affect population densities, and what the implications are for the evolution and ecology of the populations in question. It is found that both behaviours related to individual conflict and mating strategies can have an effect at the level of the population, but that various factors, such as a feedback between selection and population densities or macroevolution caused by species extinctions, may act to limit the intensity of conflicts that we observe in nature.

Evaluation of methods and applications for behavioural profiling of transgenic mice

During the last 10-15 years interest in mouse behavioural analysis has evolved considerably. The driving force is development in molecular biological techniques that allow manipulation of the mouse genome by changing the expression of genes. Therefore, with some limitations it is possible to study how genes participate in regulation of physiological functions and to create models explaining genetic contribution to various pathological conditions. The first aim of our study was to establish a framework for behavioural phenotyping of genetically modified mice. We established comprehensive battery of tests for the initial screening of mutant mice. These included tests for exploratory and locomotor activity, emotional behaviour, sensory functions, and cognitive performance. Our interest was in the behavioural patterns of common background strains used for genetic manipulations in mice. Additionally we studied the behavioural effect of sex differences, test history, and individual housing. Our findings highlight the importance of careful consideration of genetic background for analysis of mutant mice. It was evident that some backgrounds may mask or modify the behavioural phenotype of mutants and thereby lead to false positive or negative findings. Moreover, there is no universal strain that is equally suitable for all tests, and using different backgrounds allows one to address possible phenotype modifying factors. We discovered that previous experience affected performance in several tasks. The most sensitive traits were the exploratory and emotional behaviour, as well as motor and nociceptive functions. Therefore, it may be essential to repeat some of the tests in naïve animals for assuring the phenotype. Social isolation for a long time period had strong effects on exploratory behaviour, but also on learning and memory. All experiments revealed significant interactions between strain and environmental factors (test history or housing condition) indicating genotype-dependent effects of environmental manipulations. Several mutant line analyses utilize this information. For example, we studied mice overexpressing as well as those lacking extracellular matrix protein heparin-binding growth-associated molecule (HB-GAM), and mice lacking N-syndecan (a receptor for HB-GAM). All mutant mice appeared to be fertile and healthy, without any apparent neurological or sensory defects. The lack of HB-GAM and N-syndecan, however, significantly reduced the learning capacity of the mice. On the other hand, overexpression of HB-GAM resulted in facilitated learning. Moreover, HB-GAM knockout mice displayed higher anxiety-like behaviour, whereas anxiety was reduced in HB-GAM overexpressing mice. Changes in hippocampal plasticity accompanied the behavioural phenotypes. We conclude that HB-GAM and N-syndecan are involved in the modulation of synaptic plasticity in hippocampus and play a role in regulation of anxiety- and learning-related behaviour.