JNK regulates dendrite and spine architecture in the central nervous system influencing spatial learning and motor tasks

JNK1 is a MAP-kinase that has proven a significant player in the central nervous system. It regulates brain development and the maintenance of dendrites and axons. Several novel phosphorylation targets of JNK1 were identified in a screen performed in the Coffey lab. These proteins were mainly involved in the regulation of neuronal cytoskeleton, influencing the dynamics and stability of microtubules and actin. These structural proteins form the dynamic backbone for the elaborate architecture of the dendritic tree of a neuron. The initiation and branching of the dendrites requires a dynamic interplay between the cytoskeletal building blocks. Both microtubules and actin are decorated by associated proteins which regulate their dynamics. The dendrite-specific, high molecular weight microtubule associated protein 2 (MAP2) is an abundant protein in the brain, the binding of which stabilizes microtubules and influences their bundling. Its expression in non-neuronal cells induces the formation of neurite-like processes from the cell body, and its function is highly regulated by phosphorylation. JNK1 was shown to phosphorylate the proline-rich domain of MAP2 in vivo in a previous study performed in the group. Here we verify three threonine residues (T1619, T1622 and T1625) as JNK1 targets, the phosphorylation of which increases the binding of MAP2 to microtubules. This binding stabilizes the microtubules and increases process formation in non-neuronal cells. Phosphorylation-site mutants were engineered in the lab. The non-phosphorylatable mutant of MAP2 (MAP2- T1619A, T1622A, T1625A) in these residues fails to bind microtubules, while the pseudo-phosphorylated form, MAP2- T1619D, T1622D, Thr1625D, efficiently binds and induces process formation even without the presence of active JNK1. Ectopic expression of the MAP2- T1619D, T1622D, Thr1625D in vivo in mouse brain led to a striking increase in the branching of cortical layer 2/3 (L2/3) pyramidal neurons, compared to MAP2-WT. The dendritic complexity defines the receptive field of a neuron and dictates the output to the postsynaptic cells. Previous studies in the group indicated altered dendrite architecture of the pyramidal neurons in the Jnk1-/- mouse motor cortex. Here, we used Lucifer Yellow loading and Sholl analysis of neurons in order to study the dendritic branching in more detail. We report a striking, opposing effect in the absence of Jnk1 in the cortical layers 2/3 and 5 of the primary motor cortex. The basal dendrites of pyramidal neurons close to the pial surface at L2/3 show a reduced complexity. In contrast, the L5 neurons, which receive massive input from the L2/3 neurons, show greatly increased branching. Another novel substrate identified for JNK1 was MARCKSL1, a protein that regulates actin dynamics. It is highly expressed in neurons, but also in various cancer tissues. Three phosphorylation target residues for JNK1 were identified, and it was demonstrated that their phosphorylation reduces actin turnover and retards migration of these cells. Actin is the main cytoskeletal component in dendritic spines, the site of most excitatory synapses in pyramidal neurons. The density and gross morphology of the Lucifer Yellow filled dendrites were characterized and we show reduced density and altered morphology of spines in the motor cortex and in the hippocampal area CA3. The dynamic dendritic spines are widely considered to function as the cellular correlate during learning. We used a Morris water maze to test spatial memory. Here, the wild-type mice outperformed the knock-out mice during the acquisition phase of the experiment indicating impaired special memory. The L5 pyramidal neurons of the motor cortex project to the spinal cord and regulate the movement of distinct muscle groups. Thus the altered dendrite morphology in the motor cortex was expected to have an effect on the input-output balance in the signaling from the cortex to the lower motor circuits. A battery of behavioral tests were conducted for the wild-type and Jnk1-/- mice, and the knock-outs performed poorly compared to wild-type mice in tests assessing balance and fine motor movements. This study expands our knowledge of JNK1 as an important regulator of the dendritic fields of neurons and their manifestations in behavior.

Engendering Group Support Based Foresight for Capital Intensive Manufacturing Industries - Case Paper and Steel Industry Scenarios by 2018

In recent times of global turmoil, the need for uncertainty management has become ever momentous. The need for enhanced foresight especially concerns capital-intensive industries, which need to commit their resources and assets with long-term planning horizons. Scenario planning has been acknowledged to have many virtues - and limitations - concerning the mapping of the future and illustrating the alternative development paths. The present study has been initiated to address both the need of improved foresight in two capital-intensive industries, i.e. the paper and steel industries and the imperfections in the current scenario practice. The research problem has been approached by engendering a problem-solving vehicle, which combines, e.g. elements of generic scenario process, face-to-face group support methods, deductive scenario reasoning and causal mapping into a fully integrated scenario process. The process, called the SAGES scenario framework, has been empirically tested by creating alternative futures for two capital-intensive industries, i.e. the paper and steel industries. Three scenarios for each industry have been engendered together with the identification of the key megatrends, the most important foreign investment determinants, key future drivers and leading indicators for the materialisation of the scenarios. The empirical results revealed a two-fold outlook for the paper industry, while the steel industry future was seen as much more positive. The research found support for utilising group support systems in scenario and strategic planning context with some limitations. Key perceived benefits include high time-efficiency, productivity and lower resource-intensiveness. Group support also seems to enhance participant satisfaction, encourage innovative thinking and provide the users with personalised qualitative scenarios.

Teaching mathematics and programming : new approaches with empirical evaluation

Programming and mathematics are core areas of computer science (CS) and consequently also important parts of CS education. Introductory instruction in these two topics is, however, not without problems. Studies show that CS students find programming difficult to learn and that teaching mathematical topics to CS novices is challenging. One reason for the latter is the disconnection between mathematics and programming found in many CS curricula, which results in students not seeing the relevance of the subject for their studies. In addition, reports indicate that students' mathematical capability and maturity levels are dropping. The challenges faced when teaching mathematics and programming at CS departments can also be traced back to gaps in students' prior education. In Finland the high school curriculum does not include CS as a subject; instead, focus is on learning to use the computer and its applications as tools. Similarly, many of the mathematics courses emphasize application of formulas, while logic, formalisms and proofs, which are important in CS, are avoided. Consequently, high school graduates are not well prepared for studies in CS. Motivated by these challenges, the goal of the present work is to describe new approaches to teaching mathematics and programming aimed at addressing these issues: Structured derivations is a logic-based approach to teaching mathematics, where formalisms and justifications are made explicit. The aim is to help students become better at communicating their reasoning using mathematical language and logical notation at the same time as they become more confident with formalisms. The Python programming language was originally designed with education in mind, and has a simple syntax compared to many other popular languages. The aim of using it in instruction is to address algorithms and their implementation in a way that allows focus to be put on learning algorithmic thinking and programming instead of on learning a complex syntax. Invariant based programming is a diagrammatic approach to developing programs that are correct by construction. The approach is based on elementary propositional and predicate logic, and makes explicit the underlying mathematical foundations of programming. The aim is also to show how mathematics in general, and logic in particular, can be used to create better programs.

“IT’S ALL RIGHT”. Multimodal rightward spatial bias modified by age and praxis

The general goal of the present work was to study whether spatial perceptual asymmetry initially observed in linguistic dichotic listening studies is related to the linguistic nature of the stimuli and/or is modality-specific, as well as to investigate whether the spatial perceptual/attentional asymmetry changes as a function of age and sensory deficit via praxis. Several dichotic listening studies with linguistic stimuli have shown that the inherent perceptual right ear advantage (REA), which presumably results from the left lateralized linguistic functions (bottom-up processes), can be modified with executive functions (top-down control). Executive functions mature slowly during childhood, are well developed in adulthood, and decline as a function of ageing. In Study I, the purpose was to investigate with a cross-sectional experiment from a lifespan perspective the age-related changes in top-down control of REA for linguistic stimuli in dichotic listening with a forced-attention paradigm (DL). In Study II, the aim was to determine whether the REA is linguistic-stimulus-specific or not, and whether the lifespan changes in perceptual asymmetry observed in dichotic listening would exist also in auditory spatial attention tasks that put load on attentional control. In Study III, using visual spatial attention tasks, mimicking the auditory tasks applied in Study II, it was investigated whether or not the stimulus-non-specific rightward spatial bias found in auditory modality is a multimodal phenomenon. Finally, as it has been suggested that the absence of visual input in blind participants leads to improved auditory spatial perceptual and cognitive skills, the aim in Study IV was to determine, whether blindness modifies the ear advantage in DL. Altogether 180-190 right-handed participants between 5 and 79 years of age were studied in Studies I to III, and in Study IV the performance of 14 blind individuals was compared with that of 129 normally sighted individuals. The results showed that only rightward spatial bias was observed in tasks with intensive attentional load, independent of the type of stimuli (linguistic vs. non-linguistic) or the modality (auditory vs. visual). This multimodal rightward spatial bias probably results from a complex interaction of asymmetrical perceptual, attentional, and/or motor mechanisms. Most importantly, the strength of the rightward spatial bias changed as a function of age and augmented praxis due to sensory deficit. The efficiency of the performance in spatial attention tasks and the ability to overcome the rightward spatial bias increased during childhood, was at its best in young adulthood, and decreased as a function of ageing. Between the ages of 5 and 11 years probably at first develops movement and impulse control, followed by the gradual development of abilities to inhibit distractions and disengage attention. The errors especially in bilateral stimulus conditions suggest that a mild phenomenon resembling extinction can be observed throughout the lifespan, but especially the ability to distribute attention to multiple targets simultaneously decreases in the course of ageing. Blindness enhances the processing of auditory bilateral linguistic stimuli, the ability to overcome a stimulus-driven laterality effect related to speech sound perception, and the ability to direct attention to an appropriate spatial location. It was concluded that the ability to voluntarily suppress and inhibit the multimodal rightward spatial bias changes as a function of age and praxis due to sensory deficit and probably reflects the developmental level of executive functions.

Improving reporting and internal control with process thinking - case study in a multinational corporation

The aim of this Master’s Thesis is to find applicable methods from process management literature for improving reporting and internal control in a multinational corporation. The method of analysis is qualitative and the research is conducted as a case study. Empirical data collection is carried out through interviews and participating observation. The theoretical framework is built around reporting and guidance between parent company and subsidiary, searching for means to improve them from process thinking and applicable frameworks. In the thesis, the process of intercompany reporting in the case company is modelled, and its weak points, risks, and development targets are identified. The framework of critical success factors in process improvement is utilized in assessing the development targets. Also internal control is analyzed with the tools of process thinking. As a result of this thesis, suggestions for actions improving the reporting process and internal control are made to the case company, the most essential of which are ensuring top management’s awareness and commitment to improvement, creating guidelines and tools for internal control and creating and implementing improved intercompany reporting process.

Organisational purchasing of service design – Agency and client perspectives

There has been an increase in the interest in service design, as companies have become more customer-centric and their focus has shifted to customer experiences. The actual organisational purchasing of service design has been given little attention, until recent years. The purpose of this study is to explore the purchasing of service design from the perspectives of sellers (service design agencies) and buying clients (business organisations). In order to understand the phenomenon, also agencies and clients’ approaches to service design discipline, purchasing processes, challenges related to purchasing and ways of facilitating the purchasing are explored. The research follows qualitative research method and utilises abductive reasoning. A proposition framework was formed by combining services marketing, design and organisational buying behaviour literatures, and was tested against real-life business cases. Empirical data was gathered by interviewing eight service design agency representatives and five client representatives in Finland. The results of semi-structural interviews were analysed by finding repetitive themes. The proposition framework was updated according to interview findings. There were both similarities and differences in service design agencies and clients’ approaches to service design. Service design represents a strategic activity to both parties, and it helps in clients’ business development and in discovering opportunities. It is an ideology; a way of thinking and working. The driving force for purchasing service design seemed to be something else than service design itself. Projects have been bought for 1) change and innovation related development, 2) channel related development or for 3) customer experience related development. Seven purchasing challenge themes were recognised: 1) poor or differing service design understanding, 2) selling of service design, 3) varying expectations, 4) difficulty of pre-evaluation, 5) buyers and buying companies, 6) project process and nature and 7) unclear project results. These all can be considered to cause challenges in organisational service design purchasing. Challenges can be caused by either participant, the agency or the client, and take place at any point of the purchasing process. Some of the challenges could be considered as barriers to purchasing or they play a role in an unsuccessful service project – and therefore, result in an unsuccessful organisational purchase. Purchasing could be facilitated in various ways by either participant; some ways are more attitude based, others actionable improvements. Thesis’s theoretical and managerial findings can be utilised to both improve the selling and purchasing of service design services.

Model for managing non-core ideas to new companies, products and services in a Finnish forest company

Suomalainen metsäteollisuus on muutoksen partaalla. Uutisissa on nähty miten metsäyrityksen sulkevat tehtaita ja paperikoneita. Suomalaisessa metsäteollisuudessa keskitytään tällä hetkellä lähinnä kulujen alentamiseen ja tuottavuuden parantamiseen. Edellytyssille, että suomalainen metsäteollisuus pysyy kilpailukykyisenä, ovat kuitenkinuudet innovaatiot ja toimialojen välinen yhteistyö. Työn tavoitteena oli luoda toimintamalli UPM-Kymmene Oyj:lle, minkä avulla ydinliiketoimintaan kuulumattomat tuote- ja palveluideat saataisiin hyödynnettyä. Aihe on erittäin ajankohtainen, mikäli halutaan pitää tuotanto jatkossakin Suomessa. Luotumalli painottaa pk-sektorin roolia ja potentiaalia kehittää UPM-Kymmeneltä peräisin olevia ja heidän ydinliiketointaan kuulumattomista tuote ja palveluideoistauusia yrityksiä, tuotteita ja palveluita. Malli edustaa uudenlaista ajattelutapaa ja sen käyttöönotto vaatii perinteisen yrityskulttuurin uudistamista UPM-Kymmenessä.

Pain-evoked alterations on gingival blood flow and gingival crevicular fluid (GCF) neuropeptide SP and collagenase-2 (MMP-8) levels

Previous studies have demonstrated that clinical pulpal pain can induce the expression of pro-inflammatory neuropeptides in the adjacent gingival crevice fluid (GCF). Vasoactive agents such as substance P (SP) are known to contribute to the inflammatory type of pain and are associated with increased blood flow. More recent animal studies have shown that application of capsaicin on alveolar mucosa provokes pain and neurogenic vasodilatation in the adjacent gingiva. Pain-associated inflammatory reactions may initiate expression of several pro- and anti-inflammatory mediators. Collagenase-2 (MMP-8) has been considered to be the major destructive protease, especially in the periodontitis-affected gingival crevice fluid (GCF). MMP-8 originates mostly from neutrophil leukocytes, the first line of defence cells that exist abundantly in GCF, especially in inflammation. With this background, we wished to clarify the spatial extensions and differences between tooth-pain stimulation and capsaicin-induced neurogenic vasodilatation in human gingiva. Experiments were carried out to study whether tooth stimulation and capsaicin stimulation of alveolar mucosa would induce changes in GCF MMP-8 levels and whether tooth stimulation would release neuropeptide SP in GCF. The experiments were carried out on healthy human volunteers. During the experiments, moderate and high intensity painful tooth stimulation was performed by a constant current tooth stimulator. Moderate tooth stimulation activates A-delta fibres, while high stimulation also activates C-fibres. Painful stimulation of the gingiva was achieved by topical application of capsaicin-moistened filter paper on the mucosal surface. Capsaicin is known to activate selectively nociceptive C-fibres of stimulated tissue. Pain-evoked vasoactive changes in gingivomucosal tissues were mapped by laser Doppler imaging (LDI), which is a sophisticated and non-invasive method for studying e.g. spatial and temporal characteristics of pain- and inflammation-evoked blood flow changes in gingivomucosal tissues. Pain-evoked release of MMP-8 in GCF samples was studied by immunofluorometric assay (IFMA) and Western immunoblotting. The SP levels in GCF were analysed by Enzyme immunoassay (EIA). During the experiments, subjective stimulus-evoked pain responses were determined by a visual analogue pain scale. Unilateral stimulation of alveolar mucosa and attached gingiva by capsaicin evoked a distinct neurogenic vasodilatation in the ipsilateral gingiva, which attenuated rapidly at the midline. Capsaicin stimulation of alveolar mucosa provoked clear inflammatory reactions. In contrast to capsaicin stimuli, tooth stimulation produced symmetrical vasodilatations bilaterally in the gingiva. The ipsilateral responses were significantly smaller during tooth stimulation than during capsaicin stimuli. The current finding – that tooth stimulation evokes bilateral vasodilatation while capsaicin stimulation of the gingiva mainly produces unilateral vasodilatation – emphasises the usefulness of LDI in clarifying spatial features of neurogenic vasoactive changes in the intra-oral tissues. Capsaicin stimulation of the alveolar mucosa induced significant elevations in MMP-8 levels and activation in GCF of the adjacent teeth. During the experiments, no marked changes occurred in MMP-8 levels in the GCF of distantly located teeth. Painful stimulation of the upper incisor provoked elevations in GCF MMP-8 and SP levels of the stimulated tooth. The GCF MMP-8 and SP levels of the non-stimulated teeth were not changed. These results suggest that capsaicin-induced inflammatory reactions in gingivomucosal tissues do not cross the midline in the anterior maxilla. The enhanced reaction found during stimulation of alveolar mucosa indicates that alveolar mucosa is more sensitive to chemical irritants than the attached gingiva. Analysis of these data suggests that capsaicin-evoked neurogenic inflammation in the gingiva can trigger the expression and activation of MMP-8 in GCF of the adjacent teeth. In this study, it is concluded that experimental tooth pain at C-fibre intensity can induce local elevations in MMP-8 and SP levels in GCF. Depending on the role of MMP-8 in inflammation, in addition to surrogated tissue destruction, the elevated MMP-8 in GCF may also reflect accelerated local defensive and anti-inflammatory reactions.

Social Cognition and Behavior in Relationship Context

Social information processing (SIP; Crick & Dodge, 1994) and social-cognitive learning theories have been often used to understand children’s problem behaviors, such as aggression. According to these theories, children’s thinking guides their subsequent behaviors. Although most of us agree that social behavior and underlying thought processes are context-dependent, personality and social development researchers have usually engaged in searching for stable patterns of dispositions and behaviors, ignoring (or treating as error) the variance across different situations and relationship types. This, however, can result in erroneous conclusions and question the interpretation of previous findings. Four studies were conducted to explore the influence of relationship context on children’s social-cognitive evaluations and behavior. Samples were fourth to sixth graders from Estonia and Finland. Social cognitions were assessed by presenting children with hypothetical vignettes where the previously identified relationship partner’s behavior had a negative consequence for the child (Studies I, II, and IV), followed by questions measuring different social-cognitive processes (e.g., hostile attributions, behavioral strategies, outcome expectations and self-efficacy beliefs for aggression). In addition, in Studies II and IV, children provided information about their behavior within a specific relationship context. In Study III, an affective priming paradigm was employed where participants were presented with a short display of photographs of children’s liked and disliked classmates, and unknown peers. The results of this thesis suggest that children’s thinking and behavior are largely influenced by the affective valence of the relationship. Moreover, cognitions guide behavior within the relationship. The current findings offer a fruitful avenue for studying the heterogeneity of peer interactions.

Evolutionary Ecology of Mountain Birch in Subarctic Stress Gradients: Interplay of Biotic and Abiotic Factors in Plant-Plant Interactions and Evolutionary Processes

In nature, variation for example in herbivory, wind exposure, moisture and pollution impact often creates variation in physiological stress and plant productivity. This variation is seldom clear-cut, but rather results in clines of decreasing growth and productivity towards the high-stress end. These clines of unidirectionally changing stress are generally known as ‘stress gradients’. Through its effect on plant performance, stress has the capacity to fundamentally alter the ecological relationships between individuals, and through variation in survival and reproduction it also causes evolutionary change, i.e. local adaptations to stress and eventually speciation. In certain conditions local adaptations to environmental stress have been documented in a matter of just a few generations. In plant-plant interactions, intensities of both negative interactions (competition) and positive ones (facilitation) are expected to vary along stress gradients. The stress-gradient hypothesis (SGH) suggests that net facilitation will be strongest in conditions of high biotic and abiotic stress, while a more recent ‘humpback’ model predicts strongest net facilitation at intermediate levels of stress. Plant interactions on stress gradients, however, are affected by a multitude of confounding factors, making studies of facilitation-related theories challenging. Among these factors are plant ontogeny, spatial scale, and local adaptation to stress. The last of these has very rarely been included in facilitation studies, despite the potential co-occurrence of local adaptations and changes in net facilitation in stress gradients. Current theory would predict both competitive effects and facilitative responses to be weakest in populations locally adapted to withstand high abiotic stress. This thesis is based on six experiments, conducted both in greenhouses and in the field in Russia, Norway and Finland, with mountain birch (Betula pubescens subsp. czerepanovii) as the model species. The aims were to study potential local adaptations in multiple stress gradients (both natural and anthropogenic), changes in plant-plant interactions under conditions of varying stress (as predicted by SGH), potential mechanisms behind intraspecific facilitation, and factors confounding plant-plant facilitation, such as spatiotemporal, ontogenetic, and genetic differences. I found rapid evolutionary adaptations (occurring within a time-span of 60 to 70 years) towards heavy-metal resistance around two copper-nickel smelters, a phenomenon that has resulted in a trade-off of decreased performance in pristine conditions. Heavy-metal-adapted individuals had lowered nickel uptake, indicating a possible mechanism behind the detected resistance. Seedlings adapted to heavy-metal toxicity were not co-resistant to others forms of abiotic stress, but showed co-resistance to biotic stress by being consumed to a lesser extent by insect herbivores. Conversely, populations from conditions of high natural stress (wind, drought etc.) showed no local adaptations, despite much longer evolutionary time scales. Due to decreasing emissions, I was unable to test SGH in the pollution gradients. In natural stress gradients, however, plant performance was in accordance with SGH, with the strongest host-seedling facilitation found at the high-stress sites in two different stress gradients. Factors confounding this pattern included (1) plant size / ontogenetic status, with seedling-seedling interactions being competition dominated and host-seedling interactions potentially switching towards competition with seedling growth, and (2) spatial distance, with competition dominating at very short planting distances, and facilitation being strongest at a distance of circa ¼ benefactor height. I found no evidence for changes in facilitation with respect to the evolutionary histories of plant populations. Despite the support for SGH, it may be that the ‘humpback’ model is more relevant when the main stressor is resource-related, while what I studied were the effects of ‘non-resource’ stressors (i.e. heavy-metal pollution and wind). The results have potential practical applications: the utilisation of locally adapted seedlings and plant facilitation may increase the success of future restoration efforts in industrial barrens as well as in other wind-exposed sites. The findings also have implications with regard to the effects of global change in subarctic environments: the documented potential by mountain birch for rapid evolutionary change, together with the general lack of evolutionary ‘dead ends’, due to not (over)specialising to current natural conditions, increase the chances of this crucial forest-forming tree persisting even under the anticipated climate change.

Soldiering and the making of Finnish manhood : conscription and masculinity in interwar Finland, 1918–1939

Military conscription and peacetime military service were the subjects of heated political, social and cultural controversies during the early years of national independence in Finland. Both the critics and the supporters of the existing military system described it as strongly formative of young men’s physical and moral development into adult men and male citizens. The conflicts over conscription prompted the contemporaries to express their notions about what Finnish men were like, at their best and at their worst, and what should and could be done about it. This thesis studies military conscription as an arena for the “making of manhood” in peacetime Finnish society, 1918–1939. It examines a range of public images of conscripted soldiering, asking how soldiering was depicted and given gendered meanings in parliamentary debates, war hero myths, texts concerned with the military and civic education of conscripts, as well as in works of fiction and reminiscences about military training as a personal experience. Studying conscription with a focus on masculinity, the thesis explores the different cultural images of manliness, soldiering and male citizenship on offer in Finnish society. It investigates how political parties, officers, educators, journalists, writers and “ordinary” conscripts used and developed, embraced or rejected these notions, according to their political purposes or personal needs. The period between the two world wars can be described as a fast-forward into military modernity in Finland. In the process, European middle class gender ideologies clashed with Finnish agrarian masculinities. Nationalistic agendas for the militarisation of Finnish manhood stumbled against intense class conflicts and ideological resistance. Military propaganda used images of military heroism, civic virtue and individual success to persuade the conscripts into ways of thinking and acting that were shaped by bourgeois mentality, nationalistic ideology and religious morality. These images are further analysed as expressive of the personal experiences and emotions of their middle-aged, male authors. The efforts of these military educators were, however, actively resisted on many fronts, ranging from rural working class masculinities among the conscripted young men to ideological critiques of the standing army system in parliament. In narratives about military training, masculinity was depicted as both strengthened and contradicted by the harsh and even brutal practices of interwar Finnish military training. The study represents a combination of new military history and the historical study of men and masculinities. It approaches masculinity as a contested and highly political form of social and cultural knowledge that is actively and selectively used by historic actors. Instead of trying to identify a dominant or “hegemonic” form of masculinity within a pre-determined theoretical structure, this study examines how the meanings ascribed to manhood varied according to class, age, political ideology and social situation. The interwar period in Finland can be understood as a period of contest between different notions of militarised masculinity, yet to judge by the materials studied, there was no clear winning party in that contest. A gradual movement from an atmosphere of conflict surrounding conscription towards political and cultural compromises can be discerned, yet this convergence was incomplete and many division lines remained.