Triacylglycerol lipases of yeast and plants: more than just hydrolases

In the yeast, mobilization of triacylglycerols (TAG) is facilitated by TGL3, TGL4 and TGL5 gene products. Interestingly, experiments using [32P] orthophosphate as a precursor for complex glycerophospholipids revealed that tgl mutants had a lower steady-state level of these membrane lipids. To understand a possible link between TAG lipolysis and phospholipid metabolism, we performed overexpression studies with Tgl3p and Tgl5p which clearly demonstrated that these two enzymes enhanced the level of phospholipids. Domains and motifs search analyses indicated that yeast TAG hydrolases posses a GXSXG lipase motif but also a HX4D acyltransferase motif. Purified Tgl3p and Tgl5p did not only exhibit TAG lipase activity but also catalyzed acyl-CoA dependent acylation of lyso-phosphatidylethanolamine and lyso-phosphatidic acid (LPA), respectively. Search for lipase/hydrolase homologues in the Arabidopsis thaliana genome led to the identification of At4g24160 which possess three motifs that are conserved across the plant species such as GXSXG motif, a HX4D motif and a probable lipid binding motif V(X)3HGF. Characterization of At4g24160 expressed in bacteria revealed that the presence of an acyl-CoA dependent LPA acyltransferase activity. In addition, the purified recombinant At4g24160 protein hydrolyzed both TAG and phosphatidylcholine. We hypothesize that the plant enzyme may be involved in membrane repair. In summary, our results indicate that these TAG lipases play a dual role and thereby contribute to both anabolic and catabolic processes in yeast and plants.

Consensus statement on the role of Accredited Exercise Physiologists within the treatment of mental disorders: A guide for mental health professionals

- Objective The aim is to identify the role and scope of Accredited Exercise Physiologist (AEP) services in the mental health sector and to provide insight as to how AEPs can contribute to the multidisciplinary mental health team. - Methods A modified Delphi approach was utilised. Thirteen AEPs with experience in mental health contributed to the iterative development of a national consensus statement. Six mental health professionals with expertise in psychiatry, mental health nursing, general practice and mental health research participated in the review process. Reviewers were provided with a template to systematically provide feedback on the language, content, structure and relevance to their professional group. - Results This consensus statement outlines how AEPs can contribute to the multidisciplinary mental health team, the aims and scope of AEP-led interventions in mental health services and examples of such interventions, the range of physical and mental health outcomes possible through AEP-led interventions and common referral pathways to community AEP services. - Outcome AEPs can play a key role in the treatment of individuals experiencing mental illness. The diversity of AEP interventions allows for a holistic approach to care, enhancing both physical and mental health outcomes.

The Emerging Phenotype: Ecological Genetics of Color, Form and Sex in the Common Frog

One of the main aims of evolutionary biology is to explain why organisms vary phenotypically as they do. Proximately, this variation arises from genetic differences and from environmental influences, the latter of which is referred to as phenotypic plasticity. Phenotypic plasticity is thus a central concept in evolutionary biology, and understanding its relative importance in causing the phenotypic variation and differentiation is important, for instance in anticipating the consequences of human induced environmental changes. The aim of this thesis was to study geographic variation and local adaptation, as well as sex ratios and environmental sex reversal, in the common frog (Rana temporaria). These themes cover three different aspects of phenotypic plasticity, which emerges as the central concept for the thesis. The first two chapters address geographic variation and local adaptation in two potentially thermally adaptive traits, namely the degree of melanism and the relative leg length. The results show that although there is an increasing latitudinal trend in the degree of melanism in wild populations across Scandinavian Peninsula, this cline has no direct genetic basis and is thus environmentally induced. The second chapter demonstrates that although there is no linear, latitudinally ordered phenotypic trend in relative leg length that would be expected under Allen s rule an ecogeographical rule linking extremity length to climatic conditions there seems to be such a trend at the genetic level, hidden under environmental effects. The first two chapters thus view phenotypic plasticity through its ecological role and evolution, and demonstrate that it can both give rise to phenotypic variation and hide evolutionary patterns in studies that focus solely on phenotypes. The last three chapters relate to phenotypic plasticity through its ecological and evolutionary role in sex determination, and consequent effects on population sex ratio, genetic recombination and the evolution of sex chromosomes. The results show that while sex ratios are strongly female biased and there is evidence of environmental sex reversals, these reversals are unlikely to have caused the sex ratio skew, at least directly. The results demonstrate that environmental sex reversal can have an effect on the evolution of sex chromosomes, as the recombination patterns between them seem to be controlled by phenotypic, rather than genetic, sex. This potentially allows Y chromosomes to recombine, lending support for the recent hypothesis suggesting that sex-reversal may play an important role on the rejuvenation of Y chromosomes.

Surface Proteins of Lactobacillus crispatus: Adhesive Properties and Cell Wall Anchoring

Bacterial surface-associated proteins are important in communication with the environment and bacteria-host interactions. In this thesis work, surface molecules of Lactobacillus crispatus important in host interaction were studied. The L. crispatus strains of the study were known from previous studies to be efficient in adhesion to intestinal tract and ECM. L. crispatus JCM 5810 possess an adhesive surface layer (S-layer) protein, whose functions and domain structure was characterized. We cloned two S-layer protein genes (cbsA; collagen-binding S-layer protein A and silent cbsB) and identified the protein region in CbsA important for adhesion to host tissues, for polymerization into a periodic layer as well as for attachment to the bacterial cell surface. The analysis was done by extensive mutation analysis and by testing His6-tagged fusion proteins from recombinant Escherichia coli as well as by expressing truncated CbsA peptides on the surface of Lactobacillus casei. The N-terminal region (31-274) of CbsA showed efficient and specific binding to collagens, laminin and extracellular matrix on tissue sections of chicken intestine. The N-terminal region also contained the information for formation of periodic S-layer polymer. This region is bordered at both ends by a conserved short region rich in valines, whose substitution to leucines drastically affected the periodic polymer structure. The mutated CbsA proteins that failed to form a periodic polymer, did not bind collagens, which indicates that the polymerized structure of CbsA is needed for collagen-binding ability. The C-terminal region, which is highly identical in S-layer proteins of L. crispatus, Lactobacillus acidophilus and Lactobacillus helveticus, was shown to anchor the protein to the bacterial cell wall. The C-terminal CbsA peptide specifically bound to bacterial teichoic acid and lipoteichoic acids. In conclusion, the N-terminal domain of the S-layer protein of L. crispatus is important for polymerization and adhesion to host tissues, whereas the C-terminal domain anchors the protein to bacterial cell-wall teichoic acids. Lactobacilli are fermentative organisms that effectively lower the surrounding pH. While this study was in progress, plasminogen-binding proteins enolase and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) were identified in the extracellular proteome of L. crispatus ST1. In this work, the cell-wall association of enolase and GAPDH were shown to rely on pH-reversible binding to the cell-wall lipoteichoic acids. Enolase from L. crispatus was functionally compared with enolase from L. johnsonii as well as from pathogenic streptococci (Streptococcus pneumoniae, Streptococcus pyogenes) and Staphylococcus aureus. His6-enolases from commensal lactobacilli bound human plasminogen and enhanced its activation by human plasminogen activators similarly to, or even better than, the enolases from pathogens. Similarly, the His6-enolases from lactobacilli exhibited adhesive characteristics previously assigned to pathogens. The results call for more detailed analyses of the role of the host plasminogen system in bacterial pathogenesis and commensalism as well of the biological role and potential health risk of the extracellular proteome in lactobacilli.

Exposure-related human cancer: Molecular changes in sinonasal cancer and lung cancer, with focus on TP53 mutations

Cancer is a leading cause of death worldwide and the total number of cancer cases continues to increase. Many cancers, for example sinonasal cancer and lung cancer, have clear external risk factors and so are potentially preventable. The occurrence of sinonasal cancer is strongly associated with wood dust exposure and the main risk factor for lung cancer is tobacco smoking. Although the molecular mechanisms involved in lung carcinogenesis have been widely studied, very little is known about the molecular changes leading to sinonasal cancer. In this work, mutations in the tumour suppressor TP53 gene in cases of sinonasal cancer and lung cancer and the associations of these mutations with exposure factors were studied. In addition, another important mechanism in many cancers, inflammation, was explored by analyzing the expression of the inflammation related enzyme, COX-2, in sinonasal cancer. The results demonstrate that TP53 mutations are frequent in sinonasal cancer and lung cancer and in both cancers they are associated with exposure. In sinonasal cancer, the occurrence of TP53 mutation significantly increased in relation to long duration and high level of exposure to wood dust. Smoking was not associated with the overall occurrence of the TP53 mutation in sinonasal cancer, but was associated with multiple TP53 mutations. Furthermore, inflammation appears to play a part in sinonasal carcinogenesis as indicated by our results showing that the expression of COX-2 was associated with adenocarcinoma type of tumours, wood dust exposure and non-smoking. In lung cancer, we detected statistically significant associations between TP53 mutations and duration of smoking, gender and histology. We also found that patients with a tumour carrying a G to T transversion, a mutation commonly found in association with tobacco smoking, had a high level of smoking-related bulky DNA adducts in their non-tumorous lung tissue. Altogether, the information on molecular changes in exposure induced cancers adds to the observations from epidemiological studies and helps to understand the role and impact of different etiological factors, which in turn can be beneficial for risk assessment and prevention.

Elevated circulating sclerostin concentrations in individuals with high bone mass, with and without LRP5 mutations

CONTEXT: The role and importance of circulating sclerostin is poorly understood. High bone mass (HBM) caused by activating LRP5 mutations has been reported to be associated with increased plasma sclerostin concentrations; whether the same applies to HBM due to other causes is unknown. OBJECTIVE: Our objective was to determine circulating sclerostin concentrations in HBM. DESIGN AND PARTICIPANTS: In this case-control study, 406 HBM index cases were identified by screening dual-energy x-ray absorptiometry (DXA) databases from 4 United Kingdom centers (n = 219 088), excluding significant osteoarthritis/artifact. Controls comprised unaffected relatives and spouses. MAIN MEASURES: Plasma sclerostin; lumbar spine L1, total hip, and total body DXA; and radial and tibial peripheral quantitative computed tomography (subgroup only) were evaluated. RESULTS: Sclerostin concentrations were significantly higher in both LRP5 HBM and non-LRP5 HBM cases compared with controls: mean (SD) 130.1 (61.7) and 88.0 (39.3) vs 66.4 (32.3) pmol/L (both P < .001, which persisted after adjustment for a priori confounders). In combined adjusted analyses of cases and controls, sclerostin concentrations were positively related to all bone parameters found to be increased in HBM cases (ie, L1, total hip, and total body DXA bone mineral density and radial/tibial cortical area, cortical bone mineral density, and trabecular density). Although these relationships were broadly equivalent in HBM cases and controls, there was some evidence that associations between sclerostin and trabecular phenotypes were stronger in HBM cases, particularly for radial trabecular density (interaction P < .01). CONCLUSIONS: Circulating plasma sclerostin concentrations are increased in both LRP5 and non-LRP5 HBM compared with controls. In addition to the general positive relationship between sclerostin and DXA/peripheral quantitative computed tomography parameters, genetic factors predisposing to HBM may contribute to increased sclerostin levels.

Functional characterization of MutL homologue mismatch repair proteins and their variants

Mismatch repair (MMR) mechanisms repair DNA damage occurring during replication and recombination. To date, five human MMR genes, MSH2, MHS6, MSH3, MLH1 and PMS2 are known to be involved in the MMR function. Human MMR proteins form 3 different heterodimers: MutSα (MSH2 and MSH6) and MutSβ (MSH2 and MSH3), which are needed for mismatch recognition and binding, and MutLα (MLH1 and PMS2), which is needed for mediating interactions between MutS homologues and other MMR proteins. The other two MutL homologues, MLH3 and PMS1, have been shown to heterodimerize with MLH1. However, the heterodimers MutLγ (MLH1and MLH3) and MutLβ (MLH1 and PMS1) are able to correct mismatches only with low or no efficiency, respectively. A deficient MMR mechanism is associated with the hereditary colorectal cancer syndrome called hereditary nonpolyposis colorectal cancer (HNPCC) or Lynch syndrome. HNPCC is the most common hereditary colorectal cancer syndrome and accounts for 2-5% of all colorectal cancer cases. HNPCC-associated mutations have been found in 5 MMR genes: MLH1, MSH2, MSH6, PMS2 and MLH3. Most of the mutations have been found in MLH1 and MSH2 (~90%) and are associated with typical HNPCC, while mutations in MSH6, PMS2 and MLH3 are mainly linked to putative HNPCC families lacking the characteristics of the syndrome. More data of MLH3 mutations are needed to assess the significance of its mutations in HNPCC. In this study, were functionally characterized 51 nontruncating mutations in the MLH1, MLH3 and MSH2 genes to address their pathogenic significance and mechanism of pathogenicity. Of the 36 MLH1 mutations, 22 were deficient in more than one assay, 2 variants were impaired only in one assay, and 12 variants behaved like the wild type protein, whereas all seven MLH3 mutants functioned like the wild type protein in the assays. To further clarify the role and relevance of MLH3 in MMR, we analyzed the subcellular localization of the native MutL homologue proteins. Our immunofluorescence analyses indicated that when all the three MutL homologues are natively expressed in human cells, endogenous MLH1 and PMS2 localize in the nucleus, whereas MLH3 stays in the cytoplasm. The coexpression of MLH3 with MLH1 results in its partial nuclear localization. Only one MSH2 mutation was pathogenic in the in vitro MMR assay. Our study on MLH1 mutations could clearly distinguish nontruncating alterations with severe functional defects from those not or only slightly impaired in protein function. However, our study on MLH3 mutations suggest that MLH3 mutations per se are not sufficient to trigger MMR deficiency and the continuous nuclear localization of MLH1 and PMS2 suggest that MutLα has a major activity in MMR in vivo. Together with our functional assays, this confirms that MutLγ is a less efficient MMR complex than MutLα.

Simple repetitive sequences in the genome: structure and functional significance

The current explosion of DNA sequence information has generated increasing evidence for the claim that noncoding repetitive DNA sequences present within and around different genes could play an important role in genetic control processes, although the precise role and mechanism by which these sequences function are poorly understood. Several of the simple repetitive sequences which occur in a large number of loci throughout the human and other eukaryotic genomes satisfy the sequence criteria for forming non-B DNA structures in vitro. We have summarized some of the features of three different types of simple repeats that highlight the importance of repetitive DNA in the control of gene expression and chromatin organization. (i) (TG/CA)n repeats are widespread and conserved in many loci. These sequences are associated with nucleosomes of varying linker length and may play a role in chromatin organization. These Z-potential sequences can help absorb superhelical stress during transcription and aid in recombination. (ii) Human telomeric repeat (TTAGGG)n adopts a novel quadruplex structure and exhibits unusual chromatin organization. This unusual structural motif could explain chromosome pairing and stability. (iii) Intragenic amplification of (CTG)n/(CAG)n trinucleotide repeat, which is now known to be associated with several genetic disorders, could down-regulate gene expression in vivo. The overall implications of these findings vis-à-vis repetitive sequences in the genome are summarized.

Clinical teaching: Maintaining an educational role for doctors in the new health care environment

Context and objectives: Good clinical teaching is central to medical education but there is concern about maintaining this in contemporary, pressured health care environments. This paper aims to demonstrate that good clinical practice is at the heart of good clinical teaching. Methods: Seven roles are used as a framework for analysing good clinical teaching. The roles are medical expert, communicator, collaborator, manager, advocate, scholar and professional. Results: The analysis of clinical teaching and clinical practice demonstrates that they are closely linked. As experts, clinical teachers are involved in research, information retrieval and sharing of knowledge or teaching. Good communication with trainees, patients and colleagues defines teaching excellence. Clinicians can 'teach' collaboration by acting as role models and by encouraging learners to understand the responsibilities of other health professionals. As managers, clinicians can apply their skills to the effective management of learning resources. Similarly skills as advocates at the individual, community and population level can be passed on in educational encounters. The clinicians' responsibilities as scholars are most readily applied to teaching activities. Clinicians have clear roles in taking scholarly approaches to their practice and demonstrating them to others. Conclusion: Good clinical teaching is concerned with providing role models for good practice, making good practice visible and explaining it to trainees. This is the very basis of clinicians as professionals, the seventh role, and should be the foundation for the further development of clinicians as excellent clinical teachers.

Growing Flowers in the Frost: Civic Activity, Citizenship and Gender in Russia

This study analyzes civic activity, citizenship and their gendered manifestations in contemporary Russia. It is based on a case study conducted in the city of Tver , located in the vicinity of Moscow, during 2001-2005. The data consists of interviews with civic activists and municipal and regional authorities; observations of civic organizations; and a quantitative survey conducted among local civic groups. The theoretical and methodological framework of the study draws upon a micro perspective on organization, discourse analysis, gender and citizenship theories and Pierre Bourdieu s theory of fields and capital. This study develops theoretical understanding of the characteristics and logic of civic organization in Russia. It shows that social class centrally structures the field of civic activity. Organizations can be seen as a vehicle of the educated class to advocate their interests, help themselves and seek both social and individual-level change. The study also argues that civic organizations founded during the post-Soviet era are often an institutionalized form of informal social networks. Networks, which were a central element of everyday interaction in Soviet society, are a resource and often the only resource available that can be made use of in contemporary organizational activities. The study argues that gender operates as a key structuring principle in the Russian socio-political community. Civic activity is often discursively associated with femininity and institutional politics with masculinity. Women tend to participate more than men in civic organizations, while men dominate the formal political domain. The study shows that civic organizations are important loci of communality. This communality, however, differs from the communality envisioned in the communitarian and social capital debates in the West. It is selective communality , as it is restricted to the members of the organizations and does not create generalized reciprocity and trust. Civic organizations tend to build upon and reproduce the traditional Russian organizational form of circles , kruzhki. Along with the analysis of civic activities, the study also examines the redefinition of the role and functions of the state. The authorities interviewed in this study understand civic organizations as serving those goals and interests determined by the authorities, instead of viewing them as sites of citizens self-organization around interests and problems citizens themselves deem important, or as a counterforce to the state. By contrast, civic activists understand the core of organizational activity to be advocacy of their interests and rights, tackling social problems, the pursuit of wider social change and self-help. Co-operation between authorities and organizations tends to be personified and based upon unequal, hierarchical patron-client arrangements, which inhibits the development of democratic governance. The study will be published in Routledge Contemporary Russia and Eastern Europe Series later this year.

Residential Differentiation, Housing Policy and Urban Planning in the Transformation from State Socialism to a Market Economy: The Case of Tallinn

The thesis examines urban issues arising from the transformation from state socialism to a market economy. The main topics are residential differentiation, i.e., uneven spatial distribution of social groups across urban residential areas, and the effects of housing policy and town planning on urban development. The case study is development in Tallinn, the capital city of Estonia, in the context of development of Central and Eastern European cities under and after socialism. The main body of the thesis consists of four separately published refereed articles. The research question that brings the articles together is how the residential (socio-spatial) pattern of cities developed during the state socialist period and how and why that pattern has changed since the transformation to a market economy began. The first article reviews the literature on residential differentiation in Budapest, Prague, Tallinn and Warsaw under state socialism from the viewpoint of the role of housing policy in the processes of residential differentiation at various stages of the socialist era. The paper shows how the socialist housing provision system produced socio-occupational residential differentiation directly and indirectly and it describes how the residential patterns of these cities developed. The second article is critical of oversimplified accounts of rapid reorganisation of the overall socio-spatial pattern of post-socialist cities and of claims that residential mobility has had a straightforward role in it. The Tallinn case study, consisting of an analysis of the distribution of socio-economic groups across eight city districts and over four housing types in 1999 as well as examining the role of residential mobility in differentiation during the 1990s, provides contrasting evidence. The third article analyses the role and effects of housing policies in Tallinn s residential differentiation. The focus is on contemporary post-privatisation housing-policy measures and their effects. The article shows that the Estonian housing policies do not even aim to reduce, prevent or slow down the harmful effects of the considerable income disparities that are manifest in housing inequality and residential differentiation. The fourth article examines the development of Tallinn s urban planning system 1991-2004 from the viewpoint of what means it has provided the city with to intervene in urban development and how the city has used these tools. The paper finds that despite some recent progress in planning, its role in guiding where and how the city actually developed has so far been limited. Tallinn s urban development is rather initiated and driven by private agents seeking profit from their investment in land. The thesis includes original empirical research in the three articles that analyse development since socialism. The second article employs quantitative data and methods, primarily index calculation, whereas the third and the fourth ones draw from a survey of policy documents combined with interviews with key informants. Keywords: residential differentiation, housing policy, urban planning, post-socialist transformation, Estonia, Tallinn

Sense of Coherence : Determinants and consequences

ABSTRACT Sense of coherence (SOC) is a core concept within Antonovsky s salutogenic theory and is argued to be a psychological determinant of health. The present social-epidemiological study explores the associations between a wide range of generalized resistance resources of SOC among Finnish- and Swedish-speaking women and men with a view to gaining deeper insight into its developmental circumstances and determinants. Secondly, a five-year follow-up study was conducted in order to assess the stability of SOC in difficult life events. Finally the role and effect of SOC in the intentions to retire early was investigated in a prospective study. The above studies were based on two data sets: the Finnish 'Survey on Living Conditions' (ELO-94) conducted in 1994 by means of personal face-to-face interviews (N=6506), and a prospective postal survey of the 15-year Health and Social Support (HeSSup) study for which the baseline data was collected in 1998 (N=25 898) and the follow-up in 2003. The present study reveals that the level of SOC in adulthood is strongly dependent on close and successful social relationships during both childhood and adulthood, and that there is a strong association with qualitative work features. Not having a partner as well as being unable to use one s skills at work proved to threaten men s SOC in particular, whereas a lack of social support did the same for women. Otherwise, the association with generalized resistance resources turned out to be quite similar in both genders. Swedish-speaking Finns appear to have a slightly stronger SOC due to the better psycho-emotional circumstances in the childhood home and work circumstances in adulthood, in other words higher levels of generalized resistance resources compared to Finnish speakers. These language group differences did not concern any social-life factors included in the present study. The results of the five-year follow-up study suggest that SOC is not stable, and that the level clearly decreases after a negative life event. Even a strong SOC decreased during the follow-up period and, furthermore, was no more stable than a mediocre or weak SOC. There seems to be a clear and independent association with the intentions to retire early among both men and women following full adjustment. Swedish speakers appear to be less inclined to retire early than Finnish speakers. In the light of the present study, it seems that SOC is determined not only by socio-economic factors but also by close and successful social relationships during both childhood and adulthood. This applied to both genders and language groups. Interventions aimed at promoting the health of the disadvantaged should therefore focus on families with children, and extend later also to other than socio-economic spheres of life. SOC theory could also be applied in efforts to inhibit early retirement: management practices aimed at providing employees with a work environment and tasks that are comprehensible, manageable and meaningful could potentially decrease the intentions to retire early.

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.

Quantitative structural refinement of mn K edge XANES in LaMnO3 and CaMnO3 perovskites

The special magnetotransport properties of hole doped manganese perovskites originate from a complex interplay among structural, magnetic and electronic degree of freedom. In this picture the local atomic structure around Mn ions plays a special role and this is the reason why short range order techniques like X-ray absorption spectroscopy (XAS) have been deeply exploited for studying these compounds. The analysis of near edge region features (XANES) of XAS spectra can provide very fine details of the local structure around Mn, complementary to the EXAFS, so contributing to the full understanding of the peculiar physical properties of these materials. Nevertheless the XANES analysis is complicated by the large amount of structural and electronic details involved making difficult the quantitative interpretation.This work exploits the recently developed MXAN code to achieve a full structural refinement of the Mn K edge XANES of LaMnO3 and CaMnO3 compounds; they are the end compounds of the doped manganite series LaxCa1-xMnO3, in which the Mn ions are present only in one charge state as Mn3+ and Mn4+ respectively. The good agreement between the results derived from the analysis of near edge and extended region of the XAS spectra demonstrates that a quantitative picture of the local structure call be obtained from structural refinement of Mn K edge XANES data in these crystalline compounds. The XANES analysis offers, in addition.. the possibility to directly achieve information on the topology of local atomic structure around the absorber not directly achievable from EXAFS.

Real-Time PCR : A Molecular Approach to Investigate the Role of Intestinal Microbiota in the Pathophysiology of Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) is a common multifactorial functional intestinal disorder, the pathogenesis of which is not completely understood. Increasing scientific evidence suggests that microbes are involved in the onset and maintenance of IBS symptoms. The microbiota of the human gastrointestinal (GI) tract constitutes a massive and complex ecosystem consisting mainly of obligate anaerobic microorganisms making the use of culture-based methods demanding and prone to misinterpretation. To overcome these drawbacks, an extensive panel of species- and group-specific assays for an accurate quantification of bacteria from fecal samples with real-time PCR was developed, optimized, and validated. As a result, the target bacteria were detectable at a minimum concentration range of approximately 10 000 bacterial genomes per gram of fecal sample, which corresponds to the sensitivity to detect 0.000001% subpopulations of the total fecal microbiota. The real-time PCR panel covering both commensal and pathogenic microorganisms was assessed to compare the intestinal microbiota of patients suffering from IBS with a healthy control group devoid of GI symptoms. Both the IBS and control groups showed considerable individual variation in gut microbiota composition. Sorting of the IBS patients according to the symptom subtypes (diarrhea, constipation, and alternating predominant type) revealed that lower amounts of Lactobacillus spp. were present in the samples of diarrhea predominant IBS patients, whereas constipation predominant IBS patients carried increased amounts of Veillonella spp. In the screening of intestinal pathogens, 17% of IBS samples tested positive for Staphylococcus aureus, whereas no positive cases were discovered among healthy controls. Furthermore, the methodology was applied to monitor the effects of a multispecies probiotic supplementation on GI microbiota of IBS sufferers. In the placebo-controlled double-blind probiotic intervention trial of IBS patients, each supplemented probiotic strain was detected in fecal samples. Intestinal microbiota remained stable during the trial, except for Bifidobacterium spp., which increased in the placebo group and decreased in the probiotic group. The combination of assays developed and applied in this thesis has an overall coverage of 300-400 known bacterial species, along with the number of yet unknown phylotypes. Hence, it provides good means for studying the intestinal microbiota, irrespective of the intestinal condition and health status. In particular, it allows screening and identification of microbes putatively associated with IBS. The alterations in the gut microbiota discovered here support the hypothesis that microbes are likely to contribute to the pathophysiology of IBS. The central question is whether the microbiota changes described represent the cause for, rather than the effect of, disturbed gut physiology. Therefore, more studies are needed to determine the role and importance of individual microbial species or groups in IBS. In addition, it is essential that the microbial alterations observed in this study will be confirmed using a larger set of IBS samples of different subtypes, preferably from various geographical locations.