Metabarcoding successfully tracks temporal changes in eukaryotic communities in coastal sediments.

Metabarcoding is a method that combines high-throughput DNA sequencing and DNA-based identification. Previously, this method has been successfully used to target spatial variation of eukaryote communities in marine sediments, however, the temporal changes in these communities remain understudied. Here, we follow the temporal changes of the eukaryote communities in Baltic Sea surface sediments collected from two coastal localities during three seasons of two consecutive years. Our study reveals that the structure of the sediment eukaryotic ecosystem was primarily driven by annual and seasonal changes in prevailing environmental conditions, whereas spatial variation was a less significant factor in explaining the variance in eukaryotic communities over time. Therefore, our data suggests that shifts in regional climate regime or large-scale changes in the environment are the overdriving factors in shaping the coastal eukaryotic sediment ecosystems rather than small-scale changes in local environmental conditions or heterogeneity in ecosystem structure. More studies targeting temporal changes are needed to further understand the long-term trends in ecosystem stability and response to climate change. Furthermore, this work contributes to the recent efforts in developing metabarcoding applications for environmental biomonitoring, proving a comprehensive option for traditional monitoring approaches.

Predictors of perceived togetherness in very old men and women: a 5-year follow-up study.

Although a considerable amount of research has been carried out on older adults' social ties, most of it has focused on quantitative aspects and on cross-sectional samples. In this study, the subjective aspect of social interaction is described by the concept of perceived togetherness. The aim of this study was to examine the extent to which different factors predict perceived togetherness in men and women over a 5-year period. It also addresses the question of whether it is possible to identify different subgroups in perceived togetherness. The data were collected with structured interviews and laboratory tests from 225 elderly people at ages 80 and 85. The results showed that the predictors of perceived togetherness partly differed between sexes as well as within the groups of males and females. Predictors common to both genders were contacts with friends, less depressive symptoms, higher education level and better coping with instrumental activities of daily living (IADLs). The findings indicated the importance of friends. Widowhood and self-rated health were predictors in women but not in men. Moreover, there appeared to be two subgroups of women and men in perceived togetherness; these were labeled "socially embedded", "socially isolated", "socially active" and "solitary". The results indicate diversity in perceived togetherness and its predictors. More attention should be paid to individual differences in order to prevent loneliness and to promote older adults' well-being.

Testing a model of physical activity and obesity tracking from youth to adulthood: the cardiovascular risk in young Finns study.

OBJECTIVE: To test a potential model of the relationship between physical activity and obesity from youth to adulthood. DESIGN: Longitudinal study data from the cardiovascular risk in young Finns study. SUBJECTS: A total of 1319 boys (n=626) and girls (n=693) aged 9, 12, 15 and 18 years were randomly selected from five university towns and their rural surroundings in 1980. They were followed up for 21 years. In 2001 they were 30, 33, 36 and 39 years old. MEASUREMENTS: Physical activity was assessed by a short questionnaire at two measurement points. Obesity was measured by body mass index (BMI) and sum of skinfolds in 1980 and BMI and waist circumference in 2001. RESULTS: Structural equation analysis (LISREL) indicated that the prevalence of abdominal obesity in adulthood was directly affected by adult physical activity (beta (beta)=-0.16, t=-4.02, P< 0.05 for men, beta=-0.12, t=-3.35, P<0.05 for women) and indirectly via youth physical activity (beta=-0.10, t=-4.68, P< 0.05 for men, beta=-0.07, t=-4.54, P<0.05 for women). Obesity tracked significantly from youth to adulthood (beta=0.41, t=11.13, P<0.05 for men, beta=0.34, t=9.39, P<0.05 for women). Youth physical activity might reduce body weight in youth but was not directly associated with adult abdominal obesity in either men or women. The model accounted 19% of abdominal obesity in men and 13% in women. The path from youth physical activity to adult obesity through youth obesity seemed to be stronger than the path through adult physical activity. CONCLUSIONS: This study lends general support to the hypothesized model that abdominal obesity in adulthood is directly related to adult physical activity and youth overall obesity in both sexes. Youth physical activity had an indirect effect on abdominal obesity through the maintenance of physical activity in adulthood. Participation in and maintaining physical activity from youth to adulthood may have an important role in reducing obesity in adulthood.

Environmental changes in the North Atlantic Region: SCANNET as a collaborative approach for documenting, understanding and predicting changes.

The lands surrounding the North Atlantic Region (the SCANNET Region) cover a wide range of climate regimes, physical environments and availability of natural resources. Except in the extreme North, they have supported human populations and various cultures since at least the end of the last ice age. However, the region is also important at a wider geographical scale in that it influences the global climate and supports animals that migrate between the Arctic and all the other continents of the world. Climate, environment and land use in the region are changing rapidly and projections suggest that global warming will be amplified there while increasing land use might dramatically reduce the remaining wilderness areas. Because much of the region is sparsely populated--if populated at all--observational records of past environmental changes and their impacts are both few and of short duration. However, it is becoming very important to record the changes that are now in progress, to understand the drivers of these changes, and to predict future consequences of the changes. To facilitate research into understanding impacts of global change on the lands of the North Atlantic Regions, and also to monitor changes in real time, an EU-funded network of research sites and infrastructures was formed in 2000: this was called SCANNET--SCANdinavian/North European NETwork of Terrestrial Field Bases. SCANNET currently consists of 9 core sites and 5 sites within local networks that together cover the broad range of current climate and predicted change in the region. Climate observations are well replicated across the network, whereas each site has tended to select particular environmental and ecological subjects for intensive observation. This provides diversity of both subject coverage and expertise. In this paper, we summarize the findings of SCANNET to-date and outline its information bases in order to increase awareness of data on environmental change in the North Atlantic Region. We also identify important gaps in our understanding and identify where the roles of existing infrastructures and activities represented by SCANNET can facilitate future research, monitoring and ground-truthing activities.

Phylogeographical structure, distribution and genetic variation of the green algae Ulva intestinalis and U. compressa (Chlorophyta) in the Baltic Sea area.

The marine algae Ulva intestinalis and U. compressa are morphologically plastic with many overlapping characters and are therefore difficult to distinguish from each other. The present distribution of U. intestinalis and U. compressa is investigated along the salinity gradient in the Baltic Sea area through analyses of internal transcribed spacer (ITS) sequence data. Also, the amount and distribution of intraspecific genetic polymorphism in the ITS region is studied allowing inferences on the phylogeographical pattern and postglacial recolonization of the Baltic Sea area. The data show that of the two species only U. intestinalis occurs in the Baltic Sea. The distribution of U. compressa is more restricted than previously reported, and it was not found in salinities lower than 15 ppt. All of Scandinavia and the Baltic Sea were covered with ice during the last ice age and the organisms in the Baltic Sea must have colonized the area after the ice had started to melt. The genetic diversity of U. intestinalis and U. compressa in the Baltic Sea and the neighbouring area was found to be reduced compared to that in the British Isles. This reduction may be the result of either a historical reduction of diversity or an adaptation of specific clones to the northern environmental conditions.

Do neighboring lakes share common taxa of bacterioplankton? Comparison of 16S rDNA fingerprints and sequences from three geographic regions.

Bacterioplankton community composition was studied in 12 lakes in three different geographic regions in Scandinavia using denaturing gradient gel electrophoresis (DGGE) and sequencing of 16S rDNA. Area-specific abundant taxa were found in the lakes in two of the regions. In the region of Uppland the lakes had an alpha-proteobacterium, belonging to the subgroup Alpha V in common. The Alpha V bacteria appeared to be favored by neutral or higher pH values. The lakes in Lappland were found to harbor Actinobacteria, which appeared to be favored in bog lakes. No abundant taxon was found to be in common for the lakes in Svalbard, the third region studied.

Global patterns of human DNA sequence variation in a 10-kb region on chromosome 1.

Human DNA variation is currently a subject of intense research because of its importance for studying human origins, evolution, and demographic history and for association studies of complex diseases. A approximately 10-kb region on chromosome 1, which contains only four small exons (each <155 bp), was sequenced for 61 humans (20 Africans, 20 Asians, and 21 Europeans) and for 1 chimpanzee, 1 gorilla, and 1 orangutan. We found 52 polymorphic sites among the 122 human sequences and 382 variant sites among the human, chimpanzee, gorilla, and orangutan sequences. For the introns sequenced (8,991 bp), the nucleotide diversity (pi) was 0.058% among all sequences, 0.076% among the African sequences, 0.047% among the Asian sequences, and 0.045% among the European sequences. A compilation of data revealed that autosomal regions have, on average, the highest pi value (0.091%), X-linked regions have a somewhat lower pi value (0.079%), and Y-linked regions have a very low pi value (0.008%). The lower polymorphism in the present region may be due to a lower mutation rate and/or selection in the gene containing these introns or in genes linked to this region. The present region and two other 10-kb noncoding regions all show a strong excess of low-frequency variants, indicating a relatively recent population expansion. This region has a low mutation rate, which was estimated to be 0.74 x 10 per nucleotide per year. An average estimate of approximately 12,600 for the long-term effective population size was obtained using various methods; the estimate was not far from the commonly used value of 10,000. Fu and Li's tests rejected the assumption of an equilibrium neutral Wright-Fisher population, largely owing to the high proportion of low-frequency variants. The age of the most recent common ancestor of the sequences in our sample was estimated to be more than 1 Myr. Allowing for some unrealistic assumptions in the model, this estimate would still suggest an age of more than 500,000 years, providing further evidence for a genetic history of humans much more ancient than the emergence of modern humans. The fact that many unique variants exist in Europe and Asia also suggests a fairly long genetic history outside of Africa and argues against a complete replacement of all indigenous populations in Europe and Asia by a small Africa stock. Moreover, the ancient genetic history of humans indicates no severe bottleneck during the evolution of humans in the last half million years; otherwise, much of the ancient genetic history would have been lost during a severe bottleneck. We suggest that both the "Out of Africa" and the multiregional models are too simple to explain the evolution of modern humans.

Worldwide DNA sequence variation in a 10-kilobase noncoding region on human chromosome 22.

Human DNA sequence variation data are useful for studying the origin, evolution, and demographic history of modern humans and the mechanisms of maintenance of genetic variability in human populations, and for detecting linkage association of disease. Here, we report worldwide variation data from a approximately 10-kilobase noncoding autosomal region. We identified 75 variant sites in 64 humans (128 sequences) and 463 variant sites among the human, chimpanzee, and orangutan sequences. Statistical tests suggested that the region is selectively neutral. The average nucleotide diversity (pi) across the region was 0.088% among all of the human sequences obtained, 0.085% among African sequences, and 0.082% among non-African sequences, supporting the view of a low nucleotide diversity ( approximately 0.1%) in humans. The comparable pi value in non-Africans to that in Africans indicates no severe bottleneck during the evolution of modern non-Africans; however, the possibility of a mild bottleneck cannot be excluded because non-Africans showed considerably fewer variants than Africans. The present and two previous large data sets all show a strong excess of low frequency variants in comparison to that expected from an equilibrium population, indicating a relatively recent population expansion. The mutation rate was estimated to be 1.15 x 10(-9) per nucleotide per year. Estimates of the long-term effective population size N(e) by various statistical methods were similar to those in other studies. The age of the most recent common ancestor was estimated to be approximately 1.29 million years ago among all of the sequences obtained and approximately 634,000 years ago among the non-African sequences, providing the first evidence from a noncoding autosomal region for ancient human histories, even among non-Africans.

Health and functional capacity as predictors of community dwelling among elderly people.

The aim of this study was to identify factors that predict community dwelling (i.e., nonuse of institutional bed-days) among elderly people. This was a longitudinal study of institution use including both short-term and long-term use of hospitals and nursing homes. The impact of health, functional performance, and carrying out the activities of daily living on community dwelling was studied using the method of path analysis. The participants were all the 75-year-old (N = 388) and 80-year-old (N = 291) men and women resident in the City of Jyväskylä, Finland. Predictor variables included disease severity, symptoms of illness, cognitive capacity, walking speed, muscle strength, hearing, and ability to carry out the activities of daily living. The outcome variable was community dwelling. Over 70% of the elderly people had received institutional care during the 5-year follow-up. The path analysis models showed that disease severity and symptoms of illness had an effect on community dwelling: those with a more severe disease or more symptoms needed more institutional care. The effect was also mediated through limitations in physical performance and cognitive capacity and need for assistance in activities of daily living. The explanatory power of these models varied from 23% to 36%. The results of this study suggest that prevention, treatment, and rehabilitation programs aimed at the promotion of community dwelling in elderly people should focus on the severity of diseases, functional performance, and the ability to carry out the activities of daily living.

Predicting physical activity intentions using a goal perspectives approach: a study of Finnish youth.

Physical activity intentions were studied in 12- to 16-year-old Finnish girls (n= 186) and boys (n=215). Theoretical predictions were used to establish a model that was then tested separately for each sex using path analysis. Firstly, it was hypothesised that malleable conceptions of the nature of sport ability positively influence enjoyment in physical activity and intentions to participate in physical activity, mediated by a task-oriented achievement goal independent of variations in perceptions of competence. Secondly, it was hypothesised that fixed conceptions of the nature of ability decrease enjoyment in physical activity and intentions to participate, mediated by an ego-oriented achievement goal and by perceived competence. The modified models were shown to fit the data. Overall, the results showed that 63% (boys) and 45% (girls) of the variance in intentions was explained by the model. The motivational importance of task orientation and, among the boys, perceived physical competence was confirmed with their direct prediction of intentions.

Molecular phylogenetic evidence for a reversible morphogenetic switch controlling the gross morphology of two common genera of green seaweeds, Ulva and Enteromorpha.

Ulva and Enteromorpha are two of the most common, ubiquitous, and environmentally important genera of green seaweeds. They are widely regarded as easily distinguishable because of their dramatically different morphologies: Ulva species are flat, lettucelike blades two cell layers thick, and Enteromorpha species form hollow liquid- or gas-filled tubes one cell thick, which may also be highly branched. We present molecular phylogenetic analyses of nuclear ribosomal RNA ITS sequences from 39 samples representing 21 purported species within these two genera. The results clearly indicate that the two genera are not respectively monophyletic and that the characteristic Ulva and Enteromorpha morphologies have arisen independently several times throughout the evolutionary diversification of the group. The analyses demonstrate that this radical change in gross morphology can also happen within clades exhibiting sequence divergence typical of conspecific assemblages of this group. We suggest that this morphological flexibility is the result of some form of developmental switch that results in either blades or tubes, but that this putative switch must be activated relatively infrequently, since there is evidence that some lineages have retained their form for significant periods. This discovery suggests a possible new model system for study of the molecular mechanisms involved in the interplay between environmental stimuli and plant development.

Evolution of the ITS sequences of ribosomal DNA in Enteromorpha (Chlorophyceae).

Ribosomal DNA (rDNA) region, including the 3' end of the 18S rRNA gene, the entire 5.8S rRNA gene, the 5' end of the 28S rRNA gene, and the internal transcribed spacers ITS 1 and ITS 2, of Enteromorpha green algae from the Baltic Sea, were sequenced. The evolution of the Enteromorpha sequences differed from those of other green algae in several important ways. The ITS regions were short and had a high nucleotide bias. The frequency of nucleotides G and C was up to 70% in the ITS sequences, whereas the frequencies were close to 50% in the 5.8S rDNA. Furthermore, the sequence divergence was much higher in ITS 1 than in ITS 2. Two haplotypes, differing only by two nucleotides, were detected in the E. intestinalis/compressa complex. The difference coincides with a morphological differentiation (branching of thalli) and may represent distinct gene pools.

Stability of habitual physical activity and sport participation: a longitudinal tracking study.

Although one of the most important aims of physical education and public sport policy is to encourage life-long habitual physical activity, very little is known of the stability or tracking of physical activity. As a part of a larger research project called Cardiovascular Risks in Young Finns, the purpose of the study reported here was to investigate the stability (tracking) of leisure-time physical activity and sport participation at intervals of 3, 6, 9 and 12 years from age 9 to 30. The subjects, chosen by stratified random sample, represent five geographical areas of the country and eight gender-age cohorts (9, 12, 15 and 18 years old in 1980). Physical activity and sport participation were measured using a short questionnaire. Tracking was analysed by Spearman's rank order correlations and by simplex model. The tracking correlations within a 3-year interval of all individual variables were significant but rather low. The tracking correlations of the sum index of physical activity comprising five variables varied from 0.50 to 0.80 among boys and from 0.40 to 0.61 among girls. Simplex models that fitted the data very well showed higher stability coefficients than rank order correlations. With one exception the correlations of physical activity index within the 12-year interval were significant but low.

Guidelines for description of immunoassay kits.

A provisional recommendation in order to improve manufacturers' and marketers' information to users of immunoassay kits has been compiled by a Nordic Clinical Chemistry project working group.

Recommendation for collection of venous blood from children, with special reference to production reference values.

Reference values should be produced under standardized conditions. To enable comparison it is desirable to use the same procedure also in other clinical situations. A procedure for the collection of venous blood from children with special reference to production of reference values is recommended. It deals with five items: preparation of the child before specimen collection, preparation of the blood collection site, equipment for specimen collection, the specimen collection itself, and handling and storage of the specimen. Alternative methods are described since no single method is suitable for all paediatric age groups. The problem of adhering to a proposed procedure during routine clinical work is also commented upon. The recommendation has been produced as a joint effort of the Scandinavian Committee on Reference Values and a working group set up by the National Paediatric Societies in the Nordic countries.

Latent Structure Analysis of Longitudinal Data on Relations Between Intellectual Abilities and School Achievement.

Covariance structure modelling by LISREL was applied to analyze the relations between intellectual ability, as measured by ITPA, and achievement in reading, writing, foreign language and mathematics in longitudinal data with 8 to 10 years' time interval between measurements. The subjects' (N = 234) ability scores were obtained at 5-7 years of age, and their achievement was measured at 14-16 years of age. The effect of ability to achievement was studied by analyzing structural equation models on both first-order ability and achievement factors and by developing a two-stage second-order factor estimation method for structural equation parameters between first-order ability and achievement factors. Squared multiple correlations and coefficients of determination as indices of explained variance were derived for reduced forms of structural equations. The general latent intellectual ability explained 49% of variance in school achievement. The results showed the high validity of ITPA in explaining school success as well as the great flexibility and usefulness of covariance structure modelling by LISREL in analyzing longitudinal data.

Recommendation for collection of skin puncture blood from children, with special reference to production of reference values.

Reliable reference values need to be collected under standardized conditions. In order to enable comparison of values observed on patients with reference values, it is also desirable to use the same standardized conditions on patients. The present recommendation was produced as a joint effort of representatives of the clinical chemists and paediatricians of Scandinavia and describes the following details. Preparation of the child before specimen collection (food intake, time of day, physical activity, posture, environment), preparation of skin puncture site (warming, disinfection, ointment), instruments for blood collection (lancet, blood collection vessel), site of puncture (plantar surface of foot, finger, ear lobe), collection of emerging blood and handling and storage of the specimen.

Self-rated health and associated factors among men of different ages.

The connections of certain clinico-physiological indicators of health state, chronic diseases, felt symptoms, and psychic well-being with self-rated health were studied among men of different ages as a part of the more extensive research project Jyväskylä Studies on Functional Aging. Study population was selected by using systematic random sampling among men aged 31 to 35, 51 to 55 and 71 to 75 years in the city of Jyväskylä. Log-linear and logit models as well as regression and structural equation models within the framework of LISREL were used as methods of analysis. The associations between general self-rated health and the explanative variables were different in different age groups: In the youngest age group self-rated health was best explained by symptoms and index of physical fitness; among the middle-aged by symptoms and psychic well-being; and among the oldest by chronic diseases. The results suggest that self-rated health belongs to the important indicators of health, and more attention should be paid to it both in research and in medical practice.