Browsing by Subject "FITNESS"

Sort by: Order: Results:

Now showing items 1-20 of 37
  • Kneis, David; Hiltunen, Teppo; Hess, Stefanie (2019)
    Horizontal gene transfer is an essential component of bacterial evolution. Quantitative information on transfer rates is particularly useful to better understand and possibly predict the spread of antimicrobial resistance. A variety of methods has been proposed to estimate the rates of plasmid-mediated gene transfer all of which require substantial labor input or financial resources. A cheap but reliable method with high-throughput capabilities is yet to be developed in order to better capture the variability of plasmid transfer rates, e.g. among strains or in response to environmental cues. We explored a new approach to the culture-based estimation of plasmid transfer rates in liquid media allowing for a large number of parallel experiments. It deviates from established approaches in the fact that it exploits data on the absence/presence of transconjugant cells in the wells of a well plate observed over time. Specifically, the binary observations are compared to the probability of transconjugant detection as predicted by a dynamic model. The bulk transfer rate is found as the best-fit value of a designated model parameter. The feasibility of the approach is demonstrated on mating experiments where the RP4 plasmid is transfered from Serratia marcescens to several Escherichia coil recipients. The methods uncertainty is explored via split sampling and virtual experiments.
  • Geritz, S.; Gyllenberg, M.; Toivonen, J. (2018)
    We present a model for the coevolution of seed size and germination time within a season when both affect the ability of the seedlings to compete for space. We show that even in the absence of a morphological or physiological constraint between the two traits, a correlation between seed size and germination time is nevertheless likely to evolve. This raises the more general question to what extent a correlation between any two traits should be considered as an a priori constraint or as an evolved means (or instrument) to actually implement a beneficial combination of traits. We derive sufficient conditions for the existence of a positive or a negative correlation. We develop a toy model for seed and seedling survival and seedling growth and use this to illustrate in practice how to determine correlations between seed size and germination time.
  • DiLeo, Michelle F.; Rico, Yessica; Boehmer, Hans Juergen; Wagner, Helene H. (2017)
    Ecological connectivity networks have been proposed as an efficient way to reconnect communities in fragmented landscapes. Yet few studies have evaluated if they are successful at enhancing actual functional connectivity (i.e. realized dispersal or gene flow) of focal species, or if this enhanced connectivity is enough to maintain genetic diversity and fitness of plant populations. Here we test the efficacy of an ecological connectivity network implemented in southern Germany since 1989 to reconnect calcareous grassland fragments through rotational shepherding. We genotyped 1449 individuals from 57 populations and measured fitness-related traits in 10 populations of Puisatilla vulgaris, a flagship species of calcareous grasslands in Europe. We tested if the shepherding network explained functional connectivity in P. vulgaris and if higher connectivity translated to higher genetic diversity and fitness of populations. We found that population-specific F-st was lowest in populations that had high connectivity within the shepherding network, and that well-connected populations within the network had significantly higher genetic diversity than ungrazed and more isolated grazed populations. Moreover, genetic diversity was significantly positively correlated with both seed set and seed mass. Together our results suggest that the implementation of an ecological shepherding network is an effective management measure to maintain functional connectivity and genetic diversity at the landscape scale for a calcareous grassland specialist. Populations with reduced genetic diversity would likely benefit from inclusion, or better integration into the ecological connectivity network. Our study demonstrates the often postulated but rarely tested sequence of positive associations between connectivity, genetic diversity, and fitness at the landscape scale, and provides a framework for testing the efficacy of ecological connectivity networks for focal species using molecular genetic tools.
  • Yun, Jinhyeon; Muurinen, Johanna; Nykäsenoja, Suvi; Seppä-Lassila, Leena; Sali, Virpi; Suomi, Johanna; Tuominen, Pirkko; Joutsen, Suvi; Hämäläinen, Merja; Olkkola, Satu; Myllyniemi, Anna-Liisa; Peltoniemi, Olli; Heinonen, Mari (2021)
    We investigated connections between antimicrobial use (AMU), biosecurity, and the numbers of pigs and staff in ten Finnish farrow-to-finish herds. Data on AMU in each herd were collected for 12 months. AMU was quantified as treatment incidences per 1000 days at risk (TI) using the consensus defined daily dose calculation. Biosecurity was scored using the Biocheck.UGent T system. We also examined antimicrobial resistance patterns of indicator E. coli isolated from faeces of selected pigs. In each herd, two groups of five pigs were formed: 1) antimicrobial treatment group (ANT: at least one pig in the litter was identified as sick and treated with antimicrobials) and 2) non-antimicrobial treatment group (NON: the litter was not medicated). Faecal samples were taken from these pigs at 5 and 22 weeks of age, cultured, and indicator E. coli isolates were tested for antimicrobial susceptibilities. The AMU varied considerably between the herds. Altogether, most of the antimicrobial treatment courses were assigned to weaned piglets. When AMU was quantified as TIs, suckling piglets had the highest TI (mean 46.6), which was significantly higher (P < 0.05) than TIs in fatteners and breeders (9.3 and 7.3, respectively). The difference between TI in suckling and TI in weaned piglets (19.1) was not statistically significant. There was a tendency for a negative correlation between the TI in breeders and the number of sows (r = 0.56, P = 0.09). Larger herds had higher external biosecurity scores than smaller herds (LS-means; 72 vs. 66, P < 0.05). The proportions of E. coli isolates resistant to at least one antimicrobial were higher in pigs at 5 weeks than in pigs at 22 weeks of age (Binomial proportion means; 40.5 % vs. 15.5 %, P < 0.05); as well as proportions of isolates resistant to at least three antimicrobial classes (23.0 % vs. 3.7 %, P < 0.01). These proportions did not differ between the ANT and NON groups at either 5 or 22 weeks of age (P> 0.05). We found few connections: enhanced external biosecurity levels found in the large herds co-occurred with lower use of antimicrobials and herds with low biosecurity scores - especially in the internal subcategories - appeared to have higher proportions of resistant isolates. Conclusively, we suggest that enhancing internal biosecurity might contribute to a reduction in the spreading of antimicrobial resistance in pig herds.
  • Helminen, Olli; Valo, Johanna; Andersen, Heidi; Söderström, Johan; Sihvo, Eero (2021)
    Introduction With a population-based cohort in the video-assisted thoracoscopic surgery (VATS) era, we aimed to evaluate the value of the stair-climbing test (SCT) on short- and long-term outcomes of lung cancer surgery. Methods All patients operated due to primary lung cancer in Central Finland and Ostrobothnia from 2013 to June 2020 were included. For the analysis, clinical variables including the outcome of SCT and cause-specific mortality were available. Short-and long-term outcomes were compared between 12 m SCT (n=217) groups. Results Patients with poor performance (12 m group (94.2%), p=0.002. No difference was observed in cancer-specific 5-year survival. Non-cancer-specific survival (62.9% versus 83.1%, p Conclusions With SCT-based exercise testing, VATS can be performed safely, with a similar major morbidity rate in the poor performance group (12 m group. Poor exercise performance increases non-cancer-specific mortality. Being a major predictor of survival, exercise capacity should be included in prognostic models.
  • Jyväkorpi, Satu K.; Urtamo, Annele; Strandberg, Arto Y.; von Bonsdorff, Mikaela; Salomaa, Veikko; Kivimäki, Mika; Luotola, Kari; Strandberg, Timo E. (2020)
    Background & aims: Prognostic significance of metabolically healthy overweight and obesity (MHO) is under debate. However the relationship between MHO and health-related quality of life (HRQoL) is less studied. We compared successful aging (longevity plus HRQoL) in men with MHO, metabolically healthy normal weight (MHN) and metabolically unhealthy overweight and obesity (MUO). Methods: In the Helsinki Businessmen Study longitudinal cohort, consisting of men born 1919 to 1934. In 1985/86, overweight (BMI >= 25 kg/m(2)) and metabolic health were determined in 1309 men (median age 60 years). HRQoL was assessed using RAND-36/SF-36 in 2000 and 2007, and all-cause mortality retrieved from registers up to 2018. The proportion of men reaching 90 years was also calculated. Results: Of the men, 469 (35.8%), 538 (41.1%), 276 (21.1%), and 26 (2.0%) were MHN, MHO, MUO and MUN, respectively. During the 32-year follow-up, 72.3% men died. With MHN as reference, adjusted hazard ratio with all-cause mortality was 1.08 (95% confidence interval [CI] 0.93 to 1.27) for MHO, and 1.18 (95% CI 0.95 to 1.47) for MUO. During follow-up, 273 men reached 90 years. With MHN as reference, adjusted odds ratio for MHO was 0.82 (95% CI 0.59 to 1.14) and 0.62 (95% CI 0.41 to 0.95) for MUO. Men in MHN group scored generally highest in RAND-36 HRQoL subscales in 2000 and 2007, of those significantly better in Physical functioning, Role physical, Role emotional, Bodily Pain, and General health sub-scales compared to MHO group in 2000. Conclusions: As compared to MHN, MHO in late midlife does not increase mortality, but impairs odds for successful aging. (C) 2019 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.
  • O'Sullivan, Ronan James; Aykanat, Tutku; Johnston, Susan E.; Rogan, Ger; Poole, Russell; Prodohl, Paulo A.; de Eyto, Elvira; Primmer, Craig R.; McGinnity, Philip; Reed, Thomas Eric (2020)
    The release of captive-bred animals into the wild is commonly practised to restore or supplement wild populations but comes with a suite of ecological and genetic consequences. Vast numbers of hatchery-reared fish are released annually, ostensibly to restore/enhance wild populations or provide greater angling returns. While previous studies have shown that captive-bred fish perform poorly in the wild relative to wild-bred conspecifics, few have measured individual lifetime reproductive success (LRS) and how this affects population productivity. Here, we analyse data on Atlantic salmon from an intensely studied catchment into which varying numbers of captive-bred fish have escaped/been released and potentially bred over several decades. Using a molecular pedigree, we demonstrate that, on average, the LRS of captive-bred individuals was only 36% that of wild-bred individuals. A significant LRS difference remained after excluding individuals that left no surviving offspring, some of which might have simply failed to spawn, consistent with transgenerational effects on offspring survival. The annual productivity of the mixed population (wild-bred plus captive-bred) was lower in years where captive-bred fish comprised a greater fraction of potential spawners. These results bolster previous empirical and theoretical findings that intentional stocking, or non-intentional escapees, threaten, rather than enhance, recipient natural populations.
  • Lahti, Jouni; Holstila, Ansku; Mänty, Minna; Lahelma, Eero; Rahkonen, Ossi (2016)
    Background: Disability retirement is an economic, public health and work life issue causing costs for employees, workplaces and society. Adopting physical activity at middle-age has been associated with reduced risk of sickness absence and mortality. The aim of this study was to examine how changes over time in leisure time physical activity are associated with subsequent disability retirement among midlife employees. Methods: The Helsinki Health Study cohort baseline (phase 1) mail questionnaire survey data were collected in 2000, 2001 and 2002 among 40-60-year-old employees of the City of Helsinki, Finland. A phase 2 survey was conducted in 2007 (N = 3943). Respondents were classified into three groups: 1. low-active ( = 14 MET-hours/week in moderate-intensity physical activity) and 3. vigorously active (> = 14 MET-hours/week including vigorous physical activity) at both phases. This yielded nine groups for describing stability and change of leisure time physical activity. Disability retirement data were derived from the registry of the Finnish Centre for Pensions until the end of 2013. A Cox regression analysis was used to calculate hazard ratios (HR) and their 95 % confidence intervals (CI) adjusting for covariates. Results: During the follow-up, 264 (6.7 %) participants retired due to disability. Compared with those who were persistently low-active, those who increased their physical activity from low to vigorous had a lower risk of subsequent disability retirement (HR = 0.38, 95 % CI = 0.15-0.97) when adjusting for age, gender, occupational social class, strenuousness of work, smoking and binge drinking. Similarly, compared with those who were persistently moderately active, those increasing from moderate to vigorous (HR = 0.50, 95 % CI = 0.28-0.86) had a reduced risk. In contrast, those decreasing their physical activity from vigorous to low (HR = 2.42, 95 % CI = 1. 32-4.41) or moderate (HR = 1.70, 95 % CI = 1.03-2.82) had an increased risk, compared with those who were persistently vigorously active. Adjusting for BMI, limiting longstanding illness and prior sickness absence somewhat attenuated the associations. Conclusions: Adopting vigorous physical activity was associated with a reduced risk of disability retirement. Promoting vigorous physical activity among midlife employees may help prevent disability retirement.
  • Berardo, Cecilia; Geritz, Stefanus (2021)
    The war of attrition in game theory is a model of a stand-off situation between two opponents where the winner is determined by its persistence. We model a stand-off between a predator and a prey when the prey is hiding and the predator is waiting for the prey to come out from its refuge, or when the two are locked in a situation of mutual threat of injury or even death. The stand-off is resolved when the predator gives up or when the prey tries to escape. Instead of using the asymmetric war of attrition, we embed the stand-off as an integral part of the predator-prey model of Rosenzweig and MacArthur derived from first principles. We apply this model to study the coevolution of the giving-up rates of the prey and the predator, using the adaptive dynamics approach. We find that the long term evolutionary process leads to three qualitatively different scenarios: the predator gives up immediately, while the prey never gives up; the predator never gives up, while the prey adopts any giving-up rate greater than or equal to a given positive threshold value; the predator goes extinct. We observe that some results are the same as for the asymmetric war of attrition, but others are quite different. (C) 2021 The Author(s). Published by Elsevier Ltd.
  • Mattila, Anniina L. K.; Jiggins, Chris D.; Saastamoinen, Marjo (2022)
    Aposematic animals advertise their toxicity or unpalatability with bright warning coloration. However, acquiring and maintaining chemical defenses can be energetically costly, and consequent associations with other important traits could shape chemical defense evolution. Here, we have tested whether chemical defenses are involved in energetic trade-offs with other traits, or whether the levels of chemical defenses are condition dependent, by studying associations between biosynthesized cyanogenic toxicity and a suite of key life-history and fitness traits in a Heliconius butterfly under a controlled laboratory setting. Heliconius butterflies are well known for the diversity of their warning color patterns and widespread mimicry and can both sequester the cyanogenic glucosides of their Passiflora host plants and biosynthesize these toxins de novo. We find energetically costly life-history traits to be either unassociated or to show a general positive association with biosynthesized cyanogenic toxicity. More toxic individuals developed faster and had higher mass as adults and a tendency for increased lifespan and fecundity. These results thus indicate that toxicity level of adult butterflies may be dependent on individual condition, influenced by genetic background or earlier conditions, with maternal effects as one strong candidate mechanism. Additionally, toxicity was higher in older individuals, consistent with previous studies indicating accumulation of toxins with age. As toxicity level at death was independent of lifespan, cyanogenic glucoside compounds may have been recycled to release resources relevant for longevity in these long-living butterflies. Understanding the origins and maintenance of variation in defenses is necessary in building a more complete picture of factors shaping the evolution of aposematic and mimetic systems.
  • LeBlanc, Allana G.; Katzmarzyk, Peter T.; Barreira, Tiago V.; Broyles, Stephanie T.; Chaput, Jean-Philippe; Church, Timothy S.; Fogelholm, Mikael; Harrington, Deirdre M.; Hu, Gang; Kuriyan, Rebecca; Kurpad, Anura; Lambert, Estelle V.; Maher, Carol; Maia, Jose; Matsudo, Victor; Olds, Timothy; Onywera, Vincent; Sarmiento, Olga L.; Standage, Martyn; Tudor-Locke, Catrine; Zhao, Pei; Tremblay, Mark S. (2015)
    Purpose Previously, studies examining correlates of sedentary behavior have been limited by small sample size, restricted geographic area, and little socio-cultural variability. Further, few studies have examined correlates of total sedentary time (SED) and screen time (ST) in the same population. This study aimed to investigate correlates of SED and ST in children around the world. Methods The sample included 5,844 children (45.6% boys, mean age = 10.4 years) from study sites in Australia, Brazil, Canada, China, Colombia, Finland, India, Kenya, Portugal, South Africa, the United Kingdom, and the United States. Child- and parent-reported behavioral, household, and neighborhood characteristics and directly measured anthropometric and accelerometer data were obtained. Twenty-one potential correlates of SED and ST were examined using multilevel models, adjusting for sex, age, and highest parental education, with school and study site as random effects. Variables that were moderately associated with SED and/or ST in univariate analyses (p Results Children averaged 8.6 hours of daily SED, and 54.2% of children failed to meet ST guidelines. In all study sites, boys reported higher ST, were less likely to meet ST guidelines, and had higher BMI z-scores than girls. In 9 of 12 sites, girls engaged in significantly more SED than boys. Common correlates of higher SED and ST included poor weight status, not meeting physical activity guidelines, and having a TV or a computer in the bedroom. Conclusions In this global sample many common correlates of SED and ST were identified, some of which are easily modifiable (e.g., removing TV from the bedroom), and others that may require more intense behavioral interventions (e.g., increasing physical activity). Future work should incorporate these findings into the development of culturally meaningful public health messages.
  • Candolin, Ulrika; Goncalves, Sara; Pant, Pankaj (2022)
    Early life conditions can have a decisive influence on viability later in life. However, the influence of embryo density within a nest or body cavity on subsequent viability has received little attention within an ecological setting. This is surprising given that embryos often compete for limited resources, such as nutrients and oxygen, and this could influence their viability later in life through carry-over and compensatory effects. We show that the density of fertilized eggs within the nests of threespine stickleback males (Gasterosteus aculeatus) influences their viability after hatching. Embryos from larger broods hatch earlier and at a smaller size than those from smaller broods, which reduces their survival until the age of four weeks. This indicates a trade-off between the number and viability of offspring that males can raise to the hatching stage, which could explain the high incidence of partial egg cannibalism in nest-brooding fishes-as a strategy to improve the survival of remaining offspring. These results highlight the importance of considering conditions at the embryonic stage when evaluating the impact of early life conditions on viability and the adaptive value of reproductive decisions.
  • Leskinen, Tuija; Rinnankoski-Tuikka, Rita; Rintala, Mirva; Seppanen-Laakso, Tuulikki; Pollanen, Eija; Alen, Markku; Sipila, Sarianna; Kaprio, Jaakko; Kovanen, Vuokko; Rahkila, Paavo; Oresic, Matej; Kainulainen, Heikki; Kujala, Urho M. (2010)
    High physical activity/aerobic fitness predicts low morbidity and mortality. Our aim was to identify the most up-regulated gene sets related to long-term physical activity vs. inactivity in skeletal muscle and adipose tissues and to obtain further information about their link with cardio-metabolic risk factors. We studied ten same-sex twin pairs (age range 50-74 years) who had been discordant for leisure-time physical activity for 30 years. The examinations included biopsies from m. vastus lateralis and abdominal subcutaneous adipose tissue. RNA was analyzed with the genome-wide Illumina Human WG-6 v3.0 Expression BeadChip. For pathway analysis we used Gene Set Enrichment Analysis utilizing active vs. inactive co-twin gene expression ratios. Our findings showed that among the physically active members of twin pairs, as compared to their inactive co-twins, gene expression in the muscle tissue samples was chronically up-regulated for the central pathways related to energy metabolism, including oxidative phosphorylation, lipid metabolism and supportive metabolic pathways. Up-regulation of these pathways was associated in particular with aerobic fitness and high HDL cholesterol levels. In fat tissue we found physical activity-associated increases in the expression of polyunsaturated fatty acid metabolism and branched-chain amino acid degradation gene sets both of which associated with decreased 'high-risk' ectopic body fat and plasma glucose levels. Consistent with other findings, plasma lipidomics analysis showed up-regulation of the triacylglycerols containing the polyunsaturated fatty acids. Our findings identified skeletal muscle and fat tissue pathways which are associated with the long-term physical activity and reduced cardio-metabolic disease risk, including increased aerobic fitness. In particular, improved skeletal muscle oxidative energy and lipid metabolism as well as changes in adipocyte function and redistribution of body fat are associated with reduced cardio-metabolic risk.
  • Tan, Jocelyn L. K.; Ylä-Kojola, Anna-Mari; Eriksson, Johan G.; Salonen, Minna K.; Wasenius, Niko; Hart, Nicolas H.; Chivers, Paola; Rantalainen, Timo; Lano, Aulikki; Piitulainen, Harri (2022)
    Individuals at risk of Developmental Coordination Disorder (DCD) have low levels of physical activity in childhood due to impaired motor competence; however, physical activity levels in adulthood have not been established. This study sought to determine the impact of DCD risk on physical activity levels in adults using accelerometry measurement. Participants (n = 656) from the Arvo Ylppo Longitudinal Study cohort had their motor competence assessed at the age of five years, and their physical activity quantified via device assessment at the age of 25 years. Between group differences were assessed to differentiate physical activity measures for individuals based on DCD risk status, with general linear modeling performed to control for the effects of sex, body mass index (BMI), and maternal education. Participants at risk of DCD were found to have a lower total number of steps (d = 0.3, p = 0.022) than those not at risk. Statistical modeling indicated that DCD risk status increased time spent in sedentary light activity (beta = 0.1, 95% CI 0.02 to 0.3, p = 0.026) and decreased time spent in vigorous physical activity via interaction with BMI (beta = 0.04, 95% CI 0.001 to 0.1, p = 0.025). Sensitivity analysis found that visuomotor impairment did not significantly impact physical activity but did increase the role of DCD risk status in some models. This 20-year-longitudinal study indicated that DCD risk status continues to negatively impact on levels of physical activity into early adulthood.
  • Karisto, Petteri; Kisdi, Eva (2017)
    The pattern of connectivity between local populations or between microsites supporting individuals within a population is a poorly understood factor affecting the evolution of dispersal. We modify the well-known Hamilton May model of dispersal evolution to allow for variable connectivity between microsites. For simplicity, we assume that the microsites are either solitary, i.e., weakly connected through costly dispersal, or part of a well-connected cluster of sites with low-cost dispersal within the cluster. We use adaptive dynamics to investigate the evolution of dispersal, obtaining analytic results for monomorphic evolution and numerical results for the co-evolution of two dispersal strategies. A monomorphic population always evolves to a unique singular dispersal strategy, which may be an evolutionarily stable strategy or an evolutionary branching point. Evolutionary branching happens if the contrast between connectivities is sufficiently high and the solitary microsites are common. The dimorphic evolutionary singularity, when it exists, is always evolutionarily and convergence stable. The model exhibits both protected and unprotected dimorphisms of dispersal strategies, but the dimorphic singularity is always protected. Contrasting connectivities can thus maintain dispersal polymorphisms in temporally stable environments.
  • Hanhimäki, Elina; Watts, Phillip C.; Koskela, Esa; Koteja, Paweł; Mappes, Tapio; Hämäläinen, Anni M. (2022)
    Gut microbiota is expected to coevolve with the host's physiology and may play a role in adjusting the host's energy metabolism to suit the host's environment. To evaluate the effects of both evolved host metabolism and the environmental context in shaping the gut microbiota, we used a unique combination of (1) experimental evolution to create selection lines for a fast metabolism and (2) a laboratory-to-field translocation study. Mature bank voles Myodes glareolus from lines selected for high aerobic capacity (A lines) and from unselected control (C lines) were released into large (0.2 ha) outdoor enclosures for longitudinal monitoring. To examine whether the natural environment elicited a similar or more pronounced impact on the gut microbiota of the next generation, we also sampled the field-reared offspring. The gut microbiota were characterized using 16S rRNA amplicon sequencing of fecal samples. The artificial selection for fast metabolism had minimal impact on the gut microbiota in laboratory conditions but in field conditions, there were differences between the selection lines (A lines vs. C lines) in the diversity, community, and resilience of the gut microbiota. Notably, the selection lines differed in the less abundant bacteria throughout the experiment. The lab-to-field transition resulted in an increase in alpha diversity and an altered community composition in the gut microbiota, characterized by a significant increase in the relative abundance of Actinobacteria and a decrease of Patescibacteria. Also, the selection lines showed different temporal patterns in changes in microbiota composition, as the average gut microbiota alpha diversity of the C lines, but not A lines, was temporarily reduced during the initial transition to the field. In surviving young voles, the alpha diversity of gut microbiota was significantly higher in A-line than C-line voles. These results indicate that the association of host metabolism and gut microbiota is context-specific, likely mediated by behavioral or physiological modifications in response to the environment.
  • Viljanen, Anna; Salminen, Marika; Irjala, Kerttu; Korhonen, Paivi; Wuorela, Maarit; Isoaho, Raimo; Kivelä, Sirkka-Liisa; Vahlberg, Tero; Viitanen, Matti; Lopponen, Minna; Viikari, Laura (2021)
    Background In clinical practice, there is a need for an instrument to screen older people at risk of institutionalization. Aims To analyze the association of frailty, walking-ability and self-rated health (SRH) with institutionalization in Finnish community-dwelling older people. Methods In this prospective study with 10- and 18-year follow-ups, frailty was assessed using FRAIL Scale (FS) (n = 1087), Frailty Index (FI) (n = 1061) and PRISMA-7 (n = 1055). Walking ability was assessed as self-reported ability to walk 400 m (n = 1101). SRH was assessed by a question of general SRH (n = 1105). Cox regression model was used to analyze the association of the explanatory variables with institutionalization. Results The mean age of the participants was 73.0 (range 64.0-97.0) years. Prevalence of institutionalization was 40.8%. In unadjusted models, frailty was associated with a higher risk of institutionalization by FS in 10-year follow-up, and FI in both follow-ups. Associations by FI persisted after age- and gender-adjustments in both follow-ups. By PRISMA-7, frailty predicted a higher risk of institutionalization in both follow-ups. In unadjusted models, inability to walk 400 m predicted a higher risk of institutionalization in both follow-ups and after adjustments in 10-year follow-up. Poor SRH predicted a higher risk of institutionalization in unadjusted models in both follow-ups and after adjustments in 10-year follow-up. Discussion Simple self-reported items of walking ability and SRH seemed to be comparable with frailty indexes in predicting institutionalization among community-dwelling older people in 10-year follow-up. Conclusions In clinical practice, self-reported walking ability and SRH could be used to screen those at risk.
  • Åström, Max J.; von Bonsdorff, Mikaela B.; Perälä, Mia M.; Salonen, Minna K.; Rantanen, Taina; Kajantie, Eero; Simonen, Mika; Pohjolainen, Pertti; Osmond, Clive; Eriksson, Johan G. (2018)
    Aims To assess whether disturbances in glucose regulation are associated with impairment in physical performance during a 10-year follow-up. Methods 475 Men and 603 women from the Helsinki Birth Cohort Study were studied. Glucose regulation was evaluated with a 2-h 75-g oral glucose tolerance test (OGTT) in 2001-2004. Subjects were categorised as having either impaired fasting glucose (IFG), impaired glucose tolerance (IGT), newly diagnosed diabetes or previously known diabetes. Physical performance was assessed approximately 10 years later using the validated senior fitness test (SFT). The relationship between glucose regulation and the overall SFT score was estimated using multiple linear regression models. Results The mean age was 70.8 years for men and 71.0 years for women when physical performance was assessed. The mean SFT score for the whole population was 45.0 (SD 17.5) points. The SFT score decreased gradually with increased impairment in glucose regulation. Individuals with previously known diabetes had the lowest overall SFT score in the fully adjusted model (mean difference compared to normoglycaemic individuals -11.56 points, 95% CI - 16.15 to - 6.98, p <0.001). Both individuals with newly diagnosed diabetes and individuals with IGT had significantly poorer physical performance compared to those with normoglycaemia. No significant difference in physical performance was found between those with IFG and those with normoglycaemia. Conclusions Among older people, impaired glucose regulation is strongly related with poor physical performance. More severe disturbances in glucose regulation are associated with a greater decrease in physical function, indicating the importance of diagnosing these disturbances at an early stage.
  • Koskenpato, Katja; Lehikoinen, Aleksi; Lindstedt, Carita; Karell, Patrik (2020)
    Camouflage may promote fitness of given phenotypes in different environments. The tawny owl (Strix aluco) is a color polymorphic species with a gray and brown morph resident in the Western Palearctic. A strong selection pressure against the brown morph during snowy and cold winters has been documented earlier, but the selection mechanisms remain unresolved. Here, we hypothesize that selection favors the gray morph because it is better camouflaged against predators and mobbers in snowy conditions compared to the brown one. We conducted an online citizen science experiment where volunteers were asked to locate a gray or a brown tawny owl specimen from pictures taken in snowy and snowless landscapes. Our results show that the gray morph in snowy landscapes is the hardest to detect whereas the brown morph in snowy landscapes is the easiest to detect. With an avian vision model, we show that, similar to human perceivers, the brown morph is more conspicuous than the gray against coniferous tree trunks for a mobbing passerine. We suggest that with better camouflage, the gray morph may avoid mobbers and predators more efficiently than the brown morph and thus survive better in snowy environments. As winters are getting milder and shorter in the species range, the selection periods against brown coloration may eventually disappear or shift poleward.
  • Pihlajamaki, Harri K.; Parviainen, Mickael C.; Kautiainen, Hannu; Kiviranta, Ilkka (2017)
    Background: Musculoskeletal disorders and injuries are common causes of morbidity and loss of active, physically demanding training days in military populations. We evaluated the incidence, diagnosis, and risk factors of knee disorders and injuries in male Finnish military conscripts. Methods: The study population comprised 5 cohorts of 1000 men performing their military service, classified according to birth year (1969, 1974, 1979, 1984, and 1989). Follow-up time for each conscript was the individual conscript's full, completed military service period. Data for each man were collected from a standard pre-information questionnaire used by defense force healthcare officials and from all original medical reports of the garrison healthcare centers. Background variables for risk factor analysis included the conscripts' service data, i.e., service class (A, B), length of military service, age, height, weight, body mass index (BMI), underweight, overweight, obesity, smoking habit, education, diseases, injuries, and subjective symptoms. Results: Of the 4029 conscripts, 853 visited healthcare professionals for knee symptoms during their military service, and 103 of these had suffered a knee injury. Independent risk factors for the incidence of knee symptoms were: older age; service class A; overweight (BMI 25.0-29.9 kg/m(2)); smoking habit; comprehensive school education only; and self-reported previous symptoms of the musculoskeletal, respiratory, and gastrointestinal system. The majority of visits to garrison healthcare services due to knee symptoms occurred during the first few months of military service. Knee symptoms were negatively correlated with self-reported mental and behavioral disorders. Conclusions: The present study highlights the frequency of knee disorders and injuries in young men during physically demanding military training. One-fifth of the male conscripts visited defense force healthcare professionals due to knee symptoms during their service period. Independent risk factors for the incidence of knee symptoms during military service were age at military service; military service class A; overweight; smoking habit; comprehensive school education only; and self-reported previous symptoms of the musculoskeletal system, respiratory system, or gastrointestinal system. These risk factors should be considered when planning and implementing procedures to reduce knee disorders and injuries during compulsory military service.