Baden H.M.,University of Southern Denmark |
Baden H.M.,Max Planck Odense Center on the Biodemography of Aging |
Sarkinen T.,Royal Botanic Garden Edinburgh |
Conde D.A.,University of Southern Denmark |
And 9 more authors.
Edinburgh Journal of Botany | Year: 2015
The Chiquibul Forest Reserve and National Park in Belize is a priority conservation area within the 'Maya Forest' in Central America. Although taxonomic data are essential for the development of conservation plans in the region, there is limited knowledge of the existing species in the area. Here we present a botanical species list of mostly woody taxa based on voucher specimens, with particular focus on the Raspaculo watershed in the eastern part of the National Park. Within the Raspaculo watershed, a comparison is made between 0.1 ha of valley floor and 0.1 ha of hilltop vegetation, sampling trees, shrubs, palms and lianas ≥2.5 cm diameter at breast height. Additionally, a 1 ha plot was established in the Upper Raspaculo watershed. Our study shows 38 new species records for the region, and important additions to the flora of Belize. New records were recorded from forests on both metamorphic and karstic substrate, including previously overlooked hilltop forest elements. Quantitative assessment of vegetation across elevation zones shows distinct elements dominating on valley floors and hilltops. Our results show that the Chiquibul contains at least 58% of Belize's threatened plant species, and represent a source of information for the management and conservation of the area. © Copyright 2015 Trustees of the Royal Botanic Garden Edinburgh.
Koons D.N.,Utah State University |
Koons D.N.,CNRS Center of Evolutionary and Functional Ecology |
Colchero F.,Max Planck Odense Center on the Biodemography of Aging |
Colchero F.,University of Southern Denmark |
And 2 more authors.
Ecological Applications | Year: 2015
Understanding the relative effects of climate, harvest, and density dependence on population dynamics is critical for guiding sound population management, especially for ungulates in arid and semiarid environments experiencing climate change. To address these issues for bison in southern Utah, USA, we applied a Bayesian state-space model to a 72-yr time series of abundance counts. While accounting for known harvest (as well as live removal) from the population, we found that the bison population in southern Utah exhibited a strong potential to grow from low density (β0 = 0.26; Bayesian credible interval based on 95% of the highest posterior density [BCI] = 0.19-0.33), and weak but statistically significant density dependence (β1 = -0.02, BCI = -0.04 to -0.004). Early spring temperatures also had strong positive effects on population growth (βfat1 = 0.09, BCI = 0.04-0.14), much more so than precipitation and other temperature-related variables (model weight > three times more than that for other climate variables). Although we hypothesized that harvest is the primary driving force of bison population dynamics in southern Utah, our elasticity analysis indicated that changes in early spring temperature could have a greater relative effect on equilibrium abundance than either harvest or the strength of density dependence. Our findings highlight the utility of incorporating elasticity analyses into state-space population models, and the need to include climatic processes in wildlife management policies and planning. © 2015 by the Ecological Society of America.
Canudas-Romo V.,University of Southern Denmark |
Canudas-Romo V.,Family and Reproductive Health |
Canudas-Romo V.,Max Planck Odense Center on the Biodemography of Aging |
Zimmerman L.,Family and Reproductive Health |
And 2 more authors.
PLoS ONE | Year: 2014
Objective: We assessed the change over time in the contribution of maternal mortality to a life expectancy calculated between ages 15 and 49, or Reproductive-Aged Life Expectancy (RALE). Our goal was to estimate the increase in RALE in developed countries over the twentieth century and the hypothetical gains in African countries today by eliminating maternal mortality. Methods: Analogous to life expectancy, RALE is calculated from a life table of ages 15 to 49. Specifically, RALE is the average number of years that women at age 15 would be expected to live between 15 and 49 with current mortality rates. Associated single decrement life tables of causes of death other than maternal mortality are explored to assess the possible gains in RALE by reducing or eliminating maternal mortality. We used population-based data from the Human Mortality Database and the Demographic and Health Surveys. Findings: In developed countries, five years in RALE were gained over the twentieth century, of which approximately 10%, or half a year, was attributable to reductions in maternal mortality. In sub-Saharan African countries, the possible achievable gains fluctuate between 0.24 and 1.47 years, or 6% and 44% of potential gains in RALE. Conclusions: Maternal mortality is a rare event, yet it is still a very important component of RALE. Averting the burden of maternal deaths could return a significant increase in the most productive ages of human life. © 2014 Canudas-Romo et al.
Engberg H.,University of Southern Denmark |
Jeune B.,University of Southern Denmark |
Andersen-Ranberg K.,University of Southern Denmark |
Martinussen T.,Copenhagen University |
And 4 more authors.
Aging Clinical and Experimental Research | Year: 2013
Background and aims: Studies examining predictors of survival among the oldest-old have primarily focused on objective measures, such as physical function and health status. Only a few studies have examined the effect of personality traits on survival, such as optimism. The aim of this study was to examine whether an optimistic outlook predicts survival among the oldest-old. Methods: The Danish 1905 Cohort Survey is a nationwide, longitudinal survey comprising all individuals born in Denmark in 1905. At baseline in 1998, a total of 2,262 persons aged 92 or 93 agreed to participate in the intake survey. The baseline in-person interview consisted of a comprehensive questionnaire including physical functioning and health, and a question about whether the respondent had an optimistic, neutral or pessimistic outlook on his or her own future. Results: During the follow-up period of 12 years (1998-2010) there were 2,239 deaths (99 %) in the 1905 Cohort Survey. Univariable analyses revealed that optimistic women and men were at lower risk of death compared to their neutral counterparts [HR 0.82, 95 % CI (0.73-0.93) and 0.81, 95 % CI (0.66-0.99), respectively]. When confounding factors such as baseline physical and cognitive functioning and disease were taken into account the association between optimism and survival weakened in both sexes, but the general pattern persisted. Optimistic women were still at lower risk of death compared to neutral women [HR 0.85, 95 % CI (0.74-0.97)]. The risk of death was also decreased for optimistic men compared to their neutral counterparts, but the effect was non-significant [HR 0.91, 95 % CI (0.73-1.13)]. Conclusion: An optimistic outlook appears to be a significant predictor of survival among the oldest-old women. It may also be a significant predictor for men but the sample size is small. © 2013 Springer International Publishing Switzerland.
Baudisch A.,Max Planck Institute for Demographic Research |
Salguero-Gomez R.,Max Planck Institute for Demographic Research |
Salguero-Gomez R.,University of Queensland |
Jones O.R.,Max Planck Institute for Demographic Research |
And 8 more authors.
Journal of Ecology | Year: 2013
Demographic senescence, the decay in fertility and increase in the risk of mortality with age, is one of the most striking phenomena in ecology and evolution. Comparative studies of senescence patterns of plants are scarce, and consequently, little is known about senescence and its determinants in the plant kingdom. Senescence patterns of mortality can be classified by distinguishing between two metrics: pace and shape. The pace of mortality captures the speed at which life proceeds and can be measured by life expectancy, while the shape of mortality captures whether mortality increases ('senescence'), decreases ('negative senescence') or remains constant over age ('negligible senescence'). We extract mortality trajectories from ComPADRe III, a data base that contains demographic information for several hundred plant species. We apply age-from-stage matrix decomposition methods to obtain age-specific trajectories from 290 angiosperm species of various growth forms distributed globally. From these trajectories, we survey pace and shape values and investigate how growth form and ecoregion influence these two aspects of mortality using a Bayesian regression analysis that accounts for phylogenetic relationships using a resolved supertree. In contrast to the animal kingdom, most angiosperms (93%) show no senescence. Senescence is observed among phanerophytes (i.e. trees), but not among any other growth form (e.g. epiphytes, chamaephytes or cryptopyhtes). Yet, most phanerophytes (81%) do not senesce. We find that growth form relates to differences in pace, that is, life span, as woody plants are typically longer lived than nonwoody plants, while differences in shape, that is, whether or not angiosperms senesce, are related to ancestral history. Synthesis: The age trajectory of mortality captures a fundamental life-history pattern for a species that is crucial to ecological understanding. We contribute to ecological knowledge by surveying these patterns across angiosperms. The novelty and strength of our study lies in the comprehensiveness of the data set, the use of a novel Bayesian analysis that accounts for phylogenetic history and in the distinction between metrics of pace and shape as two separate aspects of mortality. We believe that our approach could prove useful in future comparative studies of mortality patterns. © 2013 The Authors. Journal of Ecology © 2013 British Ecological Society.
Oksuzyan A.,Max Planck Institute for Demographic Research |
Oksuzyan A.,University of Southern Denmark |
Shkolnikova M.,Pirogov Moscow Medical University |
Vaupel J.W.,Max Planck Institute for Demographic Research |
And 5 more authors.
PLoS ONE | Year: 2015
Background: The apparent contradiction that women live longer but have worse health than men, the so called male-female health-survival paradox, is very pronounced in Russia. The present study investigates whether men in Moscow are healthier than women at the level of biomarkers, and whether the associations between biomarkers and subjective health have sex-specific patterns. Materials: Previously collected data in the study of Stress, Aging, and Health in Russia (SAHR, n = 1800) were used to examine sex differences in biomarkers and their associations with physical functioning and self-rated health. Results: The present study found mixed directions and magnitudes for sex differences in biomarkers. Women were significantly disadvantaged with regard to obesity and waist circumference, whereas men had a tendency toward higher prevalence of electrocardiographic abnormalities. No sex differences were indicated in the prevalence of immunological biomarkers, and mixed patterns were found for lipid profiles. Many biomarkers were associated with physical functioning and general health. Obesity and waist circumference were related to lower physical functioning among females only, while major Q-wave abnormalities with high probabilities of myocardial infarction and atrial fibrillation or atrial flutter were associated with physical functioning and self-rated health among males only. Conclusion: No clear patterns of sex differences in prevalence of high-risk levels of biomarkers suggest that the male-female health-survival paradox is weaker at the level of health biomarkers. We found some evidence that certain biomarkers reflecting pathophysiological changes in the organism that do not possess acute health risks, but over many years may lead to physical disability, are associated with physical functioning and self-rated health in women, whereas others reflecting more serious life-threatening pathophysiological changes are associated with physical functioning and self-rated health in men. © 2015 Oksuzyan et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Levitis D.A.,Max Planck Odense Center on the Biodemography of Aging |
Levitis D.A.,University of Southern Denmark |
Martinez D.E.,Pomona College
Frontiers in Genetics | Year: 2013
Gerontology focuses on deterioration with increasing age, but in most populations most variables, including survival probability, improve at early ages (ontogenescence) before deteriorating at advanced ages (senescence). The extent to which gerontology needs to consider this U-shaped pattern of risk over age depends upon the mechanistic, demographic and evolutionary links and interactions between ontogenescence and senescence. In reading the literature on both senescence and ontogenescence, and in interacting with other biogerontologists, we have encountered a set of what we view as inaccurate or oversimplified claims about ontogenescence, its relationship to senescence and its importance to gerontology. Here, after briefly introducing ontogenescence, we address four of these claims. We demonstrate the counterfactual nature of Claim 1. Ontogenescence is an environmental effect largely absent in protected environments. We then briefly review the literature which leads to Claim 2. Senescence and ontogenescence are parts of the same phenomenon, and describe why we reject this view. We then explain why the rejection of Claim 2 does not necessarily support Claim 3, the idea that senescence and ontogenescence are easily separable. Finally, we examine Claim 4. Gerontologists don't need to think about ontogenescence, and give some examples of why we consider this misguided. © 2013 Levitis and Martínez.
Rizzi S.,Max Planck Odense Center on the Biodemography of Aging |
Rizzi S.,University of Southern Denmark |
Thinggaard M.,Max Planck Odense Center on the Biodemography of Aging |
Thinggaard M.,University of Southern Denmark |
And 8 more authors.
BMC Medical Research Methodology | Year: 2016
Background: Histograms are a common tool to estimate densities non-parametrically. They are extensively encountered in health sciences to summarize data in a compact format. Examples are age-specific distributions of death or onset of diseases grouped in 5-years age classes with an open-ended age group at the highest ages. When histogram intervals are too coarse, information is lost and comparison between histograms with different boundaries is arduous. In these cases it is useful to estimate detailed distributions from grouped data. Methods: From an extensive literature search we identify five methods for ungrouping count data. We compare the performance of two spline interpolation methods, two kernel density estimators and a penalized composite link model first via a simulation study and then with empirical data obtained from the NORDCAN Database. All methods analyzed can be used to estimate differently shaped distributions; can handle unequal interval length; and allow stretches of 0 counts. Results: The methods show similar performance when the grouping scheme is relatively narrow, i.e. 5-years age classes. With coarser age intervals, i.e. in the presence of open-ended age groups, the penalized composite link model performs the best. Conclusion: We give an overview and test different methods to estimate detailed distributions from grouped count data. Health researchers can benefit from these versatile methods, which are ready for use in the statistical software R. We recommend using the penalized composite link model when data are grouped in wide age classes. © 2016 Rizzi et al.
Oksuzyan A.,Max Planck Odense Center on the Biodemography of Aging |
Oksuzyan A.,Max Planck Institute for Demographic Research |
Shkolnikova M.,Max Planck Institute for Demographic Research |
Shkolnikova M.,Moscow Institute of Pediatry and Surgery |
And 6 more authors.
European Journal of Epidemiology | Year: 2014
In high income countries females outlive men, although they generally report worse health, the so-called male-female health-survival paradox. Russia has one of the world's largest sex difference in life expectancy with a male disadvantage of more than 10 years. We compare components of the paradox between Denmark and Moscow by examining sex differences in mortality and several health measures. The Human Mortality Database and the Russian Fertility and Mortality Database were used to examine sex differences in all-cause death rates in Denmark, Russia, and Moscow in 2007-2008. Self-reported health data were obtained from the Study of Middle-Aged Danish Twins (n = 4,314), the Longitudinal Study of Aging Danish Twins (n = 4,731), and the study of Stress, Aging, and Health in Russia (n = 1,800). In both Moscow and Denmark there was a consistent female advantage at ages 55-89 years in survival and a male advantage in selfrated health, physical functioning, and depression symptomatology. Only on cognitive tests males performed similarly to or worse than women. Nevertheless, Muscovite males had more than twice higher mortality at ages 55-69 years compared to Muscovite women, almost double the ratio in Denmark. The present study showed that despite similar directions of sex differences in health and mortality in Moscow and Denmark, the male-female health-survival paradox is very pronounced in Moscow suggesting a stronger sex-specific disconnect between health indicators and mortality among middle-aged and young-old Muscovites. © Springer Science+Business Media 2014.
Wensink M.J.,Max Planck Odense Center on the Biodemography of Aging |
Wensink M.J.,University of Southern Denmark |
Wensink M.J.,Max Planck Institute for Demographic Research |
Wensink M.J.,Vitality |
And 6 more authors.
Evolutionary Biology | Year: 2016
The evolution of senescence is often explained by arguing that, in nature, few individuals survive to be old and hence it is evolutionarily unimportant what happens to organisms when they are old. A corollary to this idea is that extrinsically imposed mortality, because it reduces the chance of surviving to be old, favors the evolution of senescence. We show that these ideas, although widespread, are incorrect. Selection leading to senescence does not depend directly on survival to old age, but on the shape of the stable age distribution, and we discuss the implications of this important distinction. We show that the selection gradient on mortality declines with age even in the hypothetical case of zero mortality, when survivorship does not decline. Changing the survivorship function by imposing age independent mortality has no affect on the selection gradients. A similar result exists for optimization models: age independent mortality does not change the optimal result. We propose an alternative, brief explanation for the decline of selection gradients, and hence the evolution of senescence. © 2016 The Author(s)