Associations of autozygosity with a broad range of human phenotypes

In many species, the offspring of related parents suffer reduced reproductive success, a phenomenon known as inbreeding depression. In humans, the importance of this effect has remained unclear, partly because reproduction between close relatives is both rare and frequently associated with confounding social factors. Here, using genomic inbreeding coefficients (FROH) for >1.4 million individuals, we show that FROH is significantly associated (p < 0.0005) with apparently deleterious changes in 32 out of 100 traits analysed. These changes are associated with runs of homozygosity (ROH), but not with common variant homozygosity, suggesting that genetic variants associated with inbreeding depression are predominantly rare. The effect on fertility is striking: FROH equivalent to the offspring of first cousins is associated with a 55% decrease [95% CI 44–66%] in the odds of having children. Finally, the effects of FROH are confirmed within full-sibling pairs, where the variation in FROH is independent of all environmental confounding

One sixth of Amazonian tree diversity is dependent on river floodplains

Amazonia's floodplain system is the largest and most biodiverse on Earth. Although forests are crucial to the ecological integrity of floodplains, our understanding of their species composition and how this may differ from surrounding forest types is still far too limited, particularly as changing inundation regimes begin to reshape floodplain tree communities and the critical ecosystem functions they underpin. Here we address this gap by taking a spatially explicit look at Amazonia-wide patterns of tree-species turnover and ecological specialization of the region's floodplain forests. We show that the majority of Amazonian tree species can inhabit floodplains, and about a sixth of Amazonian tree diversity is ecologically specialized on floodplains. The degree of specialization in floodplain communities is driven by regional flood patterns, with the most compositionally differentiated floodplain forests located centrally within the fluvial network and contingent on the most extraordinary flood magnitudes regionally. Our results provide a spatially explicit view of ecological specialization of floodplain forest communities and expose the need for whole-basin hydrological integrity to protect the Amazon's tree diversity and its function.Naturali

Phylogenetic conservatism in the relationship between functional and demographic characteristics in Amazon tree taxa

1. Leaf and wood functional traits of trees are related to growth, reproduction, and survival, but the degree of phylogenetic conservatism in these relationships is largely unknown. In this study, we describe the variability of strategies involving leaf, wood and demographic characteristics for tree genera distributed across the Amazon Region, and quantify phylogenetic signal for the characteristics and their relationships. 2. Leaf and wood traits are aligned with demographic variables along two main axes of variation. The first axis represents the coordination of leaf traits describing resource uptake and use, wood density, seed mass, and survival. The second axis represents the coordination between size and growth. Both axes show strong phylogenetic signal, suggesting a constrained evolution influenced by ancestral values, yet the second axis also has an additional, substantial portion of its variation that is driven by functional correlations unrelated to phylogeny, suggesting simultaneously higher evolutionary lability and coordination. 3. Synthesis. Our results suggest that life history strategies of tropical trees are generally phylogenetically conserved, but that tree lineages may have some capability of responding to environmental changes by modulating their growth and size. Overall, we provide the largest-scale synopsis of functional characteristics of Amazonian trees, showing substantial nuance in the evolutionary patterns of individual characteristics and their relationships

Mapping density, diversity and species-richness of the Amazon tree flora

Using 2.046 botanically-inventoried tree plots across the largest tropical forest on Earth, we mapped tree species-diversity and tree species-richness at 0.1-degree resolution, and investigated drivers for diversity and richness. Using only location, stratified by forest type, as predictor, our spatial model, to the best of our knowledge, provides the most accurate map of tree diversity in Amazonia to date, explaining approximately 70% of the tree diversity and species-richness. Large soil-forest combinations determine a significant percentage of the variation in tree species-richness and tree alpha-diversity in Amazonian forest-plots. We suggest that the size and fragmentation of these systems drive their large-scale diversity patterns and hence local diversity. A model not using location but cumulative water deficit, tree density, and temperature seasonality explains 47% of the tree species-richness in the terra-firme forest in Amazonia. Over large areas across Amazonia, residuals of this relationship are small and poorly spatially structured, suggesting that much of the residual variation may be local. The Guyana Shield area has consistently negative residuals, showing that this area has lower tree species-richness than expected by our models. We provide extensive plot meta-data, including tree density, tree alpha-diversity and tree species-richness results and gridded maps at 0.1-degree resolution

Consistent patterns of common species across tropical tree communities

Trees structure the Earth’s most biodiverse ecosystem, tropical forests. The vast number of tree species presents a formidable challenge to understanding these forests, including their response to environmental change, as very little is known about most tropical tree species. A focus on the common species may circumvent this challenge. Here we investigate abundance patterns of common tree species using inventory data on 1,003,805 trees with trunk diameters of at least 10 cm across 1,568 locations1,2,3,4,5,6 in closed-canopy, structurally intact old-growth tropical forests in Africa, Amazonia and Southeast Asia. We estimate that 2.2%, 2.2% and 2.3% of species comprise 50% of the tropical trees in these regions, respectively. Extrapolating across all closed-canopy tropical forests, we estimate that just 1,053 species comprise half of Earth’s 800 billion tropical trees with trunk diameters of at least 10 cm. Despite differing biogeographic, climatic and anthropogenic histories7, we find notably consistent patterns of common species and species abundance distributions across the continents. This suggests that fundamental mechanisms of tree community assembly may apply to all tropical forests. Resampling analyses show that the most common species are likely to belong to a manageable list of known species, enabling targeted efforts to understand their ecology. Although they do not detract from the importance of rare species, our results open new opportunities to understand the world’s most diverse forests, including modelling their response to environmental change, by focusing on the common species that constitute the majority of their trees

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time, and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space. While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes, vast areas of the tropics remain understudied. In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity, but it remains among the least known forests in America and is often underrepresented in biodiversity databases. To worsen this situation, human-induced modifications may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge, it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Arbetsmiljöarbete och effekter en kunskapsöversikt

Work environment improvements and effects a literature review This report addresses the question 'Do work-environment improvements have any effects?' The aim was to produce a summary of knowledge that includes the methodological problems of measuring and evaluating effects, as well as literature reviews of effects from work environment improvement efforts on musculoskeletal health, health promotion, and economy. Results show that published literature reviews do not give unambiguous support for health benefits of interventions against musculoskeletal problems, when only studies using natural science criteria with experimental or quasi-experimental design are included. There are, on the other hand, many case studies in the so called 'grey' literature that report positive effects. Further, results show that health promotion interventions, and especially physical activity, have a positive effect on low back pain. Workplace interventions to increase physical activity are effective and lead to increased physical activity amongst employees. More studies are needed, however, at the organisational level. There is some support for the profitability of work-environment investments at the organisational level; even though there are few studies and methodological problems. The review also indicates that the financial benefits come mostly from quality and productivity improvements and, to a lesser extent from reductions in costs related to sickness absenteeism. While more recent literature reviews of the effects of health promotion interventions seem to show a stronger effect than older studies, comparisons of older versus more recent studies of interventions against musculoskeletal problems give a more ambiguous picture. Often, the focus of these reviews is on study design with less priority on the quality of the interventions themselves. Multifactorial interventions are particularly difficult to evaluate. At the same time, many studies and research reviews emphasise the need for multifactorial approaches as necessary for successful intervention. Inclusion criteria in literature reviews that only consider experimental designs in organisational interventions exclude studies with good interventions that can't be evaluated with traditional experimental methods. Difficulties in proving the effectiveness of interventions depends on views of what constitutes good scientific quality in the studies. This shows a need for a critical examination of the assumptions used for knowledge generation in this area. Conclusions are that work-environment improvement efforts have effects that are clear in some cases but are difficult to show in others. Effect evaluation poses large methodological challenges. These difficulties are considered to be an important cause of the lack of clear evidence, especially in the area of interventions against musculoskeletal problems. There is a need for new non-experimental research strategies that are suited to today's complex systems and an increased focus on practical, well conducted multifactorial interventions. Key words: Intervention, health promotion, ergonomics, economy, methodology, researchDetta arbete har inriktats mot frågeställningen om arbetsmiljöarbete har några effekter. Syftet har varit att göra en kunskapssammanställning som omfattar en beskrivning och problematisering av metodiken att mäta eller utvärdera effekter, samt litteraturöversikter om vad arbetsmiljöarbete har för belastningsergonomiska, hälsofrämjande och ekonomiska effekter. Resultaten visar att publicerade litteraturöversikter inte ger säkra belägg för att belastningsergonomiska interventioner har effekter på besvärsförekomst, i de fall enbart studier inkluderats utifrån naturvetenskapliga kriterier med krav på experimentell eller kvasi-experimentell metodik. Däremot finns ett flertal fallstudier och så kallad grå litteratur som i högre grad rapporterar positiva effekter. Vidare framgår det att hälsofrämjande interventioner, och speciellt fysisk aktivitet har en positiv effekt på ländryggsbesvär. Interventioner på arbetsplatser för att öka den fysiska aktiviteten är effektiva och ger en ökad fysisk aktivitet hos arbetstagarna. Fler studier behövs emellertid på organisationsnivå. Det finns visst belägg för att arbetsmiljösatsningar ofta är lönsamma på organisationsnivå, även om studierna är få och uppvisar metodbrister. Det finns flera indikationer på att lönsamheten i huvudsak härrör från produktivitets- och kvalitetsförbättringar, och i mindre grad från minskade frånvarokostnader. Nya litteraturöversikter om hälsofrämjande interventioner tycks uppvisa starkare effekter än gamla, medan jämförelser mellan äldre och nyare studier om belastningsergonomiska interventioner ger en mer mångtydig bild. Ofta ligger fokus på utvärderingsdesign, samtidigt som kvaliteten hos interventionens genomförande och utformning i sig inte ges samma prioritet. Interventioner med multifaktoriella insatser blir synnerligen svåra och komplexa att utvärdera, samtidigt som det i många studier och forskningsöversikter betonas att en förutsättning för framgång i förändringsarbetet är att man arbetar med en mångfald av insatser. Inklusionskriterier i litteraturöversikter som förutsätter experimentella upplägg i organisationsinterventioner selekterar bort studier med goda interventioner som inte kan utvärderas med traditionella metoder. Svårigheten att identifiera effekter av interventioner bedöms bero på synen om vad som utmärker god vetenskaplig kvalitet hos studier. Detta visar på behovet att närmare kritiskt granska förutsättningarna för kunskapsbildning inom området. Slutsatsen är att arbetsmiljöarbete i vissa fall har effekter men att det i andra fall är svårt att påvisa effekter. Effektutvärdering innebär stora metodologiska svårigheter. Dessa svårigheter bedöms vara en viktig orsak till bristen på underlag, speciellt inom det belastningsergonomiska området. Det finns ett stort behov av nya icke experimentella undersökningsstrategier som är anpassade till dagens komplexa system, såväl som ett behov av starkare fokus på praktiskt väl genomförda multifaktoriella interventioner

The gut feelings of medical culture

This is the first book to consider digestive health in the nineteenth century from the combined angles of politics, literature, art, ethnography, psychiatry, emotional health, intellectual processes, morality, and spirituality. The chapters address the meanings and significance of digestive health in modern France, Northern America, Germanic Europe, Italy, colonial Australia and Britain. By revealing the particular nineteenth-century focus on digestive function and its influence on both emotion and cognition, the volume makes a new contribution not only to the history of literature, science and medicine, but also to current debates about the relationship between the gut and the brain. Here we help to show how medical breakthroughs are often historically preceded by intuitive models imagined throughout cultural production of different kinds