Resource heterogeneity does not explain the diversity–productivity relationship across a boreal island fertility gradient

Many studies at the regional scale have found either negative or hump‐shaped relationships between productivity and diversity, and some theories propose that these occur because soil resource heterogeneity is either lower or less important in more productive environments. However, there have been few explicit tests of these theories in natural ecosystems. We evaluated the relationship between soil resource heterogeneity and plant richness within a well characterized system of 30 islands in northern Sweden across which soil fertility and productivity declines, and species richness increases, as a consequence of ecosystem retrogression. On each island we created a spatially explicit grid consisting of 49 sampling points in a 9.5 m quadrat, which we used to quantify spatial heterogeneity of five soil variables (NH₄⁺‐N, amino N, PO₄^?‐P, microbial biomass, and decomposition), and plant community composition. Using a hierarchical Bayesian approach, we estimated mean semivariograms of each variable for each island size class to compare three components of spatial heterogeneity: total variability, spatial grain, and patchiness. This analysis showed that variability within islands was usually lowest on small islands, where species richness was highest and productivity lowest; however, NH₄⁺‐N and amino N had greater patchiness and spatial grain on small islands. We did not detect any significant across‐island correlations between whole‐plot plant species richness and either whole‐plot standard deviation or coefficient of variation of any soil variable. Using partial Mantel tests, we found that mean correlation coefficients between within‐plot plant community composition and the soil variables were never significant for any island size class, and did not differ between island size classes. Our findings do not provide any evidence that soil resource heterogeneity controls the productivity–diversity relationship in this system, and suggests other mechanisms are primarily responsible.     

Long‐term effects of prairie restoration on plant community structure and native population dynamics

The key to restoring degraded grassland habitats is identifying feasible and effective techniques to reduce the negative impacts of exotic species and promote self‐sustaining native populations. It is often difficult to extend monitoring of restoration efforts to evaluate long‐term success, but doing so is essential to understanding how initial outcomes change over time. To assess how initial treatment effects persist, we revisited degraded patches of Pacific Northwest prairie habitat 6 years after experimental restoration efforts ceased. We evaluated plant community composition to determine the lasting effects of supplemental native seeding and disturbance treatments (burning, mowing, and herbicide to reduce exotic species). We tracked the persistence of seeded species and measured spread of their populations to evaluate suitability of species for restoration and the ability of the habitat to support native plant populations. We found that plots that received supplemental seeding continued to exhibit higher richness of native species than those left unseeded, and that both seeding and disturbance treatments could positively influence native species abundance over the long term. The initially observed effects of disturbance treatments on reducing exotic grass abundance had diminished, highlighting the importance of long‐term monitoring and ongoing control of exotic species. Nevertheless, these treatments significantly influenced the population trajectories of 4 out of 8 seeded native species. There was evidence of spatial advance of most seeded species. Results from extended monitoring confirm that dispersal limitation of native species and difficulties maintaining the reduction of exotic grasses continue to be major barriers to success in restoration of invaded grasslands.     

Subtype distribution of Blastocystis isolates from synanthropic and zoo animals and identification of a new subtype

Blastocystis isolates from 56 Danish synanthropic and zoo animals, 62 primates primarily from United Kingdom (UK) collections and 16 UK primate handlers were subtyped by PCR, sequencing and phylogenetic analysis. A new subtype (ST) from primates and artiodactyls was identified and designated as Blastocystis sp. ST10. STs isolated from non-human primates (n = 70) included ST3 (33%), ST8 (21%), ST2 (16%), ST5 (13%), ST1 (10%), ST4 (4%) and ST10 (3%). A high prevalence of ST8 was seen among primate handlers (25%). This ST is normally very rare in humans, suggesting that acquisition of Blastocystis ST8 infections from primates by their handlers had occurred in these cases. Data from published studies of non-human primates, other mammals and birds were collected and interpreted to generate a comprehensive overview on the ST distribution in such animals. On the basis of information on 438 samples, it was found that Blastocystis from primates belong mainly to ST1, ST2, ST3, ST5 and ST8, ungulates and dogs mainly ST1, ST2, ST3, ST5 and ST10, rodents ST4 and birds mainly ST6 and ST7. The data indicate moderate host specificity, most clearly exemplified by the fact that STs isolated from avian and non-avian hosts rarely overlap.     

2-Cyano-3,10-dioxooleana-1,9(11)-dien-28-oic acid anhydride. A novel and highly potent anti-inflammatory and cytoprotective agent

2-Cyano-3,10-dioxooleana-1,9(11)-dien-28-oic acid anhydride (CDDO anhydride) has been synthesized, which is the first example of an oleanane triterpenoid anhydride. CDDO anhydride shows potency similar to or higher than the corresponding acid (CDDO) in various in vitro and in vivo assays related to inflammation and carcinogenesis. Notably, preliminary phamacokinetics studies show that CDDO anhydride levels are higher than CDDO levels in mouse tissues and blood. Further evaluation of CDDO anhydride is in progress.     

Physical activity attenuates the influence of FTO variants on obesity risk: a meta-analysis of 218,166 adults and 19,268 children

Background

The FTO gene harbors the strongest known susceptibility locus for obesity. While many individual studies have suggested that physical activity (PA) may attenuate the effect of FTO on obesity risk, other studies have not been able to confirm this interaction. To confirm or refute unambiguously whether PA attenuates the association of FTO with obesity risk, we meta-analyzed data from 45 studies of adults (n = 218,166) and nine studies of children and adolescents (n = 19,268).

Methods and Findings

All studies identified to have data on the FTO rs9939609 variant (or any proxy [r ²>0.8]) and PA were invited to participate, regardless of ethnicity or age of the participants. PA was standardized by categorizing it into a dichotomous variable (physically inactive versus active) in each study. Overall, 25% of adults and 13% of children were categorized as inactive. Interaction analyses were performed within each study by including the FTO×PA interaction term in an additive model, adjusting for age and sex. Subsequently, random effects meta-analysis was used to pool the interaction terms. In adults, the minor (A−) allele of rs9939609 increased the odds of obesity by 1.23-fold/allele (95% CI 1.20–1.26), but PA attenuated this effect (p _interaction  = 0.001). More specifically, the minor allele of rs9939609 increased the odds of obesity less in the physically active group (odds ratio  = 1.22/allele, 95% CI 1.19–1.25) than in the inactive group (odds ratio  = 1.30/allele, 95% CI 1.24–1.36). No such interaction was found in children and adolescents.

Conclusions

The association of the FTO risk allele with the odds of obesity is attenuated by 27% in physically active adults, highlighting the importance of PA in particular in those genetically predisposed to obesity. Please see later in the article for the Editors'' Summary     

Implications of childhood obesity for adult health: findings from thousand families cohort study

ObjectiveTo determine whether being overweight in childhood increases adult obesity and risk of disease.DesignProspective cohort study.SettingCity of Newcastle upon Tyne.Participants932 members of thousand families 1947 birth cohort, of whom 412 attended for clinical examination age 50.ResultsBody mass index at age 9 years was significantly correlated with body mass index age 50 (r=0.24, P<0.001) but not with percentage body fat age 50 (r=0.10, P=0.07). After adult body mass index had been adjusted for, body mass index at age 9 showed a significant inverse association with measures of lipid and glucose metabolism in both sexes and with blood pressure in women. However, after adjustment for adult percentage fat instead of body mass index, only the inverse associations with triglycerides (regression coefficient= −0.21, P<0.01) and total cholesterol (−0.17, P<0.05) in women remained significant.ConclusionsLittle tracking from childhood overweight to adulthood obesity was found when using a measure of fatness that was independent of build. Only children who were obese at 13 showed an increased risk of obesity as adults. No excess adult health risk from childhood or teenage overweight was found. Being thin in childhood offered no protection against adult fatness, and the thinnest children tended to have the highest adult risk at every level of adult obesity.

What is already known on this topic

Many studies have found that body mass index in childhood is significantly correlated with body mass index in adulthoodObese children have been found to have higher all cause mortality as adults

What this study adds

No excess health risk from childhood overweight was foundChildhood body mass index was linked to adulthood body mass index but not percentage body fatOnly children who were obese at 13 showed a significant increased risk of obesity as adultsPeople who were thinnest as children and fattest as adults tended to have the highest adult risk