Functional trait diversity is a popular tool in modern ecology, mainly used to infer assembly processes and ecosystem functioning. Patterns of functional trait diversity are shaped by ecological ...processes such as environmental filtering, species interactions and dispersal that are inherently spatial, and different processes may operate at different spatial scales. Adding a spatial dimension to the analysis of functional trait diversity may thus increase our ability to infer community assembly processes and to predict change in assembly processes following disturbance or land‐use change. Richness, evenness and divergence of functional traits are commonly used indices of functional trait diversity that are known to respond differently to large‐scale filters related to environmental heterogeneity and dispersal and fine‐scale filters related to species interactions (competition). Recent developments in spatial statistics make it possible to separately quantify large‐scale patterns (variation in local means) and fine‐scale patterns (variation around local means) by decomposing overall spatial autocorrelation quantified by Moran's coefficient into its positive and negative components using Moran eigenvector maps (MEM). We thus propose to identify the spatial signature of multiple ecological processes that are potentially acting at different spatial scales by contrasting positive and negative components of spatial autocorrelation for each of the three indices of functional trait diversity. We illustrate this approach with a case study from riparian plant communities, where we test the effects of disturbance on spatial patterns of functional trait diversity. The fine‐scale pattern of all three indices was increased in the disturbed versus control habitat, suggesting an increase in local scale competition and an overall increase in unexplained variance in the post‐disturbance versus control community. Further research using simulation modeling should focus on establishing the proposed link between community assembly rules and spatial patterns of functional trait diversity to maximize our ability to infer multiple processes from spatial community structure.
1. Clearcutting and wildfire are the two major edge-creating disturbances in boreal forests. While clearcutting retains at least a 30 m buffer, wildfires burn close to streams killing most of the ...trees and potentially creating a different edge structure. Different edge structures are likely to support different plant assemblages. The riparian buffer and fire edge structures and their effects on plant assemblages are unknown, but they have implications for forest management that aims to harvest trees and conserve biodiversity by emulating natural disturbance. 2. We hypothesized that environmental filters created by post-fire residual structures at the fire edge will support a different plant assemblage than the buffer edge. We further hypothesized that the fire edge with a weaker environmental filter because of post-fire residual structures and proximity to streams will result in lower depth of edge effects (DEEs) and magnitude of edge effects (MEEs) than buffer edges. 3. We determined the structure of canopy trees, understorey cover and the near-ground microclimate by sampling 576 (5 × 10 m) and 1820 (1 × 1 m) quadrats along 96 transects beside 24 streams near Thunder Bay, Canada. We determined DEEs and MEEs by comparing edge variables with reference forests. We used repeated measures/factorial ANOVAS with Tukey's post hoc tests to determine DEEs and MANO VA for MEEs. 4. The average microclimatic DEEs extended 8 m into the buffer but only 2·5 m from the fire edge.Similarly, the DEEs for plant life-forms extended 20 m from the buffer edge and 5 m from the fire edge. At the fire edge, the structural MEEs were significantly higher, but the microclimatic MEEs were lower than the buffer edge. We found no significant difference in the overall life-form MEEs, but shrubs, shade-tolerant herbs and grasses were increased at the buffer edge and decreased at the fire edge. 5. Synthesis and applications. We discovered that the ecological structure at buffer and fire edges in boreal forests creates different environmental filters supporting different plant assemblages. Lower structural and microclimatic DEEs and MEEs at the fire edge result from (i) edge location, (ii) intact shrub layer and (iii) disturbance-resilient riparian vegetation. We suggest that replacing the conventional sharp edges of the riparian clear-cut buffer with ' feathered' edges by selective harvesting of trees will create wider edges mimicking wildfire legacy and will help to emulate natural disturbance for conserving biodiversity.
•Species richness and functional richness relationship varies with microhabitat.•Species evenness and functional evenness relationship varies with disturbance type.•Functional trait dispersion ...explains the variation in the species and functional diversity relationship.•Landscape spatial heterogeneity should be considered in understanding the functioning of a natural landscape.
Spatial heterogeneity in site conditions and differing disturbance types are common features of natural landscapes. We asked: does the relationship between species diversity and functional trait diversity (SD-FD relationship) of plant communities vary among habitats experiencing different types of disturbance and among microhabitats (i.e., landscape position) within a landscape? We quantified the relationship between species richness and functional richness (FRic) and between species evenness and functional evenness (FEve) of riparian plant communities along small headwater streams at five spatially adjacent microhabitats in two types of disturbed (wildfire and clearcut logging with buffer) and reference habitats (unlogged mature forest) in northwestern Ontario, Canada. We found significant dependence of species richness vs. FRic relationship on microhabitat, but not on disturbance type. Species evenness vs. FEve relationship varied slightly among reference and wildfire sites, but not among microhabitats. A significant variation in functional trait dispersion (FDis) among microhabitats offered a mechanistic explanation to the observed variation in the SD-FD relationship. A very weak effect of disturbance type on the SD-FD relationship indicates that clearcut with buffer retention may emulate riparian plant composition created by wildfire. However, the microhabitat dependent variation in the SD-FD relationship indicates that the same range of species diversity may refer to different ranges of functional trait diversity depending on microhabitat. We suggest that microhabitat plays a stronger role than disturbance type in trait dispersion and ultimately modifies the SD-FD relationship in our studied communities. This result highlights the role of spatial environmental heterogeneity of a landscape and different dimensions of species diversity and functional trait diversity, e.g. richness and evenness, in understanding the functioning of a natural landscape.
In a previous investigation, a simulated annealing (SA) method was developed to optimize 14 Fourier terms in a radio-frequency waveform for active compensation of a Langmuir probe system. This ...approach was shown to find better solutions in less time than skilled human operators. However, variations in fitness indicated that the SA algorithm did not always find the precise global solution, although it came consistently close to it. This variability was caused by the limited number of fitness evaluations available due to time constraints. In this research, the chosen maximum step width has been shown to have a significant effect on the overall performance of the algorithm. A scaling function has been developed to adapt the maximum step width of the SA algorithm, on-line, as a function of the number of elapsed iterations. The modified algorithm has been shown to find fitter solutions with reduced variability in fitness.
There is evidence that persistent psychiatric disorders lead to age-related disease and premature mortality. Telomere length has emerged as a promising biomarker in studies that test the hypothesis ...that internalizing psychiatric disorders are associated with accumulating cellular damage. We tested the association between the persistence of internalizing disorders (depression, generalized anxiety disorder and post-traumatic stress disorder) and leukocyte telomere length (LTL) in the prospective longitudinal Dunedin Study (n=1037). Analyses showed that the persistence of internalizing disorders across repeated assessments from ages 11 to 38 years predicted shorter LTL at age 38 years in a dose-response manner, specifically in men (β=-0.137, 95% confidence interval (CI): -0.232, -0.042, P=0.005). This association was not accounted for by alternative explanatory factors, including childhood maltreatment, tobacco smoking, substance dependence, psychiatric medication use, poor physical health or low socioeconomic status. Additional analyses using DNA from blood collected at two time points (ages 26 and 38 years) showed that LTL erosion was accelerated among men who were diagnosed with internalizing disorder in the interim (β=-0.111, 95% CI: -0.184, -0.037, P=0.003). No significant associations were found among women in any analysis, highlighting potential sex differences in internalizing-related telomere biology. These findings point to a potential mechanism linking internalizing disorders to accelerated biological aging in the first half of the life course, particularly in men. Because internalizing disorders are treatable, the findings suggest the hypothesis that treating psychiatric disorders in the first half of the life course may reduce the population burden of age-related disease and extend health expectancy.
Genetic studies of blood pressure (BP) to date have mainly analyzed common variants (minor allele frequency > 0.05). In a meta-analysis of up to ~1.3 million participants, we discovered 106 new ...BP-associated genomic regions and 87 rare (minor allele frequency ≤ 0.01) variant BP associations (P < 5 × 10
), of which 32 were in new BP-associated loci and 55 were independent BP-associated single-nucleotide variants within known BP-associated regions. Average effects of rare variants (44% coding) were ~8 times larger than common variant effects and indicate potential candidate causal genes at new and known loci (for example, GATA5 and PLCB3). BP-associated variants (including rare and common) were enriched in regions of active chromatin in fetal tissues, potentially linking fetal development with BP regulation in later life. Multivariable Mendelian randomization suggested possible inverse effects of elevated systolic and diastolic BP on large artery stroke. Our study demonstrates the utility of rare-variant analyses for identifying candidate genes and the results highlight potential therapeutic targets.
The DNA molecule is observed to be very susceptible to short-term exposures to an atmospheric pressure plasma jet. The DNA damage induced by plasma-generated species, i.e. excited atoms, charged ...particles, electrons and UV light is determined.
Iron and vitamin D deficiencies are common during pregnancy. Our aim was to identify whether antenatal vitamin D₃ supplementation affects iron status (via hepcidin suppression) and/or inflammation. ...Using a subset of the UK multicenter Maternal Vitamin D Osteoporosis Study (MAVIDOS)-a double-blinded, randomized, placebo-controlled trial (ISRCTN82927713; EudraCT2007-001716-23)-we performed a secondary laboratory analysis. Women with blood samples from early and late pregnancy (vitamin D₃ (1000 IU/day from ~14 weeks gestation
= 93; placebo
= 102) who gave birth in the springtime (March⁻May) were selected as we anticipated seeing the greatest treatment group difference in change in 25-hydroxyvitamin D (25OHD) concentration. Outcomes were hepcidin, ferritin, C-reactive protein, and α1-acid glycoprotein concentration in late pregnancy (25OHD concentration was measured previously). By late pregnancy, 25OHD concentration increased by 17 nmol/L in the vitamin D₃ group and decreased by 11 nmol/L in the placebo group; hepcidin, ferritin, and inflammatory markers decreased but no treatment group differences were seen. In late pregnancy, positive relationships between 25OHD and hepcidin and 25OHD and ferritin in the placebo group were observed but not in the treatment group (group × 25OHD interaction,
< 0.02). Vitamin D₃ supplementation had no effect on hepcidin, ferritin, or inflammatory status suggesting no adjunctive value of vitamin D₃ in reducing rates of antenatal iron deficiency.
To evaluate the literature and identify important aspects of insulin therapy that facilitate safe and effective infusion therapy for a defined glycemic end point.
Where available, the literature was ...evaluated using Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) methodology to assess the impact of insulin infusions on outcome for general intensive care unit patients and those in specific subsets of neurologic injury, traumatic injury, and cardiovascular surgery. Elements that contribute to safe and effective insulin infusion therapy were determined through literature review and expert opinion. The majority of the literature supporting the use of insulin infusion therapy for critically ill patients lacks adequate strength to support more than weak recommendations, termed suggestions, such that the difference between desirable and undesirable effect of a given intervention is not always clear.
The article is focused on a suggested glycemic control end point such that a blood glucose ≥ 150 mg/dL triggers interventions to maintain blood glucose below that level and absolutely <180 mg/dL. There is a slight reduction in mortality with this treatment end point for general intensive care unit patients and reductions in morbidity for perioperative patients, postoperative cardiac surgery patients, post-traumatic injury patients, and neurologic injury patients. We suggest that the insulin regimen and monitoring system be designed to avoid and detect hypoglycemia (blood glucose ≤ 70 mg/dL) and to minimize glycemic variability.Important processes of care for insulin therapy include use of a reliable insulin infusion protocol, frequent blood glucose monitoring, and avoidance of finger-stick glucose testing through the use of arterial or venous glucose samples. The essential components of an insulin infusion system include use of a validated insulin titration program, availability of appropriate staffing resources, accurate monitoring technology, and standardized approaches to infusion preparation, provision of consistent carbohydrate calories and nutritional support, and dextrose replacement for hypoglycemia prevention and treatment. Quality improvement of glycemic management programs should include analysis of hypoglycemia rates, run charts of glucose values <150 and 180 mg/dL. The literature is inadequate to support recommendations regarding glycemic control in pediatric patients.
While the benefits of tight glycemic control have not been definitive, there are patients who will receive insulin infusion therapy, and the suggestions in this article provide the structure for safe and effective use of this therapy.
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