A new methodological protocol for the use of dendrogeomorphological data in flood risk analysis

Dendrogeomorphology uses information sources recorded in the roots, trunks and branches of trees and bushes located in the fluvial system to complement (or sometimes even replace) systematic and palaeohydrological records of past floods. The application of dendrogeomorphic data sources and methods to palaeoflood analysis over nearly 40 years has allowed improvements to be made in frequency and magnitude estimations of past floods. Nevertheless, research carried out so far has shown that the dendrogeomorphic indicators traditionally used (mainly scar evidence), and their use to infer frequency and magnitude, have been restricted to a small, limited set of applications. New possibilities with enormous potential remain unexplored. New insights in future research of palaeoflood frequency and magnitude using dendrogeomorphic data sources should: (1) test the application of isotopic indicators (16O/18O ratio) to discover the meteorological origin of past floods; (2) use different dendrogeomorphic indicators to estimate peak flows with 2D (and 3D) hydraulic models and study how they relate to other palaeostage indicators; (3) investigate improved calibration of 2D hydraulic model parameters (roughness); and (4) apply statistics-based cost–benefit analysis to select optimal mitigation measures. This paper presents an overview of these innovative methodologies, with a focus on their capabilities and limitations in the reconstruction of recent floods and palaeofloods.

Donor effect on cortical perfusion intensity in renal allograft recipients: a paired kidney analysis

The contributions of donor- and recipient-related factors to renal allograft hemodynamics are difficult to dissect due to methodological reasons. We analyzed 28 pairs of kidneys (each pair from the same donor) transplanted to 56 different recipients in order to define the contributions of the donor and the recipient to allograft hemodynamics.

Testing the allegiance bias hypothesis: a meta-analysis

This meta-analysis investigated whether the association between researcher allegiance (RA) and the relative effect of two psychotherapies can be explained through the methodological weaknesses of the treatment comparisons. Seventy-nine comparisons of psychotherapies for depression or posttraumatic stress disorder (PTSD) were included. Methodological quality (MQ) was investigated as both a moderator and a mediator of the RA-outcome association. MQ included balanced nonspecific factors, balanced specific factors, conceptual quality, patients-per-therapist ratio, randomization to conditions and outcome assessment. The RA-outcome association was stronger when the MQ was low, suggesting a buffering effect of MQ. In addition, differences in the conceptual quality of treatments mediated the effect of RA on outcome. The results support the view that RA acts as a bias in treatment comparisons.

Can falls risk prediction tools correctly identify fall-prone elderly rehabilitation inpatients? A systematic review and meta-analysis

Background Falls of elderly people may cause permanent disability or death. Particularly susceptible are elderly patients in rehabilitation hospitals. We systematically reviewed the literature to identify falls prediction tools available for assessing elderly inpatients in rehabilitation hospitals. Methods and Findings We searched six electronic databases using comprehensive search strategies developed for each database. Estimates of sensitivity and specificity were plotted in ROC space graphs and pooled across studies. Our search identified three studies which assessed the prediction properties of falls prediction tools in a total of 754 elderly inpatients in rehabilitation hospitals. Only the STRATIFY tool was assessed in all three studies; the other identified tools (PJC-FRAT and DOWNTON) were assessed by a single study. For a STRATIFY cut-score of two, pooled sensitivity was 73% (95%CI 63 to 81%) and pooled specificity was 42% (95%CI 34 to 51%). An indirect comparison of the tools across studies indicated that the DOWNTON tool has the highest sensitivity (92%), while the PJC-FRAT offers the best balance between sensitivity and specificity (73% and 75%, respectively). All studies presented major methodological limitations. Conclusions We did not identify any tool which had an optimal balance between sensitivity and specificity, or which were clearly better than a simple clinical judgment of risk of falling. The limited number of identified studies with major methodological limitations impairs sound conclusions on the usefulness of falls risk prediction tools in geriatric rehabilitation hospitals.

Effect of Methodological and Ecological Approaches on Heterogeneity of Nest-Site Selection of a Long-Lived Vulture

The application of scientific-based conservation measures requires that sampling methodologies in studies modelling similar ecological aspects produce comparable results making easier their interpretation. We aimed to show how the choice of different methodological and ecological approaches can affect conclusions in nest-site selection studies along different Palearctic meta-populations of an indicator species. First, a multivariate analysis of the variables affecting nest-site selection in a breeding colony of cinereous vulture (Aegypius monachus) in central Spain was performed. Then, a meta-analysis was applied to establish how methodological and habitat-type factors determine differences and similarities in the results obtained by previous studies that have modelled the forest breeding habitat of the species. Our results revealed patterns in nesting-habitat modelling by the cinereous vulture throughout its whole range: steep and south-facing slopes, great cover of large trees and distance to human activities were generally selected. The ratio and situation of the studied plots (nests/random), the use of plots vs. polygons as sampling units and the number of years of data set determined the variability explained by the model. Moreover, a greater size of the breeding colony implied that ecological and geomorphological variables at landscape level were more influential. Additionally, human activities affected in greater proportion to colonies situated in Mediterranean forests. For the first time, a meta-analysis regarding the factors determining nest-site selection heterogeneity for a single species at broad scale was achieved. It is essential to homogenize and coordinate experimental design in modelling the selection of species' ecological requirements in order to avoid that differences in results among studies would be due to methodological heterogeneity. This would optimize best conservation and management practices for habitats and species in a global context.

Risk of adverse effects of intensified treatment in insulin-dependent diabetes mellitus: a meta-analysis

While the benefits of intensified insulin treatment in insulin-dependent (Type 1) diabetes mellitus (IDDM) are well recognized, the risks have not been comprehensively characterized. We examined the risk of severe hypoglycaemia, ketoacidosis, and death in a meta-analysis of randomized controlled trials. The MEDLINE database, reference lists, and specialist journals were searched electronically or by hand to identify relevant studies with at least 6 months of follow-up and the monitoring of glycaemia by glycosylated haemoglobin measurements. Logistic regression was used for calculation of combined odds ratios and 95% confidence intervals (95% CI). The influence of covariates was examined by including covariate-by-treatment interaction terms. Methodological study quality was assessed and sensitivity analyses were performed. Fourteen trials were identified. These contributed 16 comparisons with 1028 patients allocated to intensified and 1039 allocated to conventional treatment. A total of 846 patients suffered at least one episode of severe hypoglycaemia, 175 patients experienced ketoacidosis and 26 patients died. The combined odds ratio (95% CI) for hypoglycaemia was 2.99 (2.45-3.64), for ketoacidosis 1.74 (1.27-2.38) and for death from all causes 1.40 (0.65-3.01). The risk of severe hypoglycaemia was determined by the degree of normalization of glycaemia achieved (p=0.005 for interaction term), with the results from the Diabetes Control and Complications Trial (DCCT) in line with the other trials. Ketoacidosis risk depended on the type of intensified treatment used. Odds ratios (95% CI) were 7.20 (2.95-17.58) for exclusive use of pumps, 1.13 (0.15-8.35) for multiple daily injections and 1.28 (0.90-1.83) for trials offering a choice between the two (p = 0.004 for interaction). Mortality was significantly (p = 0.007) increased for causes potentially associated with acute complications (7 vs 0 deaths, 5 deaths attributed to ketoacidosis, and 2 sudden deaths), and non-significantly (p = 0.16) decreased for macrovascular causes (3 vs 8 deaths). We conclude that there is a substantial risk of severe adverse effects associated with intensified insulin treatment. Mortality from acute metabolic causes is increased; however, this is largely counterbalanced by a reduction in cardiovascular mortality. The excess of severe hypoglycemia in the DCCT is not exceptional. Multiple daily injection schemes may be safer than treatment with insulin pumps.