SLIP4EX- a program for routine slope stability analysis to include the effects of vegetation, reinforcement and hydrological changes

SLIP4EX is a straightforward computer program developed in connection with the EU funded ECOSLOPES project for routine stability analysis and the assessment of the contribution of vegetation to slope stability. The slope section is drawn up and dimensions and parameters are fed in to the Microsoft Excel based program for stability calculations and comparisons of Factors of Safety using different methods of analysis (Bishop, Janbu, Fellenius, Simple, Greenwood). The background and assumptions involved in the derivation of each of the methods is briefly described. The simplicity of the program enables the user to understand the nature of the analysis, explore the parameter assumptions made and compare the different methods of analysis. Soil reinforcement by geosynthetic layers or anchors, and vegetation effects of enhanced cohesion, changed water pressures, mass of vegetation, wind forces and root reinforcement forces are readily included in the analysis. The program is freely available on request from the author

Tuning properties of radial phantom motion aftereffects

AbstractMotion aftereffects are normally tested in regions of the visual field that have been directly exposed to motion (local or concrete MAEs). We compared concrete MAEs with remote or phantom MAEs, in which motion is perceived in regions not previously adapted to motion. Our aim was to study the spatial dependencies and spatiotemporal tuning of phantom MAEs generated by radially expanding stimuli. For concrete and phantom MAEs, peripheral stimuli generated stronger aftereffects than central stimuli. Concrete MAEs display temporal frequency tuning, while phantom MAEs do not show categorical temporal frequency or velocity tuning. We found that subjects may use different response strategies to determine motion direction when presented with different stimulus sizes. In some subjects, as adapting stimulus size increased, phantom MAE strength increased while the concrete MAE strength decreased; in other subjects, the opposite effects were observed. We hypothesise that these opposing findings reflect interplay between the adaptation of global motion sensors and local motion sensors with inhibitory interconnections

Site investigation for the effects of vegetation on ground stability

The procedure for geotechnical site investigation is well established but little attention is currently given to investigating the potential of vegetation to assist with ground stability. This paper describes how routine investigation procedures may be adapted to consider the effects of the vegetation. It is recommended that the major part of the vegetation investigation is carried out, at relatively low cost, during the preliminary (desk) study phase of the investigation when there is maximum flexibility to take account of findings in the proposed design and construction. The techniques available for investigation of the effects of vegetation are reviewed and references provided for further consideration. As for general geotechnical investigation work, it is important that a balance of effort is maintained in the vegetation investigation between (a) site characterisation (defining and identifying the existing and proposed vegetation to suit the site and ground conditions), (b) testing (in-situ and laboratory testing of the vegetation and root systems to provide design parameters) and (c) modelling (to analyse the vegetation effects)

Investigation into diagnostic accuracy of common strategies for automated perfusion motion correction

Respiratory motion is a significant obstacle to the use of quantitative perfusion in clinical practice. Increasingly complex motion correction algorithms are being developed to correct for respiratory motion. However, the impact of these improvements on the final diagnosis of ischemic heart disease has not been evaluated. The aim of this study was to compare the performance of four automated correction methods in terms of their impact on diagnostic accuracy. Three strategies for motion correction were used: (1) independent translation correction for all slices, (2) translation correction for the basal slice with transform propagation to the remaining two slices assuming identical motion in the remaining slices, and (3) rigid correction (translation and rotation) for the basal slice. There were no significant differences in diagnostic accuracy between the manual and automatic motion-corrected datasets (p=0.88). The area under the curve values for manual motion correction and automatic motion correction were 0.93 and 0.92, respectively. All of the automated motion correction methods achieved a comparable diagnostic accuracy to manual correction. This suggests that the simplest automated motion correction method (method 2 with translation transform for basal location and transform propagation to the remaining slices) is a sufficiently complex motion correction method for use in quantitative myocardial perfusion

Shoot yield drives phosphorus use efficiency in Brassica oleracea and correlates with root architecture traits

The environmental and financial costs of using inorganic phosphate fertilizers to maintain crop yield and quality are high. Breeding crops that acquire and use phosphorus (P) more efficiently could reduce these costs. The variation in shoot P concentration (shoot-P) and various measures of P use efficiency (PUE) were quantified among 355 Brassica oleracea L. accessions, 74 current commercial cultivars, and 90 doubled haploid (DH) mapping lines from a reference genetic mapping population. Accessions were grown at two or more external P concentrations in glasshouse experiments; commercial and DH accessions were also grown in replicated field experiments. Within the substantial species-wide diversity observed for shoot-P and various measures of PUE in B. oleracea, current commercial cultivars have greater PUE than would be expected by chance. This may be a consequence of breeding for increased yield, which is a significant component of most measures of PUE, or early establishment. Root development and architecture correlate with PUE; in particular, lateral root number, length, and growth rate. Significant quantitative trait loci associated with shoot-P and PUE occur on chromosomes C3 and C7. These data provide information to initiate breeding programmes to improve PUE in B. oleracea

PoLAR-FIT: Pliocene Landscapes and Arctic Remains—Frozen in Time

This short summary presents selected results of an ongoing investigation into the feedbacks that contribute to amplified Arctic warming. The consequences of warming for Arctic biodiversity and landscape response to global warmth are currently being interpreted. Arctic North American records of large-scale landscape and paleoenvironmental change during the Pliocene are exquisitely preserved and locked in permafrost, providing an opportunity for paleoenvironmental and faunal reconstruction with unprecedented quality and resolution. During a period of mean global temperatures only ~2.5°C above modern, the Pliocene molecular, isotopic, tree-ring, paleofaunal, and paleofloral records indicate that the high Arctic mean annual temperature was 11°C–19°C above modern values, pointing to a much shallower latitudinal temperature gradient than exists today. It appears that the intense Neogene warming caused thawing and weathering to liberate sediment and create a continuous and thick (>2.5 km in places) clastic wedge from at least Banks Island to Meighen Island to form a coastal plain that provided a highway for camels and other mammals to migrate and evolve in the high Arctic. In this summary we highlight the opportunities that exist for research on these and related topics with the PoLAR-FIT community.RÉSUMÉCe bref résumé présente les résultats choisis d'une enquête en cours sur les déclencheurs qui contribuent à l’amplification du réchauffement de l'Arctique. Les conséquences du réchauffement sur la biodiversité arctique et de la réponse du paysage au réchauffement climatique sont en cours d’être interprété. Des dossiers nord-américains de paysage à grande échelle et le changement paléoenvironnementales durant le Pliocène sont exceptionnellement préservés et scellées dans un état de congélation qui fournissant une occasion pour la reconstruction paléoenvironnementale et faunistique avec une qualité et une résolution sans précédent. Pendent une période de réchauffement global seulement ~2,5°C au-dessus de moderne les dossiers, moléculaire, isotopique, annaux de croissance, paléofaunistique et paléovégétation indiquent que l'Arctique a connu une augmentation de la température annuelle moyenne de 11°C–19°C au-dessus de moderne, en montrant un inferieur gradient de température latitudinal qu'aujourd'hui. Il semble que le réchauffement intense pendent le Néogène a provoqué la décongélation et erosion pour libérer les sédiments et créer une plaine côtière continuel et épaisse (> 2,5 km dans lieux) qui a fourni une route pour les chameaux et autres mammifères pour migrer et évoluer dans l’Haut-Arctique. Dans ce résumé, nous soulignons les opportunités qui existent pour la recherche sur ces sujets et les sujets connexes avec la communauté PoLAR-FIT