Hello, world! VIVA+: A human body model lineup to evaluate sex-differences in crash protection

Finite element Human Body Models are increasingly becoming vital tools for injury assessment and are expected to play an important role in virtual vehicle safety testing. With the aim of realizing models to study sex-differences seen in the injury- and fatality-risks from epidemiology, we developed models that represent an average female and an average male. The models were developed with an objective to allow tissue-based skeletal injury assessment, and thus non-skeletal organs and joints were defined with simplified characterizations to enhance computational efficiency and robustness. The model lineup comprises female and male representations of (seated) vehicle occupants and (standing) vulnerable road users, enabling the safety assessment of broader segments of the road user population. In addition, a new workflow utilized in the model development is presented. In this workflow, one model (the seated female) served as the base model while all the other models were generated as closely-linked derivative models, differing only in terms of node coordinates and mass distribution. This approach opens new possibilities to develop and maintain further models as part of the model lineup, representing different types of road users to reflect the ongoing transitions in mobility patterns (like bicyclists and e-scooter users). In this paper, we evaluate the kinetic and kinematic responses of the occupant and standing models to blunt impacts, mainly on the torso, in different directions (front, lateral, and back). The front and lateral impacts to the thorax showed responses comparable to the experiments, while the back impact varied with the location of impact (T1 and T8). Abdomen bar impact showed a stiffer load-deflection response at higher intrusions beyond 40\ua0mm, because of simplified representation of internal organs. The lateral shoulder impact responses were also slightly stiffer, presumably from the simplified shoulder joint definition. This paper is the first in a series describing the development and validation of the new Human Body Model lineup, VIVA+. With the inclusion of an average-sized female model as a standard model in the lineup, we seek to foster an equitable injury evaluation in future virtual safety assessments

Computational homogenization of microfractured continua using weakly periodic boundary conditions

Abstract Computational homogenization of elastic media with stationary cracks is considered, whereby the macroscale stress is obtained by solving a boundary value problem on a Statistical Volume Element (SVE) and the cracks are represented by means of the eXtended Finite Element Method (XFEM). With the presence of cracks on the microscale, conventional BCs (Dirichlet, Neumann, strong periodic) perform poorly, in particular when cracks intersect the SVE boundary. As a remedy, we herein propose to use a mixed variational format to impose periodic boundary conditions in a weak sense on the SVE. Within this framework, we develop a novel traction approximation that is suitable when cracks intersect the SVE boundary. Our main result is the proposition of a stable traction approximation that is piecewise constant between crack-boundary intersections. In particular, we prove analytically that the proposed approximation is stable in terms of the LBB (inf-sup) condition and illustrate the stability properties with a numerical example. We emphasize that the stability analysis is carried out within the setting of weakly periodic boundary conditions, but it also applies to other mixed problems with similar structure, e.g. contact problems. The numerical ex- * Corresponding author. Email address: [email protected] (Erik Svenning) Preprint submitted to Comput. Methods Appl. Mech. Engrg. November 18, 2015 amples show that the proposed traction approximation is more efficient than conventional boundary conditions (Dirichlet, Neumann, strong periodic) in terms of convergence with increasing SVE size

Introduction of the VIVA+ Vulnerable Road User Models

Project VIRTUALOpen access virtual testing protocols for enhanced road user safety\ua0using Human Body Model

Gillnet catchability of brown trout Salmo trutta is highly dependent on fish size and capture site

Use of experimental gillnet fleets is common both in scientific studies of fish populations and in fish sampling for management purposes. Fish catchability may vary considerably with fish and gillnet mesh size, and catches obtained by gillnet fleets composed of nets with different mesh sizes may give length and age distributions that deviate considerably from the length and age structure of the population. We have estimated the absolute catchability of allopatric brown trout (Salmo trutta) in the littoral and pelagic habitat of a small lake based on a mark-recapture experiment. The brown trout catchability varied considerably both with fish size and habitat type, probably due to a size-related variation in swimming distance per time unit and a size-related use of the different lentic habitats. The sampling bias in experimental gillnet fishing may be reduced by operating the gillnet fleets in all possible lentic habitats and most fundamentally, by use of catchability data obtained from populations with ‘known’ length and age structures. By reducing this sampling bias, more realistic estimations of the age and length distribution for a given population will be possible

Identification and evolution of a plant cell wall specific glycoprotein glycosyl transferase, ExAD

Extensins are plant cell wall glycoproteins that act as scaffolds for the deposition of the main wall carbohydrate polymers, which are interlocked into the supramolecular wall structure through intra- and inter-molecular iso-di-tyrosine crosslinks within the extensin backbone. In the conserved canonical extensin repeat, Ser-Hyp(4), serine and the consecutive C4-hydroxyprolines (Hyps) are substituted with an α-galactose and 1–5 β- or α-linked arabinofuranoses (Arafs), respectively. These modifications are required for correct extended structure and function of the extensin network. Here, we identified a single Arabidopsis thaliana gene, At3g57630, in clade E of the inverting Glycosyltransferase family GT47 as a candidate for the transfer of Araf to Hyp-arabinofuranotriose (Hyp-β1,4Araf-β1,2Araf-β1,2Araf) side chains in an α-linkage, to yield Hyp-Araf(4) which is exclusively found in extensins. T-DNA knock-out mutants of At3g57630 showed a truncated root hair phenotype, as seen for mutants of all hitherto characterized extensin glycosylation enzymes; both root hair and glycan phenotypes were restored upon reintroduction of At3g57630. At3g57630 was named Extensin Arabinose Deficient transferase, ExAD, accordingly. The occurrence of ExAD orthologs within the Viridiplantae along with its’ product, Hyp-Araf(4), point to ExAD being an evolutionary hallmark of terrestrial plants and charophyte green algae

Less favourable climates constrain demographic strategies in plants

Correlative species distribution models are based on the observed relationship between species’ occurrence and macroclimate or other environmental variables. In climates predicted less favourable populations are expected to decline, and in favourable climates they are expected to persist. However, little comparative empirical support exists for a relationship between predicted climate suitability and population performance. We found that the performance of 93 populations of 34 plant species worldwide – as measured by in situ population growth rate, its temporal variation and extinction risk – was not correlated with climate suitability. However, correlations of demographic processes underpinning population performance with climate suitability indicated both resistance and vulnerability pathways of population responses to climate: in less suitable climates, plants experienced greater retrogression (resistance pathway) and greater variability in some demographic rates (vulnerability pathway). While a range of demographic strategies occur within species’ climatic niches, demographic strategies are more constrained in climates predicted to be less suitable

The relationship between niche breadth and range size of beech (Fagus) species worldwide

Aim: This work explores whether the commonly observed positive range size–niche breadth relationship exists for Fagus, one of the most dominant and widespread broad-leaved deciduous tree genera in temperate forests of the Northern Hemisphere. Additionally, we ask whether the 10 extant Fagus species’ niche breadths and climatic tolerances are under phylogenetic control. Location: Northern Hemisphere temperate forests. Taxon: Fagus L. Methods: Combining the global vegetation database sPlot with Chinese vegetation data, we extracted 107,758 relevés containing Fagus species. We estimated biotic and climatic niche breadths per species using plot-based co-occurrence data and a resource-based approach, respectively. We examined the relationships of these estimates with range size and tested for their phylogenetic signal, prior to which a Random Forest (RF) analysis was applied to test which climatic properties are most conserved across the Fagus species. Results: Neither biotic niche breadth nor climatic niche breadth was correlated with range size, and the two niche breadths were incongruent as well. Notably, the widespread North American F. grandifolia had a distinctly smaller biotic niche breadth than the Chinese Fagus species (F. engleriana, F. hayatae, F. longipetiolata and F. lucida) with restricted distributions in isolated mountains. The RF analysis revealed that cold tolerance did not differ among the 10 species, and thus may represent an ancestral, fixed trait. In addition, neither biotic nor climatic niche breadths are under phylogenetic control. Main Conclusions: We interpret the lack of a general positive range size–niche breadth relationship within the genus Fagus as a result of the widespread distribution, high among-region variation in available niche space, landscape heterogeneity and Quaternary history. The results hold when estimating niche sizes either by fine-scale co-occurrence data or coarse-scale climate data, suggesting a mechanistic link between factors operating across spatial scales. Besides, there was no evidence for diverging ecological specialization within the genus Fagus

TRY plant trait database – enhanced coverage and open access

Plant traits - the morphological, anatomical, physiological, biochemical and phenological characteristics of plants - determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait‐based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits - almost complete coverage for ‘plant growth form’. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait–environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

On computational homogenization of fracturing continua

Ductile fracture is important to control in many industrial processes, be it a desired phenomenon (e.g. in metal cutting) or a failure to be prevented (e.g. in structures subject to blast loading). Increased understanding of the fracture processes can be gained by using computational homogenization, where the nucleation and growth of microscopic cracks is explicitly modeled and included in the effective response of a Statistical Volume Element (SVE). Choosing suitable boundary conditions on the SVE is challenging, because conventional boundary conditions (Dirichlet, Neumann and strong periodic) are inaccurate when cracks are present in the SVE. In the present work, we instead impose periodic boundary conditions in a weak sense on the SVE, leading to a mixed variational format with displacements and boundary tractions as unknowns. By constructing a suitable traction approximation, the boundary conditions can be adapted to the problem at hand in order to gain improved convergence. To this end, we propose a stable traction approximation that is piecewise constant between crack-boundary intersections and we show analytically that the LBB (inf-sup) condition is fulfilled for the proposed approximation.The weakly periodic boundary conditions are combined with the eXtended Finite Element Method (XFEM), cohesive zones and the concept of material forces to perform numerical simulations of materials undergoing crack propagation on the microscale. The numerical examples show that weakly periodic boundary conditions with a suitably chosen traction approximation are more efficient than conventional boundary conditions in terms of convergence with increasing SVE size. This observation holds for stationary cracks as well as for propagating cracks.The work presented in this thesis is concerned with homogenization of damage evolution prior to localization, which is a prerequisite for accurate multiscale modeling of localization

The Impetuous Voice of Reason : Emotion versus reason in moral decision-making

This is a review of what the currently dominant theories of moral decision-making are and where they derive from. While the introduction serves as a common ground to explain what moral decision-making is, the earlier parts of the thesis describe older traditionalist theories within the field,  theories of emotional decision-making, in the form of the somatic marker hypothesis, as well as critique of the older traditionalist theories through the social intuitionist model. Both of these two theories are explained as the foundation of the current theories of moral decision-making and after establishing a clear basis on what the currently dominant theories of moral decision-making are built on, said theories are introduced in the form of the dual-processing theory and the event-feature-emotion complexes which are thoroughly reviewed, explained in detail and serves as the core of the text. This is afterward followed by criticism as well as arguments in favor of both theories as well as criticisms from other researchers who disagree with the methodology which the theories of moral decision-making are conducted on. The essay reviews the current state of the field of moral decision-making which has been split up into two different approaches, the locationist approach and the constructionist approach. The essay concludes that there are terms which needs to be clarified in order for the field to move forward and studies to be made regarding the social implications of gut reactions in moral decision-making