Coupling of unsaturated and saturated flow modelling - a strong point of the small research catchment Uhlířská

Modelling results in the small (1.78 km2) experimental catchment Uhlířská located in the northern part of the Czech Republic at the average elevation of 822 m a.s.l. are presented. While the basic hydrological and meteorological monitoring has started already in 1982, investigation of the subsurface flow adjoined in 1995. A detailed survey of water and isotope (18O, 2H, 3H, 3H/3He) fluxes across the catchment storage compartments has been in operation since 2006. The combined vadose/saturated zones modeling with support of partial extrapolation of 18O content in precipitation yielded the following mean balance for the period 1961-2014: 456 out of 1220 mm annual precipitation depth are percolating through the soil matrix domain and 534 mm through the preferential domain in the hillslope soil profile. The saturated zone is recharged annually by 416 mm, consisting of the entire matrix flow and 12,5 % of the preferential flow from the permeable hillslopes covered by Cambisols and Podzols, as well as by the contribution of 22 mm from the less permeable riparian wetland Histosols. The aquifer geometry was determined by means of electrical resistivity tomography (ERT) including inverse modelling (RES2DINV). Water and isotope fluxes were computed using a sequence of models. They include S1D software for the vadose zone modeling including 18O transport and Modflow, Modpath and MT3DS determining residence time and flow trajectories in the saturated zone. Isotopes 3H and 3H/3He improved the model confidence. The water residence time on the hillslopes does not exceed 1 year, while the saturated zone indicates about 10 years, with a 20% portion of water older than 100 years in the deepest part of the aquifer. The combination of numerical modelling approaches with computation of water balance and isotope-supported calibration is considered innovative, particularly the 3H/3He method to determine water residence times of young groundwater in the saturated zone.

Nine types of recommendations, guidelines and policies: an exploratory test of a proposed typology of physical activity promotion documents

Background The field of physical activity abounds with recommendations, guidelines, action plans and other documents published by experts, organizations and institutions at the national and international level. However, working with these documents is difficult since similar names (e.g. “recommendations”) may be used to label substantially different contents, while identical topics may hide behind different monikers (e.g. “guidelines” and “strategy”). Methods We built on an existing framework conceptualizing categories of physical activity evidence and on the Doern continuum for policy instruments to develop a nine-field matrix that classifies physical activity-related publications based on their evidence type and degree of coercion. We used a selection of eleven physical activity documents to perform an exploratory test of the functions and utility of the typology. Results Placing central physical activity documents into the typology shows that recommendations, guidelines, and policies are found across the entire matrix, regardless of their denomination. It also suggests that some documents transcend boundaries between types by falling into more than one category, and that some categories may be underrepresented in current physical activity promotion. Conclusions A typology to classify physical activity guidelines, recommendations, and policies can help us acquire a better overview of the landscape of existing physical activity documents than simple distinctions based on document names. It may guide both current initiatives and future development work in the field. It could also serve as a point of departure for future research, as conducting systematic overviews of the literature based on this typology may help reveal important gaps in current physical activity promotion.

Craniodental and Postcranial Characters of Non-Avian Dinosauria Often Imply Different Trees

Despite the increasing importance of molecular sequence data, morphology still makes an important contribution to resolving the phylogeny of many groups, and is the only source of data for most fossils. Most systematists sample morphological characters as broadly as possible on the principle of total evidence. However, it is not uncommon for sampling to be focused on particular aspects of anatomy, either because characters therein are believed to be more informative, or because preservation biases restrict what is available. Empirically, the optimal trees from partitions of morphological data sets often represent significantly different hypotheses of relationships. Previous work on hard-part versus soft-part characters across animal phyla revealed significant differences in about a half of sampled studies. Similarly, studies of the craniodental versus postcranial characters of vertebrates revealed significantly different trees in about one-third of cases, with the highest rates observed in non-avian dinosaurs. We test whether this is a generality here with a much larger sample of 81 published data matrices across all major dinosaur groups. Using the incongruence length difference test and two variants of the incongruence relationship difference test, we found significant incongruence in about 50% of cases. Incongruence is not uniformly distributed across major dinosaur clades, being highest (63%) in Theropoda and lowest (25%) in Thyreophora. As in previous studies, our partition tests show some sensitivity to matrix dimensions and the amount and distribution of missing entries. Levels of homoplasy and retained synapomorphy are similar between partitions, such that incongruence must partly reflect differences in patterns of homoplasy between partitions, which may itself be a function of modularity and mosaic evolution. Finally, we implement new tests to determine which partition yields trees most similar to those from the entire matrix. Despite no bias across dinosaurs overall, there are striking differences between major groups. The craniodental characters of Ornithischia and the postcranial characters of Saurischia yield trees most similar to the “total evidence” trees derived from the entire matrix. Trees from these same character partitions also tend to be most stratigraphically congruent: a mutual consilience suggesting that those partitions yield more accurate trees. [Dinosauria; homoplasy; partition homogeneity.]

Conservation of the numbers of characteristic values of polynomial and entire matrix pencils inside and outside a circle under perturbations

Let [Formula: see text] and [Formula: see text] be entire matrix-valued functions of a complex argument [Formula: see text] (entire matrix pencils) and [Formula: see text]. Let [Formula: see text] and [Formula: see text] denote the numbers of the characteristic values of [Formula: see text] taken with their multiplicities located inside and outside [Formula: see text], respectively. Besides [Formula: see text] can be infinite. We consider the following problem: how “close” should be [Formula: see text] and [Formula: see text] in order to provide the equalities [Formula: see text] and [Formula: see text]? We restrict ourselves by the entire pencils of order not more than two. Our results are new even for polynomial pencils.

The accuracy and bias of single-step genomic prediction for populations under selection

ABSTRACTIn single-step analyses, missing genotypes are explicitly or implicitly imputed, and this requires centering the observed genotypes, ideally using the mean of the unselected founders. If genotypes are only available on selected individuals, centering on the unselected founder mean is impossible. Here, computer simulation is used to study an alternative analysis that does not require centering genotypes but fits the mean µg of unselected individuals as a fixed effect. To improve numerical properties of the analysis, centering the entire matrix of observed and imputed genotypes, using their sample means can be done in addition to fitting µg. Starting with observed diplotypes from 721 cattle, a 5 generation population was simulated with sire selection to produce 40,000 individuals with phenotypes of which the 1,000 sires had genotypes. The next generation of 8,000 genotyped individuals was used for validation. Evaluations were undertaken: with (J) or without (N) µg when marker covariates were not centered; and with (JC) or without (C) µg when all marker covariates were centered. A pedigree based evaluation was less accurate than genomic analyses. Centering did not influence accuracy of genomic prediction, but fitting µg did. Accuracies were improved when the panel comprised only QTL, models JC and J had accuracies of 99.2%; and models C and N had accuracies of 85.6%. When only markers were in the panel, the 4 models had accuracies of 63.9%. In panels that included causal variants, fitting µg in the model improved accuracy, but had little impact when the panel contained only markers.

Sampling and Homogenization Strategies Significantly Influence the Detection of Foodborne Pathogens in Meat

Efficient preparation of food samples, comprising sampling and homogenization, for microbiological testing is an essential, yet largely neglected, component of foodstuff control.Salmonella entericaspiked chicken breasts were used as a surface contamination model whereas salami and meat paste acted as models of inner-matrix contamination. A systematic comparison of different homogenization approaches, namely, stomaching, sonication, and milling by FastPrep-24 or SpeedMill, revealed that for surface contamination a broad range of sample pretreatment steps is applicable and loss of culturability due to the homogenization procedure is marginal. In contrast, for inner-matrix contamination long treatments up to 8 min are required and only FastPrep-24 as a large-volume milling device produced consistently good recovery rates. In addition, sampling of different regions of the spiked sausages showed that pathogens are not necessarily homogenously distributed throughout the entire matrix. Instead, in meat paste the core region contained considerably more pathogens compared to the rim, whereas in the salamis the distribution was more even with an increased concentration within the intermediate region of the sausages. Our results indicate that sampling and homogenization as integral parts of food microbiology and monitoring deserve more attention to further improve food safety.

Complex Matrix Remodeling and Durotaxis Can Emerge From Simple Rules for Cell-Matrix Interaction in Agent-Based Models

Using a top-down approach, an agent-based model was developed within Netlogo where cells and extracellular matrix (ECM) fibers were composed of multiple agents to create deformable structures capable of exerting, reacting to and transmitting mechanical forces. Simulated cells remodeled the fibrous matrix to change both the density and alignment of the fibers and migrated within the matrix in ways that are consistent with previous experimental work. Cells compacted the matrix in their pericellular regions much more than the average compaction experienced for the entire matrix. Between pairs of cells, the anisotropy index increased, fibers became more aligned in the direction parallel to a line connecting the two cells and the matrix density increased. To explore the potential contribution of matrix stiffness gradients in the observed migration (i.e., durotaxis), a single-cell on a regular lattice of fibers possessing a stiffness gradient was simulated. Cells migrated preferentially in the direction of increasing stiffness at a rate of ∼2 cell diameter per 10,000 AU. This work demonstrates that matrix remodeling and durotaxis, both complex phenomena, might be emergent behaviors based on just a few rules that control how a cell can interact with a fibrous ECM.

Representing Meta-Artifacts

The concept of a design theory includes, among others, the components of meta-requirements and meta-systems. As an artifact, according to Simon, it is characterized in terms of its outer and inner environments, and the interface, design-type research projects may focus on one or another aspects of meta-artifacts. The purpose of this chapter is to describe a representational framework incorporating different views of meta-artifacts. The chapter introduces such a framework based on Zachman’s model for information architecture. The two dimensional model includes perspectives and categories dimensions. The former is defined in terms of four layers, including analytical, synthetic, technological, and implementation layers. The latter includes the categories of motivation, structure, behavior, and instantiation. At each layer alternative meta-artifact conceptualizations may be proposed by different researchers, implying a third dimension in the framework. A complete design research work on any given layer would correspond to a research project. A work targeting the entire matrix would constitute a design-type research program. Efforts by different design researchers on alternative conceptualizations could be regarded as research stream.

Imaging diffraction points using the local image matrices generated in prestack migration

Energy-angle distributions in the local image matrix, which is a function of local incident and receiving angles at a subsurface point, are different for a planar reflector and a diffraction point. The former exhibits a linear distribution along a certain dip direction, whereas the latter shows a scattered distribution in the entire matrix. Therefore, the singular values of the local image matrix in the local angle domain indicate the energy distribution along different dip directions. The difference between the auto- and crosscorrelation coefficients of the sets of singular values between adjacent image points can be used to distinguish these two types of targets and obtain prestack images which contain only diffraction points. Using three synthetic examples, we found that the method can effectively image diffraction points. Seismic images of diffraction points may provide important information about geological discontinuities and diffraction points can be taken as secondary sources for potential applications in imaging subsalt structures which are poorly illuminated by primary waves.