Qualitative Congruence Research Articles

Advanced modeling of higher-order kinematic hardening in strain gradient crystal plasticity based on discrete dislocation dynamics

An extensive study of size effects on the small-scale behavior of crystalline materials is carried out through discrete dislocation dynamics (DDD) simulations, intended to enrich strain gradient crystal plasticity (SGCP) theories. These simulations include cyclic shearing and tension-compression tests on two-dimensional (2D) constrained crystalline plates, with single- and double-slip systems. The results show significant material strengthening and pronounced kinematic hardening effects. DDD modeling allows for a detailed examination of the physical origin of the strengthening. The stress–strain responses show a two-stage behavior, starting with a micro-plasticity regime with a steep hardening slope leading to strengthening, and followed by a well-established hardening stage. The scaling exponent between the apparent (higher-order) yield stress and the geometrical size h varies depending on the test type. Scaling relationships of h−0.2 and h−0.3 are obtained for respectively constrained shearing and constrained tension-compression, aligning with some experimental observations. Notably, the DDD simulations reveal the occurrence of the uncommon type III (KIII) kinematic hardening of Asaro in both single- and double-slip cases, emphasizing the relevance of this hardening type in the realm of small-scale plasticity. Inspired by insights from DDD, two advanced SGCP models incorporating alternative descriptions of higher-order kinematic hardening mechanisms are proposed. The first model uses a Prager-type higher-order kinematic hardening formulation, and the second employs a Chaboche-type (multi-kinematic) formulation. Comparison of these models with DDD simulation results underscores their ability to effectively capture the observed strengthening and hardening effects. The multi-kinematic model, through the use of quadratic and non-quadratic higher-order potentials, shows a notably better qualitative congruence with DDD findings. This represents a significant step towards accurate modeling of small-scale material behaviors. However, it is noted that the proposed models still have limitations, especially in matching the DDD scaling exponents, with both models producing h−1 scaling relationships (i.e., Orowan relationship for precipitate size effects). This indicates the need for further improvements in gradient-enhanced theories in order to guarantee their suitability for practical engineering applications.

When Populist Leaders Govern: Conceptualising Populism in Policy Making

The rise of populist governance throughout the world offers a novel opportunity to study the way in which populist leaders and parties rule. This article conceptualises populist policy making by theoretically addressing the substantive and discursive components of populist policies and the decision-making processes of populist governments. It first reconstructs the implicit ideal type of policy making in liberal democracies based on the mainstream governance and policy making scholarship. Then, taking stock of the recent populism literature, the article elaborates an ideal type of populist policy making along the dimensions of content, procedures and discourses. As an empirical illustration we apply a qualitative congruence analysis to assess the conformity of a genuine case of populist governance, social policy in post-2010 Hungary with the populist policy making ideal type. Concerning the policy content, the article argues that policy heterodoxy, strong willingness to adopt paradigmatic reforms and an excessive responsiveness to majoritarian preferences are distinguishing features of any type of populist policies. Regarding the procedural features populist leaders tend to downplay the role of technocratic expertise, sideline veto-players and implement fast and unpredictable policy changes. Discursively, populist leaders tend to extensively use crisis frames and discursive governance instruments in a Manichean language and a saliently emotional manner that reinforces polarisation in policy positions. Finally, the article suggests that policy making patterns in Hungarian social policy between 2010 and 2018 have been largely congruent with the ideal type of populist policy making.

Accuracy between virtual surgical planning and actual outcomes in orthognathic surgery by iterative closest point algorithm and color maps: A retrospective cohort study.

BackgroundTo evaluate the accuracy between actual outcomes and virtual surgical planning (VSP) in orthognathic surgery regarding the use of three-dimensional (3D) surface models for registration using iterative closest point (ICP) algorithm and generated color maps.Material and MethodsConstruction of planning and postoperative 3D models in STL files format (M0 and M1, respectively) from CBCT of 25 subjects who had been submitted to bimaxillary orthognathic surgery was performed. M0 and M1 were sent to Geomagic software in semi-automatic alignment surface mesh order of M0 and M1 for registration using ICP algorithm to calculate mean deviation (MD, MD+, MD-, SD) and root mean square (RMS – 3D Error). Color maps were generated to assess qualitative congruence between M0 and M1. From deviation analysis, 3D Error was defined as accuracy measurement. To assess the reproducibility, the workflow was performed by two evaluators multiple times. t-tests were used to assess whether all means of MD, MD+, MD-, SD and 3D Error values would be ≤ - 2 mm and ≥ 2 mm.ResultsHigh intra and inter evaluators correlation were found, supporting the reproducibility of the workflow. t-tests proved that all MDs and 3D Error values were > - 2 mm and < 2 mm.Conclusions3D error mean was within the standards of clinical success lower than 2 mm. ICP algorithm provided a reproducible method of alignment between 3D models and generated color maps to evaluate 3D congruence but did not answer all methodological parameters regarding the assessment of accuracy in orthognathic surgery. Key words:Accuracy, Cone-Beam computed tomography, CAD-CAM, Orthognathic surgery, three-dimensional imaging.

Design and Evaluation of a Low-Power Sensor Device for Induced Rockfall Experiments

Rockfalls have over the last decades become a serious and frequent hazard, especially due to larger variations in precipitation and temperatures, destabilizing rocky slopes in mountainous regions. Hence, civil engineers are applying the latest simulation tools to perform risk assessments and plan mitigation strategies. These tools are based on various models with many parameters that should be calibrated and evaluated with real-world in-field measurement data. In this paper, we present a rugged low-power multisensor node termed StoneNode that has been designed to acquire and log accurate inertial sensor measurements during induced in-field experiments with falling rocks. The node hosts low-power microelectromechanical system sensors with high dynamic ranges sampled up to 1 kHz, and provides a long battery lifetime of up to 56 h, enabling long-lasting field studies with a duration of several working days. Exhaustive in-field experiments have been carried out with several differently shaped rocks on typical terrain in the Swiss alpine region. The experiments comprise more than 100 induced tests with several heavy impacts of >400 g. This paper gives a detailed summary of these results, including unprecedented in situ data of rockfall trajectories and postexperimental validation where we compare simulated rockfall deposition distributions and motion traces with in-field measurements after calibration of the simulation module. Our results and experience gained in-field confirm that the StoneNode is a reliable easy-to-use device, which greatly facilitates the data acquisition process. Further, the results obtained with the calibrated simulation tool show good quantitative and qualitative congruence with the experiments, further reaffirming our methodological approach.

A congruence analysis of the inequality–conflict nexus: Evidence from 16 cases

The relationship between inequality and civil conflict has attracted considerable interest in conflict research. Recent large -N studies have shown that inequalities significantly contribute to the outbreak of civil conflict and have proposed a number of causal pathways to account for this. These pathways, however, have rarely been assessed in systematic case-based research. This study implements a “middle -N” qualitative congruence analysis of 16 conflicts, focusing on the observable implications of the pathways through which inequalities are typically theorized to influence conflict. The study finds evidence to support some of the main pathways proposed in the quantitative literature. Furthermore, the analysis finds that different types of inequalities relate to different conflict categories. Specifically, vertical inequalities relate to non-ethnic governmental conflicts (via an “individual deprivation pathway”), regional inequalities to non-ethnic territorial conflicts (via a “separatist pathway”), and horizontal inequalities to ethnic conflicts (via a “group deprivation pathway”).

Smartphone and vehicular trajectories as data sources for agent-based infection spread modelling

Agent-based modelling (ABM) is becoming a valuable tool in understanding infection spread. In this work, two real data sets – a travel survey data set and a cellular service records data set – are used as mobility inputs in ABMs of infection spread on urban and regional scales, respectively. The data sets are novel in that they were not generated for public health purposes, but are nonetheless amenable and accessible, largely due to an emerging data culture. Data processing methods have been developed to extract trajectories of agents from the data sets, where the trajectories are then used within an ABM to simulate the spread of a close-proximity contact-based infection, such as influenza-like illnesses. Two separate models of infection spread at the scale of a city and a province were developed. Simulations were run to demonstrate infection spread within the population, as a means of exploring the applicability and contribution of the data sets to infection spread modelling. The novelty of the work is derived from the integration of disparate and non-obvious data sets, and the results – by demonstrating qualitative congruence with the results of compartmentalized mathematical models – demonstrate the robustness of the ABM approach and set a framework for future work. Our intention is to highlight the emerging opportunities within a data culture to the multidisciplinary research associated with infection spread modelling without requiring a formal background in telecommunications or intelligent transportation systems in order to better understand the use of available data, its potential, and limitations.

Effect of partial pressure of CO2 on the production of thermostable α-amylase and neutral protease by Bacillus caldolyticus

Controlling the concentration of dissolved oxygen is a standard feature in aerobic fermentation processes but the measurement of dissolved CO2 concentrations is often neglected in spite of its influence on the cellular metabolism. In this work room air and room air supplemented with 5% and 10% carbon dioxide were used for aeration during the cultivation of the thermophilic microorganism Bacillus caldolyticus (DSM 405) on starch to produce alpha-amylase (E.C. 3.2.1.1) and neutral protease (E.C. 3.4.24.27/28). The increased CO2 concentrations resulted in a 22% raise in activity of secreted alpha-amylase and a 43% raise in protease activity when compared with aeration with un-supplemented room air. There was no effect on the final biomass concentration. Furthermore, the lag-phase of fermentation was reduced by 30%, further increasing the productivity of alpha-amylase production. Determinations of dissolved CO2 in the culture broth were conducted both in situ with a probe as well as using exhaust gas analysis and both the methods of quantification showed good qualitative congruence.

Qi Gong exercises through the lens of the Alexander Technique: A conceptual congruence

This paper qualitatively reviews two complementary therapies: Qi Gong and Alexander Technique (AT). It is being suggested that Qi Gong and AT may be united through a qualitative congruence of their mutual underlying concepts. The author hypothesizes that a coherent rationale can be formed through this conceptual congruence and proposes that to some extent Qi Gong movements and AT can be considered interchangeably. Such synthesis of these two therapies is being presented to identify Qi Gong movements with the concept of somatic re-education and also to explain how this new construct can be developed. When verified, this hypothesis will allow individuals to better understand Chinese health exercises from the neurophysiology of emotions perspective.

The Performance of MRI-Based Cerebral Blood Flow Measurements in Acute and Subacute Stroke Compared With 15O-Water Positron Emission Tomography

Perfusion-weighted MRI-based maps of cerebral blood flow (CBF(MRI)) are considered a good MRI measure of penumbral flow in acute ischemic stroke but are seldom used in clinical routine due to methodical issues. We validated CBF(MRI) on quantitative CBF measurement by 15O-water positron emission tomography (CBF(PET)). Comparative CBF(MRI) and CBF(PET) were performed in patients with acute and subacute stroke. In a voxel-based seed-growing technique, predefined CBF(MRI) thresholds (<40, <30, <20, <10 mL/100 g/min) were applied and the resulting volumes were compared with the hypoperfusion volume detected by the penumbral threshold (<20 mL/100 g/min) on CBF(PET). The volumetric comparison was expressed as the C-ratio (volume CBF(MRI)/volume CBF(PET)) to identify the best MRI threshold. The influence of vessel pathology, hypoperfusion size, and time point of imaging was described. The proportion of voxels correctly classified as hypoperfused and the proportion of voxel correctly classified as nonhypoperfused of the best CBF(MRI) threshold was calculated and a Bland-Altman plot illustrated the method-specific differences. In 24 patients (median time MRI to PET: 68 minutes; 16 patients imaged within 24 hours after stroke), the median volume of hypoperfusion <20 mL/100 g/min (CBF(PET)) was 78.5 cm(3). Median hypoperfusion volume on CBF(MRI) ranged from 245.9 cm(3) (<40 mL/100 g/min) to 35.5 cm(3) (<10 mL/10 g/min). On visual inspection, an excellent qualitative congruence was found. The quantitative congruence was best for the MRI-CBF threshold <20 mL/100 g/min (median C-ratio: 1.0), reaching a proportion of voxels correctly classified as hypoperfused of 76% and a proportion of voxel correctly classified as nonhypoperfused of 96%, but a wide interindividual range (C-ratio 0.3 to 3.5) was found. Ipsilateral vessel pathology, time point of imaging, and size of hypoperfusion did not significantly influence the C-ratio. The Bland-Altman analysis for the volumetric difference of CBF(MRI) and CBF(PET) found a good overall agreement but a large SD. Hypoperfusion areas below the CBF(PET) penumbral threshold can be well identified by the CBF(MRI) threshold <20 mL/10 g/min at a group level, but a large individual variance (exceeding 20% of volume in nearly half of the patients) could not be explained. Our results support a prudent use of MRI-based quantitative CBF measurement in clinical routine.

Consequences of individual size variation for survival of an insect herbivore: an analytical model and experimental field testing using the red-legged grasshopper

Variation in body size exists within any natural population. Moreover, variation in this fundamental physiologically based trait often translates into variation in demographic rates. Here we explore the effects of variation in the initial body size of individuals on the mean survival trajectory of a generalist herbivore living in a seasonal environment. We first present the results from an individual-based model, which provided expectations for the form of the relationship between mean survival and standard deviation in initial size. We then develop a heuristic analytical model that captures the essentials of the influence of initial-size variation on mean survival to end of season. Both theoretical formulations demonstrate that as initial body size variation increases, mean survival might initially increase; however, this initial positive effect is eventually reversed, causing mean survival to fall steeply as size variation becomes high. We then test these qualitative predictions in the field by manipulating the magnitude of initial size variation in experimental populations of the generalist grasshopper, Melanoplus femurrubrum. We show good qualitative congruence between model predictions and experimental results. Because herbivore survival is strongly linked to the strength of food-web interactions, we suggest that adopting such a combined theoretical and empirical approach can provide a profitable avenue toward a full understanding of the interplay between individual trait variation and higher-level dynamics.

The systematic significance of seed morphology in Stenocereus (Cactaceae)

Seed morphology of 24 species of Stenocereus was examined by scanning electron microscopy. Quantitative and qualitative features were evaluated to identify groups of species using a phenetic analysis. Two groups were distinguished based on morphological variations of seed size, luster, multicellular sculpture, keeling, cell‐size, periclinal wall sculpture, microrelief and HM complex shape and position relative to rim. All species studied were keeled, with isodiametric cells in the lateral region. Stenocereus alamosensis, S. kerberi and S. beneckei are unique among Stenocereus species in that their seeds are flat but lack micro‐relief. Stenocereus aragonii and S. eichlamii have large, glossy seeds lacking micro‐relief unlike other Stenocereus species, but like most Pachycereus, are unique in that cells in the lateral region display partly convex, low domes. Quantitative and qualitative congruence and discordance among characters that determine species groups in stenocereus are discussed.

FLEXIBLE NUTRIENT STOICHIOMETRY MEDIATES ENVIRONMENTAL INFLUENCES ON PHYTOPLANKTON AND ITS RESOURCES

The elemental composition of plants, which affects ecosystem processes such as energy transfer to consumers and nutrient recycling, varies with the supply of nutrients and light. In contrast to most terrestrial systems, aquatic plants “compete” with abiotic light absorbents. Light supply to pelagic producers and, consequently, algal carbon to nutrient stoichiometry are therefore affected by background turbidity (light absorption by non-algal components, Kbg) and mixing depth (vertical extension of the mixed water column, z). Still, light as a dynamic variable has been neglected in models exploring the ecological consequences of flexible algal stoichiometry. In addition, there are hardly any field experiments exploring effects of light supply on planktonic systems. We present a dynamical model that accounts for the simultaneous dependence of algal production on light supply and internal algal nutrient stores and derive predictions on how a suite of state variables (algal biomass, light climate, algal nutrient stoichiometry, dissolved nutrient concentration, and nutrients in sediment) should be affected by z and Kbg. We compare these predictions with results of an enclosure experiment in a phosphorus-deficient lake, in which we manipulated z and Kbg. Algal biomass decreased at higher Kbg and showed a unimodal response to z (being limited by sinking losses at shallow z and by light at deep z). The biomass peak shifted toward lower z with increased Kbg. The seston carbon:phosphorus ratio decreased with increasing z and Kbg. Dissolved mineral phosphorus was undetectable in all treatments. Total water column phosphorus and sedimented phosphorus increased with increasing z but were unaffected by Kbg. These data are in almost complete qualitative congruence with model predictions over the examined range of mixing depths (1–15 m). The model thus provides a useful framework for the continued mechanistic exploration of how environmental drivers influence producer stoichiometry in pelagic environments.

Customized birth weight for gestational age standards: Perinatal mortality patterns are consistent with separate standards for males and females but not for blacks and whites

BackgroundSome currently available birth weight for gestational age standards are customized but others are not. We carried out a study to provide empirical justification for customizing such standards by sex and for whites and blacks in the United States.MethodsWe studied all male and female singleton live births and stillbirths (22 or more weeks of gestation; 500 g birth weight or over) in the United States in 1997 and 1998. White and black singleton live births and stillbirths were also examined. Qualitative congruence between gestational age-specific growth restriction and perinatal mortality rates was used as the criterion for identifying the preferred standard.ResultsThe fetuses at risk approach showed that males had higher perinatal mortality rates at all gestational ages compared with females. Gestational age-specific growth restriction rates based on a sex-specific standard were qualitatively consistent with gestational age-specific perinatal mortality rates among males and females. However, growth restriction patterns among males and females based on a unisex standard could not be reconciled with perinatal mortality patterns. Use of a single standard for whites and blacks resulted in gestational age-specific growth restriction rates that were qualitatively congruent with patterns of perinatal mortality, while use of separate race-specific standards led to growth restriction patterns that were incompatible with patterns of perinatal mortality.ConclusionQualitative congruence between growth restriction and perinatal mortality patterns provides an outcome-based justification for sex-specific birth weight for gestational age standards but not for the available race-specific standards for blacks and whites in the United States.

Genomic rearrangements in trypanosomatids: an alternative to the "one gene" evolutionary hypotheses?

Most molecular trees of trypanosomatids are based on point mutations within DNA sequences. In contrast, there are very few evolutionary studies considering DNA (re) arrangement as genetic characters. Waiting for the completion of the various parasite genome projects, first information may already be obtained from chromosome size-polymorphism, using the appropriate algorithms for data processing. Three illustrative models are presented here. First, the case of Leishmania (Viannia) braziliensis/L. (V.) peruviana is described. Thanks to a fast evolution rate (due essentially to amplification/deletion of tandemly repeated genes), molecular karyotyping seems particularly appropriate for studying recent evolutionary divergence, including eco-geographical diversification. Secondly, karyotype evolution is considered at the level of whole genus Leishmania. Despite the fast chromosome evolution rate, there is qualitative congruence with MLEE- and RAPD-based evolutionary hypotheses. Significant differences may be observed between major lineages, likely corresponding to major and less frequent rearrangements (fusion/fission, translocation). Thirdly, comparison is made with Trypanosoma cruzi. Again congruence is observed with other hypotheses and major lineages are delineated by significant chromosome rearrangements. The level of karyotype polymorphism within that "species" is similar to the one observed in "genus" Leishmania. The relativity of the species concept among these two groups of parasites is discussed.