Functional-structural Model Research Articles

P15. Multimodal mapping of nerve pathology with a multichannel approach

Objective Clinical electroneurography, the diagnostic standard for the assessment of thickly myelinated peripheral nerves, is of limited spatial resolution since it provides only average data (nerve conduction velocity [NCV], nerve or muscle action potential amplitude) on relatively large nerve segments. Accordingly, different distribution patterns of axonal or myelin pathologies cannot be distinguished. But precisely this is relevant to ensure correct diagnosis and therapies. These can pose a relevant burden on the patient ranging from spontaneous recovery over surgical to medical, partly highly expensive, treatment. Hence, our main objective is to optimize the diagnostic specificity via a multichannel neurographical approach. By adding ultrasound data, a functional-structural model can be developed as a novel basis for medical decision making. Methods Based on ultrasound, eight electrodes are positioned along the course of the median and ulnar nerve, respectively, and nerve depth (distance to skin) profiles are recorded. Bipolar direct current stimulation is applied close to the M. abductor pollicis brevis and the M. abductor digiti minimi, resulting in the excitation of both motor and sensory nerve fibers (mixed nerve technique) ( Buschbacher, 1999 ) such that eight mixed nerve action potentials (NAPs) can be recorded along the nerve. We performed reference measurements in 10 healthy volunteers. Results Median nerve depth ranged from 2 to 23 mm, and we recorded reproducible signals at all locations with a maximum of 8 averages (at 20 mm) in good correspondence with previously published values ( Fig. 1 ) ( Watson et al., 2002 ). Fig. 2 reports the (inverse) relationship between NAP amplitudes and depth. Discussion Using the setup described, we reliably obtain NAP and their latencies of two peripheral nerves along their course with slight or no averaging. The interesting question is, if and how different pathologies influence the amplitude level. The next step will be the assessment of nerve pathologies to test that diagnostic and therapeutic decision making benefits from structural-functional nerve mapping with high spatial resolution.

Ship Navigation System Based on Wireless Sensor

To study the application of wireless sensor in the ship dynamic positioning system, the distributed fusion function model and structure model of wireless sensor network were set up.Using the DJC model-based SVM prediction algorithm, the quadratic optimal performance index in ship dynamic positioning MPC control was solved and the optimal control thrust was obtained.According to the classic cluster routing protocol, a data fusion structure based on residual energy and dormancy scheduling mechanism was proposed. The results showed that the proposed routing protocol based on the residual energy and sleep scheduling mechanism data fusion structure was superior to the Leach protocol. It improved the real-time performance of data transmission. Thus, the network data fusion structure achieves the goal of energy balance. The energy consumption is reduced to a certain extent and the design is reasonable.

Rightsizing root phenotypes for drought resistance.

I propose that reduced root development would be advantageous for drought resistance in high-input agroecosystems. Selection regimes for crop ancestors and landraces include multiple stresses, intense competition, and variable resource distribution, which favored prolific root production, developmental plasticity in response to resource availability, and maintenance of unspecialized root tissues. High-input agroecosystems have removed many of these constraints to root function. Therefore, root phenotypes that focus on water capture at the expense of ancestral adaptations would be better suited to high-input agroecosystems. Parsimonious architectural phenotypes include fewer axial roots, reduced density of lateral roots, reduced growth responsiveness to local resource availability, and greater loss of roots that do not contribute to water capture. Parsimonious anatomical phenotypes include a reduced number of cortical cell files, greater loss of cortical parenchyma to aerenchyma and senescence, and larger cortical cell size. Parsimonious root phenotypes may be less useful in low-input agroecosystems, which are characterized by multiple challenges and trade-offs for root function in addition to water capture. Analysis of the fitness landscape of root phenotypes is a complex challenge that will be aided by the development of robust functional-structural models capable of simulating the dynamics of root-soil interactions.

Improving the functionality and performance of AA2024 corrosion sensing coatings with nanocontainers

The compatibility between nanocontainers and coating formulations is perhaps the last frontier in the quest for functional coatings. Sensing coatings for early metallic corrosion detection is an urgently needed technology by aeronautical companies to mitigate the costs of corrosion through continuous monitoring. In this work, we revisit phenolphthalein encapsulated silica nanocapsules, which were incorporated into a water-based lacquer, resulting in a novel corrosion sensing coating for aluminum alloy 2024 with improved functionality and standard performance. The ability of the coatings to detect corrosion by color change was investigated by immersion and salt-spray tests. During these tests, it was clearly demonstrated that encapsulation of the active compound is essential to obtain a functional coating, since the shell of the silica nanocapsules minimizes the detrimental interaction of the active compound with the coating formulation. The compatibility between nanostructured additives and coatings is almost never taken into consideration in the literature. Herein this aspect evidences the positive effects of active agent encapsulation, which is explored in terms of reactivity, viscoelastic properties, curing, thermal stability, release and leaching studies, hardness, mechanical properties and corrosion resistance. Computer simulations based on the density functional theory and periodic structural models were performed to unveil the interaction mode of phenolphthalein with the metallic surface.

CRootBox: a structural-functional modelling framework for root systems.

Root architecture development determines the sites in soil where roots provide input of carbon and take up water and solutes. However, root architecture is difficult to determine experimentally when grown in opaque soil. Thus, root architecture models have been widely used and been further developed into functional-structural models that simulate the fate of water and solutes in the soil-root system. The root architecture model CRootBox presented here is a flexible framework to model root architecture and its interactions with static and dynamic soil environments. CRootBox is a C++-based root architecture model with Python binding, so that CRootBox can be included via a shared library into any Python code. Output formats include VTP, DGF, RSML and a plain text file containing coordinates of root nodes. Furthermore, a database of published root architecture parameters was created. The capabilities of CRootBox for the unconfined growth of single root systems, as well as the different parameter sets, are highlighted in a freely available web application. The capabilities of CRootBox are demonstrated through five different cases: (1) free growth of individual root systems; (2) growth of root systems in containers as a way to mimic experimental setups; (3) field-scale simulation; (4) root growth as affected by heterogeneous, static soil conditions; and (5) coupling CRootBox with code from the book Soil physics with Python to dynamically compute water flow in soil, root water uptake and water flow inside roots. CRootBox is a fast and flexible functional-structural root model that is based on state-of-the-art computational science methods. Its aim is to facilitate modelling of root responses to environmental conditions as well as the impact of roots on soil. In the future, this approach will be extended to the above-ground part of the plant.

A functional-structural model of ephemeral seagrass growth influenced by environment.

Ephemeral seagrasses that respond rapidly to environmental changes are important marine habitats. However, they are under threat due to human activity and are logistically difficult and expensive to study. This study aimed to develop a new functional-structural environmentally dependent model of ephemeral seagrass, able to integrate our understanding of ephemeral seagrass growth dynamics and assess options for potential management interventions, such as seagrass transplantation. A functional-structural plant model was developed in which growth and senescence rates are mechanistically linked to environmental variables. The model was parameterized and validated for a population of Halophila stipulacea in the Persian Gulf. There was a good match between empirical and simulated results for the number of apices, net rhizome length or net number of internodes using a 330 d simulation. Simulated data were more variable than empirical data. Simulated structural patterns of seagrass rhizome growth qualitatively matched empirical observations. This new model successfully simulates the environmentally dependent growth and senescence rates of our case-study ephemeral seagrass species. It produces numerical and visual outputs that help synthesize our understanding of how the influence of environmental variables on plant functional processes affects overall growth patterns. The model can also be used to assess the potential outcomes of management interventions like seagrass transplantation, thus providing a useful management tool. It is freely available and easily adapted for new species and locations, although validation with more species and environments is required.

РОЗРОБКА ТА ОЦІНКА ВПРОВАДЖЕННЯ ІНФОРМАЦІЙНОГО ПОСІБНИКА “ЗДОРОВ’Я ТА ПРОФІЛАКТИКА СЕРЦЕВО-СУДИННИХ ЗАХВОРЮВАНЬ У ВІЙСЬКОВОСЛУЖБОВЦІВ”

Статтю присвячено розробці та впровадженню підходів щодо залучення військовослужбовців до здорового способу життя та профілактики серцево-судинних захворювань.Мета дослідження – провести розробку та оцінити впровадження інформаційного посібника “Здоров’я та профілактика серцево-судинних захворювань у військовослужбовців”.Матеріали i методи. У статті використано бібліографічний, інформаційно-аналітичний методи та метод системного підходу.Результати досліджень та їх обговорення. За результатами проведеного дослідження встановлено, що військовослужбовці позитивно оцінили інформаційний посібник та зазначили, що він написаний у доступній формі (92,7 %), більшість (86,4 %) зацікавив його матеріал, у значної частини (74,5 %) змінилось ставлення до власного здоров’я і 66,4 % збираються внести зміни, щоб зробити спосіб життя більш здоровим.Висновки. Інформаційний посібник є одним з елементів удосконаленої комплексної функціонально-структурної моделі, який розроблено та впроваджено для підвищення поінформованості військовослужбовців щодо здорового способу життя.

3D plant model assessed by terrestrial LiDAR and hemispherical photographs: A useful tool for comparing light interception among oil palm progenies

The paradigm of functional-structural models (FSPM) assumes that studying the detailed organisation of plant structure allows a better understanding of functional processes; in particular the way plants capture light for performing photosynthesis. However, much attention must be paid toward the consistency between virtual plants and plants in the field in terms of size and geometry to accurately evaluate light interception. This paper thus aimed at i) assessing the capacity of a 3D architectural model based on oil palms (Elaeis guineensis) to accurately represent plants structural characteristics at both the scale of the individual plant and the cultivated plot and ii) employing the validated 3D mock-ups to investigate how light interception efficiency varies among progenies that exhibit different architectures. Innovative indicators related to plant geometry and topology were derived from terrestrial LiDAR scanners (TLS) and hemispherical photographs (HP) in order to assess a 3D plant model. Indicators such as plant height, width and volume, gap fractions and solid angle projections were established from field measurements and were compared to equivalent indicators that had been extracted from virtual TLS (VTLS) and virtual HP (VHP) simulated on 3D mock-ups. Indicators were then evaluated for their significance in terms of light interception. Progeny effect on light interception efficiency was finally evaluated for five progenies.The structural indicators estimated from VTLS and VHP were significantly correlated with equivalent indicators estimated from TLS and HP, respectively, and with simulated outputs related to light interception. Light interception efficiencies estimated from validated 3D mock-ups differed significantly among the five progenies under study, most notably along plant development.Our results highlight the relevance of combining TLS- and HP-derived indicators to evaluate the reliability of virtual 3D reconstruction of plants in relation to light capture, at both the plant and plot scales. The study paves the way for further investigations aiming at unravelling the relationships between oil palm architecture and the physiological processes driving its production.

Reduction in Root Secondary Growth as a Strategy for Phosphorus Acquisition.

We tested the hypothesis that reduced root secondary growth of dicotyledonous species improves phosphorus acquisition. Functional-structural modeling in SimRoot indicates that, in common bean (Phaseolus vulgaris), reduced root secondary growth reduces root metabolic costs, increases root length, improves phosphorus capture, and increases shoot biomass in low-phosphorus soil. Observations from the field and greenhouse confirm that, under phosphorus stress, resource allocation is shifted from secondary to primary root growth, genetic variation exists for this response, and reduced secondary growth improves phosphorus capture from low-phosphorus soil. Under low phosphorus in greenhouse mesocosms, genotypes with reduced secondary growth had 39% smaller root cross-sectional area, 60% less root respiration, 27% greater root length, 78% greater shoot phosphorus content, and 68% greater shoot mass than genotypes with advanced secondary growth. In the field under low phosphorus, these genotypes had 43% smaller root cross-sectional area, 32% greater root length, 58% greater shoot phosphorus content, and 80% greater shoot mass than genotypes with advanced secondary growth. Secondary growth eliminated arbuscular mycorrhizal associations as cortical tissue was destroyed. These results support the hypothesis that reduced root secondary growth is an adaptive response to low phosphorus availability and merits investigation as a potential breeding target.

Virtual Plants Need Water Too: Functional-Structural Root System Models in the Context of Drought Tolerance Breeding.

Developing a sustainable agricultural model is one of the great challenges of the coming years. The agricultural practices inherited from the Green Revolution of the 1960s show their limits today, and new paradigms need to be explored to counter rising issues such as the multiplication of climate-change related drought episodes. Two such new paradigms are the use of functional-structural plant models to complement and rationalize breeding approaches and a renewed focus on root systems as untapped sources of plant amelioration. Since the late 1980s, numerous functional and structural models of root systems were developed and used to investigate the properties of root systems in soil or lab-conditions. In this review, we focus on the conception and use of such root models in the broader context of research on root-driven drought tolerance, on the basis of root system architecture (RSA) phenotyping. Such models result from the integration of architectural, physiological and environmental data. Here, we consider the different phenotyping techniques allowing for root architectural and physiological study and their limits. We discuss how QTL and breeding studies support the manipulation of RSA as a way to improve drought resistance. We then go over the integration of the generated data within architectural models, how those architectural models can be coupled with functional hydraulic models, and how functional parameters can be measured to feed those models. We then consider the assessment and validation of those hydraulic models through confrontation of simulations to experimentations. Finally, we discuss the up and coming challenges facing root systems functional-structural modeling approaches in the context of breeding.

Application of Molecular Imaging Equipment PET/MRI

To compare the principles and system frameworks on PET and MRI systems. The functional characteristics and present adoptive structural models of PET/MRI as molecular imaging equipment is introduced in particular. To compare several update techniques of attenuation correction for PET image with MRI parameters and to expatiate their deficiencies. The advantages on PET/MRI clinical applications and the future development of PET/MRI are introduced briefly.

Increased Affinity for RNA Targets Evolved Early in Animal and Plant Dicer Lineages through Different Structural Mechanisms.

Understanding the structural basis for evolutionary changes in protein function is central to molecular evolutionary biology and can help determine the extent to which functional convergence occurs through similar or different structural mechanisms. Here, we combine ancestral sequence reconstruction with functional characterization and structural modeling to directly examine the evolution of sequence-structure-function across the early differentiation of animal and plant Dicer/DCL proteins, which perform the first molecular step in RNA interference by identifying target RNAs and processing them into short interfering products. We found that ancestral Dicer/DCL proteins evolved similar increases in RNA target affinities as they diverged independently in animal and plant lineages. In both cases, increases in RNA target affinities were associated with sequence changes that anchored the RNA’s 5′phosphate, but the structural bases for 5′phosphate recognition were different in animal versus plant lineages. These results highlight how molecular-functional evolutionary convergence can derive from the evolution of unique protein structures implementing similar biochemical mechanisms.

Root Cortical Senescence Improves Growth under Suboptimal Availability of N, P, and K.

Root cortical senescence (RCS) in Triticeae reduces nutrient uptake, nutrient content, respiration, and radial hydraulic conductance of root tissue. We used the functional-structural model SimRoot to evaluate the functional implications of RCS in barley (Hordeum vulgare) under suboptimal nitrate, phosphorus, and potassium availability. The utility of RCS was evaluated using sensitivity analyses in contrasting nutrient regimes. At flowering (80 d), RCS increased simulated plant growth by up to 52%, 73%, and 41% in nitrate-, phosphorus-, and potassium-limiting conditions, respectively. Plants with RCS had reduced nutrient requirement of root tissue for optimal plant growth, reduced total cumulative cortical respiration, and increased total carbon reserves. Nutrient reallocation during RCS had a greater effect on simulated plant growth than reduced respiration or nutrient uptake. Under low nutrient availability, RCS had greater benefit in plants with fewer tillers. RCS had greater benefit in phenotypes with fewer lateral roots at low nitrate availability, but the opposite was true in low phosphorus or potassium availability. Additionally, RCS was quantified in field-grown barley in different nitrogen regimes. Field and virtual soil coring simulation results demonstrated that living cortical volume per root length (an indicator of RCS) decreased with depth in younger plants, while roots of older plants had very little living cortical volume per root length. RCS may be an adaptive trait for nutrient acquisition by reallocating nutrients from senescing tissue and secondarily by reducing root respiration. These simulated results suggest that RCS merits investigation as a breeding target for enhanced soil resource acquisition and edaphic stress tolerance.

Efficient modelling of foliage distribution and crown dynamics in monolayer tree species.

In response to the computational limitations of individual leaf-based tree growth models, this article presents a new approach for the efficient characterisation of the spatial distribution of foliage in monolayered trees in terms of 2D foliage surfaces. Much like the recently introduced 3D leaf area density, this concept accommodates local crown plasticity, which is a common weak point in large-scale growth models. Recognizing phototropism as the predominant driver of spatial crown expansion, we define the local light gradient on foliage surfaces. We consider the partial differential equation describing the evolution of a curve expanding along the light gradient and present an explicit solution. The article concludes with an illustration of the incorporation of foliage surfaces in a simple tree growth model for European beech (Fagus sylvatica L.), and discusses perspectives for applications in functional-structural models.

JUSTIFICATION OF CONDITIONING VOLITIONAL DEVELOPMENT OF CHILDREN’S MASTERING THEIR LANGUAGE SKILLS AND FUNCTIONS

The article analyzes the scientific approaches of domestic scientists to understanding the problem of will and the interrelated aspects of its development in ontogenesis. When studying ways of forming volitional behavior at its first stages, special attention is drawn to the fact that the child's volitional behavior arises with the emergence of the skills to build speech utterances, with which he begins to plan his activities and regulate the process of its implementation, that is, the mastering of planning and regulating functions of speech takes place. By analyzing the ways of forming language skills in preschool and early school age, structures for creation a speech utterance, the author clarified the term "expression speech" (stages of its construction) and language skills, provided for the implementation of each stage of verbal expression. Also it is justified the condition of volitional development of children mastering their language skills and functions; relationship stages of planning and regulatory functions of broadcasting in preschool and early school age. The paper presents the author’s functional-structural model of the optimization process of development of the planning and regulatory functions in the formation of children’s speech in their language skills.

Validation of a functional-structural tree model using terrestrial Lidar data

We compared the spatial output of the functional-structural tree growth model recently presented by Beyer et al. (2017) to empirical tree crowns of European beech (Fagus sylvatica L.) obtained via terrestrial laser scanning. Simulations are found to be morphologically similar to the observed 3D data in terms of size and shape, as well as, quantitatively, contained withing its standard range. We argue that Lidar data provides an unprecedented degree of information on tree geometry compared to traditional forest inventory measurements, and can thus greatly contribute to the parameterisation and validation of tree growth models.

Yield analysis as a function of stochastic plant architecture: Case of Spilanthes acmella in the wet and dry season

The number of organs produced by a plant varies among the individuals of a population. Taking these variations into account is an important step in understanding phenotypic variability. The aim of this study was to simulate stochastic development and growth in response to environmental change using GreenLab, an organ level functional-structural model. An annual herbaceous species, Spilanthes acmella L., was grown in pots in two climatic conditions corresponding to a wet and a dry season. Detailed records of plant development, plant architecture and organ growth were kept throughout the growing period. The concept of simple and compound organic series was introduced to target data for fitting. The model was calibrated using a mathematical model of stochastic plant development and growth. Here we describe (1) how a stochastic Functional Structural Plant Model is calibrated in two steps by first assessing the functioning parameters of meristems, and second the source-sink parameters of organs by fitting them on average organic series; (2) how dry conditions trigger the response of the plant both in the development of the inflorescence and in the allocation of biomass, quantified by model parameters. The calibration of a stochastic plant model opens a large window of opportunity to capture the common features of plant development and growth among stochastic individuals in a plant population, especially those with a branching structure. This extends the area of application of FSPM to analyzing food plants, or assisting breeding.

Modeling the spatial distribution of plants on the row for wheat crops: Consequences on the green fraction at the canopy level

This work investigates the spatial distribution of wheat plants and its consequences on the canopy structure. A set of RGB images were taken from nadir on a total 14 plots showing a range of sowing densities, cultivars and environmental conditions. The coordinates of the plants were extracted from RGB images. Results show that the distance between-plants along the row follows a gamma distribution law, with no dependency between the distances. Conversely, the positions of the plants across rows follow a Gaussian distribution, with strongly interdependent. A statistical model was thus proposed to simulate the possible plant distribution pattern. Through coupling the statistical model with 3D Adel-Wheat model, the impact of the plant distribution pattern on canopy structure was evaluated using emerging properties such as the green fraction (GF) that drives the light interception efficiency. Simulations showed that the effects varied over different development stages but were generally small. For the intermediate development stages, large zenithal angles and directions parallel to the row, the deviations across the row of plant position increased the GF by more than 0.1. These results were obtained with a wheat functional-structural model that does not account for the capacity of plants to adapt to their local environment. Nevertheless, our work will extend the potential of functional-structural plant models to estimate the optimal distribution pattern for given conditions and subsequently guide the field management practices.

Correlation effects on the interelectronic distributions of localized electron pairs

It has been shown previously that a wealth of chemical insight may be drawn from studying the interelectronic distribution function for localized electron pairs within a molecular system (Hennessey et al. in Phys Chem Chem Phys 16(46):25548–25556, 2014); however, these accounts have been limited due to the relative inaccuracy of the underlying Hartree–Fock electronic structure model that has been employed. In the current work, we study how the interelectronic distribution function of single electron pairs, represented by localized molecular orbitals, changes between a Hartree–Fock and density functional electronic structure model. We find that localized electron pairs expand, relative to a Hartree–Fock model, in a small but significant way when modelled with density functional theory. More specifically, we generally find that compact electron pairs (i.e. those pairs having narrow distribution functions near small interelectronic distances) result in a smaller change due to correlation than electron pairs more broadly distributed. This counterintuitive effect is attributed to the fact that compact electron pairs are generally held close together by a relatively rigid confining potential (i.e. attraction from local nuclei and repulsion from neighbouring electrons). However, in cases where a series of species all have nearly identical nuclear structure in the vicinity of the LMO of interest, more compact electron pairs did in fact experience the greatest change in interelectronic separation and electron repulsion upon the incorporation of a correlated model. Also, if one allows the geometry of the molecular species to relax, bonds associated with LMOs having compact interelectronic distributions tend to elongate the most with a correlated model (relative to Hartree–Fock) and the resultant deformation of the interelectronic distribution functions then show the most significant changes due to correlation. The results presented herein demonstrate the utility of Kohn–Sham density functional theory for the description of localized chemical space within the scope of the localized pair model.

The conceptual model of DFD-technology

The presence of large number of models and methods for structural modeling of business processes and systems has made urgent the development of standardized language for structural analysis and design, suitable for modeling as organizational management, and software systems (similar to UML for the object-oriented systems’ design). The paper proposes a draft of such a language based on data flow diagrams (DFD diagrams) as the most frequently used in functional structural modeling. As part of the work in this direction a conceptual model language is proposed, named DFD-technology, integrating structural models for different purposes based on DFD-diagrams, and reflecting functional, informational and behavioral aspects of the modeled object. The article also analyzes the syntax, semantic and pragmatic aspects of the introduced unified modeling language. For a formal description of the syntax, it is proposed to use the apparatus of the mixed grammars, a combination of graph and regular grammars. The article gives a grammar description to generate a simple dialect of DFD technology, informally described semantic aspects of language, particularly the semantics of relations between objects of the language. Thus, the paper proposed a solution of unification and standardization problem of structural modeling languages, based on the integrated DFD-technology. The conceptual model of the technology is prepared, the syntax of the standardized language, using the technique of the mixed grammar and the semantic aspects of the language are described in detail. It should be noted that the proposed methods in the article and models occupy the central place in modern business processes theory.