The importance of adaptive expertise in CAD learning: maintaining design intent

In CAD modelling, there is no one general standardised teaching-learning methodology. We use the strategic-learning methodology, maintaining design intent, fully aware that it is necessary to modify CAD models for their reuse. Questions concerning the thought processes of students when modelling with CAD and the strategies that they choose that best maintain design intent arise in the course of using the 3D modelling programmes. Our aim here is to determine the importance of adaptive expertise in the results of CAD models and, particularly, in one of its constructs: design intent. To do so, CAD-based experimentation took place over two years with 78 third-year students in the first year and with 53 third-year students in the second year from the subject module of Graphic Engineering, on the Degree in Mechanical Engineering of the University of Burgos (Spain). At the start of the year, the students conducted a survey to measure adaptive expertise. Subsequently, in the first year of experimentation, the students prepared various CAD models and the design intent was evaluated in one of them (a connecting rod or conrod), broken down into the skeleton, the structure, the modifications and the constraints. In the conrod exercise, the students also completed a questionnaire both before and after designing their models, which were analysed to detect the thought processes and the strategies that they had applied. In the second year of experimentation, design intent was incorporated in various exercises at the beginning of the year, in addition to the conrod. The main conclusion is that the correct division of the part into its pieces and adaptive expertise improved the results in relation to design intent in the CAD. KEYWORDS: CAD learning, design intent (DI), adaptive expertise (AE), modification of CAD

An Evaluation of a Metaheuristic Artificial Immune System for Household Energy Optimization

[EN] Devices in a smart home should be connected in an optimal way; this helps save energy and money. Among numerous optimization models that can be found in the literature, we would like to highlight artificial immune systems, which use special bioinspired algorithms to solve optimization problems effectively. The aim of this work is to present the application of an artificial immune system in the context of different energy optimization problems. Likewise, a case study is performed in which an artificial immune system is incorporated in order to solve an energy management problem in a domestic environment. A thorough analysis of the different strategies is carried out to demonstrate the ability of an artificial immune system to find a successful optima which satisfies the problem constraints

Reserve costs allocation model for energy and reserve market simulation

This paper proposes a new model to allocate reserve costs among the involved players, considering the characteristics of the several entities, and the particular circumstances at each moment. The proposed model is integrated in the Multi-Agent Simulator of Competitive Electricity Markets (MASCEM), which enables complementing the multi-agent simulation of diverse electricity market models, by including the joint simulation of energy and reserve markets. In this context, the proposed model allows allocating the payment of reserve costs that result from the reserve market. A simulation based on real data from the Iberian electricity market - MIBEL, is presented. Simulation results show the advantages of the proposed model in sharing the reserve costs fairly and accordingly to the different circumstances. This work thus contributes the study of novel market models towards the evolution of power and energy systems by adapting current models to the new paradigm of high penetration of renewable energy generation.This work has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 641794 (project DREAM-GO) and a grant agreement No 703689 (project ADAPT); and from FEDER Funds through COMPETE program and from National Funds through FCT under the project UID/EEA/00760/2013info:eu-repo/semantics/publishedVersio

Uclacyanin Proteins Are Required for Lignified Nanodomain Formation within Casparian Strips

© 2020 The Author(s) Casparian strips (CSs) are cell wall modifications of vascular plants restricting extracellular free diffusion into and out of the vascular system [1]. This barrier plays a critical role in controlling the acquisition of nutrients and water necessary for normal plant development [2–5]. CSs are formed by the precise deposition of a band of lignin approximately 2 μm wide and 150 nm thick spanning the apoplastic space between adjacent endodermal cells [6, 7]. Here, we identified a copper-containing protein, Uclacyanin1 (UCC1), that is sub-compartmentalized within the CS. UCC1 forms a central CS nanodomain in comparison with other CS-located proteins that are found to be mainly accumulated at the periphery of the CS. We found that loss-of-function of two uclacyanins (UCC1 and UCC2) reduces lignification specifically in this central CS nanodomain, revealing a nano-compartmentalized machinery for lignin polymerization. This loss of lignification leads to increased endodermal permeability and, consequently, to a loss of mineral nutrient homeostasis

Tremor Control Devices for Essential Tremor: A Systematic Literature Review

Background: There is a growing interest in nonpharmacological approaches for essential tremor (ET), including tremor cancelation devices. However, the true efficacy of such devices in ET remains unclear. Methods: A systematic literature review was conducted using standardized criteria regarding efficacy and comfortability. Devices focused on design or experimental testing in which tremor was simulated in a robot were excluded. Results: Out of 324 articles initially identified, 12 articles were included. Orthoses using biomechanical loading and neuromodulation with electrical stimulation, and external tremor cancelation devices, were the main interventions used to suppress tremor. All devices were designed to control tremor of the upper limbs at different anatomical locations. Overall, an average tremor attenuation of 50–98% was reported (level of evidence III). Interference with voluntary movements and portability was described as the main drawback. Discussion: In conclusion, this review highlights the growing interest in emerging tremor control devices and the importance of assessing comfort without affecting voluntary movements. However, the level of evidence regarding the efficacy of these tremor control devices remains low. An integrated multidisciplinary combination approach of engineering, robotics, physiology, physiotherapy, and clinical assessment is needed to improve the quality of non-pharmacological interventions for ET

The effects of soil phosphorus content on plant microbiota are driven by the plant phosphate starvation response

Phosphate starvation response (PSR) in nonmycorrhizal plants comprises transcriptional reprogramming resulting in severe physiological changes to the roots and shoots and repression of plant immunity. Thus, plant-colonizing microorganisms-the plant microbiota-are exposed to direct influence by the soil's phosphorus (P) content itself as well as to the indirect effects of soil P on the microbial niches shaped by the plant. The individual contribution of these factors to plant microbiota assembly remains unknown. To disentangle these direct and indirect effects, we planted PSR-deficient Arabidopsis mutants in a long-term managed soil P gradient and compared the composition of their shoot and root microbiota to wild-type plants across different P concentrations. PSR-deficiency had a larger effect on the composition of both bacterial and fungal plant-associated microbiota than soil P concentrations in both roots and shoots. To dissect plant-microbe interactions under variable P conditions, we conducted a microbiota reconstitution experiment. Using a 185-member bacterial synthetic community (SynCom) across a wide P concentration gradient in an agar matrix, we demonstrated a shift in the effect of bacteria on the plant from a neutral or positive interaction to a negative one, as measured by rosette size. This phenotypic shift was accompanied by changes in microbiota composition: the genus Burkholderia was specifically enriched in plant tissue under P starvation. Through a community drop-out experiment, we demonstrated that in the absence of Burkholderia from the SynCom, plant shoots accumulated higher ortophosphate (Pi) levels than shoots colonized with the full SynCom but only under Pi starvation conditions. Therefore, Pi-stressed plants are susceptible to colonization by latent opportunistic competitors found within their microbiome, thus exacerbating the plant's Pi starvation

Sculpting the soil microbiota

Soil is a living ecosystem, the health of which depends on fine interactions among its abiotic and biotic components. These form a delicate equilibrium maintained through a multilayer network that absorbs certain perturbations and guarantees soil functioning. Deciphering the principles governing the interactions within soils is of critical importance for their management and conservation. Here, we focus on soil microbiota and discuss the complexity of interactions that impact the composition and function of soil microbiota and their interaction with plants. We discuss how physical aspects of soils influence microbiota composition and how microbiota–plant interactions support plant growth and responses to nutrient deficiencies. We predict that understanding the principles determining the configuration and functioning of soil microbiota will contribute to the design of microbiota-based strategies to preserve natural resources and develop more environmentally friendly agricultural practices

Cytokinin Determines Thiol-Mediated Arsenic Tolerance and Accumulation

The presence of arsenic in soil and water is a constant threat to plant growth in many regions of the world. Phytohormones act in the integration of growth control and stress response, but their role in plant responses to arsenic remains to be elucidated. Here, we show that arsenate [As(V)], the most prevalent arsenic chemical species in nature, causes severe depletion of endogenous cytokinins (CKs) in the model plant Arabidopsis (Arabidopsis thaliana). We found that CK signaling mutants and transgenic plants with reduced endogenous CK levels showed an As(V)-tolerant phenotype. Our data indicate that in CK-depleted plants exposed to As(V), transcript levels of As(V)/phosphate-transporters were similar or even higher than in wild-type plants. In contrast, CK depletion provoked the coordinated activation of As(V) tolerance mechanisms, leading to the accumulation of thiol compounds such as phytochelatins and glutathione, which are essential for arsenic sequestration. Transgenic CK-deficient Arabidopsis and tobacco lines show a marked increase in arsenic accumulation. Our findings indicate that CK is an important regulatory factor in plant adaptation to arsenic stress

Root microbiota drive direct integration of phosphate stress and immunity

Plants live in biogeochemically diverse soils that harbor extraordinarily diverse microbiota. Plant organs associate intimately with a subset of these microbes; this community’s structure can be altered by soil nutrient content. Plant-associated microbes can compete with the plant and with each other for nutrients; they can also provide traits that increase plant productivity. It is unknown how the plant immune system coordinates microbial recognition with nutritional cues during microbiome assembly. We establish that a genetic network controlling phosphate stress response influences root microbiome community structure, even under non-stress phosphate conditions. We define a molecular mechanism regulating coordination between nutrition and defense in the presence of a synthetic bacterial community. We demonstrate that the master transcriptional regulators of phosphate stress response in Arabidopsis also directly repress defense, consistent with plant prioritization of nutritional stress over defense. Our work will impact efforts to define and deploy useful microbes to enhance plant performance