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2021 ◽  
Vol 12 ◽  
Author(s):  
Chrystle Weigand ◽  
Su-Hwa Kim ◽  
Elizabeth Brown ◽  
Emily Medina ◽  
Moises Mares ◽  
...  

Land plants evolved to quickly sense and adapt to temperature changes, such as hot days and cold nights. Given that calcium (Ca2+) signaling networks are implicated in most abiotic stress responses, heat-triggered changes in cytosolic Ca2+ were investigated in Arabidopsis leaves and pollen. Plants were engineered with a reporter called CGf, a ratiometric, genetically encoded Ca2+ reporter with an mCherry reference domain fused to an intensiometric Ca2+ reporter GCaMP6f. Relative changes in [Ca2+]cyt were estimated based on CGf’s apparent KD around 220 nM. The ratiometric output provided an opportunity to compare Ca2+ dynamics between different tissues, cell types, or subcellular locations. In leaves, CGf detected heat-triggered cytosolic Ca2+ signals, comprised of three different signatures showing similarly rapid rates of Ca2+ influx followed by differing rates of efflux (50% durations ranging from 5 to 19 min). These heat-triggered Ca2+ signals were approximately 1.5-fold greater in magnitude than blue light-triggered signals in the same leaves. In contrast, growing pollen tubes showed two different heat-triggered responses. Exposure to heat caused tip-focused steady growth [Ca2+]cyt oscillations to shift to a pattern characteristic of a growth arrest (22%), or an almost undetectable [Ca2+]cyt (78%). Together, these contrasting examples of heat-triggered Ca2+ responses in leaves and pollen highlight the diversity of Ca2+ signals in plants, inviting speculations about their differing kinetic features and biological functions.


Author(s):  
Myrianthi Hadjicharalambous ◽  
Christian T. Stoeck ◽  
Miriam Weisskopf ◽  
Nikola Cesarovic ◽  
Eleftherios Ioannou ◽  
...  

Author(s):  
tommaso taddei ◽  
Lei Zhang

We propose a model reduction procedure for rapid and reliable solution of parameterized hyperbolic partial differential equations. Due to the presence of parameter-dependent shock waves and contact discontinuities, these problems are extremely challenging for traditional model reduction approaches based on linear approximation spaces. The main ingredients of the proposed approach are (i) an adaptive space-time registration-based data compression procedure to align local features in a fixed reference domain, (ii) a space-time Petrov - Galerkin (minimum residual) formulation for the computation of the mapped solution, and (iii) a hyper-reduction procedure to speed up online computations. We present numerical results for a Burgers model problem and a shallow water model problem, to empirically demonstrate the potential of the method.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Victor Isakov ◽  
Aseel Titi

AbstractThe inverse problem in gravimetry is to find a domain 𝐷 inside the reference domain Ω from boundary measurements of gravitational force outside Ω. We found that about five parameters of the unknown 𝐷 can be stably determined given data noise in practical situations. An ellipse is uniquely determined by five parameters. We prove uniqueness and stability of recovering an ellipse for the inverse problem from minimal amount of data which are the gravitational force at three boundary points. In the proofs, we derive and use simple systems of linear and nonlinear algebraic equations for natural parameters of an ellipse. To illustrate the technique, we use these equations in numerical examples with various location of measurements points on \partial\Omega. Similarly, a rectangular 𝐷 is considered. We consider the problem in the plane as a model for the three-dimensional problem due to simplicity.


2017 ◽  
Vol 23 (1) ◽  
pp. 331-338
Author(s):  
Gheorghe Udeanu

Abstract “The multiple dimension of national security in the international contemporary context - characterized by accelerated, radical changes - is determined by the necessity of constantly promoting and permanently defending our national values and interests against the extraordinary diversity of insecurity factors - destabilizing vectors that manifest themselves in a surprising manner and create difficulties in the process of assessment of the specific disruptive effects. This complex framework of social evolution offers numerous perspectives for the analysis of the concept of security, but these studies do not need to dilute its fundamental connotations, but it is necessary for these efforts to particularly relate to the subsystems that are really relevant for individual and collective security and maintenance and, on the basis of a very good documentation, be exactly circumscribed into the legislative coordinates that correspond to the reference domain.”


Author(s):  
Ioan Neacsu

The interest towards the quality of school-bound and academic learning in the new formal and informal education environments has significantly increased in modern research data from psychology of education, education sciences and neuro epistemology. Relevant issues consistently pop up on the agenda of international organizations and within the decision makers responsible for the sustainable future of new generations of pupils as well as young people. Learning competency and efficient self-management at EU level paradigm cannot disregard curricular values. Hence, there is a need for examining the current context, the stage reached in the reference domain and in certain prestigious scientific research, whose impact is either direct or indirect on the understanding, valorization, and optimization of pupils' and/or students' learning. The arguments invoked are in connection to the nature of challenges waiting for answers, the quality of certain working hypotheses and the ecological validity of empirical research results.


2016 ◽  
Vol 6 (2) ◽  
pp. 91
Author(s):  
Diah Wulandari ◽  
Toni Prahasto ◽  
Vincencius Gunawan

This study aimed to analyze the most influential variable in the implementation of ICT in schools. Principal component analysis  using linear algebra to reduce the dimension of data with variables that are interconnected into a new set of data with variables that are not related to each other, called the principal component. Principal component is used to save and calculate how much correlation within varian. The ICT data is collected from 50 schools, this data is grouped into five group based on reference domain of ICT for education indicator by UIS 2009. Dataset per group is used as input for principal component analysis algorithm with Matlab R2014a and produce principal component. Principal component analysis produce five variable with the most influence based on their domain, there are mean hour for individual using of ICT in curicculum domain, existence school in internet in infrastructure domain, learner proportion in using computer laboratory for learning in teacher development domain, learner propostion that computer basic skill course in participation domain.


Author(s):  
Trung Pham ◽  
Christopher Hoyle ◽  
Yue Zhang ◽  
Tam Nguyen

Topology optimization (TO) aims to find a material distribution within a reference domain, which optimizes objective function(s) and satisfies certain constraints. Topology optimization has various potential applications in early phases of structural design, e.g., reducing structural weight or maximizing structural stiffness. However, most research on TO has focused on linear elastic materials, which has severely restricted applications of TO to hyperelastic structures made of, e.g., rubber or elastomer. While there is some work in literature on TO of nonlinear continua, to the best knowledge of the authors there is no work which investigates the different models of hyperelastic material. Furthermore, topology optimized designs often possess complex geometries and intermediate densities making it difficult to manufacture such designs using conventional methods. Additive Manufacturing (AM) is capable of handling such complexities. Continuing advances in AM will allow for usage of rubber-like materials, which are modeled by hyperelastic constitutive laws, in producing complex structures designed by TO. The contribution of this paper is an investigation of different models of hyperelastic materials taking account of both geometrical and material nonlinearities, and their influences on the resulting topologies. Topology optimization of nonlinear continua is the main topic of few papers. This paper considers different isotropic hyperelastic models including the Ogden, Arruda–Boyce and Yeoh model under finite deformations, which have not yet been implemented in the context of topology optimization of continua. This paper proposes to start with a reference domain having known boundary and loading conditions. Material parameters of different models that fill the domain are also known. Maximizing the stiffness of the structure subject to a volume constraint is used as the design objective. The domain is then meshed into a large number of finite elements, and each element is assigned a density between 0 and 1, which becomes design variable of the optimization problem. These densities are further penalized to make intermediate densities (i.e., not 0 or 1) less favorable. Optimized material distribution will be constructed from optimized values of design variables. Because of the penalization factors that make the problem nonlinear, the Method of Moving Asymptotes (MMA) is utilized to update it iteratively. At each iteration the nonlinear finite element problem is solved using the Finite Element Analysis Program (FEAP), which has been modified to accept penalized densities on element stiffness matrices and internal nodal forces, and a filtering scheme is applied on the sensitivities of objective function to guarantee the existence of solution. The proposed method is tested on several numerical examples. The first two examples are common benchmark models, which are a simply supported beam , and a beam fixed at two ends. Both models are subjected to a concentrated force at midpoints of their edges. The effects of linear and nonlinear material behaviors are compared with regards to resulting designs. The third example is a foremost attempt to reflect on TO in design of airless tire through a simple model, which demonstrates capability of the method in solving real-world design problems.


2015 ◽  
pp. 176
Author(s):  
Pranav Anand ◽  
Caroline Andrews ◽  
Donka Farkas ◽  
Matthew Wagers

In some contexts, plural nominals have inclusive interpretation, allowing atoms in their reference domain; in others, they are exclusive, allowing only sums. Selecting between the two interpretations has been shown to be sensitive to both world-knowledge pressures (Farkas & de Swart 2010) and contextual relevance (Grimm 2010). The principal semantic factor claimed to be involved is monotonicity direction (Sauerland, Anderssen & Yatsushiro 2005; Spector 2007; Zweig 2009; Farkas & de Swart 2010): upward monotone environments tend to select exclusive readings; downward monotone ones, inclusive readings. In four image verification experiments, we tested this claim and found support for the generalization. The effect of monotonicity direction, however, is small. Moreover we find that varying whether a plural is in the scope of a quantified description has a much larger effect on the prevalence of the exclusive interpretation. This suggests that monotonicity, though involved, is not a decisive factor in plural interpretation.


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