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•Boron stress, toxicity or deficiency, occurs frequently in plants worldwide.•This stress decreases plant production and fruit quality.•Boron stresses occur simultaneously with other ...as salinity, drought, light, etc.•This ms studies the plants response under combination stresses including Boron.
Boron (B), an essential nutrient for plants, participates in many physiological processes, with emphasis its role in the formation of the plant’s cell wall. In soil, the range between deficiency and toxicity of B is very narrow as compared to other nutrients, which makes its management in agriculture very difficult, as it depends on the soil and environmental conditions. B stress simultaneously acts with others (extreme temperatures, excess of light, high concentration of CO2, drought, salinity or heavy metal contamination, etc.). The effects of these other stresses could increase the sensitivity of plants to B toxicity or deficiency. The simultaneous combination (B stress × other abiotic stresses) is a complex interaction that should be analyzed in detail if the resistance of crops to climate change is needed. This article reviews the response of plants when facing a combination of B stress with other stresses, and compares this response with the individual stresses. Also, in the last few years, the role of B has been described in multiple plant functions that can improve its resilience to specific stresses. Thus, this article also analyses in what conditions the application of B can be efficient for the improvement of the plant’s response to other stresses.
We report the process of singlet exciton fission with high-yield upon photoexcitation of a quinoidal thiophene molecule. Efficient ultrafast triplet photogeneration and its yield are determined by ...photoinduced triplet–triplet absorption, flash photolysis triplet lifetime measurements, as well as by femtosecond time-resolved transient absorption and fluorescence methods. These experiments show that optically excited quinoidal bithiophene molecule undergoes ultrafast formation of the triplet-like state with the lifetime ∼57 μs. CASPT2 and RAS-SF calculations have been performed to support the experimental findings. To date, high singlet fission rates have been reported for crystalline and polycrystalline materials, whereas for covalently linked dimers and small oligomers it was found to be relatively small. In this contribution, we show an unprecedented quantum yield of intramolecular singlet exciton fission of ∼180% for a quinoidal bithiophene system.
A
bstract
We construct families of supersymmetric AdS
3
×
Y
7
and AdS
3
×
Y
8
solutions to type IIB string theory and M-theory, respectively. Here
Y
7
is an
S
5
fibration over Σ, while
Y
8
is an
S
4
...fibration over Σ
g
× Σ, where Σ
g
is a Riemann surface of genus
g >
1 and Σ is a two-dimensional orbifold known as a spindle. We interpret the solutions as near-horizon limits of
N
D3-branes wrapped on Σ and
N
M5-branes wrapped on Σ
g
× Σ, respectively. These are holographically dual to
d
= 2, (0
,
2) SCFTs, and we show that the central charge and superconformal R-symmetry of the gravity solutions agree with dual field theory calculations.
The study of the origin of life and current undergoing efforts to produce artificial chemical systems mimicking the behavior of natural living systems have emerged as a hot topic at the interfaces ...among disciplines. In these two problems, the spontaneous generation of free‐energy gradients by means of material interfaces plays a central role and, until recently, hindered progress. Polymerization‐induced self‐assembly (PISA) is a promising strategy for the formation of polymeric vesicles from a homogeneous mixture which, in the form of artificial biology, may reflect and inform the generation of vesicular structures in primitive Earth. In the past few years, PISA has been used for the construction of biomimetic vesicles or artificial protocells in artificial biology. These not only give inspiration for decoding some aspects of the origin of life in arbitrary environments but also offer potential for building innovative functional systems with a wide variety of applications. In this review, a brief summary of some of the unique possibilities offered by PISA and the development of PISA in exploration of artificial biology is provided, while some of the allied current challenges, limitations, and opportunities in this exciting field are highlighted.
Polymerization‐induced self‐assembly (PISA) is an emerging strategy for autonomous assembly and provides unique advantages for constructing self‐assembling cell‐like compartments in artificial biology. Developments in this field not only reveal useful clues for understanding the origin of life but also have potential practical applications. In this review recent advances, opportunities, and challenges are summarized and discussed.
Accelerating black holes and spinning spindles Ferrero, Pietro; Gauntlett, Jerome P.; Pérez Ipiña, Juan Manuel ...
Physical review. D,
08/2021, Letnik:
104, Številka:
4
Journal Article
Recenzirano
Odprti dostop
We study solutions in the Plebański–Demiański family which describe an accelerating, rotating, and dyonically charged black hole in AdS 4 . These are solutions of D = 4 Einstein-Maxwell theory with a ...negative cosmological constant and hence minimal D = 4 gauged supergravity. It is well known that when the acceleration is nonvanishing the D = 4 black hole metrics have conical singularities. By uplifting the solutions to D = 11 supergravity using a regular Sasaki-Einstein seven-manifold, SE7, we show how the free parameters can be chosen to eliminate the conical singularities. Topologically, the D = 11 solutions incorporate an S E 7 fibration over a two-dimensional weighted projective space, WCP1n−, n+, also known as a spindle, which is labeled by two integers that determine the conical singularities of the D = 4 metrics. We also discuss the supersymmetric and extremal limit and show that the near horizon limit gives rise to a new family of regular supersymmetric AdS2 × Y9 solutions of D = 11 supergravity, which generalize a known family by the addition of a rotation parameter. We calculate the entropy of these black holes and argue that it should be possible to derive this from certain N = 2 , d = 3 quiver gauge theories compactified on a spinning spindle with the appropriate magnetic flux.
Computational thinking (CT) is being located at the focus of educational innovation, as a set of problem-solving skills that must be acquired by the new generations of students to thrive in a digital ...world full of objects driven by software. However, there is still no consensus on a CT definition or how to measure it. In response, we attempt to address both issues from a psychometric approach. On the one hand, a Computational Thinking Test (CTt) is administered on a sample of 1,251 Spanish students from 5th to 10th grade, so its descriptive statistics and reliability are reported in this paper. On the second hand, the criterion validity of the CTt is studied with respect to other standardized psychological tests: the Primary Mental Abilities (PMA) battery, and the RP30 problem-solving test. Thus, it is intended to provide a new instrument for CT measurement and additionally give evidence of the nature of CT through its associations with key related psychological constructs. Results show statistically significant correlations at least moderately intense between CT and: spatial ability (r = 0.44), reasoning ability (r = 0.44), and problem-solving ability (r = 0.67). These results are consistent with recent theoretical proposals linking CT to some components of the Cattel-Horn-Carroll (CHC) model of intelligence, and corroborate the conceptualization of CT as a problem-solving ability.
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•A Computational Thinking Test (CTt) aimed at Grades 5th to 10th is provided•Computational thinking correlates moderately with spatial and reasoning abilities•Computational thinking correlates strongly with problem-solving ability•Results are consistent with proposals linking CT with the CHC model of intelligence•Gender differences in computational thinking performance are discussed
The rhizosphere microbiome is pivotal for plant health and growth, providing defence against pests and diseases, facilitating nutrient acquisition and helping plants to withstand abiotic stresses. ...Plants can actively recruit members of the soil microbial community for positive feedbacks, but the underlying mechanisms and plant traits that drive microbiome assembly and functions are largely unknown. Domestication of plant species has substantially contributed to human civilization, but also caused a strong decrease in the genetic diversity of modern crop cultivars that may have affected the ability of plants to establish beneficial associations with rhizosphere microbes. Here, we review how plants shape the rhizosphere microbiome and how domestication may have impacted rhizosphere microbiome assembly and functions via habitat expansion and via changes in crop management practices, root exudation, root architecture, and plant litter quality. We also propose a “back to the roots” framework that comprises the exploration of the microbiome of indigenous plants and their native habitats for the identification of plant and microbial traits with the ultimate goal to reinstate beneficial associations that may have been undermined during plant domestication.
•We present two mixed-integer problems for cost-based attribute selection.•The attribute acquisition costs are incorporated explicitly in our framework.•The attribute acquisition costs are estimated ...for a credit scoring project.•Our method leads to a ten-fold reduction in costs in a real-life lending dataset.
In this work we propose two formulations based on Support Vector Machines for simultaneous classification and feature selection that explicitly incorporate attribute acquisition costs. This is a challenging task for two main reasons: the estimation of the acquisition costs is not straightforward and may depend on multivariate factors, and the inter-dependence between variables must be taken into account for the modelling process since companies usually acquire groups of related variables rather than acquiring them individually. Mixed-integer linear programming models are proposed for constructing classifiers that constrain acquisition costs while classifying adequately. Experimental results using credit scoring datasets demonstrate the effectiveness of our methods in terms of predictive performance at a low cost compared to well-known feature selection approaches.
From the conceptualization to the evaluation of computer‐supported collaborative learning (CSCL) scenarios, teachers address multiple tasks, sometimes being overwhelmed on account of the required ...time and associated burden. To support teachers in this endeavor, we propose to connect the pedagogical decisions made at design time with the analysis of the participants' interactions. Thus, teachers would be provided with relevant and coarse‐grained information that could help them manage their CSCL scenarios. This paper synthesizes the main contributions obtained from a 3‐year design‐based research process, and presents the findings obtained from the evaluation of the current proposal in two authentic CSCL scenarios. The participant teachers valued the proposal positively and stated that it was helpful for their orchestration of CSCL scenarios.
Recent years have seen the massive migration of enterprise applications to the cloud. One of the challenges posed by cloud applications is Quality-of-Service (QoS) management, which is the problem of ...allocating resources to the application to guarantee a service level along dimensions such as performance, availability and reliability. This paper aims at supporting research in this area by providing a survey of the state of the art of QoS modeling approaches suitable for cloud systems. We also review and classify their early application to some decision-making problems arising in cloud QoS management.
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