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PLoS Biology ◽  
2021 ◽  
Vol 19 (7) ◽  
pp. e3001340
Author(s):  
Oskar Hagen ◽  
Benjamin Flück ◽  
Fabian Fopp ◽  
Juliano S. Cabral ◽  
Florian Hartig ◽  
...  

Understanding the origins of biodiversity has been an aspiration since the days of early naturalists. The immense complexity of ecological, evolutionary, and spatial processes, however, has made this goal elusive to this day. Computer models serve progress in many scientific fields, but in the fields of macroecology and macroevolution, eco-evolutionary models are comparatively less developed. We present a general, spatially explicit, eco-evolutionary engine with a modular implementation that enables the modeling of multiple macroecological and macroevolutionary processes and feedbacks across representative spatiotemporally dynamic landscapes. Modeled processes can include species’ abiotic tolerances, biotic interactions, dispersal, speciation, and evolution of ecological traits. Commonly observed biodiversity patterns, such as α, β, and γ diversity, species ranges, ecological traits, and phylogenies, emerge as simulations proceed. As an illustration, we examine alternative hypotheses expected to have shaped the latitudinal diversity gradient (LDG) during the Earth’s Cenozoic era. Our exploratory simulations simultaneously produce multiple realistic biodiversity patterns, such as the LDG, current species richness, and range size frequencies, as well as phylogenetic metrics. The model engine is open source and available as an R package, enabling future exploration of various landscapes and biological processes, while outputs can be linked with a variety of empirical biodiversity patterns. This work represents a key toward a numeric, interdisciplinary, and mechanistic understanding of the physical and biological processes that shape Earth’s biodiversity.


Author(s):  
Andrea Coraddu ◽  
Luca Oneto ◽  
Francesca Cipollini ◽  
Miltos Kalikatzarakis ◽  
Gert-Jan Meijn ◽  
...  

2021 ◽  
Author(s):  
Oskar Hagen ◽  
Benjamin Flück ◽  
Fabian Fopp ◽  
Juliano S. Cabral ◽  
Florian Hartig ◽  
...  

AbstractUnderstanding the origins of biodiversity has been an aspiration since the days of early naturalists. The immense complexity of ecological, evolutionary and spatial processes, however, has made this goal elusive to this day. Computer models serve progress in many scientific fields, but in the fields of macroecology and macroevolution, eco-evolutionary models are comparatively less developed. We present a general, spatially-explicit, eco-evolutionary engine with a modular implementation that enables the modelling of multiple macroecological and macroevolutionary processes and feedbacks across representative spatio-temporally dynamic landscapes. Modelled processes can include environmental filtering, biotic interactions, dispersal, speciation and evolution of ecological traits. Commonly observed biodiversity patterns, such as α, β and γ diversity, species ranges, ecological traits and phylogenies, emerge as simulations proceed. As a case study, we examined alternative hypotheses expected to have shaped the latitudinal diversity gradient (LDG) during the Earth’s Cenozoic era. We found that a carrying capacity linked with energy was the only model variant that could simultaneously produce a realistic LDG, species range size frequencies, and phylogenetic tree balance. The model engine is open source and available as an R-package, enabling future exploration of various landscapes and biological processes, while outputs can be linked with a variety of empirical biodiversity patterns. This work represents a step towards a numeric and mechanistic understanding of the physical and biological processes that shape Earth’s biodiversity.


Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Tongjin Qian ◽  
Peng Yao ◽  
Mei Guo ◽  
Dong Wang ◽  
Yuan Yao

The adaptive object model method is an effective way to develop dynamic and configurable adaptive software. It has the characteristics of metamodel, description drive, and runtime reflection. First, the core idea of the adaptive object model is explained; then, the five modes of establishing the metamodel in the adaptive object model architecture, the model engine, and supporting tools are analyzed; and the basketball tracking algorithm of the adaptive object model is discussed. Secondly, a two-dimensional joint information strategy is proposed to improve the tracking effect. When the basketball is in a very complex environment, there will always be some color information in the background that is the same as the target, which affects the effect of basketball tracking. Therefore, this paper proposes a Camshift tracking method based on the significance of histograms, through real time. The basketball movement is compared with the background histogram to continuously adjust the basketball movement tracking model. These two methods can better establish the tracking model of the basketball adaptive object, reduce the interference of background information, and achieve the effect of stable tracking of the target. The simulation experiment results show that the method proposed in this paper can effectively improve the accuracy of the basketball goal model and achieve stable tracking of the goal.


2020 ◽  
Author(s):  
Kayla Iacovino ◽  
Simon Matthews ◽  
Penny Wieser ◽  
Gordon Moore ◽  
Florence Bégué

Catalysts ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1257
Author(s):  
Evgeny A. Alikin ◽  
Sergey P. Denisov ◽  
Konstantin V. Bubnov ◽  
Aleksey A. Vedyagin

One of the most important features of the three-way catalysts is their long-term stability. However, quite often, promising catalytic compositions with excellent activity become deactivated after a relatively short period of exploitation due to various reasons. Therefore, a study on the onboard regeneration of the deactivated three-way catalysts remains its actuality. The present work is mainly focused on the self-regeneration effect of the rhodium-containing component. Aging of the catalysts in the standard and model engine braking regimes revealed the difference in the catalytic performance. Deactivated rhodium species turned to the active state as a result of rapid cooling in air flow from 1200 to 600 °C. The regenerated catalyst shows improved activity towards NOx reduction and, therefore, widened operation window, which indicates higher accessibility of the rhodium species. X-ray diffraction analysis of the aged catalysts does not reveal any noticeable phase changes. Contrary, significant changes in the Rh oxidation state were registered by X-ray photoelectron spectroscopy. The observed effect opens new horizons for the development of the onboard purification systems with prolonged exploitation lifetime.


Author(s):  
Rodolfo Romboli Narcizo ◽  
Cláudio Jorge Alves ◽  
Mauro Caetano

The choice of fleet by a given airline must consider different elements associated with both the aircraft and the airports to be operated, making it necessary a method to assist the aircraft choice process. This study assesses the take-off runway distance requirement of different aircraft models and compares the requirement to the take-off runway distance available at a group of airports. Using the Herfindahl-Hirschman index (HHI), the methodology consider the analysis of take-off runway length available on 80 Brazilian airports and compared it to the take-off distance required for 108 combinations of aircraft model, engine model and flight range, considering the take-off performance of the aircraft models with maximum payload weight. In total, 536 routes of four Brazilian airlines has been adopted to simulate the most profitable operating scenario. The result presents the take-off performance of different aircraft models and allows a performance comparison between them. In addition, this research investigates which is the most common flight range in Brazil, and what influence it exerts in the aircraft take-off performance, and contributes to a better match between the aircraft used and the airport operated in fleet optimization.


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