environmental constraint
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2021 ◽  
Vol 21 (19) ◽  
pp. 15103-15114
Author(s):  
Alyson Douglas ◽  
Tristan L'Ecuyer

Abstract. Aerosol–cloud–precipitation interactions can lead to a myriad of responses within shallow cumulus clouds, including an invigoration response, whereby aerosol loading results in a higher rain rate, more turbulence, and deepening of the cloud layer. However few global studies have found direct evidence that invigoration occurs. The few satellite-based studies that report evidence for such effects generally focus on only the deepening response. Here, we show evidence of invigoration beyond a deepening response by investigating the effects of aerosol loading on the latent heating and vertical motion profiles of warm rain. Using latent heating and vertical motion profiles derived from CloudSat radar observations, we show precipitating cumulus clouds in unstable, polluted environments exhibit a marked increase in precipitation formation rates and cloud top entrainment rates. However, invigoration is only discernible when the stability of the boundary layer is explicitly accounted for in the analysis. Without this environmental constraint, the mean polluted and pristine cloud responses are indiscernible from each other due to offsetting cloud responses in stable and unstable environments. Invigoration, or suppression depending on the environment, may induce possible feedbacks in both stable and unstable conditions that could subdue or enhance these effects, respectively. The strength of the invigoration response is found to additionally depend on cloud organization defined here by the size of the warm rain system. These results suggest that warm cloud parameterizations must account for not only the possibility of aerosol-induced cloud invigoration, but also the dependence of this invigorated state on the environment and the organization of the rain system.


2021 ◽  
Author(s):  
Linn Schäffer ◽  
Arild Helseth ◽  
Magnus Korpås

<div>We present a medium-term hydropower scheduling model that includes state-dependent environmental constraints on maximum discharge. A stochastic dynamic programming algorithm is used to enable modelling of nonconvex relationships in the problem formulation. The model is applied in a case study of a Norwegian hydropower system with multiple reservoirs. We find that the maximum discharge constraint significantly impacts the water values and simulated operation of the hydropower system. A main finding is that the nonconvex characteristics of the environmental constraint is reflected in the water values, implying a nonconvex objective function. Operation according to the computed water values is simulated for cases with and without the environmental constraint. Even though operation of the system changes considerably when the environmental constraint is included, the total electricity generation over the year is kept constant, and the total loss in expected profit limited to less than 0.8%.</div>


2021 ◽  
Author(s):  
Linn Schäffer ◽  
Arild Helseth ◽  
Magnus Korpås

<div>We present a medium-term hydropower scheduling model that includes state-dependent environmental constraints on maximum discharge. A stochastic dynamic programming algorithm is used to enable modelling of nonconvex relationships in the problem formulation. The model is applied in a case study of a Norwegian hydropower system with multiple reservoirs. We find that the maximum discharge constraint significantly impacts the water values and simulated operation of the hydropower system. A main finding is that the nonconvex characteristics of the environmental constraint is reflected in the water values, implying a nonconvex objective function. Operation according to the computed water values is simulated for cases with and without the environmental constraint. Even though operation of the system changes considerably when the environmental constraint is included, the total electricity generation over the year is kept constant, and the total loss in expected profit limited to less than 0.8%.</div>


2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Jiacan Wang ◽  
Liangzhang Hu

With the in-depth development of the trend of scientific and technological innovation and the implementation of the “Double First-Class” strategy, universities shouldering the scientific research task are constantly promoting the development of scientific research projects with the support of national policies and the scientific research funds are also significantly increased. However, due to the defects of the existing internal control system of scientific research funds in universities, scientific research corruption cases occur frequently. Therefore, it is urgent to build a strong internal control system of scientific research funds to meet the development requirements of the “Double First-class” strategy. For this reason, this paper uses the method of case study, combines the five elements of the COSO internal control system and the internal control norms of Chinese administrative institutions, selects three typical cases of university research corruption, and finally constructs the internal control constraint model of university research funds. This model puts forward suggestions to improve the internal control system of the scientific research funds in universities from four aspects of environmental constraint, psychological constraint, control constraint, and regulatory constraint. Through the construction of the model, it is expected to provide some reference for the construction of the internal control system of scientific research funds in universities.


2021 ◽  
Author(s):  
Alyson Douglas ◽  
Tristan L'Ecuyer

Abstract. Aerosol-cloud-precipitation interactions can lead to a myriad of responses within shallow cumulus clouds including an invigoration response, whereby aerosol loading results in a higher rain rate, more turbulence, and deepening of the cloud layer. However few global studies have found direct evidence that invigoration occurs. The few satellite based studies that report evidence for such effects generally focus on only the deepening response. Here, we show evidence of invigoration beyond a deepening response. Using latent heating and vertical motion profiles derived from CloudSat radar observations, we show precipitating cumulus clouds in unstable, polluted environments exhibit a marked increase in precipitation formation rates and cloud top entrainment rates. However, invigoration is only discernible when the stability of the boundary layer is explicitly accounted for in the analysis. Without this environmental constraint, the mean polluted and pristine cloud responses are indiscernible from each other due to offsetting cloud responses in stable and unstable environments. Invigoration, or suppression depending on the environment, may induce possible feedbacks in both stable and unstable conditions that could subdue or enhance these effects, respectively. The strength of the invigoration response is found to additionally depend on cloud organization defined here by the size of the warm rain system. These results suggest that warm cloud parameterizations must account for not only the possibility of aerosol-induced cloud invigoration, but also the dependence of this invigorated state on the environment and the organization of the rain system.


2021 ◽  
Vol 13 (7) ◽  
pp. 3780
Author(s):  
Seungkyu Ryu

With the increasing level of air pollution and fine dust, many countries are trying to prevent further environmental damage, with various government legislations, such as the Kyoto Protocol and the Paris Agreement. In the transportation field, a variety of environmental protection schemes are also being considered (e.g., banning old diesel vehicles, alternate no-driving systems, electric car subsidies, and environmental cost charging by tax). Imposing environmental constraints is a good approach to reflect various environmental protections. The objective of this research was to analyze the mode-choice and route-choice changes based on imposing environmental constraints. For the objective, a combined modal split and traffic assignment (CMA) model with an environmental constraint model was developed. For the environmental constraint, carbon monoxide (CO) was adopted, because most of the CO emissions in the air are emitted by motorized vehicles. After a detailed description of the model, the validity and some properties of the model and algorithm are demonstrated with two numerical examples (e.g., a small and a real network in the city of Winnipeg, Canada). From the numerical results, we can observe that imposing the small restriction (or strict) value has more efficiency in mode change and reducing network emission.


Author(s):  
Francesco Mignolli ◽  
Javier Barone ◽  
Maria Laura Vidoz

With flooding being one of the numerous challenges that ecosystems face throughout the world, plants are therefore obliged to adopt plastic responses in order to cope with this environmental constraint. When flooded, the tomato hypocotyl undergoes profound changes that entail rearrangements in its physiology and metabolism. In this work, we observed that, although soil flooding markedly dampens root respiration, the submerged hypocotyl surprisingly enhances oxygen consumption in spite of hypoxic conditions. Several pieces of evidence indicate that the respiratory pathway is indeed promoted in submerged stems. Besides, underwater hypocotyls are shown to accumulate sugars. Girdling and feeding experiments revealed that leaf-derived sucrose is metabolized and channelled to maintain respiration in underwater hypocotyls. Our data suggest that high respiration is required for sucrose unloading from phloem, since inhibition of hypocotyls respiration significantly prevents sugar build-up. As substrate availability increases, respiration is fuelled even more, leading to a sustained allocation of sugars to flooded hypocotyls.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Minjung Baek ◽  
Katherine M. Lawin ◽  
Christina J. Codden ◽  
Hangkyo Lim ◽  
Eunjin Yang ◽  
...  

Abstract Different species of water striders match leg speeds to their body sizes to maximize their jump take off velocity without breaking the water surface, which might have aided evolution of leg structures optimized for exploitation of the water surface tension. It is not understood how water striders achieve this match. Can individuals modify their leg movements based on their body mass and locomotor experience? Here we tested if water striders, Gerris latiabdominis, adjust jumping behaviour based on their personal experience and how an experimentally added body weight affects this process. Females, but not males, modified their jumping behaviour in weight-dependent manner, but only when they experienced frequent jumping. They did so within the environmental constraint set by the physics of water surface tension. Females’ ability to adjust jumping may represent their adaptation to frequent increases or decreases of the weight that they support as mating bouts, during which males ride on top of females, start or end, respectively. This suggests that natural selection for optimized biomechanics combined with sexual selection for mating adaptations shapes this ability to optimally exploit water surface tension, which might have aided adaptive radiation of Gerromorpha into a diversity of semiaquatic niches.


Author(s):  
Anuj Kumar ◽  
D. K. Dwivedi ◽  
Pradeep K. Bharti ◽  
Vineeta Singh ◽  
Preeti Kumari ◽  
...  

Rice is the single largest source of food energy for more than half of the world’s population. Salinity may be a serious environmental constraint to crop production. Salinity screening of twenty rice genotypes were performed at the reproductive stages, in the net house of department of PMB&GE. Phenotyping of the genotypes was done at EC 12dS/m at reproductive stage in net house. Most desirable genotypes days to 50% flowering were IR-68144-2B-2-2-3-1-120, CSR-13, FL-478, NDR-359, AYYAR and NUD-2, SAMBHA MANSURI and MTU-1010; for plant height IR-68144-2B-2-2-3-1-127, NUD-3, NUD-2, NDRK-2008, IR-91171-66-3-2-1-3, SAMBHA MANSURI, TARAMON and  MTU-1010; for panicle bearing tillers/plant FL-478, NDR-359 and SWARNA; for panicle length IR-68144-2B-2-2-3-1-127, IR-91167-99-1-1-1-3, IR-29, FL-478, NDRK-2008 and IR-92953-49-1-3; for spikelets/panicle IR-91167-99-1-1-1-3, NDRK-2008, SWARNA , IR-92953-49-1-3, IR-91171-66-3-2-1-3, IR-83668-35-2-2-2 and MTU-1010; for grains/panicle SWARNA, IR-92953-49-1-3, IR-91171-66-3-2-1-3, IR-83668-35-2-2-2, NDRK-2008 and MTU-1010 for spikelet fertility % NUD-3, IR-29, FL-478, NDRK-2008, SWARNA, IR-91171-66-3-2-1-3 and IR-83668-35-2-2-2; for test weight  NUD-3, NDRK-2008, IR-29 and SWARNA for biological yield/plant AYYAR, TARAMON and NUD-3; for harvest index FL-478, IR-68144-2B-2-2-3-1-120, IR-91167-133-1-1-2-3 and NUD-2; for Na+ NUD-3 and FL-478; for K+ IR-91167-133-1-1-2-3, NDR-359 and MTU-1010; for Na+/K+ IR-68144-2B-2-2-3-1-127, IR-91167-99-1-1-1-3, NUD-3, FL-478, IR-64 and SAMBHA MANSURI; for grain yield/ plant (g) AYYAR and FL-478  were reported highly significant in mean performance for yield and its components traits. Analysis of variance, estimates of phenotypic and genotypic coefficient of variation, estimates of heritability and genetic advance in percent of mean were recorded for all the characters among 20 rice genotypes in saline condition. Molecular analysis with SSR markers differentiates the rice genotypes into tolerant and susceptible based on banding pattern. The tolerant rice genotypes were NUD 3, IR-68144-2B-2-2-3-166, IR68144-2B-2-2-3-1-120, IR68100-2B-2-2-3-1-127, IR-1167-31-3-1-33 and IR-91171-66-3-2-1-3 and susceptible were NDR-359, Taramon, MTU-1010,  Swarna and IR-64. The identified salt tolerant genotypes can be potential germplasm sources for future breeding programmes.


2020 ◽  
Vol 12 (4) ◽  
pp. 1315
Author(s):  
Federico Martinelli ◽  
Francisco Javier Ollero ◽  
Antonio Giovino ◽  
Anna Perrone ◽  
Abdelkader Bekki ◽  
...  

In order to gain insight into the complex molecular networks driving legume adaptation caused by climate change, it is necessary to deeply characterize the existing germplasm in response to the environmental constraint predicted to worsen in the near future: drought. In this study, we propose to perform a three-year deep agronomic characterization of local genotypes of selected legumes in abiotic stressing conditions through controlled and field experiments conducted in several countries of the Mediterranean basin (Italy, Spain, Algeria, Tunisia, Turkey, Lebanon, and Croatia). These phenotypic analyses will be integrated with a multi-omic approach aiming at identifying the key players involved in the modulation of the analyzed traits that includes the analysis of the plant methylome, transcriptome, and proteome. Following this approach, we propose to deliver epigenomic markers linked with rapid adaptation mechanisms in response to drought. Besides, new genetic variability by breeding could be created in stressing conditions and produce the basis for the obtainment of more productive cultivars in worsening environments. The epigenetic marks identified in “omic” activities will be validated in molecular marker-assisted selection in F2–F4 populations. Finally, specific rhizobia strains for the best evaluated genotypes will be identified in order to enhance symbiotic nitrogen fixation in drought stress conditions with selected cultivars.


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