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1.
J Environ Manage ; 344: 118751, 2023 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-37573700

RESUMO

This study investigates rational ways to optimize stand-level management decisions from an economic perspective to adjust alternative subsidies, aiming to reduce the CO2 level in the atmosphere and consequently, to mitigate the global warming impacts. An objective function consisting of two parts is used to maximize the current production value that forests represent and the value of forests under the effects of different types of subsidies intended to reduce CO2 levels. The optimal ways of adjusting stand-level management decisions are determined using a general comparative statics analysis, which takes into account alternative forms of climate-related subsidies. The optimal changes to stand-level management decisions are functions of the initial conditions of the stand of trees on which the decision will be made. The results have shown that there are one or two of the alternative forms of CO2 subsidies increase: if the initially optimal values of the stock level after harvesting {V1} is lower than the stock level that maximizes the sustainable yield {VMSY}, and the time interval between harvests {t} is sufficiently short, then the initially optimal value of V1 and t increase; if the initially optimal value of V1 is lower than VMSY, and t is sufficiently long, then the initially optimal values of V1 and t may vary or stay unchanged; if the initially optimal value of V1 is equal to VMSY, and t is very short, then V1 and t are not changed; if the initially optimal value of V1 is higher than VMSY, and/or t is sufficiently long, then the initially optimal values of V1 and t decrease. Our approach of providing decisions at the stand-level can be extended to the broader scales at forest landscapes to address the related challenges.


Assuntos
Dióxido de Carbono , Florestas , Dióxido de Carbono/análise , Árvores , Clima , Aquecimento Global , Carbono
2.
Molecules ; 27(24)2022 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-36557905

RESUMO

This study investigates the bioactive properties of different extracts of cardoon leaves in rescuing neuronal development arrest in an in vitro model of Rett syndrome (RTT). Samples were obtained from plants harvested at different maturity stages and extracted with two different methodologies, namely Naviglio® and supercritical carbon dioxide (scCO2). While scCO2 extracts more hydrophobic fractions, the Naviglio® method extracts phenolic compounds and less hydrophobic components. Only the scCO2 cardoon leaves extract obtained from plants harvested in spring induced a significant rescue of neuronal atrophy in RTT neurons, while the scCO2 extract from the autumn harvest stimulated dendrite outgrowth in Wild-Type (WT) neurons. The scCO2 extracts were the richest in squalene, 3ß-taraxerol and lupeol, with concentrations in autumn harvest doubling those in spring harvest. The Naviglio® extract was rich in cynaropicrin and exerted a toxic effect at 20 µM on both WT and RTT neurons. When cynaropicrin, squalene, lupeol and 3ß-taraxerol were tested individually, no positive effect was observed, whereas a significant neurotoxicity of cynaropicrin and lupeol was evident. In conclusion, cardoon leaves extracts with high content of hydrophobic bioactive molecules and low cynaropicrin and lupeol concentrations have pharmacological potential to stimulate neuronal development in RTT and WT neurons in vitro.


Assuntos
Cynara , Síndrome de Rett , Cynara/química , Esqualeno , Extratos Vegetais/farmacologia , Extratos Vegetais/química
3.
Environ Manage ; 56(5): 1134-47, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26092050

RESUMO

Fragmentation of the forests affects forest ecosystems by changing the composition, shape, and configuration of the resulting patches. Subsequently, the prevailing conditions vary between patches. The exposure to the sun decreases from the patch boundary to the patch interior and this forms core and edge areas within each patch. Forest harvesting and, in particular, the clear-cut management system which is still preferred in many European countries has a significant impact on forest fragmentation. There are many indices of measuring fragmentation: non-spatial and spatial. The non-spatial indices measure the composition of patches, while the spatial indices measure both the shape and configuration of the resulting patches. The effect of forest harvesting on fragmentation, biodiversity, and the environment is extensively studied; however, the integration of fragmentation indices in the harvest scheduling model is a new, novel approach. This paper presents a multi-objective integer model of harvest scheduling for clear-cut management system and presents a case study demonstrating its use. Harvest balance and sustainability are ensured by the addition of constraints from the basic principle of the regulated forest model. The results indicate that harvest balance and sustainability can be also achieved in minimizing fragmentation of forest ecosystems. From the analyses presented in this study, it can be concluded that integration of fragmentation into harvest scheduling can provide better spatial structure. It depends on the initial spatial and age structure. It was confirmed that it is possible to find compromise solution while minimizing fragmentation and maximizing harvested area.


Assuntos
Conservação dos Recursos Naturais , Agricultura Florestal/métodos , Florestas , Modelos Teóricos , Biodiversidade , Picea/crescimento & desenvolvimento
4.
Nanomaterials (Basel) ; 5(1): 233-245, 2015 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-28347008

RESUMO

Within this work we define structural properties of the silicon carbonitride (SiCN) and silicon oxycarbide (SiOC) ceramics which determine the reversible and irreversible lithium storage capacities, long cycling stability and define the major differences in the lithium storage in SiCN and SiOC. For both ceramics, we correlate the first cycle lithiation or delithiation capacity and cycling stability with the amount of SiCN/SiOC matrix or free carbon phase, respectively. The first cycle lithiation and delithiation capacities of SiOC materials do not depend on the amount of free carbon, while for SiCN the capacity increases with the amount of carbon to reach a threshold value at ~50% of carbon phase. Replacing oxygen with nitrogen renders the mixed bond Si-tetrahedra unable to sequester lithium. Lithium is more attracted by oxygen in the SiOC network due to the more ionic character of Si-O bonds. This brings about very high initial lithiation capacities, even at low carbon content. If oxygen is replaced by nitrogen, the ceramic network becomes less attractive for lithium ions due to the more covalent character of Si-N bonds and lower electron density on the nitrogen atom. This explains the significant difference in electrochemical behavior which is observed for carbon-poor SiCN and SiOC materials.

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