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1.
Braz. j. biol ; 84: e256425, 2024. tab, graf, mapas
Artigo em Inglês | LILACS-Express | LILACS, VETINDEX | ID: biblio-1364525

RESUMO

Using inventory data, this study evaluates the species composition, growing stock volume (GSV), and biomass carbon (BMC) of the five major timber species in the sub-tropical, and temperate/sub-alpine regions of Pakistan. It was found that the stem density varies between 50 and 221 trees ha -1, with a mean of 142 trees ha-1 (13.68 million trees for entire forest area). Among the species, Pinus wallichiana showed a high species composition (27.80%) followed by Picea smithiana (24.64%). The GSV was found in the range of 67.81 to 425.94 m3 ha-1, with a total GSV value of 20.68 million m3 for the entire region. Similarly, The BMC ranged from 27.04 to 169.86 Mg ha-1, with a mean BMC value of 86.80 Mg ha-1. The total amount of stored carbon was found at 8.69 million tons for a total of 95842 ha of commercially managed forest. Furthermore, the correlation analysis between the basal area (BA) and GSV and BMC showed that BA is the best predictor of GSV and BMC. The findings provide insights to the policy makers and forest managers regarding the sustainable commercial forest management as well as forest carbon management in the recent global carbon management for climate change mitigation.


Usando dados de inventário, este estudo avaliou a composição de espécies, volume de estoque crescente (GSV) e carbono de biomassa (BMC) das cinco principais espécies madeireiras nas regiões subtropicais e temperadas/subalpinas do Paquistão. Constatou-se que a densidade do caule variou entre 50 e 221 árvores ha-1, com média de 142 árvores ha-1 (13,68 milhões de árvores para toda a área florestal). Entre as espécies, Pinus wallichiana apresentou alta composição de espécies (27,80%), seguida de Picea smithiana (24,64%). O GSV foi encontrado na faixa de 67,81 a 425,94 m3 ha-1, com um valor total de 20,68 milhões de m3 para toda a região. Da mesma forma, o BMC variou de 27,04 a 169,86 mg ha-1, com valor médio de 86,80 mg ha-1. A quantidade total de carbono armazenado foi de 8,69 milhões de toneladas para um total de 95.842 ha de floresta manejada comercialmente. Além disso, a análise de correlação entre área basal (BA), GSV e BMC mostrou que BA é o melhor preditor de GSV e BMC. As descobertas fornecem insights para os formuladores de políticas e gestores florestais sobre o manejo florestal comercial sustentável, bem como o manejo florestal de carbono no recente gerenciamento global de carbono para a mitigação das mudanças climáticas.


Assuntos
Árvores/crescimento & desenvolvimento , Carbono , Florestas , Biomassa
2.
Food Chem ; 398: 133822, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-35961169

RESUMO

A portable device is conducive to the on-site detection of heavy metal ions at trace level in food and the prevention of related food safety issues. In this work, an electrochemical device stacked up with flat electrodes was developed for the detection of Pb2+ and Cd2+. The top layer of the device is a carbon paper as working electrode, which is modified with amino functionalized cobalt-based metal-organic framework and gold nanoparticles. The bottom layer was constructed with the carbon counter electrode and Ag/AgCl reference electrode, and a punched sample cell (Φ = 8 mm) was in the middle. The proposed method could simultaneously determinate Pb2+ and Cd2+ via anodic stripping voltammetry with the detection limit of 7.0 × 10-2 ng mL-1 and 1.1 × 10-2 ng mL-1, and was applied in real food samples (drinking water, juice, tea, grain, fruits, vegetables, liver and aquatic products) with the recovery of 91.2-105.4 % and 90.2-111.2 %, respectively.


Assuntos
Nanopartículas Metálicas , Estruturas Metalorgânicas , Cádmio , Carbono , Eletrodos , Ouro , Íons , Chumbo
3.
Food Chem ; 398: 133935, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-35986995

RESUMO

Nitrite is a widely used food additive that has been shown to be carcinogenic and can cause health damage when consumed in excess. Therefore, developing a detection method is in demand. Here, we prepared a novel Fe-doped carbon dots (Fe-CDs) using metallic deep eutectic solvent (MDES) which showed high sensitivity and selectivity. Besides, it also showed excellent pH-dependent luminescence characteristics, which proved the feasibility as a pH sensor. Under the optimal conditions, the detection linear of nitrite ranged from 0.2 to 80 µM, and the detection limit was 50 nM. The recovery rate was between 98.8 % and 104.1 % in food and water samples. For pH monitoring, its fluorescence intensity was linearly correlated in the pH range from 2 to 7, accompanying a unique differential solution color change of colorless-yellow-green. Therefore, it can be used as an excellent fluorescent probe for detection of nitrite and pH in food and water environment.


Assuntos
Corantes Fluorescentes , Pontos Quânticos , Carbono , Solventes Eutéticos Profundos , Concentração de Íons de Hidrogênio , Nitritos , Solventes , Água
4.
Food Chem ; 399: 133970, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-35998499

RESUMO

Lateral flow immunoassays (LFIAs) are routine methods for rapid foodborne pollutants screening, with detection limits that are closely associated with the label probes used. The exploitation of high performance and robust probe is highly desirable, and remains a great challenge. Herein, we reported an emerging fluorescent nanobeads i.e. carbon-dots (CD) covalently incorporated mesoporous silicon nanoparticles (CD-MSNs) for LFIAs. CD-MSNs revealed brighter fluorescence, larger particle size and more modification sites in comparison with those of single CD. After bio-functionalisation, CD-MSNs probes were introduced to construct LFIA test strips, and designed for ultrasensitive detection of aflatoxin B1 (AFB1) and Staphylococcus aureus (S. aureus), two representative foodborne pollutants, based on the competitive and sandwich models, respectively. Very competitive quantitative detection limits i.e. 0.05 ng/mL and 102 cfu/mL were correspondingly obtained. Additionally, the test strips were successfully applied to rapidly and accurately screen AFB1 and S. aureus in food samples, highlighting their practicality.


Assuntos
Poluentes Ambientais , Nanopartículas , Aflatoxina B1/análise , Carbono , Corantes Fluorescentes , Imunoensaio/métodos , Limite de Detecção , Silício , Staphylococcus aureus
5.
Braz. j. biol ; 83: e249424, 2023. graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1345538

RESUMO

Abstract Hypoxia is a prominent feature of head and neck cancer. However, the oxygen element characteristics of proteins and how they adapt to hypoxia microenvironments of head and neck cancer are still unknown. Human genome sequences and proteins expressed data of head and neck cancer were retrieved from pathology atlas of Human Protein Atlas project. Then compared the oxygen and carbon element contents between proteomes of head and neck cancer and normal oral mucosa-squamous epithelial cells, genome locations, pathways, and functional dissection associated with head and neck cancer were also studied. A total of 902 differentially expressed proteins were observed where the average oxygen content is higher than that of the lowly expressed proteins in head and neck cancer proteins. Further, the average oxygen content of the up regulated proteins was 2.54% higher than other. None of their coding genes were distributed on the Y chromosome. The up regulated proteins were enriched in endocytosis, apoptosis and regulation of actin cytoskeleton. The increased oxygen contents of the highly expressed and the up regulated proteins might be caused by frequent activity of cytoskeleton and adapted to the rapid growth and fast division of the head and neck cancer cells. The oxygen usage bias and key proteins may help us to understand the mechanisms behind head and neck cancer in targeted therapy, which lays a foundation for the application of stoichioproteomics in targeted therapy and provides promise for potential treatments for head and neck cancer.


Resumo A hipóxia é uma característica proeminente do câncer de cabeça e pescoço. No entanto, as características do elemento oxigênio das proteínas e como elas se adaptam aos microambientes de hipóxia do câncer de cabeça e pescoço ainda são desconhecidas. Sequências do genoma humano e dados expressos de proteínas de câncer de cabeça e pescoço foram recuperados do atlas de patologia do projeto Human Protein Atlas. Em seguida, comparou o conteúdo do elemento de oxigênio e carbono entre proteomas de câncer de cabeça e pescoço, e células epiteliais escamosas da mucosa oral normal, localizações do genoma, vias e dissecção funcional associada ao câncer de cabeça e pescoço também foram estudadas. Um total de 902 proteínas expressas diferencialmente foi observado onde o conteúdo médio de oxigênio é maior do que as proteínas expressas de forma humilde em proteínas de câncer de cabeça e pescoço. Além disso, o conteúdo médio de oxigênio das proteínas reguladas positivamente foi 2,54% maior do que das outras. Nenhum de seus genes codificadores foi distribuído no cromossomo Y. As proteínas reguladas positivamente foram enriquecidas em endocitose, apoptose e regulação do citoesqueleto de actina. O conteúdo aumentado de oxigênio das proteínas altamente expressas e reguladas pode ser causado pela atividade frequente do citoesqueleto e adaptado ao rápido crescimento e divisão das células cancerosas de cabeça e pescoço. O viés do uso de oxigênio e as proteínas-chave podem nos ajudar a entender os mecanismos por trás do câncer de cabeça e pescoço na terapia direcionada, o que estabelece uma base para a aplicação da estequioproteômica na terapia direcionada e oferece uma promessa para potenciais tratamentos para o câncer de cabeça e pescoço.


Assuntos
Humanos , Neoplasias de Cabeça e Pescoço/genética , Oxigênio , Carbono , Proteoma/genética , Microambiente Tumoral
6.
Braz. j. biol ; 83: e246002, 2023. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1285612

RESUMO

Abstract Economic valuation of ecosystem services is a new concept in forest management. Economic valuation provides basis for payment for ecosystem services (PES). Therefore, objective of this study was to evaluate eco-tourism and carbon stock services of the Maindam valley, District Swat, Pakistan. For the carbon stock calculation, a sample size of 155 plots of 0.1 hectare (Ha) was taken using preliminary survey at 95% confidence interval and 10% allowable error. The data for tourism services was collected from owners of all the hotels, 100 tourists and key informants of the area at 10% sampling intensity on pretested questionnaire for twenty years period (1997-2017). Results showed that Miandam valley has carbon stock worth US$ 16,306,000 while the value of eco-tourism was US$ 1,578,458 on annual basis. The results also showed that trend of tourism has drastically declined after the 9/11 incident for foreigners and locals and the situation was further deteriorated during the era of Talibanization or militancy from 2008-2011. This study recommends implementation of PES strategy at the rate of 5%, thus a total of US$ 78,922 can be earned from eco-tourism and carbon crediting in the study area annually, which could play important role in sustainable forest management.


Resumo A valoração econômica dos serviços ecossistêmicos é um novo conceito no manejo florestal. A avaliação econômica fornece base para o pagamento por serviços ecossistêmicos (PES). Portanto, o objetivo deste estudo foi avaliar o ecoturismo e os serviços de estoque de carbono do vale de Miandam, distrito Swat, Paquistão. Para o cálculo do estoque de carbono, um tamanho de amostra de 155 parcelas de 0,1 hectare (ha) foi tirado, usando pesquisa preliminar com intervalo de confiança de 95% e erro admissível de 10%. Os dados para serviços de turismo foram coletados de proprietários de todos os hotéis, 100 turistas e informantes-chave da área em 10% de intensidade de amostragem em questionário pré-testado para um período de 20 anos (1997-2017). Os resultados mostraram que o vale de Miandam tem estoque de carbono no valor de US$ 16.306.000, enquanto o valor do ecoturismo foi de US$ 1.578.458 anualmente. Os resultados também mostraram que a tendência do turismo diminuiu drasticamente para estrangeiros e locais após o incidente de 11 de Setembro, e a situação se agravou ainda mais durante a era da talibanização ou militância de 2008-2011. Este estudo recomenda a implementação da estratégia de PES na taxa de 5%, portanto um total de US$ 78.922 pode ser ganho com ecoturismo e crédito de carbono na área de estudo anualmente, o que pode desempenhar um papel importante no manejo florestal sustentável.


Assuntos
Ecossistema , Conservação dos Recursos Naturais , Paquistão , Carbono/análise , Florestas
7.
Commun Biol ; 5(1): 164, 2022 02 24.
Artigo em Inglês | MEDLINE | ID: mdl-35210545

RESUMO

Quantification of system dynamics is a central aim of mathematical modelling in biology. Defining experimentally supported functional relationships between molecular entities by mathematical terms enables the application of computational routines to simulate and analyse the underlying molecular system. In many fields of natural sciences and engineering, trigonometric functions are applied to describe oscillatory processes. As biochemical oscillations occur in many aspects of biochemistry and biophysics, Fourier analysis of metabolic functions promises to quantify, describe and analyse metabolism and its reaction towards environmental fluctuations. Here, Fourier polynomials were developed from experimental time-series data and combined with block diagram simulation of plant metabolism to study heat shock response of photosynthetic CO2 assimilation and carbohydrate metabolism in Arabidopsis thaliana. Simulations predicted a stabilising effect of reduced sucrose biosynthesis capacity and increased capacity of starch biosynthesis on carbon assimilation under transient heat stress. Model predictions were experimentally validated by quantifying plant growth under such stress conditions. In conclusion, this suggests that Fourier polynomials represent a predictive mathematical approach to study dynamic plant-environment interactions.


Assuntos
Proteínas de Arabidopsis , Proteínas de Arabidopsis/metabolismo , Carbono/metabolismo , Folhas de Planta , Sacarose/metabolismo , Temperatura
8.
Anticancer Res ; 42(5): 2469-2477, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35489744

RESUMO

BACKGROUND/AIM: This study aimed to establish a setup for ultra-high-dose-rate (FLASH) carbon-ion irradiation, and to conduct the first human cell experiments using FLASH carbon ions. MATERIALS AND METHODS: A system for FLASH carbon-ion irradiation (1-3 Gy at 13 or 50 keV/µm) was developed. The growth and senescence of HFL1 lung fibroblasts were assessed by crystal violet staining assays and senescence-associated ß-galactosidase staining, respectively. Survival of HSGc-C5 cancer cells was assessed by clonogenic assays. RESULTS: The dose rates of carbon ions ranged from 96-195 Gy/s, meeting the definition of FLASH. With both 13 and 50 keV/µm beams, no FLASH sparing effect was observed on the growth suppression and senescence of HFL1 cells, nor on the survival of HSGc-C5 cells. CONCLUSION: We successfully conducted the first human cell experiments with FLASH carbon ions. No FLASH effect was observed under the conditions examined.


Assuntos
Carbono , Radioterapia com Íons Pesados , Fibroblastos/efeitos da radiação , Humanos , Íons
9.
Nat Commun ; 13(1): 5188, 2022 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-36057727

RESUMO

Humankind relies on specialized metabolites for medicines, flavors, fragrances, and numerous other valuable biomaterials. However, the chemical space occupied by specialized metabolites, and, thus, their application potential, is limited because their biosynthesis is based on only a handful of building blocks. Engineering organisms to synthesize alternative building blocks will bypass this limitation and enable the sustainable production of molecules with non-canonical chemical structures, expanding the possible applications. Herein, we focus on isoprenoids and combine synthetic biology with protein engineering to construct yeast cells that synthesize 10 non-canonical isoprenoid building blocks with 16 carbon atoms. We identify suitable terpene synthases to convert these building blocks into C16 scaffolds and a cytochrome P450 to decorate the terpene scaffolds and produce different oxygenated compounds. Thus, we reconstruct the modular structure of terpene biosynthesis on 16-carbon backbones, synthesizing 28 different non-canonical terpenes, some of which have interesting odorant properties.


Assuntos
Carbono , Terpenos , Sistema Enzimático do Citocromo P-450/genética , Sistema Enzimático do Citocromo P-450/metabolismo , Engenharia de Proteínas , Biologia Sintética , Terpenos/metabolismo
10.
World J Surg Oncol ; 20(1): 282, 2022 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-36058930

RESUMO

BACKGROUND: The clinical application of robotic-assisted gastrectomy remains controversial, especially as clinical studies of this operation navigated by carbon nanoparticle suspension injection (CNSI) have not been conducted. This study aims to assess the perioperative safety and efficacy of CNSI-guided robotic-assisted gastrectomy in patients with gastric cancer by focusing on short-term outcomes. METHODS: A retrospective analysis of patients who underwent CNSI-guided laparoscopic or robotic-assisted gastrectomy with a pathological diagnosis of gastric cancer was conducted. Data on demographics, surgical management, clinical-pathological results and short-term outcomes were compared among the groups. RESULTS: A total of 126 eligible patients were separated into the robotic-assisted gastrectomy (RAG) group (n = 16) and the laparoscopic gastrectomy (LG) group (n = 110) in total. The operation time of the RAG group is longer than the LG group (p = 0.0000). When it comes to perioperative and short-term complications, there exists no statistical difference between the two groups. CONCLUSION: The time required for CNSI-guided robotic-assisted gastrectomy is longer than that for CNSI-guided laparoscopic gastrectomy. CNSI-guided robotic-assisted gastrectomy is safe and effective.


Assuntos
Laparoscopia , Nanopartículas , Procedimentos Cirúrgicos Robóticos , Neoplasias Gástricas , Carbono , Gastrectomia/métodos , Humanos , Laparoscopia/métodos , Complicações Pós-Operatórias/cirurgia , Estudos Retrospectivos , Procedimentos Cirúrgicos Robóticos/métodos , Neoplasias Gástricas/patologia , Neoplasias Gástricas/cirurgia
11.
Sci Rep ; 12(1): 15064, 2022 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-36065006

RESUMO

Food systems (FSs) emit ~ 20 GtCO2e/y (~ 35% of global greenhouse gas emissions). This level tends to raise given the expected increases in food demands, which may threaten global climate targets. Through a rapid assessment, evaluating 60+ scenarios based on existing low-emission and carbon sequestration practices, we estimate that intensifying FSs could reduce its emissions from 21.4 to - 2.0 GtCO2e/y and address increasing food demands without relying on carbon offsets (e.g., related to afforestation and reforestation programs). However, given historical trends and regional contexts, a more diverse portfolio of practices, including diet shifts and new-horizon technologies, will be needed to increase the feasibility of achieving net-zero FSs. One likely pathway consists of implementing practices that shift food production to the 30th-percentile of least emission-intensive FSs (~ 45% emissions reduction), sequester carbon at 50% of its potential (~ 5 GtCO2e/y) and adopt diet shifts and new-horizon technologies (~ 6 GtCO2e/y). For a successful transition to happen, the global FSs would, in the next decade (2020s), need to implement cost-effective mitigation practices and technologies, supported by improvements in countries' governance and technical assistance, innovative financial mechanisms and research focused on making affordable technologies in the following two decades (2030-2050). This work provides options and a vision to guide global FSs to achieving net-zero by 2050.


Assuntos
Sequestro de Carbono , Gases de Efeito Estufa , Carbono , Clima , Alimentos , Efeito Estufa
12.
Nat Commun ; 13(1): 5243, 2022 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-36068201

RESUMO

Methanol is a liquid with high energy storage capacity that holds promise as an alternative substrate to replace sugars in the biotechnology industry. It can be produced from CO2 or methane and its use does not compete with food and animal feed production. However, there are currently only limited biotechnological options for the valorization of methanol, which hinders its widespread adoption. Here, we report the conversion of the industrial platform organism Escherichia coli into a synthetic methylotroph that assimilates methanol via the energy efficient ribulose monophosphate cycle. Methylotrophy is achieved after evolution of a methanol-dependent E. coli strain over 250 generations in continuous chemostat culture. We demonstrate growth on methanol and biomass formation exclusively from the one-carbon source by 13C isotopic tracer analysis. In line with computational modeling, the methylotrophic E. coli strain optimizes methanol oxidation by upregulation of an improved methanol dehydrogenase, increasing ribulose monophosphate cycle activity, channeling carbon flux through the Entner-Doudoroff pathway and downregulating tricarboxylic acid cycle enzymes. En route towards sustainable bioproduction processes, our work lays the foundation for the efficient utilization of methanol as the dominant carbon and energy resource.


Assuntos
Escherichia coli , Metanol , Carbono/metabolismo , Escherichia coli/genética , Engenharia Metabólica , Metanol/metabolismo , Pentoses
13.
Front Cell Infect Microbiol ; 12: 958555, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36072222

RESUMO

Treatment of Mycobacterium tuberculosis (Mtb) infections is particularly arduous. One challenge to effectively treating tuberculosis is that drug efficacy in vivo often fails to match drug efficacy in vitro. This is due to multiple reasons, including inadequate drug concentrations reaching Mtb at the site of infection and physiological changes of Mtb in response to host derived stresses that render the bacteria more tolerant to antibiotics. To more effectively and efficiently treat tuberculosis, it is necessary to better understand the physiologic state of Mtb that promotes drug tolerance in the host. Towards this end, multiple studies have converged on bacterial central carbon metabolism as a critical contributor to Mtb drug tolerance. In this review, we present the evidence that changes in central carbon metabolism can promote drug tolerance, depending on the environment surrounding Mtb. We posit that these metabolic pathways could be potential drug targets to stymie the development of drug tolerance and enhance the efficacy of current antimicrobial therapy.


Assuntos
Mycobacterium tuberculosis , Tuberculose dos Linfonodos , Carbono/metabolismo , Tolerância a Medicamentos , Humanos , Redes e Vias Metabólicas
14.
Nat Commun ; 13(1): 5177, 2022 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-36056025

RESUMO

The soil carbon (C) saturation concept suggests an upper limit to the storage of soil organic carbon (SOC). It is set by the mechanisms that protect soil organic matter from mineralization. Biochar has the capacity to protect new C, including rhizodeposits and microbial necromass. However, the decadal-scale mechanisms by which biochar influences the molecular diversity, spatial heterogeneity, and temporal changes in SOC persistence, remain unresolved. Here we show that the soil C storage ceiling of a Ferralsol under subtropical pasture was raised by a second application of Eucalyptus saligna biochar 8.2 years after the first application-the first application raised the soil C storage ceiling by 9.3 Mg new C ha-1 and the second application raised this by another 2.3 Mg new C ha-1. Linking direct visual evidence from one-, two-, and three-dimensional analyses with SOC quantification, we found high spatial heterogeneity of C functional groups that resulted in the retention of rhizodeposits and microbial necromass in microaggregates (53-250 µm) and the mineral fraction (<53 µm). Microbial C-use efficiency was concomitantly increased by lowering specific enzyme activities, contributing to the decreased mineralization of native SOC by 18%. We suggest that the SOC ceiling can be lifted using biochar in (sub)tropical grasslands globally.


Assuntos
Carbono , Solo , Sequestro de Carbono , Carvão Vegetal/química , Solo/química , Microbiologia do Solo
15.
Sci Rep ; 12(1): 14949, 2022 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-36056039

RESUMO

Bacterial degradation of sinking diatom aggregates is key for the availability of organic matter in the deep-ocean. Yet, little is known about the impact of aggregate colonization by different bacterial taxa on organic carbon and nutrient cycling within aggregates. Here, we tracked the carbon (C) and nitrogen (N) transfer from the diatom Leptocylindrus danicus to different environmental bacterial groups using a combination of 13C and 15N isotope incubation (incubated for 72 h), CARD-FISH and nanoSIMS single-cell analysis. Pseudoalteromonas bacterial group was the first colonizing diatom-aggregates, succeeded by the Alteromonas group. Within aggregates, diatom-attached bacteria were considerably more enriched in 13C and 15N than non-attached bacteria. Isotopic mass balance budget indicates that both groups showed comparable levels of diatom C in their biomass, accounting for 19 ± 7% and 15 ± 11%, respectively. In contrast to C, bacteria of the Alteromonas groups showed significantly higher levels of N derived from diatoms (77 ± 28%) than Pseudoalteromonas (47 ± 17%), suggesting a competitive advantage for Alteromonas in the N-limiting environments of the deep-sea. Our results imply that bacterial succession within diatom aggregates may largely impact taxa-specific C and N uptake, which may have important consequences for the quantity and quality of organic matter exported to the deep ocean.


Assuntos
Diatomáceas , Bactérias/metabolismo , Biomassa , Carbono/metabolismo , Diatomáceas/metabolismo , Nitrogênio/metabolismo
16.
J Environ Manage ; 320: 115811, 2022 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-36056479

RESUMO

The Himalayan ecosystem is critical for ecological security and environmental sustainability. However, continuous deforestation is posing a serious threat to Himalayan sustainability. Changing land-use systems exert a tenacious impact on soil carbon (C) dynamics and regulate C emissions from Himalayan ecosystem. Therefore, this study was conducted to determine the changes in different C pools and associated soil properties under diverse land-use systems, viz. natural forest, natural grassland, maize field converted from the forest, plantation, and paddy field of temperate Himalaya in the surface (0-20 cm) and subsurface (20-40 cm) soils. The highest total organic carbon (24.24 g kg-1) and Walkley-black carbon contents (18.23 g kg-1), total organic carbon (45.88 Mg ha-1), and Walkley-black carbon stocks (34.50 Mg ha-1) were recorded in natural forest in surface soil (0-20 cm depth), while soil under paddy field had least total organic carbon (36.45 Mg ha-1) and Walkley-black carbon stocks (27.40 Mg ha-1) in surface soil (0-20 cm depth). The conversion of natural forest into paddy land results in 47.36% C losses. Among the cultivated land-use system, minimum C losses (29.0%) from different pools over natural forest system were reported under maize-filed converted from forest system. Land conversion causes more C losses (21.0%) in surface soil (0-20 cm depth) as compared to subsurface soil. Furthermore, conversion of forest land into paddy fields increased soil pH by 5.9% and reduced total nitrogen contents and microbial population by 28.0% and 7.0%, respectively. However, the intensity of total nitrogen and microbial population reduction was the lowest under maize fields converted from the forest system. The study suggested that the conversion of natural forest to agricultural land must be discouraged in the temperate Himalayan region. However, to feed the growing population, converted forest land can be brought under conservation effective maize-based systems to reduce C loss from the intensive land use and contribute to soil quality improvements and climate change mitigation.


Assuntos
Carbono , Ecossistema , Agricultura , Carbono/análise , Florestas , Índia , Nitrogênio/análise , Solo/química , Zea mays
17.
J Environ Manage ; 320: 115893, 2022 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-36056495

RESUMO

The staggering rise in global temperature and abrupt change of climate are the responses of nature alerting humanity to limit the emissions of hazardous gases and adopt environmentally-benign life style. The present study explores empirically whether any changes in environmental policy stringency (EPSI), political risk (PR), and the interaction term of EPSI*PR result in any alteration of consumption-based carbon emissions (CBCE) of the 24 advanced OECD economies over the period of 1990-2020. Prior to the empirical estimations, various diagnostic tests are employed. The empirical techniques include, panel cointegration check, Cross-sectional Augmented Autoregressive Distributed Lags (CS-ARDL), and Dumitrescu & Hurlin panel causality test. The findings confirm that imports, gross domestic product, and stringency of environment policies activate CBCE in short-run. Whereas, a unit improvement in political risk and its interaction with environmental policy stringency give rise to 0.231 MtCO2 of CBCE in long run. Interestingly, the squared term of environmental policy stringency effectively tackles such emissions. Based on the findings, we conclude that the present environment related policies of OECD member states does not effectively limit CBCE. In order to achieve genuine emissions reduction goals, the selected nations should restructure their environment related policies by prioritizing increments in environmental policy stringency along with minimizing the risks involved in the political system.


Assuntos
Desenvolvimento Econômico , Organização para a Cooperação e Desenvolvimento Econômico , Biodiversidade , Carbono , Dióxido de Carbono , Estudos Transversais , Energia Renovável , Temperatura
18.
J Environ Manage ; 320: 115913, 2022 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-36056498

RESUMO

The reduction of CO2 emissions is a very challenging issue. The capture of CO2 from combustion processes is associated with high energy consumption and decreases the efficiency of power-producing facilities. This can affect the economy and in specific cases, such as waste-to-energy plants, also their classification according to legislation. To allow the minimization of energy consumption, an optimization tool for membrane-based post-combustion capture was developed. The approach allows finding optimal membrane properties, membrane areas, and pressures for individual separation stages from the point of view of energy consumption. The core of the approach is represented by a mathematical model of the separation system that is based on a network flow problem. The model utilizes external simulation modules for non-linear problems to enable finding globally optimal results. These external modules approximate non-linear dependencies with any desired precision and allow using different mathematical descriptions of individual membrane stages without making changes to the model. Moreover, it allows easy substitution of the external module by experimental data and the model can be easily modified for specific purposes such as decision making, designing the separation process, as well as for regulation of process parameters in the case of dynamic operation. The ability of the model to optimize the process was verified on a case study and the results show that the optimization can significantly reduce the energy consumption of the process. For separation of 90% of CO2 at the purity of 95% from initial flue gas with 13% CO2 with state-of-the-art membranes based on the Robeson upper bound and three-stage process, the minimum power consumption was 1.74 GJ/tCO2 including final CO2 compression.


Assuntos
Dióxido de Carbono , Carbono , Modelos Teóricos
19.
J Environ Manage ; 320: 115916, 2022 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-36056499

RESUMO

For a country like China with unbalanced development pattern among provinces, domestic circulation (i.e., cross-province trade) is important for the long-term stability and prosperous development of economic market. However, with the rapid advance of integration of domestic regional economy, while expanding the internal market scale and deepening the provincial division of labor network for promoting the economic growth, the carbon emissions embedded within the cross-province traded products and services cannot be underestimated. Under the background of climate-trade dilemma, it is necessary to exploring the spatiotemporal variations and socioeconomic determinants of provincial "invisible" carbon emissions for a better understanding of trade-induced eco-environmental effects. To that end, this study developed an environmental-economic system model through integrating the environmentally extended multiregional input-output method and weighted average structural decomposition analysis technique to explore the trade-related emissions at the provincial level and generate the mitigation-management strategies for decisionmakers. Overall, more than half the emissions were embedded within cross-province goods and services trade over the whole study period. Furthermore, the distribution of traded emissions showed obvious spatial heterogeneity and great unbalance was existed between provincial imports and exports. Among all provinces, carbon surplus provinces were always more than deficit ones and the trading patterns of approximately 65% regions remained unchanged during 2007-2017. Remarkably, the emissions trading pattern undergone transition from carbon deficit to carbon surplus in provinces like Henan, Hubei, Guizhou, and so on. Conversely, provinces like Jilin, Shanghai, and Xinjiang showed opposite change. With the prevalence of online payment and electronic commerce in the future, the central and sub-national government could consider launching a pilot project for the design and creation of personal carbon consumption account in the carbon surplus provinces such as Guangdong, Henan, and Jiangsu. Meanwhile, for the provinces with larger carbon exports, it is necessary to establish the horizontal high technical transfer channels and vertical compensation mechanisms such as financial subsidies for improving the low-carbon production level. Our findings provided a holistic depict of national traded emissions at the provincial level, highlighting the importance of cross-province emission effect in exploring ways to promote the low-carbon transition of domestic circulation and fulfill the high-quality development of 'dual circulation' new pattern and successful achievement of 'double carbon' solemn commitment.


Assuntos
Carbono , Desenvolvimento Econômico , Carbono/análise , Dióxido de Carbono/análise , China , Projetos Piloto , Fatores Socioeconômicos
20.
Comput Intell Neurosci ; 2022: 3013620, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36059423

RESUMO

Improving carbon reserves is considered to be an important way to alleviate global warming. However, there is a lack of research work based on the perspective of metropolitan area, and there is also a lack of analysis on the leading influencing factors of spatial distribution of carbon storage in subregions of metropolitan area. In this study, Nanjing metropolitan area (NMA) is taken as the research area, and the InVEST model is used to calculate the spatial distribution of regional carbon reserves, and the evolution of carbon reserves distribution in recent 20 years is analyzed. Then, based on the random forest (RF) model, taking the whole study area and subareas as the research scope, a regression model of each selected impact factor and carbon reserves is established, and the leading factors of spatial distribution of carbon reserves in NMA are obtained. The results show that the overall carbon reserves level in the study area is in a downward trend. Through the application of the RF model, the leading factors of the spatial distribution of carbon reserves in NMA and its subareas are derived. The research proves that the application of the RF model in the analysis is helpful for city planners and governments to make plans and improve regional carbon storage more effectively.


Assuntos
Carbono , Monitoramento Ambiental , Carbono/análise , Cidades , Aquecimento Global
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