Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 91
Filtrar
Mais filtros

Intervalo de ano de publicação
1.
New Phytol ; 242(5): 1932-1943, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38641865

RESUMO

Large trees in plantations generally produce more wood per unit of resource use than small trees. Two processes may account for this pattern: greater photosynthetic resource use efficiency or greater partitioning of carbon to wood production. We estimated gross primary production (GPP) at the individual scale by combining transpiration with photosynthetic water-use efficiency of Eucalyptus trees. Aboveground production fluxes were estimated using allometric equations and modeled respiration; total belowground carbon fluxes (TBCF) were estimated by subtracting aboveground fluxes from GPP. Partitioning was estimated by dividing component fluxes by GPP. Dominant trees produced almost three times as much wood as suppressed trees. They used 25 ± 10% (mean ± SD) of their photosynthates for wood production, whereas suppressed trees only used 12 ± 2%. By contrast, dominant trees used 27 ± 19% of their photosynthate belowground, whereas suppressed trees used 58 ± 5%. Intermediate trees lay between these extremes. Photosynthetic water-use efficiency of dominant trees was c. 13% greater than the efficiency of suppressed trees. Suppressed trees used more than twice as much of their photosynthate belowground and less than half as much aboveground compared with dominant trees. Differences in carbon partitioning were much greater than differences in GPP or photosynthetic water-use efficiency.


Assuntos
Carbono , Eucalyptus , Fotossíntese , Árvores , Água , Madeira , Eucalyptus/fisiologia , Eucalyptus/metabolismo , Carbono/metabolismo , Árvores/fisiologia , Árvores/metabolismo , Água/metabolismo , Madeira/fisiologia , Transpiração Vegetal/fisiologia , Modelos Biológicos
2.
PeerJ ; 12: e17022, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38563017

RESUMO

Eucalyptus camaldulensis is a multifunctional tree and is globally used for the reclamation of problematic lands. Eucalyptus camaldulensis is prone to attack by a number of pathogens, but the most important threat is the Fusarium wilt (Fusarium oxysporum). Keeping in view the importance of E. camaldulensis and to manage this disease, five plant activators, i.e., salicylic acid (C7H6O3), benzoic acid (C7H6O2), citric acid (C6H8O7), dipotassium phosphate (K2HPO4), monopotassium phosphate (KH2PO4) and nutritional mixture namely Compound (NPK) and nutriotop (Fe, Zn, Cu, B, Mn) were evaluated in the Fusarium infested field under RCBD in the Research Area, Department of Forestry and Range Management, University of Agriculture, Faisalabad (UAF). Among plant activators, salicylic acid and a combination of compound + nutriotop exhibited the lowest disease incidence and enhanced fresh and dry weight of leaves compared to other treatments and control. Results of the environmental study indicated maximum disease incidence between 35-40 °C (max. T), 6-25 °C (mini. T), 70-80% relative humidity and 1.5-2.5 km/h wind speed while pan evaporation expressed weak correlation with disease development. It was concluded that Fusarium wilt of Eucalyptus camaldulensis could be managed through activation of the basal defense system of the host plant with provision of salicylic acid and balanced nutrition by considering environmental factors. Recent exploration is expected to be helpful for future research efforts on epidemiology and ecologically sound intervention of Fusarium wilt of Eucalyptus camaldulensis.


Assuntos
Eucalyptus , Fusarium , Ácido Salicílico , Folhas de Planta , Fosfatos
3.
Waste Manag ; 172: 226-234, 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-37924598

RESUMO

Biomass is one of the renewable resources with the greatest potential, not only because of the possibility of energy recovery but also because of its content in components of interest. In this context, the regions of Galicia and Portugal have large areas of land dedicated to forestry, agriculture and livestock, and the large amount of waste generated represents a cost for the producer. The importance of these facts has aroused great interest in society to focus its interest on improving the current situation while seeking a benefit, both environmental and economic, from existing resources. That is why the integration of biotechnological processes and biorefinery for their valorization are considered key aspects in the way of producing bioproducts and bioenergy. This research article proposes a process for producing resveratrol from whey from the dairy industry and eucalyptus residues from forestry exploitation. In order to evaluate its suitability, a techno-economic analysis and an environmental assessment have been carried out using the Life Cycle Assessment (LCA) methodology. The results obtained show the potential of these scenarios both from the economic point of view, by obtaining a minimum sale price of resveratrol to ensure the viability of the process below the market average, and from the environmental point of view, being eucalyptus residues those that result in a lower contribution to the environment per unit of resveratrol produced. Future research should focus on increasing the throughput of the production process to increase its profitability and on reducing energy requirements throughout the process, as these have been the main critical points identified. In addition, following the sensitivity assessment, it has been concluded that opting for renewable energy is the most sustainable option.


Assuntos
Eucalyptus , Soro do Leite , Resveratrol , Energia Renovável , Agricultura , Biomassa
4.
PLoS One ; 18(8): e0289536, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37552668

RESUMO

Eucalyptus is an economically important genus comprising more than 890 species in different subgenera and sections. Approximately twenty species of subgenus Symphyomyrtus account for 95% of the world's planted eucalypts. Discrimination of closely related eucalypt taxa is challenging, consistent with their recent phylogenetic divergence and occasional hybridization in nature. Admixture, misclassification or mislabeling of Eucalyptus germplasm resources maintained as exotics have been suggested, although no reports are available. Moreover, hybrids with increased productivity and traits complementarity are planted worldwide, but little is known about their actual genomic ancestry. In this study we examined a set of 440 trees of 16 different Eucalyptus species and 44 interspecific hybrids of multi-species origin conserved in germplasm banks in Brazil. We used genome-wide SNP data to evaluate the agreement between the alleged phylogenetic classification of species and provenances as registered in their historical records, and their observed genetic clustering derived from SNP data. Genetic structure analyses correctly assigned each of the 16 species to a different cluster although the PCA positioning of E. longirostrata was inconsistent with its current taxonomy. Admixture was present for closely related species' materials derived from local germplasm banks, indicating unintended hybridization following germplasm introduction. Provenances could be discriminated for some species, indicating that SNP-based discrimination was directly proportional to geographical distance, consistent with an isolation-by-distance model. SNP-based genomic ancestry analysis showed that the majority of the hybrids displayed realized genomic composition deviating from the expected ones based on their pedigree records, consistent with admixture in their parents and pervasive genome-wide directional selection toward the fast-growing E. grandis genome. SNP data in support of tree breeding provide precise germplasm identity verification, and allow breeders to objectively recognize the actual ancestral origin of superior hybrids to more realistically guide the program toward the development of the desired genetic combinations.


Assuntos
Eucalyptus , Polimorfismo de Nucleotídeo Único , Filogenia , Genoma de Planta , Melhoramento Vegetal , Genômica
5.
Sci Rep ; 13(1): 14083, 2023 08 28.
Artigo em Inglês | MEDLINE | ID: mdl-37640730

RESUMO

Farm foresters and other growers are establishing a ground-durable hardwood resource, including the emerging plantation species Eucalyptus bosistoana in New Zealand. The foliage of this species contains essential oils in quantity and quality suitable for commercial extraction. Essential oil production could improve the economic viability of E. bosistoana plantations, diversifying the grower's income and providing an early revenue stream. This study assessed the economic potential for essential oil production from New Zealand grown E. bosistoana plantations. A sensitivity analysis indicated that uncertainty of leaf biomass availability, genetic as well as seasonal changes in oil content, and fluctuations in essential oil price are equally important on the viability of an essential oil operation. Small-scale essential oil production could be sustainably supplied with foliage from thinning and pruning operations sourced from the envisaged regional planting programmes and commence in 3-5 years. A large-scale operation could be supplied when trees will be harvested. Lastly, based on the operational costs of a domestic small-scale essential oil producer, oil value from E. bosistoana would exceed the cost of production.


Assuntos
Óleo de Eucalipto , Óleo de Eucalipto/economia , Eucalyptus/química , Nova Zelândia , Folhas de Planta/química , Biomassa , Agricultura/economia
6.
GM Crops Food ; 14(1): 1-14, 2023 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-37334790

RESUMO

Glyphosate herbicide treatment is essential to sustainable Eucalyptus plantation management in Brazil. Eucalyptus is highly sensitive to glyphosate, and Suzano/FuturaGene has genetically modified eucalyptus to tolerate glyphosate, with the aim of both protecting eucalyptus trees from glyphosate application damage and improving weed management. This study presents the biosafety results of the glyphosate-tolerant eucalyptus event 751K032, which expresses the selection marker neomycin phosphotransferase II (NPTII) enzyme and CP4-EPSPS, a glyphosate-tolerant variant of plant 5-enolpyruvyl-shikimate-3-phosphate synthase enzyme. The transgenic genetically modified (GM) event 751K032 behaved in the plantations like conventional non-transgenic eucalyptus clone, FGN-K, and had no effects on arthropods and soil microorganisms. The engineered NPTII and CP4 EPSPS proteins were heat-labile, readily digestible, and according to the bioinformatics analyses, unlikely to cause an allergenic or toxic reaction in humans or animals. This assessment of the biosafety of the glyphosate-tolerant eucalyptus event 751K032 concludes that it is safe to be used for wood production.


Assuntos
Eucalyptus , Herbicidas , Animais , Humanos , Canamicina Quinase , Plantas Geneticamente Modificadas , Eucalyptus/genética , Herbicidas/toxicidade
7.
Int J Toxicol ; 42(1_suppl): 57S-92S, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37010839

RESUMO

This is a safety assessment of 6 Eucalyptus globulus (eucalyptus)-derived ingredients as used in cosmetics. The reported functions of the Eucalyptus globulus (eucalyptus)-derived ingredients include abrasive, fragrance ingredient, and skin-conditioning agent (miscellaneous and occlusive). The Expert Panel for Cosmetic Ingredient Safety (Panel) reviewed the relevant data on these ingredients. Because final product formulations may contain multiple botanicals, each containing the same constituents of concern, formulators are advised to be aware of these constituents and to avoid reaching levels that may be hazardous to consumers. Industry should use good manufacturing practices to limit impurities. The Panel concluded that Eucalyptus globulus (eucalyptus)-derived ingredients are safe in cosmetics in the present practices of use and concentration described in this safety assessment when formulated to be non-sensitizing.


Assuntos
Cosméticos , Eucalyptus , Qualidade de Produtos para o Consumidor , Cosméticos/toxicidade , Medição de Risco
8.
Artigo em Inglês | MEDLINE | ID: mdl-35897444

RESUMO

Today, evaluating ecological wellbeing and ecosystem services is becoming a great concern towards conserving the natural resource base. Healthy functioning ecosystems have fundamental roles for aiding humankind to lead a healthy life and ensure an improved social welfare. Estimating the non-market benefits of ecosystem services can help experts and the public frame policy directions designed for landscape development. The ecosystem of the Eucalyptus hotspot highlands of northwestern Ethiopia, where this study was carried out, provides services that are essential to changes in the life of the society and biodiversity. However, in recent years, the ecosystem is facing a serious threat from intensive monoculture plantations of Eucalyptus. This has resulted in transformation of the cultural landscapes and a loss of biodiversity. The problem in turn calls for designing appropriate ecological improvement programs. Thus, the current study examined the preferences of residents concerning this area and estimated their willingness to pay (WTP) for the proposed ecosystem improvement programs using a Choice Experiment approach. Data were aggregated from 388 residents using a questionnaire survey in January 2020. The survey contained ecological improvement schemes and a hypothetical event by which respondents expressed their willingness to pay a yearly utility fee as a compensation for the improvement programs. Results showed significant differences in resident preferences towards the proposed ecological improvement attributes. The findings also indicated that the socioeconomic backgrounds of residents contributed for the heterogeneity in their WTP for ecological improvement schemes. Accordingly, the marginal willingness to pay of residents was USD 205/person/year for the respective ecological improvement attributes. The findings suggest that policy makers should consider such attribute-based public preferences while planning landscape development and conservation programs. This study can provide vital policy implications and contribute to knowledge as it presents how the non-market valuations of ecosystems help maximize social welfare.


Assuntos
Ecossistema , Eucalyptus , Biodiversidade , Conservação dos Recursos Naturais/métodos , Humanos , Inquéritos e Questionários
9.
Braz J Biol ; 84: e262662, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35830134

RESUMO

A socio-economic study was conducted in district Mardan of the Khyber Pakhtunkhwa (KP) province of Pakistan to get a comprehensive knowledge of the agroforestry tree species grown on the farmlands, their yield, and carbon stock. For yield and carbon stock estimation, data were collected from 59 sample plots by measuring the diameter, height, volume, and biomass of selected agroforestry tree species through D-tape and Haga altimeter. A total of 59 sample plots were inventoried using 2.5 percent sampling intensity. Each sample plot has an area of 0.5 ha, where each tree with a Diameter at Breast Height (DBH) ≥ 5 cm was inventoried. The calculated amount of volume of each tree species was then converted to biomass by multiplying it by the density of wood and the Biomass Expansion Factor (BEF). Total yield and C stock for the selected agroforestry tree species were 11535.2 metric tons and 2102.2 metric tons, respectively. Populus euroamericana is classified as the main tree with 28% growing stock prior to Morus alba by 21%, while Melia azedarach, Eucalyptus camaldulensis, Dalbergia sissoo, Acacia nilotica, Salix tetrasperma, and Bombax ceiba consist of 15%, 12%, 8%, 6%,7% and 3% growing stock respectively. Among the species found in different sampling plots the yield of Populus euroamericana was found to be 4747.5 metric tons and it was followed by the species Morus alba found at 2027.3 metric tons. Similarly, the volume for Melia azedarach, Eucalyptus camaldulensis, Dalbergia sissoo, Salix spp, Boombox ceiba, and Acacia nilotica was 1532.2 tons,1503 ton,745.7,203.5ton, 555.4ton and 220.5ton, respectively. The carbon stock for Populus euroamericana was calculated as 777.8 ton/ha, while for Eucalyptus camaldulensis, Melia azedarach, Morus alba, Dalbergia sissoo, Acacia nilotica, Salix species, and Bombax ceiba it was calculated as 312.3ton/ha, 272.1ton/ha, 363ton/ha, 245.1ton/ha, 51.4ton/ha, 27.3ton/ha and 53.2ton/ha, respectively. The questionnaire survey conducted for price dynamics showed that the majority of respondents purchase timber from the market for construction. But they use farm trees with low-quality city construction. They dislike using local timber in the conventional building as timber from farm trees is liable to insect attack. Rs. 50,000-100000, (33.33%) of daily sales was concluded from 50% of the trader while (16.7%) of the traders have their sales between Rs.150,000-200,000. Therefore, it is concluded by the authors that both provincial and federal government should promote agroforestry in Pakistan through different incentives because it has the potential to cope with dilemma of deforestation of natural forests and improve the livelihood of local peoples. It is strongly recommended that special projects just like the Ten Billion Tree Afforestation Project (T-BTTP) should be launched for agroforestry plantation and promotion in the country to sustain the ecological harmony and uplift the socio-economic condition of the peoples of Pakistan.


Assuntos
Eucalyptus , Árvores , Biomassa , Carbono/análise , Florestas , Paquistão
10.
Ecotoxicol Environ Saf ; 240: 113704, 2022 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-35653968

RESUMO

Eucalyptus is widely planted in China for wood industries, and there are increasing concerns about its ecotoxicity in the environment. This study explored the in-vitro toxicity of Eucalyptus extracts by assessing the impacts of water-soluble and dimethylsulfoxide (DMSO)-soluble fractions via a whole-cell bioreporter, Acinetobacter baylyi ADPWH_recA. Compounds identified in Eucalyptus extracts included one tannin, two phenolic acids, four terpenoids, four glycosides, and five flavonoids. The leaf extracts contained more biological-active components than barks and roots. Genotoxicity induced by Eucalyptus extracts was mainly associated with water extracts (e.g., flavonoids, phenolic acids) instead of DMSO extracts. The significant cytotoxicity was explained by programmed cell death (PCD), suggested by the results of propidium iodide (PI) and 2',7'-dichlorofluorescein-diacetate (DCFH-DA) assays. Generally, water-soluble fractions contributed more toxicities than DMSO-soluble fractions, particularly at high concentrations. A robust linear regression was built between the compromised toxicity and PCD index (Compromised toxicity = -2.192 × PCD index + 2.219; R2 = 0.8886), suggesting a PCD-dependent compromised toxicity which was greatly underestimated. Our results implied non-neglectable ecotoxicological risks of Eucalyptus extracts, hinting at the possible magnified ecological impacts of its large-scale plantation and the potential adverse outcomes to the surrounding ecosystems.


Assuntos
Eucalyptus , Dimetil Sulfóxido , Ecossistema , Flavonoides/farmacologia , Extratos Vegetais/farmacologia , Água
11.
Sci Total Environ ; 840: 156485, 2022 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-35688249

RESUMO

Honey bee colonies have shown abnormal mortality rates over the last decades. Colonies are exposed to biotic and abiotic stressors including landscape changes caused by human pressure. Modern agriculture and even forestry, rely on pesticide inputs and these chemicals have been indicated as one of the major causes for colony losses. Neonicotinoids are a common class of pesticides used worldwide that are specific to kill insect pests, with acetamiprid being the only neonicotinoid allowed to be applied outdoors in the EU. To evaluate honeybees' exposure to acetamiprid under field conditions as well as to test the use of in-situ tools to monitor pesticide residues, two honeybee colonies were installed in five Eucalyptus sp. plantations having different area where Epik® (active substance: acetamiprid) was applied as in a common spraying event to control the eucalyptus weevil pest. Flowers, fresh nectar, honey bees and colony products samples were collected and analyzed for the presence of acetamiprid residues. Our main findings were that (1) acetamiprid residues were found in samples collected outside the spraying area, (2) the amount of residues transported into the colonies increased with the size of the sprayed area, (3) according to the calculated Exposure to Toxicity Ratio (ETR) values, spraying up to 22 % of honeybees foraging area does not harm the colonies, (4) colony products can be used as a valid tool to monitor colony accumulation of acetamiprid and (5) the use of Lateral Flow Devices (LFDs) can be a cheap, fast and easy tool to apply in the field, to evaluate the presence of acetamiprid residues in the landscape and colony products.


Assuntos
Eucalyptus , Inseticidas , Praguicidas , Animais , Abelhas , Inseticidas/toxicidade , Neonicotinoides/toxicidade , Medição de Risco
12.
Food Res Int ; 157: 111362, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35761624

RESUMO

The quality evaluation and physicochemical parameters assessment of Portuguese monofloral honeys were performed. Fifty-one monofloral honeys were collected from several regions from mainland Portugal, and from the Azores islands, producer labelled as carob tree (n = 5), chestnut (n = 2), eucalyptus (n = 5), bell heather (n = 6), incense (n = 4), lavender (n = 8), orange (n = 9), rape (n = 2), raspberry (n = 2), rosemary (n = 1), sunflower (n = 3), and strawberry tree (n = 4). Pollen analysis and microbiological safety were evaluated, and the parameters such as colour index, moisture content, electrical conductivity, hydroxymethylfurfural, pH, free and total acidity, diastase activity, proline, and sugar profile were assessed for physicochemical characterization, in all 51 monofloral honeys. After melissopalynological examination, the honeys were either confirmed as monofloral, or classified as multifloral with predominance of a specific pollen type or multifloral. Microbiological analysis showed that honeys were safe for human consumption. Pairwise comparisons of physicochemical parameters, using only honey types with n ≥ 3, revealed significant differences between honey types. Despite some homogeneity in sugar profile among honeys, eucalyptus honey was significantly different in glucose, maltose and maltulose content compared to incense, orange and sunflower honeys, and also exhibited a higher isomaltose amount compared to all analyzed honeys. Electrical conductivity, colour index, free and total acidity, and diastase activity showed significant differences between the analyzed honeys, indicating that these parameters may provide an additional tool in monofloral honey identification.


Assuntos
Eucalyptus , Mel , Amilases , Eucalyptus/química , Glucose/análise , Mel/análise , Pólen/química , Portugal
13.
Environ Sci Pollut Res Int ; 29(29): 43955-43965, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35124774

RESUMO

The present study aimed to evaluate the environmental cost of the production process of broilers from the approach of emergy accounting and carbon sequestration potential for broiler farms. The study assessed a standard farm of the conventional system containing ten houses in 19 ha. We evaluated the following indices solar transformity (Tr), renewability (%R), emergy yield ratio (EYR), emergy investment ratio (EIR), environmental loading ratio (ELR), emergy sustainability index (ESI), and emergy exchange ratio (EER) and carbon sequestration potential of eucalyptus plantation. The total emergy input was 2.79E-06 seJ ha-1 y-1 for the broiler growth process. The highest investment in the production process was related to materials, which came from feeding and electricity. The renewability index indicated the low sustainability of the system with increased consumption of economical materials and equipment, with a low proportion of the emergy use of renewable resources. High investment in broilers production in the conventional system generates an environmental loading ratio that indicates high environmental degradation. Planting trees in the surrounding areas of the farm facilities can minimize the externalities of the production system with the plantation carbon sequestration potential.


Assuntos
Conservação dos Recursos Naturais , Eucalyptus , Agricultura , Animais , Brasil , Sequestro de Carbono , Galinhas , China , Ecossistema , Fazendas
14.
Arch Razi Inst ; 76(5): 1307-1314, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-35355745

RESUMO

The spread of different types of cancer has been on a rise in the recent century. The use of chemical medications develops drug resistance and causes serious side effects. Eucalyptus camaldulensis (E. camaldulensis) is one of the most famous herbal remedies considered owing to its anti-inflammatory effect and boosting the intimate immune system; moreover, it has demonstrated some anti-proliferative effects on cancerous cell lines. The current study assessed the cytotoxic activity of alcoholic extract of Eucalyptus camaldulensis (E. camaldulensis) at different concentrations of 6.125, 12.5, 25, 50, and 100 µg/mL on breast cancer cell line MCF-7. The 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS)) analyses were employed to study the antioxidant efficiency of ethanolic extract of Eucalyptus camaldulensis. The results of Fourier transmission infra-red analysis and Phytochemical screening pointed to the presence of many active compounds in this extract, such as Tannins, Saponins, Phenolic compounds, Reducing sugar, Terpenoids, Steroids, Glucosides, Alkaloids, and Flavonoids. Furthermore, the results demonstrated that this extract significantly inhibited the growth of the MCF-7 cell line in a concentration-dependent manner, as compared to the control, and the cytotoxic activity of this extract elevated with an increase in the concentration. The results pointed out that E. camaldulensis can be considered a particularly valuable source of effective anti-proliferative and cytotoxic agents. The experimental findings demonstrated that E. camaldulensis extract possessed significant antioxidant efficiency and anti-proliferative effects on cancerous cell lines.


Assuntos
Eucalyptus , Neoplasias , Extratos Vegetais , Antioxidantes , Eucalyptus/química , Humanos , Células MCF-7 , Neoplasias/tratamento farmacológico , Fenóis/farmacologia , Extratos Vegetais/química , Extratos Vegetais/farmacologia
15.
An Acad Bras Cienc ; 92(suppl 1): e20180486, 2020 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-32756835

RESUMO

The objective of this study was to evaluate the production costs of processing logs from Eucalyptus grandis Hill ex Maiden and Eucalyptus saligna Sm, using two sawing pattern in a medium-sized sawmill. Alternating tangential sawing pattern was used for logs with a mean diameter of 33.0 cm and the radial sawing pattern for logs with a mean diameter of 47.0 cm. Based on the data obtained in the different sawing pattern, the fixed, variable and total costs were calculated and, subsequently, the average value for each of these costs. For the alternating tangential sawing pattern, the fixed cost represented 19.32% and the variable cost 80.68%. For the radial sawing pattern, the fixed cost represented 18.92% and the variable cost 81.08%. The radial sawing pattern presented lower average production costs, with a difference of 22.89 R$/m³, however there is no significant difference between the sawing pattern.


Assuntos
Eucalyptus , Madeira
17.
Int J Biol Macromol ; 164: 794-807, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32659402

RESUMO

Cellulose nitrate, commonly known as nitrocellulose (NC), and its corresponding propellants naturally decompose at normal conditions. To avoid early degradation, unexpected explosion, energy loss, and ensure a safe storage, stabilizing agents are often introduced within its compositions. Conventional stabilizers, such as aromatic amines like diphenylamine (DPA) and urea, can produce carcinogenic/toxic substances during propellants shelf life. Thus, a need for alternative stabilizing agents, which offer similar/better effectiveness and display a non/low toxicity, remains a challenge. This paper investigates the stabilizing effect of two organosolv lignins (OL), obtained from Aleppo pine (AP) and Eucalyptus globulus (EG), on NC. For this purpose, conventional stability tests and kinetic modeling are applied for different samples (S1-S4) using 3% of stabilizer, which are S1, pure NC; S2, NC + DPA; S3, NC + OL(AP); and S4, NC + OL(EG). Beforehand, FTIR spectroscopy and DSC analysis have been used to check the compatibility of these potential stabilizers and NC. The obtained results via Bergmann-Jung and vacuum stability tests suggested that the prepared mixtures are stable. The kinetic study based on DSC data using isoconversional methods shows that both stabilizers display a good stabilizing effect. The reactivity between the different organosolv lignins and NOx released during the degradation of NC has been well highlighted using FTIR and TGA analyses. Hence, these efficient, environmentally friendly and readily available substances can be effectively used as stabilizers for NC-based formulations.


Assuntos
Colódio/química , Eucalyptus/química , Lignina/química , Cinética , Estrutura Molecular , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura
18.
Acta Trop ; 210: 105573, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32505595

RESUMO

Mosquitoes (Diptera; Culicidae) are a biting nuisance and are of economic and health importance, especially for people living in tropical countries like India. Given the environmental concerns and health hazards of synthetic insecticides, development of natural products for the control of mosquito and mosquito-borne diseases are needed. In view of this, an essential oil based novel liquid vaporizer formulation with citronella and eucalyptus oils has been developed using a computer aided Artificial Neural Network and Particle Swarm Optimization (ANN-PSO) algorithm approach, aiming to predict the best optimized formulation (OF). Following the development, OF was characterized by Fourier Transform-Infra Red (FT-IR) spectroscopy and gas chromatography-mass spectroscopy (GC-MS). The efficacy of the OF was assessed against two major mosquito vectors viz. Anopheles stephensi and Aedes albopictus using a Peet-Grady chamber. Finally, toxicological impacts of the OF following its inhalation were investigated as per the Organization for Economic Co-operation and Development (OECD) guidelines. The results revealed all the ideal characteristics of the OF which were found to provide a slow release of up to 450 h at room temperature. Most importantly, the OF, exhibited 50% mosquito knock down (KT50) within 11.49±1.34 and 14.15±2.15 min against An. stephensi and Ae. albopictus respectively. Toxicity assessment showed a non toxic nature of the OF following inhalation. Thus the present development would be beneficial for controlling both An. stephensi and Ae. albopictus without any associated health hazards.


Assuntos
Cymbopogon , Eucalyptus , Inseticidas/administração & dosagem , Controle de Mosquitos/métodos , Nebulizadores e Vaporizadores , Óleos Voláteis/administração & dosagem , Aedes , Animais , Anopheles
19.
PLoS One ; 15(6): e0233800, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32497070

RESUMO

Several studies suggest the relation of DNA methylation to diseases in humans and important phenotypes in plants drawing attention to this epigenetic mark as an important source of variability. In the last decades, several methodologies were developed to assess the methylation state of a genome. However, there is still a lack of affordable and precise methods for genome wide analysis in large sample size studies. Methyl sensitive double digestion MS-DArT sequencing method emerges as a promising alternative for methylation profiling. We developed a computational pipeline for the identification of DNA methylation using MS-DArT-seq data and carried out a pilot study using the Eucalyptus grandis tree sequenced for the species reference genome. Using a statistic framework as in differential expression analysis, 72,515 genomic sites were investigated and 5,846 methylated sites identified, several tissue specific, distributed along the species 11 chromosomes. We highlight a bias towards identification of DNA methylation in genic regions and the identification of 2,783 genes and 842 transposons containing methylated sites. Comparison with WGBS, DNA sequencing after treatment with bisulfite, data demonstrated a precision rate higher than 95% for our approach. The availability of a reference genome is useful for determining the genomic context of methylated sites but not imperative, making this approach suitable for any species. Our approach provides a cost effective, broad and reliable examination of DNA methylation profile on MspI/HpaII restriction sites, is fully reproducible and the source code is available on GitHub (https://github.com/wendelljpereira/ms-dart-seq).


Assuntos
Análise Custo-Benefício , Metilação de DNA/genética , Eucalyptus/genética , Técnicas de Genotipagem/métodos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Folhas de Planta/genética , Análise de Sequência de DNA/métodos , Árvores/genética , Cromossomos de Plantas/genética , Enzimas de Restrição do DNA/genética , Elementos de DNA Transponíveis/genética , Genes de Plantas/genética , Técnicas de Genotipagem/economia , Sequenciamento de Nucleotídeos em Larga Escala/economia , Projetos Piloto , Reprodutibilidade dos Testes , Mapeamento por Restrição , Análise de Sequência de DNA/economia , Sulfitos/farmacologia
20.
Appl Biochem Biotechnol ; 190(1): 197-217, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31325025

RESUMO

Eucalyptus wood is the primary source of fibers to produce paper and cellulose in South American countries. The major by-product generated in the cellulose industry is sawdust derived from chip wood production, which is designated as Eucalyptus by-product (EB). The xylooligosaccharides (XOS) are xylose-based oligomers with proven effects over maintenance and stimulation of beneficial human gut bacteria. This study reported the EB extraction and characterization along with an assessment of hemicellulose hydrolysis using commercial xylanases to produce XOS. Hemicellulose derived from extracted and NaClO2 pretreated (HEEBPT) presented xylan content of 55%, which was similar to 58.5% found in commercial Birchwood hemicellulose (CBH). The enzymatic hydrolysis of HEEBPT and CBH presented 30% as maximum conversion of xylan into XOS without significant difference among the enzymatic extracts evaluated. The XOS production from EB was proven as a technically feasible alternative to recover a value-added product from hemicellulosic fraction generated in the cellulose industry. However, lignin removal with NaClO2 from EB affects the feasibility of an industrial process because they generate toxic compounds in the pretreatment step. Thus, further studies with alternative reagents, such as ionic liquids, are required to asses selectively lignin removal from EB. Graphical Abstract.


Assuntos
Endo-1,4-beta-Xilanases/metabolismo , Eucalyptus/metabolismo , Glucuronatos/biossíntese , Oligossacarídeos/biossíntese , Polissacarídeos/química , Polissacarídeos/isolamento & purificação , Hidrólise
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA