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1.
Chemosphere ; 238: 124528, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31425869

RESUMO

A dendrochemical study of cottonwood trees (Populus deltoides) was conducted across a childhood cancer cluster in eastern Sandusky County (Ohio, USA). The justification for this study was that no satisfactory explanation has yet been put forward, despite extensive local surveys of aerosols, groundwater, and soil. Concentrations of eight trace metals were measured by ICP-MS in microwave-digested 5-year sections of increment cores, collected during 2012 and 2013. To determine whether the onset of the first cancer cases could be connected to an emergence of any of these contaminants, cores spanning the period 1970-2009 were taken from 51 trees of similar age, inside the cluster and in a control area to the west. The abundance of metals in cottonwood tree annual rings served as a proxy for their long-term, low-level accumulation from the same sources whereby exposure of the children may have occurred. A spatial analysis of cumulative metal burdens (lifetime accumulation in the tree) was performed to search for significant 'hotspots', employing a scan statistic with a mask of variable radius and center. For Cd, Cr, and Ni, circular hotspots were found that nearly coincide with the cancer cluster and are similar in size. No hotspots were found for Co, Cu, and Pb, while As and V were largely below method detection limits. Whereas our results do not implicate exposure to metals as a causative factor, we conclude that, after 1970, cottonwood trees have accumulated more Cd, Cr, and Ni, inside the childhood cancer cluster than elsewhere in Sandusky County.


Assuntos
Monitoramento Ambiental , Neoplasias/epidemiologia , Populus/química , Oligoelementos/análise , Criança , Humanos , Ohio/epidemiologia , Solo/química , Análise Espacial , Inquéritos e Questionários , Árvores/química
2.
J Sci Food Agric ; 100(2): 527-539, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31512240

RESUMO

BACKGROUND: Nitrogen is a key component of crop production and is commonly related to increases in yield and fruit size. The N fertilization rates used for low-chill peach cultivars were adapted from other peach production regions, where environmental and soil conditions are different. The growth and production as well as the effect on fruit physical and compositional attributes of two low-chill peach cultivars - 'TropicBeauty' (TB) and 'UFSharp' (UFS) - with five different N fertilization rates (0 (N0), 45 (N1), 90 (N2), 179 (N3) and 269 (N4) kg ha-1 applied each year from 2011 to 2017) were examined. RESULTS: Peach trees under higher N rates had higher pruning weights compared to the lower N0 or N1 rates. Yield was only affected in 2017 for the two cultivars tested. Physical attributes were inconsistently affected by N. Fruit from the higher N rates had lower a* value (more green) than fruit from the trees under low or zero N. While fruit firmness was not affected by N, fruit from trees under zero/low N had higher total soluble solids in some years. CONCLUSION: Considering that N is recycled in the trees, being retained and reused each season to resume growth, it is important to address peach orchard fertilization based on peach tree N status. The results of this experiment show that an increase in N beyond what is required for tree maintenance does not increase yield. In addition, reducing N does not strongly affect fruit quality, although the color and soluble solids results suggest that lower N rates may advance fruit maturation. © 2019 Society of Chemical Industry.


Assuntos
Fertilizantes/análise , Frutas/química , Nitrogênio/metabolismo , Prunus persica/metabolismo , Frutas/crescimento & desenvolvimento , Frutas/metabolismo , Cinética , Nitrogênio/química , Prunus persica/química , Prunus persica/crescimento & desenvolvimento , Estações do Ano , Árvores/química , Árvores/crescimento & desenvolvimento , Árvores/metabolismo
3.
Environ Sci Pollut Res Int ; 26(35): 35945-35956, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31709484

RESUMO

The aim of the research was to assess the possibility to use deciduous tree bark in the biomonitoring of urban areas. The tree bark taken from various deciduous tree species growing in the Opole Province (south-western Poland) was used for the research. The bark was collected from tree trunks in the period of June 2-26, 2017. Concentrations of the heavy metals were determined in the barks by flame atomic absorption spectrometry (FAAS). On the basis of the research, it was determined that type of tree, distance from pollution source, elevation off the ground and the side of trunk from which bark was sampled all influence the research results. A comparison of the values of coefficient of variation CV demonstrated that the bark Quercus robur and Betula pendula is more heterogeneous, e.g. for Fe CVQuercus robur is 48.0 % and CVBetula pendula = 42.3 %, compared to Fagus sylvatica (CVFe = 22.6%). In order to limit the influence of environmental factors (e.g. air movement caused by vehicles and pedestrians) on the samples pollution level with analytes, it seems that the optimum level for collecting the samples is 1.5-2.0 m. It was demonstrated that deciduous tree bark can be used as bioindicator in assessing the pollution of atmospheric aerosol by heavy metals, due to its occurrence in urban areas. However, it is important to validate all stages of the analysis procedure that uses deciduous tree bark.


Assuntos
Aerossóis/análise , Poluentes Atmosféricos/análise , Monitoramento Ambiental/métodos , Metais Pesados/análise , Casca de Planta/química , Betula , Poluição Ambiental/análise , Poluição Ambiental/estatística & dados numéricos , Polônia , Árvores/química
5.
Sci Total Environ ; 696: 133915, 2019 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-31461694

RESUMO

One of the most polluted areas in Chile is the Ventanas Industrial Area (VIA; 32.74°S / 71.48°W), which started in 1958 and today comprises around 16 industries in an area of ca. 4 km2. A lack of consistent long-term instrumental records precludes assessing the history of contamination in the area and also limits the evaluation of mitigation actions taken since the late 1980s. Here, we use dendrochemistry as an environmental proxy to analyze environmental changes over several decades at the VIA. We present chemical measurements of tree rings from planted, exotic Cupressus macrocarpa growing near the VIA with 4-year resolution over a period of 52 years (1960-2011). These data provide unprecedented information on regional anthropogenic pollution and are compared with a tree-ring elemental record of 48 years (1964-2011) from the Isla Negra (INE) control site not exposed to VIA emissions. For the 48 years of overlap between both sites, higher concentrations of Zn, V, Co, Cd, Ag, Fe, Cr, and Al were especially registered after the year 2000 at VIA compared to INE for the periods under study. Concentrations of Pb, Cu, As, Fe, Mo, Cr, and Zn increased through time, particularly over the period 1980-1990. Decontamination plans activated in 1992 appear to have had a positive effect on the amount of some elements, but the chemical concentration in the tree rings suggest continued accumulation of pollutants in the environment. Only after several years of implementation of the mitigation measures have some elements tended to decrease in concentration, especially at the end of the evaluated period. Dendrochemistry is a useful tool to provide a long-term perspective of the dynamics of trace metal pollution and represents a powerful approach to monitor air quality variability to extend the instrumental records back in time.


Assuntos
Monitoramento Ambiental/métodos , Poluição Ambiental/estatística & dados numéricos , Árvores/química , Chile , Indústrias
6.
Environ Monit Assess ; 191(8): 491, 2019 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-31297617

RESUMO

Leaf segmentation is significantly important in assisting ecologists to automatically detect symptoms of disease and other stressors affecting trees. This paper employs state-of-the-art techniques in image processing to introduce an accurate framework for segmenting leaves and diseased leaf spots from images. The proposed framework integrates an appearance model that visually represents the current input image with the color prior information generated from RGB color images that were formerly saved in our database. Our framework consists of four main steps: (1) Enhancing the accuracy of the segmentation at minimum time by making use of contrast changes to automatically identify the region of interest (ROI) of the entire leaf, where the pixel-wise intensity relations are described by an electric field energy model. (2) Modeling the visual appearance of the input image using a linear combination of discrete Gaussians (LCDG) to predict the marginal probability distributions of the grayscale ROI main three classes. (3) Calculating the pixel-wise probabilities of these three classes for the color ROI based on the color prior information of database images that are segmented manually, where the current and prior pixel-wise probabilities are used to find the initial labels. (4) Refining the labels with the generalized Gauss-Markov random field model (GGMRF), which maintains the continuity. The proposed segmentation approach was applied to the leaves of mangrove trees in Abu Dhabi in the United Arab Emirates. Experimental validation showed high accuracy, with a Dice similarity coefficient 90% for distinguishing leaf spot from healthy leaf area.


Assuntos
Monitoramento Ambiental/métodos , Processamento de Imagem Assistida por Computador/métodos , Doenças das Plantas , Folhas de Planta/química , Árvores/química , Algoritmos , Cor , Humanos , Distribuição Normal , Probabilidade , Sensibilidade e Especificidade , Emirados Árabes Unidos
7.
Environ Pollut ; 252(Pt B): 1772-1790, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31299507

RESUMO

Urban trees have been assumed to effectively clean air particulate matter (PM), while the inter-species differences are not yet well defined, especially the PM chemical composition. In this study, PM from leaf surface and wax layer of 3 evergreen tree species (Juniper: Juniperus rigida; Black pine: Pinus tabuliformis var. mukdeais; Spruce: Picea koraiensis) were used for finding differences in PM adsorption and its compositional traits (characterized by X-ray diffraction, X-ray photoelectron spectroscopy, Fourier transform infrared spectrum and Inductively coupled plasma-optical emission spectrometry). Possible improvement in PM removal was also evaluated by a detail whole city tree census and different scenarios of species adjustment data. We found that: 1) the amount of PM on juniper leaves was 5.73 g m-2, 2-2.5-fold higher than black pine and spruce (p < 0.05). Of them, 38.73%, 38.22%, and 23.11% were in the wax layer. 2) Compared with the explicit interspecies differences in PM quantity, more complex interspecies difference showed different patterns for different compositional traits. In general, leaf surface PM had higher O, Si, Al, Fe, N, Pb, Cu, Ni, Cr, and Cd, while the wax PM had higher C and Na contents (p < 0.05). 3) Association ordination found that the smaller leaf size, lower leaf water content, higher leaf area per unit mass, higher wax content, and larger stomatal openness aligned with the more PM adsorption by leaf, together with the higher amounts of CO stretching, O, Si, Al, N, heavy metals of Pb, Cu, Ni, Cr, and Cd in PM. 4) Compared with the other 2 species, increase of juniper percentage in urban forests is more effective for maximizing PM removal from air, accompanying more heavy metal removal but less crystalized minerals in PM. Our findings highlight that proper species configuration in urban afforestation could maximize the air PM removal capacity.


Assuntos
Poluentes Atmosféricos/análise , Monitoramento Ambiental/métodos , Metais Pesados/análise , Material Particulado/análise , Pinaceae/química , Folhas de Planta/química , Árvores/química , Adsorção , China , Cidades , Especificidade da Espécie
8.
Int J Biol Macromol ; 138: 573-581, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31348971

RESUMO

The objective of this investigation is to check the suitability novel cellulosic fibre extracted from the aerial roots of Banyan tree (ARBFs) as reinforcement in fibre reinforced plastics. The Fundamental properties of ARBFs such as density, tensile strength, chemical composition, crystallinity index, crystalline size, thermal stability, maximum degradation temperature and surface roughness were studied. The chemical analysis results revealed that after the alkalization cellulose content was improved while hemi-cellulose, lignin and wax content were demised. The enhancement in the crystallinity index (76.35% from 72.47%) and crystalline size (7.74 nm from 6.28 nm) of alkali treated ARBFs were evidenced by the X-ray diffraction analysis. Thermal analysis results confirmed that maximum degradation temperature (368 °C) and kinetic activation energy (75.45 kJ/mol) of alkali treated ARBFs had increased from 358 °C and 72.65 kJ/mol respectively. The results of scanning electron microscopic and atomic force microscopic analysis exhibited that impurities and wax on the outer surface of the ARBFs were removed after the alkali treatment. All the above finding concluded that ARBFs is the appropriate material to use as a reinforcement in fibre reinforced plastics.


Assuntos
Álcalis/química , Celulose/química , Ficus/química , Raízes de Plantas/química , Árvores/química , Celulose/ultraestrutura , Análise Espectral , Resistência à Tração , Termogravimetria
9.
PLoS One ; 14(6): e0218747, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31233563

RESUMO

A thorough understanding of the heritability, genetic correlations and additive and non-additive variance components of tree growth and wood properties is a requisite for effective tree breeding. This knowledge is essential to maximize genetic gain, that is, the amount of increase in trait performance achieved annually through directional selection. Understanding the genetic attributes of traits targeted by breeding is also important to sustain decade-long genetic progress, that is, the progress made by increasing the average genetic value of the offspring as compared to that of the parental generation. In this study, we report quantitative genetic parameters for fifteen growth, wood chemical and physical traits for the world-famous Eucalyptus urograndis hybrid (E. grandis × E. urophylla). These traits directly impact the optimal use of wood for cellulose pulp, paper, and energy production. A population of 1,000 trees sampled in a progeny trial was phenotyped directly or following the development and use of near-infrared spectroscopy calibration models. Trees were genotyped with 33,398 SNPs and 24,001 DArT-seq genome-wide markers and genomic realized relationship matrices (GRM) were used for parameter estimation with an individual-tree additive-dominant mixed model. Wood chemical properties and wood density showed stronger genetic control than growth, cellulose and fiber traits. Additive effects are the main drivers of genetic variation for all traits, but dominance plays an equally or more important role for growth, singularly in this hybrid. GRM´s with >10,000 markers provided stable relationships estimates and more accurate parameters than pedigrees by capturing the full genetic relationships among individuals and disentangling the non-additive from the additive genetic component. Low correlations between growth and wood properties indicate that simultaneous selection for wood traits can be applied with minor effects on genetic gain for growth. Conversely, moderate to strong correlations between wood density and chemical traits exist, likely due to their interdependency on cell wall structure such that responses to selection will be connected for these traits. Our results illustrate the advantage of using genome-wide marker data to inform tree breeding in general and have important consequences for operational breeding of eucalypt urograndis hybrids.


Assuntos
Eucalyptus/crescimento & desenvolvimento , Eucalyptus/genética , Brasil , Eucalyptus/química , Genoma de Planta , Genótipo , Hibridização Genética , Modelos Genéticos , Fenótipo , Melhoramento Vegetal/métodos , Polimorfismo de Nucleotídeo Único , Característica Quantitativa Herdável , Especificidade da Espécie , Espectroscopia de Luz Próxima ao Infravermelho , Árvores/química , Árvores/genética , Árvores/crescimento & desenvolvimento , Madeira/química , Madeira/genética , Madeira/crescimento & desenvolvimento
10.
Molecules ; 24(11)2019 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-31195762

RESUMO

As a valuable tree nut, walnut is a well-known member of the Juglandaceae family. The fruit is made up of an outer green shell cover or husk, the middle shell which must be cracked to release the kernel, a thin layer known as skin or the seed coat, and finally, the kernel or meat. The nutritional importance of walnut fruit is ascribed to its kernel. The shell and husk are burned as fuel or discarded away as waste products. In the past two decades, the evaluation of the phenolic content and antioxidant activity of different parts of walnut has received great interest. In this contribution, the recent reports on the extraction and quantification of phenolic content from each part of the walnut tree and fruit using different solvents were highlighted and comparatively reviewed. The current review paper also tries to describe the antioxidant content of phenolic extracts obtained from different parts of the walnut tree and fruit. Additionally, the antioxidant and antiradical activities of the prepared extracts have also been discussed.


Assuntos
Antioxidantes/análise , Antioxidantes/isolamento & purificação , Juglans/química , Árvores/química , Frutas/química , Juglans/metabolismo , Metaboloma , Solventes/química
11.
Sci Total Environ ; 659: 783-789, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-31096408

RESUMO

This study investigated the transport of 137Cs within a forest ecosystem by examining temporal changes in the inventory and determining the major pathways of transfer following significant atmospheric deposition. A forested area of eastern Japan was monitored for four years immediately after the Fukushima nuclear power plant accident in March 2011 that released a large amount of radionuclides. The long physical half-life of 137Cs means that contamination can persist for decades, so it is vital to understand the mechanisms underlying the 137Cs dynamics in ecosystems. We sampled litterfall, throughfall, and soil, mainly from a cedar stand, over a four-year period, and analyzed the 137Cs concentrations of each sample to determine the transfer rate and total inventory. After validating our methodology through a comparison with results from an earlier study, we determined the temporal changes in the 137Cs distribution and in the major transfer pathway. Results showed that most 137Cs intercepted by canopies was transferred rapidly over the first nine months, and that the major pathway was not litterfall but throughfall. The ecological half-life of the 137Cs stocked in the canopy was calculated for both the early and later stages of contamination. Although the former is consistent with previous results, the latter ecological half-life is somewhat longer, probably because of dependence on the meteorological and tree physiological conditions at the site. This study presents valuable new data on the post-Fukushima 137Cs contamination, enhancing our understanding of the associated dynamics in forest ecosystems.


Assuntos
Radioisótopos de Césio/análise , Monitoramento de Radiação , Poluentes Radioativos do Solo/análise , Árvores/química , Florestas , Acidente Nuclear de Fukushima , Japão , Folhas de Planta/química
12.
Phytochemistry ; 163: 118-125, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31048131

RESUMO

Tree peonies (Paeonia Sect. Moutan) are well-known for their medicinal and ornamental uses but most wild species in the Moutan section are endangered. The comprehensive metabolomics evaluation of tree peonies is essential to distinguish different species and to identify undescribed compounds, thereby elucidating the diversity of their metabolites and discovering potential active ingredients. In this study, the metabolome variations of root barks of nine species and their varieties collected from one botanical garden after years of localization were systematically investigated. A digital database of specialized metabolites was established to improve feature identification or annotation and various bio- and cheminformatics tools were employed to analyse and visualize the profiled metabolomic data. As a result, 384 compounds were identified or annotated, including various monoterpene glycosides, flavonoids, phenols, terpenoids and steroids, tannins, stilbenes and others. All samples were clearly divided into two subsections: Vaginatae and Delavayanae. The distribution and abundance of metabolites were also analysed and discussed in order to find potential biomarkers in different wild tree peonies.


Assuntos
Metabolômica , Paeonia/química , Árvores/química , Cromatografia Líquida de Alta Pressão , Flavonoides/análise , Flavonoides/metabolismo , Glicosídeos/análise , Glicosídeos/metabolismo , Espectrometria de Massas , Paeonia/classificação , Paeonia/metabolismo , Fenóis/análise , Fenóis/metabolismo , Casca de Planta/química , Casca de Planta/metabolismo , Raízes de Plantas/química , Raízes de Plantas/metabolismo , Esteroides/análise , Esteroides/metabolismo , Estilbenos/análise , Estilbenos/metabolismo , Taninos/análise , Taninos/metabolismo , Terpenos/análise , Terpenos/metabolismo , Árvores/classificação , Árvores/metabolismo
13.
Tree Physiol ; 39(6): 983-999, 2019 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-30976807

RESUMO

Altitudinally separated bristlecone pine populations in the White Mountains (California, USA) exhibit differential climate-growth responses as temperature and tree-water relations change with altitude. These populations provide a natural experiment to explore the ecophysiological adaptations of this unique tree species to the twentieth century climate variability. We developed absolutely dated annual ring-width chronologies, and cellulose stable carbon and oxygen isotope chronologies from bristlecone pine growing at the treeline (~3500 m) and ~200 m below for the period AD 1710-2010. These chronologies were interpreted in terms of ecophysiological adaptations to climate variability with a dual-isotope model and a leaf gas exchange model. Ring widths show positive tree growth anomalies at treeline and consistent slower growth below treeline in relation to the twentieth century warming and associated atmospheric drying until the 1980s. Growth rates of both populations declined during and after the 1980s when growing-season temperature and atmospheric vapour pressure deficit continued to increase. Our model-based interpretations of the cellulose stable isotopes indicate that positive treeline growth anomalies prior to the 1980s were related to increased stomatal conductance and leaf-level transpiration and photosynthesis. Reduced growth since the 1980s occurred with a shift to more conservative leaf gas exchange in both the treeline and below-treeline populations, whereas leaf-level photosynthesis continued to increase in response to rising atmospheric CO2 concentrations. Our results suggest that warming-induced atmospheric drying confounds positive growth responses of apparent temperature-limited bristlecone pine populations at treeline. In addition, the observed ecophysiological responses of attitudinally separated bristlecone pine populations illustrate the sensitivity of conifers to climate change.


Assuntos
Isótopos de Carbono/análise , Mudança Climática , Dessecação , Isótopos de Oxigênio/análise , Pinus/crescimento & desenvolvimento , Árvores/crescimento & desenvolvimento , Altitude , California , Pinus/química , Temperatura Ambiente , Árvores/química , Madeira/química
14.
J Environ Manage ; 239: 352-365, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-30921754

RESUMO

Phytotechnologies have been used worldwide to remediate and restore damaged ecosystems, especially those caused by industrial byproducts leaching into rivers and other waterways. The objective of this study was to test the growth, physiology, and phytoextraction potential of poplar and willow established in soils amended with heavy-metal contaminated, dredged river sediments from the Great Backa Canal near Vrbas City, Serbia. The sediments were applied to greenhouse-grown trees of Populus deltoides Bartr. ex Marsh. clone 'Bora' and Salix viminalis L. clone 'SV068'. Individual pots with trees previously grown for two months were amended with 0, 0.5 and 1.0 kg of sediment containing 400 mg Cr kg-1, 295 mg Cu kg-1, 465 mg Zn kg-1, 124 mg Ni kg-1, 1.87 mg Cd kg-1, and 61 mg Pb kg-1. Following amendment, trees were grown for two seasons (i.e., 2014, 2015), with coppicing after the first season. In addition to growth parameters, physiological traits related to the photosynthesis and nitrogen metabolism were assessed during both growing seasons. At the end of the study, trees were harvested for biomass analysis and accumulation of heavy metals in tree tissues and soils. Application of sediment decreased aboveground biomass by 37.3% in 2014, but increased height (16.4%) and leaf area (19.2%) in 2015. Sediment application negatively impacted the content of pigments and nitrate reductase activity, causing them to decrease over time. Generally, the effect of treatments on growth was more pronounced in poplars, while willows had more pronounced physiological activity. Accumulation patterns were similar to previously-published results. In particular, Zn and Cd were mostly accumulated in leaves of both poplar and willow, which indicated successful phytoextraction. In contrast, other metals (e.g., Cr, Ni, Pb, Cu) were mostly phytostabilized in the roots. Differences in metal allocation between poplar and willow were recorded only for Cu, while other metals followed similar distribution patterns in both genera. Results of this study indicated that the composition of heavy metals in the sediments determined the mechanisms of the applied phytoremediation technique.


Assuntos
Metais Pesados/análise , Populus/química , Populus/crescimento & desenvolvimento , Rios/química , Salix/química , Salix/crescimento & desenvolvimento , Solo/química , Biomassa , Sedimentos Geológicos/química , Fotossíntese , Folhas de Planta/química , Folhas de Planta/metabolismo , Raízes de Plantas/química , Raízes de Plantas/metabolismo , Populus/metabolismo , Salix/metabolismo , Sérvia , Poluentes do Solo/análise , Árvores/química , Árvores/metabolismo
15.
J Agric Food Chem ; 67(15): 4367-4374, 2019 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-30916944

RESUMO

Syringyl (S) lignin content and the syringyl-to-guaiacyl (S/G) lignin ratio are important characteristics of wood and lignocellulosic biomass. Although numerous methods are available for estimating S lignin units and the S/G ratio, in this work, a new method based on Raman spectroscopy that uses the 370 cm-1 Raman band-area intensity (370-area) was developed. The reliability of the Raman approach for determining S content was first tested by the quantitative analysis of three syringyl lignin models by sampling them, separately, in dioxane and in Avicel. Good linear correlations between the 370 cm-1 intensity and model concentrations were obtained. Next, the percent syringyl (%S) lignin units in various woods were measured by correlating the 370 cm-1 Raman intensity data with values of S units in lignin determined by three regularly used methods, namely, thioacidolysis, DFRC, and 2D-HSQC NMR. The former two methods take into account only the monomers cleaved from ß-O-4-linked lignin units, whereas the NMR method reports S content on the whole cell wall lignin. When the 370-area intensities and %S values from the regularly used methods were correlated, good linear correlations were obtained ( R2 = 0.767, 0.731, and 0.804, respectively, for the three methods). The correlation with the highest R2, i.e., with the 2D NMR method, is proposed for estimating S units in wood lignins by Raman spectroscopy as, in principle, both represent the whole cell wall lignin and not just the portion of lignin that gets cleaved to release monomers. The Raman analysis method is quick, uses minimal harmful chemicals, is carried out nondestructively, and is insensitive to the wet or dry state of the sample. The only limitations are that the sample of wood contains at least 30% S and not be significantly fluorescent, although the latter can be mitigated in some cases.


Assuntos
Lignina/química , Análise Espectral Raman/métodos , Madeira/química , Estrutura Molecular , Árvores/química
16.
Chemosphere ; 224: 407-416, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30831491

RESUMO

An open-system combustion chamber was designed and constructed for simulation of burning of various biomass types to estimate emission factors of pollutant gases, fine particulate matters and their composition to find out significant tracers. Rice straw (RS), maize residues (MR) and forest leaf litters (FLL) from mixed deciduous forest (MDF) and dry dipterocarp forest (DDF) were collected from various places in Northern Thailand based on land-use types. Approximately 1 kg of air-dried biomass sample was burned in the chamber, PM2.5 were collected. CO2 dominated during the flaming state while CO is predominant in the smoldering state. The highest EFPM2.5 was obtained from MDF burning (4.38 ±â€¯2.99 g kg-1), while the lowest value was from MR burning (2.15 ±â€¯0.95 g kg-1). Among water soluble ions, K+ (biomass burning (BB) tracer) was the most abundant species in PM2.5 followed by Cl- and SO42-. The average EFK+ from the burning of agricultural biomass was significantly higher than the burning of FLL. Scatter plot of K+/SO42- versus K+/Cl- can be used to distinguish between agricultural crop residues and FLL burning. Levoglucosan (BB tracer) was a dominant species among anhydrosugars and also a major component found in FLL burning. The ratios of levoglucosan/K+ and levoglucosan/mannosan obtained from forest and agricultural waste burnings were significantly different, therefore they can be used for BB source identification.


Assuntos
Poluentes Atmosféricos/análise , Monitoramento Ambiental/métodos , Gases/análise , Material Particulado/análise , Biomassa , Produtos Agrícolas/química , Florestas , Tailândia , Árvores/química
17.
Environ Pollut ; 248: 635-645, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30849582

RESUMO

Mangrove sediments can store high amount of pollutants that can be more or less bioavailable depending on environmental conditions. When in available forms, these elements can be subject to an uptake by mangrove biota, and can thus become a problem for human health. The main objective of this study was to assess the distribution of some trace elements (Fe, Mn, Co, Ni, Cr, As, and Cu) in tissues of different plants and snails in a tropical mangrove (Can Gio mangrove Biosphere Reserve) developing downstream a megacity (Ho Chi Minh City, Vietnam). In addition, we were interested in the relationships between mangrove habitats, sediment quality and bioaccumulation in the different tissues studied. Roots and leaves of main mangrove trees (Avicennia alba and Rhizophora apiculata) were collected, as well as different snail species: Chicoreus capucinus, Littoraria melanostoma, Cerithidea obtusa, Nerita articulata. Trace elements concentrations in the different tissues were determined by ICP-MS after digestion with concentrated HNO3 and H2O2. Concentrations differed between stands and tissues, showing the influence of sediment geochemistry, species specific requirements, and eventually adaptation abilities. Regarding plants tissues, the formation of iron plaque on roots may play a key role in preventing Fe and As translocation to the aerial parts of the mangrove trees. Mn presented higher concentrations in the leaves than in the roots, possibly because of physiological requirements. Non-essential elements (Ni, Cr and Co) showed low bioconcentration factors (BCF) in both roots and leaves, probably resulting from their low bioavailability in sediments. Regarding snails, essential elements (Fe, Mn, and Cu) were the dominant ones in their tissues. Most of snails were "macroconcentrators" for Cu, with BCF values reaching up to 42.8 for Cerithidea obtusa. We suggest that high quantity of As in all snails may result from its high bioavailability and from their ability to metabolize As.


Assuntos
Monitoramento Ambiental/métodos , Metais Pesados/análise , Caramujos/química , Oligoelementos/análise , Árvores/química , Poluentes Químicos da Água/análise , Áreas Alagadas , Animais , Ecossistema , Sedimentos Geológicos/química , Vietnã
18.
J AOAC Int ; 102(5): 1263-1270, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-30890207

RESUMO

Background: To effectively safeguard the food-allergic population and support compliance with food-labeling regulations, the food industry and regulatory agencies require reliable methods for food allergen detection and quantification. MS-based detection of food allergens relies on the systematic identification of robust and selective target peptide markers. The selection of proteotypic peptide markers, however, relies on the availability of high-quality protein sequence information, a bottleneck for the analysis of many plant-based proteomes. Method: In this work, data were compiled for reference tree nut ingredients and evaluated using a parsimony-driven global proteomics workflow. Results: The utility of supplementing existing incomplete protein sequence databases with translated genomic sequencing data was evaluated for English walnut and provided enhanced selection of candidate peptide markers and differentiation between closely related species. Highlights: Future improvements of protein databases and release of genomics-derived sequences are expected to facilitate the development of robust and harmonized LC-tandem MS-based methods for food allergen detection.


Assuntos
Alérgenos/análise , Bases de Dados de Proteínas , Nozes/química , Peptídeos/análise , Proteínas de Plantas/análise , Árvores/química , Alérgenos/química , Sequência de Aminoácidos , Biomarcadores/análise , Peptídeos/química , Proteínas de Plantas/química , Proteômica , Traqueófitas/química
19.
Glob Chang Biol ; 25(5): 1653-1664, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30737866

RESUMO

Prolonged drought and intense heat-related events trigger sudden forest die-off events and have now been reported from all forested continents. Such die-offs are concerning given that drought and heatwave events are forecast to increase in severity and duration as climate change progresses. Quantifying consequences to carbon dynamics and storage from die-off events are critical for determining the current and future mitigation potential of forests. We took stand measurements five times over 2+ years from affected and unaffected plots across the Northern Jarrah Forest, southwestern Australia, following an acute drought/heatwave in 2011. We found a significant loss of live standing carbon (49.3 t ha-1 ), and subsequently a significant increase in the dead standing carbon pool by 6 months post-die-off. Of the persisting live trees, 38% experienced partial mortality contributing to the rapid regrowth and replenishment (82%-88%) of labile carbon pools (foliage, twigs, and branches) within 26 months. Such regrowth was not substantial in terms of net carbon changes within the timeframe of the study but does reflect the resprouting resilience of this forest type. Dead carbon generated by the die-off may persist for centuries given low fragmentation and decay rates resulting in low biogenic emission rates relative to other forest types. However, future fire may threaten persistence of both dead and live pools via combustion and mortality of live tissue and impaired regrowth capacity. Resprouting forests are commonly regarded as resilient systems, however, a changing climate could see vulnerable portions of forests become carbon sources rather than carbon sinks.


Assuntos
Sequestro de Carbono , Secas , Florestas , Árvores/fisiologia , Austrália , Carbono/análise , Mudança Climática , Fogo , Árvores/química , Árvores/crescimento & desenvolvimento
20.
Fitoterapia ; 134: 141-150, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30738093

RESUMO

Azadirachta indica A. Juss. (Neem) is an Indian tree recognized for its activity as pesticide, as well as several pharmacological properties. Among the various compounds already isolated and studied from Neem tree, azadirachtin (AZA) was identified as the main bioactive compound. Azadirachtin can be found at different parts of the Neem plant but assumes its maximum concentration at the seed level. This compound features a quite complex chemical structure, which justifies the 20-plus-year difficulty to identify the synthetic pathway that subsequently permitted to carry out its artificial synthesis. Azadirachtin is widely used as a basis for production of biopesticides; nevertheless, other properties have been recognized for this substance, among which the anticancer and antimalarial activity stand out. The methods available for azadirachtin extraction are diverse, including solid-liquid extraction and extraction with solvents at high or low temperatures. Alcohol based solvents are associated with higher extraction yields and are therefore preferred for the isolation of azadirachtin from plant parts. Clean-up of the extracts is generally required for further purification. The highest azadirachtin levels have been obtained from Neem seeds but concentration values present a large variation between batches. Therefore, in addition to extraction procedures, it is essential to establish routine methods for azadirachtin identification and quantification. Chromatography-based techniques are preferably selected for detection and quantification of azadirachtin in plant matrices. Overall, this process will guarantee a future reproducible, safe and effective use of the extracts in formulations for commercial applications.


Assuntos
Azadirachta/química , Limoninas/química , Limoninas/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Estrutura Molecular , Compostos Fitoquímicos/química , Compostos Fitoquímicos/isolamento & purificação , Extratos Vegetais/análise , Sementes/química , Solventes/química , Árvores/química
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