Association between decay fungi and subterranean termites in the wood biodeterioration process of Tipuana tipu (Benth.) O. Kuntze trees of Sao Paulo city, SP

In the present paper the process of wood biodeterioration of tipuana trees planted in 7 regions of the city of Sao Paulo, SP was evaluated. On the sidewalks, 1109 trees were analyzed taking into consideration the occurrence and association of the xylophagous organisms (decay fungi and subterranean termites), the wood deterioration and the BHD (breast height diameter). The percentage of wood internal deterioration (%) was obtained by non destructive analysis, using a penetrometer. The results had shown that 75% of the tipuana trees presented BHD superior to 50 cm, characterizing them as adult. Decay fungi in the roots and/or trunk had been observed in 338 trees (30.5%). Subterranean termites of Heterotermes sp. and Coptotermes gestroi species had occurred in 307 trees (27.7%), the latter in high infestation level. The association between the fungi and termites was observed, as well as its relation with the BHD, where a greater value of BHD meant higher wood biodeterioration intensity. For tipuana trees, the BHD was considered an indicative attribute of the internal deterioration intensity, caused by these xylophagous organisms.

Storage as a tool to improve wood fuel quality

This work analysed the influence of storage in the quality of forest biomass for energy generation in the region of Lages, Brazil. Logs of Pinus taeda L. and Eucalyptus dunnii Maiden were harvested and piled during the four different seasons: spring, summer, fall and winter. The analyses were performed immediately after harvesting (without being stored), after two, four and six months of storage. The evaluated properties were: moisture content, gross and net calorific value, ash content and solubility in cold water, hot water and sodium hydroxide. The species composition, storage span, harvesting season and storage season influenced the forest biomass characteristics. In general, eucalyptus presented better results than pine, losing moisture faster, having less alteration in the chemical composition and producing greater energetic gain over storage time. For both species, the ideal storage time was four months. Furthermore, spring and summer were the best harvesting seasons. Thus, if the forest biomass is harvested at the end of winter or beginning of spring with subsequent storage during the summer, this biomass will have the best performance for energy production. (C) 2011 Elsevier Ltd. All rights reserved.

Radial variation of the wood anatomical structure of Gmelina arborea trees from different climatic and management conditions in Costa Rica

The evaluations of the effect of the climatic conditions and of the intensity of forest management in the trunk of the Gmelina arborea Linn. Roxb. trees are restricted to its physical-mechanical properties and use. The present work has as objective to study the radial variations of the wood anatomy of the gmelina trees sampled in plantations of 30 sites in Costa Rica, characterized by two climatic conditions (tropical dry and humid) and three intensities of forest management (intensive, moderate and without management). The results of the analyses demonstrated the existence of radial variation of the different anatomical parameters, except for the fiber lumen diameter and multiple vessels in the wood of the gmelina trees. For the wood anatomical elements, fibers (width, lumen diameter, and length), vessels (multiple vessels, diameter and frequency) and radial parenchyma (height) relationships were observed with the climate (tropical humid and dry). The radial variations of the wood anatomical elements were, also, influenced by the management regimes of the gmelina trees.

Changes in wood-water relationship due to heat treatment assessed on micro-samples of three Eucalyptus species

Wood-water relationship of untreated and heat-treated wood was studied. Specimens of Eucalyptus grandis, E saligna, and E citriodora were submitted to five conditions of heat treatment: 180 degrees C and 220 degrees C with air; 220 degrees C, 250 degrees C, and 280 degrees C with N(2). The wood-water relationships were accurately studied in a special device, in which the moisture content (MC) of the sample was measured with a highly sensitive electronic microbalance placed in a climatic chamber. The dimensions of the sample were collected continuously without contact by means of two high-speed laser scan micrometers. Sorption curves and shrinkage-MC relationships were observed. To study the effects of heat treatment, the following parameters were also determined: fiber saturation point (FPS), wood anisotropy (T/R ratio), shrinkage slope, reduction in hygroscopicity, and anti-shrink efficiency (ASE). The physical properties were significantly affected only at 220 degrees C and above. At heat temperature levels higher than 220 degrees C, the reduction in hygroscopicity and ASE are higher than 40% and continue to be reduced with increasing temperature level. This work also demonstrates that heat treatment does not change the slope of the curves shrinkage vs. MC, proving that heat treatment affects the domain of alterations in wood properties, but not the behavior within this domain.

Wood CO(2) efflux and foliar respiration for Eucalyptus in Hawaii and Brazil

We measured CO(2) efflux from wood for Eucalyptus in Hawaii for 7 years and compared these measurements with those on three-and four-and-a-half-year-old Eucalyptus in Brazil. In Hawaii, CO(2) efflux from wood per unit biomass declined similar to 10x from age two to age five, twice as much as the decline in tree growth. The CO(2) efflux from wood in Brazil was 8-10x lower than that for comparable Hawaii trees with similar growth rates. Growth and maintenance respiration coefficients calculated from Hawaii wood CO(2) efflux declined with tree age and size (the growth coefficient declined from 0.4 mol C efflux mol C(-1) wood growth at age one to 0.1 mol C efflux mol C(-1) wood growth at age six; the maintenance coefficient from 0.006 to 0.001 mu mol C (mol C biomass)(-1) s(-1) at 20 degrees C over the same time period). These results suggest interference with CO(2) efflux through bark that decouples CO(2) efflux from respiration. We also compared the biomass fractions and wood CO(2) efflux for the aboveground woody parts for 3- and 7-year-old trees in Hawaii to estimate how focusing measurements near the ground might bias the stand-level estimates of wood CO(2) efflux. Three-year-old Eucalyptus in Hawaii had a higher proportion of branches < 0.5 cm in diameter and a lower proportion of stem biomass than did 7-year-old trees. Biomass-specific CO(2) efflux measured at 1.4 m extrapolated to the tree could bias tree level estimates by similar to 50%, assuming no refixation from bark photosynthesis. However, the bias did not differ for the two tree sizes. Foliar respiration was identical per unit nitrogen for comparable treatments in Brazil and Hawaii (4.2 mu mol C mol N(-1) s(-1) at 20 degrees C).

Tree-ring characterization of Araucaria columnaris Hook and its applicability as a lead indicator in environmental monitoring

Tree-rings have frequently been used for dating of trees and to determine annual growth increments and forest dynamics, but little is known in tropical conditions about their utilization for environmental monitoring. This paper presents the results of Araucaria columnaris tree-ring characterization by wood anatomy and X-ray densitometric analysis and the determination of Pb concentration. Core samples from twelve araucaria trees were extracted from two sites exposed to air pollution due to intense traffic of vehicles and industrial activities. The tree-rings distinctly presented radial variation in early-latewood thickness and density, and characteristics of juvenile and mature wood. Anatomical and X-ray densitometric analysis were useful to delimit the tree-ring boundaries and to date the tree-rings, as well as to prove the annual formation. The lead concentration in annual araucaria tree-rings, analyzed with graphite furnace atomic absorption spectrometry, indicated the seasonal presence of the heavy metal in the environment during the 30 years studied, although the Pb did not affect tree growth. (c) 2008 Elsevier GmbH. All rights reserved.

Alterations in energy properties of eucalyptus wood and bark subjected to torrefaction: The potential of mass loss as a synthetic indicator

Torrefaction is a mild pyrolysis process (usually up to 300 degrees C) that changes the chemical and physical properties of biomass. This process is a possible pre-treatment prior to further processes (transport, grinding, combustion, gasification, etc) to generate energy or biofuels. In this study, three eucalyptus wood species and bark were subjected to different torrefaction conditions to determine the alterations in their structural and energy properties. The most severe treatment (280 degrees C, 5 h) causes mass losses of more than 35%, with severe damage to anatomical structure, and an increase of about 27% in the specific energy content. Bark is more sensitive to heat than wood. Energy yields are always higher than mass yields, thereby demonstrating the benefits of torrefaction in concentrating biomass energy. The overall mass loss is proposed as a relevant parameter to synthesize the effect of torrefaction conditions (temperature and duration). Accordingly, all results are summarised by analytical expressions able to predict the energy properties as a function of the overall mass loss. These expressions are intended to be used in any optimization procedure, from production in the field to the final use. (c) 2010 Elsevier Ltd. All rights reserved.

Variation of wood density and relationship with the tree-ring width of mahogany trees, Swietenia macrophylla, from Amazonian tropical forest of Peru

Mahogany trees, Swietenia macrophylla, occur in open rainforest, semi deciduous and deciduous and dense rainforest of Peruvian Amazonian tropical forest. They occur, preferentially, in areas with a defined dry season, with typical phenology and seasonal variation activity, forming distinct tree-rings. The present work had as aim to determine the wood density radial variation of 14 mahogany trees, of two populations of the Peruvian Amazonian tropical forest, through the X-ray densitometry and to evaluate their application as methodology, compared to the classic method of measurement table, for the determination of the treering width. The radial wood apparent density of the trees profiles rendered it possible to delimit the areas of juvenile-adult wood and of the heartwood-sapwood, relative to the anatomical structure and chemical composition differences, due to the extractives and the vessels obstruction by tyloses. The mean, minimum and maximum wood apparent density of the mahogany trees for the Populations A and B were of 0.70; 0.29; 1.01 g.cm(-3) and 0.81; 0.29; 1.19 g.cm(-3), respectively. The analysis of the variance and mean test indicate differences of mean wood density among the mahogany trees of each population, probably due to the age of the trees. There was no correlation between mean wood density of mahogany trees among the two populations, as well as, between the tree-ring width and the respective mean density. The X-ray densitometry technique is an important tool in the evaluation of the radial variation of wood apparent density and the delimitation of tree-ring boundaries, with correlations of 0.94 and 0.93 in relation to measurement table, for each sampled population.

The dynamic of shrinkage/moisture content behavior determined during drying of microsamples for different kinds of wood

This article presents the results obtained from an experimental device designed for the accurate determination of wood/water relationship on microsamples. The moisture content of the sample is measured with a highly sensitive electronic microbalance and two dimensions of the sample are collected continuously without contact using high-speed laser scan micrometers. The whole device is placed in a climatic chamber. The microsamples investigated were prepared with a diamond wire saw. The unique ability of this device to work with small samples allowed normal, opposite, and reaction wood to be characterized separately. Experiments were carried out on three wood species (beech, spruce, and poplar). In the case of beech, a deviation from the linear relation between tangential shrinkage and moisture content between 40 and 20% is particularly noticeable for the first desorption. A localized collapse of ray cells could explain this result. Compared to normal wood, an important longitudinal shrinkage and a low tangential shrinkage were observed in compression wood of spruce. Both the tension wood and opposite wood of poplar exhibit a high longitudinal shrinkage, but no significant difference between the three types of wood is noticeable in the tangential direction.

Multiphase flow in the vascular system of wood: From microscopic exploration to 3-D Lattice Boltzmann experiments

This paper provides insights into liquid free water dynamics in wood vessels based on Lattice Boltzmann experiments. The anatomy of real wood samples was reconstructed from systematic 3-D analyses of the vessel contours derived from successive microscopic images. This virtual vascular system was then used to supply fluid-solid boundary conditions to a two-phase Lattice Boltzmann scheme and investigate capillary invasion of this hydrophilic porous medium. Behavior of the liquid phase was strongly dependent on anatomical features, especially vessel bifurcations and reconnections. Various parameters were examined in numerical experiments with ideal vessel bifurcations, to clarify our interpretation of these features. (c) 2010 Elsevier Ltd. All rights reserved.

Genetic variation for anatomic traits and volume shrinkage and their correlation with wood basic density in an Eucalyptus camaldulensis Dehn base population

Eucalyptus camaldulensis has great importance in Brazil because of their phenotypic plasticity for different environmental conditions, as soils, altitudes and rainfall. This study is an investigation of a base population of E. camaldulensis from Australia through a progeny test implanted in Selviria, MS. The trial was established in a randomized block design, with 25 families and 60 replications of single tree plots. Genetic parameters for anatomic traits and volume shrinkage were estimated, as well as their correlations with wood basic density. No significant differences among progenies were observed for the traits studied. The additive genetic variation coefficient at individual and among progeny levels ranged from low (0.26%) to high (16.98%). The narrow sense heritability at individual and family means levels also ranged from low (0.01) to high (0.87). This indicates that some traits are under strong genetic control and can be improved by selection. In the present situation, in order to attain the highest genetic gains, the sequential selection among and within progeny would be recommended.

Chlorophyll Degradation and Formation of Colorless Chlorophyll Derivatives during Soybean (Glycine max L. Merill) Seed Maturation

The natural chlorophyll degradation results in noncolored chlorophyll catabolites (NCCs), but there are controversies if these are the final products. The formation and degradation of NCCs during soybean seed (Glycine max L. Merrill) maturation and two drying temperatures were investigated. Soybean was harvested at six maturation stages. The effect of postharvest drying at 40 and 60 degrees C on the NCC formation was analyzed by high-performance liquid chromatography (HPLC), and results were expressed as areas under the curve. All samples contained fractions with an absorption maximum at 320 nm, typical for NCC. The amounts of NCC increased until 114 days after planting and were significantly lower in advanced maturation stages. These results indicate that the NCC in soybeans might not be the final products of chlorophyll degradation. Their reduction in advanced maturation stages may be due to further metabolization. Heating soybeans at 40 and 60 degrees C promoted unnatural chlorophyll degradation and impaired the formation of NCC.

Analysis of chemokines and reactive oxygen species formation by rat and human neutrophils induced by microcystin-LA, -YR and -LR

Microcystins (MC), a family of heptapeptide toxins produced by some genera of Cyanobacteria, have potent hepatotoxicity and tumor-promoting activity. Leukocyte infiltration in the liver was observed in MC-induced acute intoxication. Although the mechanisms of hepatotoxicity are still unclear, neutrophil infiltration in the liver may play an important role in triggering toxic injury and tumor development. The present study reports the effects of MC-LA, MC-YR and MC-LR (1 and 1000 nM) on human and rat neutrophils functions in vitro. Cell viability, DNA fragmentation, mitochondrial membrane depolarization and intracellular reactive oxygen species (ROS) levels were measured by flow cytometry. Extracellular ROS content was measured by lucigenin-amplified chemiluminescence, and cytokines were determined by ELISA. We found that these MC increased interleukin-8 (IL-8), cytokine-induced neutrophil chemoattractant-2 alpha beta (CINC-2 alpha beta) and extracellular ROS levels in human and rat neutrophils. Apart from neutrophil presence during the inflammatory process of MC-induced injury, our results suggest that hepatic neutrophil accumulation is further increased by MC-induced neutrophil-derived chemokine. (c) 2008 Elsevier Ltd. All rights reserved.

Does mobilization for autologous stem cell transplantation damage stromal layer formation?

Autologous hematopoietic stem cell transplantation (HSCT) has proved efficient to treat hematological malignancies. However, some patients fail to mobilize HSCs. It is known that the microenvironment may undergo damage after allogeneic HSCT. However little is known about how chemotherapy and growth factors contribute to this damage. We studied the stromal layer formation(SLF) and velocity before and after HSC mobilization, through long-term bone marrow culture from 22 patients and 10 healthy donors. Patients` SLF was similar at pre- (12/22)and post-mobilization (9/20), however for controls this occurred more at pre- mobilization (9/10; p=0.03). SLF velocity was higher at pre than post-mobilization in both groups. Leukemias and multiple myeloma showed faster growth of SLF than lymphomas at post-mobilization, the latter being similar to controls. These findings could be explained by less uncommitted HSC in controls than patients at post-mobilization. Control HSCs may migrate more in response to mobilization, resulting in a reduced population by those cells.

Kinetic and thermodynamic investigation on clavulanic acid formation and degradation during glycerol fermentation by Streptomyces DAUFPE 3060

Clavulanic acid (CA) is a potent inhibitor of beta-lactamases, produced by some resistant pathogenic microorganisms, which allows efficient treatment of infectious diseases. The kinetic and thermodynamic parameters of CA production by a new isolate of Streptomyces DAUFPE 3060 and its degradation were evaluated. The effect of temperature on the system was investigated in the range 24-40 degrees C adopting an overall model accounting for (a) the Arrhenius-type formation of CA by fermentation, (b) the hypothetical reversible unfolding of the enzyme limiting the overall metabolism, and (c) the irreversible first-order degradation of CA. The higher rates of CA formation (k(CA) = 0,107 h(-1)) and degradation (k(d) = 0.062 h(-1)) were observed at 32 and 40 degrees C, respectively. The main thermodynamic parameters of the three above hypothesized events were estimated. In particular, the activation parameters of degradation (activation energy = 39.0 kJ/mol; Delta H(d)* = 36.5 kJ/mol; Delta S(d)* = -219.7 J/(mol K); Delta G(d)* = 103.5 kJ/mol) compare reasonably well with those reported in the literature for similar system without taking into account the other two events. (C) 2009 Elsevier Inc. All rights reserved.