Moisture content and its influence on the roughness and noise emission during wood machining

Numerous factors influencing the surface quality of wood after machining, among them we highlight the machining parameters and the properties of the wood. In the analysis of the influence of these factors on machining and in determining the quality measurement systems are used to obtain surface characteristics, these systems are divided into methods of contact and non-contact. The method for mechanical contact performed with the aid of the surface roughness tester is the most valued in the measurement of roughness of wood, however, aiming at a greater agility in these measurements, there is a need to seek alternatives for evaluation of surface quality, and one of these options is to use the forms of indirect measurements of this quality, as for example, the use of noise emission during the machining process. With this, the aim was to analyze the influence of the moisture content of the wood, at different levels, on surface quality of the species Pinus elliottii, determined by the method of mechanical probing move and relate this roughness with the sound emission issued for each class of humidity, during machining. The planning of experiments and statistical analyses were performed with the help of Taguchi method. The specimens were conditioned in greenhouses climatizadoras automatics for obtaining three classes of humidity. Machining tests of wooden pieces were performed on a machining center specific for this type of material. The roughness values were measured by a roughness verifier and the noise emission values were measured by for a measurer sound pressure level. Statistically significant differences were observed, the significance level of 10 %, on roughness and noise emission between the three levels of moisture. It was observed that with the increase in the moisture content occurred an increase of roughness and a reduction in noise emission. Monitoring of surface quality through noise level is an interesting alternative to the method of mechanical contact.

Influência da temperatura no crescimento micelial de linhagens de Lentinula edodes

The objective of the present work was to evaluate the in vitro mycelial growth of ten L. edodes strains (LED 12, LED 20, LED 25, LED 27, LED 33, LED 35, LED 51, LED 55, LED 58 and LED 75) submitted to the temperatures of 15, 20 and 25 ºC. An agar medium prepared with eucalyptus wood extract and soy bran was used and radial measurement of the mycelial growth of L. edodes strains was performed. The experimental design was totally randomized, in a 10 x 3 factorial scheme. Each treatment corresponded to a Petri plate and consisted of 5 repetitions. It was verified that L. edodes growth is influenced by the incubation temperature, that is the temperature of 25 ºC was the most favorable for the mycelial growth of all L. edodes strains, especially for LE 75, LE 55, LE 33 and LE 12 strains, which obtained the highest mycelial growth averages at 25 ºC at the end of the cultivation cycle.

Uso de resíduos madeireiros da Amazônia brasileira no cultivo in vitro de Lentinus strigosus

Lentinus strigosus (Schwein.) Fr. is an exploitable edible mushroom occurring in the Brazilian Amazon, being part of a huge diversity of edible mushrooms which are little grown. The use of regional waste is recommended to reduce production costs of any kind of edible mushroom. Thus, the mycelial growth of L. strigosus in culture media based on regional wood waste extract by using substrates based on Protium puncticulatum, Cariniana micrantha and Caryocar glabum sawdust, supplemented with 20% of wheat bran (Triticum aestivum), corn bran (Zea sp.) or rice bran (Oryza sp.) was observed. Eucalyptus (Eucaliptus sp.) sawdust was used for comparison with the other wood wastes because it is commonly used in the cultivation of edible fungi. The experimental design employed was totally randomized, in 4 x 3 factorial scheme (sawdust x bran), adding up 12 treatments with 5 repetitions, being that each repetition corresponded to a Petri dish, totalizing 60 dishes, incubated at 35 ºC. The diameter of the colony was daily evaluated until the fungus reached the borders of the Petri dish in one of the treatments. After that period, the media based on P. puncticulatum sawdust obtained thebest results of mycelial growth, showing potential to be used as an alternative residuein a future production of L. strigosus in the state of Amazonas.

Biological control of the bronze bug, Thaumastocoris peregrinus, in eucalyptus plantations in Brazil

The bronze bug Thaumastocoris peregrinus (Hemiptera: Thaumastocoridae) was detected in Brazil in 2008 and infested >180 000 ha of eucalyptus plantations in 2011. The bronze bug can cause a reduction of 10–15% in wood productivity after 2 years of heavy infestation. Although there is not an effective control method known, biological control is the main control strategy studied. An exotic egg parasitoid, Cleruchoides noackae (Hymenoptera: Mymaridae), was imported from Australia in 2012, reared in a laboratory and released in three Brazilian regions. Parasitoids were recovered at release points after 20–30 d. In 2013, preliminary evaluations demonstrated parasitoid establishment in these areas, and the parasitoid was recovered in adjacent areas after 1 year of release. Bioassays confi rmed egg parasitism of 15–20% by C. noackae. Other native natural enemies were studied. We found green lacewing Chrysoperla externa and predatory bugs Supputius cincticeps and Atopozelus opsimus preying on nymphs and/or adults of T. peregrinus. Another promising possibility is entomopathogenic fungi. Commercial formulations of Beauveria bassiana were tested with success in lab and fi eld conditions. Fusarium proliferatum and Paecilomyces cateniannulatus caused mortality of T. peregrinus in natural epizooties. After 5 years of research, it is possible to develop an integrated pest management system (IPM) for eucalyptus plantations based on biocontrol strategy for bronze bug.

Efeitos da estabulação sobre o trato respiratório de equinos em dois tipos diferentes de camas e a pasto

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Signaling via cAMP in Fungi: Interconnections with Mitogen-Activated Protein Kinase Pathways

The cAMP signal transduction pathway controls a wide variety of processes in fungi. For example, considerable progress has been made in describing the involvement of cAMP pathway components in the control of morphogenesis in Saccharomyces cerevisiae, Ustilago maydis, and Magnaporthe grisea. These morphological processes include the establishment of filamentous growth in S. cerevisiae and U. maydis, and the differentiation of an appressorial infection structure in M. grisea. The discovery that appressorium formation requires cAMP signaling provides an immediate connection to fungal virulence. This connection may have broader implications among fungal pathogens because recent work indicates that cAMP signaling controls the expression of virulence traits in the human pathogen Cryptococcus neoformans. In this fungus, cAMP also influences mating, as has been found for Schizosaccharomyces pombe and as may occur in U. maydis. Finally, cAMP and mitogen- activated protein kinase pathways appear to function coordinately to control the response of certain fungi, e.g., Saccharomyces cerevisiae and Schizosaccharomyces pombe, to environmental stress. There are clues that interconnections between these pathways may be common in the control of many fungal processes.

Marine Fungi Aspergillus sydowii and Trichoderma sp Catalyze the Hydrolysis of Benzyl Glycidyl Ether

Whole cells of the marine fungi Aspergillus sydowii Gc12, Penicillium raistrickii Ce16, P. miczynskii Gc5, and Trichoderma sp. Gc1, isolated from marine sponges of the South Atlantic Ocean (Brazil), have been screened for the enzymatic resolution of (+/-)-2-(benzyloxymethyl)oxirane (benzyl glycidyl ether; 1). Whole cells of A. sydowii Gc12 catalyzed the enzymatic hydrolysis of (R,S)-1 to yield (R)-1 with an enantiomeric excess (ee) of 24-46% and 3-(benzyloxy)propane-1,2-diol (2) with ee values < 10%. In contrast, whole cells of Trichoderma sp. Gc1 afforded (S)-1 with ee values up to 60% and yields up to 39%, together with (R)-2 in 25% yield and an ee of 32%. This is the first published example of the hydrolysis of 1 by whole cells of marine fungi isolated from the South Atlantic Ocean. The hydrolases from the two studied fungi exhibited complementary regioselectivity in opening the epoxide ring of racemic 1, with those of A. sydowii Gc12 showing an (S) preference and those of Trichoderma sp. Gc1 presenting an (R) preference for the substrate.

Macrofaunal succession in sediments around kelp and wood falls in the deep NE Pacific and community overlap with other reducing habitats

Sunken parcels of macroalgae and wood provide important oases of organic enrichment at the deep-sea floor, yet sediment community structure and succession around these habitat islands are poorly evaluated. We experimentally implanted 100-kg kelp falls and 200 kg wood falls at 1670 m depth in the Santa Cruz Basin to investigate (1) macrofaunal succession and (2) species overlap with nearby whale-fall and cold-seep communities over time scales of 0.25-5.5 yr. The abundance of infaunal macrobenthos was highly elevated after 0.25 and 0.5 yr near kelp parcels with decreased macrofaunal diversity and evenness within 0.5 m of the falls. Apparently opportunistic species (e.g., two new species of cumaceans) and sulfide tolerant microbial grazers (dorvilleid polychaetes) abounded after 0.25-0.5 yr. At wood falls, opportunistic cumaceans become abundant after 0.5 yr, but sulfide tolerant species only became abundant after 1.8-5.5 yr, in accordance with the much slower buildup of porewater sulfides at wood parcels compared with kelp falls. Species diversity decreased significantly over time in sediments adjacent to the wood parcels, most likely due to stress resulting from intense organic loading of nearby sediments (up to 20-30% organic carbon). Dorvilleid and ampharetid polychaetes were among the top-ranked fauna at wood parcels after 3.0-5.5 yr. Sediments around kelp and wood parcels provided low-intensity reducing conditions that sustain a limited chemoautrotrophically-based fauna. As a result, macrobenthic species overlap among kelp, wood, and other chemosynthetic habitats in the deep NE Pacific are primarily restricted to apparently sulfide tolerant species such as dorvilleid polychaetes, opportunistic cumaceans, and juvenile stages of chemosymbiont containing vesicomyid bivalves. We conclude that organically enriched sediments around wood falls may provide important habitat islands for the persistence and evolution of species dependent on organic- and sulfide-rich conditions at the deep-sea floor and contribute to beta and gamma diversity in deep-sea ecosystems. (C) 2010 Elsevier Ltd. All rights reserved.

DETERMINATION OF THE E/G RATIO OF WOOD LOGS USING TRANSVERSE VIBRATION

The Bernoulli's model for vibration of beams is often used to make predictions of bending modulus of elasticity when using dynamic tests. However this model ignores the rotary inertia and shear. Such effects can be added to the solution of Bernoulli's equation by means of the correction proposed by Goens (1931) or by Timoshenko (1953). But to apply these corrections it is necessary to know the E/G ratio of the material. The objective of this paper is the determination of the E/G ratio of wood logs by adjusting the analytical solution of the Timoshenko beam model to the dynamic testing data of 20 Eucalyptus citriodora logs. The dynamic testing was performed with the logs in free-free suspension. To find the stiffness properties of the logs, the residue minimization was carried out using the Genetic Algorithm (GA). From the result analysis one can reasonably assume E/G = 20 for wood logs.

Immobilization of marine fungi on silica gel, silica xerogel and chitosan for biocatalytic reduction of ketones

The scanning electron microscopy (SEM) analysis showed that whole living hyphal of marine fungi Aspergillus sclerotiorum CBMAI 849 and Penicillium citrinum CBMAI 1186 were immobilized on support matrices of silica gel, silica xerogel and/or chitosan. P. citrinum immobilized on chitosan catalyzed the quantitative reduction of 1-(4-methoxyphenyl)-ethanone (1) to the enantiomer (S)-1-(4-methoxyphenyl)-ethanol (3b), with excellent enantioselectivity (ee > 99%, yield = 95%). Interestingly, ketone 1 was reduced with moderate selectivity and conversion to alcohol 3b (ee = 69%, c 40%) by the free mycelium of P. citrinum. This free mycelium of P. citrinum catalyzed the production of the (R)-alcohol 3a, the antipode of the alcohol produced by the immobilized cells. P. citrinum immobilized on chitosan also catalyzed the bioreduction of 2-chloro-1-phenylethanone (2) to 2-chloro-1-phenylethanol (4a,b), but in this case without optical selectivity. These results showed that biocatalytic reduction of ketones by immobilization hyphal of marine fungi depends on the xenobiotic substrate and the support matrix used. (c) 2012 Elsevier B.V. All rights reserved.

EFFECT OF THERMAL TREATMENT ON THE CHEMICAL CHARACTERISTICS OF WOOD FROM Eucalyptus grandis W. Hill ex Maiden UNDER DIFFERENT ATMOSPHERIC CONDITIONS

Thermal treatment (thermal rectification) is a process in which technological properties of wood are modified using thermal energy, the result of Which is often value-added wood. Thermally treated wood takes on similar color shades to tropical woods and offers considerable resistance to destructive microorganisms and climate action, in addition to having high dimensional stability and low hygroscopicity. Wood samples of Eucalyptus grandis were subjected to various thermal treatments, as performed in presence (140 degrees C; 160 degrees C; 180 degrees C) or in absence of oxygen (160 degrees C; 180 degrees C; 200 degrees C) inside a thermal treatment chamber, and then studied as to their chemical characteristics. Increasing the maximum treatment temperatures led to a reduction in the holocellulose content of samples as a result of the degradation and volatilization of hemicelluloses, also leading to an increase in the relative lignin content. Except for glucose, all monosaccharide levels were found to decrease in samples after the thermal treatment at a maximum temperature of 200 degrees C. The thermal treatment above 160 degrees C led to increased levels of total extractives in the wood samples, probably ascribed to the emergence of low molecular weight substances as a result of thermal degradation. Overall, it was not possible to clearly determine the effect of presence or absence of oxygen in the air during thermal treatment on the chemical characteristics of the relevant wood samples.

PHOSPHORUS DOSES DETERMINE THE PREVALENCE OF NATIVE ARBUSCULAR MYCORRHIZAL FUNGI IN Araucaria angustifolia

A greenhouse experiment was installed with bait cultures to extract the AMF species present in a rhizosphere soil sample of a native Araucaria angustifolia forest in Campos do Jordao, Brazil. The experimental design was completely randomized, with four increasing phosphorus doses (0, 20, 50, and 150 mg kg(-1), as triple superphosphate), with five replicates, the bait plant was araucaria, and all pots were inoculated with 100 g of rhizospheric soil collected in an araucaria forest. After twelve months the spores were extracted, counted and identified, and the percent root colonization was also determined. When taking all four P doses into account, eleven AMF species could be identified: Acaulospora bireticulata, Acaulospora morrowiae, Acaulospora sp., Entrophospora colombiana, Gigaspora margarita, Glomus diaphanum, Glomus etunicatum, Glomus macrocarpum, Scutellospora calospora, Scutellospora gilmorei, and Scutellospora pellucida. There was no effect of the P dose on the total amount of spores neither on the percent root colonization. However, the correspondence analysis showed that the different AMF species were selectively associated mostly to either one or another P dose.

3-Hydroxypropionic Acid as an Antibacterial Agent from Endophytic Fungi Diaporthe phaseolorum

Endophytic fungi are considered a rich source of active compounds resulting from their secondary metabolism. Fungi from marine environment grow in a habitat with unique conditions that can contribute to the activation of metabolic pathways of synthesis of different unknown molecules. The production of these compounds may support the adaptation and survival of the fungi in the marine ecosystem. Mangroves are ecosystems situated between land and sea. They are frequently found in tropical and subtropical areas and enclose approximately 18.1 million hectares of the planet. The great biodiversity found in these ecosystems shows the importance of researching them, including studies regarding new compounds derived from the endophytic fungi that inhabit these ecosystems. 3-hydroxypropionic acid (3-HPA) has been isolated from the mangrove endophytic fungus Diaporthe phaseolorum, which was obtained from branches of Laguncularia racemosa. The structure of this compound was elucidated by spectroscopic methods, mainly 1D and 2D NMR. In bioassays, 3-HPA showed antimicrobial activities against both Staphylococcus aureus and Salmonella typhi. The structure of this antibiotic was modified by the chemical reaction of Fischer-Speier esterification to evaluate the biologic activity of its chemical analog. The esterified product, 3-hydroxypropanoic ethyl ester, did not exhibit antibiotic activity, suggesting that the free carboxylic acid group is important to the pharmacological activity. The antibiotic-producing strain was identified with internal transcribed spacer sequence data. To the best of our knowledge, this is the first report of antibacterial activity by 3-HPA against the growth of medically important pathogens.

Interaction between toxigenic fungi and weevils in corn grain samples

This study investigated the ability of weevils to transmit Aspergillus flavus and Fusarium verticillioides fungal spores and the consequent production of mycotoxins. For this purpose, corn grain samples were stored in flasks connected to a hose to form a closed system (flasks A and B). Flasks A were inoculated with the following groups: group 1 (corn + weevil); group 2 (corn + A. flavus); group 3 (corn + A. flavus + weevil); group 4 (corn + F. verticillioides); group 5 (corn + E verticillioides + weevil), and group 6 (corn + A. flavus + E verticillioides + weevil). Flasks B contained sterile grains. The samples were incubated for 10, 20 and 30 days, posteriorly, weight, water activity, mycoflora, aflatoxins and fumonisins. The corn grain samples were also submitted to scanning electron microscopy. Our results showed that weevils could enhance corn grains contamination by these fungi, hence, could increase mycotoxins production. These findings demonstrate the importance of weevils as fungal vectors and the need for good manipulation and storage practices of grains. (C) 2012 Elsevier Ltd. All rights reserved.