The Effects of CCA Preservative Treatment and Redrying on the Bending Properties of 2 X 6 Southern Pine Lumber

Southern pine dimension lumber (commercially graded No. 2 loblolly pine 2 x 6s) was treated with chromated copper arsenate (CCA) preservative (0.4 or 0.6 pcf) and then air-dried or kiln-dried (160, 190, or 240 F). CCA treatment significantly reduced average bending strength, but no discernible differences were found between controls and CCA-treated groups in the extreme lower portions (< 10th percentile) of the bending-strength distributions. When these same specimens were then considered solely on the basis of strength-reducing characteristics, there were obvious differences in how the CCA treatments and subsequent redrying affected these various strength-ratio grades of 2 x 6 lumber; higher grades appeared to be less affected than lower grades. Similar to the trend shown when commercially graded, the middle and upper portion of each strength-ratio grade bending-strength distribution than did drying at 240 F affected a broader range of the bending-srength distribution than did drying at 160 F. The broadened range of significant effects noted after high-temperature redrying indicates that posttreatment kiln-drying temperatures higher than 190 F should be avoided.The effects of CCA treatment and redrying were highly interactive with strength-ratio grade and the presence or absence of pith. CCA treatment reduced the strength of lumber containing pith and having a strength ratio of 0.65 and containing pith was not affected by CCA treatment. The magnitude of this pith-related interaction demands recognition

Effect of Incising and Preservative Treatment on Shear Strength of Nominal 2-Inch Lumber

This study evaluated the effects of pretreatment incising of dry lumber and preservative treatment on the shear strength of 1980 pieces of 2 X 4 dimension lumber (nominal 50 mm X 100 mm X 3.6 m long). Three species groups (Douglas-fir, Hem-Fir, adn Spruce-Pine-Fir-South) and two commercially produced machine-stress-rated grades per species group were tested in torsion to determine their shear strength. Incising and preservative treatment produced significant reductions in the average shear strength of Douglas-fir, Hem-Fir, and Spruce-Pine-Fir-South dimension lumber. These effects need to be addressed through the development of more appropriate design values for uses of preservativetreated wood of these species when shear is a governing factor. An adjustment factor of 0.70 is proposed for incised and preservative-treated nominal 2-inch lumber

Modification of the nanostructure of lignocellulose cell walls via a non-enzymatic lignocellulose deconstruction system in brown rot wood-decay fungi

Abstract Wood decayed by brown rot fungi and wood treated with the chelator-mediated Fenton (CMF) reaction, either alone or together with a cellulose enzyme cocktail, was analyzed by small angle neutron scattering (SANS), sum frequency generation (SFG) spectroscopy, Fourier transform infrared (FTIR) analysis, X-ray diffraction (XRD), atomic force microscopy (AFM), and transmission electron microscopy (TEM). Results showed that the CMF mechanism mimicked brown rot fungal attack for both holocellulose and lignin components of the wood. Crystalline cellulose and lignin were both depolymerized by the CMF reaction. Porosity of the softwood cell wall did not increase during CMF treatment, enzymes secreted by the fungi did not penetrate the decayed wood. The enzymes in the cellulose cocktail also did not appear to alter the effects of the CMF-treated wood relative to enhancing cell wall deconstruction. This suggests a rethinking of current brown rot decay models and supports a model where monomeric sugars and oligosaccharides diffuse from the softwood cell walls during non-enzymatic action. In this regard, the CMF mechanism should not be thought of as a “pretreatment” used to permit enzymatic penetration into softwood cell walls, but instead it enhances polysaccharide components diffusing to fungal enzymes located in wood cell lumen environments during decay. SANS and other data are consistent with a model for repolymerization and aggregation of at least some portion of the lignin within the cell wall, and this is supported by AFM and TEM data. The data suggest that new approaches for conversion of wood substrates to platform chemicals in biorefineries could be achieved using the CMF mechanism with >75% solubilization of lignocellulose, but that a more selective suite of enzymes and other downstream treatments may be required to work when using CMF deconstruction technology. Strategies to enhance polysaccharide release from lignocellulose substrates for enhanced enzymatic action and fermentation of the released fraction would also aid in the efficient recovery of the more uniform modified lignin fraction that the CMF reaction generates to enhance biorefinery profitability

The infectious propagules of Aspergillus fumigatus are coated with antimicrobial peptides

Fungal spores are unique cells that mediate dispersal and survival in the environment. For pathogenic fungi encountering a susceptible host, these specialised structures may serve as infectious particles. The main causative agent of the opportunistic disease aspergillosis, Aspergillus fumigatus, produces asexual spores, the conidia, that become dissipated by air flows or water currents but also serve as propagules to infect a susceptible host. We demonstrate that the defX gene of this mould encodes putative antimicrobial peptides resembling cysteine‐stabilised (CS)$_{αβ}$ defensins that are expressed in a specific spatial and temporal manner in the course of asexual spore formation. Localisation studies on strains expressing a fluorescent proxy or tagged defX alleles expose that these antimicrobial peptides are secreted to coat the conidial surface. Deletion mutants reveal that the spore‐associated defX gene products delay the growth of Gram‐positive Staphylococcus aureus and demonstrate that the defX gene and presumably its encoded spore‐associated defensins confer a growth advantage to the fungal opponent over bacterial competitors. These findings have implications with respect to the ecological niche of A. fumigatus that serves as a ‘virulence school’ for this human pathogenic mould; further relevance is given for the infectious process resulting in aspergillosis, considering competition with the host microbiome or co‐infecting microorganisms to break colonisation resistance at host surfaces

Analyse de l'évolution de la consommation de plats préparés en Belgique

Trend analysis of the consumption of ready-made food in Belgium. This study aims to analyze the evolution of the consumption of ready-made food in Belgium and to discern any trends. The data used are expenditure made on convenience food from 1999 to 2009 (in euros) and socio-demographic characteristics, obtained from the Household Budget Survey undertaken annually by the Federal Public Service Economy (DGSIE). Statistical analyses (simple, multiple and binary logistic regressions) enable the study of consumption trends in terms of expenditure and percentage of consumers as well as the determination of consumer profiles. Convenience food is part of the eating habits of Belgian households, with more than nine out of ten households being consumers. Convenience food prepared from meat is the most frequently purchased. For all ready-made food, the variable of household size explains the most variability in consumption, followed by the variables of income and age

Effect of incising and preservative treatment on shear strength of nominal 2-inch lumber

This study evaluated the effects of pretreatment incising of dry lumber and preservative treatment on the shear strength of 1980 pieces of 2 X 4 dimension lumber (nominal 50 mm X 100 mm X 3.6 m long). Three species groups (Douglas-fir, Hem-Fir. and Spruce-Pine-Fir-South) and two commercially produced machine-stress-rated grades per species group were tested in torsion to determine their shear strength. Incising and preservative treatment produced significant reductions in the average shear strength of Douglas-fir, Hem-Fir, and Spruce-Pine-Fir-South dimension lumber. These effects need to be addressed through the development of more appropriate design values for uses of preservative-treated wood of these species when shear is a governing factor. An adjustment factor of 0.70 is proposed for incised and preservative-treated nominal 2-inch lumber.Keywords: torsion, MSR lumber, grade, incising, shear strength, preservative treatmentKeywords: torsion, MSR lumber, grade, incising, shear strength, preservative treatmen

Dispersal syndromes in challenging environments: A cross‐species experiment

Dispersal is a central biological process tightly integrated into life-histories, morphology, physiology and behaviour. Such associations, or syndromes, are anticipated to impact the eco-evolutionary dynamics of spatially structured populations, and cascade into ecosystem processes. As for dispersal on its own, these syndromes are likely neither fixed nor random, but conditional on the experienced environment. We experimentally studied how dispersal propensity varies with individuals' phenotype and local environmental harshness using 15 species ranging from protists to vertebrates. We reveal a general phenotypic dispersal syndrome across studied species, with dispersers being larger, more active and having a marked locomotion-oriented morphology and a strengthening of the link between dispersal and some phenotypic traits with environmental harshness. Our proof-of-concept metacommunity model further reveals cascading effects of context-dependent syndromes on the local and regional organisation of functional diversity. Our study opens new avenues to advance our understanding of the functioning of spatially structured populations, communities and ecosystems. Keywords: context-dependent dispersal; dispersal strategy; distributed experiment; predation risk; resource limitatio

Self-cleaning and antifouling nanocomposites for stone protection: Properties and performances of stone-nanomaterial systems

The development of nanocomposites combining photocatalytic, antifouling and protective features has provided interesting and promising results in the last years. However, few data about the behaviour of the nanomaterials applied on stone surfaces are available in the literature. In the framework of the EU-Horizon 2020 project "Nano-Cathedral", nanostructured protective treatments have been designed with different nanoparticles (TiO2, Ag, ZnO), solvents and silane/siloxane-based polymeric matrices. The innovative formulations have been applied on 6 lithotypes, selected among the stones used in five medieval cathedrals (Vitoria-Gasteiz, Ghent, Cologne, Vienna and Pisa) and a contemporary theatre (Oslo Opera House), which are emblematic of different European geological and environmental areas. The treated stone specimens have been fully characterized to evaluate the surface optical and morphological compatibility, the reduction of water absorption by capillarity, the change in wettability and water vapour permeability properties. The selected treatments fulfil all these requirements and exhibit good photocatalytic and antifouling properties once applied on stone specimens. Different accelerated ageing procedures have also been performed in order to evaluate the stability of the polymeric matrices in the presence of photoactive TiO2. © Published under licence by IOP Publishing Ltd

Murine Pancreatic Adenocarcinoma Reduces Ikaros Expression and Disrupts T Cell Homeostasis

Background Maintenance of T cell immune homeostasis is critical for adequate anti-tumor immunity. The transcription factor Ikaros is essential for lymphocyte development including T cells. Alterations in Ikaros expression occur in blood malignancies in humans and mice. In this study, we investigated the role of Ikaros in regulating T cell immune balance in pancreatic cancer mouse models. Methodology and Principal Findings Using our Panc02 tumor-bearing (TB) mouse model, western blot analysis revealed a reduction in Ikaros proteins while qRT-PCR showed no differences in Ikaros mRNA levels in TB splenocytes compared to control. Treatment of naïve splenocytes with the proteasomal inhibitor, MG132, stabilized Ikaros expression and prevented Ikaros downregulation by Panc02 cells, in vitro. Western blot analyses showed a reduction in protein phosphatase 1 (PP1) and protein kinase CK2 expression in TB splenocytes while CK2 activity was increased. Immunofluorescence microscopy revealed altered punctate staining of Ikaros in TB splenocytes. Flow cytometry revealed a significant decrease in effector CD4+ and CD8+ T cell percentages but increased CD4+CD25+ regulatory T cells in TB splenocytes. Similar alterations in T cell percentages, as well as reduced Ikaros and CK2 but not PP1 expression, were observed in a transgenic, triple mutant (TrM) pancreatic cancer model. Ikaros expression was also reduced in enriched TB CD3+ T cells. MG132 treatment of naïve CD3+ T cells stabilized Ikaros expression in the presence of Panc02 cells. Western blots showed reduced PP1 and CK2 expression in TB CD3+ T cells. Conclusions/Significance The results of this study suggest that the pancreatic tumor microenvironment may cause proteasomal degradation of Ikaros, possibly via dysregulation of PP1 and CK2 expression and activity, respectively. This loss of Ikaros expression may contribute to an imbalance in T cell percentages. Ikaros may potentially be a therapeutic target to restore T cell homeostasis in pancreatic cancer hosts, which may be critical for effective anti-tumor immunity

Estudo dos efeitos da acetilação em fibras de sisal

O emprego de fibras vegetais na confecção de compósitos tem grande viabilidade, no que diz respeito ao uso de materiais oriundos de fontes renováveis, à biodegradabilidade e aos benefícios socioeconômicos gerados na produção de matéria-prima vegetal. As fibras de sisal são altamente higroscópicas e esta característica se apresenta como um dos principais problemas na produção de compósitos induzindo a variações dimensionais sob a influência da umidade, deposição dos produtos da matriz em seus poros e a degradação. Os tratamentos de acetilação nas fibras de sisal foram aplicados em diferentes temperaturas e tempos reacionais, e a eficiência desses tratamentos, considerando-se a redução da hidrofilicidade e a manutenção do desempenho mecânico das fibras, foi avaliada pela capacidade de absorção de água por imersão, ensaios de resistência mecânica e por espectroscopia de infravermelho. Fibras acetiladas apresentaram reduções de peso por absorção de até 50% quando comparadas com as não tratadas. Os tratamentos por 3 h apresentaram as maiores perdas na resistência mecânica e a 120 °C por 1h indicaram as melhores características físico-mecânicas, além de incremento satisfatório de grupos apolares com o tratamento.The use of vegetable fibers in composites is highly viable regarding about the use of materials from renewable sources, the biodegradability and the socioeconomic advantages in the production of raw vegetable. The sisal fibers are highly hygroscopic and this is a main problem in the production of composites, inducing dimensional changes under moisture influence, deposition of the matrix products and degradation. The treatment of the acetylation was applied at different temperatures and reaction times, and the efficiency of treatments, considering the reduction of the hydrophilicity and maintenance of the mechanical properties, was evaluated by water sorption, mechanical properties and the infrared spectroscopy. With acetylation the fibers had weight reductions for water sorption up to 50% compared to untreated. The treatments for 3 h decreased the mechanical properties while the 120 °C for 1 h showed better physico-mechanical properties and increase of apolar groups