Stabilization of Acoustical Properties of Wooden Musical Instruments By Acetylation

Because variable humidity affects the acoustic properties of wood, manufacturers of wood instruments must minimize dimensional changes caused by the absorption of water. Acetylation reduces the moisture content of the cell wall, thereby increasing the stability of the acoustic and dimensional properties of wood under conditions of changing humidity. The acetylation of wood slightly reduces sound velocity (by about 5%) and also reduces sound absorption when compared to unreacted wood. Hence, acetylation does not change the acoustic converting efficiency

Effect of Humidity on Vibrational Properties of Chemically Modified Wood

Changes in vibrational properties of wood can be used to determine changes in the wood cell wall resulting from chemical modification. The dynamic Young's modulus to specific gravity ratio (E'/γ) and internal friction (tan δ) for chemically modified wood compared to those for untreated wood showed major differences in cell-wall modification and lumen filling modification. Increasing the moisture content of the cell wall also has a major effect on the vibrational properties of chemically modified wood. In general, treatments that resulted in lowering the moisture content of the cell wall also lowered internal friction within the cell wall. Vapor phase reactions with formaldehyde had the greatest effect in stabilizing the cell wall against changes in dynamic mechanical properties with increasing moisture content

Dimensional Stability, Decay Resistance, and Mechanical Properties of Veneer-Faced Low-Density Particleboards Made From Acetylated Wood

Veneer-faced low-density particleboards were made using four combinations of control and acetylated veneers and particles. These boards were tested for dimensional stability in both liquid water and water vapor, for decay resistance in standard soil-block tests with Tyromyces palustris and Trametes versicolor, for strength losses during attack by T. palustris, and for mechanical strength in bending-creep and mechanical tests. Boards made from acetylated veneers and acetylated core particles showed excellent dimensional stability in both liquid water and humidity tests and were resistant to attack by both fungi in an 8-week soil-block test. During the 150-day bending-creep test, the totally acetylated boards showed no strength or weight loss during exposure to T. palustris. Modulus of elasticity and modulus of rupture were slightly reduced for totally acetylated boards compared to boards with control veneers and control particles, and internal bond strength was reduced by about 30%. Screw-holding capacity of the totally acetylated boards and boards with control veneers and particles was essentially the same

Fixation of Compressed Wood Using Melamine-Formaldehyde Resin

Methods to maximize wood hardness and dimensional stability include various combinations of compression, heating, and chemical treatment. In this study, wood was treated with increasing concentrations of a low molecular weight, water-soluble melamine-formaldehyde resin solution (mol wt 380) and compressed while heated. This method achieved a maximum bulking efficiency of 5% and an antishrink efficiency of 45%, showing that the chemical had not completely penetrated the cell wall. Once the wood was treated, its ability to retain the compressed state was tested by immersing wood specimens in water at different temperatures. Specimens treated with an 8% resin solution retained almost complete fixation when soaked in room-temperature water, while those treated with a 25% solution retained fixation in boiling water. Moreover, a 25% solution of resin and a compression of 54% increased hardness from 0.48 to 0.72 MPa

Photospheric Abundances of Volatile and Refractory Elements in Planet-Harboring Stars

By using the high-dispersion spectra of 14 bright planet-harboring stars (along with 4 reference stars) observed with the new coude echelle spectrograph at Okayama Astrophysical Observatory, we investigated the abundances of volatile elements (C, N, O, S, Zn; low condensation temperature Tc) in order to examine whether these show any significant difference compared to the abundances of other refractory elements (Si, Ti, V, Fe, Co, Ni; high Tc) which are known to be generally overabundant in those stars with planets, since a Tc-dependence is expected if the cause of such a metal-richness is due to the accretion of solid planetesimals onto the host star. We found, however, that all elements we studied behave themselves quite similarly to Fe (i.e., [X/Fe]~0) even for the case of volatile elements, which may suggest that the enhanced metallicity in those planet-bearing stars is not so much an acquired character (by accretion of rocky material) as rather primordial.Comment: 22 pages, 8 figures, to appear in PAS

Low- and Medium-Dispersion Spectropolarimetry of Nova V475 Sct (Nova Scuti 2003): Discovery of an Asymmetric High-Velocity Wind in a Moderately Fast Nova

We present low-resolution ($R\sim 90$) and medium-resolution ($R\sim 2500$) spectropolarimetry of Nova V475 Sct with the HBS instrument, mounted on the 0.91-m telescope at the Okayama Astrophysical Observatory, and with FOCAS, mounted on the 8.2-m Subaru telescope. We estimated the interstellar polarization toward the nova from the steady continuum polarization components and H$\alpha$ line emission components. After subtracting the interstellar polarization component from the observations, we found that the H$\alpha$ emission seen on 2003 October 7 was clearly polarized. In the polarized flux spectrum, the H$\alpha$ emission had a distinct red wing extending to $\sim +4900$ km s$^{-1}$ and a shoulder around $+3500$ km s$^{-1}$, showing a constant position angle of linear polarization \theta_{\rm *}\simeq 155\arcdeg\pm 15\arcdeg. This suggests that the nova had an asymmetric outflow with a velocity of $v_{\rm wind}\simeq 3500$ km s$^{-1}$ or more, which is six times higher than the expansion velocity of the ionized shell at the same epoch. Such a high-velocity component has not previously been reported for a nova in the `moderately fast' speed class. Our observations suggest the occurrence of violent mass-loss activity in the nova binary system even during the common-envelope phase. The position angle of the polarization in the H$\alpha$ wing is in good agreement with that of the continuum polarization found on 2003 September 26 ($p_{\rm *}\simeq 0.4$--0.6 %), which disappeared within the following 2 d. The uniformity of the PA between the continuum polarization and the wing polarization on October 7 suggests that the axis of the circumstellar asymmetry remained nearly constant during the period of our observations.Comment: 27 pages, 7 figures, accepted for publication in A

TIM-1 and TIM-4 Glycoproteins Bind Phosphatidylserine and Mediate Uptake of Apoptotic Cells

SummaryThe T cell immunoglobulin mucin (TIM) proteins regulate T cell activation and tolerance. Here we showed that TIM-4 is expressed on human and mouse macrophages and dendritic cells, and both TIM-4 and TIM-1 specifically bound phosphatidylserine (PS) on the surface of apoptotic cells but not any other phospholipid tested. TIM-4+ peritoneal macrophages, TIM-1+ kidney cells, and TIM-4- or TIM-1-transfected cells efficiently phagocytosed apoptotic cells, and phagocytosis could be blocked by TIM-4 or TIM-1 monoclonal antibodies. Mutations in the unique cavity of TIM-4 eliminated PS binding and phagocytosis. TIM-4 mAbs that blocked PS binding and phagocytosis mapped to epitopes in this binding cavity. These results show that TIM-4 and TIM-1 are immunologically restricted members of the group of receptors whose recognition of PS is critical for the efficient clearance of apoptotic cells and prevention of autoimmunity

Determination of fungal activity in modified wood by means of micro-calorimetry and determination of total esterase activity

Beech and pine wood blocks were treated with 1,3-dimethylol-4,5-dihydroxyethylen urea (DMDHEU) to increasing weight percent gains (WPG). The resistance of the treated specimens against Trametes versicolor and Coniophora puteana, determined as mass loss, increased with increasing WPG of DMDHEU. Metabolic activity of the fungi in the wood blocks was assessed as total esterase activity (TEA) based on the hydrolysis of fluorescein diacetate and as heat or energy production determined by isothermal micro-calorimetry. Both methods revealed that the fungal activity was related with the WPG and the mass loss caused by the fungi. Still, fungal activity was detected even in wood blocks of the highest WPG and showed that the treatment was not toxic to the fungi. Energy production showed a higher consistency with the mass loss after decay than TEA; higher mass loss was more stringently reflected by higher heat production rate. Heat production did not proceed linearly, possibly due to the inhibition of fungal activity by an excess of carbon dioxide

Association between the SERPING1 Gene and Age-Related Macular Degeneration and Polypoidal Choroidal Vasculopathy in Japanese

PURPOSE: Recently, a complement component 1 inhibitor (SERPING1) gene polymorphism was identified as a novel risk factor for age-related macular degeneration (AMD) in Caucasians. We aimed to investigate whether variations in SERPING1 are associated with typical AMD or with polypoidal choroidal vasculopathy (PCV) in a Japanese population. METHODS: We performed a case-control study in a group of Japanese patients with typical AMD (n = 401) or PCV (n = 510) and in 2 independent control groups--336 cataract patients without age-related maculopathy and 1,194 healthy Japanese individuals. Differences in the observed genotypic distribution between the case and control groups were tested using chi-square test for trend. Age and gender were adjusted using logistic regression analysis. RESULTS: We targeted rs2511989 as the haplotype-tagging single nucleotide polymorphism (SNP) for the SERPING1 gene, which was reported to be associated with the risk of AMD in Caucasians. Although we compared the genotypic distributions of rs2511989 in typical AMD and PCV patients against 2 independent control groups (cataract patients and healthy Japanese individuals), SERPING1 rs2511989 was not significantly associated with typical AMD (P = 0.932 and 0.513, respectively) or PCV (P = 0.505 and 0.141, respectively). After correction for age and gender differences based on a logistic regression model, the difference in genotypic distributions remained insignificant (P>0.05). Our sample size had a statistical power of more than 90% to detect an association of a risk allele with an odds ratio reported in the original studies for rs2511989 for developing AMD. CONCLUSIONS: In the present study, we could not replicate the reported association between SERPING1 and either neovascular AMD or PCV in a Japanese population; thus, the results suggest that SERPING1 does not play a significant role in the risk of developing AMD or PCV in Japanese

Dectin-2 recognises mannosylated O-antigens of human opportunistic pathogens and augments lipopolysaccharide activation of myeloid cells

Lipopolysaccharide (LPS) consists of a relatively conserved region of lipid A and core-oligosaccharide, and a highly variable region of O-antigen polysaccharide. While lipid A is known to bind to the toll-like receptor 4 (TLR4)-myeloid differentiation factor 2 (MD2) complex, the role of the O-antigen remains unclear. Here we report a novel molecular interaction between dendritic cell-associated C-type lectin-2 (Dectin-2) and the mannosylated O-antigen found in a human opportunistic pathogen Hafnia alvei PCM 1223, which has a repeating unit of [-Man-α1,3-Man-α1,2-Man-α1,2-Man-α1,2-Man-α1,3-]. H. alvei LPS induced higher levels of TNFα and IL-10 from mouse bone marrow-derived dendritic cells (BM-DCs), when compared to Salmonella enterica O66 LPS which has a repeat of [-Gal-α1,6-Gal-α1,4-[Glc-β1,3]GalNAc-α1,3-GalNAc-β1,3-]. In a cell-based reporter assay, Dectin-2 was shown to recognise H. alvei LPS. This binding was inhibited by mannosidase treatment of H. alvei LPS and by mutations in the carbohydrate-binding domain of Dectin-2, demonstrating that H. alvei LPS is a novel glycan ligand of Dectin-2. The enhanced cytokine production by H. alvei LPS was Dectin-2 dependent, as Dectin-2 knockout BM-DCs failed to do so. This receptor crosstalk between Dectin-2 and TLR4 involved events including spleen tyrosine kinase (Syk) activation and receptor juxtaposition. Furthermore, another mannosylated LPS from Escherichia coli O9a, also bound to Dectin-2 and augmented TLR4 activation of BM-DCs. Taken together, these data indicate that mannosylated O-antigens from several gram-negative bacteria augment TLR4 responses through interaction with Dectin-2