Incidence of treated wood in a wood recycling stream in western Oregon

The incidence of treated wood in a recycling stream was assessed at a recycling center in western Oregon. Chromated copper arsenate (CCA) was the predominant treatment present in the material, ranging from 0 to 2 percent of the material present at any given time. Treated wood was present at 38 of the 41 sampling times, and the average amount of treated wood in the waste stream was 0.98 percent (volume basis). The material from this site is typically used for hog fuel; calculations of total CCA components in the resulting ash suggested that As, Cu, and Cr levels in the ash (assuming all metal in the wood wound up in the ash) would be approximately 9,900, 6,600, and 11,000 ppm, respectively. These values exceed the current State of Oregon limits for the land application of ash; however, this waste stream represents a relatively small fraction of the overall material being burned. As a result, it is likely that there is considerable dilution in the resulting ash, although these contaminants would pose a disposal issue if treated wood residues increase in the recycling stream

Qu’apporte l’étude des town meetings à la quête d’une démocratie plus participative et délibérative?

Comme annoncé dans l’introduction, ce numéro spécial de Participations se clôt sur un entretien collectif, mené par Paula Cossart et Andrea Felicetti, rassemblant certains des plus éminents représentants de la recherche sur les town meetings de Nouvelle-Angleterre. Trois ensembles de questions ont été soumis à chaque interviewé, qui y a répondu individuellement par écrit. Hors corrections mineures, le texte des réponses n’a pas été modifié ; mais il a parfois été segmenté de manière à rendre la lecture plus fluide, et à mettre en évidence les interactions entre les différentes perspectives présentes dans ces lignes. La version finale de ce texte a été éditée et approuvée par les chercheurs interrogés

PRESERVATIVE TREATMENT OF TASMANIAN PLANTATION EUCALYPTUS NITENS USING SUPERCRITICAL FLUIDS

Short rotation plantation forests in Tasmania, Australia, are dominated by Eucalyptus nitens (common name: shining gum). These forests were primarily planted to provide material for pulp and paper production, but the timber is increasingly sought after for higher value and more enduring applications. Plantation E. nitens has a high proportion of low durability heartwood that resists penetration by conventional fluid preservatives. This limits its use to indoor applications. One approach to overcoming the refractory nature of E. nitens is to modify the treatment fluid. We investigated the use of supercritical carbon dioxide to deliver biocides deep into the wood. Timbers varying in thickness from 19 to 35 mm and 900 mm long were treated with a multicomponent biocide under supercritical conditions in a commercial facility in Denmark. The resulting timber was cut into zones inward from the surface. Wood from these zones was ground and extracted for HPLC analysis for tebuconazole and propiconazole. Preservative was detected in the inner portion of every sample examined, indicating that the process resulted in treatment throughout the boards, with concentrations meeting and on average exceeding the targeted amounts

Performance of antisapstain compounds on kiln-dried Douglas-fir and hem-fir lumber subjected to rewetting

Mold and stain fungi can be easily controlled by kiln-drying, but even this material can be rewetted during shipping and storage, allowing fungi to colonize the wood. The potential for using surface spray treatments with commercial formulations containing combinations of propiconazole, didecyldimethyl ammonium chloride, or 3-iodo-2-propynyl butylcarbamate to protect kiln-dried Douglas-fir and hem-fir lumber was evaluated over an 18-month storage period. Rewetted, untreated wood was readily colonized by fungi, while the treated boards experienced much lower levels of discoloration. Protection did appear to decline with storage time for hem-fir but not Douglas-fir. Chemical treatment of kiln-dried lumber may provide added protection against rewetting during transit and prior to installation in dry applications

Effect of wood moisture content and rod dosage on boron or fluoride movement through Douglas-fir heartwood

The potential for moisture sorption by boron and fluoride rods following application of rods to wood to affect subsequent chemical diffusion was investigated in small Douglas-fir blocks conditioned to 30, 60, or 90 percent target moisture content (MC). MCs tended to decline over the 180-day test period, but there was no evidence that the rods acted to draw moisture away from the wood. As expected, chemical movement tended to increase with increasing MC. Threshold levels were reached within 180 days for boron, even in blocks at 30 percent target MC. Fluoride levels tended to be much lower, reflecting the much lower dosages applied. There was no evidence that rods sorbed enough water to reduce moisture availability for subsequent diffusion

Potential for the use of hydroxylamine derivatives as wood preservatives

The potential of 17 hydroxylamine derivatives as wood preservatives was assessed on ponderosa pine sapwood blocks exposed to one of two decay fungi: Gloeophyllum trabeum or Trametes versicolor. Weight losses on untreated controls were generally lower with the white-rot fungus (T. versicolor) averaging 30.4 percent, while those for the brown-rot fungus (G. trabeum) were 72.0 percent. None of the test chemicals completely inhibited weight loss, although one chemical was associated with lower weight losses at the highest concentration tested. The results suggest that the hydroxlamine derivatives evaluated have little potential as wood preservatives

Discovery and Observations of ASASSN-13db, an EX Lupi-Type Accretion Event on a Low-Mass T Tauri Star

We discuss ASASSN-13db, an EX Lupi-type ("EXor") accretion event on the young stellar object (YSO) SDSS J051011.01$-$032826.2 (hereafter SDSSJ0510) discovered by the All-Sky Automated Survey for SuperNovae (ASAS-SN). Using archival photometric data of SDSSJ0510 we construct a pre-outburst spectral energy distribution (SED) and find that it is consistent with a low-mass class II YSO near the Orion star forming region ($d \sim 420$ pc). We present follow-up photometric and spectroscopic observations of the source after the $\Delta V \sim-$5.4 magnitude outburst that began in September 2013 and ended in early 2014. These data indicate an increase in temperature and luminosity consistent with an accretion rate of $\sim10^{-7}$ $\rm{M}_\odot$ yr$^{-1}$, three or more orders of magnitude greater than in quiescence. Spectroscopic observations show a forest of narrow emission lines dominated by neutral metallic lines from Fe I and some low-ionization lines. The properties of ASASSN-13db are similar to those of the EXor prototype EX Lupi during its strongest observed outburst in late 2008.Comment: 14 pages, 4 figures, 1 table. Updated May 2014 to reflect changes in the final version published in ApJL. Photometric data presented in this submission are included as ancillary files. For a brief video explaining this paper, see http://youtu.be/yRCCrNJnvt

Comprehensive analysis of epigenetic clocks reveals associations between disproportionate biological ageing and hippocampal volume

The concept of age acceleration, the difference between biological age and chronological age, is of growing interest, particularly with respect to age-related disorders, such as Alzheimer’s Disease (AD). Whilst studies have reported associations with AD risk and related phenotypes, there remains a lack of consensus on these associations. Here we aimed to comprehensively investigate the relationship between five recognised measures of age acceleration, based on DNA methylation patterns (DNAm age), and cross-sectional and longitudinal cognition and AD-related neuroimaging phenotypes (volumetric MRI and Amyloid-β PET) in the Australian Imaging, Biomarkers and Lifestyle (AIBL) and the Alzheimer’s Disease Neuroimaging Initiative (ADNI). Significant associations were observed between age acceleration using the Hannum epigenetic clock and cross-sectional hippocampal volume in AIBL and replicated in ADNI. In AIBL, several other findings were observed cross-sectionally, including a significant association between hippocampal volume and the Hannum and Phenoage epigenetic clocks. Further, significant associations were also observed between hippocampal volume and the Zhang and Phenoage epigenetic clocks within Amyloid-β positive individuals. However, these were not validated within the ADNI cohort. No associations between age acceleration and other Alzheimer’s disease-related phenotypes, including measures of cognition or brain Amyloid-β burden, were observed, and there was no association with longitudinal change in any phenotype. This study presents a link between age acceleration, as determined using DNA methylation, and hippocampal volume that was statistically significant across two highly characterised cohorts. The results presented in this study contribute to a growing literature that supports the role of epigenetic modifications in ageing and AD-related phenotypes

Photometric and spectroscopic evolution of the interacting transient at 2016jbu(Gaia16cfr)

We present the results from a high-cadence, multiwavelength observation campaign of AT 2016jbu (aka Gaia16cfr), an interacting transient. This data set complements the current literature by adding higher cadence as well as extended coverage of the light-curve evolution and late-time spectroscopic evolution. Photometric coverage reveals that AT 2016jbu underwent significant photometric variability followed by two luminous events, the latter of which reached an absolute magnitude of MV ∼-18.5 mag. This is similar to the transient SN 2009ip whose nature is still debated. Spectra are dominated by narrow emission lines and show a blue continuum during the peak of the second event. AT 2016jbu shows signatures of a complex, non-homogeneous circumstellar material (CSM). We see slowly evolving asymmetric hydrogen line profiles, with velocities of 500 km s-1 seen in narrow emission features from a slow-moving CSM, and up to 10 000 km s-1 seen in broad absorption from some high-velocity material. Late-time spectra (∼+1 yr) show a lack of forbidden emission lines expected from a core-collapse supernova and are dominated by strong emission from H, He i, and Ca ii. Strong asymmetric emission features, a bumpy light curve, and continually evolving spectra suggest an inhibit nebular phase. We compare the evolution of H α among SN 2009ip-like transients and find possible evidence for orientation angle effects. The light-curve evolution of AT 2016jbu suggests similar, but not identical, circumstellar environments to other SN 2009ip-like transients