Methylisothiocyanate Fumigant Content of Douglas-Fir Heartwood at Various Moisture Levels After Treatment With Solid Sodium N-Methyldithiocarbamate

The relationship between moisture content and the presence of methylisothiocyanate (MITC) in wood following various applications of sodium n-methyldithiocarbamate (NaMDC) was investigated with small Douglas-fir heartwood blocks. While MITC levels were initially higher in wetter blocks, MITC levels in drier blocks remained more stable over the 8-week test period. The addition of water as well as NaMDC to blocks enhanced MITC levels only initially; this effect declined over the test period for blocks at 30% MC or greater. In comparing the effect on MITC levels of applying the NaMDC in powder or pellet form, no significant difference between the two application methods emerged

AIDS and the Homeless of Boston

Homeless persons with AIDS and HIV infection face significant health hazards during the daily struggle for survival on the streets and in the crowded shelters of our cities. This article offers a historical perspective on the evolution of the AIDS epidemic within the homeless population of Boston and examines the demographics, risk behaviors, and survival statistics of that epidemic. The Boston Health Care for the Homeless Program is presented as a model of service delivery that offers quality health care to homeless persons with AIDS while addressing the special needs of those bound by the immediacy of the next meal and a night\u27s shelter. Health care is inextricably woven into the fabric of social policy and cannot be delivered without an accessible network of housing, entitlement, job training, mental health, and substance-abuse services

Assessing Wood Quality of Borer-Infested Red Oak Logs with a Resonance Acoustic Technique

Large numbers of black oak (Quercus velutina Lam.) and scarlet oak (Quercus coccinea Muenchh.) trees are declining and dying in the Missouri Ozark forest as a result of oak decline. Red oak borer-infested trees produce low-grade logs that become extremely difficult to merchandize as the level of insect attack increases. The objective of this study was to investigate the use of a resonance-based acoustic technique to evaluate the wood quality of infested red oak logs before processing as measured by grade, type and location of defects, and mechanical properties of the resulting boards. Principal component and canonical correlation analyses revealed that relationships do exist between log acoustic measurement and board grade yield, and between a linear combination of log acoustic velocity and diameter at breast height and a linear combination of board defect measurements. Although the acoustic technique was found capable of assessing wood quality at a stand level, the major advantage of the technique lies in segregating logs within the stand

Interactions of ammoniacal copper zinc arsenate (ACZA) with Douglas-fir

Tests were conducted to determine the effect of ACZA composition on fixation and the roles of adsorption and precipitation in fixation. The sites of copper and zinc adsorption within the treated wood and the bonding environment of adsorbed copper were also examined. The results generally support the finding that arsenic fixation occurs by precipitation of metal/arsenate complexes. Arsenic leaching was minimized with high solution ratios of metal oxide:arsenic pentoxide, and with formulations containing zinc. Zinc precipitated the majority of arsenic when ammonia was allowed to evaporate from the treating solution. The metal cations were leach-resistant regardless of ACZA formulation because of their low water solubility and their ability to adsorb to the wood. Copper was readily adsorbed by lignin and by model compounds that possessed phenolic hydroxyl groups, which suggests that phenolic hydroxyl groups were the primary reaction sites. Fourier Transform Infrared (FTIR) and Fast Atom Bombardment (FAB) mass spectroscopy analysis also supported this conclusion. Multiple copper species and increased free radical content were detected within lignin that had adsorbed copper. Adsorption of copper and zinc has important ramifications for arsenic fixation.Keywords: leaching, adsorption, Douglas-fir, fixation, ACZA, precipitation, ammoniacal copper zinc arsenat

Methylisothiocyanate fumigant content of Douglas-fir heartwood at various moisture levels after treatment with solid sodium N-methyldithiocarbamate

The relationship between moisture content and the presence of methylisothiocyanate (MITC) in wood following various applications of sodium n-methyldithiocarbamate (NaMDC) was investigated with small Douglas-fir heartwood blocks. While MITC levels were initially higher in wetter blocks, MITC levels in drier blocks remained more stable over the 8-week test period. The addition of water as well as NaMDC to blocks enhanced MITC levels only initially; this effect declined over the test period for blocks at 30% MC or greater. In comparing the effect on MITC levels of applying the NaMDC in powder or pellet form, no significant difference between the two application methods emerged.Keywords: fumigants, MITC, Douglas-fir heartwood, methylisothiocyanate, decomposition, sodium n-methyldithiocarbamate, moisture content, NaMD

DURABILITY OF MASS TIMBER STRUCTURES: A REVIEW OF THE BIOLOGICAL RISKS

Mass timber structures have the potential to change wooden construction on a global scale. Numerous mass timber high-rise buildings are in planning, under development or already built and their performance will alter how architects and engineers view wood as a material. To date, the discussion of material durability and biodegradation in these structures has been limited. While all materials can be degraded by wetting, the potential for biodegradation of wood in a mass timber building requires special consideration. Identifying and eliminating the conditions that might lead to this degradation will be critical for ensuring proper performance of wood in these structures. This article reviews and contrasts potential sources of biodegradation that exist for traditional wood construction with those in mass timber construction and identifies methods for limiting the degradation risk. Finally, future research needs are outlined

The effect of pH on decomposition of Mylone (dazomet) and tridipam to fungitoxic methylisothiocyanate in wood

Mylone@ and tridipam are two solid chemicals that decompose to produce methylisothiocyanate (MIT), a highly effective wood fumigant. In this study, two techniques -- a rapid, test-tube method and small-scale, wood-block assay -- were used to determine the effect of the pH of various chemical buffers on the decomposition of Mylone@ and tridipam in Douglas-fir heartwood samples colonized by Poria carbonica. Both chemicals were sensitive to pH, and higher levels of MIT were produced as the pH of the buffers increased. In general, fungal survival was not affected 1 week after chemical treatment. Complete control of P. carbonica, however, resulted after 4 weeks of exposure to 50 mg Mylone@/block or 150 mg tridipam/block, when each chemical was combined with a pH-12 buffer. These results suggest that regulating fumigant treatments according to the degree of fungal attack can substantially improve the precision of decay control in wood maintenance programs.Keywords: wood decay, Mylone, tridipam, pH, methylisothiocyanate, Poria placenta, Poria carbonica, fumigants, Douglas-fir, buffers, utility pole

Patient-reported outcome data generated in a clinical intervention in community mental health care - psychometric properties

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

The use of interpretive phenomenological analysis in couple and family therapy research

This article proposes a research methodology that is newer to the field of couple and family therapy research called Interpretive Phenomenological Analysis (IPA). Researchers exploring couple and family therapy research continue to establish the efficacy of couple and family interventions in a context that favors a positivist view of phenomena. This research continues to be critical for establishing the role of couple and family therapy in the field of mental health as well as further clarifying which interventions are best for specific clinical issues and when. IPA offers researchers the opportunity to explore how couples and families make meaning of their experiences from an intersubjective perspective. Meaning making is central to understanding couples and families as well as part of the many clinical approaches to working with couples and families. Despite the importance of meaning, few research methodologies allow for this central concept in couple and family therapy to be the focus of exploration. The following article outlines one such methodology and the possible use of IPA in couple and family therapy research