17 research outputs found
Spatiotemporal studies of black spruce forest soils and implications for the fate of C
Post-fire storage of carbon (C) in organic-soil horizons was measured in one Canadian and three Alaskan chronosequences in black spruce forests, together spanning stand ages of nearly 200 yrs. We used a simple mass balance model to derive estimates of inputs, losses, and accumulation rates of C on timescales of years to centuries. The model performed well for the surface and total organic soil layers and presented questions for resolving the dynamics of deeper organic soils. C accumulation in all study areas is on the order of 20â40 gC/m2/yr for stand ages up to âŒ200 yrs. Much larger fluxes, both positive and negative, are detected using incremental changes in soil C stocks and by other studies using eddy covariance methods for CO2. This difference suggests that over the course of stand replacement, about 80% of all net primary production (NPP) is returned to the atmosphere within a fire cycle, while about 20% of NPP enters the organic soil layers and becomes available for stabilization or loss via decomposition, leaching, or combustion. Shifts toward more frequent and more severe burning and degradation of deep organic horizons would likely result in an acceleration of the carbon cycle, with greater CO2 emissions from these systems overall
Guidelines for peer support in highârisk organizations: An international consensus study using the delphi method
Despite widespread adoption of peerâsupport programs in organizations around the world whose employees are at high risk of exposure to potentially traumatic incidents, little consensus exists regarding even the most basic concepts and procedures for these programs. In this article, consensus refers to a group decisionâmaking process that seeks not only agreement from most participants, but also resolution of minority objections. The aim of the current study was to develop evidenceâinformed peerâsupport guidelines for use in highârisk organizations, designed to enhance consistency around goals and procedures and provide the foundation for a systematic approach to evaluation. From 17 countries, 92 clinicians, researchers, and peerâsupport practitioners took part in a 3âround webâbased Delphi process rating the importance of statements generated from the existing literature. Consensus was achieved for 62 of 77 (81%) statements. Based upon these, 8 key recommendations were developed covering the following areas: (a) goals of peer support, (b) selection of peer supporters, (c) training and accreditation, (d) role of mental health professionals, (e) role of peer supporters, (f) access to peer supporters, (g) looking after peer supporters, and (h) program evaluation. This international consensus may be used as a starting point for the design and implementation of future peerâsupport programs in highârisk organizations
Review: The Journal of Dramaturgy, volume 20, 2009/2010
Contents include: Recognizing Toward a Dramaturgical Sensibility, Geoff Proehl, recipient of the 2009 ATHE Outstanding Book Award; Geoff Proehl\u27s Acceptance Speech, Association for Theatre in Higher Education Awards Ceremony August 10, 2009; Millennial Dramaturgy, A conversation about the new book Dramaturgy and Performance; Creating Sub/Text, Dramaturging the ReStaged Festival; Dramaturgy and Interdisciplinary Learning, A Case Study of Russian Theatre and Politics; Thinking about Theatre Photography; Theatre / Photography.
Issue editors: D.J. Hopkins, Sydney Cheek O\u27Donnell, Lauren Beckhttps://soundideas.pugetsound.edu/lmdareview/1040/thumbnail.jp
Finishing the euchromatic sequence of the human genome
The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers âŒ99% of the euchromatic genome and is accurate to an error rate of âŒ1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead
Australian Case Studies in Mobile Commerce
Sixteen wireless case studies highlight issues relating to mobile commerce in Australia. The issues include: the need for a clear business case; difficulty of achieving critical mass and acceptance of a new service; training and technical issues, as well as staff acceptance issues; that privacy and security issues arise through the potential to track the location of people and through the amounts of personal data collected; difficulties in integrating with existing back-end systems; projects being affected by changes to legislation, or requiring changes to the law; and that while there is potential for mobile phone operators to develop new billing methods that become new models for issuing credit, they are not covered by existing credit laws. We have placed the case studies in a Fit-Viability framework and analyzed the issues according to key success criteria. While many organizations are keen to use the technology, they are struggling to find a compelling business case for adoption and that without a strong business case projects are unlikely to progress past the pilot stage
Harmonic stability of VSC connected Low Frequency AC offshore transmission with long HVAC cables
Low Frequency AC (LFAC) transmission has been proposed as an alternative to HVDC transmission for the integration of offshore wind. The LFAC offshore grid as a fully power electronic grid with a long HVAC cable provides significant challenges to harmonic stability. This paper presents an impedance based stability analysis to determine the stability of the power electronic offshore system across the harmonic frequency range. The stability analysis is introduced and applied to the LFAC system. The impact of different current and voltage control bandwidths and component sizes on the dynamic impedance of the converters is then examined and their impact on harmonic stability of the LFAC grid is determined. It is found that detailed knowledge of the control parameters and the ability to tune the bandwidths can mitigate significant harmonic instability with the presence of a long HVAC cable. Three phase simulations are then used to validated the impedance based stability technique.Science Foundation Irelan
Concise Synthesis of Annulated Pyrido[3,4-b]indoles via Rh(I)-Catalyzed Cyclization.
The synthesis of pyridines bearing multiple ring fusions poses a considerable challenge for organic chemists. To address this problem, we describe the synthesis of a small library of pyrido[3,4-b]indoles via an efficient, five-step sequence. The key transformation is a Rh(I)-catalyzed [2 + 2 + 2] cyclization that forms three rings in one reaction flask. Our method is high yielding, accommodates a variety of functional groups, and suffers no entropic costs as ring size increases
An antitumorigenic role for the IL-33 receptor, ST2L, in colon cancer
Background: Despite the importance of inflammation in cancer, the role of the cytokine IL-33, and its receptor ST2, in colon cancer is unclear. The aim of this study was to investigate the role of IL-33, and its receptor isoforms (ST2 and ST2L), in colon cancer. Methods: Serum levels of IL-33 and sST2 were determined with ELISA. ST2 and IL-33 expression was detected with quantitative real-time PCR (qRTâPCR), western blotting and immunohistochemistry. ST2 expression in CT26 cells was stably suppressed using ST2-specific shRNA. Cytokine and chemokine gene expression was detected with qRTâPCR. Results: Human colon tumours showed lower expression of ST2L as compared with adjacent non-tumour tissue (P<0.01). Moreover, the higher the tumour grade, the lower the expression of ST2L (P=0.026). Colon cancer cells expressed ST2 and IL-33 in vitro. Functional analyses showed that stimulation of tumour cells with IL-33 induced the expression of chemokine (CâC motif) ligand 2 (CCL2). Knockdown of ST2 in murine colon cancer cells resulted in enhanced tumour growth (P<0.05) in BALB/c mice in vivo. This was associated with a decrease in macrophage infiltration, with IL-33-induced macrophage recruitment reduced by antagonising CCL2 in vitro. Conclusion: The IL-33/ST2 signalling axis may have a protective role in colon carcinogenesis
Soil carbon distribution in Alaska in relation to soil-forming factors
The direction and magnitude of soil organic carbon (SOC) changes in response to climate change remain unclear and depend on the spatial distribution of SOC across landscapes. Uncertainties regarding the fate of SOC are greater in high-latitude systems where data are sparse and the soils are affected by sub-zero temperatures. To address these issues in Alaska, a first-order assessment of data gaps and spatial distributions of SOC was conducted from a recently compiled soil carbon database. Temperature and landform type were the dominant controls on SOC distribution for selected ecoregions. Mean SOC pools (to a depth of 1-m) varied by three, seven and ten-fold across ecoregion, landform, and ecosystem types, respectively. Climate interactions with landform type and SOC were greatest in the uplands. For upland SOC there was a six-fold non-linear increase in SOC with latitude (i.e., temperature) where SOC was lowest in the Intermontane Boreal compared to the Arctic Tundra and Coastal Rainforest. Additionally, in upland systems mineral SOC pools decreased as climate became more continental, suggesting that the lower productivity, higher decomposition rates and fire activity, common in continental climates, interacted to reduce mineral SOC. For lowland systems, in contrast, these interactions and their impacts on SOC were muted or absent making SOC in these environments more comparable across latitudes. Thus, themagnitudes of SOC change across temperature gradients were non-uniformand depended on landform type. Additional factors that appeared to be related to SOC distribution within ecoregions included stand age, aspect, and permafrost presence or absence in black spruce stands. Overall, these results indicate the influence of major interactions between temperature-controlled decomposition and topography on SOC in high-latitude systems. However, there remains a need for more SOC data from wetlands and boreal-region permafrost soils, especially at depths\u3e1 m in order to fully understand the effects of climate on soil carbon in Alaska