187 research outputs found

    PROJECTING SPATIAL CHANGES IN SUGAR MAPLE SAP FLOW REGIMES IN A CHANGING CLIMATE

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    Anthropogenic climate change presents a potential threat to maple syrup production in Canada. To mitigate risks associated with climate change, information about the biological changes that may occur in a warming climate are necessary. This project studied one component- sap flow- that in part determines the economic viability of maple syrup production. A temperature-based sap flow model was used to project the start of the sap flow season in southern Ontario, and GIS applications were used to aggregate the results. The start of the sap flow season was projected for early, mid, and late-century periods under two climate change scenarios, RCP4.5 and RCP 8.5, using data from the Canadian Regional Climate Model (CRCM) CORDEX experiments. In both scenarios, a majority of the study area experienced an earlier start to sap flow; the northernmost extent of the sugar maple range saw the greatest shift to earlier sap flow dates, particularly in the RCP8.5 scenario. Some areas around the Great Lakes did not meet the criteria for sap flow to begin for the mid-century and late-century periods in both scenarios. For the mid-century period, the RCP4.5 scenario showed sap flow beginning earlier for most of the province- excluding the northernmost areas- than RCP8.5. For the late-century period, RCP8.5 showed a greater shift in sap flow dates than RCP4.5. The results suggest that maple syrup producers will need to take adaptive measures to respond to shifts in the sap flow season

    Closed-loop communication during out-of-hospital resuscitation:Are the loops really closed?

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    Training for effective communication in high-stakes environments actively promotes targeted communicative strategies. One oft-recommended strategy is closed-loop communication (CLC), which emphasises three components – call-out, checkback, and closing of the loop – to signal understanding. Using CLC is suggested to improve clinical outcomes, but research indicates that medical practitioners do not always apply CLC in team communication. Our paper analyses a context in which speakers’ linguistic choices are guided by explicit recommendations during training, namely out-of-hospital cardiac arrest (OHCA) resuscitation. We examined 20 real-life OHCA resuscitations to determine whether paramedics adopt CLC in the critical first five minutes after the arrival of the designated team leader (a paramedic specially trained in handling OHCA resuscitation), and what other related communication strategies may be used. Results revealed that standard form CLC was not consistently present in any of the resuscitations despite opportunities to use it. Instead, we found evidence of non-standard forms of CLC and closed-ended communication (containing the first two components of standard CLC). These findings may be representative of what happens when medical practitioners communicate in time-critical, real-life contexts where responses to directives can be immediately observed, and suggest that CLC may not always be necessary for effective communication in these contexts

    A proposed mechanism for nitrogen acquisition by grass seedlings through oxidation of symbiotic bacteria

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    In this paper we propose and provide evidence for a mechanism, oxidative nitrogen scavenging (ONS), whereby seedlings of some grass species may extract nitrogen from symbiotic diazotrophic bacteria through oxidation by plant-secreted reactive oxygen species (ROS). Experiments on this proposed mechanism employ tall fescue (Festuca arundinaceae) seedlings to elucidate features of the oxidative mechanism. We employed 15N2 gas assimilation experiments to demonstrate nitrogen fixation, direct microscopic visualization of bacteria on seedling surfaces to visualize the bacterial oxidation process, reactive oxygen probes to test for the presence of H2O2 and cultural experiments to assess conditions under which H2O2 is secreted by seedlings. We also made surveys of the seedlings of several grass species to assess the distribution of the phenomenon of microbial oxidation in the Poaceae. Key elements of the proposed mechanism for nitrogen acquisition in seedlings include: 1) diazotrophic bacteria are vectored on or within seeds; 2) at seed germination bacteria colonize seedling roots and shoots; 3) seedling tissues secrete ROS onto bacteria; 4) bacterial cell walls, membranes, nucleic acids, proteins and other biological molecules are oxidized; 5) nitrates and/or smaller fragments of organic nitrogen-containing molecules resulting from oxidation may be absorbed by seedling tissues and larger peptide fragments may be further processed by secreted or cell wall plant proteases until they are small enough for transport into cells. Hydrogen peroxide secretion from seedling roots and bacterial oxidation was observed in several species in subfamily Pooideae where seeds possessed adherent paleas and lemmas, but was not seen in grasses that lacked this feature or long-cultivated crop species

    Dynamic asymmetries in house price cycles: A generalized smooth transition model

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    In this paper we propose a novel nonlinear model to capture asymmetries in real estate cycles. The approach involves a particular parametrization of the transition function used in the transition equation of a smooth transition autoregressive model which improves the fit in the non-central probability region. The dynamic symmetry in house price cycles is strongly rejected for the housing markets taken into consideration. Further, our results show that the proposed model performs well in a out of sample forecasting exercise

    Verbalisation of plans during out-of-hospital cardiac arrest resuscitation

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    Planning and communication are pivotal in achieving team goals. Studies have shown that teams with effective planning and sharing of mental models display better performance in resuscitation. The Advanced Life Support (ALS) algorithm serves as an overall script regarding specific stages during resuscitation, but it does not explicitly specify how tasks should be delegated or synchronised. Team members therefore need to rely on ongoing, context-specific shared plans for effective team coordination

    Proliferative Tumor Doubling Times of Prostatic Carcinoma

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    Prostate cancer (PCa) has a variable biology ranging from latent cancer to extremely aggressive tumors. Proliferative activities of cancers may indicate their biological potential. A flow cytometric assay to calculate maximum proliferative doubling times (Tmax) of PCa in radical prostatectomy specimens after preoperative in vivo bromodeoxyuridine (BrdU) infusion is presented. Only 4/17 specimens had tumors large enough for flow cytometric analysis. The Tmax of tumors was similar and ranged from 0.6 to 3.6 months. Tumors had calculated doubling times 2- to 25-fold faster than their matched normal tissue. Variations in labeling index and Tmax were observed within a tumor as well as between different Gleason grades. The observed PSA doubling times (PSA-DT) ranged from 18.4 to 32.0 months, considerably slower than the corresponding Tmax of tumors involved. While lack of data for apoptotic rates is a limitation, apparent biological differences between latent versus aggressive PCa may be attributable to variations in apoptotic rates of these tumors rather than their cell proliferative rates

    MLK Historic District: 493 Auburn Ave. NE

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    Prepared by the Fall 2010 Conservation of Historic Building Materials class. This Historic Structure Report contains the history of the three double-shotgun houses located at 493 Auburn Avenue built by Alexander Daniel Hamilton and his father, Alexander Hamilton, African-American father-and-son builders. The existing conditions of the interior, exterior, infrastructure, and grounds of the buildings are detailed, as well as a master plan of recommendations for the site. The purpose of this report is to provide a current assessment of the condition of the property, recommendations for needed repairs and options for future consideration.https://scholarworks.gsu.edu/history_heritagepreservation/1052/thumbnail.jp

    ‘Inspired and assisted’, or ‘berated and destroyed’? Research leadership, management and performativity in troubled times

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    Research leadership in Australian universities takes place against a backdrop of policy reforms concerned with measurement and comparison of institutional research performance. In particular, the Excellence in Research in Australian initiative undertaken by the Australian Research Council sets out to evaluate research quality in Australian universities, using a combination of expert review process, and assessment of performance against &lsquo;quality indicators&rsquo;. Benchmarking exercises of this sort continue to shape institutional policy and practice, with inevitable effects on the ways in which research leadership, mentoring and practice are played out within university faculties and departments. In an exploratory study that interviewed 32 Australian academics in universities in four Australian states, we asked participants, occupying formal or informal research leadership roles, to comment on their perceptions of research leadership as envisioned and enacted in their particular workplaces. We found a pervasive concern amongst participants that coalesced around binaries characterized in metaphoric terms of &lsquo;carrots and whips&rsquo;. Research leadership was seen by many as managerial in nature, and as such, largely tethered to instrumentalist notions of productivity and performativity, while research cultures were seen as languishing under the demoralizing weight of reward and punishment systems. Here, we consider what is at stake for the future of the academic workforce under such conditions, arguing that new models of visionary research leadership are urgently needed in the &lsquo;troubled times&rsquo; of techno-bureaucratic university reforms.<br /
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