42 research outputs found

    Using Multiple Sources of Knowledge to Investigate Northern Environmental Change: Regional Ecological Impacts of a Storm Surge in the Outer Mackenzie Delta, N.W.T.

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    Field data, remote sensing, and Inuvialuit knowledge were synthesized to document regional ecological change in the outer Mackenzie Delta and to explore the timing, causes, and implications of this phenomenon. In September 1999, a large magnitude storm surge inundated low-lying areas of the outer Mackenzie Delta. The storm was among the most intense on record and resulted in the highest water levels ever measured at the delta front. Synthesis of scientific and Inuvialuit knowledge indicates that flooding during the 1999 storm surge increased soil salinity and caused widespread vegetation death. Vegetation cover was significantly reduced in areas affected by the surge and was inversely related to soil salinity. Change detection analysis, using remotely sensed imagery bracketing the 1999 storm event, indicates severe impacts on at least 13 200 ha of terrestrial vegetation in the outer delta. Inuvialuit knowledge identifying the 1999 surge as anomalous is corroborated by geochemical profiles of permafrost and by a recently published paleo-environmental study, which indicates that storm surge impacts of this magnitude have not previously occurred during the last millennium. Almost a decade after the 1999 storm surge event, ecological recovery has been minimal. This broad-scale vegetation change is likely to have significant implications for wildlife and must be considered in regional ecosystem planning and in the assessment and monitoring of the cumulative impacts of development. Our investigations show that Inuvialuit were aware of the 1999 storm surge and the environmental impacts several years before the scientific and regulatory communities recognized their significance. This study highlights the need for multidisciplinary and locally informed approaches to identifying and understanding Arctic environmental change.La synthĂšse des donnĂ©es d’exploitation et de tĂ©lĂ©dĂ©tection de mĂȘme que des connaissances des Inuvialuit a Ă©tĂ© effectuĂ©e afin de rĂ©pertorier les changements Ă©cologiques enregistrĂ©s dans la rĂ©gion extĂ©rieure du delta du Mackenzie et d’explorer la temporisation, les causes et les incidences de ce phĂ©nomĂšne. En septembre 1999, une onde de tempĂȘte de grande magnitude a inondĂ© les zones de faible Ă©lĂ©vation de l’extĂ©rieur du delta du Mackenzie. Il s’agit de la tempĂȘte la plus intense Ă  n’avoir jamais Ă©tĂ© enregistrĂ©e, ce qui s’est traduit par les niveaux d’eau les plus Ă©levĂ©s Ă  n’avoir jamais Ă©tĂ© mesurĂ©s Ă  la hauteur du delta. La synthĂšse des donnĂ©es scientifiques et des connaissances des Inuvialuit nous montre que l’inondation de 1999 a eu pour effet d’augmenter la salinitĂ© du sol et a entraĂźnĂ© la mort de la vĂ©gĂ©tation Ă  grande Ă©chelle. La couverture vĂ©gĂ©tale a Ă©tĂ© rĂ©duite considĂ©rablement dans les zones visĂ©es par l’onde et Ă©tait inversement reliĂ©e Ă  la salinitĂ© du sol. L’analyse des dĂ©tections de changement effectuĂ©e au moyen de l’imagerie tĂ©lĂ©dĂ©tectĂ©e dans le cas de la tempĂȘte de 1999 laisse entrevoir de fortes incidences sur au moins 13 200 hectares de vĂ©gĂ©tation terrestre dans l’extĂ©rieur du delta. Les connaissances des Inuvialuit, qui affirment que l’onde de 1999 Ă©tait anormale, sont corroborĂ©es par les profils gĂ©ochimiques du pergĂ©lisol ainsi que par une Ă©tude palĂ©oenvironnementale qui indique que des incidences de cette ampleur dĂ©coulant d’une onde de tempĂȘte ne se sont pas produites Ă  un autre moment donnĂ© du dernier millĂ©naire. PrĂšs d’une dĂ©cennie aprĂšs l’onde de tempĂȘte de 1999, le rĂ©tablissement Ă©cologique Ă©tait minime. Ce changement de vĂ©gĂ©tation Ă  grande Ă©chelle aura vraisemblablement d’importantes incidences sur la faune et doit entrer en considĂ©ration dans la planification de l’écosystĂšme rĂ©gional ainsi que dans l’évaluation et la surveillance des incidences cumulatives des travaux d’amĂ©nagement et de mise en valeur. Nos enquĂȘtes nous ont permis de constater que les Inuvialuit Ă©taient conscients des incidences environnementales de l’onde de tempĂȘte de 1999 plusieurs annĂ©es avant que les scientifiques et le personnel s’occupant de la rĂ©glementation ne reconnaissent leur importance. Cette Ă©tude fait ressortir la nĂ©cessitĂ© d’avoir des mĂ©thodes multidisciplinaires et de faire appel aux gens de la rĂ©gion pour dĂ©terminer et comprendre les changements environnementaux dans l’Arctique

    Koinonia

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    Spotlight FeaturesSovereign Stumbling: My Life Journey to Date, Larry Crabb Conversations About Racism, Jessie Brown Anxiety: A Growing Problem in College Students, Steven M. Conn Thinking TheologicallyTeaching the Truth, Michael and Stephanie Santarosa Book ReviewsKingdom Triangle: Recover the Christian Mind, Renovate the Soul, Restore the Spirit\u27s Power (by J.P. Moreland), reviewed by Steve Ivester The Soul of a Christian University: A Field Guide for Educators (edited by Stephen T. Beers), reviewed by Kyle Lantz The Outrageous Idea of Academic Faithfullness (by Donald Opitz and Derek Melleby), reviewed by Nathan Geer I Once Was Lost: What Postmodern Skeptics Taught Us About Their Path to Jesus (by Don Everts and Doug Schaupp), reviewed by Andrew D. Rowell FeaturesThe President\u27s Corner Editor\u27s Deskhttps://pillars.taylor.edu/acsd_koinonia/1012/thumbnail.jp

    Global declines in coral reef calcium carbonate production under ocean acidification and warming

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    Ocean warming and acidification threaten the future growth of coral reefs. This is because the calcifying coral reef taxa that construct the calcium carbonate frameworks and cement the reef together are highly sensitive to ocean warming and acidification. However, the global-scale effects of ocean warming and acidification on rates of coral reef net carbonate production remain poorly constrained despite a wealth of studies assessing their effects on the calcification of individual organisms. Here, we present global estimates of projected future changes in coral reef net carbonate production under ocean warming and acidification. We apply a meta-analysis of responses of coral reef taxa calcification and bioerosion rates to predicted changes in coral cover driven by climate change to estimate the net carbonate production rates of 183 reefs worldwide by 2050 and 2100. We forecast mean global reef net carbonate production under representative concentration pathways (RCP) 2.6, 4.5, and 8.5 will decline by 76, 149, and 156%, respectively, by 2100. While 63% of reefs are projected to continue to accrete by 2100 under RCP2.6, 94% will be eroding by 2050 under RCP8.5, and no reefs will continue to accrete at rates matching projected sea level rise under RCP4.5 or 8.5 by 2100. Projected reduced coral cover due to bleaching events predominately drives these declines rather than the direct physiological impacts of ocean warming and acidification on calcification or bioerosion. Presently degraded reefs were also more sensitive in our analysis. These findings highlight the low likelihood that the world’s coral reefs will maintain their functional roles without near-term stabilization of atmospheric CO2 emissions

    The state of the Martian climate

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    60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes

    Effects of Doxorubicin on Cardiac Fibroblasts and the Extracellular Matrix

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    Cardiotoxicity has been associated with various types of chemotherapeutic drugs contributing to a plethora of cardiac insults and is a significant side effect when treating cancer. Many highly effective anticancer drugs are severely dose dependent, and at higher doses can lead to: cardiac arrhythmias, hypertension, and lethal cardiomyopathy. A well known example of this cardiotoxic side effect is Doxorubicin, a common chemotherapeutic used to treat cancers of the breast, ovary, bladder, and thyroid. Extensive research has shown that high doses of doxorubicin detrimentally alters the normal function of cardiac fibroblasts and cardiomyocytes. In contrast to the extensive research on the toxic effects of chemotherapeutics like doxorubicin in cardiomyocytes, little is known on the effects in cardiac fibroblasts and mechanisms of these drugs on the cardiac extracellular matrix (cECM). We show that doxorubicin has a direct impact on cardiac fibroblasts and in turn the function of the cECM, indicating that the cECM plays an important role in cardiac toxicity induced by doxorubicin

    Appendix D. Results of the SIMPER analysis comparing plant community composition at impacted and unimpacted sites in the outer Mackenzie delta.

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    Results of the SIMPER analysis comparing plant community composition at impacted and unimpacted sites in the outer Mackenzie delta

    Appendix A. Photographs of vegetation types sampled in the outer Mackenzie Delta.

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    Photographs of vegetation types sampled in the outer Mackenzie Delta

    Appendix B. Map showing the location of each undisturbed transect and subplot sampled.

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    Map showing the location of each undisturbed transect and subplot sampled
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