585 research outputs found
The essential value of long-term experimental data for hydrology and water management
We would like to thank the European Research Council ERC for funding the VeWa project and most of Tetzlaff's time (project GA 335910 VeWa). No data were used in producing this manuscript.Peer reviewedPublisher PD
Tracer-based assessment of flow paths, storage and runoff generation in northern catchments : a review
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A preliminary assessment of water partitioning and ecohydrological coupling in northern headwaters using stable isotopes and conceptual runoff models
Funded by European Research Council ERC. Grant Number: GA 335910 VEWA Swedish Science Foundation (SITES) Future Forest Formas (ForWater) SKB the Kempe foundation Environment Canada the Garfield Weston Foundation the Natural Sciences and Engineering Research Council of Canada (NSERC) the Northwest Territories Cumulative Impacts Monitoring ProgramPeer reviewedPublisher PD
923-6 Intravenous Adenosine and Lidocaine to Limit Reperfusion Injury During Acute Myocardial Infarction: Preliminary Data
Adenosine (ADO) and lidocaine (LDO) given prior to restoration of blood flow reduces reperfusion injury in animals. We conducted a pilot study of intravenous ADO and LDO in pts undergoing direct angioplasty for acute myocardial infarction (AMI). Pts with ≤12 hours of chest pain and electrocardiographic evidence of AMI were given LDO 1mg/kg iv bolus and 2mg/min iv infusion beginning at the time of recruitment, and ADO 70mcg/kg iv infusion beginning when coronary occlusion (TIMI grade 0–1 blood flow) was confirmed angiographically. Pts with bronchospasm, blood pressure <100mmHg, or<1° heart block were excluded. ADO and LDO were given for 1 hour after vessel patency was restored. Myocardial area at risk and final infarction area were measured with serial Tc-99m-sestamibi perfusion studies (prior to angioplasty, before hospital discharge and 6 weeks after discharge). A salvage index (S1) was constructed by correcting the change in sestamibi perfusion defect for the mass of myocardium at risk. Analysis of 25 patients completing the protocol revealed a mean (±SD) salvage of 20±17% and S1=0.55. Salvage and S1 were 25±18% and 0.54 for anterior infarctions, 13±5% and 0.57 for inferior infarctions, respectively. These data were compared to an historical control group consisting of 50 patients undergoing direct angioplasty for AMI without adjunctive ADO/LDO. After adjustment for time to treatment and perfusion nadir, analysis of covariance revealed a similar degree of early salvage in the study and control groups (p=0.3). However, at 6 weeks, the median infarct size for study pts was 0. Using logistic regression analysis, significantly more study pts had no final measureable infarction at 6 weeks than control pts at hospital discharge (p=0.007). After adjusting for infarct size, location and time to treatment, this difference persisted (p=0.04).ConclusionsAdjunctive ADO and LDO during angioplasty for AMI may favorably affect late final infarction size. Randomized studies assessing 6 week final infarction size are needed
Energy input is primary controller of methane bubbling in subarctic lakes
Emission of methane (CH4) from surface waters is often dominated by ebullition (bubbling), a transport mode with high‐spatiotemporal variability. Based on new and extensive CH4 ebullition data, we demonstrate striking correlations (r2 between 0.92 and 0.997) when comparing seasonal bubble CH4 flux from three shallow subarctic lakes to four readily measurable proxies of incoming energy flux and daily flux magnitudes to surface sediment temperature (r2 between 0.86 and 0.94). Our results after continuous multiyear sampling suggest that CH4 ebullition is a predictable process, and that heat flux into the lakes is the dominant driver of gas production and release. Future changes in the energy received by lakes and ponds due to shorter ice‐covered seasons will predictably alter the ebullitive CH4 flux from freshwater systems across northern landscapes. This finding is critical for our understanding of the dynamics of radiatively important trace gas sources and associated climate feedback
Stable isotopes of water reveal differences in plant – soil water relationships across northern environments
Funding Information: We thank the European Research Council ERC for funding (VeWa project GA 335910). Contributions from CS were supported by the Leverhulme Trust through the ISO-LAND project (RPG 2018 375). Support for MJK and JPM were provided by the US National Science Foundation (EAR0842367) and Boise State University. We thank Dr. Samantha Evans for technical support. Thanks to the Dorset Environmental Science Centre for provision of meteorological data. The work conducted in Krycklan was partly financed by SITES (VR) and the KAW Branch-Point project. We would like to acknowledge Dr. Nadine Shatilla for collection of the Wolf Creek samples and the Global Water Futures program for financial support. We also would like to sincerely thank Jeff McDonnell for his support throughout the VeWa project and all participants in the different VeWa workshops esp. Tanya Doody and Marco Maneta for their invaluable input into the discussions.Peer reviewedPublisher PD
Regulation of stream water dissolved organic carbon (DOC) concentrations during snowmelt; the role of discharge, winter climate and memory effects
Using a 15 year stream record from a northern boreal catchment, we demonstrate that the inter-annual variation in dissolved organic carbon (DOC) concentrations during snowmelt was related to discharge, winter climate and previous DOC export. A short and intense snowmelt gave higher stream water DOC concentrations, as did long winters, while a high previous DOC export during the antecedent summer and autumn resulted in lower concentrations during the following spring. By removing the effect of discharge we could detect that the length of winter affected the modeled soil water DOC concentrations during the following snowmelt period, which in turn affected the concentrations in the stream. Winter climate explained more of the stream water DOC variations than previous DOC export during the antecedent summer and autumn
The integrated academic information system support for education 3.0 in higher education institution: lecturer perspective
Education 3.0 has been implemented in many higher education institutions (HEIs). Education 3.0 has been directed the institution toward better educational experience. But on the other hands, the implementation of Education 3.0 also caused some problems. Previous research has found administrative problem experienced by the lecturer. This research explores deeper from the lecturer and suggested the solution from lecturer perspective, combined with information technology capabilities owned by the HEIs. The research used a case study as the method and conducted a qualitative research with a semi-structured interview. The interview analysis has found that the increase of the administrative processes is caused by online and offline administrative activities. The online activities are from e-learning and the offline activities are from traditional learning (face-to-face). The administrative processes also involved the academic information system (AIS). Simplified all of the administrative processes are more preferred. To overcome the problems, integrating the AIS and e-learning become necessary. This research suggests transforming the existing AIS into an integrated AIS and hopes the solution can simplify the administration process
Demographic history shapes North American gray wolf genomic diversity and informs species' conservation
Effective population size estimates are critical information needed for evolutionary predictions and conservation decisions. This is particularly true for species with social factors that restrict access to breeding or experience repeated fluctuations in population size across generations. We investigated the genomic estimates of effective population size along with diversity, subdivision, and inbreeding from 162,109 minimally filtered and 81,595 statistically neutral and unlinked SNPs genotyped in 437 grey wolf samples from North America collected between 1986 and 2021. We found genetic structure across North America, represented by three distinct demographic histories of western, central, and eastern regions of the continent. Further, grey wolves in the northern Rocky Mountains have lower genomic diversity than wolves of the western Great Lakes and have declined over time. Effective population size estimates revealed the historical signatures of continental efforts of predator extermination, despite a quarter century of recovery efforts. We are the first to provide molecular estimates of effective population size across distinct grey wolf populations in North America, which ranged between N ~ 275 and 3050 since early 1980s. We provide data that inform managers regarding the status and importance of effective population size estimates for grey wolf conservation, which are on average 5.2–9.3% of census estimates for this species. We show that while grey wolves fall above minimum effective population sizes needed to avoid extinction due to inbreeding depression in the short term, they are below sizes predicted to be necessary to avoid long-term risk of extinction
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