1,105 research outputs found
Quantifying black carbon deposition over the Greenland ice sheet from forest fires in Canada
Black carbon (BC) concentrations observed in 22 snowpits sampled in the northwest sector of the Greenland ice sheet in April 2014 have allowed us to identify a strong and widespread BC aerosol deposition event, which was dated to have accumulated in the pits from two snow storms between 27 July and 2 August 2013. This event comprises a significant portion (57% on average across all pits) of total BC deposition over 10 months (July 2013 to April 2014). Here we link this deposition event to forest fires burning in Canada during summer 2013 using modeling and remote sensing tools. Aerosols were detected by both the CloudâAerosol Lidar with Orthogonal Polarization (on board CALIPSO) and Moderate Resolution Imaging Spectroradiometer (Aqua) instruments during transport between Canada and Greenland. We use highâresolution regional chemical transport modeling (WRFâChem) combined with highâresolution fire emissions (FINNv1.5) to study aerosol emissions, transport, and deposition during this event. The model captures the timing of the BC deposition event and shows that fires in Canada were the main source of deposited BC. However, the model underpredicts BC deposition compared to measurements at all sites by a factor of 2â100. Underprediction of modeled BC deposition originates from uncertainties in fire emissions and model treatment of wet removal of aerosols. Improvements in model descriptions of precipitation scavenging and emissions from wildfires are needed to correctly predict deposition, which is critical for determining the climate impacts of aerosols that originate from fires
Mutual Zonated Interactions of Wnt and Hh Signaling Are Orchestrating the Metabolism of the Adult Liver in Mice and Human
The Hedgehog (Hh) and Wnt/β-Catenin (Wnt) cascades are morphogen pathways whose pronounced influence on adult liver metabolism has been identified in recent years. How both pathways communicate and control liver metabolic functions are largely unknown. Detecting core components of Wnt and Hh signaling and mathematical modeling showed that both pathways in healthy liver act largely complementary to each other in the pericentral (Wnt) and the periportal zone (Hh) and communicate mainly by mutual repression. The Wnt/Hh module inversely controls the spatiotemporal operation of various liver metabolic pathways, as revealed by transcriptome, proteome, and metabolome analyses. Shifting the balance to Wnt (activation) or Hh (inhibition) causes pericentralization and periportalization of liver functions, respectively. Thus, homeostasis of the Wnt/Hh module is essential for maintaining proper liver metabolism and to avoid the development of certain metabolic diseases. With caution due to minor species-specific differences, these conclusions may hold for human liver as well
From a certain point of view: sensory phenomenological envisionings of running space and place
The precise ways in which we go about the mundane, repetitive, social actions of everyday life are central concerns of ethnographers and theorists working within the traditions of the sociology of the mundane and sociological phenomenology. In this article, we utilize insights derived from sociological phenomenology and the newly developing field of sensory sociology to investigate a particular, mundane, and embodied social practice, that of training for distance running in specific places: our favored running routes. For, despite a growing body of ethnographic studies of particular sports, little analytic attention has been devoted to the actual, concrete practices of âdoingâ or âproducingâ sporting activity, particularly from a sensory ethnographic perspective. Drawing upon data from a 2-year joint autoethnographic research project, here we explore the visual dimension, focusing upon three key themes in relation to our runnersâ visualization of, respectively, (1) hazardous places, (2) performance places, (3) the timeâspaceâplace nexus
Investigating pupilsâ interactions around digital texts: a spatial perspective on the âclassroom-nessâ of digital literacy practices in schools
This paper complements debates around use of new technologies and literacy in education by proposing a focus on âclassroom-ness.â It highlights the significance of incidental, everyday and ephemeral practices associated with classroom technology-use. Using examples from a study of primary pupilsâ interactions around digital texts, it argues that we must acknowledge the distinctiveness of technology-use in classroom contexts but also see the spaces associated with those contexts as continually constructed, relational and heterogeneous. This helps us look beyond binary distinctions â between in/out of school and global/local practices, on/off-screen and on/offline activity, material/virtual contexts and official/unofficial discourses â to recognise the complex and nuanced ways that children make meaning around new technologies. It is proposed that this theoretical lens â in recognising the complexity of classroom-ness â can help us better understand the barriers and opportunities associated with effective integration of new technologies in educational contexts
âI will not be thrown out of the country because Iâm an immigrantâ: Eastern European migrantsâ responses to hate crime in a semi-rural context in the wake of Brexit
This article examines Eastern European migrantsâ experiences of and responses to hate crime. Following the UK European Union Membership Referendum (âBrexitâ vote), there was an increase in reported hate crimes against immigrants. The study focuses on the experiences of migrants in Lincolnshire, a region of England which has a significant migrant population, and which had one of the highest âleaveâ votes. The focus on white migrants in this semi-rural setting offers an original perspective in the field of hate crime studies. We draw on semi-structured interviews and observations to identify temporal, spatial, and relational factors in responses to hate crime. We uncover the insecure occupation of a âthird spaceâ constituted by material, discursive, and emotional practices. This positioning was destabilised post referendum; but there was also evidence of the operation of agency within processes of âotheringâ, suggesting a transition from victim identity to emergent political subject
âI will not be thrown out of the country because Iâm an immigrantâ: Eastern European migrantsâ responses to hate crime in a semi-rural context in the wake of Brexit
This article examines Eastern European migrantsâ experiences of and responses to hate crime. Following the UK European Union Membership Referendum (âBrexitâ vote), there was an increase in reported hate crimes against immigrants. The study focuses on the experiences of migrants in Lincolnshire, a region of England which has a significant migrant population, and which had one of the highest âleaveâ votes. The focus on white migrants in this semi-rural setting offers an original perspective in the field of hate crime studies. We draw on semi-structured interviews and observations to identify temporal, spatial, and relational factors in responses to hate crime. We uncover the insecure occupation of a âthird spaceâ constituted by material, discursive, and emotional practices. This positioning was destabilised post referendum; but there was also evidence of the operation of agency within processes of âotheringâ, suggesting a transition from victim identity to emergent political subject
Report of the IAU/IAG Joint Working Group on Theory of Earth Rotation and Validation
This report focuses on some selected scientific outcomes of the activities developed by the IAU/IAG Joint Working Group on Theory of Earth rotation and validation along the term 2015â2019. It is based on its end-of-term report to the IAG Commission 3 published in the Travaux de lâIAG 2015â2019, which in its turn updates previous reports to the IAG and IAU, particularly the triennial report 2015â2018 to the IAU Commission A2, and the medium term report to the IAG Commission 3 (2015â2017). The content of the report has served as a basis for the IAG General Assembly to adopt Resolution 5 on Improvement of Earth rotation theories and models.JMF, AE, and JG were partially supported by Spanish Project AYA2016-79775-P (AEI/FEDER, UE). The work of RSG described in this paper was performed at the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. Support for that work was provided by the Earth Surface and Interior Focus Area of NASAâs Science Mission Directorate
Chemical data assimilation estimates of continental U.S. ozone and nitrogen budgets during the Intercontinental Chemical Transport Experiment-North America
Global ozone analyses, based on assimilation of stratospheric profile and ozone column measurements, and NOy predictions from the Real-time Air Quality Modeling System (RAQMS) are used to estimate the ozone and NOy budget over the continental United States during the July-August 2004 Intercontinental Chemical Transport Experiment-North America (INTEX-A). Comparison with aircraft, satellite, surface, and ozonesonde measurements collected during INTEX-A show that RAQMS captures the main features of the global and continental U.S. distribution of tropospheric ozone, carbon monoxide, and NOy with reasonable fidelity. Assimilation of stratospheric profile and column ozone measurements is shown to have a positive impact on the RAQMS upper tropospheric/lower stratosphere ozone analyses, particularly during the period when SAGE III limb scattering measurements were available. Eulerian ozone and NOy budgets during INTEX-A show that the majority of the continental U.S. export occurs in the upper troposphere/lower stratosphere poleward of the tropopause break, a consequence of convergence of tropospheric and stratospheric air in this region. Continental U.S. photochemically produced ozone was found to be a minor component of the total ozone export, which was dominated by stratospheric ozone during INTEX-A. The unusually low photochemical ozone export is attributed to anomalously cold surface temperatures during the latter half of the INTEX-A mission, which resulted in net ozone loss during the first 2 weeks of August. Eulerian NOy budgets are shown to be very consistent with previously published estimates. The NOy export efficiency was estimated to be 24%, with NOx + PAN accounting for 54% of the total NOy export during INTEX-A. Copyright 2007 by the American Geophysical Union
Cities in fiction: Perambulations with John Berger
This paper explores selected novels by John Berger in which cities play a central role. These cities are places, partially real and partially imagined, where memory, hope, and despair intersect. My reading of the novels enables me to trace important themes in recent discourses on the nature of contemporary capitalism, including notions of resistance and universality. I also show how Berger?s work points to a writing that can break free from the curious capacity of capitalism to absorb and feed of its critique
Diminished temperature and vegetation seasonality over northern high latitudes
Global temperature is increasing, especially over northern lands (>50°âN), owing to positive feedbacks1. As this increase is most pronounced in winter, temperature seasonality (ST)âconventionally defined as the difference between summer and winter temperaturesâis diminishing over time2, a phenomenon that is analogous to its equatorward decline at an annual scale. The initiation, termination and performance of vegetation photosynthetic activity are tied to threshold temperatures3. Trends in the timing of these thresholds and cumulative temperatures above them may alter vegetation productivity, or modify vegetation seasonality (SV), over time. The relationship between ST and SV is critically examined here with newly improved ground and satellite data sets. The observed diminishment of ST and SV is equivalent to 4° and 7° (5° and 6°) latitudinal shift equatorward during the past 30 years in the Arctic (boreal) region. Analysis of simulations from 17 state-of-the-art climate models4 indicates an additional STdiminishment equivalent to a 20° equatorward shift could occur this century. How SV will change in response to such large projected ST declines and the impact this will have on ecosystem services5 are not well understood. Hence the need for continued monitoring6 of northern lands as their seasonal temperature profiles evolve to resemble thosefurther south.Lopullinen vertaisarvioitu käsikirjoitu
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