33659 research outputs found
Sort by
Media framing and public support for China’s social credit system: An experimental study
Get PDFAlthough China’s social credit system (SCS) is widely portrayed by Western media as repressive surveillance, recent studies show that it receives high levels of support among Chinese citizens. Previous research suggests that people support the SCS because they lack knowledge about the system. This study further examines the roles of media framing (Western vs Chinese framing) and monitored behaviors (financial vs social behaviors). The results from a survey experiment conducted in China (N = 1600) demonstrate that when exposed to Western framing, public support for the SCS is lower, but only when participants are informed that the SCS monitors social behavior. By contrast, when people are told that the SCS focuses on financial behavior, Western framing exposure is not associated with low levels of public support. The findings suggest that an expansion to social domains and exposure to Western media framing will likely result in decreased support for the system
IPBES Invasive Alien Species Assessment: Chapter 1. Introducing biological invasions and the IPBES thematic assessment of invasive alien species and their control
Get PDFChapter 1: Introducing biological invasions and the IPBES thematic assessment of invasive alien species and their control of the Thematic Assessment Report on Invasive Alien Species and their Control of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services
Gaseous polycyclic aromatic hydrocarbons over the South China Sea: Implications for atmospheric transport under monsoon influences
No full textThe seasonal monsoon variations have significant impact on the atmospheric transport of semi-volatile organic pollutants over the South China Sea (SCS). We analyzed polycyclic aromatic hydrocarbons (PAHs) over the basin and island areas (Yongxing Island and Yongshu Island) in 2017. Gaseous PAHs (0.17–1.4 ng m−3) showed spatio-temporal distinctions in their composition and sources among the basin and island areas. Mixed combustion sources of PAHs were identified over the SCS, including a petroleum source near the island areas. The transport routes of PAHs were inferred by the air mass back trajectories and potential source contribution factor analysis, identifying strong biomass burning signals from the Indochina Peninsula and other Southeast Asian countries. Emissions from approximately 90 % of the combustion sources were transported to basin areas by monsoons, whereas the island areas were dominated by local emissions. This study emphasizes the main potential terrestrial source of PAHs over the SCS under monsoon influences
Polar oceans and sea ice in a changing climate
Get PDFPolar oceans and sea ice cover 15% of the Earth’s ocean surface, and the environment is changing rapidly at both poles. Improving knowledge on the interactions between the atmospheric and oceanic realms in the polar regions, a Surface Ocean-Lower Atmosphere Study (SOLAS) project key focus, is essential to understanding the Earth system in the context of climate change. However, our ability to monitor the pace and magnitude of changes in the polar regions and evaluate their impacts for the rest of the globe is limited by both remoteness and sea-ice coverage. Sea ice not only supports biological activity and mediates gas and aerosol exchange but can also hinder some in-situ and remote sensing observations. While satellite remote sensing provides the baseline climate record for sea-ice properties and extent, these techniques cannot provide key variables within and below sea ice. Recent robotics, modeling, and in-situ measurement advances have opened new possibilities for understanding the ocean-sea ice-atmosphere system, but critical knowledge gaps remain. Seasonal and long-term observations are clearly lacking across all variables and phases. Observational and modeling efforts across the sea-ice, ocean, and atmospheric domains must be better linked to achieve a system-level understanding of polar ocean and sea-ice environments. As polar oceans are warming and sea ice is becoming thinner and more ephemeral than before, dramatic changes over a suite of physicochemical and biogeochemical processes are expected, if not already underway.These changes in sea-ice and ocean conditions will affect atmospheric processes by modifying the production of aerosols, aerosol precursors, reactive halogens and oxidants, and the exchange of greenhouse gases. Quantifying which processes will be enhanced or reduced by climate change calls for tailored monitoring programs for high-latitude ocean environments. Open questions in this coupled system will be best resolved by leveraging ongoing international and multidisciplinary programs, such as efforts led by SOLAS, to link research across the ocean-sea ice-atmosphere interface
Microplastics Distribution within Western Arctic Seawater and Sea Ice
Get PDFMicroplastic pollution has emerged as a global environmental concern, exhibiting wide distribution within marine ecosystems, including the Arctic Ocean. Limited Arctic microplastic data exist from beached plastics, seabed sediments, floating plastics, and sea ice. However, no studies have examined microplastics in the sea ice of the Canadian Arctic Archipelago and Tallurutiup Imanga National Marine Conservation Area, and few have explored Arctic marginal seas’ water column. The majority of the microplastic data originates from the Eurasian Arctic, with limited data available from other regions of the Arctic Ocean. This study presents data from two distinct campaigns in the Canadian Arctic Archipelago and Western Arctic marginal seas in 2019 and 2020. These campaigns involved sampling from different regions and matrices, making direct comparisons inappropriate. The study’s primary objective is to provide insights into the spatial and vertical distribution of microplastics. The results reveal elevated microplastic concentrations within the upper 50 m of the water column and significant accumulation in the sea ice, providing evidence to support the designation of sea ice as a microplastic sink. Surface seawater exhibits a gradient of microplastic counts, decreasing from the Chukchi Sea towards the Beaufort Sea. Polyvinyl chloride polymer (~60%) dominated microplastic composition in both sea ice and seawater. This study highlights the need for further investigations in this region to enhance our understanding of microplastic sources, distribution, and transport
Podcasting practices: Mediators of archival work, ELA teacher education curricula, and digital identities
Get PDFThis paper investigates how a semester-long online course in a language and literacy teacher education department coupled a podcast project with archival pedagogy and restorying to explore how ELA (English Language Arts) teachers (preservice, inservice teachers, and those seeking re-entry) worked collaboratively to enrich understandings of instruction embedded in a high-tech environment. The course was taught in the southeastern United States at the height of a global pandemic. After the semester ended, three graduate students (from a class of 21) joined the instructor to qualitatively analyze data collected during the previous 14 weeks. Data sources included digitally stored videos, archived library objects, class emails, rubrics, asynchronous discussion boards, synchronous Zoom discussions, and student-generated podcast projects. Findings point to the merit of providing agentic-learning opportunities through podcasting practices that mediated students’ archival work, ELA teacher education curricula, and digital identity formation. Implications are drawn for ELA classroom teachers and teacher educators
Planktonic prey size selection reveals an emergent keystone predator effect and niche partitioning
Get PDFMarine herbivorous protists are often the dominant grazers of primary production. We developed a size-based model with flexible size-based grazing to encapsulate taxonomic and behavioral diversity. We examined individual and combined grazing impacts by three consumer sizes that span the size range of protistan grazers– 5, 50, and 200 μm—on a size-structured phytoplankton community. Prey size choice and dietary niche width varied with consumer size and with co-existence of other consumers. When all consumer sizes were present, distinct dietary niches emerged, with a range of consumer-prey size ratios spanning from 25:1 to 0.4:1, encompassing the canonical 10:1 often assumed. Grazing on all phytoplankton size classes maximized the phytoplankton size diversity through the keystone predator effect, resulting in a phytoplankton spectral slope of approximately -4, agreeing with field data. This mechanistic model suggests the observed size structure of phytoplankton communities is at least in part the result of selective consumer feeding
Computational Algorithms for Acoustic Signals Direction of Arrival and Sound Speed Estimation
No full textThis paper develops computationally efficient algorithms for the analysis of acoustic data to localize a target through improved angle of arrival estimation. The passive target localization problem has a wide range of applications in wireless communication, navigation, acoustic sensor networks, indoor localization, to name a few. We have focused on novel formulations and solution methods for target localization using Time Differences of Arrival (TDOA) among distinct pairs of passive sensor nodes in an acoustic sensor network with known sensor positions
Temporal Variability of the Labrador Current Pathways Around the Tail of the Grand Banks at Intermediate Depths in a High-Resolution Ocean Circulation Model
No full textThe Northwest Atlantic Shelf and Slope have warmed dramatically in the past decade, changing marine life and challenging fisheries management. A rapid warming event in 2009/2010, linked to a reduced supply of cold water from the Labrador Sea, pushed this region to a new state of unprecedentedly high temperatures that persists today. However, a mechanistic understanding of how the Labrador Current connectivity is reduced at the Tail of the Grand Banks of Newfoundland has been lacking. Here, we present the results of a 25-year (1993–2017) Lagrangian analysis using the HYbrid Coordinate Ocean Model. Synthetic particles were released in the vicinity of the Labrador Current upstream of the Grand Banks and tracked in a 2-D velocity field. We found that the Labrador Current can be completely blocked by Gulf Stream eddies and meanders that impinge on the shelf break along the Grand Banks. This blocking can occur in many different locations at, upstream, or downstream of the Tail of the Grand Banks, since the Labrador Current needs a clear passage over a long distance to continue its path. In the simulation, the Labrador Current has been blocked more often since 2008, which led to the warming of the Northwest Atlantic Shelf and Slope. These results, which are consistent with satellite observations, can provide predictability for the New England and Nova Scotia shelf environments potentially helpful for ecosystem management
Investigations into 3D-printed nautiloid-inspired pressure housings
No full textThe shell of the chambered nautilus is one of the few examples in nature of a biologically derived one-atmosphere pressure housing, which the animal uses to maintain neutral buoyancy via a series of sealed chambers. Extant species such as Nautilus pompilius live at depths from 200 to 800 m, and similar depth ranges have been hypothesized for their hyper diverse but extinct relatives, the ammonoids. Given the evolutionary success of these molluscan clades, their complex shell morphologies may reveal pressure-tolerant geometries comparable to the ‘ideal’ ones currently used in deep-sea marine robotics: simple spheres and cylinders, which have minimized surface area to volume ratio and easier manufacturability. We modeled and empirically tested 3D-printed bioinspired pressure housings for deep-sea applications using high resolution stereolithography 3D printing. These designs were modeled on the shells of N. pompilius and were compared to conventional 3D-printed spheres with similar wall thicknesses and implodable volumes. Two nautilus-inspired models with internal supports designed after their septal walls (one concave, one convex) had a higher-pressure tolerance compared to hollow models, but none outperformed spherical models with the same outer-wall thickness. Although spheres outperform the nautilus-inspired housings, the methods developed here show that pressure housings with complex geometries can be printed by additive manufacturing and empirically tested. From a biological perspective, this method can be a new tool for empirically testing viable depth tolerances for extinct coiled cephalopod morphologies