Plasma Dynamics

Contains research objectives and summary of research on twenty-one projects split into three sections, with four sub-sections in the second section and reports on twelve research projects.National Science Foundation (Grant ENG75-06242)U.S. Energy Research and Development Administration (Contract E(11-1)-2766)U.S. Energy Research and Development Agency (Contract E(11-1)-3070)U.S. Energy Research and Development Administration (Contract E(11-1)-3070)Research Laboratory of Electronics, M.I.T. Industrial Fellowshi

Minimal information for studies of extracellular vesicles (MISEV2023): From basic to advanced approaches

Extracellular vesicles (EVs), through their complex cargo, can reflect the state of their cell of origin and change the functions and phenotypes of other cells. These features indicate strong biomarker and therapeutic potential and have generated broad interest, as evidenced by the steady year-on-year increase in the numbers of scientific publications about EVs. Important advances have been made in EV metrology and in understanding and applying EV biology. However, hurdles remain to realising the potential of EVs in domains ranging from basic biology to clinical applications due to challenges in EV nomenclature, separation from non-vesicular extracellular particles, characterisation and functional studies. To address the challenges and opportunities in this rapidly evolving field, the International Society for Extracellular Vesicles (ISEV) updates its 'Minimal Information for Studies of Extracellular Vesicles', which was first published in 2014 and then in 2018 as MISEV2014 and MISEV2018, respectively. The goal of the current document, MISEV2023, is to provide researchers with an updated snapshot of available approaches and their advantages and limitations for production, separation and characterisation of EVs from multiple sources, including cell culture, body fluids and solid tissues. In addition to presenting the latest state of the art in basic principles of EV research, this document also covers advanced techniques and approaches that are currently expanding the boundaries of the field. MISEV2023 also includes new sections on EV release and uptake and a brief discussion of in vivo approaches to study EVs. Compiling feedback from ISEV expert task forces and more than 1000 researchers, this document conveys the current state of EV research to facilitate robust scientific discoveries and move the field forward even more rapidly

The Arctic

peer reviewe

Babbage River delta and lagoon : hydrology and sedimentology of an Arctic estuarine system

Inputs, transfer processes, and storage characteristics of water and sediment have been investigated in a 40-km² estuarine system on the central Yukon coast. The setting is transgressive, microtidal, and high-latitude (69°N). The Babbage Estuary system can be subdivided into fluvial, tidal-distributary, delta-plain, intertidal, lagoon, marginal-supratidal, and barrier subsystems, each associated with one or more distinctive depositional environments and characteristic lithofacies assemblages. The structure of the system has been examined in terms of links between subsystems and overall system response to input perturbations. Although the propagation of tide and surge within the estuary may be treated as a quasi-linear stochastic process, transfers of fluvial water and sediment through the system are highly non-linear. Furthermore, the parameters of the system change dramatically on an annual cycle. Inputs and associated system responses are dominated in the short run by seasonal- and synoptic-scale variance, the former reflecting major seasonal adjustments in the phase distribution, circulation process, iand input regime of the estuary. The annual salinity cycle, with a range of at least 60 ppt, exhibits a short reaction and long relaxation response to major snowmelt runoff inputs in May or June, when salt water is flushed completely out of the estuary. Wind-generated waves are effectively absent from the system during 8-9 months of the year, but play a major role during the open-water season. Although direct transport of sediment by ice is relatively unimportant, ice effects are pervasive; they include, in addition to restriction of winter runoff and surface wave generation, creation of hypersaline conditions, control of the sedimentologically important flood events on deltaic supratidal flats, enhanced rates of coastal recession due to thermal degradation of ground ice, and production of distinctive thermokarst morphology on supratidal surfaces. Water level, storage volume, salinity, and suspended sediment series during the open-water season in the lagoon are dominated by synoptic-scale wind effects. In the delta, the major synoptic-scale anomalies of sediment concentration are related to storm runoff. Fluvial clastic sediment inputs to the estuary exceed 10⁸ kg A⁻¹ almost an order of magnitude greater than the estimated littoral transport input. More than 97% of the fluvial input may occur in June; of this, approximately half may be exported directly from the system. At long time scales, the estuarine system has been dominated by rising sea level and coastal recession; Holocene climatic fluctuations may also have been important. A transgressive sequence has developed, including various distinctive features, notably the absence or limited development of aeolian, backbarrier-margin, tidal-delta, and intertidal marsh facies, a largely afaunal intertidal component, and deltaic deposits with poorly developed levees and abundant lake basins. The basal fluvial component includes a sinuous gravel channel assemblage of a hitherto poorly documented type. The Babbage Estuary barrier sequence is primarily transgressive, but incorporates localized elements of progradational and inlet-migration models. Examples of major transgressive, progradational, and inlet-fill barrier sequences occur in close proximity on the central Yukon coast.Arts, Faculty ofGeography, Department ofGraduat

The ACD Classification of Arctic Coasts

An important outcome of Arctic Coastal Dynamics I was the segmentation and characterization of the entire circum-Arctic coastline by regional experts which is presented in this dataset. This dataset contains data on coastal morphology, composition, dominant processes, ground ice, and environmental forcing parameters such as wind speed, storm counts, melt season, and wave energy. A listing of the variables included in the coastal classification can be found in Appendix A of the ACD II Science and Implementation Plan (2006). This information is available for over 800 segments, covering the coastline of all eight regional seas of the Arctic Ocean. The length of individual segments is variable (median length is 38 km), and depends on classification parameters and data availability. The segmentation format is scalable, allowing the adoption of future digital coastlines and the integration of additional data at higher spatial resolution. An assessment of the data quality for the more important quantitative variables has just been completed and the data will be publicly released on an internet map server (IMS). The goal of the IMS will be to allow individual users to prepare their own maps displaying the region and variables of interest. The ACD Classification was conceived as a broad enough framework to encompass existing classification schemes while capturing fundamental information for the assessment of climate change impacts and coastal processes. The implementation of the classification was done by so-called "regional experts", who, based on digital and paper products and personal knowledge provided information which was subsequently gathered into a circum-Arctic coastal database. The classification was primarily geomorphological in nature and considered: (1) the shape or form of the subaerial part of the coastal tract, (2) the marine processes acting upon the coast, (3) the shape or the form of the subaqueous part of the coastal tract and (4) the lithofacies of the materials constituting the coastal zone The beta version of the classification is made of 1331 segments each characterized by a series of geomorphological quantitative and qualitative variables. The classification is stored as an ISO 19115-compliant personal geodatabase and is therefore mappable in off-the-shelf Geographical Information Systems (GIS