Lymphatic vessels collect and transport lymph and pathogens to the draining lymph node (LN) to generate proper immune protection. A layer of macrophages that strategically line the LN subcapsular ...sinus (SCS) is directly exposed to the afferent lymph and are denoted as SCS macrophages. These macrophages are the frontline of immune defense that interact with lymph-borne antigens. The importance of these macrophages in limiting the spread of pathogens has been demonstrated in both viral and bacterial infection. In anti-microbial responses, these macrophages can directly or indirectly activate other LN innate immune cells to fight against pathogens, as well as activate T cells or B cells for adaptive immunity. As the first layer of immune cells embracing the tumor-derived antigens, SCS macrophages also actively participate in cancer immune regulation. Recent studies have shown that the LNs' SCS macrophage layer is interrupted in disease models. Despite their importance in fighting the spread of pathogens and in activating anti-tumor immunity, the mechanism and the immunological functional consequences for their disruption are not well-understood. Understanding the mechanism of these macrophages will enhance their capability for therapeutic targeting.
Understanding the atmospheric moisture budget of Greenland is critical for predicting future Greenland climate. However, past attempts to quantify the provenance of Greenland precipitation have been ...limited to certain seasons. Here we present an analysis of Greenland moisture sources using water tracers in the Goddard Institute for Space Studies climate model, which can provide source estimates for all time periods. The North Atlantic is found to be the dominant moisture source, except during summer when continental sources increase substantially. The variability is also found to be partially correlated with the Greenland Blocking Index. The key finding, however, is a long‐term trend in the moisture source location for Northwest Greenland, with an increase in more locally sourced moisture over time during nonsummer months. This is at least partially related to sea ice loss in the Baffin Bay region, along with a larger increase in sea surface temperatures for the region relative to other locales.
Plain Language Summary
It is still not fully clear where the precipitation that falls over Greenland actually evaporates from, and how these evaporation locations change with the climate, with previous studies being limited in terms of season or transport time. Here we use a climate model that can trace water through the atmosphere from evaporation to rainout to determine the sources of moisture for Greenland precipitation. It is found that the North Atlantic is the largest source for every season except summer, when land‐based moisture sources become larger. These sources vary over time, particularly in response to the Greenland Blocking climate index. Finally, a long‐term change in the moisture source for Northwest Greenland was found, with more water evaporating from locations closer to Greenland itself. This change is found to be at least partially related to the loss of sea ice and a warming in sea surface temperatures in the oceans and seas closest to Greenland, resulting in more evaporation and thus an increase in local moisture sources.
Key Points
Precipitation moisture source varies substantially with season and location in Greenland
Large interannual variability exists for moisture source, which is partially explained by indices like the GBI
A significant long‐term trend toward more local moisture sources exists for Northwest Greenland
In this article we document Canada’s trade policy response to late nineteenth and early twentieth century globalization by linking newly digitized annual productspecific data on the value of Canadian ...imports and duties paid from 1870–1913, to establishment-specific production and location information drawn from the manuscripts of the 1871 industrial census. We find evidence of a highly selective move towards protectionism following the adoption of the National Policy in 1879. Changes in the Canadian tariff schedule narrowly targeted manufactured import products that had close substitutes produced by relatively large, urban, politically influential domestic manufacturers.
While disordered to ordered rearrangements are relatively common, the ability of proteins to switch from one ordered fold to a completely different fold is generally regarded as rare, and few fold ...switches have been characterized. Here, in a designed system, we examine the mutational requirements for transitioning between folds and functions. We show that switching between monomeric 3α and 4β+α folds can occur in multiple ways with successive single amino acid changes at diverse residue positions, raising the likelihood that such transitions occur in the evolution of new folds. Even mutations on the periphery of the core can tip the balance between alternatively folded states. Ligand-binding studies illustrate that a new immunoglobulin G-binding function can be gained well before the relevant 4β+α fold is appreciably populated in the unbound protein. The results provide new insights into the evolution of fold and function.
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► Switching between 3α and 4β+α folds can occur in multiple ways ► Single-residue mutations at diverse positions can induce fold switching ► Mutations lead to a near-complete shift in equilibrium between the two folds ► New function can be gained before the relevant fold is significantly populated
Quantifying the distribution and abundance of ice algae is fundamental for understanding the evolving processes of algal blooms in supraglacial environments, particularly over the Greenland ice ...sheet, given the role of algal impurities in modulating surface albedo and meltwater production. Field observations of ice algae in Greenland are very limited over space and time. Here we show for the first time the regional variability in algal abundance across the dark zone in southwest Greenland, derived from Sentinel‐3 images acquired during the summertime in 2016 and 2017. We demonstrate the capacity of Sentinel‐3 imagery to characterize the spatial pattern of algal abundance using the reflectance ratios between 709‐ and 673‐nm bands, highly consistent with field measurements. The estimated algal abundance reveals a significant linear growth pattern of algal population with time after the peak of dark ice presence, shown to be tightly linked to surface runoff and meltwater production.
Plain Language Summary
Ice algae bloom plays an important role in enhancing the surface melting of the Greenland ice sheet. It has been challenging to monitor the development of ice algae at a regional scale with temporally frequent observations. In this study, we map the time series of algal abundance over southwest Greenland from space for the first time, by utilizing the advanced capability of Sentinel‐3 satellites in detecting chlorophyll‐a, a typical pigment generated by algae. The spatial pattern of algal abundance characterized by Sentinel‐3 imagery is highly consistent with field measurements. Our analysis reveals the widespread proliferation of algae on bare ice from late July to mid‐August, with increasing algal population over time after the peak of surface runoff and meltwater production. Incorporating the algal distribution derived from satellite data into regional climate models is expected to improve the projection of future mass balance over the Greenland ice sheet.
Key Points
The Sentinel‐3 Ocean and Land Colour Instrument (OLCI) can capture the spectral signals of chlorophyll‐a pigment generated by ice algae
The spatial pattern of algal abundance characterized by the reflectance ratio R709nm/R673nm is highly consistent with field measurements
The dark ice presence and ice algal abundance in southwest Greenland are closely linked to meltwater production and surface runoff
The Wedding Present—‘Dare’ Alexander, Patrick
Suomen antropologi : Suomen Antropologisen Seuran julkaisu = Antropologi i Finland : Antropologiska sällskapet i Finland,
02/2019, Volume:
43, Issue:
2
Journal Article
Peer reviewed
Open access
When the indie band The Wedding Present decided to reprise their 1992 album Seamonsters for a 20thanniversary tour, they were lacking a guitarist. By a series of fortunate events I found myself in ...that role as I boarded a flight to Los Angeles to kick off a round-the-world-trip, playing these songs to thousands of fans. As an ethnographer, from the outset I wanted to document the process of taking on this role in order to better understand what it means to learn to be in a band of untrained but highly-skilled musicians. I also wanted to understand what it means to be in a tight-knit community of fans who create meaning and belonging together. The fieldwork was deeply participatory and opportunistic in this sense: this was not a project that I could have planned for. My role as an active member in the group provided rich insights into the span of everyday life in a rock band – from the momentary, miraculous subtleties of performing together live, to the banal politics of sharing hotel rooms, loading the van, days spent driving, and time spent not doing much in particular. The song ‘Dare’ captures for me much of the magic of this strange, exhilarating fieldwork experience.
We present here a structural and mechanistic description of how a protein changes its fold and function, mutation by mutation. Our approach was to create 2 proteins that (i) are stably folded into 2 ...different folds, (ii) have 2 different functions, and (iii) are very similar in sequence. In this simplified sequence space we explore the mutational path from one fold to another. We show that an IgG-binding, 4β+α fold can be transformed into an albumin-binding, 3-α fold via a mutational pathway in which neither function nor native structure is completely lost. The stabilities of all mutants along the pathway are evaluated, key high-resolution structures are determined by NMR, and an explanation of the switching mechanism is provided. We show that the conformational switch from 4β+α to 3-α structure can occur via a single amino acid substitution. On one side of the switch point, the 4β+α fold is >90% populated (pH 7.2, 20 °C). A single mutation switches the conformation to the 3-α fold, which is >90% populated (pH 7.2, 20 °C). We further show that a bifunctional protein exists at the switch point with affinity for both IgG and albumin.
Purpose
The past two decades have seen growing pressure on vehicle manufacturers to reduce the environmental impact of their vehicles. One effective way to improve fuel efficiency and lower tailpipe ...emissions is to use advanced high-strength steels (AHSS) that offer equal strength and crash resistance at lower mass. The present study assesses the life cycle environmental impacts of two steel grades considered for the B-pillar in the Ford Fusion: A press-hardened boron steel design as used in the previous model of the vehicle and a hydroformed component made from a mix of the molybdenum-bearing dual phase steels DP800 and DP1000.
Methods
Information related to the component masses and grades was provided by Ford. Process models for the steelmaking process, finishing, forming, vehicle use and end of life were created in the GaBi LCA software tool. Sensitivity analyses were conducted on the impact of the hydroforming process for the new component, for which only proxy data were available and on the mix of DP800 and DP1000 in the B-pillar. Results have been presented for the environmental impact categories deemed most relevant to vehicle use.
Results and discussion
The life cycle assessment showed that the new DP800/DP1000 B-pillar design has a lower impact for the environmental impact categories assessed. Overall, the global warming potential (GWP) of the new DP800/DP1000 design was 29 % lower than the boron steel design over the full life cycle of the vehicle. The use phase was found to be the major source of environmental impacts, accounting for 93 % of the life cycle GWP impact. The 4 kg weight saving accounts for the majority of the difference in impacts between the two B-pillar designs. Impacts from manufacturing were also lower for the new design for all of the impact categories assessed despite the higher alloy content of the steel. A sensitivity analysis of the hydroforming process showed that even if impacts from forming were 100 % greater than for press hardening, the GWP from production of the new B-pillar design would still be lower than the boron steel version.
Conclusions and recommendations
The molybdenum-bearing DP1000/DP800 B-pillar was found to have lower life cycle and production impacts than the previous boron steel design. The assessment indicates that significant improvements in the environmental impacts associated with the body structure of vehicles could be made through the increased use of AHSS in vehicles without compromising crash performance.
Harvard's open access (OA) policy, which has become a template for many institutional OA policies, intrinsically undermines the rights of scholars, researchers, authors and university staff, and it ...adulterates a principal tenet of open access, namely, that authors should control the intellectual property rights to their material. Assessing the implications of Harvard's open access policy in the light of Peter Suber's landmark book, Open Access, as well as resources from the Scholarly Publishing and Academic Resources Coalition (SPARC) and Title 17 of the United States Code (USC), this article uncovers an intellectual 'landgrab' by universities that may at times not work in the interest of the author or creator of research and weakens the appeal of open access.
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