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"Hall, R"
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Sources of and processes controlling CO2 emissions change with the size of streams and rivers
Rivers and streams are key sources of CO
2
. Estimated emissions and aquatic productivity from across the US show that small streams predominantly emit CO
2
produced in soils, but the contribution from aquatic metabolism increases with river size.
Carbon dioxide (CO
2
) evasion from streams and rivers to the atmosphere represents a substantial flux in the global carbon cycle
1
,
2
,
3
. The proportions of CO
2
emitted from streams and rivers that come from terrestrially derived CO
2
or from CO
2
produced within freshwater ecosystems through aquatic metabolism are not well quantified. Here we estimated CO
2
emissions from running waters in the contiguous United States, based on freshwater chemical and physical characteristics and modelled gas transfer velocities at 1463 United States Geological Survey monitoring sites. We then assessed CO
2
production from aquatic metabolism, compiled from previously published measurements of net ecosystem production from 187 streams and rivers across the contiguous United States. We find that CO
2
produced by aquatic metabolism contributes about 28% of CO
2
evasion from streams and rivers with flows between 0.0001 and 19,000 m
3
s
−1
. We mathematically modelled CO
2
flux from groundwater into running waters along a stream–river continuum to evaluate the relationship between stream size and CO
2
source. Terrestrially derived CO
2
dominates emissions from small streams, and the percentage of CO
2
emissions from aquatic metabolism increases with stream size. We suggest that the relative role of rivers as conduits for terrestrial CO
2
efflux and as reactors mineralizing terrestrial organic carbon is a function of their size and connectivity with landscapes.
Journal Article
A Triple Co-Culture Model of the Human Respiratory Tract to Study Immune-Modulatory Effects of Liposomes and Virosomes
The respiratory tract with its ease of access, vast surface area and dense network of antigen-presenting cells (APCs) represents an ideal target for immune-modulation. Bio-mimetic nanocarriers such as virosomes may provide immunomodulatory properties to treat diseases such as allergic asthma. In our study we employed a triple co-culture model of epithelial cells, macrophages and dendritic cells to simulate the human airway barrier. The epithelial cell line 16HBE was grown on inserts and supplemented with human blood monocyte-derived macrophages (MDMs) and dendritic cells (MDDCs) for exposure to influenza virosomes and liposomes. Additionally, primary human nasal epithelial cells (PHNEC) and EpCAM+ epithelial progenitor cell mono-cultures were utilized to simulate epithelium from large and smaller airways, respectively. To assess particle uptake and phenotype change, cell cultures were analyzed by flow cytometry and pro-inflammatory cytokine concentrations were measured by ELISA. All cell types internalized virosomes more efficiently than liposomes in both mono- and co-cultures. APCs like MDMs and MDDCs showed the highest uptake capacity. Virosome and liposome treatment caused a moderate degree of activation in MDDCs from mono-cultures and induced an increased cytokine production in co-cultures. In epithelial cells, virosome uptake was increased compared to liposomes in both mono- and co-cultures with EpCAM+ epithelial progenitor cells showing highest uptake capacity. In conclusion, all cell types successfully internalized both nanocarriers with virosomes being taken up by a higher proportion of cells and at a higher rate inducing limited activation of MDDCs. Thus virosomes may represent ideal carrier antigen systems to modulate mucosal immune responses in the respiratory tract without causing excessive inflammatory changes.
Journal Article
Brexit and tourism : process, impacts and non-policy
\"This book offers a multidisciplinary, holistic appraisal of the implications of the UK's withdrawal from the European Union (EU) for tourism and related mobilities. It attempts to look beyond the short- to medium-term consequences of these processes for both the UK and the EU\"-- Provided by publisher.
Book
The ClusPro web server for protein–protein docking
ClusPro is a web server that performs rigid-body docking of two proteins by sampling billions of conformations. Low-energy docked structures are clustered, and centers of the largest clusters are used as likely models of the complex.
The ClusPro server (
https://cluspro.org
) is a widely used tool for protein–protein docking. The server provides a simple home page for basic use, requiring only two files in Protein Data Bank (PDB) format. However, ClusPro also offers a number of advanced options to modify the search; these include the removal of unstructured protein regions, application of attraction or repulsion, accounting for pairwise distance restraints, construction of homo-multimers, consideration of small-angle X-ray scattering (SAXS) data, and location of heparin-binding sites. Six different energy functions can be used, depending on the type of protein. Docking with each energy parameter set results in ten models defined by centers of highly populated clusters of low-energy docked structures. This protocol describes the use of the various options, the construction of auxiliary restraints files, the selection of the energy parameters, and the analysis of the results. Although the server is heavily used, runs are generally completed in <4 h.
Journal Article
Cicero's use of judicial theater
\" In Cicero's Use of Judicial Theater, Jon Hall examines Cicero's use of showmanship in the Roman law-courts, looking in particular at the nonverbal devices that he employs during his speeches as he attempts to manipulate opinion. Cicero's speeches in the law-courts often incorporate theatrical devices including the use of family relatives as props during emotional appeals, exploitation of tears and supplication, and the wearing of specially dirtied attire by defendants during a trial, all of which contrast strikingly with the practices of the modem advocate. Hall investigates how Cicero successfully deployed these techniques and why they played such a prominent part in the Roman courts. These \"judicial theatrics\" are rarely discussed by the ancient rhetorical handbooks, and Cicero's Judicial Theater argues that their successful use by Roman orators derives largely from the inherent theatricality of aristocratic life in ancient Rome--most of the devices deployed in the courts appear elsewhere in the social and political activities of the elite. While Cicero's Judicial Theater will be of interest primarily to professional scholars and students studying the speeches of Cicero, its wider analyses, both of Roman cultural customs and the idiosyncratic practices of the law-courts, will prove relevant also to social historians, as well as historians of legal procedure\"-- Provided by publisher.
Book
Near-Sun observations of an F-corona decrease and K-corona fine structure
Remote observations of the solar photospheric light scattered by electrons (the K-corona) and dust (the F-corona or zodiacal light) have been made from the ground during eclipses
1
and from space at distances as small as 0.3 astronomical units
2
–
5
to the Sun. Previous observations
6
–
8
of dust scattering have not confirmed the existence of the theoretically predicted dust-free zone near the Sun
9
–
11
. The transient nature of the corona has been well characterized for large events, but questions still remain (for example, about the initiation of the corona
12
and the production of solar energetic particles
13
) and for small events even its structure is uncertain
14
. Here we report imaging of the solar corona
15
during the first two perihelion passes (0.16–0.25 astronomical units) of the Parker Solar Probe spacecraft
13
, each lasting ten days. The view from these distances is qualitatively similar to the historical views from ground and space, but there are some notable differences. At short elongations, we observe a decrease in the intensity of the F-coronal intensity, which is suggestive of the long-sought dust free zone
9
–
11
. We also resolve the fine-scale plasma structure of very small eruptions, which are frequently ejected from the Sun. These take two forms: the frequently observed magnetic flux ropes
12
,
16
and the predicted, but not yet observed, magnetic islands
17
,
18
arising from the tearing-mode instability in the current sheet. Our observations of the coronal streamer evolution confirm the large-scale topology of the solar corona, but also reveal that, as recently predicted
19
, streamers are composed of yet smaller substreamers channelling continual density fluctuations at all visible scales.
Observations of the solar corona by the Parker Solar Probe reveal evidence for the predicted dust-free zone and confirm that streamers comprise smaller substreamers that channel continuous multiscale density fluctuations.
Journal Article
Why do models overestimate surface ozone in the Southeast United States?
Ozone pollution in the Southeast US involves complex chemistry driven by emissions of anthropogenic nitrogen oxide radicals (NOx ≡ NO+NO2) and biogenic isoprene. Model estimates of surface ozone concentrations tend to be biased high in the region and this is of concern for designing effective emission control strategies to meet air quality standards. We use detailed chemical observations from the SEAC4RS aircraft campaign in August and September 2013, interpreted with the GEOS-Chem chemical transport model at 0.25° × 0.3125° horizontal resolution, to better understand the factors controlling surface ozone in the Southeast US. We find that the National Emission Inventory (NEI) for NOx from the US Environmental Protection Agency (EPA) is too high. This finding is based on SEAC4RS observations of NOx and its oxidation products, surface network observations of nitrate wet deposition fluxes, and OMI satellite observations of tropospheric NO2 columns. Our results indicate that NEI NOx emissions from mobile and industrial sources must be reduced by 30-60%, dependent on the assumption of the contribution by soil NOx emissions. Upper-tropospheric NO2 from lightning makes a large contribution to satellite observations of tropospheric NO2 that must be accounted for when using these data to estimate surface NOx emissions. We find that only half of isoprene oxidation proceeds by the high-NOx pathway to produce ozone; this fraction is only moderately sensitive to changes in NOx emissions because isoprene and NOx emissions are spatially segregated. GEOS-Chem with reduced NOx emissions provides an unbiased simulation of ozone observations from the aircraft and reproduces the observed ozone production efficiency in the boundary layer as derived from a regression of ozone and NOx oxidation products. However, the model is still biased high by 6±14ppb relative to observed surface ozone in the Southeast US. Ozonesondes launched during midday hours show a 7ppb ozone decrease from 1.5km to the surface that GEOS-Chem does not capture. This bias may reflect a combination of excessive vertical mixing and net ozone production in the model boundary layer.
Journal Article