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This article develops the concept of ‘frontline diplomacy’ – what practitioners referring to work in embassies, consulates, and permanent representation as ‘the field’ –, defined here as all diplomats’ activities taking place away from headquarters. IR scholarship tends to focus on Ministries of Foreign Affairs located in capitals. On the contrary, building on the practice turn in IR, we first show that international politics emerge from frontline practices. Adding to criticism against the practice turn, we then explain that it has missed important transformations occurring in frontline diplomacy because it tends to privilege stability over change. We finally discuss two innovations in frontline practices: the action of Sherpas in G20 summits following the 2008 crisis and the use of Twitter by US Ambassador to Russia Michael McFaul (2012–14). For each we answer three questions: How do these activities transform traditional modes of operation? How are non-state actors involved in them? What do they tell about transformation of global politics? Because diplomatic practices at the frontlines epitomise international politics, these new directions for inquiry contribute substantively to IR scholarship. At the theoretical level, they enrich the continuing encounter between IR and diplomatic studies through practice theory and help to understand change in practice.
J. F. Cooper, NASA Goddard Space Flight Center Greenbelt, Maryland, USA,
R. E. Johnson, University of Virginia Charlottesville, Virginia, USA,
P. Kollmann, Johns Hopkins University Applied Physics Laboratory Laurel, Maryland, USA,
E. Roussos, Max Planck Institute for Solar System Studies Göttingen, GERMANY,
E. C. Sittler, NASA Goddard Space Flight Center Greenbelt, Maryland, USA
Ring systems around magnetized planets are expected to have varied interactions with the magnetic fields, hot plasma, and energetic particles of the associated magnetospheres. In our solar system all the giant planets, Jupiter to Neptune, have magnetospheres with embedded rings. Each ring system and its associated moons have strong interactions with their radiation environments (the most intense of which is at Jupiter). Such interactions both erode diffuse rings (such as the E ring of Saturn) and supply plasma and energetic particles to the magnetosphere and its radiation belts. Compositional and structural measurements of rings are enabled by these interactions, such as the information obtained by detection of the secondary neutron and gamma-ray emissions produced by galactic cosmic ray (GCR) interactions with the rings. It is also notable that Earth has both a magnetosphere with radiation belts, and an artificial ring system of satellites and debris, that continuously interact. Konradi (1988) even projected that the high energy trapped protons of the inner Van Allen Belt should now be experiencing significant depletion by this interaction, and we will later discuss the possible evidence for this. Magnetized exoplanets with rings would have similar interactions.
The ring systems of Jupiter and Saturn have been explored by multiple spacecraft. The Jovian ring environment was first explored in situ in 1974 by Pioneer 11, which subsequently flew under Saturn's main rings in 1979. After passing through the Saturn ring plane near the G ring in 1981, Voyager 2 encountered Uranus in 1986 and then Neptune in 1989, but in neither case were the rings and arcs of these two ice giant planets traversed. The Galileo Probe passed across the Jovian ring in December 1995 en route to the first direct penetration into Jupiter's atmosphere. The Cassini Orbiter crossed over the Saturn A and B rings in mid-2004 (Figure 14.1) as part of the Saturn Orbital Insertion (SOI). Cassini will again traverse the main rings during its Grand Finale orbit phase many times, crossing the ring plane just inwards of the D ring, prior to final atmospheric entry in 2017. With the exception of the Cassini Plasma Spectrometer (CAPS) instrument, turned off in 2012 due to electrical problems, Cassini will continue to operate through the final observations.
To understand increasing rates of hepatitis C virus (HCV) infection in Tennessee, we conducted testing, risk factor analysis and a nested case–control study among persons who use drugs. During June–October 2016, HCV testing with risk factor assessment was conducted in sexually transmitted disease clinics, family planning clinics and an addiction treatment facility in eastern Tennessee; data were analysed by using multivariable logistic regression. A nested case–control study was conducted to assess drug-using risks and behaviours among persons who reported intranasal or injection drug use (IDU). Of 4753 persons tested, 397 (8.4%) were HCV-antibody positive. HCV infection was significantly associated with a history of both intranasal and IDU (adjusted odds ratio (aOR) 35.4, 95% confidence interval (CI) 24.1–51.9), IDU alone (aOR 52.7, CI 25.3–109.9), intranasal drug use alone (aOR 2.6, CI 1.8–3.9) and incarceration (aOR 2.7, CI 2.0–3.8). By 4 October 2016, 574 persons with a reported history of drug use; 63 (11%) were interviewed further. Of 31 persons who used both intranasal and injection drugs, 26 (84%) reported previous intranasal drug use, occurring 1–18 years (median 5.5 years) before their first IDU. Our findings provide evidence that reported IDU, intranasal drug use and incarceration are independent indicators of risk for past or present HCV infection in the study population.
This article examines the prospects for an interamerican “paradigm of democratic solidarity.” Although the region has seen genuine progress in the promotion and defense of democracy, a significant deficit in collective and national leadership hinders the consolidation of hemispheric prodemocracy activism. As illustrated by a number of recent cases, including the controversy over Peru's May 2000 election, these impediments are not only situational but structural. This article concludes with a discussion of ways to move beyond these problems and to buttress the democratic solidarity doctrine.
The Gaia DR1 catalogue stars are taken as reference ones to reduce the Cassini ISS images of Enceladus in 2015, and a total of 494 Cassini-centered astrometric observation are obtained in right ascension(α) and declination (δ) in the international Celestial Reference Frame(ICRF). Compared with JPL ephemerides SAT367, we derive that their mean residuals are a few tens meters in α*cos(δ) and a few kilometers in δ, and their standard deviation is not over 2 kilometers. Compared with the results from UCAC4 catalogue stars, The Gaia DR1 has the equivalent precision of reduction.
Advantages of neutron moisture probes over standard snow sampling tubes include integration of water content over a greater horizontal extent, easier measurement of snow layering, and possible increase in accuracy through elimination of the need to extract a full core. However, the neutron probe is better suited for evaluation of water content changes with time at a fixed location, as in soil moisture studies, than for measurement of the total water content of a variable snow pack. Field tests in the mountains of Idaho, U.S.A., showed statistically significant differences among mean snow densities determined by a neutron probe in closely spaced holes at a single sampling station. Within-station variance was about the same as with a conventional snow tube. There were significant differences in density for a given depth from hole to hole, but statistical interactions make it difficult to interpret these differences. There was a poor correlation between measurements made in the same hole with a neutron probe and with a snow sampling tube.
Radio echo-soundings obtained during joint programmes of the US National Science Foundation (NSF), the Scott Polar Research Institute (SPRI), and the Technical University of Denmark (TUD) have provided sufficient data of good quality to map driving stress over approximately one half of the Antarctic ice sheet. Computerized averaging of data over 1 degree of latitude squares has largely eliminated local effects of longitudinal stress variations on surface slope. Methods of data handling are outlined. Variations in driving stresses between different regions are discussed in relation to the balancing restraining forces. These are primarily related to ice velocity and thickness, bedrock topography, the presence of basal water and possibly to the development of easy-glide fabric in the ice mass, to the temperature of basal ice layers, and to the excess hydrostatic pressure in areas where ice rests on bedrock well below sea-level.
Zebrafish (Danio rerio) provide many advantages as a model organism for studying ocular disease and development, and there is great interest in the ability to non-invasively assess their photoreceptor mosaic. Despite recent applications of scanning light ophthalmoscopy, fundus photography, and gonioscopy to in vivo imaging of the adult zebrafish eye, current techniques either lack accurate scaling information (limiting quantitative analyses) or require euthanizing the fish (precluding longitudinal analyses). Here we describe improved methods for imaging the adult zebrafish retina using spectral domain optical coherence tomography (OCT). Transgenic fli1:eGFP zebrafish were imaged using the Bioptigen Envisu R2200 broadband source OCT with a 12-mm telecentric probe to measure axial length and a mouse retina probe to acquire retinal volume scans subtending 1.2 × 1.2 mm nominally. En face summed volume projections were generated from the volume scans using custom software that allows the user to create contours tailored to specific retinal layer(s) of interest. Following imaging, the eyes were dissected for ex vivo fluorescence microscopy, and measurements of blood vessel branch points were compared to those made from the en face OCT images to determine the OCT lateral scale as a function of axial length. Using this scaling model, we imaged the photoreceptor layer of five wild-type zebrafish and quantified the density and packing geometry of the UV cone submosaic. Our in vivo cone density measurements agreed with measurements from previously published histology values. The method presented here allows accurate, quantitative assessment of cone structure in vivo and will be useful for longitudinal studies of the zebrafish cone mosaics.
The crystal structure of gianellaite, [(NHg2)2](SO4)(H2O)x, cubic, F4̄3m, a = 9.521(6) Å V = 863.1(1.6) Å3, Z = 4, was solved by direct methods and refined to an R1 index of 2.1% based on 167 unique observed reflections collected on a three-circle rotating-anode (MoKα X-radiation) diffractometer equipped with multilayer optics and an APEX-II detector. In the structure of gianellaite, nitrogen-centred (NHg4)5+ tetrahedra share all corners to form a framework of tetrahedra with an ordered arrangement of interstitial (SO4)2– tetrahedra that show strong orientational disorder. Infrared spectroscopy in the principal O–H stretching region shows peaks at ∼3300 and 1600 cm–1, indicating the presence of (H2O), the position(s) of which could not be discerned in difference-Fourier maps.
The ability to noninvasively image the cone photoreceptor mosaic holds significant potential as a diagnostic for retinal disease. Central to the realization of this potential is the development of sensitive metrics for characterizing the organization of the mosaic. Here we evaluated previously-described and newly-developed (Fourier- and Radon-based) methods of measuring cone orientation in simulated and real images of the parafoveal cone mosaic. The proposed algorithms correlated well across both simulated and real mosaics, suggesting that each algorithm provides an accurate description of photoreceptor orientation. Despite high agreement between algorithms, each performed differently in response to image intensity variation and cone coordinate jitter. The integration property of the Fourier transform allowed the Fourier-based method to be resistant to cone coordinate jitter and perform the most robustly of all three algorithms. Conversely, when there is good image quality but unreliable cone identification, the Radon algorithm performed best. Finally, in cases where the cone coordinate reliability was excellent, the method previously described by Pum and colleagues performed best. These descriptors are complementary to conventional descriptive metrics of the cone mosaic, such as cell density and spacing, and have the potential to aid in the detection of photoreceptor pathology.
The region surrounding the galactic centre has been surveyed with the 210-foot telescope of the Australian National Radio Astronomy Observatory at a wavelength of 10·0 cm. At this wavelength the telescope beamwidth is 6.7 between half-intensity points.
The Wisconsin Plasma Astrophysics Laboratory (WiPAL) is a flexible user facility designed to study a range of astrophysically relevant plasma processes as well as novel geometries that mimic astrophysical systems. A multi-cusp magnetic bucket constructed from strong samarium cobalt permanent magnets now confines a
, fully ionized, magnetic-field-free plasma in a spherical geometry. Plasma parameters of
provide an ideal testbed for a range of astrophysical experiments, including self-exciting dynamos, collisionless magnetic reconnection, jet stability, stellar winds and more. This article describes the capabilities of WiPAL, along with several experiments, in both operating and planning stages, that illustrate the range of possibilities for future users.
Observed massive galaxies in the distant Universe form stars at much higher rates than today. High levels of star formation are sustained by a continuous supply of fresh gas and high molecular gas fractions. But after a peak around redshift z=2-3, the star formation rate decreases by an order of magnitude. Is this evolution mostly driven by the available cold gas reservoir, or are the star formation processes qualitatively different near the star formation peak? The Kennicutt-Schmidt relation enables to characterize the star formation efficiency at low and high redshift, but resolved measurements at the scale of the star-forming regions themselves are still challenging at high redshift. Molecular gas observations carried out at the IRAM Plateau de Bure interferometer within the PHIBSS program (Tacconi, Combes et al.) permit us to study the star formation efficiency at sub-galactic scales around z=1.2 and 1.5 for a limited sample of galaxies, and thus help characterize the star formation processes at this epoch. Our results lay in the continuation of the resolved low-redshift measurements, but further studies would be necessary to complement our sample and validate our conclusions.
Various environmental factors have been associated with the timing of eruption of primary dentition, but the evidence to date comes from small studies with limited information on potential risk factors. We aimed to investigate associations between tooth emergence patterns and pre-conception, pregnancy and postnatal influences. Dentition patterns were recorded at ages 1 and 2 years in 2915 children born to women in the Southampton Women’s Survey from whom information had been collected on maternal factors before conception and during pregnancy. In mutually adjusted regression models we found that: children were more dentally advanced at ages 1 and 2 years if their mothers had smoked during pregnancy or they were longer at birth; mothers of children whose dental development was advanced at age 2 years tended to have poorer socioeconomic circumstances, and to have reported a slower walking speed pre-pregnancy; and children of mothers of Asian ethnicity had later tooth development than those of white mothers. The findings add to the evidence of environmental impacts on the timing of the eruption of primary dentition in indicating that maternal smoking during pregnancy, socio-economic status and physical activity (assessed by reported walking speed) may influence the child’s primary dentition. Early life factors, including size at birth are also associated with dentition patterns, as is maternal ethnicity.