Resonant Interactions Between Protons and Oblique Alfv\'en/Ion-Cyclotron Waves

Resonant interactions between ions and Alfv\'en/ion-cyclotron (A/IC) waves may play an important role in the heating and acceleration of the fast solar wind. Although such interactions have been studied extensively for "parallel" waves, whose wave vectors ${\bf k}$ are aligned with the background magnetic field ${\bf B}_0$, much less is known about interactions between ions and oblique A/IC waves, for which the angle $\theta$ between ${\bf k}$ and ${\bf B}_0$ is nonzero. In this paper, we present new numerical results on resonant cyclotron interactions between protons and oblique A/IC waves in collisionless low-beta plasmas such as the solar corona. We find that if some mechanism generates oblique high-frequency A/IC waves, then these waves initially modify the proton distribution function in such a way that it becomes unstable to parallel waves. Parallel waves are then amplified to the point that they dominate the wave energy at the large parallel wave numbers at which the waves resonate with the particles. Pitch-angle scattering by these waves then causes the plasma to evolve towards a state in which the proton distribution is constant along a particular set of nested "scattering surfaces" in velocity space, whose shapes have been calculated previously. As the distribution function approaches this state, the imaginary part of the frequency of parallel A/IC waves drops continuously towards zero, but oblique waves continue to undergo cyclotron damping while simultaneously causing protons to diffuse across these kinetic shells to higher energies. We conclude that oblique A/IC waves can be more effective at heating protons than parallel A/IC waves, because for oblique waves the plasma does not relax towards a state in which proton damping of oblique A/IC waves ceases

We should see certain things yet, let us hope and believe : Technology, Sex, and Politics in Mark Twain\u27s \u3cem\u3eConnecticut Yankee\u3c/em\u3e

Through his modern Yankee, Mark Twain reveals to his readers the underlying desire to overcome the very material world he seems to want to instantiate. Although the Yankee seems a modern man who simply wants to create the conditions in Arthurian England by which his body will be most comfortable, both his zeal for this project and the trajectory of his soul\u27s course during the book betray an underlying hope to overcome his mortal coil through first technological and then political projects. In charting the impetus and evolution of the Yankee\u27s psychology for us, Twain teaches us much about the nature of the modern project --its underlying hopes and its potential for dangerous, even totalitarian, excesses. As appealing as the starkly contrasting Arthurians might be, given this insight, Twain does not ultimately endorse this position but shows that its explicit claim does not ultimately satisfy our desire for noninstrumental goods

The PHASES Differential Astrometry Data Archive. I. Measurements and Description

The Palomar High-precision Astrometric Search for Exoplanet Systems (PHASES) monitored 51 sub-arcsecond binary systems to determine precision binary orbits, study the geometries of triple and quadruple star systems, and discover previously unknown faint astrometric companions as small as giant planets. PHASES measurements made with the Palomar Testbed Interferometer (PTI) from 2002 until PTI ceased normal operations in late 2008 are presented. Infrared differential photometry of several PHASES targets were measured with Keck Adaptive Optics and are presented.Comment: 33 pages emulateapj, Accepted to A

Masses, luminosities, and orbital coplanarities of the µ Orionis quadruple-star system from phases differential astrometry

μ Orionis was identified by spectroscopic studies as a quadruple-star system. Seventeen high-precision differential astrometry measurements of μ Ori have been collected by the Palomar High-precision Astrometric Search for Exoplanet Systems (PHASES). These show both the motion of the long-period binary orbit and short-period perturbations superimposed on that caused by each of the components in the long-period system being themselves binaries. The new measurements enable the orientations of the long-period binary and short-period subsystems to be determined. Recent theoretical work predicts the distribution of relative inclinations between inner and outer orbits of hierarchical systems to peak near 40 and 140 degrees. The degree of coplanarity of this complex system is determined, and the angle between the planes of the A–B and Aa–Ab orbits is found to be 136.7 ± 8.3 degrees, near the predicted distribution peak at 140 degrees; this result is discussed in the context of the handful of systems with established mutual inclinations. The system distance and masses for each component are obtained from a combined fit of the PHASES astrometry and archival radial velocity observations. The component masses have relative precisions of 5% (component Aa), 15% (Ab), and 1.4% (each of Ba and Bb). The median size of the minor axes of the uncertainty ellipses for the new measurements is 20 micro-arcseconds (μas). Updated orbits for δ Equulei, κ Pegasi, and V819 Herculis are also presented

Toll-like receptor 3 activation is required for normal skin barrier repair following UV damage.

UV damage to the skin leads to the release of noncoding RNA (ncRNA) from necrotic keratinocytes that activates Toll-like receptor 3 (TLR3). This release of ncRNA triggers inflammation in the skin following UV damage. Recently, TLR3 activation was also shown to aid wound repair and increase the expression of genes associated with permeability barrier repair. Here, we sought to test whether skin barrier repair after UVB damage is dependent on the activation of TLR3. We observed that multiple ncRNAs induced expression of skin barrier repair genes, that the TLR3 ligand Poly (I:C) also induced expression and function of tight junctions, and that the ncRNA U1 acts in a TLR3-dependent manner to induce expression of skin barrier repair genes. These observations were shown to have functional relevance as Tlr3-/- mice displayed a delay in skin barrier repair following UVB damage. Combined, these data further validate the conclusion that recognition of endogenous RNA by TLR3 is an important step in the program of skin barrier repair

Abundances of Planetary Nebula M1-42

The spectra of the planetary nebula M1-42 is reanalysed using spectral measurements made in the mid-infrared with the Spitzer Space Telescope. The aim is to determine the chemical composition of this object. We also make use of ISO, IUE and ground based spectra. Abundances determined from the mid- and far-infrared lines, which are insensitive to electron temperature, are used as the basis for the determination of the composition, which are found to substantially differ from earlier results. High values of neon, argon and sulfur are found. They are higher than in other PN, with the exception of NGC6153, a nebula of very similar abundances. The high values of helium and nitrogen found indicate that the second dredge-up and hot bottom burning has occurred in the course of evolution and that the central star was originally more massive than 4Msun. The present temperature and luminosity of the central star is determined and at first sight may be inconsistent with such a high mass.Comment: 9 pages, 8 tables, 1 figure. Accepted for publication in A&

The Relationship between M and M-L: A Review and Application to Induced Seismicity in the Groningen Gas Field, The Netherlands

In response to induced earthquakes associated with conventional gas production in the Groningen gas field in the Netherlands, several networks of seismic monitoring instruments have been installed in the region (Dost et al., 2017). The recordings recovered from these networks have been of fundamental importance to the development of ground-motion prediction models that underpin hazard and risk modeling to inform decision making regarding mitigation measures (van Elk et al., 2019). In late 2018, it was discovered that the surface accelerographs of the G-network had been installed with a calibration error such that the majority of the instruments were recording half of the correct ground-motion amplitudes. The error was swiftly corrected via the website of Royal Netherlands Meteorological Institute (KNMI), which operates the networks. The calibration error explains, for example, the relatively low amplitudes observed in some of the KNMI network recordings in figure 3 of Bommer, Dost, et al. (2017). After discovery of the calibration error, work immediately began to assess the impact on the ground-motion models that have been developed as part of the induced seismic hazard and risk modeling effort in Groningen. The early ground-motion model of Bommer et al. (2016) was not affected because it was developed using only recordings from the KNMI B-network. The subsequent ground-motion models for the prediction of peak ground acceleration (PGA), peak ground velocity (PGV), and acceleration response spectra combined recordings from the B- and G-networks but fortuitously did not use the surface accelerographs of the G-network. Rather, from these stations, recordings from the 200 m geophones were used instead, a decision partly motivated by the improved signal-to-noise ratios of the deeper recordings. Another key consideration was the desire to bypass uncertainty in the amplification factors relative to the buried reference rock horizon at ∼800 m depth because the G-network stations had not benefited from the same in situ near-surface shear-wave velocity measurements as were conducted for the B-network accelerographs (Noorlandt et al., 2018). Two elements of the more recent ground-motion models did make use of the surface accelerograph recordings from both the B- and G-networks, but in neither case did the calibration error have any impact at all. The model for predicting ground-motion durations (Bommer, Stafford, et al., 2017) uses the significant duration definition, which is determined as the interval between accumulation of 5% and 75% of the total Arias intensity, a metric that is entirely insensitive to amplitude scaling of the record. The component-to-component variability model (Stafford et al., 2019)—used to transform the geometric mean amplitudes predicted for the hazard into the arbitrary horizontal component used in the risk calculations—was derived from ratios of the two horizontal components of each accelerogram, which are also completely independent of amplitude scaling. The study by Stafford et al. (2019) additionally proposed a model for spatial correlations among response spectral ordinates in the Groningen field that made use of recordings from the G-network. The inclusion of these records will have influenced the results of that study but most likely only by a small amount given that the results were obtained by averaging over multiple datasets and modeling approaches and that some of these analyses were entirely independent of the G-network. The seismic risk calculations for the Groningen field (van Elk et al., 2019) currently approximate spatial correlation through rules for sampling variability within and between site-response zones (Rodriguez-Marek et al., 2017) rather than directly implementing the model of Stafford et al. (2019). Another element of the ground-motion modeling that made use of the surface accelerograph recordings is the relationship between local and moment magnitudes in Groningen, as presented by Dost et al. (2018). This relationship—which in the magnitude range of relevance (ML ≥ 2:5) is one of equivalence between the two scales—is invoked for assigning seismic moments to events as part of the inversions of Fourier amplitude spectra for source, path, and site parameters, as well as in calibrating the upper branches of the ground-motion logic tree to match predictions from ground-motion prediction equations derived for tectonic earthquakes. Because recordings from surface accelerographs of the G-network were included in the calculation of seismic moments, many of the moment magnitude values required correction: the changes in values are illustrated in Figure 1, and a corrected version of the electronic supplement is now presented as E Table S1 (available in the supplemental content to this erratum). As can be appreciated in Figure 1, the impact has mainly affected smaller magnitudes because the larger earthquakes in the database were predominantly recorded by the accelerographs of the B-network. The correction of the data resulted in a small change to the quadratic relationship between the two magnitude scales, as illustrated in Figure 2. The corrected equation is M = 0:0469M2L + 0:6387ML + 0:6375: (1) As would be expected, the corrected relationship predicts slightly larger moment magnitudes for local magnitudes smaller than ML 2.5, but the conclusion of equivalence, on average, at higher magnitudes is unchanged. The quadratic form of equation (1) is only a convenient way to express the relationship in a single formula, and in practice, it is probably appropriate to assume a linear relationship (Mw = ML) for larger magnitudes; consequently, the apparent divergence from this model that would be implied by extrapolation of the cyan curve in Figure 2 to larger magnitudes can be safely ignored. In light of this finding, it may be concluded that the Groningen ground-motion models have been entirely unaffected by the unfortunate calibration error. However, for any application involving smaller-magnitude induced earthquakes in the Groningen field, the updated model presented herein should now be used

Assessing the presence of Wuchereria bancrofti in vector and human populations from urban communities in Conakry, Guinea

The Global Programme to Eliminate Lymphatic Filariasis was launched in 2000 with the goal of interrupting transmission of lymphatic filariasis (LF) through multiple rounds of mass drug administration (MDA). In Guinea, there is evidence of ongoing LF transmission, but little is known about the most densely populated parts of the country, including the capital Conakry. In order to guide the LF control and elimination efforts, serological and entomological surveys were carried out to determine whether or not LF transmission occurs in Conakry.; The prevalence of circulating filarial antigen (CFA) of Wuchereria bancrofti was assessed by an immuno-chromatography test (ICT) in people recruited from all five districts of Conakry. Mosquitoes were collected over a 1-year period, in 195 households in 15 communities. A proportion of mosquitoes were analysed for W. bancrofti, using dissection, loop-mediated isothermal amplification (LAMP) assay and conventional polymerase chain reaction (PCR).; CFA test revealed no infection in the 611 individuals examined. A total of 14,334 mosquitoes were collected; 14,135 Culex (98.6 %), 161 Anopheles (1.1 %) and a few other species. Out of 1,312 Culex spp. (9.3 %) and 51 An. gambiae (31.7 %) dissected, none was infected with any stage of the W. bancrofti parasite. However, the LAMP assay revealed that 1.8 % of An. gambiae and 0.31 % of Culex spp. were positive, while PCR determined respective prevalences of 0 % and 0.19 %.; This study revealed the presence of W. bancrofti DNA in mosquitoes, despite the apparent absence of infection in the human population. Although MDA interventions are not recommended where the prevalence of ICT is below 1 %, the entomological results are suggestive of the circulation of the parasite in the population of Conakry. Therefore, rigorous surveillance is still warranted so that LF transmission in Conakry would be identified rapidly and adequate responses being implemented

Proteomic analysis of the organic matrix of the abalone Haliotis asinina calcified shell

Background: The formation of the molluscan shell is regulated to a large extent by a matrix of extracellular macromolecules that are secreted by the shell forming tissue, the mantle. This so called "calcifying matrix" is a complex mixture of proteins and glycoproteins that is assembled and occluded within the mineral phase during the calcification process. While the importance of the calcifying matrix to shell formation has long been appreciated, most of its protein components remain uncharacterised.Results: Recent expressed sequence tag (EST) investigations of the mantle tissue from the tropical abalone (Haliotis asinina) provide an opportunity to further characterise the proteins in the shell by a proteomic approach. In this study, we have identified a total of 14 proteins from distinct calcified layers of the shell. Only two of these proteins have been previously characterised from abalone shells. Among the novel proteins are several glutamine- and methionine-rich motifs and hydrophobic glycine-, alanine- and acidic aspartate-rich domains. In addition, two of the new proteins contained Kunitz-like and WAP (whey acidic protein) protease inhibitor domains.Conclusion: This is one of the first comprehensive proteomic study of a molluscan shell, and should provide a platform for further characterization of matrix protein functions and interactions