Near and mid-IR sub-arcsecond structure of the dusty symbiotic star R Aqr

The results of a high-resolution interferometric campaign targeting the symbiotic long-period variable (LPV) R~Aqr are reported. With both near-infrared measurements on baselines out to 10m and mid-infrared data extending to 32m, we have been able to measure the characteristic sizes of regions from the photosphere of the LPV and its extended molecular atmosphere, out to the cooler circumstellar dust shell. The near-infrared data were taken using aperture masking interferometry on the Keck-I telescope and show R~Aqr to be partially resolved for wavelengths out to 2.2 microns but with a marked enlargement, possibly due to molecular opacity, at 3.1 microns. Mid-infrared interferometric measurements were obtained with the U.C. Berkeley Infrared Spatial Interferometer (ISI) operating at 11.15 microns from 1992 to 1999. Although this dataset is somewhat heterogeneous with incomplete coverage of the Fourier plane and sampling of the pulsation cycle, clear changes in the mid-infrared brightness distribution were observed, both as a function of position angle on the sky and as a function of pulsation phase. Spherically symmetric radiative transfer calculations of uniform-outflow dust shell models produce brightness distributions and spectra which partially explain the data, however limitations to this approximation are noted. Evidence for significant deviation from circular symmetry was found in the mid-infrared and more tentatively at 3.08 microns in the near-infrared, however no clear detection of binarity or of non-LPV elements in the symbiotic system is reported.Comment: Accepted to Astrophysical Journal. To appear in volume 534. 14 pages; 3 postscript figure

Spectrum of Neuroradiologic Findings Associated with Monogenic Interferonopathies

The genetic interferonopathies are a heterogeneous group of disorders thought to be caused by the dysregulated expression of interferons and are now commonly considered in the differential diagnosis of children presenting with recurrent or persistent inflammatory phenotypes. With emerging therapeutic options, recognition of these disorders is increasingly important, and neuroimaging plays a vital role. In this article, we discuss the wide spectrum of neuroradiologic features associated with monogenic interferonopathies by reviewing the literature and illustrate these with cases from our institutions. These cases include intracerebral calcifications, white matter T2 hyperintensities, deep WM cysts, cerebral atrophy, large cerebral artery disease, bilateral striatal necrosis, and masslike lesions. A better understanding of the breadth of the neuroimaging phenotypes in conjunction with clinical and laboratory findings will enable earlier diagnosis and direct therapeutic strategies

On the Dynamic Stability of Cool Supergiant Atmospheres

We have developed a new formalism to compute the thermodynamic coefficient Gamma1 in the theory of stellar and atmospheric stability. We generalize the classical derivation of the first adiabatic index, which is based on the assumption of thermal ionization and equilibrium between gas and radiation temperature, towards an expression which incorporates photo-ionization due to radiation with a temperature T_rad different from the local kinetic gas temperature.Our formalism considers the important non-LTE conditions in the extended atmospheres of supergiant stars. An application to the Kurucz grid of cool supergiant atmospheres demonstrates that models with T_rad =~ T_eff between 6500 K and 7500 K become most unstable against dynamic perturbations, according to Ledoux' stability integral . This results from Gamma1 and acquiring very low values, below 4/3, throughout the entire stellar atmosphere, which causes very high gas compression ratios around these effective temperatures. Based on detailed NLTE-calculations, we discuss atmospheric instability of pulsating massive yellow supergiants, like the hypergiant rho Cas (Ia+), which exist in the extension of the Cepheid instability strip, near the Eddington luminosity limit.Comment: 54 pages including figures and the Appendix, 7 figures, Accepted for The Astrophysical Journal, Main Journal, 558, Sept. 200

Seismic constraints on the radial dependence of the internal rotation profiles of six Kepler subgiants and young red giants

Context : We still do not know which mechanisms are responsible for the transport of angular momentum inside stars. The recent detection of mixed modes that contain the signature of rotation in the spectra of Kepler subgiants and red giants gives us the opportunity to make progress on this issue. Aims: Our aim is to probe the radial dependance of the rotation profiles for a sample of Kepler targets. For this purpose, subgiants and early red giants are particularly interesting targets because their rotational splittings are more sensitive to the rotation outside the deeper core than is the case for their more evolved counterparts. Methods: We first extract the rotational splittings and frequencies of the modes for six young Kepler red giants. We then perform a seismic modeling of these stars using the evolutionary codes CESAM2k and ASTEC. By using the observed splittings and the rotational kernels of the optimal models, we perform inversions of the internal rotation profiles of the six stars. Results: We obtain estimates of the mean rotation rate in the core and in the convective envelope of these stars. We show that the rotation contrast between the core and the envelope increases during the subgiant branch. Our results also suggest that the core of subgiants spins up with time, contrary to the RGB stars whose core has been shown to spin down. For two of the stars, we show that a discontinuous rotation profile with a deep discontinuity reproduces the observed splittings significantly better than a smooth rotation profile. Interestingly, the depths that are found most probable for the discontinuities roughly coincide with the location of the H-burning shell, which separates the layers that contract from those that expand. These results will bring observational constraints to the scenarios of angular momentum transport in stars.Comment: Accepted in A&A, 27 pages, 18 figure

Whistleblowers as regulatory intermediaries: Instrumental and reflexive considerations in decentralizing regulation

This article frames whistleblowers as regulatory intermediaries who provide a response to the problem posed by the fragmentation of knowledge in a complex society and market economy. I identify two ways in which whistleblowers become regulatory intermediaries: The first is by remedying informational asymmetries between the regulator and the target (instrumental approach). Both in the United States and in the European Union, whistleblowers are protected on the basis of the value of the disclosed information for the advancement of regulatory objectives. The second way in which whistleblowers become regulatory intermediaries is by contributing to the development of “communities of compliance” and by enhancing the internal self-regulatory capacities of regulatory targets (reflexive approach). Creating internal channels of reporting and monitoring is perceived as a way to change the organizational culture of targets. Through the instrumentalism – reflexivity dipole, competing rationales and normative visions of regulatory intermediation become apparent: It could, on the one hand, facilitate state intervention and legal sanctions or, on the other hand, signal the aspiration to embed public and social values in private actors

Malaria chemoprophylaxis and the serologic response to measles and diphtheria-tetanus-whole-cell pertussis vaccines

BACKGROUND: Acute malaria has been associated with a decreased antibody response to tetanus and diphtheria toxoids, meningococcal, salmonella, and Hib vaccines. Interest in giving malaria drug therapy and prevention at the time of childhood immunizations has increased greatly following recent trials of intermittent preventive therapy during infancy (IPTi), stimulating this re-analysis of unpublished data. The effect of malaria chemoprophylaxis on vaccine response was studied following administration of measles vaccines and diphtheria-tetanus-whole cell pertussis (DTP) vaccines. METHODS: In 1975, six villages divided into two groups of children ≤74 months of age from Burkina Faso, were assigned to receive amodiaquine hydrochloride chemoprophylaxis (CH+) every two weeks for seven months or no chemoprophylaxis (CH-). After five months, children in each group received either one dose of measles or two doses of DTP vaccines. RESULTS: For recipients of the measles vaccine, the seroconversion rates in CH+ and CH- children, respectively, were 93% and 96% (P > 0.05). The seroresponse rates in CH+ and CH- children respectively, were 73% and 86% for diphtheria (P > 0.05) and 77% and 91% for tetanus toxoid (P > 0.05). In a subset analysis, in which only children who strictly adhered to chemoprophylaxis criteria were included, there were, likewise, no significant differences in seroconversion or seroresponse for measles, diphtheria, or tetanus vaccines (P > 0.05). While analysis for pertussis showed a 43% (CH+) and 67% (CH-) response (P < 0.05), analyses using logistic regression to control for sex, age, chemoprophylaxis, weight-for-height Z-score, and pre-vaccination geometric mean titer (GMT), demonstrated that chemoprophylaxis was not associated with a significantly different conversion rate following DTP and measles vaccines. Seven months of chemoprophylaxis decreased significantly the malaria IFA and ELISA GMTs in the CH+ group. CONCLUSION: Malaria chemoprophylaxis prior to vaccination in malaria endemic settings did not improve or impair immunogenicity of DTP and measles vaccines. This is the first human study to look at the association between malaria chemoprophylaxis and the serologic response to whole-cell pertussis vaccine

Atmospheric parameters of 82 red giants in the Kepler field

Context: Accurate fundamental parameters of stars are essential for the asteroseismic analysis of data from the NASA Kepler mission. Aims: We aim at determining accurate atmospheric parameters and the abundance pattern for a sample of 82 red giants that are targets for the Kepler mission. Methods: We have used high-resolution, high signal-to-noise spectra from three different spectrographs. We used the iterative spectral synthesis method VWA to derive the fundamental parameters from carefully selected high-quality iron lines. After determination of the fundamental parameters, abundances of 13 elements were measured using equivalent widths of the spectral lines. Results: We identify discrepancies in log g and [Fe/H], compared to the parameters based on photometric indices in the Kepler Input Catalogue (larger than 2.0 dex for log g and [Fe/H] for individual stars). The Teff found from spectroscopy and photometry shows good agreement within the uncertainties. We find good agreement between the spectroscopic log g and the log g derived from asteroseismology. Also, we see indications of a potential metallicity effect on the stellar oscillations. Conclusions: We have determined the fundamental parameters and element abundances of 82 red giants. The large discrepancies between the spectroscopic log g and [Fe/H] and values in the Kepler Input Catalogue emphasize the need for further detailed spectroscopic follow-up of the Kepler targets in order to produce reliable results from the asteroseismic analysis.Comment: 16 Pages, 12 Figures, accepted for publication in A&

Psychosis with paranoid delusions after a therapeutic dose of mefloquine: a case report

BACKGROUND: Convenient once-a-week dosing has made mefloquine a popular choice as malaria prophylaxis for travel to countries with chloroquine-resistant malaria. However, the increased use of mefloquine over the past decade has resulted in reports of rare, but severe, neuropsychiatric adverse reactions, such as anxiety, depression, hallucinations and psychosis. A direct causality between mefloquine and severe reactions among travelers has been partly confounded by factors associated with foreign travel and, in the case of therapeutic doses of mefloquine, the central nervous system manifestations of Plasmodium infection itself. The present case provides a unique natural history of mefloquine-induced neuropsychiatric toxicity and revisits its dose-dependent nature. CASE PRESENTATION: This report describes an acute exacerbation of neuropsychiatric symptoms after an unwarranted therapeutic dose (1250 mg) of mefloquine in a 37-year-old male previously on a once-a-week prophylactic regimen. Neuropsychiatric symptoms began as dizziness and insomnia of several days duration, which was followed by one week of escalating anxiety and subtle alterations in behaviour. The patient's anxiety culminated into a panic episode with profound sympathetic activation. One week later, he was hospitalized after developing frank psychosis with psychomotor agitation and paranoid delusions. His psychosis remitted with low-dose quetiapine. CONCLUSION: This report suggests that an overt mefloquine-induced psychosis can be preceded by a prodromal phase of moderate symptoms such as dizziness, insomnia, and generalized anxiety. It is important that physicians advise patients taking mefloquine prophylaxis and their relatives to recognize such symptoms, especially when they are accompanied by abrupt, but subtle, changes in behaviour. Patients with a history of psychiatric illness, however minor, may be at increased risk for a mefloquine-induced neuropsychiatric toxicity. Physicians must explicitly caution patients not to self-medicate with a therapeutic course of mefloquine when a malaria diagnosis has not been confirmed

Cyberspace, Blockchain, Governance:How Technology Implies Normative Power and Regulation

Technologies and their inherent design choices create normative structures that affect governance. This chapter aims to illustrate how blockchain technology in particular introduces new norms into a legal framework. We first analyze the different forms of governance by distinguishing between old and new governance. With a view to code that functions as legal norms, Blockchain technology is particularly suited to create governance structures and mechanisms. However, one needs to be aware of the norms that are implicitly introduced into the legal system by a specific blockchain technology. We look at the blockchain technology that underlies cryptocurrencies such as Bitcoin. This blockchain introduces a decentralized, transparent, cryptographically locked and thus immutable shared ledger. In summary, these design choices have normative powers over the user and over user interaction. If this is indeed the case, then regulators have to actively assess newly introduced digital ledger technology and other technologies for their effect on the normative and legal system.</p