Lord of the Rings: A Kinematic Distance to Circinus X-1 from a Giant X-Ray Light Echo

Circinus X-1 exhibited a bright X-ray flare in late 2013. Follow-up observations with Chandra and XMM-Newton from 40 to 80 days after the flare reveal a bright X-ray light echo in the form of four well-defined rings with radii from 5 to 13 arcminutes, growing in radius with time. The large fluence of the flare and the large column density of interstellar dust towards Circinus X-1 make this the largest and brightest set of rings from an X-ray light echo observed to date. By deconvolving the radial intensity profile of the echo with the MAXI X-ray lightcurve of the flare we reconstruct the dust distribution towards Circinus X-1 into four distinct dust concentrations. By comparing the peak in scattering intensity with the peak intensity in CO maps of molecular clouds from the Mopra Southern Galactic Plane CO Survey we identify the two innermost rings with clouds at radial velocity ~ -74 km/s and ~ -81 km/s, respectively. We identify a prominent band of foreground photoelectric absorption with a lane of CO gas at ~ -32 km/s. From the association of the rings with individual CO clouds we determine the kinematic distance to Circinus X-1 to be $D_{Cir X-1} = 9.4^{+0.8}_{-1.0}$ kpc. This distance rules out earlier claims of a distance around 4 kpc, implies that Circinus X-1 is a frequent super-Eddington source, and places a lower limit of $\Gamma \gtrsim 22$ on the Lorentz factor and an upper limit of $\theta_{jet} \lesssim 3^{\circ}$ on the jet viewing angle.Comment: 20 pages, 21 figures, Astrophysical Journal, in prin

Anomalous scaling and spin-charge separation in coupled chains

We use a bosonization approach to show that the three dimensional Coulomb interaction in coupled metallic chains leads to a Luttinger liquid for vanishing inter-chain hopping $t_{\bot}$, and to a Fermi liquid for any finite $t_{\bot}$. However, for small $t_{\bot} \neq 0$ the Greens-function satisfies a homogeneity relation with a non-trivial exponent $\gamma_{cb}$ in a large intermediate regime. Our results offer a simple explanation for the large values of $\gamma_{cb}$ inferred from recent photoemission data from quasi one-dimensional conductors and might have some relevance for the understanding of the unusual properties of the high-temperature superconductors.Comment: compressed and uuencoded ps-file, including the figures, accepted for publication in Phys. Rev. Lett

Visible-to-telecom quantum frequency conversion of light from a single quantum emitter

Quantum frequency conversion (QFC), a nonlinear optical process in which the frequency of a quantum light field is altered while conserving its non-classical correlations, was first demonstrated 20 years ago. Meanwhile, it is considered an essential tool for the implementation of quantum repeaters since it allows for interfacing quantum memories with telecom-wavelength photons as quantum information carriers. Here we demonstrate efficient (>30%) QFC of visible single photons (711 nm) emitted by a quantum dot (QD) to a telecom wavelength (1,313 nm). Analysis of the first and second-order coherence before and after wavelength conversion clearly proves that important properties, such as the coherence time and photon antibunching, are fully conserved during the frequency translation process. Our findings underline the great potential of single photon sources on demand in combination with QFC as a promising technique for quantum repeater schemes.Comment: 11 pages, 4 figure

Transient pluripotent cell populations during primitive ectoderm formation: correlation of in vivo and in vitro pluripotent cell development.

Formation and differentiation of a pluripotent cell population is central to mammalian development, and the isolation, identification and manipulation of human pluripotent cells is predicted to be of therapeutic use. Within the early mammalian embryo, two distinct populations of pluripotent cells have been described: the inner cell mass (ICM), which differentiates to form a second pluripotent cell populations, the primitive ectoderm. Indirect evidence suggests the existence of temporally distinct intermediate pluripotent cell populations as primitive ectoderm is formed. We coupled an in vitro model of primitive ectoderm formation (the transition of embryonic stem cells to early primitive ectoderm-like (EPL) cells) with ddPCR-based techniques to identify three novel genes, Psc1, CRTR-1 and PRCE, that were expressed differently during pluripotent cell progression. Detailed mapping of these genes with Oct4, Rex1 and Fgf5 on pregastrulation embryos provided the first molecular evidence for the existence of successive, temporally distinct pluripotent cell populations in the embryo between the ICM and primitive ectoderm. No evidence was found for spatial heterogeneity within the Oct4+ pool. The transition between populations correlated with morphological or developmental alterations in pluripotent cells in vivo. Genes that are temporally expressed during pluripotent cell progression may provide an opportunity for molecular discrimination of pluripotent cells at different stages of maturation in vivo and an understanding of the cellular origins and properties of pluripotent cell lines isolated from diverse sources. Furthermore, the strong correlation of gene expression demonstrated between EPL cell formation in vitro and primitive ectoderm formation in vivo validates EPL cells as a model for primitive ectoderm, thereby providing a model system for the investigation of pluripotent differentiation and an opportunity for directed differentiation of pluripotent cells to therapeutically useful cell populations.T. A. Pelton, S. Sharma, T. C. Schulz, J. Rathjen and P. D. Rathje

Defibrotide for Prophylaxis of Hepatic Veno-Occlusive Disease in Pediatric Hematopoietic Stem Cell Transplantation: Subanalysis Data from an Open-Label, Phase III, Randomized Trial

Introduction Hepatic veno-occlusive disease, also called sinusoidal obstruction syndrome (VOD/SOS), is a potentially life-threatening complication of conditioning for hematopoietic stem cell transplantation (HSCT) and is associated with patient and transplant-related risk factors, such as prior therapies, underlying diagnoses, and conditioning regimen. Unpredictable in its occurrence and severity, VOD/SOS is clinically characterized by painful hepatomegaly, hyperbilirubinemia, ascites, and weight gain. Overall estimated prevalence is 14% post-HSCT, while rates in some high-risk populations (eg, osteopetrosis or prior gemtuzumab ozogamicin) are >60% (Wadleigh M et al. Blood . 2003;102:1578-82; Corbacioglu S et al. Bone Marrow Transplant . 2006;38:547-53). Evidence suggests that defibrotide stabilizes endothelial cells, with direct and endothelial-cell mediated restoration of the thrombo-fibrinolytic balance. Defibrotide is approved in the European Union for the treatment of severe hepatic VOD/SOS in patients receiving HSCT, and is available in the United States through an expanded-access study. In a previously reported randomized clinical trial, defibrotide prophylaxis for VOD/SOS in high-risk pediatric patients undergoing HSCT reduced the overall incidence of VOD/SOS by day +30 post-HSCT. Here we report novel subgroup analyses of VOD/SOS incidence from this trial in patients with specific VOD/SOS risk factors at baseline. Methods This was a phase 3, multicenter, open-label, randomized, controlled trial in patients aged 5% weight gain. Patients were randomized to standard care with or without defibrotide prophylaxis dosed at 25 mg/kg/day in 4 divided infusions of 6.25 mg/kg. Osteopetrosis was a stratification variable. Defibrotide began the same day as HSCT conditioning and continued for 30 days post-HSCT, or ≥14 days for patients discharged from hospital before day +30 post-HSCT. Control patients who developed VOD/SOS received defibrotide treatment. The primary endpoint was incidence of VOD/SOS at day +30 post-HSCT. Results The intent-to-treat population included 356 patients: 180 randomized to defibrotide prophylaxis and 176 in the control group. Mean (SD) age was 6.6 (5.3) years, and 40.7% of patients were female. Demographic and clinical characteristics, including VOD/SOS risk factors (Table), were well-matched in the defibrotide and control groups. The most common risk factors among all patients were conditioning with busulfan and melphalan (58%), preexisting liver disease (27%), and second myeloablative transplantation (13%). VOD/SOS occurred by day +30 post-HSCT in 22 (12%) patients in the defibrotide prophylaxis group vs 35 (20%) patients in the control group. For the stratification variable, osteopetrosis, rates of VOD/SOS were 14% in the defibrotide prophylaxis arm and 67% in the control arm (Table). Differences in rates of VOD/SOS were lowest for adrenoleukodystrophy (no cases) and prior abdominal irradiation (11% vs 13%, respectively) (Table). Conclusions Across risk-factor subgroups, the rate of VOD/SOS was lower in patients receiving defibrotide compared with controls (except adrenoleukodystrophy: no VOD/SOS in either group). In particular, rates of VOD/SOS by day +30 were reduced by ≥50% in the defibrotide arm vs the control arm among patients with osteopetrosis, hemophagocytic lymphohistiocytosis, second myeloablative transplantation, and prior gemtuzumab treatment. Although the total numbers of patients with these risk factors were small, these between-group differences are of clinical interest and should be further explored. | Risk Factor | Defibrotide (n=180) | Control (n=176) | | ------------------------------------ | ----------------------------------------------- | --------------- | ----------------------------------------------- | | Total n | VOD/SOS incidence (n=22; 12.2%) n (%*) | Total n | VOD/SOS incidence (n=35; 20.0%) n (%*) | | Adrenoleukodystrophy | 1 | 0 (0) | 1 | 0 (0) | | Osteopetrosis | 7 | 1 (14) | 6 | 4 (67) | | Prior abdominal irradiation | 9 | 1 (11) | 8 | 1 (13) | | Hemophagocytic lymphohistiocytosis | 10 | 0 (0) | 15 | 6 (40) | | Prior gemtuzumab | 11 | 2 (18) | 5 | 2 (40) | | Allogeneic HSCT for leukemia | 17 | 2 (12) | 11 | 2 (18) | | Second myeloablative transplantation | 25 | 2 (8) | 23 | 4 (17) | | Pre-existing liver disease | 41 | 6 (15) | 54 | 12 (22) | | Busulfan/melphalan conditioning | 106 | 15 (14) | 99 | 17 (17) | * *Percent of patients with VOD/SOS. Table. Support: Jazz Pharmaceuticals Disclosures Corbacioglu: Gentium S.p.A.: Consultancy, Honoraria. Off Label Use: Defibrotide is an investigational treatment for hepatic veno-occlusive disease/sinusoidal obstruction syndrome in the United States.. Bader: Amgen: Consultancy; Medac: Other: Institutional grants; Neovii: Other: Institutional grants; Riemser: Other: Institutional grants; Novartis: Consultancy; Jazz Pharmaceuticals: Consultancy

From the abstract to the concrete - Implementation of an innovative tool in home care

Background: The implementation of innovations in practice is a critical factor for change and development processes in health and home care. We therefore analyze how an innovative tool - a mobility agreement to maintain physical mobility of home care clients - was implemented in Finnish home care. Methods: Our study involves ethnographic research of 13 home care visits, two years after the mobility agreement was implemented. We analyze the emergence of contradictions, the motives of the actors and the use of artifacts supporting or inhibiting the implementation. Two in-depth cases illustrate the implementation of the mobility agreement in home care visits. Findings: Our findings show that, first, to achieve practice change and development, the innovation implementation requires the overcoming of contradictions in the implementation process. Second, it calls for the emergence of a shared motive between the actors to transform the abstract concept of an innovation into a concrete practice. Third, artifacts, customary to the clients are important in supporting the implementation process. Fourth, the implementation brings about a modification of the innovation and the adopting social system. Conclusions: Innovation implementation should be seen as a transformation process of an abstract concept into a concrete practice, enabled by the actors involved. Concept design and implementation should be closely linked. In health/home care innovation management, the implementation of innovations needs to be understood as a complex collective learning process. Results can be far reaching - in our case leading to change of home care workers' professional understanding and elderly clients' mobility habits.Peer reviewe

Synthesis and characterization of chiral ionic liquids based on quinine, l-proline and l-valine for enantiomeric recognition

The separation of enantiomers remains a major challenge for the pharmaceutical industry. In this work, eight chiral ionic liquids (CILs) directly derived from the ‘chiral pool’ were synthesized and characterized in order to develop enantioselective systems, for the chiral resolution. According to their chiral cations, three different groups of CILs were prepared, namely based on quinine, L-proline and L-valine, and their enantiomeric recognition ability evaluated. For that purpose the diastereomeric interactions between a racemic mixture of Mosher's acid sodium salt and each CIL were studied using 19 F NMR spectroscopy. The remarkable chemical shift dispersion induced by some CILs demonstrates their potential application in chiral resolution. Additionally the optical rotation, thermophysical properties and ecotoxicity against the marine bacteria Aliivibrio fischeri of these chiral ionic liquids were addressed.publishe