An eccentric wave in the circumstellar disc of the Be/X-ray binary X Persei

We present spectroscopic observations of the Be/X-ray binary X Per obtained during the period 2017 December-2020 January (MJD 58095-58865). In 2017 December, the H α, H β, and He I 6678 emission lines were symmetric with violet-to-red peak ratio V/R ≈ 1. During the first part of the period (2017 December-2018 August), the V/R ratio decreased to 0.5 and the asymmetry developed simultaneously in all three lines. In 2018 September, a third component with velocity ≈250 km s−1 appeared on the red side of the He I line profile. Later, this component emerged in H β, accompanied by the appearance of a red shoulder in H α. Assuming that it is due to an eccentric wave in the circumstellar disc, we find that the eccentric wave appeared first in the innermost part of the disc, it spreads out with outflowing velocity vwave ≈ 1.1 ± 0.2 km s−1, and the eccentricity of the eccentric wave is ewave ≈ 0.29 ± 0.07. A detailed understanding of the origin of such eccentricities would have applications to a wide range of systems from planetary rings to AGNs

Infrared spectroscopy characterization of normal and lung cancer cells originated from epithelium

The vibrational spectral differences of normal and lung cancer cells were studied for the development of effective cancer cell screening by means of attenuated total reflection infrared spectroscopy. The phosphate monoester symmetric stretching νs(PO32-) band intensity at ~970 cm-1 and the phosphodiester symmetric stretching νs(PO2-) band intensity at ~1,085 cm-1 in nucleic acids and phospholipids appeared to be significantly strengthened in lung cancer cells with respect to the other vibrational bands compared to normal cells. This finding suggests that more extensive phosphorylation occur in cancer cells. These results demonstrate that lung cancer cells may be prescreened using infrared spectroscopy tools

The Expanding Fireball of Nova Delphini 2013

A classical nova occurs when material accreting onto the surface of a white dwarf in a close binary system ignites in a thermonuclear runaway. Complex structures observed in the ejecta at late stages could result from interactions with the companion during the common envelope phase. Alternatively, the explosion could be intrinsically bipolar, resulting from a localized ignition on the surface of the white dwarf or as a consequence of rotational distortion. Studying the structure of novae during the earliest phases is challenging because of the high spatial resolution needed to measure their small sizes. Here we report near-infrared interferometric measurements of the angular size of Nova Delphini 2013, starting from one day after the explosion and continuing with extensive time coverage during the first 43 days. Changes in the apparent expansion rate can be explained by an explosion model consisting of an optically thick core surrounded by a diffuse envelope. The optical depth of the ejected material changes as it expands. We detect an ellipticity in the light distribution, suggesting a prolate or bipolar structure that develops as early as the second day. Combining the angular expansion rate with radial velocity measurements, we derive a geometric distance to the nova of 4.54 +/- 0.59 kpc from the Sun.Comment: Published in Nature. 32 pages. Final version available at http://www.nature.com/nature/journal/v515/n7526/full/nature13834.htm

Discovery of optical flickering from the symbiotic star EF Aquilae

We report optical charge-coupled device (CCD) photometry of the recently identified symbiotic star EF Aquilae (EF Aql). Our observations in the Johnson V and B bands clearly show the presence of stochastic light variations with an amplitude of about 0.2 mag on a time scale of minutes. The observations point toward a white dwarf (WD) as the hot component in the system. It is the 11th object among more than 200 symbiotic stars known with detected optical flickering. Estimates of the mass accretion rate onto the WD and the mass loss rate in the wind of the Mira secondary star lead to the conclusion that less than 1% of the wind is captured by the WD. Eight further candidates for the detection of flickering in similar systems are suggested

MicroRNA expression profiles in human cancer cells after ionizing radiation

Introduction: MicroRNAs are regulators of central cellular processes and are implicated in the pathogenesis and prognosis of human cancers. MicroRNAs also modulate responses to anti-cancer therapy. In the context of radiation oncology microRNAs were found to modulate cell death and proliferation after irradiation. However, changes in microRNA expression profiles in response to irradiation have not been comprehensively analyzed so far. The present study's intend is to present a broad screen of changes in microRNA expression following irradiation of different malignant cell lines. Materials and methods: 1100 microRNAs (Sanger miRBase release version 14.0) were analyzed in six malignant cell lines following irradiation with clinically relevant doses of 2.0 Gy. MicroRNA levels 6 hours after irradiation were compared to microRNA levels in non-irradiated cells using the "Geniom Biochip MPEA homo sapiens". Results: Hierarchical clustering analysis revealed a pattern, which significantly (p = 0.014) discerned irradiated from non-irradiated cells. The expression levels of a number of microRNAs known to be involved in the regulation of cellular processes like apoptosis, proliferation, invasion, local immune response and radioresistance (e. g. miR-1285, miR-24-1, miR-151-5p, let-7i) displayed 2 - 3-fold changes after irradiation. Moreover, several microRNAs previously not known to be radiation-responsive were discovered. Conclusion: Ionizing radiation induced significant changes in microRNA expression profiles in 3 glioma and 3 squamous cell carcinoma cell lines. The functional relevance of these changes is not addressed but should by analyzed by future work especially focusing on clinically relevant endpoints like radiation induced cell death, proliferation, migration and metastasis

Structure-based programming of lymph-node targeting in molecular vaccines

In cancer patients, visual identification of sentinel lymph nodes (LNs) is achieved by the injection of dyes that bind avidly to endogenous albumin, targeting these compounds to LNs, where they are efficiently filtered by resident phagocytes1, 2. Here we translate this ‘albumin hitchhiking’ approach to molecular vaccines, through the synthesis of amphiphiles (amph-vaccines) comprising an antigen or adjuvant cargo linked to a lipophilic albumin-binding tail by a solubility-promoting polar polymer chain. Administration of structurally optimized CpG-DNA/peptide amph-vaccines in mice resulted in marked increases in LN accumulation and decreased systemic dissemination relative to their parent compounds, leading to 30-fold increases in T-cell priming and enhanced anti-tumour efficacy while greatly reducing systemic toxicity. Amph-vaccines provide a simple, broadly applicable strategy to simultaneously increase the potency and safety of subunit vaccines.David H. Koch Institute for Integrative Cancer Research at MIT (Koch Institute Support (core) Grant P30-CA14051)National Cancer Institute (U.S.)National Institutes of Health (U.S.) (grant AI091693)National Institutes of Health (U.S.) (grant AI104715)National Institutes of Health (U.S.) (AI095109)United States. Dept. of Defense (contract W911NF-13-D-0001)United States. Dept. of Defense (contract W911NF-07-D-0004)Ragon Institute of MGH, MIT, and Harvar

Connectivity and resilience of coral reef metapopulations in marine protected areas : matching empirical efforts to predictive needs

© 2009 The Authors. This is an open-access article distributed under the terms of the Creative Commons Attribution Noncommercial License. The definitive version was published in Coral Reefs 28 (2009): 327-337, doi:10.1007/s00338-009-0466-z.Design and decision-making for marine protected areas (MPAs) on coral reefs require prediction of MPA effects with population models. Modeling of MPAs has shown how the persistence of metapopulations in systems of MPAs depends on the size and spacing of MPAs, and levels of fishing outside the MPAs. However, the pattern of demographic connectivity produced by larval dispersal is a key uncertainty in those modeling studies. The information required to assess population persistence is a dispersal matrix containing the fraction of larvae traveling to each location from each location, not just the current number of larvae exchanged among locations. Recent metapopulation modeling research with hypothetical dispersal matrices has shown how the spatial scale of dispersal, degree of advection versus diffusion, total larval output, and temporal and spatial variability in dispersal influence population persistence. Recent empirical studies using population genetics, parentage analysis, and geochemical and artificial marks in calcified structures have improved the understanding of dispersal. However, many such studies report current self-recruitment (locally produced settlement/settlement from elsewhere), which is not as directly useful as local retention (locally produced settlement/total locally released), which is a component of the dispersal matrix. Modeling of biophysical circulation with larval particle tracking can provide the required elements of dispersal matrices and assess their sensitivity to flows and larval behavior, but it requires more assumptions than direct empirical methods. To make rapid progress in understanding the scales and patterns of connectivity, greater communication between empiricists and population modelers will be needed. Empiricists need to focus more on identifying the characteristics of the dispersal matrix, while population modelers need to track and assimilate evolving empirical results.Work by CB Paris was supported by the National Science Foundation grant NSF-OCE 0550732. Work by M-A Coffroth and SR Thorrold was supported by the National Science Foundation grant NSF-OCE 0424688. Work by TL Shearer was supported by an International Cooperative Biodiversity Group grant R21 TW006662-01 from the Fogarty International Center at the National Institutes of Health

A mammalian functional-genetic approach to characterizing cancer therapeutics

Supplementary information is available online at http://www.nature.com/naturechemicalbiology/. Reprints and permissions information is available online at http://npg.nature.com/reprintsandpermissions/.Identifying mechanisms of drug action remains a fundamental impediment to the development and effective use of chemotherapeutics. Here we describe an RNA interference (RNAi)–based strategy to characterize small-molecule function in mammalian cells. By examining the response of cells expressing short hairpin RNAs (shRNAs) to a diverse selection of chemotherapeutics, we could generate a functional shRNA signature that was able to accurately group drugs into established biochemical modes of action. This, in turn, provided a diversely sampled reference set for high-resolution prediction of mechanisms of action for poorly characterized small molecules. We could further reduce the predictive shRNA target set to as few as eight genes and, by using a newly derived probability-based nearest-neighbors approach, could extend the predictive power of this shRNA set to characterize additional drug categories. Thus, a focused shRNA phenotypic signature can provide a highly sensitive and tractable approach for characterizing new anticancer drugs.National Institute of Mental Health (U.S.) (grant RO1 CA128803-03)American Association for Cancer ResearchMassachusetts Institute of Technology. Dept. of BiologyNational Cancer Institute (U.S.). Integrative Cancer Biology Program (grant 1-U54-CA112967

Tumor Necrosis Factor Receptor Associated Factor 6 Is Not Required for Atherogenesis in Mice and Does Not Associate with Atherosclerosis in Humans

BACKGROUND: Tumor necrosis factor receptor-associated factors (TRAFs) are important signaling molecules for a variety of pro-atherogenic cytokines including CD40L, TNF alpha, and IL1beta. Several lines of evidence identified TRAF6 as a pro-inflammatory signaling molecule in vitro and we previously demonstrated overexpression of TRAF6 in human and Murine atherosclerotic plaques. This study investigated the role of TRAF6-deficiency in mice developing atherosclerosis, a chronic inflammatory disease. METHODOLOGY/PRINCIPAL FINDINGS: Lethally irradiated low density lipoprotein receptor-deficient mice (TRAF6(+/+)/LDLR(-/-)) were reconstituted with TRAF6-deficient fetal liver cells (FLC) and consumed high cholesterol diet for 18 weeks to assess the relevance of TRAF6 in hematopoietic cells for atherogenesis. Additionally, TRAF6(+/-)/LDLR(-/-) mice received TRAF6-deficient FLC to gain insight into the role of TRAF6 deficiency in resident cells. Surprisingly, atherosclerotic lesion size did not differ between the three groups in both aortic roots and abdominal aortas. Similarly, no significant differences in plaque composition could be observed as assessed by immunohistochemistry for macrophages, lipids, smooth muscle cells, T-cells, and collagen. In accord, in a small clinical study TRAF6/GAPDH total blood RNA ratios did not differ between groups of patients with stable coronary heart disease (0.034+/-0.0021, N = 178), acute coronary heart disease (0.029+/-0.0027, N = 70), and those without coronary heart disease (0.032+/-0.0016, N = 77) as assessed by angiography. CONCLUSION: Our study demonstrates that TRAF6 is not required for atherogenesis in mice and does not associate with clinical disease in humans. These data suggest that pro- and anti-inflammatory features of TRAF6 signaling outweigh each other in the context of atherosclerosis