Central Powering of the Largest Lyman-alpha Nebula is Revealed by Polarized Radiation

High-redshift Lyman-alpha blobs are extended, luminous, but rare structures that appear to be associated with the highest peaks in the matter density of the Universe. Their energy output and morphology are similar to powerful radio galaxies, but the source of the luminosity is unclear. Some blobs are associated with ultraviolet or infrared bright galaxies, suggesting an extreme starburst event or accretion onto a central black hole. Another possibility is gas that is shock excited by supernovae. However some blobs are not associated with galaxies, and may instead be heated by gas falling into a dark matter halo. The polarization of the Ly-alpha emission can in principle distinguish between these options, but a previous attempt to detect this signature returned a null detection. Here we report on the detection of polarized Ly-alpha from the blob LAB1. Although the central region shows no measurable polarization, the polarized fraction (P) increases to ~20 per cent at a radius of 45 kpc, forming an almost complete polarized ring. The detection of polarized radiation is inconsistent with the in situ production of Ly-alpha photons, and we conclude that they must have been produced in the galaxies hosted within the nebula, and re-scattered by neutral hydrogen.Comment: Published in the August 18 issue of Nature. 1750 words, 3 figures, and full Supplementary Information. Version has not undergone proofing. Reduced and processed data products are available here: http://obswww.unige.ch/people/matthew.hayes/LymanAlpha/LabPol

Interactive Effects of Time, CO\u3csub\u3e2\u3c/sub\u3e, N, and Diversity on Total Belowground Carbon Allocation and Ecosystem Carbon Storage in a Grassland Community

Predicting if ecosystems will mitigate or exacerbate rising CO2 requires understanding how elevated CO2 will interact with coincident changes in diversity and nitrogen (N) availability to affect ecosystem carbon (C) storage. Yet achieving such understanding has been hampered by the difficulty of quantifying belowground C pools and fluxes. Thus, we used mass balance calculations to quantify the effects of diversity, CO2, and N on both the total amount of C allocated belowground by plants (total belowground C allocation, TBCA) and ecosystem C storage in a periodically burned, 8-year Minnesota grassland biodiversity, CO2, and N experiment (BioCON). Annual TBCA increased in response to elevated CO2, enriched N, and increasing diversity. TBCA was positively related to standing root biomass. After removing the influence of root biomass, the effect of elevated CO2 remained positive, suggesting additional drivers of TBCA apart from those that maintain high root biomass. Removing root biomass effects resulted in the effects of N and diversity becoming neutral or negative (depending on year), suggesting that the positive effects of diversity and N on TBCA were related to treatmentdriven differences in root biomass. Greater litter production in high diversity, elevated CO2, and enhanced N treatments increased annual ecosystem C loss in fire years and C gain in non-fire years, resulting in overall neutral C storage rates. Our results suggest that frequently burned grasslands are unlikely to exhibit enhanced C sequestration with increasing atmospheric CO2 levels or N deposition

Pesan Moral Islami Dalam Film Le Grand Voyage Karya Ismael Ferroukhi: Sebuah Tinjauan Struktural

Kata kunci : Film, sastra, struktural, pesan moral, Islam.Film merupakan produk budaya yang tidak hanya menjadi hiburan di masyarakat, tetapi juga sebagai sarana penyampaian pesan moral yang mengarifkan. Salah satufilm Perancis yang dianggap menginspirasi adalah film berjudul Le grand voyageyang ditulis dan disutradarai oleh Ismaël Ferroukhi. Film ini bercerita tentang perjalanan seorang muslim keturunan Maroko dan anaknya yang bernama Reda.Mereka menempuh jarak ribuan mil dari Perancis menuju ke kota Makah untukmelaksanakan haji hanya dengan mengendarai sebuah mobil tua. Penelitian inibertujuan untuk mengetahui pesan moral islami apa saja yang terkandung dalamfilm Le grand voyage dan bagaimana pesan tersebut dimunculkan dalam film.Penelitian ini menggunakan teori Struktural untuk menjawab rumusan masalah.Penelitian ini merupakan penelitian kualitatif dengan menggunakan teknik studipustaka serta dokumentasi sebagai metode pengumpulan data, dan teknikdeskriptif dalam proses analisis data.Berdasarkan hasil penelitian ini, terdapat 13 pesan moral islami yang terkandungdalam film Le grand voyage. Semua pesan moral tersebut mengacu pada sebuahproses perbaikan moral dan spiritual antara manusia dengan manusia dan alam,serta antara manusia dengan TuhanPenulis menyarankan pada penelitian selanjutnya untuk meneliti film Le grandvoyage menggunakan pendekatan sosiologi sastra yang nantinya dapat mengupashal apa saja yang melatarbelakangi pembuatan film ini dan tujuan sebenarnyayang ingin dicapai oleh pembuat film Le grand voyage

Differential effects of testosterone, dihydrotestosterone and estradiol on carotenoid deposition in an avian sexually selected signal

Recent studies have demonstrated that carotenoid-based traits are under the control of testosterone (T) by up-regulation of carotenoid carriers (lipoproteins) and/or tissue-specific uptake of carotenoids. T can be converted to dihydrotestosterone (DHT) and estradiol (E2), and variation in conversion rate may partly explain some contradictory findings in the literature. Moreover, most studies on the effect of T on sexual signals have focused on the male sex only, while in many species females show the same signal, albeit to a lesser extent. We studied the effects of T, DHT, and E2 treatment in male and female diamond doves Geopelia cuneata in which both sexes have an enlarged red eye ring, which is more pronounced in males. We first showed that this periorbital ring contains very high concentration of carotenoids, of which most are lutein esters. Both T and DHT were effective in enhancing hue, UV-chroma and size in both sexes, while E2 was ineffective. However, E2 dramatically increased the concentration of circulating lipoproteins. We conclude that in both sexes both color and size of the secondary sexual trait are androgen dependent. The action of androgens is independent of lipoproteins regulation. Potential mechanisms and their consequences for trade-off are discussed

The MicroRNA and MessengerRNA Profile of the RNA-Induced Silencing Complex in Human Primary Astrocyte and Astrocytoma Cells

GW/P bodies are cytoplasmic ribonucleoprotein-rich foci involved in microRNA (miRNA)-mediated messenger RNA (mRNA) silencing and degradation. The mRNA regulatory functions within GW/P bodies are mediated by GW182 and its binding partner hAgo2 that bind miRNA in the RNA-induced silencing complex (RISC). To date there are no published reports of the profile of miRNA and mRNA targeted to the RISC or a comparison of the RISC-specific miRNA/mRNA profile differences in malignant and non-malignant cells.RISC mRNA and miRNA components were profiled by microarray analysis of malignant human U-87 astrocytoma cells and its non-malignant counterpart, primary human astrocytes. Total cell RNA as well as RNA from immunoprecipitated RISC was analyzed. The novel findings were fourfold: (1) miRNAs were highly enriched in astrocyte RISC compared to U-87 astrocytoma RISC, (2) astrocytoma and primary astrocyte cells each contained unique RISC miRNA profiles as compared to their respective cellular miRNA profiles, (3) miR-195, 10b, 29b, 19b, 34a and 455-3p levels were increased and the miR-181b level was decreased in U-87 astrocytoma RISC as compared to astrocyte RISC, and (4) the RISC contained decreased levels of mRNAs in primary astrocyte and U-87 astrocytoma cells.The observation that miR-34a and miR-195 levels were increased in the RISC of U-87 astrocytoma cells suggests an oncogenic role for these miRNAs. Differential regulation of mRNAs by specific miRNAs is evidenced by the observation that three miR34a-targeted mRNAs and two miR-195-targeted mRNAs were downregulated while one miR-195-targeted mRNA was upregulated. Biological pathway analysis of RISC mRNA components suggests that the RISC plays a pivotal role in malignancy and other conditions. This study points to the importance of the RISC and ultimately GW/P body composition and function in miRNA and mRNA deregulation in astrocytoma cells and possibly in other malignancies

Observations of Lyα\alpha Emitters at High Redshift

In this series of lectures, I review our observational understanding of high-$z$ Ly$\alpha$ emitters (LAEs) and relevant scientific topics. Since the discovery of LAEs in the late 1990s, more than ten (one) thousand(s) of LAEs have been identified photometrically (spectroscopically) at $z\sim 0$ to $z\sim 10$. These large samples of LAEs are useful to address two major astrophysical issues, galaxy formation and cosmic reionization. Statistical studies have revealed the general picture of LAEs' physical properties: young stellar populations, remarkable luminosity function evolutions, compact morphologies, highly ionized inter-stellar media (ISM) with low metal/dust contents, low masses of dark-matter halos. Typical LAEs represent low-mass high-$z$ galaxies, high-$z$ analogs of dwarf galaxies, some of which are thought to be candidates of population III galaxies. These observational studies have also pinpointed rare bright Ly$\alpha$ sources extended over $\sim 10-100$ kpc, dubbed Ly$\alpha$ blobs, whose physical origins are under debate. LAEs are used as probes of cosmic reionization history through the Ly$\alpha$ damping wing absorption given by the neutral hydrogen of the inter-galactic medium (IGM), which complement the cosmic microwave background radiation and 21cm observations. The low-mass and highly-ionized population of LAEs can be major sources of cosmic reionization. The budget of ionizing photons for cosmic reionization has been constrained, although there remain large observational uncertainties in the parameters. Beyond galaxy formation and cosmic reionization, several new usages of LAEs for science frontiers have been suggested such as the distribution of {\sc Hi} gas in the circum-galactic medium and filaments of large-scale structures. On-going programs and future telescope projects, such as JWST, ELTs, and SKA, will push the horizons of the science frontiers.Comment: Lecture notes for `Lyman-alpha as an Astrophysical and Cosmological Tool', Saas-Fee Advanced Course 46. Verhamme, A., North, P., Cantalupo, S., & Atek, H. (eds.) --- 147 pages, 103 figures. Abstract abridged. Link to the lecture program including the video recording and ppt files : https://obswww.unige.ch/Courses/saas-fee-2016/program.cg