1,276 research outputs found

    Dissecting the high-z interstellar medium through intensity mapping cross-correlations

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    We explore the detection, with upcoming spectroscopic surveys, of three-dimensional power spectra of emission line fluctuations produced in different phases of the Interstellar Medium (ISM) by ionized carbon, ionized nitrogen and neutral oxygen at redshift z>4. The emission line [CII] from ionized carbon at 157.7 micron, and multiple emission lines from carbon monoxide, are the main targets of planned ground-based surveys, and an important foreground for future space-based surveys like the Primordial Inflation Explorer (PIXIE). However, the oxygen [OI] (145.5 micron) line, and the nitrogen [NII] (121.9 micron and 205.2 micron) lines, might be detected in correlation with [CII] with reasonable signal-to-noise ratio (SNR). These lines are important coolants of both the neutral and the ionized medium, and probe multiple phases of the ISM. We compute predictions of the three-dimensional power spectra for two surveys designed to target the [CII] line, showing that they have the required sensitivity to detect cross-power spectra with the [OI] line, and the [NII] lines with sufficient SNR. The importance of cross-correlating multiple lines is twofold. On the one hand, we will have multiple probes of the different phases of the ISM, which is key to understand the interplay between energetic sources, the gas and dust at high redshift. This kind of studies will be useful for a next-generation space observatory such as the NASA Far-IR Surveyor. On the other end, emission lines from external galaxies are an important foreground when measuring spectral distortions of the Cosmic Microwave Background spectrum with future space-based experiments like PIXIE; measuring fluctuations in the intensity mapping regime will help constraining the mean amplitude of these lines, and will allow us to better handle this important foreground.Comment: 13 pages, 2 table, 7 figures, Accepted for publication in Ap

    Cross-correlation of cosmic far-infrared background anisotropies with large scale structures

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    We measure the cross-power spectra between luminous red galaxies (LRGs) from the Sloan Digital Sky Survey (SDSS)-III Data Release Eight (DR8) and cosmic infrared background (CIB) anisotropies from Planck and data from the Improved Reprocessing (IRIS) of the Infrared Astronomical Satellite (IRAS) at 353, 545, 857, and 3000 GHz, corresponding to 850, 550, 350 and 100 micron, respectively, in the multipole range 100<l<1000. Using approximately 6.5 10^5 photometrically determined LRGs in 7760 deg^2 of the northern hemisphere in the redshift range 0.45 < z < 0.65, we model the far-infrared background (FIRB) anisotropies with an extended version of the halo model. With these methods, we confirm the basic picture obtained from recent analyses of FIRB anisotropies with Herschel and Planck, that the most efficient halo mass at hosting star forming galaxies is log(M_ eff/M_\odot)=12.84+/-0.15. We estimate the percentage of FIRB anisotropies correlated with LRGs as approximately 11.8 %, 3.9 %, 1.8 %, and 1.0 % of the total at 3000, 857, 545, and 353 GHz, respectively. At redshift z~0.55, the bias of FIRB galaxies with respect to the dark matter density field has the value b_{FIRB}~1.45, and the mean dust temperature of FIRB galaxies is T_d=26 K. Finally, we discuss the impact of present and upcoming cross-correlations with far-infrared background anisotropies on the determination of the global star formation history and the link between galaxies and dark matter.Comment: 9 pages, 6 figures, accepted for publication in A&

    Search for CII Emission on Cosmological Scales at Redshift Z~2.6

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    We present a search for CII emission over cosmological scales at high-redshifts. The CII line is a prime candidate to be a tracer of star formation over large-scale structure since it is one of the brightest emission lines from galaxies. Redshifted CII emission appears in the submillimeter regime, meaning it could potentially be present in the higher frequency intensity data from the Planck satellite used to measure the cosmic infrared background (CIB). We search for CII emission over redshifts z=2-3.2 in the Planck 545 GHz intensity map by cross-correlating the 3 highest frequency Planck maps with spectroscopic quasars and CMASS galaxies from the Sloan Digital Sky Survey III (SDSS-III), which we then use to jointly fit for CII intensity, CIB parameters, and thermal Sunyaev-Zeldovich (SZ) emission. We report a measurement of an anomalous emission Iν=6.64.8+5.0×104\mathrm{I_\nu}=6.6^{+5.0}_{-4.8}\times10^4 Jy/sr at 95% confidence, which could be explained by CII emission, favoring collisional excitation models of CII emission that tend to be more optimistic than models based on CII luminosity scaling relations from local measurements; however, a comparison of Bayesian information criteria reveal that this model and the CIB & SZ only model are equally plausible. Thus, more sensitive measurements will be needed to confirm the existence of large-scale CII emission at high redshifts. Finally, we forecast that intensity maps from Planck cross-correlated with quasars from the Dark Energy Spectroscopic Instrument (DESI) would increase our sensitivity to CII emission by a factor of 5, while the proposed Primordial Inflation Explorer (PIXIE) could increase the sensitivity further.Comment: 15 pages, 11 figures, published in MNRA

    Vasopressin-2 receptor antagonists in autosomal dominant polycystic kidney disease: from man to mouse and back

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    nephropathy, with an esti-mated prevalence of 1:1000. The disease is characterized by the development of multiple cysts from all nephron segments leading to the enlargement of both kidneys and replacement of normal parenchyma (see [1]). Change in total kidney volume over time is the strongest predictor of renal function decline in ADPKD [2]. Glomerular filtra-tion rate remains preserved up to the age of 40 years in most patients because glomerular hyperfiltration in functioning nephrons compensates for the ongoing loss of renal tissue, until end-stage renal failure ensues in&gt;50 % of patients, usually in their fifth decade. Mutations in the PKD1 gene account for ~85 % of the affected families, whereas the remaining cases are caused by mutations in PKD2. PKD1 encodes polycystin-1, an integral membrane protein with a large extracellular domain that probably functions as a re-ceptor and/or an adhesion molecule, whereas PKD2 enco-des polycystin-2, a non-selective cation channel belonging to the family of transient receptor potential channels. The polycystins are located in the primary cilium and interact to form a mechanosensory complex that is involved in intra-cellular Ca21 homeostasis and various signalling pathways. Disruption of the complex leads to cyst development and enlargement resulting from tubular cell proliferation and transepithelial fluid secretion. The progressive understand-ing of these pathways has led to spectacular advances in the prospective treatment for ADPKD, including the blockade of vasopressin 2 receptor (V2R) to decrease the intracellu-lar level of 3#-5#-cyclic adenosine monophosphate (cAMP) in cyst-lining tubular cells [1]

    Parallelization of a relaxation scheme modelling the bedload transport of sediments in shallow water flow

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    In this work we are interested in numerical simulations for bedload erosion processes. We present a relaxation solver that we apply to moving dunes test cases in one and two dimensions. In particular we retrieve the so-called anti-dune process that is well described in the experiments. In order to be able to run 2D test cases with reasonable CPU time, we also describe and apply a parallelization procedure by using domain decomposition based on the classical MPI library.Comment: 19 page

    Aspects juridiques de la lutte contre l´importation de vins espagnols et italiens en France à la fin du XIXème siècle

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    During the last twenty years of the 19th century, France undertook the reconstruction of a vineyard ravaged by phylloxera. At the same time, it sought to put an end to the importation of Italian and Spanish wines, as the latter contributed to the congestion of the national market and fed part of the fraud on the composition and origin of French wines for everyday consumption. The legislative activity of this period shows a denunciation of the commercial treaties signed with Italy and Spain at the beginning of the 1880s. These instruments of free trade no longer seemed to correspond to the expectations of the viticultural world that was very well represented in Parliament. On the contrary, it was time to promote tariff policies, of which the laws of January 11, 1892 and February 1, 1899 were the cornerstones, against the interests of the wine trade. By significantly discouraging Italian and Spanish competition, French wine protectionism left its mark on the country's trade relations until the establishment of the common market.Durante los últimos veinte años del siglo XIX, Francia emprendió la reconstrucción de un viñedo asolado por la filoxera. Al mismo tiempo, pretendía poner fin a la importación de vinos italianos y españoles, ya que éstos contribuían a la saturación del mercado nacional y alimentaban algunos fraudes sobre la composición y el origen de los vinos franceses de consumo corriente. En la actividad legislativa de este periodo destaca la denuncia de los tratados comerciales firmados con Italia y España a principios de la década de 1880. Estos instrumentos de libre comercio ya no parecían corresponder a las expectativas de una viticultura muy bien representada en el Parlamento. Por el contrario, era el momento de promover la política arancelaria, de la que las leyes del 11 de enero de 1892 y del 1 de febrero de 1899 eran las piedras angulares, en contra de los intereses del comercio del vino. Al desalentar considerablemente la competencia italiana y española, el proteccionismo vitivinícolo francés dejó su huella en las relaciones comerciales del país hasta el establecimiento del mercado común.Au cours des vingt dernières années du XIXe siècle, la France entreprend la reconstruction de son vignoble ravagé par le phylloxera. Dans le même temps, elle cherche à mettre un terme à l'importation des vins italiens et espagnols, car ceux-ci contribuent à la saturation du marché national et alimentent certaines fraudes sur la composition ou l'origine des vins français de consommation courante. L'activité législative de cette période fait ressortir la dénonciation des traités commerciaux signés avec l'Italie et l'Espagne au début des années 1880. Ces instruments du libre-échange ne semblent effectivement plus correspondre aux attentes d’une viticulture très bien représentée au Parlement. Une nouvelle politique tarifaire, dont les lois du 11 janvier 1892 et du 1er février 1899 sont les pierres angulaires, est alors promue contre les intérêts du commerce du vin. En décourageant considérablement la concurrence italienne et espagnole, le protectionnisme viticole français marquera de son empreinte les relations commerciales du pays jusqu'à l'établissement du marché commun

    Molecular screening for Midichloria bacteria in hard and soft ticks (Acari: Ixodida).

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    Ticks can harbor complex and highly variable microbial communities. Among these microorganisms,there are important pathogens of humans and animals that can be transmitted through the blood meal.Less is known about the other members of the microbial community of Ixodida, those that do not causeovert diseases. Among these, Midichloria mitochondrii, symbiont of the tick Ixodes ricinus, is the firstdescribed member of the family Midichloriaceae, order Rickettsiales. This bacterium is present in 100%females and is vertically transmitted (Sassera, 2008). The possibility of horizontal transmission issuggested by serological and molecular analyses showing positivity of mammalian blood and sera to M.mitochondrii (Mariconti, 2012; Bazzocchi, 2013). However, its role is still unknown. Recent reports areexpanding the view of this family, now including bacteria of great biological and medical interest,indicating a widespread distribution with an increasing range of hosts, with ticks being stronglyrepresented (Epis, 2008).Here we present a molecular screening of 17 tick species (for a total of 92 individuals), detecting andquantifying bacteria closely related to M. mitochondrii in seven of them, including the first report of amidichloriacea in a soft tick species, Ornithodoros maritimus. Based on sequence identity andphylogenetic analysis we propose that these bacteria could constitute the genus Midichloria. Theperformed screening highlights different prevalence levels in different tick species including one, Ixodesaulacodi, where the bacteria is present in all examined individuals, like in I. ricinus. This result promptsus to hypothesize different roles of Midichloria bacteria in different tick species

    A Self-consistent Framework for Multiline Modeling in Line Intensity Mapping Experiments

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    Line intensity mapping (LIM) is a promising approach to study star formation and the interstellar medium (ISM) in galaxies by measuring the aggregate line emission from the entire galaxy population. In this work, we develop a simple yet physically motivated framework for modeling the line emission as would be observed in LIM experiments. It is done by building on analytic models of the cosmic infrared background that connect total infrared luminosity of galaxies to their host dark matter halos. We present models of the H I 21 cm, CO (1−0), [C II] 158 μm, and [N II] 122 and 205 μm lines consistent with current observational constraints. With four case studies of various combinations of these lines that probe different ISM phases, we demonstrate the potential for reliably extracting physical properties of the ISM, and the evolution of these properties with cosmic time, from auto- and cross-correlation analysis of these lines as measured by future LIM experiments

    DeepEOR: automated perioperative volumetric assessment of variable grade gliomas using deep learning

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    PURPOSE Volumetric assessments, such as extent of resection (EOR) or residual tumor volume, are essential criterions in glioma resection surgery. Our goal is to develop and validate segmentation machine learning models for pre- and postoperative magnetic resonance imaging scans, allowing us to assess the percentagewise tumor reduction after intracranial surgery for gliomas. METHODS For the development of the preoperative segmentation model (U-Net), MRI scans of 1053 patients from the Multimodal Brain Tumor Segmentation Challenge (BraTS) 2021 as well as from patients who underwent surgery at the University Hospital in Zurich were used. Subsequently, the model was evaluated on a holdout set containing 285 images from the same sources. The postoperative model was developed using 72 scans and validated on 45 scans obtained from the BraTS 2015 and Zurich dataset. Performance is evaluated using Dice Similarity score, Jaccard coefficient and Hausdorff 95%. RESULTS We were able to achieve an overall mean Dice Similarity Score of 0.59 and 0.29 on the pre- and postoperative holdout sets, respectively. Our algorithm managed to determine correct EOR in 44.1%. CONCLUSION Although our models are not suitable for clinical use at this point, the possible applications are vast, going from automated lesion detection to disease progression evaluation. Precise determination of EOR is a challenging task, but we managed to show that deep learning can provide fast and objective estimates
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