601 research outputs found

    HerMES: Lyman Break Galaxies Individually Detected at 0.7 ≀ z ≀ 2.0 in GOODS-N with Herschel/SPIRE

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    As part of the Herschel Multi-tiered Extragalactic Survey we have investigated the rest-frame far-infrared (FIR) properties of a sample of more than 4800 Lyman break galaxies (LBGs) in the Great Observatories Origins Deep Survey North field. Most LBGs are not detected individually, but we do detect a sub-sample of 12 objects at 0.7 2.5. The UV-to-FIR spectral energy distributions of the objects detected in the rest-frame FIR are investigated using the code CIGALE to estimate physical parameters. We find that LBGs detected by SPIRE are high-mass, luminous infrared galaxies. It appears that LBGs are located in a triangle-shaped region in the A_(FUV) versus log L_(FUV) = 0 diagram limited by A_(FUV) = 0 at the bottom and by a diagonal following the temporal evolution of the most massive galaxies from the bottom right to the top left of the diagram. This upper envelop can be used as upper limits for the UV dust attenuation as a function of L_(FUV). The limits of this region are well explained using a closed-box model, where the chemical evolution of galaxies produces metals, which in turn lead to higher dust attenuation when the galaxies age

    Crime scene and body alterations caused by arthropods: implications in death investigation

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    The activity of arthropods on corpses has been largely investigated, since they can produce information to reconstruct the peri-mortem events. However, the feeding/movement activity of insects around the crime scene, among the clothes and on the body, can also cause some alterations that can lead to wrong reconstruction and misinterpretations. This article summarises all the post-mortem arthropods artefacts related to the scene (i.e. fly artefacts and floor stripes) and the body (i.e. skin and other soft tissue alterations, bone alterations and hair alterations) that can mislead the forensic pathologist, discussing macroscopic and microscopic findings derived from forensic casework and from experimental laboratory studies, in order to provide a useful instrument to avoid misinterpretations and evaluation errors. Finally, some procedural notes for the documentation and the interpretation of findings are proposed

    Optimal floodgate operation for river flood management: The case study of Padova (Italy)

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    Study region: A large, densely populated area nearby Padova (Veneto Region, Italy) is exposed to floods owing to the Brenta-Bacchiglione river network, which is formed by two main rivers and by a set of interconnected channels, control structures and pump stations. Study focus: The Brenta and Bacchiglione rivers suffer from an increasing pressure in terms of flood events, especially for urban sprawl, anthropogenic modifications of drainage networks, and climate change. Finding and implementing effective remedies is hard in developed countries due to the presence of several constraints. Optimal flood management in complex river networks is then a way to reduce flood hazard, at a relatively low cost compared to structural measures. Hence, optimal operation rules for floodgates at an existing control structure are searched for to control the upstream water level and to divert a proper amount of the Bacchiglione discharge into the Brenta River. The operation rules have been endorsed by the Civil Engineering Department in charge of flood management and have been implemented in the flood forecasting Early Warning System of the Regional Civil Protection Office. New hydrological insights: The proper operation of control structures allows reducing flood risk by balancing the water discharge in the river networks. The engagement of end-users proves beneficial as it fosters exchange of knowledge and allows for the effective adoption of research outcomes in decision making

    Hydrogen peroxide is a neuronal alarmin that triggers specific RNAs, local translation of Annexin A2, and cytoskeletal remodeling in Schwann cells

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    Schwann cells are key players in neuro-regeneration: They sense "alarm" signals released by degenerating nerve terminals and differentiate toward a proregenerative phenotype, with phagocytosis of nerve debris and nerve guidance. At the murine neuromuscular junction, hydrogen peroxide (H2O2) is a key signal of Schwann cells' activation in response to a variety of nerve injuries. Here we report that Schwann cells exposed to low doses of H2O2 rewire the expression of several RNAs at both transcriptional and translational levels. Among the genes positively regulated at both levels, we identified an enriched cluster involved in cytoskeleton remodeling and cell migration, with the Annexin (Anxa) proteins being the most represented family. We show that both Annexin A2 (Anxa2) transcript and protein accumulate at the tips of long pseudopods that Schwann cells extend upon H2O2 exposure. Interestingly, Schwann cells reply to this signal and to nerve injury by locally translating Anxa2 in pseudopods, and undergo an extensive cytoskeleton remodeling. Our results show that, similarly to neurons, Schwann cells take advantage of local protein synthesis to change shape and move toward damaged axonal terminals to facilitate axonal regeneration

    Petrologia e GeoquĂ­mica do Complexo BĂĄsico de Lomba Grande, RS

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    O complexo bĂĄsico de Lomba Grande, RS, localizado no MunicĂ­pio de GravataĂ­, Ă© constituĂ­do por trĂȘs corpos hipabissais de afinidade toleĂ­tica encaixados em sedimentitos das FormaçÔes Botucatu e Sanga do Cabral, designados informalmente de Olivina-gabro, DiabĂĄsio Envolvente e DiabĂĄsio Oriental. O Olivina-gabro constitui um corpo irregular com volume aproximado de 0,47 km3, compreendendo mais de 95% do volume total do complexo. As caracterĂ­sticas quĂ­micas sĂŁo de magmas relativamente primitivos, com altos teores de MgO, Cr, Ni e Co e empobrecimento em elementos incompatĂ­veis (K, Rb, Ba, Zr e ETR). Os ETR mostram padrĂ”es pouco fracionados (LaN/YbN-4,3) e destituĂ­dos de anomalias negativas de Eu significativas (Eu/Eu* -0,83), revelando uma afinidade com os P-MORB. Os dados geocronolĂłgicos apontam idades correspondentes ao TriĂĄssico Superior (-160 Ma.), coincidentes com as primeiras manifestaçÔes vulcĂąnicas da Formação Serra Geral. O registro de uma margem de resfriamento (MgO-11%) permite estabelecer que o lĂ­quido Ă©, provavelmente, resultante da cristalização fracionada de magmas picrĂ­ticos em pressĂ”es entre 10 e 15 Kb. A evolução “in situ” do sistema na atual cĂąmara compreende a realimentação e diferenciação magmĂĄtica produzida por fracionamento e concentração de olivina e plagioclĂĄsio, havendo separação do lĂ­quido residual por movimentos convectivos. O DiabĂĄsio Envolvente possui idades da ordem de 125 Ma., envolvendo parcialmente o Olivina-gabro. Constitui-se de dois litotipos, similares Ă s vulcĂąnicas bĂĄsicas baixo-titĂąnio da Bacia do ParanĂĄ, com conteĂșdos de TiO2 inferiores a 1,48%, MgO entre 3 e 6,5% e elementos incompatĂ­veis relativamente baixos (Rb, Sr, Zr, La e P). Os ETR exibem um padrĂŁo com fraco fracionamento (LaN/YbN-5,5) e leve anomalia negativa de Eu (Eu/Eu* -0,7). A origem dos lĂ­quidos progenitores apresenta maior consistĂȘncia com um modelo de cristalização fracionada de um lĂ­quido picrĂ­tico assimilando pequenas fraçÔes de crosta superior. O DiabĂĄsio Oriental ocorre como uma intrusĂŁo de diĂąmetro reduzido (-400 m) composta de dois litotipos fanerĂ­ticos, com idade da ordem de 125 Ma. O quimismo caracteriza-se por teores relativamente altos de MgO, Cr e Ni no tipo olivĂ­nico, enquanto que no tipo nĂŁo olivĂ­nico estes elementos sĂŁo relativamente empobrecidos. O conteĂșdo de TiO2 e elementos incompatĂ­veis (Rb, Sr, Zr, La, P) Ă© baixo, correlacionĂĄveis Ă s vulcĂąnicas bĂĄsicas baixo-titĂąnio da Formação Serra Geral, e os ETR apresentam um padrĂŁo pouco fracionado (LaN/YbN-5,1) com uma anomalia negativa de Eu da ordem de 0,7

    Herschel observations of a z ∌ 2 stellar mass selected galaxy sample drawn from the GOODS NICMOS Survey

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    We present a study of the far-infrared (IR) properties of a stellar mass selected sample of 1.5 9.5 drawn from the Great Observatories Origins Deep Survey (GOODS) Near Infrared Camera and Multi-Object Spectrometer (NICMOS) Survey (GNS), the deepest H-band Hubble Space Telescope survey of its type prior to the installation of Wide Field Camera 3 (WFC3). We use far-IR and submm data from the Photoconductor Array Camera and Spectrometer (PACS) and Spectral and Photometric Imaging Receiver (SPIRE) instruments on-board Herschel, taken from the PACS Evolutionary Probe (PEP) and Herschel Multi-Tiered Extragalactic Survey (HerMES) key projects, respectively. We find a total of 22 GNS galaxies, with median log (M_*/M_⊙) = 10.8 and z = 2.0, associated with 250 Όm sources detected with signal-to-noise ratio (SNR) > 3. We derive mean total IR luminosity log LIR(L_⊙) = 12.36 ± 0.05 and corresponding star formation rate (SFR)_(IR + UV) = (280 ± 40) M_⊙ yr^(−1) for these objects, and find them to have mean dust temperature T_dust ≈ 35 K. We find that the SFR derived from the far-IR photometry combined with ultraviolet (UV)-based estimates of unobscured SFR for these galaxies is on average more than a factor of 2 higher than the SFR derived from extinction-corrected UV emission alone, although we note that the IR-based estimate is subject to substantial Malmquist bias. To mitigate the effect of this bias and extend our study to fainter fluxes, we perform a stacking analysis to measure the mean SFR in bins of stellar mass. We obtain detections at the 2–4σ level at SPIRE wavelengths for samples with log (M_*/M_⊙) > 10. In contrast to the Herschel detected GNS galaxies, we find that estimates of SFR_(IR + UV) for the stacked samples are comparable to those derived from extinction-corrected UV emission, although the uncertainties are large. We find evidence for an increasing fraction of dust obscured star formation with stellar mass, finding SFR_(IR)/SFR_(UV) ∝ M^(0.7±0.2)_*, which is likely a consequence of the mass–metallicity relation

    The Herschel Stripe 82 Survey (HerS): maps and early catalog

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    We present the first set of maps and band-merged catalog from the Herschel Stripe 82 Survey (HerS). Observations at 250, 350, and 500ÎŒm were taken with the Spectral and Photometric Imaging Receiver instrument aboard the Herschel Space Observatory. HerS covers 79deg 2 along the SDSS Stripe 82 to an average depth of 13.0, 12.9, and 14.8mJybeam −1 (including confusion) at 250, 350, and 500ÎŒm, respectively. HerS was designed to measure correlations with external tracers of the dark matter density field—either point-like (i.e., galaxies selected from radio to X-ray) or extended (i.e., clusters and gravitational lensing)—in order to measure the bias and redshift distribution of intensities of infrared-emitting dusty star-forming galaxies and active galactic nuclei. By locating HerS in Stripe 82, we maximize the overlap with available and upcoming cosmological surveys. The band-merged catalog contains 3.3 × 10 4 sources detected at a significance of ?3σ (including confusion noise). The maps and catalog are available at http://www.astro.caltech.edu/hers/

    HerMES: deep number counts at 250 ÎŒm, 350 ÎŒm and 500 ÎŒm in the COSMOS and GOODS-N fields and the build-up of the cosmic infrared background

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    Aims. The Spectral and Photometric Imaging REceiver (SPIRE) onboard the Herschel space telescope has provided confusion limited maps of deep fields at 250 ÎŒm, 350 ÎŒm, and 500 ÎŒm, as part of the Herschel Multi-tiered Extragalactic Survey (HerMES). Unfortunately, due to confusion, only a small fraction of the cosmic infrared background (CIB) can be resolved into individually-detected sources. Our goal is to produce deep galaxy number counts and redshift distributions below the confusion limit at SPIRE wavelengths (~20 mJy), which we then use to place strong constraints on the origins of the cosmic infrared background and on models of galaxy evolution. Methods. We individually extracted the bright SPIRE sources (>20 mJy) in the COSMOS field with a method using the positions, the flux densities, and the redshifts of the 24 ÎŒm sources as a prior, and derived the number counts and redshift distributions of the bright SPIRE sources. For fainter SPIRE sources (<20 mJy), we reconstructed the number counts and the redshift distribution below the confusion limit using the deep 24 ÎŒm catalogs associated with photometric redshift and information provided by the stacking of these sources into the deep SPIRE maps of the GOODS-N and COSMOS fields. Finally, by integrating all these counts, we studied the contribution of the galaxies to the CIB as a function of their flux density and redshift. Results. Through stacking, we managed to reconstruct the source counts per redshift slice down to ~2 mJy in the three SPIRE bands, which lies about a factor 10 below the 5σ confusion limit. Our measurements place tight constraints on source population models. None of the pre-existing models are able to reproduce our results at better than 3-σ. Finally, we extrapolate our counts to zero flux density in order to derive an estimate of the total contribution of galaxies to the CIB, finding 10.1_(-2.3)^(+2.6) nW m^(-2) sr^(-1), 6.5_(-1.6)^(+1.7) nW m^(-2) sr^(-1), and 2.8_(-0.8)^(+0.9) nW m^(-2) sr^(-1) at 250 ÎŒm, 350 ÎŒm, and 500 ÎŒm, respectively. These values agree well with FIRAS absolute measurements, suggesting our number counts and their extrapolation are sufficient to explain the CIB. We find that half of the CIB is emitted at z = 1.04, 1.20, and 1.25, respectively. Finally, combining our results with other works, we estimate the energy budget contained in the CIB between 8 ÎŒm and 1000 ÎŒm: 26_(-3)^(+7) nW m^(-2) sr^(-1)

    Remote sensing for optimal estimation of water temperature dynamics in shallow tidal environments

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    Given the increasing anthropogenic pressures on lagoons, estuaries, and lakes and considering the highly dynamic behavior of these systems, methods for the continuous and spatially distributed retrieval of water quality are becoming vital for their correct monitoring and management. Water temperature is certainly one of the most important drivers that influence the overall state of coastal systems. Traditionally, lake, estuarine, and lagoon temperatures are observed through point measurements carried out during field campaigns or through a network of sensors. However, sporadic measuring campaigns or probe networks rarely attain a density sufficient for process understanding, model development/validation, or integrated assessment. Here, we develop and apply an integrated approach for water temperature monitoring in a shallow lagoon which incorporates satellite and in-situ data into a mathematical model. Specifically, we use remote sensing information to constrain large-scale patterns of water temperature and high-frequency in situ observations to provide proper time constraints. A coupled hydrodynamic circulation-heat transport model is then used to propagate the state of the system forward in time between subsequent remote sensing observations. Exploiting the satellite data high spatial resolution and the in situ measurements high temporal resolution, the model may act a physical interpolator filling the gap intrinsically characterizing the two monitoring techniques
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