147 research outputs found
In-water lidar simulations: the ALADIN ADM-Aeolus backscattered signal at 355 nm
The Lidar Ocean Color (LiOC) Monte Carlo code has been developed to simulate the in-water propagation of the lidar beam emitted by the ALADIN ADM-Aeolus instrument in the ultraviolet (UV) spectral region (∼ 355 nm). To this end, LiOC accounts for reflection/transmission processes at the sea surface, absorption and multiple scattering in the water volume, and reflection from the sea bottom. The water volume components included in the model are pure seawater, Chlorophyll-a concentration (Chl-a), Colored Dissolved Organic Matter (CDOM), and/or a generic absorbing species. By considering the transmission/reception measurement geometry of ALADIN ADM-Aeolus, the study documents the variability of the normalized backscattered signal in different bio-optical conditions. The potential for data product retrieval based on information at 355 nm is considered by developing a demonstrative lookup table to estimate the absorption budget exceeding that explained by Chl-a. Results acknowledge the interest of space programs in exploiting UV bands for ocean color remote sensing, as, for instance, addressed by the PACE mission of NASA
The Merging System Am 2049-691
Spectroscopic and photometric observations of the peculiar object AM 2049-691
are presented here. Its systemic velocity is V(GSR) = (10956 +-30) km/s, and
the derived distance (H(0) = 75 km/s/Mpc) results 146 Mpc. A bridge is observed
between two very distinct nuclei whose separation is about 10 kpc, as well as
two tails that emerge from the extremes SW and NE of the main body and extend
up to 41 and 58 kpc respectively. The spectral characteristics of the all
observed zones are typical of H II regions of low excitation. The internal
reddening is quit high, particularly in the NE nucleus. All the derived
equivalent widths of the H(alpha)+[N II] lines indicate enhanced star formation
compared with isolated galaxies, specially in the NE nucleus; the equivalent
width corresponding to the integrated spectrum reflects starburst activity in
the whole object, and is compatible with a merger of two disk galaxies. All the
observed characteristics of AM 2049-691 indicate it is a merger, where a
overabundance of nitrogen is detected in one of the nuclei, which has the most
evolved population and would be the most massive one. The detected total IR
emission is not very high. The integrated total color B - V corresponds to a
Sc-Scd galaxy and its average integrated population is about F7 type.
Indicative B - V colors of the nuclei, corrected for internal absorption, are
in agreement with the spectroscopic results. The central radial velocity
dispersions at the nuclei suggest that the most massive galaxy would be the
progenitor of the SW component. The observed radial velocity curve shows the
presence of two subsystems, each one associated with a different nucleus.Comment: 5 pages, 4 figure
Exploring the potential of Aeolus lidar mission for ocean color applications
The Atmospheric Laser Doppler Instrument (ALADIN) onboard the Aeolus wind mission was the first High Spectral Resolution Lidar operating in the Ultra Violet (UV) region deployed in space. This study explores and documents the feasibility of deriving ocean optical properties using data from ALADIN. A three steps (i.e. data screening, analytical estimation of the total in-water signal contribution, Look Up Table-based estimation of the in-water attenuation) retrieval algorithm was developped combining data analysis and signal simulations from a radiative transfer model. The algorithm has been implemented using the signal acquired by the Mie channel, and tested for 1-year of Aeolus observations. This approach allowed estimating the first Aeolus derived Ocean Color (OC) products in terms of the total in-water signal contribution and the in-water attenuation term in a spectral region (355 nm) not covered, during Aeolous lifetime, by operational OC products. The validation process involved comparing these products with both Biogeochemical-Argo (BGC-Argo) field measurements and satellite OC dataset distributed by ESA Ocean Color Climate Change Initiative across a set of 7 selected oceanic regions representing diverse open-ocean scenarios. These validation exercises attested the general accordance between OC reference measurements and the proposed Aeolus OC parameters. Thus, this study was able to provide statistical evidence of the sensitivity of the retrieved Aeolus in-water lidar attenuation term to the CDOM variability on a temporal/seasonal and spatial/regional basis. A preliminary estimation of the uncertainty associated to the retrieved quality controlled Klid, was performed assuming the radiometric noise as unique source of uncertainty. As a result, a median/average value of absolute relative percent difference of about 50/80% was obtained. Limits of the developed technique, possible improvements, potential adaptation to planned/future space lidar missions are discussed
Sonorous memory in Jonathan Perel’s El predio (2010) and Los murales (2011)
Throughout his filmic production, Argentine director Jonathan Perel has demonstrated strict adherence to a unique aesthetic programme in which human agents appear to have only a minimal role. Each film contains only diegetic sounds and consists of fixed shots of architectural spaces and objects closely associated with the most recent Argentine military dictatorship (1976–1983) and recent attempts to memorialise the atrocities they committed. Through the close analysis of Perel’s first two films – El predio (2010) and Los murales (2011) – this article focusses on Perel’s highly distinctive use of environmental sound and argues that they are, in fact, uniquely musical works. Drawing on the work of John Cage, Michel Chion, Deleuze and Guattari, and Doreen Massey, the article proposes that Perel manipulates sound in order to situate debates over the memorialisation of recent atrocities in a perpetual present and thus critique contemporary abuses of power in Argentina
Geospatial Resolution of Human and Bacterial Diversity with City-Scale Metagenomics
The panoply of microorganisms and other species present in our environment influence human health and disease, especially in cities, but have not been profiled with metagenomics at a city-wide scale. We sequenced DNA from surfaces across the entire New York City (NYC) subway system, the Gowanus Canal, and public parks. Nearly half of the DNA (48%) does not match any known organism; identified organisms spanned 1,688 bacterial, viral, archaeal, and eukaryotic taxa, which were enriched for harmless genera associated with skin (e.g., Acinetobacter). Predicted ancestry of human DNA left on subway surfaces can recapitulate U.S. Census demographic data, and bacterial signatures can reveal a station’s history, such as marine-associated bacteria in a hurricane-flooded station. Some evidence of pathogens was found (Bacillus anthracis), but a lack of reported cases in NYC suggests that the pathogens represent a normal, urban microbiome. This baseline metagenomic map of NYC could help long-term disease surveillance, bioterrorism threat mitigation, and health management in the built environment of citie
Impact of Vutrisiran on Quality of Life and Physical Function in Patients with Hereditary Transthyretin-Mediated Amyloidosis with Polyneuropathy
INTRODUCTION: Hereditary transthyretin (ATTRv; v for variant) amyloidosis, also known as hATTR amyloidosis, is a progressive and fatal disease associated with rapid deterioration of physical function and patients' quality of life (QOL). Vutrisiran, a subcutaneously administered RNA interference (RNAi) therapeutic that reduces hepatic production of transthyretin, was assessed in patients with ATTRv amyloidosis with polyneuropathy in the pivotal HELIOS-A study. METHODS: The phase 3 open-label HELIOS-A study investigated the efficacy and safety of vutrisiran in patients with ATTRv amyloidosis with polyneuropathy, compared with an external placebo group from the APOLLO study of the RNAi therapeutic patisiran. Measures of QOL and physical function were assessed. RESULTS: At month 18, vutrisiran improved Norfolk Quality of Life-Diabetic Neuropathy (Norfolk QOL-DN) total score (least squares mean difference [LSMD] in change from baseline [CFB]: –21.0; p = 1.84 × 10–10) and Norfolk QOL-DN domain scores, compared with external placebo. This benefit relative to external placebo was evident across all baseline polyneuropathy disability (PND) scores and most pronounced in patients with baseline PND scores I–II. Compared with external placebo, vutrisiran also demonstrated benefit in EuroQoL-Visual Analog Scale (EQ-VAS) score (LSMD in CFB: 13.7; nominal p = 2.21 × 10–7), 10-m walk test (LSMD in CFB: 0.239 m/s; p = 1.21 × 10–7), Rasch-built Overall Disability Score (LSMD in CFB: 8.4; p = 3.54 × 10–15), and modified body mass index (mBMI) (LSMD in CFB: 140.7; p = 4.16 × 10–15) at month 18. Overall, Norfolk QOL-DN, EQ-VAS, and mBMI improved from pretreatment baseline with vutrisiran, whereas all measures worsened from baseline in the external placebo group. At month 18, Karnofsky Performance Status was stable/improved from baseline in 58.2/13.1% with vutrisiran versus 34.7/8.1% with external placebo. CONCLUSION: Vutrisiran treatment provided significant clinical benefits in multiple measures of QOL and physical function in patients with ATTRv amyloidosis with polyneuropathy. Benefits were most pronounced in patients with earlier-stage disease, highlighting the importance of early diagnosis and treatment
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