Recent structural evolution of forni glacier tongue (Ortles-Cevedale Group, Central Italian Alps)

Structural glaciology yields important details about the evolution of glacier dynamics in response to climate change. The maps provided here document the occurrence and evolution of brittle and ductile structures on the tongue of Forni Glacier, Ortles-Cevedale Group, Central Italian Alps, between 2003 and 2014. Through the remote sensing-based analysis of structures, we found evidence of brittle fractures such as crevasses, faults and ring faults, and ductile structures such as ogives at the base of the icefall in the eastern glacier tongue. Although each of the three glacier tongues have evolved differently, a reduction in flow-related dynamics and an increase in the number of collapse structures occurred over the study period. Analysis of the glacier structural evolution based on the numbers and the locations of different structures, suggest a slowdown of glacier flow on the eastern tongue. The recent evolution of the glacier also suggests that the occurrence of a disintegration scenario is likely to worsen over the next decades

Local and general monitoring of forni glacier (Italian alps) using multi-platform structure-from-motion photogrammetry

Experts from the University of Milan have been investigating Forni Glacier in the Italian alps for decades, resulting in the archive of a cumbersome mass of observed data. While the analysis of archive maps, medium resolution satellite images and DEM's may provide an overview of the long-term processes, the application of close-range sensing techniques offers the unprecedented opportunity to operate a 4D reconstruction of the glacier geometry at both global and local levels. In the latest years the availability of high-resolution DEM's from stereo-photogrammetry (2007) and UAV-photogrammetry (2014 and 2016) has allowed an improved analysis of the glacier ice-mass balance within time. During summer 2016 a methodology to record the local disruption processes has been investigated. The presence of vertical and sub-vertical surfaces has motivated the use of Structure-from-Motion Photogrammetry from ground-based stations, which yielded results comparable to the ones achieved using a long-range terrestrial laser scanner. This technique may be assumed as benchmarking for accuracy assessment, but is more difficult to be operated in high-mountain areas. Nevertheless, the measurement of GCP's for the terrestrial photogrammetric project has revealed to be a complex task, involving the need of a total station a GNSS. The effect of network geometry on the final output has also been investigated for SfM-Photogrammetry, considering the severe limitations implied in the Alpine environment

Virological rebound in human immunodeficiency virus-infected patients with or without residual viraemia: results from an extended follow-up

AbstractHuman immunodeficiency virus (HIV) -infected patients with HIV RNA loads of < 50 copies/mL were followed-up for a median (interquartile range) of 30.8 (11.7–32.9) months to study the effect of residual viraemia (RV) on virological rebound (VR). At baseline, 446 (60.3%) patients had undetectable HIV RNA (group A) and 293 (39.7%) had RV (1–49 HIV RNA copies/mL, group B) by kinetic PCR. VR occurred in 4 (0.9%) patients in group A and in 12 (4.1%) patients in group B (p 0.007). Time to VR was shorter among patients of group B (Log-rank test: p 0.003). However, the proportion of VR was extremely low also among patients with RV

Chemostratigraphy of the Mina Verdún Group and other cement-grade Proterozoic limestone deposits in Uruguay

The Mina Verdún Group (MVG) was erected by Poiré et al. (2003) to include a sedimentary succession exposed in the homonymous mine, which is made up (from base to top) of (Fig. 2): -Don Mario Formation: metapelites -La Toma Formation: marls -El Calabozo Formation: grey stromatolitic limestones -Gibraltar Formation: dolomitic marls, red limestones and massive dolostones Thickness of the succession at its stratotype reaches 285 m. An important feature of the thick (up to 170 m) limestones of El Calabozo Formation is the occurrence of a stromatolite assemblage composed almost exclusively by Conophyton (Fig. 2). These limestones are of considerable economic importance, because they constitute the basis of a large cement industry. A minimum age for the succession is provided by the unconformably overlying Las Ventanas Formation, which on the basis of acritarch biostratigraphy is assigned to the lower Ediacaran (635-575 Ma, Blanco & Gaucher, 2005). Gaucher et al. (2004d) assign the succession exposed in the Burgue o limestone Quarry, 40 km to the south of Mina Verdún, to the MVG. The succession exposed in the quarry, 150 m in thickness, includes (from base to top): metamarls, limestones, stromatolitic Conophytonlimestones and massive dolostones. At the stratotype and in Burgueño Quarry, conglomerates overly with erosional unconformity the MVG. These conglomerates, assigned to LVFm (Blanco & Gaucher, 2004, 2005), include a level of diamictites and breccias at the contact to the MVG, which has been recognized as a palaeokarst surface. The assocation of palaeokarst surfaces developed on top of carbonate successions and overlain by glacigenic diamictites is well known for a number of Neoproterozoic successions. Dropstones occur in laminated mudstones, associated with diamictites. However, no carbonates occur on top of the diamictites. We carried out 13C and 18O analyses of carbonates and corresponding petrographic studies at two sections of the MVG and also on carbonates mined for the cement industry at La Plata Mine (ANCAP), with the aim of testing chemostratigraphic tools as an aid for the exporation of cement-grade carbonates. corresponding petrographic studies at two sections of the MVG and also on carbonates mined for the cement industry at La Plata Mine (ANCAP), with the aim of testing chemostratigraphic tools as an aid for the exporation of cement-grade carbonates. and massive dolostones. At the stratotype and in Burgueño Quarry, conglomerates overly with erosional unconformity the MVG. These conglomerates, assigned to LVFm (Blanco & Gaucher, 2004, 2005), include a level of diamictites and breccias at the contact to the MVG, which has been recognized as a palaeokarst surface. The assocation of palaeokarst surfaces developed on top of carbonate successions and overlain by glacigenic diamictites is well known for a number of Neoproterozoic successions. Dropstones occur in laminated mudstones, associated with diamictites. However, no carbonates occur on top of the diamictites. We carried out 13C and 18O analyses of carbonates and corresponding petrographic studies at two sections of the MVG and also on carbonates mined for the cement industry at La Plata Mine (ANCAP), with the aim of testing chemostratigraphic tools as an aid for the exporation of cement-grade carbonates. corresponding petrographic studies at two sections of the MVG and also on carbonates mined for the cement industry at La Plata Mine (ANCAP), with the aim of testing chemostratigraphic tools as an aid for the exporation of cement-grade carbonates. Mina Verdún, to the MVG. The succession exposed in the quarry, 150 m in thickness, includes (from base to top): metamarls, limestones, stromatolitic Conophytonlimestones and massive dolostones. At the stratotype and in Burgueño Quarry, conglomerates overly with erosional unconformity the MVG. These conglomerates, assigned to LVFm (Blanco & Gaucher, 2004, 2005), include a level of diamictites and breccias at the contact to the MVG, which has been recognized as a palaeokarst surface. The assocation of palaeokarst surfaces developed on top of carbonate successions and overlain by glacigenic diamictites is well known for a number of Neoproterozoic successions. Dropstones occur in laminated mudstones, associated with diamictites. However, no carbonates occur on top of the diamictites. We carried out 13C and 18O analyses of carbonates and corresponding petrographic studies at two sections of the MVG and also on carbonates mined for the cement industry at La Plata Mine (ANCAP), with the aim of testing chemostratigraphic tools as an aid for the exporation of cement-grade carbonates. corresponding petrographic studies at two sections of the MVG and also on carbonates mined for the cement industry at La Plata Mine (ANCAP), with the aim of testing chemostratigraphic tools as an aid for the exporation of cement-grade carbonates. and massive dolostones. At the stratotype and in Burgueño Quarry, conglomerates overly with erosional unconformity the MVG. These conglomerates, assigned to LVFm (Blanco & Gaucher, 2004, 2005), include a level of diamictites and breccias at the contact to the MVG, which has been recognized as a palaeokarst surface. The assocation of palaeokarst surfaces developed on top of carbonate successions and overlain by glacigenic diamictites is well known for a number of Neoproterozoic successions. Dropstones occur in laminated mudstones, associated with diamictites. However, no carbonates occur on top of the diamictites. We carried out 13C and 18O analyses of carbonates and corresponding petrographic studies at two sections of the MVG and also on carbonates mined for the cement industry at La Plata Mine (ANCAP), with the aim of testing chemostratigraphic tools as an aid for the exporation of cement-grade carbonates. corresponding petrographic studies at two sections of the MVG and also on carbonates mined for the cement industry at La Plata Mine (ANCAP), with the aim of testing chemostratigraphic tools as an aid for the exporation of cement-grade carbonates. considerable economic importance, because they constitute the basis of a large cement industry. A minimum age for the succession is provided by the unconformably overlying Las Ventanas Formation, which on the basis of acritarch biostratigraphy is assigned to the lower Ediacaran (635-575 Ma, Blanco & Gaucher, 2005). Gaucher et al. (2004d) assign the succession exposed in the Burgue o limestone Quarry, 40 km to the south of Mina Verdún, to the MVG. The succession exposed in the quarry, 150 m in thickness, includes (from base to top): metamarls, limestones, stromatolitic Conophytonlimestones and massive dolostones. At the stratotype and in Burgueño Quarry, conglomerates overly with erosional unconformity the MVG. These conglomerates, assigned to LVFm (Blanco & Gaucher, 2004, 2005), include a level of diamictites and breccias at the contact to the MVG, which has been recognized as a palaeokarst surface. The assocation of palaeokarst surfaces developed on top of carbonate successions and overlain by glacigenic diamictites is well known for a number of Neoproterozoic successions. Dropstones occur in laminated mudstones, associated with diamictites. However, no carbonates occur on top of the diamictites. We carried out 13C and 18O analyses of carbonates and corresponding petrographic studies at two sections of the MVG and also on carbonates mined for the cement industry at La Plata Mine (ANCAP), with the aim of testing chemostratigraphic tools as an aid for the exporation of cement-grade carbonates. corresponding petrographic studies at two sections of the MVG and also on carbonates mined for the cement industry at La Plata Mine (ANCAP), with the aim of testing chemostratigraphic tools as an aid for the exporation of cement-grade carbonates. and massive dolostones. At the stratotype and in Burgueño Quarry, conglomerates overly with erosional unconformity the MVG. These conglomerates, assigned to LVFm (Blanco & Gaucher, 2004, 2005), include a level of diamictites and breccias at the contact to the MVG, which has been recognized as a palaeokarst surface. The assocation of palaeokarst surfaces developed on top of carbonate successions and overlain by glacigenic diamictites is well known for a number of Neoproterozoic successions. Dropstones occur in laminated mudstones, associated with diamictites. However, no carbonates occur on top of the diamictites. We carried out 13C and 18O analyses of carbonates and corresponding petrographic studies at two sections of the MVG and also on carbonates mined for the cement industry at La Plata Mine (ANCAP), with the aim of testing chemostratigraphic tools as an aid for the exporation of cement-grade carbonates. corresponding petrographic studies at two sections of the MVG and also on carbonates mined for the cement industry at La Plata Mine (ANCAP), with the aim of testing chemostratigraphic tools as an aid for the exporation of cement-grade carbonates. Mina Verdún, to the MVG. The succession exposed in the quarry, 150 m in thickness, includes (from base to top): metamarls, limestones, stromatolitic Conophytonlimestones and massive dolostones. At the stratotype and in Burgueño Quarry, conglomerates overly with erosional unconformity the MVG. These conglomerates, assigned to LVFm (Blanco & Gaucher, 2004, 2005), include a level of diamictites and breccias at the contact to the MVG, which has been recognized as a palaeokarst surface. The assocation of palaeokarst surfaces developed on top of carbonate successions and overlain by glacigenic diamictites is well known for a number of Neoproterozoic successions. Dropstones occur in laminated mudstones, associated with diamictites. However, no carbonates occur on top of the diamictites. We carried out 13C and 18O analyses of carbonates and corresponding petrographic studies at two sections of the MVG and also on carbonates mined for the cement industry at La Plata Mine (ANCAP), with the aim of testing chemostratigraphic tools as an aid for the exporation of cement-grade carbonates. corresponding petrographic studies at two sections of the MVG and also on carbonates mined for the cement industry at La Plata Mine (ANCAP), with the aim of testing chemostratigraphic tools as an aid for the exporation of cement-grade carbonates. and massive dolostones. At the stratotype and in Burgueño Quarry, conglomerates overly with erosional unconformity the MVG. These conglomerates, assigned to LVFm (Blanco & Gaucher, 2004, 2005), include a level of diamictites and breccias at the contact to the MVG, which has been recognized as a palaeokarst surface. The assocation of palaeokarst surfaces developed on top of carbonate successions and overlain by glacigenic diamictites is well known for a number of Neoproterozoic successions. Dropstones occur in laminated mudstones, associated with diamictites. However, no carbonates occur on top of the diamictites. We carried out 13C and 18O analyses of carbonates and corresponding petrographic studies at two sections of the MVG and also on carbonates mined for the cement industry at La Plata Mine (ANCAP), with the aim of testing chemostratigraphic tools as an aid for the exporation of cement-grade carbonates. corresponding petrographic studies at two sections of the MVG and also on carbonates mined for the cement industry at La Plata Mine (ANCAP), with the aim of testing chemostratigraphic tools as an aid for the exporation of cement-grade carbonates. Conophyton (Fig. 2). These limestones are of considerable economic importance, because they constitute the basis of a large cement industry. A minimum age for the succession is provided by the unconformably overlying Las Ventanas Formation, which on the basis of acritarch biostratigraphy is assigned to the lower Ediacaran (635-575 Ma, Blanco & Gaucher, 2005). Gaucher et al. (2004d) assign the succession exposed in the Burgue o limestone Quarry, 40 km to the south of Mina Verdún, to the MVG. The succession exposed in the quarry, 150 m in thickness, includes (from base to top): metamarls, limestones, stromatolitic Conophytonlimestones and massive dolostones. At the stratotype and in Burgueño Quarry, conglomerates overly with erosional unconformity the MVG. These conglomerates, assigned to LVFm (Blanco & Gaucher, 2004, 2005), include a level of diamictites and breccias at the contact to the MVG, which has been recognized as a palaeokarst surface. The assocation of palaeokarst surfaces developed on top of carbonate successions and overlain by glacigenic diamictites is well known for a number of Neoproterozoic successions. Dropstones occur in laminated mudstones, associated with diamictites. However, no carbonates occur on top of the diamictites. We carried out 13C and 18O analyses of carbonates and corresponding petrographic studies at two sections of the MVG and also on carbonates mined for the cement industry at La Plata Mine (ANCAP), with the aim of testing chemostratigraphic tools as an aid for the exporation of cement-grade carbonates. corresponding petrographic studies at two sections of the MVG and also on carbonates mined for the cement industry at La Plata Mine (ANCAP), with the aim of testing chemostratigraphic tools as an aid for the exporation of cement-grade carbonates. and massive dolostones. At the stratotype and in Burgueño Quarry, conglomerates overly with erosional unconformity the MVG. These conglomerates, assigned to LVFm (Blanco & Gaucher, 2004, 2005), include a level of diamictites and breccias at the contact to the MVG, which has been recognized as a palaeokarst surface. The assocation of palaeokarst surfaces developed on top of carbonate successions and overlain by glacigenic diamictites is well known for a number of Neoproterozoic successions. Dropstones occur in laminated mudstones, associated with diamictites. However, no carbonates occur on top of the diamictites. We carried out 13C and 18O analyses of carbonates and corresponding petrographic studies at two sections of the MVG and also on carbonates mined for the cement industry at La Plata Mine (ANCAP), with the aim of testing chemostratigraphic tools as an aid for the exporation of cement-grade carbonates. corresponding petrographic studies at two sections of the MVG and also on carbonates mined for the cement industry at La Plata Mine (ANCAP), with the aim of testing chemostratigraphic tools as an aid for the exporation of cement-grade carbonates. Mina Verdún, to the MVG. The succession exposed in the quarry, 150 m in thickness, includes (from base to top): metamarls, limestones, stromatolitic Conophytonlimestones and massive dolostones. At the stratotype and in Burgueño Quarry, conglomerates overly with erosional unconformity the MVG. These conglomerates, assigned to LVFm (Blanco & Gaucher, 2004, 2005), include a level of diamictites and breccias at the contact to the MVG, which has been recognized as a palaeokarst surface. The assocation of palaeokarst surfaces developed on top of carbonate successions and overlain by glacigenic diamictites is well known for a number of Neoproterozoic successions. Dropstones occur in laminated mudstones, associated with diamictites. However, no carbonates occur on top of the diamictites. We carried out 13C and 18O analyses of carbonates and corresponding petrographic studies at two sections of the MVG and also on carbonates mined for the cement industry at La Plata Mine (ANCAP), with the aim of testing chemostratigraphic tools as an aid for the exporation of cement-grade carbonates. corresponding petrographic studies at two sections of the MVG and also on carbonates mined for the cement industry at La Plata Mine (ANCAP), with the aim of testing chemostratigraphic tools as an aid for the exporation of cement-grade carbonates. and massive dolostones. At the stratotype and in Burgueño Quarry, conglomerates overly with erosional unconformity the MVG. These conglomerates, assigned to LVFm (Blanco & Gaucher, 2004, 2005), include a level of diamictites and breccias at the contact to the MVG, which has been recognized as a palaeokarst surface. The assocation of palaeokarst surfaces developed on top of carbonate successions and overlain by glacigenic diamictites is well known for a number of Neoproterozoic successions. Dropstones occur in laminated mudstones, associated with diamictites. However, no carbonates occur on top of the diamictites. We carried out 13C and 18O analyses of carbonates and corresponding petrographic studies at two sections of the MVG and also on carbonates mined for the cement industry at La Plata Mine (ANCAP), with the aim of testing chemostratigraphic tools as an aid for the exporation of cement-grade carbonates. corresponding petrographic studies at two sections of the MVG and also on carbonates mined for the cement industry at La Plata Mine (ANCAP), with the aim of testing chemostratigraphic tools as an aid for the exporation of cement-grade carbonates. o limestone Quarry, 40 km to the south of Mina Verdún, to the MVG. The succession exposed in the quarry, 150 m in thickness, includes (from base to top): metamarls, limestones, stromatolitic Conophytonlimestones and massive dolostones. At the stratotype and in Burgueño Quarry, conglomerates overly with erosional unconformity the MVG. These conglomerates, assigned to LVFm (Blanco & Gaucher, 2004, 2005), include a level of diamictites and breccias at the contact to the MVG, which has been recognized as a palaeokarst surface. The assocation of palaeokarst surfaces developed on top of carbonate successions and overlain by glacigenic diamictites is well known for a number of Neoproterozoic successions. Dropstones occur in laminated mudstones, associated with diamictites. However, no carbonates occur on top of the diamictites. We carried out 13C and 18O analyses of carbonates and corresponding petrographic studies at two sections of the MVG and also on carbonates mined for the cement industry at La Plata Mine (ANCAP), with the aim of testing chemostratigraphic tools as an aid for the exporation of cement-grade carbonates. corresponding petrographic studies at two sections of the MVG and also on carbonates mined for the cement industry at La Plata Mine (ANCAP), with the aim of testing chemostratigraphic tools as an aid for the exporation of cement-grade carbonates. and massive dolostones. At the stratotype and in Burgueño Quarry, conglomerates overly with erosional unconformity the MVG. These conglomerates, assigned to LVFm (Blanco & Gaucher, 2004, 2005), include a level of diamictites and breccias at the contact to the MVG, which has been recognized as a palaeokarst surface. The assocation of palaeokarst surfaces developed on top of carbonate successions and overlain by glacigenic diamictites is well known for a number of Neoproterozoic successions. Dropstones occur in laminated mudstones, associated with diamictites. However, no carbonates occur on top of the diamictites. We carried out 13C and 18O analyses of carbonates and corresponding petrographic studies at two sections of the MVG and also on carbonates mined for the cement industry at La Plata Mine (ANCAP), with the aim of testing chemostratigraphic tools as an aid for the exporation of cement-grade carbonates. corresponding petrographic studies at two sections of the MVG and also on carbonates mined for the cement industry at La Plata Mine (ANCAP), with the aim of testing chemostratigraphic tools as an aid for the exporation of cement-grade carbonates. Conophytonlimestones and massive dolostones. At the stratotype and in Burgueño Quarry, conglomerates overly with erosional unconformity the MVG. These conglomerates, assigned to LVFm (Blanco & Gaucher, 2004, 2005), include a level of diamictites and breccias at the contact to the MVG, which has been recognized as a palaeokarst surface. The assocation of palaeokarst surfaces developed on top of carbonate successions and overlain by glacigenic diamictites is well known for a number of Neoproterozoic successions. Dropstones occur in laminated mudstones, associated with diamictites. However, no carbonates occur on top of the diamictites. We carried out 13C and 18O analyses of carbonates and corresponding petrographic studies at two sections of the MVG and also on carbonates mined for the cement industry at La Plata Mine (ANCAP), with the aim of testing chemostratigraphic tools as an aid for the exporation of cement-grade carbonates. corresponding petrographic studies at two sections of the MVG and also on carbonates mined for the cement industry at La Plata Mine (ANCAP), with the aim of testing chemostratigraphic tools as an aid for the exporation of cement-grade carbonates. 13C and 18O analyses of carbonates and corresponding petrographic studies at two sections of the MVG and also on carbonates mined for the cement industry at La Plata Mine (ANCAP), with the aim of testing chemostratigraphic tools as an aid for the exporation of cement-grade carbonates.Fil: Gaucher, Claudio. Universidad de la República; UruguayFil: Sial, Alcides. Universidade Federal de Pernambuco; BrasilFil: Poire, Daniel Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Geológicas. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Investigaciones Geológicas; ArgentinaFil: Cernuschi, Federico. Universidad de la República; UruguayFil: Ferreira, Valderez P.. Universidade Federal de Pernambuco; BrasilFil: Ghiglino, Leticia. Universidade Federal de Pernambuco; BrasilFil: Gozález, Pablo. Universidad de la República; UruguayFil: Martinez, Gabriela. Universidad de la República; UruguayFil: Pimmentel, Marcio M.. Universidade do Brasília; Brasil5th South Ameri

Emissivity measurements at room temperature on polymeric and inorganic samples

Abstract An evaluation of the emissivity of polymeric and inorganic materials has been carried out in the spectral range 8-121J.m using a direct technique. For polymeric samples the study focused on the dependence on the doping level. In the case of the inorganic samples measurements were aimed at the evaluation of the emissivity variations with the temperature Furthermore the effects on the emissivity of temperature differences between the sample and the background on the emissivity evaluation have been studied

Optical and Infrared Analysis of Type II SN 2006BC

We present nebular phase optical imaging and spectroscopy and near/mid-IR imaging of the Type II SN 2006bc. Observations reveal the central wavelength of the symmetric H$\alpha$ line profile to be red-shifted with respect to the host galaxy H$\alpha$ emission by day 325. Such an phenomenon has been argued to result from an asymmetric explosion in the iron-peak elements resulting in a larger mass of $^{56}$Ni and higher excitation of hydrogen on the far side of the SN explosion. We also observe a gradual blue-shifting of this H$\alpha$ peak which is indicative of dust formation in the ejecta. Although showing a normal peak brightness, V $\sim$ -17.2, for a core-collapse SN, 2006bc fades by $\sim$6 mag during the first 400 days suggesting either a relatively low $^{56}$Ni yield, an increase in extinction due to new dust, or both. A short duration flattening of the light curve is observed from day 416 to day 541 suggesting an optical light echo. Based on the narrow time window of this echo, we discuss implications on the location and geometry of the reflecting ISM. With our radiative transfer models, we find an upper limit of 2 x 10$^{-3}$ M$_{\odot}$ of dust around SN 2006bc. In the event that all of this dust were formed during the SN explosion, this quantity of dust is still several orders of magnitude lower than that needed to explain the large quantities of dust observed in the early universe.Comment: 6 pages, 10 figures, accepted for publication in Ap

Monitoring alpine glaciers from close-range to satellite sensors

In this paper the use of different types of remote-sensing techniques for monitoring topographic changes of Alpine glaciers is presented and discussed. Close range photogrammetry based on Structure-from-Motion approach is adopted to process images recorded from ground-based and drone-based stations in order to output dense point clouds. These are then directly compared to detect local changes by mean of M3C2 algorithm, while digital elevation models are interpolated to find global ice thinning and retreat. Medium-resolution satellite imagery can be exploited to monitor the glacier evolution at lower resolution but including the development and collapse of large crevasses. A case study concerning the Forni Glacier in the Raethian Alps (Italy) is presented to demonstrate the feasibility of the proposed approach by adopting data sets collected from 2016 to 2018