The discovery of englacial diagenesis, involving neoformation of minerals at depth within ice sheets, has the potential to reshape the interpretation of insoluble dust records in ice cores and the origin of planetary ice-bearing deposits on Mars. Mineralogical changes in deep ice involve iron geochemistry, and are driven by the circulation of acidic fluids within pre-melted ice during ice metamorphism, leading to the authigenic formation of jarosite. Here we show that englacial diagenesis is a widespread process in deep Antarctic ice and involves the authigenic growth of mineral phases like goethite (lepidocrocite) and hematite (maghemite) in addition to jarosite. The coexistence of these neoformed phases reflects micron-scale variability in pH and water activity within the englacial brine network. Englacial diagenesis has major consequences: it introduces systematic biases in bulk mineralogical proxies used to reconstruct dust source conditions, and it provides a grounded explanation for the anomalously high dust magnetization observed in deep Antarctic ice. We further propose that repeated burial of dust within planetary ice reservoirs, as expected on Mars over orbital timescales, represents a viable and previously underexplored mechanism for the oxidation, aggregation and magnetic activation of Martian airborne dust, without requiring prolonged warm and wet surface conditions.

Examining the composition of aerosols in Antarctic ice cores can provide insights into past atmospheric circulation. However, interpreting this data requires an understanding of the characteristics and variability of present-day aerosols over time. In 2019, we performed the first year-round, multiparametric optical characterisation of atmospheric aerosols at Concordia Station in East Antarctica using OPTAIR, a novel instrument based on the Single Particle Extinction and Scattering (SPES) technique. We compared this data with the chemical composition of PM10 samples collected at the site and with meteorological data. We also compared it with synchronous data from a LIDAR and a ceilometer operating at Concordia Station. Significant temporal irregularities were observed in the atmospheric aerosol load, with more than one-third of the particles being dry-deposited during brief air mass subsidence events (‘spikes’), which mainly occurred in winter. The aerosol particles detected during these events were primarily composed of sea salt. Their optical properties differ significantly depending on whether they originate from frost flowers or the open ocean. Due to the intermittent nature of aerosol advection to Antarctica and its radiative effect, we estimate that glaciological, time-integrated samples may lead to an overestimation of light extinction by a factor of 3.5 or more.

Glaciers are well known for providing valuable climatice and environmental information which are made available through the retrieval of ice cores. Not all glaciers are equal in this respect, however. The best sites to drill ice cores for paleoclimatic purposes are the cold portions of accumulation basins. The term cold, when referred to ice, indicates ice whose temperature is constantly below the pressure melting point. The importance of cold sites for ice core science is related to the fact that under cold conditions, the stratigraphic signals used for paleoclimatic reconstructions are best preserved because of the absence of meltwater. Because of climate change, cold portions of mountain glaciers are rapidly changing. The rise of atmospheric temperature is impacting the thermal properties of ice and firn, leading to their warming. As a consequence of this, many cold accumulation basins of high-altitude glaciers are turning to temperate and their mass balances are approaching negative values. This is posing issues on the ability of glaciers to preserve climatic and environmental signals. This is related to two distinct processes. At first, temperate ice, by definition contains a fraction of liquid water which can interfere with the preservation of chemical and physical signals. Secondarily, negative mass balances related to increased melt rates, imply the loss of upper ice layers, obliterating the most recent stratigraphic signals normally used for calibration with instrumental data. The possibility to retrieve reliable paleoclimatic records from mountain glaciers in the future, is thus questionable. This will only be possible if the ice core science community develops new methods and competencies to extract information from temperate ice addressing meltwater disturbances. To this aim, a 223 m long ice core was drilled in 2021 at the Adamello glacier, in the Italian Alps. At the drilling site (3100 m a.s.l.) the glacier has a negative mass balance and a temperate regime. Thus, the site is ideal to test to what extent temperate ice can be used as a paleoclimatic archive. To this aim, a set of paleoclimatic proxies has been investigated in the upper part of the ice core. We present here preliminary results. They show that while most of the analytes are significantly affected by meltwater percolation and regelation, some of them, in particular the less soluble ones, still exhibit a detectable seasonality. This has allowed to develop a chronology, estimate the age of surface ice and identify what proxies are best preserved in temperate ice.

Bosino A., La Licata M., Franceschi L., Hafiz A., Maggi V., Maerker M., Szatten D., De Amicis M., Multi-strata geomorphological database (MorphDB): a methodological breakthrough in geomorphological mapping approach. (IT ISSN 0391-9838, 2024). From the beginning of the past century geomorphological maps have been generated through detailed field surveys representing Earth surface landforms and deposits fixed on sheets of printed paper. The introduction of Geographic Information Systems (GIS) in the last decades has allowed the addition of more information to each mapped landform through the construction of specific geodatabases. However, the prerequisite to compile a detailed map is the detection of the landforms with the highest degree of accuracy without losing information and respecting the geomorphological criteria and cartographic rules. In fact, arbitral hierarchy between landforms (i.e., order of overlapping landforms) as well as the derived topological issues can significantly affect the represented geomorphological information in the map. We propose here an innovative GIS-based methodology to overcome the above-mentioned issues, introducing a multi-strata geomorphological database (MorphDB). This approach offers the possibility to map each landform with high spatial and temporal detail by implementing geomorphological information, and other morphometric evidence into a structured and searchable geodatabase. The proposed methodology was tested in a portion of the upper Arda Valley (Northern Apennines, Italy) compiling the geodatabase and assembling a geomorphological map. Finally, the MorphDB was shared in a GeoPackage file (.gpkg) in order to allow its use in other in other morphogenetic contexts. This study will open a new perspective in geomorphological mapping, contributing to reduce cartographic errors, loss of information due to generalization processes and the production of derived maps exploitable for territorial planning.

Paleoclimate and paleoenvironmental stratigraphic reconstructions from temperate glaciers are hindered by surface melting and ice metamorphism, which cause mobilization and concentration of impurities, as well as their interaction through englacial reactions. Despite meltwater intrusions, other impurities such as pollen grains and other palynomorphs remain to their original depth of deposition thanks to their large grain-size. Temperate glaciers close to vegetated areas, therefore, can include palynomorphs of different types that i) can be reliable annual markers for ice-core dating and, ii) allow reconstructing paleoenvironmental changes through time. The Adamello Glacier (Central Alps, Italy) is a temperate glacier that extends over ca 14.35 km2 (2020) at elevations ranging between 2560 and 3420 m a.s.l. In the framework of the CLIMADA Project, a 224 m long ice core (ADA 270) was recovered in 2021 from Pian di Neve, the summit plateau at about 3200 m a.s.l. in the accumulation area of the glacier. Preliminary estimates date the surface ice of the glacier to the 1980s while the bottom of the core might be Medieval in age. Radionuclide-based dating (3H, 14C, 137Cs, 210Pb) is in progress. The multiproxy approach adopted in this study includes black carbon, dust grain size and mineralogy, oxygen and hydrogen stable isotopes and palynomorphs, these last being the main object of this work. Given the site location, the palaeoecological signal is believed to be of regional significance. Despite the stratigraphy may not be preserved for some soluble chemical species, the core contains a high variety of palynomorphs, which allow the reconstruction of palaeoenvironmental and paleoclimatic variations at subannual resolution. The mean ice accumulation rate is about 0.9 m w.eq. yr-1. Consequently, the mean sampling resolution adopted for the palynomorph study is 0.1 m, increased to 0.01 m in specific intervals. Palynomorphs are mainly found in layers representing the spring-summer deposition while their concentration is very low during other periods of the year. Pollen grains, spores, diatom frustules, phytoliths and charcoals characterize the spring-summer layers; glass shards of volcanic origin and green algae have been observed in few intervals. Sporadic but massive Saharan dust events, carrying characteristic dust particles and pollen of African provenance, were identified throughout the core. The comparison between these intervals and the historical “red rain” events in Northern Italy will help better constraining the ice core dating. At ca 66 m depth, an ice interval characterized by a high impurity content has been investigated at 0.01 m resolution. Different palynomorphs are recorded in this interval, implying a quasi-continuous presence of humans and animals on the glacier for few years. Preliminary results link these layers to World War I, intensively fought between Italians and Austro-Hungarians on the slopes surrounding the Pian di Neve. The comparison between historical, archeological and ice core data allow delineating, at subannual resolution, the climate and environmental changes that characterized those years.

The FAMU experiment at RIKEN-RAL is a muonic atom experiment with the aim to determine the Zemach radius of the proton by measuring the 1s hyperfine splitting in muonic hydrogen. The activity of the FAMU Collaboration in the years 2015-2023 enabled the final optimisation of the detector-target setup as well as the gas working condition in terms of temperature, pressure and gas mixture composition. The experiment has started its data taking in July 2023. The status of the detector setup for the 2023 experimental runs, for the beam characterisation and muonic X-ray detection in the 100-200 keV energy range, is presented and discussed.

Glacier flow velocity is crucial information to assess the impact of global warming on glaciers since it is related to the ice thickness, its variations provide information on mass balance and, in general, on the current state of glacier “health”. Moreover, flow anomalies are often an indicator of glacier instabilities. Therefore, more attention has been dedicated to surveying glacier kinematics. Historically, flow velocity was the first quantitative variable measured on glaciers since the 19th century. In the last decades, terrestrial monoscopic time-lapse digital cameras have permitted to conduct automatic surveying at high spatial and temporal resolutions using digital image correlation. Even though terrestrial time-lapse imagery is currently a consolidated technique in glacier monitoring, possible strategies, limitations and potentialities have never been systematically reviewed. This work aims to illustrate the typical procedures required to monitor glacier flow velocity using terrestrial monoscopic time-lapse cameras. We describe possible inconveniences that can arise during the survey and provide some guidelines to minimise such issues. We present six study cases in the European Alps (Mont Blanc and Bernina massifs) that feature different monitoring equipment, site geometry and glacier morphodynamics to illustrate possible solutions for terrestrial imagery monitoring. The results of this review highlight the high benefit-to-cost ratio of terrestrial time-lapse cameras in glacier flow surveying.

Objectives To investigate the rate and outcome of emergency Cesarean delivery (CD) in women with placenta previa with or without placenta accreta spectrum disorders (PAS) and to elucidate the diagnostic accuracy of ultrasound in predicting emergency CD. Methods This was a secondary analysis of a multicenter prospective study involving 16 referral hospitals in Italy (ADoPAD study). Inclusion criteria were women with placenta previa minor (< 20 mm from the internal cervical os) or placenta previa major (covering the os), aged >= 18 years, who underwent transabdominal and transvaginal ultrasound assessment at >= 26 + 0 weeks of gestation. The primary outcome was the occurrence of emergency CD, defined as the need for immediate surgical intervention performed for emergency maternal or fetal indication, including active labor, cumulative maternal bleeding > 500 mL, severe and persistent vaginal bleeding such that maternal hemodynamic stability could not be achieved or maintained, or category-III fetal heart rate tracing unresponsive to resuscitative measures. The primary outcome was reported separately in the population of women with placenta previa and no PAS confirmed after birth and in those with PAS. The secondary aim was to report on the strength of association and to test the diagnostic accuracy of ultrasound in predicting emergency CD. Univariate, multivariate and diagnostic accuracy analyses were used to analyze the data. Results A total of 450 women, including 97 women with placenta previa and PAS and 353 with placenta previa only, were analyzed. In women with placenta previa and PAS, emergency CD was required in 20.6% (95% CI, 14-30%), and 60.0% (12/20) delivered before 34 weeks of gestation. The mean gestational age at delivery was 32.3 +/- 2.7 weeks in women undergoing emergency CD and 34.9 +/- 1.8 weeks in those undergoing elective CD (P < 0.001). Women undergoing emergency CD had a higher median estimated blood loss (2500 (interquartile range (IQR), 1350-4500) vs 1100 (IQR, 625-2500) mL; P = 0.012), mean units of blood transfused (7.3 +/- 8.8 vs 2.5 +/- 3.4; P = 0.02) and more frequent placement of a mechanical balloon (50.0% vs 16.9%; P = 0.002) compared with those undergoing elective CD. On univariate analysis, the presence of interrupted retroplacental space, interrupted bladder line and placental lacunae was more common in women not experiencing emergency CD. No comprehensive multivariate analysis could be performed in this subgroup of women. Ultrasound signs of PAS, including presence of interrupted retroplacental space, interrupted bladder line and placental lacunae, were not predictive of emergency CD. In women with placenta previa but no PAS, emergency CD was required in 31.2% (95% CI, 26.6-36.2%), and 32.7% (36/110) delivered before 34 weeks of gestation. The mean gestational age at delivery was lower in women undergoing emergency CD compared with those undergoing elective CD (34.2 +/- 2.9 vs 36.7 +/- 1.6 weeks; P < 0.001). Pregnancies complicated by emergency CD were associated with a lower birth weight (2330 +/- 620 vs 2800 +/- 480 g; P < 0.001) and had a higher risk of need for blood transfusion (22.7% vs 10.7%; P = 0.003) compared with those who underwent elective CD. On multivariate analysis, only placental thickness (odds ratio (OR), 1.02 (95% CI, 1.00-1.03); P = 0.046) and cervical length < 25 mm (OR, 3.89 (95% CI, 1.33-11.33); P = 0.01) were associated with emergency CD. However, a short cervical length showed low diagnostic accuracy for predicting emergency CD in these women. Conclusion Emergency CD occurred in about 20% of women with placenta previa and PAS and 30% of those with placenta previa only and was associated with worse maternal outcome compared with elective intervention. Prenatal ultrasound is not predictive of the risk of emergency CD in women with these disorders. (c) 2023 International Society of Ultrasound in Obstetrics and Gynecology.

The article discusses the use of tritium (3H) and cesium (137Cs) as temporal markers in ice cores extracted from temperate glaciers. We present a complete tritium profile for a 46 m ice core drilled from the Adamello Glacier, a temperate glacier in the Italian Alps, and compare it to the 137Cs profile from the same ice core. Our analysis reveals tritium contamination between 19 and 32 m of depth, which can be attributed to the global radioactive fallout caused by atmospheric nuclear-bomb testing that took place in the 1950s and 1960s. Results show that the radioactive peak associated with 1963 does not occur at the same depth for both 3H and 137Cs; instead, the tritium peak is 1.5 m above the cesium one. Our hypothesis is that this misalignment is caused by meltwater-induced post-depositional processes that affect 137Cs, which is more sensitive to percolation than 3H. The total inventory of 137Cs in this ice core is also among the lowest ever reported, providing additional evidence that the presence of meltwater has affected the distribution of this radionuclide within the ice. In contrast, the total tritium inventory is comparable to what is reported in the literature, making it a more reliable temporal marker for temperate glaciers.

The expansion of glacier-free forelands after glacier retreat is emerging as a typical climate change-dependent feature that is widely studied for assessing biogeomorphic feedbacks and analysing the vertical processes and changes occurring in the critical zone (CZ). However, the horizontal processes occurring in the CZ environment are still poorly understood. Here, we comprehensively analyse the development of the CZ environment over time in the Forni Glacier forefield, Italian Alps, since the end of the Little Ice Age (LIA) by considering different sectors (air, forest, water and soil) in two portions of the glacier forefield: the lower portion, which occurs below the glacier-forefield treeline (GFT), where a fully functioning CZ environment has developed, and the upper portion, which occurs above the GFT, in the proglacial area (PA), where only an incipient CZ exists. The early stages of CZ development in the PA are highly influenced by katabatic winds, which impact the colonisation patterns of saplings and young trees, and characterised by high-energy geomorphic processes that cause sediment reworking and initial stages of soil development. Below the GFT, the minimum tree ecesis interval after glacier retreat reaches a median value of 38 years (n = 8), and the fully developed CZ environment (with trees reaching at least 2 m in height after 20 years) formed after similar to 60 years following glacier retreat and is characterised by forest cover, soils organised in a chronosequence and contrasting isotopic signatures of surface and running waters. The correlation with the isotopic signatures of tree rings allowed us to estimate a groundwater flow period of approximately 2 months from the slopes into the CZ of the valley floor. By analysing the horizontal processes driving the geomorphic and biotic evolution patterns of a glacier forefield, this work introduces a novel approach for assessing the development of the CZ environment over time.

Maggi V., Salvatore M.C., Casarotto C., Mangili C., Carton A., Baccolo G., Brugger S.O., Jenk T.M., Eichler A., Schwikowski M., Baroni C., Late Holocene evolution of the Adamello Glacier (Rhaetian Alps): New insights for Alpine temperate glaciers. (IT ISSN 0391-9838, 2023). The Adamello Glacier is the largest and the thickest glacier in the Italian Alps, with a maximum ice thickness of 270 m. Here we provide an overview of its evolution since the Little Ice Age and of the results obtained from the ice core drilling activities carried out on this glacier. A review of the existing cartography from the 19th century onwards, surveys by the Italian Glaciological Committee, geomorphological studies and mass balance data are here combined to quantitatively describe the evolution of the Adamello Glacier from the Little Ice Age to the present day. Within this interval, the glacier has lost half of its surface, and its main front has receded by 2.8 km. Despite the rapid decline, in the last years ice cores were extracted from the former accumulation area of the glacier (Pian di Neve). In 2021, a 224 m-long ice core was drilled to bedrock. We also consider a previous ice core (ADA16), drilled in 2016 to the depth of 46 m. The analysis and inspection of these ice cores show that, despite the glacier consist of temperate ice and is subject to severe melting, some environmental signals are partially preserved in the ice stratigraphy, including visible layers related to Saharan dust transport and cryoconite. Using information from the upper layers of the glacier and a one-dimensional age-depth model, it was possible to estimate the age of the basal ice at approximately 2000 years ago. According to these preliminary results, the Adamello Glacier, despite being a temperate glacier and being subject to heavy melting during summer, is still able to preserve, at least partially, signals that are suitable to construct climatic and environmental records. This implies that, contrary to the previous view, environmental records can be obtained from ice cores drilled at temperate glaciers subject to melting. In the context of climate change, this is a relevant result with important implications for paleoclimatic and environmental reconstructions

The article gives the motivations for the measurement of the hyperfine splitting (hfs) in the ground state of muonic hydrogen to explore the properties of the proton at low momentum transfer. It summarizes these proposed measurement methods and finally describes the FAMU experiment in more detail.

We reconstructed vegetation, fire and watershed history during the Late Roman-Early Middle Ages and in the last three centuries in a mixed conifer forest forming the middle mountain elevational belt in the inner Alpine region, analyzing co-registered micro-botanical data, charcoal particles, sediment lithology, nutrients, and modern pollen deposition from a high-resolution peat record in Valmalenco (Italian Alps). During Late Roman Age the site hosted a dump mixed conifer forest dominated by Picea abies and Abies alba on peaty forest soil, locally affected by fires which also triggered episodes of hillslope denudation. Fire frequency increases during Early Middle Ages dry and warm phases, favoring Alnus viridis and Larix, while Abies alba and Alnus glutinosa type maintained a main role in the pre- and post-fire. Specifically, Abies alba, nowadays eradicated from the Valmalenco watershed, withstood the local regime of low intensity surface fires for more than a millennium, from the Late Roman throughout the Early Middle Ages. Larix, Alnus viridis and Fraxinus excelsior abundance in modern vegetation is ascribed to effects of intensified disturbance in the Early Modern Age, and to further woodland thickening triggered by fire suppression and abandonment after the Second World War.

&lt;p&gt;Glacier surface velocity is a crucial information to assess the impact of global warming on glaciers, since it is related to the ice thickness; its variations provide information on mass balance and, in general, on the current state of glacier &amp;#8220;health&amp;#8221;. Moreover, velocity anomalies are often an indicator of glacier instabilities. Therefore, attention has been dedicated to surveying glacier velocity. Historically, surface velocity was the first quantitative variable measured on glaciers since the 19&lt;sup&gt;th&lt;/sup&gt; century, using phototheodolites. In the last decades, terrestrial monoscopic digital time-lapse cameras (TLC) have permitted to conduct automatic surveying for long periods at high spatial and temporal resolutions using digital image correlation. Even though terrestrial time-lapse imagery is currently a consolidated technique in glacier monitoring, the number of dedicated publications is relatively small. In particular, possible strategies, limitations and potentialities have never been systematically reviewed.&lt;/p&gt; &lt;p&gt;This work aims to illustrate the typical procedures required to monitor glacier surface velocity using terrestrial monoscopic TLC, which can be synthetically listed as: 1) correct deployment of the equipment and image acquisition; 2) data pre-processing: 2.1) image selection, 2.2) colour/feature enhancement and 2.3) image registration; 3) data processing: displacement measurement using image correlation; 4) data post-processing: 4.1) outlier correction, 4.2) image geocoding and 4.3) time-series extraction. We describe possible inconveniences that can arise during the survey &amp;#8211; e.g., image misregistration, distortion and defocusing, illumination and chromatic variation (shadows, snow patches), presence of outliers, and geocoding issues &amp;#8211; and provide some guide lines to minimise such problematics. We present six study cases in the European Alps &amp;#8211; Planpincieux, Grandes Jorasses, Freney and Brenva glaciers in the Mont Blanc massif, and Western and Eastern Fellaria glaciers in the Bernina massif &amp;#8211; that feature different monitoring equipment, site geometry and glacier morphodynamics to illustrate possible solutions for terrestrial imagery monitoring.&lt;/p&gt; &lt;p&gt;The results revealed that terrestrial TLC provided high spatial resolution and acquisition frequency to detect small kinematic sectors and fast-occurring velocity anomalies, which would be difficult to identify using alternative approaches (e.g., satellites or topographic). However, like other passive optical sensors, the principal limitation is that they are affected by poor visibility and cannot acquire during the night. This study highlighted the great potentiality of TLC in glacier kinematics surveying, which can be conducted using either professional cameras or low-cost webcam and IP cameras, according to the scope and financial availability. The contained costs and ease of installation make TLC a very high benefit-to-cost tool and permit the development of strategies for widespread glacier monitoring at a regional scale with relatively low financial efforts.&lt;/p&gt;

&lt;p&gt;Mineral dust aerosol plays an important role in climate and biogeochemical processes by providing nutrients to marine and terrestrial ecosystems and by influencing the radiation balance of the atmosphere. In turn, mineral dust responds to natural and anthropogenic alterations of land cover and land use resulting from several environmental changes that occurred on different timescales. Contamination by aerosols is a very tangible threat to the cryosphere in the European Alps due to its proximity to highly urbanized areas, cultivated landscapes, and the largest hot desert in the world. We recently developed and assembled a continuous flow analysis system for studying the solid content of ice cores with a high time resolution, focusing on optical characterization methods based on light scattering. The line is designed to provide an integrated measurement of dust particles with Single-Particle Extinction and Scattering (SPES), digital holography, and an optical particle sizer (Abakus). Many of the particles found in ice are efficient scatterers and absorbers close to the size range of the visible light wavelength. We report some preliminary results from ice cores drilled during the ADA270 project, aiming at an in-depth characterization of the samples that provide essential information on the fast climate evolution, which is causing a severe degeneration of glaciers, among other consequences. &lt;/p&gt;

Abstract. The article discusses the use of 3H and 137Cs as temporal markers in ice cores extracted from temperate glaciers. We present a complete tritium (3H) profile for a 46 m ice core drilled from Adamello glacier, a temperate glacier in the Italian Alps, and compare it to 137Cs profile from the same ice core. Our analysis reveals contamination of tritium between 19 and 32 m of depth, which can be attributed to the worldwide radioactive contamination caused by atmospheric nuclear bomb testing in the 1950s and 1960s. Results show that the radioactive peak associated with 1963 is not coincident for 3H and 137Cs, but the 3H peak occurs 1.5 m above the 137Cs one. This misalignment is caused by meltwater-induced postdepositional processes that affect 137Cs, which is more sensitive to percolation than 3H. The total inventory of 137Cs in this ice core is also among the lowest ever reported, providing additional evidence that meltwater disturbed its distribution into the ice. On the contrary, the total tritium inventory is comparable to what is reported in literature, making it a more reliable temporal marker for temperate glaciers.

Objective To evaluate the performance of third-trimester ultrasound for the diagnosis of clinically significant placenta accreta spectrum disorder (PAS) in women with low-lying placenta or placenta previa. Methods This was a prospective multicenter study of pregnant women aged >= 18 years who were diagnosed with low-lying placenta (< 20 mm from the internal cervical os) or placenta previa (covering the internal cervical os) on ultrasound at >= 26 + 0 weeks' gestation, between October 2014 and January 2019. Ultrasound suspicion of PAS was raised in the presence of at least one of these signs on grayscale ultrasound: (1) obliteration of the hypoechogenic space between the uterus and the placenta; (2) interruption of the hyperechogenic interface between the uterine serosa and the bladder wall; (3) abnormal placental lacunae. Histopathological examinations were performed according to a predefined protocol, with pathologists blinded to the ultrasound findings. To assess the ability of ultrasound to detect clinically significant PAS, a composite outcome comprising the need for active management at delivery and histopathological confirmation of PAS was considered the reference standard. PAS was considered to be clinically significant if, in addition to histological confirmation, at least one of these procedures was carried out after delivery: use of hemostatic intrauterine balloon, compressive uterine suture, peripartum hysterectomy, uterine/hypogastric artery ligation or uterine artery embolization. The diagnostic performance of each ultrasound sign for clinically significant PAS was evaluated in all women and in the subgroup who had at least one previous Cesarean section and anterior placenta. Post-test probability was assessed using Fagan nomograms. Results A total of 568 women underwent transabdominal and transvaginal ultrasound examinations during the study period. Of these, 95 delivered in local hospitals, and placental pathology according to the study protocol was therefore not available. Among the 473 women for whom placental pathology was available, clinically significant PAS was diagnosed in 99 (21%), comprising 36 cases of placenta accreta, 19 of placenta increta and 44 of placenta percreta. The median gestational age at the time of ultrasound assessment was 31.4 (interquartile range, 28.6-34.4) weeks. A normal hypoechogenic space between the uterus and the placenta reduced the post-test probability of clinically significant PAS from 21% to 5% in women with low-lying placenta or placenta previa in the third trimester of pregnancy and from 62% to 9% in the subgroup with previous Cesarean section and anterior placenta. The absence of placental lacunae reduced the post-test probability of clinically significant PAS from 21% to 9% in women with low-lying placenta or placenta previa in the third trimester of pregnancy and from 62% to 36% in the subgroup with previous Cesarean section and anterior placenta. When abnormal placental lacunae were seen on ultrasound, the post-test probability of clinically significant PAS increased from 21% to 59% in the whole cohort and from 62% to 78% in the subgroup with previous Cesarean section and anterior placenta. An interrupted hyperechogenic interface between the uterine serosa and bladder wall increased the post-test probability for clinically significant PAS from 21% to 85% in women with low-lying placenta or placenta previa and from 62% to 88% in the subgroup with previous Cesarean section and anterior placenta. When all three sonographic markers were present, the post-test probability for clinically significant PAS increased from 21% to 89% in the whole cohort and from 62% to 92% in the subgroup with previous Cesarean section and anterior placenta. Conclusions Grayscale ultrasound has good diagnostic performance to identify pregnancies at low risk of PAS in a high-risk population of women with low-lying placenta or placenta previa. Ultrasound may be safely used to guide management decisions and concentrate resources on patients with higher risk of clinically significant PAS. (c) 2022 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Mineral dust archived in polar ice cores can be used to document past atmospheric circulation variability and past climate conditions over the dust source areas. Thanks to its relative immobility and stability, eolian dust concentration has been used to synchronize deep ice cores as well as ice stratigraphies and marine sediment records. However, mineral impurities in deep ice can be affected by post-depositional physical and chemical alterations, deriving from small-scale relocation of dust grains and subsequent alteration in acidic micro-environments. By applying a set of different techniques spanning from dust concentration and grain size to iron mineralogy and elemental composition, here we provide evidence of in situ dust physical and chemical alterations observed below 1000 m depth in the 1620-m deep TALDICE ice core drilled at Talos Dome (peripheral East Antarctica, 72°49’S, 159°11’E; 2315 m a.s.l.). Results highlight significant dust aggregation and alteration of Fe-minerals with englacial precipitation of neo-formed jarosite, occurring in parallel with the decline of ferrous minerals and depletion of some major elements. Therefore, below 1000 m depth the TALDICE dust record can be considered partly affected by acidic-oxidative weathering resulting from the interaction of dust particles with highly saline acidic brines. Although limited to only one specific site, this study opens new issues concerning the interpretation of climate signals in the deepest part of ice cores.

Antarctic ice cores play a central role in paleoclimatic reconstructions, as they provide a high resolution archive of past climatic and environmental processes. This study focuses on the TALDICE ice core drilled at Talos Dome (East Antarctica, 72°49’S, 159°11’E), which covers more than 343k years of climate history. A comparison is presented between samples analyzed through two different techniques: low background instrumental neutron activation analysis (INAA) and inductively coupled plasma mass spectrometry (ICP-SFMS). While the former is used to investigate only the insoluble fraction of dust, as it can only be applied to solid samples, the latter is used to assess the elemental composition of both the total and the soluble fraction of dust. We thus observe how different elements partition between soluble and insoluble phase at different depths of the ice core and link the geochemical patterns of the considered elements to the main climatic oscillations covered in the Talos Dome ice core. We determined 45 elements through ICP-SFMS and 39 through INAA, with a good overlapping of the elements between the two techniques. Besides the determination of major elements (Na, Mg, Al, Si, K, Ca, Ti, Mn, Fe), which is important in the assessment of the impact of dust on the ecosystem (e.g. source of nutrients in the Southern Ocean), the high sensibility of both techniques also permitted the determination of trace elements. Among these, rare earth elements (REE) are of particular importance as they have been widely used as a geochemical tracer of aeolian dust sources. We present enrichment factors and correlation matrices to assess the crustal or non-crustal origin of the considered elements. The high correlations and low enrichment factors found among insoluble elements confirm a prevalent crustal composition for mineral dust. Regarding solubility, the majority of elements exhibits a minimum in solubility during the last glacial maximum. This is the result of higher fluxes of mineral dust transported to the Antarctic continent during cold climate periods and is consistent with the crustal origin we documented for most of the elements considered.

During the last glaciation the Eurasian continent was impacted by the global reorganization of atmo-spheric circulation caused by North Atlantic events, through changes in moisture storm tracks modulated by orography. Our research explores the linkages between climate evolution in the North Atlantic and in the Alps between 30.6 and 12.5 ka, This period, centered on the Last Glacial Maximum, experienced the most recent phase of maximum global ice volume, corresponding to a millennia-long phase of sea-level lowstand, minima in reconstructed sea surface temperatures and isotopic values from polar ice. We present a high-resolution multiproxy record from Lake Fimon at the southern Alpine foothills, where a larch forest-steppe persisted throughout the coldest spells. We analyse the fine climate structure of the MIS 3-2 transition, of the Alpine Last Glacial Maximum stepped by HS2, and provide an unprecedented fine resolution and accurate 14C dating of the Last Glacial Maximum and the early Alpine Lateglacial. We reconstructed quantitative climate parameters based on sensitive pollen descriptors, and derived co -registered sedimentary proxies for dust flux. Reconstructed series suggest that extreme continental spells in the Alps and cold boreal winters match the timing of Heinrich Stadials 2 and 1, episodes of iceberg discharge and release of rock fragments (Ice Rafted Debris) in the North Atlantic. The initiation of the LGM at 27.3 ka is marked by a 4 degrees C drop in July temperatures, likely responsible for the onset of glacial build-up in the Southern Alpine piedmont. The first extreme continental spell coincides with the British -Irish-sourced IRD event at 26.2 ka and with glacier retreat in the Southern Alps, persisting in the sub-sequent HS2. Late Glacial glacier collapse and extreme drought occurred during the first half of the HS1, 17.4-16.2 ka. The comparison of the results obtained at Lake Fimon with other terrestrial Eurasian re-cords and with recalibrated marine chronologies from the North Atlantic suggests in-phase reactions of the British-Irish Ice Sheet and of Alpine glaciers and ecosystems to changes in the Atlantic Meridional Circulation. Asymmetric ecoclimatic effects produced by North Atlantic events at the windward and leeward sides of the Alps confirm a southern provenance of moist air masses throughout the LGM.(c) 2022 Elsevier Ltd. All rights reserved.