Transitional Domain Research Articles

Acoustic emission monitoring of damage modes in reinforced concrete beams by using narrow partial power bands

This work presents an acoustic emission (AE) based method, named a series of narrow partial power bands (SN2PB), to monitor the damage mechanisms within reinforced concrete beams during quasi-static bending tests. Unlike conventional time-domain methods, which give a global view of the involved cracking modes, SN2PB has the advantage of obtaining information on cracking modes within each AE hit in reduced frequency bands. SN2PB is applied by dividing the frequency content of each AE signal into narrow bands. Results show that the same AE signal can contain shear and tension cracking signatures at the lower and upper frequency bands, respectively. This work shows also the presence of a transitional domain between the two distinct bands. Changes and fluctuations corresponding to the involved mechanisms during the entire mechanical tests are therefore followed and visualized in the form of a heatmap. Moreover, the densities of the shear and tensile mechanisms at an instant are also determined using a Gaussian Mixture Model. Results show that the separation obtained using the SN2PB method is more advantageous than that of the conventional method based on the average frequency and the RA parameter.

Contributions of computing in geosciences: a case study of geometallurgical forecasting

Geometallurgical modeling has been improved over the years with the incorporation of mineralogical, chemical, and metallurgical information. However, the diversity of the database brings challenges since the information is not unified in procedures, sample support, or quantities. Characteristics such as nonlinearity and nonadditivity of the geometallurgical database impose even more difficulties. The objective of this article is to demonstrate the feasibility of geometallurgical models from multivariate techniques combined with computational tools. The algorithms used in this study were developed in Python programming language. The multivariate analysis and machine learning techniques allowed the grouping of transitional typological domains and the quantification of uncertainty; the selection and reduction of the dimensionality of the heterotopic database; and the prediction of metallurgical behavior from exhaustive primary variables using a transfer function. The results were verified and proved to be satisfactory. Other benefits of the computational structure were: reduction of subjectivity; automation; and dynamic updates of models using new data.

Perspectives on supporting Veterans’ social needs during hospital to home health transitions: findings from the Transitions Nurse Program

BackgroundVeterans who need post-acute home health care (HHC) are at risk for adverse outcomes and unmet social needs. Veterans’ social needs could be identified and met by community-based HHC clinicians due to their unique perspective from the home environment, acuity of Veterans they serve, and access to Veterans receiving community care. To understand these needs, we explored clinician, Veteran, and care partner perspectives to understand Veterans’ social needs during the transition from hospital to home with skilled HHC.MethodsQualitative data were collected through individual interviews with Veterans Health Administration (VHA) inpatient & community HHC clinicians, Veterans, and care partners who have significant roles facilitating Veterans’ hospital to home with HHC transition. To inform implementation of a care coordination quality improvement intervention, participants were asked about VHA and HHC care coordination and Veterans’ social needs during these transitions. Interviews were recorded, transcribed, and analyzed inductively using thematic analysis and results were organized deductively according to relevant transitional care domains (Discharge Planning, Transition to Home, and HHC Delivery).ResultsWe conducted 35 interviews at 4 VHA Medical Centers located in Western, Midwestern, and Southern U.S. regions during March 2021 through July 2022. We organized results by the three care transition domains and related themes by VHA, HHC, or Veteran/care partner perspective. Our themes included (1) how social needs affected access to HHC, (2) the need for social needs screening during hospitalization, (3) delays in HHC for Veterans discharged from community hospitals, and (4) a need for closed-loop communication between VHA and HHC to report social needs.ConclusionsHHC is an underexplored space for Veterans social needs detection. While this research is preliminary, we recommend two steps forward from this work: (1) develop closed-loop communication and education pathways with HHC and (2) develop a partnership to integrate a social risk screener into HHC pathways.

Salt tectonics evolution in the Provençal Basin, Western Mediterranean Sea

The Messinian Salt Giant in the Provençal Basin represents a good example to study salt tectonics: salt deposition occurred throughout the basin well after basin opening, with a tectonic context stable since ∼16 Ma, in a closed system. Also, the youth of salt tectonics has led to less mature structures and an evolutionary history that is easier to decipher than in older salt-bearing margins. We conducted an analysis of the chronology of salt deformation, from its deposition to the present-day, thanks to the basin-wide correlation of the Late Miocene and Pliocene-Pleistocene stratigraphic markers. The large seismic dataset provided detailed analysis of the causes and timing of salt deformation at a regional level. The salt tectonics started relatively early, during the Messinian Upper Unit (UU) deposition (phase 1) in the deepest part of the basin. From the Pliocene to the present-day, salt movement is divided into two more main phases (phases 2 and 3), the first of small intensity, occurred during the Pliocene and the second, more intense, during the Pleistocene. The geometric relationship between salt tectonics and crustal nature domains has revealed, regardless of the timing deformation phases, a more rapid and intense salt deformation above the proto-oceanic crust domain than in the continental or transitional crust domain. This observation, remaining unexplained, emphasizes the role of the influence of crustal nature, associated thermal regime and fluid circulation system on salt tectonics.

Cross-Conditions Fault Diagnosis of Rolling Bearing Based on Transitional Domain Adversarial Network

Cross-Conditions Fault Diagnosis of Rolling Bearing Based on Transitional Domain Adversarial Network

Lack of strong seasonality in macrobenthic communities from the northern Barents Sea shelf and Nansen Basin

The Barents Sea has been coined ‘the Arctic hotspot’ of climate change due to the rapidity with which environmental changes are taking place. This transitional domain from Atlantic to Arctic waters is home to highly productive benthic communities. This system strongly fluctuates on a seasonal basis in its sympagic-pelagic-benthic coupling interactions, with potential effects on benthic standing stocks and production. Recent discoveries have questioned the marked seasonality for several high Arctic seafloor communities in coastal waters of Svalbard. Still, the seasonal variability of benthic process in the extensive Barents Sea open shelf remains poorly understood. Therefore, we studied the seasonality of macrofauna communities along a transect in the northwestern Barents Sea comprising two hydrographic domains (Arctic vs. Atlantic Water, across the Polar Front) and three geomorphological settings (shelf, continental slope and abyssal plain). Overall, we did not find strong signs of seasonal variation in taxonomic community structure and functional diversity. However, we found some weak signs of seasonality when examining each station separately, especially at a station close to the Polar Front, with high seasonal fluctuations in abiotic drivers indicating a stronger pelagic-benthic coupling. The lack of seasonality found both at the shelf stations south and north of the Polar Front could be related to organic matter stored in the sediments, reflected in constant levels of total organic carbon in surface sediment across time for all stations. We did observe, as expected, highly spatially structured environmental regimes and macrofauna communities associated to them from shelf to slope and basin locations. Understanding the underlying spatio-temporal mechanisms by which soft-bottom benthic communities are structured along environmental gradients is necessary to predict future impacts of climate change in this area. Our results indicate that short-term climate driven changes in the phenology of pelagic ecosystem components might not be directly reflected in the Arctic benthic system, as seafloor processes seem to be partially decoupled from those in the overlying water.

Continental block motion in the Northern Andes from GPS measurements

SUMMARYNorthwestern South America is a plate boundary zone where the Nazca, Caribbean and South American plates interact to produce a wide area of active continental deformation from the Gulf of Guayaquil (latitude 3°S) to Venezuela. Previous studies have identified a ∼2000-km-long continental sliver, referred as the North Andean Sliver (NAS), squeezed between the Nazca, Caribbean and South American plates and escaping at ∼1 cm yr−1 northeastward with respect to South America. Subduction of the Nazca Plate beneath the NAS has produced a sequence of large and great earthquakes during the 20th century along the coast of Ecuador and Colombia. Large crustal earthquakes up to magnitude 7.7 have been documented along the proposed eastern boundary of the NAS. However, active tectonics data, historical and recent earthquakes all indicate active fault systems within the NAS, possibly resulting from the interaction of several tectonic blocks. Here, we derive an extensive horizontal velocity field using continuous and episodic GNSS data from 1994 to 2019.9, covering northern Peru, Ecuador, Colombia, Panama and Venezuela. We model the GNSS velocity field using a kinematic elastic block approach that simultaneously solves for rigid tectonic block rotations and interseismic coupling along the subduction interfaces and along major crustal faults. In contrast to previous results that considered a single rigid NAS, our dense GNSS velocity field demonstrates that the NAS undergoes significant internal deformation and cannot be modelled as single rigid block. We find that block kinematics in the northern Andes are well described by the rotation of 6 tectonic blocks, showing increasing eastward motion from south to north. The Eastern boundary of the sliver is defined by a right-lateral transpressive fault system accommodating 5.6–17 mm yr−1 of motion. Fragmentation of the NAS occurs through several fault systems with slip rates of 2–4 mm yr−1. Slow reverse motion is found across the sub-Andean domain in Ecuador and northern Peru at 2–4 mm yr−1, marking a transitional area between the NAS and stable South America. In contrast, such a transitional sub-Andean domain does not exist in Colombia and western Venezuela. At the northwestern corner of Colombia, fast (∼15 mm yr−1) eastward motion of the Panama block with respect to the NAS results in arc-continent collision. We propose that the Uramita fault and Eastern Panama Deformed Zone define the current Panama/NAS boundary, accommodating 6 and 15 mm yr−1 of relative motion, respectively. A fraction of the Panama motion appears to transfer northeastward throughout the San Jacinto fold belt and as far east as longitude ∼75°W. Along the Caribbean coast, our model confirms, slow active subduction at ∼4.5 mm yr−1 along the South Caribbean Deformed Belt offshore northern Colombia and a relatively uniform rate of ∼1–2 mm yr−1 offshore northern Venezuela. Along the Nazca/NAS subduction interface, interseismic coupling shows a first-order correlations between highly locked patches and large past earthquake ruptures. These patches are separated by narrow zones of low/partial coupling where aseismic transients are observed. Compared to previous studies, our interseismic coupling model highlights the presence of deep coupling down to 70 km in Ecuador.

How post‐salt sediment flux and progradation rate influence salt tectonics on rifted margins: Insights from geodynamic modelling

AbstractContinental rifted margins can be associated with widespread and thick salt deposits, which are often formed during the final stages of rifting, prior to breakup. These salt‐bearing margins are typically characterized by pronounced post‐rift salt tectonics with variable and complex structural styles and evolution. We use a lithosphere‐scale geodynamic numerical model to investigate the role of varying post‐rift sediment fluxes and progradation rates on rifted margin salt tectonics. We focus on a single, intermediate, rifted margin type and salt basin geometry to explore scenarios with different: (i) constant and (ii) time‐varying post‐salt sediment fluxes. We demonstrate that these promote significant contrasts in the style and magnitude of salt tectonics in the proximal, transitional and distal margin domains. The differences are primarily controlled by the relationship between the rates of sediment progradation (Vprog) and salt flow (Vs). When Vprog > Vs, the salt is rapidly buried and both vertical and lateral salt flow are suppressed across the entire margin. When Vprog < Vs, the salt flows vertically and seaward faster than sediments prograde producing major diapirism in the proximal domain and major distal nappe advance, but only moderate overburden extension and distal diapirism. When Vprog ~ Vs, there is moderate proximal diapirism and distal nappe advance, but major updip extension and downdip shortening, which produces major distal diapirism. Modelling results are comparable to various natural systems and help improve our understanding of the controls and dynamics of salt tectonics along salt‐bearing rifted margins.

Severe simplification of the structure of dung beetle assemblages in neotropical soybean croplands regardless of the native vegetation domain

The conversion of native vegetation into agricultural areas is arguably the key driver of biodiversity declines globally. We assessed the responses of dung beetle assemblages (Coleoptera: Scarabaeidae: Scarabaeinae) to the effects of native vegetation conversion into soybean monoculture in different vegetation domains (Amazonian forest, scrubland savannahs and transitional vegetation) in the world’s largest tropical soybean (Glycine max L.) agricultural frontier. We also assessed the effects of landscape variables (amount of native habitat and amount of pasture) and land use history (time of land use change including soybean cultivation and cattle pastures). We sampled dung beetles at 100 study landscapes throughout the state of Mato Grosso, Brazil, within a region encompassing Amazonian forests, the drier Cerrado savannahs, and transitional vegetation domain between these biomes. In total, we recorded 71,043 individuals of 165 species, with 39,090 individuals (155 species) sampled in native vegetation and 31,953 individuals (75 species) in soybean monoculture areas, 30 species of which could persist in croplands. We found differences in species composition, and lower species richness, overall abundance and biomass in monoculture areas, compared to adjacent native habitat. Time since land-use change into pasture was the main determinant of species richness and species compositional similarity in monocultures, while none of the landscape and land use history variables were informative in explaining overall abundance. We provide clear evidence that the conversion of native vegetation into soybean monoculture negatively affects dung beetle assemblages. Furthermore, croplands harboured their own unique dung beetle assemblages containing species typical of open-habitats and pasturelands, which are likely tracking the historical advance of the agricultural frontier. However, species typical of forest environments were most detrimentally affected and were largely missing in cropland areas.

Role of inheritance during tectonic inversion of a rift system in basement-involved to salt-decoupled transition: analogue modelling and application to the Pyrenean–Biscay system

Abstract. The reactivation of former rift systems and passive margins during tectonic inversion and their incorporation into fold-and-thrust belts result in significant structural differences not only between internal and external domains, but also along-strike. The Basque–Cantabrian and Asturian systems are among the best examples to address the role of along-strike changes in rift inheritance since they show a transition from salt to basement-inherited structures divided by a transition zone separating thick- from thin-skinned structural domains. While both domains have been widely described in the literature, the transfer system separating the two has not been sufficiently investigated due to poor seismic imaging and the lack of large-scale outcrops. This contribution aims to address the linkage between basement-controlled (i.e. thick-skinned) and salt-decoupled (i.e. thin-skinned) domains and to describe how deformation is accommodated in the transitional zone between these domains. An experimental programme based on analogue models has been designed that was inspired by the transition from the thin-skinned Basque–Cantabrian Pyrenees to the east to the thick-skinned Asturian Massif to the west. As observed in nature, experimental results show that oblique structures (at low angle with the shortening direction) form in the transitional domain, and their location depends on the linkage of the active structures occurring in both surrounding thick- and thin-skinned domains at different positions. Nevertheless, their orientation and evolution are controlled by the underlying decoupling horizon (i.e. salt). The deformation in the thick-skinned domain produces significant topography over a narrow deformation area due to the lack of effective decoupling levels. On the contrary, deformation in the thin-skinned domain is more distributed due to decoupling, resulting in a wider deformation area of less topography. As a result, syn-contractional sedimentation occurs mainly in the foreland basin in front of the thick-skinned domain, whereas it is observed in the foreland but also in piggyback basins in the thin-skinned domain.

Imaging exhumed continental and proto-oceanic crusts in the Camamu triple junction, Brazil

During the SALSA experiment, in 2014, twelve combined wide-angle refraction and coincident multi-channel seismic profiles were acquired in the Jequitinhonha-Almada-Camamu, Jacuípe, and Sergipe-Alagoas basins, NE Brazil. Profile SL09 images the Almada-Camamu basin and the São Francisco craton, with 18 four-channel ocean-bottom seismometers and 22 land stations. The datasets were forward modelled and combined with pre-stack depth migration to increase the horizontal resolution of the velocity models.Our results show that sediment thickness varies between 3.8 km in the oceanward part of the profile, 4.3 km in the Almada basin and 6.5 km in the Camamu basin. Crustal thickness at the north-western edge of the profile is of around 40 km, with velocity gradients indicating a continental origin.The Camamu basin, which corresponds to the triple junction between the aborted N–S oriented Tucano rift, the SW-NE oriented Jacuipe-Sergipe-Alagoas branch, and the N–S Jequitinhonha-Almada branch, presents two crustal layers: a very thin upper layer, about 1.5 km thick, which increases seawards to 3 km in the Almada basin, and an higher velocity (HV) layer (6.8–7.2 km/s) about 4 km thick. This lower layer gradually disappears in the Almada basin. At the south-eastern edge of the profile, the resolution is lower but the thickness of the crust seems to increase up to 5 km. Deep wide-angle reflections indicate upper mantle stratification.Crustal organisation and P-wave propagation velocities in the Almada and Camamu basins indicate a transitional crust domain of exhumed continental crust affinity. In the Camamu triple junction and beneath this thin exhumed continental crust, the HV layer may probably reflect intruded materials. No exhumed upper mantle is observed along the entire profile. The easternmost part of the profile may correspond to a proto-oceanic crust. Typical oceanic crust is never imaged along the 260 km-long offshore profile.

Vertical, spatial, size, and taxonomic variations in stable isotopes (δ13C and δ15N) of zooplankton and other pelagic organisms in the western North Pacific

Stable isotopes (δ13C and δ15N) of zooplankton and other marine organisms are useful for evaluating trophic levels and the food web structure of marine ecosystems. Further, taxonomic variations and regressions between δ15N and δ13C can provide details of regional differences in the food web structure. Despite their ecological importance, information on the taxonomic differences in the stable isotopes of various pelagic biota and vertical, latitudinal, and size variations in the stable isotopes of the mesozooplankton are scarce in the western North Pacific. In this study, we compared regional differences in the taxonomic variations of the stable isotopes of the all pelagic organisms collected by gillnets and various plankton nets in the subarctic and transitional domains (37–44°N) of the western North Pacific during spring. Additionally, we evaluated the vertical, size, and latitudinal variations in the stable isotopes of mesozooplankton in the western North Pacific. Regressions between δ15N and δ13C were highly significant for the subarctic and transitional domains, while they varied significantly between the two regions (P < 0.0001, ANCOVA). These regional differences in the stable isotopes were characterised by the high δ15N and low δ13C values in the subarctic region, whereas the opposites trend was observed in the transitional domains. Vertical observations from the sea surface to a depth of 3000 m at five stations (29°, 31°, 33°, 37°, and 41°N) showed that there were no significant changes in the δ13C stable isotope of mesozooplankton with depth across the stations. However, for δ15N, the significance of regressions increased with increasing depths at the subtropical stations (29°, 31°, and 33°N), while no significant trends with depth were observed for the subarctic and transitional domain stations (37°, 41°N). The dominance of interzonal copepods (e.g., Neocalanus spp.) in the mesozooplankton biomass in the subarctic and transitional region may mask the vertical changes in δ15N values in that region. Further, δ13C varied neither with size nor latitude. In contrast, δ15N showed clear size and latitudinal patterns. Thus, δ15N values increased with increasing zooplankton size (112 μm < 407 μm < 925 μm), and significant regressions increased with increasing latitude for all three size classes (P < 0.001). Subsequent ANCOVA revealed that the regression did not vary with organism size. Thus, the changing latitudinal patterns in δ15N values (higher for high latitude) had much greater effects than the size differences for mesozooplankton.

Dehydration of the Subducting Juan de Fuca Plate and Fluid Pathways Revealed by Full Waveform Inversion of Teleseismic P and SH Waves in Central Oregon

AbstractThe dehydration of subducting slabs expels a massive amount of water into the forearc and backarc mantle which is responsible for the serpentinization of the mantle wedge, as well as the production of melt and arc magmatism. These processes are expected to have characteristic signatures in density and seismic velocities models, which remain largely elusive to date due to the limited spatial resolution of classical passive tomographic approaches. Here we present a tomographic model of density, VP, VS, and VP/VS beneath central Oregon, obtained by inverting complete teleseismic P and SH waveforms recorded by the CASC93 temporary experiment. The final model shows an east‐dipping low‐velocity layer less than 10 km thick that can be associated with the fluid‐saturated Juan de Fuca oceanic crust. The distribution of tremors at the surface closely coincides with the horizontal extent of this low‐velocity layer. Below 40 km depth, seismic velocities and density increase progressively to the values of a typical mantle. This transitional domain corresponds to the eclogitization of the oceanic crust. Silica‐saturated fluids released by pore collapse migrate upward, producing serpentinization reactions in the forearc mantle that lower the density and seismic velocities. The very low VP/VS ratio documented in the Cascadia forearc crust is evidence that these silica‐saturated fluids reach the crust, where they produce extensive quartz mineralization. At greater depth, a low seismic velocity and high VP/VS ratio anomaly provides evidence for partial melting at around 75 km depth beneath the volcanic arc.

Estimation of sea surface pCO2 and air–sea CO2 flux in the East China Sea using in-situ and satellite data over the period 2000–2016

The partial pressure of carbon dioxide (pCO2) is an important variable to characterize the state of the seawater carbonate system. It is required to calculate the air-sea CO2 flux (FCO2) and for understanding ocean acidification. Surface ocean pCO2 is influenced by thermodynamic process, physical mixing, biological activity and air-sea gas exchange. Knowledge of the surface pCO2 in the East China Sea (ECS) is limited due to a lack of observations and well-informed models. This study employed in situ hydrographic (sea surface temperature and salinity) and carbonate system observations combined with satellite observations of chlorophyll a to develop a regional multiple non-linear regression (MNR) model to estimate pCO2 for three different physical-biogeochemical domains of the ECS. Comparison of the pCO2 from in situ observations with the MNR model had a root mean square error (RMSE) of 45.19 μatm and coefficient of determination (R2) of 0.87 in the transitional domain, an RMSE of 11.59 μatm and R2 of 0.92 in the shelf-dominated domain and an RMSE of 3.73 μatm and R2 of 0.97 in the open water domain. The reliability of the MNR model was also validated using an independent dataset with a good accuracy (RMSE of 9.15 μatm for domain II and RMSE of 7.71 μatm for domain III). The MNR model was applied to estimate the surface pCO2 and FCO2 for ten cruises on the period of 2013–2018, and also used to predict monthly surface pCO2 by using Changjiang Biology Finite-Volume Coastal Ocean Model (FVCOM) outputs for the period of 2000–2016 on the ECS inner shelf, and analyzed the seasonal and interannual variability of surface pCO2 and FCO2. The seasonal dynamics of sea surface pCO2 were mainly attributed to temperature changes, biological activities and water mixing process over the seasons. The time series of surface pCO2 and FCO2 on the ECS inner shelf showed an increasing trend of 3.32 ± 0.79 μatm yr−1 and 0.018 ± 0.0125 mol CO2 m−2 yr−2, and the region was a CO2 sink with an CO2 uptake of 0.12 ± 0.48 Tg C yr−1.

Analogical simulation of salt flow and associated structures in different extensional conditions

The salt layer thickness variability and the timing of salt deposition in relation to rifting (prerift salt, synrift salt, and late synrift/postrift salt) influence salt flow and the resulting growth, geometry, and kinematics of salt bodies under different extensional conditions. We apply analogue modelling to analyze the influence and interplay of each of these parameters through three series of experiments focusing on extensional salt tectonics. The first (Series I) simulates thick-skinned extension of a tabular salt layer in the absence of basement structures and explore the effects of variable salt thicknesses and extensional structural styles. Series II tests the degree of mechanical coupling of sub- and supra-salt faults according to contrasting salt thicknesses over a rotating rift block. Series III explores thin-skinned, gravity-driven deformation implementing models of i) pure-gliding (S1), ii) pure-spreading (S2) and iii) a combination of both (S3). Series I shows that the degree of symmetry and the kinematics of the structures vary due to the influence of the thickness of the salt layer. Thick salt layers tend to nucleate symmetric rifts and associated diapirs, while thin salt layers form rifts that are strongly asymmetric and rotated towards the direction of extension. Series II demonstrates that the number and dimensions of peripheral post-salt grabens, rollers, and reactive diapirs depends on the degree of coupling between sub- and supra-salt, which in turn is controlled by how the salt layer is distributed over active rift structures. Series III shows that deformation is compartmentalized into proximal, transitional, and distal domains which are characterized by extension, translation and contraction, respectively. The style and lateral extent of these domains however vary. In models where deformation is driven exclusively by tilting of the salt layer (S1) and open-toe salt advance, there is development of linear grabens cored by reactive-passive diapirs throughout most of the model length. This produces a more abrupt transition between the extensional and contractional domains and limited downdip salt inflation. In the pure-spreading model (S2), where deformation is driven solely by differential loading there is formation of a wide zone of salt inflation at the toe-of-slope and an overall greater number of contractional structures at the downdip end of the model, beyond the slope. In S3 there is development of a more variable suite of salt and overburden structures as typically observed along salt-bearing passive margins. In this model, deformation is characterized by the development of rollover and normal growth faults in the proximal domain that transition downdip onto upright diapirs associated with bowl-shaped minibasins, halokinetic sequences rotated and megaflaps. Our study improves our understanding of the extensional salt tectonic systems and the controls on different salt and post-salt geometries and kinematics.

Peculiarities and evolution of Raman spectra of multilayer Ge/Si(001) heterostructures containing arrays of low‐temperature MBE‐grown Ge quantum dots of different size and number density: Experimental studies and numerical simulations

AbstractGe/Si(001) multilayer heterostructures containing arrays of low‐temperature self‐assembled Ge quantum dots and very thin SixGe1−x layers of varying composition and complex geometry have been studied using Raman spectroscopy and scanning tunneling microscopy (STM). The dependence of Raman spectra on the effective thickness of deposited Ge layers has been investigated in detail in the range from 4 to 18 Å. The position and shape of both Ge and SiGe vibrational modes are of great interest because they are closely related to the strain and composition of the material that plays a role of active component in perspective optoelectronic devices based on such structures. In this work, we present an explanation for some peculiar features of Raman spectra, which makes it possible to control the quality of the grown heterostructures more effectively. A dramatic increase of intensity of both the Ge–Ge and Si–Ge bands for the structure containing Ge layers of 10 Å and anomalous shift and broadening of the Si–Ge band for structures comprising Ge layers of 8 and 9 Å thick were observed. In our model, the anomalous behavior of the Raman spectra with the change of thickness of deposited Ge is connected with the flatness of Ge layers as well as transitional SiGe domains formed via the stress‐induced diffusion from {105} facets of quantum dots. The conclusions are supported by the STM studies and the numerical calculations.

Digital Biomarkers for Supporting Transitional Care Decisions: Protocol for a Transnational Feasibility Study.

BackgroundVirtual Health and Wellbeing Living Lab Infrastructure is a Horizon 2020 project that aims to harmonize Living Lab procedures and facilitate access to European health and well-being research infrastructures. In this context, this study presents a joint research activity that will be conducted within Virtual Health and Wellbeing Living Lab Infrastructure in the transitional care domain to test and validate the harmonized Living Lab procedures and infrastructures. The collection of data from various sources (information and communications technology and clinical and patient-reported outcome measures) demonstrated the capacity to assess risk and support decisions during care transitions, but there is no harmonized way of combining this information.ObjectiveThis study primarily aims to evaluate the feasibility and benefit of collecting multichannel data across Living Labs on the topic of transitional care and to harmonize data processes and collection. In addition, the authors aim to investigate the collection and use of digital biomarkers and explore initial patterns in the data that demonstrate the potential to predict transition outcomes, such as readmissions and adverse events.MethodsThe current research protocol presents a multicenter, prospective, observational cohort study that will consist of three phases, running consecutively in multiple sites: a cocreation phase, a testing and simulation phase, and a transnational pilot phase. The cocreation phase aims to build a common understanding among different sites, investigate the differences in hospitalization discharge management among countries, and the willingness of different stakeholders to use technological solutions in the transitional care process. The testing and simulation phase aims to explore ways of integrating observation of a patient’s clinical condition, patient involvement, and discharge education in transitional care. The objective of the simulation phase is to evaluate the feasibility and the barriers faced by health care professionals in assessing transition readiness.ResultsThe cocreation phase will be completed by April 2022. The testing and simulation phase will begin in September 2022 and will partially overlap with the deployment of the transnational pilot phase that will start in the same month. The data collection of the transnational pilots will be finalized by the end of June 2023. Data processing is expected to be completed by March 2024. The results will consist of guidelines and implementation pathways for large-scale studies and an analysis for identifying initial patterns in the acquired data.ConclusionsThe knowledge acquired through this research will lead to harmonized procedures and data collection for Living Labs that support transitions in care.International Registered Report Identifier (IRRID)PRR1-10.2196/34573

Cenozoic structural deformation between the southern Lamprea fold-belt and Salina del Bravo salt province by interacting salt and shale detachments, western Gulf of Mexico

The Lamprea fold-belt is a 300 km-long, 20-60 km-wide, deep-water, passive margin fold-belt located southeast of the Salina del Bravo salt province and trending parallel to the eastern continental margin of Mexico. The Lamprea fold-belt detaches along Eocene shale layers to form a compressional toe of the gravitationally-driven system that forms a transitional domain between the salt province to the north and the shale-detached Mexican Ridges fold-belt to the south. Area-depth strain measurements performed for ten characteristic folds across two regional seismic profiles through the Lamprea fold-belt provide insight into its timing of deformation, depth to detachment, and controls on the pre-growth and syn-growth sedimentary deposits. Miocene-age deformation across the Lamprea fold-belt coincides with a phase of renewed salt canopy emplacement driven by ongoing up-dip sediment loading and extensional deformation west of the Salina del Bravo salt province. These results are consistent with early Miocene fold growth onset controlled primarily by the advancing salt canopy and only minor influence from underlying autochthonous salt. The timing of trap formation, tectonic interaction of salt bodies with shale structures, and the mechanisms for fold-belt formation all control hydrocarbon migration from deep Mesozoic source intervals into overlying Oligocene fold-belt reservoirs.

The onset of seafloor spreading at the northeastern continent-ocean boundary of the South China Sea

The transition from continental to oceanic crust and the initial formation of typical oceanic crust at passive rifted margin are still poorly understood. In this study, deep crustal structures in the transitional domain of the northeastern South China Sea (SCS) margin are investigated and studied according to newly-acquired high-resolution reflection seismic data and gravity modeling. Three strong reflectors (R1, R2 and R3) are imaged in the narrow transitional domain. About 1 s in the two-way travel time (TWTT) beneath the top basement, R1 shows a similar morphology to the top basement, and quite likely represents a partial serpentinization interface. The presence of R1 suggests a tectonically dominated extensional stage prior to the final lithospheric rupture of the SCS. R2 is from magmatic intrusions or plutons (sills or dikes) from decompression melting. R3 is observed at ~2.5–2.2 s TWTT beneath the top basement but shoals seawards. R3 likely resulted from magmatic relicts in the paleo-melt transfer channels and/or from frozen molten materials in a shear zone of the lithospheric and asthenospheric mantle. The occurrence of R3 indicates the onset of a robust seafloor spreading system. The gradual seaward increase in magmatic activity highlights that, towards the final lithospheric breakup, tectonic extension was overtaken by magmatism. Increased magmatism and partial serpentinization formed a narrow hybrid transitional crust. Nevertheless, the breakup was not an instantaneous event. The last-stage transient magmatism occurred in a very narrow zone and does not rule out that the margin was predominantly amagmatic during the rifting and breakup. Based on reflection seismic and gravity modeling, we propose that the onset of typical seafloor spreading occurred at about 30 Ma around the study area, and the continent-ocean boundary (COB) should be located further seawards in the northeastern SCS margin.

Ferroelectric domain evolution in a Ba(Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3 piezoceramic studied using piezoresponse force microscopy

Lead-free Ba(Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3 (BZT-0.5BCT) ceramics have drawn attention in recent years because of their outstanding dielectric and electromechanical properties, such as a piezoelectric coefficient d33 ∼ 620 pC N−1 and a large signal of d33* ∼ 1100 pm V−1 at 0.5 kV mm−1 at room temperature (RT). These particular properties are relevant to a range of applications. However, the structural origin of this high piezoelectric coefficient is still a subject of discussion. An in-depth understanding of the ferroelectric domain evolution of BZT-0.5BCT ceramics is crucial for probing the underlying mechanisms and for guiding practical applications. Using piezoresponse force microscopy (PFM), we have directly visualized the evolution of the BZT-0.5BCT domain structure using temperature and electric field stimulation on micrometer and nanometer scales. The PFM results unambiguously evidence the coexistence of wedge-shaped and lamellar domains with miniaturized nanodomain structures at RT. The temperature- and electric-field-dependent PFM study presented here highlights the critical role of wedge-shaped domains in domain evolution. Wedge-shaped domains turn into small domains with curved domain walls after the heating cycle and then become lamellar domains after the poling cycle at RT. Transitional domain structures with an increased density of nanodomains appear in both the thermal and poling cycles. More interestingly, the electric-field-dependent domain structure evolution at different temperatures shows better domain structure reversibility at high temperatures than at temperatures close to the phase boundary. This demonstrates that the BZT-0.5BCT ceramic has superior stability at medium temperatures (40 °C–60 °C), implying excellent stability for applications.