High Spatial Resolution Analysis Research Articles

Automatic mapping and spatial analysis of high spatial resolution closed terrain depressions and mounds on martian landscapes

The purpose of this paper is to illustrate a methodology for the automatic mapping and spatial analysis of high spatial resolution (metric scale) closed depressions and mounds on Mars landscapes. The proposed automatic procedure requires only a digital elevation model, a sink-filling algorithm and a basic map algebra operation all of which are available in the most commonly used Geographical Information Systems. Six high spatial resolution (1 m to 2 m) digital elevation models obtained from images of the High-Resolution Imaging Science Experiment (HiRISE) were selected as representatives of various Martian landscapes representing hypothesized aeolian, volcanic, hydrated, cratered, reticulate and sublimated terrains. This is not an exhaustive list of landscapes but it is representative of the variety of Martian landscapes. Metric spatial-scale closed depressions and mounds are commonly distributed in all the landscapes selected for this study and closed terrain depressions cover, on average, 25% of the Martian surface. Most closed depressions are small and shallow and have a complex shape. The area covered by mounds is more variable and is up to 36% in reticulate terrain and 43% in volcanic terrain. Again, most mounds are small, low and have complex shapes. For sublimated terrains the percentage covered by depressions, in the form of radiating araneiform channels, is equal to the percentage of mounds (material accumulated between the channels). Size distribution analysis reveals the fractal character of both closed depressions and mounds with the emergence of two main groups of landscapes. One group characterizes a detached geomorphology (aeolian and sublimated terrains), and the other group characterizes a connected geomorphology (volcanic, impact craters and reticulate terrain). The hydrated terrain is intermediate between the two main groups perhaps because of its plastic rheology. The proposed methodology is completely general and can be applied to any digital elevation model. The mapping and morphometric analysis of closed terrain depressions and mounds can assist planetary geologists in the mapping and interpretation of geological and geomorphological units and in the inference of geological processes.

Identification and spatial mapping of tracers of PM10 emission sources using a high spatial resolution distributed network in an urban setting

We employed an experimental approach for high spatial resolution sampling and analysis of PM10, allowing identification and spatial mapping of tracers of PM10 emission sources. Very-low-volume samplers were used at 17 sites in Amersfoort and at one regulatory reference site in Utrecht, The Netherlands, in a 5-month monitoring period (from September 2018 to February 2019), to assess the monthly spatial distribution of PM10 mass and PM10 chemical compounds. By performing principal component analysis on the obtained spatially-resolved data, selective and reliable source tracers were identified for soil dust (Ca+, Cl−, insoluble Al, Ce, Li, U and V), brake dust (insoluble Fe, Mn, Mo, Nb, Sb, Sn, W and Zr, water-soluble Fe, Mn, Mo and Sb), industrial and/or agricultural emissions (NH4+, water-soluble As, Co, Fe, Mn, Mo, Pb, Sb, Se, Sn and Ti), secondary organic and inorganic aerosols (water-soluble organic carbon, NO3− and SO42−), biomass domestic heating (water-soluble organic carbon, levoglucosan, water-soluble Cs, Li, Rb and Tl) and New Year's Eve fireworks (K+, Mg2+, Na+, water-soluble Al, Ba, Bi, Cr, Cu and Sr). The autumn and winter spatial mapping of the identified source tracers allowed us to effectively assess and localize the impact of the different PM10 sources and to evaluate the diffusion of the PM10 particles. This approach proved to be very effective to trace low-intensity PM10 sources and to map their seasonal spatial distribution. The obtained spatially-resolved chemical data can be used in further studies to evaluate spatial relationships between the concentration of PM10 air pollutants and adverse outcomes for human health. This approach promises to be a powerful tool for obtaining seasonal and spatially-resolved information about PM composition and sources in several study areas, having high impact on the air quality management.

The next big earthquake may inflict a multi-hazard crisis – Insights from COVID-19, extreme weather and resilience in peripheral cities of Israel

The occurrence of a natural disaster in an area already coping with an epidemic, constitutes a multi-hazard event. Such events are more likely than ever during the ongoing COVID-19 pandemic. In regions that seasonally experience extreme-weather disasters, such multi-hazard crises are imminent.People living along the Dead Sea Fault and in the Negev are used to harsh weather conditions and to the hardship of living in isolation. While self-reliance and community-support are often the norm in the daily life of residents in in peripheral communities, in an emergency they may be crucial for survival. Worldwide remote communities with limited response and medical infrastructure and resources may struggle to cope with the aftermath of an earthquake while potentially coping with a concurrent epidemic or extreme weather. In this work we focus on the effect of concurring disasters and seasonal stressors. In particular we discuss how various disasters would affect the Covid-19 infection rate, and we demonstrate that in Israel's periphery cities, heat-stress is a consistent and significant seasonal stressor that would hamper emergency and recovery operations. We also suggest that transient tourist population in these remote cities is expected to burden local emergency efforts and facilities. A seasonal over burden parameter is proposed to describe how seasonal tourism and weather conditions enhance the hardship and risk in a multi-hazard situation. A case study shows that high-resolution spatial analysis of risk and preparedness together with a temporal analysis of seasonal effects, may be used to detect specific neighborhoods with high or low resilience and capacity to cope with disasters.Our work demonstrates the need for spatial and temporal, multi-hazard analysis for improving local resilience and emergency plans in periphery cities and communities exposed to seasonal harsh weather.

Bacterial predation transforms the landscape and community assembly of biofilms

The bacterium Bdellovibrio bacteriovorus attaches to the exterior of a Gram-negative prey cell, enters the periplasm, and harvests resources to replicate before lysing the host to find new prey.1-7 Predatory bacteria such as this are common in many natural environments,8-13 as are groups of matrix-bound prey cell clusters, termed biofilms.14-16 Despite the ubiquity of both predatory bacteria and biofilm-dwelling prey, the interaction between B.bacteriovorus and prey inside biofilms has received little attention and has not yet been studied at the micrometer scale. Filling this knowledge gap is critical to understanding bacterial predator-prey interaction in nature. Here we show that B.bacteriovorus is able to attack biofilms of the pathogen Vibrio cholerae, but only up until a critical maturation threshold past which the prey biofilms are protected from their predators. Using high-resolution microscopy and detailed spatial analysis, we determine the relative contributions of matrix secretion and cell-cell packing of the prey biofilm toward this protection mechanism. Our results demonstrate that B.bacteriovorus predation in the context of this protection threshold fundamentally transforms the sub-millimeter-scale landscape of biofilm growth, as well as the process of community assembly as new potential biofilm residents enter the system. We conclude that bacterial predation can be a key factor influencing the spatial community ecology of microbial biofilms.

Highly volatile element (H, C, F, Cl, S) abundances and H isotopic compositions in chondrules from carbonaceous and ordinary chondrites

The partial pressures and isotopic compositions of volatiles present during chondrule formation can be constrained by the highly volatile element or HVE (H, C, F, Cl, and S) abundances and isotopic compositions in chondrules. Here we present the results of high spatial resolution and low background secondary ion mass spectroscopy (SIMS) analyses of the HVE concentrations and H isotopic compositions in type I and II chondrules in primitive ordinary chondrites Semarkona (LL3.00) and Queen Alexandra Range (QUE) 97008 (L3.05), and the primitive carbonaceous chondrite Dominion Range (DOM) 08006 (CO3.00). The HVEs in the chondrules primarily reside in the mesostases, in which the HVE contents and H isotopic compositions vary significantly (H2O: 8–10,200 ppm, CO2: 2.4–1170 ppm, F: 0.3–30 ppm, Cl: 0.07–175 ppm, S: 0.38–4400 ppm, δD: 77–15,000‰). To dissolve such HVE contents in a silicate melt requires significantly higher total pressures (up to 1900 bars), and in some cases requires anomalous gas compositions (CO dominated), compared to those expected from canonical conditions of chondrule formation (∼10−3 bars, H2 + H2O dominated). Rather, the enrichments of H2O, CO2, Cl, and F in the mesostases at the edges of some chondrules suggest that there were secondary influxes of HVEs into the chondrule mesostases from the surrounding matrix during parent body processes. Consistent with this, melt inclusions sealed in olivine phenocrysts have significantly lower HVE contents than the mesostases in contact with the surrounding matrix material. Further, the calculated diffusion distances of H2O in silicate glasses under the relevant conditions are comparable to the radii of the chondrules. The high δD values in the mesostases could have been generated through isotopic Rayleigh fractionation as a result of the loss of very D-poor H2 generated from Fe metal oxidation by H2O in the parent bodies. Based on these results, we hypothesize that the bulk of the HVEs in the chondrules are secondary in origin. However, a small portion of the HVEs in chondrules could be primary, as there are low but measurable amounts of HVEs in the melt inclusions that are sealed in phenocrysts. Further, measured S contents in some chondrule mesostases agree with those predicted in a sulfide saturated silicate melt based on an experimentally calibrated thermodynamic model. We constrain the upper limits of primary HVEs in the chondrules based on the lowest measured HVE contents to minimize the effects of the secondary influx of HVEs (type I H2O: 7–11 ppm, CO2: 0.3–0.6 ppm, F: 0.1–0.2 ppm, Cl: 0.01–0.03 ppm, S: 0.3–60 ppm, and type II H2O: 50–85 ppm, CO2: 0.4–3 ppm, F: 0.04–2 ppm, Cl: 0.04–2 ppm, S: 190–260 ppm).

Chemical Imaging of Fingerprint on RMB Banknotes Using Time-of-Flight Secondary Ion Mass Spectrometry

The development of latent fingerprints on long-circulated RMB banknotes has been one of the challenging task in forensic science research. In this work, time-of-flight secondary ion mass spectrometry (TOF-SIMS) was used to perform chemical imaging of latent fingerprints on the surface of the substrate due to its advantages such as in-situ, quasi-nondestructive, high-throughput, simultaneous analysis of multi-components and high spatial resolution. The developing effect of TOF-SIMS was firstly compared with that of several traditional methods, and the reasons for the unique advantages of TOF-SIMS were discussed. Its applicability was further discussed from the perspective of universality, sensitivity and fingerprint three-level feature acquisition capability. Finally, exogenous substances in fingerprints were also analyzed by using this technology to detect the molecular ions (m/z 92.06) and fragment ion peaks (m/z 43.02) of glycerol in the moisture lotion and developed clear fingerprint images. Preliminary research results showed that TOF-SIMS technology could provide an effective method for the development of latent fingerprints on long-circulated RMB banknotes and was expected to be used for the detection of substances in fingerprints on the surface of various substrates.

Prioritising resilience policies to reduce welfare losses from natural disasters: A case study for coastal Bangladesh

Quantified flood risk assessments focus on asset losses, neglecting longer-term impacts to household welfare via income and consumption losses. The extent of welfare losses depends upon resilience – the ability to anticipate, resist, cope, recover and learn from a shock. Here, we use a novel welfare loss modelling framework and perform a high-resolution spatial analysis in coastal Bangladesh to quantify welfare losses from a tropical cyclone under present and future climatic and socio-economic conditions. We further test various adaptation options that are intended to enhance resilience. Results show that poor households experience, on average, 7% of the asset losses, but 42% of the welfare losses. Combining dike heightening, post-disaster support and stronger housing can reduce welfare losses by up to 70%, and foster sustainable development by benefitting the poor, increasing resilience and demonstrating robustness under socio-economic and climatic uncertainties. Thus, a welfare-orientated perspective helps to identify adaptation options that enhance resilience and leave no-one behind.

Pemanfaatan Citra Landsat 8 untuk Identifikasi Sebaran Vegetasi di Kecamatan Pangandaran

This study aims to determine: (1) the density of vegetation in Pangandaran district. (2)the result of comparison of vegetation density from digital image interpretation using the NDVI transformation with the results of validation. This research was done in pangandaran regency, which is located at coordinates 108º 41 - 1090 East Longitude and 07o 41-07 07 50 South Latitude has an area of up to 61 km². This research was conducted in several stages, namely: (1) the preparation of tools and data, (2) digital data processing, (3) field data collection, and (4) data analysis. Thanks to the density of vegetation can be done quickly by way of digital image interpretation using NDVI (Normalized Difference Vegetation Index) transformation. The purpose of this research is to know the land arrangement in Pangandaran District and for vegetation index of residential area in Pangandaran District. The object of this research is residential area in Pangandaran District. The data used are Landsat Image 8 year 2018. The software used is ENVI 5.1 and ArcGIS 10.3 software. The method used is the classification of land use and the calculation of NDVI in ENVI which then classified based on the range of NDVI index values. The results showed that the density of vegetation in Pangandaran District was dominating classified and as quite dense but it needed a lot of updating of its digital image and data so that the accuracy rate increased between imagery and field data. Vegetation in Pangandaran Subdistrict is mostly dominated by teak, waru, coconut, Chinese petai, goat, santigi, and ketapang. Based on the results of the interpretation accuracy test, obtained an accuracy value for the entire sample of 57% so that the results of image interpretation and field checks regarding vegetation density cannot be accepted because the expected level of interpretation accuracy is 85%, while the accuracy test results get a value of 57%. To get a complete picture of the availability of green open space in Pangandaram Regency, fast and relatively more accurate analysis of high spatial resolution is needed. The satellite imagery used in this study is Landsat 8 Imagery which has never been used in previous studies. Analysis of these images uses a vegetation index / NDVI that can directly distinguish plants from non-plants. The results of this image analysis also produce digital data that can be processed quantitatively for further research purposes.

Oscillation and Evolution of Coronal Loops in a Dynamical Solar Corona

Observations have revealed two regimes of kink oscillations of coronal loops. Large amplitude oscillations excited by impulsive energy releases such as coronal mass ejections are characterised by their strong damping by resonant absorption. Lower amplitude oscillations may also be excited and sustained by the ubiquitous motions present in the corona and so are characterised as being decayless. We perform numerical simulations to study the oscillation and evolution of coronal loops in a dynamical environment. We investigate the observational signatures of kink oscillations and the Kelvin-Helmholtz instability in terms of high-resolution seismological and spatial data analysis techniques. We find that low amplitude kink oscillations are capable of generating significant changes in the loop profile which can affect estimates of the transverse loop inhomogeneity based on seismological and forward modelling methods. The disparity between methods may be indicative of nonlinear evolution of coronal loops. The influence on forward modelling estimates could also account for previous observational evidence favouring loops having wider inhomogeneous layers.

Primary environmental factors controlling gully distribution at the local and regional scale: An example from Northeastern China

Gully erosion is the main cause of global land degradation. The factors controlling gully erosion at watershed scale have been extensively studied, but the spatial pattern of gullies and their primary environmental factors are unclear. In order to explore the primary factors at the regional scale of over thousands of square kilometers, 34 sample areas were selected in northeastern China and 10 environmental factors were proposed. Based on gully interpretations from high-resolution Google Earth images and spatial analysis, kernel density estimation (with polyline features), and correlation analysis, the results show that the maximum kernel density (KD) of the 34 sample areas ranged from 0.11 to 87.16, and there were significant positive correlations between the average KD and the maximum value and standard deviation. At the regional scale, topography (relief amplitude, slope, surface roughness, surface incision, and elevation with correlation coefficients (ρ) of 0.60, 0.59, 0.57, 0.48, and 0.41 respectively) was the primary environmental factor, with a significant positive correlation with KD. The correlation coefficients of the normalized difference vegetation index (NDVI) (ρ = 0.32), annual precipitation (ρ = 0.19), and soil (silt, sand, and clay content with ρ of 0.139, −0.117, and 0.085, respectively) decreased successively with the KD. At sample area scale, there were six areas with weak correlations between environmental factors and KD, 20 areas with topographic factors, six areas with annual precipitation, and two areas with NDVI as the primary factor. The correlation between soil texture and KD was low. There were different positive or negative correlations between the environmental factors and KD. The spatial distribution of gullies in northeastern China is heterogeneous, and the primary environmental factors were diverse. This study will help to understand the spatial pattern and formation mechanism of gullies at large scale.

High spatial resolution analysis of H2O in silicate glass using attenuated total reflection FTIR spectroscopy coupled with a focal plane array detector

High resolution spectroscopic techniques that are used to determine volatile concentration in geological glasses are on the forefront for determining small scale degassing or hydration processes. Several spectroscopic methods are used for this purpose but they mostly require complicated sample preparation. Here, these methods are extended by the use of attenuated total reflectance (ATR) FTIR spectroscopy coupled with a focal plane array detector (FPA). ATR-FTIR spectroscopy requires only singly polished samples. The coupling to an FPA detector, which is novel for the analysis of volatile bearing glasses, enables spatial resolution on a micrometer scale. An ATR-FPA calibration to quantify H2O concentration in peralkaline rhyolitic glass is presented, which is comparable to conventional ATR calibrations using a single element detector. The results confirm that calibrations for different glass compositions are comparable after correction for glass density as suggested by a previous study. A method is developed to compare calibrations obtained with ATR objectives that have different angles of incidence. Despite the larger errors that come with the use of an FPA detector, the method allows the detection of H2O concentration gradients on a micrometer scale.The ATR-FPA calibration was applied to experimentally vesiculated melts that were quenched to glasses. It was possible to resolve only several μm-sized H2O resorption halos around vesicles that formed during isobaric cooling. Besides vesiculated glasses, the new method may enable the analysis of small melt inclusions and partially crystallized glasses and may allow the spatially resolved analysis of CO2 dissolved in silicate glasses.

High-resolution spatial analysis of the variability in the subdaily rainfall time structure

The paper is motivated by the generally large variability in the rainfall time structure during the events with high subdaily precipitation totals in Czechia, which should be taken into account when designing water management systems to handle precipitation. The presented spatial analysis of the variability in the rainfall time structure is based on the regional frequency analysis of the 6-h totals with a spatial resolution of 1 km. The totals are quantified with the synergy method using the weather-radar-derived precipitation intensities and the totals measured by rain gauges. The frequency analysis employs the progressive and robust region-of-influence method. Instead of only one design storm hyetograph, each site is characterized by the possible occurrence of six hyetographs that are synthetized from the heavy rainfalls in Czechia. The percentage of individual hyetographs for a given design precipitation depth is assessed through the combination of the frequency analyses of the totals with respect to and regardless of the course of precipitation. The spatial heterogeneity in the percentages is significantly affected by the topography and amplifies with the increasing return period of the totals. The six synthetic hyetographs are represented relatively evenly in the lowlands. In contrast, the mountainous areas are characterized by a notable increase in the percentages of events of long-lasting steady rain, which are triggered by their circulation causes together with the significant role of the orographic precipitation enhancements, particularly through the windward orographic lifting, which is mainly on the northern and eastern slopes of the mountains. Future research on the dependence between the return period of the events of a specific precipitation course and the magnitude of the antecedent totals might be even more applicable to hydrological modeling in small catchments.

Precision, Equity, and Public Health and Epidemiology Informatics - A Scoping Review.

Summary Objectives : This scoping review synthesizes the recent literature on precision public health and the influence of predictive models on health equity with the intent to highlight central concepts for each topic and identify research opportunities for the biomedical informatics community. Methods : Searches were conducted using PubMed for publications between 2017-01-01 and 2019-12-31. Results : Precision public health is defined as the use of data and evidence to tailor interventions to the characteristics of a single population. It differs from precision medicine in terms of its focus on populations and the limited role of human genomics. High-resolution spatial analysis in a global health context and application of genomics to infectious organisms are areas of progress. Opportunities for informatics research include (i) the development of frameworks for measuring non-clinical concepts, such as social position, (ii) the development of methods for learning from similar populations, and (iii) the evaluation of precision public health implementations. Just as the effects of interventions can differ across populations, predictive models can perform systematically differently across subpopulations due to information bias, sampling bias, random error, and the choice of the output. Algorithm developers, professional societies, and governments can take steps to prevent and mitigate these biases. However, even if the steps to avoid bias are clear in theory, they can be very challenging to accomplish in practice. Conclusions : Both precision public health and predictive modelling require careful consideration in how subpopulations are defined and access to data on subpopulations can be challenging. While the theory for both topics has advanced considerably, there is much work to be done in understanding how to implement and evaluate these approaches in practice.

Genesis of baddeleyite and high δ18O zircon in impure marble from the Tongbai orogen, Central China: insights from petrochronology and Hf–O isotope compositions

Coexistence of baddeleyite and zircon is rarely documented in metacarbonate rocks and poorly understood. In this study, metamorphic baddeleyite and zircon were recognized in marbles from the Tongbai orogen, central China. We carried out high spatial resolution analysis of trace element geochemistry and U‒Pb‒Lu‒Hf‒O isotope systematics for the zircon and baddeleyite. SIMS (Secondary Ion Mass Spectroscopy) U‒Pb analysis yields weighted average 207Pb/206Pb ages of 1848.0 ± 3.3 Ma (MSDW = 1.2, n = 12) for baddeleyite and 1840 ± 13 Ma (MSWD = 1.7, n = 13) for zircon. The baddeleyite grains have relatively low REE (Rare Earth Element) contents (ΣREE = 1.30–47.3 ppm) with flat chondrite-normalized patterns and moderate contents of HFSE (High Field Strength Element), which are ascribed to the nature of its host metacarbonate rock and mineral assemblage. The zircon grains have low Ti contents (1.63–3.56 ppm), positive Ce anomalies (Ce/Ce* = 1.91–6.96), and mineral inclusions of hematite, calcite, dolomite, lizardite and H2O. These characteristics indicate zircon formation in a relatively low-temperature setting under oxidizing and water-rich conditions. The baddeleyite and zircon have similar ranges of eHf(t) values of – 7.7 to – 10.5 and – 7.8 to – 11.6, respectively, which suggest their derivation from a relatively uniform Hf source. The high δ18O values of these zircon grains (20.0–21.0‰) preclude any percolation of external meteoric fluids during their crystallization. Therefore, a “detrital-zircon-dissolution” reaction is preferred to provide the Zr for the metamorphic zircon and baddeleyite in this study. The O isotope disequilibrium between whole-rock (δ18O = 16.2–16.3‰) and metamorphic zircon is most likely caused by metamorphic devolatilization or interaction with an H2O-dominant fluid during later metamorphism. On the other hand, the baddeleyite grains yield δ18O values ranging from 4.5 to 8.7‰, which is in disequilibrium with metamorphic zircon at the temperature of “detrital-zircon-dissolution” reaction (ca. 660–710 °C; Zircon + Dolomite → Baddeleyite + Forsterite + Calcite + CO2). The genesis of metamorphic zircon can be interpreted by a baddeleyite-to-zircon reaction of ZrO2 + SiO2 → ZrSiO4 at a retrograde stage, consistent with the low Ti-in-Zircon temperatures. The results highlight the importance of integrating trace element and multiple isotopic compositions in studying the genesis of metamorphic baddeleyite and zircon. Additionally, the U–Pb geochronology data also indicate that the protoliths of the marble were deposited in the early Paleoproterozoic and experienced a metamorphism at 1.85 Ga. The ca. 1.85 Ga high-grade metamorphic event might have been induced by the coeval magmatism in an extensional setting.

Multimethod U–Pb baddeleyite dating: insights from the Spread Eagle Intrusive Complex and Cape St. Mary's sills, Newfoundland, Canada

Abstract. Baddeleyite (ZrO2) is widely used in U–Pb geochronology but analysis and age interpretation are often difficult, especially for samples which have experienced post-intrusive alteration and/or metamorphism. Here, we combine high spatial resolution (secondary ionization mass spectrometry, SIMS) and high-precision (isotope dilution thermal ionization mass spectrometry, ID-TIMS) analyses of baddeleyite from the Spread Eagle Intrusive Complex (SEIC) and Cape St. Mary's sills (CSMS) from Newfoundland. Literature data and our own detailed microtextural analysis suggest that at least seven different types of baddeleyite–zircon intergrowths can be distinguished in nature. These include secondary baddeleyite inclusions in altered zircon, previously unreported from low-grade rocks, and likely the first discovery of xenocrystic zircon inclusions mantled by baddeleyite. 207Pb∕206Pb baddeleyite dates from SIMS and ID-TIMS mostly overlap within uncertainties. However, some SIMS sessions of grain mounts show reverse discordance, suggesting that bias in the U ∕ Pb relative sensitivity calibration affected 206Pb∕238U dates, possibly due to crystal orientation effects, and/or alteration of baddeleyite crystals, which is indicated by unusually high common-Pb contents. ID-TIMS data for SEIC and CSMS single baddeleyite crystals reveal normal discordance as linear arrays with decreasing 206Pb∕238U dates, indicating that their discordance is dominated by recent Pb loss due to fast pathway diffusion or volume diffusion. Hence, 207Pb∕206Pb dates are more reliable than 206Pb∕238U dates even for Phanerozoic baddeleyite. Negative lower intercepts of baddeleyite discordia trends for ID-TIMS dates for SEIC and CSMS and direct correlations between ID-TIMS 207Pb∕206Pb dates and the degree of discordance may indicate preferential 206Pb loss, possibly due to 222Rn mobilization. In such cases, the most reliable crystallization ages are concordia upper intercept dates or weighted means of the least discordant 207Pb∕206Pb dates. We regard the best estimates of the intrusion ages to be 498.7±4.5 Ma (2σ; ID-TIMS upper intercept date for one SEIC dike) and 439.4±0.8 Ma (ID-TIMS weighted mean 207Pb∕206Pb date for one sill of CSMS). This first radiometric age for the SEIC is consistent with stratigraphic constraints and indicates a magmatic episode prior to opening of the Rheic Ocean. Sample SL18 of the Freetown Layered Complex (FLC), Sierra Leone, was investigated as an additional reference. For SL18, we report a revised 201.07±0.64 Ma intrusion age, based on a weighted mean 207Pb∕206Pb date of previous and new baddeleyite ID-TIMS data, agreeing well with corresponding SIMS data. Increasing discordance with decreasing crystal size in SL18 indicates that Pb loss affected baddeleyite rims more strongly than cores. Our SL18 results validate that the SIMS in situ approach, previously used for Precambrian and Paleozoic samples, is also suitable for Mesozoic baddeleyite.

Spatial resolution limits of EPMA

The development of field emission EPMA, has significantly improved the lateral resolution of EPMA. Two strategies are available for achieving high spatial resolution, either low overvoltage or low voltage analysis. Determining the spatial resolution for a particular analysis is complex and depends on the voltage, spot size, beam current, density of the sample, X-rays analysed and the precision and sensitivity required. Monte carlo simulations can be used to evaluate the spatial resolution for different analytical conditions and samples, provided the minimum spot size achievable at the conditions is known. Spot size is important in determining lateral resolution, which initially improves with decreasing accelerating voltages, and then increases as the minimum spot size becomes more significant than the distance electrons travel. For trace elements, the requirement for precision and sensitivity demands either higher overvoltages increasing the volume from which X-rays are generated, and/or higher beam currents increasing the spot size. At low overvoltage or low voltage conditions many additional factors must be considered: carbon contamination, coat thickness, erosion of the carbon coat, the stability of the sample and the problems surrounding the measurement of soft X-ray lines including L-lines for first row transition metals. When analysing L-lines for quantifying first row transition metals, either calibration curves must be used, or the anomalous mass absorption and variations in the fluorescence yields from partial shell occupancy must be accounted for, by using fits to experimentally determined values. By taking these factors into consideration, high quality measurements can be performed.

High spatial resolution analysis of polybrominated diphenyl ethers (PBDEs) using transplanted lichen Evernia prunastri: A case study in central Italy

The ability of transplanted lichen Evernia (E.) prunastri (L.) to act as a high spatial biomonitoring tool for 14 polybrominated diphenyl ethers (PBDEs) was evaluated at 23 monitoring sites in a very polluted area in central Italy. The selected area is characterized by the presence of numerous emission sources, such as waste-to-energy plant, steel plant, vehicular traffic, and domestic heating. Transplanted E. prunastri proved to be a useful tool to biomonitor PBDEs, due to its ability to bioaccumulate individual congeners in varying concentrations in relation to the strength of the emission sources present over the territory. PBDEs levels widely ranged from 132 to 24,237 ng kg−1 dry weight, according to the sources of emission located around the monitoring sites. The highest concentrations were detected at the sites close to the municipal solid waste incinerator, steel plant, and high busy roads, confirming their important role as PBDEs emissions sources.

High resolution spatial analyses of trace elements in coccoliths reveal new insights into element incorporation in coccolithophore calcite

Coccolithophores are phytoplanktonic algae which produce an exoskeleton made of single platelets of calcite named coccoliths. They are widespread in all oceans and directly impact the short- and long-term C cycle. The study of coccolith size, morphology and elemental composition reveals important information regarding the ability of the cell to calcify and on the factors that influence this process. In this regard, very little is known about coccolith composition and its changes under altered environmental conditions. Here, we present high resolution (50 × 50 nm) elemental spatial distribution in pristine coccoliths of Coccolithus pelagicus and Gephyrocapsa oceanica reconstructed via X-ray fluorescence analyses at synchrotron. The studied specimens are from control culture and metal-enriched (V, Ni, Zn and Pb) experiments. The analysed specimens produced under stress conditions, display an irregular shape and are thinner, especially in the external rim, with ca. 1/3 lower Ca concentrations compared to specimens from the control. The same specimens also have higher Sr/Ca ratio with highest values in the coccolith external rim, suggesting that difficulty in calcification is additionally reflected in increased Sr/Ca ratios. Selenium is found in the coccolith as possible substitute of carbonate in the calcite. V and Pb apparently did not interact with the coccoliths while Zn and Ni were deposited on the coccolith surface.

Spatial distribution of levoglucosan and alternative biomass burning tracers in atmospheric aerosols, in an urban and industrial hot-spot of Central Italy

Domestic biomass heating and wildfires strongly affect particulate matter (PM) concentration in the atmosphere. The individuation of alternative chemical tracers may provide a valuable tool to apportion different possible contributions to biomass burning. In this study, we used a new experimental procedure, based on high spatial resolution analyses of PM10, to assess the spatial distribution of levoglucosan (LVG) and evaluate the possible use of alternative biomass burning tracers in the Terni basin, a wide urban and industrial hot-spot of Central Italy, which includes several spatially disaggregated sources. Spatially-resolved chemical characterization of PM10 was obtained through the use of innovative samplers working in parallel in a dense monitoring network (20 sampling sites, about 1 km between each other), during wintertime. PM10 samples were analyzed for LVG, water-soluble organic carbon (WSOC) and water-soluble and insoluble fraction of 33 elements. Principal component analysis (PCA) on the obtained spatially-resolved data allowed us to identify biomass burning tracers across the polluted study area. Analyses of size-segregated PM samples showed the presence of LVG, and water-soluble Cd, Cs, K, Rb and Tl in particles with size fraction smaller than 1 μm, confirming them as tracers of combustion processes (mainly related to biomass burning). Pearson correlation coefficients demonstrated that concentrations of WSOC and water-soluble Cd, Cs, K, Rb and Tl were well correlated with the spatial variability of LVG concentration. The combined use of spatially and dimensionally resolved data was found to be particularly advantageous for the identification of alternative source tracers, which were used to reliably trace the main local biomass burning sources in the study area.

Demarcation of Sepsis-Induced Peripheral and Central Acidosis with pH (Low) Insertion Cycle Peptide.

Acidosis is a key driver for many diseases, including cancer, sepsis, and stroke. The spatiotemporal dynamics of dysregulated pH across disease remain elusive, and current diagnostic strategies do not provide localization of pH alterations. We sought to explore if PET imaging using hydrophobic cyclic peptides that partition into the cellular membrane at low extracellular pH (denoted as pH [low] insertion cycles, or pHLIC) can permit accurate in vivo visualization of acidosis. Methods: Acid-sensitive cyclic peptide c[E4W5C] pHLIC was conjugated to bifunctional maleimide-NO2A and radiolabeled with 64Cu (half-life, 12.7 h). C57BL/6J mice were administered lipopolysaccharide (15 mg/kg) or saline (vehicle) and serially imaged with [64Cu]Cu-c[E4W5C] over 24 h. Ex vivo autoradiography was performed on resected brain slices and subsequently stained with cresyl violet to enable high-resolution spatial analysis of tracer accumulation. A non-pH-sensitive cell-penetrating control peptide (c[R4W5C]) was used to confirm specificity of [64Cu]Cu-c[E4W5C]. CD11b (macrophage/microglia) and TMEM119 (microglia) immunostaining was performed to correlate extent of neuroinflammation with [64Cu]Cu-c[E4W5C] PET signal. Results: [64Cu]Cu-c[E4W5C] radiochemical yield and purity were more than 95% and more than 99%, respectively, with molar activity of more than 0.925 MBq/nmol. Significantly increased [64Cu]Cu-c[E4W5C] uptake was observed in lipopolysaccharide-treated mice (vs. vehicle) within peripheral tissues, including blood, lungs, liver, and small intestines (P < 0.001-0.05). Additionally, there was significantly increased [64Cu]Cu-c[E4W5C] uptake in the brains of lipopolysaccharide-treated animals. Autoradiography confirmed increased uptake in the cerebellum, cortex, hippocampus, striatum, and hypothalamus of lipopolysaccharide-treated mice (vs. vehicle). Immunohistochemical analysis revealed microglial or macrophage infiltration, suggesting activation in brain regions containing increased tracer uptake. [64Cu]Cu-c[R4W5C] demonstrated significantly reduced uptake in the brain and periphery of lipopolysaccharide mice compared with the acid-mediated [64Cu]Cu-c[E4W5C] tracer. Conclusion: Here, we demonstrate that a pH-sensitive PET tracer specifically detects acidosis in regions associated with sepsis-driven proinflammatory responses. This study suggests that [64Cu]Cu-pHLIC is a valuable tool to noninvasively assess acidosis associated with both central and peripheral innate immune activation.