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International audience; The structural characterization of supported molecular catalysts is challenging due to the low concentration of surface sites and the presence of several organic/organometallic surface groups resulting from the often complex surface chemistry associated with support functionalization. Here, we provide a complete atomic-scale description of all surface sites in a silica-supported iridium-N-heterocyclic carbene (Ir-NHC) catalytic material, at all stages of its synthesis. By combining a suitable isotope labelling strategy with the implementation of multi-nuclear dipolar recoupling DNP enhanced NMR experiments, the 3D structure of the Ir-NHC sites, as well as that of the synthesis intermediates were determined. As a significant fraction of parent surface fragments does not react during the multi-step synthesis, site-selective experiments were implemented to specifically probe proximities between the organometallic groups and the solid support. The NMR-derived structure of the iridium sites points to a well-defined conformation. By interpreting extended x-ray absorption fine structure (EXAFS) spectroscopy and chemical analysis data augmented by computational studies, the presence of two coordination geometries is demonstrated: Ir-NHC fragments coordinated by a 1,5-cyclooctadiene and one Cl ligand, as well as, more surprisingly, a fragment coordinated by two NHC and two Cl ligands. This study demonstrates a unique methodology to disclose individual surface structures in complex, multi-site environments, a long-standing challenge in the field of heterogeneous/supported catalysts, while revealing new, unexpected structural features of metallo-NHC supported substrates. It also highlights the potentially large diversity of surface sites present in functional materials prepared by surface chemistry, an essential knowledge to design materials with improved performances.

We developed an efficient approach to obtain information on small-scale fishing fleet that act in Amazonian floodplain lakes. This approach employs techniques of Geographical Information Systems (GIS) and can be incorporated in traditional systems of fishing statistics. The basic data are catch and fishing effort. With this approach we are able to obtain fundamental information to fishery management like spatial distribution of fishing effort and most preferred habitats of exploited species. &nbsp

The subtidal surface water circulation at the northern margin of the Gulf of Cádiz, at the southern extremity of the Iberian upwelling system, is described based on validated hourly high-frequency radar measurements from 2016 to 2020. Statistical analyses (mean, standard deviation, eccentricity and empirical orthogonal functions) are applied to the dataset, which is completed with ADCP time series from multiple moorings at five inner-shelf stations and ERA5 wind. Off the shelf, the main circulation pattern consists of a slope current, best developed in summer when north-westerlies dominate, in particular at the most exposed western region. Mechanisms other than upwelling must contribute to this flow in order to explain its seasonal persistence. The slope circulation reverses for regional wind events with an east component > 10 m s−1, approximately. On the shelf, currents are mainly alongshore and balanced. The circulation is generally continuous along the coast, except for weak (< 0.1 m s−1, broadly) poleward flows. In the latter case, the flow tends to remain equatorward near Cape Santa Maria. In winter, coastal poleward flows often extend over the entire margin and are mainly wind-driven. In summer, these flows generally consist of coastal counter currents (CCCs) with the poleward direction opposed to that of the slope current. The CCCs are associated with significant cyclonic recirculation, strongest to the west, where a transient eddy is shortly observed for weak wind stress. This circulation develops after periods of strong north-westerlies, supporting that CCCs result from the imbalance of a regional alongshore pressure gradient.

Lake Peipsi, one of the world's largest lakes, is shared between Estonia and Russia. The water quality in different parts of the lake has so far been assessed independently. Here we explore opportunities for com-bining data of Estonian and Russian monitoring. For that, we 1) analysed the compatibility of data for some water quality variables; 2) estimated the potential effects of the differences in sampling frequency; 3) provided a few regression models to calculate the missing data for months not sampled by the Russian side. Data of the concurrent Estonian and Russian sampling indicated a good compatibility. Estonian data analysis suggested that water quality assessment results are sensitive to sampling frequency. For exam-ple, total phosphorus (TP) in the largest basin showed a long-term decreasing trend in three month data that disappeared when data for other months were added. Disregarding some months may lead to under -or overestimation of certain factors with no consistency in the response of different basins. Hence, data of the whole ice-free period are recommended for an adequate water quality assessment. Furthermore, we demonstrated that monthly values of the water quality variables of the same year are autocorrelated. Based on this, we filled the gaps in the long-term data and compiled a dataset for the whole lake that enables its most comprehensive use in water quality assessment and management. Long-term data revealed no water quality improvement of Lake Peipsi. Further reduction of the external nutrient load is needed. Eutrophication is sustained by high internal phosphorus load.(c) 2022 The Authors. Published by Elsevier B.V. on behalf of International Association for Great Lakes Research. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/ 4.0/).

This study is the first research attempt to assess the environmental risks of an agricultural area contaminated with the p,p '-DDT and its metabolites (DDX) on human and terrestrial species through exposure to soil and agricultural products, simultaneously. The study was carried out for a DDX-contaminated agricultural area in Turkey. Soil samples obtained in two different harvest applications were analyzed in terms of DDX levels. Similarly, stem, leaf, and fruit samples of an agricultural product grown on the same soils were analyzed. Using the results of these analyses, DDX intake values were calculated for 5 different human receptor groups, 4 different bird species, and 4 different mammal species, and the risk values were calculated by using a stochastic approach based on a Monte Carlo simulation. Findings indicated a substantial level of carcinogenic risk in the human receptor groups. Furthermore, a significant risk of reproductive toxicity was determined for the birds and mammals. The findings prominently showed that these risks can develop not only through exposure to DDX-contaminated soils but also through the consumption of plants grown on these soils. WOS:000646960900001 2-s2.0-85105462892 PubMed: 33948847

Polycyclic aromatic hydrocarbons (PAHs) and their alkylated (RPAHs), nitrated (NPAHs) and oxygenated (OPAHs) derivatives are air pollutants. Many of these substances are long-lived, can undergo long-range atmospheric transport and adversely affect human health upon exposure. However, the occurrence and fate of these air pollutants have hardly been studied in the marine atmosphere. In this study, we report the atmospheric concentrations over the Mediterranean Sea, the Red Sea, the Arabian Sea, the Gulf of Oman and the Arabian Gulf, determined during the AQABA (Air Quality and Climate Change in the Arabian Basin) project, a comprehensive ship-borne campaign in summer 2017. The average concentrations of ∑26PAHs, ∑19RPAHs, ∑11OPAHs and ∑17NPAHs, in the gas and particulate phases, were 2.99 ± 3.35 ng m−3, 0.83 ± 0.87 ng m−3, 0.24 ± 0.25 ng m−3 and 4.34 ± 7.37 pg m−3, respectively. The Arabian Sea region was the cleanest for all substance classes, with concentrations among the lowest ever reported. Over the Mediterranean Sea, we found the highest average burden of ∑26PAHs and ∑11OPAHs, while the ∑17NPAHs were most abundant over the Arabian Gulf (known also as the Persian Gulf). 1,4-Naphthoquinone (1,4-O2NAP) followed by 9-fluorenone and 9,10-anthraquinone were the most abundant studied OPAHs in most samples. The NPAH composition pattern varied significantly across the regions, with 2-nitronaphthalene (2-NNAP) being the most abundant NPAH. According to source apportionment investigations, the main sources of PAH derivatives in the region were ship exhaust emissions, residual oil combustion and continental pollution. All OPAHs and NPAHs except 2-nitrofluoranthene (2-NFLT), which were frequently detected during the campaign, showed elevated concentrations in fresh shipping emissions. In contrast, 2-NFLT and 2-nitropyrene (2-NPYR) were highly abundant in aged shipping emissions due to secondary formation. Apart from 2-NFLT and 2-NPYR, benz(a)anthracene-7,12-dione and 2-NNAP also had significant photochemical sources. Another finding was that the highest concentrations of PAHs, OPAHs and NPAHs were found in the sub-micrometre fraction of particulate matter (PM1).

Like many other lakes in the world, the interconnected Abaya and Chamo lakes in the Southern Main Ethiopian Rift are affected by rapid sediment accumulation. Although land degradation is a well-known issue in this part of the African continent, the main sediment sources, their spatial distribution and interaction in the Abaya–Chamo lakes’ basin have not yet been documented. Here, we present a systematic inventory, characterization, and spatial analysis of landslides and gullies as concentrated sediment sources, for four representative river catchments impacted by landscape rejuvenation. Using Google Earth imagery and field surveys, we mapped with high accuracy a total of 7336 gullies and 430 landslides. Recent landslides observed during the last decade were few, small and shallow, and appear to have played a minor role in the current sediment dynamics. Large landslides are old and inactive. Although they do not contribute to the current sediment budget, they contribute indirectly to landscape dynamics by favoring the occurrence of gullies. Overall, large percentages of severe to extremely degraded areas of gully erosion are located in rejuvenated landscapes, especially at the level of the old landslides. Many active gullies are connected to the river network, as such acting as the source of sediment. Our analysis is a step towards understanding the nature and control of anthropic activities on sediment production in the region. We also highlight the importance of considering the interactions between sediment sources and the connectivity of the geomorphological system.

Termites (Isoptera) are among the most globally dominant macroinvertebrates in terrestrial environments and are an ecologically important group of soil biota in tropical and subtropical ecosystems. These insects function as essential ecosystem engineers that facilitate nutrient cycling, especially in the regulation of the physical and chemical properties of soil and the decomposition of organic matter that maintains heterogeneity in tropical and subtropical ecosystems. Termites, like all living organisms, require certain environmental parameters to support the distribution, abundance, and activities of the species. South Africa’s Kruger National Park (KNP)—one of the most important protected areas in the world and a popular safari tourist destination—is an extraordinary savanna ecosystem in which termite mounds, or termitaria, are widely distributed. A range of biotic and abiotic factors found in the natural environment of KNP provide highly suitable ecological conditions for termite habitat range, and thus the development of termitaria. Previous research has shown that the most important factors affecting habitat suitability for termites and the geographic distribution of termitaria include climate factors, land cover, and other environmental characteristics such as soil composition and plant-litter biomass. However, the specific environmental mechanisms that regulate termite occurrence and the spatial distribution of termitaria in KNP are not fully understood, especially in the context of climate and land-cover changes. The present study examines the relationship between the spatial distribution of termitaria and selected climate and environmental factors in the Kruger Lowveld region, which contains one of the largest numbers of termitaria in KNP. Using high-resolution satellite imagery, 8200 training points of termitaria occurrence were collected throughout the study area to train classifiers and produce land-cover-classification maps for the Kruger Lowveld region of interest. We then applied a hybrid approach through the integration of remote sensing (RS) and a GIS-based analytical hierarchy process (AHP) and frequency-ratio (FR) methods to model the relationship between the spatial distribution of termitaria and selected environmental variables and to produce suitability maps. To our knowledge, this study is the first of its kind to examine the influence of combined sets of environmental attributes on the spatial distribution of termitaria in the Lowveld region of KNP. The results indicate that moderately and highly suitable conditions for termite range tolerance and termitaria development are correlated with undulating plains with clay soils, greater distance to drainage streams, high solar radiation, and low depth of groundwater. The findings of this study shed light on the need for future research that investigates the impact of climate and land-cover changes on termite habitat range and spatial distribution and that can inform park managers and policymakers about Kruger National Park and other protected areas with similar environmental conditions.

Many marine species are shifting their distribution poleward in response to climate change. The Barents Sea, as a doorstep to the fast-warming Arctic, is experiencing large scale changes in its environment and its communities. This paper aims at understanding what environmental predictors limit fish species habitats in the Barents Sea and discuss their possible evolution in response to the warming of the Arctic.Species distribution models usually aim at predicting the probability of presence or the average abundance of a species, conditional on environmental drivers. A complementary approach is to determine suitable habitats by modelling the upper limit of a species’ response to environmental factors. Using quantile regressions, we model the upper limit of biomass for 33 fish species in the Barents Sea in response to 10 environmental predictors. Boreal species are mainly limited by temperatures and most of them are expected to be able to expand their distribution in the Barents Sea when new thermally suitable habitats become available, in the limit of bathymetric constraints. Artic species are often limited by several predictors, mainly depth, bottom and surface temperature and ice cover, and future habitats are hard to predict qualitatively. Widespread species like the Atlantic cod are not strongly limited by the selected variables at the scale of the study, and current and future suitable habitats are harder to predict. These models can be used as input to integrative tools like end-to-end models on the habitat preference and tolerance at the species scale to inform resource management and conservation.

Forest canopies are incredibly complex self-maintaining biological structures. Conditions above and within the canopy can differ vastly, often resulting in a vertical gradient of microclimate conditions. Canopy epiphytic plants have to deal with climatic variability on much more variable scales compared to many other plant groups. The difficulty of sensor installation and their high cost can explain why it has been ignored in many studies on canopy epiphytes. Direct measurements of microenvironmental conditions are the only accurate way to assess specific intra-canopy environmental conditions, as there is also still a lack of methodologically and financially viable alternatives to allow the collection of this type of data. This study aims to make recommendations for the direct use of microclimate measurements in epiphyte research and to summarize key discussion points concerning the number and placement of sensors required for different types of epiphyte studies. In addition, we presented high-resolution field data from the United Kingdom, where we employed over 56 microclimate sensors, to demonstrate the spatial and temporal variability of radiation, temperature, and relative humidity (RH) in a tree canopy. Our data demonstrated that sensor height in the tree and leaf-set were the most important factors determining microclimate variability in the canopy. For the first time, we have made recommendations regarding the placement and number of sensors required in studies that specifically require the use of microclimate sensors in epiphyte studies in forest canopies.

Heart development is topographically complex and requires visualization to understand its progression. No comprehensive 3-dimensional primer of human cardiac development is currently available. We prepared detailed reconstructions of 12 hearts between 3.5 and 8 weeks post fertilization, using Amira (R) 3D-reconstruction and Cinema4D (R)-remodeling software. The models were visualized as calibrated interactive 3D-PDFs. We describe the developmental appearance and subsequent remodeling of 70 different structures incrementally, using sequential segmental analysis. Pictorial timelines of structures highlight age-dependent events, while graphs visualize growth and spiraling of the wall of the heart tube. The basic cardiac layout is established between 3.5 and 4.5 weeks. Septation at the venous pole is completed at 6 weeks. Between 5.5 and 6.5 weeks, as the outflow tract becomes incorporated in the ventricles, the spiraling course of its subaortic and subpulmonary channels is transferred to the intrapericardial arterial trunks. The remodeling of the interventricular foramen is complete at 7 weeks.Hikspoors et al. generate a pictorial account of human embryonic heart development between 3.5 and 8 weeks. This resource provides detailed, interactive 3D anatomical models and quantifies the developmental milestones of key structures in cardiac function.

Plankton is an integral part of wetland biodiversity and plays a vital role in the functioning of wetlands. Diversity patterns of plankton in wetlands and factors structuring its community composition are poorly understood, albeit important for identifying areas for restoration and conservation. Here we investigate patterns in local and regional plankton richness and taxonomic and functional community composition in riverine papyrus swamps, river mouth wetlands, and lacustrine wetlands in the Lake Tana sub-basin, Ethiopia. Data on phytoplankton, zooplankton, and environmental variables were collected from 12 wetlands during the dry and wet seasons of 2018. Redundancy analysis, and linear mixed effect models, were used to investigate differences in local environmental conditions and variation in plankton community richness and composition between wetland types. We also assessed the ecological uniqueness of the plankton community by calculating the contribution of a single wetland: local contributions to overall beta diversity (LCBD) and contributions of individual species (SCBD) to overall beta diversity (BDTotal). Beta regression models were used to investigate the relationships of LCBD and SCBD to environmental variables, wetland, and taxa characteristics. A total of 85 phytoplankton taxa, distributed among 18 Reynolds functional groups, and 57 zooplankton taxa were observed over the entire set of samples. Local plankton taxon richness was significantly higher in riverine papyrus swamps (mean taxa of 30 phytoplankton and 21 zooplankton) compared to river mouth wetlands (mean taxa of 27 phytoplankton and 13 zooplankton). Several local environmental variables and the composition of the plankton community differed significantly between the three wetland types. The highest phytoplankton ecological uniqueness (LCBD) was detected in lacustrine wetlands, whereas the riverine papyrus swamps had the highest zooplankton ecological uniqueness. Based on our analyses, we recommend protecting the wetlands with high LCBD values and stress the importance of various wetland types for preserving the diverse plankton communities of Lake Tana wetlands.

A solar-type system starts from an initial molecular core that acquires organic complexity as it evolves. The so-called prestellar cores that can be studied are rare, which has hampered our understanding of how organic chemistry sets in and grows. Aims. We selected the best prestellar core targets from the cold core catalogue that represent a diversity in terms of their environment to explore their chemical complexity: 1390 (in the compressed shell of Lambda Ori), 869 (in the MBM12 cloud), and 4149 (in the California nebula). We obtained a spectral survey with the IRAM 30 m telescope in order to explore the molecular complexity of the cores. We carried out a radiative transfer analysis of the detected transitions in order to place some constraints on the physical conditions of the cores and on the molecular column densities. We also used the molecular ions in the survey to estimate the cosmic-ray ionisation rate and the S/H initial elemental abundance using a gas-phase chemical model to reproduce their abundances. We found large differences in the molecular complexity (deuteration, complex organic molecules, sulphur, carbon chains, and ions) and compared their chemical properties with a cold core and two prestellar cores. The chemical diversity we found in the three cores seems to be correlated with their chemical evolution: two of them are prestellar (1390 and 4149), and one is in an earlier stage (869). The influence of the environment is likely limited because cold cores are strongly shielded from their surroundings. The high extinction prevents interstellar UV radiation from penetrating deeply into the cores. Higher spatial resolution observations of the cores are therefore needed to constrain the physical structure of the cores, as well as a larger-scale distribution of molecular ions to understand the influence of the environment on their molecular complexity., 26 pages, 13 figures, accepted in A&A in January 2022

Some of the youngest stars (age $\lesssim 10$ Myr) are clustered, while many others are observed scattered throughout star forming regions or in complete isolation. It has been intensively debated whether the scattered or isolated stars originate in star clusters, or if they form truly isolated, which could help constrain the possibilities how massive stars are formed. We adopt the assumption that all stars form in gravitationally bound star clusters embedded in molecular cloud cores ($\Gamma$-$1\;$ model), which expel their natal gas, and compare the fraction of stars found in clusters with observational data. The star clusters are modelled by the code nbody6, which includes stellar and circumbinary evolution, gas expulsion, and the external gravitational field of their host galaxy. We find that small changes in the assumptions in the current theoretical model estimating the fraction, $\Gamma$, of stars forming in embedded clusters have a large influence on the results, and we present a counterexample as an illustration. This calls into question theoretical arguments about $\Gamma$ in embedded clusters, and it suggests that there is no firm theoretical ground for low $\Gamma$ in galaxies with lower star formation rates (SFRs). Instead, the assumption that all stars form in embedded clusters is in agreement with observational data for the youngest stars (age $\lesssim 10$ Myr). In the $\Gamma$-$1\;$ scenario, the observed fraction of the youngest stars in clusters increases with the SFR only weakly; the increase is caused by the presence of more massive clusters in galaxies with higher SFRs, which release fewer stars to the field in proportion to their mass. The $\Gamma$-$1\;$ model yields a higher fraction of stars in clusters for older stars (age between $10$ and $300$ Myr) than what is observed. This discrepancy can be caused by interactions with molecular clouds., Comment: 16 pages, 9 figures, accepted to A&A

International audience; Land degradation due to soil erosion presents a major challenge for sustainable development. We investigated run-off and sediment yield (SY) dynamics in the northwestern highlands of Ethiopia. The study area included 14 zero-order catchments with a surface area ranging from 324 to 1715 m2. V-notch weirs produced from plastic jars were introduced as measuring alternatives that met local constraints. Run-off (RO) depth at the weir was registered manually at 5-min intervals during two rainy seasons in 2018 and 2019, and a total of 618 events were monitored. Rainfall was measured using tipping-bucket rain gauges. RO samples were collected in 1-L bottles, and suspended sediment concentration was determined. The mean event RO coefficient ranged from 3% for forests to 56% for badlands. Similarly, the mean annual SY was lowest for forests (0.8 Mg ha−1 yr−1) and highest for badlands (43.4 Mg ha−1 yr−1), with significant differences among land-use types (14.8 Mg ha−1 yr−1 in cropland, 5.7 Mg ha−1 yr−1 in grazing land, and 2.9 Mg ha−1 yr−1 in plantations). Soil organic matter (SOM) reduced RO and SY, necessitating the consideration of agronomic and land management practices that enhance SOM. Annual SY decreased exponentially with the rock fragment cover (RFC). In fields where RFC was less than 20%, collecting rock fragments for installing stone bunds resulted in a net increase in SY. Rehabilitating badlands and enhancing SOM content in croplands can substantially reduce catchment SY and hence contribute to the sustainability of land uses in the subhumid highlands.

Early limb bud development has been of considerable interest for the study of embryological development and especially morphogenesis. The focus has long been on biochemical signalling and less on cell biomechanics and mechanobiology. However, their importance cannot be understated since tissue shape changes are ultimately controlled by active forces and bulk tissue rheological properties that in turn depend on cell-cell interactions as well as extracellular matrix composition. Moreover, the feedback between gene regulation and the biomechanical environment is still poorly understood. In recent years, novel experimental techniques and computational models have reinvigorated research on this biomechanical and mechanobiological side of embryological development. In this review, we consider three stages of early limb development, namely: outgrowth, elongation, and condensation. For each of these stages, we summarize basic biological regulation and examine the role of cellular and tissue mechanics in the morphogenetic process. ispartof: CELLS vol:11 issue:3 ispartof: location:Switzerland status: published

Unraveling the geological processes ongoing at Io’s numerous sites of active volcanism requires high spatial resolution to, for example, measure the areal coverage of lava flows or identify the presence of multiple emitting regions within a single volcanic center. In de Kleer et al. (2017) we described observations with the Large Binocular Telescope during an occultation of Io by Europa at ∼6:17 UT on 2015 March 8 and presented a map of the temperature distribution within Loki Patera derived from these data. Here we present emission maps of three other volcanic centers derived from the same observation: Pillan Patera, Kurdalagon Patera, and the vicinity of Ulgen Patera/PV59/N Lerna Regio. The emission is localized by the light curves and resolved into multiple distinct emitting regions in two of the cases. Both Pillan and Kurdalagon Paterae had undergone eruptions in the months prior to our observations, and the location and intensity of the emission are interpreted in the context of the temporal evolution of these eruptions observed from other facilities. The emission from Kurdalagon Patera is resolved into two distinct emitting regions separated by only a few degrees in latitude that were unresolved by Keck observations from the same month.

The Aegean Sea is one of the most contaminated by marine litter (ML) in the World. In this study, the Turkish Aegean Region was evaluated in light of the sources, abundance and composition of ML along cakalburnu Lagoon coast. Macroscopic ML with > 3 cm was collected and separated into composition and sources categories. ML abundance was calculated by its density in items/m(2) (Mean +/- SD). Beach cleanliness was evaluated according to Clean-Coast Index (CCI). Seasonality was found as factor for ML composition, sources and abundance at cakalburnu coast. Plastic was the most abundant material, followed by unidentifiable items. The major sources of ML were mixed packaging, domestic and fisheries activities. The mean ML density was 0.64 +/- 0.09 items/m(2). cakalburnu coast was classified as dirty during all seasons. Therefore, ML contamination on cakalburnu coast represent a potential threat to coastal and marine environments. Thus, the present study can serve as a base for the elaboration of mitigating actions urgently needed at cakalburnu Lagoon.

The high-resolution analysis of single-channel, seismic reflection data from Lake Ercek (Eastern Anatolia) revealed a wide range of shallow gas anomalies consisting of enhanced reflections, seismic chimneys, acoustic blanking/acoustic turbidity, strong reflectors, and pockmarks, including both surface and buried pockmarks. The enhanced reflections are represented by the higher amplitude reflection patterns resulting from high acoustic impedance variations. They are mostly clustered in the NW-corner of the lake. Seismic chimneys are represented by vertical and thinned columnar disturbances of amplitude blanking and mostly occurred in deep basinal and faulted sections in the West and East of the lake. Some seismic chimneys, occurring together with pockmarks, represent vertical vent activations. Acoustic gas masking was represented by chaotic and diffuse seismic reflection patterns, including acoustic blanking and acoustic turbidity. As diffuse acoustic turbidity indicates gas-charged sediments, columnar disturbances showing acoustic blanking indicate degassing of the sediments. These features extend from SE to NW, coinciding with the deep basin morphology of the lake. A very local strong reflector was identified in the W-section of the lake, simulating the lake floor. This reflector is due to extended enhanced reflections, suggesting shallow free gas. Pockmarks observed in the lake are structurally classified into the two distinct types; surface (active) pockmarks found in the SE-part of the lake and buried (passive) pockmarks found in the NW. The former enlarge through deeper gas reservoir feedback, as the layering is impermeable, while the latter have resulted from a cessation of the reservoir feedback mechanism and/or permeable layering. In the lake, shallow gas distribution is controlled by faults, that provide the faulting-driven depositional control and earthquakes, that provide the seismicity-driven overpressure control. The shallow gas is then vertically-horizontally distributed and shaped by asymmetric depositional-stratigraphic factors. This study of Lake Ercek presents complementary information about a possible tectono-thermal origin of observed shallow gas. Yuzuncu Yil University, Scientific Research Projects-Coordination Unit (SRP-CU), Van, Turkey; Yuzuncu Yil UniversityYuzuncu Yil University [2015-MIM-B119]; University of Oulu (Oulu, Finland) The authors would like to thank Yuzuncu Yil University, Scientific Research Projects-Coordination Unit (SRP-CU), Van, Turkey for supporting the Lake Ercek Seismic Survey project, 2015 (Toker, 2015) and the research vessel scientific crew during the survey. This research was undertaken as part of a multidisciplinary LESS-2015 project of Istanbul University Cerrahpasa (IU), Department of Geophysical Engineering, Istanbul and Yuzuncu Yil University (YYU), Division of Earth Physics, Van (Turkey). The LESS-2015 project was supported by Research Fund of the Yuzuncu Yil University (under Scientific Research Project Number: 2015-MIM-B119), and was partly supported by the University of Oulu (Oulu, Finland) post-doctoral research grant. The authors offer their greatest thanks to the editors and the two anonymous reviewers for their constructive comments and suggestions, which helped to improve the manuscript. The maps in this paper were generated using public domain generics.

Microplastic pollution is a growing, yet poorly understood problem. Here, we assessed the relationship between microplastic concentration and distance to rivers, shorelines, cities, sediment grain size or water depth in sediments of the world's largest (semi-)enclosed aquatic basins. Microplastic was extracted from sediment using density separation, elutriation and hydrophobic adhesion. Fibers and transparent or white microplastic particles were the most abundant shape and color. The microplastic concentration in sediments of the Black Sea was about twice as high compared to that in the Caspian Sea. Fragment concentrations decreased with depth, while fiber concentrations were independent of depth. Overall, no relationship with distance to shores, rivers and cities or with grain size was observed. However, within some depth classes concentrations were related to the distance from rivers, shores and cities. ispartof: MARINE POLLUTION BULLETIN vol:173 issue:Pt A ispartof: location:England status: published

WOS:000702121700001; Harmful algal blooms (HABs) are becoming widely distributed and more frequent, threatening socioecosystems and human health. We determined species composition, abundance and spatial distribution of dinoflagellate cysts in the upper sediment of the Oualidia Lagoon located on the Atlantic coast of Morocco. Sediment samples were collected in 2017 at 51 stations, and environmental parameters were measured together with microphytoplankton abundance. Sediment characteristics including water percentage, organic matter content and grain size were determined. Fourteen dinoflagellate cyst morphotypes were identified, with Lingulodinium polyedrum (50%) and Gonyaulax spinifera (22%) dominating the assemblages. Total cyst densities ranged from 0 to 293 cysts g(-1) dry sediment. Cyst densities were positively correlated with water content and organic matter content and increased with decreasing sediment grain size. We revealed the presence of three neurotoxic dinoflagellate species: Alexandrium minutum, the Alexandrium tamarense species complex, and Gymnodinium catenatum. Numerous cysts had accumulated in the sediment, and, because they are likely responsible for the initiation of HABs in Oualidia Lagoon, they should be monitored.

This study describes Apseudopsis formosus sp. nov., a new apseudomorph tanaidacean species from the Ria Formosa lagoon (southern Portugal). Species description was based on 223 individuals (22 juveniles, 60 males and 141 females), comprising diverse developmental stages (juveniles II, males I and II, preparatory, copulatory and intermediate females). The total length of the studied population ranged from 2.2 to 3.0 mm in juveniles, 2.5 to 4.8 mm in males and 2.9 to 4.9 mm in females. Overall, Apseudopsis formosus sp. nov. differs from congeneric tanaidaceans from the Atlantic Ocean and Mediterranean Sea by the presence of combined different morphological characters such as short pointed rostrum, posterolateral pointed corners on pereonites 2-6, hyposphenium only on pereonite 6, antennular outer flagellum 7- to 10-segmented, inner flagellum 3-segmented and five spines on propodus of pereopod 1, and sexual dimorphism evidenced by a pronounced mid-dorsal triangular wing-shaped protuberance on male merus cheliped, unique in Apseudopsis genus. At each studied developmental stage, some individuals presented abnormalities in spination, having only four spines in one of the propodus of pereopod 1. Additionally, five first records of Apseudopsis from the Algarve coast (A. adami, A. bacescui, A. elisae, A. mediterraneus and A. uncidigitatus) are reported for Portuguese waters. A biogeographic overview of the genus Apseudopsis is presented through the compilation and mapping of all worldwide reported occurrences. Passive dispersion can explain the most recent species distribution, yet not disregarding that the study area is taxonomically understudied. This study contributes to improve the current knowledge on tanaidacean taxonomy and updates the geographical distribution range of the Apseudopsis-complex. Portuguese Fisheries Operational Programme (Mar2020) [MAR-02-01-02-FEAMP-0061] European Maritime and Fisheries Fund (EMFF 2014-2020) Fundacao para a Ciencia e a Tecnologia (FCT)Portuguese Foundation for Science and Technology [SFRH/BPD/94985/2013] Centro de Estudos do Ambiente e do Mar (CESAM) [UID/AMB/50017] FCT/MEC FEDER, within the PT2020 Partnership Agreement FEDER, within Compete 2020European Union (EU)

Fine-scale geographic variation in the transmission intensity of mosquito-borne diseases is primarily caused by variation in the density of female adult mosquitoes. Therefore, an understanding of fine-scale mosquito population dynamics is critical to understanding spatial heterogeneity in disease transmission and persistence at those scales. However, mathematical models of dengue and malaria transmission, which consider the dynamics of mosquito larvae, generally do not account for the fragmented structure of larval breeding sites. Here, we develop a stochastic metapopulation model of mosquito population dynamics and explore the impact of accounting for breeding site fragmentation when modelling fine-scale mosquito population dynamics. We find that, when mosquito population densities are low, fragmentation can lead to a reduction in population size, with population persistence dependent on mosquito dispersal and features of the underlying landscape. We conclude that using non-spatial models to represent fine-scale mosquito population dynamics may substantially underestimate the stochastic volatility of those populations., Clare McCormack et al. explore the way in which breeding site fragmentation affects the fine-scale dynamics of mosquito populations. They show that fragmentation can lead to a reduction in population size when densities are low, with population persistence relying on adult dispersal.

© 2018 Elsevier B.V. The efficacy of soil and water conservation measures (SWCMs) on reducing the loss of soil and water has been widely tested at the plot scale in China. However, an integrated comparison of the efficacy and an overall investigation of the controlling factors of the efficacy is absent. Therefore, an extensive dataset compiling erosion plot measurement of applying SWCMs on controlling soil loss and runoff in China was established in this study. In total, 848 erosion plots representing 2494 plot years were retained in this dataset which compiled from 108 publications and 2 data reports. The 15 most frequently tested SWCMs were identified and described. Soil loss ratio (SLR) and runoff ratio (RR) of each SWCMs was calculated to assess the efficacy of an SWCMs on reducing soil and water loss. The potential controlling factors, such as slope, slope length, annual precipitation, were evaluated for the controlling factor for both SLR and RR. Our results suggested that in general, applying the SWCMs can reduce soil loss by ca. 70% (overall SLR is 0.39 ± 0.02) and runoff by ca. 50% (overall RR is 0.54 ± 0.05), respectively. However, erosion rates on plots with SWCMs in China were, in general, still significantly higher than erosion rates measured under permanent vegetation cover land and, on average, ca. one order of magnitude higher than soil formation rates which required for a soil-neutral agriculture. On overall, the SLR presented a significant relation with topographic factors: positive with slope gradient and negative with slope length. This suggests that the support practice factor (P factor) of RUSLE model might be overestimated when values measured from plot scale are directly applied to larger areas (catchment or region scale). The SLR and RR values presented in this study can be applied for the planning of SWCMs in China and can be used to estimate the P factor when applying RUSLE model whereby the effect of topographic factors on SWCM efficacy can be accounted for. ispartof: GEODERMA vol:337 pages:729-741 status: published

The Antarctic Zone, the southernmost belt of the Antarctic Circumpolar Current, plays an important role in the control of atmospheric carbon dioxide concentrations. In the last decade, a number of studies have highlighted the importance of diatom assemblage composition in influencing the magnitude of the organic carbon and biogenic silica fluxes exported out of the mixed layer in Southern Ocean ecosystems. Here we investigate the relationship between the makeup of the diatom assemblage, organic carbon and biogenic silica export and several significant environmental parameters using sediment trap records deployed in different sectors of the Antarctic Zone. The study is divided in two parts. We first present unpublished diatom species flux data collected by a sediment trap in the offshore waters of Prydz Bay (Station PZB-1) over a year. The results of this study revealed a major export peak of diatom valves in Austral summer and two small unexpected secondary flux pulses during full winter conditions. The summer diatom sinking assemblages were largely composed of small and rapidly dividing species such as Fragilariopsis cylindrus, Fragilariopsis curta and Pseudo-nitzschia lineola, while winter assemblages were dominated by Fragilariopsis kerguelensis most reflecting its persistent strategy and selective preservation. In the second part of the study, we compare the annual diatom assemblage composition and biogeochemical fluxes of Station PZB-1 with flux data documented in previous sediment trap studies conducted in other sectors of the Antarctic Zone in order to investigate how diatom floristics influence the composition and magnitude of particle fluxes in the Antarctic Zone. The lack of correlation between the annual diatom valve, organic carbon and biogenic silica fluxes across stations indicates that other factors aside from diatom abundance play a major role in the carbon and silica export in AZ. Among these factors, the composition of the diatom assemblage appears to be critical, as suggested by the strong and significant correlation between Bio-SiO2 and the valve fluxes of F. kerguelensis alone, that this species is the main Bio-SiO2 vector from the surface layer to the deep ocean in the AZ waters, regardless of its relative abundance. Lastly, the good correlation between the annual fluxes of the group of small Fragilariopsis species with satellite-derived chlorophyll-a concentration estimates over the study stations, suggest that high abundances of these species in the Southern Ocean paleorecords could be used as a proxy of high algal biomass accumulation. © 2018 Elsevier Ltd, We are grateful to the scientific members of CHINARE 15/16, as well as the many people of the Australian Antarctic Division and at the Antarctic CRC (Hobart, Tasmania) who provided much of the technical assistance in numerous phases of the project. We also thank Captain Shao Yuan of the Xue Long and his crew for assistance in the PZB-1 mooring work. This project was funded by NSF OPP-9726186 to C. Pilskaln and F. Chai. Additional thanks are conveyed to Dr J.J-Pichon (University of Bordeaux) and Dr I. Grigorov (Uni South Hampton) for diatom discussions. F. Abrantes received funding from CCMAR (Associated Lab PEstC/MAR/LA0015/2013). We would like to thank three anonymous reviewers for their valuable comments that helped to improve the manuscript.

International audience; Southern Ocean ecosystems are globally important and vulnerable to global drivers of change, yet they remain challenging to study. Fish and squid make up a significant portion of the biomass within the Southern Ocean, filling key roles in food webs from forage to mid-trophic species and top predators. They comprise a diverse array of species uniquely adapted to the extreme habitats of the region. Adaptations such as antifreeze glycoproteins, lipid-retention, extended larval phases, delayed senescence, and energy-conserving life strategies equip Antarctic fish and squid to withstand the dark winters and yearlong subzero temperatures experienced in much of the Southern Ocean. In addition to krill exploitation, the comparatively high commercial value of Antarctic fish, particularly the lucrative toothfish, drives fisheries interests, which has included illegal fishing. Uncertainty about the population dynamics of target species and ecosystem structure and function more broadly has necessitated a precautionary, ecosystem approach to managing these stocks and enabling the recovery of depleted species. Fisheries currently remain the major local driver of change in Southern Ocean fish productivity, but global climate change presents an even greater challenge to assessing future changes. Parts of the Southern Ocean are experiencing ocean-warming, such as the West Antarctic Peninsula, while other areas, such as the Ross Sea shelf, have undergone cooling in recent years. These trends are expected to result in a redistribution of species based on their tolerances to different temperature regimes. Climate variability may impair the migratory response of these species to environmental change, while imposing increased pressures on recruitment. Fisheries and climate change, coupled with related local and global drivers such as pollution and sea ice change, have the potential to produce synergistic impacts that compound the risks to Antarctic fish and squid species. The uncertainty surrounding how different species will respond to these challenges, given their varying life histories, environmental dependencies, and resiliencies, necessitates regular assessment to inform conservation and management decisions. Urgent attention is needed to determine whether the current management strategies are suitably precautionary to achieve conservation objectives in light of the impending changes to the ecosystem.

In this study, types and quantities of marine litter in Urla (İzmir) Kum Denizi Beach and Demircili Koyu Beach were determined seasonally between October 2017 and October 2018. At the beaches, marine litter larger than 2,5 centimetres were collected with 3 people along 2-meter lines, which are determined to be parallel to the sea. The collected litters were classified according to the United Nations Environment Program (UNEP, 2009), quantities were determined and the pollution status of the beaches was evaluated according to the Clean Coast Index. A total of 1,265 litter from Kum Denizi Beach and 2,099 litter from Demircili Koyu Beach were collected. In total, 3,364 pieces of litter weighing 90.81 kg were collected from the two beaches. Among the litters collected, plastic litter was found to be dominant with 2,794 pieces. This was followed by 145 metals, 141 papers, 110 fabrics, 87 foam plastics, 42 wood, 32 glass, 8 other litters and 5 rubber. Given the seasonal averages of the clean coast index values; Kum Denizi Beach was found to be clean and Demircili Koyu Beach was found to be moderately polluted.

This study investigates the distribution of selected trace metals (As, Cd, Cr, Cu, Ni, Pb, and Zn) and associated risk in coastal sediment samples taken from the Northwest Anatolia coastline of Turkey. The 451 km long coastal area contains many industrial areas and tourist sites. Trace metal concentrations in sediment samples collected from 100 stations were determined by inductively coupled plasma mass spectrometry (ICP-MS). The ecological risk was evaluated according to the Sediment Quality Guidelines (SQG) of the United States Environmental Protection Agency (EPA) and by calculating and examining pollution indices including the degree of contamination (Cd), modified degree of contamination (mCd), potential ecological risk index (Ri), and enrichment factors (EF). Trace metal concentrations were visualized and spatially described utilizing bubble maps. Based on the risk analysis, arsenic was found to be the most dominant pollutant in the study area and the other metals did not indicate a serious anthropogenic pollution., Ege University Scientific Research Projects Coordination [17-FEN-053], This work was financially supported by the Ege University Scientific Research Projects Coordination under the project 17-FEN-053.

WOS:000685355700007; International audience; Nurseries are crucial habitats that play an important role for many marine fish species; which rely on them to complete their life cycle. Juvenile stages of dab (Limanda limanda), plaice (Pleuronectes platessa) and sole (Solea solea) present in the English Channel are common in the Seine estuary nursery grounds. To further explore the estuary's nursery function, we investigated the heterogeneity in spatial distribution patterns of these three flatfish at their juvenile stage, between 1996 and 2019. We used geostatistical indices and multivariate analyses to demonstrate species specific spatiotemporal dynamic. Sole favoured the most upstream part of the nursery, dab was found in the most marine areas, and plaice preferred the southern coast. We then performed clusters analysis based on spatial indices and spatial patterns extracted from a Minimum/Maximum Autocorrelation Factor (MAF). We showed that the average positions of the three flatfish species were stable across time. Each flatfish appeared to have its own spatial preference inside the nursery. No temporal variability in the spatial pattern nor trend was found that would correspond to the major stress imposed on the community by harbour development within the 2000-2005 period. We conclude that segregation of the juveniles of the three species within the nursery may reflect different ecological needs and underlying mechanisms to minimise interspecific competition.

How an earthquake rupture propagates strongly influences the potentially destructive ground shaking. Complex ruptures often involve slip along multiple faults, which masks information on the frictional behaviour of fault zones. Geometrically smooth ocean transform fault plate boundaries offer a favourable environment to study fault dynamics, because strain is accommodated along a single, wide fault zone that offsets the homogeneous geology. Here we present an analysis of the 2016 Mw 7.1 earthquake on the Romanche fracture zone in the equatorial Atlantic, using data from both nearby seafloor seismometers and global seismic networks. We show that this rupture had two phases: (1) upward and eastward propagation towards a weaker region where the transform fault intersects the mid-ocean ridge, and then (2) an unusual back-propagation westwards at a supershear speed towards the centre of the fault. We suggest that deep rupture into weak fault segments facilitated greater seismic slip on shallow locked zones. This highlights that even earthquakes along a single distinct fault zone can be highly dynamic. Observations of back-propagating ruptures are sparse, and the possibility of reverse propagation is largely absent in rupture simulations and unaccounted for in hazard assessments. In one earthquake, an oceanic transform fault ruptured in one direction and then backwards at a speed exceeding that of shear-wave propagation, according to an analysis of data recorded by nearby seafloor and global seismometers.

Large lakes of the world are habitats for diverse species, including endemic taxa, and are valuable resources that provide humanity with many ecosystem services. They are also sentinels of global and local change, and recent studies in limnology and paleolimnology have demonstrated disturbing evidence of their collective degradation in terms of depletion of resources (water and food), rapid warming and loss of ice, destruction of habitats and ecosystems, loss of species, and accelerating pollution. Large lakes are particularly exposed to anthropogenic and climatic stressors. The Second Warning to Humanity provides a framework to assess the dangers now threatening the world's large lake ecosystems and to evaluate pathways of sustainable development that are more respectful of their ongoing provision of services. Here we review current and emerging threats to the large lakes of the world, including iconic examples of lake management failures and successes, from which we identify priorities and approaches for future conservation efforts. The review underscores the extent of lake resource degradation, which is a result of cumulative perturbation through time by long-term human impacts combined with other emerging stressors. Decades of degradation of large lakes have resulted in major challenges for restoration and management and a legacy of ecological and economic costs for future generations. Large lakes will require more intense conservation efforts in a warmer, increasingly populated world to achieve sustainable, high-quality waters. This Warning to Humanity is also an opportunity to highlight the value of a long-term lake observatory network to monitor and report on environmental changes in large lake ecosystems. (C) 2020 The Authors. Published by Elsevier B.V. on behalf of International Association for Great Lakes Research.

The ESA-JAXA BepiColombo mission will provide simultaneous measurements from two spacecraft, offering an unprecedented opportunity to investigate magnetospheric and exospheric dynamics at Mercury as well as their interactions with the solar wind, radiation, and interplanetary dust. Many scientific instruments onboard the two spacecraft will be completely, or partially devoted to study the near-space environment of Mercury as well as the complex processes that govern it. Many issues remain unsolved even after the MESSENGER mission that ended in 2015. The specific orbits of the two spacecraft, MPO and Mio, and the comprehensive scientific payload allow a wider range of scientific questions to be addressed than those that could be achieved by the individual instruments acting alone, or by previous missions. These joint observations are of key importance because many phenomena in Mercury's environment are highly temporally and spatially variable. Examples of possible coordinated observations are described in this article, analysing the required geometrical conditions, pointing, resolutions and operation timing of different BepiColombo instruments sensors.

We use deep, spatially resolved spectroscopy from the LEGA-C Survey to study radial variations in the stellar population of 17 spectroscopically-selected post-starburst (PSB) galaxies. We use spectral fitting to measure two Lick indices, $H{\delta}_A$ and $Fe4383$, and find that, on average, PSB galaxies have radially decreasing $H{\delta}_A$ and increasing $Fe4383$ profiles. In contrast, a control sample of quiescent, non-PSB galaxies in the same mass range shows outwardly increasing $H{\delta}_A$ and decreasing $Fe4383$. The observed gradients are weak ($\approx-0.2$ \r{A}/$R_e$), mainly due to seeing convolution. A two-SSP model suggests intrinsic gradients are as strong as observed in local PSB galaxies ($\approx -0.8$ \r{A}$/R_e$). We interpret these results in terms of inside-out growth (for the bulk of the quiescent population) vs star formation occurring last in the centre (for PSB galaxies). At $z\approx0.8$, central starbursts are often the result of gas-rich mergers, as evidenced by the high fraction of PSB galaxies with disturbed morphologies and tidal features (40%). Our results provide additional evidence for multiple paths to quiescence: a standard path, associated with inside-out disc formation and with gradually decreasing star-formation activity, without fundamental structural transformation, and a fast path, associated with centrally-concentrated starbursts, leaving an inverse age gradient and smaller half-light radius., Comment: 18 pages, 9 figures

Developing a comprehensive understanding of the modification of material properties by neutron irradiation is important for the design of future fission and fusion power reactors. Self-ion implantation is commonly used to mimic neutron irradiation damage, however an interesting question concerns the effect of ion energy on the resulting damage structures. The reduction in the thickness of the implanted layer as the implantation energy is reduced results in the significant quandary: Does one attempt to match the primary knock-on atom energy produced during neutron irradiation or implant at a much higher energy, such that a thicker damage layer is produced? Here we address this question by measuring the full strain tensor for two ion implantation energies, 2 MeV and 20 MeV in self-ion implanted tungsten, a critical material for the first wall and divertor of fusion reactors. A comparison of 2 MeV and 20 MeV implanted samples is shown to result in similar lattice swelling. Multi-reflection Bragg coherent diffractive imaging (MBCDI) shows that implantation induced strain is in fact heterogeneous at the nanoscale, suggesting that there is a non-uniform distribution of defects, an observation that is not fully captured by micro-beam Laue diffraction. At the surface, MBCDI and high-resolution electron back-scattered diffraction (HR-EBSD) strain measurements agree quite well in terms of this clustering/non-uniformity of the strain distribution. However, MBCDI reveals that the heterogeneity at greater depths in the sample is much larger than at the surface. This combination of techniques provides a powerful method for detailed investigation of the microstructural damage caused by ion bombardment, and more generally of strain related phenomena in microvolumes that are inaccessible via any other technique., Comment: Please refer to the supplementary information and movies SM1-3 for data visualisation

We study numerically the formation of a vortex lattice inside a rotating bucket containing superfluid helium, paying attention to an important feature which is practically unavoidable in all experiments: the microscopic roughness of the bucket's surface. We model this using the Gross-Pitaevskii for a weakly-interacting Bose gas, a model which is idealised when applied to superfluid helium but captures the key physics of the vortex dynamics which we are interested in. We find that the vortex lattice arises from the interaction and reconnections of nucleated U-shaped vortex lines, which merge and align along the axis of rotation. We quantify the effects which the surface roughness and remanent vortex lines play in this process., 11 pages, 12 figures

Reactive oxygen species (ROS) can act as signaling molecules involved in the acclimation of plants to various abiotic and biotic stresses. However, it is not clear how the generalized increases in ROS and downstream signaling events that occur in response to stressful conditions are coordinated to modify plant growth and development. Previous studies of maize (Zea mays L.) primary root growth under water deficit stress showed that cell elongation is maintained in the apical region of the growth zone but progressively inhibited further from the apex, and that the rate of cell production is also decreased. It was observed that apoplastic ROS, particularly hydrogen peroxide (H2O2), increased specifically in the apical region of the growth zone under water stress, resulting at least partly from increased oxalate oxidase activity in this region. To assess the function of the increase in apoplastic H2O2 in root growth regulation, transgenic maize lines constitutively expressing a wheat oxalate oxidase were utilized in combination with kinematic growth analysis to examine effects of increased apoplastic H2O2 on the spatial pattern of cell elongation and on cell production in well-watered and water-stressed roots. Effects of H2O2 removal (via scavenger pretreatment) specifically from the apical region of the growth zone were also assessed. The results show that apoplastic H2O2 positively modulates cell production and root elongation under well-watered conditions, whereas the normal increase in apoplastic H2O2 in water-stressed roots is causally related to down-regulation of cell production and root growth inhibition. The effects on cell production were accompanied by changes in spatial profiles of cell elongation and in the length of the growth zone. However, effects on overall cell elongation, as reflected in final cell lengths, were minor. These results reveal a fundamental role of apoplastic H2O2 in regulating cell production and root elongation in both well-watered and water-stressed conditions.