Search

In the context of worldwide biodiversity and wild bee decline, it is increasingly important to better understand the effect of land-use changes on wild bee communities at a global scale. To do so, we studied the effect of city area and urban green spaces layout on wild bee species richness and community composition, as well as on wild bee species with an unfavorable UICN conservation status. This study was based on a large European dataset encompassing 20 cities from France, Belgium and Switzerland. We found a mean wild bee species richness in cities of 96 ± 48 (SD), showing that this species richness was highly variable among cities. The main factor positively influencing wild bee species richness in cities was the area of the city. Conversely, species richness was not significantly related to the total area of urban green spaces in a given city, measured as the spatial extent of urban parks, wastelands and other semi-natural habitats, excluding urban private gardens. Species with conservation status were quite scarce in urban environments, especially when compared to the European Red List of Bees, and we could not link their presence to either city or urban green space area. Dissimilarities in wild bee species community compositions were not associated with any of the studied characteristics of cities. We found that the dissimilarity of wild bee community composition among cities was mainly driven by the rarest species, as the most common ones were found in a majority of the cities sampled. Overall, these results emphasize that larger cities host more wild bee species, but are no refuge for the ones with concerning conservation status. Thus, stakeholders are encouraged to design their cities in favor of biodiversity to better support wild bee communities, and perhaps mitigate the established effect of the urban ecological filter. [ABSTRACT FROM AUTHOR]

The increase in studies on bee microbiomes is prompted by concerns over global pollinator declines. Bumble bees host core and non-core microbiota which may contribute to increased lifetime fitness. The presence of Fructobacillus in the gut microbiomes of bumble bee workers, or the replacement of core symbionts with Fructobacillus bacteria, has been considered a marker of dysbiosis. A phylogenomic analysis and functional genomic characterization of the genomes of 21 Fructobacillus isolates from bumble bees demonstrated that they represented four species, i.e. Fructobacillus cardui , Fructobacillus fructosus, Fructobacillus tropaeoli , and the novel species Fructobacillus evanidus sp. nov. Our results confirmed and substantiated the presence of two phylogenetically and functionally distinct Fructobacillus species clades that differ in genome size, percentage G + C content, the number of coding DNA sequences and metabolic characteristics. Clade 1 and clade 2 species differed in amino acid and, to a lesser extent, in carbohydrate metabolism, with F. evanidus and F. tropaeoli genomes featuring a higher number of complete metabolic pathways. While Fructobacillus genomes encoded genes that allow adhesion, biofilm formation, antibacterial activity and detoxification, other bacteria isolated from the bumble bee gut appeared better equipped to co-exist with the bumble bee host. The isolation and identification of multiple Fructobacillus species from several bumble bee gut samples in the present study also argued against a specific partnership between Fructobacillus species and their bumble bee hosts. [ABSTRACT FROM AUTHOR]

Insect pollinators are declining worldwide due to many challenges and several approaches have been implemented to mitigate their loss. Farming with Alternative Pollinators (FAP) uses marketable habitat enhancement plants (MHEP) that yield substantial benefits for farmers from the first year. Studies with small-scale farmers have shown that FAP sustains high diversity and abundance of flower visitors and natural enemies, resulting in significant increases in smallholders' incomes, on average 121% higher. For the first time, we analyzed this approach in large-scale fields. Trials were conducted in 16 farms in two regions of Morocco, Sidi Slimane and Ksar El-Kebir, in 2021. We used melon (Cucumis melo) as the main crop and coriander, anise and sunflower as MHEP and selected in each farm 1 ha as trial area in larger monocultures. We compared FAP and control fields regarding abundance and richness of flower visitors, natural enemies and pests as well as net income of the whole field (1 ha). Flower visitors and natural enemies were significantly more diverse and abundant in FAP fields and there were also fewer pests. Our economic results show 17% higher net income per ha in FAP fields versus control fields in the Ksar El-Kebir region, and 12% higher net income in FAP fields compared to control fields in Sidi Slimane region. Although the mean yield difference was statistically significant, the income difference was not. We suggest more FAP trials are needed in different large-scale fields systems. • The importance of pollinators for ecosystem resilience underscores the need to address the current decline of pollinators worldwide. • Farming with Alternative Pollinators, developed for pollinator protection in low- and middle-income countries that targets farmers' and policymakers' minds. • Marketable habitat enhancement plants attract a high number and richness of flower visitors in FAP fields. • FAP approach provides a way to mitigate the loss of pollinators with pollinator-dependent-crop. [ABSTRACT FROM AUTHOR]

• Key apple pollinating species contract their ranges under projected climate changes. • Widespread contractions are only projected under worst-case scenarios (RCP8.5). • Pollinator overlap with suitable apple growing conditions decreases. • Many species track suitable apple conditions, except under worst-case scenarios. • Range and overlap losses may reduce apple production in key producing nations. Visitation by wild bee species alongside managed pollinators is necessary to ensure consistent yields and fruit quality in apple fields. Wild bee species are vulnerable to several environmental changes. Climate change is expected to lead to broad-scale changes to wild bee distributions that will impact the service they provide as crop pollinators. We modelled selected wild bee species known to be important for apple production in Europe and we quantified the shifts in distribution range for these key apple-pollinating bee species (KABS) under three climate‌ change scenarios (RCP 2.6, 4.5 and 8.5) for 2041–2060 and 2061–2080. We compared species distribution maps (after the expected range changes) to the distribution of areas with suitable habitat for apple orchards and with national apple production statistics to estimate potential pollination service at the landscape scale. Overall, ‌KABS are widespread species found across Europe and while most species have projected range contractions, these contractions are limited (∼10% loss). Only under the worst-case climate change scenario (RCP8.5) do we project range contractions over 50% and only under RCP8.5 is the average loss of overlap between suitable apple conditions and KABS likely to decrease by over 10%. However, range contractions at the southern limit of many species' ranges mean that the potential impact of climate change on apple pollination is not evenly shared between apple producing countries; France and Italy for example are projected to have high range loss of KABS and loss in potential pollination service. Climate change is not the only threat to apple pollination and future pollination deficits will also depend on local orchard intensification and ecological infrastructure. Key changes to intensive, commercial apple orchards towards a more agroecological approach are needed to maintain a diverse wild bee community and apple production in areas that may become climatically unsuitable in the future. [ABSTRACT FROM AUTHOR]

A new insight into the electrochemical reduction mechanism of imidazolium cations is given by examining the cathodic stability of the 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide [BMIm][NTf 2 ] ionic liquid at platinum, gold, copper and mercury electrodes. Potentiostatic electrolyses were performed under nitrogen-saturated conditions and the major reduction products of the BMIm + cation were quantified by 1 H NMR spectroscopy. The product selectivity is influenced by the electrode material and by the presence of an additional proton source in the medium, evidencing the key role of adsorbed hydrogen in the mechanism of BMIm + electroreduction. [ABSTRACT FROM AUTHOR]

Among physiological processes, the maintenance of immunity is one of the most energetically costly in invertebrates. Disease resistance can be quantified by measuring immunocompetence, which is defined as the ability of an organism to mount an immune response, either in cellular, humoral or behavioural forms. In insects, immune capacity can be affected by a variety of factors including pesticides, genetic diversity or diet. Here we focus on an important species of domesticated pollinator, Bombus terrestris , and the potential impact of a poor pollen diet (low nutritional content and toxic) on its health. We investigate three responses at both colony and individual levels: behavioural, humoral and cellular. Our results show that poor pollen diets decrease larval and pupal masses and increase larval ejection as well as adult constitutive immunity (i.e., prophenoloxidase assays). The susceptibility of bumblebees to disease and infection might therefore be greater after a nutritive stress. These findings raise the importance of available plant hosts, especially floral plant species providing pollen with suitable nutritive quality (i.e., nutrient pollen content) for bumblebees. [ABSTRACT FROM AUTHOR]

Riparian zones are key landscape features, representing the interface between terrestrial and aquatic ecosystems. Although they have been influenced by human activities for centuries, their degradation has increased during the 20th century. Concomitant with (or as consequences of) these disturbances, the invasion of exotic species has increased throughout the world’s riparian zones. In our study, we propose a easily reproducible methodological framework to map three riparian invasive taxa using Unmanned Aerial Systems (UAS) imagery: Impatiens glandulifera Royle, Heracleum mantegazzianum Sommier and Levier, and Japanese knotweed ( Fallopia sachalinensis (F. Schmidt Petrop.), Fallopia japonica (Houtt.) and hybrids). Based on visible and near-infrared UAS orthophoto, we derived simple spectral and texture image metrics computed at various scales of image segmentation (10, 30, 45, 60 using eCognition software). Supervised classification based on the random forests algorithm was used to identify the most relevant variable (or combination of variables) derived from UAS imagery for mapping riparian invasive plant species. The models were built using 20% of the dataset, the rest of the dataset being used as a test set (80%). Except for H. mantegazzianum , the best results in terms of global accuracy were achieved with the finest scale of analysis (segmentation scale parameter = 10). The best values of overall accuracies reached 72%, 68%, and 97% for I. glandulifera , Japanese knotweed, and H. mantegazzianum respectively. In terms of selected metrics, simple spectral metrics (layer mean/camera brightness) were the most used. Our results also confirm the added value of texture metrics (GLCM derivatives) for mapping riparian invasive species. The results obtained for I. glandulifera and Japanese knotweed do not reach sufficient accuracies for operational applications. However, the results achieved for H. mantegazzianum are encouraging. The high accuracies values combined to relatively light model-inputs needed (delineation of a few umbels) make our approach a serious contender as a cost-effective tool to improve the field management of H. mantegazzianum . [ABSTRACT FROM AUTHOR]

Highlights: [•] Riparian zones attributes are extracted from aerial LiDAR data as indicators of the ecological integrity of riparian zones. [•] Analysis is performed from local scale to network scale by using a disaggregation/re-aggregation process. [•] Graphical visualisation is proposed to allow natural resource managers to identify priority action areas. [•] In the study case, results showed a general decrease of the riparian forests and lower flooding frequency in built-up areas. [ABSTRACT FROM AUTHOR]

Highlights: [•] A new TCAD tool taking into account dose effects is presented: E.CO.R.C.E. [•] We model Total Ionizing Dose on power MOSFET. [•] Total Ionizing Dose at room temperature can be modeled using only one trap level. [•] Four traps levels are needed to model temperature effects during irradiation. [•] Traps parameters can be quickly estimated using a simple 1D MOS capacitor. [Copyright &y& Elsevier]

Abstract: The EUNIS (European Union Nature Information System) habitat classification system aims to provide a common European reference set of habitat types within a hierarchical classification, and to cover all terrestrial, freshwater and marine habitats of Europe. The classification facilitates reporting of habitat data in a comparable manner, for use in nature conservation (e.g. inventories, monitoring and assessments), habitat mapping and environmental management. For the marine environment the importance of a univocal habitat classification system is confirmed by the fact that many European initiatives, aimed at marine mapping, assessment and reporting, are increasingly using EUNIS habitat categories and respective codes. For this reason substantial efforts have been made to include information on marine benthic habitats from different regions, aiming to provide a comprehensive geographical coverage of European seas. However, there still remain many concerns on its applicability as only a small fraction of Europe’s seas are fully mapped and increasing knowledge and application raise further issues to be resolved. This paper presents an overview of the main discussion and conclusions of a workshop, organised by the MeshAtlantic project, focusing upon the experience in using the EUNIS habitats classification across different countries and seas, together with case studies. The aims of the meeting were to: (i) bring together scientists with experience in the use of the EUNIS marine classification and representatives from the European Environment Agency (EEA); (ii) agree on enhancements to EUNIS that ensure an improved representation of the European marine habitats; and (iii) establish practices that make marine habitat maps produced by scientists more consistent with the needs of managers and decision-makers. During the workshop challenges for the future development of EUNIS were identified, which have been classified into five categories: (1) structure and hierarchy; (2) biology; (3) terminology; (4) mapping; and (5) future development. The workshop ended with a declaration from the attendees, with recommendations to the EEA and European Topic Centre on Biological Diversity, to take into account the outputs of the workshop, which identify weaknesses in the current classification and include proposals for its modification, and to devise a process to further develop the marine component of the EUNIS habitat classification. [Copyright &y& Elsevier]

Abstract: We report the measurement of reflected neutron intensity “hysteresis loops” from Co/Ru multilayers that have both antiferromagnetically and ferromagnetically coupled regions. We show that by measuring the four neutron spin-resolved reflectivities at a particular value of wavevector transfer, the normalised value of the relevant magnetic order parameter may be determined. The response of that order parameter to an applied magnetic field may hence be tracked. We have benchmarked our results against conventional magnetometry and magnetotransport measurements. [Copyright &y& Elsevier]

Hybrid organic/inorganic interfaces could pave the way to chemically designed or new multifunctional electronic devices, in particular in the spintronics field where, for instance, the interfacial spin polarization can be tuned through chemical interactions and surface modifications. We report herein, for the very first time, the assays of self-assembled monolayers (SAMs) formation on Mn 5 Ge 3 surface. Interestingly, Mn 5 Ge 3 is a ferromagnetic metal possessing interesting features for spintronics such as a high Curie temperature, a capability to grow epitaxially on Ge germanium that is a key point for integration in the mainstream Si technology. Mn 5 Ge 3 thin films are synthesized by molecular beam epitaxy under ultra-vacuum condition. We studied the Mn 5 Ge 3 surface prior to deposition of SAMs, meaning the surface exposed to air and different solvents, by XPS and contact angle measurements leading to the value of the surface tension of this surface. Then SAMs of octanethiol and perfluorodecanethiol are formed on Mn 5 Ge 3 surface at room temperature. The best experimental conditions to form the SAMs are found for an immersion time of 36 h and a concentration of 4 mM. [ABSTRACT FROM AUTHOR]

The species international trade leads to multiple non-native invasions. Besides species invasions, commercial exchanges may also contribute to translocation between closely related taxa or allopatric populations. Consequently, preserving endemic taxa and specificity of local populations require to regulate commercial translocations of species or populations. To be efficient such regulation needs a resolved taxonomy and a thorough analysis of the population structure of native taxa/populations. To provide guidelines for an efficient regulation of the trade of Bombus terrestris within its natural range, we analyzed its taxonomy and its population structure using an integrative taxonomic approach. Our results show that B. terrestris translocations involve two species, three subspecies, and several populations with weak differentiation. These different levels of differentiation imply specific and appropriate regulations of translocations with different levels of prioritization. We ultimately assess the relevance of current policies and propose potentially efficient regulations for policy-makers. Such integrative taxonomic approach should be used in other traded polytypic species. [ABSTRACT FROM AUTHOR]

Remote sensing can be used to collect information related to forest management. Previous studies demonstrated the potential of using multispectral satellite imagery for classifying tree species. However, methods that can map tree species in mixed forest stands on a large scale are lacking. We propose an innovative method for mapping the proportions of tree species using Sentinel-2 imagery. A convolutional neural network was used to quantify the per-pixel basal area proportions of tree species considering the neighbouring environment (spectral–spatial deep learning). A nested U-shaped neural network (UNet++) architecture was implemented. We produced a map of the entire Wallonia Region (southern Belgium). Nine species or groups of species were considered: Spruce genus, Oak genus, Beech , Douglas fir , Pine genus, Poplar genus, Larch genus, Birch genus, and remaining species. The training dataset for the convolutional neural network model was prepared using a map of forest parcels extracted from the public forest administration's geodatabase of Wallonia. The accuracy of the predicted map covering the region was independently assessed using data from the regional forest inventory of Wallonia. A robust assessment method for tree species proportions maps was proposed for assessing the (1) majority species, (2) species composition (presence or absence), and (3) species proportions (proportion values). The achieved value of indicator OA m a j (0.73) shows that our approach can map the majority tree species in mixed and pure forest stands. Indicators MS (0.89), MPS (0.72) and MUS (0.83) support that the model can predict the species composition in most cases in the study area. Spruce genus, Oak genus, Beech , and Douglas fir achieved the best results, with PAs and UAs close to or higher than 0.70. Particularly, high performance was achieved for detecting Oak genus and Beech in low area proportions: PAs and UAs higher than 0.70 from the 0.4 proportion. Predicted proportions had a R a d j 2 of 0.50. The proposed method, which uses spectral–spatial deep learning to map the proportions of tree species, is innovative because it was adapted to the complexity of mixed forests and spatial resolution of current satellite imagery. Additionally, it optimises the use of available forest data in the model conception by considering all pixels from pure stands to highly mixed forest stands. When forest inventories are available in a broad sense, that is, georeferenced areas with the proportions of tree species, this method is highly reproducible and applicable at a large scale, offering potential for use in forest management. • Tree species proportions were predicted using spectral–spatial deep learning. • Proportions were mapped over a large and diversified geographical area. • A CNN was trained using georeferenced areas from forest administration's geodatabase. • Majority class, composition, and proportions were evaluated at the NFI plot level. [ABSTRACT FROM AUTHOR]

Abstract: Epitaxial Mn5Ge3/Ge(111) heterostructures were grown by Solid Phase Epitaxy (SPE) method, which consists of a room temperature Mn deposition followed by thermal annealing. It is shown that upon annealing at a temperature of about ~430–450  °C, the Mn5Ge3 phase is formed and it is stable up to ~850  °C. This phase is the unique epitaxial phase observed on the Ge(111) substrate. Transmission electron diffraction (TED) patterns confirm that the hexagonal basal (001) plan of Mn5Ge3 is parallel to the (111) plan of the Ge substrate and cross-sectional transmission electronic microscopy (TEM) analyses reveal a relatively smooth interface at the atomic scale. Magnetic characterizations indicate that epitaxial Mn5Ge3 films present a strong ferromagnetism up to room temperature. However, in contrast to bulk Mn5Ge3 material which has uniaxial anisotropy along the c axis, epitaxial Mn5Ge3 films exhibit easy axis of magnetization lying in the hexagonal basal (001) plane, parallel to the interface between the Mn5Ge3 films and the substrate. [Copyright &y& Elsevier]

Pear and apple are among the main fruit crops worldwide. These species can be planted in mixed orchards, and they both depend on insect pollination for fruit set. As pollinating insects are attracted by the floral resources, we investigated nectar and pollen production and chemical composition in four pear (‘Concorde’, ‘Conférence’, ‘Doyenné du Comice’, ‘Triomphe de Vienne’) and five apple (‘Braeburn’, ‘Golden Reinders’, ‘Jonagored’, ‘Pinova’, ‘Wellant’) cultivars commonly grown in Belgium. We also investigated whether insect flower visitation rate and pollination efficiency are linked to floral resource quantity and quality. The pear cultivars flowered one week before the apple cultivars in early spring, and their flowers were about six times less visited by insects. The visitors foraged more on the pollen of the pear trees and the nectar of the apple trees. Pear flowers produced higher volumes of nectar than apple flowers (1.3–3.2 μl vs. 0.4-0.6 μl), but with lower sugar concentration (9.6%-10.8% vs. 28.3%-36.4%). Pear flowers also produced fewer pollen grains per anther than apple flowers (2425–4937 vs. 3284–7919), but these had higher polypeptide (346–362 μg/mg vs. 216–303 μg/mg), amino-acid (40–77 μg/mg vs. 12–18 μg/mg) and phytosterol (21–47 μg/mg vs. 15–43 μg/mg) concentrations. The foraging behavior of the insects is thus better explained by nectar and pollen quality rather than quantity. Despite the differences in flower visitation rates, pollination of both species resulted in valuable fruit production. [ABSTRACT FROM AUTHOR]

In a context of rapid global change, understanding how environmental stressors can impact phenotypic variation, and which phenotypic traits are predominantly affected can be particularly relevant. Indeed, potential phenotypic modifications could affect the functionality of traits from taxa that are in decline but that are keystone species in many ecosystems. In this study, we assessed the impact of environmental drivers and agricultural intensification on two crucial pollinator species: the honeybee (Apis mellifera) and the buff-tailed bumblebee (Bombus terrestris). Among eight countries representing four major European biogeographical regions [i.e., Boreal (Sweden and Estonia), Atlantic (Ireland and United Kingdom), Continental (Germany and Switzerland) and Mediterranean (Spain and Italy)] and two type of crops (i.e., apple orchards and oilseed rape) we assessed how landscape structure, latitude and pesticide management could impact their wing morphology. Two sampling sessions were conducted: the first one when the hives/nests were settled on the field (T0) and a second sampling session after the potential effect of agricultural intensification (T1). Using a dataset of more than 7238 wings, we measured the wing size, shape and asymmetry. We observed that, in several countries, a shift in most of the morphological traits occurred between T0 and T1. When focusing on the drivers of phenotypic variation in T1, the levels of significance for some potential drivers were sometimes high, while most of the variation remained unexplained. The latitude and, more rarely, grassland cover were found to partly explain the wing modifications. In light of these results, we conclude that phenotypic shifts can occur in a very short period, after encountering new field conditions. Further studies should be conducted to better understand which alternative drivers could explain morphological changes in the agro-ecosystem after crop exposition, as well as the potential consequences of these changes on foraging performance or pollination efficiency. • Results are obtained from broad geographic coverage, among eight countries. • Shift of morphological traits occurs over a very short period of time. • Bumblebee wing size decreases when exposed to field conditions. • Asymmetry in shape and trait variance often increases in field conditions. [ABSTRACT FROM AUTHOR]

The possible fabrication of spintronic devices based on the Mn–Ge binary system supports extensive investigations on the magnetic properties of Mn–Ge structures. However, the global magnetic signal of a given sample is sometime complex due to the coexistence of several objects of unknown magnetic properties. We report the existence of ferromagnetic Mn–Ge nanoclusters (2–4 nm) containing only 4–6% Mn with a Curie temperature of ∼43.5 K, usually attributed to an 1.2% Mn-rich diluted magnetic semiconductuor. [ABSTRACT FROM AUTHOR]

• Wild bees provide sustainable pollination services. • Wild bee diversity is positively related to apple seed set. • Apple yields are mainly driven by management practices. • A heavy use of honey bees is detrimental to the surrounding pollinator diversity. Climate, landscape composition, management practice, and wild bee pollination are all variables thought to play significant roles in commercial apple production. However, how these variables affect production efficiency under field-realistic conditions has not been investigated at large geographical scales. We combined intensive standardized field surveys (using netting and pan traps) with structural equation models to explore the relative impact of biotic and abiotic variables on bee diversity, apple yield and fruit quality, and their ability to represent reliable proxies of apple production. Here we show that apple yields are mainly driven by management practice, without evidence for a significantly superior contribution by managed honey bees. Total wild bee diversity, while negatively correlated with honey bee dominance, promoted apple quality by enhancing seed set number. Our study demonstrates that even across a broad geographical range there is potential to harness wild bee diversity as nature-based solution and as a substitute to an exclusive reliance on honey bees in the context of commercial apple production. [ABSTRACT FROM AUTHOR]

Abstract: Bismuth sulfide (Bi2S3) nanocrystalline thin films exhibit a low band gap, a high absorbance coefficient and good dispersity. In this study, the structural, optical and electrical properties of Bi2S3 nanocrystalline thin films prepared from bismuth chloride (BiCl3) and thiourea (CS(NH2)2) solutions and deposited by a spray pyrolysis method, are investigated as a function of the substrate temperature (T S ). T S has been increased from 140 to 280°C by step of 40°C. Characterizations of the films have been carried out using X-ray diffraction (XRD), scanning electron microscopy, ultra-violet–visible–near infrared (UV–vis–NIR) spectroscopy and electrical resistivity measurements. These studies reveal that Bi2S3 films consist of nanocrystalline grains. Average grain size was calculated using Debye–Scherrer formula. As T S increases, the grain size of Bi2S3 crystallites increases from 40 to 60nm. In addition, a blue shift of 0.20eV in the optical band gap energy E g , which is in agreement with Slater's model, and a decrease in electrical resistivity from 2.61 to 1.05Ωcm was observed. [Copyright &y& Elsevier]

Safeguarding crop pollination services requires the identification of the pollinator species involved and the provision of their ecological requirements at multiple spatial scales. However, the potential for agroecological intensification of pollinator-dependent crops by harnessing pollinator diversity is limited by our capacity to characterise the community of pollinator species for each crop, and to determine how it is influenced by the different survey methods used, as well as by climatic variables at larger geographic scales. Here, we surveyed wild bees using a standardised protocol at an unprecedented scale including 62 commercial apple orchards in Western and Central Europe (i) to validate recent findings on pollinator community divergence as measured by common survey methods (netting and pan trapping) using conventional and alternative biodiversity metrics (phylogenetic and functional diversity), and (ii) to investigate the impact of climatic variation on the patterns observed. Our results confirm the significant divergence in pollinator communities measured using the two common methods at the larger, sub-continental scale, and we provide evidence for a significant influence of climate on the magnitude of pollinator community divergence (beta diversity and its turnover component) between survey methods, particularly when comparing colder to warmer sites and regions. We also found that warmer sites are more dissimilar than colder sites in terms of species composition, functional traits, or phylogenetic affinities. This result probably stems from the comparatively larger species pool in Southern Europe and because apple flowers are accessible to a wide spectrum of pollinator species; hence, two distant survey localities in Southern Europe are more likely to differ significantly in their pollinator community. Collectively, our results demonstrate the spatially-varying patterns of pollinator communities associated with common survey methods along a climate gradient and at the sub-continental scale in Europe. • Netting and pan trapping showed distinct communities at a large-spatial scale. • Contrasting communities characterised by taxonomic, functional, and phylogenetic diversities. • Climate influences divergences between communities of both methods. • Divergence between communities increased in warmer regions (increasing temperatures). • A " filtering " effect is occurring in apple orchards in Europe. [ABSTRACT FROM AUTHOR]

Highlights: [•] The nature of the occurred failure in an IGBT Trench Field Stop is an SEB. [•] The sensitive volume of the IGBT is located in the top side of the epilayer region. [•] Thermal effect contributes to the precocity of failure triggering. [•] Failure triggering is related to impact ionization in the epilayer and not to the turning on of the parasitic BJT. [Copyright &y& Elsevier]

Abstract: Mn5Ge3 compound, with its room-temperature ferromagnetism and possibility to epitaxially grow on Ge, acts as a potential spin injector into group-IV semiconductors. It is shown that the realization of Ge/Mn5Ge3 heterostructures is highly hampered by Mn segregation toward the Ge growing surface. The Mn segregation length can be estimated in-situ and in real time by means of reflection high-energy electron diffraction. We present here an approach allowing to greatly reduce or even to prevent the Mn segregation, whose principle is based on filling the Mn5Ge3 lattice with interstitial carbon atoms. In addition, we show that interstitial carbon in Mn5Ge3 allows to enhance not only the Curie temperature of Mn5Ge3Cx layers but also in the whole Ge/Mn5Ge3/Ge heterostructures. [Copyright &y& Elsevier]

Commercial apple production relies on managed honey bees (Apis mellifera) for pollination, and on intensive management for pest control. Previous studies have highlighted the potentially detrimental effects of intensive crop management on wild bee diversity in agroecosystems, potentially jeopardizing the pollination services they provide. However, the extent to which honey bee dominance and crop management interact under field-realistic conditions and drive the structure of wild bee assemblages has not been investigated so far. In this study, we measured species richness, as well as the functional and phylogenetic diversity of wild bee assemblages in 36 paired organic and non-organic apple orchards during their flowering season and along a geographic gradient across western Europe. Our results show a strong significant and negative association between honey bee dominance and all wild bee diversity metrics, regardless of local management. Semi-natural habitats had a significant and positive effect on functional diversity, while urbanization and crop cover around the orchards showed no effect on all measured diversity metrics. A greater number of species exhibited less common, or frequent, combinations of functional traits at sites with high honey bee dominance, especially larger bee species with longer tongues. Collectively, we show that wild bee diversity decreases with increasing honey bee dominance, and that this negative association is not buffered by alternative (i.e., organic) management practices in commercial apple orchards. Although organic farming can bring about biodiversity benefits, our study demonstrates that, in the context of commercial apple production, other measures are needed to enhance and harness biodiversity for sustainable and profitable crop production. In particular, a lowered reliance on honey bees and a redesign of orchards through configurational crop heterogeneity and/or the restoration of in-field semi‐natural elements are required beyond agricultural input substitution. • Wild bee diversity decreases with increasing honey bee dominance. • Organic apple orchards do not show diversity benefits for wild bees. • Semi-natural habitats are positively correlated with functional diversity. • Large bees with dietary preferences are more frequent with high honey bee dominance. • Lower reliance on honey bees and orchard redesign required to sustain biodiversity. [ABSTRACT FROM AUTHOR]

[Display omitted] • Unmanned aerial systems assist to characterize vegetation complexity. • Common rules that shape workflows applied in UAS-based studies can be identified. • Proposed framework allows to design surveys according to its purpose. • Crucial are knowledge of the phenomenon and choice of UAS, resolution and model. • Proper design of UAS survey minimizes the efforts while maximizing the quality. Ecosystem complexity is among the important drivers of biodiversity and ecosystem functioning, and unmanned aerial systems (UASs) are becoming an important tool for characterizing vegetation patterns and processes. The variety of UASs applications is immense, and so are the procedures to process UASs data described in the literature. Optimizing the workflow is still a matter of discussion. Here, we present a comprehensive synthesis aiming to identify common rules that shape workflows applied in UAS-based studies facing complexity in ecosystems. Analysing the studies, we found similarities irrespective of the ecosystem, according to the character of the property addressed, such as species composition (biodiversity), ecosystem structure (stand volume/complexity), plant status (phenology and stress levels), and dynamics (disturbances and regeneration). We propose a general framework allowing to design UAS-based vegetation surveys according to its purpose and the component of ecosystem complexity addressed. We support the framework by detailed schemes as well as examples of best practices of UAS studies covering each of the vegetation properties (i.e. composition, structure, status and dynamics) and related applications. For an efficient UAS survey, the following points are crucial: knowledge of the phenomenon, choice of platform, sensor, resolution (temporal, spatial and spectral), model and classification algorithm according to the phenomenon, as well as careful interpretation of the results. The simpler the procedure, the more robust, repeatable, applicable and cost effective it is. Therefore, the proper design can minimize the efforts while maximizing the quality of the results. [ABSTRACT FROM AUTHOR]

The decline of pollinators has been demonstrated scientifically and this phenomenon is widely recognized by both the general public and by stakeholders. Since pollinators face different threats that are all linked to human activities, there is a unique and unprecedented responsibility for people to conserve pollinators, requiring political action to counter the substantial worldwide risk of pollinator loss. As our perception of the situation is rapidly changing, as a result of the steady accumulation of international and national reports as well as new scientific findings, we propose here to provide an updated overview of pollinator conservation globally. We present the key messages and the proposed solutions found in international reports and assessments, how European countries have interpreted these solutions proposed in the context of existing international frameworks. Next, we analyze how scientific research is addressing the issue of pollinator conservation through different international, European and national programs. The analysis of the keywords used in published scientific articles also allows us to characterize how the scientific community has engaged with this issue over time. Finally, we focus on how France and Belgium have reacted to the observed decline of pollinators, and examine their national interpretations, conservation actions and research contributions. • We propose here to provide an updated overview of pollinator conservation globally. • We investigated how European countries have interpreted the existing international frameworks. • We analyzed the keywords used in published scientific articles on pollinators and pollination. • We focus on how France and Belgium have reacted to the observed decline of pollinators. • We examine their national interpretations, conservation actions and research contributions. [ABSTRACT FROM AUTHOR]

Climate change is an important driver of bee decline despite the fact that many species might respond to climate change differently. One method to predict how a species will respond to climate change is to identify its thermal tolerance limits. However, differences in thermal tolerance might also occur among distant populations of the same species based on their local environment or even among castes of social insects. Here, we investigated intraspecific differences in thermal tolerance among subspecies of the large earth bumble bee, Bombus terrestris (Apidae). We determined the critical thermal minima and maxima (CT min and CT max , respectively) of workers and queens from three lab-reared B. terrestris subspecies (B. t. terrestris , B. t. audax, and B. t. canariensis) which originated from different thermal environments. Our results showed that caste has an influence on critical thermal minima, with queens being most cold-tolerant, but the values of critical thermal maxima were not correlated to caste or size. The thermal tolerance of workers did not differ among the subspecies. Although heat tolerance was similar in queens, B. t. canariensis queens (originating from the warmest environments) were the least cold tolerant. Overall, we showed that B. terrestris may be generally robust against climate warming, but that particular subspecies and/or populations may be more vulnerable to extreme temperature variability. Future research should focus on responses of B. terrestris populations to short, extreme thermal events. • Intraspecies differences in thermal tolerance might occur between subspecies or even among castes of social insects. • Critical thermal limits were measured for both workers and queens from three lab-reared B. terrestris subspecies. • Thermal tolerances of workers did not differ among subspecies, but critical thermal minima (CT min) differed with caste. • Heat tolerance was similar in queens, but B. t. canariensis queens (from warmest environments) were the least cold tolerant. • Particular subspecies/populations of Bombus terrestris are likely to be more vulnerable to extreme temperature variability. [ABSTRACT FROM AUTHOR]

With 2000 species currently recorded in Europe, bees are a highly diversified and efficient group of pollinating insects. Their decline could therefore lead to a risk for ecosystems functioning and crop yields. The drivers of this decline have been well documented in Europe and involve multiple factors such as pesticides, pathogens, poor nutrition, climate change, and their respective interactions. For pesticides, there is a lack of information concerning the impacts of exposure when the bees have access to pollen diet of different nutritional quality (e.g. variation in sterol and protein content). We performed bioassays on nine groups consisting of 10 Bombus terrestris microcolonies (i.e. queen less colonies) each in a fully crossed experiment including controls without pesticide, two different doses of neonicotinoid imidacloprid (2 and 20 μg/L) and three pollen diets (i.e. Salix mix, cellulose-diluted Salix mix and cellulose-diluted Salix mix enriched with soy protein). All colonies were fed ad libitum with syrup and pollen. We measured the collection of pollen and syrup, the brood mass and the pollen efficacy (ratio of brood mass/pollen) at the end of the experiment. All these variables were affected by the imidacloprid doses, especially pollen efficacy, which was two and 10 times lower than the control for the 2 and 20 μg/L treatments, respectively. As expected, pollen efficacy was also affected by the pollen diet. However, when exposed to imidacloprid, the three different pollen diets did not affect micro-colonies performances. Overall, we show that diet quality does not affect sensitivity to imidacloprid exposure. It seems therefore that the negative effects of imidacloprid exposure cannot be compensated for by a pollen diet of high quality. • Bumblebee micro-colonies were exposed to imidacloprid and fed on three pollen diets. • Both diet quality and imidacloprid exposure affected micro-colony performances. • When exposed to pesticide, diet quality does no longer affect brood development. • Rich-nutrient diet did not reduce the negative effects of pesticide exposure. • Mitigation strategies should include measures to prevent agrochemical use. [ABSTRACT FROM AUTHOR]

Abstract: We report on the Mn segregation and diffusion during the epitaxial overgrowth of Ge on Mn5Ge3/Ge(111) heterostructures. It is shown that the underneath Mn5Ge3 layers remain stabilized at the interface with the substrate while a small amount of Mn can leave the layers and floats at the Ge growth front. Mn can then act as a surfactant during Ge growth along the (111) orientation. The Mn segregation length and also the state of Mn atoms incorporated in the Ge layers are found to depend on the growth temperature. At a growth temperature of 250°C, a segregation length of ~10nm is observed and Mn atoms incorporated in the Ge layers are uniformly distributed. At 450°C, segregated Mn atoms can react with Ge to form Mn5Ge3 clusters inside the Ge overgrown layer. Such Mn5Ge3 clusters display random orientations and induce modification of the magnetic anisotropy of the whole film. [Copyright &y& Elsevier]

Abstract: We report on the structural and magnetic properties of epitaxial Mn5Ge3 films grown by molecular beam epitaxy (MBE) on Ge(111) substrates with film thicknesses ranging from 5 to ~185nm. It is shown that epitaxial Mn5Ge3 films with a thickness as large as 185nm can be obtained despite a misfit of ~3.7% between two materials. Measurements of the in-plane lattice parameter carried out by means of reflection high-energy electron diffraction (RHEED) revealed that Mn5Ge3 films were fully relieved of strain after deposition of the first monolayer. For film thicknesses smaller than 50nm, the easy axis of magnetization is found to lie in the hexagonal basal (001) plan, parallel to the interface and the hard axis is perpendicular to the layers. When the film thickness increases above 50nm, magnetization measurements with magnetic field applied in-plane of the samples reveal that the easy axis of magnetization progressively turns out of the hexagonal basal (001) plan of Mn5Ge3. Even for Mn5Ge3 films with a thickness larger than 185nm, the easy axis of magnetization never becomes perpendicular to the sample surface as being expected for bulk Mn5Ge3 materials. [Copyright &y& Elsevier]