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This letter presents the bulk diamond field-effect transistor (FET) with the highest current value reported at this moment on 3.5 $\times $ 3.5 mm2 Ib diamond substrate. The goal was to drastically increase the current of this type of device by increasing the total gate width thanks to an interdigitated architecture and homogeneous growth properties. The device develops a total gate width of 14.7 mm, with 24 paralleled fingers and a current higher than 50 mA at V $_{\text {DS}} = -15$ V and V $_{\text {GS}} =0$ V, at 450 K and under illumination. Its specific ON-resistance and threshold voltage are respectively 608 m $\Omega $ .cm2, 50 V. Resistivity of 3.6 m $\Omega $ .cm for a heavily boron-doped (p++)-diamond layer and $1.52\Omega \cdot $ cm for a $2.10^{{17}}$ cm−3 p-doped diamond layer were extracted at 450 K. This study indicates that it is possible to drastically improve the ON-state of FETs by using an interdigitated architecture, while using homogeneous large size diamond layers grown by CVD.

Due to the expansion of defects like single Shockley-type Stacking Faults inside the SiC epitaxial drift layer, during high current stress, classical SiC MOSFETs can be victims of the degradation of their electrical characteristics. The introduction of an epitaxial SiC buffer layer between the substrate and the n- drift epilayer, called recombination-enhancing buffer layer, was shown to avoid this degradation. In this paper, TCAD simulations of the electrical behavior of such a commercial SiC MOSFET device with varying buffer layer thickness are studied, indicating only small modifications of the electrical characteristics. These simulations are combined with the characterization of the local electrical properties using an AFM-sMIM technique, allowing to determine the real thickness of the different layers of the device. These measurements highlight an inhomogeneous conductivity in the SiC substrate, being probably compensated by the introduction of the SiC buffer layer.

This article reports the influence of proton irradiation on the dark current of Ga-free InAs/InAsSb type II superlattice (T2SL) midwave infrared barrier photodetectors, with a cutoff wavelength of $4.8~\mu $ m at 150 K. The proton irradiation is performed with 60-MeV protons and fluence up to $8~\boldsymbol {\times } 10^{11}$ H+/cm2 on a T2SL detector kept at its operating temperature (150 K) in a cryostat or at room temperature (300 K). Degradation in dark current is observed under proton irradiation due to displacement damage dose (DDD) effects, with the presence of trap-assisted tunneling (TAT) current at -1 V. Trap carrier density, absorbing layer (AL) doping, and minority carrier lifetime are extracted from the measured J–V characteristics.

AbstractThis study provides the first record of Lasioglossum subfasciatum(Imhoff, 1832) (Hymenoptera, Apoidea, Halictidae) in the Sila National Park (Calabria, Italy), a Biosphere Reserve included in the UNESCO program. The species has been classified as endangered (EN) on the IUCN Red List, throughout Europe. Three specimens were found during a monitoring activity, in May 2022. Here, we provide a description of the species, the environmental characteristics of the site where it was found and a chronological map of its European distribution.

AbstractFood production is highly dependent on pollination services provided by insects; 75% of the leading global food crops need animals for successful production. Pollinators, including managed and wild bees, are declining in many parts of the world. The loss of natural habitats providing nesting sites is considered as one of the main factors driving the decline of crop-visiting wild bees. The researchers had hypothesized that providing bee hotels in cherry orchards may be a useful strategy to support visitors of cherry flowers (Prunus avium). To test this hypothesis, observation was made on the attractiveness of bee hotels to wild bees in cherry orchards in Sefrou Province (Morocco). Bee hotels were installed at the border of two cherry orchards. Surrounding landscapes were described and pollinator communities were observed and sampled within bee hotels, cherry flowers, and also within the surrounding landscape. Bumblebees (Bombusspp.), Mason bees (Osmiaspp.), sand bees (Andrenaspp.), and sweat bees (Lasioglossumspp.) are the most abundant genera representing almost two-thirds of all wild bee visitors of cherry trees. Mason bees (Osmiaspp.) are the most abundant bees nesting in bee hotels with almost three-quarters of all insects recorded. Bee hotels could therefore be used to sustain or even increase cavity-nesting bees visiting cherry orchards in Morocco.

CARactérisation et Modélisation de l’Environne- ment 2 and 3 (CARMEN 2 and 3) Centre National d’ Études Spatiales (CNES) missions aim to measure particle fluxes in the radiation belts via Influence sur les Composants Avancés des Radiations de l’Espace-Nouvelle Génération (ICARE-NG) monitor embedded on low Earth orbit (LEO) satellites. In this article, we find a projection model of these data onto the elliptical orbit satellite radiation belt storm probes (RBSP) flux particle-level measurements. The projection is done with a machine learning (ML) algorithm. Trained with data from CARMEN missions, the algorithm aims to predict particle flux measured by RBSP. We obtain satisfying results, and we find a good projection model on a large ${L^{*}}$ interval ( ${L^{*} = 3.4}$ –5.5 for CARMEN 2). While the global trend of the temporal variation of electron flux values is well predicted, the algorithm is not able to predict the suddenness of solar events, which produces abrupt slope changes and maxima in the temporal evolution of fluxes.

With its diverserange of climates and landscapes, the Middle East offers a remarkable area for the study of bee taxonomy and biogeography. In this work, a new species of pantaloon bee (Dasypoda delectabilisGhisbain & Michez sp. nov.) is described from a single male collected in south-eastern Iran. Although the new species shows affinities with the subgenus HeterodasypodaMichez, its morphology is highly intriguing due to the presence of characters shared by representatives of the subgenus Dasypodasensu stricto Latreille. A diagnostic comparison with phenotypically close Dasypodaspecies is provided, along with comparative remarks on the morphology and biogeography of the subgenus Heterodasypoda. Finally, a checklist of the genus Dasypodais given for the Middle East, highlighting the need for increased attention to this highly interesting yet largely overlooked fauna.http://www.zoobank.org/urn:lsid:zoobank.org:pub:EBB22897-6F94-4544-AA03-CC97AACE344B

Phenolamides are abundant specialized metabolites found in nature and consist of hydroxycinnamic acids mono- or polyconjugated with polyamines. Their participation in flower development is well-documented, and their presence in pollen raises the question of their role in pollen/pollinator interactions. The structural characterization of phenolamides is complicated by the presence of positional isomers and stereoisomers. Liquid chromatography coupled to tandem mass spectrometry in the positive ionization mode is becoming very popular in phenolamide structural characterization. However, collision-induced transamidation processes that cause the swapping of side chains have been detected, making it difficult to distinguish regioisomers with this technique. In the present report, we explore the dissociation processes undergone by the [M – H]−ions of spermidine-based phenolamides as model compounds. We describe two original competitive dissociation routes, namely, the phenolate and imidate pathways, to account for the observed fragmentation reactions undergone by collisional activated standard phenolamide anions. Whereas the phenolate pathway is regioselective at the central position for spermidine, the imidate pathway, requiring a deprotonated amide, only occurs at the extremities. Tandem mass spectrometry experiments on negatively charged phenolamide ions may then outperform their positive ionization mode counterparts for the distinction between phenolamide regioisomers and globally for the identification of phenolamides in natural extracts.

Habitat degradation and climate change are globally acting as pivotal drivers of wildlife collapse, with mounting evidence that this erosion of biodiversity will accelerate in the following decades1–3. Here, we quantify the past, present and future ecological suitability of Europe for bumblebees, a threatened group of pollinators ranked among the highest contributors to crop production value in the northern hemisphere4–8. We demonstrate coherent declines of bumblebee populations since 1900 over most of Europe and identify future large-scale range contractions and species extirpations under all future climate and land use change scenarios. Around 38–76% of studied European bumblebee species currently classified as ‘Least Concern’ are projected to undergo losses of at least 30% of ecologically suitable territory by 2061–2080 compared to 2000–2014. All scenarios highlight that parts of Scandinavia will become potential refugia for European bumblebees; it is however uncertain whether these areas will remain clear of additional anthropogenic stressors not accounted for in present models. Our results underline the critical role of global change mitigation policies as effective levers to protect bumblebees from manmade transformation of the biosphere.

Bumble bees are important pollinators for many temperate crops. Because of the growing demand for food from entomophilous crops, bumble bee colonies are commercially reared and placed in fields or greenhouses to guarantee sufficient pollination services. Besides, commercial colonies are increasingly used in laboratories for various bioassays under controlled conditions. For both usages, bumble bee colonies are commonly provided with sugar solution and honey bee-collected pollen pellets. However, the latter display several disadvantages since they may contain pollutants, pathogens, or toxic phytochemicals. Consequently, companies have developed pollen-free artificial diets to sustain colonies. Such diets are designed to boost worker health in the field, in complement of floral pollen collected by workers outside the colonies, but their suitability in ‘closed’ systems without access to floral pollen, such as in laboratory bioassays, is arguable. Here, we used microcolonies of the commercially important bumble bee Bombus terrestrisL. (Hymenoptera: Apidae) to assess the suitability of five artificial pollen substitutes and three mixed diets. We also assessed the evaporation rate of the different diets as it could impact their suitability. At the end of the bioassays, microcolonies fed the artificial diets showed a reduced offspring development when compared to microcolonies fed natural pollen, which was partly offset by mixing these diets with natural pollen. By contrast, the artificial diets did not have deleterious effects on worker’s health. We discuss the potential nutritional and physical causes of artificial diets unsuitability for offspring development and encourage further research to accordingly establish appropriate pollen-free diets for bumble bee breeding.

The SEM‐2 (Space Environment Monitor‐2) instrument embedded on the NOAA‐15 Low Earth Orbit satellite provides measurements of trapped protons in the Van Allen inner belt from 1998 to nowadays. This continuous set of measurements enables us to study the dynamics of the South Atlantic Anomaly (SAA) over more than two solar cycles, particularly, its temporal evolution. We observe that the area of the SAA is anti‐correlated with the solar activity. Two physical processes explain this anticorrelation. First, the more the Sun is active the more it disables the cosmic rays to reach the Earth's magnetosphere and fill in the inner radiation belt with protons. Then, when the Sun is more active, the upper atmosphere is warmer and therefore absorbs more protons from the radiation belt. Then, we investigate the protons flux centroid of the SAA. The temporal evolution of its position, latitude and, longitude is studied over the same time interval (1998–2022). We notice that the latitude of the centroid is also anti‐correlated with the solar activity whereas the longitude seems absolutely independent. The temporal evolution of the position of the centroid shows a drift of the SAA. Indeed from 1998 to 2022 the SAA drifted of about 7° West. The SEM‐2 instrument measures flux for protons of different energies (16, 36, 70, and, 140 MeV). For each energy, the SAA dynamic has a similar trend but with different values. These differences are investigated and the results are discussed. The SAA is studied from proton flux measurements values in the inner radiation belt collected during the 1998–2022 period by the SEM‐2 instrument embedded on the NOAA‐15 satelliteThe SAA drifts globally Northward with an anticorrelation of its latitude with the solar activity and 7° Westward over a 24‐years periodThe higher the energy of the protons, the farther north and west the SAA shifts The SAA is studied from proton flux measurements values in the inner radiation belt collected during the 1998–2022 period by the SEM‐2 instrument embedded on the NOAA‐15 satellite The SAA drifts globally Northward with an anticorrelation of its latitude with the solar activity and 7° Westward over a 24‐years period The higher the energy of the protons, the farther north and west the SAA shifts

Dealing with electronic devices for high reliability applications in terrestrial environments, neutron-induced Single Event Effects must be investigated. In this paper, the experimental observation of an atmospheric-like neutron-induced Single Event Burnout (SEB) on a packaged commercial SiC power MOSFET is presented after irradiation at ISIS-ChipIr. The effects of the SEB in the electrical properties of the MOSFET are established, and the SiC damaged zone is observed by scanning electron microscopy. Based on this failure analysis at the die level, the distinct stages during the SEB mechanism can be defined. The sensitive volume where the secondary particle deposited enough energy to trigger the SEB mechanism is identified and located inside the SiC n-drift epitaxial layer near the epitaxial layer/substrate junction.

Bee populations have declined in many parts of the world, raising concerns over their conservation and the pollination services they provide. As a result of declines in agricultural areas, agri-environment schemes have been designed and implemented in order to reverse these trends. Until now, these schemes have largely focused on providing an abundance of herbaceous flowering plants which predominantly provide pollen and nectar during the summer, but flowering trees and shrubs may have been overlooked as a source of earlier-flowering resources. Using Bombus terrestris (L.) microcolonies, we investigated differences in pollen quality from eight woody and six herbaceous plant species using compositional analyses and efficacy assays. Pollen from herbaceous plants had a higher average crude protein and lipid content, but there were no differences in the protein:lipid ratio when compared to woody plants. However, when measuring amino acids directly, woody plants had a slightly higher total and essential amino acid content. Despite these minor differences, microcolonies fed on woody plant pollen produced a greater mass of larval offspring and had a lower rate of larval ejection. There was substantial variation between individual studied plant species, and whilst no individual woody plant pollen outperformed the best herbaceous pollen, they all exceeded the performance of the worst herbaceous pollen. This consistent performance suggests that woody plants may be good candidates for inclusion in bee-focused agri-environment schemes in order to provide suitable pollen resources in the early part of the season.

SummaryAlgeria, the largest country in Africa, has a species rich bee fauna because of its ecological conditions, climate and diversified flora. The present work represents a list of the genus AndrenaFabricius, 1775 in western Algeria. The survey, carried out during the period 2017–2019, has allowed identification of 56 species of Andrenain a total of 787 specimens (496 females, 291 males), with one species new for the fauna of Algeria, Andrena(Aenandrena) hystrixSchmiedeknecht, 1883. Preliminary pollen preferences of the most common species were analysed in Algeria for the first time, comprising seven polylectic and 12 oligolectic species. The current work provides a baseline for future studies on the diet of Andrena and is one of the first studies on the floral preferences of North African bees.

SummaryDasypoda morawitziRadchenko, 2016, a cryptic bee species separated from D. hirtipes(Fabricius, 1793) and recently described from Eastern Europe, Western Kazakhstan, Caucasus and Turkey, is for the first time recorded from Czech Republic, Romania and Spain. We also provide additional new records for several other countries. An additional comparative morphological analysis of D. morawitziwith D. hirtipesusing light and electron microscopy is provided. New morphological differences between these two species are highlighted. Significant variation in hair morphology on some parts of the female body of these two species are shown. Differences and similarities between D. morawitziand D. hirtipesare discussed and the impossibility of a synonymy of D. graecaLepeletier & Serville, 1828 with D. morawitziis discussed. Corrected and new diagnostic features of the subgenus Dasypoda s. str. are given.

The mutualism between plants and their pollinators provides globally important ecosystem services, but it is likely to be disrupted by global warming that can cause mismatches between both halves of this interaction. In this review, we summarise the available evidence on (i) spatial or (ii) phenological shifts of one or both of the actors of this mutualism. While the occurrence of future spatial mismatches is predominantly theoretical and based on predictive models, there is growing empirical evidence of phenological mismatches occurring at the present day. Mismatches may also occur when pollinators and their host plants are still found together. These mismatches can arise due to (iii) morphological modifications and (iv) disruptions to host attraction and foraging behaviours, and it is expected that these mismatches will lead to novel community assemblages. Overall plant–pollinator interactions seem to be resilient biological networks, particularly because generalist species can buffer these changes due to their plastic behaviour. However, we currently lack information on where and why spatial mismatches do occur and how they impact the fitness of plants and pollinators, in order to fully assess if adaptive evolutionary changes can keep pace with global warming predictions.

SummaryWest Palearctic bumblebees are common wildflowers and crop pollinators that are well studied in their central and northern distribution ranges, but fewer information is available on their southern distribution areas. Lebanon falls on the southern limit of their distribution and no published information is available on the local bumblebees. Our study aims to produce a data baseline of the local bumblebee species. In order to do so we grouped available old records of bumblebees in Lebanon with recent author collections and produced preliminary distribution maps. We listed four species: Bombus terrestris, B. argillaceus, B. niveatus vorticosusand B. melanurus. Preliminary distribution shows that Bombus terrestrisand B. argillaceusare widespread and have a large foraging range, whereas B. niveatus vorticosusand B. melanurushave a restricted distribution to altitudes above 1800 m with a smaller foraging range. The male cephalic labial gland secretions analysis of local Bombus terrestrisspecimens provides preliminary evidence that the local subspecies could be Bombus terrestris calabricus. Therefore, we highlight the importance of regulating foreign Bombus terrestrissubspecies importation for agriculture purposes, as well as monitoring B. niveatus vorticosusand B. melanurusthat are rendered vulnerable by their isolated populations.

Males of many bumblebee species exhibit a conspicuous pre-mating behavior with two distinct behavioral components: scent marking and patrol flying. The marking pheromone is produced by the cephalic part of the labial gland (CLG). As far as is known, the CLG secretion is species specific, and it usually consists of two types of compounds: (i) straight-chain aliphatic alcohols, aldehydes or esters, and (ii) acyclic mono-, sesqui- and diterpenes (alcohols or acetates). Here, we summarize data from the literature reporting chemical composition of the CLG secretions of more than 80 bumblebee species. Similarities and differences within and between subgenera are discussed in the context of biosynthetic pathways and evolution.

In this work, we have combined scanning tunneling microscopy with high-resolution transmission electron microscopy (HR-TEM) to investigate the initial stages of Mn deposition on Ge(001) surfaces. The growth temperature was chosen to be (353 ± 5) K, which is typical for the synthesis of Ge1–xMnxthin films. At the early stage of the Mn deposition, two distinct kinds of islands are observed even for Mn coverage much smaller than a monolayer with an average size of 1–2 nm and 4–5 nm, respectively. Small islands were found to nucleate in the hollow between the Ge dimer rows, and they were formed by consuming Ge from two adjacent rows. This indicates that Mn–Ge alloying has been taken place even at the early stage of the Mn deposition. When the Mn coverage increases, coarsening between small islands with newly deposited ad-atoms occurs, giving rise to the formation of monosized islands. Interestingly, these nanostructures have an average size of 4–5 nm and separated by a spacing of 7–8 nm that are similar to the spatial ordering of nanocolumns resulting from spinodal decomposition in (Ge,Mn) thin films. HR-TEM analyses indicate that those nanoislands are epitaxial, defect-free, and perfectly coherent with the Ge substrate. A subsequent anneal will result in the formation of Mn5Ge3islands.

PKD2-related autosomal dominant polycystic kidney disease (ADPKD) is widely acknowledged to be of milder severity than PKD1-related disease, but population-based studies depicting the exact burden of the disease are lacking. We aimed to revisit PKD2prevalence, clinical presentation, mutation spectrum, and prognosis through the Genkyst cohort.

SummaryThe present study is an update to the first Red List of European Bees published in 2014. The additional records are based on (i) comprehensive review of literature; (ii) new data provided by bee specialists in response to the publication of the first Red List; (iii) new developments in taxonomy of European bees including description of new cryptic species; (iv) new specimens from recent field collections. While the first Red List included a list of 1965 wild bee species with 75 genera, we found 86 additional species, while two more genera have been erected (Seladoniaand Vestitohalictus), giving an updated total of 2051 species and 77 genera. The authors discuss the artificial framework of the study considered by International Union for Conservation of Nature (IUCN) to produce the first Red List and they propose the more meaningful West Palaearctic biogeographical region. For this whole region, a first estimation gives 3408 wild bee species in 105 genera. The next taxa have been erected from subspecies to species status: Andrena(Euandrena) limosaWarncke, 1969, stat. n., Andrena(Plastandrena) oligotrichaMavromoustakis, 1952, stat. n.

In this paper, we report investigations concerning the fabrication of a diluted Ge (Mn) solution using solid state Mn diffusion, and Mn/Ge reactive diffusion for spintronic applications. The study of Mn diffusion shows that the quasi-totality of the incorporated Mn atoms occupies Ge substitutional sites and probably exhibits two negative elementary charges. The solubility limit of Mn in Ge is comprised between 0.7 and 0.9 % (T  600 °C). We show that substitutional Mn atoms are not ferromagnetic in Ge and consequently that Ge (Mn) diluted magnetic semiconductor can not be produced. Beside the ferromagnetic signal from Mn5Ge3, ferromagnetic signals detected in the samples could be always attributed to surface or bulk Mn-Ge clusters. Furthermore, we show that the CMOS Salicide process is potentially applicable to Mn5Ge3 nanolayer fabrication on Ge for spintronic applications. During Mn (thin-film)/Ge reaction, Mn5Ge3 is the first phase to form, being thermally stable up to 310 °C and exhibiting ferromagnetic properties up to TC ~ 300 K.

The Mn5Ge3 compound, thanks to its room-temperature ferromagnetism, metallic character and ability to epitaxially grow on germanium, has emerged as a potential candidate for spin injection into group-IV semiconductors. We investigate the effect of carbon doping in epitaxial Mn5Ge3 films and show that incorporation of carbon into interstitial sites of Mn5Ge3 can allow not only to enhance the magnetic properties but also increase the thermal stability of Mn5Ge3 up to a temperature as high as 850 degC. These results open perspectives to realize spintronic devices based on Mn5Ge3Cx/Ge heterostructures that are compatible with the Si-based complementary metal-oxide-semiconductor (CMOS) technology.

AbstractWe here describe six new specimens of gynanders (i.e. specimens where male and female phenotypic characters occur on the same individual) from distinct families of wild bees (Hymenoptera, Apoidea). The newly described cases include Melitta haemorrhoidalis(Fabricius 1775) (Melittidae), Dasypoda hirtipes(Fabricius 1775) (Melittidae), Anthophora plumipes(Pallas 1772) (Apidae), Bombus monticola rondouiVogt 1909 (Apidae), Bombus vestalis vestalis(Fourcroy 1785) (Apidae) and Bombus vestalis sorgonis(Strand 1917) (Apidae). Descriptions are accompanied by behavioural observations of gynanders under natural conditions before their capture for two cases. We also list 109 gynanders already described in bees and we interpret the newly described cases along these previous records. The putative origins of gynandromorphy are then discussed in the light of recent advances in the field of sex determination in Hymenoptera.

AbstractBombus terrestrisis one of the most abundant bumblebee species in the West-Palaearctic. Its widespread domestication results in the movement of many colonies. The aim of this paper is to describe the 9 subspecies currently recognised and to list some of their most obvious characteristics. Bombus terrestrisis not declining anywhere, on the contrary, its synanthropic spread through domestication may be expected. However, its autumn and winter populations rely on a restricted choice of flowers so they may be threatened locally by scrub clearance and the destruction of their favourite autumnal flowers.

AbstractA new specimen of the rare fossil bee Thaumastobombus andreniformisEngel 2001 (Apidae: Apinae: Electrapini) is reported and figured from middle Eocene (Lutetian) Baltic amber. The new specimen, a female of the worker caste, agrees in every respect with the holotype except some morphometric differences. These minor size differences are likely related to the degree of sociality of T andreniformis.

AbstractBees comprise a monophyletic group of seven families with more than 16000 described species worldwide. Convincing new phylogenetic hypotheses suggest that one of the smallest families, the Melittidae, could be the basal group of the bee clade. Among the 14 melittid genera, the genus MelittaKirby 1802, is the most widespread and one of the most diverse. Most revisionary studies of Melittawere confined to limited geographical areas. An overview of the literature and the examination of 7817 specimens from various collections, including type material, have enabled the first monographic revision of the genus Melitta. This revision includes a cladistic analysis, comprehensive catalogue and identification key. We provide diagnoses, global distributions, phenology and host plants for the 43 known species (including 2 new ones). Lectotypes are designated for M. albofasciataFriese 1900, M. caroliCameron 1909, M. schultzeiFriese 1909 and M. sibirica(Morawitz 1888). We described M. rasmontin. sp., M. guichardin. sp., the previously unknown male of M. bicollarisWarncke 1973 and unknown female of M. murcianaWarncke 1973.

AbstractThe family Halictidae includes four subfamilies, Halictinae, Nomioidinae, Nomiinae and Rophitinae, apparently monophyletic. SystrophaIlliger is the most diverse genus in Rophitinae (the Holartic genus Dufoureaexcluded). Several unique morphological, biogeographical and ecological features characterise the species within this taxon raising its interest for evolutionary studies. Now, to date there has been no extensive revision of the genus. The present work aims to alleviate this lack. In the first part, the authors propose an exhaustive catalogue, including the synonymy of the 26 described species. The last described species, Systropha heinziDubitzky 2004 syn. nov.is proposed as a junior synonym of S. kazakhstaniensisPatiny 2004, described one day earlier. The next parts of the study include a comprehensive key for the World species and the analysis of the species phylogeny based on 34 morphological characters. Converging with the conclusions of several former studies, this analysis points out the existence of 3 clades within the genus. These latter are described as 3 subgenera: S. (Systropha) Illiger 1806, S. (Systrophidia) Cockerell 1936 and S. (Austrosystropha) n. sg.Lastly, distribution and floral choices of taxa are specified.

AbstractThe genus MacropisPanzer 1809 includes 16 species, with the new taxon described here: M. (Sinomacropis) orientalisn. sp.The present paper is the first global revision of the genus. The authors propose a comprehensive catalogue, a key to the species and maps of some species. On the basis of an extensive morphological revision, the subgenera earlier proposed by Michenerare further discussed and assessed. Moreover, several notable range expansions are reported and discussed. The species floral choices are discussed: all the species are oligolectic on various Lysimachiaspecies.

RésuméLa phylogénie des Melittidae fait encore l’objet de discussions. En particulier, il n’est pas encore établi que la famille soit monophylétique. La présente étude a pour premier but d’établir la monophylie et la classification subgénérique phylogénétique de l’un des 14 genres de Melittidae: le genre DasypodaLatreille 1802. L’étude cladistique basée sur des caractères morphologiques des imagos confirme la monophylie des Dasypodaau sein des Dasypodainae. Quatre sous-genres sont reconnus et décrits: Microdasypodan. subg., Heterodasypodan. subg., Dasypodan. comb. et Megadasypodan. subg. Les cartes de richesse spécifique de ces sous-genres semblent indiquer une cohérence biogéographique avec le clade basé sur la morphologie. Les centres de diversité respectifs trouvent leur meilleure explication dans le rapprochement avec d’anciens refuges glaciaires méditerranéens. Létude des choix floraux renforce aussi l’option taxonomique proposée. Chaque sous-genre pollinise préférentiellement des familles végétales particulières (Asteraceae, Cistaceae, Dipsacaceae ou Malvaceae). Ces nouvelles données permettent de proposer une hypothèse sur l’origine géographique et la période d’apparition des Dasypoda.

Structural and magnetic characterisations along with first-principles total energy calculations based on the density functional theory have been combined to investigate the effects of (001) and (111)-oriented Ge substrates on the formation of GeMn nanocolumns. The samples were grown by means of molecular beam epitaxy (MBE) at the growth temperature (TS) of 130 °C, the Mn concentration of ?6% and the film thickness of ?80 nm. We found that due to the surfactant effect of Mn atoms, Ge0,94Mn0,06films grown on the Ge(001) substrate exhibit the nanocolumn structure along the growth direction and the Curie temperature (TC) is higher than 400 K. On the other hand, for the Ge0,94Mn0,06films grown on the Ge(111) substrate, Mn adatoms can easily diffuse into deeper layers through the interstitial sites, resulting in the formation of Ge3Mn5streaks along the preferred direction [110] and surrounded by diluted matrix. The physical origin of the contrasting behaviour of Mn atoms is therefore strongly related to the different surface reconstruction.

The use of Bombus terrestris L. commercial colonies for outdoor and greenhouse crop pollination is currently widespread. Colony breeding includes bumblebee feeding, mostly by using the honeybee pollen loads of diverse palynological composition. Because the chemical content of pollen is highly variable, the choice of commercial blend should not be random but has to be carefully selected to ensure the optimal development of workers and then pollination efficacy. In this work, we compared the impact of three common commercial blends on the development of bumblebee microcolonies, namely, Actinidia deliciosa L., Cistus sp., and Salix sp. We focus on amino acids (i.e., composition and amount), as they are currently used as an indicator of diet performance. Five parameters were used to determine microcolonies growth rate: 1) number of eggs, 2) number of alive larvae, 3) number of ejected larvae, 4) number of pupae, and 5) total number of offspring. Syrup collection was also monitored to estimate energetic requirement for colony growth. Results revealed that the three commercial blends chemically differed in their amino acid contents, with those displaying higher concentrations (i.e., Salix sp. and A. deliciosa) accelerating microcolony development along with an increase of syrup collection. The advantages of rearing bumblebee commercial colonies using a pollen diet with an optimal amino acid content are discussed.

Through computer resolution of the transport equations, the authors show the influence of deep centres on the behaviour of P+-N-N+ or P+-I-N+ GaAs diodes at high forward current levels. Depending on the nature (hole or electron trap) and density of these deep centres, it is possible to decrease the voltage drop at high forward current density and thus to increase the power efficiency of the devices.

The development of active spintronic devices, such as spin-transistors and spin-diodes, calls for new materials that are able to efficiently inject the spin-polarized current into group-IV semiconductors (Ge and Si). In this paper we review recent achievements of the synthesis and the magnetic properties of Mn5Ge3/Ge and carbon-doped Mn5Ge3/Ge heterostructures. We show that high crystalline quality and threading-dislocation free Mn5Ge3films can be epitaxially grown on Ge(111) substrates despite the existence of a misfit as high as 3.7% between two materials. We have investigated the effect of carbon doping in epitaxial Mn5Ge3films and show that incorporation of carbon into interstitial sites of Mn5Ge3can allow not only enhancement of the magnetic properties but also an increase of the thermal stability of Mn5Ge3. Finally, toward the perspective to realize Ge/Mn5Ge3/Ge multilayers for spintronic applications, we shall show how to use carbon to prevent Mn out-diffusion from Mn5Ge3during Ge overgrowth on top of Mn5Ge3/Ge heterostructures. The above results open the route to develop spintronic devices based on Mn5Ge3Cx/Ge heterostructures using a Schottky contact without needing an oxide tunnel barrier at the interface.

Structural and magnetic characterizations have been combined to investigate the growth kinetics of Ge1?xMnxdiluted magnetic semiconductors (DMSs) on Ge(001) substrates by means of molecular beam epitaxy (MBE). We have identified the growth process window allowing stabilization of a high Curie temperature (TC) nanocolumn phase and provide evidence that the growth of semiconducting Ge1?xMnxnanocolumns and metallic Mn5Ge3clusters is a competing process. Due to a continuous increase of the Mn concentration inside nanocolumns, induced by Mn segregation along the growth direction from the interface toward the film surface, nanocolumns become unstable when the Mn concentration reaches a value of ~40?at.% then transform into Mn5Ge3clusters. We propose a real-time approach to realize stacked layers consisting of nanocolumns separated by a Ge barrier layer, allowing exploitation of the effect of giant magneto-resistance in multilayer structures