Supplementary note on the solitary bee fauna from the Suez Canal region of Egypt (Hymenoptera: Apoidea)

Previous surveys (2011–2013) of the bee fauna from the Suez Canal region, Egypt, recorded a total of 55 species.  Those surveys did not include important floral species among the Asteraceae, a family known to be associated with various oligolectic bees.  The aim of the present note is to report bees visiting four uncultivated species of Asteraceae that are common in the region during the Spring of 2014.  Nine species of bees were recorded from these flowers, these increasing the number of species recorded from the Suez Canal region to 62.  Some species, such as Daypoda sinuata Pérez (Melittidae) and Panurgus dentatus Friese (Andrenidae), are known oligoleges of Asteraceae.

Magnetic anisotropy in epitaxial Mn5Ge3 films

High crystalline quality Mn 5 Ge 3 films with thicknesses ranging 4–200 nm have been grown on Ge(111) substrates by solid phase epitaxy. The basal hexagonal plane of Mn 5 Ge 3 is in epitaxy with the Ge(111) plane. Magnetic properties of the films have been investigated as a function of the film thickness and the magnetization curves have been analyzed using a theory that includes a description of magnetic domains in uniaxial thin films. The results clearly indicate the existence of a critical thickness below which the magnetic stripe phase disappears. We have determined the value of this thickness to lie between 10 and 25 nm from the analysis of experimental magnetization curves and the theoretical fit of the in-plane remanent magnetization. Although analogies can be drawn between the behavior observed in our system and that of hcp Co, we have shown that the critical thickness is considerably smaller in Mn 5 Ge 3 ; this has the potential to open new fields of applications for Mn 5 Ge 3 thin films in magnetic recording and spintronics

The oldest fossil of a melittid bee (Hymenoptera: Apiformes) from the early Eocene of Oise (France)

peer reviewedPhylogenetic relationships among and within major groups of bees are still poorly resolved. The main gap is the identification of the basal branch of bee phylogeny. In this context, more information is needed about the early fossil record of bees. Here, we describe Palaeomacropis eocenicus gen. nov. sp. nov., discovered in early Eocene amber of Oise (France). It is the oldest record of Melittidae and the fourth oldest fossil bee. The remarkable state of preservation of the specimen allows a detailed description of the cuticle and the setae. A cladistic analysis supports the classification of this species among the Macropidinae (Melittidae). Together with the existing records on a Maastrichtian Apidae and a Palaeocene Megachilidae, the discovery of an early Eocene Melittidae supports the hypothesis that Melittidae could constitute the basal branch of bee phylogeny. Moreover, the morphology and disposition of the setae of P. eocenicus are similar to those of the contemporary oil-collecting bee Macropis. The presence of a bee with such specialized structures would support the hypothesis that a close relationship existed between bees and oil flowers since the early Eocene.  © 2007 The Linnean Society of London, Zoological Journal of the Linnean Society, 2007, 150, 7012013709

Aging and gate bias effects on TID sensitivity of wide bandgap power devices

The effect of oxide stress on the total ionizing dose (TID) radiation sensitivity of silicon carbide (SiC) power MOSFETS and TID sensitivity of gallium nitride (GaN) power transistor is reported. Difference in TID response for stressed and unstressed devices was observed

Morphometric analysis of fossil bumble bees (Hymenoptera, Apidae, Bombini) reveals their taxonomic affinities

This work is licensed under a Creative Commons Attribution 4.0 International License.Bumble bees (Bombus spp.) are a widespread corbiculate lineage (Apinae: Corbiculata: Bombini), mostly found among temperate and alpine ecosystems. Approximately 260 species have been recognized and grouped recently into a simplified system of 15 subgenera. Most of the species are nest-building and primitively eusocial. Species of Bombus have been more intensely studied than any other lineages of bees with the exception of the honey bees. However, most bumble bee fossils are poorly described and documented, making their placement relative to other Bombus uncertain. A large portion of the known and presumed bumble bee fossils were re-examined in an attempt to better understand their affinities with extant Bombini. The taxonomic affinities of fossil specimens were re-assessed based on morphological features and previous descriptions, and for 13 specimens based on geometric morphometrics of forewing shape. None of the specimens coming from Eocene and Oligocene deposits were assigned within the contemporary shape space of any subgenus of Bombus. It is shown that Calyptapis florissantensis Cockerell, 1906 (Eocene-Oligocene boundary, Florissant shale, Colorado, USA) and Oligobombus cuspidatus Antropov, 2014 (Late Eocene, Bembridge Marls) likely belong to stem-group Bombini. Bombus anacolus Zhang, 1994, B. dilectus Zhang, 1994, B. luianus Zhang, 1990 (Middle Miocene, Shanwang Formation), as well as B. vetustus Rasnitsyn & Michener, 1991 (Miocene, Botchi Formation) are considered as species inquirenda. In the Miocene, affinities of fossils with derived subgenera of Bombus s. l. increased, and some are included in the shape space of contemporary subgenera: Cullumanobombus (i.e., B. pristinus Unger, 1867, B. randeckensis Wappler & Engel, 2012, and B. trophonius Prokop, Dehon, Michez & Engel, 2017), Melanobombus (i.e., B. cerdanyensis Dehon, De Meulemeester & Engel, 2014), and Mendacibombus (i.e., B. beskonakensis (Nel & Petrulevičius, 2003), new combination), agreeing with previous estimates of diversification

Andrena (Hymenoptera: Apoidea: Andrenidae) fauna of Western Algeria, with a preliminary assessment of their pollen preferences

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Antiquity of cleptoparasitism among bees revealed by morphometric and phylogenetic analysis of a Paleocene fossil nomadine (Hymenoptera: Apidae)

peer reviewedCleptoparasitism is a way of life involving the theft of resources by one animal from another. This behavior occurs in many bee tribes but its origin and evolution remain obscure, particularly owing to the relative scarcity of bees in the fossil record. Hitherto, no fossil evidence has been previously recorded to trace the origin of cleptoparasitim among bees. In the current study, we present the first cleptoparasitic bee fossil, providing analyses of its taxonomic affinities and a complete description. The specimen happens to also be one of the earliest bee fossils, having been discovered in the spongo-diatomitic volcanic paleolake of Menat (Paleocene) in France. We employed geometric morphometrics of the forewing shape to assess the taxonomic affinities of the fossil with modern apoid tribes. Our data set included 979 specimens representing 50 tribes and 226 extant species. Based on linear and geometric morphometrics, we demonstrate that the fossil's forewing shape is similar to Apidae, and particularly to the tribe Epeolini (Nomadinae). The fossil is described as Paleoepeolus micheneri gen.n., sp.n. and provides the first direct evidence on the antiquity of cleptoparasitism among bees. This published work has been registered on Zoobank. URL: http://zoobank.org/References/BBBE2217-6CAE-48F9-851F-716B813DFEBF

Unveiling the atomic position of C in Mn5Ge3 Cx thin films

Heavily carbon-doped Mn5Ge3 is a unique compound for spintronics applications as it meets all the requirements for spin injection and detection in group-IV semiconductors. Despite the great improvement of the magnetic properties induced by C incorporation into Mn5Ge3 compounds, very little information is available on its structural properties and the genuine role played by C atoms. In this paper, we have used a combination of advanced techniques to extensively characterize the structural and magnetic properties of Mn5Ge3Cx films grown on Ge(111) by solid phase epitaxy as a function of C concentration. The increase of the Curie temperature induced by C doping up to 435 K is accompanied by a decrease of the out-of-plane c-lattice parameter. The Mn and C chemical environments and positions in the Mn5Ge3 lattice have been thoroughly investigated using x-ray absorption spectroscopy techniques (x-ray absorption near-edge structures and extended x-ray absorption fine structures) and scanning transmission electronic microscopy (STEM) combined to electron energy loss spectroscopy for the chemical analysis. The results have been systematically compared to a variety of structures that were identified as favorable in terms of formation energy by ab initio calculations. For x≤0.5, the C atoms are mainly located in the octahedral voids formed by Mn atoms, which is confirmed by simulations and seen for the first time in real space by STEM. However, the latter reveals an inhomogeneous C incorporation, which is qualitatively correlated to the broad magnetic transition temperature. A higher C concentration leads to the formation of manganese carbide clusters that we identified as Mn23C6. Interestingly, other types of defects, such as interstitial Ge atoms, vacancies of Mn, and their association into line defects have been detected. They take part in the strain relaxation process and are likely to be intimately related to the growth process. This paper provides a complete picture of the structure of Mn5Ge3Cx in thin films grown by solid phase epitaxy, which is essential for optimizing their magnetic properties

New fossil evidence of the early diversification of bees: Paleohabropoda oudardi from the French Paleocene (Hymenoptera, Apidae, Anthophorini)

peer reviewedPhylogenetic relationships among and within the major groups of bees (Apoidea Apiformes) were recently reconsidered using extensive molecular and morphological datasets. The next step in the study of bee evolution will consist in estimating the antiquity of the nodes within the inferred topologies. We describe here the third oldest bee fossil, Paleohabropoda oudardi gen. n. sp. N. (Apidae, Apinae, Anthophorini) from the Paleocene of Menat (France, Puy-de-Dôme; 60 Myr). Phylogenetic analysis of 17 morphological characters and morphometric analysis of the wing shape were used to recover, respectively, its taxonomic position and morphological affinities. Our results indicate that Paleohabropoda oudardi gen. n. sp. n. clearly belongs to the Anthophorini. Paleohabropoda is therefore the oldest fossil that can be confidently date and place to an extant tribe. Its wing shape is surprisingly close to the extant genus Habropoda. The discovery of Paleohabropoda oudardi gen. n., sp. n. brings further evidence for the Cretaceous diversification of major lineages of bees and for strong constancy of wing shape within the Anthophorini

Pollen nutrients better explain bumblebee colony development than pollen diversity

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