Children experience Science

In the last two years, researchers from the Metapopulation Research Centre (MRC) at the University of Helsinki, Finland, have, under the initiative of Dr. Anna-Liisa Laine, introduced more than 150 pre-school children to Biological Science and the profession of researcher. The project is called “Tiede Tulee Tarhaan” in Finnish, which translates into “Science goes Kindergarden”

High Wolbachia Strain Diversity in a Clade of Dung Beetles Endemic to Madagascar

Determining the drivers of diversity is a major topic in biology. Due to its high level of micro-endemism in many taxa, Madagascar has been described as one of Earth's biodiversity hotspot. The exceptional Malagasy biodiversity has been shown to be the result of various eco-evolutionary mechanisms that have taken place on this large island since its isolation from other landmasses. Extensive phylogenetic analyses have, for example, revealed that most of the dung beetle radiation events have arisen due to allopatric speciation, and adaptation to altitudinal and/or longitudinal gradients. But other biotic factors, that have yet to be identified, might also be at play. Wolbachia is a maternally transmitted endosymbiotic bacterium widespread in insects. The bacterium is well-known for its ability to modify its host reproductive system in ways that may lead to either discordance patterns between the host mitochondrial and nuclear phylogenies, and in some cases to speciation. Here, we used theMultiLocus Sequence Typing system, to identify and characterize five Wolbachia strains infecting several species within the Nanos clypeatus dung beetle clade. We discuss the implications of these Wolbachia strains for the evolution and diversification of their dung beetle hosts in Madagascar.Peer reviewe

Wolbachia in the genus Bicyclus : a forgotten player

Bicyclus butterflies are key species for studies of wing pattern development, phenotypic plasticity, speciation and the genetics of Lepidoptera. One of the key endosymbionts in butterflies, the alpha-Proteobacterium Wolbachia pipientis, is affecting many of these biological processes; however, Bicyclus butterflies have not been investigated systematically as hosts to Wolbachia. In this study, we screen for Wolbachia infection in several Bicyclus species from natural populations across Africa as well as two laboratory populations. Out of the 24 species tested, 19 were found to be infected, and no double infection was found, but both A- and B-supergroup strains colonise this butterfly group. We also show that many of the Wolbachia strains identified in Bicyclus butterflies belong to the ST19 clonal complex. We discuss the importance of our results in regard to routinely screening for Wolbachia when using Bicyclus butterflies as the study organism of research in eco-evolutionary biology.Peer reviewe

Uncovering the hidden players in Lepidoptera biology: the heritable microbial endosymbionts

The Lepidoptera is one of the most widespread and recognisable insect orders. Due to their remarkable diversity, economic and ecological importance, moths and butterflies have been studied extensively over the last 200 years. More recently, the relationship between Lepidoptera and their heritable microbial endosymbionts has received increasing attention. Heritable endosymbionts reside within the host’s body and are often, but not exclusively, inherited through the female line. Advancements in molecular genetics have revealed that host-associated microbes are both extremely prevalent among arthropods and highly diverse. Furthermore, heritable endosymbionts have been repeatedly demonstrated to play an integral role in many aspects of host biology, particularly host reproduction. Here, we review the major findings of research of heritable microbial endosymbionts of butterflies and moths. We promote the Lepidoptera as important models in the study of reproductive manipulations employed by heritable endosymbionts, with the mechanisms underlying male-killing and feminisation currently being elucidated in both moths and butterflies. We also reveal that the vast majority of research undertaken of Lepidopteran endosymbionts concerns Wolbachia. While this highly prevalent bacteria is undoubtedly important, studies should move towards investigating the presence of other, and interacting endosymbionts, and we discuss the merits of examining the microbiome of Lepidoptera to this end. We finally consider the importance of understanding the influence of endosymbionts under global environmental change and when planning conservation management of endangered Lepidoptera species.Peer reviewe

One’s trash is someone else’s treasure: sequence read archives from Lepidoptera genomes provide material for genome reconstruction of their endosymbionts

Background Maternally inherited bacterial symbionts are extremely widespread in insects. They owe their success to their ability to promote their own transmission through various manipulations of their hosts’ life-histories. Many symbionts however very often go undetected. Consequently, we have only a restricted idea of the true symbiont diversity in insects, which may hinder our understanding of even bigger questions in the field such as the evolution or establishment of symbiosis. Results In this study, we screened publicly available Lepidoptera genomic material for two of the most common insect endosymbionts, namely Wolbachia and Spiroplasma, in 1904 entries, encompassing 106 distinct species. We compared the performance of two screening software, Kraken2 and MetaPhlAn2, to identify the bacterial infections and using a baiting approach we reconstruct endosymbiont genome assemblies. Of the 106 species screened, 20 (19%) and nine (8.5%) were found to be infected with either Wolbachia or Spiroplasma, respectively. Construction of partial symbiotic genomes and phylogenetic analyses suggested the Wolbachia strains from the supergroup B were the most prevalent type of symbionts, while Spiroplasma infections were scarce in the Lepidoptera species screened here. Conclusions Our results indicate that many of the host-symbiont associations remain largely unexplored, with the majority of associations we identify never being recorded before. This highlights the usefulness of public databases to explore the hidden diversity of symbiotic entities, allowing the development of hypotheses regarding host-symbiont associations. The ever-expanding genomic databases provide a diverse databank from which one can characterize and explore the true diversity of symbiotic entities.Peer reviewe

One’s trash is someone else’s treasure: sequence read archives from Lepidoptera genomes provide material for genome reconstruction of their endosymbionts

Background Maternally inherited bacterial symbionts are extremely widespread in insects. They owe their success to their ability to promote their own transmission through various manipulations of their hosts’ life-histories. Many symbionts however very often go undetected. Consequently, we have only a restricted idea of the true symbiont diversity in insects, which may hinder our understanding of even bigger questions in the field such as the evolution or establishment of symbiosis. Results In this study, we screened publicly available Lepidoptera genomic material for two of the most common insect endosymbionts, namely Wolbachia and Spiroplasma, in 1904 entries, encompassing 106 distinct species. We compared the performance of two screening software, Kraken2 and MetaPhlAn2, to identify the bacterial infections and using a baiting approach we reconstruct endosymbiont genome assemblies. Of the 106 species screened, 20 (19%) and nine (8.5%) were found to be infected with either Wolbachia or Spiroplasma, respectively. Construction of partial symbiotic genomes and phylogenetic analyses suggested the Wolbachia strains from the supergroup B were the most prevalent type of symbionts, while Spiroplasma infections were scarce in the Lepidoptera species screened here. Conclusions Our results indicate that many of the host-symbiont associations remain largely unexplored, with the majority of associations we identify never being recorded before. This highlights the usefulness of public databases to explore the hidden diversity of symbiotic entities, allowing the development of hypotheses regarding host-symbiont associations. The ever-expanding genomic databases provide a diverse databank from which one can characterize and explore the true diversity of symbiotic entities.Peer reviewe

Wideband reconfigurable vector antenna for 3-D direction finding application

Direction finding plays a crucial role in various civilian and military applications, related to either radionavigation or radiolocation. Most of the direction finding antennas operate over a wide frequency band, but only a minority of them enable the direction of arrival estimation of an incoming electromagnetic field over a 3-D angular coverage (i.e., estimation of both azimuth and elevation angles). An original approach to obtain a 3-D angular coverage consists in measuring the six components of the incident electromagnetic field through a so-called vector antenna. The aim of this Ph.D. is to design a passive, compact and wideband vector antenna in order to cover a maximum of applications. Two vector antennas have been designed, manufactured and experimentally characterized. Unlike conventional topology, they enable the measurement of the components of an incoming electromagnetic field thanks to the radiation pattern reconfigurability of an original arrangement of Vivaldi antennas. The first prototype is mounted over a finite metallic support and enables the direction of arrival estimation of vertically-polarized electromagnetic fields over a 1.69:1 bandwidth while the second one can be used regardless of the polarization of the incoming electromagnetic fields over a 8:1 bandwidth. Moreover, the direction finding performances of these vector antennas have been improved in terms of estimation accuracy, sensitivity, robustness to angular ambiguity and polarization mismatch by synthesizing new radiation patterns in the estimation process. A method based on the Cramer-Rao lower bound has been proposed to select efficiently and rapidly the additional radiation pattern

Exploring bycatch diversity of organisms in whole genome sequencing of Erebidae moths (Lepidoptera)

Models estimate that up to 80% of all butterfly and moth species host vertically transmitted endosymbiotic microorganisms, which can affect the host fitness, metabolism, reproduction, population dynamics, and genetic diversity, among others. The supporting empirical data are however currently highly biased towards the generally more colourful butterflies, and include less information about moths. Additionally, studies of symbiotic partners of Lepidoptera predominantly focus on the common bacterium Wolbachia pipientis, while infections by other inherited microbial partners have more rarely been investigated. Here, we mine the whole genome sequence data of 47 species of Erebidae moths, with the aims to both inform on the diversity of symbionts potentially associated with this Lepidoptera group, and discuss the potential of metagenomic approaches to inform on host associated microbiome diversity. Based on the result of Kraken2 and MetaPhlAn2 analyses, we found clear evidence of the presence of Wolbachia in four species. Our result also suggests the presence of three other bacterial symbionts (Burkholderia spp., Sodalis spp. and Arsenophonus spp.) in three other moth species. Additionally, we recovered genomic material from bracovirus in about half of our samples. The detection of the latter, usually found in mutualistic association to braconid parasitoid wasps, may inform on host-parasite interactions that take place in the natural habitat of the Erebidae moths, suggesting either contamination with material from species of the host community network, or horizontal transfer of members of the microbiome between interacting species.Peer reviewe

Observations sur l'usage des noms en -ίδης et en -άδης aux époques archaïque et classique

International audienceLes problèmes de définition des élites grecques ne manquent pas. Pour beaucoup d'historiens, la noblesse de naissance (eugeneia) aurait assuré pendant plusieurs siècles la survie d'une nobilitas archaïque. Il existerait donc des lignées d'aristocrates. Celles-ci seraient aussi fréquentes que les multiples noms en -ίδαι et en -άδαι qui apparaissent dans les sources antiques. La contribution offre une enquête générale sur les noms en -ίδης et en -άδης et sur leur signification aux époques archaïque et classique. Après une enquête lexicologique aussi large que possible, les occurrences peuvent être réparties en six catégories distinctes, qui se justifient tant du point de vue sémantique qu'historique : patronymes, anthroponymes, lignages, toponymes, subdivisions du corps civique et associations professionnelles. L'abondance des termes en -ίδης et en -άδης témoigne tout d'abord de l'importance du schème gentilice aux époques archaïque et classique pour penser l'existence de nombreuses entités sociales, mais aussi pour définir les relations - d'équivalence ou de hiérarchie - que les individus entretenaient. Toutefois, l'apparence familiale de ces groupes, voire leur réalité gentilice, ne renvoie nullement à une société aristocratique. Le nombre de noms en -ίδαι ou -άδαι désignant sans ambiguïté des "grandes familles" historiques est en effet particulièrement restreint face à l'ensemble des autres catégories

Preliminary Investigation of Rare Earth Elements Ion Exchange on Zeolites

Found together in nature, the isolation of rare earth elements (REEs) has always been challenging. Their separation usually involves processes including solvent extraction, precipitation and ion exchange. Zeolites are well-known for their ion exchange capabilities that would be potentially applicable for the REEs separation. This study primarily investigated the ion exchange behavior of REEs onto several types of zeolites, namely the Ferrierite, the Faujasite and the Linde Type L. These zeolites were chosen because of their altered framework type and controllable charge density through synthesis. The commercially available zeolites were systematically characterized by means of X-Ray Diffraction (XRD), Energy Dispersive X-ray spectroscopy (EDX) and Attenuated Total Reflectance Fourier Transform Infrared spectroscopy (ATR-FTIR). Lanthanum was chosen as the model REE. The pH-uptake behavior of La on zeolites was studied extensively. Results showed that among all our selected zeolites, only LTL gave reasonable amount of La ion exchange capacity (0.16 mmol/g at pH 3). Subsequently, the ion exchange isotherm of La on LTL was described at pH 3. The isotherm followed Langmuir type with a maximum capacity of 0.25 mmol/g. An equimolar ternary mixture of lanthanum, neodymium and dysprosium was used to test the selectivity of LTL zeolite towards different REEs. Results suggested that the uptake sequence followed La > Nd > Dy, which indicated the decrease of capacity with increased atomic number. Almost all the REEs could be leached off from the REE loaded zeolites with a pH 1.51 nitric acid solution