17 research outputs found

    Coevolution of avian ectoparasites in the tropics

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    Host-parasite associations are born by cospeciations or by host switches. Feather lice have traditionally been used as model parasites for studying these events and underlying ecological factors. By now tens of analyses have addressed comparisons of host and parasite phylogenies to study cospeciations and host switches in lice, however, these analyses are strongly biased towards the temperate zone. Tropical environment could provide new insight into the origin of host-parasite interactions, because it is ecologically unique. This work aims to supplement the knowledge of host-parasite associations in lice using coevolution analyses of two feather lice genera and their passerine hosts in tropical rainforest in Cameroon. It shows that lice in the tropics cospeciate rarely. To assess whether host switches are non-random and occur preferentially between hosts with specific traits, this work also analyses relations between parasite genetic distances and hosts' trait similarities. No effect of host morphology and spatial distribution was found. However, genetic distances of the lice strongly correlate with genetic distances of their hosts

    Cospeciation of bird ectoparasites

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    In a case when two taxa are ecologically very closely related, speciation in one of them may induce speciation in the other one. This phenomenon is called cospeciation. Host specific parasites and their hosts are one of the systems where cospeciation has been frequently studied. Birds and their ectoparasites traditionally serve as a model system. Up to now dozens of cospeciation studies have been done on birds and their ectoparasites by comparing their phylogenetic trees. This work reviews the results of these studies and evaluates the possible effect of ecological and other factors. Cospeciation appears to take place often among birds and their permanent ectoparasites. 64% of the performed studies showed significant cospeciation. The rate of cospeciation varies greatly between different taxa. Some ecological aspects seem to play prominent role, especially those that provide dispersal opportunities to parasites

    Coevolution of avian ectoparasites in the tropics

    No full text
    Host-parasite associations are born by cospeciations or by host switches. Feather lice have traditionally been used as model parasites for studying these events and underlying ecological factors. By now tens of analyses have addressed comparisons of host and parasite phylogenies to study cospeciations and host switches in lice, however, these analyses are strongly biased towards the temperate zone. Tropical environment could provide new insight into the origin of host-parasite interactions, because it is ecologically unique. This work aims to supplement the knowledge of host-parasite associations in lice using coevolution analyses of two feather lice genera and their passerine hosts in tropical rainforest in Cameroon. It shows that lice in the tropics cospeciate rarely. To assess whether host switches are non-random and occur preferentially between hosts with specific traits, this work also analyses relations between parasite genetic distances and hosts' trait similarities. No effect of host morphology and spatial distribution was found. However, genetic distances of the lice strongly correlate with genetic distances of their hosts.Vazby parazitických druhů na druhy hostitelské vznikají dvěma způsoby: kospeciací hostitelským přeskokem. K výzkumu těchto událostí a ekologických faktorů, které jejich frekvenci mohou ovlivňovat, jsou tradičně využívány jako modelová skupina všenky. Doposud byly provedeny desítky analýz zkoumajících kospeciace a hostitelské přeskoky srovnáváním fylogenezí všenek a hostitelů, téměř výhradně se však zaměřovaly na parazity mírného pásma. Tropické prostředí, které je ekologicky velmi unikátní, by parazitických asociací. Tato práce proto doplňuje poznatky o kospeciacích tropech analýzou proběhlé koevoluce mezi dvěma rody všenek a pralesa v Kamerunu. Ukazuje, že všenky v tropech kospeciují poměrně vzácně. Na základě předpokladu, že hostitelské přeskoky, které jsou v tropech zřejmě častější než kospeciace, neprobíhají zcela náhodně, ale preferenčně na hostitele, kteří disponují určitými vlastnostmi, dále e analyzuje, zda příbuznost všenek souvisí s určitými vzájemnými podobnostmi jejich hostitelů. Nebyl nalezen vliv morfologie ani prostorového rozšíření hostitelů, nicméně příbuznost všenek silně souvisí s příbuzností hostitelů a tento jev je výrazně patrný obzvláště v některýchKatedra zoologieDepartment of ZoologyFaculty of SciencePřírodovědecká fakult

    Community metabarcoding uncovers vast diversity and a lack of barcode references for aquatic invertebrates in Carpathian spring fens

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    Recent studies on diversity of stream amphipods proposed that the Western Carpathians have served as an important glacial refugium of freshwater fauna. If this scenario is true, a considerably high molecular diversity can be expected in this biogeographic region also for other taxa. In our project, we aimed to uncover and characterize molecular diversity of benthic macroinvertebrate fauna of spring fens, a well studied and hence convenient model community. Using a DNA metabarcoding approach, we sequenced a fragment of the COI gene of pooled spring fen invertebrate communities from 21 localities in the Western Carpathians. The preliminary analysis of the sequences revealed a substantially higher amount of operational taxonomic units (OTUs), when compared to the number of taxa identified in the same spring fens based on morphological characters. The lack of reference sequences in public databases (Barcoding of Life Database, GenBank) for the majority of the detected OTUs indicates that the Western Carpathian region is not yet sufficiently covered by barcoding efforts, and suggests that there indeed may be a considerable unrecognized diversity of macrozoobenthos. However, most newly uncovered diversity is concentrated in a few taxa such as the dipteran families Tabanidae and Ceratopogonidae, annelid species (complexes) Eiseniella tetraedra and Helobdella stagnalis or the amphipod genus Gammarus. In the future, these findings will be the basis for several levels of research: detailed investigation of seemingly hyperdiverse taxa (phylogeography, phylogeny, reference coverage) and comparison of overall molecular diversity of these communities in the Western Carpathians and neighbouring Bohemian Massif, a region where we expect much lower diversity due to different biogeographic history

    Polyacrylamide brushes with varied morphologies as a tool for control of the intermolecular interactions within EPDM/MVQ blends

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    The specific interactions between polyacrylamide brushes composed of polyacrylamide chains tethered to montmorillonite particles (Mt-g-PAm) and the individual components of immiscible ethylene-propylene-diene modified with sorbic acid (EPDM) and methyl vinyl silicone (MVQ) blends were studied. The effect of various lengths of PAm chains and their grafting density on montmorillonite (Mt) surface was investigated. It was determined that, due to interactions generated within the system through carboxyl and amide groups the brush particles were selectively located at the EPDM/MVQ interphase and in the EPDM phase. Furthermore, the longer PAm chains resulted in an increase of the glass transition of EPDM, unification of blend morphology, and the reduction of crystallinity of the MVQ phase. Therefore, precisely designed polymer brushes could be considered as novel functional compatibilizers, that provide a new tool for the future material designing. © 2021 Elsevier LtdNational Science Centre, PolandNational Science Center, PolandNational Science Centre, Poland [UMO-2016/23/P/ST5/02131]; European UnionEuropean Commission [665778]; Ministry of Education, Youth and Sports of the Czech republic -DKRVO [RP/CPS/2020/003]; Research & Innovation Operational Programme - ERDF [313021T081]; [VEGA 2/0129/19]; [APVV-19-0338]665778; UMO-2016/23/P/ST5/02131; Slovenská Akadémia Vied, SAV: 313021T081; Ministerstvo Školství, Mládeže a Tělovýchovy, MŠMT: RP/CPS/2020/003; Narodowe Centrum Nauki, NCN; European Regional Development Fund, FEDER: APVV-19-0338, VEGA 2/0129/1

    Activity of stygobionts in spring habitats: behavioral, ecological and evolutionary insights

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    Cave-dwelling animals might be regarded as dead-end points when it comes to their evolution and habitat exploitation. However, in the past different observations of the olms’ typical troglomorphic populations have been reported for springs of Venetia Giulia, along with a community rich in stygobionts (Bressi et al. 1999; Stoch 2017). The aim of this work is to point out the non-random active use of surface habitats by this community, providing a comparison with the occurrence observed in caves and performing an assessment of factors favouring ecotone habitats exploitation. Since 2020 we started multiple day and night surveys of olms in both 71 springs and 11 caves. Each spring and cave habitat monitored has been characterised by respect to abiotic and biotic features, including planktonic and benthic prey availability. Additionally, cave and spring populations of Troglocaris sp. were tested to determine whether they showed any behavioral differenceregarding their response to light stimuli and predatory cues, as potential adaptations to the different conditions found in the two habitats. We used 34 individuals sampled from three springs and 24 from two caves of the Italian karst. We detected the olm at least once in 12 springs, with a maximum of 9 individuals occurring together. Detection probability in springs and caves was similar. Spring habitats provided higher density of potential prey available. Olms seem to prefer springs without predator fish and temporary hydroperiod. We recorded in one spring a larva of 3.5 cm which could be the smallest ever recorded in the field. Preliminary results of the behavioral experiments show no susceptibility to light neither for spring nor cave populations of Troglocaris sp., as for chemical cues we expect a difference in reactivity depending on the habitat of origin of the shrimp, consistently with the top predator present. We suggest that epigean habitats and borders with surface may have an underestimated importance for animals adapted to subterranean environments (Manenti and Piazza 2021),including the olm. Further studies focusing on the ipogean community which actively exploits spring habitats are underway, with the aim of determining the diel occupation of these complex ecotones

    Results of the 2022 ECFA Early-Career Researchers Panel survey on career prospects and diversity

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    International audienceThis document presents the outcomes of a comprehensive survey conducted among early career researchers (ECRs) in academic particle physics. Running from September 24, 2022, to March 3, 2023, the survey gathered responses from 759 ECRs employed in 39 countries. The study aimed to gain insights into the career prospects and experiences of ECRs while also delving into diversity and sociological aspects within particle physics research. The survey results are presented in a manner consistent with the survey choices. The document offers insights for the particle physics community, and provides a set of recommendations for enhancing career prospects, fostering diversity, and addressing sociological dimensions within this field

    Expanding ecological assessment by integrating microorganisms into routine freshwater biomonitoring

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    Bioindication has become an indispensable part of water quality monitoring in most countries of the world, with the presence and abundance of bioindicator taxa, mostly multicellular eukaryotes, used for biotic indices. In contrast, microbes (bacteria, archaea and protists) are seldom used as bioindicators in routine assessments, although they have been recognized for their importance in environmental processes. Recently, the use of molecular methods has revealed unexpected diversity within known functional groups and novel metabolic pathways that are particularly important in energy and nutrient cycling. In various habitats, microbial communities respond to eutrophication, metals, and natural or anthropogenic organic pollutants through changes in diversity and function. In this review, we evaluated the common trends in these changes, documenting that they have value as bioindicators and can be used not only for monitoring but also for improving our understanding of the major processes in lotic and lentic environments. Current knowledge provides a solid foundation for exploiting microbial taxa, community structures and diversity, as well as functional genes, in novel monitoring programs. These microbial community measures can also be combined into biotic indices, improving the resolution of individual bioindicators. Here, we assess particular molecular approaches complemented by advanced bioinformatic analysis, as these are the most promising with respect to detailed bioindication value. We conclude that microbial community dynamics are a missing link important for our understanding of rapid changes in the structure and function of aquatic ecosystems, and should be addressed in the future environmental monitoring of freshwater ecosystems

    The ECFA Early Career Researcher's Panel: composition, structure, and activities, 2021 -- 2022

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    The European Committee for Future Accelerators (ECFA) Early Career Researcher's (ECR) panel, which represents the interests of the ECR community to ECFA, officially began its activities in January 2021. In the first two years, the panel has defined its own internal structure, responded to ECFA requests for feedback, and launched its own initiatives to better understand and support the diverse interests of early career researchers. This report summarises the panel composition and structure, as well as the different activities the panel has been involved with during the first two years of its existence

    The ECFA Early Career Researcher's Panel: composition, structure, and activities, 2021 -- 2022

    No full text
    The European Committee for Future Accelerators (ECFA) Early Career Researcher's (ECR) panel, which represents the interests of the ECR community to ECFA, officially began its activities in January 2021. In the first two years, the panel has defined its own internal structure, responded to ECFA requests for feedback, and launched its own initiatives to better understand and support the diverse interests of early career researchers. This report summarises the panel composition and structure, as well as the different activities the panel has been involved with during the first two years of its existence
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