716 research outputs found
Microcondylaea bonellii as a new host for the European bitterling Rhodeus amarus
We report for the first time that the freshwater mussel Microcondylaea bonellii (Ferussac, 1827) functions as a suitable host for the European bitterling Rhodeus amarus (Bloch, 1782). Given the recent expansion of R. amarus in Europe, the possible physiological cost (e.g. competition for oxygen, reduction in water circulation, and consequent impairment of filter-feeding) of this interaction may further affect the already poor conservation status of M. bonellii populations.We acknowledge the two anonymous referees for the helpful suggestions that improve the clarity of our manuscript. This research was funded by FCT under project ConBiomics No NORTE-01-0145-FEDER-030286, cofinanced by COMPETE 2020, Portugal 2020 and the European Union through the ERDF
Cryptotomography: reconstructing 3D Fourier intensities from randomly oriented single-shot diffraction patterns
We reconstructed the 3D Fourier intensity distribution of mono-disperse
prolate nano-particles using single-shot 2D coherent diffraction patterns
collected at DESY's FLASH facility when a bright, coherent, ultrafast X-ray
pulse intercepted individual particles of random, unmeasured orientations. This
first experimental demonstration of cryptotomography extended the
Expansion-Maximization-Compression (EMC) framework to accommodate unmeasured
fluctuations in photon fluence and loss of data due to saturation or background
scatter. This work is an important step towards realizing single-shot
diffraction imaging of single biomolecules.Comment: 4 pages, 4 figure
Diversity, biogeography, evolutionary relationships, and conservation of Eastern Mediterranean freshwater mussels (Bivalvia: Unionidae)
Located at the junction between Europe, Africa, and Asia, with distinct evolutionary origins and varied ecological and geographical settings, together with a marked history of changes in orogeny and configuration of the main river basins, turned the Eastern Mediterranean into a region of high diversity and endemism of freshwater taxa. Freshwater mussels (Bivalvia, Unionidae) from the Western Palearctic have been widely studied in their European range, but little attention has been dedicated to these taxa in the Eastern Mediterranean region and their diversity and phylogeography are still poorly understood. The present study aims to resolve the diversity, biogeography, and evolutionary relationships of the Eastern Mediterranean freshwater mussels. To that end, we performed multiple field surveys, phylogenetic analyses, and a thorough taxonomic revaluation. We reassessed the systematics of all Unionidae species in the region, including newly collected specimens across Turkey, Israel, and Iran, combining COI+16S+28S phylogenies with molecular species delineation methods. Phylogeographical patterns were characterized based on published molecular data, newly sequenced specimens, and species distribution data, as well as ancestral range estimations. We reveal that Unionidae species richness in the Eastern Mediterranean is over 70% higher than previously assumed, counting 19 species within two subfamilies, the Unioninae (14) and Gonideinae (5). We propose two new species, Anodonta seddoni sp. nov. and Leguminaia anatolica sp. nov. Six additional taxa, Unio delicatus stat. rev., Unio eucirrus stat. rev., Unio hueti stat. rev., Unio sesirmensis stat. rev., Unio terminalis stat. rev. removed from the synonymy of Unio tigridis, as well as Unio damascensis stat. rev. removed from the synonymy of Unio crassus, are re-described. The nominal taxa Unio rothi var. komarowi O. Boettger, 1880 and Unio armeniacus Kobelt, 1911 are proposed as new synonyms of Unio bruguierianus, and Anodonta cyrea Drouët, 1881 and Anodonta cilicica Kobelt & Rolle, 1895 as new synonyms of Anodonta anatina. Also, the presence of Unio tumidus in the Maritza River is confirmed. The phylogeographic patterns described here are interpreted concerning major past geological events. Conservation needs and implications are presented, together with populations and species conservation priorities
Complete mitochondrial genomes of the freshwater mussels Amblema plicata (Say, 1817), Pleurobema oviforme (Conrad, 1834), and Popenaias popeii (Lea, 1857) (Bivalvia: Unionidae: Ambleminae)
Freshwater mussels are a critically imperiled group of mollusks that play key ecological roles and provide important services to humans. The Ambleminae is the only subfamily of these mussels, endemic to North America. Complete mitogenomes have only been sequenced for two of five tribes of the subfamily. Pleurobema oviforme, Amblema plicata, and Popenaias popeii each belong to tribes Pleurobemini, Amblemini, and Popenaidini, respectively, and have not had published mitogenomes. Thus, this study aims to present the complete mitogenomes for these species, to provide a phylogeny of the Ambleminae and confirm the gene arrangements with representation from each of its tribes. The newly sequenced mitogenomes range from 15,852 to 15,993 nucleotides, are composed of 13 PCGs, 22 tRNAs, and two rRNAs and all share the same (UF1) gene order.This work was supported by Portuguese Foundation for Science and
Technology (FCT) [grant number ConBioMics/BI-Lic/2019-037 (JTT), grant
number SFRH/BD/137935/2018 (AGS)]; COMPETE 2020, Portugal 2020
and the European Union through the ERDF, and by Portuguese
Foundation for Science and Technology (FCT) through national funds
[UID/Multi/04423/2019] under project ConBiomics: the missing approach
for the Conservation of Bivalves Project, and [project number NORTE-01-
0145-FEDER-030286]. Fieldwork in Texas was funded by the U.S. Fish and Wildlife Service, and Texas Parks and Wildlife Department (TPWD) as a Joint Traditional Section 6 Project 407348.info:eu-repo/semantics/publishedVersio
Expansion and systematics redefinition of the most threatened freshwater mussel family, the Margaritiferidae.
Two Unionida (freshwater mussel) families are present in the Northern Hemisphere; the Margaritiferidae, representing the most threatened of unionid families, and the Unionidae, which include several genera of unresolved taxonomic placement. The recent reassignment of the poorly studied Lamprotula rochechouartii from the Unionidae to the Margaritiferidae motivated a new search for other potential species of margaritiferids from members of Gibbosula and Lamprotula. Based on molecular and morphological analyses conducted on newly collected specimens from Vietnam, we here assign Gibbosula crassa to the Margaritiferidae. Additionally, we reanalyzed all diagnostic characteristics of the Margaritiferidae and examined museum specimens of Lamprotula and Gibbosula. As a result, two additional species are also moved to the Margaritiferidae, i.e. Gibbosula confragosa and Gibbosula polysticta. We performed a robust five marker phylogeny with all available margaritiferid species and discuss the taxonomy within the family. The present phylogeny reveals the division of Margaritiferidae into four ancient clades with distinct morphological, biogeographical and ecological characteristics that justify the division of the Margaritiferidae into two subfamilies (Gibbosulinae and Margaritiferinae) and four genera (Gibbosula, Cumberlandia, Margaritifera, and Pseudunio). The systematics of the Margaritiferidae family is re-defined as well as their distribution, potential origin and main biogeographic patterns
The male and female complete mitochondrial genomes of the threatened freshwater pearl mussel Margaritifera margaritifera (Linnaeus, 1758) (Bivalvia: Margaritiferidae)
The complete mitogenomes of one (M-)ale (North America), one Hermaphroditic (Europe), and two (F-)emale (North America and Europe) individuals of the freshwater pearl mussel Margaritifera margaritifera were sequenced. The M-type and F-type (Female and Hermaphroditic) mitogenomes have 17,421 and 16,122 nucleotides, respectively. All with the same content: 13 protein-coding genes, 22 transfer RNA, two ribosomal RNA genes, and one sex-related ORF. The M-type is highly divergent (37.6% uncorrected p-distance) from the F-type mitogenomes. North American and European F-type mitogenomes exhibit low genetic divergence (68 nt substitutions), and the Female and Hermaphroditic European mitogenomes are almost identical, and matching sex-related ORFs.This work was supported by Portuguese Foundation for Science and Technology (FCT) [grant number SFRH/BD/115728/2016 (MLL), grant number SFRH/BD/137935/2018 (AGS)]; Russian Foundation for Basic Research [grant number 18-34-20033 (IVV)]; Dawson Fellowship at St. Catharine's College, Cambridge (DCA); Life Margal Ulla [number LIFE09 NAT/ES/000514 (RA and PO)]; COMPETE 2020, Portugal 2020 and the European Union through the ERDF, and by Portuguese Foundation for Science and Technology (FCT) through national funds [UID/Multi/04423/2019] under project ConBiomics: the missing approach for the Conservation of freshwater Bivalves Project, and [project number NORTE-01-0145-FEDER-030286]; Federal Agency for Scientific Organizations under Grants [grant number 0409-2015-0143 (INB and IVV)
EphA2 is a functional receptor for the growth factor progranulin.
Although the growth factor progranulin was discovered more than two decades ago, the functional receptor remains elusive. Here, we discovered that EphA2, a member of the large family of Ephrin receptor tyrosine kinases, is a functional signaling receptor for progranulin. Recombinant progranulin bound with high affinity to EphA2 in both solid phase and solution. Interaction of progranulin with EphA2 caused prolonged activation of the receptor, downstream stimulation of mitogen-activated protein kinase and Akt, and promotion of capillary morphogenesis. Furthermore, we found an autoregulatory mechanism of progranulin whereby a feed-forward loop occurred in an EphA2-dependent manner that was independent of the endocytic receptor sortilin. The discovery of a functional signaling receptor for progranulin offers a new avenue for understanding the underlying mode of action of progranulin in cancer progression, tumor angiogenesis, and perhaps neurodegenerative diseases
Climatic aridity increases temporal nestedness of invertebrate communities in naturally drying rivers
Climate change is altering the water cycle globally, increasing the frequency and magnitude of floods and droughts. An outstanding question is whether biodiversity responses to hydrological disturbance depend on background climatic context â and if so, which contexts increase vulnerability to disturbance. Answering this question requires comparison of organismal responses across environmental gradients. However, opportunities to track disturbed communities against an undisturbed baseline remain rare. Here we gathered a global dataset capturing responses of aquatic invertebrate communities to river drying, which includes 112 sites spanning a gradient of climatic aridity. We measured the effects of river drying on taxonomic richness and temporal ÎČâdiversity (turnover and nestedness components). We also measured the relative abundance of aquatic invertebrates with strategies that confer resilience (or resistance) to drying. Contrary to our expectations, we found that taxonomic richness recovered from drying similarly across the aridity gradient. The turnover component of ÎČâdiversity (i.e. species replacements over time) largely accounted for differences in community composition before versus after drying. However, increasing aridity was associated with greater nestednessâdriven compositional changes at intermittent sites â that is, after drying communities became subsets of those before drying. These results show that climatic context can explain variation in community responses to the same hydrological disturbance (drying), and suggest that increased aridity will constrain biodiversity responses at regional scales. Further consideration of the climatic context in hydroecological research may help improve predictions of the local impacts of hydrological disturbance by identifying climate regions where communities are more (or less) sensitive to extremes, including river drying events
Induced pseudoscalar coupling of the proton weak interaction
The induced pseudoscalar coupling is the least well known of the weak
coupling constants of the proton's charged--current interaction. Its size is
dictated by chiral symmetry arguments, and its measurement represents an
important test of quantum chromodynamics at low energies. During the past
decade a large body of new data relevant to the coupling has been
accumulated. This data includes measurements of radiative and non radiative
muon capture on targets ranging from hydrogen and few--nucleon systems to
complex nuclei. Herein the authors review the theoretical underpinnings of
, the experimental studies of , and the procedures and uncertainties
in extracting the coupling from data. Current puzzles are highlighted and
future opportunities are discussed.Comment: 58 pages, Latex, Revtex4, prepared for Reviews of Modern Physic
X ray emission spectroscopy of bulk liquid water in no man s land
The structure of bulk liquid water was recently probed by x ray scattering below the temperature limit of homogeneous nucleation TH of amp; 8764;232 K [J. A. Sellberg et al., Nature 510, 381 384 2014 ]. Here, we utilize a similar approach to study the structure of bulk liquid water below TH using oxygen K edge x ray emission spectroscopy XES . Based on previous XES experiments [T. Tokushima et al., Chem. Phys. Lett. 460, 387 400 2008 ] at higher temperatures, we expected the ratio of the 1b1 amp; 8242; and 1b1 amp; 8242; amp; 8242; peaks associated with the lone pair orbital in water to change strongly upon deep supercooling as the coordination of the hydrogen H bonds becomes tetrahedral. In contrast, we observed only minor changes in the lone pair spectral region, challenging an interpretation in terms of two interconverting species. A number of alternative hypotheses to explain the results are put forward and discussed. Although the spectra can be explained by various contributions from these hypotheses, we here emphasize the interpretation that the line shape of each component changes dramatically when approaching lower temperatures, where, in particular, the peak assigned to the proposed disordered component would become more symmetrical as vibrational interference becomes more importan
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