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Benthic foraminiferal composition assemblages and their temporal changes, ecological indices and foraminiferal densities are used to compare three coastal environments with different physicogeographical features in the Aegean Sea (coastal environment of Avdira–Vistonikos Gulf and Kitros–Thermaikos Gulf and open lagoonal environment of Vravron–South Evoikos Gulf). Three main foraminiferal assemblages have been recognized: a) “Assemblage A”; high degree of similarity between living and dead foraminiferal species, dominated by Ammonia beccarii, Elphidium spp. and relatively abundant and diverse miliolids, b) “Assemblage B1”; intermediate degree of similarity between live and dead assemblages, characterized by highly-abundant and well-diversified foraminiferal assemblages including the algal symbiont bearing Peneroplis pertusus together with Ammonia tepida and several small epiphytic rotaliids and miliolids, and c) “Assemblage B2”; absence of living individuals, strongly dominated by the opportunistic species A. tepida. Our results suggest a good comparison between living and dead assemblages from different coastal environments in the Aegean Sea, however the prevailing environmental conditions (vegetation cover, hydrodynamics, fresh water influx) have a strong impact on the taphonomic processes.  相似文献   

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Sex and temporal differences are assessed in relation to dietary habits and activity patterns in three ancient populations from Corinth, Greece. The skeletal sample spans time from the Geometric to the Early Byzantine Period (9th c. BCE-5th c. CE). Dental caries and tooth wear have been proven to be reliable dietary indicators. Similarly, spinal osteoarthritis, spinal facet remodeling and Schmorl’s nodes, have been used to infer activity patterns.  相似文献   

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The benthic environment in the Gulf of Cadiz, north-eastern Atlantic, is strongly affected by the Mediterranean outflow water undercurrent (MOW) which flows northwards along the western Iberian Margin at 500–1500 m water depth. Foraminiferal census counts of living and dead assemblages from 27 surface samples ranging from 103 to 1917 m water depth, and the examination of hard substrates reveal a close correlation of the fauna with the local hydrography and sediment facies. Four different faunal groups are separated by factor analysis of the living fauna. Assemblage 1 contains typical lower slope species and dominates samples from the lower MOW core layer and in the North Atlantic deep water below. Shelf edge foraminifera are common in assemblage 2a which shows the highest proportions in samples from 103 to 272 m. Assemblage 2b is dominated by upper slope species and suspension-feeders that are frequent in the upper MOW core layer and in distal settings between 396 and 901 m. Species from assemblage 3 prefer epibenthic habitats and are recorded with high proportions exclusively in the immediate flow paths of the upper MOW between 496 and 881 m. Colonisation structures and species composition of epibenthic assemblages from the proximal facies largely differ from those in distal settings. In general, epibenthic foraminifers only use elevated substrates under the influence of near-bottom flow. Under high current velocities, epibenthic foraminifers prefer large and heavy objects. They colonise high attachment levels where a maximum yield of advected food particles can be achieved. In distal settings at lower flow velocities, the elevation height does not exceed 20 mm above the surrounding sediment surface. This level is related to a hydrologic transition layer with high concentrations of suspended particles. The comparison of microhabitat preferences and faunal structure under high and low current velocities reveal that substrate stability may be a confining environmental variable for endobenthic and shallow epibenthic foraminifers. The observations also indicate that the preferential settling height of epibenthic foraminifera is related to the highest lateral flux rates of food particles within reach from the sea floor. A dynamic selection of elevated microhabitats is only used by 7.8% of all species recognised in the Gulf of Cadiz area.  相似文献   

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Horse mackerel, Trachurus trachurus (L.), is a multiple spawning fish with most probably an indeterminate fecundity. Histological sections of gonads were used to identify the hydrated oocytes, the migratory-nucleus stage oocytes, and the new and old post-ovulatory follicles. Spawning frequency determination, based on the mean percentage estimation of the females that occurred in different spawning states such as migratory-nucleus stage oocytes and post-ovulatory follicles during two successive reproductive periods, was found to average once every 5.8 and 4.8 days, respectively. High spawning frequency was observed at the peak of spawning. Relative batch fecundity of 205 oocytes/g fish weight was estimated by the hydrated and migratory-nucleus method. Since potential annual spawnings were found to be equal to 16, potential annual relative fecundity could be 3280 oocytes/g fish weight.  相似文献   

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The wrasses (Labridae) are one of the most successful and species-rich families of the Perciformes order of teleost fish. Its members display great morphological diversity, and occupy distinct trophic levels in coastal waters and coral reefs. The cleaning behaviour displayed by some wrasses, such as corkwing wrasse (Symphodus melops), is of particular interest for the salmon aquaculture industry to combat and control sea lice infestation as an alternative to chemicals and pharmaceuticals. There are still few genome assemblies available within this fish family for comparative and functional studies, despite the rapid increase in genome resources generated during the past years. Here, we present a highly continuous genome assembly of the corkwing wrasse using PacBio SMRT sequencing (x28.8) followed by error correction with paired-end Illumina data (x132.9). The present genome assembly consists of 5040 contigs (N50?=?461,652?bp) and a total size of 614 Mbp, of which 8.5% of the genome sequence encode known repeated elements. The genome assembly covers 94.21% of highly conserved genes across ray-finned fish species. We find evidence for increased copy numbers specific for corkwing wrasse possibly highlighting diversification and adaptive processes in gene families including N-linked glycosylation (ST8SIA6) and stress response kinases (HIPK1). By comparative analyses, we discover that de novo repeats, often not properly investigated during genome annotation, encode hundreds of immune-related genes. This new genomic resource, together with the ballan wrasse (Labrus bergylta), will allow for in-depth comparative genomics as well as population genetic analyses for the understudied wrasses.  相似文献   

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The selectivity of five entomopathogens and a chemical insecticide (positive control) to pupae and adults of the egg parasitoid Telenomus remus (Nixon) was evaluated in the laboratory under controlled environmental conditions according to protocols established by the International Organization for Biological Control. Baculovirus anticarsia (Baculovirus AEE®), Bacillus thuringiensis var. kurstaki (Thuricide®), Bacillus thuringiensis var. aizawai (Agree®), Beauveria bassiana (Boveril®), Metarhizium anisopliae (Metarril®) and Trichoderma harzianum (Trichodermil®) are harmless to T. remus pupae, and adults. Thus, our results suggest that the insect control strategies applied here are compatible since entomopathogens were classified as harmless to T. remus in most examined cases and therefore facilitate a joint application to control different pests. Bacillus thuringiensis var. kurstaki (Dipel®), despite being classified as slightly harmful in some of the evaluations, can still be considered compatible for use together with T. remus, especially when compared with chemical insecticides such as chlorpyrifos that might be considered harmful to the parasitoid survival.  相似文献   

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The dynamics of phytoplankton biomass were studied in an Eastern Mediterranean semi-enclosed coastal system (Maliakos Gulf, Aegean Sea), over 1 year. In particular, chlorophyll a (chl a) was fractionated into four size classes: picoplankton (0.2–2 μm), nanoplankton (2–20 μm), microplankton (20–180 μm) and net phytoplankton (>180 μm). The spatial and temporal variation in dissolved inorganic nutrients and particulate organic carbon (POC) were also investigated. The water column was well mixed throughout the year, resulting in no differences between depths for all the measured parameters. Total chl a was highest in the inner part of the gulf and peaked in winter (2.65 μg l–1). During the phytoplankton bloom, microplankton and net phytoplankton together dominated the autotrophic biomass (67.2–95.0% of total chl a), while in the warmer months the contribution of pico- and nanoplankton was the most significant (77.5–93.4% of total chl a). The small fractions, although showing low chl a concentrations, were important contributors to the POC pool, especially in the outer gulf. No statistically significant correlations were found between any chl a size fraction and inorganic nutrients. For most of the year, phytoplankton was not limited by inorganic nitrogen concentrations. Electronic Publication  相似文献   

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According to recent studies, leucyl-tRNA synthetase (LRS) acts as a leucine sensor and modulates the activation of the mammalian target of rapamycin complex 1 (mTORC1) activation. Because overactive mTORC1 is associated with several diseases, including colon cancer, LRS-targeted mTORC1 inhibitors represent a potential option for anti-cancer therapy. In this work, we developed a series of simplified leucyladenylate sulfamate analogues that contain the N-(3-chloro-4-fluorophenyl)quinazolin-4-amine moiety to replace the adenine group. We identified several compounds with comparable activity to previously reported inhibitors and exhibited selective mTORC1 inhibition and anti-cancer activity. This study further supports the hypothesis that LRS is a promising target to modulate the mTORC1 pathway.  相似文献   

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《Marine Micropaleontology》1997,29(2):105-127
The development of benthic foraminiferal assemblages from the Paleocene outcrops of the El Haria Formation near El Kef, Tunisia is discussed qualitatively and quantitatively. The aim of the study is to reconstruct the paleoenvironmental evolution between the K/Pg boundary interval and the late Paleocene event, and to compare this evolution with results from other sites along the southern Tethyan margin. Eighty-four samples, covering virtually the entire Paleocene, provide a dataset that allows detailed qualitative and multivariate analysis. The benthic foraminiferal faunas indicate a complex pattern of environmental changes during the Paleocene, marked by the succession of different benthic associations. Following the K/Pg boundary event, community restoration was characterized by the gradual build-up of faunal diversity. Decreasing dominance and the entry of taxa common to normal marine, outer neritic to upper bathyal environments indicate the completion of the ecosystem restoration in Zone Plb. A highly diverse benthic foraminiferal assemblage persisted throughout the remainder of the early Paleocene into the earliest late Paleocene. At the P3a-P3b zonal transition relative sea-level lowering is evidenced by the sudden disappearance or decreasing abundance of deeper-water taxa (e.g. Anomalinoides affinis, A. susanaensis, Gavelinella beccariiformis). Neritic deposition continued into Zone P4, when trophic levels at the seafloor increased as indicated by the entry and increasing dominance of species such as Anomalinoides cf. aegyptiacus, Bulimina midwayensis, and B. strobila, which we consider to be sensitive to eutrophication. The combined effect of shallowing and the subsequent eutrophication led to the establishment of assemblages similar to late Paleocene benthic foraminiferal assemblages from Egyptian sections, some of which record the latest Paleocene extinction event. These assemblages were interpreted to be indicative of a middle neritic, highly eutrophic environment. Enhanced vertical fluxes of organic matter along the southern Tethyan margin may have resulted from intensified upwelling. This eventually led to oxygen deficiency at the seafloor. It appears that oxygen-deficient, high-productivity shelves were a common feature of the southern Tethyan margin during the latest Paleocene.  相似文献   

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Lactic acid bacteria, which are involved in the fermentation of vegetables, meats, and dairy products, are widely used for the productions of small organic molecules and bioactive peptides. Here, a novel acetylesterase (LaAcE) from Lactobacillus acidophilus NCFM was identified, functionally characterized, immobilized, and subjected to site-directed mutagenesis for biotechnological applications. The enzymatic properties of LaAcE were investigated using biochemical and biophysical methods including native polyacrylamide gel electrophoresis, acetic acid release, biochemical assays, enzyme kinetics, and spectroscopic methods. Interestingly, LaAcE exhibited the ability to act on a broad range of substrates including glucose pentaacetate, glyceryl tributyrate, fish oil, and fermentation-related compounds. Furthermore, immobilization of LaAcE showed good recycling ability and high thermal stability compared with free LaAcE. A structural model of LaAcE was used to guide mutational analysis of hydrophobic substrate-binding region, which was composed of Leu156, Phe164, and Val204. Five mutants (L156A, F164A, V204A, L156A/F164A, and L156A/V204A) were generated and investigated to elucidate the roles of these hydrophobic residues in substrate specificity. This work provided valuable insights into the properties of LaAcE, and demonstrated that LaAcE could be used as a model enzyme of acetylesterase in lactic acid bacteria, making LaAcE a great candidate for industrial applications.  相似文献   

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<正>Epigenetics refers to how chromatin-associated factors and reversible chromatin modifications maintain DNA-based programs by regulating the chromatin structure (Strahl and Allis,2000).In recent years,genome sequencing studies of cancer have shown that genes encoding epigenetic factors are commonly mutated in cancer(Garraway and Lander,2013).Dys regulated,or mutant,epigenetic factors influence tumorigenesis progression (Dawson and Kouzarides,  相似文献   

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Crickets belonging to Teleogryllus spp. are widely distributed in East Asia and they are difficult to distinguish. In this study, a phylogenetic tree of Teleogryllus is reconstructed by COI gene, and all species can be distinguished well. The possible evolutionary histories of male genitalia, songs and life history are discussed. The result supports establishing subgenera Macroteleogryllus and Brachyteleogryllus of Teleogryllus spp. from East Asia. T. boninensis is moved to Brachyteleogryllus. The calling song of four species includes both long and short chirps, and the rest just have single chirps. The species inhabit sympatrically trend to have different type of calling song. Egg overwinter type evolved several times independently.  相似文献   

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