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11.
BŁAŻEJ BERKOWSKI CHRISTIAN KLUG 《Lethaia: An International Journal of Palaeontology and Stratigraphy》2012,45(1):24-33
Berkowski, B & Klug, C. 2011: Lucky rugose corals on crinoid stems: unusual examples of subepidermal epizoans from the Devonian of Morocco. Lethaia, Vol. 45, pp. 24–33. In the fossil record, evidence for true epizoans, i.e. living animals inhabiting other living host‐animals, is rather rare. A host reaction is usually needed to proof the syn vivo‐settling of the epizoan. Herein, we provide a first report of such an epizoan biocoenosis from various strata of the Early Devonian of Hamar Laghdad, the world‐renowned Moroccan mud‐mound locality. In this case, solitary rugose corals settled as larvae on crinoid stems, perhaps at a spot where the epidermis was missing for some reason (injury, disease). Both the crinoid and the coral began to grow around each other. By doing so, the affected crinoid columnals formed a swelling, where ultimately only an opening slightly larger than the coral orifice remained. We discuss both macroecological and small‐scale synecological aspects of this biocoenosis. The coral profited from its elevated home because it reached into more rapid currents providing the polyp with more food than at the densely populated seafloor, which was probably covered by a coral‐meadow around the mounds and hydrothermal vents. □Corals, crinoids, Early Devonian, epizoans, Morocco, Rugosa. 相似文献
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V I Pantin N V Sats V L Surin L V Egorov G Ia Solov'ev T V Borovkova N I Grineva 《Molekuliarnaia biologiia》1991,25(1):177-184
The transport regularity of the [32P]-oligo/polynucleotides and their polyalkylating derivatives into SH2 rat cells transformed with SA7 adenovirus DNA was investigated. Derivatives penetrate the SH2 cells and their distribution in the subcellular fractions are proportional to the concentration of reagent in the medium. The transport efficiency of the derivatives is inhibited sharply with cell concentration increase and practically does not depend on the action of cell metabolism inhibitors. The data obtained assumes the mechanism of the derivatives transport to be liquid endocytosis. Being distributed in the cell components the polyalkylating derivatives were accumulated by the cell nuclei up to 10(5)-10(7) molecules per nucleus. Transport efficiency is much greater in the anchored cells than in the suspended ones. Though essential dephosphorylation of the utilized substances is observed in the SH2 cells, part of them maintain native chain length and the 5'-phosphate group after 1 h incubation in nucleic acids obtained from the cell nuclei. 相似文献
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Annemarie MM Vlaar Marinus JPG van Kroonenburgh Alfons GH Kessels Wim EJ Weber 《BMC neurology》2007,7(1):27
Background
Parkinson's disease (PD) is the second most common neurodegenerative disorder. One of the most widely used techniques to diagnose PD is a Single Photon Emission Computer Tomography (SPECT) scan to visualise the integrity of the dopaminergic pathways in the brain. Despite this there remains some discussion on the value of SPECT in the differential diagnosis of PD. We did a meta-analysis of all the existing literature on the diagnostic accuracy of both pre- and post-synaptic SPECT imaging in the differential diagnosis of PD. 相似文献14.
G Ia Solov'ev V I Pantin V L Surin E L Zhukova V M Kotel'nikov 《Molekuliarnaia genetika, mikrobiologiia i virusologiia》1989,(7):14-18
Murine fibroblasts NIH 3T3 were transfected with the plasmid pASP containing simian adenovirus oncogene insertion. Focus forming transformants were cloned with a final dilution technique and a new cell line G11 was created as a result. Transformed status of this cell line is evidenced by changes in morphology, specific cytochemical and adhesion properties, ability to grow in semisolid agar and FCS concentration growth independence. Presence of intact integrated E1a-region of adenovirus SA7 oncogene was shown by blot-hybridization technique. Transformed status of G11 cells can be explained by integration of SA7 oncogene, that is evidenced indirectly by the increased resistance to heat shock. 相似文献
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Data are presented to show that a microcomputer can be programmed to: (1) analyse a standard allergy questionnaire, (2) reliably predict the ranked order probabilities with which IgE antibody tests will produce positive results, (3) store the IgE test results, and (4) print a comprehensive report that summarises and integrates the clinical and laboratory data. Consequently, the practitioner who refers a blood sample and a questionnaire completed by the patient to a centre where both can be analysed will obtain enough practical information to decide whether to treat or refer that patient to a specialist. The microcomputer is therefore potentially of great value in any preliminary allergy investigation. 相似文献
17.
Vincent EJ Jassey Geneviève Chiapusio Philippe Binet Alexandre Buttler Fatima Laggoun‐Défarge Frédéric Delarue Nadine Bernard Edward AD Mitchell Marie‐Laure Toussaint André‐Jean Francez Daniel Gilbert 《Global Change Biology》2013,19(3):811-823
Peatlands contain approximately one third of all soil organic carbon (SOC). Warming can alter above‐ and belowground linkages that regulate soil organic carbon dynamics and C‐balance in peatlands. Here we examine the multiyear impact of in situ experimental warming on the microbial food web, vegetation, and their feedbacks with soil chemistry. We provide evidence of both positive and negative impacts of warming on specific microbial functional groups, leading to destabilization of the microbial food web. We observed a strong reduction (70%) in the biomass of top‐predators (testate amoebae) in warmed plots. Such a loss caused a shortening of microbial food chains, which in turn stimulated microbial activity, leading to slight increases in levels of nutrients and labile C in water. We further show that warming altered the regulatory role of Sphagnum‐polyphenols on microbial community structure with a potential inhibition of top predators. In addition, warming caused a decrease in Sphagnum cover and an increase in vascular plant cover. Using structural equation modelling, we show that changes in the microbial food web affected the relationships between plants, soil water chemistry, and microbial communities. These results suggest that warming will destabilize C and nutrient recycling of peatlands via changes in above‐ and belowground linkages, and therefore, the microbial food web associated with mosses will feedback positively to global warming by destabilizing the carbon cycle. This study confirms that microbial food webs thus constitute a key element in the functioning of peatland ecosystems. Their study can help understand how mosses, as ecosystem engineers, tightly regulate biogeochemical cycling and climate feedback in peatlands 相似文献
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ADRIAN KIN MICHAŁ GRUSZCZYŃSKI DAVID MARTILL JIM D. MARSHALL BŁAŻEJ BŁAŻEJOWSKI 《Lethaia: An International Journal of Palaeontology and Stratigraphy》2013,46(1):71-81
A rich assemblage of exceptionally preserved marine and terrestrial fossils occurs in fine‐grained limestones in the upper part of the Late Tithonian (Middle Volgian) shallowing upward carbonate sequence in Central Poland. The richest horizon, a deposit known locally as the Corbulomima horizon, is named after the shallow burrowing suspension feeding bivalve Corbulomima obscura, moulds of which occur in densities of up to 500 per square metre on some bedding planes. The fauna in this bed also includes organic and phosphatic remains of a wide range of other creatures including the exuviae of limulids and decapods, disarticulated fish skeletons and rare isolated pterosaur bones and teeth. There are also perfectly preserved dragonfly wings and beetle exoskeletons. The average stable carbon and oxygen isotope values for ostracod shells and fine‐grained sediment from this horizon suggest precipitation of the calcium carbonate from warm seawater of normal marine salinity. The carbonate sediments overlying the fossiliferous horizon have been interpreted as nearshore to shoreface facies. These pass abruptly into coarse reworked intraclastic sediments interpreted as possible tsunami or storm surge over‐wash deposits. The clasts in this deposit have more positive oxygen isotope values than those in the underlying limestone, which may indicate that they were lithified in a slightly more evaporative, perhaps intertidal, setting. The succession terminates with silicified fine‐grained limestones likely to have formed in extremely shallow lagoonal environments. In contrast with the Solnhofen limestones of Lower Tithonian age in south‐central Germany the Corbulomima horizon is interpreted as a transitional deposit formed in a shallow marine setting by rapid burial with elements of both Konservat‐ and Konzentrat‐Lagerstätte preservation. □Konzentrat and Konservat‐Lagerstätte, Taphonomy, Palaeoenvironment, Paleogeography, Late Jurassic, Poland. 相似文献
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Pantin EJ Kraidin JL Ginsberg SH Denny JT Solina AR 《Innovations (Philadelphia, Pa.)》2012,7(1):62-64
Coronary sinus cannulation for retrograde cardioplegia administration during cardiac surgery is common practice. Several of the cannulas that are placed by the cardiac surgeon on open procedures are now placed by the cardiac anesthesiologist during minimally invasive cardiac surgery, including the coronary sinus catheter. The understanding of the cardiac venous anatomy is very important during coronary sinus catheter placement. We present a case where a percutaneously placed coronary sinus catheter was inadvertently placed into the middle cardiac vein but detected with the use of fluoroscopy. 相似文献
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Paul R Bessell Darren J Shaw Nicholas J Savill Mark EJ Woolhouse 《BMC veterinary research》2008,4(1):40