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91.
Malte C. Ebach Christopher J. Humphries Rhys A. Newman David M. Williams Stig A. Walsh 《Journal of Biogeography》2005,32(5):781-787
Aim The aim of this paper was to revise the historical biogeographical method for resolving complicated distribution patterns through a technique that has come to be called assumption 2. Assumption 2 was used to resolve multiple areas on a single terminal branch (masts) as well as paralogous and missing areas in two or more areagrams. Recent examples, however, have shown that assumption 2 may be using rather than resolving paralogy. The paper attempts to resolve this problem by formulating a separate procedure to avoid using paralogous (redundant) area data in area cladistic analyses. Method The revision results in a new derivative method, the transparent method, to replace assumptions 1 and 2. It separates the procedures for resolving paralogy and for solving distribution patterns that occur in more than one area (masts). Results Several hypothetical examples show how the transparent method reduces paralogy and masts. The results show that paralogy can be reduced if the paralogy subtree method is applied after uncovering all possible relationships as single components on the terminals of areagrams. Conclusion The transparent method is a significant step forward in cladistic biogeography as it utilizes area relationships rather than generating general areagrams based on paralogous data. 相似文献
92.
Malte C. Ebach David M. Williams 《Cladistics : the international journal of the Willi Hennig Society》2020,36(2):218-226
Ronald Brady was the first philosopher to defend pattern cladistics as an independent scientific field. That independence was achieved through the decoupling of biological systematics from phylogenetics––that is, inferred evolutionary processes (e.g. character transformation). Brady saw parallels between biological systematics and Wolfgang von Goethe's Morphology, an empirical scientific field that incorporates human observation and perception to discover coherent morphological structures. Goethe's Morphology and pre-Darwinian systematics were independent from evolutionary narratives, a tradition that continued into the 20th Century through the work of biologists such as Agnes Arber. Most importantly, Brady provided the philosophical and historical foundations to an independent systematics by demonstrating the links between phenomenology, Goethe's Morphology and comparative biology. 相似文献
93.
Elizabeth M. Dowding Malte C. Ebach Evgeny V. Mavrodiev 《Cladistics : the international journal of the Willi Hennig Society》2019,35(4):435-445
A structural approach to temporality in distributional data for use in palaeobiogeography is described herein. Pre-established areas in the distributional data matrix are split temporally, allowing a single geographical space to have multiple iterations [e.g. Area A (Lower Devonian), Area A (Middle Devonian)]. The resulting temporal matrix will allow the representation and capture of any differing relationships through time. Designed primarily for Parsimony Analysis of Endemicity (PAE) and biotic similarity analyses, this approach simply structures distributional data within a temporal partition, meaning that numerical methods can be used to assess relationships between areas to find a branching diagram. Created through the application of the temporal matrix to a given analysis, Temporal Area Approach (TAAp) is a structural approach that facilitates exploration of the data rather than being a hypothesis-driven model following analysis. Understanding the behaviour of non-phylogenetic palaeobiogeographical data and reducing the prevalence of temporal artefacts will lead to more robust area classifications. 相似文献
94.
Malte Elbrächter 《Helgoland Marine Research》1998,52(3-4):235-242
Flagellate species have been shown to survive transocean passage by ballast water and the large dinoflagellateGymnodinium catenatum was introduced from Japanese to Tasmanian waters in this way.Gymnodinium mikimotoi—better known asGyrodinium aureolum—andFibrocapsa japonica as well asAlexandrium leeii are good candidates to have been introduced recently. Species which seem to have been introduced recently into the North Sea but apparently are transported from adjacent seas by currents into the region areGymnodinium chlorophorum andAlexandrium minutum. Species reported as introduced due to misidentifications areGymnodinium catenatum andLepidodinium viride. Under other names the speciesProrocentrum minimum, Prorocentrum redfieldii, andHeterosigma akashiwo have been known for a long time in the North Sea. The recent reports of threeChattonella species may be either due to introduction or they have been overlooked. The reasons why the introduction of flagellates into coastal North Sea waters is difficult to prove will be discussed. 相似文献
95.
96.
Grau M Hendgen-Cotta UB Brouzos P Drexhage C Rassaf T Lauer T Dejam A Kelm M Kleinbongard P 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2007,851(1-2):106-123
Nitric oxide (NO) plays a pivotal role in the modulation of multiple physiological processes. It acts as a messenger molecule within the cardiovascular system. NO is a highly unstable free radical in circulating blood and is oxidized rapidly to nitrite and nitrate. Recent studies suggest that nitrite has the potential to function as a surrogate of NO production under physiological and pathophysiological conditions and could therefore be of high relevance as a biochemical parameter in experimental and clinical studies. Under hypoxic conditions nitrite is reduced to bioactive NO by deoxyhemoglobin. This mechanism may represent a dynamic cycle of NO generation to adapt the demand and supply for the vascular system. Because of these potential biological functions the concentration of nitrite in blood is thought to be of particular importance. The determination of nitrite in biological matrices represents a considerable analytical challenge. Methodological problems often arise from pre-analytical sample preparation, sample contamination due to the ubiquity of nitrite, and from lack of selectivity and sensitivity. These analytical difficulties may be a plausible explanation for reported highly diverging concentrations of nitrite in the human circulation. The aim of this article is to review the methods of quantitative analysis of nitrite in the human circulation, notably in plasma and blood, and to discuss pre-analytical and analytical factors potentially affecting accurate quantification of nitrite in these human fluids. 相似文献
97.
Malte C Kleinschmidt Martin Michaelis Henry Ogbomo Hans-Wilhelm Doerr Jindrich CinatlJr 《BMC microbiology》2007,7(1):49
Background
West Nile virus (WNV) infection can cause severe meningitis and encephalitis in humans. Apoptosis was recently shown to contribute to the pathogenesis of WNV encephalitis. Here, we used WNV-infected glioma cells to study WNV-replication and WNV-induced apoptosis in human brain-derived cells. 相似文献98.
Importance of tRNA interactions with 23S rRNA for peptide bond formation on the ribosome: studies with substrate analogs 总被引:1,自引:0,他引:1
The major enzymatic activity of the ribosome is the catalysis of peptide bond formation. The active site -- the peptidyl transferase center -- is composed of ribosomal RNA (rRNA), and interactions between rRNA and the reactants, peptidyl-tRNA and aminoacyl-tRNA, are crucial for the reaction to proceed rapidly and efficiently. Here, we describe the influence of rRNA interactions with cytidine residues in A-site substrate analogs (C-puromycin or CC-puromycin), mimicking C74 and C75 of tRNA on the reaction. Base-pairing of C75 with G2553 of 23S rRNA accelerates peptide bond formation, presumably by stabilizing the peptidyl transferase center in its productive conformation. When C74 is also present in the substrate analog, the reaction is slowed down considerably, indicating a slow step in substrate binding to the active site, which limits the reaction rate. The tRNA-rRNA interactions lead to a robust reaction that is insensitive to pH changes or base substitutions in 23S rRNA at the active site of the ribosome. 相似文献
99.
Safiya Khurshid Shuhua Chen Pia Hasskamp Tamina Seeger‐Nukpezah Katharina Schilberg Lukas Heukamp Tobias Lamkemeyer Martin L Sos Roman K Thomas Drew Lowery Frederik Roels Matthias Fischer Max C Liebau Ulrike Resch Tülay Kisner Fabian Röther Malte P Bartram Roman Ulrich Müller Francesca Fabretti Peter Kurschat Björn Schumacher Matthias Gaestel René H Medema Michael B Yaffe Bernhard Schermer Thomas Benzing 《The EMBO journal》2012,31(20):3961-3975
100.
The von Hippel-Lindau tumor suppressor protein controls ciliogenesis by orienting microtubule growth
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Schermer B Ghenoiu C Bartram M Müller RU Kotsis F Höhne M Kühn W Rapka M Nitschke R Zentgraf H Fliegauf M Omran H Walz G Benzing T 《The Journal of cell biology》2006,175(4):547-554
Cilia are specialized organelles that play an important role in several biological processes, including mechanosensation, photoperception, and osmosignaling. Mutations in proteins localized to cilia have been implicated in a growing number of human diseases. In this study, we demonstrate that the von Hippel-Lindau (VHL) protein (pVHL) is a ciliary protein that controls ciliogenesis in kidney cells. Knockdown of pVHL impeded the formation of cilia in mouse inner medullary collecting duct 3 kidney cells, whereas the expression of pVHL in VHL-negative renal cancer cells rescued the ciliogenesis defect. Using green fluorescent protein-tagged end-binding protein 1 to label microtubule plus ends, we found that pVHL does not affect the microtubule growth rate but is needed to orient the growth of microtubules toward the cell periphery, a prerequisite for the formation of cilia. Furthermore, pVHL interacts with the Par3-Par6-atypical PKC complex, suggesting a mechanism for linking polarity pathways to microtubule capture and ciliogenesis. 相似文献