4,516 research outputs found
Taxonomy and biostratigraphy of new and emended species of Cenozoic deep-water agglutinated foraminifera from the Labrador and North Seas
Deep marine, fine grained sedimentary strata of Maastrichtian through Miocene age in the Labrador and North Sea sedimentary basins are rich in agglutinated benthic foraminifera. Six new taxa have been found in these regions, several of which also extend to other circum-Atlantic Paleogene localities. The new taxa are: Ammomarginulina aubertae, n. sp. (Maastrichtian to Eocene), Adercotryma agterbergi, n. sp. (middle Eocene to lower Oligocene), Reticulophragmoides jarvisi (Thalmann) emended herein (Paleocene to lower Oligocene), Reticulophragmoides sp. 5 (Oligocene to Miocene), and Spiroplectammina navarroana Cushman emended herein (Maastrichtian to lower middle Eocene). The last occurrences of these taxa are important elements in the high-resolution probabilistic biozonations for the Labrador and North Sea basins
Probing amyloid protein aggregation with optical superresolution methods: from the test tube to models of disease.
The misfolding and self-assembly of intrinsically disordered proteins into insoluble amyloid structures are central to many neurodegenerative diseases such as Alzheimer's and Parkinson's diseases. Optical imaging of this self-assembly process in vitro and in cells is revolutionizing our understanding of the molecular mechanisms behind these devastating conditions. In contrast to conventional biophysical methods, optical imaging and, in particular, optical superresolution imaging, permits the dynamic investigation of the molecular self-assembly process in vitro and in cells, at molecular-level resolution. In this article, current state-of-the-art imaging methods are reviewed and discussed in the context of research into neurodegeneration.This work was funded by grants from the Wellcome Trust, the Medical Research Council UK, the Alzheimer Research UK Trust, the Engineering and Physical Sciences Research Council UK, the Biotechnology and Biological Sciences Research Council, and the Swiss National Science Foundation.This is the final version of the article. It first appeared from the Society of Photo-optical Instrumentation Engineers via http://dx.doi.org/10.1117/1.NPh.3.4.04180
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Advanced fluorescence imaging of in situ protein aggregation.
The aggregation of intrinsically disordered proteins is a hallmark of neurodegenerative diseases, such as Alzheimer's, Parkinson's and Huntington's disease. Although we currently have a good molecular level understanding on how protein aggregation occurs in vitro, the details of its self-assembly in live cells are still mainly unknown. During the last ten years, we have witnessed the rapid development of advanced imaging techniques, especially super-resolution and fluorescence lifetime-based microscopy, in different areas of cell biology. These methods have been revolutionising our understanding of how proteins aggregate, providing unprecedented high spatial-temporal resolution which permits us to capture the kinetics of aggregate seeding and expansion, the motion and distribution of individual aggregates within the cells, and its structural change. In this article, we will review the study of in situ protein aggregation using advanced imaging techniques, with the focus on protein aggregate structure and its assembly dynamics
From single-molecule spectroscopy to super-resolution imaging of the neuron: a review.
For more than 20 years, single-molecule spectroscopy has been providing invaluable insights into nature at the molecular level. The field has received a powerful boost with the development of the technique into super-resolution imaging methods, ca. 10 years ago, which overcome the limitations imposed by optical diffraction. Today, single molecule super-resolution imaging is routinely used in the study of macromolecular function and structure in the cell. Concomitantly, computational methods have been developed that provide information on numbers and positions of molecules at the nanometer-scale. In this overview, we outline the technical developments that have led to the emergence of localization microscopy techniques from single-molecule spectroscopy. We then provide a comprehensive review on the application of the technique in the field of neuroscience research.This work was supported by grants from the UK Engineering and Physical Sciences Research Council (EPSRC), The Wellcome Trust, Alzheimer’s Research UK, the Medical Research Council (MRC), and the Biotechnology and Biological Sciences Resesarch Council (BBSRC)
A joint Richardson-Lucy deconvolution algorithm for the reconstruction of multifocal structured illumination microscopy data.
We demonstrate the reconstruction of images obtained by multifocal structured illumination microscopy, MSIM, using a joint Richardson-Lucy, jRL-MSIM, deconvolution algorithm, which is based on an underlying widefield image-formation model. The method is efficient in the suppression of out-of-focus light and greatly improves image contrast and resolution. Furthermore, it is particularly well suited for the processing of noise corrupted data. The principle is verified on simulated as well as experimental data and a comparison of the jRL-MSIM approach with the standard reconstruction procedure, which is based on image scanning microscopy, ISM, is made. Our algorithm is efficient and freely available in a user friendly software package.This work was supported by grants from the Leverhulme Trust, the Engineering and Physical Sciences Research Council, UK (grant EP/H018301/1) and by the Medical Research Council (grant MR/K015850/1). FS wishes to acknowledge support from the Studienstiftung des deutschen Volkes and the Erlangen Graduate School in Advanced Optical Technologies (SAOT) by the German Research Foundation (DFG).This was originally published in Methods and Applications in Fluorescence (F Ströhl, CF Kaminski, Methods and Applications in Fluorescence 2015, 3, 014002
New dispersion relations in the description of scattering amplitudes
We present a set of once subtracted dispersion relations which implement
crossing symmetry conditions for the scattering amplitudes below 1
GeV. We compare and discuss the results obtained for the once and twice
subtracted dispersion relations, known as Roy's equations, for three
partial JI waves, S0, P and S2. We also show that once subtracted dispersion
relations provide a stringent test of crossing and analyticity for
partial wave amplitudes, remarkably precise in the 400 to 1.1 GeV region, where
the resulting uncertainties are significantly smaller than those coming from
standard Roy's equations, given the same input.Comment: 8 pages, 2 figures, to appear in the Proceedings of the Meson 2008
conference, June 6-10, 2008, Cracow, Polan
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