Search

Today, adaptive optics (AO) is installed on all very large astronomical telescopes. It allows to overcome the limitation in angular resolution imposed on large ground-based telescopes by the atmospheric turbulence perturbations. This review paper presents the state of the art of the field for astronomical applications. It gives the principles of AO and describes its main components which are the deformable mirrors, the wavefront sensors and the control algorithms. The paper also presents the main recent achievements and ongoing projects. First, for the direct imaging of extra-solar planets by extreme AO and coronography, taking as example the SPHERE instrument. Then to solve the problem of the very limited sky coverage by using laser guide star and to extend the AO correction beyond the isoplanatic patch. Thus, the various laser-assisted tomographic AO concepts are presented with examples of each realization as for the laser tomography AO, the multi-conjugate AO and the multi-object AO. Finally, the challenges of the new generation of giant telescopes are discussed at the end of the paper with a particular focus on the European Extremely Large Telescope (ELT) project.

Microscopic X-ray computed tomography (MicroCT) is a tomographic imaging technique for high-resolution 3D visualization and quantitative analysis of samples. Whereas twenty years ago this technique was considered to be exotic within biological and biomedical basic research and was hardly ever used, it is thought to be indispensable in these fields of research today. The present article focuses on both basic technical principles and application fields of microCT for the science of biology. Furthermore, it discusses some practical aspects important for researchers and institutions planning to establish a microCT setup in their labs. [ABSTRACT FROM AUTHOR]

Copyright of Der Ophthalmologe is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The efficiency of columns for fluid separation can be increased by the application of sandwich packings. During the operation, different load‐dependent regimes with peculiar separation performance arise. In order to account for the effects of the individual flow regimes in a single model, both separation performance measurements and tomographic imaging are applied. A rate‐based model is presented, which takes the heterogeneous regimes in sandwich packings into account by means of appropriate correlations. The model is tested with experimental data for CO2 absorption. [ABSTRACT FROM AUTHOR]

Abstract The study of cultural heritage objects represents a challenge for materials sciences, because of their intrinsic complexity as well as because of their rare and precious nature, which requires the use of non-destructive methods. One of the major difficulties encountered by the methods of structural analysis of these materials is the presence of mixtures of crystallized and amorphous phases, the conventional methods of crystallography being poorly adapted to the latter. Here we present the Pair Distribution Function analysis method, which based on diffraction data, allows access to the identification, microstructural characterization and quantification of phases constituting a complex mixture, independently of their amorphous or crystalline character. Two recent examples will be presented to illustrate the use of this method in studies of cultural heritage materials. [ABSTRACT FROM AUTHOR]

Copyright of Technisches Messen is the property of De Gruyter and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Archives of Cardiovascular Diseases is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Zusammenfassung: Die Magnetpartikel‐Bildgebung (Magnetic Particle Imaging, MPI) detektiert superparamagnetische Eisenoxid‐Nanopartikel hochsensitiv und hochspezifisch auch im Inneren von Körpern. Physikalisch nutzt sie die nichtlineare Magnetisierungsfunktion dieser Partikel. MPI eröffnet der Medizin so einen neuen Zugang zu markerbasierten Anwendungen, der im Gegensatz zu etablierten Verfahren auf Radionuklide verzichtet und damit gerade in der klinischen Anwendung enormes Potenzial besitzt. Mit der Realisierung erster MPI‐MRT‐Hybridsysteme ist bereits ein wichtiger Schritt in Richtung einer diagnostischen Anwendbarkeit getan. Dabei erfasst MPI das Markersignal und MRT den anatomischen Bildhintergrund. MPI ist auch in den Materialwissenschaften bei der zerstörungsfreien Materialprüfung einsetzbar. [ABSTRACT FROM AUTHOR]

Abstract: A limiting factor of solvent‐induced nanoparticle self‐assembly is the need for constant sample dilution in assembly/disassembly cycles. Changes in the nanoparticle concentration alter the kinetics of the subsequent assembly process, limiting optical signal recovery. Herein, we show that upon confining hydrophobic nanoparticles in permeable silica nanocapsules, the number of nanoparticles participating in cyclic aggregation remains constant despite bulk changes in solution, leading to highly reproducible plasmon band shifts at different solvent compositions. [ABSTRACT FROM AUTHOR]

Mesocrystals of high-magnesian calcites are commonly found in biogenic calcites. Under ambient conditions, it remains challenging to prepare mesocrystals of high-magnesian calcite in aqueous solution. We report that mesocrystals of calcite with magnesium content of about 20 mol % can be obtained from the phase transformation of magnesian amorphous calcium carbonate (Mg-ACC) in lipid solution. The limited water content on the Mg-ACC surface would reduce the extent of the dissolution-reprecipitation process and bias the phase transformation pathway toward solid-state reaction. We infer from the selected area electron diffraction patterns and the dark-field transmission electron microscopic images that the formation of Mg-calcite mesocrystals occurs through solid-state secondary nucleation, for which the phase transformation is initiated near the mineral surface and the crystalline phase propagates gradually toward the interior part of the microspheres of Mg-ACC. [ABSTRACT FROM AUTHOR]

Droplets, bubbles or solid particles concentration and their particle size distribution markedly influence process conditions. In this article an overview in respect to popular invasive and non-invasive local measurement techniques for bubbles and droplets will be given. It starts with capillary suction probes, laser Doppler anemometry and finally covers actual developments in tomography and optical endoscopic measurement techniques. Furthermore, the possibilities and limitations of analyzing particle size distributions within different methods as well as application fields and their limits will be discussed. [ABSTRACT FROM AUTHOR]

Fluid catalytic cracking is a chemical conversion process of industrial scale. This process, utilizing porous catalysts composed of clay and zeolite, converts heavy crude-oil fractions into transportation fuel and petrochemical feedstocks. Among other factors iron-rich reactor and feedstream impurities cause these catalyst particles to permanently deactivate. Herein, we report tomographic X-ray absorption spectroscopy measurements that reveal the presence of dissimilar iron impurities of specific localization within a single deactivated particle. Whereas the iron natural to clay in the composite seems to be unaffected by operation, exterior-facing and feedstream-introduced iron was found in two forms. Those being minute quantities of ferrous oxide, located near regions of increased porosity, and impurities rich in Fe3+, preferentially located in the outer dense part of the particle and suggested to contribute to the formation of an isolating amorphous silica alumina envelope. [ABSTRACT FROM AUTHOR]

To improve lithium and sodium ion battery technology, it is imperative to understand how the properties of the different components are controlled by their chemical structures. Operando structural studies give us some of the most useful information for understanding how batteries work, but it remains difficult to separate out the contributions of the various components of a battery stack (e.g., electrodes, current collectors, electrolyte, and binders) and examine specific materials. We have used operando X-ray diffraction computed tomography (XRD-CT) to study specific components of an essentially unmodified working cell and extract detailed, space-resolved structural information on both crystalline and amorphous phases that are present during cycling by Rietveld and pair distribution function (PDF) methods. We illustrate this method with the first detailed structural examination of the cycling of sodium in a phosphorus anode, revealing surprisingly different mechanisms for sodiation and desodiation in this promising, high-capacity anode system. [ABSTRACT FROM AUTHOR]

Copyright of Der Ophthalmologe is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Herz is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Hydrogen sulfide (H2S) has multifunctional roles as a gas signaling molecule in living systems. However, the efficient detection and imaging of H2S in live animals is very challenging. Herein, we report the first radioisotope-based immobilization technique for the detection, quantification, and in vivo imaging of endogenous H2S. Macrocyclic 64Cu complexes that instantly reacted with gaseous H2S to form insoluble 64CuS in a highly sensitive and selective manner were prepared. The H2S concentration in biological samples was measured by a thin-layer radiochromatography method. When 64Cu-cyclen was injected into mice, an elevated H2S concentration in the inflamed paw was clearly visualized and quantified by Cerenkov luminescence and positron emission tomography (PET) imaging. PET imaging was also able to pinpoint increased H2S levels in a millimeter-sized infarcted lesion of the rat heart. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Geotechnical Journal is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Various material properties of solids are influenced by the particle morphology. Therefore, precise, rapid and inexpensive determination of the internal and external morphology of particles is of great interest. Measurement of the particle shapes was considerably simplified by combination of watershed and the active contour model. The technique is applicable to a variety of particle populations and allows the generation of a sufficient number of shapes for the static characterization of particles within a few hours. [ABSTRACT FROM AUTHOR]

Durch schnelle Röntgentomographie auf der Grundlage eines magnetisch abgelenkten Elektronenstrahls ist es möglich, 2D-Abbildungen von fluiden Medien zu erzeugen. 3D-Abbildungen wären zwar wünschenswert, sind aber vorerst noch nicht mit vertretbarem Aufwand realisierbar. Trotzdem soll bereits jetzt versucht werden, methodische Studien zur Bestimmung von Geschwindigkeiten in röntgentomographischen 3D-Abbildungen durchzuführen. Speziell werden dynamische Vorgänge in flüssigem Schaum betrachtet. 2D images of fluid media can be generated using fast X-ray tomography on the basis of a magnetically deflected electron beam. 3D images are highly desired, but cannot yet be realised with acceptable effort for the time being. However, methodological studies for the determination of velocities in X-ray tomographic 3D images should already be studied right now. Dynamic processes in liquid foam are particularly considered. [ABSTRACT FROM AUTHOR]

Red lead, a semiconductor pigment used by artists since antiquity, is known to undergo several discoloration phenomena. These transformations are either described as darkening of the pigment caused by the formation of either plattnerite (β-PbO2) or galena (PbS) or as whitening by which red lead is converted into anglesite (PbSO4) or (hydro)cerussite (2 PbCO3⋅Pb(OH)2; PbCO3). X-ray powder diffraction tomography, a powerful analytical method that allows visualization of the internal distribution of different crystalline compounds in complex samples, was used to investigate a microscopic paint sample from a Van Gogh painting. A very rare lead mineral, plumbonacrite (3 PbCO3⋅ Pb(OH)2⋅PbO), was revealed to be present. This is the first reported occurrence of this compound in a painting dating from before the mid 20th century. It constitutes the missing link between on the one hand the photoinduced reduction of red lead and on the other hand (hydro)cerussite, and thus sheds new light on the whitening of red lead. [ABSTRACT FROM AUTHOR]

A complete cranium of Ursus deningeri from Petralona (Chalkidiki, Greece) covered by a thick carbonate crust has been virtually liberated through CT scan and 3D image reconstruction, and compared with a specimen from the Sima de los Huesos, Sierra de Atapuerca (Spain) Middle Pleistocene site. X-ray computed tomography allowed for the identification of previously unrecognized and phylogenetically relevant traits. Analysis of these traits and an additional series of classically defined traits demonstrate the near identity of these specimens, thereby, confirming an early stage of the speloid “(cave bear)” condition. The replicate luminescence ages obtained for the SH deposit provide a combined minimum age estimate of 427 ± 12 ka for the underlying fossils. Based on a series of primitive and derived morphological features of these two crania, a similar age is here proposed for the Petralona and SH U. deningeri . [ABSTRACT FROM AUTHOR]

Computed tomography has become an important component in the initial assessment of severely injured patients over the last years. The liberal use coupled with advances in imaging technology often result in incidental findings. In our present investigation, the prevalence incidence of incidental findings of the spine and skull amounted to 58% of all patients with trauma. Degenerative changes were most commonly found, followed by congenital defects and neoplasms. Within the latter, further investigation was necessary in six cases, of which two findings proved to be malignant neoplasms. The high incidence of incidental findings calls for a uniform documentation, handling and clarification of responsibility in treatment and insurance-related competence. [ABSTRACT FROM AUTHOR]

Copyright of HNO is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract: The growth of fatigue cracks at small length scales is known to be influenced by a variety of factors, including local microstructure, varying stress states and crack shape. High resolution computed tomography allows for sub-micron resolution imaging of failure processes in small test coupons undergoing in situ cyclic loading, providing detailed three-dimensional (3D) assessment of propagation processes across the entire crack front (surface and depth). In this work fatigue crack growth has been examined in an advanced Direct Chill (DC) cast aluminium alloy, along with a fine grained powder-metallurgy alloy. The latter is identified as a model material, offering considerably simpler microscopic crack paths than the DC cast alloy, and hence a means of separating bulk mechanical effects (such as stress state variations across a crack front and plasticity induced closure) from microstructural effects (such as crystallographic deflection and roughness induced crack closure). Crack growth has been studied in both materials under both constant amplitude (CA) and single peak overload (OL) conditions. Experimental results are presented in the present paper, particularly in relation to micromechanical understanding of failure. A modelling approach based on those results, and some typical results, is also presented. [Copyright &y& Elsevier]

Abstract: Ductile fracture of metals is accompanied at the microscopic scale with the appearance of damage, in the form of small cavities. Damage progress is divided into three distinct and consecutive phases: initiation, growth and coalescence. This article illustrates the use of three-dimensional nondestructive imaging to study this damage development. Two techniques, mainly based on the attenuation of X-rays are now used for this type of studies at high resolution: tomography and laminography. The interest of laminography is that samples with larger dimensions (in the form of sheets) than the conventional tomography ones can be used. Examples of images obtained with the two techniques, as well as quantification using X-ray tomography, are presented. [Copyright &y& Elsevier]

Abstract: Recent developments of more powerful synchrotron sources have led to vast improvements in the performance of X-ray imaging. This is manifested by a continuous increase in the impact of synchrotron experiments in many research areas on materials, in particular solidification science. X-ray imaging has been established as a method of choice for in situ and real-time studies of solidification microstructure formation in metallic alloys, with spatio-temporal resolutions at the scales of relevance. In this article, we present illustrative results of the current capabilities of synchrotron X-ray imaging in this field of research, each of them using different X-ray techniques (radiography, topography and tomography). Those results demonstrate the high potential of these techniques for the investigation of dynamical phenomena in materials processing. [Copyright &y& Elsevier]

Background: Headache is a common complaint in general practice and it is known that most headaches are primary and that the yield of neuroimaging like cranial computed tomography (CT) in headache is generally low. In this study, we were able to demonstrate that the yield of neuroimaging in non-acute and recurrent headache could be higher if cases are reviewed fi rst by a specialist Neurologist before cranial CT. Method: Seventy-four cases that were referred to the specialist neurology clinic with complaints of chronic and recurrent headaches without focal neurological defi cit that had CT scan were reviewed consecutively using the short form of the International Classifi cation of Headache Disorders second edition (ICHD 2) criteria after their demographics of age, sex were captured, to fi nd out the proportion and characteristics of study cases that had identifi able cranial lesions on cranial CT scan. All cases were reviewed by a specialist Neurologist before CT scan and all CT fi lms were reviewed by a specialist Radiologist. Age, sex and the distribution of CT fi ndings were described from a frequency table and mean age of study cases with and without identifi able lesions on CT were compared with t-test for any signifi cant difference and the effect of gender on the presence of identifi able lesions was tested with chi square and the agreement between clinical and CT diagnoses were tested on kappa statistics. Results: (1) Mean age of cases was 37.55 (22.06) years. (2) No signifi cant effect of gender was found on intracranial lesions (P = 0.345). (3) Intracranial lesions were found in 47.3% of cases and the mean age was higher compared to cases with normal fi ndings on cranial CT (P = 0.019). (4) Clinical and CT diagnoses agreed in 56.2% of the cases (P = 0.000). Conclusion: The high yield of intracranial lesions may be accounted for by the method of selection of cases for cranial CT. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents flow imaging techniques developed for investigating flow in ejectors. These visualization techniques use the laser sheet method but differ from each other by the kind of the illumination source, the polarization direction of the incident light and the type of the scattering tracers. Each of these methods enables the visualization of specific phenomena (shock structure, flow instabilities, mixing process). Although the flow visualizations are primarily qualitative, they allow the determination of the flow regime, the measurement of the non-mixing length, can indicate suggestions for the design of ejectors and provide the possibility to validate numerical simulations. [Copyright &y& Elsevier]

Abstract: The aim of this article is to investigate a possible way to improve ambient noise tomography by expanding the data base of useful cross-correlation measurements. We show that the curvelet transform makes it possible to compute synthetic noise correlations by simulating directly seismic ambient noise using the spectral element method. These synthetic correlations can in turn be used to identify surface waves and overtones even on correlations having a signal to noise ratio much lower than one. We hope that the possibility to compute SEM synthetic correlations and to extract more information from correlations will be useful to improve ambient noise tomography and monitoring. [Copyright &y& Elsevier]

Abstract: The emergence of large-scale arrays of seismometers across several continents presents the opportunity to image the Earth''s structure at unprecedented resolution, but methods must be developed to exploit the capabilities of these deployments. The capabilities and limitations of a method called “eikonal tomography” applied to ambient noise data are discussed here. In this method, surface wave wavefronts are tracked across an array and the gradient of the travel time field produces estimates of phase slowness and propagation direction. Application data from more than 1000 stations from EarthScope USArray in the central and western US and new Rayleigh wave isotropic and anisotropic phase velocity maps are presented together with an isotropic and azimuthally anisotropic 3D Vs model of the crust and uppermost mantle. As a ray theoretic method, eikonal tomography models bent rays but not other wavefield complexities. We present evidence, based on the systematics of an observed 1ψ component of anisotropy that we interpret as anisotropic bias caused by backscattering near an observing station, that finite frequency phenomena can be ignored in ambient noise tomography at periods shorter than ∼40 to 50s. At longer periods a higher order term based on wavefront amplitudes or finite frequency sensitivity kernels must be introduced if the amplitude of isotropic anomalies and the amplitude and fast-axis direction of azimuthal anisotropy are to be determined accurately. [Copyright &y& Elsevier]

Copyright of Zeitschrift für Medizinische Physik is the property of Elsevier GmbH, Urban & Fischer Verlag and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract: Objective: A cancer diagnostics method is proposed using the 3D reconstruction of luminescence-based optical imaging data. Material and methods: The diffusion equation solution for a cube was used to tackle the forward problem. The forward solution for two-layered media is also applied in the reconstruction method. The inverse problem was solved using a linear reconstruction technique based on the approximation that the light source needing reconstruction can be decomposed into a weighted sum of unit light sources positioned at each node in the search volume. The calculation for the light propagation in the forward problem was done using values cited in literature for the optical properties of the involved tissue. Results: The system was tested with numerical simulations that assumed correct as well as erroneous values of the optical coefficients for canine prostate at 810nm. The quantitative accuracy of reconstructed sources diminished from 100% to approximately 50% with an increase from 0 to 50% in the error for the values of the absorption coefficient, and from 0 to 20% in the error for the values of the reduced scattering coefficient, respectively. Conclusion: The absolute determination of the tumor locations is dependent on the information gathered by the recorded data by the detectors monitoring the light propagation through the tissue under investigation. For a determined or an over-determined system, the locations have been extracted accurately, and partially determined for an under-determined system. [ABSTRACT FROM AUTHOR]

Copyright of Annals of Forest Science (EDP Sciences) is the property of EDP Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract: Seismic and electrical resistivity tomography allow subsurface characterization from acoustic P-waves (Vp), shear S-waves (Vs) velocities, and electrical resistivity (ρ). Both geophysical methods were used to monitor water flow during a controlled rainfall experiment on a clay-shale hillslope located in the Laval catchment at Draix (Alpes-de-Haute-Provence, France). The objectives of the rainfall experiment were to analyse the water infiltration processes and identify possible water pathways by combining multi-method observations. The seismic data provide information on fissure density and the electrical resistivity data provide information on soil water content within the hillslope. Changes of the Vp and electrical resistivity fields with time show some similar pattern. To go further in the analysis of the water flow a geophysical data fusion strategy based on fuzzy set theory is applied. The computed fuzzy cross-sections based on expert hypotheses show the possibility for the material to be saturated during the rainfall experiment. The data fusion process is repeated in time for each acquisition set. The relative difference between the obtained fuzzy cross-sections is calculated and reveals possible locations where water may be transferred within the hillslope. [Copyright &y& Elsevier]

Copyright of Canadian Geotechnical Journal is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract: Due to the numerous discoveries of fossils and the technical and analytical improvements in paleoanthropology that occurred recently, a new investigation on the first inhabitants in Eurasia was necessary. The research deals with the facial pattern of the fossil hominids from Europe and Asia and focussed on the ones discovered in the Atapuerca-Gran Dolina site in Spain, which are oldest than 850,000 years and in the Yunxian site in China, which are dated by 936,000 years. Methods used combined 2D and 3D morphometrics providing with the possibility to consider not only the overall conformation but also the more localized measurements. The Procrustes analysis, which put apart the individual size parameter, were used to investigate the morphological alteration of the face during growth in order to interpret the facial conformation juvenile fossils such as those from Atapuerca-Gran Dolina. Moreover, a specific protocol using tomography and 3D imaging techniques was carried out to reconstruct the Yunxian specimens which have been badly crushed during fossilization process. The results of this research put in light two facial patterns: (1) a facial pattern in extension expressed in Neandertals which european lineage could have been older than previously thought including the Atapuerca-Gran Dolina specimens and (2) a facial pattern in contraction shared between modern humans and the oldest fossil hominids from continental Asia (i.e. Yunxian specimens) which suggests that this conformation corresponds to a primitive condition. [Copyright &y& Elsevier]

Copyright of Annals of Forest Science (EDP Sciences) is the property of EDP Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Forestry Chronicle is the property of Canadian Institute of Forestry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract: Rimicaris exoculata flourishes around deep-sea hydrothermal vent environments along the Mid-Atlantic Ridge (MAR). Epibiotic bacteria and minerals found within the branchial chamber of the shrimp are of interest in the search for the metabolic energy pathways sustaining shrimp swarms at the Rainbow vent site (MAR). Here we examine the three-dimensional (3D) relationships between epibionts and their associated minerals. The morphology and chemical composition of the minerals were analysed by Energy Filtering Transmission Electron Microscopy (EFTEM) and the 3D organisation was determined by Transmission Electron Tomography (TET). The minerals are preferentially associated with small, rod-shaped bacteria. The iron oxide deposits exhibit three main associations with the bacterial exterior: (1) close, (2) zoned/layered and (3) distant. Iron is the most prevalent element, with a close association with the bacteria, and co-occurs with oxygen. 3D reconstructions reveal a discontinuous network of deposits around the bacteria, showing the intricate nature of these iron oxides. [Copyright &y& Elsevier]

Abstract: The most deadly of the human malaria parasites, Plasmodium falciparum, invades the erythrocytes of its host and initiates a remarkable series of morphological rearrangements within the host cell cytoplasm. The mature erythrocyte is effectively a floating sack of haemoglobin with no endogenous protein synthesis or protein trafficking machinery. In order to colonise and remodel its extracellular space, the parasite generates a series of novel structures that are involved in the export of virulence factors to the surface of the host cell. These include extensions of the parasite''s vacuolar membrane, known as the tubulovesicular network, and structures referred to as Maurer''s clefts. Maurer''s clefts are convoluted collections of distorted discs that are tethered to the red blood cell membrane by structures with stalk-like profiles. Recently electron tomography has enabled visualisation – in three dimensions and at unprecedented resolution – the complexity of the membrane systems within the infected RBC cytoplasm. [Copyright &y& Elsevier]

Abstract: Geophysical methods such as seismic surveying and electrical resistivity imaging appear to be well-adapted to investigate and understand landslide mechanisms. They allow direct and non-intrusive measurement of acoustic velocity and electrical resistivity, two fundamental parameters used to define the physical properties of the reworked moving materials. Both methods were applied at the Super-Sauze site in the French South Alps, where a typical example of an intra-material earthflow-mudslide can be observed. Measurements were taken simultaneously along two orthogonal profiles: one 325 m in length is perpendicular to the axis of the earthflow; the other 235 m in length is located along the axis of the earthflow. The results show a correlation between the seismic and electrical resistivity data, confirming that the simultaneous use of both methods gives complementary information about landslide mechanisms. The seismic data provide information on fracture density variations, whereas the electrical resistivity data provide information on water content variations. To cite this article: G. Grandjean et al., C. R. Geoscience 338 (2006). [Copyright &y& Elsevier]

Copyright of Annals of Telecommunications is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Annals of Telecommunications is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Simple fluid dynamic constraints aid in the interpretation of lower mantle tomograms. The geothermal gradient away from slabs and plumes is subadiabatic between the upper (lithosphere) and lower (D″) boundary layers by ∼400 K. Slabs widen proportionally with the square root of the viscosity as they sink through the lower mantle. The time scale for the persistence of slab graveyards at the base of the mantle is comparable to the time for plate motions to reorganize ∼120–200 Myr. At most a few starting plume heads currently exist in the lower mantle. Tomographic inversions may include more sophisticated numerical-modeling versions of these constraints. [Copyright &y& Elsevier]

We present an overview of the present knowledge of the Earth''s lower mantle 3D structure, as currently obtained owing to progress, in the last ten years, in seismic tomography as well as forward modelling of seismic travel times and waveforms. We discuss constraints that seismic modelling brings to the debate concerning major geodynamical questions, in particular the issue of global ‘1 layer’ or ‘2 layer’ circulation, of the missing geochemical reservoir, as well as of the role in global dynamics of the thermochemical boundary layer at the base of the mantle. [Copyright &y& Elsevier]

Copyright of Der Unfallchirurg is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)