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The ability to track cells in small animal models of human disease. is important because it gives the potential to improve our understanding of the processes of disease progression as well as the therapeutic effects of interventions. In this work gold nano-particles have been used as a permanent marker of implanted normal and malignant cell grafts in combination with a suitable x-ray apparatus.
Utilizing x-ray computed tomography the micrometric three-dimensional distribution of these marked cells could be displayed with penetration depth, high cell sensitivity and high spatial resolution in rodent models of human diseases. In principle the method allows quantification of cell numbers at any anatomical location over time in small animals.

We present here a new data analysis technique, based on X-ray microtomography measurements and on shape preferred orientation analysis, to obtain the orientation distribution functions of the constituents of volcanic rocks. This procedure proved to be very suitable for volcanic samples, where diffraction-based techniques, developed for crystallographic preferred orientation studies, are of limited utilization, in addition to the fact that they cannot provide any information about vesicles or bubbles. Moreover the analysis performed directly in 3D overcomes the problems that usually occur when employing stereological methods for the analysis of the images obtained via microscopy-based techniques. In this study, two scoriae (from Stromboli and Etna) and a tube pumice (from Campi Flegrei) were measured via X-ray microtomography and then the resulting volumes were analyzed following the proposed procedure. Results highlight little preferred orientation for the vesicles in the two scoria samples, whereas the pumice shows a marked preferred orientation. Crystals (also divided by mineral species) were taken into account as well and in the two scoria samples there is no crystal preferred orientation, in contrast with the pumice, where crystal preferred orientation features are very similar to the ones found for the vesicles.

Overall we found strong differences in preferred orientation: weak for vesicles in scoriae, showing an axial symmetry with the axis parallel to the elongation axis of the sample, and a stronger and more complex orientation texture in the pumice sample for both crystals and vesicles. The promising results obtained suggest that this procedure is potentially very useful for the analysis of preferred orientation in volcanic rocks and geomaterials in general.

Texture analysis of volcanic rock samples: 3D shape preferred orientation of crystals and vesicles obtained from X-ray microtomography experiments, M. Voltolini, D. Zandomeneghi, L. Mancini, and M. Polacci, J. of Volcanology and Geothermal Research,202, Issues 1-2 (2011) 83-95, DOI:10.1016/j.jvolgeores.2011.02.003.

The 3D approach allowed to characterize all internal cavity structures: a network of thin canals, gastropores, dactylopores, and ampullae. The main feature highlighted by this reconstruction is a dense network of thin canals extended to the entire colony. This network gives rise to and surrounds each cyclosystem. Moreover, the 3D analysis made it possible to study the reciprocal relationship between adjacent cyclosystems and to hypothesize the growth process of the branches of Stylaster sp.: each new cyclosystem buds between the gastropore and the dactylopores of the last formed one. The dactylopores of each cyclosystem are partially derived from the precedent one and are partially newly formed.

The thin canals enveloping the dactylopores are actively involved in both the formation of a new gastropore and in the re-establishment of the typical amount of dactylopores in each cyclosystem. This growth process was conWrmed by the scanning electron microscopy (SEM) observations of apical cyclosystems of several specimens. Results indicate that the non-destructive X-ray  microtomography technique can be fruitfully applied to characterize the coenosteal structures of stylasterids allowing the repetitive study of a specimen by means of virtually inWnite section planes and diVerent kinds of analyses (e.g., channel width and porosity).

The virtual histological analysis showed that the mother’s and baby's death occurred between the 31^st and 33^rd gestational weeks. Measurements also pointed out the occurrence of three severe physiological stresses that affected both individuals during the last two and a half months of pregnancy. This was highlighted by the presence of microscopic stress markers in the dental enamel, which are usually formed after stressful events as a consequence of an altered secretion. Finally, in line wtith previous studies of ancient Romans, the present results indicate an accelerated fetal development in the past

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On the basis of the obtained results, inferences about the control of pore network properties on permeability were made for both host rock and deformation bands. In the host rocks, high values of connectivity seem to be associated with high values of permeability, whereas higher values of the specific surface area seem to correspond to lower permeability. Within the deformation bands, both porosity and pore connectivity are reduced except for local solution-enlarged stylolites and fractures (slip surfaces) preferentially connected parallel to the deformations bands.
The morphology and distribution of connected pores may have an impact on the permeability may explain variability on their permeability reported for the studied rocks.
In the fault zones, both connected porosity and pore connectivity decrease drastically due to the collapse or occlusion of pores by compaction, cataclasis or cementation. Therefore, the cemented and the cataclastic zones could be considered as local buffer zones or barriers to fluid flow. On the contrary, the connected pore-network, made of solution-enlarged stylolites and slip surfaces, is preferably connected and distributed parallel to the fault. Therefore, this configuration of conduits and local barriers may cause an anisotropy in the permeability within the fault zone.

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