138 research outputs found
Lensless digital holographic microscope with light-emitting diode illumination
No full textWe demonstrate the operation of a digital in-line microscope with LED illumination. We show with a practical example that, for typical setups, the limited temporal coherence and the spatial incoherence of the source do not affect the resolving power of the system. On the contrary, important advantages are obtained in terms of signal-to-noise ratio and alignment simplification
Temporary embolization in urological practice: myth or reality?
No full textClot embolization through percutaneous transcatheter technique has proved to be a highly effective and reliable method for stopping bleeding from renal or pelvic areas. The recanalization of the embolized vessels is constant and the recovery of the renal function quite satisfactory. In case of priapism temporary embolization may be very useful in selected cases
Infrared lensless holographic microscope with a vidicon camera for inspection of metallic evaporations on silicon wafers
No full textThe lensless digital in-line microscope is proposed as a simple tool for post-production inspection of metallic film
patterns on silicon wafers. Transmission holographic imaging is achieved by using a superluminescent diode emitting
in the near infrared coupled into a single-mode high numerical aperture optical fiber and an infrared vidicon camera.
Images of 300 nm thick vapor-deposited aluminum bolometers are presented
Parathyroid gland autotransplantation: long-term results and direct test of the function of the implant by selective parathyroid hormone determination and stress test
No full textThe precision of PTH measurement and the location of the implant allow the functioning of the transplanted tissue to be easily checked by separately measuring the PTH concentration in the arm bearing the transplant in comparison with the other side. In 10 of the 13 patients operated on by us it was observed that the transplant had grown and was functioning satisfactorily. In 2 further patients, in whom the PTH concentration alone gave no clear information on the functioning of the transplanted tissue, the tolerance test was for this purpose decisive. In fact the transplanted parathyroid tissue showed a rapid and clear response to pharmacodynamic stimulus, which demonstrated the viability of the transplant. We therefore venture to say that pharmacodynamic investigation is of a certain use in postoperative examinations of these patients, especially in doubtful cases. Unfortunately we have had no opportunity to perform a histological investigation of the implanted endocrine tissue, but this has already been reported on in print
Identifying Ecological Corridors of the Bush Cricket Saga pedo in Fragmented Landscapes
No full textThe bush cricket Saga pedo, listed as Vulnerable globally by the IUCN and included in Annex IV of the EU Habitats Directive, is a parthenogenetic species highly sensitive to environmental changes, facing threats from forest expansion and agricultural intensification. S. pedo prefers dry, open habitats with sparse vegetation, and its pronounced thermo-heliophily makes it an indicator of xerothermic habitats. In many areas of Italy, including the Northern Apennines (Piedmont), semi-natural grasslands are fragmented. Open habitats have been reduced to small, isolated patches surrounded by forests due to the abandonment of agropastoral activities. Consequently, the occurrence of open habitat species is related to the quality and availability of suitable areas and ecological connectivity. We developed a spatial Bayesian framework to identify areas of occurrence for S. pedo. Using the inverse probability of occurrence, we derived ecological corridors among suitable patches. Our findings indicate that the occurrence and connectivity of S. pedo are reduced by intensive cultivation but favored by open habitats with 10–50% woody tree cover, suggesting sustainable land management is crucial for supporting the species. Given the extinction risk S. pedo faces, we urge local administrations to maintain and improve suitable areas and guarantee the network of ecological corridors identified
Ecology and abundance of a relict population of the bush cricket Saga pedo in the Northern Apennines, Italy
No full textThe expansion of forest cover and intensification of agriculture represent the main threats to the bush cricket Saga pedo, currently listed as Vulnerable globally by the IUCN and included in Annex IV of the European Union Habitats Directive. Gathering information on its ecology and population size is challenging due to its low abundance and localized distribution. Additionally, the elusive and cryptic behavior of this species reduces the likelihood of its detection, potentially resulting in population underestimations. Thus, in this study, we aimed to (1) estimate S. pedo population size in relation
to environmental variables and prey availability and (2) predict abundance of S. pedo in our study area for future monitoring in nearby territories. We found that the population of S. pedo in our study area consists of 197 (±115) individuals with a detection probability of 21.01% (±11.09). Detection probability of S. pedo further decreases on windy days. Moreover, we found that the investigated population of S. pedo occupies suboptimal areas, as highlighted not only by the predicted abundances but also by the association between S. pedo and other subfamilies of orthoptera that are ecologically very distant from our target species and mostly linked to mesophilic biotopes. Most of the individuals we observed are concentrated in small clearings completely within wooded matrices and therefore isolated from each other. Based on our results, it is possible that forest expansion toward open meadows represents the main threat to this population, transforming the clearings and xeric meadows (to which S. pedo is
linked) into small and fragmented patches that are suboptimal and insufficient to host viable populations
Gabor’s hologram in a modern perspective
No full textWe review Dennis Gabor’s early results in light of more than fifty years of technological achievements, including the advent of CCD cameras and fast computers. By applying digital reading to one of the first holograms, we demonstrate the continuity between the classical technique and the digital implementation. This experiment can be used as a demonstration without needing the instrumentation of an optics laboratory
Ion induced spinodal dewetting of thin solid films
No full textWe present experimental data and numerical simulations in order to show that the mechanism of spinodal dewetting is active during ion beam irradiation of thin solid films. The expected scaling law for the characteristic wavelengths versus the initial film thickness is modified by the presence of sputtering. The conclusion is fully supported by model simulation which shows a square law dependence for null sputtering yield and a bimodal trend when sputtering is included. This result is in contrast to earlier studies and opens the possibility to control and use ion induced dewetting for the fabrication of functional nanostructures
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