Biology subjects

Surdo, S.

Publications and source records attributed to Surdo, S..

2 recordsLinked to original sources

bioRxiv2022

Optical-quality assessment of a miniaturized intraocular telescope

PurposeEvaluating the optical transmission and geometrical aberrations of an intraocular device, namely, the Small-Incision New Generation Implantable Miniature Telescope (SING IMT, Samsara Vision), designed to correct age-related macular degeneration. MethodsOptical transmission in the spectral range 350-750 nm of the implantable optics was recorded with a fiber-optic spectrometer. Geometrical aberrations were studied by measuring the wavefront of a laser beam after passing through the implantable optics and performing an expansion of the measured wavefront into a Zernike polynomial basis. The study was conducted under in-vitro experimental conditions. A second monofocal intraocular lens (SY60WF, Alcon) was tested and used as reference for assessing the optical quality of the SING IMT device. ResultsSpectroscopy measurements revealed that the SING IMT and monofocal IOL element feature UV-rejection and blue-rejection capabilities, respectively. Wavefront concavity indicated that the SING IMT behaves as a diverging lens with a focal length of approximately -100 mm; Zernike analysis showed that SING IMT has negligible coma, trefoil, astigmatism, and spherical aberrations of any order and along any direction. ConclusionsThe SING IMT exhibited even optical transmission in the whole visible spectrum and curvature capable of magnifying the retinal images without introducing geometrical aberrations, which proves the feasibility of this device as high-quality optical element for imaging. The rigidity of the compound lens of the SING IMT prevents mechanically-induced distortions, an issue encountered with polymeric lenses. Translational RelevanceSpectrometry and in vitro wavefront analysis provide evidence supporting the new generation miniaturized telescopic intraocular lens as a favorable option to intraocular implant in age-related macular degeneration.

biophysics↗

bioRxiv2020

Italian Odonates in the Pandora's Box: A Comprehensive DNA Barcoding Inventory Shows Taxonomic Warnings at the Holarctic Scale

The Odonata are considered among the most endangered freshwater faunal taxa. Their DNA-based monitoring relies on validated reference datasets that are often lacking or do not cover important biogeographical centres of diversification. This study presents the results of a DNA barcoding campaign on Odonata, based on the standard 658 bp 5 end region of the mitochondrial COI gene, involving the collection of 812 specimens (409 of which barcoded) from peninsular Italy and its main islands (328 localities), belonging to all the 88 species (31 Zygoptera and 57 Anisoptera) known from the country. Additional BOLD and GenBank data from Holarctic samples expanded the dataset to 1294 DNA barcodes. A multi-approach species delimitation analysis involving two distance (OT and ABGD) and four tree-based (PTP, MPTP, GMYC, bGMYC) methods were used to explore these data. Of the 88 investigated morphospecies, 75 (85%) unequivocally corresponded to distinct Molecular Operational Units, whereas the remaining ones were classified as warnings (i.e., showing a mismatch between morphospecies assignment and DNA-based species delimitation). These results are in contrast with other DNA barcoding studies on Odonata showing up to 95% of identification success. The species causing warnings were grouped in three categories depending on if they showed low, high, or mixed genetic divergence patterns. The analysis of haplotype networks revealed unexpected intraspecific complexity at the Italian, Palearctic, and Holarctic scale, possibly indicating the occurrence of cryptic species. Overall, this study provides new insights into the taxonomy of odonates and a valuable basis for future DNA and eDNA-based monitoring studies.

zoology↗