Search results for "EHL"
showing 10 items of 39 documents
Some families of big and stable bundles on $K3$ surfaces and on their Hilbert schemes of points
2021
Here we investigate meaningful families of vector bundles on a very general polarized $K3$ surface $(X,H)$ and on the corresponding Hyper--Kaehler variety given by the Hilbert scheme of points $X^{[k]}:= {\rm Hilb}^k(X)$, for any integer $k \geqslant 2$. In particular, we prove results concerning bigness and stability of such bundles. First, we give conditions on integers $n$ such that the twist of the tangent bundle of $X$ by the line bundle $nH$ is big and stable on~$X$; we then prove a similar result for a natural twist of the tangent bundle of $X^{[k]}$. Next, we prove global generation, bigness and stability results for tautological bundles on $X^{[k]}$ arising either from line bundles…
Early intestinal perforation secondary to congenital mesenteric defects
2016
Abstract Gastrointestinal perforation (GIP) in preterm neonates may be idiopathic, due to necrotizing enterocolitis (NEC), or mechanical obstruction. The predominant cause of GIP in the neonatal period is NEC. Differential diagnosis with congenital malformations, including mesenteric defects leading to internal hernias, is mandatory if the onset is early. We describe two newborns with trans-mesenteric herniation resulting in GIP, and we discuss the presence of possible additional risk factors such as prematurity and predisposing vascular disruption in connective tissue disorders (Ehlers-Danlos syndrome), twinning, and use of assisted reproductive technologies. These cases prompted us to rev…
Acs aberāciju un gaismas izkliedes ietekme uz redzes kvalitāti.
2020
Darbs ir uzrakstīts angļu valodā 66 lapām. Tā satur 33 attēlus, 3 tabulas, 8 grafiki un 121 atsauces uz literatūras avotiem. Mērķis. Izpētīt saistību starp cilvēka redzi un acs iekšējo gaismas izkliedi un mēģināt saprast, vai intraokulārā gaismas izkliede ietekmē acs aberācijas. Izpētīta Strehl koeficientu normalitāte. Metodes. Redzes asumu un jutīgumu pret kontrastu novērtē parastā stāvoklī un ar 3 dažādiem izkliedes filtriem 10 jaunu un veselīgu acu grupai. Pašizveidota modeļa acs viļņu frontes kļūdas tiek izmeklētas ar izkliedes filtriem un bez tiem. Rezultāti. Redzes asums un jutība pret kontrastu ir sliktāka, ja izkliedēšanas filtri tiek novietoti subjekta acu priekšā (p <.05). VA iete…
Gāzu hromatogrāfijas-augstas izšķirtspējas masspektrometrijas metodes izstrāde dehlorānu grupas savienojumu noteikšanai pārtikas produktos
2017
Gāzu hromatogrāfijas-augstas izšķirtspējas masspektrometrijas metodes izstrāde dehlorānu grupas savienojumu noteikšanai pārtikas produktos. Brizga A., zinātniskais vadītājs prof. Vīksna A. un zinātniskā konsultante Mg. chem., doktorante Rjabova J. Maģistra darbs, 47 lappuses, 16 attēli, 14 tabulas, 32 literatūras avots, 1 pielikums latviešu valodā. Darba literatūras apskatā aplūkota un analizēta informācija par dehlorānu grupas savienojumu īpašībām, izplatību apkārtējā vidē un cilvēku organismā, kā arī par noteikšanas metodēm. Izvērtēti piemērotākie paraugu sagatavošanas un instrumentālās analīzes parametri. Darbā izstrādāta dehlorānu grupas savienojumu noteikšanas metode, izmantojot gāzu h…
Ehlers-Danlos syndrome type VII: phenotype and genotype
1994
A patient suffering from a severe form of Ehlers-Danlos syndrome is presented (EDS type VII). The presence of bilateral congenital hip dislocation, generalized joint hypermobility and a soft hyperelastic skin with abnormal scarring suggested a specific collagen type I defect. SDS-PAGE analysis of collagens secreted into the medium of fibroblast cultures showed a retarded migration of more than half of the alpha 2(I) chains. CNBr peptide mapping of the HPLC-purified altered chain localized the mutant locus to the N-terminal region of the protein. cDNA analysis of the corresponding gene COL1A2 revealed, in addition to the expected collagen sequence, a transcript missing the entire exon 6. Thi…
Lack of effect of intraocular lens asphericity on visual performance with acrylic intraocular lenses.
2011
Purpose. To determine whether implantation of acrylic intraocular lens (IOL) with aspheric design (Tecnis Z9003, AMO) results in improved visual acuity or contrast sensitivity compared with conventional spherical acrylic IOL (AR40e, AMO). Methods. In an intraindividual randomized prospective study of 60 patients with bilateral cataract, the Tecnis Z9003 IOL was compared with the AR40e IOL. Ocular aberrations for a 4.0-mm pupil and 6.0-mm pupil were measured with a Hartmann-Shack aberrometer. Quality of vision was measured using visual acuity and contrast sensitivity under mesopic and photopic conditions. Results. Eyes with the Tecnis Z9003 IOL had significantly less spherical aberration and…
Optical quality comparison among different Boston contact lens materials.
2014
BACKGROUND The aim was to assess the optical quality of four Boston contact lens materials with an optical device based on Schlieren interferometry. METHODS The NIMO TR1504 (Lambda-X, Nivelles, Belgium) was used to measure higher-order aberrations and their corresponding root mean square values of four different rigid gas permeable contact lenses made from four different Boston materials: EO, ES, XO and XO2 . For each lens, 30 measurements were performed with two optical apertures: 3.0 mm and 6.0 mm. The modulation transfer function, point spread function, Strehl ratio and a simulation of the image provided by the lens were computed from the Zernike coefficients measured up to the fourth or…
Mitchell in Italia
2017
L'articolo, postfazione al libro Pictorial Turn. Saggi di cultura visuale, mette in evidenza e collega gli studi italiani che hanno subito l'influenza delle teorizzazioni di WJT Mitchell e che hanno contribuito a creare la corrente italiana della visual culture attraverso discipline differenti come le letterature comparate, l'estetica, la filosofia, gli studi sul cinema, persino l'architettura.
In vitro optical quality comparison of 2 trifocal intraocular lenses and 1 progressive multifocal intraocular lens.
2015
Purpose To evaluate the optical quality of 3 multifocal intraocular lenses (IOLs): the Mini Well Ready progressive multifocal aspheric IOL, the AT LISA trifocal diffractive IOL, and the Finevision full diffractive trifocal IOL. Setting University of Valencia, Valencia, Spain. Design Experimental study. Methods An instrument designed for measuring real-time modulation transfer function (MTF) and IOL power was used to measure the optical quality of each IOL for 3.0 mm and 4.5 mm apertures. This instrument measures both sagittal and tangential MTFs. The optical quality of each IOL was evaluated with the MTF, through-focus MTF, defocus tolerance, Strehl ratio MTF, and relative percentage of lig…
Il pedone, dal viadotto alle greenway. Figure architettoniche del suolo per camminare in città, 1960-2015
2022
L’articolo traccia un quadro nel quale le fasi successive dell’architettura della città europea del Novecento si leggono attraverso il rapporto fra il pedone e la strada, e pone l’ipotesi che la condizione contemporanea di tale rapporto sia l’aggiornamento di un tema indicatore dell’evoluzione del ruolo della maglia viaria. Come ogni strada, la via pedonale è un’infrastruttura, in cui interagiscono l’idea di progresso, i modi di fabbricazione e consumo degli spazi urbani, nuovi orizzonti politici e di investimento economico, e che rinvia ad immaginari collettivi. A partire dall’inizio della pedonalizzazione, nei primi anni Sessanta, l’articolo discute in un’ottica comparativa e genealogica …