Search results for "Clad"

2018

We present the design, fabrication and characterization of long-range surface plasmon polariton waveguide arrays with materials, mainly silicones, carefully selected with the aim to be used as mechanically flexible single-mode optical interconnections, the so-called “plasmonic arc” working at 1.55µm. The fabricated plasmonic arcs show a TM/TE polarization ratio of ~25 dB. By using the cut-back method, the straight propagation loss at 1.55µm is estimated to 0.5-1 dB/mm and coupling loss to ~1-2 dB/facet after dicing. In the free-standing S-curved configuration, the bending loss of single cladding plasmonic arc is 2.2-2.8 dB/90° at bending radius 2.5 mm. For double cladding plasmonic arcs, it…

Monitoring the Etching Process in LPFGs towards Development of Highly Sensitive Sensors

2017

Trabajo presentado en la Eurosensors 2017 Conference. París, 3–6 de septiembre de 2017. In this work, the monitoring of the etching process up to a diameter of 30 µm of two LPFG structures has been compared, one of them had initially 125 µm, whereas the second one had 80 µm. By tracking the wavelength shift of the resonance bands during the etching process it is possible to check the quality of etching process (the 80 µm fibre performs better than de 125 µm fibre), and to stop for a specific cladding mode coupling, which permits to obtain an improved sensitivity compared to the initial structure. This work was supported by the Spanish Agencia Estatal de Investigación (AEI) and Fondo Europeo…

Accurate mode characterization of two-mode optical fibers by in-fiber acousto-optics.

2016

Acousto-optic interaction in optical fibers is exploited for the accurate and broadband characterization of two-mode optical fibers. Coupling between LP01 and LP1m modes is produced in a broadband wavelength range. Difference in effective indices, group indices, and chromatic dispersions between the guided modes, are obtained from experimental measurements. Additionally, we show that the technique is suitable to investigate the fine modes structure of LP modes, and some other intriguing features related with modes' cut-off.

Crocidura cossyrensis Contoli, 1989 (Mammalia, Soricidae): karyotype, biochemical genetics and hybridization experiments

2004

The shrew Crocidura cossyrensis Contoli, 1989 from Pantelleria (I), a Mediterranean island 100 km south of Sicily and 70 km west from Tunisia, was investigated in order to understand its origin and its relationship with C. russula from Tunisia, Morocco and Switzerland. With the exception of a single heterozygote centric fusion, C. cossyrensis had a karyotype identical with that of C. russula from Tunisia (2N = 42, NF = 70 to 72), but it differed from C. russula from Morocco and Switzerland (2N = 42, NF = 60). The former have 5-6 pairs of chromosomes with small arms that are acrocentric in the latter. Genetic comparisons with allozyme data revealed small genetic distance (0.04) between C. co…

Molecular data attest to the occurrence of autochthonous Daphnia pulex (Crustacea, Branchiopoda) populations in Sicily, Italy

2021

Biological invasions are known to be among the most important threats to the long-term conservation of native biota, and their effects might be even more difficult to contrast when they are cryptic, i.e., when the non-native invaders cannot be easily recognised based on morphology, and can thus be confused with native taxa. Such cryptic invasions are known to widely occur in the cladoceran genus Daphnia O.F. Müller, 1785, so that the actual distribution and status of most species and lineages need to be checked with a genetic approach. In the frame of this work, we investigated if the Sicilian populations of D. (Daphnia) pulex Leydig, 1860 belonged to the allochthonous North American lineag…

Influence of dibutyryl cyclic AMP on thymidine uptake by herpes simplex virus infected cells and the intracellular level of cyclic AMP.

1977

Abstract Dibutyryl cyclic AMP inhibits the increase of dThd and BrdUrd transport normally observed after infection with Herpesvirus hominis, type I and II. Incorporation is also reduced. Inhibition of uptake is non-competitive as analysed by the Lineweaver-Burk plot. Addition of this drug to infected cells also reduces the activity of the thymidine kinase (EC 2.7.1.75). Transport of dUrd, dCyd and dAdo is not reduced. 4–8 h after infection with thymidine kinase (+) herpes strains the level of cAMP increases. On infection with a thymidine kinase (−) virus, only a small elevation of cAMP can be shown. It was also found that early addition of actinomycin D or of cycloheximide prevents the incr…

An MLSA approach for the taxonomic update of the Splendidus clade, a lineage containing several fish and shellfish pathogenic Vibrio spp.

2016

A multilocus sequence analysis was undertaken in order to redefine the Splendidus clade of the genus Vibrio, a large group of species containing several pathogenic members that affect fish and shellfish, and are difficult to identify through both phenotypic and genotypic approaches. The study included analysis of partial sequences of recA, gyrB, mreB, rpoD and pyrH genes, as well as the 16S rRNA gene. Seventeen type strain species were included that were complemented with other reference strains and a collection of isolates tentatively identified as members of this clade, as well as a set of other Vibrio species. The clade was well defined and stable in all analyses, and was confirmed to co…

Multilocus sequence analysis of putative Vibrio mediterranei strains and description of Vibrio thalassae sp. nov.

2014

A multilocus sequence analysis based on partial gyrB, mreB, rpoD and pyrH genes was undertaken with 61 putative Vibrio mediterranei/V. shilonii strains from different hosts (mussels, oysters, clams, coral, fish and plankton) or habitat (seawater and sediment) and geographical origins (Mediterranean, Atlantic and Pacific). A consistent grouping was obtained with individual and concatenated gene sequences, and the clade, comprising 54 strains, was split into three subclades by all methods: subclade A (40 strains, including AK1, the former type strain of Vibrio shilonii), subclade B (8 strains) corresponding to the species V. mediterranei, and subclade C (six strains) representing a new specie…

Pseudomonas litolaris sp. nov., isolated from mediterranean seawater

2012

Strains 2SM5T and 2SM6, two strictly aerobic chemo-organotrophic gammaproteobacteria, were isolated from Mediterranean seawater off the coast of Vinaroz, Castellón, Spain, in February, 1990. They were extensively characterized by a polyphasic study that placed them in the genus Pseudomonas. Phylogenetic analysis of 16S rRNA gene sequences showed that both strains shared 100 % sequence similarity and were closely related to members of the Pseudomonas pertucinogena clade, with less than 97.3 % similarity to strains of established species; Pseudomonas xiamenensis was the closest relative. Analysis of sequences of three housekeeping genes, rpoB, rpoD and gyrB, further confirmed the phylogenetic…

Description of Tropicibacter mediterraneus sp. nov. and Tropicibacter litoreus sp. nov.

2013

Four strains (M15∅_3, M17(T), M49 and R37(T)) were isolated from Mediterranean seawater at Malvarrosa beach, Valencia, Spain. Together with an older preserved isolate (strain 2OM6) from cultured oysters at Vinaroz, Castellón, Spain, the strains were thoroughly characterized in a polyphasic study and were placed phylogenetically within the Roseobacter clade in the family Rhodobacteraceae. Highest 16S rRNA sequence similarities of the five strains to the types of any established species corresponded to Tropicibacter multivorans (95.8-96.4%), Phaeobacter inhibens (95.9-96.3%) and Phaeobacter gallaeciensis (95.9-96.2%). On the other hand, whole genome (ANI) and protein fingerprinting (MALDI-TOF…