3,665 research outputs found
Recommended from our members
Improved model for air pressure due to wind on 2D freak waves in finite depth
This paper presents an improved model for evaluating air pressure acting on 2D freak waves in a finite depth due to the presence of winds. This pressure model is developed by analysing the pressure distribution over freak waves using the QALE-FEM/StarCD approach, which combines the quasi arbitrary Lagrangian-Eulerian finite element method (QALE-FEM) with the commercial software package StarCD and has been proven to be sufficiently accurate for such cases according to our previous publication Yan and Ma (2010) [8]. In this model for air pressure, the pressure is decomposed into the components related to the local wave profiles and others. By coupling with the QALE-FEM, the accuracy of the pressure model is tested using various cases. The results show that the pressure distribution estimated using this model is close to that computed by using the QALE-FEM/StarCD approach when there is no significant vortex shedding and wave breaking. The accuracy investigation in predicting the freak wave heights and elevations demonstrates that this pressure model is much better than others in the literature so far used for modelling wind effects on freak waves in finite depth
Leishmania donovani complex: genotyping with the ribosomal internal transcribed spacer and the mini-exon.
Intergenic region typing by restriction analysis of the ribosomal internal transcribed spacer (ITS) and mini-exon provide diagnostic markers for some Leishmania. Here, we evaluate restriction analysis of these targets for genotyping and phylogenetic analysis within the Leishmania donovani complex (agents of visceral leishmaniasis). Each method was useful for genotyping of both L. donovani complex strains and Old World Leishmania species. The targets produced less robust groups than gp63 intergenic regions, but support the need for re-evaluation of the taxonomy of the L. donovani complex
Immunological selection for Leishmania (Viannia) braziliensis antigens.
Comparative ELISA and selective immunoblotting procedures were used in attempts to identify differential serological indicators of infection with the Leishmania (Viannia) braziliensis complex, infection with the L. braziliensis species, and therapeutic cure of localized or mucocutaneous leishmaniasis (LCL or MCL). Although mean ELISA absorbance values were significantly higher for MCL sera than for LCL sera, absorbance could not be used as a reliable indicator of the clinical form of disease. Immunoblotting profiles were similar with sera from MCL and LCL. Pre-adsorption with heterologous trypanosomatid antigens indicated that recognition of antigens of about 56, 60, 66, 72, 88 and 110 kDa might be specific to the subgenus Viannia. In two-colour, sequential, dual ELISA-based immunoblotting, no antigens recognized only by sera from MCL patients were detected. After glucantime therapy, immunoblotting profiles with LCL sera were reduced both in intensity and in the range of antigens detected; a 104-kDa antigen was newly detected with post-treatment LCL sera. Overall, the results show the value of differential immunological detection strategies and support the close relationship between species of the subgenus Viannia but fail to indicate a prognostic antigen for MCL
First detection of Leishmania major in peridomestic Phlebotomus papatasi from Isfahan province, Iran: comparison of nested PCR of nuclear ITS ribosomal DNA and semi-nested PCR of minicircle kinetoplast DNA.
Two PCR methods were compared for their sensitivity in detecting cultured Leishmania major, before being used to estimate infection rates in female sandflies (Phlebotomus papatasi) collected from peridomestic animal shelters and the nearby burrows of the gerbil reservoir hosts, Rhombomys opimus, in Isfahan province, central Iran. A semi-nested PCR was used to amplify a fragment of minicircle kinetoplast (k) DNA with a length and sequence diagnostic for L. major, and a nested PCR was developed to amplify a fragment containing the internal transcribed spacers of the ribosomal RNA genes (ITS-rDNA) with a sequence diagnostic for L. major. The semi-nested PCR was less sensitive than the nested PCR when using DNA extracted from cultured promastigotes of L. major, but it was more sensitive for detecting L. major in wild-caught sandflies. At the edges of two Isfahan villages, infection rates were significantly higher in P.papatasi collected outside gerbil burrows (14/28) compared with those from peridomestic animal shelters (2/21). This is the first record of L. major detected in P.papatasi from peridomestic sites in Isfahan province
Measurement of the spin-orbit coupling interaction in ring-core optical fibers
Ring-core optical fibers have been designed to carry orbital angular momentum modes. We demonstrate the imaging of these modes, individually identifying modes separated temporally by only 30 ps. A single-pixel camera operating in the short-wave infrared detection range is used to image the 1550 nm wavelength optical modes. With this technique, examination of these optical modes can be performed with significantly higher temporal resolution than is possible with conventional imaging systems, such that the imaging of modes separated by spin-orbit coupling is achieved and evaluated. Deconvolution is required to separate the instrument response from the optical mode signal, increasing the clarity and temporal resolution of the measurement system
Assembly and force measurement with SPM-like probes in holographic optical tweezers
We report a high fidelity tomographic reconstruction of the quantum state of photon pairs generated by parametric down-conversion with orbital angular momentum (OAM) entanglement. Our tomography method allows us to estimate an upper and lower bound for the entanglement between the down-converted photons. We investigate the two-dimensional state subspace defined by the OAM states ±â and superpositions thereof, with â=1, 2, ..., 30. We find that the reconstructed density matrix, even for OAMs up to around â=20, is close to that of a maximally entangled Bell state with a fidelity in the range between F=0.979 and F=0.814. This demonstrates that, although the single count-rate diminishes with increasing â, entanglement persists in a large dimensional state space
- âŠ