5,427 research outputs found
Photonic crystal fiber with a hybrid honeycomb cladding
We consider an air-silica honeycomb lattice and demonstrate a new approach to
the formation of a core defect. Typically, a high or low-index core is formed
by adding a high-index region or an additional air-hole (or other low-index
material) to the lattice, but here we discuss how a core defect can be formed
by manipulating the cladding region rather than the core region itself.
Germanium-doping of the honeycomb lattice has recently been suggested for the
formation of a photonic band-gap guiding silica-core and here we experimentally
demonstrate how an index-guiding silica-core can be formed by fluorine-doping
of the honeycomb lattice.Comment: 5 pages including 3 figures. Accepted for Optics Expres
Intranasal immunization with pneumococcal polysaccharide conjugate vaccines with nontoxic mutants of Escherichia coli heat-labile enterotoxins as adjuvants protects mice against invasive pneumococcal infections
To access publisher full text version of this article. Please click on the hyperlink in Additional Links fieldHost defenses against Streptococcus pneumoniae depend largely on phagocytosis following opsonization by polysaccharide-specific immunoglobulin G (IgG) antibodies and complement. Since colonization of the respiratory mucosa is the first step in pneumococcal pathogenesis, mucosal immune responses may play a significant role. In addition to inducing systemic immune responses, mucosal vaccination with an effective adjuvant has the advantage of inducing mucosal IgA antibodies. The heat-labile enterotoxin (LT) of Escherichia coli is a well-studied mucosal adjuvant, and adjuvant activity of nontoxic LT mutants has been demonstrated for several protein antigens. We investigated the immunogenicity of pneumococcal polysaccharide conjugate vaccines (PNC) of serotypes 1 and 3 in mice after intranasal (i.n.) immunization by using as an adjuvant the nontoxic LT mutant LT-K63 or LT-R72, which has minimal residual toxicity. Pneumococcal serotype-specific antibodies were measured in serum (IgM, IgG, and IgA) and saliva (IgA), and vaccine-induced protection was evaluated by i.n. challenge with virulent pneumococci of the homologous serotype. When administered with LT mutants, i.n. immunization with both conjugates induced systemic and mucosal immune responses, and serum IgG antibody levels were significantly higher than after subcutaneous immunization. All mice immunized i.n. with PNC-1 and LT mutants were protected against bacteremia and cleared the pneumococci from the lung 24 h after i.n. challenge; pneumococcal density correlated significantly with serum IgG antibody levels. Similarly, the survival of mice immunized i.n. with PNC-3 and LT mutants was significantly prolonged. These results demonstrate that i.n. vaccination with PNC and potent adjuvants can protect mice against invasive and lethal pneumococcal infections, indicating that mucosal vaccination with PNC may be an alternative vaccination strategy for humans
Speckles and their dynamics for structured target illumination: optical spatial filtering velocimetry
Wave Influenced Wind and the Effect on Offshore Wind Turbine Performance
In this paper the effect of wave influenced wind on offshore wind turbines is studied numerically. The wave is seen as a dynamical roughness that influences the wind flow and hence the wind turbine performance. An actuator line representation of the NREL's 5 MW offshore baseline wind turbine is placed in a simulation domain with a moving mesh that resolves the ocean waves. These wave influenced wind turbine simulations, WIWiTS, show that the wave will influence the wind field at the turbine rotor height. Both the produced power and the tangential forces on the rotor blades will vary according to the three different cases studied: wind aligned with a swell, wind opposing the swell and wind over a surface with low roughness (no waves).publishedVersio
Laudatores Temporis Acti, or Why Cosmology is Alive and Well - A Reply to Disney
A recent criticism of cosmological methodology and achievements by Disney
(2000) is assessed. Some historical and epistemological fallacies in the said
article have been highlighted. It is shown that---both empirically and
epistemologically---modern cosmology lies on sounder foundations than it is
portrayed. A brief historical account demonstrates that this form of
unsatisfaction with cosmology has had a long tradition, and rather meagre
results in the course of the XX century.Comment: 11 pages, no figures; a criticism of astro-ph/0009020; Gen. Rel.
Grav., accepted for publicatio
SUSPENSION-FEEDING IN MARINE SPONGES HALICHONDRIA-PANICEA AND HALICLONA-URCEOLUS - EFFECTS OF TEMPERATURE ON FILTRATION-RATE AND ENERGY-COST OF PUMPING
EP-1514: Soft tissue vs. bony anatomy registration in an adaptive plan selection protocol for bladder cancer
Ultra-large bandwidth hollow-core guiding in all-silica Bragg fibers with nano-supports
We demonstrate a new class of hollow-core Bragg fibers that are composed of
concentric cylindrical silica rings separated by nanoscale support bridges. We
theoretically predict and experimentally observe hollow-core confinement over
an octave frequency range. The bandwidth of bandgap guiding in this new class
of Bragg fibers exceeds that of other hollow-core fibers reported in the
literature. With only three rings of silica cladding layers, these Bragg fibers
achieve propagation loss of the order of 1 dB/m.Comment: 9 pages including 5 figure
Managerial Quality And Risk of Depressive Disorders Among Danish Eldercare Workers:A Multi-Level Cohort Study
The discontinuous Galerkin method for fractional degenerate convection-diffusion equations
We propose and study discontinuous Galerkin methods for strongly degenerate
convection-diffusion equations perturbed by a fractional diffusion (L\'evy)
operator. We prove various stability estimates along with convergence results
toward properly defined (entropy) solutions of linear and nonlinear equations.
Finally, the qualitative behavior of solutions of such equations are
illustrated through numerical experiments
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