We propose an ultracompact high-efficiency polarizing beam splitter that operates over a wide wavelength range and is based on a hybrid photonic crystal and a conventional waveguide structure. Within a small area (15 microm x 10 microm), this polarizing beam splitter separates TM- and TE-polarized modes into orthogonal output waveguides. Results of simulations with the two-dimensional finite-di...

The Drosophila body axes are established in the oocyte during oogenesis. Oocyte polarization is initiated by Gurken, which signals from the germline through the epidermal growth factor receptor (Egfr) to the posterior follicle cells (PFCs). In response the PFCs generate an unidentified polarizing signal that regulates oocyte polarity. We have identified a loss-of-function mutation of flapwing, ...

We introduce a novel polarizing beam splitter that uses the anisotropic spectral reflectivity (ASR) characteristics of a high spatial frequency multilayer binary grating. By combining the form birefringence effect of a high spatial frequency grating with the resonant reflectivity of a periodic multilayer structure, the ASR characteristics for the two orthogonal linear polarizations are obtained...

Fibroblast growth factors (FGFs) act as signals in the developing limb and can maintain proliferation of limb bud mesenchyme cells. Remarkably, beads soaked in FGF-1, FGF-2, or FGF-4 and placed in the presumptive flank of chick embryos induce formation of ectopic limb buds, which can develop into complete limbs. The entire flank can produce additional limbs, but generally wings are formed anter...

Several characteristics of oviductal cells, cultured under either polarizing or nonpolarizing conditions, were studied. In vitro produced bovine embryos tested the embryotrophic abilities of the respective conditioned media. Conditioned medium from the apical face of polarized cell monolayers supported higher rates of development to blastocyst and expanded blastocysts. In contrast, conditioned ...

Thermally stimulated depolarization current (TSDC) characteristics of Polyvinyl Pyrrolidone (PVP) electrets are studies in the temperature range 30 to 210 C as functions of the polarizing field (5 to 100kV/cm) and polarizing temperature (40 to 80C). The TSDC spectra comprise two maxima, namely, β and α with their respective locations around 90 C and 172.5 C. These are attributed to dipoleorient...

When polarizing mesoderm from the posterior border of the 4-day chick limb bud is placed adjacent to anterior limb mesoderm and ectodermal ridge, the anterior ridge thickens and mesodermal outgrowth ensues, resulting in supernumerary limb structures. This apposition of anterior and posterior limb tissues can be accomplished by cutting off the apical one third of the limb bud and reimplanting it...

Dielectric multilayer reflectors that are non-polarizing are an important class of optical device and have numerous applications within optical fibres [1], dielectric waveguides [2] and LEDs [3]. Here we report analyses of a biological non-polarizing optical mechanism found in the broadband guanine-cytoplasm "silver" multilayer reflectors of three species of fish. Present in the fish stratum ar...

Impermeable barriers were inserted into the stage-20 to -21 leg bud to test whether or not such an interruption of diffusion of the proposed morphogen from the polarizing zone would result in failure of leg elements to develop anterior to the barrier. Tantalum foil was placed at somite levels 30/31 or mid-31 through the dorsoventral extent of the leg bud separating anterior from posterior mesod...

Much of contemporary political debate in the United States focuses on the issue of polarization: specifically, its causal antecedents and its consequences for policymaking and political conflict. In this article, we argue that partisan preference polarization – conventionally defined as the difference in the favored policy positions of legislators from the two major parties – is not a sufficien...