Exothermic isospin-violating dark matter after SuperCDMS and CDEX

We show that exothermic isospin-violating dark matter (IVDM) can make the results of the latest CDMS-Si experiment consistent with recent null experiments, such as XENON10, XENON100, LUX, CDEX, and SuperCDMS, whereas for the CoGeNT experiment, a strong tension still persists. For CDMS-Si, separate exothermic dark matter or isospin-violating dark matter cannot fully ameliorate the tensions among these experiments; the tension disappears only if exothermic scattering is combined with an isospin-violating effect of f_n/f_p=-0.7. For such exothermic IVDM to exist, at least a new vector gauge boson (dark photon or dark Z') that connects SM quarks to Majorana-type DM particles is required.Comment: 12 pages, 6 figure

Functional interplay between NTP leaving group and base pair recognition during RNA polymerase II nucleotide incorporation revealed by methylene substitution.

RNA polymerase II (pol II) utilizes a complex interaction network to select and incorporate correct nucleoside triphosphate (NTP) substrates with high efficiency and fidelity. Our previous 'synthetic nucleic acid substitution' strategy has been successfully applied in dissecting the function of nucleic acid moieties in pol II transcription. However, how the triphosphate moiety of substrate influences the rate of P-O bond cleavage and formation during nucleotide incorporation is still unclear. Here, by employing β,γ-bridging atom-'substituted' NTPs, we elucidate how the methylene substitution in the pyrophosphate leaving group affects cognate and non-cognate nucleotide incorporation. Intriguingly, the effect of the β,γ-methylene substitution on the non-cognate UTP/dT scaffold (∼3-fold decrease in kpol) is significantly different from that of the cognate ATP/dT scaffold (∼130-fold decrease in kpol). Removal of the wobble hydrogen bonds in U:dT recovers a strong response to methylene substitution of UTP. Our kinetic and modeling studies are consistent with a unique altered transition state for bond formation and cleavage for UTP/dT incorporation compared with ATP/dT incorporation. Collectively, our data reveals the functional interplay between NTP triphosphate moiety and base pair hydrogen bonding recognition during nucleotide incorporation

Polarizing Lamp

A polarizing lamp includes a polarization beam splitter, a metallic grating reflector having metallic gratings with a trapezoidal profile, and an unpolarized light source positioned between the polarization beam splitter and the metallic grating reflector

Wide-Angle and Broadband Polarization Converter

Apparatus and methods for a polarization converter comprising a polarization beam splitter for receiving an input light beam and allows a transverse magnetic to pass through the polarization beam splitter and reflects a transverse electric wave and a diffraction grating having a reflectivity and polarization convertible grating for receiving the transverse electric wave reflects back a reflected transverse electric wave having a polarization rotation. The broadband wide-angle polarization beam splitter can be alternative optical elements such as a prism or an optical device having multi-layered films. The diffraction grating can be a diffraction grating having alternating parallel protrusions and recesses, metallic diffraction grating, metal-coated diffraction grating, metal-coated multi-layered diffraction grating, non-metallic reflective material surface grating, volume grating, a multi-layer grating, diffractive grating having sub-wavelength grating periods or diffractive grating h