Ultralight vector dark matter search using data from the KAGRA O3GK run

Among the various candidates for dark matter (DM), ultralight vector DM can be probed by laser interferometric gravitational wave detectors through the measurement of oscillating length changes in the arm cavities. In this context, KAGRA has a unique feature due to differing compositions of its mirrors, enhancing the signal of vector DM in the length change in the auxiliary channels. Here we present the result of a search for U(1)B−L gauge boson DM using the KAGRA data from auxiliary length channels during the first joint observation run together with GEO600. By applying our search pipeline, which takes into account the stochastic nature of ultralight DM, upper bounds on the coupling strength between the U(1)B−L gauge boson and ordinary matter are obtained for a range of DM masses. While our constraints are less stringent than those derived from previous experiments, this study demonstrates the applicability of our method to the lower-mass vector DM search, which is made difficult in this measurement by the short observation time compared to the auto-correlation time scale of DM

Racial variation in the O-acetylation phenotype of human colonic mucosa

O-acetylated and non-O-acetylated sialoglycoproteins can be distinguished by the mPAS (mild periodic acid-Schiff) histochemical technique. Individual adults show one of three different patterns of staining of large intestinal mucosa: uniformly mPAS-positive, uniformly mPAS-negative, or mPAS-negative with scattered mPAS-positive crypts. To test our hypothesis that these variations are the result of a single autosomal gene (oat) polymorphism, we have studied the frequency of the three patterns of staining in a total of 435 adult colon specimens from six geographically separate populations: British, South African blacks, Icelanders, Japanese, Hong Kong Chinese, and Bahrainis. The distribution of the three types of staining fell into two groups. In Japanese and Chinese, uniformly mPAS-positive cases were much more frequent than uniformly mPAS-negative cases; this distribution differed significantly (χ 2 P<0.001) from that in non-Sine-Japanese, where the uniformly mPAS-positive phenotype was much less frequently found than the uniformly mPAS-negative phenotype. In neither of the groups did the frequency of the three phenotypes differ significantly from that predicted for a single gene polymorphism by the Hardy-Weinberg law. The variation in staining patterns between populations is consistent with variation in frequency of a single polymorphic autosomal gene (oat) controlling O-acetylation of sialic acid, probably by an O-acetyl transferase enzyme. Loss of function mutation in the high acetylator gene (oat a) in a colonic crypt stem cell in heterozygous individuals would account for the scattered discordant crypts. Gene frequencies for a variety of enzymes differ between the Sine-Japanese and non-Sine-Japanese races. This newly described gene polymorphism may be related to differential susceptibility to organisms binding specifically to either O-acetylated or non-O-acetylated sialoglycoproteins, or to differential enteric colonization by bacterial flora that vary in their relative secretion of sialidases and sialate O-acetyl esterases.link_to_subscribed_fulltex