Building a 3.5 m prototype interferometer for the Q & A vacuum birefringence experiment and high precision ellipsometry

We have built and tested a 3.5 m high-finesse Fabry-Perot prototype inteferometer with a precision ellipsometer for the QED test and axion search (Q & A) experiment. We use X-pendulum-double-pendulum suspension designs and automatic control schemes developed by the gravitational-wave detection community. Verdet constant and Cotton-Mouton constant of the air are measured as a test. Double modulation with polarization modulation 100 Hz and magnetic-field modulation 0.05 Hz gives 10^{-7} rad phase noise for a 44-minute integration.Comment: This draft has been presented in the 5th Edoardo Amaldi Conference on Gravitational Wave

Global quantum phase diagram and non-Abelian chiral spin liquid in a spin-3/2 square lattice antiferromagnet

Since strong quantum fluctuations are essential for the emergence of quantum spin liquids, there have been extensive exploration and identification of spin liquid candidates in spin-$1/2$ systems, while such activities are rare in higher spin systems. Here we report an example of non-Abelian chiral spin liquid emerging in spin-$3/2$ Heisenberg model on a square lattice. By tuning Heisenberg exchange interaction and scalar chirality interaction, we map out a quantum phase diagram enclosing three conventional magnetic orders and a chiral spin liquid based on density matrix renormalization group studies. The nature of the spin liquid is identified as a long-sought bosonic version of Read-Rezayi state that supports non-Abelian Fibonacci anyonic statistics, identified by the ground state entanglement spectrum. Significantly, we establish that the non-Abelian CSL emerges through the enlarged local degrees of freedom and enhanced quantum fluctuations near the classical phase boundaries of competing magnetic orders. Our numerical discovery of an exotic quantum spin liquid in spin-$3/2$ system suggests a new route for discovering fractionalized quantum phases in frustrated higher spin magnetic compounds.Comment: LA-UR-22-3320

Q & A Experiment to Search for Vacuum Dichroism, Pseudoscalar-Photon Interaction and Millicharged Fermions

A number of experiments are underway to detect vacuum birefringence and dichroism -- PVLAS, Q & A, and BMV. Recently, PVLAS experiment has observed optical rotation in vacuum by a magnetic field (vacuum dichroism). Theoretical interpretations of this result include a possible pseudoscalar-photon interaction and the existence of millicharged fermions. Here, we report the progress and first results of Q & A (QED [quantum electrodynamics] and Axion) experiment proposed and started in 1994. A 3.5-m high-finesse (around 30,000) Fabry-Perot prototype detector extendable to 7-m has been built and tested. We use X-pendulums and automatic control schemes developed by the gravitational-wave detection community for mirror suspension and cavity control. To polarize the vacuum, we use a 2.3-T dipole permanent magnet, with 27-mm-diameter clear borehole and 0.6-m field length,. In the experiment, the magnet is rotated at 5-10 rev/s to generate time-dependent polarization signal with twice the rotation frequency. Our ellipsometer/polarization-rotation-detection-system is formed by a pair of Glan-Taylor type polarizing prisms with extinction ratio lower than 10-8 together with a polarization modulating Faraday Cell with/without a quarter wave plate. We made an independent calibration of our apparatus by performing a measurement of gaseous Cotton-Mouton effect of nitrogen. We present our first experimental results and give a brief discussion of our experimental limit on pseudo-scalar-photon interaction and millicharged fermions.Comment: 21 pages, 13 figures, submitted to Modern Physics Letter

Enhanced oxidative stress and the glycolytic switch in superficial urothelial carcinoma of urinary bladder

AbstractObjectiveTo examine whether oxidative stress and the glycolytic switch are correlated to tumor grading, tumor recurrence, and disease progression in urothelial carcinoma (UC) of the urinary bladder (UB).MethodsAll surgical specimens obtained from 27 patients (each containing their UC and normal tissues of UB) were subjected to a pathological examination by computerized tomography, and a portion of each specimen was used for the analysis of molecular biomarkers. The mRNA expression levels of pyruvate dehydrogenase kinase-1 (PDK1), hypoxia-inducible factor 1 alpha (HIF-1α), lactate dehydrogenase A (LDHA), pyruvate dehydrogenase, and glucose transporter protein 1 (Glut-1) were measured using TaqMan-based real-time quantitative polymerase chain reaction. In addition, 8-hydroxy-2-deoxyguanosine (8-OHdG) and the mitochondrial DNA (mtDNA) copy number were also determined.ResultsThe 8-OHdG content and glycolytic genes expression were higher in UC of the UB than those in the normal tissues of UB, whereas the mtDNA copy number was depleted. According to the multivariate analysis, patients with Grade 3 tumors had higher expression levels of HIF-1α, LDHA, and Glut-1 than those with Grades 1 and 2 tumors. In addition, patients with locally recurrent tumors had a higher expression of HIF-1α and LDHA than those with nonrecurrent tumors. Furthermore, patients under disease progression had higher levels of HIF-1α and PDK1 than those not under disease progression.ConclusionsUC of the UB manifested that the glycolytic phenotype would reflect the Warburg effect. We suggest that the molecular mechanism in the regulation of glycolytic switch in UC of the UB might provide a specific biomarker for the future development of cancer diagnosis

A role of ygfZ in the Escherichia coli response to plumbagin challenge

Plumbagin is found in many herbal plants and inhibits the growth of various bacteria. Escherichia coli strains are relatively resistant to this drug. The mechanism of resistance is not clear. Previous findings showed that plumbagin treatment triggered up-regulation of many genes in E. coli including ahpC, mdaB, nfnB, nfo, sodA, yggX and ygfZ. By analyzing minimal inhibition concentration and inhibition zones of plumbagin in various gene-disruption mutants, ygfZ and sodA were found critical for the bacteria to resist plumbagin toxicity. We also found that the roles of YgfZ and SodA in detoxifying plumbagin are independent of each other. This is because of the fact that ectopically expressed SodA reduced the superoxide stress but not restore the resistance of bacteria when encountering plumbagin at the absence of ygfZ. On the other hand, an ectopically expressed YgfZ was unable to complement and failed to rescue the plumbagin resistance when sodA was perturbed. Furthermore, mutagenesis analysis showed that residue Cys228 within YgfZ fingerprint region was critical for the resistance of E. coli to plumbagin. By solvent extraction and HPLC analysis to follow the fate of the chemical, it was found that plumbagin vanished apparently from the culture of YgfZ-expressing E. coli. A less toxic form, methylated plumbagin, which may represent one of the YgfZ-dependent metabolites, was found in the culture supernatant of the wild type E. coli but not in the ΔygfZ mutant. Our results showed that the presence of ygfZ is not only critical for the E coli resistance to plumbagin but also facilitates the plumbagin degradation

Functional connectivity decreases in autism in emotion, self, and face circuits identified by knowledge-based enrichment analysis

A powerful new method is described called Knowledge based functional connectivity Enrichment Analysis (KEA) for interpreting resting state functional connectivity, using circuits that are functionally identified using search terms with the Neurosynth database. The method derives its power by focusing on neural circuits, sets of brain regions that share a common biological function, instead of trying to interpret single functional connectivity links. This provides a novel way of investigating how task- or function-related related networks have resting state functional connectivity differences in different psychiatric states, provides a new way to bridge the gap between task and resting-state functional networks, and potentially helps to identify brain networks that might be treated. The method was applied to interpreting functional connectivity differences in autism. Functional connectivity decreases at the network circuit level in 394 patients with autism compared with 473 controls were found in networks involving the orbitofrontal cortex, anterior cingulate cortex, middle temporal gyrus cortex, and the precuneus, in networks that are implicated in the sense of self, face processing, and theory of mind. The decreases were correlated with symptom severity