Generalized early dark energy and its cosmological consequences

We investigate cosmological consequences of a generalized early dark energy (EDE) model where a scalar field behaves as dark energy at various cosmological epochs for a broad range of parameters such as the energy scale and the initial field value. We consider power-law and axion-type potentials for such an EDE field and study how it affects the cosmological evolution. We show that gravitational wave background can be significantly enhanced to be detected in future observations such as LISA and DECIGO in some parameter space. Implications of the EDE model are also discussed for a scenario where a blue-tilted inflationary tensor power spectrum can explain the recent NANOGrav 15-year signal. We argue that the bounds on the reheating temperature can be relaxed compared to the case of the standard thermal history.Comment: 23 pages, 8 figures, references adde

The variability in abundance of eugregarines living in the Antarctic krill

The variability in abundance of eugregarines associated with the Antarctic krill Euphausia superba was studied using samples collected from the vicinity of the Antarctic Peninsula. Body length, maturity stage and moult stage with respect to variation in eugregarines infection in krill were examined. Body length was significantly correlated with abundance of eugregarines. The interaction between moult stage and maturity stage was statistically analyzed by ANCOVA with body length as the covariate. The analysis of moult stage did not show a significant effect on abundance of eugregarines while the interaction between maturity stage and body length showed significance. Larger krill have more eugregarines than smaller krill at the same maturity stage. Body length appears to be the most important factor determining the abundance of eugregarines

Dielectric microwave resonator with large optical apertures for spin-based quantum devices

Towards a spin-based quantum microwave-optical photon transducer, we demonstrate a low-loss dielectric microwave resonator with an internal quality factor of $2.30\times10^4$ while accommodating optical apertures with a diameter of $8\, \mathrm{mm}$. The two seemingly conflicting requirements, high quality factor and large optical apertures, are satisfied thanks to the large dielectric constant of rutile ($\mathrm{TiO_2}$). The quality factor is limited by radiation loss, and we confirmed by numerical simulation that this dielectric resonator can achieve a quality factor exceeding $10^6$ by extending the height of the resonator enclosure. Using this resonator, we performed both continuous-wave (cw) and pulse electron spin resonance (ESR) spectroscopy on 2,2-diphenyl-1-picrylhydrazyl (DPPH) crystalline powder and P1 centers in a diamond crystal in a dilution refrigerator. The cw ESR spectroscopy demonstrated high-cooperativity and strong spin-resonator coupling with the DPPH and P1 centers respectively, while the pulse ESR spectroscopy successfully measured longitudinal and transverse relaxation times

Zooplankton distribution patterns in relation to the Antarctic Polar Front Zones Recorded by Continuous Plankton Recorder (CPR) during 1999/2000 Kaiyo Maru cruise

During the 8th Antarctic Expedition of the R/V Kaiyo Maru of the Japan Fisheries Agency, October 1999 to March 2000,a Continuous Plankton Recorder (CPR) was used to investigate zooplankton composition and abundance in the surface of the Indian sector of Southern Ocean between South Africa and Antarctica. Total zooplankton abundance ranged from 0 to 432 individuals/segment (a 5 nautical miles of the surface towing) (Mean±SD=69.7±83.5). Zooplankton abundance tended to be higher in the high latitudes than the Sub-Antarctic Front (SAF). Opposite correlations were observed between zooplankton and seawater temperature (negative), salinity (positive) and in vivo fluorescence value (positive) reflecting the higher abundance of zooplankton found in the cooler waters south of the SAF, which also have higher salinities and phytoplankton. Among twenty-nine species/taxa identified, cyclopoid copepod Oithona spp. were found throughout the transect, and accounted for 53.3% of total zooplankton abundance. Cluster analysis based on seventeen dominant zooplankton species/taxa revealed two groups and three ungrouped individual species/taxa at the 84% dissimilarity level. On the other hand, the cluster analysis based on the samples obtained in a 5 nautical miles indicated two major distinctive zooplankton community groups at 89% dissimilarity level. The main group included most segments in the Polar Frontal Zone (PFZ : region between SAF and the Polar Front) and Antarctic Zone (AZ : south of the Polar Front) with high zooplankton abundance while the second mainly group comprised lower latitude segment with low abundance (<100 individuals/segment)

Regulation of Cytochrome b5 Expression by miR-223 in Human Liver: Effects on Cytochrome P450 Activities

Purpose: Cytochrome b 5 (b 5) is a hemoprotein that transfers electrons to several enzymes to fulfill functions in fatty acid desaturation, methemoglobin reduction, steroidogenesis, and drug metabolism. Despite the importance of b 5, the regulation of b 5 expression in human liver remains largely unknown. We investigated whether microRNA (miRNA) might be involved in the regulation of human b 5. Methods: Twenty-four human liver specimens were used for correlation analysis. In silico analysis and luciferase assay were performed to determine whether the predicted miRNAs functionally target to b 5. The miR-223 was overexpressed into HepG2 cells infected with adenovirus expressing human cytochrome P450. Results: In human livers, the b 5 protein levels were not positively correlated with the b 5 mRNA levels, and miR-223 levels were inversely correlated with the b 5 mRNA levels or the translational efficiencies. The luciferase assay showed that miR-223 functionally binds to the element in the 3′-untranslated region of b 5 mRNA. The overexpression of miR-223 significantly reduced the endogenous b 5 protein level and the mRNA stability in HepG2 cells. Moreover, the overexpression of miR-223 significantly reduced CYP3A4-catalyzed testosterone 6β-hydroxylation activity and CYP2E1-catalyzed chlorzoxazone 6-hydroxylase activity but not CYP1A2-catalyzed 7-ethoxyresorufin O-deethylase activity. Conclusions: miR-223 down-regulates b 5 expression in the human liver, modulating P450 activities. © 2013 Springer Science+Business Media New York

Cigarette smoking substantially alters plasma microRNA profiles in healthy subjects

Circulating microRNAs (miRNAs) are receiving attention as potential biomarkers of various diseases, including cancers, chronic obstructive pulmonary disease, and cardiovascular disease. However, it is unknown whether the levels of circulating miRNAs in a healthy subject might vary with external factors in daily life. In this study, we investigated whether cigarette smoking, a habit that has spread throughout the world and is a risk factor for various diseases, affects plasma miRNA profiles. We determined the profiles of 11 smokers and 7 non-smokers by TaqMan MicroRNA array analysis. A larger number of miRNAs were detected in smokers than in non-smokers, and the plasma levels of two-thirds of the detected miRNAs (43 miRNAs) were significantly higher in smokers than in non-smokers. A principal component analysis of the plasma miRNA profiles clearly separated smokers and non-smokers. Twenty-four of the miRNAs were previously reported to be potential biomarkers of disease, suggesting the possibility that smoking status might interfere with the diagnosis of disease. Interestingly, we found that quitting smoking altered the plasma miRNA profiles to resemble those of non-smokers. These results suggested that the differences in the plasma miRNA profiles between smokers and non-smokers could be attributed to cigarette smoking. In addition, we found that an acute exposure of ex-smokers to cigarette smoke (smoking one cigarette) did not cause a dramatic change in the plasma miRNA profile. In conclusion, we found that repeated cigarette smoking substantially alters the plasma miRNA profile, interfering with the diagnosis of disease or signaling potential smoking-related diseases. © 2013 Elsevier Inc

Redox-sensitive transient receptor potential channels in oxygen sensing and adaptation

Regulation of ion channels is central to the mechanisms that underlie immediate acute physiological responses to changes in the availability of molecular oxygen (O2). A group of cation-permeable channels that are formed by transient receptor potential (TRP) proteins have been characterized as exquisite sensors of redox reactive species and as efficient actuators of electric/ionic signals in vivo. In this review, we first discuss how redox-sensitive TRP channels such as TRPA1 have recently emerged as sensors of the relatively inert oxidant O2. With regard to the physiological significance of O2 sensor TRP channels, vagal TRPA1 channels are mainly discussed with respect to their role in respiratory regulation in comparison with canonical pathways in glomus cells of the carotid body, which is a well-established O2-sensing organ. TRPM7 channels are discussed regarding hypoxia-sensing function in ischemic cell death. Also, ubiquitous expression of TRPA1 and TRPM7 together with their physiological relevance in the body is examined. Finally, based upon these studies on TRP channels, we propose a hypothesis of “O2 remodeling.” The hypothesis is that cells detect deviation of O2 availability from appropriate levels via sensors and adjust local O2 environments in vivo by controlling supply and consumption of O2 via pathways comprising cellular signals and transcription factors downstream of sensors, which consequently optimize physiological functions. This new insight into O2 adaptation through ion channels, particularly TRPs, may foster a paradigm shift in our understanding in the biological significance of O2

Timing jitter removers of photon detectors

Among various performances of photon detectors, the timing jitter is difficult to improve because of its trade-offs with other important performances such as detection efficiency. Such trade-offs have been an issue in applications, especially for high-purity non-Gaussian-state generation necessary in optical quantum computation. Here, we introduce a method using an external fast optical switch -- Timing Jitter Remover (TJR) -- whose time window limits the photon-detectable time of photon detectors and improve the timing jitter without sacrificing other performances. By using a TJR, we experimentally improve the timing jitter of a photon-number-resolving detector based on a transition edge sensor, from 50 ns to 10 ns. Using this improved detector, we generate one of important non-Gaussian states, a Schr\"{o}dinger cat state with Wigner negativity of -0.01, which cannot be observed without TJRs. TJRs would be the key technology for the realization of ultra-fast, fault-tolerant, universal optical quantum computer.Comment: 26 pages, 6 figure