Gravitational waves from an SMBH binary in M87

In this paper, we study gravitational-wave (GW) emission from a hypothetical supermassive black-hole (SMBH) binary at the center of M87. The existence of a SMBH other than that usually identified with the central AGN is a possible explanation for the observed displacement ($\sim O(1)~{\rm pc}$) between the AGN and the galactic centroid, and it is reasonable to assume consid- ering the evolution of SMBHs through galaxy mergers. Because the period of the binary and the resulting GWs is much longer than the observational time span, we calculate the variation of the GW amplitude, rather than the amplitude itself. We investigate the dependence on the orbital elements and the second BH mass taking the observational constraints into account. The frequency of the GWs is too low to be detected with the conventional pulsar timing array and we propose a new method to detect such low-frequency GWs with the distribution func- tion of pulsar spin-down rates. Although the GWs from a SMBH binary which explains the observed displacement is extremely hard to be detected even with the new method, GWs are still a useful way to probe the M87 center.Comment: 5 pages, 6 figures. Accepted for Publications of the Astronomical Society of Japa

The Meter of Metabolism

The circadian system orchestrates the temporal organization of many aspects of physiology, including metabolism, in synchrony with the 24 hr rotation of the Earth. Like the metabolic system, the circadian system is a complex feedback network that involves interactions between the central nervous system and peripheral tissues. Emerging evidence suggests that circadian regulation is intimately linked to metabolic homeostasis and that dysregulation of circadian rhythms can contribute to disease. Conversely, metabolic signals also feed back into the circadian system, modulating circadian gene expression and behavior. Here, we review the relationship between the circadian and metabolic systems and the implications for cardiovascular disease, obesity, and diabetes

Epidermal stem cells ride the circadian wave

An intriguing study shows that, in epidermal progenitor cells, circadian genes are expressed in successive waves that modulate responses to differentiation signals

Scalable Empirical Dynamic Modeling With Parallel Computing and Approximate k-NN Search

Empirical Dynamic Modeling (EDM) is a mathematical framework for modeling and predicting non-linear time series data. Although EDM is increasingly adopted in various research fields, its application to large-scale data has been limited due to its high computational cost. This article presents kEDM, a high-performance implementation of EDM for analyzing large-scale time series datasets. kEDM adopts the Kokkos performance-portable programming model to efficiently run on both CPU and GPU while sharing a single code base. We also conduct hardware-specific optimization of performance-critical kernels. kEDM achieved up to 6.58× speedup in pairwise causal inference of real-world biology datasets compared to an existing EDM implementation. Furthermore, we integrate multiple approximate k-NN search algorithms into EDM to enable the analysis of extremely large datasets that were intractable with conventional EDM based on exhaustive k-NN search. EDM-based time series forecast enhanced with approximate k-NN search demonstrated up to 790× speedup compared to conventional Simplex projection with less than 1% increase in MAPE.journal articl

Circadian control of interferon-sensitive gene expression in murine skin.

The circadian clock coordinates a variety of immune responses with signals from the external environment to promote survival. We investigated the potential reciprocal relationship between the circadian clock and skin inflammation. We treated mice topically with the Toll-like receptor 7 (TLR7) agonist imiquimod (IMQ) to activate IFN-sensitive gene (ISG) pathways and induce psoriasiform inflammation. IMQ transiently altered core clock gene expression, an effect mirrored in human patient psoriatic lesions. In mouse skin 1 d after IMQ treatment, ISGs, including the key ISG transcription factor IFN regulatory factor 7 (Irf7), were more highly induced after treatment during the day than the night. Nuclear localization of phosphorylated-IRF7 was most prominently time-of-day dependent in epidermal leukocytes, suggesting that these cell types play an important role in the diurnal ISG response to IMQ. Mice lacking Bmal1 systemically had exacerbated and arrhythmic ISG/Irf7 expression after IMQ. Furthermore, daytime-restricted feeding, which affects the phase of the skin circadian clock, reverses the diurnal rhythm of IMQ-induced ISG expression in the skin. These results suggest a role for the circadian clock, driven by BMAL1, as a negative regulator of the ISG response, and highlight the finding that feeding time can modulate the skin immune response. Since the IFN response is essential for the antiviral and antitumor effects of TLR activation, these findings are consistent with the time-of-day-dependent variability in the ability to fight microbial pathogens and tumor initiation and offer support for the use of chronotherapy for their treatment

Hole-doped, High-Temperature Superconductors Li_{x}BC, Na_{x}BC and C_{x} : A Coherent-Potential-Based Prediction

Using density-functional-based methods, we show that the hole-doped Li_{x}BC and Na_{x}BC in P6_{3}/mmc crystal structure and C_{x} in graphite structure are capable of showing superconductivity, possibly with a T_{c} much higher than that of MgB_{2}. We use full-potential methods to obtain the optimized lattice constants a and c, coherent-potential approximation to describe the effects of disorder, Gaspari-Gyorffy formalism to obtain the electron-phonon coupling constant $\lambda$, and Allen-Dynes equation to calculate T_{c} as a function of hole concentration in these alloys.Comment: 4 pages, 5 figure

A new allele of flower color gene W1 encoding flavonoid 3'5'-hydroxylase is responsible for light purple flowers in wild soybean Glycine soja

<p>Abstract</p> <p>Background</p> <p><it>Glycine soja </it>is a wild relative of soybean that has purple flowers. No flower color variant of <it>Glycine soja </it>has been found in the natural habitat.</p> <p>Results</p> <p>B09121, an accession with light purple flowers, was discovered in southern Japan. Genetic analysis revealed that the gene responsible for the light purple flowers was allelic to the <it>W1 </it>locus encoding flavonoid 3'5'-hydroxylase (F3'5'H). The new allele was designated as <it>w1-lp</it>. The dominance relationship of the locus was <it>W1 </it>><it>w1-lp </it>><it>w1</it>. One F₂plant and four F₃plants with purple flowers were generated in the cross between B09121 and a Clark near-isogenic line with <it>w1 </it>allele. Flower petals of B09121 contained lower amounts of four major anthocyanins (malvidin 3,5-di-<it>O</it>-glucoside, petunidin 3,5-di-<it>O</it>-glucoside, delphinidin 3,5-di-<it>O</it>-glucoside and delphinidin 3-<it>O</it>-glucoside) common in purple flowers and contained small amounts of the 5'-unsubstituted versions of the above anthocyanins, peonidin 3,5-di-<it>O</it>-glucoside, cyanidin 3,5-di-<it>O</it>-glucoside and cyanidin 3-<it>O</it>-glucoside, suggesting that F3'5'H activity was reduced and flavonoid 3'-hydroxylase activity was increased. F3'5'H cDNAs were cloned from Clark and B09121 by RT-PCR. The cDNA of B09121 had a unique base substitution resulting in the substitution of valine with methionine at amino acid position 210. The base substitution was ascertained by dCAPS analysis. The polymorphism associated with the dCAPS markers co-segregated with flower color in the F₂population. F₃progeny test, and dCAPS and indel analyses suggested that the plants with purple flowers might be due to intragenic recombination and that the 65 bp insertion responsible for gene dysfunction might have been eliminated in such plants.</p> <p>Conclusions</p> <p>B09121 may be the first example of a flower color variant found in nature. The light purple flower was controlled by a new allele of the <it>W1 </it>locus encoding F3'5'H. The flower petals contained unique anthocyanins not found in soybean and <it>G. soja</it>. B09121 may be a useful tool for studies of the structural and functional properties of F3'5'H genes as well as investigations on the role of flower color in relation to adaptation of <it>G. soja </it>to natural habitats.</p

System-Driven and Oscillator-Dependent Circadian Transcription in Mice with a Conditionally Active Liver Clock

The mammalian circadian timing system consists of a master pacemaker in neurons of the suprachiasmatic nucleus (SCN) and clocks of a similar molecular makeup in most peripheral body cells. Peripheral oscillators are self-sustained and cell autonomous, but they have to be synchronized by the SCN to ensure phase coherence within the organism. In principle, the rhythmic expression of genes in peripheral organs could thus be driven not only by local oscillators, but also by circadian systemic signals. To discriminate between these mechanisms, we engineered a mouse strain with a conditionally active liver clock, in which REV-ERBα represses the transcription of the essential core clock gene Bmal1 in a doxycycline-dependent manner. We examined circadian liver gene expression genome-wide in mice in which hepatocyte oscillators were either running or arrested, and found that the rhythmic transcription of most genes depended on functional hepatocyte clocks. However, we discovered 31 genes, including the core clock gene mPer2, whose expression oscillated robustly irrespective of whether the liver clock was running or not. By contrast, in liver explants cultured in vitro, circadian cycles of mPer2::luciferase bioluminescence could only be observed when hepatocyte oscillators were operational. Hence, the circadian cycles observed in the liver of intact animals without functional hepatocyte oscillators were likely generated by systemic signals. The finding that rhythmic mPer2 expression can be driven by both systemic cues and local oscillators suggests a plausible mechanism for the phase entrainment of subsidiary clocks in peripheral organs