Sequential Formation of Low-Mass Stars in the BRC 14 Region

We have carried out a deep near-infrared survey of a bright-rimmed molecular cloud, BRC 14 (IC 1848A). The 10 sigma limiting magnitude of the survey is 17.7 mag at the K-band. Seventy-four sources are classified as young stellar object (YSO) candidates based on the near-infrared color-color diagram. The faintest YSO candidates may have masses of an order of tenths of the solar mass, assuming the age of 1 Myr. We examined three values as indicators of star formation; fraction of the YSO candidates, extinctions of all sources, and near-infrared excesses of the YSO candidates. All indicators increase from outside of the rim to the center of the molecular cloud, which suggests that the formation of the low-mass stars in the BRC 14 region proceeds from outside to the center of the cloud.Comment: 12 pages, 5 figures, 1 table, PASJ accepte

Near-Infrared Spectroscopy of the Cool Brown Dwarf, SDSS 1624+00

Using the Subaru Telescope, we have obtained multiple near-infrared spectra of the cool brown dwarf, SDSS 1624+00, in search of spectral variability in an 80 minute time span. We have found the suspected variability of water vapor absorption throughout the observations, which requires confirmation by a longer time baseline. After coadding the spectra, we have obtained a high-quality spectrum covering 1.05 to 1.8 um. Three kinds of spectral indicators, the water vapor bands, methane band, and KI lines in J band, suggest that SDSS 1624+00 is warmer and dustier than Gl 229B.Comment: 6 figures, to appear in PAS

Modes of Retrotransposition of Long Interspersed Element-1 by Environmental Factors

Approximately 42% of the human genome is composed of endogenous retroelements, and the major retroelement component, long interspersed element-1 (L1), comprises ∼17% of the total genome. A single human cell has more than 5 × 105 copies of L1, 80∼100 copies of which are competent for retrotransposition (RTP). Notably, L1 can induce RTP of other retroelements, such as Alu and SVA, and is believed to function as a driving force of evolution. Although L1-RTP during early embryogenesis has been highlighted in the literature, recent observations revealed that L1-RTP also occurs in somatic cells. However, little is known about how environmental factors induce L1-RTP. Here, we summarize our current understanding of the mechanism of L1-RTP in somatic cells. We have focused on the mode of L1-RTP that is dependent on the basic helix–loop–helix/per–arnt–sim (bHLH/PAS) family of transcription factors. Along with the proposed function of bHLH/PAS proteins in environmental adaptation, we discuss the functional linking of L1-RTP and bHLH/PAS proteins for environmental adaptation and evolution

Role of the rasGAP-associated docking protein p62^(dok) in negative regulation of B cell receptor-mediated signaling

Antigenic stimulation of the B-cell receptor (BCR) is a central event in the immune response. In contrast, antigen bound to IgG negatively regulates signals from the BCR by cross-linking it to the inhibitory receptor FcγRIIB. Here we show that upon cross-linking of BCR or BCR with FcγRIIB, the rasGAP-associated protein p62^(dok) is prominently tyrosine phosphorylated in a Lyn-dependent manner. Inactivation of the dok gene by homologous recombination has shown that upon BCR cross-linking, p62^(dok) suppresses MAP kinase and is indispensable for FcγRIIB-mediated negative regulation of cell proliferation. We propose that p62^(dok), a downstream target of many PTKs, plays a negative role in various signaling situations

Characteristics of systolic and diastolic potentials recorded in the left interventricular septum in verapamil-sensitive left ventricular tachycardia

We studied the electrophysiological characteristics of systolic (SP) and diastolic (DP) potentials recorded during sinus rhythm (SR) in the left interventricular septum of a 27 year-old woman presenting with verapamil-sensitive idiopathic left ventricular tachycardia (VT). During SR, and during VT, SP was activated from ventricular base-to-apex, and DP from apex-to-base. SP and DP were both detected at the site of successful ablation during SR, whereas during VT, DP was detected away from the earliest activation site. Thus, SP apparently reflected a critical component of the reentrant circuit, while DP reflected the activation of a bystander pathway

Un autre visage de l’art contemporain japonais : festivals d’art et îles musées

Il y a deux visages bien connus de l’art contemporain japonais : l’un exubérant, explosif et pop – le superflat de Murakami Takashi ; l’autre extrêmement épuré, minimaliste, proche d’une forme de sacralité – comme les photographies d’Hiroshi Sugimoto. Cette dualité bien tranchée et bien connue – si l’on pense notamment à la séquence manga / art traditionnel – pourrait suffire de cadre interprétatif pour nous guider dans les productions japonaises d’aujourd’hui ; et pourtant il semble que ce s..

Simultaneous Two-Photon Absorption of the Thioguanosine Analogue 2′,3′,5′-Tri‑<i>O</i>‑acetyl-6,8-dithioguanosine with Its Potential Application to Photodynamic Therapy

2',3',5'-Tri-O-acetyl-6,8-dithioguanosine (taDTGuo) is an analogue of nucleosides and currently under investigation as a potential agent for photodynamic therapy (PDT). Excitation by simultaneous two-photon absorption of visible or near-infrared light would provide an efficient PDT for deep-seated tumors. The two-photon absorption spectrum of taDTGuo was obtained by optical-probing photoacoustic spectroscopy (OPPAS). A two-photon absorption band corresponding to the S5 ← S0 transition was observed at 556 nm, and the two-photon absorption cross-section σ(2) was determined to be 26 ± 3 GM, which was much larger than that of other nucleobases and nucleosides. Quantum chemical calculations suggested that the large σ(2) value of taDTGuo was responsible for large transition dipole moments and small detuning energy resulting from the thiocarbonyl group at 6- and 8-positions. This is the first report on two-photon absorption spectra and cross-sections of thionucleoside analogues, which could be used to develop a more specific PDT for cancers in deep regions