230 research outputs found
On the Global Structure of Stellar Magnetospheres with Stellar Winds
The solutions for the magnetic field and stellar wind in axially symmetric stellar magnetospheres are obtained through perturbational method in three artificial extreme situations, i.e., the limits of weak magnetic field, strong magnetic field and weak electromagnetic coupling. The set of basic equations are derived from MHD equations in the two-fluid approximation of a plasma by assuming quasi-neutrality and small mass ratio of electrons to protons. It is emphasized in this treatment that, since the inertial term in the generalized Ohm\u27s law has generally a non-zero rotation, the \u27violation of flux-freezing\u27 arises even in a perfectly conducting plasma. This fact makes it possible for a stellar wind to blow across the magnetic lines of force. The global structure of a stellar magnetosphere is inferred from the results obtained in the three extreme situations. It is suggested that the magnetosphere have generally the closed magnetic lines of force and the stellar wind blows across them forming a current sheet which may result in a very elongated shape of the lines of force at about the equatorial plane
Spectropolarimetric Study on Circumstellar Structure of Microquasar LS I +61deg 303
We present optical linear spectropolarimetry of the microquasar LS I
+61 303. The continuum emission is mildly polarized (up to 1.3 %) and
shows almost no temporal change. We find a distinct change of polarization
across the H emission line, indicating the existence of polarization
component intrinsic to the microquasar. We estimate the interstellar
polarization (ISP) component from polarization of the H line and derive
the intrinsic polarization component. The wavelength dependence of the
intrinsic component is well explained by Thomson scattering in equatorial disk
of the Be-type mass donor. The position angle (PA) of the intrinsic
polarization represents the rotational axis of the Be disk.
This PA is nearly perpendicular to the PA of the radio jet found during
quiescent phases. Assuming an orthogonal disk-jet geometry around the compact
star, the rotational axis of the accretion disk is almost perpendicular to that
of the Be disk. Moreover, according to the orbital parameters of the
microquasar, the compact star is likely to get across the Be disk around their
periastron passage. We discuss the peculiar circumstellar structure of this
microquasar inferred from our observation and possible connection with its
high-energy activities.Comment: 17pages, 7figures; accepted for Publications of the Astronomical
Society of Japa
Drastic Spectroscopic Variability of the Be/X-ray Binary A0535+262/V725 Tau during and after the 2009 Giant Outburst
We report on high-dispersion optical spectroscopic observations of the
Be/X-ray binary A0535+262/V725 Tau during the giant outburst in
November/December 2009 and after it. The observed emission line profiles,
reflecting the structure of the geometrically thin circumstellar envelope of
the Be star (Be disk), show drastic variabilities and indicate the existence of
a warped component. The enhanced blue shoulder seen after periastron passage
implies the gas stream from a dense part of the Be disk to the neutron star.Comment: accepted to PAS
mtDNA and Hemodynamics in Mood Disorders
Background: Given a lack of markers, diagnoses of bipolar disorder (BD) and major depressive disorder (MDD) rely on clinical assessment of symptoms. However, the depressive mood states of BD and depressive symptoms of MDD are often difficult to distinguish, which leads to misdiagnoses, which in turn leads to inadequate treatment. Previous studies have shown that the hemodynamic responses of the left frontopolar cortex measured by near-infrared spectroscopy (NIRS) differ between BD and MDD; these hemodynamic responses are associated with altered mitochondrial metabolism; and mitochondrial DNA copy number (mtDNAcn), an index of mitochondrial dysfunction, tends to decrease in BD and increase in MDD patients. In this study, we confirmed that mtDNAcn trends in opposite directions in BD and MDD. We then determined whether mtDNAcn could enhance the utility of NIRS as a diagnostic marker to distinguish between BD and MDD.
Methods: We determined mtDNAcn in peripheral blood samples from 58 healthy controls, 79 patients with BD, and 44 patients with MDD. Regional hemodynamic responses during a verbal fluency task (VFT) in 24 BD patients and 44 MDD patients, matched by age and depression severity, were monitored using NIRS.
Results: Measurements of mtDNAcn were lower in BD patients and higher in MDD patients than in controls. The left frontopolar region exhibited the most significant differences in mean VFT-related oxy-Hb changes between the BD and MDD groups. Multivariate logistic regression analysis with variables including age, sex, hemodynamic response of the left frontopolar region, and mtDNAcn showed high accuracy for distinguishing BD from MDD (area under the curve = 0.917; 95% confidence interval = 0.849–0.985). For the BD group, we observed a positive correlation between hemodynamic responses in the left frontopolar region and mtDNAcn, while for the MDD group, we observed a negative correlation.
Conclusions: Our findings suggest that the association between hemodynamic response and mitochondrial dysfunction in BD or MDD plays an important role in differentiating the pathophysiological mechanisms of BD from those of MDD
BALB/c-Fcgr2b−/−Pdcd1−/− mouse expressing anti-urothelial antibody is a novel model of autoimmune cystitis
We report the impact of anti-urothelial autoantibody (AUAb) on urinary bladder phenotype in BALB/c mice deficient of the FcγRIIb and PD-1. AUAb was present in serum samples from approximately half of the double-knockout (DKO) mice, as detected by immunofluorescence and immunoblots for urothelial proteins including uroplakin IIIa. The AUAb-positive DKO mice showed degeneration of urothelial plaque and umbrella cells, along with infiltration of inflammatory cells in the suburothelial layer. TNFα and IL-1β were upregulated in the bladder and the urine of AUAb-positive DKO mice. Voiding behavior of mice was analyzed by the Voided Stain on Paper method. 10-week-old and older AUAb-positive DKO mice voided significantly less urine per void than did wild type (WT) mice. Furthermore, administration of the AUAb-containing serum to WT mice significantly reduced their urine volume per void. In summary, this report presents a novel comprehensive mouse model of autoimmune cystitis
Loss of miR-542-3p enhances IGFBP-1 expression in decidualizing human endometrial stromal cells
Endometrial decidualization represents an essential step for the successful implantation of the embryo; however, the molecular mechanism behind this differentiation process remains unclear. This study aimed to identify novel microRNAs (miRNAs) involved in the regulation of decidual gene expression in human endometrial stromal cells (HESCs). An in vitro analysis of primary undifferentiated and decidualizing HESCs was conducted. HESCs were isolated from hysterectomy specimens from normally cycling premenopausal women with uterine fibroids, who were not on hormonal treatment at the time of surgery. Primary HESCs were expanded in culture and decidualized with 8-bromo-cyclic adenosine monophosphate and medroxyprogesterone acetate. Microarray analysis identified six miRNAs differentially expressed in response to decidualization of HESCs. All but one miRNA were downregulated upon decidualization, including miR-542-3p. We demonstrated that miR-542-3p overexpression inhibits the induction of major decidual marker genes, including IGFBP1, WNT4 and PRL. In addition, miR-542-3p overexpression inhibited the morphological transformation of HESCs in response to deciduogenic cues. A luciferase reporter assay confirmed that the 3′-untranslated region of IGFBP1 mRNA is targeted by miR-542-3p. The results suggest that miR-542-3p plays an important role in endometrial decidualization by regulating the expression of major decidual marker genes
The Recognition of The Childminder Choice Student about The Information Appliance Utilization in The Preschool Education
In this study, we clarified how a childminder choice student understood the use of the information appliance for preschool education. Specifically, we performed a cluster analysis based on student responses that we obtained by Silent Dialogue, and analyzed the answers both quantitatively and qualitatively. Based on the results, we considered methods for increasing effectiveness of future practice. In addition, for training subjects such as“preschool education methods,” we piloted some concrete practices to consider the best approaches for teaching. Finally, the results of this study are discussed and future problems are described
Peculiar mechanisms of graft recovery through anti-inflammatory responses after rat lung transplantation from donation after cardiac death
Background: Although lung transplantation from donation after cardiac death (DCD), especially uncontrolled DCD, is limited by warm ischemic periods, the molecular mechanism of warm ischemia-reperfusion-injury (IRI) has not been well elucidated. The purpose of this study was to clarify the particular longitudinal mechanisms of molecular factors involved in warm IRI.
Methods: Cold ischemic-time (CIT)-group lungs were retrieved and subjected to 3-h of cold preservation, whereas warm ischemic-time (WIT)-group lungs were retrieved after 3-h of warm ischemia. Orthotopic rat lung transplantation was performed and the grafts were reperfused for 1 or 4-h. The graft functions, gene expression, and activation of inflammatory molecules in the grafts were analyzed. Exhaled-carbon-monoxide-concentration (ExCO-C) was measured during reperfusion.
Results: Only the WIT-group showed obvious primary graft dysfunction at 1-h reperfusion, but the graft function was recovered during 4-h reperfusion. Most of pro-inflammatory cytokines and stress-induced molecules showed different expression and activation patterns between CIT and WIT groups. In the WIT-group, the expressions of anti-inflammatory molecules, IL-10 and HO-1, were significantly increased at 1-h reperfusion compared to the CIT-group, and these high levels were maintained through 4-h reperfusion. Furthermore, ExCO-C levels in the WIT-group increased immediately after reperfusion compared to the CIT-group.
Conclusions: This study indicates that warm IRI may involve a different mechanism than cold IRI and anti-inflammatory pathways may play important roles in the graft recovery after lung transplantation from uncontrolled DCD
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