181 research outputs found

    An analysis of the debate between economic gobalization and regionalization based on Rawls’s theory of justice

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    Driven by globalization, international economic integration has become unavoidable. Within this broader trend, two distinctive modes of international regime building can be identified globalism and regionalism. Globalism, illustrated using the case of the World Trade Organization (WTO), pushes forward global economic integration using established norms. In contrast, regionalism involves gradual expansion of regional integration mechanisms based on interests of member states. This study assesses these two development modes with justice as a concept of moral rightness. To this effect, Rawls’s theory of justice is applied to evaluate standards of justice in international regimes. Based on Rawls’s two principles of justice, three assessment criteria are developed: (1) equal qualification principle, (2) equal opportunity principle, and (3) difference principle. These criteria are applied for comparative analysis of justice in the development of global and regional regimes in order to develop a model for international regimes that is consistent with the concept of justice. A comparison of (1) qualifications for membership; (2) fairness of decision making mechanisms, and (3) institutionalization of differential treatment shows that justice in global regimes is superior to that in regional regimes. In other words, in terms of the philosophy of moral rightness, states should pursue integration based on the principles of globalism

    The Herbig Be Star V1818 Ori and Its Environment

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    The little-studied Herbig Be star V1818 Ori is located in the direction of the southern L1641 cloud and the Mon R2 star-forming complex, and is most likely associated with the latter at a distance of ~900 pc. A high-resolution spectrum is consistent with a spectral type around B7 V, with lines of Hα, the red Ca ii triplet, and several forbidden lines in emission. An All Sky Automated Survey V-band light curve spanning 9 yr reveals major variability with deep absorption episodes reminiscent of the UX Orionis stars. We have searched for additional young stars clustering around V1818 Ori using grism images and the 2MASS and Wide-field Infrared Survey Explorer catalogs, and have found almost two dozen fainter stars with evidence of youth. Direct images show that the bright star IRAS 05510–1025, only about 3 arcmin from V1818 Ori, is surrounded by a reflection nebula, indicating its association with a molecular cloud. A spectrum of the star shows no emission-lines, and it is found to be a close binary with late B and early G type components. Its radial velocity indicates that it is an interloper, accidentally passing through the cloud and not physically associated with V1818 Ori

    The Brightening of Re50N: Accretion Event or Dust Clearing?

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    The luminous Class I protostar HBC 494, embedded in the Orion A cloud, is associated with a pair of reflection nebulae, Re50 and Re50N, which appeared sometime between 1955 and 1979. We have found that a dramatic brightening of Re50N has taken place sometime between 2006 and 2014. This could result if the embedded source is undergoing a FUor eruption. However, the near-infrared spectrum shows a featureless very red continuum, in contrast to the strong CO bandhead absorption displayed by FUors. Such heavy veiling, and the high luminosity of the protostar, is indicative of strong accretion but seemingly not in the manner of typical FUors. We favor the alternative explanation that the major brightening of Re50N and the simultaneous fading of Re50 is caused by curtains of obscuring material that cast patterns of illumination and shadows across the surface of the molecular cloud. This is likely occurring as an outflow cavity surrounding the embedded protostar breaks through to the surface of the molecular cloud. Several Herbig-Haro objects are found in the region.Comment: 8 pages, accepted by Ap

    Resolved Depletion Zones and Spatial Differentiation of N2H+ and N2D+

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    We present a study on the spatial distribution of N2D+ and N2H+ in thirteen protostellar systems. Eight of thirteen objects observed with the IRAM 30m telescope show relative offsets between the peak N2D+ (J=2-1) and N2H+ (J=1-0) emission. We highlight the case of L1157 using interferometric observations from the Submillimeter Array and Plateau de Bure Interferometer of the N2D+ (J=3-2) and N2H+ (J=1-0) transitions respectively. Depletion of N2D+ in L1157 is clearly observed inside a radius of ~2000 AU (7") and the N2H+ emission is resolved into two peaks at radii of ~1000 AU (3.5"), inside the depletion region of N2D+. Chemical models predict a depletion zone in N2H+ and N2D+ due to destruction of H2D+ at T ~ 20 K and the evaporation of CO off dust grains at the same temperature. However, the abundance offsets of 1000 AU between the two species are not reproduced by chemical models, including a model that follows the infall of the protostellar envelope. The average abundance ratios of N2D+ to N2H+ have been shown to decrease as protostars evolve by Emprechtinger et al., but this is the first time depletion zones of N2D+ have been spatially resolved. We suggest that the difference in depletion zone radii for N2H+ and N2D+ is caused by either the CO evaporation temperature being above 20 K or an H2 ortho-to-para ratio gradient in the inner envelope.Comment: Accepted to ApJ. 44 pages 13 Figure

    Distinct Tumor Microenvironment at Tumor Edge as a Result of Astrocyte Activation Is Associated With Therapeutic Resistance for Brain Tumor

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    Tumor vasculatures and hypoxia are critical tumor micro-environmental factors associated with tumor response to the therapy and heterogeneous in both time- and location-dependent manner. Using a murine orthotopic anaplastic astrocytoma model, ALTS1C1, this study showed that brain tumor edge had a very unique microenvironment, having higher microvascular density (MVD) and better vessel function than the tumor core, but on the other hand was also positive for hypoxia markers, such as pimonidazole (PIMO), hypoxia inducible factor-1α (HIF-1α), and carbonic anhydrase IV (CAIX). The hypoxia at tumor edge was transient, named as peripheral hypoxia, and caused by different mechanisms from the chronic hypoxia in tumor core. The correlation of CAIX staining with astrocyte activation marker, glial fibrillary acid protein (GFAP), at the tumor edge indicated the involvement of astrocyte activation on the development of peripheral hypoxia. Peripheral hypoxia was a specific trait of orthotopic brain tumors at tumor edge, regardless of tumor origin. The hypoxic cells were resistant to the therapy, regardless of their location. Surviving cells, particularly those at the hypoxic region of tumor edge, are likely the cause of tumor recurrence after the therapy. New therapeutic platform that targets cells in tumor edge is likely to achieve better treatment outcomes

    Protoplanetary Disks in ρ\rho Ophiuchus as Seen From ALMA

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    We present a high angular resolution (0.2\sim 0.2^{\prime\prime}), high sensitivity (σ0.2\sigma \sim 0.2 mJy) survey of the 870 μ\mum continuum emission from the circumstellar material around 49 pre-main sequence stars in the ρ\rho Ophiuchus molecular cloud. Because most millimeter instruments have resided in the northern hemisphere, this represents the largest high-resolution, millimeter-wave survey of the circumstellar disk content of this cloud. Our survey of 49 systems comprises 63 stars; we detect disks associated with 29 single sources, 11 binaries, 3 triple systems and 4 transition disks. We present flux and radius distributions for these systems; in particular, this is the first presentation of a reasonably complete probability distribution of disk radii at millimeter-wavelengths. We also compare the flux distribution of these protoplanetary disks with that of the disk population of the Taurus-Auriga molecular cloud. We find that disks in binaries are both significantly smaller and have much less flux than their counterparts around isolated stars. We compute truncation calculations on our binary sources and find that these disks are too small to have been affected by tidal truncation and posit some explanations for this. Lastly, our survey found 3 candidate gapped disks, one of which is a newly identified transition disk with no signature of a dip in infrared excess in extant observations.Comment: 26 pages, 16 figures. Accepted for publication in Ap

    A Sub-arcsecond Survey Toward Class 0 Protostars in Perseus: Searching for Signatures of Protostellar Disks

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    We present a CARMA 1.3 mm continuum survey toward 9 Class 0 protostars in the Perseus molecular cloud at \sim0.3^{\prime\prime} (70 AU) resolution. This study approximately doubles the number of Class 0 protostars observed with spatial resolutions << 100 AU at millimeter wavelengths, enabling the presence of protostellar disks and proto-binary systems to be probed. We detect flattened structures with radii >> 100 AU around 2 sources (L1448 IRS2 and Per-emb-14) and these sources may be strong disk candidates. Marginally-resolved structures with position angles within 30^{\circ} of perpendicular to the outflow are found toward 3 protostars (L1448 IRS3C, IRAS 03282+3035, and L1448C) and are considered disk candidates. Two others (L1448 IRS3B and IRAS 03292+3039) have resolved structure, possibly indicative of massive inner envelopes or disks; L1448 IRS3B also has a companion separated by 0.9^{\prime\prime} (\sim210 AU). IC348-MMS does not have well-resolved structure and the candidate first hydrostatic core L1451-MMS is marginally resolved on 1^{\prime\prime} scales. The strong disk candidate sources were followed-up with C18^{18}O (J=21J=2\rightarrow1) observations, detecting velocity gradients consistent with rotation, but it is unclear if the rotation is Keplerian. We compare the observed visibility amplitudes to radiative transfer models, finding that visibility amplitude ratios suggest a compact component (possibly a disk) is necessary for 5 of 9 Class 0 sources; envelopes alone may explain the other 4 systems. We conclude that there is evidence for the formation of large disks in the Class 0 phase with a range of radii and masses dependent upon their initial formation conditions.Comment: Accepted to ApJ, 58 pages, 19 Figures, 5 Table
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