Ionized Gas Motions and the Structure of Feedback Near a Forming Globular Cluster in NGC 5253

We observed Brackett $\alpha$ 4.05$\mu$m emission towards the supernebula in NGC 5253 with NIRSPEC on Keck II in adaptive optics mode, NIRSPAO, to probe feedback from its exciting embedded super star cluster (SSC). NIRSPEC's Slit-Viewing Camera was simultaneously used to image the K-band continuum at $\sim$$0.1''$ resolution. We register the IR continuum with HST imaging, and find that the visible clusters are offset from the K-band peak, which coincides with the Br $\alpha$ peak of the supernebula and its associated molecular cloud. The spectra of the supernebula exhibit Br $\alpha$ emission with a strong, narrow core. The linewidths are 65-76 km s$^{-1}$, FWHM, comparable to those around individual ultra-compact HII regions within our Galaxy. A weak, broad (FWHM$\simeq$150-175 km s$^{-1}$) component is detected on the base of the line, which could trace a population of sources with high-velocity winds. The core velocity of Br $\alpha$ emission shifts by +13 km s$^{-1}$ from NE to SW across the supernebula, possibly indicating a bipolar outflow from an embedded object, or linked to a foreground redshifted gas filament. The results can be explained if the supernebula comprises thousands of ionized wind regions around individual massive stars, stalled in their expansion due to critical radiative cooling and unable to merge to drive a coherent cluster wind. Based on the absence of an outflow with large mass loss, we conclude that feedback is currently ineffective at dispersing gas, and the SSC retains enriched material out of which it may continue to form stars.Comment: 24 pages, 9 figure

Perturbative Theoretical Model of Electronic Transient Circular Dichroism Spectroscopy of Molecular Aggregates

A chiral analog of transient absorption spectroscopy, transient circular dichroism (TCD) spectroscopy is an emerging time-resolved method. Both spectroscopic methods can probe the electronic transitions of a sample, and TCD is additionally sensitive to the dynamic aspects of chirality, such as those induced by molecular excitons. Here, we develop a theoretical description of TCD for electronic multi-level models in which the pump pulse is linearly polarized and probe pulse is alternately left- and right-circularly polarized. We derive effective response functions analogous to those often used to describe other four-wave mixing methods and then simulate and analyze TCD spectra for three representative multi-level electronic model systems. We elaborate on the presence and detection of the spectral signatures of electronic coherences

International and Interstate Approaches to Taxing Business Income

In the United States, many states have sought the objective of uni- formity by enacting the Uniform Division of Income for Tax Purposes Act (UDITPA). In addition, many of those same states have entered into the Multistate Tax Compact (MTC). The salutary objective of both the UDITPA and the MTC is to provide uniform rules for the allocation and apportionment of income, in order to facilitate both compliance and enforcement, as well as to reduce the likelihood of double taxation. The promised uniformity, however, has been at the same time both illusive and elusive. Experience with the UDITPA and the MTC in the United States has demonstrated that a multilateral treaty would not achieve uni- formity amongst the numerous sovereign countries of the world, primarily because there is no paramount supervisory body in the international arena. At the same time, uniformity could be achieved within the United States by pre-emptive federal legislation uniformly interpreted and ap- plied to all of the states. The uniform application of an apportionment formula to distribute the tax base of a multijurisdictional unitary enter- prise would avoid many of the problems of the separate entity approach, producing a fair, equitable determination of the tax base for state income taxes. Part II of this article will examine the treatment of business income of multinational enterprises under tax treaties, and Part III discusses the determination of the tax base of such enterprises. Part IV examines the evolution of the law pertaining to state imposed taxes on, or measured by, the net business income of multistate unitary enterprises, the issues of jurisdiction and the determination of the tax base. Part V addresses vari- ous attempts to achieve uniformity in state taxation. Part VI suggests that in the international setting, the goal of uniformity is unlikely to be achieved by a multilateral treaty, but that within the United States, pre- emptive federal legislation should be enacted

International and Interstate Approaches to Taxing Business Income

In the United States, many states have sought the objective of uni- formity by enacting the Uniform Division of Income for Tax Purposes Act (UDITPA). In addition, many of those same states have entered into the Multistate Tax Compact (MTC). The salutary objective of both the UDITPA and the MTC is to provide uniform rules for the allocation and apportionment of income, in order to facilitate both compliance and enforcement, as well as to reduce the likelihood of double taxation. The promised uniformity, however, has been at the same time both illusive and elusive. Experience with the UDITPA and the MTC in the United States has demonstrated that a multilateral treaty would not achieve uni- formity amongst the numerous sovereign countries of the world, primarily because there is no paramount supervisory body in the international arena. At the same time, uniformity could be achieved within the United States by pre-emptive federal legislation uniformly interpreted and ap- plied to all of the states. The uniform application of an apportionment formula to distribute the tax base of a multijurisdictional unitary enter- prise would avoid many of the problems of the separate entity approach, producing a fair, equitable determination of the tax base for state income taxes. Part II of this article will examine the treatment of business income of multinational enterprises under tax treaties, and Part III discusses the determination of the tax base of such enterprises. Part IV examines the evolution of the law pertaining to state imposed taxes on, or measured by, the net business income of multistate unitary enterprises, the issues of jurisdiction and the determination of the tax base. Part V addresses vari- ous attempts to achieve uniformity in state taxation. Part VI suggests that in the international setting, the goal of uniformity is unlikely to be achieved by a multilateral treaty, but that within the United States, pre- emptive federal legislation should be enacted

Conformal GaP layers on Si wire arrays for solar energy applications

We report conformal, epitaxial growth of GaP layers on arrays of Si microwires. Silicon wires grown using chlorosilane chemical vapor deposition were coated with GaP grown by metal-organic chemical vapor deposition. The crystalline quality of conformal, epitaxial GaP/Si wire arrays was assessed by transmission electron microscopy and x-ray diffraction. Hall measurements and photoluminescence show p- and n-type doping with high electron mobility and bright optical emission. GaP pn homojunction diodes on planar reference samples show photovoltaic response with an open circuit voltage of 660 mV

10 µm minority-carrier diffusion lengths in Si wires synthesized by Cu-catalyzed vapor-liquid-solid growth

The effective electron minority-carrier diffusion length, L_(n,eff), for 2.0 µm diameter Si wires that were synthesized by Cu-catalyzed vapor-liquid-solid growth was measured by scanning photocurrent microscopy. In dark, ambient conditions, L_(n,eff) was limited by surface recombination to a value of ≤ 0.7 µm. However, a value of L_(n,eff) = 10.5±1 µm was measured under broad-area illumination in low-level injection. The relatively long minority-carrier diffusion length observed under illumination is consistent with an increased surface passivation resulting from filling of the surface states of the Si wires by photogenerated carriers. These relatively large L_(n,eff) values have important implications for the design of high-efficiency, radial-junction photovoltaic cells from arrays of Si wires synthesized by metal-catalyzed growth processes

Childhood Obesity and Slipped Capital Femoral Epiphysis

We thank Emma Morely of STEPS Charity Worldwide (www.steps-charity.org.uk), the patient charity that helped direct the research agenda and will assist in the dissemination of results. We also thank the Information Services Division (ISD) of NHS Scotland for the provision of data from ISD Scotland, particularly Andrew Duffy, the research coordinator within National Services Scotland. FUNDING: Dr Perry is funded by a UK National Institute for Health Research Clinician Scientist Award (grant NIHR/CS/2014/14/012). This article presents independent research funded by the National Institute for Health Research (NIHR). The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR, or the Department of Health.Peer reviewedPostprin

Perceptions of the intergroup structure and anti-Asian prejudice amongst white Australians

Proof oSubjective intergroup beliefs and authoritarianism were assessed in a field study (N= 255) of White Australians’ anti-Asian stereotyping and prejudice. A social identity analysis of intergroup prejudice was adopted, such that perceptions of the intergroup structure (instability, permeability, legitimacy and higher ingroup status) were proposed as predictors of higher prejudice (blatant and covert) and less favorable stereotyping. Consistent with the social identity approach, both independent and interacting roles for sociostructural predictors of Anti-Asian bias were observed, even after demographic and personality variables were controlled. For example, perceived legitimacy was associated with higher prejudice when White Australians’ status position relative to Asian Australians was valued. Moreover, when participants evaluated Whites’ position as unstable and high status or legitimate, perceptions of permeable intergroup boundaries were associated with anti-Asian bias. The present findings demonstrate status protection responses in advantaged group members in a field setting, lending weight to the contention that perceptions of sociostructural threat interact to predict outgroup derogation. Implications for theories of intergroup relations are discussed