5,133 research outputs found

    The Manchester occulting mask imager (MOMI) - first results on the environment of P Cygni

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    The design and first use of the Manchester occulting mask imager (MOMI) is described. This device, when combined with the Cassegrain or Ritchey-Chretien foci of large telescopes, is dedicated to the imagery of faint line emission regions around bright central sources. Initial observations, with MOMI on the Nordic Optical telescope (NOT), of the V=4.8 mag P~Cygni environment, have revealed a ≥\geq~5~arcmin long [NII] 6584A emitting filament projecting from the outer nebular shell of this luminous blue variable (LBV) star. The presence of a mono-polar lobe older than both the inner (22 arcsec diameter) and outer (1.6 arcmin diameter) shells is suggested.Comment: 4 pages, 4 figures, accepted MNRAS 1998 June 1

    An assessment of the quality of the I-DSD and the I-CAH registries - international registries for rare conditions affecting sex development

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    With the proliferation of rare disease registries, there is a need for registries to undergo an assessment of their quality against agreed standards to ensure their long-term sustainability and acceptability.This study was performed to evaluate the I-DSD and I-CAH Registries and identify their strengths and weaknesses. The design and operational aspects of the registries were evaluated against published quality indicators. Additional criteria included the level of activity, international acceptability of the registries and their use for research. The design of the I-DSD and I-CAH Registries provides them with the ability to perform multiple studies and meet the standards for data elements, data sources and eligibility criteria. The registries follow the standards for data security, governance, ethical and legal issues, sustainability and communication of activities. The data have a high degree of validity, consistency and accuracy and the completeness is maximal for specific conditions such as androgen insensitivity syndrome and congenital adrenal hyperplasia. In terms of research output, the external validity is strong but the wide variety of cases needs further review. The internal validity of data was condition specific and highest for conditions such as congenital adrenal hyperplasia. The shift of the registry from a European registry to an international registry and the creation of a discrete but linked CAH registry increased the number of users and stakeholders as well as the international acceptability of both registries. The I-DSD and I-CAH registries comply with the standards set by expert organisations. Recent modifications in their operation have allowed the registries to increase their user acceptability

    Spitzer/MIPS Imaging of NGC 650: Probing the History of Mass Loss on the Asymptotic Giant Branch

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    We present the far-infrared (IR) maps of a bipolar planetary nebula (PN), NGC 650, at 24, 70, and 160 micron taken with the Multiband Imaging Photometer for Spitzer (MIPS) on-board the Spitzer Space Telescope. While the two-peak emission structure seen in all MIPS bands suggests the presence of a near edge-on dusty torus, the distinct emission structure between the 24 micron map and the 70/160 micron maps indicates the presence of two distinct emission components in the central torus. Based on the spatial correlation of these two far-IR emission components with respect to various optical line emission, we conclude that the 24 micron emission is largely due to the [O IV] line at 25.9 micron arising from highly ionized regions behind the ionization front, whereas the 70 and 160 micron emission is due to dust continuum arising from low-temperature dust in the remnant asymptotic giant branch (AGB) wind shell. The far-IR nebula structure also suggests that the enhancement of mass loss at the end of the AGB phase has occurred isotropically, but has ensued only in the equatorial directions while ceasing in the polar directions. The present data also show evidence for the prolate spheroidal distribution of matter in this bipolar PN. The AGB mass loss history reconstructed in this PN is thus consistent with what has been previously proposed based on the past optical and mid-IR imaging surveys of the post-AGB shells.Comment: 9 pages in the emulated ApJ format with 6 figures, to appear in Ap

    Mercury deposition in southern New Hampshire, 2006–2009

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    The atmospheric deposition of mercury (Hg) occurs via several mechanisms including wet, dry, and occult processes. In an effort to understand the atmospheric cycling and seasonal depositional characteristics of Hg, event-based wet deposition samples and reactive gaseous Hg (RGM) measurements were collected for approximately 3 years at Thompson Farm (TF), a near-coastal rural site in Durham, NH, part of the University of New Hampshire AIRMAP Observing Network. Total aqueous mercury exhibited seasonal patterns in Hg wet deposition at TF. The lowest Hg wet deposition was measured in the winter with an average total seasonal deposition of 1.56 μg m−2compared to the summer average of 4.71 μg m−2. Inter-annual differences in total wet deposition are generally linked with precipitation volume, with the greatest deposition occurring in the wettest year. Relationships between surface level RGM and Hg wet deposition were also investigated based on continuous RGM measurements at TF from November 2006 to September 2009. No correlations were observed between RGM mixing ratios and Hg wet deposition, however the ineffective scavenging of RGM during winter precipitation events was evidenced by the less frequent depletion of RGM below the detection level. Seasonal dry deposition of reactive gaseous Hg (RGM) was estimated using an order-of-magnitude approach. RGM mixing ratios and dry deposition estimates were greatest during the winter and spring. The seasonal ratios of Hg wet deposition to RGM dry deposition vary by up to a factor of 80

    Lewiston Community Health Improvement Project

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    Community Health improvement project about low back pain and alternative treatment options. Particularly focuses on different treatment options in Lewiston, ME.https://scholarworks.uvm.edu/fmclerk/1225/thumbnail.jp

    Gravitational microlensing as a diagnostic tool for stellar astrophysics

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    Chapter One introduces the theory of galactic microlensing and develops the necessary formulae needed to discuss extended source events in the subsequent Chapters. Some of the complications encountered by groups observing such events are discussed, as are a few of the more notable events themselves. In Chapter Two an extended source model for microlensing is presented and applied to different atmosphere models, with different surface brightness profiles including simple one and two parameter limb darkening models and the more sophisticated and recently developed "Next Generation" stellar atmosphere models. It is shown that microlensing can distinguish between these different surfaces brightness profiles and thus, the underlying stellar atmosphere models, for realistic observational strategies. In Chapter Three a second stellar atmosphere models is introduced. This model includes the effects of a non-radial surface brightness profile, i.e. starspots. Such effects are interesting for several reasons. Firstly, the existence or otherwise of starspots is an important indicator of stellar surface activity and would provide valuable information for the testing and development of more sophisticated stellar atmosphere models. Additionally, there has been concern that starspots could mimic planetary microlensing lightcurves making it important to consider how their observational signatures could be distinguished from those of planets. The microlensing signatures of starspots are considered for point mass lens in Chapter Three and for fold caustic crossings in Chapter Four. In Chapter Five the extended source model used previously is applied to a source model with a small level of radial and temperature variability, to allow examination of how such events, if observed, would compare to standard microlensing events. In Chapter Six an investigation is made of the spectroscopic signatures of microlensing from circumstellar envelopes and the opportunities of using microlensing to diagnose bulk motion in these envelopes during caustic crossing events is examined

    Immunohistochemical Localization of Kisspeptin and Its Receptor in the Equine Ovary

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    Kisspeptin is recognized for its role as the gatekeeper of reproduction in most mammalian species. However, its role in regulation of reproduction at the ovarian level is poorly understood in the horse. In this study, ovaries from follicular phase, luteal phase, anestrous period, and mares treated with ECP-sulpiride were subjected to immunohistochemistry to characterize kisspeptin-10 (Kp10) and its receptor (Kiss1r) protein expression throughout each reproductive stage and follicle type. Kisspeptin and receptor staining was detected in all follicle types (primordial, preantral, and antral) throughout all reproductive stages, as well as oocytes, corpora lutea, and ovulation fossa. The pattern of Kp10 and Kiss1r staining was affected by follicle type (P \u3c 0.0001) and reproductive stage (P \u3c 0.001). Kisspeptin-10 immunostaining intensity was greatest in antral follicles, with no differences (P \u3e 0.05) between reproductive stages. Kisspeptin receptor immunostaining intensity was greatest in antral follicles, with no differences between reproductive stages except when comparing follicular phase to anestrous phase ovaries (P \u3c 0.05). The results of this study indicate kisspeptin and its receptor may have potential roles in the period leading up to ovulation, as indicated by the intensity of immunostaining in antral follicles, follicular development, and steroidogenesis
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