577 research outputs found
Compact Radio Cores in Seyfert Galaxies
We have observed a sample of 157 Seyfert galaxies with a 275 km baseline
radio interferometer to search for compact, high brightness temperature radio
emission from the active nucleus. We obtain the surprising result that compact
radio cores are much more common in Seyfert 2 than in Seyfert 1 galaxies, which
at first seems to be inconsistent with orientation unification schemes. We
propose a model, involving optical depth effects in the narrow-line region,
which can reconcile our result with the standard unified scheme. (Accepted for
publication in ApJ 1994 Sep 10)Comment: 21 pages and 7 figures, uuencoded tar-compressed postscript files,
ATP18
Expression of selected pathway-marker genes in human urothelial cells exposed chronically to a non-cytotoxic concentration of monomethylarsonous acid
AbstractBladder cancer has been associated with chronic arsenic exposure. Monomethylarsonous acid [MMA(III)] is a metabolite of inorganic arsenic and has been shown to transform an immortalized urothelial cell line (UROtsa) at concentrations 20-fold less than arsenite. MMA(III) was used as a model arsenical to examine the mechanisms of arsenical-induced transformation of urothelium. A previous microarray analysis revealed only minor changes in gene expression at 1 and 2 months of chronic exposure to MMA(III), contrasting with substantial changes observed at 3 months of exposure. To address the lack of information between 2 and 3 months of exposure (the critical period of transformation), the expression of select pathway marker genes was measured by PCR array analysis on a weekly basis. Cell proliferation rate, anchorage-independent growth, and tumorigenicity in SCID mice were also assessed to determine the early, persistent phenotypic changes and their association with the changes in expression of these selected marker genes. A very similar pattern of alterations in these genes was observed when compared to the microarray results, and suggested that early perturbations in cell signaling cascades, immunological pathways, cytokine expression, and MAPK pathway are particularly important in driving malignant transformation. These results showed a strong association between the acquired phenotypic changes that occurred as early as 1–2 months of chronic MMA(III) exposure, and the observed gene expression pattern that is indicative of the earliest stages in carcinogenesis
Examining the efficacy of six published time-lapse imaging embryo selection algorithms to predict implantation to demonstrate the need for the development of specific, in-house morphokinetic selection algorithms.
OBJECTIVE: To study the efficacy of six embryo-selection algorithms (ESAs) when applied to a large, exclusive set of known implantation embryos. DESIGN: Retrospective, observational analysis. SETTING: Fertility treatment center. PATIENT(S): Women undergoing a total of 884 in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) treatment cycles (977 embryos) between September 2014 and September 2015 with embryos cultured using G-TL (Vitrolife) at 5% O2, 89% N2, 6% CO2, at 37°C in EmbryoScope instruments. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Efficacy of each ESA to predict implantation defined using specificity, sensitivity, positive predictive value (PPV), negative predictive value (NPV), area under the receiver operating characteristic curve (AUC), and likelihood ratio (LR), with differences in implantation rates (IR) in the categories outlined by each ESA statistically analyzed (Fisher's exact and Kruskal-Wallis tests). RESULT(S): When applied to an exclusive cohort of known implantation embryos, the PPVs of each ESA were 42.57%, 41.52%, 44.28%, 38.91%, 38.29%, and 40.45%. The NPVs were 62.12%, 68.26%, 71.35%, 76.19%, 61.10%, and 64.14%. The sensitivity was 16.70%, 75.33%, 72.94%, 98.67%, 51.19%, and 62.33% and the specificity was 85.83%, 33.33%, 42.33%, 2.67%, 48.17%, and 42.33%, The AUC were 0.584, 0.558, 0.573, 0.612, 0.543, and 0.629. Two of the ESAs resulted in statistically significant differences in the embryo classifications in terms of IR. CONCLUSION(S): These results highlight the need for the development of in-house ESAs that are specific to the patient, treatment, and environment. These data suggest that currently available ESAs may not be clinically applicable and lose their diagnostic value when externally applied
Preliminary investigation of the prevalence and implantation potential of abnormal embryonic phenotypes assessed using time-lapse imaging.
This retrospective, single site observational study aimed to delineate five abnormal embryonic developmental phenotypes, assessing their prevalence, development potential and suitability for inclusion in embryo selection models for IVF. In total, 15,819 embryos from 4559 treatment cycles cultured in EmbryoScope® incubators between January 2014 and January 2016 were included. Time-lapse images were assessed retrospectively for five abnormal embryo phenotypes: direct cleavage, reverse cleavage, absent cleavage, chaotic cleavage and cell lysis. The prevalence of each abnormal phenotype was assessed. Final embryo disposition, embryo quality and implantation rate were determined and compared with a control embryo cohort. The collective prevalence for the five abnormal phenotypes was 11.4%; chaotic cleavage and direct cleavage together constituted 9.7%. Implantation rates were 17.4%, 0%, 25%, 2.1% and 0% for direct, reverse, absent, chaotic cleavage and cell lysis, respectively. The overall implantation rate for all abnormal embryos with known implantation status was significantly lower compared with the control population (6.9% versus 38.7%, P < 0.0001). The proportion of good quality embryos in each category of abnormal cleavage remained below 25%. Embryos exhibiting an abnormal phenotype may have reduced developmental capability, manifested in both embryo quality and implantation potential, when compared with embryos of normal phenotype
Elemental Abundances of Kepler Objects of Interest in APOGEE. I. Two Distinct Orbital Period Regimes Inferred from Host Star Iron Abundances
The Apache Point Observatory Galactic Evolution Experiment (APOGEE) has
observed 600 transiting exoplanets and exoplanet candidates from
\textit{Kepler} (Kepler Objects of Interest, KOIs), most with 18 epochs.
The combined multi-epoch spectra are of high signal-to-noise (typically
100) and yield precise stellar parameters and chemical abundances. We
first confirm the ability of the APOGEE abundance pipeline, ASPCAP, to derive
reliable [Fe/H] and effective temperatures for FGK dwarf stars -- the primary
\textit{Kepler} host stellar type -- by comparing the ASPCAP-derived stellar
parameters to those from independent high-resolution spectroscopic
characterizations for 221 dwarf stars in the literature. With a sample of 282
close-in ( days) KOIs observed in the APOGEE KOI goal program, we find a
correlation between orbital period and host star [Fe/H] characterized by a
critical period, = days, below which small
exoplanets orbit statistically more metal-enriched host stars. This effect may
trace a metallicity dependence of the protoplanetary disk inner-radius at the
time of planet formation or may be a result of rocky planet ingestion driven by
inward planetary migration. We also consider that this may trace a metallicity
dependence of the dust sublimation radius, but find no statistically
significant correlation with host and orbital period to
support such a claim.Comment: 18 Pages, Accepted to A
Custom moulded plastic spinal orthoses
Abstract A review of fifty patients with wide ranging clinical conditions who had been fitted with one-piece moulded plastic spinal orthoses was carried out to determine prescription criteria for these orthoses. The review showed that patients with scoliosis (idiopathic and paralytic), kyphoscoliosis, as well as a selected number of patients with low back pain derive benefit. Patients with kyphosis and localized vertebral body disease are unlikely to gain benefit since they commonly cannot tolerate the excessive skin pressures which occur as a consequence of the corrective and distractive forces applied by the devices. Introduction Spinal orthoses are one of the most commonly prescribed types of orthoses delivered in the United Kingdom. A review of prescription practices in Dundee during one year showed that a total of 520 spinal orthoses had been prescribed and subsequently fabricated representing 17 per cent of the total orthotic supply for a district with a population of 180,000 people. Ninety one per cent of these orthoses were fabric supports but the remainder were rigid devices. These devices have traditionally been fabricated from metal and leather but in recent years it has been the practice in Dundee to make increased use of moulded plastic jackets (McDougall and Condie, 1982)
Rapid Rotation of Low-Mass Red Giants Using APOKASC: A Measure of Interaction Rates on the Post-main-sequence
We investigate the occurrence rate of rapidly rotating (10 km
s), low-mass giant stars in the APOGEE-Kepler (APOKASC) fields with
asteroseismic mass and surface gravity measurements. Such stars are likely
merger products and their frequency places interesting constraints on stellar
population models. We also identify anomalous rotators, i.e. stars with 5 km
s10 km s that are rotating significantly faster
than both angular momentum evolution predictions and the measured rates of
similar stars. Our data set contains fewer rapid rotators than one would expect
given measurements of the Galactic field star population, which likely
indicates that asteroseismic detections are less common in rapidly rotating red
giants. The number of low-mass moderate (5-10 km s) rotators in our
sample gives a lower limit of 7% for the rate at which low-mass stars interact
on the upper red giant branch because single stars in this mass range are
expected to rotate slowly. Finally, we classify the likely origin of the rapid
or anomalous rotation where possible. KIC 10293335 is identified as a merger
product and KIC 6501237 is a possible binary system of two oscillating red
giants.Comment: 39 pages, 8 figures, 4 tables. Accepted for publication in the
Astrophysical Journal. For a brief video discussing key results from this
paper see http://youtu.be/ym_0nV7_YqI . The full table 1 is available at
http://www.astronomy.ohio-state.edu/~tayar/tab1_full.tx
(±)-2-exo- and endo-Methylamino-1,2,3,4-tetrahydro-1,4-ethanonapthalene Hydrochloride
This is the published version
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