The atomistic structure and energies of high-index interphase boundaries are explored using a combination of molecular statics and dynamics simulations with embedded atom potentials. We investigate ...planar boundaries between the α^sub 2^ and γ phases in the Ti-Al system. The class of boundaries considered has a high-index boundary orientation; the orientation relationship between the α^sub 2^ and γ phases also is high index, and a set of planes from each phase meet edge to edge at the boundary plane. For the particular case of a boundary that is commensurate in one direction and coincides with a moiré plane given by the so-called "Δg" diffraction condition, the boundary is not structurally singular, but it is energetically stable and does not appear to dissociate into other low-energy configurations. Misfit compensating defects are not observed: misfit in directions other than the commensurate one appears to be distributed uniformly. The boundary energy is evaluated as a function of the orientation of the boundary plane, and the edge-to-edge (moiré) boundary is found to lie in an energy cusp. PUBLICATION ABSTRACT
Results from regular monitoring of relativistic compact binaries like PSR 1913+16 are consistent with the dominant (quadrupole) order emission of gravitational waves (GWs). We show that observations ...associated with the binary black hole (BBH) central engine of blazar OJ 287 demand the inclusion of gravitational radiation reaction effects beyond the quadrupolar order. It turns out that even the effects of certain hereditary contributions to GW emission are required to predict impact flare timings of OJ 287. We develop an approach that incorporates this effect into the BBH model for OJ 287. This allows us to demonstrate an excellent agreement between the observed impact flare timings and those predicted from ten orbital cycles of the BBH central engine model. The deduced rate of orbital period decay is nine orders of magnitude higher than the observed rate in PSR 1913+16, demonstrating again the relativistic nature of OJ 287's central engine. Finally, we argue that precise timing of the predicted 2019 impact flare should allow a test of the celebrated black hole "no-hair theorem" at the 10% level.
The results of an investigation of a new coral disease affecting Indo-Pacific reefs are presented. Porites ulcerative white spot disease (PUWS) is characterized by discrete, bleached, round foci, 3 ...to 5 mm in diameter, that may either regress or progress to full tissue-thickness ulcerations that coalesce, occasionally resulting in colony mortality. Monitoring of 25 diseased and 5 healthy reference colonies for 17 mo revealed that advanced stages of the disease were characterized by lesion coalescence, partial colony death (i.e. portions of the colony still alive; n = 17) and total colony death (n = 2). Field transmission experiments revealed that 95% of healthy colonies developed lesions within 5 wk after continual exposure to diseased branches, while 60% of the reference colonies remained healthy. The host range of PUWS includes branching and massive Porites spp., and prevalence per species was positively correlated with species density. On 10 reefs surveyed in the Central Philippines, 22 +/- 7% (mean +/- SE) of poritid colonies were infected, and the disease was present on 80% of the surveyed reefs. Poritids are dominant Indo-Pacific reef builders; a disease targeting this genus could cause major shifts in community structure over time. This report contributes to the limited knowledge of PUWS impacts in this region.
A 13-year-old female presented with traumatized maxillary central incisors that had been endodontically treated. Five years later, at a different dental office, she had the clinical crowns removed, ...leaving subgingival margins. From the patient's history and our initial assessment, it
seemed as if the teeth had been fractured and luxated but not avulsed. Endodontic posts with spot-welded orthodontic brackets were temporarily cemented to enable orthodontic extrusion. Once access to restorable margins was obtained, the temporary posts were removed and conventional fiber posts
with interim composite crowns were placed. The restorations were still satisfactory at the one-year follow-up, with a healthy periodontium, intact apical seal, and no signs of external re- sorption observed. Combined specialty treatment provided an esthetically acceptable outcome in a difficult
restorative situation for a growing child. The purpose of this case report is to discuss an interim treatment until the child reaches dentofacial maturity, when definitive restorations can be provided.
A UK-based company, Current Controlled Trials, is mounting an ambitious effort to build a comprehensive international "metaRegister" of Controlled Trials in all areas of health care.
Scant knowledge exists describing health care providers' and staffs' experiences sharing imaging studies. Additional research is needed to determine the extent to which imaging studies are shared in ...diverse health care settings, and the extent to which provider or practice characteristics are associated with barriers to viewing external imaging studies on portable media.
This analysis uses qualitative data to 1) examine how providers and their staff accessed outside medical imaging studies, 2) examine whether use or the desire to use imaging studies conducted at outside facilities varied by provider specialty or location (urban, suburban, and small town) and 3) delineate difficulties experienced by providers or staff as they attempted to view and use imaging studies available on portable media.
Semi-structured interviews were conducted with 85 health care providers and medical facility staff from urban, suburban, and small town medical practices in North Carolina and Virginia. The interviews were audio recorded, transcribed, then systematically analyzed using ATLAS.ti.
Physicians at family and pediatric medicine practices rely primarily on written reports for medical studies other than X-rays; and thus do not report difficulties accessing outside imaging studies. Subspecialists in urban, suburban, and small towns view imaging studies through internal communication systems, internet portals, or portable media. Many subspecialists and their staff report experiencing difficulty and time delays in accessing and using imaging studies on portable media.
Subspecialists have distinct needs for viewing imaging studies that are not shared by typical primary care providers. As development and implementation of technical strategies to share medical records continue, this variation in need and use should be noted. The sharing and viewing of medical imaging studies on portable media is often inefficient and fails to meet the needs of many subspeciality physicians, and can lead to repeated imaging studies.
Energetic nuclear outbursts have been discovered in luminous and ultraluminous infrared galaxies (U/LIRGs) at unexpectedly high rates. To investigate this population of transients, we performed a ...search in mid-IR data from the Wide-field Infrared Survey Explorer (WISE) satellite and its NEOWISE survey to detect and characterise luminous and smoothly evolving transients in a sample of 215 U/LIRGs. We report three new transients, all with Δ
L
> 10
43
erg s
−1
, in addition to two previously known cases. Their host galaxies are all part of major galaxy mergers, and through radiative transfer model fitting we find that all have a significant contribution from an active galactic nucleus (AGN). We characterised the transients through measurements of their luminosities and resulting energetics, all of which are between 10
50.9
erg and 10
52.2
erg. The IR emission of the five transients was found to be consistent with re-radiation by the hot dust of emission at shorter wavelengths, presumably originating from an accretion event, onto the supermassive black hole. The corresponding transient rate of (1.6–4.6) × 10
−3
yr
−1
galaxy
−1
is over an order of magnitude higher than the rate of large amplitude flares shown by AGN in the optical. We suggest that the observed transients are part of a dust-obscured population of tidal disruption events (TDEs) that have remained out of the reach of optical surveys due to the obscuring dust. In one case, this is supported by our radio observations. We also discuss other plausible explanations. The observed rate of events is significantly higher than optical TDE rates, which can be expected in U/LIRG hosts undergoing a major galaxy merger with increased stellar densities in the nuclear regions. Continued searches for such transients and their multi-wavelength follow-up is required to constrain their rate and nature.
Biotinidase deficiency is an autosomal recessively inherited disorder that results in the inability to recycle the vitamin biotin. The disorder can cause neurologic and cutaneous abnormalities that ...can be treated effectively with pharmacologic doses of biotin. We identified 21 mutations that cause profound biotinidase deficiency in 37 symptomatic children (30 different probands and 7 siblings), as well as provide relevant biochemical and clinical information for each child. The two most common mutations (G98:d7i3 and R538C) were found in 31 of 60 alleles (52%), whereas the remainder of the alleles are accounted for by the 19 other unique mutations. Serum samples were available from 18 children, of these 11 had no detectable cross-reacting material (CRM) to antibody prepared against normal human serum biotinidase, three had reduced quantities of CRM and four had normal quantities of CRM in serum. All of these mutations result in complete absence of biotinyl-transferase activity in serum. Two polymorphisms were also identified in normal individuals. It is apparent that a child who inherits any of these mutations, either in the homozygous state or in combination, can develop the clinical features of the disorder if untreated. There are, however, no clear genotype/phenotype correlations that would allow for the prediction of the type, severity, or age of onset of symptoms.
Very-high-energy (VHE; > 100 GeV) gamma-ray emission from the blazar RGB J2243+203 was discovered with the VERITAS Cherenkov telescope array, during the period between 2014 December 21 and 24. The ...VERITAS energy spectrum from this source can be fitted by a power law with a photon index of 4.6 0.5, and a flux normalization at 0.15 TeV of . The integrated Fermi-LAT flux from 1 to 100 GeV during the VERITAS detection is , which is an order of magnitude larger than the four-year-averaged flux in the same energy range reported in the 3FGL catalog, ( ). The detection with VERITAS triggered observations in the X-ray band with the Swift-XRT. However, due to scheduling constraints Swift-XRT observations were performed 67 hr after the VERITAS detection, rather than simultaneously with the VERITAS observations. The observed X-ray energy spectrum between 2 and 10 keV can be fitted with a power law with a spectral index of 2.7 0.2, and the integrated photon flux in the same energy band is . EBL-model-dependent upper limits of the blazar redshift have been derived. Depending on the EBL model used, the upper limit varies in the range from z to z .
Solid-state exchange reactions between carbon halides and lithium acetylide catalyzed by cobalt dichloride enable the rapid synthesis of carbon nanotubes as observed by TEM. Without the catalyst, ...only graphite and amorphous carbon form. These reactions are self-propagating and can be initiated with a heated filament. Regulating the reaction temperature provides a method for controlling these reactions. The theoretical temperature for a reaction between hexachloroethane and lithium acetylide is 2302 K assuming adiabatic conditions. Calculations indicate that increasing the length of the carbon chain can lower the reaction temperature by up to 61 K. Replacing chlorine with fluorine can further reduce the temperature by up to 384 K. Replacing chlorine with hydrogen can, in principle, lower the reaction temperature by up to 925 K. These calculations suggest that polymers such as poly(vinyl chloride), poly(vinylidene chloride), and poly(tetrafluoroethylene) can be used as precursors to carbon nanotubes. This is confirmed experimentally using a copolymer of poly(vinyl chloride) and poly(vinylidene chloride) with a 5 mol % (based on carbon) iron trichloride catalyst to produce multi-walled carbon nanotubes.
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