21,149 research outputs found
A localised co-rotating auroral absorption event observed near noon using imaging riometer and EISCAT
No full textInternational audienceAn isolated region of energetic electron precipitation observed near local noon in the auroral zone has been investigated using imaging riometer (IRIS) and incoherent-scatter radar (EISCAT) techniques. IRIS revealed that the absorption event was essentially co-rotating with the Earth for about 2 h. The spatial and temporal variations in D-region electron density seen by EISCAT were able to be interpreted within a proper context when compared with the IRIS data. EISCAT detected significant increases in electron density at altitudes as low as 65 km as the event drifted through the radar beam. The altitude distribution of incremental radio absorption revealed that more than half of the absorption occurred below 75 km, with a maximum of 67 km. The energy spectrum of the precipitating electrons was highly uniform throughout the event, and could be described analytically by the sum of three exponential distributions with characteristic energies of 6, 70 and 250 keV. A profile of effective recombination coefficient that resulted in self-consistent agreement between observed electron desities and those inferred from an inversion procedure has been deduced. The observations suggest a co-rotating magnetospheric source region on closed dayside field lines. However, a mechanism is required that can sustain such hard precipitation for the relatively long duration of the event
Audit exemption and the demand for voluntary audit: A comparative study of the UK and Denmark
No full textThis is the accepted version of the following article: Collis, J. (2010), Audit Exemption and the Demand for Voluntary Audit: A Comparative Study of the UK and Denmark. International Journal of Auditing, 14: 211–231, which has been published in final form at http://onlinelibrary.wiley.com/doi/10.1111/j.1099-1123.2010.00415.x/abstract.This study investigates the sufficiency of turnover as a surrogate for demand for voluntary audit and compares the determinants in the UK and Denmark. Empirical data for the study were drawn from government surveys of the directors of small private companies in both countries, which were based on the same research instrument, Bivariate tests support the hypothesised effects of turnover and a range of firm-specific factors suggested by economic rationality and agency theory. The main contribution of the study is the finding that turnover alone is not a sufficient surrogate for the costs and benefits of audit. The main predictors are turnover and a slightly different combination of management and agency factors in each country. The study provides a model that can be tested in other jurisdictions and its findings should be of interest to the accountancy profession and national regulators planning to introduce or revise audit exemption for small companies
A 2 h periodic variation in the low-mass X-ray binary Ser X-1
No full textSpectroscopy of the low-mass X-ray binary Ser X-1 using the Gran Telescopio Canarias have revealed a ?2 h periodic variability that is present in the three strongest emission lines. We tentatively interpret this variability as due to orbital motion, making it the first indication of the orbital period of Ser X-1. Together with the fact that the emission lines are remarkably narrow, but still resolved, we show that a main-sequence K dwarf together with a canonical 1.4 M? neutron star gives a good description of the system. In this scenario, the most likely place for the emission lines to arise is the accretion disc, instead of a localized region in the binary (such as the irradiated surface or the stream-impact point), and their narrowness is due instead to the low inclination (?10°) of Ser X-1
Exacerbations of chronic obstructive pulmonary disease: Time to rename
No full textIn medicine, our terminology becomes fixed, with repercussions when translated between languages, discussed among health-care professionals, and converted into lay terms for patients. For example, for chronic obstructive pulmonary disease, in using COPD as an abbreviation, the letters C, O, P, and D in some languages do not exist, whereas in lay terms, chronic obstructive pulmonary disease literally means a long-term lung problem. To overcome the non-specificity of using a catch-all term that does not characterise the unique features of an individual patients' symptoms, we now try to establish phenotypes and treatable traits of COPD. Nonetheless, the respiratory health community have neglected translating the term exacerbation, an event that substantially affects morbidity and mortality in patients with COPD. Defining the exacerbation event accurately will be a great advance; however, it is also imperative to redefine the term itself and we propose that an exacerbation of COPD should be renamed a COPD crisis
Windows to cell function and dysfunction: signatures written in the boundary layers
No full textThe medium surrounding cells either in culture or in tissues contains a chemical mix varying with cell state. As solutes move in and out of the cytoplasmic compartment they set up characteristic signatures in the cellular boundary layers. These layers are complex physical and chemical environments the profiles of which reflect cell physiology and provide conduits for intercellular messaging. Here we review some of the most relevant characteristics of the extracellular/intercellular space. Our initial focus is primarily on cultured cells but we extend our consideration to the far more complex environment of tissues, and discuss how chemical signatures in the boundary layer can or may affect cell function. Critical to the entire essay are the methods used, or being developed, to monitor chemical profiles in the boundary layers. We review recent developments in ultramicro electrochemical sensors and tailored optical reporters suitable for the task in hand
Role for malic enzyme, pyruvate carboxylation, and mitochondrial malate import in glucose-stimulated insulin secretion
No full textPyruvate cycling has been implicated in glucose-stimulated insulin secretion (GSIS) from pancreatic beta-cells. The operation of some pyruvate cycling pathways is proposed to necessitate malate export from the mitochondria and NADP(+)-dependent decarboxylation of malate to pyruvate by cytosolic malic enzyme (ME1). Evidence in favor of and against a role of ME1 in GSIS has been presented by others using small interfering RNA-mediated suppression of ME1. ME1 was also proposed to account for methyl succinate-stimulated insulin secretion (MSSIS), which has been hypothesized to occur via succinate entry into the mitochondria in exchange for malate and subsequent malate conversion to pyruvate. In contrast to rat, mouse beta-cells lack ME1 activity, which was suggested to explain their lack of MSSIS. However, this hypothesis was not tested. In this report, we demonstrate that although adenoviral-mediated overexpression of ME1 greatly augments GSIS in rat insulinoma INS-1 832/13 cells, it does not restore MSSIS, nor does it significantly affect GSIS in mouse islets. The increase in GSIS following ME1 overexpression in INS-1 832/13 cells did not alter the ATP-to-ADP ratio but was accompanied by increases in malate and citrate levels. Increased malate and citrate levels were also observed after INS-1 832/13 cells were treated with the malate-permeable analog dimethyl malate. These data suggest that although ME1 overexpression augments anaplerosis and GSIS in INS-1 832/13 cells, it is not likely involved in MSSIS and GSIS in pancreatic islets
"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
No full textBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
The L-p-to-L-q boundedness of commutators with applications to the Jacobian operator
No full textSupplying the missing necessary conditions, we complete the characterisation of the L-p -> L-q boundedness of commutators [b, T] of pointwise multiplication and Calderon-Zygmund operators, for arbitrary pairs of 1 q, our results are new even for special classical operators with smooth kernels. As an application, we show that every f is an element of L-p(R-d) can be represented as a convergent series of normalised Jacobians J(u) = det del uof u is an element of (over dot(W))(1,dp)(R-d)(d). This extends, from p = 1 to p > 1, a result of Coifman, Lions, Meyer and Semmes about J:. (over dot(W))(1,d)(R-d)(d) -> H-1(R-d), and supports a conjecture of Iwaniec about the solvability of the equation Ju = f is an element of L-p(R-d). (C) 2021 The Author(s). Published by Elsevier Masson SAS.Peer reviewe
Dark Matter Decay and the Spiral Galaxy NGC891
No full textWe study the implications for NGC 891 of the decaying Dark matter (DDM) hypothesis which states that dark matter decays into hydrogen-ionizing photons on a time-scale of 1023 s. We are able to derive many details of the observed Hα emission of this galaxy using only its rotation curve and properties of our own very similar Galaxy. We also use the hypothesis to determine the distance and the peculiar velocity of NGC 891 and obtain agreement with an independent estimate of those quantities. The detailed agreement of the consequences of the DDM hypothesis with observations of NGC 891 provides strong support for this hypothesis. (author
Promotional leaflet promoting new City of Huntington, ca. 1871-72, b&w.
No full textPromotional leaflet promoting new City of Huntington, ca. 1871-72, b&w. Leaflet written by D. W. Emmons, for Central Land Company, when City of Huntington was getting started, ca. 1871. Mentions C&O Railroad Co. Central Land Co. was opened by Collis P. Huntington.https://mds.marshall.edu/james_casto_papers/1045/thumbnail.jp
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