4,871 research outputs found
Historical antecedents shaping corporate reporting in Iran
This research paper examines the evolution of corporate reporting and governance in Iran over the last century. The approach adopted was to provide an historical perspective to examine the environment within which Iranian corporate reporting has emerged and been shaped. An historical framework allows the study to focus on the evolution and development of corporate reporting practice in Iran. By adopting an historical framework, this study is able to inform future research based on models that adopt an evolutionary approach to the assessment of environmental factors on economic systems. The conclusion reached in this study is that socio-economic and political changes during the century have been opportune as drivers of corporate reporting in Iran. The study makes an incremental contribution to the existing accounting history literature for Asia / Middle East / developing countries
Criteria for the experimental observation of multi-dimensional optical solitons in saturable media
Criteria for experimental observation of multi-dimensional optical solitons
in media with saturable refractive nonlinearities are developed. The criteria
are applied to actual material parameters (characterizing the cubic
self-focusing and quintic self-defocusing nonlinearities, two-photon loss, and
optical-damage threshold) for various glasses. This way, we identify operation
windows for soliton formation in these glasses. It is found that two-photon
absorption sets stringent limits on the windows. We conclude that, while a
well-defined window of parameters exists for two-dimensional solitons (spatial
or spatiotemporal), for their three-dimensional spatiotemporal counterparts
such a window \emph{does not} exist, due to the nonlinear loss in glasses.Comment: 8 pages, to appear in Phys. Rev.
A survey of business education in the public high schools of New England
Thesis (Ed.M.)--Boston University
Amplitude expansion of the binary phase field crystal model
Amplitude representations of a binary phase field crystal model are developed
for a two dimensional triangular lattice and three dimensional BCC and FCC
crystal structures. The relationship between these amplitude equations and the
standard phase field models for binary alloy solidification with elasticity are
derived, providing an explicit connection between phase field crystal and phase
field models. Sample simulations of solute migration at grain boundaries,
eutectic solidification and quantum dot formation on nano-membranes are also
presented.Comment: 11 pages, 8 figure
Elevated Thromboxane Levels in the Rat during Endotoxic Shock: Protective Effects of Imidazole, 13-azaprostanoic Acid, or Essential Fatty Acid Deficiency
The potential deleterious role of the proaggregatory vasoconstrictor, thromboxane A2, in endotoxic shock was investigated in rats. Plasma thromboxane A2 was determined by radioimmunoassay of its stable metabolite thromboxane B2. After intravenous administration of Salmonella enteritidis endotoxin (20 mg/kg), plasma thromboxane B2 levels increased from nondetectable levels (\u3c375 pg/ml) in normal control rats to 2,054±524 pg/ml (n = 8), within 30 min to 2,071+429 at 60 min, and decreased to 1,119+319 pg/ml, at 120 min. Plasma levels of prostaglandin E also increased from 146±33 pg/ml in normal controls (n = 5) to 2,161+606 pg/ml 30 min after endotoxin (n = 5). In contrast to shocked controls, rats pretreated with imidazole, a thromboxane synthetase inhibitor, or essential fatty acid-deficient rats, which are deficient in arachidonate and its metabolites, did not exhibit significant elevations in plasma levels of thromboxane B2. Imidazole did not however inhibit endotoxin-induced elevations in plasma prostaglandin E. Essential fatty acid deficiency significantly reduced mortality to lethal endotoxic shock. This refractoriness could be duplicated in normal rats pretreated with the fatty acid cyclo-oxygenase inhibitor, indomethacin (10 mg/kg), intravenously 30 min before endotoxin injection. Imidazole (30 mg/kg) administered intraperitoneally 1 h before or intravenously 30 min before endotoxin, also significantly (P \u3c 0.01) reduced mortality from lethal endotoxin shock to 40% compared to a control mortality of 95% at 24 h. Likewise pretreatment with 13-azaprostanoic acid (30 mg/kg), a thromboxane antagonist, reduced mortality from endotoxic shock at 24 h from 100% in control rats to only 50% (P \u3c 0.01). The results suggest that endotoxin induces increased synthesis of thromboxane A2 that may contribute to the pathogenesis of endotoxic shock
Near-field radiative heat transfer between macroscopic planar surfaces
Near-field radiative heat transfer allows heat to propagate across a small
vacuum gap in quantities that are several orders of magnitude greater then the
heat transfer by far-field, blackbody radiation. Although heat transfer via
near-field effects has been discussed for many years, experimental verification
of this theory has been very limited. We have measured the heat transfer
between two macroscopic sapphire plates, finding an increase in agreement with
expectations from theory. These experiments, conducted near 300 K, have
measured the heat transfer as a function of separation over mm to m and as
a function of temperature differences between 2.5 and 30 K. The experiments
demonstrate that evanescence can be put to work to transfer heat from an object
without actually touching it
A case-matched study of neurophysiological correlates to attention /working memory in people with somatic hypervigilance
Accepted 14 June 2016Somatic hypervigilance describes a clinical presentation in which people report more, and more intense, bodily sensations than is usual. Most explanations of somatic hypervigilance implicate altered information processing, but strong empirical data are lacking. Attention and working memory are critical for information processing, and we aimed to evaluate brain activity during attention/working memory tasks in people with and without somatic hypervigilance. Method: Data from 173 people with somatic hypervigilance and 173 controls matched for age, gender, handedness, and years of education were analyzed. Event-related potential (ERP) data, extracted from the continuous electroencephalograph recordings obtained during performance of the Auditory Oddball task, and the Two In A Row (TIAR) task, for N1, P2, N2, and P3, were used in the analysis. Between-group differences for P3 amplitude and N2 amplitude and latency were assessed with two-tailed independent t tests. Between-group differences for N1 and P2 amplitude and latency were assessed using mixed, repeated measures analyses of variance (ANOVAs) with group and Group × Site factors. Linear regression analysis investigated the relationship between anxiety and depression and any outcomes of significance. Results: People with somatic hypervigilance showed smaller P3 amplitudes—Auditory Oddball task: t(285) = 2.32, 95% confidence interval, CI [3.48, 4.47], p = .026, d = 0.27; Two-In-A-Row (TIAR) task: t(334) = 2.23, 95% CI [2.20; 3.95], p = .021, d = 0.24—than case-matched controls. N2 amplitude was also smaller in people with somatic hypervigilance—TIAR task: t(318) = 2.58, 95% CI [0.33, 2.47], p = .010, d = 0.29—than in case-matched controls. Neither depression nor anxiety was significantly associated with any outcome. Conclusion: People with somatic hypervigilance demonstrated an event-related potential response to attention/working memory tasks that is consistent with altered information processing.Carolyn Berryman, Vikki Wise, Tasha R. Stanton, Alexander McFarlane and G. Lorimer Mosele
Ostrogradsky's Hamilton formalism and quantum corrections
By means of a simple scalar field theory it is demonstrated that the Lagrange
formalism and Ostrogradsky's Hamilton formalism in the presence of higher
derivatives, in general, do not lead to the same results. While the two
approaches are equivalent at the classical level, differences appear due to the
quantum corrections.Comment: 10 pages, 1 figure, REVTeX
Compensation of B-L charge of matter with relic sneutrinos
We consider massless gauge boson connected to B-L charge with and without
compensation to complete the investigation of the gauging of B and L charges.
Relic sneutrinos predicted by SUSY and composite models may compensate B-L
charge of matter. As a consequence of the possible compensation mechanism we
have shown that the available experimental data admit the range of the B-L
interaction constant, 10^{-29} < {\alpha}_{B-L} < 10^{-12}, in addition to
{\alpha}_{B-L} < 10^{-49} obtained without compensation.Comment: 6 page
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