On Axion's Effect on Propagation of Monochromatic Electromagnetic Wave Through Strong Magnetic Field

A possibility of detecting the effect of photon-axion mixing in a cavity experiment is discussed. There are two photon-axion modes that acquire different indices of refraction and split in an inhomogeneous magnetic field. For a magnetic field inhomogeneous in the direction transverse to the light propagation an analytical solution is obtained both for the index of refraction and the beams' trajectories. In a cavity experiment, the beam splitting creates a bifurcation effect, which results in a decrease of the light intensity in the central region. Modulation of magnetic field can separate this effect from background by providing a narrow frequency range for any observed signal. When one integrates this effect over time and accounts for bandwidth, the overall drop in FWHM intensity is of order 10-2%. This is a very measurable effect.Comment: 5 pages with 2 figure

Well-Posed Two-Temperature Constitutive Equations for Stable Dense Fluid Shockwaves using Molecular Dynamics and Generalizations of Navier-Stokes-Fourier Continuum Mechanics

Guided by molecular dynamics simulations, we generalize the Navier-Stokes-Fourier constitutive equations and the continuum motion equations to include both transverse and longitudinal temperatures. To do so we partition the contributions of the heat transfer, the work done, and the heat flux vector between the longitudinal and transverse temperatures. With shockwave boundary conditions time-dependent solutions of these equations converge to give stationary shockwave profiles. The profiles include anisotropic temperature and can be fitted to molecular dynamics results, demonstrating the utility and simplicity of a two-temperature description of far-from-equilibrium states.Comment: 19 pages with 10 figures, revised following review at Physical Review E and with additional figure/discussion, for presentation at the International Summer School and Conference "Advanced Problems in Mechanics" [Saint Petersburg, Russia] 1-5 July 2010

Nonequilibrium Temperature and Thermometry in Heat-Conducting Phi-4 Models

We analyze temperature and thermometry for simple nonequilibrium heat-conducting models. We show in detail, for both two- and three-dimensional systems, that the ideal gas thermometer corresponds to the concept of a local instantaneous mechanical kinetic temperature. For the Phi-4 models investigated here the mechanical temperature closely approximates the local thermodynamic equilibrium temperature. There is a significant difference between kinetic temperature and the nonlocal configurational temperature. Neither obeys the predictions of extended irreversible thermodynamics. Overall, we find that kinetic temperature, as modeled and imposed by the Nos\'e-Hoover thermostats developed in 1984, provides the simplest means for simulating, analyzing, and understanding nonequilibrium heat flows.Comment: 20 pages with six figures, revised following review at Physical Review

A multicenter study on chronic cough in children: Burden and etiologies based on a standardized management pathway

Background: While the burden of chronic cough in children has been documented, etiologic factors across multiple settings and age have not been described. In children with chronic cough, we aimed (1) to evaluate the burden and etiologies using a standar

Interplay Between Gravity and Quintessence: A Set of New GR Solutions

A set of new exact analytical General Relativity (GR) solutions with time-dependent and spatially inhomogeneous quintessence demonstrate 1) a static non-empty space-time with a horizon-type singular surface; 2) time-dependent spatially homogeneous `spheres' which are completely different in geometry from the Friedmann isotropic models; 3) infinitely strong anti-gravity at a `true' singularity where the density is infinitely large. It is also found that 4) the GR solutions allow for an extreme `density-free' form of energy that can generate regular space-time geometries

The structure of CrgA from Neisseria meningitidis reveals a new octameric assembly state for LysR transcriptional regulators

LysR-type transcriptional regulators (LTTRs) form the largest family of bacterial regulators acting as both auto-repressors and activators of target promoters, controlling operons involved in a wide variety of cellular processes. The LTTR, CrgA, from the human pathogen Neisseria meningitidis, is upregulated during bacterial–host cell contact. Here, we report the crystal structures of both regulatory domain and full-length CrgA, the first of a novel subclass of LTTRs that form octameric rings. Non-denaturing mass spectrometry analysis and analytical ultracentrifugation established that the octameric form of CrgA is the predominant species in solution in both the presence and absence of an oligonucleotide encompassing the CrgA-binding sequence. Furthermore, analysis of the isolated CrgA–DNA complex by mass spectrometry showed stabilization of a double octamer species upon DNA binding. Based on the observed structure and the mass spectrometry findings, a model is proposed in which a hexadecameric array of two CrgA oligomers binds to its DNA target site

The genetic architecture of the human cerebral cortex

The cerebral cortex underlies our complex cognitive capabilities, yet little is known about the specific genetic loci that influence human cortical structure. To identify genetic variants that affect cortical structure, we conducted a genome-wide association meta-analysis of brain magnetic resonance imaging data from 51,665 individuals. We analyzed the surface area and average thickness of the whole cortex and 34 regions with known functional specializations. We identified 199 significant loci and found significant enrichment for loci influencing total surface area within regulatory elements that are active during prenatal cortical development, supporting the radial unit hypothesis. Loci that affect regional surface area cluster near genes in Wnt signaling pathways, which influence progenitor expansion and areal identity. Variation in cortical structure is genetically correlated with cognitive function, Parkinson's disease, insomnia, depression, neuroticism, and attention deficit hyperactivity disorder

The problem of constitutional legitimation: what the debate on electoral quotas tells us about the legitimacy of decision-making rules in constitutional choice

Proponents of electoral quotas have a ‘dependent interpretation’ of democracy, i.e. they have formed an opinion on which decision-making rules are fair on the basis of their prior approval of the outcomes these rules are likely to generate. The article argues that this position causes an irresolvable problem for constitutional processes that seek to legitimately enact institutional change. While constitutional revision governed by formal equality allows the introduction of electoral quotas, this avenue is normatively untenable for proponents of affirmative action if they are consistent with their claim that formal equality reproduces biases and power asymmetries at all levels of decision-making. Their critique raises a fundamental challenge to the constitutional revision rule itself as equally unfair. Without consensus on the decision-making process by which new post-constitutional rules can be legitimately enacted, procedural fairness becomes an issue impossible to resolve at the stage of constitutional choice. This problem of legitimation affects all instances of constitutional choice in which there are opposing views not only about the desired outcome of the process but also about the decision-making rules that govern constitutional choice

The effect of dexamethasone on the 24-hour profiles of adrenocorticotropin and cortisol in cushing’s syndrome

ACTH and cortisol are normally secreted episodically rather than continuously. This characteristic of episodic secretion is preserved in patients with Cushing's syndrome. To determine whether exogenous glucocorticoids modulate this pulsatility and to study its possible etiological implications, we obtained 24-h plasma cortisol profiles in seven patients with Cushing's syndrome (five Cushing's disease, one adrenal adenoma, and one bilateral adrenal cortical macronodular hyperpla-sia) before and during suppression with various doses of dexa-methasone [low (0.5 mg, every 6 h), high (2 mg, every 6 h), and very high (4 mg, every 6 h)]. Simultaneous 24-h plasma ACTH profiles were obtained in two patients with Cushing's disease. Blood was drawn at 30-min intervals for 25 h. Individual profiles were analyzed to determine the 24-h mean level, the presence of a circadian component and its amplitude, and the number and magnitude of significant secretory pulses over the 24-h span. The concordance between significant ACTH and cortisol pulses also was quantified. Baseline values in patients were compared o t those in seven normal subjects. Under basal conditions, the 24-h mean cortisol level was 3-t o 4-fold higher than normal in all patients with Cushing's syndrome. In contrast, the basal 24-h mean ACTH level was normal in one, and slightly elevated in the other of the two patients with Cushing's disease in whom plasma ACTH concentrations were measured. However, in contrast to the normal subjects, all ACTH values were above 10 pg/ml even during the period of minimal secretion. Basal circadian variation in adre-nocortical activity, albeit of reduced amplitude, was found in four of five patients with Cushing's disease; it was absent in the patient with adrenal adenoma. Low dose dexamethasone reduced the 24-h mean cortisol level and increased the amplitude of the circadian rhythm, unmasking a diurnal rhythm in the single patient with Cushing's disease in whom no significant circadian periodicity was present in the basal condition. This effect was further increased with the high dose of dexamethasone, which concomitantly reduced the number and increments of the secretory pulses. A lesser effect was found in the patient with bilateral nodular hyperplasia, and no effect was seen in the patient with adrenal adenoma. ACTH pulsatility, but not diurnal rhythm, also was dampened by dexamethasone. Reduction in the magnitude, but not the number, of ACTH secretory pulses by dexamethasone produced a reduced concordance ratio of ACTH with cortisol pulses of 0.39, compared to 0.64 in the basal state. The concordance ratios of cortisol with ACTH pulses remained unchanged (0.89 and 0.88) during the basal state and the administration of high doses of dexamethasone, respectively. These data indicate that during dexamethasone suppression, fewer of the low amplitude ACTH pulses elicit a significant cortisol response and that episodic cortisol secretion is ACTH induced. These data do not support the concept of a defect in the neural clock generating the 24-h periodicity in Cushing's disease. They suggest that the expression of the diurnal rhythm is masked, since it could be magnified and even uncovered by dexamethasone, in association with the reduction in the episodic pulsatility. In adrenal cortical macronodular hyperplasia, the low but persistent circadian variation in cortisol, obliterated by high dose dexamethasone, is in agreement with the postulated dual pituitary and adrenal etiology of this condition. © 1985 by The Endocrine Society.SCOPUS: ar.jinfo:eu-repo/semantics/publishe