The laboratory diagnosis of gonorrhoea in the female

No Abstract

On collisional capture rates of irregular satellites around the gas-giant planets and the minimum mass of the solar nebula

We investigated the probability that an inelastic collision of planetesimals within the Hill sphere of the Jovian planets could explain the presence and orbits of observed irregular satellites. Capture of satellites via this mechanism is highly dependent on not only the mass of the protoplanetary disk, but also the shape of the planetesimal size distribution. We performed 2000 simulations for integrated time intervals $\sim 2$ Myr and found that, given the currently accepted value for the minimum mass solar nebula and planetesimal number density based upon the \citet{Nesvorny2003} and \citet{Charnoz2003} size distribution $dN \sim D^{-3.5} dD$, the collision rates for the different Jovian planets range between $\sim 0.6$ and \gtrsim 170 \, \Myr^{-1} for objects with radii, 1 \, \km \le r \le 10 \, \km. Additionally, we found that the probability that these collisions remove enough orbital energy to yield a bound orbit was $\lesssim 10^{-5}$ and had very little dependence on the relative size of the planetesimals. Of these collisions, the collision energy between two objects was $\gtrsim 10^3$ times the gravitational binding energy for objects with radii $\sim 100$ km. We find that, capturing irregular satellites via collisions between unbound objects can only account for $\sim 0.1$ of the observed population, hence can this not be the sole method of producing irregular satellites.Comment: 11 pages 4 figures 1 table; This replaces a prior submission, which contained some minor contradictions within the text accepted by MNRAS in pres

The free energy of NOAA active region AR 11029

The NOAA active region AR 11029 was a small but highly active sunspot region which produced 73 GOES soft X-ray flares. The flares appear to show a departure from the well known power-law frequency-size distribution. Specifically, too few GOES C-class and no M-class flares were observed by comparison with a power-law distribution (Wheatland in Astrophys. J. 710, 1324, 2010). This was conjectured to be due to the region having insufficient magnetic energy to power large events. We construct nonlinear force-free extrapolations of the coronal magnetic field of active region AR 11029 using data taken on 24 October by the SOLIS Vector-SpectroMagnetograph (SOLIS/VSM), and data taken on 27 October by the Hinode Solar Optical Telescope SpectroPolarimeter (Hinode/SP). Force-free modeling with photospheric magnetogram data encounters problems because the magnetogram data are inconsistent with a force-free model, and we employ a recently developed `self-consistency' procedure which addresses this and accommodates uncertainties in the boundary data (Wheatland and Regnier in Astrophys. J. 700, L88, 2009). We calculate the total energy and free energy of the self-consistent solution and find that the free energy was 4x10^29 erg on 24 October, and 7x10^31 erg on 27 October. An order of magnitude scaling between RHESSI non-thermal energy and GOES peak X-ray flux is established from a sample of flares from the literature and is used to estimate flare energies from observed GOES peak X-ray flux. Based on the scaling, we conclude that the estimated free energy of AR 11029 on 27 October when the flaring rate peaked is sufficient to power M-class or X-class flares, and hence the modeling does not appear to support the hypothesis that the absence of large flares is due to the region having limited energy.Comment: Accepted for publication in Solar Physic

On Physical Equivalence between Nonlinear Gravity Theories

We argue that in a nonlinear gravity theory, which according to well-known results is dynamically equivalent to a self-gravitating scalar field in General Relativity, the true physical variables are exactly those which describe the equivalent general-relativistic model (these variables are known as Einstein frame). Whenever such variables cannot be defined, there are strong indications that the original theory is unphysical. We explicitly show how to map, in the presence of matter, the Jordan frame to the Einstein one and backwards. We study energetics for asymptotically flat solutions. This is based on the second-order dynamics obtained, without changing the metric, by the use of a Helmholtz Lagrangian. We prove for a large class of these Lagrangians that the ADM energy is positive for solutions close to flat space. The proof of this Positive Energy Theorem relies on the existence of the Einstein frame, since in the (Helmholtz--)Jordan frame the Dominant Energy Condition does not hold and the field variables are unrelated to the total energy of the system.Comment: 37 pp., TO-JLL-P 3/93 Dec 199

Constraining primordial non-Gaussianity with cosmological weak lensing: shear and flexion

We examine the cosmological constraining power of future large-scale weak lensing surveys on the model of \emph{Euclid}, with particular reference to primordial non-Gaussianity. Our analysis considers several different estimators of the projected matter power spectrum, based on both shear and flexion, for which we review the covariances and Fisher matrices. The bounds provided by cosmic shear alone for the local bispectrum shape, marginalized over $\sigma_8$, are at the level of $\Delta f_\mathrm{NL} \sim 100$. We consider three additional bispectrum shapes, for which the cosmic shear constraints range from $\Delta f_\mathrm{NL}\sim 340$ (equilateral shape) up to $\Delta f_\mathrm{NL}\sim 500$ (orthogonal shape). The competitiveness of cosmic flexion constraints against cosmic shear ones depends on the galaxy intrinsic flexion noise, that is still virtually unconstrained. Adopting the very high value that has been occasionally used in the literature results in the flexion contribution being basically negligible with respect to the shear one, and for realistic configurations the former does not improve significantly the constraining power of the latter. Since the flexion noise decreases with decreasing scale, by extending the analysis up to $\ell_\mathrm{max} = 20,000$ cosmic flexion, while being still subdominant, improves the shear constraints by $\sim 10$ when added. However on such small scales the highly non-linear clustering of matter and the impact of baryonic physics make any error estimation uncertain. By considering lower, and possibly more realistic, values of the flexion intrinsic shape noise results in flexion constraining power being a factor of $\sim 2$ better than that of shear, and the bounds on $\sigma_8$ and $f_\mathrm{NL}$ being improved by a factor of $\sim 3$ upon their combination. (abridged)Comment: 30 pages, 4 figures, 4 tables. To appear on JCA

Electric current circuits in astrophysics

Cosmic magnetic structures have in common that they are anchored in a dynamo, that an external driver converts kinetic energy into internal magnetic energy, that this magnetic energy is transported as Poynting fl ux across the magnetically dominated structure, and that the magnetic energy is released in the form of particle acceleration, heating, bulk motion, MHD waves, and radiation. The investigation of the electric current system is particularly illuminating as to the course of events and the physics involved. We demonstrate this for the radio pulsar wind, the solar flare, and terrestrial magnetic storms

A new Contribution to Cosmological Perturbations of some Inflationary Models

We show that there are inflationary models for which perturbations in the energy momentum tensor, which are of second order in the scalar field, cannot be neglected. We first specify the conditions under which the usual first order perturbations are absent. We then analyze classically, the growth and decay of our new type of perturbations for one mode of fluctuations \de\phi_k in the scalar field. We generalize this analysis, considering the contribution from the whole spectrum of \de\phi to a given wavelength of geometrical perturbations. Finally, we discuss the evolution of the perturbations during the subsequent radiation dominated era and discuss the resulting spectrum of density fluctuations. In the case of a massless scalar field we find a spectral index $n=4$. For massive scalar fields we obtain $n=0$ but the resulting amplitude of fluctuations for inflation around a GUT scale are by far too high. Hence, 'conventional' inflationary models must not be influenced by this new type of perturbations, in order to lead to acceptable matter and CMB fluctuations.Comment: LaTeX file, 15p, 2 Postscript Figs. available on request, Zurich University Preprint ZU-TH9/9

Fluctuations of the Gravitational Constant Induced by Primordial Bubbles

We consider the classical fluctuations of the gravitational constant generated by bubbles in the inflationary universe. For extended inflation, we demonstrate numerically how and how large fluctuations are produced during bubble expansion. The amplitude of the fluctuations depends on the Brans-Dicke parameter $\omega$: if $\omega$ is of the order of unity, the amplitude becomes of the order of unity within one Hubble expansion time; if $\omega$ is large (say, $\omega=1000$), the growth rate of the fluctuations is small, but it keeps growing without freezing during inflation. We also discuss some astrophysical implications of our results.Comment: 8 pages, revtex, postscript figures, some comments are corrected, to appear in Phys. Rev.

Microflares and the Statistics of X-ray Flares

This review surveys the statistics of solar X-ray flares, emphasising the new views that RHESSI has given us of the weaker events (the microflares). The new data reveal that these microflares strongly resemble more energetic events in most respects; they occur solely within active regions and exhibit high-temperature/nonthermal emissions in approximately the same proportion as major events. We discuss the distributions of flare parameters (e.g., peak flux) and how these parameters correlate, for instance via the Neupert effect. We also highlight the systematic biases involved in intercomparing data representing many decades of event magnitude. The intermittency of the flare/microflare occurrence, both in space and in time, argues that these discrete events do not explain general coronal heating, either in active regions or in the quiet Sun.Comment: To be published in Space Science Reviews (2011

Use of hydrophilic and hydrophobic polymers for the development of controlled release tizanidine matrix tablets

The aim of the present study was to develop tizanidine controlled release matrix. Formulations were designed using central composite method with the help of design expert version 7.0 software. Avicel pH 101 in the range of 14-50% was used as a filler, while HPMC K4M and K100M in the range of 25-55%, Ethylcellulose 10 ST and 10FP in the range of 15 - 45% and Kollidon SR in the range of 25-60% were used as controlled release agents in designing different formulations. Various physical parameters including powder flow for blends and weight variation, thickness, hardness, friability, disintegration time and in-vitro release were tested for tablets. Assay of tablets were also performed as specified in USP 35 NF 32. Physical parameters of both powder blend and compressed tablets such as compressibility index, angle of repose, weight variation, thickness, hardness, friability, disintegration time and assay were evaluated and found to be satisfactory for formulations K4M2, K4M3, K4M9, K100M2, K100M3, K100M9, E10FP2, E10FP9, KSR2, KSR3 & KSR9. In vitro dissolution study was conducted in 900 ml of 0.1N HCl, phosphate buffer pH 4.5 and 6.8 medium using USP Apparatus II. In vitro release profiles indicated that formulations prepared with Ethocel 10 standard were unable to control the release of drug while formulations K4M2, K100M9, E10FP2 & KSR2 having polymer content ranging from 40-55% showed a controlled drug release pattern in the above mentioned medium. Zero-order drug release kinetics was observed for formulations K4M2, K100M9, E10FP2 & KSR2. Similarity test (f2) results for K4M2, E10FP2 & KSR2 were found to be comparable with reference formulation K100M9. Response Surface plots were also prepared for evaluating the effect of independent variable on the responses. Stability study was performed as per ICH guidelines and the calculated shelf life was 24-30 months for formulation K4M2, K100M9 and E10FP2