Symmetry breaking in crossed magnetic and electric fields

We present the first observations of cylindrical symmetry breaking in highly excited diamagnetic hydrogen with a small crossed electric field, and we give a semiclassical interpretation of this effect. As the small perpendicular electric field is added, the recurrence strengths of closed orbits decrease smoothly to a minimum, and revive again. This phenomenon, caused by interference among the electron waves that return to the nucleus, can be computed from the azimuthal dependence of the classical closed orbits.Comment: 4 page REVTeX file including 5 postscript files (using psfig) Accepted for publication in Physical Review Letters. Difference from earlier preprint: we have discovered the cause of the earlier apparent discrepancy between experiment and theory and now achieve excellent agreemen

Statutory Assessment of the class? Supporting the additional needs of the learning context

This paper considers issues of funding of support for students facing difficulties in learning, and the role of assessment and labelling within this process. It explores the tensions within this process using a Foucauldian framework, and from the key perspectives of social justice and rights. Drawing on a range of literature it identifies the focus upon the individual within assessment processes around the world, and then considers in detail the strengths and weaknesses of the current form of Statutory Assessment of Special Educational Needs within England. The paper proposes an alternative funding system that resolves shortcomings within the individual approach and the English system. It suggests that a Class Funding Approach could build on a notion of justice for all, reduce the opportunities for wide variations in provision, and minimise the negative impact of current dividing practices

Ser649 and Ser650 Are the Major Determinants of Protein Kinase A-Mediated Activation of Human Hormone-Sensitive Lipase against Lipid Substrates

BACKGROUND: Hormone-sensitive lipase (HSL) is a key enzyme in the mobilization of fatty acids from stored triacylglycerols. Its activity is regulated by reversible protein phosphorylation. In rat HSL Ser563, Ser659 and Ser660 have been shown to be phosphorylated by protein kinase A (PKA) in vitro as well as in vivo. METHODOLOGY/PRINCIPAL FINDINGS: In this study we employed site-directed mutagenesis, in vitro phosphorylation and mass spectrometry to show that in vitro phosphorylation of human HSL by PKA occurs primarily on Ser649 and Ser650 (Ser659 and Ser660 in rat HSL). The wild type enzyme and four mutants were expressed in C-terminally His-tagged form in Sf9 insect cells and purified to homogeneity. HSL variants in which Ser552 and/or Ser554 were mutated to Ala or Glu retained both lipolytic and non-lipolytic activity and were phosphorylated by PKA and activated to a similar extent as the wild type enzyme. (32)P-labeling studies revealed that the bulk of the phosphorylation was on the Ser649/Ser650 site, with only a minor phosphorylation of Ser552 and Ser554. MS/MS analysis demonstrated that the peptide containing Ser649 and Ser650 was primarily phosphorylated on Ser650. The mutant lacking all four serines had severely reduced lipolytic activity, but a lesser reduction in non-lipolytic activity, had S(0.5) values for p-nitrophenol butyrate and triolein comparable to those of wild type HSL and was not phosphorylated by PKA. PKA phosphorylation of the wild type enzyme resulted in an increase in both the maximum turnover and S(0,5) using the TO substrate. CONCLUSIONS: Our results demonstrate that PKA activates human HSL against lipid substrates in vitro primarily through phosphorylation of Ser649 and Ser650. In addition the results suggest that Ser649 and Ser650 are located in the vicinity of a lipid binding region and that PKA phosphorylation controls the accessibility of this region

New constraints on ΩM, ΩΛ and w from an independent set of 11 high-redshift supernovae observed with the Hubble Space Telescope

We report measurements of ΩM, ΩΛ nd w from 11 supernovae (SNe) at z = 0.36-0.86 with high-quality light curves measured using WFPC2 on the Hubble Space Telescope (HST). This is an independent set of high-redshift SNe that confirms previous SN evidence for an accelerating universe. The high-quality light curves available from photometry on WFPC2 make it possible for these 11 SNe alone to provide measurements of the cosmological parameters comparable in statistical weight to the previous results. Combined with earlier Supernova Cosmology Project data, the new SNe yield a measurement of the mass density ΩM = 0.25 -0.06+0.07 (statistical) ± 0.04 (identified systematics), or equivalently, a cosmological constant of ± = 0.75 -0.07+0.06 (statistical) ± 0.04 (identified systematics), under the assumptions of a flat universe and that the dark energy equation-of-state parameter has a constant value w = -1. When the SN results are combined with independent flat-universe measurements of ΩM from cosmic microwave background and galaxy redshift distortion data, they provide a measurement of w = -1.05-0.20+0.15 (statistical) ± 0.09 (identified systematic), if w is assumed to be constant in time. In addition to high-precision light-curve measurements, the new data offer greatly improved color measurements of the high-redshift SNe and hence improved host galaxy extinction estimates. These extinction measurements show no anomalous negative E(B-V) at high redshift. The precision of the measurements is such that it is possible to perform a host galaxy extinction correction directly for individual SNe without any assumptions or priors on the parent E(B-V) distribution. Our cosmological fits using full extinction corrections confirm that dark energy is required with P(ΩΛ \u3e 0) \u3e 0.99, a result consistent with previous and current SN analyses that rely on the identification of a low-extinction subset or prior assumptions concerning the intrinsic extinction distribution

Contemporary changes and civil society in Portugal and the Russian Federation

Portugal and the Russian Federation share some aspects of traditional culture and similar experiences in modern history, but they also exhibit significant differences that determine specific modes of civil society’s development. Results of a comparative and diachronic analysis show that the major differences between the two countries reside in civil society’s openness and composition. Organized civil society is not very distinct in relative size when comparing Portugal and the Russian Federation, but it is globally more autonomous, expressive, trusted and institutionalized in Portugal than in the Russian Federation and among the factors that contribute to this condition are an earlier and revolutionary transition to democracy, a larger middle class, a greater prevalence of the value of interdependence, and a regime that endorses bigger public social expenditure in Portugal, all this within the framework of the European Union that has a longer history of social demand and institutional incentives for civil society. Despite those unequal conditions, civil society faces similar current challenges in both countries, mainly with the outsourcing of the public provision of social services.info:eu-repo/semantics/acceptedVersio

Light chain deposition disease presenting as paroxysmal atrial fibrillation: a case report

<p>Abstract</p> <p>Introduction</p> <p>Light chain deposition disease (LCDD) can involve the heart and cause severe heart failure. Cardiac involvement is usually described in the advanced stages of the disease. We report the case of a woman in whom restrictive cardiomyopathy due to LCDD presented with paroxysmal atrial fibrillation.</p> <p>Case presentation</p> <p>A 55-year-old woman was admitted to our emergency department because of palpitations. In a recent blood test, serum creatinine was 1.4 mg/dl. She was found to have high blood pressure, left ventricular hypertrophy and paroxysmal atrial fibrillation. An ACE-inhibitor was prescribed but her renal function rapidly worsened and she was admitted to our nephrology unit. On admission serum creatinine was 9.4 mg/dl, potassium 6.8 mmol/l, haemoglobin 7.7 g/dl, N-terminal pro-brain natriuretic peptide 29894 pg/ml. A central venous catheter was inserted and haemodialysis was started. She underwent a renal biopsy which showed kappa LCDD. Bone marrow aspiration and bone biopsy demonstrated kappa light chain multiple myeloma. Echocardiographic findings were consistent with restrictive cardiomyopathy. Thalidomide and dexamethasone were prescribed, and a peritoneal catheter was inserted. Peritoneal dialysis has now been performed for 15 months without complications.</p> <p>Discussion</p> <p>Despite the predominant tubular deposition of kappa light chain, in our patient the first clinical manifestation of LCDD was cardiac disease manifesting as atrial fibrillation and the correct diagnosis was delayed. The clinical management initially addressed the cardiovascular symptoms without paying sufficient attention to the pre-existing slight increase in our patient's serum creatinine. However cardiac involvement is a quite uncommon presentation of LCDD, and this unusual case suggests that the onset of acute arrhythmias associated with restrictive cardiomyopathy and impaired renal function might be related to LCDD.</p

Resonant nonlinear magneto-optical effects in atoms

In this article, we review the history, current status, physical mechanisms, experimental methods, and applications of nonlinear magneto-optical effects in atomic vapors. We begin by describing the pioneering work of Macaluso and Corbino over a century ago on linear magneto-optical effects (in which the properties of the medium do not depend on the light power) in the vicinity of atomic resonances, and contrast these effects with various nonlinear magneto-optical phenomena that have been studied both theoretically and experimentally since the late 1960s. In recent years, the field of nonlinear magneto-optics has experienced a revival of interest that has led to a number of developments, including the observation of ultra-narrow (1-Hz) magneto-optical resonances, applications in sensitive magnetometry, nonlinear magneto-optical tomography, and the possibility of a search for parity- and time-reversal-invariance violation in atoms.Comment: 51 pages, 23 figures, to appear in Rev. Mod. Phys. in Oct. 2002, Figure added, typos corrected, text edited for clarit

New Constraints on ΩM, ΩΛ, and w from an Independent Set of 11 High-Redshift Supernovae Observed with the Hubble Space Telescope

36 pags., 13 figs., 31 tabs., 1 app.We report measurements of ΩM, ΩΛ w from 11 supernovae (SNe) at z ¼ 0:36 0:86 with high-quality light curves measured using WFPC2 on the Hubble Space Telescope (HST). This is an independent set of high-redshift SNe that confirms previous SN evidence for an accelerating universe. The high-quality light curves available from photometry on WFPC2 make it possible for these 11 SNe alone to provide measurements of the cosmological parameters comparable in statistical weight to the previous results. Combined with earlier Supernova Cosmology Project data, the new SNe yield a measurement of the mass density ΩM ¼ 0:25þ0:07 Ω0:06 ðstatisticalÞ Λ 0:04 (identified systematics), or equivalently, a cosmological constant of ΩΛ ¼ 0:75þ0:06 Ω0:07 ðstatisticalÞ Λ 0:04 (identified systematics), under the assumptions of a flat universe and that the dark energy equation-of-state parameter has a constant value w ¼ Ω1.When the SN results are combined with independent flat-universe measurements of ΩM from cosmic microwave background and galaxy redshift distortion data, they provide a measurement of w ¼ Ω1:05þ0:15 Ω0:20 ðstatisticalÞ Λ 0:09 (identified systematic), if w is assumed to be constant in time. In addition to high-precision light-curve measurements, the new data offer greatly improved color measurements of the high-redshift SNe and hence improved host galaxy extinction estimates. These extinction measurements show no anomalous negative E(BΩ) at high redshift. The precision of the measurements is such that it is possible to perform a host galaxy extinction correction directly for individual SNe without any assumptions or priors on the parent E(BΩV) distribution. Our cosmological fits using full extinction corrections confirm that dark energy is required with PðΩΛ > 0Þ > 0:99, a result consistent with previous and current SN analyses that rely on the identification of a low-extinction subset or prior assumptions concerning the intrinsic extinction distribution.Support for this work was provided by NASA through grants HST-GO-07336.01-A and HST-GO-08346.01-A from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. This work was supported in part by the Director, Office of Science,Office of High Energy and Nuclear Physics, of the US Department of Energy under Contract DE-AC03- 76SF000098, by the Center for Particle Astrophysics, an NSF Science and Technology Center operated by the University of California, Berkeley, under Cooperative Agreement AST 91-20005. This work was supported in part by a NASA LTSA grant to P. E. N., G. A., S. P., and S. E. D., and W. M. W.-V. was supported in part by a National Science Foundation Graduate Research Fellowship. A.G. is a Royal Swedish Academy Research Fellow supported by a grant from the Knut and Alice Wallenberg Foundation.Peer Reviewe

New Constraints on ΩM\Omega_M, ΩΛ\Omega_\Lambda, and w from an Independent Set of Eleven High-Redshift Supernovae Observed with HST

We report measurements of $\Omega_M$, $\Omega_\Lambda$, and w from eleven supernovae at z=0.36-0.86 with high-quality lightcurves measured using WFPC-2 on the HST. This is an independent set of high-redshift supernovae that confirms previous supernova evidence for an accelerating Universe. Combined with earlier Supernova Cosmology Project data, the new supernovae yield a flat-universe measurement of the mass density $\Omega_M=0.25^{+0.07}_{-0.06}$ (statistical) $\pm0.04$ (identified systematics), or equivalently, a cosmological constant of $\Omega_\Lambda=0.75^{+0.06}_{-0.07}$ (statistical) $\pm0.04$ (identified systematics). When the supernova results are combined with independent flat-universe measurements of $\Omega_M$ from CMB and galaxy redshift distortion data, they provide a measurement of $w=-1.05^{+0.15}_{-0.20}$ (statistical) $\pm0.09$ (identified systematic), if w is assumed to be constant in time. The new data offer greatly improved color measurements of the high-redshift supernovae, and hence improved host-galaxy extinction estimates. These extinction measurements show no anomalous negative E(B-V) at high redshift. The precision of the measurements is such that it is possible to perform a host-galaxy extinction correction directly for individual supernovae without any assumptions or priors on the parent E(B-V) distribution. Our cosmological fits using full extinction corrections confirm that dark energy is required with $P(\Omega_\Lambda>0)>0.99$, a result consistent with previous and current supernova analyses which rely upon the identification of a low-extinction subset or prior assumptions concerning the intrinsic extinction distribution.Comment: Accepted for publication in Astrophysical Journal; For data tables and full-resolution figures, see http://supernova.lbl.go