Identification of spin wave modes in yttrium iron garnet strongly coupled to a co-axial cavity

We demonstrate, at room temperature, the strong coupling of the fundamental and non-uniform magnetostatic modes of an yttrium iron garnet (YIG) ferrimagnetic sphere to the electromagnetic modes of a co-axial cavity. The well-de ned eld pro le within the cavity yields a speci c coupling strength for each magnetostatic mode. We experimentally measure the coupling strength for the di erent magnetostatic modes and, by calculating the expected coupling strengths, are able to identify the modes themselves.We would like to acknowledge support from Hitachi Cambridge Laboratory, and EPSRC Grant No. EP/K027018/1. A.J.F. is supported by a Hitachi Research fellowship.This is the author accepted manuscript. The final version is available from AIP at http://scitation.aip.org/content/aip/journal/jap/117/5/10.1063/1.4907694#fulltextAbstract

Cavity-mediated coherent coupling of magnetic moments

We demonstrate the long range strong coupling of magnetostatic modes in spatially separated ferromagnets mediated by a microwave frequency cavity. Two spheres of yttrium iron garnet are embedded in the cavity and their magnetostatic modes probed using a dispersive measurement technique. We find they are strongly coupled to each other even when detuned from the cavity modes, and investigate the dependence of the magnet-magnet coupling on the cavity detuning. Dark states of the coupled magnetostatic modes of the system are observed, and ascribed to mismatches between the symmetries of the modes and the drive field.We would like to acknowledge support from Hitachi Cambridge Laboratory, EPSRC Grant No. EP/K027018/1 and ERC Grant No. 648613. A.J.F. is supported by a Hitachi Research Fellowship. A.C.D. is supported by the ARC via the Centre of Excellence in Engineered Quantum Systems (EQuS), Project No. CE110001013.This is the author accepted manuscript. The final version is available from the American Physical Society via http://dx.doi.org/10.1103/PhysRevA.93.02180

Magneto-optical coupling in whispering-gallery-mode resonators

We demonstrate that yttrium iron garnet microspheres support optical whispering gallery modes similar to those in non-magnetic dielectric materials. The direction of the ferromagnetic moment tunes both the resonant frequency via the Voigt effect as well as the degree of polarization rotation via the Faraday effect. An understanding of the magneto-optical coupling in whispering gallery modes, where the propagation direction rotates with respect to the magnetization, is fundamental to the emerging field of cavity optomagnonics.Engineering and Physical Sciences Research Council (Grant IDs: EP/M50693X/1, EP/L027151/1), European Research Council (Grant ID: 648613), Hitachi (research fellowship), Royal Society (University Research Fellowship), Winton programme for the Physics of SustainabilityThis is the author accepted manuscript. The final version is available from the American Physical Society via http://dx.doi.org/10.1103/PhysRevA.92.06384

Nonabelian (2,0) Tensor Multiplets and 3-algebras

Using 3-algebras we obtain a nonabelian system of equations that furnish a representation of the (2,0)-supersymmetric tensor multiplet. The on-shell conditions are quite restrictive so that the system can be reduced to five-dimensional gauge theory along with six-dimensional abelian (2,0) tensor multiplets. We briefly discuss possible applications to D4-branes using a spacelike reduction and M5-branes using a null reduction.Comment: 17 pages, Latex; v2: Typos corrected and references adde

First-trimester or second-trimester screening, or both, for Down's syndrome

BACKGROUND: It is uncertain how best to screen pregnant women for the presence of fetal Down's syndrome: to perform first-trimester screening, to perform second-trimester screening, or to use strategies incorporating measurements in both trimesters.METHODS: Women with singleton pregnancies underwent first-trimester combined screening (measurement of nuchal translucency, pregnancy-associated plasma protein A [PAPP-A], and the free beta subunit of human chorionic gonadotropin at 10 weeks 3 days through 13 weeks 6 days of gestation) and second-trimester quadruple screening (measurement of alpha-fetoprotein, total human chorionic gonadotropin, unconjugated estriol, and inhibin A at 15 through 18 weeks of gestation). We compared the results of stepwise sequential screening (risk results provided after each test), fully integrated screening (single risk result provided), and serum integrated screening (identical to fully integrated screening, but without nuchal translucency).RESULTS: First-trimester screening was performed in 38,167 patients; 117 had a fetus with Down's syndrome. At a 5 percent false positive rate, the rates of detection of Down's syndrome were as follows: with first-trimester combined screening, 87 percent, 85 percent, and 82 percent for measurements performed at 11, 12, and 13 weeks, respectively; with second-trimester quadruple screening, 81 percent; with stepwise sequential screening, 95 percent; with serum integrated screening, 88 percent; and with fully integrated screening with first-trimester measurements performed at 11 weeks, 96 percent. Paired comparisons found significant differences between the tests, except for the comparison between serum integrated screening and combined screening.CONCLUSIONS: First-trimester combined screening at 11 weeks of gestation is better than second-trimester quadruple screening but at 13 weeks has results similar to second-trimester quadruple screening. Both stepwise sequential screening and fully integrated screening have high rates of detection of Down's syndrome, with low false positive rates

Veteran athletes exercise at higher maximum heart rates than are achieved during standard exercise (stress) testing

Objective. The stress electrocardiogram (sECG) is routinely used to screen individuals for underlying cardiac pathology before an exercise programme is prescribed. The underlying assumption is that the cardiac responses elicited during the sECG test are similar to those achieved during participation in sportiilg activities. However, this premise may be incorrect since the physical demands of different modes of exercise vary substantially.Design. Ten veteran league squash players (LSP), 10 social squash players (SSP), 10 league runners (LR), 10 social runners (SR) and 10 sedentary individuals (SED) were recruited for the study. All subjects completed a lifestyle questionnaire, a full medical examination and a routine sECG. Thereafter each subject's heart rate (HR) was monitored on two separate occasions while participating in sporting activity.Results. No sECG exercise-induced abnormalities were observed, although five subjects showed resting abnormalities. Maximal HR during the sECG, and maximal and mean HR during the field tests, were not significantly diHerent between groups. However, maximal HR was significantly higher in all groups during their sporting activities than during stress testing in the laboratory (P < 0.01).Conclusions. Maximal HR in veteran athletes during specific sporting activities was significantly higher than that attained during a routine sECG. This finding was not sport-specific, nor was it related to the level of competitiveness of the trial participants. These data show that a routine sECG is a submaximal test of exercise performance, and should be interpreted as such

Higgsing M2 to D2 with gravity: N=6 chiral supergravity from topologically gauged ABJM theory

We present the higgsing of three-dimensional N=6 superconformal ABJM type theories coupled to conformal supergravity, so called topologically gauged ABJM theory, thus providing a gravitational extension of previous work on the relation between N M2 and N D2-branes. The resulting N=6 supergravity theory appears at a chiral point similar to that of three-dimensional chiral gravity introduced recently by Li, Song and Strominger, but with the opposite sign for the Ricci scalar term in the lagrangian. We identify the supersymmetry in the broken phase as a particular linear combination of the supersymmetry and special conformal supersymmetry in the original topologically gauged ABJM theory. We also discuss the higgsing procedure in detail paying special attention to the role played by the U(1) factors in the original ABJM model and the U(1) introduced in the topological gauging.Comment: 53 pages, Late

Checkpoints are blind to replication restart and recombination intermediates that result in gross chromosomal rearrangements

Replication fork inactivation can be overcome by homologous recombination, but this can cause gross chromosomal rearrangements that subsequently missegregate at mitosis, driving further chromosome instability. It is unclear when the chromosome rearrangements are generated and whether individual replication problems or the resulting recombination intermediates delay the cell cycle. Here we have investigated checkpoint activation during HR-dependent replication restart using a site-specific replication fork-arrest system. Analysis during a single cell cycle shows that HR-dependent replication intermediates arise in S phase, shortly after replication arrest, and are resolved into acentric and dicentric chromosomes in G2. Despite this, cells progress into mitosis without delay. Neither the DNA damage nor the intra-S phase checkpoints are activated in the first cell cycle, demonstrating that these checkpoints are blind to replication and recombination intermediates as well as to rearranged chromosomes. The dicentrics form anaphase bridges that subsequently break, inducing checkpoint activation in the second cell cycle