Long-term Outcome after Surgical Closure of Atrial Septal Defect in Childhood with Extensive Assessment Including MRI Measurement of the Ventricles

Surgical closure of the secundum type of atrial septal defect (ASD) in childhood leads to excellent survival. However, relevant morbidity has been reported. Transcatheter closure of these defects has now become an alternative approach. To compare the results of the two different interventions, reliable data are needed on the long-term morbidity after defect closure with both methods. Patients were evaluated after a minimum of 10 years after surgical closure of an ASD in childhood. Assessment included analysis of perioperative data, interview, clinical examination, electrocardiogram, (ECG), 24-hour ECG, ergometry, chest radiograph, echocardiography, and MRI. A total of 66 patients underwent operation between 1971 and 1986 at our institution. Forty-eight of them (73%) were interviewed and 38 (58%) participated fully in the study program. Eighteen (27%) either refused to participate or were lost to follow-up. There were no substantial residual disorders, such as arrhythmias, right-sided heart dilatation, pulmonary hypertension, or reduced work capacity. Surgical closure of an ASD in childhood has an excellent long-term outcome. Surgical closure is thus the standard against which transcatheter closure needs to be measure

Simple atomic quantum memory suitable for semiconductor quantum dot single photons

Quantum memories matched to single photon sources will form an important cornerstone of future quantum network technology. We demonstrate such a memory in warm Rb vapor with on-demand storage and retrieval, based on electromagnetically induced transparency. With an acceptance bandwidth of $\delta f$ = 0.66~GHz the memory is suitable for single photons emitted by semiconductor quantum dots. In this regime, vapor cell memories offer an excellent compromise between storage efficiency, storage time, noise level, and experimental complexity, and atomic collisions have negligible influence on the optical coherences. Operation of the memory is demonstrated using attenuated laser pulses on the single photon level. For 50 ns storage time we measure $\eta_{\textrm{e2e}}^{\textrm{50ns}} = 3.4(3)\%$ \emph{end-to-end efficiency} of the fiber-coupled memory, with an \emph{total intrinsic efficiency} $\eta_{\textrm{int}} = 17(3)\%$. Straightforward technological improvements can boost the end-to-end-efficiency to $\eta_{\textrm{e2e}} \approx 35\%$; beyond that increasing the optical depth and exploiting the Zeeman substructure of the atoms will allow such a memory to approach near unity efficiency. In the present memory, the unconditional readout noise level of $9\cdot 10^{-3}$ photons is dominated by atomic fluorescence, and for input pulses containing on average $\mu_{1}=0.27(4)$ photons the signal to noise level would be unity

Ringing the eigenmodes from compact manifolds

We present a method for finding the eigenmodes of the Laplace operator acting on any compact manifold. The procedure can be used to simulate cosmic microwave background fluctuations in multi-connected cosmological models. Other applications include studies of chaotic mixing and quantum chaos.Comment: 11 pages, 8 figures, IOP format. To be published in the proceedings of the Cleveland Cosmology and Topology Workshop 17-19 Oct 1997. Submitted to Class. Quant. Gra

W UMa-type Binary Stars in Globular Clusters

A sample of 86 contact binary systems in 14 globular clusters with available color index data in (B-V) or in (V-I) has been analyzed. At least one third of all systems are numerous foreground Galactic Disk projections over long lines of sight to the clusters. Since the selection of the cluster members has been based on the MV(logP, color) calibrations, the matter of a metallicity-correction required particular attention with the result that such a correction is apparently not needed at the present level of accuracy. Analysis of the color-magnitude and period-color relations shows that globular cluster members are under-luminous relative to the Galactic Disk contact systems mainly because of the smaller sizes and, consequently, shorter orbital periods; the color-index effect of the diminished blanketing is less important, especially for (V-I). The variability amplitudes for the Blue Straggler systems show a significantly different distribution from that for systems below the Turn Off Point (TOP): The BS systems show only small amplitudes while the distribution for the systems below the TOP is peculiar in containing only large amplitude systems. This difference is linked to an observational selection effect so that efforts at determining the frequency of occurrence of the contact systems below the TOP have been judged to be premature; the frequency among the BS stars could be at about 45+-10 BS stars per one contact BS binary.Comment: submitted for publication in Astronomical Journal; 8 figures, 3 tables (Table 1 in landscape

All-Sky spectrally matched UBVRI-ZY and u'g'r'i'z' magnitudes for stars in the Tycho2 catalog

We present fitted UBVRI-ZY and u'g'r'i'z' magnitudes, spectral types and distances for 2.4M stars, derived from synthetic photometry of a library spectrum that best matches the Tycho2 BtVt, NOMAD Rn and 2MASS JHK_{2/S} catalog magnitudes. We present similarly synthesized multi-filter magnitudes, types and distances for 4.8M stars with 2MASS and SDSS photometry to g<16 within the Sloan survey region, for Landolt and Sloan primary standards, and for Sloan Northern (PT) and Southern secondary standards. The synthetic magnitude zeropoints for BtVt, UBVRI, ZvYv, JHK_{2/S}, JHK_{MKO}, Stromgren uvby, Sloan u'g'r'i'z' and ugriz are calibrated on 20 calspec spectrophotometric standards. The UBVRI and ugriz zeropoints have dispersions of 1--3%, for standards covering a range of color from -0.3 < V-I < 4.6; those for other filters are in the range 2--5%. The spectrally matched fits to Tycho2 stars provide estimated 1-sigma errors per star of ~0.2, 0.15, 0.12, 0.10 and 0.08 mags respectively in either UBVRI or u'g'r'i'z'; those for at least 70% of the SDSS survey region to g<16 have estimated 1-sigma errors per star of ~0.2, 0.06, 0.04, 0.04, 0.05 in u'g'r'i'z' or UBVRI. The density of Tycho2 stars, averaging about 60 stars per square degree, provides sufficient stars to enable automatic flux calibrations for most digital images with fields of view of 0.5 degree or more. Using several such standards per field, automatic flux calibration can be achieved to a few percent in any filter, at any airmass, in most workable observing conditions, to facilitate inter-comparison of data from different sites, telescopes and instruments.Comment: 36 pages, 30 figures, 3 printed tables, several electronic tables, accepted PASP Dec 201

Measuring Responsiveness to Feedback as a Personal Trait

People typically update their beliefs about their own abilities too little in response to feed-back, a phenomenon known as “conservatism”, and some studies suggest that they overweight good relative to bad signals (“asymmetry”). We measure individual conservatism and asymmetry in three tasks that test different cognitive skills, and study entry into a winner-takes-all competition based on similar skills. We show that individual differences in feedback responsiveness explain an important part of the variation in confidence and competition entry decisions. Conservatism is correlated across tasks and predicts competition entry both by influencing beliefs and independently of beliefs, suggesting it can be considered a personal trait. Subjects tend to be more conservative in tasks that they see as more ego-relevant and women are more conservative than men. Asymmetry is less stable across tasks, but predicts competition entry by increasing self-confidence

Isospectral domains with mixed boundary conditions

We construct a series of examples of planar isospectral domains with mixed Dirichlet-Neumann boundary conditions. This is a modification of a classical problem proposed by M. Kac.Comment: 9 figures. Statement of Theorem 5.1 correcte

M-grid: Using Ubiquitous Web Technologies to create a Computational Grid

There are many potential users and uses for grid computing. However, the concept of sharing computing resources excites security concerns and, whilst being powerful and flexible, at least for novices, existing systems are complex to install and use. Together these represent a significant barrier to potential users who are interested to see what grid computing can do. This paper describes m-grid, a system for building a computational grid which can accept tasks from any user with access to a web browser and distribute them to almost any machine with access to the internet and manages to do this without the installation of additional software or interfering with existing security arrangements

The Peculiar Type Ia Supernova 1999by: Spectroscopy at Early Epochs

We present medium resolution (lambda/Delta lambda = 2500) optical spectroscopy of SN 1999by in NGC 2841 made around its light maximum. The depth ratio of the two Si II features at 5800 AA and 6150 AA being R(SiII) approx. 0.63 at maximum indicates that this SN belongs to the peculiar, sub-luminous SNe Ia. Radial velocities inferred from the minimum of the 6150 AA trough reveal a steeper decline of the velocity curve than expected for ``normal'' SNe Ia, consistent with the behavior of published VRI light curves. A revised absolute magnitude of SN 1999by and distance to its host galaxy NGC 2841 is estimated based on the Multi-Color Light Curve Shape (MLCS) method, resulting in M_V(max)=-18.06+/- 0.1 mag and d = 17.1+/-1.2 Mpc, respectively. An approximative linear dependence of the luminosity parameter Delta on R(SiII) is presented.Comment: accepted for publication in Astron. Journal (2001 June