Penetration of Andreev bound states into the ferromagnet in a SrRuO3_{3}/(110)YBa2_2Cu3_3O7−δ_{7-\delta} bilayer: a scanning tunneling spectroscopy study

Scanning tunneling spectroscopy of thin epitaxial $SrRuO_{3}/(110)YBa_2Cu_3O_{7-\delta}$ ferromagnet/superconductor bilayers, reveal a clear penetration of the Andreev bound states into the ferromagnetic layer. The penetration is manifested in the density of states of the ferromagnet as a split zero bias conductance peak with an imbalance between peak heights. Our data indicate that the splitting occurs at the superconductor side as a consequence of induced magnetization, confirming recent theoretical predictions. The imbalance is attributed to the spin polarization in the ferromagnet.Comment: 4 figure

JMPI: implementing the message passing standard in Java

The Message Passing Interface (MPI) standard provides a uniform Application Programmers Interface (API) that abstracts the underlying hardware from the parallel applications. Recent research efforts have extended the MPI standard to Java either through wrapper implementations or as subsets of larger parallel infrastructures. In this paper, we describe JMPI, a reference implementation of MPI developed at the Architecture and Real-Time Laboratory at the University of Massachusetts Amherst. In this implementation, we explore using Java's Remote Method Invocation (RMI), Object Serialization and Introspection technologies for message passing. We discuss the architecture of our implementation, adherence to emerging standards for MPI bindings for Java, our performance results, and future research direction

Recent developments in monolithic integration of InGaAsP/InP optoelectronic devices

Monolithically integrated optoelectronic circuits combine optical devices such as light sources (injection lasers and light emitting diodes) and optical detectors with solid-state semiconductor devices such as field effect transistors, bipolar transistors, and others on a single semiconductor crystal. Here we review some of the integrated circuits that have been realized and discuss the laser structures suited for integration with emphasis on the InGaAsP/InP material system. Some results of high frequency modulation and performance of integrated devices are discussed

Optimal Grid Drawings of Complete Multipartite Graphs and an Integer Variant of the Algebraic Connectivity

How to draw the vertices of a complete multipartite graph $G$ on different points of a bounded $d$-dimensional integer grid, such that the sum of squared distances between vertices of $G$ is (i) minimized or (ii) maximized? For both problems we provide a characterization of the solutions. For the particular case $d=1$, our solution for (i) also settles the minimum-2-sum problem for complete bipartite graphs; the minimum-2-sum problem was defined by Juvan and Mohar in 1992. Weighted centroidal Voronoi tessellations are the solution for (ii). Such drawings are related with Laplacian eigenvalues of graphs. This motivates us to study which properties of the algebraic connectivity of graphs carry over to the restricted setting of drawings of graphs with integer coordinates.Comment: Appears in the Proceedings of the 26th International Symposium on Graph Drawing and Network Visualization (GD 2018

Software-based adaptive and concurrent self-testing in programmable network interfaces

Emerging network technologies have complex network interfaces that have renewed concerns about network reliability. In this paper, we present an effective low-overhead failure detection technique, which is based on a software watchdog timer that detects network processor hangs and a self-testing scheme that detects interface failures other than processor hangs. The proposed adaptive and concurrent self-testing scheme achieves failure detection by periodically directing the control flow to go through only active software modules in order to detect errors that affect instructions in the local memory of the network interface. The paper shows how this technique can be made to minimize the performance impact on the host system and be completely transparent to the user

Stratiform cloud electrification: comparison of theory with multiple in-cloud measurements

Stratiform clouds constitute ~40% of global cloud cover and play a key role in determining the planetary radiation budget. Electrification remains one of the least understood effects on their microphysical processes. Droplet charging at the top and bottom edges of stratiform clouds arises from vertical current flow through clouds driven by the Global atmospheric Electric Circuit. In-cloud charge data are central in assessing the role of charge in droplet growth processes, which influence droplet size distributions and associated cloud radiative properties and precipitation. This study presents the first high vertical resolution electrical measurements made in multiple layer clouds. Of the 22 clouds sampled, all were charged at their edges, demonstrating unequivocally that all stratiform clouds can be expected to contain charge at their upper and lower boundaries to varying extent. Cloud base and cloud top are shown to charge asymmetrically, with mean cloud top space charge +32 pCm-3 and base space charge -24 pCm-3. The larger cloud top charges are associated with strong temperature inversions and large vertical electrical conductivity gradients at the upper cloud boundary. Greater charging was observed in low altitude (2km) cloud layers (7.0 pCm-3), consistent with the smaller air conductivity at lower altitudes caused by reduced cosmic ray ionisation. Taken together, these measurements show that the greatest cloud droplet charges in extensive stratiform clouds occur at cloud tops for low altitude (<2km) clouds, when vertical mixing is suppressed by appreciable temperature inversions, confirming theoretical expectations. The influence of cloud dynamics on layer cloud edge charging reported here should inform modelling studies of cloud droplet charging effects on cloud microphysics

Attitudes towards treatment among patients suffering from sleep disorders. A Latin American survey

BACKGROUND: Although sleep disorders are common, they frequently remain unnoticed by the general practitioner. Few data are available about the willingness and reasons of patients with sleep disturbances to seek for medical assistance. METHODS: The results of a cross-sectional community-based multinational survey in three major Latin American urban areas, i.e. Buenos Aires, Mexico City and Sao Paulo, are reported. Two-hundred subjects suffering sleep disturbances and 100 non-sufferers were selected from the general population in each city (total number: 600 sufferers vs. 300 non-sufferers). A structured interview was conducted, sleep characteristics, feelings about sleep disturbances and strategies to cope with those problems being recorded. Data were analyzed by employing either t-test or analysis of variance (ANOVA) to the Z-transformed proportions. RESULTS: 22.7 ± 3.5 % (mean ± SEM) of subjects reported to suffer from sleep disturbances every night. About 3 out of 4 (74.2 ± 2.0 %) considered their disorder as mild and were not very concerned about it. Only 31 ± 2 % of sufferers reported to have sought for medical help. Although 45 ± 2 % of sufferers reported frequent daily sleepiness, trouble to remember things, irritability and headaches, they did not seek for medical assistance. Among those patients who saw a physician with complaints different from sleep difficulties only 1 out of 3 (33 ± 2 % of patients) were asked about quality of their sleep by the incumbent practitioner. Strategies of patients to cope with sleep problems included specific behaviors (taking a warm bath, reading or watching TV) (44 ± 1.6 %), taking herbal beverages (17 ± 1.2 %) or taking sleeping pills (10 ± 1.1 %). Benzodiazepines were consumed by 3 ± 0.6 % of sufferers. CONCLUSION: Public educational campaigns on the consequences of sleep disorders and an adequate training of physicians in sleep medicine are needed to educate both the public and the general practitioners about sleep disorders