Geodesy by radio interferometry: Effects of atmospheric modeling errors on estimates of baseline length

Analysis of very long baseline interferometry data indicates that systematic errors in prior estimates of baseline length, of order 5 cm for ~8000-km baselines, were due primarily to mismodeling of the electrical path length of the troposphere and mesosphere ("atmospheric delay"). Here we discuss observational evidence for the existence of such errors in the previously used models for the atmospheric delay and develop a new "mapping" function for the elevation angle dependence of this delay. The delay predicted by this new mapping function differs from ray trace results by less than ~5 mm, at all elevations down to 5° elevation, and introduces errors into the estimates of baseline length of •< 1 cm, for the multistation intercontinental experiment analyzed here

Spectral Orbits and Peak-to-Average Power Ratio of Boolean Functions with respect to the {I,H,N}^n Transform

We enumerate the inequivalent self-dual additive codes over GF(4) of blocklength n, thereby extending the sequence A090899 in The On-Line Encyclopedia of Integer Sequences from n = 9 to n = 12. These codes have a well-known interpretation as quantum codes. They can also be represented by graphs, where a simple graph operation generates the orbits of equivalent codes. We highlight the regularity and structure of some graphs that correspond to codes with high distance. The codes can also be interpreted as quadratic Boolean functions, where inequivalence takes on a spectral meaning. In this context we define PAR_IHN, peak-to-average power ratio with respect to the {I,H,N}^n transform set. We prove that PAR_IHN of a Boolean function is equivalent to the the size of the maximum independent set over the associated orbit of graphs. Finally we propose a construction technique to generate Boolean functions with low PAR_IHN and algebraic degree higher than 2.Comment: Presented at Sequences and Their Applications, SETA'04, Seoul, South Korea, October 2004. 17 pages, 10 figure

Comparative sensitivity and specificity of Typhidot and Typhidot-M tests in the diagnosis of Enteric fever in Malaysian children

Suntu penelitian untuk mengetahui sensitivitas dan spesifisitas uji Typhidot dan Typhidot-M daLam mendiagnosis demam enterik pada anak-anak Malaysia telah dilakukan. Pasien dibagi dalam dua kelompok: (i) pasien dengan biakan darah dan-/ ataufeses positif S. typhi dan/atau dengan gambaran klinis yang jelas untuk demam enterik; (ii) pasien dengan kedua biakan negatif dan dengan gambaran klinis atau bukti lain adanya demam oleh sebab lain. Hasilnya menunjukkan bahwa Typhidot maupun TyphidorM sama sensitifnya dengan uji Widal. Uji Typhidot-M memiliki spesifisins yang sedikit Lebih tinggi daripada uji Typhido4 keduanya memiliki spesifisitas sekitar l0% Iebih baik daripada uji Widal. Data juga menunjukkan bahwa uji Typhidot-M mungkin dapat meningkntkan ketepatan diagnosis demam oleh sebab lain pada anak-anak, yang dibuktikan dengan perbaikan spesifitas. Baik uji Typhidot maupun Typhidot-M adalah alat bantu diagnosis yang cepat dan dapat diandalkan dalam penatalaksanaan demam enterik. Uji Typhidot-M mungkin lebih disukai daripada uji Typhidot dalam mengidentifikasi pasien yang menderita demam oleh sebab lain sementara ia daLam masa penyembuhan demam enterik. A study was carcied out to compare the sensitivity and specificity of Typhidot and Typhidot-M tests in the diagnosis of enteric fever in Malaysian children. The patients were divided into two groups: (i) those who were bLood and /or stool culture positive for S. typhi and/or who had clinical features strongly suggestive of enteric fever; (ii) those who were both culture - negative and had clinical or other evidence of another febrile illness. The results showed both Typhidot and Typhidot-M tests.were as sensitive as WidaL test. The Typhidot-M test hnd slightly greater specificity than the Typhidot test; both had around l07a better specificity than the Widal test. The data aLso suggest that the Typhidot-M test may, as evidenced by improved specificity, increase diagnostic accuracy for other febrile iLlnesses in children. The Typhidot and Typhidot-M are both prompt and reliable diagnostic aids in the management of enteric fever The typhidot-M test may be more preferable to the orginal Typhidot test in identifiing patients who develop other febrile illnesses whilst recovering from enteric fever

Breaking up the band: European regulatory cooperation in a post-Brexit world

Since 1995, the European Medicines Agency (EMA) has progressed from harmonising regulation for human and veterinary medicines across the European Union Member State national competent authorities, to galvanising one of the most successful cooperative initiatives for regulation globally. Although the EMA is the focal point for stakeholders, regulation is delivered through the European medicines regulatory network, in which national authorities, like the UK’s Medicines & Healthcare products Regulatory Agency (MHRA), contribute. As with any collaboration, contributions by individual members vary, and the MHRA has been noted as an innovative and highly productive member of the network. Progress in regulation not only in Europe – but also around the world through convergence – can be attributed to this unique European cooperation. The decision by the UK to leave the European Union threatens to mark the end of this cooperation; we argue here that the best decision is to maintain regulatory cooperation under new structures

A Coloring Algorithm for Disambiguating Graph and Map Drawings

Drawings of non-planar graphs always result in edge crossings. When there are many edges crossing at small angles, it is often difficult to follow these edges, because of the multiple visual paths resulted from the crossings that slow down eye movements. In this paper we propose an algorithm that disambiguates the edges with automatic selection of distinctive colors. Our proposed algorithm computes a near optimal color assignment of a dual collision graph, using a novel branch-and-bound procedure applied to a space decomposition of the color gamut. We give examples demonstrating the effectiveness of this approach in clarifying drawings of real world graphs and maps

Preschool hearing, speech, language, and vision screening

Child health surveillance is part of a broad set of activities, the objective of which is to reduce childhood disability by identifying and managing a multiplicity of conditions at an early stage.1 This includes several screening programmes which are focused on the detection of specific disorders. The value of surveillance and monitoring of child health, growth, and development used to be regarded as self evident. The Hall reports emphasised the importance of applying rigorous criteria for screening programmes in community child health and helped to produce a more coordinated national programme.2–4 However, there is still considerable variation both within and between health authorities in the content, timing, and delivery of child health surveillance. This paper summarises the research evidence presented in a recent issue of the Effective Health Care bulletin, Vol 4, No 2; April, 1998 about hearing, speech and language, and vision screening and is based on recent systematic reviews commissioned by the National Health Service (NHS) Health Technology Assessment Programme. Details of the methods and the results are available in the full reports.5–

Multipole expansion of strongly focussed laser beams

Multipole expansion of an incident radiation field - that is, representation of the fields as sums of vector spherical wavefunctions - is essential for theoretical light scattering methods such as the T-matrix method and generalised Lorenz-Mie theory (GLMT). In general, it is theoretically straightforward to find a vector spherical wavefunction representation of an arbitrary radiation field. For example, a simple formula results in the useful case of an incident plane wave. Laser beams present some difficulties. These problems are not a result of any deficiency in the basic process of spherical wavefunction expansion, but are due to the fact that laser beams, in their standard representations, are not radiation fields, but only approximations of radiation fields. This results from the standard laser beam representations being solutions to the paraxial scalar wave equation. We present an efficient method for determining the multipole representation of an arbitrary focussed beam.Comment: 13 pages, 7 figure