The AM Canum Venaticorum binary SDSS J173047.59+554518.5

The AM Canum Venaticorum (AM CVn) binaries are a rare group of hydrogen-deficient, ultrashort period, mass-transferring white dwarf binaries and are possible progenitors of Type Ia supernovae. We present time-resolved spectroscopy of the recently discovered AM CVn binary SDSS J173047.59+554518.5. The average spectrum shows strong double-peaked helium emission lines, as well as a variety of metal lines, including neon; this is the second detection of neon in an AM CVn binary, after the much brighter system GP Com. We detect no calcium in the accretion disc, a puzzling feature that has been noted in many of the longer period AM CVn binaries. We measure an orbital period, from the radial velocities of the emission lines, of 35.2 ± 0.2 min, confirming the ultracompact binary nature of the system. The emission lines seen in SDSS J1730 are very narrow, although double-peaked, implying a low-inclination, face-on accretion disc; using the measured velocities of the line peaks, we estimate i ≤ 11°. This low inclination makes SDSS J1730 an excellent system for the identification of emission lines

Modelling the control of visual attention in Stroop-like tasks

The authors discuss the issue of how visual orienting, selective stimulus processing, and vocal response planning are related in Stroop-like tasks. The evidence suggests that visual orienting is dependent on both visual processing and verbal response planning. They also discuss the issue of selective perceptual processing in Stroop-like tasks. The evidence suggests that space-based and object-based attention lead to a Trojan horse effect in the classic Stroop task, which can be moderated by increasing the spatial distance between colour and word and by making colour and word part of different objects. Reducing the presentation duration of the colour-word stimulus or the duration of either the colour or word dimension reduces Stroop interference. This paradoxical finding was correctly simulated by the WEAVER++ model. Finally, the authors discuss evidence on the neural correlates of executive attention, in particular, the ACC. The evidence suggests that the ACC plays a role in regulation itself rather than only signalling the need for regulation

The development of a prototype intelligent user interface subsystem for NASA's scientific database systems

The National Space Science Data Center (NSSDC) has initiated an Intelligent Data Management (IDM) research effort which has as one of its components the development of an Intelligent User Interface (IUI).The intent of the latter is to develop a friendly and intelligent user interface service that is based on expert systems and natural language processing technologies. The purpose is to support the large number of potential scientific and engineering users presently having need of space and land related research and technical data but who have little or no experience in query languages or understanding of the information content or architecture of the databases involved. This technical memorandum presents prototype Intelligent User Interface Subsystem (IUIS) using the Crustal Dynamics Project Database as a test bed for the implementation of the CRUDDES (Crustal Dynamics Expert System). The knowledge base has more than 200 rules and represents a single application view and the architectural view. Operational performance using CRUDDES has allowed nondatabase users to obtain useful information from the database previously accessible only to an expert database user or the database designer

Active noise compensation for multichannel magnetocardiography in an unshielded environment

A multichannel high-T/sub c/-SQUID-based heart scanner for unshielded environments is under development, Outside a magnetically shielded room, sensitive SQUID measurements are possible using gradiometers. However, it is difficult to realize large-baseline gradiometers in high-T/sub c/ materials, Therefore, the authors developed two active noise compensation techniques. In the Total Field Compensation technique, a Helmholtz type coil set is placed around the sensors. One magnetometer is used as a zero detector controlling the compensation current through the coil set. For Individual Flux Compensation, the reference signal is sent to the separate SQUIDs (or their flux transformer circuits) to compensate the local environmental noise fluxes, The latter technique was tested on low-T/sub c/ rf-SQUID magnetometers, each sensor set to a field resolution SQUID magnetometers, i.e. 0.1 pT/sub RMS///spl radic/Hz. The authors were able to suppress the environmental disturbances to such an extent that magnetocardiograms could be recorded in an ordinary environment. Here the two suppression techniques are described and experimental results are presente

The crustal dynamics intelligent user interface anthology

The National Space Science Data Center (NSSDC) has initiated an Intelligent Data Management (IDM) research effort which has, as one of its components, the development of an Intelligent User Interface (IUI). The intent of the IUI is to develop a friendly and intelligent user interface service based on expert systems and natural language processing technologies. The purpose of such a service is to support the large number of potential scientific and engineering users that have need of space and land-related research and technical data, but have little or no experience in query languages or understanding of the information content or architecture of the databases of interest. This document presents the design concepts, development approach and evaluation of the performance of a prototype IUI system for the Crustal Dynamics Project Database, which was developed using a microcomputer-based expert system tool (M. 1), the natural language query processor THEMIS, and the graphics software system GSS. The IUI design is based on a multiple view representation of a database from both the user and database perspective, with intelligent processes to translate between the views

Genomics technology for assessing soil pollution

Transcription and metabolite analysis is a powerful way to reveal physiological shifts in response to environmental pollution. Recent studies on earthworms, including one in BMC Biology, show that the type of pollution and its availability for uptake by organisms can differentially affect transcription and metabolism

A mutation in exon 7 of the human cytochrome P-4501A1 gene as marker for sensitivity to anti-cancer drugs?

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