Abstract

Abstract

Abstract
We have investigated the sensitivity of arc-induced long-period gratings to changes of ambient refractive index. Two pure-silica-core fibres with different cladding diameters and a standard fibre were used in this study. For a 6 x 10(-3) change of the refractive index, a 240 pm shift of the resonant wavelength was achieved with long-period gratings written in the 125 mu m cladding diameter pure-silica-core fibre.

Abstract
We investigate here an approach to modelling the dynamic information requirements of a user performing a number of tasks, addressing both the provision and representation of information, viewing the information as being distributed across a set of resources. From knowledge of available resources at the user interface, and task information needs we can identify whether the system provides the user with adequate support for task execution. We look at how we can use tools to help reason about these issues, and illustrate their use through an example. We also consider a full range of analyses suggested using this approach which could potentially be supported by automated reasoning systems.

Abstract
Larvae of the freshwater swan mussel, Anodonta cygnea, were cultured in artificial media at the controlled temperature of 23 degrees +/- 2 degrees C, with successful metamorphosis for the first time. The artificial medium contained a mixture of M199, common carp plasma, and antibiotics/antimycotics. Glochidia were reared to the juvenile stage in the medium after 10-11 d of culture. After 15 d of controlled feeding with phytoplankton, the juveniles showed an elongated shell with several growth lines. Larval survival was 34.3 +/- 9.3%, whereas the proportion undergoing metamorphosis was <= 60.8 +/- 4.2%. The ultrastructure of early developmental stages was observed by scanning electron microscopy, from the glochidial to the juvenile stage. Glochidia had a hooked shell, with two equal triangular valves formed by a calcareous layer with numerous pores and covered by a thin cuticle of chitin-keratin. The appearance of the complete foot within 11 d of in vitro culture was considered the final feature of metamorphosis to the juvenile stage. The main alteration during juvenile development was the formation, under the glochidial shell, of a new periostracum with growth lines. The prominent foot, gradually covered by long, dense cilia, showed rhythmical movements involved in the capture of particulate matter. Similarly, cilia and microvilli present in the mantle also performed the same role. Longer cilia, sparsely distributed in the mantle, may function as chemotactile sensors.

Abstract
All-optical switching devices based on fibre Bragg grating (FBG) structures written on a standard single-mode fibre and in an erbium-doped fibre have been experimentally demonstrated in the third telecommunication window. The switching devices work due to the thermal changes induced by a high-power continuous-wave laser diode. The filters tunability characteristics have been demonstrated for different pump powers (up to 900 mW) and different pump laser wavelengths (at 980 and 1480 nm), presenting different thermal absorption behaviour within different working regimes. (c) 2006 Wiley Periodicals, Inc.