A case study is presented of an autistic boy aged 11 years. The analysis is based on audio-visual recordings made in both his home and school. The focus of the study is on that subset of immediate echolalia that has been referred to as pure echoing. Using an approach informed by conversation analysis and descriptive phonetics, distinctions are drawn between different forms of pure echo. It is argued that one of these forms, what we call 'unusual echoes', has distinctive interactional and phonetic properties which do not have a counterpart in the speech of non-autistic children. These principally consist of a particular segmental and suprasegmental relationship to the prior adult turn, a particular rhythmic timing and a functional opaqueness. This behaviour is set within the context of this child's general communicative behaviour which, in various ways, places a premium on the use of repetition skills. These skills also inform the child's use of repetition in unusual echoes. though here the interactional and phonetic properties of such repetitions suggest that they display a distinct interactional stance to the questions that precede them.

Refineries are a source of emissions of volatile hydrocarbons that contribute to the formation of smog and ozone. Fugitive emissions of hydrocarbons are difficult to measure and quantify. Currently these emissions are estimated based on standard emission factors for the type and use of equipment installed. Differential absorption light detection and ranging (DIAL) can remotely measure concentration profiles of hydrocarbons in the atmosphere up to several hundred meters from the instrument. When combined with wind speed and direction, downwind vertical DIAL scans can be used to calculate mass fluxes of the measured gas leaving the site. Using a mobile DIAL unit, a survey was completed at a Canadian refinery to quantify fugitive emissions of methane, C 2ϩ hydrocarbons, and benzene and to apportion the hydrocarbon emissions to the various areas of the refinery. Refinery fugitive emissions as measured with DIAL during this demonstration study were 1240 kg/hr of C 2ϩ hydrocarbons, 300 kg/hr of methane, and 5 kg/hr of benzene. Storage tanks accounted for over 50% of the total emissions of C 2ϩ hydrocarbons and benzene. The coker area and cooling towers were also significant sources. The C 2ϩ hydrocarbons emissions measured during the demonstration amounted to 0.17% of the mass of the refinery hydrocarbon throughput for that period. If the same loss were repeated throughout the year, the lost product would represent a value of US$3.1 million/yr (assuming US$40/bbl). The DIAL-measured hourly emissions of C 2ϩ hydrocarbons were 15 times higher than the emission factor estimates and gave a different perspective on which areas of the refinery were the main source of emissions. Methods, such as DIAL, that can directly measure fugitive emissions would improve the effectiveness of efforts to reduce emissions, quantify the reduction in emissions, and improve the accuracy of emissions data that are reported to regulators and the public.

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This is a book containing reports of original research on children aged somewhere between seven and eighteen. All the contributors are based in the US, and with one exception all the thirteen studies were also carried out in the US; the exception, by Marilyn Merritt, also incorporates material from work which she has done in various parts of the African continent. Taken together, the studies cover many aspects of these young people's lives – home, school, playground, voluntary group meetings and work schemes. In most cases, one is struck by the extensive fieldwork which lies behind these research reports. Long periods of observation seem to be commonplace; and the efforts are impressive because, as Shirley Brice Heath points out in her chapter, obtaining naturalistic data from young people of this age can pose problems regarding both access and quality of data. In almost all cases, a corpus of audio or audio-visual recordings forms a basis for at least part of the analysis, though chapters are generally written so as to focus on only a small set of conversation extracts – a strategy which often does little justice to the range of data gathered within the research.