An in vitro study of the accuracy and precision of Breathalyzer models 900, 900A, and 1000

Ninety Breathalyzer instruments (Model 1000) and twenty instruments (Models 900, 900A) were studied using a protocol described by the Department of Transportation's "Standard for Devices to Measure Breath Alcohol." Although the mean of each of three concentrations tested (0.05, 0.10, and 0.15 g/210 L) compared favorably in both series, the standard deviation was consistently higher for the Model 1000 instruments. The Model 1000 instruments also produced a significant number of test results which exceeded the normally expected scientific deviation.     

Reply to Lowe

The concept 'community' is underspecified in the political theory literature — it must have a more specific reference than just some collectivity or some network of social relations. But attempts to specify what is specific about the relation of community are unsatisfactory. And references to 'actual physical' communities overlook the symbolic and imagined aspects of community, which furthermore destabilise putative communities as much as they stabilise them. Analysis of social relations and networks, and theories of what patterns of relations are conducive to human flourishing should deploy more precise sociological categories.     

An inconclusive digital audio authenticity examination: a unique case

This case report sets forth an authenticity examination of 35 encrypted, proprietary-format digital audio files containing recorded telephone conversations between two codefendants in a criminal matter. The codefendant who recorded the conversations did so on a recording system he developed; additionally, he was both a forensic audio authenticity examiner, who had published and presented in the field, and was the head of a professional audio society's writing group for authenticity standards. The authors conducted the examination of the recordings following nine laboratory steps of the peer-reviewed and published 11-step digital audio authenticity protocol. Based considerably on the codefendant's direct involvement with the development of the encrypted audio format, his experience in the field of forensic audio authenticity analysis, and the ease with which the audio files could be accessed, converted, edited in the gap areas, and reconstructed in such a way that the processes were undetected, the authors concluded that the recordings could not be scientifically authenticated through accepted forensic practices.