Simplified, high performance transceiver for phase modulated RFID applications

In this paper results are presented for a simple yet highly sensitive transceiver for phase modulated RFID applications. This is an advance on other simple RFID readers which can only operate with amplitude shift keyed (ASK) signals. Simple circuitry is achieved by the use of a novel injection locked PLL configuration which replaces the standard superhet type architecture normally used. The transceiver is shown to operate with a number of phase modulation modes which have certain advantages relating to distance to target. The paper concludes with practical results obtained for the transceiver when operated within a backscatter RFID application. A unique advantage of this transceiver is its complete immunity to the problem of TX/RX isolation, allowing for long ranges, estimated to be in the region of 80m at 1 GHz, to be achieved even in the presence of a simple backscatter target.

Debating Darwin at the Cape

This paper focuses attention on the fortunes of Darwin's theory among the English-speaking community in Cape Colony during the latter part of the nineteenth century. The paper begins with a review of early encounters with Darwin dwelling particularly on the response of figures like Roderick Noble - professor and editor of the Cape Monthly Magazine, the geologist John Shaw, and Sir Henry Barkly, governor of the colony. Besides these more theoretical responses, Darwin's ideas were also mobilised in a range of scientific inquiries on such subjects as birds and butterflies. But most conspicuous was the use of evolutionary thought-forms in the work of the eminent philologist Wilhelm Bleek, cousin of Darwin's leading German apologist, Ernst Haeckel. The prevailing sense is of a liberal intelligentsia calmly interacting with a novel theory with all due deference. During the 1870s, an address by Langham Dale at the South African Public Library injected new energy into the Darwin discussion. Dale expressed disquiet over some of the anthropological implications of evolution as well as its apparent reductionism, and this stimulated a range of reactions. Several anonymous commentators responded but the most sustained evaluation of Dale's position emanated from the Queenstown physician and later politician, Sir William Bisset Berry. Then, in 1874, copious extracts from John Tyndall's infamous 'Belfast Address' were printed in the Cape Monthly and this added yet further impetus to the debate. Tyndall's seeming materialism bothered a number of readers, not least Hon William Porter, former attorney-general of Cape Colony. To figures like these the materialist extrapolations of radical Darwinians such as Haeckel were deeply disturbing, not just for religious reasons, but because they seemed to destabilise the moral and pedagogic progressivism that lay at the heart of their civilising credo. While reservations about Darwin's proposals were certainly audible, taken in the round Darwinian conversations among the English-speaking literati at the Cape were conducted with liberal sentiments, not least when evolutionary science approached questions of race. For Darwin's writings were seen to confirm a monogenetic account of the origin and unity of the human race, and could readily be called upon to justify the paternalistic ideology that governed colonial affairs.

Operators for Similarity Search: Semantics, Techniques and Usage Scenarios

This book provides a comprehensive tutorial on similarity operators. The authors systematically survey the set of similarity operators, primarily focusing on their semantics, while also touching upon mechanisms for processing them effectively.

The book starts off by providing introductory material on similarity search systems, highlighting the central role of similarity operators in such systems. This is followed by a systematic categorized overview of the variety of similarity operators that have been proposed in literature over the last two decades, including advanced operators such as RkNN, Reverse k-Ranks, Skyline k-Groups and K-N-Match. Since indexing is a core technology in the practical implementation of similarity operators, various indexing mechanisms are summarized. Finally, current research challenges are outlined, so as to enable interested readers to identify potential directions for future investigations.

In summary, this book offers a comprehensive overview of the field of similarity search operators, allowing readers to understand the area of similarity operators as it stands today, and in addition providing them with the background needed to understand recent novel approaches.

Do Cochrane summaries help student midwives understand the findings of Cochrane systematic reviews: the BRIEF randomised trial

BACKGROUND: Abstracts and plain language summaries (PLS) are often the first, and sometimes the only, point of contact between readers and systematic reviews. It is important to identify how these summaries are used and to know the impact of different elements, including the authors' conclusions. The trial aims to assess whether (a) the abstract or the PLS of a Cochrane Review is a better aid for midwifery students in assessing the evidence, (b) inclusion of authors' conclusions helps them and (c) there is an interaction between the type of summary and the presence or absence of the conclusions.

METHODS: Eight hundred thirteen midwifery students from nine universities in the UK and Ireland were recruited to this 2 × 2 factorial trial (abstract versus PLS, conclusions versus no conclusions). They were randomly allocated to one of four groups and asked to recall knowledge after reading one of four summary formats of two Cochrane Reviews, one with clear findings and one with uncertain findings. The primary outcome was the proportion of students who identified the appropriate statement to describe the main findings of the two reviews as assessed by an expert panel.

RESULTS: There was no statistically significant difference in correct response between the abstract and PLS groups in the clear finding example (abstract, 59.6 %; PLS, 64.2 %; risk difference 4.6 %; CI -0.2 to 11.3) or the uncertain finding example (42.7 %, 39.3 %, -3.4 %, -10.1 to 3.4). There was no significant difference between the conclusion and no conclusion groups in the example with clear findings (conclusions, 63.3 %; no conclusions, 60.5 %; 2.8 %; -3.9 to 9.5), but there was a significant difference in the example with uncertain findings (44.7 %; 37.3 %; 7.3 %; 0.6 to 14.1, p = 0.03). PLS without conclusions in the uncertain finding review had the lowest proportion of correct responses (32.5 %). Prior knowledge and belief predicted student response to the clear finding review, while years of midwifery education predicted response to the uncertain finding review.

CONCLUSIONS: Abstracts with and without conclusions generated similar student responses. PLS with conclusions gave similar results to abstracts with and without conclusions. Removing the conclusions from a PLS with uncertain findings led to more problems with interpretation.