The forgotten veterinary entrepreneurs of the 29th century

February 2018 A Page From History column from Texas Veterinaria

Design techniques for high performance asynchronous arithmetic operators

High performance asynchronous arithmetic operator design techniques are proposed, which adopt some of the techniques commonly used in synchronous systems such as fast precharged logic and efficient latch design, while maintaining the features of localized and elastic pipelining control inherent in asynchronous design. A pipelined sixteen bit multiplier designed using these techniques is presented and its performance compared with several previously reported asynchronous and synchronous designs

An 180 MHz 16 bit multiplier using asynchronous logic design techniques

A CMOS digital logic design technique is described which exploits the advantages of fast precharged logic and efficient latch design commonly used in synchronous systems while maintaining the features of localized control inherent in asynchronous design. A pipelined sixteen bit multiplier is presented and its performance compared with several previously reported asynchronous and synchronous designs

A history of exemplifying leadership

April 2018 A Page From History column from Texas Veterinaria

User perceptions of multi-source feedback tools for junior doctors

Context:  The effectiveness of multi-source feedback (MSF) tools, which are increasingly important in medical careers, will be influenced by their users’ attitudes. This study compared perceptions of two tools for giving MSF to UK junior doctors, of which one provides mainly textual feedback and one provides mainly numerical feedback. We then compared the perceptions of three groups, including: trainees; raters giving feedback, and supervisors delivering feedback. Methods:  Postal questionnaires about the usability, usefulness and validity of a feedback system were distributed to trainees, raters and supervisors across the north of England. Results:  Questionnaire responses were analysed to compare opinions of the two tools and among the different user groups. Overall there were few differences. Attitudes towards MSF in principle were positive and the tools were felt to be usable, but there was little agreement that they could effectively identify doctors in difficulty or provide developmental feedback. The text-oriented tool was rated as more useful for giving feedback on communication and attitude, and as more useful for identifying a doctor in difficulty. Raters were more positive than other users about the usefulness of numerical feedback, but, overall, text was felt to be more useful. Some trainees expressed concern that feedback was based on insufficient knowledge of their work. This was not supported by raters’ responses, although many did use indirect information. Trainees selected raters mainly for the perceived value of their feedback, but also based on personal relationships and the simple pragmatics of getting a tool completed. Discussion:  Despite positive attitudes to MSF, the perceived effectiveness of the tools was low. There are small but significant preferences for textual feedback, although raters may prefer numerical scales. Concerns about validity imply that greater awareness of contextual and psychological influences on feedback generation is necessary to allow the formative benefits of MSF to be optimised and to negate the risk of misuse in high-stakes contexts

The effect of host structure on the selectivity and mechanism of supramolecular catalysis of Prins cyclizations.

The effect of host structure on the selectivity and mechanism of intramolecular Prins reactions is evaluated using K12Ga4L6 tetrahedral catalysts. The host structure was varied by modifying the structure of the chelating moieties and the size of the aromatic spacers. While variation in chelator substituents was generally observed to affect changes in rate but not selectivity, changing the host spacer afforded differences in efficiency and product diastereoselectivity. An extremely high number of turnovers (up to 840) was observed. Maximum rate accelerations were measured to be on the order of 105, which numbers among the largest magnitudes of transition state stabilization measured with a synthetic host-catalyst. Host/guest size effects were observed to play an important role in host-mediated enantioselectivity

Veterinary practitioners’ selection of diagnostic tests for the primary evaluation of colic in the horse

The aim of this study was to survey veterinary practitioners’ selection of diagnostic tests for horses with clinical signs of abdominal pain. A questionnaire was distributed to veterinary surgeons involved in the primary evaluation of horses with abdominal pain, including the respondent's demographics, selection of diagnostic tests and factors affecting decision-making. Data analysis included descriptive analysis, categorisation of free text and simple univariable correlations to explore the relationships between independent variables and the relative self-estimated frequency that diagnostic tests were performed. A total of 228 responses were analysed. Participants worked in mixed practice (55.7 per cent), first opinion equine (22.8 per cent), first and second opinion equine (17.9 per cent) and referral practice (3.1 per cent). The majority (48.2 per cent, 105/218) were very confident managing a colic case (confidence level 4/5). The most frequently used diagnostic tests were ‘response to analgesia’ (87.2±24.0 per cent cases), rectal examination (75.9±21.2 per cent) and nasogastric intubation (43.8±27.6 per cent). Approach varied between practitioners, and for all diagnostic tests with frequency of use ranging from 0 to 100 per cent of cases. ‘Risk to personal safety’ was the most common reason for not using rectal examination. Practitioner's opinion of their confidence level in managing a colic case was associated with how frequently they used different diagnostic tests. There was marked variation in practitioners’ approaches, highlighting the need for further evidence to support decision-making

Lattice study of B→πB\to \pi semileptonic decay using nonrelativistic lattice QCD

We present an exploratory lattice study of $B\to\pi$ semileptonic decay form factors using the nonrelativistic lattice QCD for heavy quark with Wilson light quark on a $16^3 \times 32$ quenched lattice at $\beta=5.8$. The matrix elements are calculated at eight values of heavy quark mass in a range of $1.5-8$ GeV and with three values of light quark mass. The $1/m_B$ corrections to the matrix elements are found to be fairly small except for the spatial component proportional to the $B$ meson momentum. We find that the $q^2$ dependence of the form factor $f^+(q^2)$ near $q_{max}^2$ becomes much stronger for larger heavy quark mass, which may suggest the increase of a pole contribution. We perform a model independent fit of the form factors and study whether the $q^2$ dependence is consistent with the pole contribution. Although the soft pion theorem predicts $f^0(q_{max}^2)=f_B/f_{\pi}$ in the chiral limit, we observe a significant violation of this relation.Comment: 42 pages, Revised March 1998, REVTeX, 30 eps figures, uses psfig.st