A user evaluation of hierarchical phrase browsing

Phrase browsing interfaces based on hierarchies of phrases extracted automatically from document collections offer a useful compromise between automatic full-text searching and manually-created subject indexes. The literature contains descriptions of such systems that many find compelling and persuasive. However, evaluation studies have either been anecdotal, or focused on objective measures of the quality of automatically-extracted index terms, or restricted to questions of computational efficiency and feasibility. This paper reports on an empirical, controlled user study that compares hierarchical phrase browsing with full-text searching over a range of information seeking tasks. Users found the results located via phrase browsing to be relevant and useful but preferred keyword searching for certain types of queries. Users experiences were marred by interface details, including inconsistencies between the phrase browser and the surrounding digital library interface

Subject Classification of Collection-level Descriptions Using DDC for Information Landscaping

Collection-level description (CLD) has emerged as an important tool for facilitating user access to large heterogeneous collections within digital library and hybrid information environments. Such metadata enables "information landscaping" techniques to be deployed, thereby allowing users to survey, discover and identify relevant collections. This can aid the precision of item-level queries by eliminating collections which may produce a significant number of false-drops or may contain no relevant items. The ability to provide suitable subject indexing and subject-based organization within such collection-level environments is an increasingly important user requirement, particularly for landscaping; yet it remains highly problematic owing to, for example, the broad subject coverage of many collections and the item-level nature of controlled vocabularies. In this paper we propose a methodology for the subject designation of collections using the Dewey Decimal Classification (DDC). The proposed approach allows the establishment of reliable, consistent and meaningful DDC class numbers to facilitate improved user browsing and searching tools within CLD systems. The methodology will be demonstrated using the Scottish Collections Network (SCONE) and alternative techniques to facilitate general subject analysis will also discussed

Ariel - Volume 9 Number 3

Executive Editor Emily Wofford Business Manager Fredric Jay Matlin University News John Patrick Welch World News George Robert Coar Editorials Editor Steve Levine Features Mark Rubin Brad Feldstein Photo Rick Spaide Circulation Victor Onufreiczuk Lee Wugofski Graphics and Art Steve Hulkower Commons Editor Brenda Peterso

Designing theoretically-informed implementation interventions

Clinical and health services research is continually producing new findings that may contribute to effective and efficient patient care. However, the transfer of research findings into practice is unpredictable and can be a slow and haphazard process. Ideally, the choice of implementation strategies would be based upon evidence from randomised controlled trials or systematic reviews of a given implementation strategy. Unfortunately, reviews of implementation strategies consistently report effectiveness some, but not all of the time; possible causes of this variation are seldom reported or measured by the investigators in the original studies. Thus, any attempts to extrapolate from study settings to the real world are hampered by a lack of understanding of the effects of key elements of individuals, interventions, and the settings in which they were trialled. The explicit use of theory offers a way of addressing these issues and has a number of advantages, such as providing: a generalisable framework within which to represent the dimensions that implementation studies address, a process by which to inform the development and delivery of interventions, a guide when evaluating, and a way to allow for an exploration of potential causal mechanisms. However, the use of theory in designing implementation interventions is methodologically challenging for a number of reasons, including choosing between theories and faithfully translating theoretical constructs into interventions. The explicit use of theory offers potential advantages in terms of facilitating a better understanding of the generalisability and replicability of implementation interventions. However, this is a relatively unexplored methodological area

Rhythmic rhymes for boosting phonological awareness in socially disadvantaged children

This study evaluated the ability for two rhythmic rhyming programs to raise phonological awareness in the early literacy classroom. Year 1s (5-6 year olds) from low socio-economic status schools in Bedfordshire, learned a program of sung or spoken rhythmic rhymes, or acted as controls. The project ran with two independent cohorts (Cohort 1 N= 98, Cohort 2 N= 136). Gains from pre to post tests of phonological awareness (Rhyme Detection, Rhyme Production and Phoneme Deletion), were statistically significant with the exception of Rhyme Detection in the Spoken group (Cohort 1) and Rhyme Production in the Sung group (Cohort 2). The Spoken program achieved medium and large effect sizes for Cohort 1 on measures of rhyming awareness (although the effect size was small for Cohort 2). Comparatively, the Sung program was associated with smaller effects (small, negligible or with a small positive effect for controls) across tasks and cohorts

Studies on the biosynthesis of penicillins

A high yielding synthesis of the acyclic precursor of the penicillins, δ— (L—α—aminoadipyl)—L—cysteinyl—D— valine (LLD-ACV) was developed. Using this synthesis the isotopically enriched ACV peptides, δ-(DL-α—aminoadipyl)—L—cysteinyl—D— (3R)— [4-¹ ³C]—valine and δ—(L—α - aminoadipyl)—L— [3-¹ ³c]—cysteinyl-D— [¹ ³N]—valine were prepared. In an extension to this work the tetrapeptide, δ— (L—α—aminoadipyl)— L— cysteinyl—D— valylglycine (LLD-ACVG) was prepared.A putative intermediate in the biosynthesis of isopenicillin N, N— [δ— (L—α—aminoadipyl)—L—cysteinyl ]—N—hydroxy—D—valine (LLD-AC( N-OH) V), was synthesised from N—hydroxy—D—valine benzyl ester.A cell-free system capable of converting δ— (L—α—aminoadipyl )—L— cysteinyl—D—valine to isopenicillin N was obtained from cultures of the cephalosporin producing fungus Cephalosporium acremonium CW19. The cell-free system was used to test the importance of the above synthesised compounds in penicillin biosynthesis. N— [ δ— (L—α—aminoadipyl )—L—cysteinyl ]-N—hydroxy—D—valine was shown not to be a substrate for the enzyme "isopenicillin N synthetase" but to be a potent inhibitor of the LLD-ACV to isopenicillin N conversion. The tetrapeptide, δ— (L—α—aminoadipyl )—L—cysteinyl—D—valylglycine, was found to be a weak inhibitor of this conversion.The isotopically enriched ACV peptides were used to confirm the stereochemistry of the valine C3 centre in biosynthesised δ— (L—α— aminoadipyl)—L—cysteinyl—D—valine and to allow preliminary ¹ ³C n.m.r. studies on the biosynthesis of isopenicillin N

Retrospective Analysis of Serotype Switching of Vibrio cholerae O1 in a Cholera Endemic Region Shows It Is a Non-random Process.

Genomic data generated from clinical Vibrio cholerae O1 isolates collected over a five year period in an area of Kolkata, India with seasonal cholera outbreaks allowed a detailed genetic analysis of serotype switching that occurred from Ogawa to Inaba and back to Ogawa. The change from Ogawa to Inaba resulted from mutational disruption of the methyltransferase encoded by the wbeT gene. Re-emergence of the Ogawa serotype was found to result either from expansion of an already existing Ogawa clade or reversion of the mutation in an Inaba clade. Our data suggests that such transitions are not random events but rather driven by as yet unidentified selection mechanisms based on differences in the structure of the O1 antigen or in the serotype-determining wbeT gene