About Reference Disciplines and Reference Differences: A Critique of Wade et al.

Two articles published in this issue (Wade et al. and ours) through similar analyses reach contrasting conclusions on whether Information Systems, as a field, is evolving toward a reference discipline. In this article, we provide a critique of Wade et al. We first assess our different interpretations of reference discipline, and then discuss the consequences of including highly related disciplines in citation analysis. Finally, we illustrate the sensitivity of Wade et al.\u27s results to the inclusion and exclusion of certain journals. We also consider potential interpretations of second degree citations. It is hoped that the arguments presented here reconcile the differences as we collectively advance thinking on the state of IS as a reference discipline

A Citation Analysis of the Evolution and State of Information Systems within a Constellation of Reference Disciplines

For the past two decades notions of cumulative tradition and reference disciplines have been a significant part of the introspective debates on the IS field. We provide an exploratory test on these notions using sociometric analysis. In doing so, we extend the work of Culnan and Swanson originally carried out about 25 years ago. By using the concept of a work point and reference points to identify where an IS article is published and the extent to which it draws from or contributes to other disciplines, we can position research in the IS field. First, a quantitative analysis of over 72,600 citations spread across 1406 IS articles in 16 journals over the period 1990-2003 reveals a distinct trend toward a cumulative tradition, a changing mix of reference disciplines, and a two-way relationship between IS and some of the more mature disciplines. Second, post-hoc content analysis provides a glimpse of how IS work is being utilized by other disciplines. Overall, our analysis indicates that IS is taking up a more socio-technical persona, building upon its own knowledge base, and repaying its debts by contributing to other disciplines. We interpret the movement towards building a cumulative tradition, and informing work in other disciplines as positive, as we strive toward being part of an intellectual network and establish centrality in areas that matter to us most

Mutations in Yeast Proliferating Cell Nuclear Antigen Define Distinct Sites for Interaction with DNA Polymerase δ and DNA Polymerase ε

The importance of the interdomain connector loop and of the carboxy-terminal domain of Saccharomyces cerevisiae proliferating cell nuclear antigen (PCNA) for functional interaction with DNA polymerases delta (Poldelta) and epsilon (Pol epsilon) was investigated by site-directed mutagenesis. Two alleles, pol30-79 (IL126,128AA) in the interdomain connector loop and pol30-90 (PK252,253AA) near the carboxy terminus, caused growth defects and elevated sensitivity to DNA-damaging agents. These two mutants also had elevated rates of spontaneous mutations. The mutator phenotype of pol30-90 was due to partially defective mismatch repair in the mutant. In vitro, the mutant PCNAs showed defects in DNA synthesis. Interestingly, the pol30-79 mutant PCNA (pcna-79) was most defective in replication with Poldelta, whereas pcna-90 was defective in replication with Pol epsilon. Protein-protein interaction studies showed that pcna-79 and pcna-90 failed to interact with Pol delta and Pol epsilon, respectively. In addition, pcna-90 was defective in interaction with the FEN-1 endo-exonuclease (RTH1 product). A loss of interaction between pcna-79 and the smallest subunit of Poldelta, the POL32 gene product, implicates this interaction in the observed defect with the polymerase. Neither PCNA mutant showed a defect in the interaction with replication factor C or in loading by this complex. Processivity of DNA synthesis by the mutant holoenzyme containing pcna-79 was unaffected on poly(dA) x oligo(dT) but was dramatically reduced on a natural template with secondary structure. A stem-loop structure with a 20-bp stem formed a virtually complete block for the holoenzyme containing pcna-79 but posed only a minor pause site for wild-type holoenzyme, indicating a function of the POL32 gene product in allowing replication past structural blocks

Clinical disorders affecting mesopic vision

Vision in the mesopic range is affected by a number of inherited and acquired clinical disorders. We review these conditions and summarize the historical background, describing the clinical characteristics alongside the genetic basis and molecular biological mechanisms giving rise to rod and cone dysfunction relevant to twilight vision. The current diagnostic gold standards for each disease are discussed and curative and symptomatic treatment strategies are summarized

First documented cure of a suggestive exogenous reinfection in polymyositis with same but multidrug resistant M. tuberculosis

BACKGROUND: MDR Mycobacterium tuberculosis is the major cause of treatment failure in tuberculosis patients, especially in immunosuppressed. We described a young polymyositis patient on immunosuppressive therapy who was started with antituberculosis therapy as a susceptible strain of M. tuberculosis was isolated from a single cutaneous abscess in his neck and from regional lymph nodes. CASE PRESENTATION: He had non-reactive miliary tuberculosis and multiple cutaneous abscesses 6 months later with the same strain, which was resistant this time to 9 antituberculosis drugs. We described clinical presentation, radiological and laboratory work-up, treatment and follow-up as the patient was cured after 1.5 years with 6 antituberculosis drugs. CONCLUSION: To our knowledge, this is the first reported case where an immunosuppressed patient with suggestive exogenous reinfection within 6 months with the same but MDR strain of M. tuberculosis was cured. Intense management and regular follow up were important since the patient was a potent source of MDR M. tuberculosis infection and there was limited choice for therapy

Novel mutations in XLRS1 causing retinoschisis, including first evidence of putative leader sequence change

Juvenile retinoschisis is an X-linked recessive disease caused by mutations in the XLRS1 gene. We screened 31 new unrelated patients and families for XLRS1 mutations in addition to previously reported mutations for 60 of our families (Retinoschisis Consortium, Hum Mol Genet 1998;7:1185–1192). Twenty-three different mutations including 12 novel ones were identified in 28 patients. Mutations identified in this study include 19 missense mutations, two nonsense mutations, one intragenic deletion, four microdeletions, one insertion, and one intronic sequence substitution that is likely to result in a splice site defect. Two novel mutations, c.38T→C (L13P) and c.667T→C (C223R), respectively, present the first genetic evidence for the functional significance of the putative leader peptide sequence and for the functional significance at the carboxyl terminal of the XLRS1 protein beyond the discoidin domain. Mutations in 25 of the families were localized to exons 4–6, emphasizing the critical functional significance of the discoidin domain of the XLRS1 protein. Hum Mutat 14:423–427, 1999. © 1999 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/35178/1/8_ftp.pd