On learning context-free and context-sensitive languages

The long short-term memory (LSTM) is not the only neural network which learns a context sensitive language. Second-order sequential cascaded networks (SCNs) are able to induce means from a finite fragment of a context-sensitive language for processing strings outside the training set. The dynamical behavior of the SCN is qualitatively distinct from that observed in LSTM networks. Differences in performance and dynamics are discussed.

Sensitivity and specificity of pooled faecal culture and serology as flock-screening tests for detection of ovine paratuberculosis in Australia

The flock-level sensitivity of pooled faecal culture and serological testing using AGID for the detection of ovine Johne's disease-infected flocks were estimated using non-gold-standard methods. The two tests were compared in an extensive field trial in 296 flocks in New South Wales during 1998. In each flock, a sample of sheep was selected and tested for ovine Johne's disease using both the AGID and pooled faecal culture. The flock-specificity of pooled faecal culture also was estimated from results of surveillance and market-assurance testing in New South Wales. The overall flock-sensitivity of pooled faecal culture was 92% (95% CI: 82.4 and 97.4%) compared to 61% (50.5 and 70.9%) for serology (assuming that both tests were 100% specific). In low-prevalence flocks (estimated prevalence

Public Intellectuals, Book Culture and Civil Society

Introduction: the rise and rise of the public intellectual My starting point is the remarkable rise to prominence of public intellectuals – and talk about public intellectuals – over the last decade in Australia. Since 1997, especially, this has occurred around Indigenous questions with the result that issues such as the stolen generations, genocide, the apology and reconciliation have also gained new prominence. This is undeniably a good thing. New ways of thinking about history and the nation and new kinds of public ethical discourse have been put into circulation. History as battleground is preferable to the great Australian silence. And yet – my starting point is also the ambivalent effects and meanings of these recent developments, not least the way that the debates have centred so much around the figure of the 'public intellectual', the way that certain kinds of intellectuals and intellectual discourse have come to dominate the mainstream representation of the issues.

Spontaneous generation and survival of blood dendritic cells in mononuclear cell culture without exogenous cytokines

Studies on purified blood dendritic cells (DCs) are hampered by poor viability in tissue culture. We, therefore, attempted to study some of the interactions/relationships between DCs and other blood cells by culturing unseparated peripheral blood mononuclear cell (PBMC) preparations in vitro. Flow cytometric techniques were used to undertake a phenotypic and functional analysis of DCs within the cultured PBMC population. We discovered that both the CD11c(+) and CD11c(-) CD123(hi) DC subsets maintained their viability throughout the 3-day culture period, without the addition of exogenous cytokines. This viability was accompanied by progressive up-regulation of the surface costimulatory (CD40, CD80, CD86) and activation (CMRF-44, CMRF-56, CD83) molecules. The survival and apparent production of DCs in PBMC culture (without exogenous cytokines) and that of sorted DCs (with cytokines) were evaluated and compared by using TruCOUNT analysis. Absolute DC counts increased (for CD123hi and CD11c+ subsets) after overnight culture of PBMCs. Single-cell lineage depletion experiments demonstrated the rapid and spontaneous emergence of new in vitro generated DCs from CD14(+)/CD16(+) PBMC radioresistant precursors, additional to the preexisting ex vivo DC population. Unlike monocyte-derived DCs, blood DCs increased dextran uptake with culture and activation. Finally, DCs obtained after culture of PBMCs for 3 days were as effective as freshly isolated DCs in stimulating an allogeneic mixed leukocyte reaction. (C) 2002 by The American Society of Hematology.

Initial effects of elbow taping on pain-free grip strength and pressure pain threshold

Study design: Single-blind, placebo control, randomized, crossover, experimental Study with repeated measures, Objective: To determine the initial effects of a taping technique on grip strength and pain in individuals with lateral epicondylalgia. Background: Taping techniques are advocated for chronic musculoskeletal conditions such as lateral epicondylalgia, a prevalent disorder with significant impact on the individual and community. Little evidence exists supporting the effects of taping techniques on musculoskeletal pain. Methods and Measures: Sixteen participants (mean age +/- SD, 45.8 +/- 10.2 years) with chronic lateral epicondylalgia (rnean duration +/- SD, 13.1 +/- 9.9 months) participated in a placebo control study of an elbow taping technique. Outcome measures were pain-free grip strength and pressure pain threshold taken before, immediately after, and 30 minutes after application of tape. Results: The taping technique significantly improved pain-free grip strength by 24% from baseline (P = .028). The treatment effect was greater than that for placebo and control conditions. Changes in pressure pain threshold (19%), although positive, were not statistically significant. Conclusion: This preliminary study demonstrated an initial ameliorative effect of a taping technique for lateral epicondylalgia and suggests that it should be considered as an adjunct in the management of this condition.

The first strand transfer reaction of HIV-1 reverse transcription is more efficient in infected cells than in cell-free natural endogenous reverse transcription reactions

Background: In the presence of dNTPs, intact HIV-1 virions are capable of reverse transcribing at least part of their genome, a process known as natural endogenous reverse transcription (NERT). PCR analysis of virion DNA produced by NERT revealed that the first strand transfer reaction (1stST) was inefficient in intact virions, with minus strand (-) strong stop DNA (ssDNA) copy numbers up to 200 times higher than post-1stST products measured using primers in U3 and U5. This was in marked contrast to the efficiency of 1stST observed in single-round cell infection assays, in which (-) ssDNA and U3-U5 copy numbers were indistinguishable. Objectives: To investigate the reasons for the discrepancy in first strand transfer efficiency between intact cell-free virus and the infection process. Study design: Alterations of both NERT reactions and the conditions of cell infection were used to test whether uncoating and/or entry play a role in the discrepancy in first strand transfer efficiency. Results and Conclusions: The difference in 1stST efficiency could not be attributed simply to viral uncoating, since addition of very low concentrations of detergent to NERT reactions removed the viral envelope without disrupting the reverse transcription complex, and these conditions resulted in no improvement in 1stST efficiency. Virus pseudotyped with surface glycoproteins from either vesicular stomatitis virus or amphotrophic murine leukaemia virus also showed low levels of 1stST in low detergent NERT assays and equivalent levels of (-) ssDNA and 1stST in single-round infections of cells, demonstrating that the gp120-mediated infection process did not select for virions capable of carrying out 1stST. These data indicate that a post-entry event or factor may be involved in efficient HIV-1 reverse transcription in vivo. (C) 2002 Elsevier Science B.V. All rights reserved.