Identification of vaccine candidate antigens from a genomic analysis of Porphyomonas gingivalis

Porphyromonas gingivalis is a key periodontal pathogen which has been implicated in the etiology of chronic adult periodontitis. Our aim was to develop a protein based vaccine for the prevention and or treatment of this disease. We used a whole genome sequencing approach to identify potential vaccine candidates. From a genomic sequence, we selected 120 genes using a series of bioinformatics methods. The selected genes were cloned for expression in Escherichia coli and screened with P. gingivalis antisera before purification and testing in an animal model. Two of these recombinant proteins (PG32 and PG33) demonstrated significant protection in the animal model, while a number were reactive with various antisera. This process allows the rapid identification of vaccine candidates from genomic data. (C) 2001 Elsevier Science Ltd. All rights reserved.

The nutritive value of Rhodes grass (Chloris gayana) when treated with CaO, NaOH or a microbial inoculant and offered to dairy heifers as big-bale silage

A series of laboratory and animal studies examined the use of chemical and biological agents to enhance the digestibility of Rhodes grass (grass) cut at 60 (young) and 100 (mature) days of regrowth and ensiled as big round bales. The treatments included an untreated control (C), a microbial inoculant (I), NaOH, CaO and NaOH plus inoculant (NaOH + I). Inoculant was grown anaerobically, using a starter culture of rumen fluid from cattle given Rhodes grass. Treatments C, 1, NaOH, NaOH + I, were offered separately to twelve dairy heifers, in a 3 X 4 randomized complete block design, repeated twice for each grass silage. C and I had substantial mould growth, compared with no visible mould in NaOH or NaOH + 1. CaO treatment was effective in preventing mould growth, but had little effect on the chemical composition and in sacco digestibility of mature grass silage. NaOH reduced NDF content and increased in sacco digestibility (P < 0.05) but not the in vivo digestibility (P > 0.05) of both mature- and young-grass silage. The effects of other treatments on nutritive value were non-significant at both stages of maturity. NaOH increased the intake of mature-grass silage by 24-26% (P < 0.05), but had little effect on the intake of young-grass silage (P > 0.05). Treatment I consistently reduced grass silage intake (P < 005) for young-grass silage. The findings of these studies show that treating mature Rhodes grass with NaOH will improve its nutritive value and reduce mould growth in conserved herbage. However none of the treatments in this study had any consistently positive effects on the in vivo nutritive value or storage quality of young-grass silage.

Seasonal Effects on Transient Evoked Otoacoustic Emission Screening Outcomes in Infants versus 6-Year-Old Children

The purpose of this study was to compare transient evoked otoacoustic emission (TEOAE) screening outcomes (pass/fail) across the seasons (spring, autumn, and winter) between infants and schoolchildren. A total of 526 infants (275 boys, 251 girls) with a mean age of 2.0 months (SD = 0.38 months) and 975 schoolchildren (513 boys, 462 girls) with a mean age of 6.2 years (SD = 0.36 years) were screened using the ILO Otodynamics Quickscreen program. The same TEOAE pass/fail criterion was applied to the two groups. The results indicated a significant difference in pass rates between infants (91.2% of 1052 ears) and schoolchildren (86.0% of 1950 ears). A seasonal effect was found only for schoolchildren, with a significantly lower pass rate in winter than in spring or autumn. There was no difference in pass rates between spring and autumn. Implications for the seasonal effect on TEOAE screening outcomes for infants and schoolchildren are discussed.

Handedness effects in transient evoked otoacoustic emissions in school children

Handedness, as a potentially influencing, nonpathologic factor, has not been investigated in relation to transient evoked otoacoustic emissions (TEOAEs). The present study aimed to examine the effects of handedness on the TEOAE spectrum in entry-level schoolchildren, with attention also to possible ear asymmetry. A total of 228 subjects (114 males, 114 females, mean age = 6.3 years) were tested using the ILO292 Otodynamics Analyzer (Quickscreen mode) in quiet rooms in 22 schools. For statistical analysis, subjects were matched for factors such as handedness, gender, age, and history of recent ear infection. The results from subjects with passing TEOAE, pure-tone screening, and tympanometry revealed no significant handedness effect overall, although a significant ear asymmetry effect on the measurement parameters of AB difference, noise level, response level, whole-wave reproducibility, band reproducibility, and signal-to-noise ratios was found.

Implementing the quantum random walk

Recently, several groups have investigated quantum analogues of random walk algorithms, both on a line and on a circle. It has been found that the quantum versions have markedly different features to the classical versions. Namely, the variance on the line, and the mixing time on the circle increase quadratically faster in the quantum versions as compared to the classical versions. Here, we propose a scheme to implement the quantum random walk on a line and on a circle in an ion trap quantum computer. With current ion trap technology, the number of steps that could be experimentally implemented will be relatively small. However, we show how the enhanced features of these walks could be observed experimentally. In the limit of strong decoherence, the quantum random walk tends to the classical random walk. By measuring the degree to which the walk remains quantum, '' this algorithm could serve as an important benchmarking protocol for ion trap quantum computers.

Quantum dynamics of two coupled qubits

We investigate the difference between classical and quantum dynamics of coupled magnetic dipoles. We prove that in general the dynamics of the classical interaction Hamiltonian differs from the corresponding quantum model, regardless of the initial state. The difference appears as nonpositive-definite diffusion terms in the quantum evolution equation of an appropriate positive phase-space probability density. Thus, it is not possible to express the dynamics in terms of a convolution of a positive transition probability function and the initial condition as can be done in the classical case. It is this feature that enables the quantum system to evolve to an entangled state. We conclude that the dynamics are a quantum element of nuclear magnetic resonance quantum-information processing. There are two limits where our quantum evolution coincides with the classical one: the short-time limit before spin-spin interaction sets in and the long-time limit when phase diffusion is incorporated.

Preparing encoded states in an oscillator

Recently a scheme has been proposed for constructing quantum error-correcting codes that embed a finite-dimensional code space in the infinite-dimensional Hilbert space of a system described by continuous quantum variables. One of the difficult steps in this scheme is the preparation of the encoded states. We show how these states can be generated by coupling a continuous quantum variable to a single qubit. An ion trap quantum computer provides a natural setting for a continuous system coupled to a qubit. We discuss how encoded states may be generated in an ion trap.

DNA sequence variation in the ITS-1 rDNA subunit and host relationships in sorghum midge, Stenodiplosis sorghicola (Coquillett) (Diptera : Cecidomyiidae), in Australia

Sequence variation in the internal transcribed spacer (ITS-1) ribosomal DNA subunit was examined for sorghum midge obtained from introduced and native hosts in south-eastern and central Queensland. No variation was observed relative to host plant or geographical distance for midges collected from two introduced hosts, grain sorghum (Sorghum bicolor ) and Johnson grass (S. halepense ); however, sequence differences were observed between midges from introduced and native hosts and among midges from a single native host, slender bluegrass (Dichanthium affine ). No evidence was observed of introduced midges on native hosts, or vice versa. These results agree with previously hypothesised host distributions for native and introduced midges in Australia, and expand the sample of introduced hosts to include Johnson grass. They suggest that Stenodiplosis sorghicola , the principal midge infesting grain sorghum, is also the most common species on Johnson grass. This confirms that Johnson grass plays a role in the population dynamics of S. sorghicola and suggests that midges originating from Johnson grass may influence levels of infestation in grain sorghum.

Expression of MUC1 splice variants in benign and malignant ovarian tumours

MUC1 is expressed on the surface of ovarian cancer cells. Nine different splice variants of MUC1 have been described, but no study has reported on the expression of MUC1 iso-forms in human ovarian cancer. Our study compares patterns of expression of MUC1 splice variants of malignant and benign ovarian tumours. Ovarian tissue samples were taken from patients with benign ovarian tumours (n = 34) and from patients who had surgery for primary (n = 47) or recurrent (n = 8) ovarian cancer. RT-PCR for MUC1 splice variants A, B, C, D, X, Y, Z, REP and SEC was performed and their expression compared to clinical and histopathologic parameters. Variants A, D, X, Y and Z were more frequently expressed in malignant than in benign tumours. All primary ovarian cancer cases were positive for variant REP but negative for variant SEC. No significant association of the expression of MUC1 splice variants with the response to chemotherapy or patient survival could be demonstrated. Expression of MUC1 splice variants A, D, X, Y, Z and REP is associated with the presence of malignancy, whereas expression of MUC1/SEC is associated with the absence of malignancy. (C) 2002 Wiley-Liss, Inc.

Beyond hearing aid fitting: improving communication for older adults

Many older adults with hearing impairment continue to have substantial communication difficulties after being fitted with hearing aids, and many do not choose to wear hearing aids. Two group communication education programs aimed at such older people are described. The 'Keep on Talking' program has a health promotion focus, and is aimed at maintaining communication for older adults living in the community. An experimental group (n=120) attended the program, and a control group (n=130) received a communication assessment but no intervention. Significant improvements were found in the experimental participants in terms of knowledge about communication changes with age and about strategies to maintain communication skills. At the follow-up evaluation at 1 year, 45% of the experimental group, compared to 10% of the control group, had acted to improve their communication skills. The 'Active Communication Education' program focuses on the development of problem-solving strategies to improve communication in everyday life situations. Preliminary outcomes have been assessed on a small scale (n=14) to date. It is concluded that communication programs represent an important adjunct to, or supplement for, the traditional approach that focuses on hearing aid fitting.

Experimental investigation of continuous-variable quantum teleportation

We report the experimental demonstration of quantum teleportation of the quadrature amplitudes of a light field. Our experiment was stably locked for long periods, and was analyzed in terms of fidelity F and with signal transfer T-q=T++T- and noise correlation V-q=Vinparallel to out+Vinparallel to out-. We observed an optimum fidelity of 0.64+/-0.02, T-q=1.06+/-0.02, and V-q=0.96+/-0.10. We discuss the significance of both T-q>1 and V-q

Optical experiments beyond the quantum limit: Squeezing entanglement and teleportation

Results of experiments recently performed are reported, in which two optical parametric amplifiers were set up to generate two independently quadrature squeezed continuous wave laser beams. The transformation of quadrature squeezed states into polarization squeezed states and into states with spatial quantum correlations is demonstrated. By utilizing two squeezed laser beams, a polarization squeezed state exhibiting three simultaneously squeezed Stokes operator variances was generated. Continuous variable polarization entanglement was generated and the Einstein-Podolsky-Rosen paradox was observed. A pair of Stokes operators satisfied both the inseparability criterion and the conditional variance criterion. Values of 0.49 and 0.77, respectively, were observed, with entanglement requiring values below unity. The inseparability measure of the observed quadrature entanglement was 0.44. This value is sufficient for a demonstration of quantum teleportation, which is the next experimental goal of the authors.