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R W Jones

Publications and source records attributed to R W Jones.

At least 37 records · Page 2Linked to original sources
PubMed2003

Characterization of the glucose-6-phosphate isomerase gene in Phytophthora infestans reveals the presence of multiple alleles.

Glucose-6-phosphate isomerase (GPI) plays a key role in both glycolysis and gluconeogenesis. Isoforms of GPI are common, and therefore, its isozyme pattern is widely used to characterize isolates of Phytophthora infestans. Despite the importance of GPI in P. infestans studies, the gene encoding this enzyme has not yet been characterized. Furthermore, it has been suggested that P. infestans contains multiple copies of the gene but this hypothesis remains to be demonstrated. We have cloned and characterized GPI in various isolates of P. infestans as well as in several species of the genus Phytophthora. The gene contains 1671bp and encodes a protein with a predicted molecular weight of 60.8kDa. Multiple different alleles were identified and Southern analysis indicated certain P. infestans isolates carry several copies of the gene. Phylogenetic analysis revealed that P. infestans GPI is most closely related to sequences from Toxoplasma gondii, Arabidopsis thaliana, and Clarkia lewisii.

Alleles↗
PubMed2003

Longitudinal trends in exercise capacity and health status after pulmonary rehabilitation in patients with COPD.

Pulmonary rehabilitation (PR) programmes produce initial improvements in exercise tolerance and health status in patients with chronic obstructive pulmonary disease (COPD). However, there is limited data on the longer term effects of PR. This study has examined whether the initial benefits gained in exercise tolerance and health status may be maintained after a 1-year follow-up programme. Sixty-six patients with COPD were assessed with the MRC Dyspnoea Scale and found to be moderately disabled due to dyspnoea (MRC Grades 3 and 4). These patients were then randomised to an 8 week outpatient programme of either exercise training and education (Exercise group) or to education alone (Control group). Exercise performance was assessed with the shuttle walking test and health status assessed with two disease-specific measures, the St Georges Respiratory Questionnaire and the Chronic Respiratory Disease Questionnaire. After PR, all patients were invited to attend monthly follow-up sessions for 1 year. Fifty-six patients were available for follow-up immediately after the programme and were assessed at 6 months and 1 year. This study has shown that the patients in the Exercise group maintained improvements in exercise capacity and health status up to 6 months after an 8 week programme. At 1 year there was a significant difference between the Exercise and Control groups in terms of exercise tolerance due to a considerable decline experienced by the Control group. However, neither group had maintained improvements in health status at 1 year. Further study is required to assess whether benefit may be sustained for a longer period using alternative follow-up strategies.

Activities of Daily Living↗
PubMed2002

Visual search in Alzheimer's disease: a deficiency in processing conjunctions of features.

Human vision often needs to encode multiple characteristics of many elements of the visual field, for example their lightness and orientation. The paradigm of visual search allows a quantitative assessment of the function of the underlying mechanisms. It measures the ability to detect a target element among a set of distractor elements. We asked whether Alzheimer's disease (AD) patients are particularly affected in one type of search, where the target is defined by a conjunction of features (orientation and lightness) and where performance depends on some shifting of attention. Two non-conjunction control conditions were employed. The first was a pre-attentive, single-feature, "pop-out" task, detecting a vertical target among horizontal distractors. The second was a single-feature, partly attentive task in which the target element was slightly larger than the distractors-a "size" task. This was chosen to have a similar level of attentional load as the conjunction task (for the control group), but lacked the conjunction of two features. In an experiment, 15 AD patients were compared to age-matched controls. The results suggested that AD patients have a particular impairment in the conjunction task but not in the single-feature size or pre-attentive tasks. This may imply that AD particularly affects those mechanisms which compare across more than one feature type, and spares the other systems and is not therefore simply an 'attention-related' impairment. Additionally, these findings show a double dissociation with previous data on visual search in Parkinson's disease (PD), suggesting a different effect of these diseases on the visual pathway.

Aged↗
PubMed2001

The graphical presentation of decision support information in an intelligent anaesthesia monitor.

This contribution examines the graphical presentation of decision support information generated by an intelligent monitor, named SENTINEL, developed for use during anaesthesia. Clinicians make diagnoses in real-time during operations by examining clinically significant trends in multiple signals. SENTINEL attempts to mimic this decision process by using a system of fuzzy trend templates. SENTINEL's implementation of fuzzy trend templates is capable of providing the dual fuzzy measures of belief and plausibility, which are derived from the theory of evidence. It is thus capable of generating fairly rich diagnostic decision support information. However, for SENTINEL to be effective, the visual presentation of this information must be intuitive to the anaesthetist, who may not be familiar with the theory of evidence. This paper discusses techniques that are being evaluated to meet the requirements of the SENTINEL anaesthesia monitor. Specifically, the paper presents methods for highlighting clinically significant trends in physiological (or derived) signals by superimposing a coloured band on the signal that reflects fuzzy output from the intelligent monitor. This paper also discusses the intuitive graphical presentation of binary diagnostic fuzzy measures, including their further interpretation and presentation as crisp "alarm" and "warning" conditions.

Anesthesia, General↗
PubMed2001

Vaginal adenosis with adenocarcinoma in situ in a woman with no recognised antecedent factors.

We present a case of vaginal adenosis with adenocarcinoma in situ in a woman with no recognised antecedent factors. This case demonstrates the importance of continuing thorough colposcopic assessment of the entire lower genital tract with repeated biopsies of all abnormal epithelium in women with persistent or recurrent cervical cytology abnormalities. Successful management requires accurate definition of the vaginal lesion.

Adenocarcinoma↗
PubMed2001

Wave transmission through structural inserts.

The transmission of waves through two discontinuities in a one-dimensional waveguide system is considered. Attention is focused on transmission through a structural insert, which is defined here to be a waveguide segment which is inserted into an otherwise continuous structural member with different properties. A general expression for the net transmission through the insert is found. It has bandpass/stop characteristics and its frequency average is somewhat greater than that normally assumed due to the coherent interaction of the waves in the insert. The particular case is then considered where the insert comprises a three-layer composite beam inserted in a thin beam which vibrates in bending. The composite beam comprises two elastic faceplates and a core filled with a tunable electro- or magneto-rheological fluid. The net transmission and the stop bands depend on the properties of the insert. Since these properties are tunable by adjusting the field to which the tunable fluid is exposed, then so too are the transmission characteristics of the insert.

Journal Article↗
PubMed2001

Ecology and phenology of the boll weevil (Coleoptera: Curculionidae) on an unusual wild host, Hibiscus pernambucensis, in southeastern Mexico.

The phenology and ecology of Hibiscus pernambucensis Arruda and its interaction and importance in maintaining populations of the boll weevil, Anthonomus grandis Boheman, were studied over a period of 3 yr in the Soconusco Region of the state of Chiapas, Mexico. H. pernambucensis is a small tree of Neotropical distribution, restricted to lowland areas, and generally associated with halophytic vegetation. This species is found exclusively along the shores of brackish estuaries, in or near mangrove swamps in southeastern Mexico. In this region, H. pernambucensis has a highly seasonal flowering pattern in which the greatest bud production occurs shortly after the start of the rainy season in May and the highest fruit production occurs in July and August. Boll weevil larvae were found in buds of H. pernambucensis during all months but February and densities of buds and weevils were highest from May through September. The percentage of buds infested with boll weevil larvae rarely exceeded 30%. Because plant densities and reproductive output of H. pernambucensis is relatively low and, consequently, the number of oviposition and larval development sites for boll weevils is limited, the importance of this plant as a source of boll weevils with potential of attacking commercial cotton is minimal in comparison with the quantity produced in cultivated cotton. However, the plant could be important as a reservoir of boll weevils in areas of boll weevil quarantine and eradication programs. The factors and circumstances that may have led to this apparent recent host shift of the boll weevil in this region are discussed.

Animals↗
PubMed2001

Vulval intraepithelial neoplasia: current perspectives.

The heterogeneous clinical features of vulval intraepithelial neoplasia (VIN), its uncertain and variable natural history, difficulties in the management of certain cases and the frequency of recurrences provide a continuing challenge for gynaecologists. Patients with VIN present to a diverse range of physicians, all of whom provide differing perspectives on the multifarious issues relating to the condition. The importance of VIN relates principally to the symptoms it causes and its potential to progress to invasive vulval cancer. Both the International Society for the Study of Vulvovaginal Diseases and the International Society of Gynaecological Pathologists have stressed the importance of eliminating eponymous terminology and recommend only the term vulval intraepithelial neoplasia (VIN). This terminology includes both squamous and non-squamous varieties (Table 1). The latter includes both Paget's disease of the vulva and melanoma in situ. Non-squamous VIN will not be considered in this paper. Until 30 years ago VIN was an uncommon condition, seen principally in middle and later life. The incidence particularly in younger women has increased significantly since then [1-3]. Since that time the mean age in our unit has fallen from 52.7 years to 35.8 years (Figure 1) [2]. The increasing incidence of the condition parallels similar trends in cervical intraepithelial neoplasia (CIN) and relates at least in part to changing sexual morés, human papilloma virus (HPV) infection, and cigarette smoking.

Female↗
PubMed2000

Guidelines for the management of women with abnormal cervical smears 1998.

Four important changes have been introduced in the revised guidelines for the management of women with abnormal cervical smears, 1998. 1. For the purposes of management, atypical squamous cells of undetermined significance (ASCUS) and atypical glandular cells of undetermined significance (AGUS) have been included with low grade squamous intraepithelial lesions (LSIL/CIN1/HPV) except where the smear raises the possibility of a high grade squamous intraepthelial lesion (HSIL) or favours glandular dysplasia. 2. Women with low grade cytological and histological intraepithelial abnormalities will, after initial follow-up, revert to three yearly screening. 3. Requirements for those practising colposcopy have been defined. 4. A formal review of all cases of invasive cervical cancer is advocated.

Adenocarcinoma↗
PubMed2000

Evidence for intact memory monitoring in Alzheimer's disease: metamemory sensitivity at encoding.

Previous research claiming that there is a metamemory deficit in Alzheimer's Disease (AD) has been based on paradigms in which metamemory judgements are compared with performance. These methods confound predictive accuracy with very poor memory performance. In the experiments presented here this confound is removed by focusing on the sensitivity of metamemory judgements to item differences at encoding, rather than on predictive accuracy. In Experiment 1 participants studied words of high or low recallability, and either made judgements of learning (JOLs) or declared recall readiness. It was found that the AD group discriminate between items in their metamemory judgements to the same extent as age matched controls. Both groups rated the highly recallable words as being more likely to be recalled, and allocated more study time to low recallability items. In Experiment 2 participants were asked to rank the likelihood of recall of items that varied in objective recallability. Once again, AD patients were as sensitive to objective differences in stimuli as controls. Therefore, using measures based on sensitivity to item differences, we find no evidence of a metamemory deficit at encoding in AD. The findings are discussed in terms of metamemory functioning in AD, and its relationship with memory performance.

Aged↗
PubMed2000

The effects of repetition on allocation of study time and judgements of learning in Alzheimer's disease.

Greene et al. [12] suggest that Alzheimer's disease (AD) patients approach repeated trials in a learning test as if they are single unrelated trials. Previous research [7] indicates that AD patients do not have explicit memory for item repetition when asked at test how many times a word was presented, but they do show benefits of repeated presentation in implicit tasks. In this experiment we examine metacognitive judgements made during study for repeated items. It was hypothesised that a lack of awareness of repetition may exacerbate the episodic memory impairment found in AD. To explore this, two measures of metamemory were taken for items presented once, twice or three times in a list: judgements of learning (JOLs), which are a declaration of how well an item has been learned, and recall readiness, which is the study time allocated by participants to ensure proficient learning of an item. With repetition, age matched controls made recall readiness judgements more quickly and reported higher JOLs. The AD patients showed faster recall readiness, but did not alter their JOLs. This suggests a dissociation in the AD group between judgements of learning and the allocation of study time. We discuss the implications for theories of the learning deficit in AD, and the use of metamemory measurements in clinical populations.

Aged↗
PubMed2000

Spontaneous regression of vulvar intraepithelial neoplasia 2-3.

OBJECTIVE: To determine the background and clinical features of a group of women who experienced spontaneous regression of vulvar intraepithelial neoplasia (VIN) 2-3 before treatment was undertaken. METHODS: A retrospective review was made of the records of 14 women who experienced spontaneous regression of VIN 2-3. RESULTS: The women were 15-27 years of age (median 19.5 years). Ninety-three percent were non-white. All women were seen initially in a sexual health clinic, and with one exception, all had been treated previously for genital condyloma acuminata. Four of the 14 cases were pregnancy-associated. Half of the women were asymptomatic. The transit time to regression of VIN 2-3 was 3-30 months (median 9.5 months). The median follow-up was 3 years. All lesions were multiple and pigmented. CONCLUSION: Spontaneous regression of VIN 2-3 can occur in young women with multifocal pigmented lesions.

Adolescent↗