PubMed Health⌕ Search

Biomedical subjects

D Hennessy

Publications and source records attributed to D Hennessy.

At least 19 recordsLinked to original sources
PubMed2001

Pharmacokinetics of moxidectin and ivermectin following intravenous injection in pigs with different body compositions.

Macrocyclic lactones (ML) are highly effective anthelmintics that provide a long protective period after administration because of their extensive distribution into fat. This study examined whether the body composition of the animal at the time of treatment had any influence on the pharmacokinetics of two MLs, moxidectin (MOX) and ivermectin (IVM). 'Fat' and 'lean' lines of pigs were established using two different diets, with weekly determination of liveweight and backfat thickness confirming the difference in body condition between the groups. Blood samples were taken at regular intervals following i.v. injection of IVM or MOX at a dose of 300 microg/kg and the plasma was analysed using fluorescence high performance liquid chromatography (HPLC) to determine the concentration of IVM or MOX in the samples. Regardless of body composition IVM and MOX kinetics were very different with MOX having a greater apparent volume of distribution, longer distribution and elimination half-lives and a slower clearance rate than IVM, which led to MOX being detectable in plasma for >40 days compared with only 8-10 days for IVM. Altering body composition had no detectable influence on the kinetic disposition of IVM in this study. In contrast, although there was no difference in AUC or the volume of distribution, MOX was distributed within and eliminated from the lean animals more rapidly than from the fat animals.

Animals↗
PubMed2000

Statistical methods for the objective design of screening procedures for macromolecular crystallization.

The crystallization of a new macromolecule is still very much a trial-and-error process. As is well known, it requires the search of a large parameter space of experimental settings to find the relatively few idiosyncratic conditions that lead to diffraction-quality crystals. Crystallographers have developed a variety of screens to help identify initial crystallization conditions, including those based on systematic grids, incomplete factorial and sparse-matrix approaches. These are somewhat subjectively formulated based on accumulated data from past crystallization experiments. Ideally, one would prefer as objective a procedure as possible; however, that requires objective methods that incorporate a broad source of crystallization data. The Biological Macromolecular Crystallization Database (BMCD), a repository of all published crystallization conditions, is an obvious source of this data. This database has been augmented with a hierarchical classification of the macromolecules contained in the BMCD as well as extensive data on the additives used with them. A statistical analysis of the augmented BMCD shows the existence of significant correlations between families of macromolecules and the experimental conditions under which they crystallize. This in turn leads to a Bayesian technique for determining the probability of success of a set of experimental conditions based on the data in the BMCD as well as facts about a macromolecule known prior to crystallization. This has been incorporated into software that enables users to rank experimental conditions for new macromolecules generated by a dense partial factorial design. Finally, an additional advantage of the software described here is that it also facilitates the accumulation of the data required for improving the accuracy of estimation of the probabilities of success - knowledge of the conditions which lead to failure of crystallization.

Crystallization↗
PubMed2000

The Driving Vengeance Questionnaire (DVQ): the development of a scale to measure deviant drivers' attitudes.

The Driving Vengeance Questionnaire (DVQ) was developed and administered to assess drivers' use of vengeance when faced with common driving situations. Subjects in the development of the scale were 266 male and female university students. The scale was then administered to 271 university students (both male and female) and 74 male inmates who were classified as either violent or nonviolent offenders on the basis of the amount of force used in committing the offence. A Cronbach alpha of .83 (M = 40.76, n = 310) indicated a high level of internal consistency for the DVQ. Younger drivers (18-23 years old) indicated higher levels of vengeance while driving than did older drivers (24-66 years old, M = 44.35 and 37.81, respectively). Those with less driving experience (0-6 years) expressed higher levels of vengeance while driving than more experienced drivers (6+ years, M = 42.95 and 38.81, respectively). Male drivers responded with greater vengeance to the questionnaire items than females (M = 42.07 and 39.62, respectively). The level of force used in commission of crime failed to correlate with the DVQ. A factor analysis was performed with a different sample of subjects using a slightly modified version of the DVQ to deal with the issue of whether horn honking constituted an appropriate measure of aggression. When the two relevant DVQ items were changed to read "leaning on horn" rather than mere honking, a strong, single factor of vengeance was found to characterize the scale. Suggestions were made for the use of DVQ in the screening of driving license applicants and in the study of problem drivers.

Adolescent↗
PubMed1999

Evidence-based educational commissioning and policy making: a case for the prospective use of a psychometric approach in defining the role and preparation of the nurse practitioner in Australia.

The concept of evidence-based care and the profile of the nurse practitioner (NP) have together assumed mounting importance as possible solutions to the problem of meeting escalating demands for high quality health care with decreasing resources. With regard to the former, concerted efforts to ensure that clinical practice has its base in scientific evidence, have resulted in health care delivery that is increasingly informed by research rather than ritual and tradition. This success notwithstanding, health management and policy-making have remained grounded in assumption, principally because of the paucity of available research in these areas. With regard to the NP, there is little agreement regarding the boundaries of professional practice and preparatory education, both of which need to be defined to some degree at the local level, if the health needs of the indigenous population are to be met. If these two issues are integrated, the policies regarding the preparation and occupational scope of the NP could incorporate research-based decision-making, and thus could simultaneously develop the NP according to locally specified needs, as well as meeting the requirements of the evidence-based care culture. This paper discusses a psychometrically valid and reliable instrument that has the capacity to provide research data which can inform strategic thinking regarding the definition, education and operation of the NP at a variety of levels. The technique has been used extensively in the UK, repeatedly demonstrating its value in NP educational commissioning. While the instrument has not yet been used to inform NP education in Australia, it has been administered to a cohort of acute sector nurses in Victoria. It is argued that the relevance of the instrument to the Australian health system, coupled with its proven importance in the development of the NP in comparable health care cultures, makes this approach worthy of consideration for the preparation of the NP for a variety of Australian health contexts.

Australia↗
PubMed1999

A task-based approach to defining the role of the nurse practitioner: the views of UK acute and primary sector nurses.

There exists within the United Kingdom considerable confusion relating to the definition and occupational boundaries of the nurse practitioner (NP). In consequence, the clinical practice and training of the NP remain unregulated, unstandardized and heavily dependent on local forces. Such a situation is regrettable, particularly in view of the potential value the nurse practitioner has for health care provision and also for influencing national policy decisions. It is conceivable that one reason for the current failure to reach agreement over the role definition of the nurse practitioner relates to the fact that their essential job functions depend upon the context in which the nurse practitioner operates, with primary-based practice differing from acute sector service delivery in sufficient critical ways as to make a generic, inclusive definition impossible. To investigate the veracity of this view, two cohorts of United Kingdom nurses were sampled, one of which worked within the acute sector (n = 49) and the other in the community (n = 420). These groups were surveyed using a unique training needs analysis instrument that had been developed along formal psychometric principles. Both groups perceived advanced clinical activities, including examination and diagnosis, and a range of research activities to be central to the role of the nurse practitioner. The primary sample, however, reported business and management activities as essential tasks, while the acute sector nurses regarded high levels of communication skills, autonomy and risk management to be more important. The implications of the similarities and differences between the two data sets are discussed with reference to different clinical domains.

Humans↗
PubMed1999

Quality in post-basic nurse education: the need for evidence-based provision.

BACKGROUND: As one means of addressing the problem of providing high quality health care within a context of diminishing resources, the British National Health Service (NHS) has promoted the concept of evidence-based clinical care. In order to integrate this concept effectively within routine practice, nurses need a sound knowledge of fundamental research methods. Unfortunately, the research skills courses that have been provided have typically relied on assumption to determine course content and chance factors for recruitment. Unsurprisingly, such haphazard provision is highly wasteful of resources, targeting neither the real skill deficits of the workforce nor the personnel most in need of this type of training. AIM: To demonstrate a more systematic approach to identifying the skill deficits of any specified workforce. METHODS: A survey was conducted with a random sample of nurses, who covered a range of grades and clinical specialities, using a psychometrically valid and reliable training needs analysis tool. FINDINGS: The results revealed both common training needs as well as skill deficits pertinent to a given locality and clinical area. CONCLUSIONS: Using more objectively derived information affords the commissioning of customized research skills courses that have the capacity to meet the needs of both the local organization and its employees. In this way, limited training budgets can be more effectively targeted.

Adult↗
PubMed1998

A triangulation approach to the identification of acute sector nurses' training needs for formal nurse practitioner status.

The current confusion surrounding the definition and role function of the nurse practitioner (NP) has created a situation in which advanced clinical practice is delivered in a variety of ways and at many levels. Not surprisingly, this has led to difficulties in regulating educational provision for NPs. This study reports a survey of the perceptions of the role definitions and training needs of all nurses working at advanced clinical levels within an acute sector Trust. Although this concept is not a novel one in advanced nursing practice, the procedure adopted differed from previous studies in two fundamental ways: firstly, a unique training needs assessment instrument was used, which because of its validity and opacity, was capable of yielding a highly reliable data-base, comprising a prioritized profile of real training needs as opposed to the standard wish-list typically elicited. Secondly, it did not rely simply on the self-reported needs of the nurse sample, but also included the perceptions of the sample's immediate medical and managerial colleagues. In this way, a triangulation paradigm was adopted. The results indicated that overall, there was high agreement between the nurses and their managers, regarding both the definition of the NP role and the essential training requirements, with somewhat different opinions being offered by the medical staff. When the raw scores were standardized to correct for response bias, the data provided an operational definition of the role of the NP and a prioritized profile of training needs for nurses who wished to train to this level.

Clinical Competence↗
PubMed1997

Mixed messages in nursing research: their contribution to the persisting hiatus between evidence and practice.

The current emphasis in the United Kingdom on evidence-based health care requires that medical and non-medical professionals ensure that their clinical practice is founded on scientifically derived findings rather than on intuition and ritual. To this end, many initiatives have been introduced which are intended to increase both the corpus of available research evidence and the extent to which it informs practice. To date, however, there has been a disappointing shortfall in published research in the paramedical domain, which has been largely attributed to a number of structural and organizational issues. This paper suggests that confusion about what constitutes valid and useful research may be an additional significant contributory factor in the documented research/practice hiatus. Moreover, the emphasis on experimentation and Randomized Controlled Trials (RCTs), with the relative marginalization of alternative, more qualitative forms of research may seriously limit the nursing research data-base because of its inappropriateness for many nursing investigations. It is suggested that a more eclectic approach to evidence-based care is considered, with more attention being diverted to qualitative methodologies at the funding and dissemination stages. In this way, a comprehensive and balanced overview of relevant information can be obtained which has the potential to influence some of the less quantifiable aspects of care delivery.

Attitude of Health Personnel↗
PubMed1997

The use of a customized training needs analysis tool for nurse practitioner development.

The role and professional boundaries of the nurse practitioner (NP) in the UK have not yet been unequivocally defined. This confusion has served to limit the expansion of the NP in both the acute and primary care sectors, despite a mounting body of evidence that attests to their value. This lack of coherence has necessarily impacted upon the educational provision currently available for NP development, with a range of courses of variable nature and standards being provided. The lack of nationally agreed educational criteria and the importance of taking account of local needs, together suggest that a formal training needs analysis might be valuable in systematizing and unifying the present position. Such a survey would have the function of informing both the definition and regional training requirements of NPs, provided the data were obtained through the use of a reliable assessment instrument. To this end a total population survey of all nurses employed in general practice within a large regional health authority was undertaken, using a psychometrically valid and reliable training needs analysis questionnaire. The information obtained provided a preliminary definition of the NP role and a clear index of the content and level of prospective educational provision. In addition, the survey offered an estimate of the numbers of potential participants on NP courses, by FHSA and preferred educational institution. In this way, the use of a scientifically constructed and specifically customized training needs analysis tool may have the potential to inform precise educational commissioning, thereby rationalizing resources and enhancing the quality of both training and ultimate care provision.

Adult↗
PubMed1997

Identifying training objectives: the role of negotiation.

Current training initiatives for health care professionals tend to be based on management assumptions of need or on the wish-list demands of potential course attenders. Each approach has major disadvantages, in that neither has the capacity to simultaneously satisfy the organization's objectives, whilst maintaining the motivation and commitment of the participants. This short report discusses an alternative approach that used a valid and reliable training needs analysis instrument with nurses and managers to inform Nurse Practitioner development. The results facilitated the commissioning of relevant education courses, clarified new role boundaries and acted as an agent for negotiation and change between the two groups.

Curriculum↗
PubMed1996

Investigating attitudes to research in primary health care teams.

Despite top-down professional body and government agency pressure to increase the research base of clinical practice, there remains a considerable body of evidence which suggests that many ineffective, and even dangerous, health care interventions continue to be practised in areas where there are significant contradictory findings. While numerous explanations have been put forward which implicate the role of structural, organizational and informational barriers to integrating research with practice, less attention has been focused on the individual and psychological contributions. The study reported here forms part of a larger scale project aimed at developing a diagnostic instrument for identifying research training needs, in the widest sense, within primary health care groups. To provide the instrument with content validity, following formal psychometric guidelines, opaque and transparent techniques of data collection were employed at the development stage. This yielded some interesting and unexpected results from the respondents, which suggested that despite overt statements to the contrary, the majority of the primary health care professionals studied perceived research as being unimportant and peripheral to their jobs, and the responsibility of other health care professionals. Moreover, the subjects' understanding of research and its methodologies was discordant both within and across professional groups. The implications of these results from this pilot phase suggest that fundamental and deep-seated attitudes which are resistant to research may be a contributory factor to the persistence of ritualistic, non-evidence-based care.

Attitude of Health Personnel↗
PubMed1996

Development of a psychometrically valid training needs analysis instrument for use with primary health care teams.

The growing demand for professional updating and training within the health service has created a proliferation of post-registration courses, many of which fail to reach the appropriate personnel or the real training objectives of the participants and their managers. One reason behind this problem relates to the fact that many such courses are constructed and delivered in a haphazard way, without systematic reference to the direct and indirect consumers of the educational programmes. A more rational approach to post-experience provision of this sort might involve the methodical collection of information regarding the training needs of target health professional populations. Such a data base would afford a global overview of competencies and deficiencies, both within and between individuals. From this the content, level and focus of training could be customized to meet the reported needs, thereby streamlining the commissioning process to enhance efficiency and effectiveness. Previous attempts to rationalize provision through the prior use of training needs analysis instruments have been compromised by the shortcomings of the analysis tool. This study, then, was an attempt to redress this problem, using a training needs analysis instrument developed along traditional psychometric principles. The tool was intended to be used with primary health care teams because of the increasing role this sector of the health service will play in the future delivery of care, although this would not preclude its use with other health care professionals (following appropriate modification), since the principles behind its construction and format are transferable. The instrument has demonstrable construct, content and face validity and significant reliability. Moreover, preliminary investigations suggest that it also has criterion validity in the areas tested. These findings suggest that the instrument is unique of its kind. Early use of the tool has demonstrated its value in a variety of ways, such as in team building exercises and skill mix reviews as well as in precise and effective commissioning of training and education in a range of areas.

Community Health Nursing↗
PubMed1994

Induction of rules for biological macromolecule crystallization.

X-ray crystallography is the method of choice for determining the 3-D structure of large macromolecules at a high enough resolution. The rate limiting step in structure determination is the crystallization itself. It takes anywhere between a few weeks to several years to obtain macromolecular crystals that yield good diffraction patterns. The theory of forces that promote and maintain crystal growth is preliminary, and crystallographers systematically search a large parameter space of experimental settings to grow good crystals. There is a wealth of experimental data on crystal growth most of which is in paper laboratory notebooks. Some of the data has been gathered in electronic form, e.g., the Biological Macromolecular Crystallization Database (BMCD) which is a repository of successful experimental conditions for growing over 800 different macromolecules (Gilliland 1987). Crystallographers are in need of computational tools to gather and analyze past data to design new crystal growth trails. We are building the Crystallographer's Assistant (CA) to help crystallographers record and maintain experimental context in electronic form, offer suggestions on experimental conditions that are likely to be successful, and provide explanations for failed experiments. As an initial step in this project, we have applied RL, an inductive learning program, to the BMCD. In this paper we report initial experiments and findings in applying RL to the BMCD. From the point of view of crystallography, we have discovered possibly significant new empirical relationships in crystal growth. From the point of view of machine learning, our work suggests refinements of existing methods for incorporating detailed domain knowledge into inductive analysis techniques.

Animals↗
PubMed1980

Factors contributing to postweaning diarrhoea in a large intensive piggery.

Some aspects of postweaning diarrhoea (PWD) in a piggery during the first week after early weaning were investigated. A haemolytic enterotoxigenic strain of E. coli (O149:K88:H10) was regularly recovered from piglets with PWD while rotavirus was demonstrated on a number of occasions. Prior to weaning piglets were either free of, or shed very few, haemolytic E. coli in their faeces. However, all piglets were excreting haemolytic E. coli between 5 and 7 days after weaning. The role of rotavirus in PWD was unclear. There appeared to be a direct relationship between serum antibodies to rotavirus in the slow at farrowing and those of the piglets soon after birth. The decline of maternal neutralising antibody to rotavirus coincided with the immediate postweaning period (3 to 5 weeks after birth). This was followed by an increase in antibody levels, 5 to 8 weeks after birth. There was no significant difference in the growth rate between affected and unaffected piglets over a period of 120 days. Medication of water during the first week after weaning had no significant effect on the incidence of PWD in the herd. A change in both the weaner diet and the weaning procedure reduced piglet mortality associated with PWD by more than half.

Animals↗
PubMed1980

Controlled release of anthelmintic drugs: a new concept for prevention of helminthosis in sheep.

Anthelmintic effects of oxfendazole continuously released at 0:17, 0.28 and 0.47 mg/kg/day from intraruminal capsules were assessed in groups of sheep artificially infected with Ostertagia circumcincta. Removal of worms was directly related to both release rate and plasma concentrations of drug. At the highest level, worm burdens were removed within seven days of administration and anthelmintic efficiency was 99.9 +/- 0.04, 99.3 +/- 0.5 and 98.9 +/- 0.7 per cent against adult worms, developing fourth stage and early fourth stage larvae respectively. In a field experiment, comparisons were made of the parasitological and animal production differences between groups of weaned lambs which were given no treatment, a single oral dose of 5 mg/kg oxfendazole and capsules releasing either 0.24 or 0.48 mg/kg oxfendazole daily. By four days after administration of capsules worm egg counts were reduced and remained below detectable levels for up to 86 days. Worm counts from 'tracer' and flock sheep showed a reduction in worm numbers, especially for Trichostrongylus spp. Compared with untreated controls, live weight gain and fleece weight of sheep given capsules releasing 0.48 mg/kg oxfendazole daily was increased.

Animals↗