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Paul Wilson

Publications and source records attributed to Paul Wilson.

17 recordsLinked to original sources
PubMed2006

Estimating health workforce needs for antiretroviral therapy in resource-limited settings.

BACKGROUND: Efforts to increase access to life-saving treatment, including antiretroviral therapy (ART), for people living with HIV/AIDS in resource-limited settings has been the growing focus of international efforts. One of the greatest challenges to scaling up will be the limited supply of adequately trained human resources for health, including doctors, nurses, pharmacists and other skilled providers. As national treatment programmes are planned, better estimates of human resource needs and improved approaches to assessing the impact of different staffing models are critically needed. However there have been few systematic assessments of staffing patterns in existing programmes or of the estimates being used in planning larger programmes. METHODS: We reviewed the published literature and selected plans and scaling-up proposals, interviewed experts and collected data on staffing patterns at existing treatment sites through a structured survey and site visits. RESULTS: We found a wide range of staffing patterns and patient-provider ratios in existing and planned treatment programmes. Many factors influenced health workforce needs, including task assignments, delivery models, other staff responsibilities and programme size. Overall, the number of health care workers required to provide ART to 1000 patients included 1-2 physicians, 2-7 nurses, <1 to 3 pharmacy staff, and a much wider range of counsellors and treatment supporters. We estimate from these data that the equivalent of 20,000 to 100,000 physicians, nurses, pharmacists and other core clinical staff will be needed to meet the WHO target of treating 3 million people by the end of 2005. The total number of staff, including counsellors, administrators and other cadres, could be substantially higher. DISCUSSION: These data are consistent with other estimates of human resource requirements for antiretroviral therapy, but highlight the considerable variability of current staffing models and the importance of a broad range of factors in determining personnel needs. Few outcome or cost data are currently available to assess the effectiveness and efficiency of different staffing models, and it will be important to develop improved methods for gathering this information as treatment programmes are scaled up.

Journal Article↗
PubMed2005

Anther evolution: pollen presentation strategies when pollinators differ.

Male-male competition in plants is thought to exert selection on flower morphology and on the temporal presentation of pollen. Theory suggests that a plant's pollen dosing strategy should evolve to match the abundance and pollen transfer efficiency of its pollinators. Simultaneous pollen presentation should be favored when pollinators are infrequent or efficient at delivering the pollen they remove, whereas gradual dosing should optimize delivery by frequent and wasteful pollinators. Among Penstemon and Keckiella species, anthers vary in ways that affect pollen release, and the morphology of dried anthers reliably indicates how they dispense pollen. In these genera, hummingbird pollination has evolved repeatedly from hymenopteran pollination. Pollen production does not change with evolutionary shifts between pollinators. We show that after we control for phylogeny, hymenopteran-adapted species present their pollen more gradually than hummingbird-adapted relatives. In a species pair that seemed to defy the pattern, the rhythm of anther maturation produced an equivalent dosing effect. These results accord with previous findings that hummingbirds can be more efficient than bees at delivering pollen.

Adaptation, Physiological↗
PubMed2004

A SIFT ion-molecule study of some reactions in Titan's atmosphere. reactions of N(+), N(2)(+), and HCN(+) with CH(4), C(2)H(2), and C(2)H(4).

The results of a study of the ion-molecule reactions of N(+), N(2)(+), and HCN(+) with methane, acetylene, and ethylene are reported. These studies were performed using the FA-SIFT at the University of Canterbury. The reactions studied here are important to understanding the ion chemistry in Titan's atmosphere. N(+) and N(2)(+) are the primary ions formed by photo-ionization and electron impact in Titan's ionosphere and drive Titan's ion chemistry. It is therefore very important to know how these ions react with the principal trace neutral species in Titan's atmosphere: Methane, acetylene, and ethylene. While these reactions have been studied before the product channels have been difficult to define as several potential isobaric products make a definitive answer difficult. Mass overlap causes difficulties in making unambiguous species assignments in these systems. Two discriminators have been used in this study to resolve the mass overlap problem. They are deuterium labeling and also the differences in reactivities of each isobar with various neutral reactants. Several differences have been found from the products in previous work. The HCN(+) ion is important in both Titan's atmosphere and in the laboratory.

Atmosphere↗
PubMed2003

Endovascular abdominal aortic aneurysm repair outside a tertiary referral centre: feasibility and impact upon workload.

In the UK, the majority of endovascular abdominal aortic aneurysm repairs (EVAR) are carried out in tertiary referral centres. We studied the feasibility and impact upon workload of an endovascular programme introduced into a district general hospital. Data was collected prospectively on all patients considered for EVAR since the inception of the programme in April 1999. Evaluation was by contrast enhanced CT scan followed by angiography if potentially suitable for EVAR. We recorded eligibility for EVAR, reasons for exclusion and the outcome of all patients irrespective of the mode of repair. Ninety patients were assessed over a 26-month period, nine of which did not complete the evaluation process. Sixty patients had one or more morphological features that precluded EVAR. Twenty-one patients were eligible for EVAR (26%), of which eighteen proceeded to EVAR, one awaits EVAR and two were below the treatment threshold (<5.5 cm). Seventeen had successful aneurysm exclusion and one required immediate conversion. One patient died within 30 days from gastrointestinal haemorrhage. There was one type-II endoleak at 1 month and to date we have encountered no ruptures or aneurysm-related deaths. Of the remaining 60 patients, 29 have proceeded to elective and 8 to urgent open repair with 2 deaths within 30 days in each group. EVAR is feasible outside tertiary referral centres and satisfactory early results can be achieved. An endovascular programme has important implications upon radiological and surgical workload. The operative mortality of patients undergoing open aortic repair remains acceptable following the introduction of an endovascular service into a district general hospital.

Aged↗
PubMed2003

Termolecular ion-molecule reactions in Titan's atmosphere. IV. A search made at up to 1 micron in pure hydrocarbons.

The results of a study of ion-molecule reactions occurring in pure methane, acetylene, ethylene, ethane, propyne, propene, propane, and diacetylene at pressures up to 40 microns of pressure are reported. A variety of experimental methods are used: The standard double resonance in an ICR, for determination of the precursor ions and the modulated double resonance ejection in an ICR, for the determination of the daughter ions. The FA-SIFT technique was used for validation and examination of termolecular reactions with rate coefficients that are less than 10(-26) cm(6) s(-1). An extensive database of reaction kinetics already exists for many of these reactions. The main point of this study was the determination of the accuracy of this database and to search for any missing reactions and reaction channels that may have been omitted from earlier investigations. A specific objective of this work was to extend the study to the highest pressures possible to find out if there were any important termolecular reaction channels occurring. A new approach was used here. In the pure hydrocarbon gases the mass spectra were followed as a function of the pressure changes of the gas. An initial guess was first made using the current literature as a source of the reaction kinetics that were expected. A model of the ion abundances was produced from the solution of the partial differential equations in terms of reaction rate coefficients and initial abundances. The experimental data was fitted to the model for all of the pressures by a least squares minimization to the reaction rate coefficients and initial abundances. The reaction rate coefficients obtained from the model were then compared to the literature values. Several new channels and reactions were discovered when the modeled fits were compared to the actual data. This is all explained in the text and the implications of these results are discussed for the Titan atmosphere.

Atmosphere↗
PubMed2003

Physiological adaptations of the gut in the Lake Magadi tilapia, Alcolapia grahami, an alkaline- and saline-adapted teleost fish.

We describe the gut physiology of the Lake Magadi tilapia (Alcolapia grahami), specifically those aspects associated with feeding and drinking while living in water of unusually high carbonate alkalinity (titratable base=245 mequiv l(-1)) and pH (9.85). Drinking of this highly alkaline lake water occurs at rates comparable to or higher than those seen in marine teleosts. Eating and drinking take place throughout the day, although drinking predominates during hours of darkness. The intestine directly intersects the esophagus at the anterior end of the stomach forming a 'T', and the pyloric sphincter, which comprises both smooth and striated muscle, is open when the stomach is empty and closed when the stomach is full. This unique configuration (a functional trifurcation) allows imbibed alkaline water to bypass the empty stomach, thereby avoiding a reactive mixing with acidic gastric fluids, and minimizes interference with a full stomach. No titratable base was present in the stomach, where the mean pH was 3.55, but the intestine was progressively more alkaline (foregut 6.96, midgut 7.74, hindgut 8.12, rectum 8.42); base levels in the intestinal fluid were comparable to those in lake water. The gut was highly efficient at absorbing water (76.6%), which accompanied the absorption of Na(+) (78.5%), titratable base (80.8%), and Cl(-) (71.8%). The majority of Na(+), base and water absorption occurred in the foregut by an apparent Na(+) plus base co-transport system. Overall, more than 70% of the intestinal flux occurred via Na(+) plus base co-transport, and less than 30% by Na(+) plus Cl(-) co-transport, a very different situation from the processes in the intestine of a typical marine teleost.

Adaptation, Physiological↗
PubMed2003

Spatial knowledge of a real school environment acquired from virtual or physical models by able-bodied children and children with physical disabilities.

In Experiment 1, 2 groups of able-bodied children were exposed to both a complex single-tier virtual environment (VE) and a physical model of a different environment. For 1 group, the VE accurately modeled a real school, and for the other group the physical model did so. In transfer testing in the real school, orientation accuracy was greater in the group exposed to the VE of the real school. In Experiment 2, children with physical disabilities explored the VE model of the real school and were tested as in the 1st experiment. Measures of orientation accuracy and map-placing were significantly better in this group than in the guessing adult control group. The results illustrate the potential for VEs as useful spatial training media.

Adolescent↗
PubMed2003

Access to the online evidence base in general practice: a survey of the Northern and Yorkshire Region.

AIMS: To assess the awareness and use of NHSnet within general practice. To investigate the presence of skills necessary to maximize the benefits of NHSnet connections. METHODS: Postal survey of general practice staff in the Northern and Yorkshire Region. RESULTS: At least one completed questionnaire was obtained from 65% of the general practices surveyed, and the individual response rate to the general practice survey was 44%. Ninety per cent of all respondents reported that their practice was connected to the NHSnet, with 59% of respondents reporting that they use NHSnet at least once a week. Although NHSnet was used to search for research information or guidance, all respondents in this survey still reported greater access to and use of paper-based information resources. Respondents indicated that they still needed further training on how to use NHSnet (42%), how to search the Internet (31%) and how to search electronic databases such as medline (49%). CONCLUSIONS: Since our 1999 survey, reported NHSnet connectivity has increased greatly, with a majority of respondents reporting that they use NHSnet at least once a week. Although encouraging, this level of usage suggests that using the Internet/NHSnet to find research has yet to become a core activity in general practice.

Computer User Training↗
PubMed2003

Pollen transfer by hummingbirds and bumblebees, and the divergence of pollination modes in Penstemon.

We compared pollen removal and deposition by hummingbirds and bumblebees visiting bird-syndrome Penstemon barbatus and bee-syndrome P. strictus flowers. One model for evolutionary shifts from bee pollination to bird pollination has assumed that, mostly due to grooming, pollen on bee bodies quickly becomes unavailable for transfer to stigmas, whereas pollen on hummingbirds has greater carryover. Comparing bumblebees and hummingbirds seeking nectar in P. strictus, we confirmed that bees had a steeper pollen carryover curve than birds but, surprisingly, bees and birds removed similar amounts of pollen and had similar per-visit pollen transfer efficiencies. Comparing P. barbatus and P. strictus visited by hummingbirds, the bird-syndrome flowers had more pollen removed, more pollen deposited, and a higher transfer efficiency than the bee-syndrome flowers. In addition, P. barbatus flowers have evolved such that their anthers and stigmas would not easily come into contact with bumblebees if they were to forage on them. We discuss the role that differences in pollination efficiency between bees and hummingbirds may have played in the repeated evolution of hummingbird pollination in Penstemon.

Adaptation, Biological↗
PubMed2003

Tackling childhood obesity.

The number of overweight or obese children has increased markedly over the past 20 years in the UK. How can health-care staff best tackle sedentary lifestyles and poor eating habits?

Child↗
PubMed2002

Oxidized lipoproteins and macrophages.

Macrophages are important participants in the development of atherosclerotic lesions, in cholesterol accumulation, as mediators of the immune response, and as sources of secreted enzymes and growth factors. Besides potentially contributing to local oxidation of lesion lipoproteins, many aspects of macrophage function can be affected by interaction with oxidized lipoproteins. Here we review macrophage responses to oxidized lipoproteins and provide novel data on the effects of a major oxidation product, 7-ketocholesterol, on high-density lipoprotein (HDL) function in cholesterol removal from macrophages.

Animals↗
PubMedDate not supplied

Obligatory urea production and the cost of living in the Magadi tilapia revealed by acclimation to reduced salinity and alkalinity.

Alcolapia grahami is a unique ureotelic tilapia that lives in the highly alkaline, saline Lake Magadi, Kenya (pH, approximately 10.0; alkalinity, approximately 380 mmol L(-1); Na(+), approximately 350 mmol L(-1); Cl(-), approximately 110 mmol L(-1); osmolality, approximately 580 mosm kg(-1)). The fish survived well upon gradual exposure to dilute lake water (down to 1%, essentially freshwater). Urea excretion continued, and there was no ammonia excretion despite favorable conditions, indicating that ureotelism is obligatory. Levels of most ornithine-urea cycle enzymes in the liver were unchanged relative to controls kept for the same period in 100% lake water. The fish exhibited good abilities for hypo- and hyperregulation, maintaining plasma Na(+), Cl(-), and osmolality at levels typical of marine and freshwater teleosts in 100% and 1% lake water, respectively. Plasma total CO(2) did not change with environmental dilution. Routine oxygen consumption (Mo(2)) was extremely high in 100% lake water but decreased by 40%-68% after acclimation to dilute lake water. At every fixed swimming speed, Mo(2) was significantly reduced (by 50% at high speeds), and critical swimming speed was elevated in fish in 10% lake water relative to 100% lake water. Osmotic and Cl(-) concentration gradients from water to plasma were actually increased, and osmotic and Na(+) gradients were reversed, in 10% and 1% dilutions relative to 100% lake water, whereas acid-base gradients were greatly reduced. We suggest that approximately 50% of the animal's high metabolic demand originates from the cost of acid-base regulation in the highly alkaline Lake Magadi. When this load is reduced by environmental dilution, the energy saved can be diverted to enhanced swimming performance.

Adaptation, Physiological↗
PubMedDate not supplied

Carotid artery imaging in the United kingdom: a postal questionnaire of current practice.

There has been a steady rise in the use of carotid duplex imaging in the selection of patients for carotid endarterectomy (CEA). Some would suggest that CEA could be safely performed without preoperative contrast angiography. The purpose of this study was to focus on the role of duplex imaging among vascular surgeons in the United Kingdom and to highlight current practices in imaging prior to CEA. A postal questionnaire was sent to all consultant members of the Vascular Surgical Society of Great Britain and Ireland about the choice of imaging prior to selection of patients for CEA, preoperative imaging, and choice of imaging (if any) in the confirmation of carotid occlusion indicated by duplex scanning. Of 396 questionnaires sent, 323 (82%) were returned. Of these, 259 (80%) consultants performed carotid surgery, 118 (45%) in university hospitals (UHs) and 141 (53%) in district general hospitals (DGHs). One hundred eighteen (100%) and 137 (97%) respondents, respectively, chose duplex scanning as their first-line investigation. Sixty (51%) respondents in UHs and 49 (35%) respondents in DGHs repeated duplex scanning immediately preoperatively, with 57 (95%) and 46 (94%), respectively, using duplex scanning. Forty-seven (40%) respondents in UHs and 78 (55%) respondents in DGHs would reconfirm an occlusion, with 30 (64%) and 48 (62%), respectively, using computed tomography and magnetic resonance imaging as their preferred tool. Our study shows that duplex scanning is the first-line imaging technique for patient selection for CEA by vascular surgeons in the United Kingdom. Magnetic resonance imaging and computed tomography are replacing conventional angiography where duplex scanning is equivocal.

Arterial Occlusive Diseases↗