Biomedical subjects

N Humphrey

Publications and source records attributed to N Humphrey.

9 recordsLinked to original sources

PubMed2005

Estimation of diffuse and point source microbial pollution in the ribble catchment discharging to bathing waters in the north west of England.

Achieving compliance with the mandatory standards of the 1976 Bathing Water Directive (76/160/EEC) is required at all U.K. identified bathing waters. In recent years, the Fylde coast has been an area of significant investments in 'point source' control, which have not proven, in isolation, to satisfactorily achieve compliance with the mandatory, let alone the guide, levels of water quality in the Directive. The potential impact of riverine sources of pollution was first confirmed after a study in 1997. The completion of sewerage system enhancements offered the potential for the study of faecal indicator delivery from upstream sources comprising both point sources and diffuse agricultural sources. A research project to define these elements commenced in 2001. Initially, a desk study reported here, estimated the principal infrastructure contributions within the Ribble catchment. A second phase of this investigation has involved acquisition of empirical water quality and hydrological data from the catchment during the 2002 bathing season. These data have been used further to calibrate the 'budgets' and 'delivery' modelling and these data are still being analysed. This paper reports the initial desk study approach to faecal indicator budget estimation using available data from the sewerage infrastructure and catchment sources of faecal indicators.

Bathing Beaches↗

PubMed2004

Decay of intestinal enterococci concentrations in high-energy estuarine and coastal waters: towards real-time T90 values for modelling faecal indicators in recreational waters.

Intestinal enterococci are the principal 'health-evidence-based' parameter recommended by WHO for the assessment of marine recreational water compliance. Understanding the survival characteristics of these organisms in nearshore waters is central to public health protection using robust modelling to effect real-time prediction of water quality at recreation sites as recently suggested by WHO and the Commission of the European Communities Previous models have more often focused on the coliform parameters and assumed two static day-time and night-time T90 values to characterise the decay process. The principal driver for enterococci survival is the received dose of irradiance from sunlight. In the water column, transmission of irradiance is determined by turbidity produced by suspended material. This paper reports the results of irradiated microcosm experiments using simulated sunlight to investigate the decay of intestinal enterococci in relatively turbid estuarine and coastal waters collected from the Severn Estuary and Bristol Channel, UK. High-turbidity estuarine waters produced a T90 value of 39.5 h. Low-turbidity coastal waters produced a much shorter T90 value of 6.6 h. In experiments receiving no irradiation, high-turbidity estuarine waters also produced a longer T90 of 65.1 h compared with corresponding low-turbidity coastal waters, T90 24.8 h. Irradiated T90 values were correlated with salinity, turbidity and suspended solids (r>0.8, p<0.001). The results suggest that enterococci decay in irradiated experiments with turbidity >200 NTU is similar to decay observed under dark conditions. Most significantly, these results suggest that modelling turbidity and or suspended solids offers a potential means of predicting T90 values in 'real-time' for discrete cells of a hydrodynamic model.

Dose-Response Relationship, Radiation↗

PubMed2001

Are better ratings of the patient-provider relationship associated with higher quality care for depression?

BACKGROUND: The interpersonal patient-provider relationship (PPR) is an essential part of health care quality, particularly for patients with depression, yet little is known neither about how to measure this relationship nor about its association with quality of care. OBJECTIVES: To evaluate properties of patient rating measures, understand the relation between 2 types of ratings, and determine the association of ratings with quality depression care. SETTING AND PARTICIPANTS: 1,104 patients with current depressive symptoms and lifetime or 12-month disorder identified through screening 27,332 consecutive primary care visitors in 6 managed care organizations participating in Partners in Care (PIC). DESIGN: Cross-sectional analysis of 18-month data (collected in 1998) after the start of PIC depression quality improvement (QI) interventions (in which clinics were randomized to 1 of 2 QI interventions or usual care). MEASURES: Patient ratings of the interpersonal relationship with the primary care provider and satisfaction with health care, and quality of depression care indicators. ANALYSIS: Factor analysis and multitrait scaling to evaluate the psychometric properties of multiitem constructs and analysis of covariance to evaluate associations between patient ratings and quality. RESULTS: Patient ratings had high internal consistency and met criteria for discriminant validity tapping unique aspects of care. Patients receiving quality care, especially for medication use, had significantly higher ratings of the interpersonal relationship (by 22% to 27% of a SD) and were more satisfied (by 26% to 34% of a SD) than patients who did not receive quality care. CONCLUSIONS: Ratings of the interpersonal relationship and satisfaction measure distinct aspects of care and are positively associated with quality care for depression.

Adult↗

PubMed1998