Catchment water quality: the inconvenient but necessary truth of fractal functioning

This commentary concerns catchment water quality functioning in relation to environmental impact assessment, with a view to proposing that much more emphasis be placed on issues of within-catchment complexity and its manifestation within stream water chemistry: fractal dynamics. The commentary is based, with closure, on my long-term research. Encouragement is given for new avenues to be pursued, including dealing with the complexities of within-stream biological functioning, and their integration into environmental legislation

Estimating nutrient concentrations from catchment characteristics across the UK

Within a Geographical Information System (GIS) framework, the distributions of nitrate and orthophosphate concentrations at monitoring sites across the UK were examined and empirical relationships with catchment characteristics were established. The mean orthophosphate concentrations were linked strongly with the urban component, and less significantly with effective rainfall and agricultural coverage. This is of strategic importance in relation to phosphorus and the Water Framework Directive. Correspondingly, mean nitrate concentrations were linked to land-use types, base flow index and effective rainfall. Within-catchment residence times and effective-rainfall (runoff) were important in relation to nitrate. The issue of nitrate and the Water Framework Directive is more complex than that for orthophosphate and involves a strong agricultural as well as an urban component

How to Unravel and Solve Soil Fertility Problems

Land Economics/Use,

Coupling of spontaneous changes in muscle sympathetic nerve activity to blood pressure in humans : potential influence of age [abstract]

Previous studies indicate a 5.5 second latency between a burst of muscle sympathetic nerve activity (MSNA) and the resultant peak blood pressure response, which averages up to 3 mmHg. Aging may attenuate α-adrenergic sensitivity, impair baroreflex function, and hence affect the ability to sympathetically modulate blood pressure. Yet a thorough examination of these relationships in older adults has not been performed. Purpose: To compare the relationship between spontaneous changes in MSNA to changes in blood pressure in young and older men

Selective attenuation of carotid-cardiac responses to hypertension at the onset of static handgrip in humans [abstract]

Previous studies have indicated that at the onset of exercise cardiac baroreflex function is reduced in an intensity-dependent manner, which appears to be mediated by a blunted ability to buffer hypertensive challenges. However, whether cardiac baroreflex responses to a hypotensive stimulus are altered at exercise onset is unclear

Insulin-mediated increases in arterial baroreflex control of muscle sympathetic nerve activity following meal intake in humans [abstract]

Animal studies indicate that insulin enhances arterial baroreflex (ABR) control of sympathetic nerve activity (SNA); however, the extent to which these findings can be extrapolated to humans is unknown. To begin to address this, we utilized a mixed meal as a physiological method to evoke sustained increases in plasma insulin

The magnitude of educational disadvantage amongst indigenous minority groups in Australia.

Indigenous groups are amongst the most disadvantaged minority groups in the developed world. This paper examines the educational disadvantage of indigenous Australians by assessing academic performance at a relatively early age. We find that, by the age of 10, indigenous Australians are substantially behind non-indigenous Australians in academic achievement. Their relative performance deteriorates further over the next 2 years. School and locality do not appear to be important determinants of the indigenous to non-indigenous achievement gap. However, geographic remoteness, indigenous ethnicity and language use at home have a marked influence on educational achievement. A current focus of Australian indigenous policy is to increase school resources. Our results suggest that this will not eliminate indigenous educational disadvantage on its own