The Kasei Valles, Mars: a unified record of episodic channel flows and ancient ocean levels.

There is widespread evidence across Mars of past flows in major channel systems as well as more than one palaeo ocean level. However, evidence for the timing of channel flows and ocean levels is based on geographically diverse sources with a limited number of dates, making reconstructions of palaeo flows and ocean levels patchy. Here, based on high-resolution topography, image analysis and crater statistics, we have dated 35 different surfaces in Kasei Valles, that are predominantly found within erosional units enabling us to reconstruct a fascinating timeline of episodic flooding events (ranging from 3.7 to 3.6 Ga to ca. 2.0 Ga) interacting with changing ocean/base levels. The temporal correlation of the different surfaces indicates five periods of channel flows driving the evolution of Kasei Valles, in conjunction with the development of (at least) two ocean levels. Furthermore, our results imply that such ocean rose in elevation (ca. 1000 m) between ca. 3.6 Ga and 3.2 Ga and soon afterwards disappeared, thereby indicating a complex ancient Martian hydrosphere capable of supporting a vast ocean, with an active hydrological cycle stretching into the Amazonian.

Knickpoints in Martian channels indicate past ocean levels.

On Mars, the presence of extensive networks of sinuous valleys and large channels provides evidence for a wetter and warmer environment where liquid water was more abundant than it is at present. We undertook an analysis of all major channel systems on Mars and detected sharp changes in elevation along the river long profiles associated with steep headwall theatre-like valleys and terraces left downstream by channel incision. These breaks in channel longitudinal slope, headwalls and terraces exhibit a striking resemblance with terrestrial fluvial features, commonly termed 'knickpoints'. On Earth, such knickpoints can be formed by more resistant bedrock or where changes in channel base-level have initiated erosion that migrates upstream (such as tectonic uplift or sea level change). We observed common elevations of Martian knickpoints in eleven separate channel systems draining into the Martian Northern lowlands. Numerical modeling showed that the common elevations of some of these knickpoints were not random. As the knickpoints are spread across the planet, we suggest that these Martian knickpoints were formed in response to a common base level or ocean level rather than local lithology. Thus, they potentially represent a record of past ocean levels and channel activity on Mars.

Cluster randomised controlled trial of a theory-based multiple behaviour change intervention aimed at healthcare professionals to improve their management of type 2 diabetes in primary care.

BACKGROUND: National diabetes audits in the UK show room for improvement in the quality of care delivered to people with type 2 diabetes in primary care. Systematic reviews of quality improvement interventions show that such approaches can be effective but there is wide variability between trials and little understanding concerning what explains this variability. A national cohort study of primary care across 99 UK practices identified modifiable predictors of healthcare professionals' prescribing, advising and foot examination. Our objective was to evaluate the effectiveness of an implementation intervention to improve six guideline-recommended health professional behaviours in managing type 2 diabetes in primary care: prescribing for blood pressure and glycaemic control, providing physical activity and nutrition advice and providing updated diabetes education and foot examination. METHODS: Two-armed cluster randomised trial involving 44 general practices. Primary outcomes (at 12 months follow-up): from electronic medical records, the proportion of patients receiving additional prescriptions for blood pressure and insulin initiation for glycaemic control and having a foot examination; and from a patient survey of a random sample of 100 patients per practice, reported receipt of updated diabetes education and physical activity and nutrition advice. RESULTS: The implementation intervention did not lead to statistically significant improvement on any of the six clinical behaviours. 1,138,105 prescriptions were assessed. Intervention (29% to 37% patients) and control arms (31% to 35%) increased insulin initiation relative to baseline but were not statistically significantly different at follow-up (IRR 1.18, 95%CI 0.95-1.48). Intervention (45% to 53%) and control practices (45% to 50%) increased blood pressure prescription from baseline to follow-up but were not statistically significantly different at follow-up (IRR 1.05, 95%CI 0.96 to 1.16). Intervention (75 to 78%) and control practices (74 to 79%) increased foot examination relative to baseline; control practices increased statistically significantly more (OR 0.84, 95%CI 0.75-0.94). Fewer patients in intervention (33%) than control practices (40%) reported receiving updated diabetes education (OR = 0.74, 95%CI 0.57-0.97). No statistically significant differences were observed in patient reports of having had a discussion about nutrition (intervention = 73%; control = 72%; OR = 0.98, 95%CI 0.59-1.64) or physical activity (intervention = 57%; control = 62%; OR = 0.79, 95%CI 0.56-1.11). Development and delivery of the intervention cost £1191 per practice. CONCLUSIONS: There was no measurable benefit to practices' participation in this intervention. Despite widespread use of outreach interventions worldwide, there is a need to better understand which techniques at which intensity are optimally suited to address the multiple clinical behaviours involved in improving care for type 2 diabetes. TRIAL REGISTRATION: ISRCTN, ISRCTN66498413 . Registered April 4, 2013.

The epidemiology of teaching and training practices in North-East England.

INTRODUCTION: Teaching and training practices in England serve less ethnically diverse and urban environments than non-teaching practices. However, it is not known if these trends are consistent across the country. METHODS: We linked data on teaching and training status for all North-East England practices to practice characteristics, locality and patient variables, calculated the association with each variable and compared to the national figures. RESULTS: Teaching and training practices in North-East England are larger than non-teaching and non-training practices (mean list size (SD) 9109 (4080) vs. 5547 (5325), p < 0.001), have fewer patients per GP (1649 (404) vs. 2302 (1245), p < 0.001), higher patient satisfaction (43.45 (1.61) vs. 42.77 (2.14), p < 0.005) and quality and outcomes framework scores (98.3% (2.2%) vs. 95.5% (6.9%), p < 0.001), and are less likely to be in deprived areas (OR = 0.63; 95% CI 0.42-1.44). However, rurality, ethnic diversity, and patients' health status were not significantly associated with teaching and training status. CONCLUSIONS: In North-East England, general practices' teaching and training status is not associated with serving an urban or more ethnically diverse locality, in contrast with the national picture. The national profile may mask significant regional variations.

Improving Diabetes care through Examining, Advising, and prescribing (IDEA): protocol for a theory-based cluster randomised controlled trial of a multiple behaviour change intervention aimed at primary healthcare professionals.

BACKGROUND: New clinical research findings may require clinicians to change their behaviour to provide high-quality care to people with type 2 diabetes, likely requiring them to change multiple different clinical behaviours. The present study builds on findings from a UK-wide study of theory-based behavioural and organisational factors associated with prescribing, advising, and examining consistent with high-quality diabetes care. AIM: To develop and evaluate the effectiveness and cost of an intervention to improve multiple behaviours in clinicians involved in delivering high-quality care for type 2 diabetes. DESIGN/METHODS: We will conduct a two-armed cluster randomised controlled trial in 44 general practices in the North East of England to evaluate a theory-based behaviour change intervention. We will target improvement in six underperformed clinical behaviours highlighted in quality standards for type 2 diabetes: prescribing for hypertension; prescribing for glycaemic control; providing physical activity advice; providing nutrition advice; providing on-going education; and ensuring that feet have been examined. The primary outcome will be the proportion of patients appropriately prescribed and examined (using anonymised computer records), and advised (using anonymous patient surveys) at 12 months. We will use behaviour change techniques targeting motivational, volitional, and impulsive factors that we have previously demonstrated to be predictive of multiple health professional behaviours involved in high-quality type 2 diabetes care. We will also investigate whether the intervention was delivered as designed (fidelity) by coding audiotaped workshops and interventionist delivery reports, and operated as hypothesised (process evaluation) by analysing responses to theory-based postal questionnaires. In addition, we will conduct post-trial qualitative interviews with practice teams to further inform the process evaluation, and a post-trial economic analysis to estimate the costs of the intervention and cost of service use. DISCUSSION: Consistent with UK Medical Research Council guidance and building on previous development research, this pragmatic cluster randomised trial will evaluate the effectiveness of a theory-based complex intervention focusing on changing multiple clinical behaviours to improve quality of diabetes care. TRIAL REGISTRATION: ISRCTN66498413.

Were rivers flowing across the Sahara during the last interglacial? Implications for human migration through Africa.

Human migration north through Africa is contentious. This paper uses a novel palaeohydrological and hydraulic modelling approach to test the hypothesis that under wetter climates c.100,000 years ago major river systems ran north across the Sahara to the Mediterranean, creating viable migration routes. We confirm that three of these now buried palaeo river systems could have been active at the key time of human migration across the Sahara. Unexpectedly, it is the most western of these three rivers, the Irharhar river, that represents the most likely route for human migration. The Irharhar river flows directly south to north, uniquely linking the mountain areas experiencing monsoon climates at these times to temperate Mediterranean environments where food and resources would have been abundant. The findings have major implications for our understanding of how humans migrated north through Africa, for the first time providing a quantitative perspective on the probabilities that these routes were viable for human habitation at these times.

Integration of shelf evolution and river basin models to simulate Holocene sediment dynamics of the Humber Estuary during periods of sea-level change and variations in catchment sediment supply.

Three modelling elements and sedimentary evidence provide an understanding of sediment characteristics, river basin processes, tidal regimes and sea-level changes to explain sediment supply to the Humber Estuary through the Holocene (the last 10,000 years). An upscaled cellular catchment model simulates water and sediment fluxes from river basins, illustrating significant variations in response to climate change, especially precipitation and vegetation changes, principally deforestation. Much of the sediment mobilised remains in stores within the catchment and only a small fraction reaches the Humber tidal system. An empirical model helps to explain sediment erosion, transport and deposition from the offshore and coastal zones through the Holocene and sea-level rise caused the transgression of the continental shelf of the North Sea. Comparison with the sediment fill of the lowlands around of the Humber estuary, that represent the extent of the estuary during the Holocene, demonstrates that most of the fill (approximately 95-98%) was derived from non-fluvial sources. A shelf evolution model, with reconstructions of sea level, palaeogeography and palaeobathymetry for 1,000 year time steps through the Holocene predicts significant changes in tidal regimes, first over wide areas of the coast as the transgression of the continental shelf progresses. The most significant changes occur with the inner reaches of the palaeo-estuaries, especially those of the Humber and the Fenland. Throughout the mid-Holocene they are characterised by significantly lower tidal ranges (MWHST approximately 2.5 m less than present) and low tidal currents. The simulated patterns of tidal currents concur with the transport of fine grain sediment from the coastal zone into the estuaries. The major tidal range changes revise estimates of late Holocene and ongoing relative sea and land level changes.