Modelling phosphorus fluxes in Loweswater

1. This is the final report to the Loweswater Care Project (in support of the Catchment Restoration Fund for England) ECRC-ENSIS Project 298, 'Loweswater 12-13'. The study was concerned with the spatial and temporal concentrations of sediment phosphorus (P) in the lake and the use of P measurements from the water column and inflow and outflow samples to derive a simple mass balance model for P in the lake. 2. A review of published and unpublished literature on Loweswater highlighted trends in water chemistry since the mid-eighteenth century. Land use and farming practises have changed over the past 200 years which have led to increased nutrient loading to the lake with significant increases occurring in the mid part of the last century. Agricultural intensification is likely to be a significant cause of the problem as well as inadequate septic tank management. Local management efforts, led by the Loweswater Care Project, has sought to reduce the primary sources of nutrients reaching the lake, but total phosphorus (TP) concentrations in the lake remain higher than desired. 3. Temperature and dissolved oxygen (DO) profiling confirmed that the site stratified in summer with major changes in DO occurring below a depth of 8 m. The deeper waters were almost entirely anoxic. During stratification the maximum TP value was recorded at the lake bottom. This is a clear indication that P is being released from the lake bed during summer stratification. 4. Analysis of the stream water from the Dub Beck inflow (data for 2013), shows that P influx remains high enough to explain the elevated lake water P concentrations, despite considerable efforts to reduce catchment P sources. 5. Analysis of the water column P profiles shows that P release from the sediment is only a minor contribution to the P load. While the sediment core data reveals a substantial pool of P in the sediment very little of this should be released each year to the water column. In 2013 it is estimated that more than 90% of the P came from the catchment and only ~10% from the sediment. 6. As with all modelling exercises there are uncertainties inherent in the approach. In this case the model output is based on a single year of input data for the inflow P flux calculations and it would be preferable to have a longer data series to inform the modelling. Inflow fluxes are highly dependent on flow conditions and here, in the absence of flow data from Dub Beck, we used data from a nearby stream. Further, the monthly sampling has resulted in most samples being taken in low flow conditions, thus missing potential storm flow conditions. Finally, stream input information is restricted to Dub Beck, and contributions from the other stream is unknown. 7. Nevertheless, the results from the modelling are clear and on that basis we conclude that the priority is for P loading to the lake to be reduced by better catchment management and that lake manipulation is not warranted. Integrated catchment management supported by modelling together with local stakeholder engagement should provide the most effective means of improving the condition of the lake

Content and timing of feedback and reflection: A multi-center qualitative study of experienced bedside teachers

Background: Competency-based medical education increasingly recognizes the importance of observation, feedback, and reflection for trainee development. Although bedside rounds provide opportunities for authentic workplace-based implementation of feedback and team-based reflection strategies, this relationship has not been well described. The authors sought to understand the content and timing of feedback and team-based reflection provided by bedside teachers in the context of patient-centered bedside rounds

Etiologic workup in cases of cryptogenic stroke: protocol for a systematic review and comparison of international clinical practice guidelines

Background Stroke is a leading cause of death and disability worldwide. Identifying the aetiology of ischaemic stroke is essential in order to initiate appropriate and timely secondary prevention measures to reduce the risk of recurrence. For the majority of ischaemic strokes, the aetiology can be readily identified, but in at least 30% of cases the exact aetiology cannot be determined using existing investigative protocols. Such strokes are classed as ‘cryptogenic’ or as a stroke of unknown origin. However, there exists substantial variation in clinical practice when investigating cases of seemingly cryptogenic stroke, often reflecting local service availability and the preferences of treating clinicians. This variation in practice is compounded by the lack of international consensus as to the optimum level and timing of investigations required following a stroke. To address this gap, we aim to systematically review and compare recommendations in evidence-based clinical practice guidelines (CPGs) that relate to the assessment and investigation of the aetiology of ischaemic stroke, and any subsequent diagnosis of cryptogenic stroke. Method We will search for CPGs using electronic databases (MEDLINE, Health Management Information Consortium (HMIC), EMBASE, and CINAHL); relevant websites and search engines (e.g. guideline specific websites, governmental, charitable, professional practice organisations); and hand-searching of bibliographies and reference lists. Two reviewers will independently screen titles, abstracts and CPGs using a pre-defined relevance criteria form. From each included CPG we will extract definitions and terms for cryptogenic stroke; recommendations related to assessment and investigation of the aetiology of stroke, including grade of recommendations and underpinning evidence. Quality of the included CPGs will be assessed using the AGREE II (Appraisal of Guidelines for Research & Evaluation) tool. Recommendations across the CPGs will be summarised descriptively highlighting areas of convergence and divergence between CPGs. Discussion To our knowledge this will be the first review to systematically compare recommendations of international CPGs on investigating the aetiology of ischaemic stroke. The findings will allow for a better understanding of international perspectives on the optimum level of investigations required following a stroke, and thus contribute to achieving greater international consensus on best practice in this important and complex area

Simple Ways to Measure Behavioral Responses of Drosophila to Stimuli and Use of These Methods to Characterize a Novel Mutant

The behavioral responses of adult Drosophila fruit flies to a variety of sensory stimuli – light, volatile and non-volatile chemicals, temperature, humidity, gravity, and sound - have been measured by others previously. Some of those assays are rather complex; a review of them is presented in the Discussion. Our objective here has been to find out how to measure the behavior of adult Drosophila fruit flies by methods that are inexpensive and easy to carry out. These new assays have now been used here to characterize a novel mutant that fails to be attracted or repelled by a variety of sensory stimuli even though it is motile