The subterranean or underground rivers of London are the tributaries of the River Thames and River Lea that were built over during the growth of the metropolis of London. The rivers now flow through underground culverts, with a number of them now integral parts of London's sewerage system. North of the River Thames The Walbrook The River Fleet, the largest. In January 2009, a partnership among the Environment Agency, Natural England, The River Restoration Centre, the Greater London Authority set out a strategy for putting this into effect by creating the London Rivers Action Plan. Blue Ribbon Network – the major waterways of London List of rivers of England London sewerage system Subterranean London Subterranean river Tributaries of the River Thames Dangerfield, Andy. "The lost rivers that lie beneath London". BBC News. London, UK. "The Underground City: Beneath the streets of London's capital city is a world of tunnels and hidden history". Heritage Magazine. April–May 2000. Archived from the original on 10 December 2002.

Retrieved 10 December 2002. CS1 maint: BOT: original-url status unknown "Deep Topographical site with special emphasis on London's lost watercourses". Middlexex County Council. Middlesex County, UK. Mackie, Gordon. "London's Lost Rivers: Wayback Machine Snapshot". Archived from the original on 7 January 2004. CS1 maint: BOT: original-url status unknown "Map of London's Underground Rivers". OpenGuides.org. London, UK. "Photographs from inside London's'Lost' Rivers". SilentUK.com. "Strange Maps". London's Lost Rivers

Lazy loading is a design pattern used in computer programming to defer initialization of an object until the point at which it is needed. It can contribute to efficiency in the program's operation; the opposite of lazy loading is eager loading. This makes it ideal in use cases where network content is accessed and initialization times are to be kept at a minimum, such as in the case of web pages. There are four common ways of implementing the lazy load design pattern: lazy initialization; each has its own disadvantages. With lazy initialization, the object to be lazily loaded is set to null, every request for the object checks for null and creates it "on the fly" before returning it first, as in this C# example: Or with the null-coalescing operator'??' This method is the simplest to implement, although if null is a legitimate return value, it may be necessary to use a placeholder object to signal that it has not been initialized. If this method is used in a multithreaded application, synchronization must be used to avoid race conditions.

Virtual Proxy is an object with the same interface as the real object. The first time one of its methods is called it loads the real object and delegates. A "ghost" is the object, to be loaded in a partial state, it may only contain the object's identifier, but it loads its own data the first time one of its properties is accessed. For example, consider that a user is about to request content via an online form. At the time of creation all we know is that content will be accessed but what action or content is unknown. PHP Example: A value holder is a generic object that handles the lazy loading behavior, appears in place of the object's data fields: Design pattern Proxy Lazy inheritance Lazy evaluation Lazy initialization

The Centre for Evidence-Based Medicine based in the Nuffield Department of Primary Care Health Sciences in the University of Oxford is an academic-led centre dedicated to the practice and dissemination of high quality evidence-based medicine to improve healthcare in everyday clinical practice. CEBM was founded by David Sackett in 1995, it was subsequently directed by and Paul Glasziou. Since 2010 it has been led by Professor Carl Heneghan, a Clinical Epidemiologist and General Practitioner. There are over 25 active staff and honorary members of the CEBM. Many of the active staff include other clinicians, epidemiologists, information specialists and qualitative researchers. Philosopher of Evidence-Based Medicine Jeremy Howick is a former fellow of the CEBM. CEBM is the academic lead for Oxford University's Graduate School in Evidence-Based Healthcare, together with the Department of Continuing Education at the University of Oxford; the Graduate School includes a MSc in Evidence-Based Health Care and a DPhil in Evidence-Based Health Care.

Along with a range of short courses, including a course on the History and Philosophy of Evidence-Based Healthcare. Every year, CEBM organises EBM Live, a multi-day conference focussing on developments in the area of evidence-based medicine; the conference is organised in collaboration with the British Medical Journal. Themes for the conference include Improving the Quality of Research. CEBM has developed a adopted systematic hierarchy of the quality of medical research evidence, named the levels of evidence. Systematic reviews of randomised clinical trials are seen as the highest possible level of evidence, as full assessment and aggregated synthesis of underlying evidence is possible. In collaboration with the British Medical Journal, Carl Heneghan and team found no evidence that Tamiflu helped to reduce complications of influenza; this has become a controversial topic, as the United Kingdom government spend £473 million on the purchase of Tamiflu, despite the systematic review claiming to find no evidence for the effectiveness of it.

A systematic review conducted in 2012 discovered a little effect of carbohydrate drinks on sport performance of the general population. This work formed part of a joint investigation with the British Medical Journal. A linked article published in the BMJ reported a "Striking lack of evidence" to back up claims for popular sports brands. A further analysis of a broad range of sports products showed that the evidence for many sports products is poor quality and insufficient to inform the public about the benefits and harms of sports products. Systematic review and individual patient data meta analysis research in the centre has shown that with little training people on oral anticoagulation can self-monitor, self-manage their disease in the community. Patients capable of self-monitoring and self-adjusting therapy have fewer thromboembolic events and lower mortality than those who self-monitor alone. In 2014, Carl Heneghan along with Alison Ward became directors of a World Health Organization Collaborating Centre for Self-Care in Non-communicable disease.

The centre is one of the co-founders of the AllTrials campaign, influential in ensuring that the results of all clinical trials are registered and reported in full. The centre has a strong diagnostic theme which includes assessing novel Diagnostic Technologies relevant to improving the diagnosis of disease in primary care and to improving diagnostic reasoning. In 2015, the centre produced a report for the Department of Health on Antimicrobial resistance diagnostics which highlighted the considerable number of new diagnostic technologies in development to underpin rational prescribing of antibiotics. In 2015 the COMPare project was launched: Outcome switching in clinical trials is a serious problem; the project systematically checks every trial published in the top five medical journals, to see if they have misreported their findings, comparing each clinical trial report against its registry entry. The project has found that some trials report their outcomes but for many others outcomes specified in the registry entry were never reported.

The updates to the trials are updated live on the COMPare website. The project highlights how researchers are duped by the common practice in clinical trial reporting of "outcome switching". In March 2016, research in the centre systematically identified 353 medicinal products withdrawn worldwide because of adverse drug reactions, assessed the level of evidence used for making the withdrawal decisions, found that only 40 drugs were withdrawn worldwide. Withdrawal was less in Africa than in other continents. Furthermore, in 47% of the 95 drugs for which death was documented as a reason for withdrawal more than 2 years elapsed between the first report of a death and drug withdrawal. 2015 Research fellows listed on the CEBM website include: Jeffrey Aronson, president emeritus of the British Pharmacological Society Susannah Fleming Ben Goldacre, senior research fellow Carl Heneghan, professor of evidence-based medicine Kamal Mahtani, deputy director David Nunan Igho Onakpoya Annette Pluddemann Rafael Perera Liz Spencer Alice Tompson Brian Nicholson Notable fellows include: Jon Brassey, founder of Trip Iain Chalmers Muir Gray Professor Rod Jackson, University of Auckland Tom Jefferson, Cochrane Acute Respir