Phytosociology and community boundaries of the British heath foundation

A review of phytosociological techniques, including the Zurich-Montipellier (Z-M) system. Association analysis and Simple ordination is made, using a standard data set. The complementary nature of the results obtained is noted. As classification erects divisions and boundaries in a data set, and the prime method used in the analysis of Heath vegetation is classificatory, evidence for the prescence of ' real' vegetation boundaries is presented, together with a discussion of their nature and function. Heathland vegetation in Britain has been classified using the Z-M phytosociological system, and four main types have been distinguished, which are equated with alliances at present in use in Europe. These are; Erica cinerea Heath: Ulicion nanae (Duvigud, 1944)em. Van den Bergen. Calluna vulgaris Heath: Calluno-Genisition pilosae (Duvignd, 1944) Vaccinium myrtillus Heath: Llyrtillion bore ale (Bocher, 1943). Erica tetralix Heath: Ericion tetralicis (Schuick, 1933).The first three are typical of Dry heaths, whereas the fourth indicates wet heath. A phytogeographical analysis of the Heath vegetation gives further validity to these four types, indicating the dependence of the three dry 'Heaths' on species which are geographically restricted. Use of the Z-M system and some other techniques to indicate the nature of recent vegetation in areas now urbanised or agriculturalised is made, using South Gloucestershire as such an area

A Statistical Mechanical Load Balancer for the Web

The maximum entropy principle from statistical mechanics states that a closed system attains an equilibrium distribution that maximizes its entropy. We first show that for graphs with fixed number of edges one can define a stochastic edge dynamic that can serve as an effective thermalization scheme, and hence, the underlying graphs are expected to attain their maximum-entropy states, which turn out to be Erdos-Renyi (ER) random graphs. We next show that (i) a rate-equation based analysis of node degree distribution does indeed confirm the maximum-entropy principle, and (ii) the edge dynamic can be effectively implemented using short random walks on the underlying graphs, leading to a local algorithm for the generation of ER random graphs. The resulting statistical mechanical system can be adapted to provide a distributed and local (i.e., without any centralized monitoring) mechanism for load balancing, which can have a significant impact in increasing the efficiency and utilization of both the Internet (e.g., efficient web mirroring), and large-scale computing infrastructure (e.g., cluster and grid computing).Comment: 11 Pages, 5 Postscript figures; added references, expanded on protocol discussio

Time to endoscopic intervention in patients with upper gastrointestinal patients can be improved with pathway provision

BACKGROUND:Patients with upper gastrointestinal malignancy often require admission to hospital with dysphagia or jaundice requiring therapeutic endoscopy. Endoscopic intervention is often effective permitting rapid discharge. An efficient service would permit rapid discharge for patients who are often at the end of life. We noted that a majority of patients in hospital under the gastroenterological oncology were admitted with symptoms requiring therapeutic endoscopy. METHODS: We conducted an audit cycle of the inpatient days before and after pathway implementation. A wait of 1 day was set as acceptable for patients with bleeding as defined by NICE guidance and we set an arbitrary standard of 2 days for patients without bleeding but requiring therapeutic endoscopy. Between the audit cycles, a pathway was built to accommodate these patients. RESULTS: Inpatient waits improved from a median of 3 days to 1 day. There was no difference in outcome between those presenting with bleeding and other symptoms or any difference in patients requiring different procedures. CONCLUSIONS: Waiting times for endoscopy can be improved with the introduction of a targeted pathway of cancer patients. Further issues including cost, quality of life and nutrition require further intervention

Marijuana Legalization: Still an Open Question?

Marijuana, a well-studied drug in scientific field, now has been being enabled to be a legal recreational substance by some U.S. states that evoked a wide discussion on its potential effects on our future life. A majority of people hold negative points on this drug; most of them are scientists, educators, physicians, and parents who have kids. However, another huge party who positively advocates the pot legalization is the people like businessmen, retailers, planters, and drug users. Along with the recent approval for banks allowed to open accounts for marijuana business, as well as the vigorous appeal for the drug’s legalization, can the science win over the battle? For the drug itself, we need objectively to evaluate its possible effects. Everything has two sides like a double-edged sword, if you take the yin, and the yang is also there, and then is vise versa. Maybe marijuana legalization for recreational use was an out and out wrong, and maybe it was a wise decision. Who knows? The only thing we can do today is let time tell us the answer

Funnel plots, performance variation and the Myocardial Infarction National Audit Project 2003–2004

BACKGROUND: Clinical governance requires health care professionals to improve standards of care and has resulted in comparison of clinical performance data. The Myocardial Infarction National Audit Project (a UK cardiology dataset) tabulates its performance. However funnel plots are the display method of choice for institutional comparison. We aimed to demonstrate that funnel plots may be derived from MINAP data and allow more meaningful interpretation of data. METHODS: We examined the attainment of National Service Framework standards for all hospitals (n = 230) and all patients (n = 99,133) in the MINAP database between 1(st )April 2003 and 31(st )March 2004. We generated funnel plots (with control limits at 3 sigma) of Door to Needle and Call to Needle thrombolysis times, and the use of aspirin, beta-blockers and statins post myocardial infarction. RESULTS: Only 87,427 patients fulfilled criteria for analysis of the use of secondary prevention drugs and 15,111 patients for analysis by Door to Needle and Call to Needle times (163 hospitals achieved the standards for Door to Needle times and 215 were within or above their control limits). One hundred and sixteen hospitals fell outside the 'within 25%' and 'more than 25%' standards for Call to Needle times, but 28 were below the lower control limits. Sixteen hospitals failed to reach the standards for aspirin usage post AMI and 24 remained below the lower control limits. Thirty hospitals were below the lower CL for beta-blocker usage and 49 outside the standard. Statin use was comparable. CONCLUSION: Funnel plots may be applied to a complex dataset and allow visual comparison of data derived from multiple health-care units. Variation is readily identified permitting units to appraise their practices so that effective quality improvement may take place

Traveling Granular Segregation Patterns in a Long Drum Mixer

Mixtures of granular media often exhibit size segregation along the axis of a partially-filled, horizontal, rotating cylinder. Previous experiments have observed axial bands of segregation that grow from concentration fluctuations and merge in a manner analogous to spinodal decomposition. We have observed that a new dynamical state precedes this effect in certain mixtures: bi-directional traveling waves. By preparing initial conditions, we found that the wave speed decreased with wavelength. Such waves appear to be inconsistent with simple PDE models which are first order in time.Comment: 11 page