Reinforcement learning interfaces for biomedical database systems

Studies of neural function that are carried out in different laboratories and that address different questions use a wide range of descriptors for data storage, depending on the laboratory and the individuals that input the data. A common approach to describe non-textual data that are referenced through a relational database is to use metadata descriptors. We have recently designed such a prototype system, but to maintain efficiency and a manageable metadata table, free formatted fields were designed as table entries. The database interface application utilizes an intelligent agent to improve integrity of operation. The purpose of this study was to investigate how reinforcement learning algorithms can assist the user in interacting with the database interface application that has been developed to improve the performance of the system.

A comparison of lungworm faecal larval counts and trichostrongyloid faecal egg counts between red deer (Cervus elaphus) and red deer x wapiti F1 hybrids

To determine if breed differences in susceptibility to trichostrongyloid and lungworm infection exist, two groups of weaner deer containing seven red deer and red deer x wapiti F1 hybrids were compared using faecal egg counts and faecal larval counts. All animals were run on the same pasture at the same time and treated with the same anthelmintics at the same time. Results indicated that there were significant differences between red deer and red deer x wapiti hybrids, with red deer having higher faecal lungworm counts and red deer x wapiti hybrids having significantly higher faecal egg counts. It is likely that these differences were due to breed. Differences in the efficacy of anthelmintic treatments were also noted between the two groups, with oral oxfendazole being less effective at reducing faecal lungworm counts in red deer X wapiti hybrids than red deer.

High-pressure polymorphism of cyclopentanol (C5H10O): the structure of cyclopentanol phase-V at 1.5 GPa

The fully ordered high-pressure crystal structure of cyclopentanol (C5H10O) has been solved using single-crystal X-ray diffraction techniques on station 9.8 at the SRS Daresbury Laboratory. At pressures above 1.5 GPa, cyclopentanol crystallizes in the monoclinic P2(1)/c space group with a=17.882 (3), b=5.4573 (3), c=9.6817 (14) A, beta=104.699 (8) degrees and Z'=2. The crystal structure is characterized by the formation of hydrogen-bonded molecular chains, denoted C_2;2(4) in graph set notation, which lie parallel to the crystallographic c-axis, with the molecules adopting a pseudo fourfold arrangement around the central core of hydrogen bonds.

Clinical service organisation for heart failure

BACKGROUND

Chronic heart failure (CHF) is a serious, common condition associated with frequent hospitalisation. Several different disease management interventions (clinical service organisation interventions) for patients with CHF have been proposed.

OBJECTIVES

To assess the effectiveness of disease management interventions for patients with CHF.

SEARCH STRATEGY

We searched: Cochrane CENTRAL Register of Controlled Trials (to June 2003); MEDLINE (January 1966 to July 2003); EMBASE (January 1980 to July 2003); CINAHL (January 1982 to July 2003); AMED (January 1985 to July 2003); Science Citation Index Expanded (searched January 1981 to March 2001); SIGLE (January 1980 to July 2003); DARE (July 2003); National Research Register (July 2003); NHS Economic Evaluations Database (March 2001); reference lists of articles and asked experts in the field.

SELECTION CRITERIA

Randomised controlled trials comparing disease management interventions specifically directed at patients with CHF to usual care.

DATA COLLECTION AND ANALYSIS

At least two reviewers independently extracted data information and assessed study quality. Study authors were contacted for further information where necessary.

MAIN RESULTS

Sixteen trials involving 1,627 people were included. We classified the interventions into three models: multidisciplinary interventions (a holistic approach bridging the gap between hospital admission and discharge home delivered by a team); case management interventions (intense monitoring of patients following discharge often involving telephone follow up and home visits); and clinic interventions (follow up in a CHF clinic). There was considerable overlap within these categories, however the components, intensity and duration of the interventions varied. Case management interventions tended to be associated with reduced all cause mortality but these findings were not statistically significant (odds ratio 0.86, 95% confidence interval 0.67 to 1.10, P = 0.23), although the evidence was stronger when analysis was limited to the better quality studies (odds ratio 0.68, 95% confidence interval 0.46 to 0.98, P = 0.04). There was weak evidence that case management interventions may be associated with a reduction in admissions for heart failure. It is unclear what the effective components of the case management interventions are. The single RCT of a multidisciplinary intervention showed reduced heart-failure related re-admissions in the short term. At present there is little available evidence to support clinic based interventions.

AUTHORS' CONCLUSIONS

The data from this review are insufficient for forming recommendations. Further research should include adequately powered, multi-centre studies. Future studies should also investigate the effect of interventions on patients' and carers' quality of life, their satisfaction with the interventions and cost effectiveness.

The duplicity of floc strength

The breakage of flocs is dependent upon the strength of the bonds holding the aggregate together. The present work describes the breakage and re-growth behaviour of three different types of floc, these were: 1) coagulant precipitate flocs, 2) turbidity flocs and 3) organic matter flocs. Floc aggregates were exposed to increased levels of shear on a conventional jar tester and the sizes of the flocs were observed dynamically using a laser diffraction instrument. The organic flocs showed most resistance to breakage across the whole range of shears under investigation. The dynamic procedure provided detailed information on particle size distributions (PSD). Large and small scale degradation events could be identified from analysis of the PSD data. All of the flocs under investigation showed little re-growth potential after breakage. The precipitate and organic flocs showed slightly better re-aggregation of the small floc sizes.

Calcium release events in excitation-contraction coupling in smooth muscle

Although smooth muscle cells are not organized in sarcomeres, as are striated muscles, nevertheless Ca2+ for contraction is released from the sarcoplasmic reticulum (SR) at certain preferred sites. These sites commonly discharge packets of Ca2+ spontaneously and have been called frequent discharge sites (FDSs). Each spontaneous release of a Ca2+ packet usually leads to a burst of openings of Ca2+-activated K+ channels in the cell membrane which produces a spontaneous transient outward current (STOC) in smooth muscle cells under voltage clamp. When fluorescent Ca2+ indicators such as Fluo-3 became available, the spontaneous transient increases in [Ca2+]i produced by Ca2+ packets released from the SR were also detected in cardiac muscle as flashes of fluorescence or 'sparks'. Sparks in smooth muscle consist of smaller Ca2+ packets that can give rise to 'microsparks'. In some smooth muscles which have Ca2+-activated Cl- channels, STICs (spontaneous transient inward currents) are also found to be associated with sparks. FDSs have been found to be important initiating sites for a Ca2+ wave in response to an action potential or in response to receptor activation and possibly other stimuli, such as stretch. In both cases Ca2+-induced Ca2+ release seems to be crucially involved.