It's all in the name, or is it? The impact of labelling on health state values

Many descriptions of health used in vignettes and condition-specific measures refer to the medical condition. This paper assesses the impact of referring to the medical condition in the descriptions of health states valued by members of the general population. A sample of 241 members of the UK general population each valued 8 health states using time trade-off. All respondents valued essentially the same health states, but for each respondent the descriptions featured either an irritable bowel syndrome label, a cancer label or no label. Regression techniques were used to estimate the impact of each label and experience of the condition on health state values. We find that the inclusion of a cancer label in health state descriptions affects health state values and that the impact is dependent upon the severity of the state. A condition label can affect health state values, but this is dependent upon the specific condition and severity. It is recommended to avoid condition labels in health state descriptions (where possible) to ensure that values are not affected by prior knowledge or preconception of the condition that may distort the health state being valued

Locations of marine animals revealed by carbon isotopes

Knowing the distribution of marine animals is central to understanding climatic and other environmental influences on population ecology. This information has proven difficult to gain through capture-based methods biased by capture location. Here we show that marine location can be inferred from animal tissues. As the carbon isotope composition of animal tissues varies with sea surface temperature, marine location can be identified by matching time series of carbon isotopes measured in tissues to sea surface temperature records. Applying this technique to populations of Atlantic salmon (Salmo salar L.) produces isotopically-derived maps of oceanic feeding grounds, consistent with the current understanding of salmon migrations, that additionally reveal geographic segregation in feeding grounds between individual philopatric populations and age-classes. Carbon isotope ratios can be used to identify the location of open ocean feeding grounds for any pelagic animals for which tissue archives and matching records of sea surface temperature are available

A robot trace maker: modeling the fossil evidence of early invertebrate behavior.

The study of trace fossils, the fossilized remains of animal behavior, reveals interesting parallels with recent research in behavior-based robotics. This article reports robot simulations of the meandering foraging trails left by early invertebrates that demonstrate that such trails can be generated by mechanisms similar to those used for robot wall-following. We conclude with the suggestion that the capacity for intelligent behavior shown by many behavior-based robots is similar to that of animals of the late Precambrian and early Cambrian periods approximately 530 to 565 million years ago

Does relatedness influence migratory timing and behaviour in Atlantic salmon smolts?

Aggregating and moving with relatives may enable animals to increase opportunities for kin selection to occur. To gain group-living benefits, animals must coordinate their behaviour. Atlantic salmon, Salmo salar, demonstrate both territoriality and schooling: the two key social behaviours performed by fish. In this investigation we compared the migratory timing and behaviour of six distinct full-sibling groups of tagged S. salar smolts with a large control sample from the same wild population. The results clearly demonstrate that the incidence of schooling and diel migratory timing is not significantly influenced by relatedness, and this adds further support to the hypothesis that S. salar smolt migration is primarily an adaptive response to environmental conditions, rather than a behaviour based solely on genetics or kin-biased behaviour. Used in conjunction with the results of two previous investigations, this is the first study to illustrate that kin discrimination among full-sibling groups of parr does not lead to kin-biased schooling in smolts. Thus, even within the same full-sibling groups, the extent of kin-biased behaviour in fish can both differ within a life history stage under varying ecological conditions and shift from one life history stage to the next

Effect of nucleon exchange on projectile multifragmentation in the reactions of 28Si + 112Sn and 124Sn at 30 and 50 MeV/nucleon

Multifragmentation of quasiprojectiles was studied in reactions of 28Si beam with 112Sn and 124Sn targets at projectile energies 30 and 50 MeV/nucleon. The quasiprojectile observables were reconstructed using isotopically identified charged particles with Z_f <= 5 detected at forward angles. The nucleon exchange between projectile and target was investigated using isospin and excitation energy of reconstructed quasiprojectile. For events with total reconstructed charge equal to the charge of the beam (Z_tot = 14) the influence of beam energy and target isospin on neutron transfer was studied in detail. Simulations employing subsequently model of deep inelastic transfer, statistical model of multifragmentation and software replica of FAUST detector array were carried out. A concept of deep inelastic transfer provides good description of production of highly excited quasiprojectiles. The isospin and excitation energy of quasiprojectile were described with good overall agreement. The fragment multiplicity, charge and isospin were reproduced satisfactorily. The range of contributing impact parameters was determined using backtracing procedure.Comment: 11 pages, 8 Postscript figures, LaTeX, to appear in Phys. Rev. C ( Dec 2000

Is the involvement of opinion leaders in the implementation of research findings a feasible strategy?

BACKGROUND: There is only limited empirical evidence about the effectiveness of opinion leaders as health care change agents. AIM: To test the feasibility of identifying, and the characteristics of, opinion leaders using a sociometric instrument and a self-designating instrument in different professional groups within the UK National Health Service. DESIGN: Postal questionnaire survey. SETTING AND PARTICIPANTS: All general practitioners, practice nurses and practice managers in two regions of Scotland. All physicians and surgeons (junior hospital doctors and consultants) and medical and surgical nursing staff in two district general hospitals and one teaching hospital in Scotland, as well as all Scottish obstetric and gynaecology, and oncology consultants. RESULTS: Using the sociometric instrument, the extent of social networks and potential coverage of the study population in primary and secondary care was highly idiosyncratic. In contrast, relatively complex networks with good coverage rates were observed in both national specialty groups. Identified opinion leaders were more likely to have the expected characteristics of opinion leaders identified from diffusion and social influence theories. Moreover, opinion leaders appeared to be condition-specific. The self-designating instrument identified more opinion leaders, but it was not possible to estimate the extent and structure of social networks or likely coverage by opinion leaders. There was poor agreement in the responses to the sociometric and self-designating instruments. CONCLUSION: The feasibility of identifying opinion leaders using an off-the-shelf sociometric instrument is variable across different professional groups and settings within the NHS. Whilst it is possible to identify opinion leaders using a self-designating instrument, the effectiveness of such opinion leaders has not been rigorously tested in health care settings. Opinion leaders appear to be monomorphic (different leaders for different issues). Recruitment of opinion leaders is unlikely to be an effective general strategy across all settings and professional groups; the more specialised the group, the more opinion leaders may be a useful strategy

Neurology

Contains reports on six research projects.U. S. Public Health Service (B-3055-4, B-3090-4, MH-06175-02)U. S. Air Force (AF49(638)-1313)U.S. Navy. Office of Naval Research (Nonr-1841(70)

Patient and physician satisfaction in an observational study with methyl aminolevulinate daylight-photodynamic therapy in the treatment of multiple actinic keratoses of the face and scalp in 6 European countries

BACKGROUND Guidelines recommend treating actinic keratoses (AKs) as they are recognized as precursors of invasive squamous cell carcinoma. OBJECTIVE The objective of this study was to collect real-world clinical data on the use of methyl aminolevulinate daylight photodynamic therapy (MAL DL-PDT) for the treatment of face and scalp AK in Europe. METHODS A prospective, multicenter, non-interventional study was conducted in six European countries in patients receiving a single treatment of MAL DL-PDT for face and/or scalp AK. Patient-reported outcomes were assessed by patient questionnaires at baseline and at 3 months after treatment, efficacy was assessed at 3 months using a 6-point global improvement scale, and adverse events (AE) were recorded at each visit. RESULTS Overall, 325 patients were enrolled from 52 investigational centres, 314 of whom attended the 3-month visit. Most patients had multiple lesions (58.4% had >10 lesions) with lesions mainly located on the scalp (60.0%) and/or forehead (54.2%). AKs were predominantly grade I (39.4%) or grade II (33.2%), and 10.5% of patients had grade III lesions. The proportions of patients and physicians that were overall satisfied to very satisfied with the MAL DL-PDT treatment were 80.4% and 90.3%, respectively. The vast majority of patients (90.0%) would consider using MAL DL-PDT again if needed. Physician-assessed efficacy at 3 months was at least much improved in 83.5% of patients, with 45.9% of patients requiring no retreatment. Related AEs were reported in 15% of patients. CONCLUSION Use of MAL DL-PDT for multiple face and/or scalp AKs resulted in high levels of patient and physician satisfaction in clinical practice in Europe, reflecting the good efficacy and high tolerability of this convenient procedure

The price of rapid exit in venture capital-backed IPOs

This paper proposes an explanation for two empirical puzzles surrounding initial public offerings (IPOs). Firstly, it is well documented that IPO underpricing increases during “hot issue” periods. Secondly, venture capital (VC) backed IPOs are less underpriced than non-venture capital backed IPOs during normal periods of activity, but the reverse is true during hot issue periods: VC backed IPOs are more underpriced than non-VC backed ones. This paper shows that when IPOs are driven by the initial investor’s desire to exit from an existing investment in order to finance a new venture, both the value of the new venture and the value of the existing firm to be sold in the IPO drive the investor’s choice of price and fraction of shares sold in the IPO. When this is the case, the availability of attractive new ventures increases equilibrium underpricing, which is what we observe during hot issue periods. Moreover, I show that underpricing is affected by the severity of the moral hazard problem between an investor and the firm’s manager. In the presence of a moral hazard problem the degree of equilibrium underpricing is more sensitive to changes in the value of the new venture. This can explain why venture capitalists, who often finance firms with more severe moral hazard problems, underprice IPOs less in normal periods, but underprice more strongly during hot issue periods. Further empirical implications relating the fraction of shares sold and the degree of underpricing are presented