Functional co-monotony of processes with applications to peacocks and barrier options

We show that several general classes of stochastic processes satisfy a functional co-monotony principle, including processes with independent increments, Brownian diffusions, Liouville processes. As a first application, we recover some recent results about peacock processes obtained by Hirsch et al. which were themselves motivated by a former work of Carr et al. about the sensitivity of Asian Call options with respect to their volatility and residual maturity (seniority). We also derive semi-universal bounds for various barrier options.Comment: 27 page

Collaborating for Success! Building a Digital Learning Object Repository

At the Florida State College at Jacksonville, the Library and the Center for e-Learning collaborated to build a searchable repository of digital learning objects for faculty to easily locate and upload into their courses. In this program, the presenters will address how to create instructional information for online students in a format that is understandable, usable and accessible. Additionally, they will outline the way they developed an authoritative system of tagging and organizing these resources

The discrete fragmentation equations : semigroups, compactness and asynchronous exponential growth

In this paper we present a class of fragmentation semigroups which are compact in a scale of spaces defined in terms of finite higher moments. We use this compactness result to analyse the long time behaviour of such semigroups and, in particular, to prove that they have the asynchronous growth property. We note that, despite compactness, this growth property is not automatic as the fragmentation semigroups are not irreducible

The Anomaly in the Candidate Microlensing Event PA-99-N2

The lightcurve of PA-99-N2, one of the recently announced microlensing candidates towards M31, shows small deviations from the standard Paczynski form. We explore a number of possible explanations, including correlations with the seeing, the parallax effect and a binary lens. We find that the observations are consistent with an unresolved RGB or AGB star in M31 being microlensed by a binary lens. We find that the best fit binary lens mass ratio is about one hundredth, which is one of most extreme values found for a binary lens so far. If both the source and lens lie in the M31 disk, then the standard M31 model predicts the probable mass range of the system to be 0.02-3.6 solar masses (95 % confidence limit). In this scenario, the mass of the secondary component is therefore likely to be below the hydrogen-burning limit. On the other hand, if a compact halo object in M31 is lensing a disk or spheroid source, then the total lens mass is likely to lie between 0.09-32 solar masses, which is consistent with the primary being a stellar remnant and the secondary a low mass star or brown dwarf. The optical depth (or alternatively the differential rate) along the line of sight toward the event indicates that a halo lens is more likely than a stellar lens provided that dark compact objects comprise no less than 15 per cent (or 5 per cent) of haloes.Comment: Latex, 23 pages, 9 figures, in press at The Astrophysical Journa

Access to interpreting services in England: secondary analysis of national data

Background: Overcoming language barriers to health care is a global challenge. There is great linguistic diversity in the major cities in the UK with more than 300 languages, excluding dialects, spoken by children in London alone. However, there is dearth of data on the number of non-English speakers for planning effective interpreting services. The aim was to estimate the number of people requiring language support amongst the minority ethnic communities in England. Methods: Secondary analysis of national representative sample of subjects recruited to the Health Surveys for England 1999 and 2004. Results: 298,432 individuals from the four main minority ethnic communities (Indian, Pakistani, Bangladeshi and Chinese) who may be unable to communicate effectively with a health professional. This represents 2,520,885 general practice consultations per year where interpreting services might be required. Conclusion: Effective interpreting services are required to improve access and health outcomes of non-English speakers and thereby facilitate a reduction in health inequalities

The POINT-AGAPE survey II: An Unrestricted Search for Microlensing Events towards M31

An automated search is carried out for microlensing events using a catalogue of 44554 variable superpixel lightcurves derived from our three-year monitoring program of M31. Each step of our candidate selection is objective and reproducible by a computer. Our search is unrestricted, in the sense that it has no explicit timescale cut. So, it must overcome the awkward problem of distinguishing long-timescale microlensing events from long-period stellar variables. The basis of the selection algorithm is the fitting of the superpixel lightcurves to two different theoretical models, using variable star and blended microlensing templates. Only if microlensing is preferred is an event retained as a possible candidate. Further cuts are made with regard to (i) sampling, (ii) goodness of fit of the peak to a Paczynski curve, (iii) consistency of the microlensing hypothesis with the absence of a resolved source, (iv) achromaticity, (v) position in the colour-magnitude diagram and (vi) signal-to-noise ratio. Our results are reported in terms of first-level candidates, which are the most trustworthy, and second-level candidates, which are possible microlensing but have lower signal-to-noise and are more questionable. The pipeline leaves just 3 first-level candidates, all of which have very short full-width half-maximum timescale (<5 days) and 3 second-level candidates, which have timescales of 31, 36 and 51 days respectively. We also show 16 third-level lightcurves, as an illustration of the events that just fail the threshold for designation as microlensing candidates. They are almost certainly mainly variable stars. Two of the 3 first-level candidates correspond to known events (PA 00-S3 and PA 00-S4) already reported by the POINT-AGAPE project. The remaining first-level candidate is new.Comment: 22 pages, 18 figures, MNRAS, to appea

The hidden burden of adult allergic rhinitis : UK healthcare resource utilisation survey

Funding Funding for this survey was provided by Meda Pharma.Peer reviewedPublisher PD

Classical novae from the POINT-AGAPE microlensing survey of M31 -- I. The nova catalogue

The POINT-AGAPE survey is an optical search for gravitational microlensing events towards the Andromeda Galaxy (M31). As well as microlensing, the survey is sensitive to many different classes of variable stars and transients. Here we describe the automated detection and selection pipeline used to identify M31 classical novae (CNe) and we present the resulting catalogue of 20 CN candidates observed over three seasons. CNe are observed both in the bulge region as well as over a wide area of the M31 disk. Nine of the CNe are caught during the final rise phase and all are well sampled in at least two colours. The excellent light-curve coverage has allowed us to detect and classify CNe over a wide range of speed class, from very fast to very slow. Among the light-curves is a moderately fast CN exhibiting entry into a deep transition minimum, followed by its final decline. We have also observed in detail a very slow CN which faded by only 0.01 mag day$^{-1}$ over a 150 day period. We detect other interesting variable objects, including one of the longest period and most luminous Mira variables. The CN catalogue constitutes a uniquely well-sampled and objectively-selected data set with which to study the statistical properties of classical novae in M31, such as the global nova rate, the reliability of novae as standard-candle distance indicators and the dependence of the nova population on stellar environment. The findings of this statistical study will be reported in a follow-up paper.Comment: 21 pages, 13 figures, re-submitted for publication in MNRAS, typos corrected, references updated, figures 5-9 made cleare

On the Possibility of Observing the Shapiro Effect for Pulsars in Globular Clusters

For pulsars in globular clusters, we suggest using observations of the relativistic time delay of their radiation in the gravitational eld of a massive body (the Shapiro effect) located close to the line of sight to detect and identify invisible compact objects and to study the distribution of both visible and dark matter in globular clusters and various components of the Galaxy. We have derived the dependences of the event probability on the Galactic latitude and longitude of sources for two models of the mass distribution in the Galaxy: the classical Bahcall-Soneira model and the more recent Dehnen-Binney model. Using three globular clusters (M15, 47 Tuc, Terzan 5) as an example, we show that the ratios of the probability of the events due to the passages of massive Galactic objects close to the line of sight to the parameter f2 for pulsars in the globular clusters 47 Tuc and M15 are comparable to those for close passages of massive objects in the clusters themselves and are considerably higher than those for the cluster Terzan 5. We have estimated the rates of such events. We have determined the number of objects near the line of sight toward the pulsar that can produce a modulation of its pulse arrival times characteristic of the effect under consideration; the population of brown dwarfs in the Galactic disk, whose concentration is comparable to that of the disk stars, has been taken into account for the first time.Comment: 26 pages, 9 figure