Long period variables and mass loss in the globular clusters NGC 362 and NGC 2808

The pulsation periods of long period variables (LPVs) depend on their mass and helium abundance as well as on their luminosity and metal abundance. Comparison of the observed periods of LPVs in globular clusters with models is capable of revealing the amount of mass lost on the giant branch and the helium abundance.} {We aim to determine the amount of mass loss that has occurred on the giant branches of the low metallicity globular clusters NGC 362 and NGC 2808. We also aim to see if the LPVs in NGC 2808 can tell us about helium abundance variations in this cluster.} We have used optical monitoring of NGC 362 and NGC 2808 to determine periods for the LPVs in these clusters. We have made linear pulsation models for the pulsating stars in these clusters taking into account variations in mass and helium abundance. Reliable periods have been determined for 11 LPVs in NGC 362 and 15 LPVs in NGC 2808. Comparison of the observed variables with models in the logP - K diagram shows that mass loss of ~0.15-0.2 Msun is required on the first giant branch in these clusters, in agreement with estimates from other methods. In NGC 2808, there is evidence that a high helium abundance of Y~0.4 is required to explain the periods of several of the LPVs. It would be interesting to determine periods for LPVs in other Galactic globular clusters where a helium abundance variation is suspected to see if the completely independent test for a high helium abundance provided by the LPVs can confirm the high helium abundance estimates.Comment: 13 pages, 12 figures, accepted for publication in Astronomy & Astrophysic

Emission from Very Small Grains and PAH Molecules in Monte Carlo Radiation Transfer Codes: Application to the Edge-On Disk of Gomez's Hamburger

We have modeled optical to far infrared images, photometry, and spectroscopy of the object known as Gomez's Hamburger. We reproduce the images and spectrum with an edge-on disk of mass 0.3M_sun and radius 1600AU, surrounding an A0 III star at a distance of 280pc. Our mass estimate is in excellent agreement with recent CO observations. However, our distance determination is more than an order of magnitude smaller than previous analyses which inaccurately interpreted the optical spectrum. To accurately model the infrared spectrum we have extended our Monte Carlo radiation transfer codes to include emission from polycyclic aromatic hydrocarbon (PAH) molecules and very small grains (VSG). We do this using pre-computed PAH/VSG emissivity files for a wide range of values of the mean intensity of the exciting radiation field. When Monte Carlo energy packets are absorbed by PAHs/VSGs we reprocess them to other wavelengths by sampling from the emissivity files, thus simulating the absorption and re-emission process without reproducing lengthy computations of statistical equilibrium, excitation and de-excitation in the complex many level molecules. Using emissivity lookup tables in our Monte Carlo codes gives the flexibility to use the latest grain physics calculations of PAH/VSG emissivity and opacity that are being continually updated in the light of higher resolution infrared spectra. We find our approach gives a good representation of the observed PAH spectrum from the disk of Gomez's Hamburger. Our models also indicate the PAHs/VSGs in the disk have a larger scaleheight than larger radiative equilibrium grains, providing evidence for dust coagulation and settling to the midplane.Comment: ApJ accepte

Unitary and non-unitary N=2N=2 minimal models

The unitary $N = 2$ superconformal minimal models have a long history in string theory and mathematical physics, while their non-unitary (and logarithmic) cousins have recently attracted interest from mathematicians. Here, we give an efficient and uniform analysis of all these models as an application of a type of Schur-Weyl duality, as it pertains to the well-known Kazama-Suzuki coset construction. The results include straightforward classifications of the irreducible modules, branching rules, (super)characters and (Grothendieck) fusion rules.Comment: 32 page

Industrial change in the north east region and the implications for further education departments of electrical and electronic engineering

The research study examines a number of recent developments in the electrical/electronics industry in terms of new skill requirements of the workforce and in-service training provision for both employees in industry and teaching staff in the providing colleges of further education in the North East Region. Many of the major changes which are taking place in the Region's industries are due mainly to the introduction or planned introduction of new microelectronic/computerised technology. Therefore, it is imperative that the relevant manpower planning which takes place in industry is supported by recent and relevant further education and training of its employees so that an adequate supply of sufficiently-skilled personnel is made available in order that companies can take advantage of high technology in their manufacturing processes. Data was collected, using structured interview questionnaires, from samples of managers employed in local industry and teachers in further education departments of electrical/electronic engineering. The results were later analysed using computer standard non-parametric statistics. Much of the data obtained from the survey shows that, although further training and retraining of staff was often necessary with the introduction of new computerised equipment into a company, very little reliance was actually placed on further education. Many of the in- service training needs were provided by equipment manufacturers, external agencies, and in-company programmes. Staff development in a number of the sampled colleges did no always place sufficient emphasis on regular retraining/updating of the teachers' subject area. Therefore, as a consequence, many FE teachers had not attended any recent subject-specific in-service training courses and often had to rely on text-books and other sources for information on new subject and curricular developments. Although most of the sampled managers were aware of the lack of close liaison between their industry and colleges of further education, many recognised the need to further their own involvement in local education and contribute to the content and organisation of college course curricula. In education, a disproportionately large percentage of those teachers interviewed had little or no contact with local firms, even at a superficial level of involvement e.g. an industrial visit, and many had never consulted with industry nor discussed any issues involving the courses offered by their department. The absence of any structured links between the two samples has inevitably helped to exacerbate many existing problems, and in a number of cases has, unfortunately, resulted in a complete lack of co-operation and co-ordination in terms of course planning and design

A Genetic Approach towards Modulating Pre-Harvest Pod Shatter in Brassica napus (Oilseed Rape)

Pre-harvest pod-shattering in Brassica napus (Oilseed Rape) is a serious agricultural and economic problem, with losses of 11-25% reported (Price et al., 1996) resulting in lost revenues of an estimated £66 million per annum for the U.K. alone. Reductions in this loss will provide benefits for both society and the environment. Lines from a doubled haploid B. napus mapping population, segregating for Pod Shatter Resistance (PSR), termed POSH 1-3 exhibited a range of shatter resistance phenotypes. A Random Impact Test (RIT) was used to measure the difference between levels of PSR in population lines. An assessment of pod physiology among these lines revealed that PSR is associated with increases in the amount of vasculature and changes in vascular orientation as reported in the resistant DK142 parent line (Child et al.2003). PSR was also found to result from differences in degradation of a key tissue required for valve separation in both B. napus and Arabidopsis. A genetic linkage map has been produced for the population and includes a number of candidate gene markers with established roles in fruit development in Arabidopsis. The linkage map was used as a basis to perform a QTL analysis where a number of loci associated with increases in PSR in B. napus have been identified. Genetic markers linked to these loci could provide a valuable tool for marker assisted selection (MAS) to improve pre-harvest pod shatter in B. napus. A novel assay has also been developed to investigate differences in PSR between Arabidopsis ecotypes. Shatter resistant ecotypes have been identified within the accessions tested. This could enable the differences between the model and crop species to be compared to assess if factors regulating such traits are conserved. This may also provide insight into new candidates to modulate preharvest pod shatter for agronomic improvement of Brassica species

Public health of schools : and the necessity for a state department of hygiene

The question of Hygiene, in relation to the spread of disease in schools, and the exclusion of children therefrom, also the subject of hygienic furnishings, such as school desks and seats, periodic disinfection of school buildings, along with all slates, books, maps, etc., as well as careful medical supervision and inspection, has, considering the great and vital importance of the subject, received far too little consideration from the present constituted authorities.Medical Science has made great strides respecting the knowledge of contagious and dangerous diseases, and their dissemination. Vital statistics clearly prove that this knowledge, and the measures recommended when practically applied, have had a most beneficial effect in preventing the spread of those diseases, and in checking mortality therefrom. Hillier (Public Health, March 1903, p. 301) calls attention to the probable extinction of Phthisis in a generation or more, and presents a diagram, in which the descending line for England shows a probability of such an extinction about 1945 to 50 and in Prussia 1925 to 30. The death rate from this disease has fallen in England from 24 per 10,000 of the living population in 1886 to 19 in 1900; in Prussia there has been a more rapid fall, viz., from 31 per 10,000 in 1886 to 21 in 1900. This decrease is largely attributable to the discovery of the tubercle bacillus and the measures taken to prevent the spread of the disease since its infectious character has become better known.Public schools bring children from all kinds of homes into close contact with each other; they therefore become the means of spreading infectious diseases, consequently the greater knowledge we now have of their specific cause and propagation, entail new and greater duties on School Authorities, and it necessitates their taking every care and precaution lest the school should become an agent for the spreading of disease. The individual rights of every child are such, that it ought not to be exposed in school to contagion, or infection, if by taking certain precautionary measures such exposure may be avoided

Visual analysis of social networks in space and time using smartphone logs

We designed and applied novel interactive visualisation to investigate how social networks - derived from smartphone logs - are embedded in time and space. Social networks were identified through direct calls between participants and calls to mutual contacts of participants. Direct contact between participants was sparse and deriving networks through mutual contacts helped enrich the social networks. Our resulting interactive visualisation tool offers four linked and co-ordinated views of spatial, temporal, individual and social network aspects of the data. Brushing and altering techniques help us investigate how these aspects relate. We also simultaneously display some demographic and attitudinal variables to help add context to the behaviours we observe. Using these techniques, we were able to characterise spatial and temporal aspects of participants' social networks and suggest explanations for some of them. We reflect on the extent to which such analysis helps us understand social communication behaviour

Interpreting Spectral Energy Distributions from Young Stellar Objects. I. A grid of 200,000 YSO model SEDs

We present a grid of radiation transfer models of axisymmetric young stellar objects (YSOs), covering a wide range of stellar masses (from 0.1Msun to 50Msun) and evolutionary stages (from the early envelope infall stage to the late disk-only stage). The grid consists of 20,000 YSO models, with spectral energy distributions (SEDs) and polarization spectra computed at ten viewing angles for each model, resulting in a total of 200,000 SEDs. [...]. These models are publicly available on a dedicated WWW server: http://www.astro.wisc.edu/protostars/ . In this paper we summarize the main features of our models, as well as the range of parameters explored. [...]. We examine the dependence of the spectral indices of the model SEDs on envelope accretion rate and disk mass. In addition, we show variations of spectral indices with stellar temperature, disk inner radius, and disk flaring power for a subset of disk-only models. We also examine how changing the wavelength range of data used to calculate spectral indices affects their values. We show sample color-color plots of the entire grid as well as simulated clusters at various distances with typical {\it Spitzer Space Telescope} sensitivities. We find that young embedded sources generally occupy a large region of color-color space due to inclination and stellar temperature effects. Disk sources occupy a smaller region of color-color space, but overlap substantially with the region occupied by embedded sources, especially in the near- and mid-IR. We identify regions in color-color space where our models indicate that only sources at a given evolutionary stage should lie. [...].Comment: 69 pages, 28 figures, Accepted for publication in ApJS. Preprint with full resolution figures available at http://www.astro.wisc.edu/protostars