Portable Gamma Spectrometry Surveys of Sites in Portugal in Support of the VADOSE Project

The VADOSE project involves the use of multiple techniques to evaluate dose rate variability on different spatial scales. Several sites in central northern Portugal, mostly in the vicinity of Aveiro, have been investigated. As part of this investigation, portable gamma spectrometry techniques were used to map areas of approximately 100x100m around each sampling location. The SUERC portable gamma spectrometry system used consists of a 3x3” NaI(Tl) spectrometer with integral GPS receiver. Measurements were conducted with 10s integration time. Maps of the dose rate variability in each area were generated in the field, and used to confirm data quality and coverage and identify any remaining locations that would benefit from further measurements prior to leaving the site. Maps of natural radionuclide distribution (40K, 214Bi from the 238U decay series, and 208Tl from the 232Th decay series) were produced after the conclusion of measurements each day. Natural radionuclide specific activities (Bq kg-1 ) were estimated using a spectral windows method with stripping1 , using a working calibration assuming planar geometry and uniform activity distribution. As agreed prior to the start of work, a working calibration derived from field measurements and photon fluence calculations conducted for similar detectors in the 1990s2 has been used here, with calibration parameters given in the appendix. This report presents the dose rate maps produced during the field work, with a very brief description of the data. Summary statistics for each data set are presented in Table 1. All data have been mapped using a UTM (zone 29T) grid, with the approximate location of ground features added by hand as a guide. Further work could be conducted to produce more accurate overlays of ground features. At each site in-situ gamma spectrometry measurements were also conducted by ITN, and the data collected by the two detector systems and the soil samples will be compared at a later date

Cohort, Year and Age Effects in Canadian Wage Data

We use Canadian Surveys of Consumer Finances 1971-1993 to study the wages of full-time, full-year male and female workers. Median real wages of 24-year-old males without a university degree fell by 25% between 1978 and 1993. For 24-year-old females the decline was more modest and reversed in 1987, but real wages in 1993 were still significantly lower than they were in 1978. We investigate whether these changes are permanent "cohort" effects or more temporary "year" effects. Graphs of median wages against year and age indicate some periods where year effects are more prominent than cohort effects and other periods where the reverse is true. We then compare the results from two models, one assigning the trends to year effects, the other assigning them to cohort effects, and use these models to produce real wage projections.SCF; wages; cohort

Existential Psychotherapy with Adults in Assisted Living

This study explored aging individuals’ perceptions of existential poetry therapy. Six existential themes served as guides. They were: hope, gratitude, mindfulness, loss of mobility, forgiveness, and meaning in life. The data were analyzed via three sub-inquiries: (a) What thoughts and feelings do these six themes elicit; (b) What additional themes (existential or non) would the participants like to explore; and (c) What roadblocks hinder this population for accessing poetry therapy to its optimal extent. The research method involved two focus groups with a total of five participants, and data were analyzed using qualitative content analysis. The three most common themes elicited were orientation towards others, issues of life and death, and loss of mobility. Additional themes for future exploration, derived from inter-group data, were: faith, gratitude (irrespective of Gratitude theme), loss, nature, hope, and beauty

Synthesis of the Elements in Stars

Man inhabits a universe composed of a great variety of elements and their isotopes. In Table I,1 a count of the stable and radioactive elements and isotopes is listed. Ninety elements are found terrestrially and one more, technetium, is found in stars; only promethium has not been found in nature

Pneumococcal conjugate vaccine given shortly after birth stimulates effective antibody concentrations and primes immunological memory for sustained infant protection.

BACKGROUND: In developing countries, newborn immunization with pneumococcal conjugate vaccines (PCVs) could protect young infants who are at high risk of invasive pneumococcal disease (IPD) but might lead to immune tolerance. METHODS: In a randomized trial, young infants received 7-valent PCV at 6, 10, and 14 weeks (Expanded Programme on Immunization [EPI] group) or 0, 10, and 14 weeks (newborn group). Safety was monitored actively at 2-7 days and then passively. Serum samples obtained at birth and 6, 10, 14, 18, 36, and 37 weeks were assayed by enzyme-linked immunosorbent assay for anticapsular immunoglobulin G concentration and avidity. Infants were boosted with either 7-valent PCV or one-fifth dose of pneumococcal polysaccharide vaccine at 36 weeks. Nasopharyngeal swab samples were obtained at 18 and 36 weeks. RESULTS: Three-hundred neonates and young infants were enrolled. Newborn vaccination was well tolerated. Adverse events occurred equally in each group; none was related to immunization. One infant, immunized at birth, died of unrelated neonatal sepsis. At 18 weeks, protective concentrations (≥0.35 μg/mL) were achieved against each serotype by ≥87% of infants with no significant differences between groups. Geometric mean concentrations were higher in the EPI group for serotypes 4, 9V, 18C, and 19F at 18 weeks and for serotype 4 at 36 weeks. Avidity was greater in the newborn group for serotypes 4, 6B, and 19F at 18 weeks and for serotype 19F at 36 weeks. Booster responses and vaccine-type/nonvaccine-type carriage prevalence did not differ between groups. CONCLUSIONS: PCV was safe, immunogenic, and primed for memory when given at birth. There was no evidence of immune tolerance. Vaccination beginning at birth offers an alternative to control IPD in vulnerable young infants

Do Quasars Lens Quasars?

If the unexpectedly high frequency of quasar pairs with very different component redshifts is due to the lensing of a population of background quasars by the foreground quasar, typical lens masses must be \sim10^{12}M_{\sun} and the sum of all such quasar lenses would have to contain $\sim0.005$ times the closure density of the Universe. It then seems plausible that a very high fraction of all \sim10^{12} M_{\sun} gravitational lenses with redshifts $z\sim1$ contain quasars. Here I propose that these systems have evolved to form the present population of massive galaxies with M$_{\rm B}\leq-22$ and M >5\times10^{11} M_{\sun}.Comment: 6 pages, aas style, ams symbols, ApJL (accepted

Constraining the Accretion Rate Onto Sagittarius A* Using Linear Polarization

Two possible explanations for the low luminosity of the supermassive black hole at the center of our galaxy are (1) an accretion rate of order the canonical Bondi value (roughly 10^{-5} solar masses per year), but a very low radiative efficiency for the accreting gas or (2) an accretion rate much less than the Bondi rate. Both models can explain the broad-band spectrum of the Galactic Center. We show that they can be distinguished using the linear polarization of synchrotron radiation. Accretion at the Bondi rate predicts no linear polarization at any frequency due to Faraday depolarization. Low accretion rate models, on the other hand, have much lower gas densities and magnetic field strengths close to the black hole; polarization may therefore be observable at high frequencies. If confirmed, a recent detection of linear polarization from Sgr A$^*$ above 150 GHz argues for an accretion rate of order 10^{-8} solar masses per year, much less than the Bondi rate. This test can be applied to other low-luminosity galactic nuclei.Comment: final version accepted by ApJ; references added, somewhat shortene

Using climate change models to inform the recovery of the western ground parrot Pezoporus flaviventris

Translocation of species to areas of former habitat after threats have been mitigated is a common conservation action. However, the long-term success of reintroduction relies on identification of currently available habitat and areas that will remain, or become, habitat in the future. Commonly, a short-term view is taken, focusing on obvious and assumed threats such as predators and habitat degradation. However, in areas subject to significant climate change, challenges include correctly identifying variables that define habitat, and considering probable changes over time. This poses challenges with species such as the western ground parrot Pezoporus flaviventris, which was once relatively common in near-coastal south-western Australia, an area subject to major climate change. This species has declined to one small population, estimated to comprise \u3c 150 individuals. Reasons for the decline include altered fire regimes, introduced predators and habitat clearing. The establishment of new populations is a high priority, but the extent to which a rapidly changing climate has affected, and will continue to affect, this species remains largely conjecture, and understanding probable climate change impacts is essential to the prioritization of potential reintroduction sites. We developed high-resolution species distribution models and used these to investigate climate change impacts on current and historical distributions, and identify locations that will remain, or become, bioclimatically suitable habitat in the future. This information has been given to an expert panel to identify and prioritize areas suitable for site-specific management and/or translocation

Visco-plastic models of isothermal lava domes

Author Posting. © Cambridge University Press, 2000. This article is posted here by permission of Cambridge University Press for personal use, not for redistribution. The definitive version was published in Journal of Fluid Mechanics 403 (2000): 37-65, doi:10.1017/S0022112099006916.The dynamics of expanding domes of isothermal lava are studied by treating the lava as a viscoplastic material with the Herschel–Bulkley constitutive law. Thin-layer theory is developed for radially symmetric extrusions onto horizontal plates. This provides an evolution equation for the thickness of the fluid that can be used to model expanding isothermal lava domes. Numerical and analytical solutions are derived that explore the effects of yield stress, shear thinning and basal sliding on the dome evolution. The results are briefly compared with an experimental study. It is found that it is difficult to unravel the combined effects of shear thinning and yield stress; this may prove important to studies that attempt to infer yield stress from morphology of flowing lava.The financial support of an EPSRC Advanced Fellowship is gratefully acknowledged by R.V. C. N. J. B. was partially supported by the NSF Grant OCE-9616017 and an EPSRC Visiting Fellowship Grant GR/M50409