Development and evaluation of probability density functions for a set of human exposure factors

The purpose of this report is to describe efforts carried out during 1998 and 1999 at the Lawrence Berkeley National Laboratory to assist the U.S. EPA in developing and ranking the robustness of a set of default probability distributions for exposure assessment factors. Among the current needs of the exposure-assessment community is the need to provide data for linking exposure, dose, and health information in ways that improve environmental surveillance, improve predictive models, and enhance risk assessment and risk management (NAS, 1994). The U.S. Environmental Protection Agency (EPA) Office of Emergency and Remedial Response (OERR) plays a lead role in developing national guidance and planning future activities that support the EPA Superfund Program. OERR is in the process of updating its 1989 Risk Assessment Guidance for Superfund (RAGS) as part of the EPA Superfund reform activities. Volume III of RAGS, when completed in 1999 will provide guidance for conducting probabilistic risk assessments. This revised document will contain technical information including probability density functions (PDFs) and methods used to develop and evaluate these PDFs. The PDFs provided in this EPA document are limited to those relating to exposure factors

Baboon-to-human liver transplantation

Our ability to control both the cellular and humoral components of xenograft rejection in laboratory experiments, together with an organ shortage that has placed limits on clinical transplantation services, prompted us to undertake a liver transplantation from a baboon to a 35-year-old man with B virus-associated chronic active hepatitis and human immunodeficiency virus infection. Liver replacement was performed according to conventional surgical techniques. Immunosuppression was with the FK 506-prednisone-prostaglandin regimen used routinely for hepatic allotransplantation, to which a daily non-myelotoxic dose of cyclophosphamide was added. During 70 days of survival, there was little evidence of hepatic rejection by biochemical monitoring or histopathological examination. Products of hepatic synthesis, including clotting factors, became those of the baboon liver with no obvious adverse effects. Death followed a cerebral and subarachnoid haemorrhage that was caused by an angioinvasive aspergillus infection. However, the underlying cause of death was widespread biliary sludge that formed in the biliary tree despite a seemingly satisfactory choledochojejunostomy. During life and in necropsy samples, there was evidence of the chimerism that we believe is integral to the acceptance of both xenografts and allografts. Our experience has shown the feasibility of controlling the rejection of the baboon liver xenograft in a human recipient. The biliary stasis that was the beginning of lethal infectious complications may be correctable by modifications of surgical technique. In further trials, the error of over-immunosuppression should be avoidable. © 1993

Corrections to flat-space particle dynamics arising from space granularity

The construction of effective Hamiltonians describing corrections to flat space particle dynamics arising from the granularity of space at very short distances is discussed in the framework of an heuristic approach to the semiclassical limit of loop quantum gravity. After some general motivation of the subject, a brief non-specialist introduction to the basic tools employed in the loop approach is presented. The heuristical semiclassical limit is subsequently defined and the application to the case of photons and spin 1/2 fermions is described. The resulting modified Maxwell and Dirac Hamiltonians, leading in particular to Planck scale corrections in the energy-momentum relations, are presented. Alternative interpretations of the results and their limitations, together with other approaches are briefly discussed along the text. Three topics related to the above methods are reviewed: (1) The determination of bounds to the Lorentz violating parameters in the fermionic sector, obtained from clock comparison experiments.(2) The calculation of radiative corrections in preferred frames associated to space granularity in the framework of a Yukawa model for the interactions and (3) The calculation of synchrotron radiation in the framework of the Myers-Pospelov effective theories describing Lorentz invariance violations, as well as a generalized approach to radiation in Planck scale modified electrodynamics. The above exploratory results show that quantum gravity phenomenology provides observational guidance in the construction of quantum gravity theories and opens up the possibility of probing Planck scale physics.Comment: 49 pages, 6 figures and 4 tables. Extended version of the talk given at the 339-th WE-Heraeus-Seminar: Special Relativity, will it survive the next 100 years?, Potsdam, february 200

Multi-lingual and multi-cultural information literacy; perspectives, models and good practice

Purpose This paper reviews current approaches to, and good practice, in information literacy development in multi-lingual and multi-cultural settings, with particular emphasis on provision for international students. Design/methodology/approach A selective and critical review of published literature is extended by evaluation of examples of multi-lingual information literacy tutorials and MOOCs. Findings Multi-lingual and multi-cultural information literacy are umbrella terms covering a variety of situations and issues. This provision is of increasing importance in an increasingly mobile and multi-cultural world. This article evaluates current approaches and good practice, focusing on issues of culture vis a vis language, the balance between individual and group needs, specific and generic information literacy instruction, and models for information literacy, pedagogy and culture. Recommendations for good practice and for further research are given, Originality/value This is one of very few articles critically reviewing how information literacy development is affected by linguistic and cultural factors

Probing Lorentz and CPT violation with space-based experiments

Space-based experiments offer sensitivity to numerous unmeasured effects involving Lorentz and CPT violation. We provide a classification of clock sensitivities and present explicit expressions for time variations arising in such experiments from nonzero coefficients in the Lorentz- and CPT-violating Standard-Model Extension.Comment: 15 page

Limb Spicules from the Ground and from Space

We amassed statistics for quiet-sun chromosphere spicules at the limb using ground-based observations from the Swedish 1-m Solar Telescope on La Palma and simultaneously from NASA's Transition Region and Coronal Explorer (TRACE) spacecraft. The observations were obtained in July 2006. With the 0.2 arcsecond resolution obtained after maximizing the ground-based resolution with the Multi-Object Multi-Frame Blind Deconvolution (MOMFBD) program, we obtained specific statistics for sizes and motions of over two dozen individual spicules, based on movies compiled at 50-second cadence for the series of five wavelengths observed in a very narrow band at H-alpha, on-band and in the red and blue wings at 0.035 nm and 0.070 nm (10 s at each wavelength) using the SOUP filter, and had simultaneous observations in the 160 nm EUV continuum from TRACE. The MOMFBD restoration also automatically aligned the images, facilitating the making of Dopplergrams at each off-band pair. We studied 40 H-alpha spicules, and 14 EUV spicules that overlapped H-alpha spicules; we found that their dynamical and morphological properties fit into the framework of several previous studies. From a preliminary comparison with spicule theories, our observations are consistent with a reconnection mechanism for spicule generation, and with UV spicules being a sheath region surrounding the H-alpha spicules

De geprotocolleerde Interapy-behandeling van depressie via het internet; resultaten van een gerandomiseerde trial

Psychologische behandelingen via internet bieden een nieuwe mogelijkheid voor de geestelijke gezondheidszorg. In samenwerking met de Stichting Mentrum ggz Amsterdam heeft Interapy een behandeling voor depressie via internet opgezet. De behandeling bestaat uit cognitief-gedragstherapeutische interventies, zoals psycho-educatie, schrijfopdrachten, registratie, activatie, het uitdagen van negatieve automatische gedachten en terugvalpreventie. Dit artikel beschrijft de procedure, de behandeling en de resultaten van een vergelijkende studie onder cliënten die matig tot ernstig depressief waren. De cliënten die direct actief werden behandeld (N = 32) verbeterden significant meer dan de cliënten in de psycho-educatieconditie (N = 14). Deze tweede groep kreeg de actieve behandeling ongeveer twaalf weken later. De effecten waren groot. In de actief behandelde groep liet 75 procent van de cliënten klinisch relevante verbetering zien, in de psycho-educatieconditie was dat percentage 36. Uit de follow-up na zes weken bleek dat de verbeteringen standhielden

Vacancy supersaturations produced by high-energy ion implantation

A new technique for detecting the vacancy clusters produced by high-energy ion implantation into silicon is proposed and tested. This technique takes advantage of the fact that metal impurities, such as Au, are gettered near one-half of the projected range ({1/2}R{sub p}) of MeV implants. The vacancy clustered region produced by a 2 MeV Si{sup +} implant into silicon has been labeled with Au diffused in from the front surface. The trapped Au was detected by Rutherford backscattering spectrometry (RBS) to profile the vacancy clusters. Cross section transmission electron microscopy (XTEM) analysis shows that the Au in the region of vacancy clusters is in the form of precipitates. By annealing MeV implanted samples prior to introduction of the Au, changes in the defect concentration within the vacancy clustered region were monitored as a function of annealing conditions

Boron-enhanced diffusion of boron from ultralow-energy boron implantation

The authors have investigated the diffusion enhancement mechanism of BED (boron enhanced diffusion), wherein the boron diffusivity is enhanced three to four times over the equilibrium diffusivity at 1,050 C in the proximity of a silicon layer containing a high boron concentration. It is shown that BED is associated with the formation of a fine-grain polycrystalline silicon boride phase within an initially amorphous Si layer having a high B concentration. For 0.5 keV B{sup +}, the threshold implantation dose which leads to BED lies between 3 {times} 10{sup 14} and of 1 {times} 10{sup 15}/cm{sup {minus}2}. Formation of the shallowest possible junctions by 0.5 keV B{sup +} requires that the implant dose be kept lower than this threshold