Field Emission and Radial Distribution Function Studies of Fractal-like Amorphous Carbon Nanotips

The short-range order of individual fractal-like amorphous carbon nanotips was investigated by means of energy-filtered electron diffraction in a transmission electron microscope (TEM). The nanostructures were grown in porous silicon substrates in situ within the TEM by the electron beam-induced deposition method. The structure factorS(k) and the reduced radial distribution functionG(r) were calculated. From these calculations a bond angle of 124° was obtained which suggests a distorted graphitic structure. Field emission was obtained from individual nanostructures using two micromanipulators with sub-nanometer positioning resolution. A theoretical three-stage model that accounts for the geometry of the nanostructures provides a value for the field enhancement factor close to the one obtained experimentally from the Fowler-Nordheim law

Discursos de viajeros europeos en la Argentina del siglo XIX: comunicación transatlántica, na(rra)ción y alteridad

Esta investigación tuvo sus antecedentes en dos proyectos anteriores, consolidando la línea: Comunicación e Historia. El análisis de los discursos de viajeros europeos que recorrieron estas latitudes durante el siglo XIX ha permitido profundizar ahora en la reflexión, en primer lugar, acerca del rol histórico, cultural y político de los viajeros en los procesos de construcción, lucha y reconfiguración de los proyectos político-culturales regional y nacional, al hilo de las comunicaciones transatlánticas establecidas a través de los “discursos de (en) viaje”, materializados en el objeto cultural “libro” (al decir de Raymond Williams, el primero de los medios modernos de comunicación). En segundo término, acerca de las narrativas de los viajeros europeos, a través de las publicaciones resultantes de esos viajes y sus traducciones, en tanto conjunto de procesos y de prácticas que suponen el traslado de un texto o conjunto de textos de la tradición cultural y el contexto en el que fueron producidos a otra. Finalmente, a partir de la puesta en relación entre discurso y alteridad, se analizan los modos en que tales viajeros establecieron su vinculación con la otredad y, por tanto, los efectos de sentido que se materializaron en la construcción discursiva de las figuras del “otro"

The FLUKA code: present applications and future developments

The main features of the FLUKA Monte Carlo code, which can deal with transport and interaction of electromagnetic and hadronic particles, are summarised. The physical models embedded in FLUKA are mentioned, as well as examples of benchmarking against experimental data. A short history of the code is provided and the following examples of applications are discussed in detail: prediction of calorimetric performances, atmospheric neutrino flux calculations, dosimetry in atmosphere and radiobiology applications, including hadrontherapy and space radiation protection. Finally a few lines are dedicated to the FLUKA server, from which the code can be downloaded.Comment: talk from the 2003 Computing in High Energy and Nuclear Physics (CHEP03), La Jolla, Ca, USA, March 2003, 8 pages, pd

The sympathomimetic agonist mirabegron did not lower JAK2-V617F allele burden, but restored nestin-positive cells and reduced reticulin fibrosis in patients with myeloproliferative neoplasms: results of phase II study SAKK 33/14

The β-3 sympathomimetic agonist BRL37344 restored nestin-positive cells within the stem cell niche, and thereby normalized blood counts and improved myelofibrosis in a mouse model of JAK2-V617F positive myeloproliferative neoplasms. We therefore tested the effectiveness of mirabegron, a β-3 sympathomimetic agonist, in a phase II trial including 39 JAK2-V617F positive MPN with a mutant allele burden >20%. Treatment consisted of mirabegron 50 mg daily for 24 weeks. The primary endpoint, reduction of the JAK2-V617F allele burden ≥50%, was not reached in any of the patients. One patient achieved a 25% reduction in JAK2-V617F allele burden by 24 weeks. A small subgroup of patients showed hematological improvement. As a side study, bone marrow biopsies were evaluated in 20 patients.We found an increase in the nestin+ cells from a median of 1.09 (interquartile range 0.38-3.27)/mm2 to 3.95 (interquartile range 1.98-8.79)/mm2 (p<0.0001) and a slight decrease of reticulin fibrosis from a median grade of 1.0 (interquartile range 0-3) to 0.5 (interquartile range 0-2) (p=0.01) between start and end of mirabegron treatment. Despite the fact that the primary endpoint of reducing JAK2-V617F allele burden was not reached, the observed effects on nestin+ MSCs and reticulin fibrosis is encouraging and shows that mirabegron can modify the microenvironment where the JAK2-mutant stem cells are maintained

Parenting Science Gang : radical co-creation of research projects led by parents of young children

Background Parents are increasingly searching online for information supported by research but can find it difficult to identify results relevant to their own experiences. More troublingly, a number of studies indicate that parenting information found online often can be misleading or wrong. The goal of the Parenting Science Gang (PSG) project was to use the power of the Internet to help parents ask questions they wanted to have answered by scientific research and to feel confident in assessing research evidence. Methods By using Facebook to recruit groups and facilitate interactions, PSG was able to engage fully the target public of parents of young children in the radical co-production of scientific studies, while not creating an undue burden on time or restricting participants due to disability, financial status or location. By giving parents true partnership and control of creation of projects, PSG ensured that the chosen questions were ones that were of most relevance and interest to them. Results This paper presents a summary of eight projects, with three in more detail, designed and implemented by PSG Facebook groups in collaboration with experts. Most projects had health related themes, often prompted by dissatisfaction with treatment of parents by health professionals or by feelings of being marginalised by pregnancy and motherhood, as well as by the lack of evidence for their questions and concerns. The PSG approach meant that these frustrations were channelled into actions. All eight of the PSG groups engaged in meaningful interactions with experts and co-produced studies with the groups defining the questions of interest. Conclusions This radically user-led design meant that the PSG staff and the collaborating experts had to live with a high degree of uncertainty. Nevertheless, PSG achieved its goal of academically productive, truly co-produced projects, but as important were the positive effects it had on many of the participants, both parents and experts. At the point of writing this paper, PSG projects have led to outputs including at least eight papers published, in press or in preparation, seven conference presentations, testimony to the Infant Feeding All-Party Parliamentary Group, and with more to come

The CERES/NA45 Radial Drift Time Projection Chamber

The design, calibration, and performance of the first radial drift Time Projection Chamber (TPC) are presented. The TPC was built and installed at the CERES/NA45 experiment at the CERN SPS in the late nineties, with the objective to improve the momentum resolution of the spectrometer. The upgraded experiment took data twice, in 1999 and in 2000. After a detailed study of residual distortions a spatial resolution of 340 um in the azimuthal and 640 um in the radial direction was achieved, corresponding to a momentum resolution of Dp/p = sqrt{(1% * p/GeV)^2 + (2%)^2}.Comment: 57 pages, 59 figure