Simulations of the heating of the Galactic stellar disc

The velocity dispersion of nearby stars in the Galactic disc is well known to increase substantially with age; this is the so-called Age-Velocity relation, and is interpreted as a ``heating'' of the disc as a function of time. We have studied the heating of the disc due to giant molecular clouds and halo black holes, using simulations of the orbits of tracer stars embedded in a patch of the local Galactic disc. We examine a range of masses and number densities of the giant molecular cloud and halo black hole perturbers. The heating of the stellar disc in the simulations is fit with a simple power law, and we also fit this form to the best determinations of Age-Velocity relation as derived from stars in the solar neighbourhood for which ages can be reliably assigned. Observationally, the Age-Velocity relation remains poorly constrained and its determination is probably still dominated by systematic errors. Our simulations confirm the well known results that there are insufficient GMCs to heat the Galactic disc appropriately. A range of dark halo black hole scenarios are verified to heat the stellar disc in the manner expected from analytical studies, and they reproduce the observed ratio of the stellar velocity dispersions. Simulations featuring a combination of giant molecular clouds and halo black holes can explain the observed heating of the stellar disc, but since other perturbing mechanisms, such as spiral arms, are yet to be included,we regard this solution as ad hoc.Comment: 13 pages, 8 figures, accepted by MNRA

Genomic relatedness within five common Finnish Campylobacter jejuni pulsed-field gel electrophoresis genotypes studied by amplified fragment length polymorphism analysis, ribotyping and serotyping

Thirty-five Finnish Campylobacter jejuni strains with five SmaI/SacII pulsed-field gel electrophoresis (PFGE) genotypes selected among human and chicken isolates from 1997 and 1998 were used for comparison of their PFGE patterns, amplified fragment length polymorphism (AFLP) patterns, HaeIII ribotypes, and heat-stable (HS) serotypes. The discriminatory power of PFGE, AFLP, and ribotyping with HaeIII were shown to be at the same level for this selected set of strains, and these methods assigned the strains into the same groups. The PFGE and AFLP patterns within a genotype were highly similar, indicating genetic relatedness. The same HS serotypes were distributed among different genotypes, and different serotypes were identified within one genotype. HS serotype 12 was only associated with the combined genotype G1 (PFGE-AFLP-ribotype). These studies using polyphasic genotyping methods suggested that common Finnish C. jejuni genotypes form genetic lineages which colonize both humans and chickens

REMARK ON MEDIAN OSCILLATION DECOMPOSITION AND DYADIC POINT WISE DOMINATION

In this note, we extend Lerner's local median oscillation decomposition to arbitrary (possibly non-doubling) measures. In the light of the analogy between median and mean oscillation, our extension can be viewed as a median oscillation decomposition adapted to the dyadic (martingale) BMO. As an application of the decomposition, we give an alternative proof for the dyadic (martingale) John-Nirenberg inequality, and for Lacey's domination theorem, which states that each martingale transform is pointwise dominated by a positive dyadic operator of zero complexity. Furthermore, by using Lacey's recent technique, we give an alternative proof for Conde-Alonso and Rey's domination theorem, which states that each positive dyadic operator of arbitrary complexity is pointwise dominated by a positive dyadic operator of zero complexity.Peer reviewe

360º Communication and social advertising in «Pills for other persons’ pain»: case study

La campaña «Pastillas contra el dolor ajeno» está considerada una de las cinco mejores campañas españolas de los últimos cincuenta años, ello viene avalado, entre otras razones, por la obtención de prestigiosos galardones en festivales de publicidad, más de quince en un año. La campaña ha marcado un punto de inflexión en la publicidad social. Consideramos que la estrategia 360º empleada es la base del éxito de la campaña, más allá de la utilización de personajes públicos de gran notoriedad o de la propia organización a la que representa, Médicos sin Fronteras. Realizamos una exploración teórica y mediática de la campaña, con el objetivo de profundizar en la estrategia integral de “Pastillas…”, así como de comprobar el respaldo mediático obtenido e identificar los discursos emitidos por la prensa.The campaign «Pills for other persons’ pain» is considered one of best five Spanish campaigns of the past fifty years, a fact confirmed by the large number of prizes obtained in several advertising festivals, altogether more that fifteen per year. This campaign has marked a new starting point for social advertising. We consider that the 360 degree strategy is one of the bases for the success of the campaign, more than the use of public personalities of great visibility and personnel of the organizations represented; Doctors without Borders. We have carried out a theoretical and media exploration of the campaign, with the objective of getting a deeper look at the integrated strategy of the campaign “Pills...”, as well as exploring the media cover received by the campaign in order to identify the press discourses

Tiny tape recorder

The following report details the creation of my thesis film, Tiny Tape Recorder, from the genesis of the original idea through writing, pre-production, production and post-production. Tiny Tape Recorder is a short narrative fiction film about a man who discovers a tape recorder embedded in his head and the physical and emotional pain he must endure as the tape recorder malfunctions and replays his past. This science-fiction project attempts to balance the absurdist nature of this premise with a naturalistic treatment of the material in a desire to keep the focus of the film on the characters. This report seeks to serve as both a documentary representation of the process of creating Tiny Tape Recorder as well as an attempt to reveal and decode the intentions and motivations behind the use of that process.Radio-Television-Fil

Respiratory response to walking training in overweight men

The aim of the study was to follow up changes in physiological responses to incremental exercise after 4 weeks of moderate-intensity training in overweight men. Prior to the training, all subjects underwent 2 identical control tests (C1 and C2). Each test included three treadmill running exercises, starting at the treadmill speed of 4 km/h, and increased by 1 km/h at the end of each 4 min stage. The same protocol was repeated after 4 weeks of training (T1). The subjects’ body mass index was not changed after the training. Heart rate, oxygen uptake and blood pressure were significantly reduced in C2 as compared with C1 test. After 4 weeks of training the respiratory frequency (Rf), was lower than that in the C2 but a significant difference was noted only at the running speeds of 4 and 6kmhr-1 (P<0.04). Tidal volume (TV) increased after training in comparison with C2. A significant difference was found at the running speeds of 5 and 6 km/h (P<0.03 and P<0.04, respectively). Minute ventilation (VE) was not significantly different between the tests. The present study showed that in obese subjects 4 weeks of moderate uncontrolled walking training is advantageous for changes in the respiratory pattern. However, it is too short for the cardiovascular adaptation and body weight loss. Familiarization of the subjects with the experimental procedure diminished activation of the sympathetic nervous system and has a important role for the results interpretation

Hydrogen effects on mechanical performance of nodular cast iron

The ferritic nodular cast iron grade EN-GJS-400-15 intended for use as the load-bearing part of canisters for long-term disposal of spent nuclear fuel was studied in order to evaluate its sensitivity to the hydrogen-induced effects on mechanical performance. Hydrogen was introduced in the cast iron electrochemically from 1N H2SO4 solution under controlled cathodic potential. Hydrogen uptake in the course of tensile testing was measured using hydrogen thermal desorption method. It was found that plastic deformation of the specimens in the continuous hydrogen charging results in a remarkable increase of hydrogen uptake in the studied cast iron. Constant extension rate tests (CERT) and constant load tests (CLT) performed under continuous electrochemical hydrogen charging showed a remarkable reduction of elongation to fracture in CERT and time to fracture in CLT as compared to the corresponding values obtained by testing in air and water environments. The most important finding is that hydrogen increases dramatically the creep rate of the cast iron in CLT already at applied load of about 0.5 x yield stress. The tensile tests were followed with SEM observations of the hydrogen-induced cracking appearance on the tensile specimen outer and fracture surfaces. The obtained results are discussed in terms of the specific role of the graphite nodules as abundant sources of hydrogen and the nodule distribution in the cast iron matrix in the mechanisms of hydrogen-induced cracking