Desingularization of vortices for the Euler equation

We study the existence of stationary classical solutions of the incompressible Euler equation in the plane that approximate singular stationnary solutions of this equation. The construction is performed by studying the asymptotics of equation -\eps^2 \Delta u^\eps=(u^\eps-q-\frac{\kappa}{2\pi} \log \frac{1}{\eps})_+^p with Dirichlet boundary conditions and $q$ a given function. We also study the desingularization of pairs of vortices by minimal energy nodal solutions and the desingularization of rotating vortices.Comment: 40 page

Exposure to bioaerosols at open dumpsites: A case study of bioaerosols exposure from activities at Olusosun open dumpsite, Lagos Nigeria

Activities associated with the open dumping of municipal solid waste has the potential for greater impact on the environment and public health compared to other forms of waste-to-land treatment of such wastes. However, there is a lack of quantitative data on the exposure to bioaerosols from open dumpsites, hence impeding the development of effective interventions that would reduce the risk of respiratory symptoms among scavengers and waste workers at such dumpsites. This study investigated exposure to bioaerosols at Olusosun open dumpsite, Lagos Nigeria using three methodologies; (1) Conducting a cross-sectional survey on the respiratory health of the population on the dumpsite, (2) Measuring bioaerosol concentrations in the ambient air by measuring four bioaerosols indicator groups (total bacteria, gram-negative bacteria, Aspergillus fumigatus and total fungi) using a Anderson six stage impactor sampler, (3) Measuring activity related exposures to bioaerosols using an SKC button personal sampler. After a cross sectional health survey of 149 participants (waste workers, scavengers, middlemen, food vendors and business owners), smokers reported higher symptoms of chronic cough (21%) and chronic phlegm (15%) compared to non-smokers (chronic cough 15%, chronic phlegm 13%). Years of work > 5 years showed no statistically significant association with chronic phlegm (OR 1.2, 95% CI 0.4–3.4; p > 0.05) or asthma (OR 1.8, 95% CI 0.6–5.2; p > 0.05). At the 95th percentile, the concentration of total bacteria was the highest (2189 CFU/m3), then gram negative bacteria (2188 CFU/m3), total fungi (843 CFU/m3) and Aspergillus fumigatus (441 CFU/m3) after ambient air sampling. A comparison of the data showed that the activity-based sampling (undertaken using body worn personal sampler) had higher bioaerosols concentrations (104 –106 CFU/m3), i.e. 2–3 logs higher than those recorded from static ambient air sampling. Bioaerosol exposure was highest during scavenging activities compared to waste sorting and site supervision. Particle size distributions showed that 41%, 46%, 76% and 63% of total bacteria, gram-negative bacteria, Aspergillus fumigatus and total fungi respectively were of respirable sizes and would therefore be capable of penetrating deep into the respiratory system, posing a greater human health risk. This study has shown that exposure to bioaerosols can be associated with activities undertaken at open dumpsites and may contribute to the high prevalence of the chronic respiratory symptoms among the workers in such environments

The Earth: Plasma Sources, Losses, and Transport Processes

This paper reviews the state of knowledge concerning the source of magnetospheric plasma at Earth. Source of plasma, its acceleration and transport throughout the system, its consequences on system dynamics, and its loss are all discussed. Both observational and modeling advances since the last time this subject was covered in detail (Hultqvist et al., Magnetospheric Plasma Sources and Losses, 1999) are addressed

Effects of ionizing radiation on the metabolism of DNA in cultivated mammalian cells

Contains fulltext : mmubn000001_238517888.pdf (publisher's version ) (Open Access)Promotor : C. Kuyper88 p

Sociale media in en rondom de vluchtelingen-noodopvang bij Nijmegen

Social media in and around the emergency shelter for refugees near Nijmegen, the Netherlands To cope with the limited capacity of the established reception centres during the refugee crisis of 2015, the Central Agency for the Reception of Asylum Seekers (COA) set up emergency reception centers for refugees such as Heumensoord nearby the Dutch city of Nijmegen. At the peak of the crisis, the Heumensoord centre hosted about 3,000 asylum seekers. COA’s organizational approach to manage reception centers was characterized by a top-down policy. At the same time, host communities of local residents around the emergency reception center developed horizontal relations within and beyond the walls of the center, actively using available social media platforms such as Facebook. These horizontal relations enabled the development of social relations, and facilitated the exchange of goods and services. This article demonstrates the different communication strategies used by the stakehol- ders at Heumensoord, and how the different worlds of asylum seekers and the receiving, host communities came together. It also presents bottom-up alternatives to the top-down crisis approaches by unravelling cooperation options and the use of social media platforms that can lead to a more resili- ent interaction between asylum seekers and local communities