Digital Literacy Circulation: Adolescents and Flows of Knowledge about New Media

The aim of this paper is to discuss the output of an empirical research on digital skills in order to develop a typology of skills circulation among young digital users. Relying on research on digital literacy in media studies and on users in STS, in this article we start criticizing the concepts of \u201cdigital divide\u201d, \u201cdigital inequalities\u201d and \u201cdigital competencies\u201d. Then, we present the principal results of a research study involving 50 adolescents in Italy about how they acquired their competences in the use of digital media. This gave us the opportunity to focus on the digital skills of young people and the development of their abilities in using digital media. The research outlines the patterns of circulation in digital competences among young people in relation to family, school and peer group, defining four kinds of \u201cflows\u201d: parental flow (involving fathers and mothers), peer flow (connected to friends and people of the same age), educational flow (referring to formal education) and technological flow (involving technological devices, such as computers, laptops, smartphones, tablets, etc.). The aim is to understand the interactions between digital skills and the social, institutional and technological conditions that influence the youth\u2019s digital literacy for the everyday use of digital media

No. 53: Migration-Induced HIV and AIDS in Rural Mozambique and Swaziland

South Africa’s gold mining workforce has the highest prevalence rates of tuberculosis and HIV infection of any industrial sector in the country. The contract migrant labour system, which has long outlived apartheid, is responsible for this unacceptable situation. The spread of HIV to rural communities in Southern Africa is not well understood. The accepted wisdom is that migrants leave for the mines, engage in high-risk behaviour, contract the virus and return to infect their rural partners. This model fails to deal with the phenomenon of rural-rural transmission and cases of HIV discordance (when the female migrant is infected and the male migrant not). Nor does it reveal whether all rural partners are equally at risk of infection. This study examines the vulnerability of rural partners in southern Mozambique and southern Swaziland, which are two major source areas for migrant miners. It presents the results of surveys with miners and partners in these two sending-areas and affords the opportunity to compare two different mine-sending areas. The two areas are not only geographically and culturally different, they have had contrasting experiences with the mine labour system over the last two decades. The spread of HIV in Southern Africa in the 1990s coincided with major downsizing and retrenchment in the gold mining industry which impacted differently on Mozambique and Swaziland. Swaziland has been in decline as a source of mine migrants while Mozambique remained a relatively stable source of mine migrants. The study therefore aims not only to shed light on vulnerability in mine sending areas, but also to draw out any contrasts that might exist between two mine-sending areas that were inserted into the mine migrant labour system in different ways during the expansion of the HIV epidemic. The surveys collected data on (a) the age and socio-economic profiles of miners and partners; (b) migration behaviour (particularly how often migrants returned home and for how long; (c) the knowledge of and attitudes towards HIV and AIDS among both groups; (d) sexual behaviour and protection measures against infection and (e) perceptions of vulnerability and risk. Knowledge of HIV and AIDS is reasonably good amongst residents of both areas. Many of the common myths about HIV are held by only a tiny minority. Most seem to know what puts them at risk, know that the disease is fatal, know that ART is not a remedy and do not appear to have a great deal of faith in traditional healers. One exception is the rather large proportion of Mozambican miners who believe the disease is curable. If anything, rural partners are better informed than miners. In both Mozambique and Swaziland, the main source of knowledge is not workplace programmes on the mines or in the community nor peer education nor the medical community, but radio. Perception of personal vulnerability is also high. Yet, both miners and female rural partners of migrants are at risk through their behaviour. The reasons, though, are quite different. In the case of miners, high risk behaviour is a consequence of the migrant labour system which sees them spend the greater part of the working year away from home in an all-male environment of macho masculinity with easy access to transactional sex. These miners are aware that condom use would reduce their risk of contracting HIV but actual use is sporadic to non-existent. Condom use is rejected on grounds of personal preference or attributed to forgetfulness. Miners at home are even less likely to use condoms than when they are on the mine. The risks of contracting HIV are certainly lower (since commercial sex workers on the mines exhibit much higher HIV prevalence than rural partners). But their unwillingness to use protection puts their rural partners at greatly increased risk. Rural partners perceive themselves to be at high risk precisely because their partners do not wish to use protection. Miners clearly expect their partners to be faithful and do not see themselves at risk when they go home. Any woman who insists on condom use is seen to be implicitly questioning her partner’s fidelity. Women’s lack of use of condoms has virtually nothing to do with personal preference. Partners of migrant miners wish to use condoms to protect themselves. Their inability to do so with the frequency and consistency that they would like is related to the demands of men for unprotected sex. Ultimately, therefore, it is the gendered relations of inequality that make it very difficult for women to protect themselves against the high-risk environment of the mines. One of the basic hypotheses of this study was that different migration patterns affect the risk profile of miners and rural partners. Mozambican miners return home only once a year for annual leave. Swazi miners, in contrast, visit home at least once a month or every month or two. Yet, both engage in equally risky behaviour while they are away at work. This places Swazi women at greater personal risk than their Mozambican counterparts. On the other hand, the comparison between Mozambican and Swazi women suggests that the Mozambican partners may be more prone to forming other relationships outside their primary relationship with their usually absent partner for a host of different reasons including emotional and financial support. In some cases, increased poverty from a reduced flow of remittances may force some rural women to seek support through other relationships

Turbulent flow over a house in a simulated hurricane boundary layer

Every year hurricanes and other extreme wind storms cause billions of dollars in damage worldwide. For residential construction, such failures are usually associated with roofs, which see the largest aerodynamic loading. However, determining aerodynamic loads on different portions of North American houses is complicated by the lack of clear load paths and non-linear load sharing in wood frame roofs. This problem of fluid-structure interaction requires both wind tunnel testing and full-scale structural testing. A series of wind tunnel tests have been performed on a house in a simulated atmospheric boundary layer (ABL), with the resulting wind-induced pressures applied to the full-scale structure. The ABL was simulated for flow over open country terrain where both velocity and turbulence intensity profiles, as well as spectra, were matched with available full scale measurements for this type of terrain. The first set of measurements was 600 simultaneous surface pressure measurements over the entire house. A key feature of the surface pressure field is the occurrence of large, highly non-Gaussian, peak uplift (suctions) on the roof. In order to better understand which flow features cause this, PIV experiments were performed on the wind tunnel model. These experiments were performed with time-resolved PIV (sampling rate of 500 Hz) for a duration of 30 seconds. From the fluid dynamics videos (low- and high-resolution) generated from the PIV data it is clear that strong circulation is generated at the windward edge of the roof. These vortices are eventually shed and convect along the roof. It is the presence of this concentrated circulation which is responsible for the peak loading observed.Comment: Abstract for Gallery of Fluid Motion 2009 in Minneapoli

Strategic Payments in Financial Networks

In their seminal work on systemic risk in financial markets, Eisenberg and Noe [Larry Eisenberg and Thomas Noe, 2001] proposed and studied a model with n firms embedded into a network of debt relations. We analyze this model from a game-theoretic point of view. Every firm is a rational agent in a directed graph that has an incentive to allocate payments in order to clear as much of its debt as possible. Each edge is weighted and describes a liability between the firms. We consider several variants of the game that differ in the permissible payment strategies. We study the existence and computational complexity of pure Nash and strong equilibria, and we provide bounds on the (strong) prices of anarchy and stability for a natural notion of social welfare. Our results highlight the power of financial regulation - if payments of insolvent firms can be centrally assigned, a socially optimal strong equilibrium can be found in polynomial time. In contrast, worst-case strong equilibria can be a factor of ?(n) away from optimal, and, in general, computing a best response is an NP-hard problem. For less permissible sets of strategies, we show that pure equilibria might not exist, and deciding their existence as well as computing them if they exist constitute NP-hard problems