African peasants on the move: turmoil between global dynamics, migration and food insecurity

This issue presents some of the publications resulting from the research project “African societies facing global dynamics: Turbulences between external intervention, migration, and food insecurity” [Dynamics]1. The underlying idea was to investigate contemporary global dynamics faced by African societies, how they interact with internal processes of change and these societies’ responses to these pressures. The contributions address the key issues raised in the Dynamics research project in different ways. They focus on an analysis of migration (internal as well as international), agricultural transformation and food (in)security in different societies and locations. They also explore the links between them and their interrelations with global dynamics. The work was based on case studies conducted in Guinea-Bissau, São Tomé and Príncipe (STP), Cape Verde and Senegal. An additional contribution from Mozambique was also included as it addressed the central issues of the project. Although this research project in itself can only address a few aspects of this complex set of interactions and highlight some of the key issues at play in specific case studies, the project is part of a long-term investigation about the dynamics of change in African agrarian societies which contemplates a wider range of issues.info:eu-repo/semantics/publishedVersio

mHealth initiatives in Portugal

Comunicação apresentada à CISTI'2017 - 12ª Conferência Ibérica de Sistemas e Tecnologias de Informação, realizada de 21-24 de junho de 2017, em Lisboa, Portugal.O paradigma da prestação de cuidados de saúde está lentamente a alinhar-se com as necessidades e hábitos do paciente moderno. A computação móvel pode ser uma solução para responder à crescente tendência e necessidade para a partilha e colaboração de cuidados de saúde, possibilitando o redesenhar de processos e dando origem a novos modelos de prestação de cuidados de saúde. Para conhecer a situação em Portugal das iniciativas de computação móvel neste setor (mobile health) e o seu estado de implementação, seguimos a metodologia de Levac et al. para realizar um levantamento, através de um inquérito e de um estudo exploratório, cujos resultados ficaram espelhados numa matriz desenvolvida para o efeito. O mapeamento do estudo visa sumariar o conhecimento adquirido, num formato acessível e resumido para que decisores políticos, profissionais e consumidores possam fazer uso efetivo das conclusões.The paradigm of health care delivery is slowly aligning with the needs and habits of modern patients. Mobile computing may be a solution to respond to the growing trend and need for health care sharing and collaboration, enabling the redesign of processes giving rise to new models of health care delivery. Seeking to determine the situation in Portugal regarding mobile computing initiatives in this domain (mobile health) and their status of implementation, and following the methodology of Levac et al., we conducted a survey and an exploratory study whose results were mirrored in a matrix developed for this purpose. The mapping of the study aims to summarize the acquired knowledge in an accessible and summarized format so that decision-makers, practitioners and consumers can make effective use of the findings.info:eu-repo/semantics/publishedVersio

Space Weathering Experiments on Spacecraft Materials

A project to investigate space environment effects on specific materials with interest to remote sensing was initiated in 2016. The goal of the project is to better characterize changes in the optical properties of polymers found in multi-layered spacecraft insulation (MLI) induced by electron bombardment. Previous analysis shows that chemical bonds break and potentially reform when exposed to high energy electrons like those seen in orbit. These chemical changes have been shown to alter a material's optical reflectance, among other material properties. This paper presents the initial experimental results of MLI materials exposed to various fluences of high energy electrons, designed to simulate a portion of the geosynchronous Earth orbit (GEO) space environment. It is shown that the spectral reflectance of some of the tested materials changes as a function of electron dose. These results provide an experimental benchmark for analysis of aging effects on satellite systems which can be used to improve remote sensing and space situational awareness. They also provide preliminary analysis on those materials that are most likely to comprise the high area-to-mass ratio (HAMR) population of space debris in the geosynchronous orbit environment. Finally, the results presented in this paper serve as a proof of concept for simulated environmental aging of spacecraft polymers that should lead to more experiments using a larger subset of spacecraft materials

Influence of oxygen ordering kinetics on Raman and optical response in YBa_2Cu_3O_{6.4}

Kinetics of the optical and Raman response in YBa_2Cu_3O_{6.4} were studied during room temperature annealing following heat treatment. The superconducting T_c, dc resistivity, and low-energy optical conductivity recover slowly, implying a long relaxation time for the carrier density. Short relaxation times are observed for the B_{1g} Raman scattering -- magnetic, continuum, and phonon -- and the charge transfer band. Monte Carlo simulations suggest that these two relaxation rates are related to two length scales corresponding to local oxygen ordering (fast) and long chain and twin formation (slow).Comment: REVTeX, 3 pages + 4 PostScript (compressed) figure

Plasmodynamic synthesis of product based on aluminum in the oxygen atmosphere of a reactor-chamber

In this paper, the possibility is shown to synthesize oxide aluminum using a high-speed electro discharge plasma jet. The synthesized products were characterized by X-Ray diffractometry and transmission electron microscopy

Specification of progression in glaucomatous visual field loss, applying locally condensed stimulus arrangements

The goal of this work was to (i) determine patterns of progression in glaucomatous visual field loss, (ii) compare the detection rate of progression between locally condensed stimulus arrangements and conventional 6° × 6° grid, and (iii) assess the individual frequency distribution of test locations exhibiting a local event (i.e., an abrupt local deterioration of differential luminance sensitivity (DLS) by more than -10dB between any two examinations). The visual function of 41 glaucomatous eyes of 41 patients (16 females, 25 males, 37 to 75 years old) was examined with automated static perimetry (Tuebingen Computer Campimeter or Octopus 101-Perimeter). Stimuli were added to locally enhance the spatial resolution in suspicious regions of the visual field. The minimum follow-up was four subsequent sessions with a minimum of 2-month (median 6-month) intervals between each session. Progression was identified using a modified pointwise linear regression (PLR) method and a modified Katz criterion. The presence of events was assessed in all progressive visual fields. Eleven eyes (27%) showed progression over the study period (median 2.5 years, range 1.3–8.6 years). Six (55%) of these had combined progression in depth and size and five eyes (45%) progressed in depth only. Progression in size conformed always to the nerve fiber course. Seven out of 11 (64%) of the progressive scotomata detected by spatially condensed grids would have been missed by the conventional 6° × 6° grid. At least one event occurred in 64% of all progressive eyes. Five of 11 (46%) progressive eyes showed a cluster of events. The most common pattern of progression in glaucomatous visual fields is combined progression in depth and size of an existing scotoma. Applying individually condensed test grids remarkably enhances the detection rate of glaucomatous visual field deterioration (at the expense of an increased examination time) compared to conventional stimulus arrangements

The impact of low erythrocyte density in human blood on the fitness and energetic reserves of the African malaria vector Anopheles gambiae

Background Anaemia is a common health problem in the developing world. This condition is characterized by a reduction in erythrocyte density, primarily from malnutrition and/or infectious diseases such as malaria. As red blood cells are the primary source of protein for haematophagous mosquitoes, any reduction could impede the ability of mosquito vectors to transmit malaria by influencing their fitness or that of the parasites they transmit. The aim of this study was to determine the impact of differences in the density of red blood cells in human blood on malaria vector (Anopheles gambiae sensu stricto) fitness. The hypotheses tested are that mosquito vector energetic reserves and fitness are negatively influenced by reductions in the red cell density of host human blood meals commensurate with those expected from severe anaemia. Methods Mosquitoes (An. gambiae s.s.) were offered blood meals of different packed cell volume(PCV) of human blood consistent with those arising from severe anaemia (15%) and normalPCV (50%). Associations between mosquito energetic reserves (lipid, glucose and glycogen)and fitness measures (reproduction and survival) and blood meal PCV were investigated. Results The amount of protein that malaria vectors acquired from blood feeding (indexed by haematin excretion) was significantly reduced at low blood PCV. However, mosquitoes feeding on blood of low PCV had the same oviposition rates as those feeding on blood of normal PCV, and showed an increase in egg production of around 15%. The long-term survival of An. gambiae s.s was reduced after feeding on low PCV blood, but PCV had no significant impact on the proportion of mosquitoes surviving through the minimal period required to develop and transmit malaria parasites (estimated as 14 days post-blood feeding). The impact of blood PCV on the energetic reserves of mosquitoes was relatively minor. Conclusions These results suggest that feeding on human hosts whose PCV has been depleted due to severe anaemia does not significantly reduce the fitness or transmission potential of malaria vectors, and indicates that mosquitoes may be able exploit resources for reproduction more efficiently from blood of low rather than normal PCV

Contribution of Alaskan glaciers to sea level rise derived from satellite imagery

International audienceOver the last 50 years, retreating glaciers and ice caps (GIC) contributed 0.5 mm/yr to sea level rises (SLR), and one third is believed to originate from ice masses bordering the Gulf of Alaska. However, these estimates of ice wastage in Alaska are based on methods that measure a limited number of glaciers and extrapolate the results to estimate ice loss for the many thousands of others. How these methods capture the complex pattern of decadal elevation changes at the scale of individual glacier and mountain range is unclear. Here, combining a comprehensive glacier inventory with elevation changes derived from sequential digital elevation models (DEMs), we found that, between 1962 and 2006, Alaskan glaciers lost 41.9 ± 8.6 km**3/yr water equivalent (w.e.) and contributed 0.12±0.02 mm/yr to SLR. Our ice loss is 34% lower than previous estimates. Reasons for our lower values include the higher spatial resolution of our glacier inventory and the reduction of ice thinning under debris and at the glacier margins which were not resolved in earlier work. Estimates of mass loss from GIC in other mountain regions could be subject to similar revisions