340 research outputs found

    Impact of intermittent preventive anti-malarial treatment on the growth and nutritional status of preschool children in rural Senegal (west Africa).

    Get PDF
    Negative consequences of malaria might account for seasonality in nutritional status in children in the Sahel. We report the impact of a randomized, double-blind, placebo-controlled trial of seasonal intermittent preventive anti-malarial treatment on growth and nutritional status in 1,063 Senegalese preschool children. A combination of artesunate and sulfadoxine-pyrimethamine was given monthly from September to November. In the intervention arm, mean weight gain was significantly greater (122.9 +/- 340 versus 42.9 +/- 344 [SD] g/mo, P < 0.0001) and losses in triceps and subscapular skinfold measurements were less (-0.39 +/- 1.01 versus -0.66 +/- 1.01 mm/mo, and -0.15 +/- 0.64 versus -0.36 +/- 0.62 mm/mo, respectively, P < 0.0001 for both). There was no difference in height increments. The prevalence of wasting increased significantly in the control arm (4.6% before versus 9.5% after, P < 0.0001), but remained constant in intervention children: 5.6% versus 7.0% (P = 0.62). The prevention of malaria would improve child nutritional status in areas with seasonal transmission

    No long-term excess mortality after measles infection : a community study from Senegal

    Get PDF
    Because measles immunization has been found in all studies to reduce mortality with more than the share of deaths attributed to acute measles, the authors examined mortality after measles infection in a study in a rural area of Senegal that included 6924 unimmunized children, of whom 1118 developped measles. Age-adjusted post-measles mortality was similar to the mortality of unvaccinated, uninfected children (mortality ratio (MR) = 1.04, 95% confidence interval (CI) 0.80-1.35). When controlling for source of infection, mortality rate was significantly different for children who contracted measles from a person outside the home (index cases vs. unvaccinated, uninfected MR = 0.27 95% CI 0.009-0.85) and for children infected at home (secondary cases vs. unvaccinated, uninfected MR = 1.10 95% CI 0.80-1.51). Hence, secondary cases had markedly higher long-term mortality than did index cases (MR = 4.13 95% CI 1.26-13.58). These estimates were essentially unchanged when the effects of season, period, separation from mother, size of community, and size of compound were investigated using a multivariate Cox regression model. The authors conclude that measles infection was not associated with increased mortality after the acute phase of infection and that index cases had lower mortality than uninfected, unvaccinated children. The reduction in mortality after measles immunization can therefore not be explained by the prevention of post-measles mortality

    Comparative safety and immunogenicity of an acellular versus whole- cell pertussis component of Diphteria-Tetanus-Pertussis vaccines in senegalese infants

    Get PDF
    A diphtheria and tetanus toxoid two-component acellular pertussis vaccine (DTaP), consisting of 25 microg glutaraldehyde-detoxified pertussis toxin (PT) and 25 microg native filamentous hemagglutinin (FHA), was compared with diphtheria and tetanus toxoid whole-cell pertussis vaccine (DTwP) in a randomized, double-blind manner in 286 Senegalese infants inoculated at two, four, and six months of age. In infants receiving DTaP a significantly lower rate of local reactions, crying and fever was observed than in infants receiving DTwP. One month after the third dose, the geometric mean titres for FHA antibodies were higher in the DTaP group, whereas increases in PT antibody titres were higher in the DTwP group. More than 90% of the infants had a fourfold or more increase in antibodies to both PT and FHA with either vaccine. Diphtheria, tetanus, and polio antibody responses were also measured and found to be comparable between the two groups. The results of this pilot study support the implementation of a field trial to compare the protective efficacy of these vaccines against pertussis in the same setting. (Résumé d'auteur

    Child mortality following standard, medium or high titre measles immunization in West Africa

    Get PDF
    The World Health Organization (WHO) recommended the use of high titre measles vaccine in 1989. Subsequent long term follow-up of several trials yielded results suggesting higher mortality among children inoculated with medium and high titre vaccines compared to standard titre vaccines, although none of the individual trials found significant differences in mortality. Long term survival after standard, medium and high titre measles vaccines has been investigated in a combined analysis of all West African trials with mortality date. In trials from Guinea-Bissau, The Gambia and Senegal, children received medium or high titre vaccines from 4 months of age and were compared to control groups recruited at the same time later receiving standard titre vaccine from 9 months of age. All children were followed up to at least 3 years old. Combining trials of high titre vaccines showed higher mortality among the high titre group compared to the standard group : mortality ratio (MR) = 1.33 (95 % CI : 1.02-1.73). Mortality among recipients of medium titre vaccines was not different from that in the standard vaccine group, MR = 1.11 (95 % CI : 0.54-2,27). In a combined analysis by sex, the adjusted mortality ratios comparing high titre vaccine with standard vaccine were 1.86 ( 95 % CI : 1.28-2.70) for females and 0.91 ( 95 % CI : 0.61-1.35) for males. The trials were not designed to study long term mortality. Adjustments for several possible sources of bias did not alter the results. The combined analysis showed a decreased survival related to hith titre measles vaccine compared with standard titre vaccines, though solely among females. As a result of these studies from West Africa and a study from Haiti, WHO has recommended that high titre measles vaccine no longer be used. (Résumé d'auteur

    Impact of materials technology on the breeding blanket design – Recent progress and case studies in materials technology

    Get PDF
    A major part in the EUROfusion materials research program is dedicated to characterize and quantify nuclear fusion specific neutron damage in structural materials. While the majority of irradiation data gives a relatively clear view on the displacement damage, the effect of transmutation – i.e. especially hydrogen and helium production in steels – is not yet explored very well. However, few available results indicate that EUROFER-type steels will reach their operating limit as soon as the formation of helium bubbles reaches a critical amount or size. At that point, the material would fail due to embrittlement at the considered load. This paper presents a strategy for the mitigation of the before-mentioned problem using the following facts: • the neutron dose and related transmutation rate decreases quickly inside the first wall, that is, only a plasma-near area is extremely loaded • nanostructured oxide dispersion strengthened (ODS) steels may have an enormous trapping effect on helium and hydrogen, which would suppress the formation of large helium bubbles • compared to conventional steels, ODS steels show improved irradiation tensile ductility and creep strength In summary, producing the plasma facing, highly neutron and heat loaded part of blankets by an ODS steel, while using EUROFER97 for everything else, would allow a higher heat flux as well as a longer operating period. Consequently, we (1) developed and produced 14 % Cr ferritic ODS steel plates. (2) We fabricated a mockup with 5 cooling channels and a plated first wall of ODS steel, using the same production processes as for a real component. And finally, (3) we performed high heat flux tests in the HELOKA facility (Helium Loop Karlsruhe at KIT) applying short and up to 2 h long pulses, in which the operating temperature limit for EUROFER97 (i.e., 550 °C) was finally exceeded by 100 K. Thereafter, microstructure and defect analyses did not reveal defects or recognizable damage. Only a heat affected zone in the EUROFER/ODS steel interface could be detected. This demonstrates that the use of ODS steel could make a decisive difference in the future design and performance of breeding blankets

    ‘Mind the gap’: Responding to the indeterminable in migration

    Get PDF
    Prompted by the paper by Miriam Tedeschi, this commentary attempts to unsettle the dominant understanding of a relation in migration research that prioritises linkages between people, places and organisations while treating boundaries as limits to overcome. Building on geographers’ earlier engagements with Adorno, Levinas and extending this conversation to include Blanchot, the analysis attempts to move beyond the hold of mastery on a relation with alterity. The paper argues for an interruptive non-relation that resists the appropriation and affirms the dispersion of the self by the alterity it cannot internalise. It offers an alternative response to difference in migration that avoids bringing it to unifying continuity. Instead of treating interruptions in migration as gaps to be resolved through language, the paper considers the possibility of a neutral writing that reflects the powerlessness to say the unspeakable. In a movement of inscription and effacement, neutral writing invokes the unspeakable pain and affliction that exceeds the concepts to which it gives rise. The neuter answers for the non-subject of loss and trauma, the nothing often haunting international migrants

    Philosophy as political technē: The tradition of invention in Simondon’s political thought

    Get PDF
    Gilbert Simondon has recently attracted the interest of political philosophers and theorists, despite he is rather renowned as a philosopher of technics – as the author of Of the Mode of Existence of Technical Objects – who also elaborated a general theory of complex systems in Individuation in the Light of the Notions of Form and Information. A group of scholars has developed Gilles Deleuze’s early suggestion that Simondon’s social ontology might offer the basis for a re-theorisation of radical democracy. Others, following Herbert Marcuse, have instead focused on Simondon’s analysis of the relationship between technology and society. However, only a joint study of Simondon’s two major works can reveal their implicit political stakes. As I will argue, Simondon’s anti-Aristotelianism and his anti-Heideggerian understanding of the Greek origins of philosophy, allow us to conceive philosophical thought as a ‘tradition of invention’, that is, a pedagogical technē endowed with the political task of maintaining the openness of the social system and allowing normative invention to emerge from within

    Fabrication routes for advanced first wall design alternatives

    Get PDF
    In future nuclear fusion reactors, plasma facing components have to sustain specific neutron damage. While the majority of irradiation data provides a relatively clear picture of the displacement damage, the effect of helium transmutation is not yet explored in detail. Nevertheless, available results from simulation experiments indicate that 9%-chromium steels will reach their operating limit as soon as the growing helium bubbles extent a critical size. At that point, the material would most probably fail due to grain boundary embrittlement. In this contribution, we present a strategy for the mitigation of the before-mentioned problem using the following facts. (1) The neutron dose and related transmutation rate decreases quickly inside the first wall of the breeding blankets, that is, only a plasma-near area is extremely loaded. (2) Nanostructured oxide dispersion strengthened (ODS) steels may have an enormous trapping effect on helium, which would suppress the formation of large helium bubbles for a much longer period. (3) Compared to conventional steels, ODS steels also provide improved irradiation tensile ductility and creep strength. Therefore, a design, based on the fabrication of the plasma facing and highly neutron and heat loaded parts of blankets by an ODS steel, while using EUROFER97 for everything else, would extend the operating time and enable a higher heat flux. Consequently, we (i) developed and produced 14%Cr ferritic ODS steel plates and (ii) optimized and demonstrated a scalable industrial production route. (iii) We fabricated a mock-up with five cooling channels and a plated first wall of ODS steel, using the same production processes as for a real component. (iv) Finally, we performed high heat flux tests in the Helium Loop Karlsruhe, applying a few hundred short and a few 2 h long pulses, in which the operating temperature limit for EUROFER97 (i.e. 550 â—¦C) was finally exceeded by 100 K. (v) Thereafter, microstructure and defect analyses did not reveal critical defects or recognizable damage. Only a heat affected zone in the EUROFER/ODS steel interface could be detected. However, a solution to prohibit the formation of such heat affected zones is given. These research contributions demonstrate that the use of ODS steel is not only feasible and affordable but could make a decisive difference in the future design and performance of breeding blankets
    • …
    corecore