| 331. |
- Somarriba Jarquín, Oscar
(författare)
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On Constrained Power Control for Spatial TDMA in Multi-hop Ad Hoc Radio Networks
- 2002
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Konferensbidrag (refereegranskat)abstract
- A very attractive alternative for communications in areas in which there is little or no telecommunications infrastructure is to use Multi-hop packet radio networks (MPRNet:s). One major design issue in MPRNet:s is the formulation of Medium Access Control (MAC) protocols. Spatial TDMA (S-TDMA) is a `conflict-free' multiple access for MPRNet:s, which ensures that a packet transmission, whenever made, is successful . Since the transmitter power is at a premium in wireless systems, it is important to utilize it in an efficient way. High S-TDMA system capacities can be achieved by incorporating traffic load information into the MAC protocol design. However, the impact of power control in traffic-sensitive Spatial TDMA schemes control has not received enough attention in the literature. A suitable power control scheme has been chosen and applied to S-TDMA. The resulting delay performance, as determined via network simulations, is presented in this paper. As would be expected the introduction of power control markedly improved the delay performance of Traffic Sensitive S-TDMA.
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| 332. |
- Zapata, Patrik, 1967, et al.
(författare)
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Urban policy mobilities and local translations of compliance and contestation within development-aid regeneration programs. The case of the Acahualinca Integrated Development Programme in Managua, Nicaragua.
- 2013
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Ingår i: Paper presented at the International RC21 Conference 2013 Session: Making up cities: urban policy mobilities, assemblages and urban politics in a global age. 29-31 August 2013..
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Konferensbidrag (refereegranskat)abstract
- The study is based on the case of La Chureca, the rubbish dump and slum of Managua, Nicaragua, and its regeneration programme, the Barrio Acahualinca Integrated Development Programme, funded by a development aid agency and implemented by the Managua municipality. The programme includes since 2009 until 2013, the construction of new housing for the slum dwellers, the construction of a new sanitary landfill and a recycling station where most of the waste pickers will work formally employed by the municipality. In previous papers we have examined the formulation and implementation of the Programme in terms of the construction of an action net in which, by a chain of translations, the programme was transformed from an aid programme managed by international aid organisations into the urban policies carried out by the City of Managua. Despite the initial compliance with the programme; little by little, local actors (mostly community leaders, residents, trade unions and waste collectors) enacted a myriad of small acts of defiance and resistance, changes and transformations (translations) of the programme implementation. In the paper we unfold how waste collectors trade union, slum community leaders, community grass-root associations and local residents under the pressure of securing both jobs and houses (either in symbiosis with local mass media, by using physical force, political negotiations, circumvention) attempted to twist the programme to fit local needs of those groups that felt that were not fairly benefit by the Program, such as older workers, women or non-residents in La Chureca. The paper finally discusses its theoretical contribution to the notion of urban policy mobilities from the city management literature.
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| 333. |
- Gonda, Noemi
(författare)
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Re-politicizing the gender and climate change debate: The potential of feminist political ecology to engage with power in action in adaptation policies and projects in Nicaragua
- 2019
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Ingår i: Geoforum. - : Elsevier BV. - 0016-7185. ; 106, s. 87-96
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Tidskriftsartikel (refereegranskat)abstract
- The time of gender-blind climate change policies and projects has passed. However, while research is increasingly moving away from understanding the relationship between gender and climate change in a linear, technocratic, and instrumental way, gender and climate change policy-makers and project practitioners are having difficulties operationalizing this progress. In the meantime, as climate change effects are increasingly felt worldwide, and because the policy context after the Paris Agreement (2015) is bringing new challenges for gender and equity concerns, (re-)politicizing the climate justice debate in a policy and project-relevant way is more crucial than ever. My aim in this article is to contribute to this endeavor by exploring how a feminist political ecology framework applied to a specific case study in Nicaragua one of the countries most affected by climate change in the world can generate new policy and project-relevant lessons and insights from the ground that can in turn strengthen the conceptual debate on gender and climate change adaptation. Based on ethnographic fieldwork carried out in 2013 and 2014, as well as eight years of professional experience as a development worker in Nicaragua, I discuss the workings of power in the feminist political ecology of climate change adaptation; in so doing I raise new questions that will, I hope, lead policy-makers and project practitioners to explore how adaptation processes could open up the conceptual possibility for emancipation, transformation, and new ways of living life in common.
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| 334. |
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| 335. |
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| 336. |
- Pena, R., et al.
(författare)
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Evaluating a peer intervention strategy for the promotion of sexual health-related knowledge and skills in 10- to 14-year-old girls. Findings from the "Entre Amigas" project in Nicaragua
- 2008
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Ingår i: American Journal of Health Promotion. - 0890-1171 .- 2168-6602. ; 22:4, s. 275-281
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Tidskriftsartikel (refereegranskat)abstract
- Purpose. Report effects on knowledge of sexual health and gender from an intervention using peer methodology in Nicaragua. Design. A prepost nonequivalent control group design. Setting. Ciudad Sandino, Managua, Nicaragua. Subjects. A total of 599 girls were surveyed, 60% nonintervened and 40% intervened. Intervention. Peer methodology consisted of (1) meetings in which. girls talked and worked with other girls, (2) mothers taking an active role in the peer groups, and/or (3) girls watching the soap opera "Sexto Sentido." Measures. Indices measuring changes in sexual knowledge and gender vision. Results. Girls participating in the peer groups were twice us likely to have satisfactory sexual health-related self-esteem as those who did not participate. Eleven percent of the girls achieved satisfactory self-esteem as a result of the (peer groups X mothers) interaction and 15% due to the (peer groups X mothers X "Sexto Sentido') interaction. Girls participating in the peer groups were three times as likely to have satisfactory gender visions; if exposed to all three components, they were almost four times as likely to develop satisfactory gender visions. Conclusions. Peer methodology, participation of a female family member, and an educational soap opera seem beneficial in promoting sexual health-related knowledge and gender vision in young girls.
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| 337. |
- Vanegas, Hernan, et al.
(författare)
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Zika RNA and Flavivirus-Like Antigens in the Sperm Cells of Symptomatic and Asymptomatic Subjects
- 2021
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Ingår i: Viruses. - : MDPI. - 1999-4915. ; 13:2
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Tidskriftsartikel (refereegranskat)abstract
- Zika virus (ZIKV) RNA has been found to remain in human semen for up to one year after infection, but the presence of Flavivirus antigens in the different compartments of semen has been largely unexplored. Following the introduction of ZIKV in Nicaragua (2016), a prospective study of patients with clinical symptoms consistent with ZIKV was conducted in Leon to investigate virus shedding in different fluids. ZIKV infection was confirmed in 16 male subjects (>= 18 years of age) by RT-qPCR in either blood, saliva or urine. Of these, three provided semen samples at 7, 14, 21, 28, 60 and 180 days postsymptom onset (DPSO) for Flavivirus antigens and RNA studies. These cases were compared with 19 asymptomatic controls. Flavivirus antigens were examined by immunofluorescence (IF) using the 4G2 Mabs, and confocal microscopy was used to explore fluorescence patterns. The three (100%) symptomatic subjects and 3 (16%) of the 19 asymptomatic subjects had Flavivirus antigens and viral RNA in the spermatozoa fraction. The percentage of IF Flavivirus-positive spermatozoa cells ranged from 1.9% to 25% in specimens from symptomatic subjects, as compared with 0.8% to 3.8% in specimens from asymptomatic controls. A marked IF-pattern in the cytoplasmic droplets and tail of the spermatozoa was observed. The sperm concentrations (45 x 10(6)/mL vs. 63.5 x 10(6)/mL, p = 0.041) and the total motility percentage (54% vs. 75%, p = 0.009) were significantly lower in specimens from ZIKV-positive than in those of ZIKV-negative. In conclusion, this study demonstrated the presence of Flavivirus antigens and RNA within a time frame of 28 DPSO in sperm cells of symptomatic and asymptomatic subjects during the ZIKV epidemic. These findings have implications for public health, in terms of nonarthropod-born, silent transmission facilitated by sperm cells and potential transmission from asymptomatic males to pregnant women, with consequences to the fetus.
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| 338. |
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| 339. |
- Benavente, Martha, et al.
(författare)
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Speciation and Removal of Arsenic in column packed with chitosan
- 2006
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Ingår i: Water Practice & Technology. - : International Water Association (IWA). - 1751-231X. ; 1:4, s. 2006-89
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Tidskriftsartikel (refereegranskat)abstract
- The arsenic speciation and arsenic removal in chitosan packed column were studied. Arsenic removal experiments were carried out with an arsenic standard solution (1.0 mg/l) and drilled well water samples from Limon Mine Community at different pH, water flowrate, and volume of adsorbent material. The simulation of arsenic speciation was carried out at a pH range from 0 to 12, a temperature of 25ºC, a pE equal to 4, and a total arsenic concentration of 1.34 x 10-5 mol kg-1. According to speciation calculations arsenic is found mainly in oxidized form in the conditions of Limon Mine’s drilled well waters, dihydrogen arsenate ion (H2AsO4-), and hydrogen arsenate ion (HAsO42-) being the major species. The experiments showed that arsenic adsorption depends mainly on the pH as well as the activity of functional groups that compose the chitosan structure. At pH 3 and volume of adsorbent material of 337.8 cm3 an adsorption of 94% was obtained from arsenic standard solution, and the arsenic present in the Limon Community’s water was almost totally removed at pH 3 and 7. The use of the results for designing purposes demands the breakthrough curves for chitosan to be determined.
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| 340. |
- Bucardo, Filemon, et al.
(författare)
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Impact of vaccination on the molecular epidemiology and evolution of group A rotaviruses in Latin America and factors affecting vaccine efficacy
- 2015
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Ingår i: Infection, Genetics and Evolution. - : ELSEVIER SCIENCE BV. - 1567-1348 .- 1567-7257. ; 34, s. 106-113
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Forskningsöversikt (refereegranskat)abstract
- Despite high rotavirus (RV) vaccine coverage (similar to 83%) and good effectiveness (similar to 77%) against RV-diarrhea hospitalization, RV is still contributing to the burden of diarrhea that persists in hospital settings in several Latin American countries, where RV vaccination is being implemented. Due to the extensive genomic and antigenic diversity, among co-circulating human RV, a major concern has been that the introduction of RV vaccination could exert selection pressure leading to higher prevalence of strains not included in the vaccines and/or emergence of new strains, thus, reducing the efficacy of vaccination. Here we review the molecular epidemiology of RV in Latin America and explore issues of RV evolution and selection in light of vaccination. We further explore etiologies behind the large burden of diarrhea remaining after vaccination in some countries and discuss plausible reasons for vaccine failures. (C) 2015 Elsevier B.V. All rights reserved.
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