Achieving high coverage of larval-stage mosquito surveillance: challenges for a community-based mosquito control programme in urban Dar es Salaam, Tanzania

Background: Preventing malaria by controlling mosquitoes in their larval stages requires regular sensitive monitoring of vector populations and intervention coverage. The study assessed the effectiveness of operational, community-based larval habitat surveillance systems within the Urban Malaria Control Programme (UMCP) in urban Dar es Salaam, Tanzania. Methods: Cross-sectional surveys were carried out to assess the ability of community-owned resource persons (CORPs) to detect mosquito breeding sites and larvae in areas with and without larviciding. Potential environmental and programmatic determinants of habitat detection coverage and detection sensitivity of mosquito larvae were recorded during guided walks with 64 different CORPs to assess the accuracy of data each had collected the previous day. Results: CORPs reported the presence of 66.2% of all aquatic habitats (1,963/2,965), but only detected Anopheles larvae in 12.6% (29/230) of habitats that contained them. Detection sensitivity was particularly low for late-stage Anopheles (2.7%, 3/111), the most direct programmatic indicator of malaria vector productivity. Whether a CORP found a wet habitat or not was associated with his/her unfamiliarity with the area (Odds Ratio (OR) [95% confidence interval (CI)] = 0.16 [0.130, 0.203], P < 0.001), the habitat type (P < 0.001) or a fence around the compound (OR [95% CI] = 0.50 [0.386, 0.646], P < 0.001). The majority of mosquito larvae (Anophelines 57.8% (133/230) and Culicines 55.9% (461/825) were not reported because their habitats were not found. The only factor affecting detection of Anopheline larvae in habitats that were reported by CORPs was larviciding, which reduced sensitivity (OR [95% CI] = 0.37 [0.142, 0.965], P = 0.042). Conclusions: Accessibility of habitats in urban settings presents a major challenge because the majority of compounds are fenced for security reasons. Furthermore, CORPs under-reported larvae especially where larvicides were applied. This UMCP system for larval surveillance in cities must be urgently revised to improve access to enclosed compounds and the sensitivity with which habitats are searched for larvae

Epifluorescence imaging of electrochemically Switchable Langmuir-Blodgett films of Nafion

Reforestation of riparian zones is increasingly practiced in many regions for purposes of biodiversity conservation, bank stabilisation, and improvement in water quality. This is in spite of the actual benefits of reforestation for recovering underlying soil properties and function remaining poorly understood. Here we compare remnant riparian rainforest, pasture and reforestation plantings aged 2-20 years in an Australian subtropical catchment on ferrosols to determine the extent to which reforestation restores key soil properties. Of the nine soil attributes measured (total nitrogen, nitrate and ammonium concentrations, net nitrification and ammonification rates, organic carbon, bulk density, fine root biomass and water infiltration rates), only infiltration rates were significantly lower in pasture than remnant riparian rainforest. Within reforestation plantings, bulk density decreased up to 1.4-fold and infiltration rates increased up to 60-fold with time post-reforestation. Our results suggest that the main outcome of belowground processes of early reforestation is the recovery of the soils' physical structure, with potential beneficial ecosystem services including reduced runoff, erosion and associated sediment and nutrient loads in waterways. We also demonstrate differential impacts of two commonly planted tree species on a subset of soil properties suggesting that preferential planting of select species could accelerate progress on specific restoration objectives

A balance between protected lands and population growth

[Extract] G. Wittenmyer et al. (Reports, "Accelerated human population growth at protected area edges," 4 July 2008, p.123) provide strong evidence that human population growth on the borders of protected areas is greater (nearly double) than average rural growth in African and Latin American countries. What is inferred, but not tested, is that the gazetting of protected areas is the initial trigger for population growth and accompanying deforestation. The authors conclude that the disparity in growth rates is driven by people actively immigrating to edges of established protected areas in response to improved social and economic opportunities. This deduction is important because it suggests that the establishment of protected areas may in fact "exacerbate the same anthropogenic threats to biodiversity it aims to alleviate.

Ecological restoration success is higher for natural regeneration than for active restoration in tropical forests

Is active restoration the best approach to achieve ecological restoration success (the return to a reference condition, that is, old-growth forest) when compared to natural regeneration in tropical forests? Our meta-analysis of 133 studies demonstrated that natural regeneration surpasses active restoration in achieving tropical forest restoration success for all three biodiversity groups (plants, birds, and invertebrates) and five measures of vegetation structure (cover, density, litter, biomass, and height) tested. Restoration success for biodiversity and vegetation structure was 34 to 56% and 19 to 56% higher in natural regeneration than in active restoration systems, respectively, after controlling for key biotic and abiotic factors (forest cover, precipitation, time elapsed since restoration started, and past disturbance). Biodiversity responses were based primarily on ecological metrics of abundance and species richness (74%), both of which take far less time to achieve restoration success than similarity and composition. This finding challenges the widely held notion that natural forest regeneration has limited conservation value and that active restoration should be the default ecological restoration strategy. The proposition that active restoration achieves greater restoration success than natural regeneration may have arisen because previous comparisons lacked controls for biotic and abiotic factors; we also did not find any difference between active restoration and natural regeneration outcomes for vegetation structure when we did not control for these factors. Future policy priorities should align the identified patterns of biophysical and ecological conditions where each or both restoration approaches are more successful, cost-effective, and compatible with socioeconomic incentives for tropical forest restoration

Multilingualism in Computer mediated communication. A study of language choice among youngsters in rural Tanzania.

Mastergradsoppgave i digital kommunikasjon og kultur, Høgskolen i Innlandet, 2019.African youth linguistic practices have merely been regarded as an urban phenomenon that has nothing to do with rural areas. They have sometimes been labelled as urban vernaculars, a label that excludes creative linguistic practices of rural youths. This thesis aims to study how linguistic practices of Tanzania’s multilingual rural based youngsters are reflected in Computer mediated communication by examining to what extent are their linguistic practices fixed in the sense that they orient to the monolingual system and standard varieties or fluid in the sense that their whole linguistic repertoire is involved in the meaning-making process. I also examine which languages these youngsters use. I introduce multilingualism by considering its historical background regarding its evolution during the last six decades as well as a brief explanation of Computer mediated communication in general and in Africa. I have chosen to briefly introduce and explain language situation in Tanzania because its awareness will ensure understanding of the aim of research topic and the analysis of the youngsters’ linguistic practices in Computer mediated communication. Throughout the theory chapter, there will be a discussion of multilingualism’s central concepts such are language choice and code-switching. However, data in this thesis will be analyzed in the light of fixity and fluidity, and theories that suppose fluid linguistic practices, such as metrolingualism and translanguaging are also introduced in the theory. This study is done through a qualitative research design. Data used in this thesis is based on individual interviews and observation collected from six rural based Tanzania’s youths. There is a total of 22 examples of both interviews and observation selected to represent the main tendencies in the data. Findings of this study shows how youths’ linguistic practices in computer mediated communication challenge the monolingual approach to language emphasized by once but no longer hegemony state that is Tanzania. Online youth linguistic practices appear in many different shapes characterized by both local and global practices witnessed in many various social networking sites. Such linguistic diversity in computer mediated communication is contributed by various motives

Explicit lower bound of the first eigenvalue of the Laplacian on K\"ahler manifolds

We establish an explicit lower bound of the first eigenvalue of the Laplacian on K\"ahler manifolds based off the comparison results of Li and Wang. The lower bound will depend on the diameter, dimension, holomorphic sectional curvature and orthogonal Ricci curvature.Comment: Accepted for publication to Involve, a Journal of Mathematic