17 research outputs found
Transmission of malaria in relation to distribution and coverage of long-lasting insecticidal nets in central Côte d'Ivoire
No full textThe use of long-lasting insecticidal nets (LLINs) is an effective malaria control strategy. However, there are challenges to achieve high coverage, such as distribution sustainability, and coverage keep-up. This study assessed the effect of LLINs coverage and contextual factors on entomological indicators of malaria in rural Côte d'Ivoire.; The study was carried out between July 2009 and May 2012 in three villages (Bozi, N'Dakonankro and Yoho) of central Côte d'Ivoire. In Bozi and Yoho, LLINs were distributed free of charge by the national malaria control programme in 2008. In Bozi, an additional distribution was carried out in May 2011. No specific interventions were done in N'Dakonankro. Entomological surveys were conducted in July 2009 and July 2010 (baseline), and in August and November 2011 and in February 2012. Frequency of circumsporozoite protein was determined using an enzyme-linked immunosorbent assay. Regression models were employed to assess the impact of LLINs and changing patterns of irrigated rice farming on entomological parameters, and to determine associations with LLINs coverage and other contextual factors.; In Bozi, high proportion of LLIN usage was observed (95-100%). After six months, 95% of LLINs were washed at least once and 79% were washed up to three times within one year. Anopheles gambiae was the predominant malaria vector (66.6% of all mosquitoes caught). From 2009 to 2012, in N'Dakonankro, the mean annual entomological inoculation rate (EIR) increased significantly from 116.8 infectious bites/human/year (ib/h/y) to 408.8 ib/h/y, while in the intervention villages, the EIR decreased significantly from 514.6 ib/h/y to 62.0 ib/h/y (Bozi) and from 83.9 ib/h/y to 25.5 ib/h/y (Yoho). The risk of an infectious bite over the three-year period was significantly lower in the intervention villages compared to the control village (p >0.001).; High coverage and sensitization of households to use LLINs through regular visits (particularly in Bozi) and abandoning irrigated rice farming (in Yoho) resulted in highly significant reductions of EIR. The national malaria control programme should consider household sensitization and education campaigns and other contextual factors to maximize the benefit of LLINs
Long-term trends in Anopheles gambiae insecticide resistance in Côte d'Ivoire
No full textMalaria control is heavily dependent on the use of insecticides that target adult mosquito vectors via insecticide treated nets (ITNs) or indoor residual spraying (IRS). Four classes of insecticide are approved for IRS but only pyrethroids are available for ITNs. The rapid rise in insecticide resistance in African malaria vectors has raised alarms about the sustainability of existing malaria control activities. This problem might be particularly acute in Côte d¿Ivoire where resistance to all four insecticide classes has recently been recorded. Here we investigate temporal trends in insecticide resistance across the ecological zones of Côte d¿Ivoire to determine whether apparent pan-African patterns of increasing resistance are detectable and consistent across insecticides and areas.MethodsWe combined data on insecticide resistance from a literature review, and bioassays conducted on field-caught Anopheles gambiae mosquitoes for the four WHO-approved insecticide classes for ITN/IRS. The data were then mapped using Geographical Information Systems (GIS) and the IR mapper tool to provide spatial and temporal distribution data on insecticide resistance in An. gambiae sensu lato from Côte d¿Ivoire between 1993 and 2014.ResultsBioassay mortality decreased over time for all insecticide classes, though with significant spatiotemporal variation, such that stronger declines were observed in the southern ecological zone for DDT and pyrethroids than in the central zone, but with an apparently opposite effect for the carbamate and organophosphate. Variation in relative abundance of the molecular forms, coupled with dramatic increase in kdr 1014F frequency in M forms (An. coluzzii) seems likely to be a contributory factor to these patterns. Although records of resistance across insecticide classes have become more common, the number of classes tested in studies has also increased, precluding a conclusion that multiple resistance has also increased.ConclusionOur analyses attempted synthesis of 22 years of bioassay data from Côte d¿Ivoire, and despite a number of caveats and potentially confounding variables, suggest significant but spatially-variable temporal trends in insecticide resistance. In the light of such spatio-temporal dynamics, regular, systematic and spatially-expanded monitoring is warranted to provide accurate information on insecticide resistance for control programme management
On the Lifecycle Management of Standards [Elektronisk resurs]
No full textPopular Abstract in Swedish Globala internationella standards har stort inflyttande i var nutida teknikorienterade värld. Exemplen är många: vi kan importera och exportera produkter och tjänster i de flesta andra länder, vi kan kommunicera med andra personer var de än befinner sig, vi kan även resa snabbt och effektivt. Men skapande och underhåll av internationella standarder är ingen enkel process. Förutom de tekniska förutsättningar som måste finnas för att skapa en standard finns även politiska, ekonomiska och kulturella aspekter som måste beaktas. Föreliggande avhandling gör inget anspråk för att tolka alla dessa aspekter i skapande och underhåll av internationella standarder. Målet med avhandlingen är att bistå teknikern som kommer att delta i processen för att skapa en ny global standard, med en karta som beskriver de olika steg som ingår i en standards livscykel, men även samspelet i utvecklingsgruppen. I avhandlingen används en modell, utvecklad i (Söderström, 2004). Modellen kompletteras medD-S-N processen som beskrivs i (Fomin, 2003). Den sammansatta modellen har sedan utvecklats till en modellprocess genom införande av krav på ingångs- och utgångsvillkor av respektive processteg i modellen med hjälp av Six-Sigma metoden (Brassard, 2002). För att standardisera även detta processarbete har respektive processteg kompletterats med förslag på metoder att använda för fullgörande av de olika processtegen. Denna processmodell har fått namnet LMS - Lifecycle Management of Standards och ska kunna appliceras för global utveckling avseende EDI standardisering inom bilindustrin. Modellen kan vidare generaliseras för standardiseringsarbete där utveckling av programvara ingår som ett verktyg för standarden. Författaren har varit aktiv i internationella standardiseringsgrupper som representant för svensk bilindustrin under nio år. Den framtagna modellen för en standardiseringslivscykel har verifierats dels genom att studera protokoll från SASIG och Odette Sweden åren 2000-2007 dels genom författarens egna erfarenheter från global standardisering avseende ENGDAT V3, OFTP2 och PDQ V2.Standards are used everywhere in the modern world and are a fundamental part of a functioning society. But the creation and maintenance of international standards is not an easy task. In addition to the technical prerequisites that must exist to create a standard, there are also political, economic and cultural aspects that must be considered. The present thesis does not interpret all these aspects in the creation and maintenance of international standards. The goal of the thesis is to assist the technical specialist who will participate in the process of creating a new global standard, with a map that describes the various steps involved in a standards life cycle, but also the interaction of the development team. A composite model was created based on the work described in (Söderström, 2004) supplemented with the D-S-N process described in (Fomin, 2003). The composite model was then further developed into a modelling process using Six-Sigma methodology (Brassard, 2002), with requirements for input and output conditions for each process step. To standardize the development process model each process step was complemented with suggested methods for the completion of each process step. The developed process model, LMS-Lifecycle Management of Standards, can be applied for the development of global EDI standards in the automotive industry. The model can also be generalized to describe the standardization process where the development of software is included. The author has been active in international standardisation groups as representative of the Swedish car industry for nine years. The elaborated model for a standardization lifecycle has been verified using the SASIG and Odette Sweden protocols from 2000-2007 and by the author's own experiences during standardization work on the global EDI standards ENGDAT V3, OFTP2 and PDQ V2
A Novel Airframe Design Methodology For Silent Aircraft
No full textThe impact of noise on civil aviation is not just a localised airport problem, but a global concern, due
to the ever-increasing demands for passenger travel. The challenge of designing a ‘Silent Aircraft’
lies within the development, integration, and optimisation of efficient airframe-engine technologies.
This research study investigates the design of novel airframes with the aim of producing a
methodology that incorporates airframe noise. Studies investigating the design of Broad Deltas (BD),
Blended Wing Bodies (BWB), and Joined Wing airframe configurations are integrated with
innovative propulsion systems designs to identify key parameters in order to design a Silent Aircraft.
The airframe configuration plays an important role in the total aircraft noise, where the novel
airframes that are analysed, are compared to a datum ‘baseline’ aircraft. All novel configurations
show significant improvements in airframe noise reduction, enhanced by the addition of ultra-efficient
propulsion systems, for which integration studies are discussed. The research into novel airframes
uses a developed design methodology which integrates design considerations such as aerodynamics,
performance, and cost models to complement the noise analysis and identify the most silent airframe
configuration.
The research goal was to identify a silent airframe solution for a future viable short-medium range
airliner, where the final solutions described suggest proposals for the future development of aviation.
The proposals suggested describe a short-term solution to the noise challenge, with a longer-term
solution to aid the development of technologies, maturity in technology release levels (TRLs), and
development of a future 2050 medium capacity civil airliner
The Role of Information Technology in the Airport Business: A Retail-Weighted Resource Management Approach for Capacity-Constrained Airports
No full textMuch research has been undertaken to gain insight into business alignment of IT. This
alignment basically aims to improve a firm’s performance by an improved
harmonization of the business function and the IT function within a firm. The thesis
discusses previous approaches and constructs an overall framework, which a potential
approach needs to fit in.
Being in a highly regulated industry, for airports there is little space left to increase
revenues. However, the retailing business has proven to be an area that may contribute
towards higher income for airport operators. Consequently, airport management should
focus on supporting this business segment. Nevertheless, it needs to be taken into
account that smooth airport operations are a precondition for successful retailing
business at an airport.
Applying the concept of information intensity, the processes of gate allocation and
airport retailing have been determined to appraise the potential that may be realized
upon (improved) synchronization of the two. It has been found that the lever is largest
in the planning phase (i.e. prior to operations), and thus support by means of
information technology (for information distribution and improved planning) may help
to enable an improved overall retail performance.
In order to determine potential variables, which might influence the output, a process
decomposition has been conducted along with the development of an appropriate
information model.
The derived research model has been tested in different scenarios. For this purpose an
adequate gate allocation algorithm has been developed and implemented in a purposewritten
piece of software. To calibrate the model, actual data (several hundred thousand
data items from Frankfurt Airport) from two flight plan seasons has been used.
Key findings: The results show that under the conditions described it seems feasible to
increase retail sales in the magnitude of 9% to 21%. The most influential factors
(besides the constraining rule set and a retail area’s specific performance) proved to be a
flight’s minimum and maximum time at a gate as well as its buffer time at gate.
However, as some of the preconditions may not be accepted by airport management or
national regulators, the results may be taken as an indication for cost incurred, in case
the suggested approach is not considered.
The transferability to other airport business models and limitations of the research
approach are discussed at the end along with suggestions for future areas of research
Édition en perspective 2010-2011 : rapport d\u27activité du Syndicat national de l\u27édition (L\u27)
No full textRapport annuel du Syndicat national de l\u27Édition
Modélisation des interactions biophysiques entre la dynamique du biofilm épilithique et l'hydrodynamique locale
No full textLes interactions entre l'hydrodynamique locale, la structure et la dynamique temporelle du biofilm épilithique ont été étudiées par analyse et modélisation de séries temporelles de biomasse et de la composition algale sur trois séries de données obtenues en canaux expérimentaux et in situ. Deux séries temporelles ont été obtenues dans des conditions contrôlées à l'Institut de Mécanique des Fluides de Toulouse: la première dans un canal à vitesse constante d'écoulement, et la second dans un canal à trois sections avec trois vitesses d'écoulement incluant un test d'arrachage du biofilm en fin d'expérience. La dernière série temporelle a été collectée sur un banc de galet de la Garonne (France) en amont de Toulouse durant la période de Septembre 2008 à Septembre 2009. Trois formulations décrivant le processus de détachement chronique du biofilm ont été confrontées à la première série de données. Ces trois formulations sont respectivement fonction du débit Q, de la vitesse de frottement u* et du nombre de Reynolds rugueux k+. Elles sont intégrées dans un modèle simple décrivant la dynamique de croissance du biofilm épilithique comme un équilibre entre une croissance phototrophique et une perte chronique dépendante de l'hydrodynamique. Les résultats d'application de ces trois formulations à la première série de données obtenues en canal, ont montré que la dynamique du biofilm épilithique est mieux reproduite en considérant comme variables externes de forçage du détachement chronique, des descripteurs de l'hydrodynamique locale et de la turbulence en proche parois que sont la vitesse de frottement (u*) et la rugosité turbulente (k+). Néanmoins l'utilisation de la rugosité turbulente donne le meilleur résultat car ce descripteur tient compte non seulement de l'effet de l'hydrodynamique mais aussi de l'évolution de la forme et des dimensions du substratum qui est fonction de l'épaisseur et de la structure du biofilm qui le colonise. L'analyse de la série temporelle obtenue dans le canal à trois vitesses d'écoulement a révélé que la structure du biofilm, sa composition algale et sa résistance au détachement catastrophique étaient fortement conditionnées par les caractéristiques hydrodynamiques locales subies pendant la période de croissance. Ceci met en évidence l'importance de la prise en compte du rôle de cette hydrodynamique locale dans la modélisation du processus de détachement catastrophique associé aux crues, et plus généralement, son rôle dans les différents processus régissant la dynamique temporelle du biofilm épilithique. En tenant compte des résultats obtenus dans les expérimentations et modélisations des interactions biofilm/écoulement dans les canaux expérimentaux précédemment décrites, une nouvelle approche est utilisée pour la modélisation de la série temporelle obtenue in situ. Cette approche tient compte de l'effet des interactions hydrodynamiques locales/structure et composition du biofilm sur sa dynamique temporelle et de la pression de broutage par les invertébrés aquatiques. Cette nouvelle approche permet ainsi de reproduire tous les cycles de croissance et de détachement du biofilm observés in situ en prenant en compte l'effet de la température, de l'intensité lumineuse, des différents processus de détachement (chronique, catastrophique et autogénique) ainsi que la perte par broutage. L'action par broutage direct semble être négligeable face à l'action indirecte des invertébrés liée à leurs déplacements qui déstructurent les couches algo-bactériennes et modifient les capacités d'accrochage du biofilm au substrat.Interactions between local hydrodynamics and epilithic biofilm structure and temporal dynamics have been investigated through analyses and modeling of temporal data of biomass, algal composition and local hydrodynamics evolution obtained in experimental channels and in situ. Two of the used temporal data were obtained in controlled conditions at the Institut de Mécanique des Fluids de Toulouse: the first one in a channel with constant flow velocity, and the second in a channel with three sections and three different flow velocities including a test of detachment of the epilithic biomass at the end of the experiment. The last temporal data was collected on a bench of pebble of the Garonne (France) upstream to Toulouse during period from September, 2008 till September, 2009. Three formulations of biomass chronic detachment that integrated successively the discharge Q, the friction velocity u* and the roughness Reynolds number k+=u* ks /v (v=water kinematic viscosity) as descriptors of flow conditions have been confronted to the first series of data. These formulations were integrated into a simple model describing the dynamics of growth of epilithic biomass as a balance between phototrophic growth and a chronic loss dependent on the hydrodynamics. The results of application of these three formulations to the first series of data showed that the dynamics of the epilithic biomass is better reproduced by considering as external variable of forcing the chronic detachment, the friction velocity (u*) and the turbulent roughness (k+) that are descriptors of local hydrodynamics and turbulence in the near bed region. Nevertheless the use of the turbulent roughness gives the best result because this descriptor takes into account not only the effect of the hydrodynamics but also the evolution of the shape and the dimensions of the substratum according to the thickness and the structure of the biofilm which colonizes it. The analysis of the temporal series obtained in the channel with three flow velocities revealed that the structure, the algal composition and its resistance in the catastrophic detachment of the epilithic biomass were strongly conditioned by the local hydrodynamics endured during the period of growth. This brings to light the importance and the role of this local hydrodynamics in modeling the catastrophic detachment process associated with the floods and more generally its role in the various processes governing the temporal dynamics of epilithic biomass. Considering the previously described results obtained in the experiments and the in the modeling of the biofilm / flow interactions in the experimental channels, a new approach was used for modeling the in situ temporal series. This approach takes into account the effect of the interactions between local hydrodynamics /structure and composition of the biofilm on its temporal dynamics and the grazing pressure of the aquatic invertebrates. This new approach allows reproducing all the growth and detachment cycles of epilithic biofilm observed in situ. This, by considering the effects of temperature, luminous intensity, various detachment processes (chronic, catastrophic and autogenic), as well as the loss by grazing pressure. This last one seems to be unimportant in front of the indirect action of the invertebrates related to their movements which disintegrate the alo-bacterial layers and modify their capacities of to hang on the substrata
A semiotic analysis of the short stories of Leonid Andreyev, 1900-1909
No full textThis thesis applies the techniques of semiotic analysis to a selection of short stories by Leonid Andreyev in an attempt to offer one answer to the problems of categorising Andreyev's unique art and placing it within a literary-evolutionary perspective. The semiotic method was chosen because of its ability both to assimilate literary texts to the supra-individual processes with which it works, and at the same time to delineate an author's particular contribution to these processes. Drawing on a range of literary theory from early Russian Formalism onwards, the study proceeds from one level to another according to a principle of "degree of abstraction", so that each level constitutes firstly an independent account of Andreyev's texts in itself, and secondly one stage in an overall analysis. The analysis at each level pinpoints, in its own terms, a series of semiotic tensions or clashes as being at the heart of Andreyev's literary system. Conflict within his stories between the principles of poetry and prose, metaphor and metonymy, 'discourse' and 'story' and between codes of allegory and codes of reference are among the major tensions highlighted. These tensions are in turn used to account for the fantastic element in Andreyev's stories (tension and ambiguity being the key features of Fantastic literature as defined by many literary theoreticians).The unique, Andreyevan version of the Fantastic is viewed as an index of Andreyev's position in literary evolution at a point of transition between an older, authoritative, transitive mode of narration and a more recent, non-authoritative mode which has come to dominate much twentieth-century literature. The final reference-point for all these tensions is demonstrated to be a shift in modern culture as a whole towards a more impersonal. Mythic thought-system, a shift at the centre of which the art of Leonid Andreyev can be convincingly placed. The material drawn upon includes, in addition to the corpus of Andreyev stories specified, a wide range of works by Andreyev's contemporaries and also the hitherto unexploited draft-manuscripts to a number of Andreyev stories held in the Hoover Institution, U.S.A.A Glossary of the most commonly used theoretical terms is provided at the end of the study
