Mosques against malaria

In a community-based malaria control project covering a predominantly Muslim population in the United Republic of Tanzania, difficulty was encountered in motivating people to have their mosquito nets reimpregnated with insecticide at six-monthly intervals. Education on this subject was therefore provided in mosques during Friday noon prayers. People who attended these services considered them an appropriate forum for discussing health concerns and viewed them as a credible source of information.Insecticide-impregnated bednets help to control the spread of the malaria parasite Plasmodium falciparum. The Bagamoyo Bednet Project is a community-based scheme to develop a sustainable system for the distribution and promotion of such bednets among 21,000 people in a rural coastal area 60 km north of Dar es Salaam. While the 13 village committees have sold and distributed the bednets, they have been unable to motivate people to have their nets impregnated with insecticide every 6 months, key to thwarting the spread of malaria. Posters and meetings also had only a limited impact upon user motivation. The target population is mainly Muslim. The sheikh in each of 4 villages was therefore recruited to teach during Friday noon religious services, when attendance levels are relatively high, the merits of regular bednet impregnation. This approach was chosen because people expect to receive some form of teaching or instruction during the service, and the religious leaders who run it are respected and seen as reliable sources of information. There are also many health teachings in the Koran and Sunna. Although only a minority of villagers attended, a considerable proportion disseminated the information to family and friends. This approach seemed most effective in reaching men aged 30-50 years, and ineffective in reaching youth; fewer women attended prayers than men. The project achieved 52-98% regular bednet reimpregnation except in one village where the level reached only 25%

Social and cultural factors affecting rates of regular retreatment of mosquito nets with insecticide in Bagamoyo District, Tanzania

Insecticide-treated mosquito nets have an impact on mortality and morbidity in young children under controlled conditions. When integrated into larger control programs, there is the danger that rates of regular retreatment of the nets with insecticide will drop, greatly limiting their effectiveness as a public health intervention. In Bagamoyo District, Tanzania, rates of retreatment dropped significantly when payment for the insecticide was introduced. A series of neighbourhood (hamlet) meetings were held in all study villages to discuss people\u27s concerns about the insecticide and ways to increase rates of retreatment. Although changes were made in the procedure for retreatment, rates of retreatment remained lower than expected and showed marked variation within as well as between villages. We then conducted unstructured key informant interviews as well as informal discussions in a village with strong variation between different sectors of the village in rates of retreatment. While logistical problems were most frequently cited as reasons not to bring nets for retreatment, political and social divisions within the community provided a better explanation. This is borne out by the low response to rearrangements in logistics which made retreating the nets significantly easier for households, and the higher response when changes were made in the channels of communication as well as the logistic features. It is clearly more difficult for villagers to appreciate the benefits of the insecticide than those of the nets. Great emphasis needs to be placed on the insecticide and its beneficial effects from the outset for any large-scale programme to be sustainable

Viscoelastic relaxation of insoluble monomolecular films

Glycerol mono-oleate monolayers at the air-water interface have been investigated by quasielastic light scattering from thermally excited capillary waves over a wide range of wave numbers. Using a relatively novel data analysis procedure four surface viscoelastic properties were deduced ab initio from the light scattering data : surface elastic moduli and viscosities governing shear normal to the monolayer (≡ tension) and dilation in the film plane. The tension and dilational modulus were compared with classical, equilibrium values in the first rigorous comparison of its kind. Various effects suggested that the two moduli were affected by rather different relaxation processes : discrepancies between the light scattering and equilibrium values of the two elastic moduli occurred in different states of the monolayer, and the two surface viscosities (both zero for the clean subphase) behaved very differently on monolayer compression. These effects were observed to be frequency dependent. In the fully compressed monolayer state the transverse shear modulus was characterised by an exponential relaxation, of time scale ∼ 9 μs. This relaxation time fell exponentially on monolayer expansion, reaching 100 ns for molecular areas ∼ 60 Å 2. Slower processes than these were rigorously excluded. The dilational modulus was generally less well determined than that affecting transverse shear. However in the expanded monolayer state, the data sufficed to demonstrate much slower relaxation, τ ∼ 290 μs. Possible molecular mechanisms are briefly discussed.On étudie les monocouches du mono-oléate de glycérol à l'interface eau-air en utilisant les ondes capillaires excitées thermiquement qu'on observe dans une grande plage de nombres d'onde par diffusion quasi élastique de la lumière. Par une nouvelle procédure d'analyse des résultats on obtient ab initio 4 propriétés viscoélastiques de la surface : les modules élastiques de surface et les viscosités qui gouvement les cisaillements normaux à la monocouche (≡ tension) ainsi que la dilatation dans le plan de la couche. Ces mesures permettent la première comparaison rigoureuse des modules de tension et de dilatation avec leurs valeurs d'équilibre classiques. Plusieurs effets suggèrent que ces deux modules subissent des processus de relaxation différents : pour les modules élastiques on trouve des différences entre les valeurs dynamiques et statiques dans différents états de la monocouche, et pour les viscosités, on trouve des comportements différents suivant l'état de compression de la monocouche. Ces effets dépendent également de la fréquence. Dans la monocouche complètement comprimée, le module de cisaillement transverse est caractérisé par une relaxation exponentielle, avec un temps ∼ 9 μs. Ce temps de relaxation décroît exponentiellement lorsque la monocouche est dilatée, et atteint 100 ns pour des aires par molécule de 60 Å2. On peut exclure rigoureusement la présence de processus plus lents. Le module de dilatation est généralement moins bien déterminé que celui de cisaillement transverse ; toutefois, dans l' état dilaté de la monocouche, les données démontrent l'existence d'une relaxation beaucoup plus lente, vers τ ∼ 290 μs. On discute brièvement les mécanismes moléculaires associés à ces relaxations