21 research outputs found

    Offsprings of a point vortex

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    The distribution engendered by successive splitting of one point vortex are considered. The process of splitting a vortex in three using a reverse three-point vortex collapse course is analysed in great details and shown to be dissipative. A simple process of successive splitting is then defined and the resulting vorticity distribution and vortex populations are analysed

    The malaria challenge : after one hundred years of malariology

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    The organophosphate pirimiphos-methyl and the carbamate carbosulfan were evaluated in comparison to the pyrethroid alphacypermethrin and the 'near-pyrethroid' etofenprox against pyrethroid resistant #Anopheles gambiae and #Culex spp. in an experimental hut station located in central Côte d'Ivoire. Bednets were impregnated with the above mentioned compounds and randomly allocated to the huts. On the 40 consecutive mornings, after sleepers had occupied the huts overnight, mosquitoes were collected from the huts, identified and scored as live or dead (including delayed mortality). #An. gambiae s.l. that had been collected were tested for the presence of the kdr allele in heterozygous or homozygous form. Both non-pyrethroid treatments caused very high mortality, whereas mortality with alpha-cypermethrin and etofenprox generally did not differ from the levels observed with untreated control nets in this experiment. The nets had holes cut in them and there was considerable bloodfeeding on the sleepers, which was only significantly reduced for #An. gambiae by carbosulfan and alpha-cypermethrin. PCR genotyping suggested that there was selection for the kdr resistance allele by the pyrethroid treated nets. Organophosphates and carbamates may therefore present an alternative to be used on bednets especially in areas of pyrethroid resistance, but the safety of these insecticides will have to be carefully considered. (Résumé d'auteur

    Experimental and molecular genetic analysis of the impact of pyrethroid and non-pyrethroid insecticide impregnated bednets for mosquito control in an area of pyrethroid resistance

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    Experimental huts in Côte d'Ivoire were used to evaluate the pyrethroid alpha-cypermethrin, the non-ester pyrethroid etofenprox, the organophosphate pirimiphos-methyl and the carbamate carbosulfan on bednets against pyrethroid-resistant #Anopheles gambiae Giles. To test for selection for the resistance gene by the treated nets, #A. gambiae collected live or dead from the huts were kept and analysed for the presence of the kdr gene using a new polymerase chain reaction followed by sequence-specific oligonucleotide probing (PCR-SSOP) for kdr-genotyping. Deliberately holed bednets freshly treated with pirimiphos-methyl or carbosulfan caused over 90% kill of #A. gambiae$ s.s. on the sleepers under the nets was only significantly reduced by alpha-cypermethrin and carbosulfan. Tests of the residual activity of the bednets after seven months showed that pirimiphos-methyl had lost its efficacy while carbosulfan still performed well. Once again the pyrethroid treated nets gave similar results to the untreated nets. Selection for the kdr-allele by alpha-cypermethrin and etofenprox, but not by carbosulfan, was indicated by PCR-SSOP genotyping of mosquitoes. Thus carbamates such as carbosulfan, or organophosphates of longer persistance than pirimiphos-methyl and of low mammalian toxicity, would seem to be a promising alternative to be used on bednets, particularly in areas of pyrethroid resistance. (Résumé d'auteur

    The malaria challenge : after one hundred years of malariology

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    The organophosphate pirimiphos-methyl and the carbamate carbosulfan were evaluated in comparison to the pyrethroid alphacypermethrin and the 'near-pyrethroid' etofenprox against pyrethroid resistant #Anopheles gambiae and #Culex spp. in an experimental hut station located in central Côte d'Ivoire. Bednets were impregnated with the above mentioned compounds and randomly allocated to the huts. On the 40 consecutive mornings, after sleepers had occupied the huts overnight, mosquitoes were collected from the huts, identified and scored as live or dead (including delayed mortality). #An. gambiae s.l. that had been collected were tested for the presence of the kdr allele in heterozygous or homozygous form. Both non-pyrethroid treatments caused very high mortality, whereas mortality with alpha-cypermethrin and etofenprox generally did not differ from the levels observed with untreated control nets in this experiment. The nets had holes cut in them and there was considerable bloodfeeding on the sleepers, which was only significantly reduced for #An. gambiae by carbosulfan and alpha-cypermethrin. PCR genotyping suggested that there was selection for the kdr resistance allele by the pyrethroid treated nets. Organophosphates and carbamates may therefore present an alternative to be used on bednets especially in areas of pyrethroid resistance, but the safety of these insecticides will have to be carefully considered. (Résumé d'auteur

    Public Duty and Private Prejudice: Sexualities, Equalities and Local Government

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    Rather than critiquing social institutions and practices that have historically excluded lesbians and gay men, as did earlier social movements in the 1960s and 1970s, since the 1990s the politics of sexuality has increasingly been about demanding equal rights of citizenship. These citizenship demands have, at least to a degree, been answered via a raft of recent legislation in the UK including the Adoption and Children Act 2002, Employment Equality (Sexual Orientation) Regulations 2003, Gender Recognition Act 2004 and the Civil Partnership Act 2004, and by associated changes in policy making and practice that emphasize ‘Equality and Diversity’. In this article we consider how the implementation of sexualities equalities policies is related to processes of privatization and individualization. This is illustrated by using sexualities equalities work in local government as a case study to indicate how processes of change and resistance are aided by these processes. The article draws on findings from a study of lesbian, gay, bisexual and transgender (LGBT) equalities initiatives in local government in England, Wales and Northern Ireland, which examined the views of those who now have a public duty to implement recent legislative and policy shifts and are obliged to develop equalities initiatives concerning ‘sexual orientation' and ‘gender reassignment’
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