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Attracting, trapping and killing disease-transmitting mosquitoes using odor-baited stations - The Ifakara Odor-Baited Stations  

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Abstract Background To accelerate efforts towards control and possibly elimination of mosquito-borne diseases such as malaria and lymphatic filariasis, optimally located outdoor interventions could be used to complement existing intradomicilliary vector control methods such as house spraying with insecticides and insecticidal bednets. Methods We describe a new odor-baited station for trapping, contaminating and killing disease-transmitting mosquitoes. This devic...

Okumu Fredros O; Madumla Edith P; John Alex N; Lwetoijera Dickson W; Sumaye Robert D

2010-01-01

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A Modified Experimental Hut Design for Studying Responses of Disease-Transmitting Mosquitoes to Indoor Interventions: The Ifakara Experimental Huts  

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Differences between individual human houses can confound results of studies aimed at evaluating indoor vector control interventions such as insecticide treated nets (ITNs) and indoor residual insecticide spraying (IRS). Specially designed and standardised experimental huts have historically provided a solution to this challenge, with an added advantage that they can be fitted with special interception traps to sample entering or exiting mosquitoes. However, many of these experimental hut desi...

Okumu, Fredros O.; Moore, Jason; Mbeyela, Edgar; Sherlock, Mark; Sangusangu, Robert; Ligamba, Godfrey; Russell, Tanya; Moore, Sarah J.

2012-01-01

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Common Host-Derived Chemicals Increase Catches of Disease-Transmitting Mosquitoes and Can Improve Early Warning Systems for Rift Valley Fever Virus  

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Rift Valley fever (RVF), a mosquito-borne zoonosis, is a major public health and veterinary problem in sub-Saharan Africa. Surveillance to monitor mosquito populations during the inter-epidemic period (IEP) and viral activity in these vectors is critical to informing public health decisions for early warning and control of the disease. Using a combination of field bioassays, electrophysiological and chemical analyses we demonstrated that skin-derived aldehydes (heptanal, octanal, nonanal, dec...

Tchouassi, David P.; Sang, Rosemary; Sole, Catherine L.; Bastos, Armanda D. S.; Teal, Peter E. A.; Borgemeister, Christian; Torto, Baldwyn

2013-01-01

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Photoacoustically-guided photothermal killing of mosquitoes targeted by nanoparticles.  

Science.gov (United States)

In biomedical applications, nanoparticles have demonstrated the potential to eradicate abnormal cells in small localized pathological zones associated with cancer or infections. Here, we introduce a method for nanotechnology-based photothermal (PT) killing of whole organisms considered harmful to humans or the environment. We demonstrate that laser-induced thermal, and accompanying nano- and microbubble phenomena, can injure or kill C. elegans and mosquitoes fed carbon nanotubes, gold nanospheres, gold nanoshells, or magnetic nanoparticles at laser energies that are safe for humans. In addition, a photoacoustic (PA) effect was used to control nanoparticle delivery. Through the integration of this technique with molecular targeting, nanoparticle clustering, magnetic capturing and spectral sharpening of PA and PT plasmonic resonances, our laser-based PA-PT nano-theranostic platform can be applied to detection and the physical destruction of small organisms and carriers of pathogens, such as malaria vectors, spiders, bed bugs, fleas, ants, locusts, grasshoppers, phytophagous mites, or other arthropod pests, irrespective of their resistance to conventional treatments. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim). PMID:23450780

Foster, Stephen R; Galanzha, Ekaterina I; Totten, Daniel C; Beneš, Helen; Shmookler Reis, Robert J; Zharov, Vladimir P

2014-07-01

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Surplus Killing by Predatory Larvae of Corethrella appendiculata: Prepupal Timing and Site-Specific Attack on Mosquito Prey  

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Surplus or ‘wasteful’ killing of uneaten prey has been documented in the fourth larval instar of various species of the mosquito genus Toxorhynchites that occur in treeholes and other phytotelmata. Here we document surplus killing by the predatory midge Corethrella appendiculata, which in Florida cohabits treeholes and artificial containers with larvae of Toxorhynchites rutilus. Provided with a surfeit of larval mosquito prey, surplus killing was observed only in the fourth instar of C. a...

Lounibos, L. P.; Makhni, S.; Alto, B. W.; Kesavaraju, B.

2008-01-01

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Parasite Killing in Malaria Non-Vector Mosquito Anopheles culicifacies Species B: Implication of Nitric Oxide Synthase Upregulation  

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Background Anopheles culicifacies, the main vector of human malaria in rural India, is a complex of five sibling species. Despite being phylogenetically related, a naturally selected subgroup species B of this sibling species complex is found to be a poor vector of malaria. We have attempted to understand the differences between vector and non-vector Anopheles culicifacies mosquitoes in terms of transcriptionally activated nitric oxide synthase (AcNOS) physiologies to elucidate the mechanism of refractoriness. Identification of the differences between genes and gene products that may impart refractory phenotype can facilitate development of novel malaria transmission blocking strategies. Methodology/Principal Findings We conducted a study on phylogenetically related susceptible (species A) and refractory (species B) sibling species of An. culicifacies mosquitoes to characterize biochemical and molecular differences in AcNOS gene and gene elements and their ability to inhibit oocyst growth. We demonstrate that in species B, AcNOS specific activity and nitrite/nitrates in mid-guts and haemolymph were higher as compared to species A after invasion of the mid-gut by P. vivax at the beginning and during the course of blood feeding. Semiquantitative RT-PCR and real time PCR data of AcNOS concluded that this gene is more abundantly expressed in midgut of species B than in species A and is transcriptionally upregulated post blood meals. Dietary feeding of L-NAME along with blood meals significantly inhibited midgut AcNOS activity leading to an increase in oocyst production in An. culicifacies species B. Conclusions/Significance We hypothesize that upregulation of mosquito innate cytotoxicity due to NOS in refractory strain to Plasmodium vivax infection may contribute to natural refractoriness in An. culicifacies mosquito population. This innate capacity of refractory mosquitoes could represent the ancestral function of the mosquito immune system against the parasite and could be utilized to understand the molecular basis of refractoriness in planning effective vector control strategies.

Vijay, Sonam; Rawat, Manmeet; Adak, Tridibes; Dixit, Rajnikant; Nanda, Nutan; Srivastava, Harish; Sharma, Joginder K.; Prasad, Godavarthi B. K. S.; Sharma, Arun

2011-01-01

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Wash resistance and repellent properties of Africa University mosquito blankets against mosquitoes  

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Full Text Available The effect of permethrin-treated Africa University (AU mosquito blankets on susceptible female Anopheles gambiae sensu lato mosquitoes was studied under laboratory conditions at Africa University Campus in Mutare, Zimbabwe. Wash resistance (ability to retain an effective dose that kills ?80% of mosquitoes after a number of washes and repellence (ability to prevent ?80% of mosquito bites properties were studied. The AU blankets were wash resistant when 100% mortality was recorded up to 20 washes, declining to 90% after 25 washes. Untreated AU blankets did not cause any mortality on mosquitoes. However, mosquito repellence was 96%, 94%, 97.9%, 87%, 85% and 80.7% for treated AU blankets washed 0, 5, 10, 15, 20 and 25 times, respectively. Mosquito repellence was consistently above 80% from 0-25 washes. In conclusion, AU blankets washed 25 times were effective in repelling and killing An. gambiae sl mosquitoes under laboratory conditions.

M. Zimba

2013-04-01

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Wash resistance and repellent properties of Africa University mosquito blankets against mosquitoes  

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The effect of permethrin-treated Africa University (AU) mosquito blankets on susceptible female Anopheles gambiae sensu lato mosquitoes was studied under laboratory conditions at Africa University Campus in Mutare, Zimbabwe. Wash resistance (ability to retain an effective dose that kills ?80% of mosquitoes after a number of washes) and repellence (ability to prevent ?80% of mosquito bites) properties were studied. The AU blankets were wash resistant when 100% mortality was reco...

Lukwa, N.; Makuwaza, A.; Chiwade, T.; Mutambu, S. L.; Zimba, M.; Munosiyei, P.

2013-01-01

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Oral toxicity of Bacillus thuringiensis subsp. israelensis to adult mosquitoes.  

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The solubilized entomotoxin of Bacillus thuringiensis subsp. israelensis killed adult male and female mosquitoes of several genera and of various physiological states when it was administered orally. Adult mosquito mortality was further influenced when the preparation was contained in sucrose solution. The potential implication for the control of adult mosquitoes is discussed.

1984-01-01

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Entomopathogenic fungi for mosquito control: A review  

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Full Text Available Fungal diseases in insects are common and widespread and can decimate their populations in spectacular epizootics. Virtually all insect orders are susceptible to fungal diseases, including Dipterans. Fungal pathogens such as Lagenidium, Coelomomyces and Culicinomyces are known to affect mosquito populations, and have been studied extensively. There are, however, many other fungi that infect and kill mosquitoes at the larval and/or adult stage. The discovery, in 1977, of the selective mosquito-pathogenic bacterium Bacillus thuringiensis Berliner israelensis (Bti curtailed widespread interest in the search for other suitable biological control agents. In recent years interest in mosquito-killing fungi is reviving, mainly due to continuous and increasing levels of insecticide resistance and increasing global risk of mosquito-borne diseases. This review presents an update of published data on mosquito-pathogenic fungi and mosquito-pathogen interactions, covering 13 different fungal genera. Notwithstanding the potential of many fungi as mosquito control agents, only a handful have been commercialized and are marketed for use in abatement programs. We argue that entomopathogenic fungi, both new and existing ones with renewed/improved efficacies may contribute to an expansion of the limited arsenal of effective mosquito control tools, and that they may contribute in a significant and sustainable manner to the control of vector-borne diseases such as malaria, dengue and filariasis.

Ernst-Jan Scholte

2004-06-01

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MICROBIOLOGY: Mosquitoes Cut Short  

Science.gov (United States)

Access to the article is free, however registration and sign-in are required. Forty years ago, as the first drug- and insecticide-based global malaria eradication plan was being abandoned, the concept was raised of using evolutionary genetics to fight vector-borne diseases like malaria, dengue, and river blindness (1).The idea was to exploit selfish genetic elements, entities that can spread through host populations by distorting normal Mendelian inheritance, thereby enhancing their own transmission. In a Perspective by Read and Thomas, they discuss how McMeniman et al. (2) report a major step in a lateral development of this approach. They have infected the mosquito species that transmit dengue viruses to humans with an inheritance-distorting bacterium that kills mosquitoes likely to be infectious.

Andrew F. Read (Pennsylvania State University;Center for Infectious Disease Dynamics, Department of Biology); Matthew B. Thomas (Pennsylvania State University;Center for Infectious Disease Dynamics, Department of Entomology, Pennsylvania State University, University Park, PA 16802, USA.)

2009-01-02

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The Plasmodium bottleneck: malaria parasite losses in the mosquito vector  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Nearly one million people are killed every year by the malaria parasite Plasmodium . Although the disease-causing forms of the parasite exist only in the human blood, mosquitoes of the genus Anopheles are the obligate vector for transmission. Here, we review the parasite life cycle in the vector and [...] highlight the human and mosquito contributions that limit malaria parasite development in the mosquito host. We address parasite killing in its mosquito host and bottlenecks in parasite numbers that might guide intervention strategies to prevent transmission.

Smith, Ryan C; Vega-Rodríguez, Joel; Jacobs-Lorena, Marcelo.

2014-04-29

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TRANSMISSION MODEL OF CHIKUNGUNYA FEVER IN THE PRESENCE OF TWO SPECIES OF AEDES MOSQUITOES  

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In 2008 there was a large outbreak of Chikungunya fever in the south of Thailand. Chikungunya fever is a febrile disease transmitted to humans by the bite of infected Aedes mosquitoes. The symptoms of this disease are a sudden onset of a fever, chills, headache, nausea, vomiting, joint pain with or without swelling, low back pain and rash. In this study we study the effects of there being two species of Aedes mosquito (Aedes aegypti and Aedes albopictus) present. I...

Surapol Naowarat; Ming Tang, I.

2013-01-01

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HERBAL CONTROL OF MOSQUITO LARVAE  

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Full Text Available Mosquitoes are the vectors for the dreadful diseases of mankind. For control of larval stages of mosquito, herbal plant extracts/ botanical insecticides are being tried. In the present study aqueous extract of some traditional medicinal herbal plants i.e. Neem (Azadirechta indica, Tobacco (Nicotiana tabacum, Turmeric (Curcuma longa, Tulasi (Ocimum santum, and Ginger (Zingiber officinale were tested for their Larvicidal activity. The successful attempt is made to kill the larvae, the premature stage of mosquitoes by using safe and socio-economical herbal plant extract mixtures. Ginger+Tobacco, Neem+Tobbaco and Ginger Neem, Turmeric, Tobacco and Tulasi showed highest larvicidal activity. The results obtained show that this plant material exhibited larvicidal activity and could be considered as potent natural larvicidal agent without any toxic effects.

Chaudhari Priyanka S, Chaudhari SV* Jangam Sampada, Shinde JS, Wankhede Sneha

2013-04-01

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Next-Generation Site-Directed Transgenesis in the Malaria Vector Mosquito Anopheles gambiae: Self-Docking Strains Expressing Germline-Specific phiC31 Integrase  

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Diseases transmitted by mosquitoes have a devastating impact on global health and the situation is complicated due to difficulties with both existing control measures and the impact of climate change. Genetically modified mosquitoes that are refractory to disease transmission are seen as having great potential in the delivery of novel control strategies. The Streptomyces phage phiC31 integrase system has been successfully adapted for site-directed transgene integration in a range of insects, ...

2013-01-01

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Killing fetuses and killing newborns.  

Science.gov (United States)

The argument for the moral permissibility of killing newborns is a challenge to liberal positions on abortion because it can be considered a reductio of their defence of abortion. Here I defend the liberal stance on abortion by arguing that the argument for the moral permissibility of killing newborns on ground of the social, psychological and economic burden on the parents recently put forward by Giubilini and Minerva is not valid; this is because they fail to show that newborns cannot be harmed and because there are morally relevant differences between fetuses and newborns. PMID:23637456

Di Nucci, Ezio

2013-05-01

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Natural Plant Sugar Sources of Anopheles Mosquitoes Strongly Impact Malaria Transmission Potential  

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An improved knowledge of mosquito life history could strengthen malaria vector control efforts that primarily focus on killing mosquitoes indoors using insecticide treated nets and indoor residual spraying. Natural sugar sources, usually floral nectars of plants, are a primary energy resource for adult mosquitoes but their role in regulating the dynamics of mosquito populations is unclear. To determine how the sugar availability impacts Anopheles sergentii populations, mark-release-recapture ...

2011-01-01

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PERCEPTIONS REGARDING MOSQUITO BORNE DISEASES IN AN URBAN AREA OF RAJKOT CITY  

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Full Text Available Background: Mosquito borne diseases is a growing urban problem because of unplanned urbanization, industrialization and excessive population growth coupled with rural to urban migration. For developing a suitable and effective health education strategy, it is inevitable to understand the level of knowledge of the community, their attitude and practices regarding mosquito borne diseases. Materials and Methods: The present study was carried out in an urban field practice area of Urban Health Centre in Rajkot city. Total 500 houses were selected for study by systematic random sampling. Data was collected using a semi-structured questionnaire during transmission season of vector borne diseases. The results were analyzed using the SPSS 17 software. Results: 90% respondents agreed that mosquitoes are a problem. 30.4% didn?t know breeding sites of mosquitoes. Only 11.6% of people associated clean water collections with mosquito breeding. Regarding diseases transmitted by mosquito, 62% answered malaria, 37.4% were not aware and 8.8% people mentioned about Filariasis, Dengue or Japanese encephalitis. 4.7% granted mosquito control as responsibility of community. 61.4 % were using repellents for prevention against mosquito bites and 39% not taking any preventive measure. 67.8% consulted private practitioner for treatment. Conclusion: Intensified efforts towards creating public awareness and mobilizing the community regarding the preventive measures they can take are needed. [National J of Med Res 2011; 1(2.000: 45-47

Amul B. Patel

2011-04-01

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Target product profile choices for intra-domiciliary malaria vector control pesticide products: repel or kill?  

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Abstract Background The most common pesticide products for controlling malaria-transmitting mosquitoes combine two distinct modes of action: 1) conventional insecticidal activity which kills mosquitoes exposed to the pesticide and 2) deterrence of mosquitoes away from protected humans. While deterrence enhances personal or household protection of long-lasting insecticidal nets and indoor residual sprays, it may also attenuate or even reverse communal protection if it diverts ...

Killeen Gerry F; Chitnis Nakul; Moore Sarah J; Okumu Fredros O

2011-01-01

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Interrupting malaria transmission by genetic manipulation of anopheline mosquitoes  

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Full Text Available Malaria ranks among the deadliest infectious diseases that kills more than one million persons everyyear. The mosquito is an obligatory vector for malaria transmission. In the mosquito, Plasmodiumundergoes a complex series of developmental events that includes transformation into severaldistinct morphological forms and the crossing of two different epithelia—midgut and salivarygland. Circumstantial evidence suggests that crossing of the epithelia requires specific interactionsbetween Plasmodium and epithelial surface molecules. By use of a phage display library we haveidentified a small peptide-SM1—that binds to the surfaces of the mosquito midgut and salivaryglands. Transgenic Anopheles stephensi mosquitoes expressing a SM1 tetramer from a bloodinducibleand gut-specific promoter are substantially impaired in their ability to sustain parasitedevelopment and transmission. A second effector gene, phospholipase A2, also impairs parasitetransmission in transgenic mosquitoes. These findings have important implications for the developmentof new strategies for malaria control.

Marcelo Jacobs-Lorena

2003-09-01

 
 
 
 
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Multiple-Insecticide Resistance in Anopheles gambiae Mosquitoes, Southern Côte d’Ivoire  

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Preventing malaria used to seem as simple as killing the vector, the mosquito; however, a recent study shows that this concept is now anything but simple. The highly effective use of insecticide-treated bed nets and indoor insecticide spraying is being challenged by mosquito resistance to insecticides. In West Africa, populations of this mosquito vector are now resistant to all 4 classes of insecticide approved for this use. And no new classes of insecticide are anticipated until 2020, at the...

Edi, Constant V. A.; Koudou, Benjamin G.; Jones, Christopher M.; Weetman, David; Ranson, Hilary

2012-01-01

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Pesticides and Mosquito Control  

Science.gov (United States)

This factsheet from the Environmental Protection Agency includes several summary documents on the problem of mosquito-borne diseases and the pesticides used to control mosquitoes. The resources cover issues from mosquito biology through the EPA's recent findings on the negative health impacts of Malathion.

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Mosquito Specimens Making Technology  

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Full Text Available Mosquito is a kind of important medical insects. Mosquito biological and morphological taxonomic research is the premise of effective control of mosquitoes. Specimen making of the mosquito egg, larvae, pupa and adult, genitalia is essential for taxonomic study. However, the technology for mosquito specimens making is yet to be improved and perfected. With many years of practice and improvement, this paper proposes the ideal and portable tools of specimen making, and the specimen making processing of the eggs, larvae, pupae, larval and pupal exuviae, adults, male and female genitalia, and also introduces the packaging and mailing method of mosquito pincushion specimens and slide specimens. These techniques have a lot of improvements on the basis of earlier protocols, and can provide with for the making, and transport of mosquito specimens.

WANG Chuang-xin

2013-05-01

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Mosquito larvicidal activity of botanical-based mosquito repellents.  

Science.gov (United States)

The larvicidal activity of 4 plant essential oils--innamon oil, lemon eucalyptus oil, sandalwood oil, and turmeric oil--previously reported as insect repellents was evaluated in the laboratory against 4th instars of Aedes albopictus, Ae. aegypti, and Culex pipiens. Sandalwood oil appeared to be the most effective of the larvicides, killing larvae of all 3 mosquito species in relatively short times. The values of LT50 and LT90 at the application dosage (0.2 mg/ml) were 1.06 +/- 0.11 and 3.24 +/- 0.14 h for Ae. aegypti, 1.82 +/- 0.06 and 3.33 +/- 0.48 h for Ae. albopictus, and 1.55 +/- 0.07 and 3.91 +/- 0.44 h for Cx. pipiens, respectively. Chemical compositions of these essential oils were also studied, and the lavicidal activity of their major ingredient compounds was compared with that of each of the essential oils. The acute toxicity of the 4 essential oils to fathead minnows was also evaluated. The safe use of these natural plant essential oils in future applications of mosquito control was discussed. PMID:18437833

Zhu, Junwei; Zeng, Xiaopeng; O'Neal, Megan; Schultz, Gretchen; Tucker, Brad; Coats, Joel; Bartholomay, Lyric; Xue, Rui-De

2008-03-01

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Metarhizium anisopliae Pathogenesis of Mosquito Larvae: A Verdict of Accidental Death  

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Metarhizium anisopliae, a fungal pathogen of terrestrial arthropods, kills the aquatic larvae of Aedes aegypti, the vector of dengue and yellow fever. The fungus kills without adhering to the host cuticle. Ingested conidia also fail to germinate and are expelled in fecal pellets. This study investigates the mechanism by which this fungus adapted to terrestrial hosts kills aquatic mosquito larvae. Genes associated with the M. anisopliae early pathogenic response (proteinases Pr1 and P...

Butt, Tariq M.; Greenfield, Bethany P. J.; Greig, Carolyn; Maffeis, Thierry G. G.; Taylor, James W. D.; Piasecka, Justina; Dudley, Ed; Abdulla, Ahmed; Dubovskiy, Ivan M.; Garrido-jurado, Inmaculada; Quesada-moraga, Enrique; Penny, Mark W.; Eastwood, Daniel C.

2013-01-01

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Activation of Akt Signaling Reduces the Prevalence and Intensity of Malaria Parasite Infection and Lifespan in Anopheles stephensi Mosquitoes  

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Malaria (Plasmodium spp.) kills nearly one million people annually and this number will likely increase as drug and insecticide resistance reduces the effectiveness of current control strategies. The most important human malaria parasite, Plasmodium falciparum, undergoes a complex developmental cycle in the mosquito that takes approximately two weeks and begins with the invasion of the mosquito midgut. Here, we demonstrate that increased Akt signaling in the mosquito midgut disrupts parasite ...

2010-01-01

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Strategic Mass Killings  

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Since World War II there have been about fifty episodes of large-scale mass killings of civilians and massive forced displacements. They were usually meticulously planned and independent of military goals. We provide a model where conflict onset, conflict intensity and the decision to commit mass killings are all endogenous, with two main goals: (1) to identify the key variables and situations that make mass killings more likely to occur; and (2) to distinguish conditions under which mass kil...

Esteban, Joan; Morelli, Massimo; Rohner, Dominic

2010-01-01

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Null Killing vectors  

International Nuclear Information System (INIS)

Space-times admitting a null Killing vector are studied, using the Newman-Penrose spin coefficient formalism. The properties of the eigenrays (principal null curves of the Killing bivector) are shown to be related to the twist of the null Killing vector. Among the electrovacs, the ones containing a null Maxwell field turn out to belong to the twistfree class. An electrovac solution is obtained for which the null Killing vector is twisting and has geodesic and shearfree eigenrays. This solution is parameterless and appears to be the field of a zero-mass, spinning and charged source. (author)

1980-01-01

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Killing Forms and Applications  

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Full Text Available Characterizations of Semi-simple algebra were initiated by Cartan. In recent years, semi-simple Lie algebras have been characterized with the help of Killing forms. In this study we have made an attempt to define generalized killing forms and have applied these to the question of existence of Lagrangians in a physical system.

Md. Haider Ali Biswas

2005-01-01

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Play the Mosquito Game  

Science.gov (United States)

... and Insulin DNA - RNA - Protein DNA - the Double Helix Ear Pages ECG/Electrocardiogram Immune Responses Immune System ... parasite that is transmitted to humans by a female mosquito's bite. Read More » The Nobel Prize The ...

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Toxicity of Bacillus thuringiensis subsp. israelensis to adult Aedes aegypti mosquitoes.  

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Adult female Aedes aegypti mosquitoes were killed by the parasporal crystals of Bacillus thuringiensis subsp. israelensis (ONR-60A) when the crystals were introduced into the insect midgut as an enema. The 50% lethal dose for intact parasporal crystals was 0.21 microgram/mg of mosquito (wet weight), and for solubilized crystals the 50% lethal dose was 0.04 microgram/mg. These values were compared with 50% lethal concentrations in a free-feeding larval mosquito bioassay of 0.018 and 1.28 micro...

1983-01-01

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Evaluation of selected South African ethnomedicinal plants as mosquito repellents against the Anopheles arabiensis mosquito in a rodent model  

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Full Text Available Abstract Background This study was initiated to establish whether any South African ethnomedicinal plants (indigenous or exotic, that have been reported to be used traditionally to repel or kill mosquitoes, exhibit effective mosquito repellent properties. Methods Extracts of a selection of South African taxa were tested for repellency properties in an applicable mosquito feeding-probing assay using unfed female Anopheles arabiensis. Results Although a water extract of the roots of Chenopodium opulifolium was found to be 97% as effective as DEET after 2 mins, time lag studies revealed a substantial reduction in efficacy (to 30% within two hours. Conclusions None of the plant extracts investigated exhibited residual repellencies >60% after three hours.

Folb Peter I

2010-10-01

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Mosquito repellents in frog skin  

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The search for novel insect repellents has been driven by health concerns over established synthetic compounds such as diethyl-m-toluamide (DEET). Given the diversity of compounds known from frog skin and records of mosquito bite and ectoparasite infestation, the presence of mosquito repellents in frogs seemed plausible. We investigated frog skin secretions to confirm the existence of mosquito repellent properties. Litoria caerulea secretions were assessed for mosquito repellency by topical a...

Williams, C. R.; Smith, B. P. C.; Best, S. M.; Tyler, M. J.

2006-01-01

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Mosquito Feeding Affects Larval Behaviour and Development in a Moth  

Science.gov (United States)

Organisms are attacked by different natural enemies present in their habitat. While enemies such as parasitoids and predators will kill their hosts/preys when they successfully attack them, enemies such as micropredators will not entirely consume their prey. However, they can still have important consequences on the performance and ecology of the prey, such as reduced growth, increased emigration, disease transmission. In this paper, we investigated the impact of a terrestrial micropredator, the yellow fever mosquito Aedes aegypti, on its unusual invertebrate host, the Egyptian cotton leaf worm, Spodoptera littoralis. Larvae developing in presence of mosquitoes showed a slower development and reached a smaller pupal weight when compared to a control without mosquitoes, apparently because of a reduced feeding time for larvae. In addition, larvae tended to leave the plant in presence of mosquitoes. These results suggest that mosquitoes act as micropredators and affects lepidopteran larvae behaviour and development. Ecological impacts such as higher risks of food depletion and longer exposure to natural enemies are likely to be costly consequences. The importance of this phenomenon in nature – the possible function as last resort when vertebrates are unavailable – and the evolutionary aspects are discussed.

Martel, Veronique; Schlyter, Fredrik; Ignell, Rickard; Hansson, Bill S.; Anderson, Peter

2011-01-01

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Study of mosquito attractants for photo catalytic mosquito trap  

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Full Text Available Photo catalytic mosquito trap is made of TiO2-Activated Carbon (AC with a certain composition of AC. Research concerns on the heat spectrum which is produced by combination process of existing CO2 and humid air. The purpose of performance testing is to observe capability of this device in trapping mosquitoes related to the air temperature profile for heat spectrum is play important role for attracting mosquitoes. Result shows photo catalytic mosquito trap is more effective than devices which only consist of UV light or stream of CO2 and the humid air. A number of mosquitoes trapped by the photo catalyst coated panel configuration and UV lamps were lit proved far more effective because the heat production from recombination process. A little difference in temperature can be detected by mosquito.   Keywords: Photo Catalytic, Mosquito, Recombination.

Dewi Tristantini

2014-01-01

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Perspectives in the control of infectious diseases by transgenic mosquitoes in the post-genomic era: a review  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Arthropod-borne diseases caused by a variety of microorganisms such as dengue virus and malaria parasites afflict billions of people worldwide imposing major economic and social burdens. Despite many efforts, vaccines against diseases transmitted by mosquitoes, with the exception of yellow fever, ar [...] e not available. Control of such infectious pathogens is mainly performed by vector management and treatment of affected individuals with drugs. However, the numbers of insecticide-resistant insects and drug-resistant parasites are increasing. Therefore, inspired in recent years by a lot of new data produced by genomics and post-genomics research, several scientific groups have been working on different strategies to control infectious arthropod-borne diseases. This review focuses on recent advances and perspectives towards construction of transgenic mosquitoes refractory to malaria parasites and dengue virus transmission.

Márcia Aparecida, Sperança; Margareth Lara, Capurro.

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Mosquito transcriptome changes and filarial worm resistance in Armigeres subalbatus  

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Abstract Background Armigeres subalbatus is a natural vector of the filarial worm Brugia pahangi, but it rapidly and proficiently kills Brugia malayi microfilariae by melanotic encapsulation. Because B. malayi and B. pahangi are morphologically and biologically similar, the Armigeres-Brugia system serves as a valuable model for studying the resistance mechanisms in mosquito vectors. We have initiated transcriptome profilin...

Aliota Matthew T; Fuchs Jeremy F; Mayhew George F; Chen Cheng-Chen; Christensen Bruce M

2007-01-01

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Mosquito-Degradative-Potential of Cockroach and Mosquito Borne Bacteria  

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Full Text Available The type of bacteria present on two insects (cockroach and mosquito were investigated. These microorganisms were screened for microbial control of mosquito employing their degradative ability at various microbial cell loads. The degradation of the mosquito was observed spectrophotometrically for an incubation period of 5 to 7 days. Six bacterial species (Escherichia coli, Pseudomonas aeruginosa, Bacillus cereus, Serratia marcescens, Staphylococcus aureus and Aerobacter aerogenes were isolated from cockroach. Mosquito borne E. coli, P. aeruginosa, B. cereus and Staph. aureus. All the bacteria digested the mosquito with activity ranging from 0.02 to 1.27. Microorganisms associated with cockroach showed higher degradation activity (0.02-1.27 during the incubation than those obtained from mosquito (0.02-1.00.

F.O. Omoya

2009-01-01

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Shallow gas blowout kill operations  

International Nuclear Information System (INIS)

Shallow gas blowouts, as a general class, are the most difficult type of blowout to kill. This paper discusses current industry myths about shallow gas, typical results from a shallow gas blowout that affect the kill operation, kill options and selection criteria, rig selection criteria, and well killing guidelines. The new kill technique of vertical intervention is discussed relative to shallow gas blowouts. Also, a new technique for using horizontal wells in combination with the reservoir flood technique for killing shallow gas, cratered blowouts is explained

1991-11-16

40

Screening of selected ethnomedicinal plants from South Africa for larvicidal activity against the mosquito Anopheles arabiensis  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Background This study was initiated to establish whether any South African ethnomedicinal plants (indigenous or exotic), that have been reported to be used traditionally to repel or kill mosquitoes, exhibit effective mosquito larvicidal properties. Methods Extracts of a selection of plant taxa sourced in South Africa were tested for larvicidal properties in an applicable assay. Thirty 3rd instar Anopheles arabiensis larvae were expos...

Maharaj Rajendra; Maharaj Vinesh; Crouch Neil R; Bhagwandin Niresh; Folb Peter I; Pillay Pamisha; Gayaram Reshma

2012-01-01

 
 
 
 
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An elaborated feeding cycle model for reductions in vectorial capacity of night-biting mosquitoes by insecticide-treated nets  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Background Insecticide Treated Nets (ITNs) are an important tool for malaria control. ITNs are effective because they work on several parts of the mosquito feeding cycle, including both adult killing and repelling effects. Methods Using an elaborated description of the classic feeding cycle model, simple formulas have been derived to describe how ITNs change mosquito behaviour and the intensity of malaria transmission, as summarized by vectorial capacit...

2007-01-01

42

TRANSMISSION MODEL OF CHIKUNGUNYA FEVER IN THE PRESENCE OF TWO SPECIES OF AEDES MOSQUITOES  

Directory of Open Access Journals (Sweden)

Full Text Available In 2008 there was a large outbreak of Chikungunya fever in the south of Thailand. Chikungunya fever is a febrile disease transmitted to humans by the bite of infected Aedes mosquitoes. The symptoms of this disease are a sudden onset of a fever, chills, headache, nausea, vomiting, joint pain with or without swelling, low back pain and rash. In this study we study the effects of there being two species of Aedes mosquito (Aedes aegypti and Aedes albopictus present. In this study, we assume that both the human and mosquito populations are constant. A dynamical model of Chikungunya fever is proposed and analyzed. The Routh-Hurwitz criteria are used to determine the stability of the model. The conditions which would lead to either the disease free equilibrium state or the disease endemic equilibrium state to exist is determined. The numerical simulations are done in order to illustrate the behaviors of transmission of disease for different values of parameters. It is shown that the destruction of breeding sites could be an effective method to control this disease.

I. Ming Tang

2013-01-01

43

Mosquitoes of western Uganda.  

Science.gov (United States)

The mosquito fauna in many areas of western Uganda has never been studied and is currently unknown. One area, Bwamba County, has been previously studied and documented but the species lists have not been updated for >40 yr. This paucity of data makes it difficult to determine which arthropod-borne viruses pose a risk to human or animal populations. Using CO2 baited-light traps, from 2008 through 2010, 67,731 mosquitoes were captured at five locations in western Uganda including Mweya, Sempaya, Maramagambo, Bwindi (BINP), and Kibale (KNP). Overall, 88 mosquito species, 7 subspecies, and 7 species groups in 10 genera were collected. The largest number of species was collected at Sempaya (65 species), followed by Maramagambo (45), Mweya (34), BINP (33), and KNP (22). However, species diversity was highest in BINP (Simpson's Diversity Index 1-D = 0.85), followed by KNP (0.80), Maramagambo (0.79), Sempaya (0.67), and Mweya (0.56). Only six species Aedes (Aedimorphus) cumminsii (Theobald), Aedes (Neomelaniconion) circumluteolus (Theobald), Culex (Culex) antennatus (Becker), Culex (Culex) decens group, Culex (Lutzia) tigripes De Grandpre and De Charmoy, and Culex (Oculeomyia) annulioris (Theobald), were collected from all five sites suggesting large differences in species composition among sites. Four species (Aedes (Stegomyia) metallicus (Edwards), Anopheles (Cellia) rivulorum Leeson, Uranotaenia (Uranotaenia) chorleyi (Edwards), and Uranotaenia (Uranotaenia) pallidocephala (Theobald) and one subspecies (Aedes (Stegomyia) aegypti formosus (Walker)) were collected in Bwamba County for the first time. This study represents the first description of the mosquito species composition of Mweya, Maramagambo, BINP, and KNP. A number of morphological variations were noted regarding the postspiracular scales, hind tibia, and sternites that make Culex (Culex) neavei (Theobald) challenging to identify. At least 50 species collected in this study have previously been implicated in the transmission of arboviruses of public health importance suggesting a high potential for maintenance and transmission of a wide variety of arboviruses in western Uganda. PMID:23270157

Mutebi, J-P; Crabtree, M B; Kading, R C; Powers, A M; Lutwama, J J; Miller, B R

2012-11-01

44

'Doctors must not kill'.  

Science.gov (United States)

Four physicians respond to "It's over, Debbie," an anonymous resident physician's account of an incident when he or she injected a terminally ill cancer patient with a lethal dose of morphine (JAMA 1988 Jan 8; 259(2): 272). Gaylin and his colleagues condemn both the physician's violation of legal and ethical norms, and the conduct of JAMA's editor in publishing the article without editorial rebuke or comment. They warn that the issue of active euthanasia "touches medicine at its very moral center," and that, as pressure to legalize euthanasia in response to patient demand increases, the medical profession must repudiate direct and intentional killing of patients and discipline doctors who kill. PMID:3346989

Gaylin, W; Kass, L R; Pellegrino, E D; Siegler, M

1988-04-01

45

A simple non-powered passive trap for the collection of mosquitoes for arbovirus surveillance.  

Science.gov (United States)

Mosquitoes often are collected as part of an arbovirus surveillance program. However, trapping and processing of mosquitoes for arbovirus detection is often costly and difficult in remote areas. Most traps, such as the gold standard Center for Disease control light trap, require batteries that must be charged and changed overnight. To overcome this issue we have developed several passive traps for collection of mosquitoes that have no power requirements. The passive traps capture mosquitoes as they follow a CO2 plume up a polyvinyl chloride pipe leading to a clear chamber consisting of a plastic crate. We believe the translucent, clear windows created by the crate inhibits escape. Once inside the crate mosquitoes readily feed on honey-treated Flinders Technology Associates cards that then can be processed by polymerase chain reaction for viral ribonucleic acid. Of the two designs tested, the box or crate-based passive trap (passive box trap, PBT) generally caught more mosquitoes than the cylinder trap. In Latin square field trials in Cairns and Florida, PBTs collected mosquitoes at rates of 50 to 200% of Center for Disease Control model 512 light traps. Mosquito collections by PBTs can be increased by splitting the CO2 gas line so it services two traps, or by placing an octenol lure to the outside of the box. Very large collections can lead to crowding at honey-treated cards, reducing feeding rates. Addition of fipronil to the honey killed mosquitoes and did not impact feeding rates nor the ability to detect Kunjin viral ribonucleic acid by polymerase chain reaction; this could be used to minimize crowding affects on feeding caused by large collections. The passive traps we developed are made from inexpensive, commonly available materials. Passive traps may thus be suitable for collection of mosquitoes and potentially other hematophagous dipterans for pathogen surveillance. PMID:23427669

Ritchie, Scott A; Cortis, Giles; Paton, Christopher; Townsend, Michael; Shroyer, Donald; Zborowski, Paul; Hall-Mendelin, Sonja; Van Den Hurk, Andrew F

2013-01-01

46

Asymptotic symmetries on Killing horizons  

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We investigate asymptotic symmetries regularly defined on spherically symmetric Killing horizons in the Einstein theory with or without the cosmological constant. Those asymptotic symmetries are described by asymptotic Killing vectors, along which the Lie derivatives of perturbed metrics vanish on a Killing horizon. We derive the general form of asymptotic Killing vectors and find that the group of the asymptotic symmetries consists of rigid O(3) rotations of a horizon two-s...

Koga, Jun-ichirou

2001-01-01

47

Wolbachia surface protein induces innate immune responses in mosquito cells.  

Science.gov (United States)

BACKGROUND: Wolbachia endosymbiotic bacteria are capable of inducing chronic upregulation of insect immune genes in some situations and this phenotype may influence the transmission of important insect-borne pathogens. However the molecules involved in these interactions have not been characterized. RESULTS: Here we show that recombinant Wolbachia Surface Protein (WSP) stimulates increased transcription of immune genes in mosquito cells derived from the mosquito Anopheles gambiae, which is naturally uninfected with Wolbachia; at least two of the upregulated genes, TEP1 and APL1, are known to be important in Plasmodium killing in this species. When cells from Aedes albopictus, which is naturally Wolbachia-infected, were challenged with WSP lower levels of upregulation were observed than for the An. gambiae cells. CONCLUSIONS: We have found that WSP is a strong immune elicitor in a naturally Wolbachia-uninfected mosquito species (Anopheles gambiae) while a milder elicitor in a naturally-infected species (Aedes albopictus). Since the WSP of a mosquito non-native (nematode) Wolbachia strain was used, these data suggest that there is a generalized tolerance to WSP in Ae. albopictus. PMID:22375833

Pinto, Sofia B; Mariconti, Mara; Bazzocchi, Chiara; Bandi, Claudio; Sinkins, Steven P

2012-01-18

48

Wolbachia surface protein induces innate immune responses in mosquito cells  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Wolbachia endosymbiotic bacteria are capable of inducing chronic upregulation of insect immune genes in some situations and this phenotype may influence the transmission of important insect-borne pathogens. However the molecules involved in these interactions have not been characterized. Results Here we show that recombinant Wolbachia Surface Protein (WSP stimulates increased transcription of immune genes in mosquito cells derived from the mosquito Anopheles gambiae, which is naturally uninfected with Wolbachia; at least two of the upregulated genes, TEP1 and APL1, are known to be important in Plasmodium killing in this species. When cells from Aedes albopictus, which is naturally Wolbachia-infected, were challenged with WSP lower levels of upregulation were observed than for the An. gambiae cells. Conclusions We have found that WSP is a strong immune elicitor in a naturally Wolbachia-uninfected mosquito species (Anopheles gambiae while a milder elicitor in a naturally-infected species (Aedes albopictus. Since the WSP of a mosquito non-native (nematode Wolbachia strain was used, these data suggest that there is a generalized tolerance to WSP in Ae. albopictus.

Pinto Sofia B

2012-01-01

49

What Killed Substantial Form?  

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What killed substantial form, and can it live again? Substantial form died at the beginning of the scientific revolution when a new method made it unnecessary and a new view of the senses revealed by this new method made it unknowable. Conway's Game of Life as a model for Mechanism reveals not only the problems that make it impossible for contemporary thinkers to take substantial form seriously, but also a way in which the idea might be revived in a different form. The proponent of substantia...

2007-01-01

50

Assessing the optimal virulence of malaria-targeting mosquito pathogens: a mathematical study of engineered Metarhizium anisopliae  

Science.gov (United States)

Background Metarhizium anisopliae is a naturally occurring fungal pathogen of mosquitoes. Recently, Metarhizium has been engineered to act against malaria by directly killing the disease agent within mosquito vectors and also effectively blocking onward transmission. It has been proposed that efforts should be made to minimize the virulence of the fungal pathogen, in order to slow the development of resistant mosquitoes following an actual deployment. Results Two mathematical models were developed and analysed to examine the efficacy of the fungal pathogen. It was found that, in many plausible scenarios, the best effects are achieved with a reduced or minimal pathogen virulence, even if the likelihood of resistance to the fungus is negligible. The results for both models depend on the interplay between two main effects: the ability of the fungus to reduce the mosquito population, and the ability of fungus?infected mosquitoes to compete for resources with non?fungus?infected mosquitoes. Conclusions The results indicate that there is no obvious choice of virulence for engineered Metarhizium or similar pathogens, and that all available information regarding the population ecology of the combined mosquito?fungus system should be carefully considered. The models provide a basic framework for examination of anti?malarial mosquito pathogens that should be extended and improved as new laboratory and field data become available.

2014-01-01

51

Killing Spinors -- Beyond Supergravity  

CERN Document Server

This is a doctoral thesis on the application of techniques originally developed in the programme of characterisation of supersymmetric solutions to Supergravity theories, to finding alternative backgrounds. We start by discussing the concept of a Killing spinor, and how these are paramount to the process of classifying of these aforementioned supersymmetric solutions. Moreover, these geometric objects also have applications when considered in different scenarios (the 'beyond' in the title). In particular, techniques based on a parallelising rule for a spinorial field can be used for obtaining solutions to Einstein-Maxwell-De Sitter theories, as well as a (partial) classification of Lorentzian Einstein-Weyl manifolds, a problem of geometrical interest. The annexe contain an introduction and summary in Spanish language. The appendices discuss the tensorial and spinorial conventions employed, some relevant geometrical information on the scalar manifolds for the matter contents of interest, as well as for the nul...

Palomo-Lozano, Alberto

2012-01-01

52

What Killed Substantial Form?  

Directory of Open Access Journals (Sweden)

Full Text Available What killed substantial form, and can it live again? Substantial form died at the beginning of the scientific revolution when a new method made it unnecessary and a new view of the senses revealed by this new method made it unknowable. Conway's Game of Life as a model for Mechanism reveals not only the problems that make it impossible for contemporary thinkers to take substantial form seriously, but also a way in which the idea might be revived in a different form. The proponent of substantial form in the modern world should not oppose mechanism, but should insist upon it. If a thoroughgoing mechanism is true, it implies its own limits and requires the resurrection of form in a way that even a mechanist could love.

David Banach

2007-01-01

53

Development of the gravid Aedes trap for the capture of adult female container-exploiting mosquitoes (Diptera: Culicidae).  

Science.gov (United States)

Monitoring dengue vector control by sampling adult Aedes aegypti (L.) recently has been used to replace both larval and pupal surveys. We have developed and evaluated the Gravid Aedes Trap (GAT) through a sequential behavioral study. The GAT does not require electricity to function, and trapped mosquitoes are identified easily during trap inspections. The GAT concept relies on visual and olfactory cues to lure gravid Ae. aegypti and an insecticide to kill trapped mosquitoes. Gravid mosquitoes are lured to a black bucket base containing oviposition attractant (infusion) and are trapped in a translucent chamber impregnated with a pyrethroid insecticide where they are killed within 3-15 min. In semifield observations, the GAT captured a significantly higher proportion of gravid mosquitoes than the double sticky ovitrap. We also demonstrated that the visual cues of the prototype GAT-LgBF (large black base bucket with a black funnel at the top of the translucent chamber) captured a significantly higher proportion of gravid mosquitoes than the other prototypes. The visual contrast created by the addition of a white lid to the top of the black funnel significantly increased the number of captured gravid mosquitoes when compared with the GAT-LgBF in semifield trials. We conclude that the GAT is more efficient in recapturing gravid Ae. aegypti when compared with sticky ovitraps. The GAT is an effective, practical, low cost, and easily transportable trap, features that are essential in large-scale monitoring programs, particularly in areas where funding is limited. PMID:24605470

Eiras, Alvaro E; Buhagiar, Tamara S; Ritchie, Scott A

2014-01-01

54

Killing Horizons as Equipotential Hypersurfaces  

CERN Multimedia

We present a new, more general proof that Killing horizons are equipotential hypersurfaces for the electric and magnetic scalar potentials, that makes no use of gravitational field equations or the assumption about the existence of bifurcation surface. Also, we note that under certain conditions the electrodynamic equipotential hypersurfaces are necessarily Killing horizons.

Smoli?, Ivica

2012-01-01

55

Mosquito age and dengue transmission  

Science.gov (United States)

This online portal features a research project funded by The Grand Challenges in Global Health Initiative to develop new strategies to control mosquitoes that transmit human disease. Specifically, the project is focused on a method to reduce dengue transmission using naturally occurring bacterial symbionts that reduce mosquito life span. The site includes a background of this work, participating research programs and researchers, project publications, current progress, news and events, and FAQs.

Initiative, The G.

56

Gene Expression Studies in Mosquitoes  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Research on gene expression in mosquitoes is motivated by both basic and applied interests. Studies of genes involved in hematophagy, reproduction, olfaction, and immune responses reveal an exquisite confluence of biological adaptations that result in these highly-successful life forms. The requirement of female mosquitoes for a bloodmeal for propagation has been exploited by a wide diversity of viral, protozoan and metazoan pathogens as part of their life cycles. Identifying genes involved i...

Chen, Xlao-guang; Mathur, Geetika; James, Anthony A.

2008-01-01

57

Indoor Use of Plastic Sheeting Impregnated with Carbamate Combined with Long-Lasting Insecticidal Mosquito Nets for the Control of Pyrethroid-Resistant Malaria Vectors  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The combined efficacy of a long-lasting insecticidal net (LLIN) and a carbamate-treated plastic sheeting (CTPS) or indoor residual spraying (IRS) for control of insecticide-resistant mosquitoes was evaluated in experimental huts in Burkina Faso. Anopheles gambiae from the area is resistant to pyrethroids and to a lesser extent, carbamates. Relatively low mortality rates were observed with the LLIN (44%), IRS (42%), and CTPS (52%), whereas both combinations killed significantly more mosquitoes...

2010-01-01

58

Mosquito-borne illnesses in travelers: a review of risk and prevention.  

Science.gov (United States)

In 2008, residents of the United States made 12 million visits to developing countries in Asia, South America, Central America, Oceania, the Middle East, and Africa. Due to the presence of Anopheles, Aedes, and Culex mosquitoes, travel to these destinations poses a risk for diseases such as malaria, yellow fever, and Japanese encephalitis that cause significant morbidity and mortality. To gain a better understanding of the major emerging and established travel-related infectious diseases transmitted principally by mosquitoes and the measures for their prevention in U.S. residents who travel to these developing countries, we performed a literature search of the PubMed and MEDLINE databases (January 1950-February 2010). Information from the Centers for Disease Control and Prevention and the World Health Organization and relevant references from the publications identified were also reviewed. Vaccines for the prevention of Japanese encephalitis and yellow fever are commercially available to U.S. travelers and should be administered when indicated. However, the prevention of malaria, dengue fever, chikungunya, and West Nile virus relies on personal insect protection measures and chemoprophylaxis for malaria. As the rate of international travel continues to rise, individuals traveling overseas should be made aware of the risk of various infectious diseases and the importance of prevention. Physicians, pharmacists, nurses, and other practitioners can play a vital role in disease education and prevention, including the administration of vaccines and provision of chemoprophylactic drugs. PMID:20874041

Mirzaian, Edith; Durham, Melissa J; Hess, Karl; Goad, Jeffery A

2010-10-01

59

PCR detection of malaria parasites in desiccated Anopheles mosquitoes is uninhibited by storage time and temperature  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Reliable methods to preserve mosquito vectors for malaria studies are necessary for detecting Plasmodium parasites. In field settings, however, maintaining a cold chain of storage from the time of collection until laboratory processing, or accessing other reliable means of sample preservation is often logistically impractical or cost prohibitive. As the Plasmodium infection rate of Anopheles mosquitoes is a central component of the entomological inoculation rate and other indicators of transmission intensity, storage conditions that affect pathogen detection may bias malaria surveillance indicators. This study investigated the effect of storage time and temperature on the ability to detect Plasmodium parasites in desiccated Anopheles mosquitoes by real-time polymerase chain reaction (PCR. Methods Laboratory-infected Anopheles stephensi mosquitoes were chloroform-killed and stored over desiccant for 0, 1, 3, and 6 months while being held at four different temperatures: 28, 37, -20 and -80°C. The detection of Plasmodium DNA was evaluated by real-time PCR amplification of a 111 base pair region of block 4 of the merozoite surface protein. Results Varying the storage time and temperature of desiccated mosquitoes did not impact the sensitivity of parasite detection. A two-way factorial analysis of variance suggested that storage time and temperature were not associated with a loss in the ability to detect parasites. Storage of samples at 28°C resulted in a significant increase in the ability to detect parasite DNA, though no other positive associations were observed between the experimental storage treatments and PCR amplification. Conclusions Cold chain maintenance of desiccated mosquito samples is not necessary for real-time PCR detection of parasite DNA. Though field-collected mosquitoes may be subjected to variable conditions prior to molecular processing, the storage of samples over an inexpensive and logistically accessible desiccant will likely ensure accurate assessment of malaria parasite presence without diminishing PCR-detection of parasites in mosquitoes stored for at least six months.

Rider Mark A

2012-06-01

60

Sheep skin odor improves trap captures of mosquito vectors of Rift Valley fever.  

Science.gov (United States)

In recent years, the East African region has seen an increase in arboviral diseases transmitted by blood-feeding arthropods. Effective surveillance to monitor and reduce incidence of these infections requires the use of appropriate vector sampling tools. Here, trapped skin volatiles on fur from sheep, a known preferred host of mosquito vectors of Rift Valley fever virus (RVFV), were used with a standard CDC light trap to improve catches of mosquito vectors. We tested the standard CDC light trap alone (L), and baited with (a) CO(2) (LC), (b) animal volatiles (LF), and (c) CO(2) plus animal volatiles (LCF) in two highly endemic areas for RVF in Kenya (Marigat and Ijara districts) from March-June and September-December 2010. The incidence rate ratios (IRR) that mosquito species chose traps baited with treatments (LCF, LC and LF) instead of the control (L) were estimated. Marigat was dominated by secondary vectors and host-seeking mosquitoes were 3-4 times more likely to enter LC and LCF traps [IRR?=?3.1 and IRR?=?3.8 respectively] than the L only trap. The LCF trap captured a greater number of mosquitoes than the LC trap (IRR?=?1.23) although the difference was not significant. Analogous results were observed at Ijara, where species were dominated by key primary and primary RVFV vectors, with 1.6-, 6.5-, and 8.5-fold increases in trap captures recorded in LF, LC and LCF baited traps respectively, relative to the control. These catches all differed significantly from those trapped in L only. Further, there was a significant increase in trap captures in LCF compared to LC (IRR?=?1.63). Mosquito species composition and trap counts differed between the RVF sites. However, within each site, catches differed in abundance only and no species preferences were noted in the different baited-traps. Identifying the attractive components present in these natural odors should lead to development of an effective odor-bait trapping system for population density-monitoring and result in improved RVF surveillance especially during the inter-epidemic period. PMID:23133687

Tchouassi, David P; Sang, Rosemary; Sole, Catherine L; Bastos, Armanda D S; Mithoefer, Klaus; Torto, Baldwyn

2012-01-01

 
 
 
 
61

Another pipeline disaster: Molasses kills  

...Another pipeline disaster: Molasses kills Climate & Capitalism An ecosocialist journal Home About Ecosocialist Notebook Book Reviews Archives Articles By Subject Articles by ...Press MRzine Economist’s Travelogue You are here: Home / 2013 / September / 16 / Another pipeline disaster: Molasses kills Posted on September 16, 2013 Another pipeline disaster: ... Molasses kills Think about this the next time someone tells you pipelines are safe … Experts say this is the worst maritime environmental disaster ... leaked in Honolulu, spilling 233,000 gallons of molasses into the bay. That’s right, molasses. Sounds like a joke, doesn’t it?...

62

Larvicidal Activity of Tephrosia vogelii Crude Extracts on Mosquito Larval Stages  

Directory of Open Access Journals (Sweden)

Full Text Available The use of natural products and biological insect control methods is gaining importance because of concerns about the environment, since they are more easily biodegradable. In some parts of Uganda, organic farmers have adopted the use of Tephrosia vogelii, a shrubby, leguminous and woody plant for control of storage pests. However, the efficacy of Tephrosia vogelii crude extracts in the control of Dipteran insect larvae under field conditions has not been well tested. Their use for the control of insect vectors such as mosquitoes has not also been fully evaluated. Tephrosia vogelii plant materials were collected from two selected sites, one on a higher altitude than the other using polythene study. The material was chopped, properly labeled and air-dried in a shade for two weeks. Four solvents where used for extraction: Water, Petroleum ether, Chloroform, Methanol. The extract was dried in an oven at about 32-33°C for several days, after which it was weighed and stored in the fridge at 4°C until the time of exposing the mosquito larvae. Shoot Evening Methanol (SEM was the most effective among methanol extracts; killing an average of 4.57 mosquito larvae in 8 min while Shoot Evening Water (SEW was the most effective of water extracts killing an average of 2.57 mosquito larvae in 8 min; hence the SEM was considered to be nearly two times more efficacious than SEW on mosquito larvae, at a concentration of 25%: 10.8% or 2.3:1 SEM: SEW, respectively. Tephrosia vogelii crude extracts could potentially therefore be used to control the larval stages of mosquitoes.

2007-01-01

63

Analysis of mosquito larvicidal potential exhibited by vegetative cells of Bacillus thuringiensis subsp. israelensis.  

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Vegetative Bacillus thuringiensis subsp. israelensis cells (6 X 10(5)/ml) achieved 100% mortality of Aedes aegypti larvae within 24 h. This larvicidal potential was localized within the cells; the cell-free supernatants did not kill mosquito larvae. However, they did contain a heat-labile hemolysin which was immunologically distinct from the general cytolytic (hemolytic) factor released during solubilization of B. thuringiensis subsp. israelensis crystals. The larvicidal potential of the vege...

1986-01-01

64

Control of pyrethroid-resistant Anopheles gambiae and Culex quinquefasciatus mosquitoes with chlorfenapyr in Benin  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Objective To compare the efficacy of chlorfenapyr applied on mosquito nets and as an indoor residual spray against populations of Anopheles gambiae and Culex quinquefasciatus in an area of Benin that shows problematic levels of pyrethroid resistance. Method Eight-week trial conducted in experimental huts. Results Indoor residual spraying killed 82.9% of An. gambiae overall (mean mortality: 79.5%) compared to 53.5% overall (mean mortality: 61.7%) in the hut containing the lower dosed ITN. Anal...

2009-01-01

65

33 CFR 117.801 - Newtown Creek, Dutch Kills, English Kills and their tributaries.  

Science.gov (United States)

...2010-07-01 false Newtown Creek, Dutch Kills, English Kills and their tributaries...New York § 117.801 Newtown Creek, Dutch Kills, English Kills and their tributaries...apply to all bridges across Newtown Creek, Dutch Kills, English Kills, and their...

2010-07-01

66

Radiation biology of mosquitoes  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract There is currently renewed interest in assessing the feasibility of the sterile insect technique (SIT to control African malaria vectors in designated areas. The SIT relies on the sterilization of males before mass release, with sterilization currently being achieved through the use of ionizing radiation. This paper reviews previous work on radiation sterilization of Anopheles mosquitoes. In general, the pupal stage was irradiated due to ease of handling compared to the adult stage. The dose-response curve between the induced sterility and log (dose was shown to be sigmoid, and there was a marked species difference in radiation sensitivity. Mating competitiveness studies have generally been performed under laboratory conditions. The competitiveness of males irradiated at high doses was relatively poor, but with increasing ratios of sterile males, egg hatch could be lowered effectively. Males irradiated as pupae had a lower competitiveness compared to males irradiated as adults, but the use of partially-sterilizing doses has not been studied extensively. Methods to reduce somatic damage during the irradiation process as well as the use of other agents or techniques to induce sterility are discussed. It is concluded that the optimal radiation dose chosen for insects that are to be released during an SIT programme should ensure a balance between induced sterility of males and their field competitiveness, with competitiveness being determined under (semi- field conditions. Self-contained 60Co research irradiators remain the most practical irradiators but these are likely to be replaced in the future by a new generation of high output X ray irradiators.

Knols Bart GJ

2009-11-01

67

Natural plant sugar sources of Anopheles mosquitoes strongly impact malaria transmission potential.  

Science.gov (United States)

An improved knowledge of mosquito life history could strengthen malaria vector control efforts that primarily focus on killing mosquitoes indoors using insecticide treated nets and indoor residual spraying. Natural sugar sources, usually floral nectars of plants, are a primary energy resource for adult mosquitoes but their role in regulating the dynamics of mosquito populations is unclear. To determine how the sugar availability impacts Anopheles sergentii populations, mark-release-recapture studies were conducted in two oases in Israel with either absence or presence of the local primary sugar source, flowering Acacia raddiana trees. Compared with population estimates from the sugar-rich oasis, An. sergentii in the sugar-poor oasis showed smaller population size (37,494 vs. 85,595), lower survival rates (0.72 vs. 0.93), and prolonged gonotrophic cycles (3.33 vs. 2.36 days). The estimated number of females older than the extrinsic incubation period of malaria (10 days) in the sugar rich site was 4 times greater than in the sugar poor site. Sugar feeding detected in mosquito guts in the sugar-rich site was significantly higher (73%) than in the sugar-poor site (48%). In contrast, plant tissue feeding (poor quality sugar source) in the sugar-rich habitat was much less (0.3%) than in the sugar-poor site (30%). More important, the estimated vectorial capacity, a standard measure of malaria transmission potential, was more than 250-fold higher in the sugar-rich oasis than that in the sugar-poor site. Our results convincingly show that the availability of sugar sources in the local environment is a major determinant regulating the dynamics of mosquito populations and their vector potential, suggesting that control interventions targeting sugar-feeding mosquitoes pose a promising tactic for combating transmission of malaria parasites and other pathogens. PMID:21283732

Gu, Weidong; Müller, Günter; Schlein, Yosef; Novak, Robert J; Beier, John C

2011-01-01

68

Insecticide-resistant mosquitoes and malaria control.  

Science.gov (United States)

The emergence of insecticide-resistant mosquitoes strongly challenges the fight against mosquito-borne diseases, in particular malaria. In this paper, we formulate a system of nonlinear difference equations for malaria transmission cycle. Our model incorporates compartments for insecticide-resistant mosquitoes, where mutation is the only evolutionary force involved in the occurrence of resistant allele in the mosquito population. By deriving an epidemiological threshold, the global stability of the disease and the resistance-free fixed point is established for reduced recruitment rates of resistant mosquitoes. Furthermore, by employing numerical techniques, we showed that the mosquito-human transmission cycle of malaria and its prevalence could be impacted by mutation rate, the personal protection of hosts and the density of mosquitoes. Our results highlight that given a large mosquito population, the presence of even a small number of resistant mosquitoes to an insecticide could make the insecticide ineffective for malaria control. This suggests the need for effective insecticide management strategy, alternate mosquito control approaches, educating the public about personal protection and reduction of mosquito population in a given environment. PMID:24657875

Blayneh, Kbenesh W; Mohammed-Awel, Jemal

2014-06-01

69

Rural buyers' perception about mosquito repellants  

Directory of Open Access Journals (Sweden)

Full Text Available Mosquito repellants prevent mosquito bites and prevention of "man-mosquito contact" is a critical factor in transmission and spread of any disease through mosquitoes particularly in rural area. There has been a long standing 'bias' towards rural buyers. The rural markets are considered rigid in the nature but it is not the case in real sense. Marketing to rural buyers is not only a challenge to the marketers but to the manufacturers, communicators, national planners and economists as well. That is why it has been necessary to understand the various aspects of selected rural areas and consumption pattern for such a fast growing market i.e. mosquito repellants and rural buyers’ perception towards such urban products. The present paper aims to find out the factors influencing the purchase decisions of rural buyers for mosquito repellants and to study the perceptions of present and potential rural buyers' of selected mosquito repellant brands.

D. MEHTA

2010-06-01

70

Pharmacological Validation of an Inward-Rectifier Potassium (Kir) Channel as an Insecticide Target in the Yellow Fever Mosquito Aedes aegypti  

Science.gov (United States)

Mosquitoes are important disease vectors that transmit a wide variety of pathogens to humans, including those that cause malaria and dengue fever. Insecticides have traditionally been deployed to control populations of disease-causing mosquitoes, but the emergence of insecticide resistance has severely limited the number of active compounds that are used against mosquitoes. Thus, to improve the control of resistant mosquitoes there is a need to identify new insecticide targets and active compounds for insecticide development. Recently we demonstrated that inward rectifier potassium (Kir) channels and small molecule inhibitors of Kir channels offer promising new molecular targets and active compounds, respectively, for insecticide development. Here we provide pharmacological validation of a specific mosquito Kir channel (AeKir1) in the yellow fever mosquito Aedes aegypti. We show that VU590, a small-molecule inhibitor of mammalian Kir1.1 and Kir7.1 channels, potently inhibits AeKir1 but not another mosquito Kir channel (AeKir2B) in vitro. Moreover, we show that a previously identified inhibitor of AeKir1 (VU573) elicits an unexpected agonistic effect on AeKir2B in vitro. Injection of VU590 into the hemolymph of adult female mosquitoes significantly inhibits their capacity to excrete urine and kills them within 24 h, suggesting a mechanism of action on the excretory system. Importantly, a structurally-related VU590 analog (VU608), which weakly blocks AeKir1 in vitro, has no significant effects on their excretory capacity and does not kill mosquitoes. These observations suggest that the toxic effects of VU590 are associated with its inhibition of AeKir1.

Rouhier, Matthew F.; Raphemot, Rene; Denton, Jerod S.; Piermarini, Peter M.

2014-01-01

71

Killing spinors and gravitational perturbations  

International Nuclear Information System (INIS)

It is shown that in a vacuum space-time, possibly with a nonzero cosmological constant, which admits a D(1,0) Killing spinor, one component of the perturbed Weyl spinor that satisfies a decoupled equation, when multiplied by an appropriate factor made out of the components of the Killing spinor, constitutes a Debye potential that generates metric perturbations of the considered background. It is also shown that in the case where the background is of type N, there is an operation that relates the gravitational perturbations and the zero-rest-mass fields of spin-0, - 1/2 , and -1

1986-01-01

72

Measurement of landing mosquito density on humans.  

Science.gov (United States)

In traditional vector surveillance systems, adult mosquito density and the rate of mosquito-human host contact are estimated from the mosquito numbers captured in mechanical traps. But the design of the traps, their placement in the habitat and operating time, microclimate, and other environmental factors bias mosquito responses such that trapped mosquito numbers may be at variance with the numbers actually making human contact. As an alternative to mechanical traps, direct measurement of landing mosquito density enables real-time estimation of the mosquito-human-host-contact parameter. Based on this paradigm, we studied methods to measure mosquito landing responses to a human host. Our results showed: (a) an 18% difference (Planding responses of Culex nigripalpus Theobald and Cx. quinquefasciatus Say with increased sampling time; (c) no difference (P>0.55) in the average number of Ae. albopictus landing on the arm (8.6±1.6min(-1)) compared with the leg (9.2±2.5min(-1)) of the same human subject; (d) differences among day-to-day landing patterns for the mosquito species we studied but measurable periodicity (Planding mosquito density from air temperature (Planding density on a human subject. PMID:24769003

Barnard, Donald R; Dickerson, Catherine Z; Murugan, Kadarkarai; Xue, Rui-De; Kline, Daniel L; Bernier, Ulrich R

2014-08-01

73

Killing horizons as equipotential hypersurfaces  

International Nuclear Information System (INIS)

In this note we present a new proof that Killing horizons are equipotential hypersurfaces for the electric and the magnetic scalar potential, which makes no use of gravitational field equations or the assumption about the existence of a bifurcation surface. (note)

2012-10-21

74

Spills on the Arthur Kill and the Kill Van Kull  

International Nuclear Information System (INIS)

The Arthur Kill between Staten Island, New York City, and New Jersey is a heavily industrialized corridor, the site of major petroleum refineries and chemical processing facilities. New York Harbor is a busy port, second largest in the U.S. on a tonnage basis. Six thousand vessels call on the port annually, including 1700 tankers. eighteen billion gallons of petroleum are delivered annually, of which 2/3 are handled on the Kills. In this interplay of wildlife, oil and marine based transfer operations, New York harbor COTP area experiences oil spills, releasing 250,000 average total annual volume. In the first three months of 1990 the volume of oil spilled approximately 750,000 gallons was released, threefold the annual average. The three major spills which caused this large release, and the governmental response, from the subject of this paper

1990-05-15

75

New Nebraska mosquito distribution records.  

Science.gov (United States)

Larval collections in Nebraska during 2000 established 2 new state distribution records for Ochlerotatus epactius and Anopheles perplexens and confirmed the presence of Culiseta melanura, bringing the total number of mosquito species reported from Nebraska to 50. Fifteen new county records for 10 species are noted, including the 1st report of Aedes albopictus from Lancaster County, marking its westernmost collection in Nebraska to date. PMID:11804465

Moore, J P

2001-12-01

76

North American Wetlands and Mosquito Control  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Wetlands are valuable habitats that provide important social, economic, and ecological services such as flood control, water quality improvement, carbon sequestration, pollutant removal, and primary/secondary production export to terrestrial and aquatic food chains. There is disagreement about the need for mosquito control in wetlands and about the techniques utilized for mosquito abatement and their impacts upon wetlands ecosystems. Mosquito control in wetlands is a complex issue influenced ...

2012-01-01

77

North American wetlands and mosquito control.  

Science.gov (United States)

Wetlands are valuable habitats that provide important social, economic, and ecological services such as flood control, water quality improvement, carbon sequestration, pollutant removal, and primary/secondary production export to terrestrial and aquatic food chains. There is disagreement about the need for mosquito control in wetlands and about the techniques utilized for mosquito abatement and their impacts upon wetlands ecosystems. Mosquito control in wetlands is a complex issue influenced by numerous factors, including many hard to quantify elements such as human perceptions, cultural predispositions, and political climate. In spite of considerable progress during the last decades, habitat protection and environmentally sound habitat management still remain inextricably tied to politics and economics. Furthermore, the connections are often complex, and occur at several levels, ranging from local businesses and politicians, to national governments and multinational institutions. Education is the key to lasting wetlands conservation. Integrated mosquito abatement strategies incorporate many approaches and practicable options, as described herein, and need to be well-defined, effective, and ecologically and economically sound for the wetland type and for the mosquito species of concern. The approach will certainly differ in response to disease outbreaks caused by mosquito-vectored pathogens versus quality of life issues caused by nuisance-biting mosquitoes. In this contribution, we provide an overview of the ecological setting and context for mosquito control in wetlands, present pertinent information on wetlands mosquitoes, review the mosquito abatement options available for current wetlands managers and mosquito control professionals, and outline some necessary considerations when devising mosquito control strategies. Although the emphasis is on North American wetlands, most of the material is applicable to wetlands everywhere. PMID:23222252

Rey, Jorge R; Walton, William E; Wolfe, Roger J; Connelly, C Roxanne; O'Connell, Sheila M; Berg, Joe; Sakolsky-Hoopes, Gabrielle E; Laderman, Aimlee D

2012-12-01

78

North American Wetlands and Mosquito Control  

Directory of Open Access Journals (Sweden)

Full Text Available Wetlands are valuable habitats that provide important social, economic, and ecological services such as flood control, water quality improvement, carbon sequestration, pollutant removal, and primary/secondary production export to terrestrial and aquatic food chains. There is disagreement about the need for mosquito control in wetlands and about the techniques utilized for mosquito abatement and their impacts upon wetlands ecosystems. Mosquito control in wetlands is a complex issue influenced by numerous factors, including many hard to quantify elements such as human perceptions, cultural predispositions, and political climate. In spite of considerable progress during the last decades, habitat protection and environmentally sound habitat management still remain inextricably tied to politics and economics. Furthermore, the connections are often complex, and occur at several levels, ranging from local businesses and politicians, to national governments and multinational institutions. Education is the key to lasting wetlands conservation. Integrated mosquito abatement strategies incorporate many approaches and practicable options, as described herein, and need to be well-defined, effective, and ecologically and economically sound for the wetland type and for the mosquito species of concern. The approach will certainly differ in response to disease outbreaks caused by mosquito-vectored pathogens versus quality of life issues caused by nuisance-biting mosquitoes. In this contribution, we provide an overview of the ecological setting and context for mosquito control in wetlands, present pertinent information on wetlands mosquitoes, review the mosquito abatement options available for current wetlands managers and mosquito control professionals, and outline some necessary considerations when devising mosquito control strategies. Although the emphasis is on North American wetlands, most of the material is applicable to wetlands everywhere.

Gabrielle E. Sakolsky-Hoopes

2012-12-01

79

Plant extracts as potential mosquito larvicides  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Mosquitoes act as a vector for most of the life threatening diseases like malaria, yellow fever, dengue fever, chikungunya ferver, filariasis, encephalitis, West Nile Virus infection, etc. Under the Integrated Mosquito Management (IMM), emphasis was given on the application of alternative strategies in mosquito control. The continuous application of synthetic insecticides causes development of resistance in vector species, biological magnification of toxic substances through the food chain an...

Ghosh, Anupam; Chowdhury, Nandita; Chandra, Goutam

2012-01-01

80

Genetically Modified Mosquito: Myth and Reality  

Directory of Open Access Journals (Sweden)

Full Text Available Sterile Insect Technique (SIT has been applied successfully in some agricultural pest control programs in the past, but in many cases, success has not been sustainable in the long run. Various attempts have been made to duplicate this limited success SIT application in agriculture to other areas of applications, particularly in vector control. For example, a recent mosquito control program has been initiated in Malaysia to eliminate dengue-mosquitoes Aedes aegypti by releasing large amount of genetically modified GM male mosquitoes into the field to outcompete the wild male mosquitoes. Field experimental data that has been made available in the literature is limited, rendering it difficult to make independent assessment on its short-term efficacy and long-term sustainability of this GM control strategy. This paper presents a preliminary assessment of the effectiveness of GM mosquito in controlling dengue mosquito population by means of model simulations via DEER (Dengue Encephalitis Eradication Routines. Preliminary results indicate negative conclusion regarding the effectiveness of GM mosquitoes in controlling wild A. aegypti population over the long-term. Essentially, significant reduction of wild mosquito population is possible only if large over-flooding ratios are applied. Further, repeated releases must be maintained over an infinite time horizon to continue to sustain low population of mosquitoes. Major difficulty remains to be resolved. In particular, in-depth costbenefit analysis on this control program is essential to ensure long-term institutional and social support.

Teh Su Yean

2013-02-01

 
 
 
 
81

Gentamicin kills intracellular Listeria monocytogenes.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The purpose of the experiments described here was to test whether membrane-impermeant antibiotics present in the extracellular milieu could kill bacteria within macrophages. For this, mouse macrophage hybrids and elicited mouse peritoneal macrophages first were allowed to phagocytose the facultative intracellular bacterium Listeria monocytogenes. The cells were incubated with or without gentamicin, and their bactericidal activity was measured. The results show that gentamicin caused normally ...

Drevets, D. A.; Canono, B. P.; Leenen, P. J.; Campbell, P. A.

1994-01-01

82

Fluid dynamics kill Wyoming icicle  

Energy Technology Data Exchange (ETDEWEB)

Control of a blowout in which a portion of the drill collar string was extending through the rotary table and into the derrick was compounded by ice building up on the derrick and substructure. However, the momentum kill procedure proved successful. Topics considered in this paper include oil wells, natural gas wells, sleeves, rotary drills, drilling rigs, fluid mechanics, occupational safety, blowouts, drill pipes, rotary drilling, ice removal, and freezing.

Grace, R.D.

1987-04-01

83

Wind power and bird kills  

Energy Technology Data Exchange (ETDEWEB)

The accidental killing of birds by wind generators, and design improvements in the towers that support the turbines that might cut down on the bird killings were discussed. The first problem for the industry began in the late 1980s when the California Energy Commission reported as many as 160 birds (the majority being raptors, including the protected golden eagle) killed in one year in the vicinity of wind power plants. The key factor identified was the design of the towers as birds of prey are attracted to lattice towers as a place to hunt from. Tubular towers do not provide a place for the birds to perch, therefore they reduce the potential for bird strikes. Bird strikes also have been reported in Spain and the siting of the towers have been considered as the principal cause of the bird strikes. In view of these incidents, the wind power industry is developing standards for studying the potential of bird strikes and is continuing to study bird behaviour leading to collisions, the impact of topography, cumulative impacts and new techniques to reduce bird strikes. Despite the reported incidents, the risk of bird strikes by wind turbines, compared to other threats to birds such as pollution, oil spills, and other threats from fossil and nuclear fuels, is considered to be negligible. With continuing efforts to minimize incidents by proper design and siting, wind power can continue to grow as an environmentally sound and efficient source of energy.

Raynolds, M.

1998-12-01

84

Wind power and bird kills  

International Nuclear Information System (INIS)

The accidental killing of birds by wind generators, and design improvements in the towers that support the turbines that might cut down on the bird killings were discussed. The first problem for the industry began in the late 1980s when the California Energy Commission reported as many as 160 birds (the majority being raptors, including the protected golden eagle) killed in one year in the vicinity of wind power plants. The key factor identified was the design of the towers as birds of prey are attracted to lattice towers as a place to hunt from. Tubular towers do not provide a place for the birds to perch, therefore they reduce the potential for bird strikes. Bird strikes also have been reported in Spain and the siting of the towers have been considered as the principal cause of the bird strikes. In view of these incidents, the wind power industry is developing standards for studying the potential of bird strikes and is continuing to study bird behaviour leading to collisions, the impact of topography, cumulative impacts and new techniques to reduce bird strikes. Despite the reported incidents, the risk of bird strikes by wind turbines, compared to other threats to birds such as pollution, oil spills, and other threats from fossil and nuclear fuels, is considered to be negligible. With continuing efforts to minimize incidents by proper design and siting, wind power can continue to grow as an environmentally sound and efficient source of energy

1998-12-01

85

Killing-Yano tensors and Nambu mechanics  

International Nuclear Information System (INIS)

Killing-Yano tensors were introduced in 1952 by Kentaro-Yano from mathematical point of view. The physical interpretation of Killing-Yano tensors of rank higher than two was unclear. We found that all Killing-Yano tensors ?i1i2...in with covariant derivative zero are Nambu tensors. We found that in the case of flat space case all Killing-Yano tensors are Nambu tensors. In the case of Taub-NUT and Kerr-Newmann metric Killing-Yano tensors of order two generate Nambu tensors of rank 3

1998-01-01

86

Oviposition-Modifying Substances for Mosquitoes.  

Science.gov (United States)

The objectives of this research project are to study the chemistry and the biology of oviposition-modifying substances for mosquitoes, to investigate the possibility of applying them in the management of mosquito populations, and to evaluate the role of o...

Y. S. Hwang

1980-01-01

87

Aquatic insect predators and mosquito control.  

Science.gov (United States)

Mosquitoes are serious biting pests and obligate vectors of many vertebrate pathogens. Their immature larval and pupal life stages are a common feature in most tropical and many temperate water bodies and often form a significant proportion of the biomass. Control strategies rely primarily on the use of larvicides and environmental modification to reduce recruitment and adulticides during periods of disease transmission. Larvicides are usually chemical but can involve biological toxins, agents or organisms. The use of insect predators in mosquito control has been exploited in a limited fashion and there is much room for further investigation and implementation. Insects that are recognized as having predatorial capacity with regard to mosquito prey have been identified in the Orders Odonata, Coleoptera, Diptera (primarily aquatic predators), and Hemiptera (primarily surface predators). Although their capacity is affected by certain biological and physical factors, they could play a major role in mosquito control. Furthermore, better understanding for the mosquitoes-predators relationship(s) could probably lead to satisfactory reduction of mosquito-borne diseases by utilizing either these predators in control programs, for instance biological and/or integrated control, or their kairomones as mosquitoes' ovipoisting repellents. This review covers the predation of different insect species on mosquito larvae, predator-prey-habitat relationships, co-habitation developmental issues, survival and abundance, oviposition avoidance, predatorial capacity and integrated vector control. PMID:20237438

Shaalan, Essam Abdel-Salam; Canyon, Deon V

2009-12-01

88

Free flight of the mosquito Aedes aegypti  

CERN Multimedia

High speed video observations of free flying male Aedes aegypti mosquitoes, the dengue and yellow fever vector, along with custom measurement methods, enable measurement of wingbeat frequency, body position and body orientation of mosquitoes during flight. We find these mosquitoes flap their wings at approximately 850 Hz. We also generate body yaw, body pitch and wing deviation measurements with standard deviations of less than 1 degree and find that sideways velocity and acceleration are important components of mosquito motion. Rapid turns involving changes in flight direction often involve large sideways accelerations. These do not correspond to commensurate changes in body heading, and the insect's flight direction and body heading are decoupled during flight. These findings call in to question the role of yaw control in mosquito flight. In addition, using orientation data, we find that sideways accelerations are well explained by roll-based rotation of the lift vector. In contrast, the insect's body pitch...

Iams, S M

2012-01-01

89

Human to Mosquito Transmission of Dengue Viruses  

Science.gov (United States)

The successful transmission of dengue virus from a human host to a mosquito vector requires a complex set of factors to align. It is becoming increasingly important to improve our understanding of the parameters that shape the human to mosquito component of the transmission cycle so that vaccines and therapeutic antivirals can be fully evaluated and epidemiological models refined. Here we describe these factors, and discuss the biological and environmental impacts and demographic changes that are influencing these dynamics. Specifically, we examine features of the human infection required for the mosquito to acquire the virus via natural blood feeding, as well as the biological and environmental factors that influence a mosquito’s susceptibility to infection, up to the point that they are capable of transmitting the virus to a new host.

Carrington, Lauren B.; Simmons, Cameron P.

2014-01-01

90

9 CFR 113.205 - Newcastle Disease Vaccine, Killed Virus.  

Science.gov (United States)

...2009-01-01 2009-01-01 false Newcastle Disease Vaccine, Killed Virus. 113...REQUIREMENTS Killed Virus Vaccines § 113.205 Newcastle Disease Vaccine, Killed Virus. Newcastle Disease Vaccine (Killed Virus)...

2009-01-01

91

9 CFR 113.201 - Canine Distemper Vaccine, Killed Virus.  

Science.gov (United States)

... 2009-01-01 2009-01-01 false Canine Distemper Vaccine, Killed Virus. 113...REQUIREMENTS Killed Virus Vaccines § 113.201 Canine Distemper Vaccine, Killed Virus. Canine Distemper Vaccine, Killed Virus,...

2009-01-01

92

9 CFR 113.204 - Mink Enteritis Vaccine, Killed Virus.  

Science.gov (United States)

... 1 2010-01-01 2010-01-01 false Mink Enteritis Vaccine, Killed Virus. 113.204...REQUIREMENTS Killed Virus Vaccines § 113.204 Mink Enteritis Vaccine, Killed Virus. Mink Enteritis Vaccine, Killed Virus, shall...

2010-01-01

93

Ecology of vector mosquitoes in Sri Lanka--suggestions for future mosquito control in rice ecosystems.  

Science.gov (United States)

Mosquito-borne diseases are a major public health threat in Asia. To explore effective mosquito control strategies in rice ecosystems from the ecological point of view, we carried out ecological analyses of vector mosquitoes in Sri Lanka. During the 18-month study period, 14 Anopheles, 11 Culex, 5 Aedes, 2 Mansonia, and 1 Armigeres species were collected, most of which are disease vectors for malaria, filariasis, Japanese encephalitis, or dengue in Sri Lanka and elsewhere in Asia. The density and occurrence of Anopheles and Culex species were the highest in seepage pools and paddy fields, where the majority of niche overlaps between larval mosquito and aquatic insect species were observed. All 7 aquatic insect species, which are larval mosquito predators, overlapped their niche with both Anopheles and Culex larvae. This suggests that conserving these aquatic insect species could be effective in controlling mosquito vectors in the study site. Correlations between several climatic factors and mosquito density were also analyzed, and weather conditions, including higher temperature, lower relative humidity, and higher wind velocity, were found to affect mosquito oviposition, propagation, and survival. These findings deepen our understanding of mosquito ecology and will strengthen future mosquito control strategies in rice ecosystems in Asia. PMID:17883002

Yasuoka, Junko; Levins, Richard

2007-07-01

94

Hyperthermic cell killing and radiosensitization  

International Nuclear Information System (INIS)

Hyperthermic inhibition of DNA repair may not only cause radiosensitization, but might also play a substantial role in the mechanism of cell killing by heat alone, e.g. by the inhibition of post-replication repair. If cell survival after hyperthermia or a combined heat plus radiation treatment is determined by the impairment of only one specific step of DNA repair, the degree of impairment has to correlate with survival after heat alone or in combination with radiation, under a variety of conditions that alter cell survival. The protective effect of thermotolerance and erythritol, and sensitization by step-down heating and procaine were used as tools to study whether such a correlation could be found for the inhibition of strand-break repair or DNA polymerase inactivation. During this study a small number of DNA strand breaks (or alkali-labile lesions) was observed to arise from hyperthermia alone. The relationship of these lesions to hyperthermic cell killing was further investigated. 524 refs.; 59 figs.; 15 tabs

1986-01-01

95

Integrability Conditions for Killing-Yano Tensors and Conformal Killing-Yano Tensors  

CERN Document Server

The integrability conditions for the existence of a conformal Killing-Yano tensor of arbitrary order are worked out in all dimensions. As a consequence, the integrability conditions for the existence of a Killing-Yano tensor are also obtained. By means of such conditions, it is shown that in certain Einstein spaces one can use a conformal Killing-Yano tensor of order p to generate a Killing-Yano tensor of order (p-1). Finally, it is proved that in maximally symmetric spaces the covariant derivative of a Killing-Yano tensor is a closed conformal Killing-Yano tensor and that every conformal Killing-Yano tensor is the sum of a Killing-Yano tensor and a closed conformal Killing-Yano tensor.

Batista, Carlos

2014-01-01

96

Evidence that Killing Escalates Within-Subjects in a Bug-Killing Paradigm.  

Science.gov (United States)

Prior research has examined killing behavior using a paradigm in which participants believe (falsely) that they are killing bugs. This work suggests that killing behavior escalates. In the present study, we sought to replicate the basic escalation effect within-subjects. Further, in doing so, we controlled for experimenter "sanctioning" of killing that may have differed with key between-subjects manipulations in the prior research. To control for this possible confound, the present experiment held experimenter instructions constant and examined whether killing naturally escalated within-subjects across two 12-sec bug-killing tasks. Additionally, to verify that escalation is due to killing per se and not just physical practice of the procedure, we manipulated whether the procedure was described as real killing or simulated killing. Results showed that when participants thought they were killing bugs, the number of bugs put into the grinder increased from the first to the second killing task. No such escalation occurred when participants performed the procedure while knowing the killing was simulated. Thus, killing of bugs escalates and is not simply a consequence of perceived sanctioning of killing by an experimenter or simulated practice of the procedure. PMID:22331599

Martens, Andy; Kosloff, Spee

2012-02-13

97

Diversity and function of bacterial microbiota in the mosquito holobiont  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Mosquitoes (Diptera: Culicidae) have been shown to host diverse bacterial communities that vary depending on the sex of the mosquito, the developmental stage, and ecological factors. Some studies have suggested a potential role of microbiota in the nutritional, developmental and reproductive biology of mosquitoes. Here, we present a review of the diversity and functions of mosquito-associated bacteria across multiple variation factors, emphasizing recent findings. Mosquito microbiota is consi...

Minard, Guillaume; Mavingui, Patrick; Moro, Claire Valiente

2013-01-01

98

Ecology of mosquitoes of Midwestern Nigeria  

Directory of Open Access Journals (Sweden)

Full Text Available Background & objectives: The ecology and distribution of various mosquito species is important inthe determination of mosquito vector abundance and associated diseases prevalence. The distributionof various mosquito genera in natural and artificial habitats and their relative species abundancewas studied between August 2002 and July 2003 in three foci (Uromi, Ekpoma and Auchi comprisingthe Esan and Etsako regions of Midwestern Nigeria.Methods: Sampling was carried out by the method of Hopkins (1952 by dipping using a pipette orladle depending on container types. Pooled contents of smaller containers were sampled with a pondnet. All breeding sources of mosquito larvae were grouped into five (5 depending on their nature,constitution and the physiochemical properties. Artificial mosquito cultures were also carried out infour different container types; plastics, metal cans, earthenware pots and bamboo strips, in parts oftwo different macro habitats subdivided into area of high human activities (AHHA and areas ofderived/secondary vegetation (ADSV. Environmental temperatures, rainfall and relative humiditywere monitored during the study.Results: The present study revealed 17 mosquito species belonging to three genera (Anopheles,Culex and Aedes which are potential vectors of four human diseases in the areas surveyed. A total of736 mosquito larvae were encountered in artificial sources and 568 larvae were harvested from naturalsources. Pools, plastics and metal cans were the predominant artificial sources of mosquito larvae.Conclusion: The contribution of human activities and increasing environmental modification to thebreeding of human disease vector mosquitoes is of importance and selective vector control measuresincluding larviciding are recommended particularly before onset of rainy season

Godwin R.A. Okogun, Jude C. Anosike, Anthony N. Okere & Bethran E.B. Nwoke

2005-03-01

99

Killing tensors in pp-wave spacetimes  

International Nuclear Information System (INIS)

The formal solution of the second-order Killing tensor equations for the general pp-wave spacetime is given. The Killing tensor equations are integrated fully for some specific pp-wave spacetimes. In particular, the complete solution is given for the conformally flat plane wave spacetimes and we find that irreducible Killing tensors arise for specific classes. The maximum number of independent irreducible Killing tensors admitted by a conformally flat plane wave spacetime is shown to be six. It is shown that every pp-wave spacetime that admits an homothety will admit a Killing tensor of Koutras type and, with the exception of the singular scale-invariant plane wave spacetimes, this Killing tensor is irreducible.

2010-12-21

100

Attracted to the enemy: Aedes aegypti prefers oviposition sites with predator-killed conspecifics.  

Science.gov (United States)

Oviposition habitat choices of species with aquatic larvae are expected to be influenced by both offspring risk of mortality due to predation, and offspring growth potential. Aquatic predators may indirectly influence growth potential for prey by reducing prey density and, for filter-feeding prey, by increasing bacterial food for prey via added organic matter (feces, partially eaten victims), creating the potential for interactive effects on oviposition choices. We tested the hypothesis that the mosquito Aedes aegypti preferentially oviposits in habitats with predatory Toxorhynchites larvae because of indirect effects of predation on chemical cues indicating bacterial abundance. We predicted that A. aegypti would avoid oviposition in sites with Toxorhynchites, but prefer to oviposit where bacterial food for larvae is abundant, and that predation by Toxorhynchites would increase bacterial abundances. Gravid A. aegypti were offered paired oviposition sites representing choices among: predator presence; the act of predation; conspecific density; dead conspecific larvae; and bacterial activity. A. aegypti preferentially oviposited in sites with Toxorhynchites theobaldi predation, and with killed conspecific larvae, but failed to detect preferences for other treatments. The antibiotic tetracycline eliminated the strongest oviposition preference. Both predation by Toxorhynchites and killed larvae increased bacterial abundances, suggesting that oviposition attraction is cued by bacteria. Our results show the potential for indirect effects, like trophic cascades, to influence oviposition choices and community composition in aquatic systems. Our results suggest that predators like Toxorhynchites may be doubly beneficial as biocontrol agents because of the attraction of ovipositing mosquitoes to bacterial by-products of Toxorhynchites feeding. PMID:24590205

Albeny-Simões, Daniel; Murrell, Ebony G; Elliot, Simon L; Andrade, Mateus R; Lima, Eraldo; Juliano, Steven A; Vilela, Evaldo F

2014-06-01

 
 
 
 
101

Attract-and-kill strategy. Laboratory studies on hatched larvae of Culex pipiens.  

Science.gov (United States)

The attract-and-kill strategy is a new pest management technique that presupposes the intelligent combination of an attracting agent (e.g. pheromone) and a killing agent (e.g. insecticide). In the present study, the potential combination of the microencapsulated synthetic oviposition pheromone 6-acetoxy-5-hexadecanolide with an insecticide has been tested. Initially, polyurea microcapsules containing 6-acetoxy-5-hexadecanolide, the synthetic mixture of diastereomers of the oviposition pheromone of the mosquito species Culex quinquefasciatus Say (Diptera: Culicidae), were studied. Laboratory bioassays were performed to confirm the bioactivity of the microencapsulated pheromone on the oviposition activity of Culex pipiens L. biotype molestus Førskal (Diptera: Culicidae) with the aim of determining the optimum dose for oviposition response. Its effect was dose dependent, revealing an optimum dose of 300 mg of dried microcapsules. Attractancy over time was also studied. The microencapsulated pheromone was found to be sufficiently attractive to gravid female mosquitoes for a period of 40 days. Finally, the combination of the synthetic pheromone with the control agent temephos showed both an acceptable oviposition activity and sufficient larvicidal effect. PMID:17708518

Michaelakis, Antonios; Mihou, Anastasia P; Koliopoulos, George; Couladouros, Elias A

2007-10-01

102

Can mosquitoes fly in the rain?  

CERN Multimedia

Collisions with raindrops are one of many obstacles insects face during flight. In this fluid dynamics video, we present a series of high-speed films of impacts between mosquitoes and raindrops. We also present drop impacts upon insect mimics, which are unsupported styrofoam balls of the same mass as mosquitoes. High-speed videography and particle tracking during collision are employed to determine the insect position versus time. We determine the magnitude of acceleration by considering the momentum transfer and impact duration. Experiments with live mosquitoes indicate a surprising ability to quickly recover flight post-collision, despite accelerations of 30-300 gravities over durations of 1 ms.

Dickerson, Andrew; Madhavan, Nihar; Hu, David

2011-01-01

103

The discerning predator: decision rules underlying prey classification by a mosquito-eating jumping spider  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Evarcha culicivora is an East African jumping spider that feeds indirectly on vertebrate blood by choosing blood-fed female Anopheles mosquitoes as prey. Previous studies have shown that this predator can identify its preferred prey even when restricted to using only visual cues. Here, we used lures and virtual mosquitoes to investigate the optical cues underlying this predator's prey-choice behaviour. We made lures by dissecting and then reconstructing dead mosquitoes, combining the head plu...

Nelson, Ximena J.; Jackson, Robert R.

2012-01-01

104

Male-killing in African butterflies  

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Female-biased sex ratios occur in many insect species as a consequence of infection by maternally-inherited male-killing bacterial endosymbionts. In this paper, we revise the research conducted on the phenomenon of male-killing in African nymphalid butterflies, with special focus on the cases of Danaus chrysippus, Acraea encedon and Acraea encedana. The evolution of male-killing in each case was addressed, together with the phylogeny of male-killers that were identi...

Hassan, Sami Saeed M.; Eihab Idris

2013-01-01

105

Models for dynamic kill of blowouts  

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Blowouts represent one of the largest risks oil companies are exposed to during exploration and exploitation of petroleum resources, and the increasing complexity of e.g. drilling operations states the need for more sophisticated well control modeling tools. Dynamic kill is a technique combining the static head of a kill fluid with frictional pressure losses in order to suppress the reservoir pressure and kill the blowout. The technique can be modeled dynamically with the use of two-phase flo...

2011-01-01

106

Fish Kills in Ireland in 1989  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The final estimate for the number of fish kills in 1989 was 111. The increase in 1989 is largely accounted for by the exceptional warm weather conditions which prevailed. Details of all the incidents are given in the following pages. When these are analysed some very significant facts emerge. The number of fish kills while higher than in 1988 (50 kills) was about nine percent lower than in 1987 (122 kills). Low water due to dry weather conditions was the most important factor in 1989 raising ...

Moriarty, C.

1990-01-01

107

Efficacy of Mosquito Traps for Collecting Potential West Nile Mosquito Vectors in a Natural Mediterranean Wetland  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Surveillance, research, and control of mosquito-borne diseases such as West Nile virus require efficient methods for sampling mosquitoes. We compared the efficacy of BG-Sentinel and Centers for Disease Control and Prevention (CDC)-CO2 traps in terms of the abundances of host-seeking and blood-fed female mosquitoes and the origin of mosquito bloodmeals. Our results indicate that BG-Sentinel traps that use CO2 and attractants are as effective as CDC-CO2 traps for Cule...

2012-01-01

108

Chromosome phylogenies of malaria mosquitoes.  

Science.gov (United States)

Malaria mosquitoes often belong to complexes of sibling species, members of which are morphologically and genetically similar to each other. However, members within these complexes can vary significantly in their ecological adaptations and abilities to transmit the malaria parasite. The high degree of genetics similarity among sibling species makes the reconstruction of phylogenetic relationships within species complexes difficult. This paper reviews studies that infer the ancestral--descendant relationships among sibling species using molecular markers and chromosomal inversions. A methodology based on analyzing breakpoints of fixed overlapping inversions is shown to be useful for rooting phylogenies in complexes of sibling species, if the chromosomal arrangements in outgroup species are known. The construction of detailed phylogenies for malaria vectors will help to identify the association of evolutionary genomic changes with the origin of human blood choice and specific ecological adaptations. PMID:23875455

Sharakhov, I V

2013-01-01

109

Mosquito transcriptome changes and filarial worm resistance in Armigeres subalbatus  

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Full Text Available Abstract Background Armigeres subalbatus is a natural vector of the filarial worm Brugia pahangi, but it rapidly and proficiently kills Brugia malayi microfilariae by melanotic encapsulation. Because B. malayi and B. pahangi are morphologically and biologically similar, the Armigeres-Brugia system serves as a valuable model for studying the resistance mechanisms in mosquito vectors. We have initiated transcriptome profiling studies in Ar. subalbatus to identify molecular components involved in B. malayi refractoriness. Results These initial studies assessed the transcriptional response of Ar. subalbatus to B. malayi at 1, 3, 6, 12, 24, 48, and 72 hrs after an infective blood feed. In this investigation, we initiated the first holistic study conducted on the anti-filarial worm immune response in order to effectively explore the functional roles of immune-response genes following a natural exposure to the parasite. Studies assessing the transcriptional response revealed the involvement of unknown and conserved unknowns, cytoskeletal and structural components, and stress and immune responsive factors. The data show that the anti-filarial worm immune response by Ar. subalbatus to be a highly complex, tissue-specific process involving varied effector responses working in concert with blood cell-mediated melanization. Conclusion This initial study provides a foundation and direction for future studies, which will more fully dissect the nature of the anti-filarial worm immune response in this mosquito-parasite system. The study also argues for continued studies with RNA generated from both hemocytes and whole bodies to fully expound the nature of the anti-filarial worm immune response.

Chen Cheng-Chen

2007-12-01

110

An innovative mosquito trap for testing attractants.  

Science.gov (United States)

We describe a simple trap modification for testing volatile attractants to collect flying mosquitoes. The trap uses a standard Centers for Disease Control and Prevention trap modified for release of test chemicals. Test chemicals and other materials can be added and removed easily without spills or cross contamination. In preliminary studies using lactic acid and octenol, modified traps collected 40% more mosquitoes than controls (n = 164 and n = 117, respectively). Modifications cost less than $2.00 per trap. PMID:22533089

Dees, William H; Sylvester, Terry L; Clark, Benjamin M; Canning, Linda D; Schultz, George W; Kline, Daniel L

2012-03-01

111

Techniques of Mosquitoes Collecting and Laboratory Rearing  

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Full Text Available The field collecting and laboratory rearing of mosquitoes is essential for mosquito research. The mosquito specimens with perfect completeness and species richness are the foundation for extensive study on their biology, ecology, morphological taxonomy, molecular biology and insecticide resistance; however, the techniques for field colleting and laboratory rearing are still to be further improved and perfected. With many years of practice and improvement, the present paper introduces the ideal and operable tools of field collecting and laboratory rearing. Most importantly, here it summarizes in detail the collecting environment and method of mosquito larvae, pupae and adults, the techniques of the individual (with single-tube and laboratory rearing of larvae and pupae and the progeny rearing of adults, the preservation method of larval and pupal exuviae and adults, and the field transportation method of all stages of mosquitoes. These technologies and methods are of instructive significance for mosquito field investigation and the acquirement of body-completed specimens and biological-ecological information.

TANG Yao

2012-11-01

112

Immunopathological Features Developing in the Mosquito Midgut after Feeding on Anopheles gambiae Mucin-1 / Interleukin-12 cDNA Immunized Mice / Desarrollo de Características Inmunopatológicas en el Intestino Medio del Mosquito Después de Alimentarse de Ratones Inmunizados con Mucina-1 / Interleucina-12 ADNc de Anopheles gambiae  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: English Abstract in spanish El intestino medio es el órgano al cual pasa la sangre consumida por el mosquito y donde, mediante una membrana peritrófica secretada por el epitelio, esta sangre es mantenida durante la digestión y absorción. El intestino del mosquito está revestido por microvellosidades llenas de actina que son ex [...] puestas a las complejas condiciones en torno a la luz intestinal, tales como la abrasión producida por partículas de alimentos, hidrolasas digestivas y el ataque de patógenos y parásitos que son tomados en la sangre consumida. Estas microvellosidades se protegen de estos efectos mediante la matriz peritrófica, el glicocálix y las proteínas de mucina que revisten las superficies epiteliales. La inmunización con AgMUC1/IL-12 ADNc en ratones BALB/c ha demostrado ser útil para matar los mosquitos cuando se alimentan de estos ratones. La mucina es una de las proteínas producidas en el intestino medio del mosquito después de consumir sangre. La fina estructura del epitelio del intestino interactúa con factores inmunes tales como anticuerpos o células inmunes es de especial importancia para interpretar los eventos tempranos en la interacción entre el revestimiento del intestino medio y los componentes inmunológicos específicos presentes en la sangre de ratones BALB/c inmunizados con AgMUC1/IL-12 cDNA. Después de observar mediante microscopías de luz, electrónica de barrido y de transmisión las características de secciones del intestino medio del mosquito Anopheles gambiae alimentado de ratones BALB/c inmunizados con AgMUC1/IL-12 cDNA, mecanismos inmunes mediados por citotoxicidad celular dependiente de anticuerpos (ADCC) podrían ser los responsables de matar a los mosquitos. Los procesos necróticos y apoptóticos que pueden ser la causa de la muerte del mosquito tienen lugar en las células que recubren el epitelio del intestino medio. Abstract in english The mosquito midgut is the organ into which the blood meal passes and in which, within a peritrophic membrane secreted by the epithelium, the blood is retained during digestion and absorption. The mosquito midgut is lined with an actin filled microvilli that are exposed to the harsh environment of t [...] he gut lumen such as food particle abrasion, digestive hydrolases and attack by pathogens and parasites that are taken in by the blood meal. These microvilli are protected them these effects by the peritrophic matrix, the glycocalyx and the mucin proteins that line their epithelial surfaces. Immunization of BALB/c mice with AgMUC1/IL-12 cDNA has been shown to kill mosquitoes when fed on these mice. Mucin is one of the proteins produced in the mosquito midgut after a blood meal. The fine structure of the mosquito midgut epithelium interacting with immune factors such as antibodies or immune cells is of special significance for interpreting early events in the interaction between the mosquito midgut lining and the specific immune components present in the blood of AgMUC1/IL-12 cDNA immunized BALB/c mice. Following bright light microscopy, scanning electron and transmission electron microscopic observations of the features seen in mosquito midgut sections from An. gambiae mosquitoes fed on BALB/c mice immunized with AgMUC1/IL-12 cDNA, the most likely immune mechanisms responsible for mosquito killing could be cell mediated, most likely antibody dependent cellular cytotoxicity. Both necrotic and apoptotic processes that could be the cause of mosquito death were seen to take place in the cells lining the midgut epithelium.

Wilfred E, Injera; Elphantus W, Kabiru; Michael M, Gicheru; John I, Githure; John C, Beier.

113

Immunopathological Features Developing in the Mosquito Midgut after Feeding on Anopheles gambiae Mucin-1 / Interleukin-12 cDNA Immunized Mice Desarrollo de Características Inmunopatológicas en el Intestino Medio del Mosquito Después de Alimentarse de Ratones Inmunizados con Mucina-1 / Interleucina-12 ADNc de Anopheles gambiae  

Directory of Open Access Journals (Sweden)

Full Text Available The mosquito midgut is the organ into which the blood meal passes and in which, within a peritrophic membrane secreted by the epithelium, the blood is retained during digestion and absorption. The mosquito midgut is lined with an actin filled microvilli that are exposed to the harsh environment of the gut lumen such as food particle abrasion, digestive hydrolases and attack by pathogens and parasites that are taken in by the blood meal. These microvilli are protected them these effects by the peritrophic matrix, the glycocalyx and the mucin proteins that line their epithelial surfaces. Immunization of BALB/c mice with AgMUC1/IL-12 cDNA has been shown to kill mosquitoes when fed on these mice. Mucin is one of the proteins produced in the mosquito midgut after a blood meal. The fine structure of the mosquito midgut epithelium interacting with immune factors such as antibodies or immune cells is of special significance for interpreting early events in the interaction between the mosquito midgut lining and the specific immune components present in the blood of AgMUC1/IL-12 cDNA immunized BALB/c mice. Following bright light microscopy, scanning electron and transmission electron microscopic observations of the features seen in mosquito midgut sections from An. gambiae mosquitoes fed on BALB/c mice immunized with AgMUC1/IL-12 cDNA, the most likely immune mechanisms responsible for mosquito killing could be cell mediated, most likely antibody dependent cellular cytotoxicity. Both necrotic and apoptotic processes that could be the cause of mosquito death were seen to take place in the cells lining the midgut epithelium.El intestino medio es el órgano al cual pasa la sangre consumida por el mosquito y donde, mediante una membrana peritrófica secretada por el epitelio, esta sangre es mantenida durante la digestión y absorción. El intestino del mosquito está revestido por microvellosidades llenas de actina que son expuestas a las complejas condiciones en torno a la luz intestinal, tales como la abrasión producida por partículas de alimentos, hidrolasas digestivas y el ataque de patógenos y parásitos que son tomados en la sangre consumida. Estas microvellosidades se protegen de estos efectos mediante la matriz peritrófica, el glicocálix y las proteínas de mucina que revisten las superficies epiteliales. La inmunización con AgMUC1/IL-12 ADNc en ratones BALB/c ha demostrado ser útil para matar los mosquitos cuando se alimentan de estos ratones. La mucina es una de las proteínas producidas en el intestino medio del mosquito después de consumir sangre. La fina estructura del epitelio del intestino interactúa con factores inmunes tales como anticuerpos o células inmunes es de especial importancia para interpretar los eventos tempranos en la interacción entre el revestimiento del intestino medio y los componentes inmunológicos específicos presentes en la sangre de ratones BALB/c inmunizados con AgMUC1/IL-12 cDNA. Después de observar mediante microscopías de luz, electrónica de barrido y de transmisión las características de secciones del intestino medio del mosquito Anopheles gambiae alimentado de ratones BALB/c inmunizados con AgMUC1/IL-12 cDNA, mecanismos inmunes mediados por citotoxicidad celular dependiente de anticuerpos (ADCC podrían ser los responsables de matar a los mosquitos. Los procesos necróticos y apoptóticos que pueden ser la causa de la muerte del mosquito tienen lugar en las células que recubren el epitelio del intestino medio.

Wilfred E Injera

2013-03-01

114

Repellent, irritant and toxic effects of 20 plant extracts on adults of the malaria vector Anopheles gambiae mosquito.  

Science.gov (United States)

Pyrethroid insecticides induce an excito-repellent effect that reduces contact between humans and mosquitoes. Insecticide use is expected to lower the risk of pathogen transmission, particularly when impregnated on long-lasting treated bednets. When applied at low doses, pyrethroids have a toxic effect, however the development of pyrethroid resistance in several mosquito species may jeopardize these beneficial effects. The need to find additional compounds, either to kill disease-carrying mosquitoes or to prevent mosquito contact with humans, therefore arises. In laboratory conditions, the effects (i.e., repellent, irritant and toxic) of 20 plant extracts, mainly essential oils, were assessed on adults of Anopheles gambiae, a primary vector of malaria. Their effects were compared to those of DEET and permethrin, used as positive controls. Most plant extracts had irritant, repellent and/or toxic effects on An. gambiae adults. The most promising extracts, i.e. those combining the three types of effects, were from Cymbopogon winterianus, Cinnamomum zeylanicum and Thymus vulgaris. The irritant, repellent and toxic effects occurred apparently independently of each other, and the behavioural response of adult An. gambiae was significantly influenced by the concentration of the plant extracts. Mechanisms underlying repellency might, therefore, differ from those underlying irritancy and toxicity. The utility of the efficient plant extracts for vector control as an alternative to pyrethroids may thus be envisaged. PMID:24376515

Deletre, Emilie; Martin, Thibaud; Campagne, Pascal; Bourguet, Denis; Cadin, Andy; Menut, Chantal; Bonafos, Romain; Chandre, Fabrice

2013-01-01

115

Mayaro virus isolated from a Trinidadian mosquito, Mansonia venezuelensis.  

Science.gov (United States)

A strain of Mayaro virus has been isolated in Trinidad from the mosquito Mansonia venezuelensis. This is the first record of isolation of this agent from naturally infected mosquitoes, caught in the wild. PMID:13792204

AITKEN, T H; DOWNS, W G; ANDERSON, C R; SPENCE, L; CASALS, J

1960-04-01

116

The role of mosquito behaviour on parasite transmission  

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I use a combination of theory and experiments to explore the role of various aspects of mosquito behaviour on the ability of mosquitoes to transmit parasites. Special focus is given to the mosquito Anopheles gambiae s.s., the principal vector for Plasmodium falciparum, a parasite that causes human malaria. Female mosquitoes require host blood for egg production, but also use sugar from nectar sources; however, the extent of sugar use is poorly understood. Sugar can be used to fuel somatic mai...

Ma, Brian Oh-bong

2010-01-01

117

Mosquito/microbiota interactions: from complex relationships to biotechnological perspectives  

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To date around 3500 different species of mosquito have been described, several tens of which are vectors of pathogens of remarkable interest in public health. Mosquitoes are present all around the world showing a great ability to adapt to very different types of habitats where they play relevant ecological roles. It is very likely that components of the mosquito microbiota have given the mosquito a great capacity to adapt to different environments. Current advances in understanding the mosqui...

Ricci, Irene; Damiani, Claudia; Capone, Aida; Defreece, Chenoa; Rossi, Paolo; Favia, Guido

2012-01-01

118

A Spatial Model of Mosquito Host-Seeking Behavior  

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Mosquito host-seeking behavior and heterogeneity in host distribution are important factors in predicting the transmission dynamics of mosquito-borne infections such as dengue fever, malaria, chikungunya, and West Nile virus. We develop and analyze a new mathematical model to describe the effect of spatial heterogeneity on the contact rate between mosquito vectors and hosts. The model includes odor plumes generated by spatially distributed hosts, wind velocity, and mosquito behavior based on ...

Cummins, Bree; Cortez, Ricardo; Foppa, Ivo M.; Walbeck, Justin; Hyman, James M.

2012-01-01

119

The Effects of Climate Change and Globalization on Mosquito Vectors: Evidence from Jeju Island, South Korea on the Potential for Asian Tiger Mosquito (Aedes albopictus) Influxes and Survival from Vietnam Rather Than Japan  

Science.gov (United States)

Background Climate change affects the survival and transmission of arthropod vectors as well as the development rates of vector-borne pathogens. Increased international travel is also an important factor in the spread of vector-borne diseases (VBDs) such as dengue, West Nile, yellow fever, chikungunya, and malaria. Dengue is the most important vector-borne viral disease. An estimated 2.5 billion people are at risk of infection in the world and there are approximately 50 million dengue infections and an estimated 500,000 individuals are hospitalized with dengue haemorrhagic fever annually. The Asian tiger mosquito (Aedes albopictus) is one of the vectors of dengue virus, and populations already exist on Jeju Island, South Korea. Currently, colder winter temperatures kill off Asian tiger mosquito populations and there is no evidence of the mosquitos being vectors for the dengue virus in this location. However, dengue virus-bearing mosquito vectors can inflow to Jeju Island from endemic area such as Vietnam by increased international travel, and this mosquito vector's survival during colder winter months will likely occur due to the effects of climate change. Methods and Results In this section, we show the geographical distribution of medically important mosquito vectors such as Ae. albopictus, a vector of both dengue and chikungunya viruses; Culex pipiens, a vector of West Nile virus; and Anopheles sinensis, a vector of Plasmodium vivax, within Jeju Island, South Korea. We found a significant association between the mean temperature, amount of precipitation, and density of mosquitoes. The phylogenetic analyses show that an Ae. albopictus, collected in southern area of Jeju Island, was identical to specimens found in Ho Chi Minh, Vietnam, and not Nagasaki, Japan. Conclusion Our results suggest that mosquito vectors or virus-bearing vectors can transmit from epidemic regions of Southeast Asia to Jeju Island and can survive during colder winter months. Therefore, Jeju Island is no longer safe from vector borne diseases (VBDs) due to the effects of globalization and climate change, and we should immediately monitor regional climate change to identify newly emerging VBDs.

Jeong, Ji Yeon; Yoo, Seung Jin; Koh, Young-Sang; Lee, Seogjae; Heo, Sang Taek; Seong, Seung-Yong; Lee, Keun Hwa

2013-01-01

120

The survival probability of diffusion with killing  

CERN Document Server

We present a general framework to study the effect of killing sources on moving particles, trafficking inside biological cells. We are merely concerned with the case of spine-dendrite communication, where the number of calcium ions, modeled as random particles is regulated across the spine microstructure by pumps, which play the killing role. In particular, we study here the survival probability of ions in such environment and we present a general theory to compute the ratio of the number of absorbed particles at specific location to the number of killed particles during their sojourn inside a domain. In the case of a dendritic spine, the ratio is computed in terms of the survival probability of a stochastic trajectory in a one dimensional approximation. We show that the ratio depends on the distribution of killing sources. The biological conclusion follows: changing the position of the pumps is enough to regulate the calcium ions and thus the spine-dendrite communication.

Holcman, D; Schuss, Z

2005-01-01

 
 
 
 
121

Male-killing in African butterflies  

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Full Text Available Female-biased sex ratios occur in many insect species as a consequence of infection by maternally-inherited male-killing bacterial endosymbionts. In this paper, we revise the research conducted on the phenomenon of male-killing in African nymphalid butterflies, with special focus on the cases of Danaus chrysippus, Acraea encedon and Acraea encedana. The evolution of male-killing in each case was addressed, together with the phylogeny of male-killers that were identified from this group. Moreover, the potential impacts that male-killers might impose on the evolution of their butterfly hosts were thoroughly investigated. In the end of this review, we present a number of unanswered questions to be targeted by future research work on the male-killing in these butterflies.

Sami Saeed M. Hassan

2013-02-01

122

The geometry of D = 11 Killing spinors  

Science.gov (United States)

We propose a way to classify all supersymmetric configurations of D=11 supergravity using the G-structures defined by the Killing spinors. We show that the most general bosonic geometries admitting a Killing spinor have at least a local SU(5) or an (Spin(7)l × R8) × R structure, depending on whether the Killing vector constructed from the Killing spinor is timelike or null, respectively. In the former case we determine what kind of local SU(5) structure is present and show that almost all of the form of the geometry is determined by the structure. We also deduce what further conditions must be imposed in order that the equations of motion are satisfied. We illustrate the formalism with some known solutions and also present some new solutions including a rotating generalisation of the resolved membrane solutions and generalisations of the recently constructed D=11 Godel solution.

Gauntlett, Jerome P.; Pakis, Stathis

2003-04-01

123

The geometry of D=11 Killing spinors  

International Nuclear Information System (INIS)

We propose a way to classify all supersymmetric configurations of D=11 supergravity using the G-structures defined by the Killing spinors. We show that the most general bosonic geometries admitting a Killing spinor have at least a local SU(5) or an (Spin(7)lxR8)xR structure, depending on whether the Killing vector constructed from the Killing spinor is timelike or null, respectively. In the former case we determine what kind of local SU(5) structure is present and show that almost all of the form of the geometry is determined by the structure. We also deduce what further conditions must be imposed in order that the equations of motion are satisfied. We illustrate the formalism with some known solutions and also present some new solutions including a rotating generalisation of the resolved membrane solutions and generalisations of the recently constructed D=11 Godel solution. (author)

2003-04-01

124

Honor Killing in Pakistan: An Islamic Perspective  

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Full Text Available Islamic Republic of Pakistan is considered as one of the most dangerous and unsafe country for women in the world, because of the increasing rate of crimes against women in the shape of honor killing and honor related violence. Which are known as assaults committed against women for what is considered immoral behavior. Some researchers and Islamic scholars links act of honor killing with Islam, they tried to justify this crime with some general sayings of Prophet Peace be upon him. In this paper the issue of honor killing has examined in the light of fundamental resources of Islam i.e Quran (the Saying of Allah and Hadees (The Saying of Prophet Muhammad SAH to clarify the true guidance of Islam in such cases. The claim of some researchers that honor killing get encouragement from Islamic Guidance has also been examined through Primary and Secondary Sources of Islam. Effort is made to bring forth the correct Islamic teachings.

Niaz Muhammad

2012-09-01

125

Killing Initial Data on spacelike conformal boundaries  

CERN Document Server

We analyze Killing Initial Data on Cauchy surfaces in conformally rescaled vacuum space-times satisfying Friedrich's conformal field equations. As an application, we derive the KID equations on a spacelike $\\mathcal{J}^-$.

Paetz, Tim-Torben

2014-01-01

126

Fish Kills in Ireland in 1988  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The number of fish kills reported in 1988 showed a very welcome reduction to 50 incidents after the 1987 record of 122. The principal source of trouble has continued to be inadequately planned agricultural practices. Run-off from silage was once more the most serious problem, accounting for 13 kills. Slurry or manure accounted for seven more. While weather conditions may have alleviated the problem, due credit for the improvement must be given to the farmers who responded to the campaign orga...

Mccarthy, D.; Moriarty, C.

1989-01-01

127

Law of Policy of Targeted Killing  

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This is a chapter from our forthcoming book, 'Laws, Outlaws, and Terrorists: Lessons from the War on Terrorism', (MIT Press, September 2010). This chapter addresses the legal, ethical, and strategic aspects of targeted killings as a counterterrorism measure, drawing on the American and Israeli experience. We argue that since terrorism is neither a traditional war nor a traditional crime, its non-traditional nature must affect how, where, and when we employ targeted killings. Specifically, we ...

Blum, Gabriella; Heymann, Philip B.

2010-01-01

128

Fish Kills in Ireland in 1985  

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Fish kills reported by the water pollution officers of the Regional Fisheries Boards in 1985 are evaluated as were similar incidents in 1983 and 1984. Trout, Salmo trutta, was the species most widely implicated and the suspected cause of death was oxygen depletion resulting from agricultural activities. The small number of kills (37), compared with other years, was attributed to weather conditions and particularly to high rainfall in 1985.

1986-01-01

129

Dirac operators and Killing spinors with torsion  

International Nuclear Information System (INIS)

On a Riemannian spin manifold with parallel skew torsion, we use the twistor operator to obtain an eigenvalue estimate for the Dirac operator with torsion. We consider the equality case in dimensions four and six. In odd dimensions we describe Sasaki manifolds on which equality in the estimate is realized by Killing spinors with torsion. In dimension five we characterize all Killing spinors with torsion and obtain certain naturally reductive spaces as exceptional cases.

2012-01-01

130

Evaluation of botanicals as repellents against mosquitoes.  

Science.gov (United States)

Repellent properties of three plant extracts--essential oil (steam distillate) of Zanthoxylum limonella (fruits), Citrus aurantifolia (leaf) and petroleum ether extract of Z. limonella (fruits) were evaluated as repellent against Aedes (S.) albopictus mosquitoes in mustard (Dhara) and coconut (Parachute) oil base under laboratory conditions. Three concentrations--10, 20 and 30% of the repellents were evaluated. Repellents in mustard oil afforded longer protection time against the bites of Aedes (S.) albopictus mosquitoes than those in coconut oil. At 30% concentration, 296-304 min protection time was achieved by the test repellents in mustard oil base while repellents in coconut oil exhibited 223.5-245 min protection time at the same concentration. Oil of Z. limonella gave the highest protection time against the bites of Aedes (S.) albopictus mosquitoes at all the concentrations than other herbal repellents tested both in mustard and coconut oil. PMID:15119071

Das, N G; Baruah, I; Talukdar, P K; Das, S C

2003-01-01

131

Evaluation of botanicals as repellents against mosquitoes  

Directory of Open Access Journals (Sweden)

Full Text Available Repellent properties of three plant extracts—essential oil (steam distillate of Zanthoxylumlimonella (fruits, Citrus aurantifolia (leaf and petroleum ether extract of Z. limonella (fruitswere evaluated as repellent against Aedes (S. albopictus mosquitoes in mustard (Dhara and coconut(Parachute oil base under laboratory conditions. Three concentrations—10, 20 and 30% of therepellents were evaluated. Repellents in mustard oil afforded longer protection time against thebites of Aedes (S. albopictus mosquitoes than those in coconut oil. At 30% concentration, 296–304 min protection time was achieved by the test repellents in mustard oil base while repellents incoconut oil exhibited 223.5–245 min protection time at the same concentration. Oil of Z. limonellagave the highest protection time against the bites of Aedes (S. albopictus mosquitoes at all theconcentrations than other herbal repellents tested both in mustard and coconut oil.

N.G. Das, I. Baruah, P.K. Talukdar & S.C. Das

2003-03-01

132

Genetic control of mosquitoes: population suppression strategies.  

Science.gov (United States)

Over the last two decades, morbidity and mortality from malaria and dengue fever among other pathogens are an increasing Public Health problem. The increase in the geographic distribution of vectors is accompanied by the emergence of viruses and diseases in new areas. There are insufficient specific therapeutic drugs available and there are no reliable vaccines for malaria or dengue, although some progress has been achieved, there is still a long way between its development and actual field use. Most mosquito control measures have failed to achieve their goals, mostly because of the mosquito's great reproductive capacity and genomic flexibility. Chemical control is increasingly restricted due to potential human toxicity, mortality in no target organisms, insecticide resistance, and other environmental impacts. Other strategies for mosquito control are desperately needed. The Sterile Insect Technique (SIT) is a species-specific and environmentally benign method for insect population suppression, it is based on mass rearing, radiation mediated sterilization, and release of a large number of male insects. Releasing of Insects carrying a dominant lethal gene (RIDL) offers a solution to many of the drawbacks of traditional SIT that have limited its application in mosquitoes while maintaining its environmentally friendly and species-specific utility. The self-limiting nature of sterile mosquitoes tends to make the issues related to field use of these somewhat less challenging than for self-spreading systems characteristic of population replacement strategies. They also are closer to field use, so might be appropriate to consider first. The prospect of genetic control methods against mosquito vectored human diseases is rapidly becoming a reality, many decisions will need to be made on a national, regional and international level regarding the biosafety, social, cultural and ethical aspects of the use and deployment of these vector control methods. PMID:22983293

Wilke, André Barretto Bruno; Marrelli, Mauro Toledo

2012-01-01

133

Arthritides caused by mosquito-borne viruses.  

Science.gov (United States)

Five different mosquito-borne viruses (chikungunya, o'nyong-nyong, Mayaro, Ross River, and Sindbis) have been associated with arthritis in humans. These agents occur most commonly in the tropics and subtropics. The symptoms they produce are similar and typically consist of fever, arthralgia, and rash. In general, the symptoms are of short duration (less than one week) and recovery is complete, although some patients have recurrent episodes of joint swelling and tenderness for months after infection. Treatment is symptomatic. There are no vaccines currently available; the best prevention is to avoid mosquito bites when traveling or living in areas where these diseases occur. PMID:6123291

Tesh, R B

1982-01-01

134

NO BUG: biobased mosquitoes repellent textiles  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This research work is part of the FP7 No-Bug project (Novel release system and biobased utilities for insect repellent textiles). The main interest of the project is personal protective textiles against insects (mosquitoes) for application not only in tropical areas where vector borne diseases are a major threat to the public health but also in European countries where the presence of mosquitoes can be nuisance. Malaria and dengue fever are well known diseases that cause a lot of deaths in th...

2011-01-01

135

Individual experience affects host choice in malaria vector mosquitoes  

Science.gov (United States)

Background Despite epidemiological importance, few studies have explored whether individual experience and learning could affect the vertebrate host choice of mosquito disease vectors. Here, we investigated whether a first successful blood meal can modulate mosquito preference during a second blood meal. Methods In no-choice situations, females of the mosquito Anopheles coluzzii, one of the primary African malaria vectors, were first allowed to feed on either human, rabbit or guinea pig. Four days later in dual-choice situations, the same mosquitoes were allowed to choose between the two uncommon hosts, rabbit and guinea pig, as a source of blood. ELISA assays were then used to determine which host mosquitoes fed on. Results Our results indicate that, overall, mosquitoes preferred to feed on rabbit over guinea pig and that the nature of the first blood meal had a significant impact on the mosquito host choice during the second blood meal. Compared to mosquitoes that previously fed on guinea pigs or humans, mosquitoes that fed on rabbits were less likely to choose this host species during a second exposition. The decreased preference for rabbit was observed four days after mosquitoes were first exposed to this host, suggesting that the effect lasts at least the duration of a gonotrophic cycle. Furthermore, this effect was observed after only one successful blood meal. Fitness measurements on mosquitoes fed on the three different vertebrate hosts showed that the origin of the blood meal affected mosquito longevity but not fecundity. In particular, human-fed mosquitoes lived longer than guinea pig-fed or rabbit-fed mosquitoes. Conclusions Our study demonstrates that individual experience affects host choice in this mosquito species and might have strong repercussions on biting patterns in natural conditions and hence on malaria transmission.

2014-01-01

136

Isolation of mosquito-toxic bacteria from mosquito-breeding sites in Kenya.  

Science.gov (United States)

A large number of source materials were collected for isolating entomopathogenic bacteria from larval mosquito habitats in Kirinyaga District, Kenya. Mosquito-toxic bacteria were included among the numerous types of microorganisms isolated from the habitats. The pathogenic isolates shared common structural characteristics; they were gram-positive, spore-forming bacilli that produced parasporal inclusions conferring broad-spectrum larvicidal activity against Anopheles, Culex and Aedes mosquitoes. Based on structural and growth characteristics, coupled with larvicidal activity, the pathogenic isolates were tentatively identified as variants of Bacillus thuringiensis. Although the collection consisted of a variety of items including soil, silt and mud, the most productive materials were larval bodies. Using healthy mosquito larvae held in a fully permeable plastic bottle, a baiting technique was developed as a means of recovering bacteria from the environment. PMID:1583497

Asimeng, E J; Mutinga, M J

1992-03-01

137

Metarhizium anisopliae pathogenesis of mosquito larvae: a verdict of accidental death.  

Science.gov (United States)

Metarhizium anisopliae, a fungal pathogen of terrestrial arthropods, kills the aquatic larvae of Aedes aegypti, the vector of dengue and yellow fever. The fungus kills without adhering to the host cuticle. Ingested conidia also fail to germinate and are expelled in fecal pellets. This study investigates the mechanism by which this fungus adapted to terrestrial hosts kills aquatic mosquito larvae. Genes associated with the M. anisopliae early pathogenic response (proteinases Pr1 and Pr2, and adhesins, Mad1 and Mad2) are upregulated in the presence of larvae, but the established infection process observed in terrestrial hosts does not progress and insecticidal destruxins were not detected. Protease inhibitors reduce larval mortality indicating the importance of proteases in the host interaction. The Ae. aegypti immune response to M. anisopliae appears limited, whilst the oxidative stress response gene encoding for thiol peroxidase is upregulated. Cecropin and Hsp70 genes are downregulated as larval death occurs, and insect mortality appears to be linked to autolysis through caspase activity regulated by Hsp70 and inhibited, in infected larvae, by protease inhibitors. Evidence is presented that a traditional host-pathogen response does not occur as the species have not evolved to interact. M. anisopliae retains pre-formed pathogenic determinants which mediate host mortality, but unlike true aquatic fungal pathogens, does not recognise and colonise the larval host. PMID:24349111

Butt, Tariq M; Greenfield, Bethany P J; Greig, Carolyn; Maffeis, Thierry G G; Taylor, James W D; Piasecka, Justyna; Dudley, Ed; Abdulla, Ahmed; Dubovskiy, Ivan M; Garrido-Jurado, Inmaculada; Quesada-Moraga, Enrique; Penny, Mark W; Eastwood, Daniel C

2013-01-01

138

Diversity and function of bacterial microbiota in the mosquito holobiont.  

Science.gov (United States)

Mosquitoes (Diptera: Culicidae) have been shown to host diverse bacterial communities that vary depending on the sex of the mosquito, the developmental stage, and ecological factors. Some studies have suggested a potential role of microbiota in the nutritional, developmental and reproductive biology of mosquitoes. Here, we present a review of the diversity and functions of mosquito-associated bacteria across multiple variation factors, emphasizing recent findings. Mosquito microbiota is considered in the context of possible extended phenotypes conferred on the insect hosts that allow niche diversification and rapid adaptive evolution in other insects. These kinds of observations have prompted the recent development of new mosquito control methods based on the use of symbiotically-modified mosquitoes to interfere with pathogen transmission or reduce the host life span and reproduction. New opportunities for exploiting bacterial function for vector control are highlighted. PMID:23688194

Minard, Guillaume; Mavingui, Patrick; Moro, Claire Valiente

2013-01-01

139

Effect of Feronia limonia on mosquito larvae.  

Science.gov (United States)

Bioassay guided fractionation of the acetone extract of Feronia limonia dried leaves afforded a potent mosquito larvicide, identified as n-hexadecanoic acid and found to be effective against fourth instar larvae of Culex quinquefasciatus, Anopheles stephensi and Aedes aegypti, with LC50 of 129.24, 79.58 and 57.23 ppm, respectively. PMID:11449505

Rahuman, A A; Gopalakrishnan, G; Ghouse, B S; Arumugam, S; Himalayan, B

2000-09-01

140

Avian malaria parasites share congeneric mosquito vectors.  

Science.gov (United States)

Assessing parasite specificity to vector is crucial to understanding the emergence of vector-borne diseases and the evolution of parasite diversity. Avian malaria parasites have a cosmopolitan distribution and broad avian host range, which together predict they are vector generalists, but little is known about parasite-vector associations in the wild. We tested this prediction by asking if 5 different mosquito species, known to feed on birds and abundant in the northeastern United States, were naturally infected in the field with identical avian Plasmodium spp. lineages. Mosquitoes were not pooled but rather analyzed individually, and, possibly as a result, lineage diversity was higher than reported in previous avian malaria vector studies. Plasmodium spp. lineages were rare in Aedes canadensis and absent in Aedes aurifer and Culiseta melanura. We sequenced a standard Plasmodium cytochrome b marker from Culex pipiens pipiens, Culex restuans, and Ae. canadensis. Most Plasmodium clades were shared by Cx. pipiens and Cx. restuans. In addition, 4 individual lineages were shared by both mosquito species, including the most common lineage. One Plasmodium clade, however, was only found in Cx. restuans. We therefore found limited support for our prediction that avian Plasmodium spp. vector breadth accompanies host breadth. The association of both Culex species with most Plasmodium clades, and the presence of a single parasite lineage in 3 mosquito species representing 2 genera, suggests that avian Plasmodium species are not tightly coevolved with vector species. PMID:19697968

Kimura, M; Darbro, J M; Harrington, L C

2010-02-01

 
 
 
 
141

Review of the anopheline mosquitoes of Myanmar.  

Science.gov (United States)

This study examined the species of anopheline mosquitoes in Myanmar. Out of 36 species of anophelines distributed throughout the country, ten species were found to be infected with the malaria parasite. These vectors are presented with particular reference to their distribution and a summary of bionomics and infection rates. PMID:15266738

Ool, Thin Thin; Storch, Volker; Becker, Norbert

2004-06-01

142

Universal properties from local geometric structure of Killing horizon  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We consider universal properties that arise from a local geometric structure of a Killing horizon. We first introduce a non-perturbative definition of such a local geometric structure, which we call an asymptotic Killing horizon. It is shown that infinitely many asymptotic Killing horizons reside on a common null hypersurface, once there exists one asymptotic Killing horizon. The acceleration of the orbits of the vector that generates an asymptotic Killing horizon is then co...

Koga, Jun-ichirou

2006-01-01

143

The Cry4B toxin of Bacillus thuringiensis subsp. israelensis kills Permethrin-resistant Anopheles gambiae, the principal vector of malaria.  

Science.gov (United States)

Resurgence of malaria has been attributed, in part, to the development of resistance by Anopheles gambiae, a principal vector of the disease, to various insecticidal compounds such as Permethrin. Permethrin, a neurotoxicant, is widely used to impregnate mosquito nets. An alternative strategy to control mosquitoes is the use of Bacillus thuringiensis subsp. israelensis (Bti) because there is no observable resistance in the field to the bacterium. Bti kills mosquitoes by targeting cadherin molecules residing in the midgut epithelium of larvae of the insect. Cry proteins (Cry4A, Cry4B, Cry10A and Cry11A) produced by the bacterium during the sporulation phase of its life cycle bind to the cadherin molecules, which serve as receptors for the proteins. These Cry proteins have variable specificity to a variety of mosquitoes, including Culex and Aedes as well as Anopheles. Importantly, selective mosquitocidal action is occasioned by binding of the respective Cry toxins to cadherins distinctive to individual mosquito species. Differential fractionation of the four Cry proteins from a novel Bti isolate (M1) and cloning and expression of their genes in Escherichia coli revealed that Cry4B is the only Cry protein that exerts insecticidal action against An. gambiae. Indeed, it does so against a Permethrin-resistant strain of the mosquito. The other three Cry proteins are ineffective. Multiple sequence alignments of the four Cry proteins revealed a divergent sequence motif in the Cry4B toxin, which most likely determines binding of the toxin to its cognate receptor, BT-R3, in An. gambiae and to its specific toxicity. A model showing Cry4B toxin binding to BT-R3 is presented. PMID:23760000

Ibrahim, Mohamed A; Griko, Natalya B; Bulla, Lee A

2013-04-01

144

Internet Resources on Genocide and Mass Killings  

Science.gov (United States)

Internet Resources on Genocide and Mass Killings is an extensive compilation of primary materials and annotated links related to "twentieth-century genocidal and mass man-made killing occurrences." Divided into fifteen sections, subject coverage includes topics such as The Jewish Holocaust, War Crimes and Criminals, Yugoslavia and Kosovo, among others. Most of the original documents in the compilation have been uploaded to the site, facilitating navigation and research. Documents not residing at the site are linked via succinct annotations. The compilation is searchable and updated continuously by its creator Dr. Stuart D. Stein, Senior Lecturer in Sociology and Social Psychology at the University of West England.

145

Cytotoxic Killing and Immune Evasion by Repair  

Science.gov (United States)

The interaction between the immune system and pathogens is a complex one, with pathogens constantly developing new ways of evading destruction by the immune system. The immune system's task is made even harder when the pathogen in question is an intra-cellular one (such as a virus or certain bacteria) and it is necessary to kill the infected host cell in order to eliminate the pathogen. This causes damage to the host, and such killing therefore needs to be carefully controlled, particularly in tissues with poor regenerative potential, or those involved in the immune response itself. Host cells therefore possess repair mechanisms which can counteract killing by immune cells. These in turn can be subverted by pathogens which up-regulate the resistance of infected cells to killing. In this paper, we explore the hypothesis that this repair process plays an important role in determining the efficacy of evasion and escape from immune control. We model a situation where cytotoxic T lymphocytes (CTL) and natural killer (NK) cells kill pathogen-infected and tumour cells by directed secretion of preformed granules containing perforin and granzymes. Resistance to such killing can be conferred by the expression of serine protease inhibitors (serpins). These are utilized by several virally infected and tumour cells, as well as playing a role in the protection of host bystander, immune and immuneprivileged cells. We build a simple stochastic model of cytotoxic killing, where serpins can neutralize granzymes stoichiometrically by forming an irreversible complex, and the survival of the cell is determined by the balance between serpin depletion and replenishment, which in its simplest form is equivalent to the well known shot noise process. We use existing analytical results for this process, and additional simulations to analyse the effects of repair on cytotoxic killing. We then extend the model to the case of a replicating target cell population, which gives a branching process coupled to shot noise. We show how the process of repair can have a major impact on the dynamics of pathogen evasion and escape of tumour cells from immune surveillance

Chan, Cliburn; George, Andrew J. T.; Stark, Jaroslav

2007-07-01

146

Conformal Killing Tensors and covariant Hamiltonian Dynamics  

CERN Document Server

A covariant algorithm for deriving the conserved quantities for natural Hamiltonian systems is combined with the non-relativistic framework of Eisenhart, and of Duval, in which the classical trajectories arise as geodesics in a higher dimensional space-time, realized by Brinkmann manifolds. Conserved quantities which are polynomial in the momenta can be built using time-dependent conformal Killing tensors with flux. Illustrations of the general theory include the Runge-Lenz vector for planetary motion with a time-dependent gravitational constant $G(t)$, quantum dots, the Henon-Heiles and Holt systems, respectively, providing us with Killing tensors of rank that ranges from one to six.

Cariglia, M; van Holten, J -W; Horvathy, P A; Zhang, P -M

2014-01-01

147

Mothers who killed or attempted to kill their child: life circumstances, childhood abuse, and types of killing.  

Science.gov (United States)

The objectives of the present study were to examine the life circumstances, childhood abuse, and types of homicidal acts of 48 mothers who killed/attempted to kill their child(ren) under age 12 between 1970-96 in Finland. Data on the mothers'life stresses, psychological problems, and childhood abuse were collected from mental state examination (MSE) reports. The cases were divided into 15 neonaticides and 33 mothers who killed an older child. Childhood abuse was documented in 63% of the mothers' MSE reports. Qualitative analysis identified neonaticides,joint homicide-suicide attempts, impulsive aggression, psychotic acts, postpartum depression, and abusive acts. Nonlinear principal components analysis showed that different variables were related to the neonaticide and non-neonaticide cases. We concluded that despite differences in the psychosocial profiles of neonaticides and other maternal homicidal acts the cycle of violence perspective can be applied to both cases, even though it may not be a sufficient explanation for maternal child killings. PMID:10606431

Haapasalo, J; Petäjä, S

1999-01-01

148

Spatiotemporal monitoring of floodwater mosquito dispersal in Osijek, Croatia.  

Science.gov (United States)

This paper demonstrates the possibility of using geostatistics to monitor the dispersal of mosquitoes for mosquito control programs at the municipal level. The case study objective was to quantify the dispersal of floodwater mosquitoes from the natural marshland Kopacki rit into the city of Osijek, Croatia, and to analyze the main factors controlling it. Fifty thousand adult Aedes vexans, Ochlerotatus sticticus, and Ochlerotatus caspius mosquitoes were marked with a powdered fluorescent pigment and released from the southern part of Kopacki rit on April 28, 2004. Forty CO2-baited Centers for Disease Control and Prevention traps were set in the area of the municipality of Osijek (171 km2) and were monitored for 10 days. A total of 582,471 mosquitoes were captured and examined in the laboratory. The mosquito counts from different sites were then interpolated using ordinary kriging and visualized dynamically to detect the dominant migrational directions. Mosquito dispersal and frequency were greatly influenced by wind speed (r = 0.82). The marked mosquitoes were found at 12 sites located from 1 km to 11.7 km away from the release point. The recapture rate was 0.044% (54% Oc. sticticus, 32% Ae. vexans, and 14% Oc. caspius). Based on the Lincoln index, the estimated total population size for floodwater mosquitoes in the study area ranged from 875 million to 2.0 billion mosquitoes. Limitations of the approach, recommendations for the improvement of the monitoring network, and spatial predictions are further discussed. PMID:17847840

Bogojevi?, Mirta Sudari?; Hengl, Tomislav; Merdi?, Enrih

2007-06-01

149

Predictors of mosquito net use in Ghana  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background During the past decade the malaria control community has been successful in dramatically increasing the number of households that own mosquito nets. However, as many as half of nets already in households go unused. This study examines the factors associated with use of nets owned in Ghana. Methods The data come from an August 2008 survey in Ghana of households with a pregnant woman or a guardian of a child under five, conducted during the rainy season. 1796 households were included in this analysis, which generated a sample of 1,852 mosquito nets. Using each net owned as the unit of analysis, multivariate logistic regression was used to examine the relationship of net used last night with 23 potentially explanatory variables having to do with characteristics of the household, of the respondent, and of the net. Odds Ratios, p-values, and confidence intervals were calculated for each variable to develop an explanatory model. Results The final multivariate model consisted of 10 variables statistically associated with whether or not the net was used the prior night: rural location, lower SES, not using coils for mosquito control, fewer nets in the household, newer nets and those in better condition, light blue colour, higher level of education of the guardian of the child under five, knowing that mosquitoes transmit malaria, and paying for the net instead of obtaining it free of charge. Conclusions The results of this study suggest that net use would increase in Ghana if coloured nets were made available in mass distributions as well as in the commercial market; if programmes emphasize that malaria is caused only by night-biting mosquitoes, and that nets protect against mosquitoes better than coils and need to be used even if coils are burning; if donated nets are replaced more frequently so that households have nets that are in good condition; and if there were support for the commercial market so that those who can afford to purchase a net and want to choose their own nets can do so.

Baume Carol A

2011-09-01

150

Insecticidal effect of aliphatic alcohols against aquatic stages of Aedes mosquitoes.  

Science.gov (United States)

Effectiveness of certain long carbon chain aliphatic alcohols as ovicides and larvicides was investigated under laboratory conditions against eggs and larvae of Aedes aegypti and Aedes scutellaris. Out of the eight alcohols tested, three (1-decanol, 1-undecanol and 1-dodecanol) proved to be very effective. The hatching of mosquito eggs was inhibited at a dosage of 5 to 7 litres/hectare. First, third and fourth instar larvae were killed at a dosage of 3 to 7 litres/hectare. First instar larvae were more sensitive to the alcohols than the older larvae. The shorter carbon chain alcohols (2-mercapto-ethanol, 1-butanol, benzyl alcohol and 2-octanol) proved unsatisfactory due to their volatility and solubility. Longer carbon chain alcohols (1-tetradecanol, 1-hexadecanol and 1-octadecanol), Which are solid and wax-like at room temperature, proved unsatisfactory when dissolved in hexane and applied to eggs and larvae. PMID:6683011

Sinniah, B

1983-01-01

151

Rift Valley Fever Virus (RVFv Dissemination inside Mosquitoes and Investigation of the Influence of Climate on Mosquitoes Abundance  

Directory of Open Access Journals (Sweden)

Full Text Available One year surveys were conducted at two sites in Khartoum State capital of Sudan: Hellat Kuku and Soba West. The study was focused into two species of mosquitoes: Aedes vexans and Culex quinquefasciatus. This selection was based on previous investigations indicated their being positive for RVF. The study aimed to investigate on RVFv dissemination inside two species mosquitoes in Khartoum State (Sudan and investigation of the influence of climate on mosquitoes abundance. Weekly aspiration of wild mosquitoes has been conducted during 1st July 2011- 1st July 2012. The collected mosquitoes were identified by using classical keys. Data of climate were obtained from Sudan Meteorology Authorities. Males and females of the two mosquitoes species were divided into three cohorts: salivary glands, abdomen, and wings and legs. RVF Virus was therefore examined into twelve pools using Real- Time PCR technique. Results showed that Temperature, precipitation, and RH were significantly associated with the number of aspirated mosquitoes. The virus has been detected inside the pools of the abdomen and salivary glands of Ae. vexans mosquitoes. However, pools of salivary glands of Cx. quinquefasciatus were negative of the virus in spite of dissemination of the virus in the wings and legs. Based on these results it can be concluded that climatic factors affected on the number of aspirated mosquitoes during the study period. Ae. vexans mosquitoes exhibited an indicator of being competent to transmit the virus in contrast to Cx. quinquefasciatus.

Rania Ali El Hadi Mohamed

2013-10-01

152

Can Vet Schools Teach without Killing Animals?  

Science.gov (United States)

Discusses a protest by students at the University of Illinois (Urbana) College of Veterinary Medicine over the killing of animals that led to temporary curtailing of lethal animal experiments. Examines the conflict between animal rights groups and some faculty who are openly skeptical about the effectiveness of alternatives to the hands-on…

Mangan, Katherine S.

2000-01-01

153

Killing Hitler: A Writer's Journey and Angst.  

Science.gov (United States)

Describes the author's experiences in preparing a talk that "evokes the specter" of Adolf Hitler and in writing an historical account of a British plot to kill Hitler. Address the question of why the British allowed him to live that final year of the war. Muses on why scholars write, and the impact of violence and terrorism. (SG)

Thaler, Paul

2002-01-01

154

Killing-yano tensors in general relativity  

International Nuclear Information System (INIS)

It is shown that space-times admitting more than one independent Killing-Yano tensor belong to a small collection of highly idealized space-times. A new characterization of Robertson-Walker space-times arises as a corollary of the main theorem

1987-01-01

155

Equation of geodesic deviation and Killing tensors  

International Nuclear Information System (INIS)

It is shown that every Killing tensor (KT) identifies a solution for the equation of geodesic deviation (e.g.d.). The general integral of the above equation is also explicitly exhibited in a class of static spherically symmetric space-times found by Kimura. (author)

1982-01-01

156

Membrane Fas Ligand Kills Human Peripheral Blood T Lymphocytes, and Soluble Fas Ligand Blocks the Killing  

Digital Repository Infrastructure Vision for European Research (DRIVER)

It has been believed that the Fas expressed on human peripheral blood T cells (PBT) is nonfunctional, because these cells are insensitive to agonistic anti-Fas/Apo-1 mAbs that efficiently kill in vitro–activated T cells and many Fas-expressing cell lines. Here, we demonstrate that membrane-bound Fas ligand (FasL) kills both fresh and in vitro–activated PBT, indicating that the Fas expressed on fresh PBT is functional. In contrast, soluble FasL kills only the latter. Naive T cells in um...

Suda, Takashi; Hashimoto, Hideo; Tanaka, Masato; Ochi, Takahiro; Nagata, Shigekazu

1997-01-01

157

A nestable fiber pot for sampling resting mosquitoes.  

Science.gov (United States)

To enhance the effectiveness of an arbovirus monitoring program, we evaluated a commercially available device for sampling resting vector mosquitoes. Diverse Anopheles, Culiseta, and Culex mosquitoes were taken in these nestable fiber pots. The pots sample about as many Culiseta melanura mosquitoes per device as do conventional resting boxes, but fewer than do boxes fitted with expanded frames. More Cs. melanura, and more bloodfed mosquitoes, but fewer species of mosquitoes are harvested with fiber pots than with CDC light traps. Fiber pots are more readily used, transported, and stored and are less expensive than conventional resting box devices or CDC light traps. A monitoring program based on the use of fiber pots, therefore, expends fewer resources than one using conventional resting boxes and collects about as many vector mosquitoes. PMID:8825509

Komar, N; Pollack, R J; Spielman, A

1995-12-01

158

Screening of selected ethnomedicinal plants from South Africa for larvicidal activity against the mosquito Anopheles arabiensis  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background This study was initiated to establish whether any South African ethnomedicinal plants (indigenous or exotic, that have been reported to be used traditionally to repel or kill mosquitoes, exhibit effective mosquito larvicidal properties. Methods Extracts of a selection of plant taxa sourced in South Africa were tested for larvicidal properties in an applicable assay. Thirty 3rd instar Anopheles arabiensis larvae were exposed to various extract types (dichloromethane, dichloromethane/methanol (1:1, methanol and purified water of each species investigated. Mortality was evaluated relative to the positive control Temephos (Mostop; Agrivo, an effective emulsifiable concentrate larvicide. Results Preliminary screening of crude extracts revealed substantial variation in toxicity with 24 of the 381 samples displaying 100% larval mortality within the seven day exposure period. Four of the high activity plants were selected and subjected to bioassay guided fractionation. The results of the testing of the fractions generated identified one fraction of the plant, Toddalia asiatica as being very potent against the An. arabiensis larvae. Conclusion The present study has successfully identified a plant with superior larvicidal activity at both the crude and semi pure fractions generated through bio-assay guided fractionation. These results have initiated further research into isolating the active compound and developing a malaria vector control tool.

Maharaj Rajendra

2012-09-01

159

In vivo, in vitro, and in silico studies suggest a conserved immune module that regulates malaria parasite transmission from mammals to mosquitoes.  

Science.gov (United States)

Human malaria can be caused by the parasite Plasmodium falciparum that is transmitted by female Anopheles mosquitoes. "Immunological crosstalk" between the mammalian and anopheline hosts for Plasmodium functions to control parasite numbers. Key to this process is the mammalian cytokine transforming growth factor-?1 (TGF-?1). In mammals, TGF-?1 regulates inducible nitric oxide (NO) synthase (iNOS) both positively and negatively. In some settings, high levels of NO activate latent TGF-?1, which in turn suppresses iNOS expression. In the mosquito, ingested TGF-?1 induces A. stephensi NOS (AsNOS), which limits parasite development and which in turn is suppressed by activation of the mosquito homolog of the mitogen-activated protein kinases MEK and ERK. Computational models linking TGF-?1, AsNOS, and MEK/ERK were developed to provide insights into this complex biology. An initial Boolean model suggested that, as occurs in mammalian cells, MEK/ERK and AsNOS would oscillate upon ingestion of TGF-?1. An ordinary differential equation (ODE) model further supported the hypothesis of TGF-?1-induced multiphasic behavior of MEK/ERK and AsNOS. To achieve this multiphasic behavior, the ODE model was predicated on the presence of constant levels of TGF-?1 in the mosquito midgut. Ingested TGF-?1, however, did not exhibit this behavior. Accordingly, we hypothesized and experimentally verified that ingested TGF-?1 induces the expression of the endogenous mosquito TGF-? superfamily ligand As60A. Computational simulation of these complex, cross-species interactions suggested that TGF-?1 and NO-mediated induction of As60A expression together may act to maintain multiphasic AsNOS expression via MEK/ERK-dependent signaling. We hypothesize that multiphasic behavior as represented in this model allows the mosquito to balance the conflicting demands of parasite killing and metabolic homeostasis in the face of damaging inflammation. PMID:23764028

Price, Ian; Ermentrout, Bard; Zamora, Ruben; Wang, Bo; Azhar, Nabil; Mi, Qi; Constantine, Gregory; Faeder, James R; Luckhart, Shirley; Vodovotz, Yoram

2013-10-01

160

Evaluation of botanicals as repellents against mosquitoes  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Repellent properties of three plant extracts—essential oil (steam distillate) of Zanthoxylumlimonella (fruits), Citrus aurantifolia (leaf) and petroleum ether extract of Z. limonella (fruits)were evaluated as repellent against Aedes (S.) albopictus mosquitoes in mustard (Dhara) and coconut(Parachute) oil base under laboratory conditions. Three concentrations—10, 20 and 30% of therepellents were evaluated. Repellents in mustard oil afforded longer protection time against thebites of Aedes ...

2003-01-01

 
 
 
 
161

Climate change and mosquito-borne disease.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Global atmospheric temperatures are presently in a warming phase that began 250--300 years ago. Speculations on the potential impact of continued warming on human health often focus on mosquito-borne diseases. Elementary models suggest that higher global temperatures will enhance their transmission rates and extend their geographic ranges. However, the histories of three such diseases--malaria, yellow fever, and dengue--reveal that climate has rarely been the principal determinant of their pr...

2001-01-01

162

Genetic elimination of dengue vector mosquitoes  

Digital Repository Infrastructure Vision for European Research (DRIVER)

An approach based on mosquitoes carrying a conditional dominant lethal gene (release of insects carrying a dominant lethal, RIDL) is being developed to control the transmission of dengue viruses by vector population suppression. A transgenic strain, designated OX3604C, of the major dengue vector, Aedes aegypti, was engineered to have a repressible female-specific flightless phenotype. This strain circumvents the need for radiation-induced sterilization, allows genetic sexing resulting in male...

2011-01-01

163

NO BUG: biobased mosquitoes repellent personal protective equipment (PPE)  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In tropical regions (South America, Asia and Africa) diseases like malaria and dengue cause many deaths. These diseases are transmitted through mosquitoes bites (Anopheles sp. and Aedes aegypti respectively). The current practice to protect against transmission of these diseases is by use of mosquito repellents. Common mosquito repellents used today are synthetic in nature and are suspected or have been proved to be harmful to the user and environment (e.g. DEET, DDT, dimethylphylphthalate, p...

Ciera, Lucy Wanjiru; Nierstrasz, Vincent; Langenhove, Lieva

2012-01-01

164

Preliminary evaluation of mosquito larvicidal efficacy of plant extracts  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Mosquitoes are the most important single group ofinsects in terms of public health importance, whichtransmit a number of diseases, such as malaria, filariasis,dengue, Japanese encephalitis, etc. causing millionsof deaths every year. Repeated use of syntheticinsecticides for mosquito control has disrupted naturalbiological control systems and led to resurgencesin mosquito populations. It has also resulted in thedevelopment of resistance1, undesirable effects onnon-target organisms and fostered...

2007-01-01

165

Advances in methods for colour marking of mosquitoes  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Background: Different techniques are available for colour marking insects and each technique may be suitable for different insect species. Mosquitoes can be marked to determine population size, distribution and flight distance or distinguish closely related species. In this study, two methods of colour marking mosquitoes were described in detail and the impact of both methods on the survival and host-seeking behaviour of the malaria mosquito Anopheles gambiae sensu stricto was investigated. M...

Verhulst, N. O.; Loonen, J. A. C. M.; Takken, W.

2013-01-01

166

Transcriptome of the adult female malaria mosquito vector Anopheles albimanus.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

UNLABELLED: ABSTRACT: BACKGROUND: Human Malaria is transmitted by mosquitoes of the genus Anopheles. Transmission is a complex phenomenon involving biological and environmental factors of humans, parasites and mosquitoes. Among more than 500 anopheline species, only a few species from different branches of the mosquito evolutionary tree transmit malaria, suggesting that their vectorial capacity has evolved independently. Anopheles albimanus (subgenus Nyssorhynchus) is an important malaria vec...

2012-01-01

167

Toxicity of aqueous crude neem leaf extract against culex mosquitoes  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Prevention of mosquitoes from biting is one of the major problems in the world. Mosquitoes transmitting serious human diseases and causing millions of death every year. The repeated use of synthetic insecticides to control mosquitoes has created resistance to vectors and adverse environmental effects in addition to high operational cost. Many natural products have been reported as insect antifeedants or repellents. Azadirachta indica contains several active ingredients that are toxic to inse...

2011-01-01

168

[Mosquitoes as vectors for exotic pathogens in Germany].  

Science.gov (United States)

As a result of intensified globalization of international trade and of substantial travel activities, mosquito-borne exotic pathogens are becoming an increasing threat for Europe. In Germany some 50 different mosquito species are known, several of which have vector competence for pathogens. During the last few years a number of zoonotic arboviruses that are pathogenic for humans have been isolated from mosquitoes in Germany including Usutu, Sindbis and Batai viruses. In addition, filarial worms, such as Dirofilaria repens have been repeatedly detected in mosquitoes from the federal state of Brandenburg. Other pathogens, in particular West Nile virus, are expected to emerge sooner or later in Germany as the virus is already circulating in neighboring countries, e.g. France, Austria and the Czech Republic. In upcoming years the risk for arbovirus transmission might increase in Germany due to increased occurrence of new so-called "invasive" mosquito species, such as the Asian bush mosquito Ochlerotatus japonicus or the Asian tiger mosquito Aedes albopictus. These invasive species are characterized by high vector competence for a broad range of pathogens and a preference for human blood meals. For risk assessment, a number of mosquito and pathogen surveillance projects have been initiated in Germany during the last few years; however, mosquito control strategies and plans of action have to be developed and put into place to allow early and efficient action against possible vector-borne epidemics. PMID:24781910

Becker, N; Krüger, A; Kuhn, C; Plenge-Bönig, A; Thomas, S M; Schmidt-Chanasit, J; Tannich, E

2014-05-01

169

DsRed2 transient expression in Culex quinquefasciatus mosquitoes  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Culex quinquefasciatus mosquitoes have been successfully genetically modified only once, despite the efforts of several laboratories to transform and establish a stable strain. We have developed a transient gene expression method, in Culex, that delivers plasmid DNA directly to the mosquito haemoly [...] mph and additional tissues. We were able to express DsRed2 fluorescent protein in adult Cx. quinquefasciatus mosquitoes by injecting plasmids directly into their thorax. The expression of DsRed2 in adult Cx. quinquefasciatus mosquitoes is an important stepping stone to genetic transformation and the potential use of new control strategies and genetic interactions.

Wilke, Andre Barretto Bruno; Scaife, Sarah; Alphey, Luke; Marrelli, Mauro Toledo.

2013-06-01

170

Field evaluation of New Mountain Sandalwood Mosquito Sticks and New Mountain Sandalwood Botanical Repellent against mosquitoes in North Queensland, Australia.  

Science.gov (United States)

The mosquito repellent efficacy of New Mountain Sandalwood Mosquito Sticks (containing 0.5% w/w essential oils) and New Mountain Sandalwood Botanical Repellent (containing soybean and geranium oils) was assessed. Tests were conducted in the field with 4 volunteers in a wooded area near Cairns, North Queensland, Australia. Predominant biting species were Verrallina funerea and Ve. lineata. A pair of burning Mosquito Sticks immediately upwind of the subject (acting as an area repellent) provided a 73.1% mean reduction in mosquito landing and probing over the 3-h test period. The Botanical Repellent and a DEET-based control were both 100% effective in preventing mosquito probing for 3 h. These data are consistent with other studies of area repellents in that such products provide significant protection from mosquito bites, albeit inferior to the protection provided by topically applied repellents. PMID:16646344

Ritchie, Scott A; Williams, Craig R; Montgomery, Brian L

2006-03-01

171

Evaluation of lurex 3, octenol, and CO2 sachet as baits in Mosquito Magnet Pro traps against floodwater mosquitoes.  

Science.gov (United States)

Field evaluation of Lurex 3, 1-octen-3-ol (octenol), and CO2 sachet as baits in Mosquito Magnet Pro traps (MMP) for collecting adult mosquitoes was conducted at 2 different locations in northeast Florida. A total of 18 species of mosquitoes were collected by the MMP baited with the 3 attractant baits in St. Augustine, FL. The MMP baited with octenol collected significantly more mosquitoes than the traps baited with Lurex 3 and the CO2 sachet. A total of 6 floodwater mosquito species were collected by the MMP baited with the 3 attractant baits in Elkton, FL. The MMP baited with Lurex 3 or octenol collected more mosquitoes than the MMP baited with CO2 sachet or MMP alone. PMID:21033066

Xue, Rui-De; Qualls, Whitney A; Kline, Daniel L; Zhao, Tong-Yan

2010-09-01

172

Dirac operators and Killing spinors with torsion; Dirac-Operatoren und Killing-Spinoren mit Torsion  

Energy Technology Data Exchange (ETDEWEB)

On a Riemannian spin manifold with parallel skew torsion, we use the twistor operator to obtain an eigenvalue estimate for the Dirac operator with torsion. We consider the equality case in dimensions four and six. In odd dimensions we describe Sasaki manifolds on which equality in the estimate is realized by Killing spinors with torsion. In dimension five we characterize all Killing spinors with torsion and obtain certain naturally reductive spaces as exceptional cases.

Becker-Bender, Julia

2012-12-17

173

Re-introducing bacteria in mosquitoes - A method for determination of mosquito feeding preferences based on coloured sugar solutions  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this study, sugar-feeding was investigated as a possible means of re-introducing bacteria into mosquito midguts with the aim of identifying bacteria that are suitable for creating paratransgenic mosquitoes. In a paratransgenic approach, bacteria are utilised to deliver effector molecules capable of inhibiting pathogen development in the midgut of the vector. To determine if mosquitoes discriminate between sterile sugar solutions and sugar solutions with bacteria, a method for screening mos...

Lindh, J. M.; Terenius, O.; Eriksson-gonzales, K.; Knols, B. G. J.; Faye, I.

2006-01-01

174

Laboratory Efficacy Tests of Pyrethroid-Treated Bed Nets on the Malaria Vector Mosquito, Anopheles stephensi, in a Baited Excito-Repellency Chamber  

Directory of Open Access Journals (Sweden)

Full Text Available Insecticide-treated net is currently the best available method to control malaria. The extensive use of pyrethroid insecticides and the challenges of mosquito resistance to these chemical compounds are the main reasons for undertaking this study. The excito-repellency impacts of three different concentrations of three synthetic pyrethroid insecticide (lambdacyhalothrin, deltamethrin and cyfluthrin impregnated bednets were evaluated against the susceptible and endophilic primary malaria vector, Anopheles stephensi Liston (Diptera: Culicidae India susceptible strain under laboratory conditions. Young unfed female adult mosquitoes were exposed to animal bait covered with net in a dark exposure chamber. For each test, the results of mosquitoes` behavior were recorded after half an hour as dead, survived, blood-fed, recovered and retrieved in the exit trap. These studies clearly showed that populations of malaria vectors can be effectively controlled by the use of pyrethroid-treated bednets. The results inferred that deltamethrin was partially superior to other insecticides in terms of toxicity and revealed that cyfluthrin was clearly least effective and deltamethrin was most effective. The latter was 1.6 and 2.0 times more effective than lambdacyhalothrin and cyfluthrin, respectively, in killing An. stephensi mosquitoes. In addition, the mean recovery rate due to deltamethrin was 3.8 and 2.4 times less effective than cyfluthrin and lambdacyhalothrin, respectively. In conclusion, these data ranked the relative potency of the three pyrethroids in the order deltamethrin > lambdacyhalothrin > cyfluthrin.

H. Alipour

2006-01-01

175

Dose-response curves and cell killing  

International Nuclear Information System (INIS)

In the literature on dose-response curves (drc) for radiation-induced cancer, it is customary to include an exponential term to describe the downturn of drcs at high doses. This term is supposed to describe the effect of cell killing on the frequency of radiation-induced cancers. A closer look at the point estimates, which are fit by mathematical models, reveals that most authors plot frequency estimates without considerations of time since exposure and of competing risks. The authors suggest plots of the estimated frequency of tumor appearance corrected for independent competing risks at a fixed and equal time since exposure against dose to correct these short comings and demonstrate with several examples (e.g. /sup 239/Pu in beagles and /sup 226/Ra in man) the disappearance of the downtrend in such plots. Application of Ockham's razor suggests, therefore, the abandonment of the cell killing hypothesis as the complete explanation of the downturn

1984-03-01

176

Heterotic supergravity on manifolds with Killing spinors  

Energy Technology Data Exchange (ETDEWEB)

The present work deals with the construction of heterotic string backgrounds on manifolds with real Killing spinors. The latter have played an important role in string theory for a long time, mainly due to Baer's correspondence between Killing spinors on a manifold M and parallel spinors on the cone over M. Given the fact that parallel spinors always lead to exact supergravity BPS backgrounds, it implies that the cone admits a solution of the BPS equations. Furthermore, in type II string theory and in M-theory it is possible to place a brane at the tip of the cone, in appropriate dimensions, and the resulting supergravity solutions are exactly known. In the limit far away from the brane they converge to the empty space solution, whereas in the near horizon limit one obtains a so-called Freund-Rubin solutions, consisting of an anti-de Sitter space times our base manifold M. In heterotic supergravity on the other hand two types of brane-like solutions are known; the NS5-brane, consisting of an R{sup 4}-factor with fluxes and a transverse 6-dimensional Minkowski space, and what is sometimes called the gauge solitonic branes. These come equipped with an instanton gauge field on some Euclidean space R{sup p}, which carries further non-vanishing fluxes, and again a transverse (10-p)-dimensional Minkowski space. The possible values for p that appeared in the literature so far are p=4, 7 and 8, and the corresponding instantons are the famous BPST and octonionic instantons. Manifolds with real Killing spinors have been classified: besides the round spheres they are either 6-dimensional nearly Kaehler, 7-dimensional nearly parallel G{sub 2}, Sasaki-Einstein, or 3-Sasakian. I present a generalization of the gauge solitonic branes to the cone over any real Killing spinor manifold, based upon this classification. In particular, this involves the construction of instantons on the cone. Additionally, I show that for homogeneous manifolds with real Killing spinors there is a solution similar to the near horizon limit of the NS5-brane. Finally, the instanton equation on the cylinder over the cone over a 6-dimensional nearly Kaehler manifold is investigated. Several instanton solutions exist, and to embed these into heterotic supergravity is an interesting problem for future work. Besides the cone, the so-called sine-cone over a Killing spinor manifold is important. For instance, it is known that the sine-cone over a 5-dimensional Sasaki-Einstein manifold is nearly Kaehler, and the one over a nearly Kaehler manifold is nearly parallel G{sub 2}. I generalize these results by proving that the sine-cone over an arbitrary real Killing spinor manifold has a real Killing spinor again. It is shown in particular, that the iterated sine-cone over a Sasaki-Einstein manifold also carries a Sasaki-Einstein-structure.

Noelle, Christoph

2012-01-23

177

Inflatable packers kill Algerian gas blowout  

Energy Technology Data Exchange (ETDEWEB)

SONATRACH killed an 18-month underground blowout at its No. 1 Jebel Bessi gas well, a wildcat about 30 miles (50 km) southeast of Algeria's giant Hassi R'Mel field, by isolating the casing ruptures with three pairs of inflatable external casing packers set on a 5-in. drill-pipe/casing production string. About 180 million CF/day of gas had been leaking around the surface casing shoe and escaping near the rig, and the kill efforts were complicated by two fish in the hole (various pieces of pipe and equipment lost downhole previously) and by several windows that were accidentally cut into the upper part of the casing during fishing operations (attempts to retrieve the lost items). To isolate the high-pressure gas, the operators set the packers between the windows and the fish.

Moore, W.D. III

1980-09-15

178

Underground blowout killed with quick snubbing operation  

Energy Technology Data Exchange (ETDEWEB)

A shallow underground blowout off the island of Trinidad required quick action and the importing of snubbing equipment to kill the well and avert cratering the sea floor beneath the platform. The blowout was controlled in 16 days. The blowout at Trintomar's Pelican platform on the east coast of Trinidad posed a most challenging well control problem. Most of the service companies with equipment to control the well were not available in this relatively remote area. Because of the high gas and condensate flow rates and high pressure, the blowout at the Pelican platform had the potential to destroy the entire platform, endanger the lives of many crew members, result in the loss of natural resources, and interrupt the supply of natural gas to the island of Trinidad. The paper discusses the Pelican platform, the underground blowout, temperature survey, the kill plan, and snubbing operations.

Grace, R. (Grace, Shursen, Moore and Associates Inc., Amarillo, TX (United States)); Stanislaus, G. (Trinmar Ltd., Point Fortin (Trinidad and Tobago)); Cudd, B. (Cudd Pressure Control, Woodward, OK (United States))

1993-10-18

179

Zeroth law for Killing horizons in Lanczos-Lovelock gravity  

CERN Multimedia

We study the zeroth law for Killing horizons in Lanczos-Lovelock gravity. We prove that the surface gravity of a general Killing horizon in Lanczos-Lovelock gravity is constant provided the matter source satisfies dominant energy condition.

Sarkar, Sudipta

2012-01-01

180

Killing tensors and canonical geometry in classical dynamics  

CERN Document Server

The systematic derivation of constants of the motion, based on Killing tensors and the gauge covariant approach, is outlined. Quantum dots are shown to support second-, third- and fourth-rank Killing tensors.

Cariglia, M; van Holten, J -W; Horvathy, P A; Kosinski, P; Zhang, P -M

2014-01-01

 
 
 
 
181

Myeloperoxidase Selectively Binds and Selectively Kills Microbes ? †  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Myeloperoxidase (MPO) is reported to selectively bind to bacteria. The present study provides direct evidence of MPO binding selectivity and tests the relationship of selective binding to selective killing. The microbicidal effectiveness of H2O2 and of OCl? was compared to that of MPO plus H2O2. Synergistic microbicidal action was investigated by combining Streptococcus sanguinis, a H2O2-producing microbe showing low MPO binding, with high-MPO-binding Escherichia coli, Staphylococcus aureus...

Allen, Robert C.; Stephens, Jackson T.

2011-01-01

182

Generalized Killing spinors in dimension 5  

CERN Document Server

We study the intrinsic geometry of hypersurfaces in Calabi-Yau manifolds of real dimension 6 and, more generally, SU(2)-structures on 5-manifolds defined by a generalized Killing spinor. We prove that in the real analytic case, such a 5-manifold can be isometrically embedded as a hypersurface in a Calabi-Yau manifold in a natural way. We classify nilmanifolds carrying invariant structures of this type, and present examples of the associated metrics with holonomy SU(3).

Conti, D; Conti, Diego; Salamon, Simon

2005-01-01

183

Monoclonal antibody targets, kills leukemia cells  

Science.gov (United States)

Researchers at the University of California, San Diego Moores Cancer Center have identified a humanized monoclonal antibody that targets and directly kills chronic lymphocytic leukemia (CLL) cells. The findings, published in the online Early Edition of the Proceedings of the National Academy of Sciences on March 25, 2013 represent a potential new therapy for treating at least some patients with CLL, the most common type of blood cancer in the United States.

184

Novel innate cancer killing activity in humans  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Background In this study, we pilot tested an in vitro assay of cancer killing activity (CKA) in circulating leukocytes of 22 cancer cases and 25 healthy controls. Methods Using a human cervical cancer cell line, HeLa, as target cells, we compared the CKA in circulating leukocytes, as effector cells, of cancer cases and controls. The CKA was normalized as percentages of total target cells during selected periods of incubation time and at selected effecto...

Blanks Michael J; Stehle John R; Du Wei; Adams Jonathan M; Willingham Mark C; Allen Glenn O; Hu Jennifer J; Lovato James; Molnar Istvan; Cui Zheng

2011-01-01

185

On the classification of Killing submersions and their isometries  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A Killing submersion is a Riemannian submersion from an orientable 3-manifold to an orientable surface whose fibers are the integral curves of a unit Killing vector field in the 3-manifold. We classify all Killing submersions over simply-connected Riemannian surfaces and give explicit models for many Killing submersions including those over simply-connected constant Gaussian curvature surfaces. We also fully describe the isometries of the total space preserving the vertical ...

Manzano, Jose? M.

2012-01-01

186

Potassium channels mediate killing by human natural killer cells.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Human natural killer (NK) cells in peripheral blood spontaneously recognize and kill a wide variety of target cells. It has been suggested that ion channels are involved in the killing process because there is a Ca-dependent stage and because killings by presensitized cytotoxic T lymphocytes, which in many respects resembles NK killing, is associated with changes in K and Na transport in the target cell. However, no direct evidence exists for ion channels in NK cells or in their target cells....

Schlichter, L.; Sidell, N.; Hagiwara, S.

1986-01-01

187

78 FR 43063 - Drawbridge Operation Regulations; Arthur Kill, NY  

Science.gov (United States)

...governing the operation of the Arthur Kill AK Railroad Bridge across Arthur Kill, mile 11.6, between Staten...Railroad Bridge, across Arthur Kill, mile 11.6, between Staten...at the end of the designated time period. This deviation...

2013-07-19

188

Method for Dispensing Planaria (Dugesia dorotocephala) for Mosquito Control,  

Science.gov (United States)

Predation studies of mosquitoes by the planarian dugesia dorotocephala have since shown that D. dorotocephala is an effective predator on all larval stages of mosquitoes. Densities of 25 planaria/m2 have been cited as sufficient to effect significant cont...

W. M. Darby L. R. Boobar M. R. Sardelis

1988-01-01

189

The Knowledge and Experience of Dengue Mosquitoes among Housewives.  

Directory of Open Access Journals (Sweden)

Full Text Available Dengue Hemorrhagic Fever (DHF prevention programs in Semarang, were focused through controlling mosquito breeding sites (PSN, but the implementation of PSN was not become a habit in every household. The objective of this study was to explore knowledge and experience of dengue mosquitoes among housewives in the endemic villages.The research was using qualitative methods. Subjects of the study were 17 housewives which selected by purposive sampling. The data collection was carried in Sendangmulyo village, Semarang, through observation, focus groups discussions, and indepth interviews. The techniques used to test data validity were triangulation and member checking method. Data were analyzed using content analysis approached. The results showed that housewives classifying mosquito based on time occurrence whether the presence of mosquito in environment was perceived naturally. Unoptimalized PSN behavior was based on the lack of housewives knowledge on larvae development stages. Mosquito was not considered as a threatening because night mosquito biting was directly more disturbing rather than day mosquitoes’. Health promotion program could increase dasa wisma cadres knowledge and skill, particularly on mosquito life cycle and the correct stages of PSN behavior. This study did not distinguish the demographic characteristics of informants. Further reserch could explore it or develop media based on local knowledge and experience.

Atik Triratnawati

2011-06-01

190

Injection of dsRNA into Female A. aegypti Mosquitos  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Reverse genetic approaches have proven extremely useful for determining which genes underly resistance to vector pathogens in mosquitoes. This video protocol illustrates a method used by the James lab to inject dsRNA into female A. aegypti mosquitoes, which harbor the dengue virus. The technique for calibrating injection needles, manipulating the injection setup, and injecting dsRNA into the thorax is illustrated.

Luna, Brian M.; Juhn, Jennifer; James, Anthony A. A.

2007-01-01

191

Aedes aegypti Mosquitoes Imported into the Netherlands, 2010  

Digital Repository Infrastructure Vision for European Research (DRIVER)

During summer 2010, Aedes aegypti mosquitoes were discovered in the Netherlands. Using genetic markers, we tracked the origin of these mosquitoes to a tire shipment from Miami, Florida, USA. Surveillance of tire exports from the United States should be included as part of a comprehensive surveillance system.

Brown, Julia E.; Scholte, Ernst-jan; Dik, Marian; Den Hartog, Wietse; Beeuwkes, Jacob; Powell, Jeffrey R.

2011-01-01

192

Statics and dynamics of malaria infection in Anopheles mosquitoes  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract The classic formulae in malaria epidemiology are reviewed that relate entomological parameters to malaria transmission, including mosquito survivorship and age-at-infection, the stability index (S), the human blood index (HBI), proportion of infected mosquitoes, the sporozoite rate, the entomological inoculation rate (EIR), vectorial capacity (C) and the basic reproductive number (R0). The synthesis emphasizes the relationships among classic formulae and...

Smith David L; Ellis McKenzie F

2004-01-01

193

UV light and urban pollution: Bad cocktail for mosquitoes?  

Energy Technology Data Exchange (ETDEWEB)

Highlights: •Mosquito tolerance to temephos is induced by PAHs and UV exposure. •Toxicity of fluoranthene for mosquito Malpighian tubules cells is induced by UV. •Fluoranthene crystallizes in mosquito Malpighian tubules upon UV exposure. •Mixture of two PAHs is less toxic for mosquitoes than each PAHs separately. •Combination of abiotic parameters (PAHs and UV) affect mosquito physiology. -- Abstract: Mosquito breeding sites consist of water pools, which can either be large open areas or highly covered ponds with vegetation, thus with different light exposures combined with the presence in water of xenobiotics including polycyclic aromatic hydrocarbons (PAHs) generated by urban pollution. UV light and PAHs are abiotic factors known to both affect the mosquito insecticide resistance status. Nonetheless, their potential combined effects on the mosquito physiology have never been investigated. The present article aims at describing the effects of UV exposure alongside water contamination with two major PAH pollutants (fluoranthene and benzo[a]pyrene) on a laboratory population of the yellow fever mosquito Aedes aegypti. To evaluate the effects of PAH exposure and low energetic UV (UV-A) irradiation on mosquitoes, different parameters were measured including: (1) The PAH localization and its impact on cell mortality by fluorescent microscopy; (2) The detoxification capacities (cytochrome P450, glutathione-S-transferase, esterase); (3) The responses to oxidative stress (Reactive Oxygen Species–ROS) and (4) The tolerance of mosquito larvae to a bioinsecticide (Bacillus thuringiensis subsp. israelensis–Bti) and to five chemical insecticides (DDT, imidacloprid, permethrin, propoxur and temephos). Contrasting effects regarding mosquito cell mortality, detoxification and oxidative stress were observed as being dependent on the pollutant considered, despite the fact that the two PAHs belong to the same family. Moreover, UV is able to modify pollutant effects on mosquitoes, including tolerance to three insecticides (imidacloprid, propoxur and temephos), cell damage and response to oxidative stress. Taken together, our results suggest that UV and pollution, individually or in combination, are abiotic parameters that can affect the physiology and insecticide tolerance of mosquitoes; but the complexity of their direct effect and of their interaction will require further investigation to know in which condition they can affect the efficacy of insecticide-based vector control strategies in the field.

Tetreau, Guillaume, E-mail: guillaume.tetreau@gmail.com [Laboratoire d’Ecologie Alpine, LECA-UMR 5553, Université de Grenoble 1, BP 53, 38041 Grenoble cedex 09 (France); Department of Entomology, Cornell University, New York State Agricultural Experiment Station, Geneva, NY 14456 (United States); Chandor-Proust, Alexia; Faucon, Frédéric; Stalinski, Renaud; Akhouayri, Idir; Prud’homme, Sophie M.; Régent-Kloeckner, Myriam; Raveton, Muriel; Reynaud, Stéphane [Laboratoire d’Ecologie Alpine, LECA-UMR 5553, Université de Grenoble 1, BP 53, 38041 Grenoble cedex 09 (France)

2014-01-15

194

UV light and urban pollution: Bad cocktail for mosquitoes?  

International Nuclear Information System (INIS)

Highlights: •Mosquito tolerance to temephos is induced by PAHs and UV exposure. •Toxicity of fluoranthene for mosquito Malpighian tubules cells is induced by UV. •Fluoranthene crystallizes in mosquito Malpighian tubules upon UV exposure. •Mixture of two PAHs is less toxic for mosquitoes than each PAHs separately. •Combination of abiotic parameters (PAHs and UV) affect mosquito physiology. -- Abstract: Mosquito breeding sites consist of water pools, which can either be large open areas or highly covered ponds with vegetation, thus with different light exposures combined with the presence in water of xenobiotics including polycyclic aromatic hydrocarbons (PAHs) generated by urban pollution. UV light and PAHs are abiotic factors known to both affect the mosquito insecticide resistance status. Nonetheless, their potential combined effects on the mosquito physiology have never been investigated. The present article aims at describing the effects of UV exposure alongside water contamination with two major PAH pollutants (fluoranthene and benzo[a]pyrene) on a laboratory population of the yellow fever mosquito Aedes aegypti. To evaluate the effects of PAH exposure and low energetic UV (UV-A) irradiation on mosquitoes, different parameters were measured including: (1) The PAH localization and its impact on cell mortality by fluorescent microscopy; (2) The detoxification capacities (cytochrome P450, glutathione-S-transferase, esterase); (3) The responses to oxidative stress (Reactive Oxygen Species–ROS) and (4) The tolerance of mosquito larvae to a bioinsecticide (Bacillus thuringiensis subsp. israelensis–Bti) and to five chemical insecticides (DDT, imidacloprid, permethrin, propoxur and temephos). Contrasting effects regarding mosquito cell mortality, detoxification and oxidative stress were observed as being dependent on the pollutant considered, despite the fact that the two PAHs belong to the same family. Moreover, UV is able to modify pollutant effects on mosquitoes, including tolerance to three insecticides (imidacloprid, propoxur and temephos), cell damage and response to oxidative stress. Taken together, our results suggest that UV and pollution, individually or in combination, are abiotic parameters that can affect the physiology and insecticide tolerance of mosquitoes; but the complexity of their direct effect and of their interaction will require further investigation to know in which condition they can affect the efficacy of insecticide-based vector control strategies in the field

2014-01-01

195

Mosquito transmission of the rodent malaria parasite Plasmodium chabaudi  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Serial blood passage of Plasmodium increases virulence, whilst mosquito transmission inherently regulates parasite virulence within the mammalian host. It is, therefore, imperative that all aspects of experimental malaria research are studied in the context of the complete Plasmodium life cycle. Methods Plasmodium chabaudi chabaudi displays many characteristics associated with human Plasmodium infection of natural mosquito vectors and the mammalian host, and thus provides a unique opportunity to study the pathogenesis of malaria in a single infection setting. An optimized protocol that permits efficient and reproducible vector transmission of P. c. chabaudi via Anopheles stephensi was developed. Results and conclusions This protocol was utilized for mosquito transmission of genetically distinct P. c. chabaudi isolates, highlighting differential parasite virulence within the mosquito vector and the spectrum of host susceptibility to infection initiated via the natural route, mosquito bite. An apposite experimental system in which to delineate the pathogenesis of malaria is described in detail.

Spence Philip J

2012-12-01

196

Control of mosquitoes by the sterile male technique  

International Nuclear Information System (INIS)

Field tests on the applicability of SIT to mosquito control have been conducted since the late 1950s. Early field experiments were conducted by releasing radiation-sterilized males. Methods of chemically sterilizing mosquitoes were also developed. Genetically altered strains which are partially sterile were also developed, studied and then used in field experiments. The earliest release experiments with mosquitoes were unsuccessful in introducing sterility into natural populations or reducing insect density, but identified problems and developed methodology. A summary of the releases conducted since the 1950s is given as background and then recent tests are reviewed in more detail where population control was achieved. The advances made in understanding the dynamics of field populations of mosquitoes when subjected to SIT are also reviewed. The problems associated with SIT for mosquito control - absolute density, growth rate, migration and others - are also discussed. (author)

1981-07-03

197

Mosquito fauna of Ubin Island, Singapore.  

Science.gov (United States)

We report the mosquito species and their distribution records for Ubin Island, Singapore, based on our field collections in February 2010, routine adult and larval surveys from 1993 to 2009 by Singapore operational officers, and accessioned specimens deposited in the Environmental Health Institute, Singapore, and the US National Museum of Natural History, Washington, DC. A total of 25 species and 6 unidentified species belonging to 9 genera (Aedes, Anopheles, Armigeres, Coquillettidia, Culex, Lutzia, Mansonia, Uranotaenia, and Verrallina) were identified and recorded from Ubin Island, based on specimens collected from 1993 to 2010. PMID:23833906

Lee, Ruth Mee Lian; Lam-Phua, Sai Gek; Tan, Wilson Cheong Huat; Pang, Sook Cheng; Vythilingam, Indra; Ng, Lee Ching; Rueda, Leopoldo M

2012-09-01

198

Cholate-dependent killing of Giardia lamblia by human milk.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We showed previously that nonimmune human milk (NHM) kills Giardia lamblia trophozoites in vitro and presented evidence that killing requires the bile salt-stimulated lipase of milk. Since this enzyme is activated by bile salts, killing should be dependent on the presence of bile salts. We now show that killing by fresh NHM or NHM stored at -70 degrees C is totally dependent on sodium cholate (a bile salt). With less than 0.4 mM cholate, no parasites were killed, whereas with 1 mM cholate, gr...

1985-01-01

199

Universal properties from local geometric structure of Killing horizon  

CERN Multimedia

We consider universal properties that arise from a local geometric structure of a Killing horizon. We first introduce a non-perturbative definition of such a local geometric structure, which we call an asymptotic Killing horizon. It is shown that infinitely many asymptotic Killing horizons reside on a common null hypersurface, once there exists one asymptotic Killing horizon. The acceleration of the orbits of the vector that generates an asymptotic Killing horizon is then considered. We show that there exists the $\\textit{diff}(S^1)$ or $\\textit{diff}(R^1)$ sub-algebra on an asymptotic Killing horizon universally, which is picked out naturally based on the behavior of the acceleration. We also argue that the discrepancy between string theory and the Euclidean approach in the entropy of an extreme black hole may be resolved, if the microscopic states responsible for black hole thermodynamics are connected with asymptotic Killing horizons.

Koga, J

2006-01-01

200

Tree-hole breeding mosquitoes in Israel.  

Science.gov (United States)

A survey was conducted to evaluate the number of tree-hole breeding mosquito species and their distribution in the six principal woodland types in Israel. Out of approximately 3,000 mature trees examined, only 38 contained holes that retained water for extended periods of time, and breeding mosquitoes were observed in 27 of them. Two specialized tree-hole breeders, Aedes pulchritarsis Rondani and Aedes geniculatus Oliver, were found breeding at several sites in northern Israel, always at locations 500 m above sea level (a.s.l) and with high annual precipitation. Aedes albopictus Skuse which, in Israel, is known as an opportunistic container breeder, was found in this study to have adapted remarkably well to breeding in tree holes and was found in most forest types investigated and in most tree species which had adequate tree holes. Two other species, Culiseta annulata Schrank and Culex pipiens Linnaeus instars, were found in one of the tree holes, but did not survive to reach maturity. PMID:22548543

Müller, Günter C; Kravchenko, Vasiliy D; Junnila, Amy; Schlein, Yosef

2012-06-01

 
 
 
 
201

Male reproductive biology of Aedes mosquitoes.  

Science.gov (United States)

Among Aedes mosquitoes are species responsible for transmission of serious pathogens to humans. To cope with the current threats to long-term effectiveness of the traditional vector control methods, non-conventional control strategies are being developed. These include autocidal control such as the release of sterile males (sterile insect technique) and the release of Wolbachia-infected males to induce sexual sterility (incompatible insect technique) and pathogen-refractory strain replacement variations using Wolbachia. Sterile male types of techniques particularly depend on released males' ability to successfully mate with wild females. For that reason, a good understanding of male mating biology, including a thorough understanding of the reproductive system and mating capacity, increases the likelihood of success of such genetic vector control programmes. Here we review the literature concerning the reproduction of Aedes mosquitoes with an emphasis on the male biology. We consider sexual maturation, mate finding, insemination, male reproductive capacity, and the occurrence of multiple matings. We also discuss which parameters are of greatest importance for the successful implementation of autocidal control methods and propose questions for future research. PMID:24308996

Oliva, Clelia F; Damiens, David; Benedict, Mark Q

2014-04-01

202

The 1990 Arthur Kill oil spills  

International Nuclear Information System (INIS)

On January 1-2, 1990, Exxon discharged 567,000 gallons of No. 2 heating oil in the Arthur Kill, the strait separating Staten Island, New York from New Jersey. Lawsuits against Exxon were filed by the State of New Jersey, New York City, and the City of Elizabeth. They seek to force Exxon to reimburse the municipalities and the state for cleanup costs and to restore damaged wetlands and other natural resources. The three plaintiffs, joined by New York State and the federal government, initiated a three-tiered natural resource damage assessment study (Tier II), currently underway, includes sampling and chemical analysis of sediments and benthic invertebrates, mapping of impacted wetlands and measurement of direct impacts on water birds and their prey. The purposes of the study are to quantify the damages and determine the presence of Exxon's oil in the sediments. Since the Exxon spill, there have been two major spills and an intermediate-size spill. During the first size months of 1990, over one million gallons of petroleum products have been discharged into the Arthur Kill and nearby waters. This paper reports that a review of these incidents provides lessons for the prevention, investigation, and cleanup of spills in urban estuaries

1990-05-15

203

Dirofilaria repens microfilariae in Aedes vexans mosquitoes in Slovakia.  

Science.gov (United States)

In this study, we screened field-caught mosquitoes for presence of Dirofilaria spp. by using a polymerase chain reaction (PCR) assay. Potential occurrence of Dirofilaria repens and Dirofilaria immitis microfilariae was examined in 3,600 mosquitoes of eight species (Aedes vexans, Aedes cinereus, Aedes rossicus, Culex pipiens, Culiseta annulata, Ochlerotatus sticticus, Ochlerotatus cantans and Ochlerotatus caspius) collected from five locations in two districts (Kosice and Trebisov) of Eastern Slovakia, endemic region of canine dirofilariasis. Collection of mosquitoes was performed between May and August 2012 in premises known to be inhabited by Dirofilaria-infected dogs. PCR assays were performed on 72 pools, each pool containing 50 mosquitoes of the same species, collected on the same location. Each pool was examined separately for the presence of D. immitis and D. repens, respectively. A positive finding of D. repens was recorded in one pool of A. vexans mosquitoes collected in Košické Olšany village. Minimum infection rate in A. vexans was 1:1,750, i.e. 0.57 per 1,000 mosquitoes. The identity of D. repens was confirmed by direct sequencing of PCR product which has shown 100% homology with sequence attributed to D. repens (GenBank accession number AJ271614). This study represents the first molecular evidence of D. repens microfilariae in mosquitoes in Slovakia and highlights a need for better surveillance of zoonotic dirofilariasis in central Europe. PMID:23846240

Bocková, Eva; Rudolf, Ivo; Ko?išová, Alica; Betášová, Lenka; Venclíková, Kristýna; Mendel, Jan; Hubálek, Zden?k

2013-10-01

204

Identification of mosquito repellent odours from Ocimum forskolei  

Science.gov (United States)

Background Native mosquito repellent plants have a good potential for integrated mosquito control in local settings. Ocimum forskolei, Lamiaceae, is used in Eritrea as a spatial mosquito repellent inside houses, either through crushing fresh plants or burning dry plants. We verified whether active repellent compounds could be identified using gas-chromatography coupled electroantennogram recordings (GC-EAD) with headspace extracts of crushed plants. Results EAD active compounds included (R)-(-)-linalool, (S)-(+)-1-octen-3-ol, trans-caryophyllene, naphthalene, methyl salicylate, (R)-(-)-?-copaene, methyl cinnamate and (E)-ocimene. Of these compounds (R)-(-)-linalool, methyl cinnamate and methyl salicylate reduced landing of female Aedes aegypti on human skin-odor baited tubes. The latter two are novel mosquito repellent compounds. Conclusions The identification of mosquito repellent compounds contributes to deciphering the mechanisms underlying repulsion, supporting the rational design of novel repellents. The three mosquito repellent compounds identified in this study are structurally dissimilar, which may indicate involvement of different sensory neurons in repulsion. Repulsion may well be enhanced through combining different repellent plants (or their synthetic mimics), and can be a locally sustainable part in mosquito control efforts.

2011-01-01

205

Culicinae mosquitoes in Sanandaj county, Kurdistan province, western Iran  

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Full Text Available Background & objectives: This study aims at studying mosquito-borne diseases as the major publichealth threat in Iran. Sanandaj outskirts are considered suitable habitats for mosquito larvae. Inview of scanty reports on mosquito-borne disease implementation in this area, a study was undertakento determine the mosquito fauna and frequency of mosquito larvae at Sanandaj City.Methods: In order to study the mosquito (Diptera: Culicidae fauna, the samples were collectedfrom May to July 2009 using dipping and night catch methods in Sanandaj district, Kurdistanprovince, western Iran.Results: Three genera and 11 species of the Culicinae subfamily were identified—Aedes vexansMeigen, Ochlerotatus caspius s.l. Pallas (indicating new occurrence records for the province,Culex hortensis Ficalbi, Cx. pipiens Linnaeus, Cx. mimeticus Noe, Cx. theileri Theobald, Culisetalongiareolata Macquart, and Cs. subochrea Edwards.Interpretation & conclusion: Present study revealed that Ae. vexans and Ochlerotatus caspius s.lcaught had not been previously recorded in Kurdistan province, highlighting the deficient knowledgeof the fauna and distribution of Culicinae mosquitoes of this part of Iran

S.H. Moosa Kazemi

2010-06-01

206

Identification of mosquito repellent odours from Ocimum forskolei  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Native mosquito repellent plants have a good potential for integrated mosquito control in local settings. Ocimum forskolei, Lamiaceae, is used in Eritrea as a spatial mosquito repellent inside houses, either through crushing fresh plants or burning dry plants. We verified whether active repellent compounds could be identified using gas-chromatography coupled electroantennogram recordings (GC-EAD with headspace extracts of crushed plants. Results EAD active compounds included (R-(--linalool, (S-(+-1-octen-3-ol, trans-caryophyllene, naphthalene, methyl salicylate, (R-(--?-copaene, methyl cinnamate and (E-ocimene. Of these compounds (R-(--linalool, methyl cinnamate and methyl salicylate reduced landing of female Aedes aegypti on human skin-odor baited tubes. The latter two are novel mosquito repellent compounds. Conclusions The identification of mosquito repellent compounds contributes to deciphering the mechanisms underlying repulsion, supporting the rational design of novel repellents. The three mosquito repellent compounds identified in this study are structurally dissimilar, which may indicate involvement of different sensory neurons in repulsion. Repulsion may well be enhanced through combining different repellent plants (or their synthetic mimics, and can be a locally sustainable part in mosquito control efforts.

Glinwood Robert

2011-09-01

207

Production of wetland Chironmidae (Diptera) and the effects of using Bacillus thuringiensis israelensis for mosquito control  

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Massive mosquito nuisance problems, caused by the flood-water mosquito Aedes sticticus, occur after floods in the flood plains of the River Dalälven, central Sweden. Since 2002, the biological mosquito larvicide Bacillus thuringiensis var. israelensis (Bti) has been used to control these mosquitoes. Here, we report results from the first six years of monitoring Chironomidae, the most susceptible non-target organisms, in three wetlands with Bti-treatment against mosquitoes and in three wetlan...

Lundstro?m, J. O.; Scha?fer, M. L.; Petersson, E.; Persson Vinnersten, T. Z.; Landin, Jan; Brodin, Y.

2010-01-01

208

A systematic review of mosquito coils and passive emanators: defining recommendations for spatial repellency testing methodologies  

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Mosquito coils, vaporizer mats and emanators confer protection against mosquito bites through the spatial action of emanated vapor or airborne pyrethroid particles. These products dominate the pest control market; therefore, it is vital to characterize mosquito responses elicited by the chemical actives and their potential for disease prevention. The aim of this review was to determine effects of mosquito coils and emanators on mosquito responses that reduce human-vector contact and to propos...

2012-01-01

209

A Systematic Review of Mosquito Coils and Passive Emanators: Defining Recommendations for Spatial Repellency Testing Methodologies.  

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Mosquito coils, vaporizer mats and emanators confer protection against mosquito bites through the spatial action of emanated vapor or airborne pyrethroid particles. These products dominate the pest control market; therefore, it is vital to characterize mosquito responses elicited by the chemical actives and their potential for disease prevention. The aim of this review was to determine effects of mosquito coils and emanators on mosquito responses that reduce human-vector contact and to propos...

2012-01-01

210

A systematic review of mosquito coils and passive emanators: defining recommendations for spatial repellency testing methodologies  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Mosquito coils, vaporizer mats and emanators confer protection against mosquito bites through the spatial action of emanated vapor or airborne pyrethroid particles. These products dominate the pest control market; therefore, it is vital to characterize mosquito responses elicited by the chemical actives and their potential for disease prevention. The aim of this review was to determine effects of mosquito coils and emanators on mosquito responses that reduce human-vector co...

2012-01-01

211

Human skin emanations in the host-seeking behaviour of the malaria mosquito Anopheles gambiae  

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Malaria is an infectious disease caused by a parasite ( Plasmodium spp.) that is transmitted between human individuals by mosquitoes, belonging to the order of insects, Diptera, family of Culicidae (mosquitoes) and genus of Anopheles (malaria mosquitoes). Mosquitoes feed on humans (and other animals) because they need blood for their reproduction. Like most other haematophagous insects, only the female mosquitoes bite and use the protein-rich blood meal for egg development. Whilst feeding on ...

1999-01-01

212

UV light and urban pollution: bad cocktail for mosquitoes?  

Science.gov (United States)

Mosquito breeding sites consist of water pools, which can either be large open areas or highly covered ponds with vegetation, thus with different light exposures combined with the presence in water of xenobiotics including polycyclic aromatic hydrocarbons (PAHs) generated by urban pollution. UV light and PAHs are abiotic factors known to both affect the mosquito insecticide resistance status. Nonetheless, their potential combined effects on the mosquito physiology have never been investigated. The present article aims at describing the effects of UV exposure alongside water contamination with two major PAH pollutants (fluoranthene and benzo[a]pyrene) on a laboratory population of the yellow fever mosquito Aedes aegypti. To evaluate the effects of PAH exposure and low energetic UV (UV-A) irradiation on mosquitoes, different parameters were measured including: (1) The PAH localization and its impact on cell mortality by fluorescent microscopy; (2) The detoxification capacities (cytochrome P450, glutathione-S-transferase, esterase); (3) The responses to oxidative stress (Reactive Oxygen Species-ROS) and (4) The tolerance of mosquito larvae to a bioinsecticide (Bacillus thuringiensis subsp. israelensis-Bti) and to five chemical insecticides (DDT, imidacloprid, permethrin, propoxur and temephos). Contrasting effects regarding mosquito cell mortality, detoxification and oxidative stress were observed as being dependent on the pollutant considered, despite the fact that the two PAHs belong to the same family. Moreover, UV is able to modify pollutant effects on mosquitoes, including tolerance to three insecticides (imidacloprid, propoxur and temephos), cell damage and response to oxidative stress. Taken together, our results suggest that UV and pollution, individually or in combination, are abiotic parameters that can affect the physiology and insecticide tolerance of mosquitoes; but the complexity of their direct effect and of their interaction will require further investigation to know in which condition they can affect the efficacy of insecticide-based vector control strategies in the field. PMID:24275062

Tetreau, Guillaume; Chandor-Proust, Alexia; Faucon, Frédéric; Stalinski, Renaud; Akhouayri, Idir; Prud'homme, Sophie M; Régent-Kloeckner, Myriam; Raveton, Muriel; Reynaud, Stéphane

2014-01-01

213

Biocontrol of larval mosquitoes by Acilius sulcatus (Coleoptera: Dytiscidae  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Problems associated with resistant mosquitoes and the effects on non-target species by chemicals, evoke a reason to find alternative methods to control mosquitoes, like the use of natural predators. In this regard, aquatic coleopterans have been explored less compared to other insect predators. In the present study, an evaluation of the role of the larvae of Acilius sulcatus Linnaeus 1758 (Coleoptera: Dytiscidae as predator of mosquito immatures was made in the laboratory. Its efficacy under field condition was also determined to emphasize its potential as bio-control agent of mosquitoes. Methods In the laboratory, the predation potential of the larvae of A. sulcatus was assessed using the larvae of Culex quinquefasciatus Say 1823 (Diptera: Culicidae as prey at varying predator and prey densities and available space. Under field conditions, the effectiveness of the larvae of A. sulcatus was evaluated through augmentative release in ten cemented tanks hosting immatures of different mosquito species at varying density. The dip density changes in the mosquito immatures were used as indicator for the effectiveness of A. sulcatus larvae. Results A single larva of A. sulcatus consumed on an average 34 IV instar larvae of Cx. quinquefasciatus in a 24 h period. It was observed that feeding rate of A. sulcatus did not differ between the light-on (6 a.m. – 6 p.m., and dark (6 p.m. – 6 a.m. phases, but decreased with the volume of water i.e., space availability. The prey consumption of the larvae of A. sulcatus differed significantly (P A. sulcatus larvae, while with the withdrawal, a significant increase (p A. sulcatus in regulating mosquito immatures. In the control tanks, mean larval density did not differ (p > 0.05 throughout the study period. Conclusion the larvae of the dytiscid beetle A. sulcatus proved to be an efficient predator of mosquito immatures and may be useful in biocontrol of medically important mosquitoes.

Banerjee Siddhartha S

2008-10-01

214

Annotated checklist of the mosquitoes of the Republic of Moldova.  

Science.gov (United States)

The mosquito fauna of the Republic of Moldova is poorly known. In an effort to understand the Culicidae fauna better, mosquito collections have been conducted between early April and middle November from 2008 to 2012. A total of 10,923 larval specimens and 8,246 adults were collected from 20 regions of Moldova. Altogether 36 species have been recorded during the recent study, bringing the total Moldovan mosquito fauna to 40 species in 9 genera and 11 subgenera. New state records include the following 7 species: Anopheles pseudopictus, An. melanoon, Aedes geminus, Culex torrentium, Culiseta longiareolata, Coquillettidia buxtoni, and Uranotaenia unguiculata. PMID:23923323

Sulesco, Tatiana M; Toderas, Ion K; Toderas, Lidia G

2013-06-01

215

MULTIPLICATION OF DENGUE AND CHIKUNGUNYA VIRUSES IN AEDES MOSQUITOES  

Directory of Open Access Journals (Sweden)

Full Text Available Colonies of Aedes aegypti (Surabaya strain and Aedes albopictus (Malang strain were studied to compare their susceptibility to oral infection with dengue type 3 and Chikungunya viruses. Growth curves of dengue type 3 and Chikungunya viruses in these mosquitoes indicated that both mosquito species were susceptible to oral infection with these viruses. Electron microscopic observation of the salivary glands of A. aegypti and A. albopictus infected with Chikungunya virus showed that this organ plays an important role in producing and maintaining high virus titers in these mosquitoes. The results suggest that both Aedes species are potentially important vectors on the transmission of dengue and Chikungunya infection in Indonesia.

Soedarto Soekiman

2012-09-01

216

Olfactory search-image use by a mosquito-eating predator  

Digital Repository Infrastructure Vision for European Research (DRIVER)

By choosing blood-carrying mosquitoes as prey, Evarcha culicivora, an East African salticid spider, specializes at feeding indirectly on vertebrate blood. It also has an exceptionally complex mate-choice system. An earlier study revealed that search-image use assists E. culicivora in finding prey and mates when restricted to using vision alone. Here we show that search-image use assists E. culicivora in finding prey and mates when restricted to using olfaction alone. After being primed with p...

Cross, Fiona R.; Jackson, Robert R.

2010-01-01

217

How blood-derived odor influences mate-choice decisions by a mosquito-eating predator  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Evarcha culicivora (Araneae, Salticidae) feeds indirectly on vertebrate blood by choosing, as preferred prey, bloodcarrying female mosquitoes. Mutual mate-choice behavior is also pronounced in this species. Here we show that, when E. culicivora feeds indirectly on blood, it acquires a diet-related odor that makes it more attractive to the opposite sex. The mate-choice decisions of the adults of both sexes were investigated in a series of experiments based on comparing how long the test spider...

Cross, Fiona R.; Jackson, Robert R.; Pollard, Simon D.

2009-01-01

218

Mosquito cell line glycoproteins: an unsuitable model system for the Plasmodium ookinete-mosquito midgut interaction?  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Mosquito midgut glycoproteins may act as key recognition sites for the invading malarial ookinete. Effective transmission blocking strategies require the identification of novel target molecules. We have partially characterised the surface glycoproteins of two cell lines from two mosquito species; Anopheles stephensi and Anopheles gambiae, and investigated the binding of Plasmodium berghei ookinetes to carbohydrate ligands on the cells. Cell line extracts were run on SDS-PAGE gels and carbohydrate moieties determined by blotting against a range of biotinylated lectins. In addition, specific glycosidases were used to cleave the oligosaccharides. Results An. stephensi 43 and An. gambiae 55 cell line glycoproteins expressed oligosaccharides containing oligomannose and hybrid oligosaccharides, with and without ?1-6 core fucosylation; N-linked oligosaccharides with terminal Gal?1-3GalNAc or GalNAc?1-3Gal; O-linked ?/?GalNAc. An. stephensi 43 cell line glycoproteins also expressed N-linked Gal?1-4R and O-linked Gal?1-3GalNAc. Although P. berghei ookinetes bound to both mosquito cell lines, binding could not be inhibited by GlcNAc, GalNAc or Galactose. Conclusions Anopheline cell lines displayed a limited range of oligosaccharides. Differences between the glycosylation patterns of the cell lines and mosquito midgut epithelial cells could be a factor why ookinetes did not bind in a carbohydrate inhibitable manner. Anopheline cell lines are not suitable as a potential model system for carbohydrate-mediated adhesion of Plasmodium ookinetes.

Wilkins Simon

2010-03-01

219

Potential Use of Mosquito’s Salivary Components as Novel Target for The Development of Transmission Blocking Vaccine (TBV  

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Full Text Available Mosquito-borne diseases are rampant in most tropical regions of the world, especially rural, forested, and coastal areas such as Indonesia. Despite long-standing chemotherapeutic intercession and vector control programs, mosquito-borne diseases exact a heavy burden on human health in Indonesia. Two major public health problems transmitted by mosquito in Indonesia are malaria and dengue haemorrhagic fever (DHF, causing millions of clinical episodes occurring annually. Malaria is now recognized as a serious re-emerging threat to public health. DHF cases were first observed in 1968; since then, the incidence has been constantly increasing and the disease is now one of the principal causes of child lethality. It has been widely observed that saliva of mosquito that transmits the diseases contains several factors that could enhance pathogen infection. Therefore, it should be possible to control pathogen transmission by vaccinating the host against the molecule(s in saliva that potentiate the infection. However, specific component as a potential target for TBV in mosquito vectors of malaria & dengue, i.e. Anopheles and Aedes aegypti, has not been identified so far. This paper wanted to elaborate the potential role of salivary component from mosquitoes, particularly from Indonesian vectors as molecular target for developing TBV against two major Mosquito borne-diseases in Indonesia i.e. malaria and DHF.

KARTIKA SENJARINI

2013-11-01

220

Novel Selective and Irreversible Mosquito Acetylcholinesterase Inhibitors for Controlling Malaria and Other Mosquito-Borne Diseases  

Science.gov (United States)

We reported previously that insect acetylcholinesterases (AChEs) could be selectively and irreversibly inhibited by methanethiosulfonates presumably through conjugation to an insect-specific cysteine in these enzymes. However, no direct proof for the conjugation has been published to date, and doubts remain about whether such cysteine-targeting inhibitors have desirable kinetic properties for insecticide use. Here we report mass spectrometric proof of the conjugation and new chemicals that irreversibly inhibited African malaria mosquito AChE with bimolecular inhibition rate constants (kinact/KI) of 3,604-458,597 M-1sec-1 but spared human AChE. In comparison, the insecticide paraoxon irreversibly inhibited mosquito and human AChEs with kinact/KI values of 1,915 and 1,507 M-1sec-1, respectively, under the same assay conditions. These results further support our hypothesis that the insect-specific AChE cysteine is a unique and unexplored target to develop new insecticides with reduced insecticide resistance and low toxicity to mammals, fish, and birds for the control of mosquito-borne diseases.

Dou, Dengfeng; Park, Jewn Giew; Rana, Sandeep; Madden, Benjamin J.; Jiang, Haobo; Pang, Yuan-Ping

2013-01-01

 
 
 
 
221

Conformal Killing vectors in Robertson-Walker spacetimes  

International Nuclear Information System (INIS)

It is well known that Robertson-Walker spacetimes admit a conformal Killingl vector normal to the spacelike homogeneous hypersurfaces. Because these spacetimes are conformally flat, there are a further eight conformal Killing vectors, which are neither normal nor tangent to the homogeneous hypersurfaces. The authors find these further conformal Killing vectors and the Lie algebra of the full G_1_5 of conformal motions. Conditions on the metric scale factor are determined which reduce some of the conformal Killing vectors to homothetic Killing vectors or Killing vectors, allowing one to regain in a unified way the known special geometries. The non-normal conformal Killing vectors provide a counter-example to show that conformal motions do not, in general, map a fluid flow conformally. These non-normal vectors are also used to find the general solution of the null geodesic equation and photon Liouville equation. (author)

1986-09-01

222

Lyme disease assay which detects killed Borrelia burgdorferi.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We developed an in vitro assay showing that Borrelia burgdorferi organisms were killed by serum from patients with Lyme disease. Twenty of 20 Lyme disease serum samples caused B. burgdorferi killing in a range of 36 to 99% compared with the mean number of viable spirochetes when sera from 10 healthy individuals were used. The percentage of killing of B. burgdorferi increased with convalescent serum from patients with early Lyme disease. The borreliacidal activity was detectable in some sera d...

Callister, S. M.; Schell, R. F.; Lovrich, S. D.

1991-01-01

223

Effect of Ertapenem Protein Binding on Killing of Bacteria  

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The effect of protein binding on the antimicrobial activity of ertapenem was evaluated using the bacterial kill rate and concentration-response studies. Various proportions of human serum were utilized to determine the total and free-drug concentrations using a validated high-performance liquid chromatography assay. The MICs and kill curves were determined for test isolates of Enterobacter cloacae and Staphylococcus aureus at various percentages of human serum. The killing of bacteria was ana...

Nix, David E.; Matthias, Kathryn R.; Ferguson, Emily C.

2004-01-01

224

Comment on 'Collective dose: kill or cure?'  

International Nuclear Information System (INIS)

Full text: In his editorial 'Collective dose: kill or cure?' John Dunster (2000 J. Radiol. Prot. 20 (1) 3-4) states that a build up of small doses from many sources could easily be prevented in the future. Based on our experience with other sources of pollution, I feel this is somewhat rash. The early producers (The West) of CFC and carbon dioxide pollution incurred no internal costs. Now highly populated developing countries want to industrialise and create these gases on a level playing field with developed countries. The consequences of the rest of human kind producing US per caput levels of pollution are catastrophic. A lot is being said about this dilemma; the only thing that is not being said is that the problem can 'easily be prevented'. (author). Letter-to-the-editor

2000-06-01

225

Method of dynamically killing a well blowout  

Energy Technology Data Exchange (ETDEWEB)

A process for dynamically killing a well blowout by means of a relief well is claimed. A low density fluid is pumped down the relief well and into the blowout well at a rate to produce a frictional pressure loss in the blowout well which when added to the hydrostatic pressure in the blowout well is greater than the static formation pressure but less than the formation fracturing pressure. Injection of the low density fluid is continued until the blowout well goes from two-phase to single-phase flow. Thereafter, a high density fluid such as a drilling mud is pumped down the relief well and into the blowout well. This fluid produces a hydrostatic pressure in the blowout well which is greater than the static formation pressure.

Blount, E.M.

1980-09-30

226

Self-forces from generalized Killing fields  

Energy Technology Data Exchange (ETDEWEB)

A non-perturbative formalism is developed that simplifies the understanding of self-forces and self-torques acting on extended scalar charges in curved spacetimes. Laws of motion are locally derived using momenta generated by a set of generalized Killing fields. Self-interactions that may be interpreted as arising from the details of a body's internal structure are shown to have very simple geometric and physical interpretations. Certain modifications to the usual definition for a center-of-mass are identified that significantly simplify the motions of charges with strong self-fields. A derivation is also provided for a generalized form of the Detweiler-Whiting axiom that pointlike charges should react only to the so-called regular component of their self-field. Standard results are shown to be recovered for sufficiently small charge distributions.

Harte, Abraham I [Enrico Fermi Institute, University of Chicago, Chicago, IL 60637 (United States)], E-mail: harte@uchicago.edu

2008-12-07

227

Aparelho de sucção tipo aspirador para captura de mosquitos A "vacuum-cleaner" type of suction apparatus for the collection of mosquitoes  

Directory of Open Access Journals (Sweden)

Full Text Available É feita a descrição de aparelho portátil de sucção tipo aspirador, para captura de mosquitos Culicidae. São sugeridas adaptações para coletas em diferentes situações. São feitos comentários sobre sua aplicação em pesquisa de mosquitos.A portable suction apparatus, which functions like a vacuum cleaner used for the collection of Culicidae mosquitoes is described. Adaptations for collecting in differents situations are suggested and some comments about its application in mosquitoes surveys are made.

Délsio Natal

1984-10-01

228

Higher Mosquito Production in Low-Income Neighborhoods of Baltimore and Washington, DC: Understanding Ecological Drivers and Mosquito-Borne Disease Risk in Temperate Cities  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Mosquito-vectored pathogens are responsible for devastating human diseases and are (re)emerging in many urban environments. Effective mosquito control in urban landscapes relies on improved understanding of the complex interactions between the ecological and social factors that define where mosquito populations can grow. We compared the density of mosquito habitat and pupae production across economically varying neighborhoods in two temperate U.S. cities (Baltimore, MD and Washington, DC). Se...

Ladeau, Shannon L.; Leisnham, Paul T.; Dawn Biehler; Danielle Bodner

2013-01-01

229

Spacelike conformal Killing vectors and spacelike congruences  

International Nuclear Information System (INIS)

Necessary and sufficient conditions are derived for space-time to admit a spacelike conformal motion with symmetry vector parallel to a unit spacelike vector field n/sup a/. These conditions are expressed in terms of the shear and expansion of the spacelike congruence generated by n/sup a/ and in terms of the four-velocity of the observer employed at any given point of the congruence. It is shown that either the expansion or the rotation of this spacelike congruence must vanish if Dn/sup a//dp = 0, where p denotes arc length measured along the integral curves of n/sup a/, and also that there exist no proper spacelike homothetic motions with constant expansion. Propagation equations for the projection tensor and the rotation tensor are derived and it is proved that every isometric spacelike congruence is rigid. Fluid space-times are studied in detail. A relation is established between spacelike conformal motions and material curves in the fluid: if a fluid space-time admits a spacelike conformal Killing vector parallel to n/sup a/ and n/sub a/u/sup a/ = 0, where u/sup a/ is the fluid four-velocity, then the integral curves of n/sup a/ are material curves in an irrotational fluid, while if the fluid vorticity is nonzero, then the integral curves of n/sup a/ are material curves if and only if they are vortex lines. An alternative derivation, based on the theory of spacelike congruences, of some of the results of Collins [J. Math. Phys. 25, 995 (1984)] on conformal Killing vectors parallel to the local vorticity vector in shear-free perfect fluids with zero magnetic Weyl tensor is given

1985-01-01

230

Phagocytic killing of Neisseria gonorrhoeae by human monocytes.  

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The ability of human monocytes to phagocytize and kill nonpiliated opaque (T3) and transparent (T4) gonococci was investigated in a tumbling tube suspension assay. A serum-sensitive strain, F62, and a serum-resistant strain, FA19, were studied. CFU remaining after incubation with monocytes were used to assess the extent of killing. The data show that 50% of T3 and T4 gonococci of both strains were killed by monocytes over a 2-h period. Serum was necessary for the killing of transparent gonoco...

1983-01-01

231

Killing-Yano Tensors of Order n-1  

CERN Document Server

The properties of a Killing-Yano tensor of order n-1 in an n-dimensional manifold are investigated. The integrability conditions are worked out and all metrics admitting a Killing-Yano tensor of order n-1 are found. It is pointed out a connection between such tensors and a generalization of the concept of angular momentum. A theorem on how to generate closed conformal Killing vectors using the symmetries of a manifold is proved and used to find all Killing-Yano tensors of order n-1 of a maximally symmetric space.

Batista, Carlos

2014-01-01

232

Evaluation of Tribulus terrestris Linn (Zygophyllaceae) acetone extract for larvicidal and repellence activity against mosquito vectors.  

Science.gov (United States)

Acetone extracts of leaves and seeds from the Tribulus terrestris (Zygophyllaceae) were tested against mature and immature different mosquito vectors under laboratory condition. The extract showed strong larvicidal, properties 100 per cent mortality in the 3rd-instar larvae was observed in the bioassays with An. culicifacies Giles species A, An. stephensi Liston, Culex quinquefasciatus Say and Aedes aegypti Linn, against 200 ppm of the leaf acetone extract and 100 ppm seed acetone extract. The LC50 values of leaf acetone extract estimated for 3rd-instars An. culicifacies species A, An. stephensi, Cx. quinquefasciatus and Ae. aegypti after 24 hour of exposure were 117, 124, 168 and 185 ppm respectively. The LC50 values of seed acetone extract estimated for 3rd-instars An. culicifacies species A, An. stephensi, Cx. quinquefasciatus and Ae. aegypti after 24 hour of exposure were 100, 72, 91 and 91 ppm respectively. It is confirmed from the LC50 values that the seed acetone extract of T. terrestris is more effective compared to leaf extracts. A significant (P<0.004) higher concentration of acetone extract leaf was required to kill equal number of larvae i.e. against acetone extract of seed. The seed acetone extract showed strong repellent activity against adults mosquitoes. Per cent protection obtained against Anopheles culicifacies species A 100% repellency in 1 h, 6 h; Anopheles stephensi 100% repellency in 0 h, 4 h, 6 h; and Culex quinquefasciatus 100% repellency in 0 h, 2 h, 4 h, at 10% concentration respectively. Against Deet- 2.5% An. culicifacies Giles species A has shown 100% repellency in 1 h, 2 h, 6 h, An. stephensi Liston 99% repellency in 4 h, and Culex quinquefasciatus Say has shown 100% repellency in 1 h, 2 h. PMID:19579717

Singh, S P; Raghavendra, K; Singh, R K; Mohanty, S S; Dash, A P

2008-12-01

233

Comparative repellency of 38 essential oils against mosquito bites.  

Science.gov (United States)

The mosquito repellent activity of 38 essential oils from plants at three concentrations was screened against the mosquito Aedes aegypti under laboratory conditions using human subjects. On a volunteer's forearm, 0.1 mL of oil was applied per 30 cm2 of exposed skin. When the tested oils were applied at a 10% or 50% concentration, none of them prevented mosquito bites for as long as 2 h, but the undiluted oils of Cymbopogon nardus (citronella), Pogostemon cablin (patchuli), Syzygium aromaticum (clove) and Zanthoxylum limonella (Thai name: makaen) were the most effective and provided 2 h of complete repellency. From these initial results, three concentrations (10%, 50% and undiluted) of citronella, patchouli, clove and makaen were selected for repellency tests against Culex quinquefasciatus and Anopheles dirus. As expected, the undiluted oil showed the highest protection in each case. Clove oil gave the longest duration of 100% repellency (2-4 h) against all three species of mosquito. PMID:16041723

Trongtokit, Yuwadee; Rongsriyam, Yupha; Komalamisra, Narumon; Apiwathnasorn, Chamnarn

2005-04-01

234

Novel flaviviruses detected in different species of mosquitoes in Spain.  

Science.gov (United States)

We report the characterization of three novel flaviviruses isolated in Spain. Marisma Mosquito virus, a novel mosquito borne virus, was isolated from Ochlerotatus caspius mosquitoes; Spanish Ochlerotatus flavivirus and Spanish Culex flavivirus, two novel insect flaviviruses, were isolated from Oc. caspius and Culex pipiens, respectively. During this investigation, we designed a sensitive RT-nested polymerase chain reaction method that amplifies a 1019bp fragment of the flavivirus NS5 gene and could be directly used in clinical or environmental samples for flavivirus characterization and surveillance. Analysis of the sequence generated from that amplicon contains enough phylogenetic information for proper taxonomic studies. Moreover, the use of this tool allowed the detection of additional flavivirus DNA forms in Culex, Culiseta, and Ochlerotatus mosquitoes. PMID:22022811

Vázquez, Ana; Sánchez-Seco, María-Paz; Palacios, Gustavo; Molero, Francisca; Reyes, Noelia; Ruiz, Santiago; Aranda, Carles; Marqués, Eduard; Escosa, Raul; Moreno, Juana; Figuerola, Jordi; Tenorio, Antonio

2012-03-01

235

Vector potential of culicine mosquitoes in Faiyum Governorate, Egypt.  

Science.gov (United States)

Culicine mosquito populations were studied for 1 year in 2 neighboring villages in Faiyum Governorate, Egypt. Dominant species in larval collections included Culex pipiens, Cx. univitattus, Cx. antennatus, Aedes caspius and Uranotaenia unguiculata; Culiseta longiareolata was less common. Culex pipiens accounted for 98% of 3,743 mosquitoes captured in human-biting collection (164 man-nights), 96% of 1,136 mosquitoes collected inside houses and animal sheds (396 inspections), and 98% of 15,000 mosquitoes from 22 donkey-baited traps. Adult Cx. univittatus, Cx. antennatus and Ae. caspius were infrequently captured by any of the collection techniques. Although larval collections identified 5 common species, only Cx. pipiens showed a significant association with the human population. PMID:2906968

Beier, J C; Kenawy, M A; el Said, S; Merdan, A I

1986-06-01

236

Aspirator Gun for High-Throughput Mosquito Bioassays.  

Science.gov (United States)

We describe an innovative aspirator gun designed to transfer individual anesthetized mosquitoes directly into glass bioassay tubes. The gun has been used for thousands of transfers with extremely low associated mortality and is the central component of a ...

K. J. Linthicum R. L. Aldridge S. C. Britch W. W. Wynn

2012-01-01

237

Pesticide-Free Device a Fatal Attraction for Mosquitoes  

Science.gov (United States)

Are those pesky mosquitoes getting more entertainment out of your family picnic than you are? If the answer is yes, then it is time to reclaim your backyard with assistance from an unlikely partner. Nowadays, NASA is developing tools to track and predict the spread of the West Nile Virus on a global scale, but several years ago, the Space Agency carved out some time to collaborate with an outdoor products manufacturer in order to help control mosquito populations on a local level. The technology resulting from this union leveraged a space-age heat blanket to attract mosquitoes, which would then be eliminated without the use of harmful pesticides or chemicals. technical assistance from NASA and is an environmentally safe way to reduce the mosquito population.

2005-01-01

238

Selection for Virulent Dengue Viruses Occurs in Humans and Mosquitoes  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Dengue is the most common mosquito-borne viral disease in humans. The spread of both mosquito vectors and viruses has led to the resurgence of epidemic dengue fever (a self-limited flu-like syndrome) and the emergence of dengue hemorrhagic fever (severe dengue with bleeding abnormalities) in urban centers of the tropics. There are no animal or laboratory models of dengue disease; indirect evidence suggests that dengue viruses differ in virulence, including their pathogenicities for humans and...

Cologna, Raymond; Armstrong, Philip M.; Rico-hesse, Rebeca

2005-01-01

239

Fighting malaria with engineered symbiotic bacteria from vector mosquitoes  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The most vulnerable stages of Plasmodium development occur in the lumen of the mosquito midgut, a compartment shared with symbiotic bacteria. Here, we describe a strategy that uses symbiotic bacteria to deliver antimalaria effector molecules to the midgut lumen, thus rendering host mosquitoes refractory to malaria infection. The Escherichia coli hemolysin A secretion system was used to promote the secretion of a variety of anti-Plasmodium effector proteins by Pantoea agglomerans, a common mos...

2012-01-01

240

Pesticides and public health: integrated methods of mosquito management.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Pesticides have a role in public health as part of sustainable integrated mosquito management. Other components of such management include surveillance, source reduction or prevention, biological control, repellents, traps, and pesticide-resistance management. We assess the future use of mosquito control pesticides in view of niche markets, incentives for new product development, Environmental Protection Agency registration, the Food Quality Protection Act, and improved pest management strate...

Rose, R. I.

2001-01-01

 
 
 
 
241

Olfaction-based anthropophily in a mosquito-specialist predator  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Evarcha culicivora is an unusual salticid spider because it feeds indirectly on vertebrate blood by choosing blood-carrying mosquitoes as preferred prey. Its preferred mosquitoes are Anopheles, the genus to which all human malaria vectors belong. Here, we show that human odour, which is known to be salient to malaria vectors, is also salient to the adults and juveniles of E. culicivora. Test spiders spent more time in the vicinity of a source of human odour (previously worn socks) when the al...

2011-01-01

242

Taxis assays measure directional movement of mosquitoes to olfactory cues  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Malaria control methods targeting indoor-biting mosquitoes have limited impact on vectors that feed and rest outdoors. Exploiting mosquito olfactory behaviour to reduce blood-feeding outdoors might be a sustainable approach to complement existing control strategies. Methodologies that can objectively quantify responses to odour under realistic field conditions and allow high-throughput screening of many compounds are required for development of effective odour-based control strategies. The ol...

Lorenz, Lena M.; Keane, Aidan; Moore, Jason D.; Munk, Cristina J.; Seeholzer, Laura; Mseka, Antony; Simfukwe, Emmanuel; Ligamba, Joseph; Turner, Elizabeth L.; Biswaro, Lubandwa R.; Okumu, Fredros O.; Killeen, Gerry F.; Mukabana, Wolfgang R.; Moore, Sarah J.

2013-01-01

243

Mosquito Surveillance for West Nile Virus in Southeastern Wisconsin - 2002  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In 2001, West Nile virus (WNV) was identified among dead American crows and bluejays in five counties in southeastern Wisconsin. In response to the introduction of WNV, a pilot mosquito surveillance program was initiated in these five southeastern Wisconsin counties during the summer of 2002. Forty sites were selected for surveillance one night each week during a 17-week period. Mosquitoes were collected in carbon dioxide-baited light traps and gravid traps. During the study period 31,419 mos...

Meece, Jennifer K.; Henkel, James S.; Glaser, Linda; Reed, Kurt D.

2003-01-01

244

Spraying quality assessment of sprayers devoted to mosquito control  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Mosquito control in France is achieved through the spraying in natural areas including water surfaces a wide range of sprayers with a combination of terrestrial and aerial applications. Classical evaluation of the application is mainly related to biological efficacy in terms of mosquito (larvae or adults) mortality [1]. The IMCM Life + project encompasses the evaluation of the spraying quality of terrestrial sprayers for both larvicide and adulticide applications by testing sprayer performanc...

Rudnicki, V.; Douzals, J. P.; Tolosa, M.; Sidos, N.; Cotteux, E.

2012-01-01

245

Toxicity of a plant based mosquito repellent/killer  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The mission to make humans less attractive to mosquitoes has fuelled decades of scientific research on mosquito behaviour and control. The search for the perfect topical insect repellent/killer continues. This analysis was conducted to review and explore the scientific information on toxicity produced by the ingredients/contents of a herbal product. In this process of systemic review the following methodology was applied. By doing a MEDLINE search with key words of selected plants, plant base...

Singh, Bhoopendra; Singh, Prakash Raj; Mohanty, Manoj Kumar

2012-01-01

246

Early skin immunological disturbance after Plasmodium-infected mosquito bites  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Although the role of regulatory T cells (Tregs) during malaria infection has been studied extensively, such studies have focused exclusively on the role of Treg during the blood stage of infection; little is known about the detailed mechanisms of Tregs and sporozoite deposition in the dermis by mosquito bites. In this paper we show that sporozoites introduced into the skin by mosquito bites increase the mobility of skin Tregs and dendritic cells (DCs). We also show differences in MHC class II...

2012-01-01

247

BIOACTIVIDAD DE ACEITES ESENCIALES DE Minthostachys mollis CONTRA MOSQUITOS  

Digital Repository Infrastructure Vision for European Research (DRIVER)

El control químico de vectores es una herramienta principal de prevención de enfermedades transmitidas por mosquitos. Los aceites esenciales (AE) de plantas pueden ser una alternativa a los compuestos sintéticos. Se extrajeron por arrastre con vapor AE de Minthostachys mollis y se evaluó su actividad insecticida contra larvas, pupas y adultos de mosquitos, según protocolos estándar de la Organización Mundial de la Salud. Se evaluaron concentraciones entre 10 y 160 ppm del AE y se regis...

2007-01-01

248

Guppies as predators of common mosquito larvae in Malaysia.  

Science.gov (United States)

Observation on predation activities of guppies (Poecilia reticulata) on the larvae of three species of mosquito, namely Aedes albopictus, Aedes aegypti, and Culex quinquefasciatus was carried out under laboratory conditions. Male and female guppies were used as predators for predation experiments on the 4th instars of mosquito larvae. The daily feeding rates comparing male and female guppies on mosquito larvae were different; the female guppies consumed more mosquito larvae than male guppies did. The daily feeding rates of female guppies were 121.3 for Ae. aegypti, 105.6 for Ae. albopictus, and 72.3 for Cx. quinquefasciatus. The daily feeding rates of male guppies were 98.6 for Ae. aegypti, 73.6 for Ae. albopictus, and 47.6 for Cx. quinquefasciatus. In terms of prey preference, there was greater preference towards mosquito larvae of Ae. aegypti, followed by Ae. albopictus, and the least preferred was Cx. quinquefasciatus. Male and female guppies consumed more mosquito larvae during lights on (day time) compared with lights off (night time). The water volume, prey species, number of fish predators available, prey densities, and prey's sex also influenced the predation activities. PMID:24968669

Saleeza, S N R; Norma-Rashid, Y; Sofian-Azirun, M

2014-03-01

249

Mosquito (Diptera: Culicidae Fauna of Qom Province, Iran  

Directory of Open Access Journals (Sweden)

Full Text Available Background: There is very little information about the mosquito fauna of Qom Province, central Iran. By now only three species; Anopheles claviger, An. multicolor, and An. superpictus have been reported in the province. To study mosquito fauna and providing a primary checklist, an investigation was carried out on a collection of mosquitoes in this province.Methods: To study the mosquito (Diptera: Culicidae fauna, larval collections were carried out from different habitats on 19 occasions using the standard dipping technique during spring and summer 2008 and 2009.Results: In total, 371 mosquito larvae were collected and morphologically identified including 14 species representing four genera: Anopheles claviger, An. marteri, An. turkhudi, An. superpictus, Culex arbieeni, Cx. hortensis, Cx. mimeticus, Cx. modestus, Cx. pipiens, Cx. territans, Cx. theileri, Culiseta longiareolata, Cs. subochrea, and Ochlerotatus caspius s.l. All species except for An. claviger and An. superpictus were collected for the first time in the province. All larvae were found in natural habitats. The association occasions and percentages of the mosquito larvae in Qom Province were discussed.Conclusion: There are some potential or proven vectors of different human and domesticated animal pathogens in Qom Province. The ecology of these species and the unstudied areas of Qom Province need to be investigated extensively.

A Saghafipour

2012-06-01

250

Mosquito (Diptera: Culicidae Fauna of Qom Province, Iran  

Directory of Open Access Journals (Sweden)

Full Text Available Background: There is very little information about the mosquito fauna of Qom Province, central Iran. By now only three species; Anopheles claviger, An. multicolor, and An. superpictus have been reported in the province. To study mosquito fauna and providing a primary checklist, an investigation was carried out on a collection of mosquitoes in this province.Methods: To study the mosquito (Diptera: Culicidae fauna, larval collections were carried out from different habitats on 19 occasions using the standard dipping technique during spring and summer 2008 and 2009. Results: In total, 371 mosquito larvae were collected and morphologically identified including 14 species representing four genera: Anopheles claviger, An. marteri, An. turkhudi, An. superpictus, Culex arbieeni, Cx. hortensis, Cx. mimeticus, Cx. modestus, Cx. pipiens, Cx. territans, Cx. theileri, Culiseta longiareolata, Cs. subochrea, and Ochlerotatus caspius s.l. All species except for An. claviger and An. superpictus were collected for the first time in the province. All larvae were found in natural habitats. The association occasions and percentages of the mosquito larvae in Qom Province were discussed.Conclusion: There are some potential or proven vectors of different human and domesticated animal pathogens in Qom Province. The ecology of these species and the unstudied areas of Qom Province need to be investigated extensively.

A Saghafipour

2012-06-01

251

Crustacean biodiversity as an important factor for mosquito larval control.  

Science.gov (United States)

Newly established ponds, which are highly dynamic systems with changing levels of biological interactions among species, are common larval mosquito habitats. We investigated the impact of crustacean abundance and taxa diversity on mosquito oviposition and larval development. The effects of the biological larvicide Bacillus thuringiensis israelensis (Bti) on mosquito larvae were monitored according to fluctuations in crustacean communities. Populations of the mosquito Culex pipiens colonized artificial ponds that contained crustacean communities at different time points of colonization by crustaceans: 1) 'no colonization' (no crustaceans), 2) 'simultaneous colonization' by crustaceans and mosquitoes, and 3) 'head-start colonization' by crustaceans (preceding colonization by mosquitoes). All types of ponds were treated with three concentrations of Bti (10, 100, or 1,000 µg/liter). Colonization of all ponds by Cx. pipiens (in terms of oviposition, larval abundance, and larval development) decreased significantly with increasing diversity of crustacean taxa. The total abundance of crustaceans had a minor effect on colonization by Cx. pipiens. The presence of crustaceans increased the sensitivity of Cx. pipiens larvae to Bti treatment by a factor of 10 and delayed the time of recolonization. This effect of Bti was relevant in the short term. In the long term, the presence of Cx. pipiens was determined by crustacean biodiversity. PMID:24581370

Kroeger, Iris; Duquesne, Sabine; Liess, Matthias

2013-12-01

252

Kinetics of killing Listeria monocytogenes by macrophages: rapid killing accompanying phagocytosis  

International Nuclear Information System (INIS)

The kinetics of bactericidal activity of activated macrophages can be precisely described by a mathematical model in which phagocytosis, killing, digestion, and release of degraded bacterial material are considered to occur continuously. To gain a better understanding of these events, I have determined the period of time between first contact of bacteria with macrophages and the onset of killing. Activated rat peritoneal macrophages were incubated for various times up to 15 min with Listeria monocytogenes previously labeled with 3H-thymidine and the unassociated bacteria removed by two centrifugations through a density interface. Both cell-associated radioactivity and cell-associated viable bacteria, determined as colony forming units after sonication of the cell pellet, increased with time of incubation. However, the specific viability of these bacteria, expressed as the ratio of number of viable bacteria per unit radioactivity declined with time, as an approximate inverse exponential, after a lag period of 2.9 +/- 0.8 min. Evidence is given that other possible causes for this decline in specific viability, other than death of the bacteria, such as preferential ingestion of dead Listeria, clumping of bacteria, variations in autolytic activity, or release of Listericidins are unlikely. I conclude therefore that activated macrophages kill Listeria approximately 3 min after the cell and the bacterium first make contact

1983-01-01

253

An elaborated feeding cycle model for reductions in vectorial capacity of night-biting mosquitoes by insecticide-treated nets  

Science.gov (United States)

Background Insecticide Treated Nets (ITNs) are an important tool for malaria control. ITNs are effective because they work on several parts of the mosquito feeding cycle, including both adult killing and repelling effects. Methods Using an elaborated description of the classic feeding cycle model, simple formulas have been derived to describe how ITNs change mosquito behaviour and the intensity of malaria transmission, as summarized by vectorial capacity and EIR. The predicted changes are illustrated as a function of the frequency of ITN use for four different vector populations using parameter estimates from the literature. Results The model demonstrates that ITNs simultaneously reduce mosquitoes' lifespans, lengthen the feeding cycle, and by discouraging human biting divert more bites onto non-human hosts. ITNs can substantially reduce vectorial capacity through small changes to all of these quantities. The total reductions in vectorial capacity differ, moreover, depending on baseline behavior in the absence of ITNs. Reductions in lifespan and vectorial capacity are strongest for vector species with high baseline survival. Anthropophilic and zoophilic species are affected differently by ITNs; the feeding cycle is lengthened more for anthrophilic species, and the proportion of bites that are diverted onto non-human hosts is higher for zoophilic species. Conclusion This model suggests that the efficacy of ITNs should be measured as a total reduction in transmission intensity, and that the quantitative effects will differ by species and by transmission intensity. At very high rates of ITN use, ITNs can generate large reductions in transmission intensity that could provide very large reductions in transmission intensity, and effective malaria control in some areas, especially when used in combination with other control measures. At high EIR, ITNs will probably not substantially reduce the parasite rate, but when transmission intensity is low, reductions in vectorial capacity combine with reductions in the parasite rate to generate very large reductions in EIR.

Le Menach, Arnaud; Takala, Shannon; McKenzie, F Ellis; Perisse, Andre; Harris, Anthony; Flahault, Antoine; Smith, David L

2007-01-01

254

An elaborated feeding cycle model for reductions in vectorial capacity of night-biting mosquitoes by insecticide-treated nets  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Insecticide Treated Nets (ITNs are an important tool for malaria control. ITNs are effective because they work on several parts of the mosquito feeding cycle, including both adult killing and repelling effects. Methods Using an elaborated description of the classic feeding cycle model, simple formulas have been derived to describe how ITNs change mosquito behaviour and the intensity of malaria transmission, as summarized by vectorial capacity and EIR. The predicted changes are illustrated as a function of the frequency of ITN use for four different vector populations using parameter estimates from the literature. Results The model demonstrates that ITNs simultaneously reduce mosquitoes' lifespans, lengthen the feeding cycle, and by discouraging human biting divert more bites onto non-human hosts. ITNs can substantially reduce vectorial capacity through small changes to all of these quantities. The total reductions in vectorial capacity differ, moreover, depending on baseline behavior in the absence of ITNs. Reductions in lifespan and vectorial capacity are strongest for vector species with high baseline survival. Anthropophilic and zoophilic species are affected differently by ITNs; the feeding cycle is lengthened more for anthrophilic species, and the proportion of bites that are diverted onto non-human hosts is higher for zoophilic species. Conclusion This model suggests that the efficacy of ITNs should be measured as a total reduction in transmission intensity, and that the quantitative effects will differ by species and by transmission intensity. At very high rates of ITN use, ITNs can generate large reductions in transmission intensity that could provide very large reductions in transmission intensity, and effective malaria control in some areas, especially when used in combination with other control measures. At high EIR, ITNs will probably not substantially reduce the parasite rate, but when transmission intensity is low, reductions in vectorial capacity combine with reductions in the parasite rate to generate very large reductions in EIR.

Harris Anthony

2007-01-01

255

Distribution of Mosquitoes and Mosquito-Borne Arboviruses in Yunnan Province near the China–Myanmar–Laos Border  

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Economic development and increased tourism in the southern region of Yunnan Province in China, adjacent to several countries in Southeast Asia, has increased the likelihood of import and export of vectors and vector-borne diseases. We report the results of surveillance of mosquitoes and mosquito-borne arboviruses along the border of China–Myanmar–Laos in 2005 and 2006, and information associating several arboviruses with infections and possibly disease in local human populations. Seventee...

Wang, Jinglin; Zhang, Hailin; Sun, Xiaohong; Fu, Shihong; Wang, Huanqin; Feng, Yun; Wang, Huanyu; Tang, Qing; Liang, Guo-dong

2011-01-01

256

Mortality in immatures of the floodwater mosquito Ochlerotatus albifasciatus (Diptera: Culicidae) and effects of parasitism by Strelkovimermis spiculatus (Nematoda: Mermithidae) in Buenos Aires Province, Argentina  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Life tables were constructed for six cohorts of immature stages of the floodwater mosquito Ochlerotatus albifasciatus (Macquart) in a park in Buenos Aires, highlighting the mortality attributable to the parasitic nematode, Strelkovimermis spiculatus Poinar & Camino. Two cohorts were selected to comp [...] are parasite incidence in all mosquito stages when low and high parasitism occurred. Development time of Oc. albifasciatus from first instar to adult was 7.7-10 days in the spring, 6 days in the summer, and 10.9-21.9 days in the fall. Survival was estimated as 0-1.4% in the spring, 2% in the summer and 0.2-4.4% in the fall. The highest "K" value (Killing power) occurred during a fall cohort when prevalence of the parasite was 86.9%, and the lowest in a spring cohort. Parasitism occurred during all seasons, but S. spiculatus persisted to adult only in the summer and fall, when adult mosquitoes developed from parasitized third and fourth instars larvae. The abundance of S. spiculatus differed between old and young larvae only when parasite prevalence was the highest. Although pupae and adults of Oc. albifasciatus were parasitized, no pupal mortality attributable to parasitism was recorded. The proportion of parasitized adults ranged from 14.2% and 5.7% in the two cohorts compared. Pupal wet weight and adult wing lengths did not differ between parasitized and unparasitized individuals.

Ernesto Campos, Raúl; Sy, Victoria Elena.

257

Mortality in immatures of the floodwater mosquito Ochlerotatus albifasciatus (Diptera: Culicidae and effects of parasitism by Strelkovimermis spiculatus (Nematoda: Mermithidae in Buenos Aires Province, Argentina  

Directory of Open Access Journals (Sweden)

Full Text Available Life tables were constructed for six cohorts of immature stages of the floodwater mosquito Ochlerotatus albifasciatus (Macquart in a park in Buenos Aires, highlighting the mortality attributable to the parasitic nematode, Strelkovimermis spiculatus Poinar & Camino. Two cohorts were selected to compare parasite incidence in all mosquito stages when low and high parasitism occurred. Development time of Oc. albifasciatus from first instar to adult was 7.7-10 days in the spring, 6 days in the summer, and 10.9-21.9 days in the fall. Survival was estimated as 0-1.4% in the spring, 2% in the summer and 0.2-4.4% in the fall. The highest "K" value (Killing power occurred during a fall cohort when prevalence of the parasite was 86.9%, and the lowest in a spring cohort. Parasitism occurred during all seasons, but S. spiculatus persisted to adult only in the summer and fall, when adult mosquitoes developed from parasitized third and fourth instars larvae. The abundance of S. spiculatus differed between old and young larvae only when parasite prevalence was the highest. Although pupae and adults of Oc. albifasciatus were parasitized, no pupal mortality attributable to parasitism was recorded. The proportion of parasitized adults ranged from 14.2% and 5.7% in the two cohorts compared. Pupal wet weight and adult wing lengths did not differ between parasitized and unparasitized individuals.

Raúl Ernesto Campos

2003-03-01

258

Experimental hut evaluation of bednets treated with an organophosphate (chlorpyrifos-methyl or a pyrethroid (lambdacyhalothrin alone and in combination against insecticide-resistant Anopheles gambiae and Culex quinquefasciatus mosquitoes  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Pyrethroid resistant mosquitoes are becoming increasingly common in parts of Africa. It is important to identify alternative insecticides which, if necessary, could be used to replace or supplement the pyrethroids for use on treated nets. Certain compounds of an earlier generation of insecticides, the organophosphates may have potential as net treatments. Methods Comparative studies of chlorpyrifos-methyl (CM, an organophosphate with low mammalian toxicity, and lambdacyhalothrin (L, a pyrethroid, were conducted in experimental huts in Côte d'Ivoire, West Africa. Anopheles gambiae and Culex quinquefasciatus mosquitoes from the area are resistant to pyrethroids and organophosphates (kdr and insensitive acetylcholinesterase Ace.1R. Several treatments and application rates on intact or holed nets were evaluated, including single treatments, mixtures, and differential wall/ceiling treatments. Results and Conclusion All of the treatments were effective in reducing blood feeding from sleepers under the nets and in killing both species of mosquito, despite the presence of the kdr and Ace.1R genes at high frequency. In most cases, the effects of the various treatments did not differ significantly. Five washes of the nets in soap solution did not reduce the impact of the insecticides on A. gambiae mortality, but did lead to an increase in blood feeding. The three combinations performed no differently from the single insecticide treatments, but the low dose mixture performed encouragingly well indicating that such combinations might be used for controlling insecticide resistant mosquitoes. Mortality of mosquitoes that carried both Ace.1R and Ace.1S genes did not differ significantly from mosquitoes that carried only Ace.1S genes on any of the treated nets, indicating that the Ace.1R allele does not confer effective resistance to chlorpyrifos-methyl under the realistic conditions of an experimental hut.

Corbel Vincent

2005-05-01

259

Using a Near-Infrared Spectrometer to Estimate the Age of Anopheles Mosquitoes Exposed to Pyrethroids  

Science.gov (United States)

We report on the accuracy of using near-infrared spectroscopy (NIRS) to predict the age of Anopheles mosquitoes reared from wild larvae and a mixed age-wild adult population collected from pit traps after exposure to pyrethroids. The mosquitoes reared from wild larvae were estimated as NIRS as ?8 d for both susceptible and resistant groups. The age structure of wild-collected mosquitoes was not significantly different for the pyrethroid-susceptible and pyrethroid-resistant mosquitoes (P?=?0.210). Based on these findings, NIRS chronological age estimation technique for Anopheles mosquitoes may be independent of insecticide exposure and the environmental conditions to which the mosquitoes are exposed.

Sikulu, Maggy T.; Majambere, Silas; Khatib, Bakar O.; Ali, Abdullah S.; Hugo, Leon E.; Dowell, Floyd E.

2014-01-01

260

Dimensional reduction in space-times admitting killing vectors  

International Nuclear Information System (INIS)

We present a systematic method for performing dimensional reduction on theories constructed in (d + n)-dimensional space-times with torsion, which admit n Killing vectors. For one and two commuting Killing vectors, the field content of the corresponding (d + 1)- and (d + 2)-dimensional theories is completely worked out. (orig.)

1983-08-04

 
 
 
 
261

Mechanisms of Dendritic Cell Lysosomal Killing of Cryptococcus  

Science.gov (United States)

Cryptococcus neoformans is an opportunistic pulmonary fungal pathogen that disseminates to the CNS causing fatal meningitis in immunocompromised patients. Dendritic cells (DCs) phagocytose C. neoformans following inhalation. Following uptake, cryptococci translocate to the DC lysosomal compartment and are killed by oxidative and non-oxidative mechanisms. DC lysosomal extracts kill cryptococci in vitro; however, the means of antifungal activity remain unknown. Our studies determined non-oxidative antifungal activity by DC lysosomal extract. We examined DC lysosomal killing of cryptococcal strains, anti-fungal activity of purified lysosomal enzymes, and mechanisms of killing against C. neoformans. Results confirmed DC lysosome fungicidal activity against all cryptococcal serotypes. Purified lysosomal enzymes, specifically cathepsin B, inhibited cryptococcal growth. Interestingly, cathepsin B combined with its enzymatic inhibitors led to enhanced cryptococcal killing. Electron microscopy revealed structural changes and ruptured cryptococcal cell walls following treatment. Finally, additional studies demonstrated that osmotic lysis was responsible for cryptococcal death.

Hole, Camaron R.; Bui, Hoang; Wormley, Floyd L.; Wozniak, Karen L.

2012-10-01

262

Mouse oocyte killing by neutrons: target considerations  

International Nuclear Information System (INIS)

Highly radiosensitive primordial mouse oocytes, the principal cells at genetic risk in the female, have been studied using 0.43 MeV neutrons. Analysis of the survival curve (D37 = 0.055 Gy) indicates that the diameter of the radiosensitive target (assumed spherical and of unit density) is larger than that of the nucleus but not of the oocyte, implicating a non-nuclear but sub-cellular target. This is consistent with results from the 3H-thymidine incorporated in DNA. Efforts to identify the extraordinarily radiosensitive lethality target in these primordial oocytes suggest it is the plasma membrane. Monte Carlo calculations for 0.43 MeV neutrons show that at the D37 only a single proton recoil will traverse the plasma membrane, consistent with the observed exponential survival curve. A highly sensitive non-DNA target for mouse oocyte killing may importantly influence interpretations of genetic mutation data from mice and their use in estimating genetic risk in humans. (author)

1985-01-01

263

Novel innate cancer killing activity in humans  

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Full Text Available Abstract Background In this study, we pilot tested an in vitro assay of cancer killing activity (CKA in circulating leukocytes of 22 cancer cases and 25 healthy controls. Methods Using a human cervical cancer cell line, HeLa, as target cells, we compared the CKA in circulating leukocytes, as effector cells, of cancer cases and controls. The CKA was normalized as percentages of total target cells during selected periods of incubation time and at selected effector/target cell ratios in comparison to no-effector-cell controls. Results Our results showed that CKA similar to that of our previous study of SR/CR mice was present in human circulating leukocytes but at profoundly different levels in individuals. Overall, males have a significantly higher CKA than females. The CKA levels in cancer cases were lower than that in healthy controls (mean ± SD: 36.97 ± 21.39 vs. 46.28 ± 27.22. Below-median CKA was significantly associated with case status (odds ratio = 4.36; 95% Confidence Interval = 1.06, 17.88 after adjustment of gender and race. Conclusions In freshly isolated human leukocytes, we were able to detect an apparent CKA in a similar manner to that of cancer-resistant SR/CR mice. The finding of CKA at lower levels in cancer patients suggests the possibility that it may be of a consequence of genetic, physiological, or pathological conditions, pending future studies with larger sample size.

Lovato James

2011-08-01

264

Killing, letting die and moral perception.  

Science.gov (United States)

There are a number of arguments that purport to show, in general terms, that there is no difference between killing and letting die. These are used to justify active euthanasia on the basis of the reasons given for allowing patients to die. I argue that the general and abstract arguments fail to take account of the complex and particular situations which are found in the care of those with terminal illness. When in such situations, there are perceptions and intuitions available that do not easily find propositional form but lead most of those whose practice is in the care of the dying to resist active euthanasia. I make a plea for their intuitions to be heeded above the sterile voice of abstract premises and arguments by examining the completeness of the outline form of the pro-euthanasia argument. In doing so, I make use of Nussbaum's discussion of moral perception and general claims to be found in the literature of moral particularism. PMID:11654118

Gillett, Grant

1994-10-01

265

Mosquito population dynamic (diptera: culicidae) in a eutrophised dam Dinâmica populacional de mosquitos em açude eutrofizado  

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This study observed the mosquito population in a rural eutrophised dam. Larvae of L3 and L4 stages and pupae were dipped out during twelve month collections and the reared to the adult stage for identification. The collections were done along nine metres from the edge of the dam divided in three parts (P1, P2 and P3), each part being 3 m long. P1 did not have vegetation (grass) along its edge,which would reach or sink into the water to promote some shade on the marginal water. A total of 217 ...

Ed, Wermelinger; Cv, Benigno; Rnm, Machado; Ph, Cabello; Am, Meira; Ap, Ferreira; Jc, Zanuncio

2012-01-01

266

On pseudo-Riemannian manifolds with many Killing spinors  

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Let M be a pseudo-Riemannian spin manifold of dimension n and signature s and denote by N the rank of the real spinor bundle. We prove that M is locally homogeneous if it admits more than (3/4)N independent Killing spinors with the same Killing number, unless n ? 1(mod 4) and s ? 3(mod 4). We also prove that M is locally homogeneous if it admits k+ independent Killing spinors with Killing number ? and k- independent Killing spinors with Killing number -? such that k++k->(3/2)N, unless n ? s ? 3(mod 4). Similarly, a pseudo-Riemannian manifold with more than (3/4)N independent conformal Killing spinors is conformally locally homogeneous. For (positive or negative) definite metrics, the bounds (3/4)N and (3/2)N in the above results can be relaxed to (1/2)N and N, respectively. Furthermore, we prove that a pseudo-Riemannnian spin manifold with more than (3/4)N parallel spinors is flat and that (1/4)N parallel spinors suffice if the metric is definite. Similarly, a Riemannnian spin manifold with more than (3/8)N Killing spinors with the Killing number ?(set-membership sign)R has constant curvature 4?2. For Lorentzian or negative definite metrics the same is true with the bound (1/2)N. Finally, we give a classification of (not necessarily complete) Riemannian manifolds admitting Killing spinors, which provides an inductive construction of such manifolds.

2009-02-02

267

Analyzing Mosquito (Diptera: Culicidae) Diversity in Pakistan by DNA Barcoding  

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Background Although they are important disease vectors mosquito biodiversity in Pakistan is poorly known. Recent epidemics of dengue fever have revealed the need for more detailed understanding of the diversity and distributions of mosquito species in this region. DNA barcoding improves the accuracy of mosquito inventories because morphological differences between many species are subtle, leading to misidentifications. Methodology/Principal Findings Sequence variation in the barcode region of the mitochondrial COI gene was used to identify mosquito species, reveal genetic diversity, and map the distribution of the dengue-vector species in Pakistan. Analysis of 1684 mosquitoes from 491 sites in Punjab and Khyber Pakhtunkhwa during 2010–2013 revealed 32 species with the assemblage dominated by Culex quinquefasciatus (61% of the collection). The genus Aedes (Stegomyia) comprised 15% of the specimens, and was represented by six taxa with the two dengue vector species, Ae. albopictus and Ae. aegypti, dominant and broadly distributed. Anopheles made up another 6% of the catch with An. subpictus dominating. Barcode sequence divergence in conspecific specimens ranged from 0–2.4%, while congeneric species showed from 2.3–17.8% divergence. A global haplotype analysis of disease-vectors showed the presence of multiple haplotypes, although a single haplotype of each dengue-vector species was dominant in most countries. Geographic distribution of Ae. aegypti and Ae. albopictus showed the later species was dominant and found in both rural and urban environments. Conclusions As the first DNA-based analysis of mosquitoes in Pakistan, this study has begun the construction of a barcode reference library for the mosquitoes of this region. Levels of genetic diversity varied among species. Because of its capacity to differentiate species, even those with subtle morphological differences, DNA barcoding aids accurate tracking of vector populations.

Ashfaq, Muhammad; Hebert, Paul D. N.; Mirza, Jawwad H.; Khan, Arif M.; Zafar, Yusuf; Mirza, M. Sajjad

2014-01-01

268

MosquitoMap and the Mal-area calculator: new web tools to relate mosquito species distribution with vector borne disease  

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Full Text Available Abstract Background Mosquitoes are important vectors of diseases but, in spite of various mosquito faunistic surveys globally, there is a need for a spatial online database of mosquito collection data and distribution summaries. Such a resource could provide entomologists with the results of previous mosquito surveys, and vector disease control workers, preventative medicine practitioners, and health planners with information relating mosquito distribution to vector-borne disease risk. Results A web application called MosquitoMap was constructed comprising mosquito collection point data stored in an ArcGIS 9.3 Server/SQL geodatabase that includes administrative area and vector species x country lookup tables. In addition to the layer containing mosquito collection points, other map layers were made available including environmental, and vector and pathogen/disease distribution layers. An application within MosquitoMap called the Mal-area calculator (MAC was constructed to quantify the area of overlap, for any area of interest, of vector, human, and disease distribution models. Data standards for mosquito records were developed for MosquitoMap. Conclusion MosquitoMap is a public domain web resource that maps and compares georeferenced mosquito collection points to other spatial information, in a geographical information system setting. The MAC quantifies the Mal-area, i.e. the area where it is theoretically possible for vector-borne disease transmission to occur, thus providing a useful decision tool where other disease information is limited. The Mal-area approach emphasizes the independent but cumulative contribution to disease risk of the vector species predicted present. MosquitoMap adds value to, and makes accessible, the results of past collecting efforts, as well as providing a template for other arthropod spatial databases.

Christensen Jamie

2010-02-01

269

Psychological traits underlying different killing methods among Malaysian male murderers.  

Science.gov (United States)

Murder is the most notorious crime that violates religious, social and cultural norms. Examining the types and number of different killing methods that used are pivotal in a murder case. However, the psychological traits underlying specific and multiple killing methods are still understudied. The present study attempts to fill this gap in knowledge by identifying the underlying psychological traits of different killing methods among Malaysian murderers. The study adapted an observational cross-sectional methodology using a guided self-administered questionnaire for data collection. The sampling frame consisted of 71 Malaysian male murderers from 11 Malaysian prisons who were selected using purposive sampling method. The participants were also asked to provide the types and number of different killing methods used to kill their respective victims. An independent sample t-test was performed to establish the mean score difference of psychological traits between the murderers who used single and multiple types of killing methods. Kruskal-Wallis tests were carried out to ascertain the psychological trait differences between specific types of killing methods. The results suggest that specific psychological traits underlie the type and number of different killing methods used during murder. The majority (88.7%) of murderers used a single method of killing. Multiple methods of killing was evident in 'premeditated' murder compared to 'passion' murder, and revenge was a common motive. Examples of multiple methods are combinations of stabbing and strangulation or slashing and physical force. An exception was premeditated murder committed with shooting, when it was usually a single method, attributed to the high lethality of firearms. Shooting was also notable when the motive was financial gain or related to drug dealing. Murderers who used multiple killing methods were more aggressive and sadistic than those who used a single killing method. Those who used multiple methods or slashing also displayed a higher level of minimisation traits. Despite its limitations, this study has provided some light on the underlying psychological traits of different killing methods which is useful in the field of criminology. PMID:24763234

Kamaluddin, M R; Md Shariff, N S; Nur-Farliza, S; Othman, A; Ismail, K; Mat Saat, G A

2014-04-01

270

Checklist of Iranian mosquitoes (Diptera: Culicidae).  

Science.gov (United States)

The mosquito fauna of Iran includes seven genera, 64 species, and three subspecies. The records of 12 other species should be verified. There are 24 species in the most recent checklist of Iranian Anopheles. Two species, An. peditaeniatus and An. fluviatilis species V, have been reported since. An. atroparvus, An. labranchiae, and An. martinius of the Maculipennis Group, and An. cinereus, An. nigerrimus, and An. rhodesiensis rupicola were recorded previously but are not included in the checklist. The checklist of Iranian Culicinae includes ten species of the tribe Aedini, but there are some records of four other species: Aedes aegypti, Ochlerotatus berlandi, Oc. chelli, and Oc. dorsalis. The genus Culex includes 19 species, excluding Cx. impudicus, which has not been collected recently, and some doubtful records of Cx. univittatus, Cx. vishnui, and Cx. vagans. The genus Culiseta includes five species and the genera Coquillettidia and Uranotaenia each include one species in Iran. No information is available for the An. subpictus, Oc. caspius, Oc. detritus, and Oc. pulcritaris species complexes in Iran. The An. claviger and Cx. pipiens complexes and the An. hyrcanus group require review. PMID:18260513

Azari-Hamidian, Shahyad

2007-12-01

271

Host selection patterns of some Pakistan mosquitoes.  

Science.gov (United States)

The host selection patterns of 18 species of Pakistan mosquitoes are described, emphasizing the presumed malaria vectors, Anopheles culicifacies, An. fluviatilis, and An. stephensi, and the probable vectors of West Nile virus, Culex pipiens fatigans and Cx. tritaeniorhynchus. All species tested, with the exception of Cx, p. fatigans, were considered to be essentially zoophilic. Few human feeds were recorded for An. annularis (0.7%), An. culicifacies (0.5%), An. fluviatilis (1.1%), An. nigerrimus (14.3%), and Cx. bitaeniorhynchus (2.8%), while Cx. p. fatigans (37.6%) commonly fed on man. No human positive feeds were recorded for An. stephensi. Temporal or spatial changes in host selection patterns were not discerned with the exception of Cx. p. fatigans, whose feeding patterns varied opportunistically with host availability. Cx. p. fatigans females collected from houses fed more commonly on man than those resting in cattle sheds or in agricultural fields. Cx. p. fatigans resting in cattle sheds during winter fed mostly on birds and bovids, changing to man and bovids during the spring and then to man and birds during summer. The relationships between these results and vector-borne disease transmission in Pakistan are discussed. PMID:110157

Reisen, W K; Boreham, P F

1979-03-01

272

Biological Activity of alpha-Mangostin, a Larvicidal Botanic Mosquito Sterol Carrier Protein-2 Inhibitor.  

Science.gov (United States)

Mangostin derived from mangosteen was identified as a mosquito sterol carrier protein-2 inhibitor via high throughput insecticide screening. - Mangostin was tested for its larvicidal activity against third instar larvae of six mosquito species, and the me...

G. G. Clark J. J. Becnel J. M. Lorch J. W. Pridgeon R. T. Larson

2010-01-01

273

Effect of Wolbachia on replication of West Nile virus in a mosquito cell line and adult mosquitoes.  

Science.gov (United States)

Wolbachia as an endosymbiont is widespread in insects and other arthropods and is best known for reproductive manipulations of the host. Recently, it has been shown that wMelpop and wMel strains of Wolbachia inhibit the replication of several RNA viruses, including dengue virus, and other vector-borne pathogens (e.g., Plasmodium and filarial nematodes) in mosquitoes, providing an alternative approach to limit the transmission of vector-borne pathogens. In this study, we tested the effect of Wolbachia on the replication of West Nile Virus (WNV). Surprisingly, accumulation of the genomic RNA of WNV for all three strains of WNV tested (New York 99, Kunjin, and New South Wales) was enhanced in Wolbachia-infected Aedes aegypti cells (Aag2). However, the amount of secreted virus was significantly reduced in the presence of Wolbachia. Intrathoracic injections showed that replication of WNV in A. aegypti mosquitoes infected with wMel strain of Wolbachia was not inhibited, whereas wMelPop strain of Wolbachia significantly reduced the replication of WNV in mosquitoes. Further, when wMelPop mosquitoes were orally fed with WNV, virus infection, transmission, and dissemination rates were very low in Wolbachia-free mosquitoes and were completely inhibited in the presence of Wolbachia. The results suggest that (i) despite the enhancement of viral genomic RNA replication in the Wolbachia-infected cell line the production of secreted virus was significantly inhibited, (ii) the antiviral effect in intrathoracically infected mosquitoes depends on the strain of Wolbachia, and (iii) replication of the virus in orally fed mosquitoes was completely inhibited in wMelPop strain of Wolbachia. PMID:23115298

Hussain, Mazhar; Lu, Guangjin; Torres, Shessy; Edmonds, Judith H; Kay, Brian H; Khromykh, Alexander A; Asgari, Sassan

2013-01-01

274

European Surveillance for West Nile Virus in Mosquito Populations  

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Full Text Available A wide range of arthropod-borne viruses threaten both human and animal health either through their presence in Europe or through risk of introduction. Prominent among these is West Nile virus (WNV, primarily an avian virus, which has caused multiple outbreaks associated with human and equine mortality. Endemic outbreaks of West Nile fever have been reported in Italy, Greece, France, Romania, Hungary, Russia and Spain, with further spread expected. Most outbreaks in Western Europe have been due to infection with WNV Lineage 1. In Eastern Europe WNV Lineage 2 has been responsible for human and bird mortality, particularly in Greece, which has experienced extensive outbreaks over three consecutive years. Italy has experienced co-circulation with both virus lineages. The ability to manage this threat in a cost-effective way is dependent on early detection. Targeted surveillance for pathogens within mosquito populations offers the ability to detect viruses prior to their emergence in livestock, equine species or human populations. In addition, it can establish a baseline of mosquito-borne virus activity and allow monitoring of change to this over time. Early detection offers the opportunity to raise disease awareness, initiate vector control and preventative vaccination, now available for horses, and encourage personal protection against mosquito bites. This would have major benefits through financial savings and reduction in equid morbidity/mortality. However, effective surveillance that predicts virus outbreaks is challenged by a range of factors including limited resources, variation in mosquito capture rates (too few or too many, difficulties in mosquito identification, often reliant on specialist entomologists, and the sensitive, rapid detection of viruses in mosquito pools. Surveillance for WNV and other arboviruses within mosquito populations varies between European countries in the extent and focus of the surveillance. This study reviews the current status of WNV in mosquito populations across Europe and how this is informing our understanding of virus epidemiology. Key findings such as detection of virus, presence of vector species and invasive mosquito species are summarized, and some of the difficulties encountered when applying a cost-effective surveillance programme are highlighted.

Nicholas Johnson

2013-10-01

275

Generalized Killing-Yano equations in D=5 gauged supergravity  

International Nuclear Information System (INIS)

We propose a generalization of the (conformal) Killing-Yano equations relevant to D=5 minimal gauged supergravity. The generalization stems from the fact that the dual of the Maxwell flux, the 3-form *F, couples naturally to particles in the background as a 'torsion'. Killing-Yano tensors in the presence of torsion preserve most of the properties of the standard Killing-Yano tensors - exploited recently for the higher-dimensional rotating black holes of vacuum gravity with cosmological constant. In particular, the generalized closed conformal Killing-Yano 2-form gives rise to the tower of generalized closed conformal Killing-Yano tensors of increasing rank which in turn generate the tower of Killing tensors. An example of a generalized Killing-Yano tensor is found for the Chong-Cvetic-Lue-Pope black hole spacetime [Z.W. Chong, M. Cvetic, H. Lu, C.N. Pope, (hep-th/0506029)]. Such a tensor stands behind the separability of the Hamilton-Jacobi, Klein-Gordon, and Dirac equations in this background.

2009-07-13

276

[Human diseases transmitted by Culicidae in southwest Indian Ocean islands].  

Science.gov (United States)

South-West Indian Ocean islands were inhabited at the beginning and free from all kind of vector. In Madagascar, Mayotte, Moheli and Anjouan, malaria vectors were carried by the first settlements. According to epidemics, the anopheles arrived in 1867 in Mauritius, 1869 in La Reunion and 1920 in Grande Comore. Rodrigues, Saint-Brandon and the Seychelles are still free from malaria vectors in the coastal part of Madagascarcar and in Comores archipelago, malaria is stable with a permanent transmission. Unstable malaria is seasonaly transmitted in the high territories of Madagascar; it was the same in Mauritius and Reunion island before the eradication campaign. Lymphatic filariasis is quoted in Madagascar, but Comores archipelago is an area with high transmission. The incidence of the disease is moderate in La Reunion and Mauritius and very low in Chagos and Seychelles archipelagos. There is no transmission in Rodrigues and St Brandon. Epidemics of dengue were described during the second part of the XIXth century in Mauritius and La Reunion, then in 1943 in Mayotte. But the disease was controlled in the fifties by the antimalaria campaign. A new epidemy appeared in Seychelles by the end of 1976 and then in Reunion and Mauritius next year. An isolated outbreak was described in Grande Comore only in 1994. PMID:9559180

Julvez, J; Ragavoodoo, C; Gopaul, A R; Mouchet, J

1998-01-01

277

Dinotefuran: a potential neonicotinoid insecticide against resistant mosquitoes.  

Science.gov (United States)

Because pyrethroid, organophosphate, and carbamate resistance is more and more developed in mosquitoes of medical importance, there is an urgent need for alternative insecticides for vector control. Dinotefuran, a new neonicotinoid insecticide commercialized by Mitsui Chemicals (Tokyo, Japan), could be a useful candidate in public health because it shows low mammalian toxicity and great insecticidal activity against a broad range of pests. In this study, the intrinsic toxicity of dinotefuran was evaluated by larval bioassay and topical application against different mosquito strains of Anopheles gambiae Giles, Culex quinquefasciatus Say, and Aedes aegypti L. having none, one, or several resistance mechanisms, respectively, to insecticides. The results showed that dinotefuran was less toxic than most of the commonly used insecticides (e.g., deltamethrin, carbosulfan, and temephos) against the susceptible mosquitoes tested (between 6- and 100-fold at the LD50 level). However, the toxicity of dinotefuran was not strongly affected by the presence of common resistance mechanism, i.e., kdr mutation and insensitive acetylcholinesterase (resistance ratio [RR] from 1.3 to 2.3). More interestingly, the carbamate-resistant strain of Cx. quinquefasciatus was significantly more affected by dinotefuran than the susceptible strain (RR = 0.70), probably because the insensitive acetylcholinesterase is less efficient to degrade nicotinic substrates than normal acetylcholinesterase. Despite the relatively low toxicity of dinotefuran against susceptible mosquitoes, the absence of cross-resistance with common insecticides (pyrethroids, carbamates, and organophosphates) makes neonicotinoids potential candidates for disease vector control, especially in area where mosquitoes are resistant to insecticides. PMID:15311465

Corbel, Vincent; Duchon, Stephane; Zaim, Morteza; Hougard, Jean-Marc

2004-07-01

278

REPELLENCY OF LANTANA CAMARA LEAVES SMOKE AGAINST FEMALE ANOPHELES MOSQUITOES  

Directory of Open Access Journals (Sweden)

Full Text Available The study was done to investigate the Mosquito repellency properties of the smoke of Lantana camara in different solvents viz; methanol, ethyl acetate, ethanol and diethyl ether. Plant samples were dried, burned and extracted using various solvents. The extracts were concentrated using a Rota vapor and various concentrations ranging from 50ppm-1000ppm of the repellents were prepared and evaluated. Methanol extract at 400ppm concentration significantly gave the highest protection against the bites of female Anopheles mosquito (P> 0.01 for over 300 minutes. This extract yielded significantly the better protection time (P> 0.05. The methanol extract seemed to have a steady repellency over a longer period than the rest of the extracts. The results from this study shows that the plant Lantana camara can be used effectively to repel Anopheles mosquitoes, hence a great achievement in the development of safe organic repellants to control transmission of malaria by female anopheles mosquitoes. However, more research needs to be done to identify the specific compounds which are repelling the mosquitoes their structures and also mode of action.

Akumu Edwin O, Kebenei Sellah Anthoney Swamy T* and Ngule Chrispus Mutuku

2014-01-01

279

Interspecific and Intraspecific Differences in Foraging Preferences of Container-Dwelling Mosquitoes  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Feeding preferences of larval container-dwelling mosquitoes are not well understood. Primary production is often absent in container systems and external inputs of animal and plant detritus supply the energy base of container food webs by supporting microorganism prey for mosquitoes. We quantified the feeding preferences of Aedes albopictus (Skuse), a non-native invasive mosquito, and Ochlerotatus triseriatus (Say), a native mosquito, when given a choice of animal and plant detritus. We teste...

Kesavaraju, Banugopan; Yee, Donald A.; Juliano, Steven A.

2007-01-01

280

Serratia odorifera a Midgut Inhabitant of Aedes aegypti Mosquito Enhances Its Susceptibility to Dengue-2 Virus  

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Mosquito midgut plays a crucial role in its vector susceptibility and pathogen interaction. Identification of the sustainable microflora of the midgut environment can therefore help in evaluating its contribution in mosquito-pathogen interaction and in turn vector competence. To understand the bacterial diversity in the midgut of Aedes aegypti mosquitoes, we conducted a screening study of the gut microbes of these mosquitoes which were either collected from fields or reared in the laboratory ...

Apte-deshpande, Anjali; Paingankar, Mandar; Gokhale, Mangesh D.; Deobagkar, Dileep N.

2012-01-01

 
 
 
 
281

Developmentally regulated infectivity of malaria sporozoites for mosquito salivary glands and the vertebrate host  

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Sporozoites are an invasive stage of the malaria parasite in both the mosquito vector and the vertebrate host. We developed an in vivo assay for mosquito salivary gland invasion by preparing Plasmodium gallinaceum sporozoites from infected Aedes aegypti mosquitoes under physiological conditions and inoculating them into uninfected female Ae. aegypti. Sporozoites from mature oocysts were isolated from mosquito abdomens 10 or 11 d after an infective blood meal. Salivary gland sporozoites were i...

1992-01-01

282

Modulation of La Crosse Virus Infection in Aedes albopictus Mosquitoes Following Larval Exposure to Coffee Extracts  

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The mosquito-borne La Crosse virus (LACV; Family Bunyaviridae) may cause encephalitis, primarily in children, and is distributed throughout much of the eastern United States. No antivirals or vaccines are available for LACV, or most other mosquito-borne viruses, and prevention generally relies on mosquito control. We sought to determine whether coffee extracts could interfere with LACV replication and vector mosquito development. Both regular and decaffeinated coffee demonstrated significant ...

Eastep, Nicole E.; Albert, Rachel E.; Anderson, Justin R.

2012-01-01

283

Remote Sensing and Modeling of Mosquito Abundance and Habitats in Coastal Virginia, USA  

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The increase in mosquito populations following extreme weather events poses a major threat to humans because of mosquitoes’ ability to carry disease-causing pathogens, particularly in low-lying, poorly drained coastal plains vulnerable to tropical cyclones. In areas with reservoirs of disease, mosquito abundance information can help to identify the areas at higher risk of disease transmission. Using a Geographic Information System (GIS), mosquito abundance is predicted across the City of Ch...

Cleckner, Haley L.; Allen, Thomas R.; Scott Bellows, A.

2011-01-01

284

A mosquito 2-Cys peroxiredoxin protects against nitrosative and oxidative stresses associated with malaria parasite infection  

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Malaria parasite infection in anopheline mosquitoes induces nitrosative and oxidative stresses that limit parasite development, but also damage mosquito tissues in proximity to the response. Based on these observations, we proposed that cellular defenses in the mosquito may be induced to minimize self-damage. Specifically, we hypothesized that peroxiredoxins (Prxs), enzymes known to detoxify reactive oxygen species (ROS) and reactive nitrogen oxide species (RNOS), protect mosquito cells. We i...

Peterson, Tina M. L.; Luckhart, Shirley

2006-01-01

285

Temporal and spatial distribution of anopheline mosquitos in an Ethiopian village: implications for malaria control strategies.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The spatial and temporal distribution of Anopheles gambiae mosquitos in houses in the village of Sille in Ethiopia was monitored in 1990-91. Monthly mosquito densities in over 300 houses were obtained, and the data for each month were plotted on maps, which indicated clustering of mosquitos within the village. Spatial analysis using "kriging" techniques demonstrated clustering towards the edges of the village, the pattern of which changed with time. For example, the low density of mosquitos i...

Ribeiro, J. M.; Seulu, F.; Abose, T.; Kidane, G.; Teklehaimanot, A.

1996-01-01

286

Predicting mosquito infection from Plasmodium falciparum gametocyte density and estimating the reservoir of infection  

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Transmission reduction is a key component of global efforts to control and eliminate malaria; yet, it is unclear how the density of transmission stages (gametocytes) influences infection (proportion of mosquitoes infected). Human to mosquito transmission was assessed using 171 direct mosquito feeding assays conducted in Burkina Faso and Kenya. Plasmodium falciparum infects Anopheles gambiae efficiently at low densities (4% mosquitoes at 1/mu l blood), although substantially more (> 200/mu l) ...

2013-01-01

287

Direct and indirect immunosuppression by a malaria parasite in its mosquito vector  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Malaria parasites develop as oocysts within the haemocoel of their mosquito vector during a period that is longer than the average lifespan of many of their vectors. How can they escape from the mosquito's immune responses during their long development? Whereas older oocysts might camouflage themselves by incorporating mosquito-derived proteins into their surface capsule, younger stages are susceptible to the mosquito's immune response and must rely on other methods of immune evasion. We show...

2004-01-01

288

HIV transcription is induced with some forms of cell killing  

International Nuclear Information System (INIS)

Using HeLa cells stably transfected with an HIV-LTR-CAT construct', we demonstrated a peak in CAT induction that occurs in viable (but not necessarily cell-division-competent) cells 24 h following exposure to some cell-killing agents. ? rays were the only cell-killing agent which did not induce HIV transcription; this can be attributed to the fact that ?-ray-induced apoptotic death requires function p53, which is missing in HeLa cells. For all other agents, HIV-LTR induction was dose-dependent and correlated with the amount of cell killing that occurred in the culture

1996-01-01

289

Purified by blood: honour killings amongst Turks in the Netherlands  

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Honour killings are murders that are carried out to purify tarnished honour, the honour in question being namus. Both men and women possess namus. For women and girls, namus means chastity, while for men it means having chaste female family members. Honour killing is a widely known phenomenon in Turkey, where the Hürriyet newspaper reports an average of six such killings a month. As a result of migration since the 1960s and 1970s, we also encounter it in Western Europe (the Netherlands, Belg...

Eck, Clementine

2002-01-01

290

Reducibility of Killing tensors in d>4 NHEK geometry  

CERN Document Server

An extremal rotating black hole in arbitrary dimension, along with time translations and rotations, possesses a number of hidden symmetries characterized by the second rank Killing tensors. As is known, in the near horizon limit the isometry group of the metric is enhanced to include the conformal factor SO(2,1). It is demonstrated that for the near horizon extremal Kerr (NHEK) geometry in arbitrary dimension one of the Killing tensors decomposes into a quadratic combination of the Killing vectors corresponding to the conformal group, while the rest is functionally independent.

Chernyavsky, Dmitry

2013-01-01

291

40 CFR 180.1107 - Delta endotoxin of Bacillus thuringiensis variety kurstaki encapsulated into killed Pseudomonas...  

Science.gov (United States)

...variety kurstaki encapsulated into killed Pseudomonas fluorescens; exemption from the requirement...kurstaki encapsulated into killed Pseudomonas fluorescens; exemption from the requirement...kurstaki encapsulated into killed Pseudomonas fluorescens is exempt from the...

2010-07-01

292

Transcriptome of the adult female malaria mosquito vector Anopheles albimanus  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Background Human Malaria is transmitted by mosquitoes of the genus Anopheles. Transmission is a complex phenomenon involving biological and environmental factors of humans, parasites and mosquitoes. Among more than 500 anopheline species, only a few species from different branches of the mosquito evolutionary tree transmit malaria, suggesting that their vectorial capacity has evolved independently. Anopheles albimanus (subgenus Nyssorhynchus

2012-01-01

293

Larvicidal activity of neem oil (Azadirachta indica) formulation against mosquitoes  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Background Mosquitoes transmit serious human diseases, causing millions of deaths every year. Use of synthetic insecticides to control vector mosquitoes has caused physiological resistance and adverse environmental effects in addition to high operational cost. Insecticides of botanical origin have been reported as useful for control of mosquitoes. Azadirachta indica (Meliaceae) and its derived products have shown a variety of insecticidal properties. The pre...

2009-01-01

294

Environmental Factors Affecting Efficacy of Bifenthrin-Treated Vegetation for Mosquito Control.  

Science.gov (United States)

The use of pesticide-treated vegetation as a barrier for control of nuisance and disease-bearing mosquitoes has become an option for mosquito management for home owners and public health and mosquito control professionals. Potted wax myrtle and azalea pla...

D. L. Kline S. A. Allan T. Walker

2009-01-01

295

Survey of new mosquito species of Meghalaya, India.  

Science.gov (United States)

A study on mosquitoes in parts of Meghalaya revealed the presence of 64 species of mosquitoes under 10 genera. In monsoon (June to October) and post-monsoon (November to May) survey, 42 and 48 species of mosquitoes were detected, respectivily. Higher species diversity was found at lower elevations (up to 1050 m). Anopheles peditaeniatus, An. sinensis, Aedes vexans, Ae. nigrostriatus, Ae. annandalei, Culex. fuscocephala, Cx. pseudovishnui, Cx. murrelli, Cx. brevipalpis, Coquillettidia novochracea, Lutzia halifaxii, Malaya genurostris, Ml. jacobsoni, Tripteroides aranoides, Toxorhynchites minimus, Uranotaenia campestris, Ur. edwardsi and Ur. testaceae which were never reported earlier from Meghalaya state were detected in the present study and the findings were discussed with previously published reports from the state. PMID:24620578

Khan, S A; Dutta, P; Borah, J; Mahanta, J

2013-03-01

296

Molecular discrimination of mosquito vectors and their pathogens.  

Science.gov (United States)

Mosquitoes are responsible for the transmission of pathogens that cause disease in over 400 million people each year worldwide. The capacity to transmit disease-causing pathogens can differ greatly between different species of the same genus or even populations of the same species. The geographic distribution and prevalence of vector-borne diseases is proportional to the distribution and prevalence of the relevant mosquito vectors. Furthermore, vector-borne pathogens can differ greatly in virulence and drug-resistance attributes. Accurate and rapid identification and discrimination of vector mosquito species and the pathogens they transmit are, therefore, essential components of disease prevention and control strategies, as well as of epidemiological and ecological research studies. Here, we review advances in diagnostic methods and tools for both vectors and pathogens which cause human disease. PMID:19817558

Sim, Shuzhen; Ramirez, José Luis; Dimopoulos, George

2009-10-01

297

Control of mosquito breeding through Gambusia affinis in rice fields.  

Science.gov (United States)

Studies on mosquito breeding and its control through Gambusia affinis in nursery and paddy fields after transplantation of seedlings were carried out during June to October 1991 in about 10 ha rice field area. Six anopheline species, viz. An. culicifacies, An. annularis, An. subpictus, An. nigerrimus, An. barbirostris and An. aconitus, and four culicine species, viz. Cx. tritaeniorhynchus, Cx. bitaeniorhynchus, Cx. quinquefasciatus, and Aedes sp. could be identified. These were found breeding in rice fields with fluctuations in their percentage composition, exhibiting species succession in different months. G. affinis survived well in submerged rice fields and provided 87.8% mosquito larval control. In rice fields which exhibited intermittent drying up leading to formation of pools, puddles etc., moderate larval control was achieved. However, in nursery rice fields, this method was not applicable. Mosquito larval control through larvivorous fish in rice fields can be achieved but the method has limitations. PMID:8405595

Prasad, H; Prasad, R N; Haq, S

1993-06-01

298

Maternally transmitted target antigen for unrestricted killing by NZB T lymphocytes  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A new target antigen for unrestricted killing was defined by NZB T lymphocytes which were immunized and restimulated with H-2-identical BALB/c spleen cells. These effector cells killed nearly all target cells tested, irrespective of their H-2 type, but did not kill NZB target cells. The response was shown to have three major components: unrestricted killing specific for Qed-1b, H-2d-restricted killing specific for minor histocompatibility antigens, and unrestricted killing specific for a new ...

1980-01-01

299

Evaluation of commercial products for personal protection against mosquitoes.  

Science.gov (United States)

Human landing catch studies were conducted in a semi-field setting to determine the efficacy of seven commercial products used for personal protection against mosquitoes. Experiments were conducted in two empty, insecticide free, mesh-enclosed greenhouses, in Israel, with either 1500 Aedes albopictus or 1500 Culex pipiens released on consecutive study nights. The products tested in this study were the OFF!(®) Clip-On™ Mosquito Repellent (Metofluthrin 31.2%) and the Terminix(®) ALLCLEAR(®) Sidekick Mosquito Repeller (Cinnamon oil 10.5%; Eugenol 13%; Geranium oil 21%; Peppermint 5.3%; Lemongrass oil 2.6%), which are personal diffusers; Super Band™ Wristband (22% Citronella oil) and the PIC(®) Citronella Plus Wristband (Geraniol 15%; Lemongrass oil 5%, Citronella oil 1%); the Sonic Insect Repeller Keychain; the Mosquito Guard Patch (Oil of Lemon Eucalyptus 80mg), an adhesive-backed sticker for use on textiles; and the Mosquito Patch (vitamin B1 300mg), a transdermal patch. It was determined that the sticker, transdermal patch, wristbands and sonic device did not provide significant protection to volunteers compared with the mosquito attack rate on control volunteers who were not wearing a repellent device. The personal diffusers: - OFF!(®) Clip-On™ and Terminix(®) ALLCLEAR(®) Sidekick - provided superior protection compared with all other devices in this study. These diffusers reduced biting on the arms of volunteers by 96.28% and 95.26% respectively, for Ae. albopictus, and by 94.94% and 92.15% respectively, for Cx. pipiens. In a second trial conducted to compare these devices directly, biting was reduced by the OFF!(®) Clip-On™ and the Terminix(®) ALLCLEAR(®) by 87.55% and 92.83%, respectively, for Ae. albopictus, and by 97.22% and 94.14%, respectively, for Cx. pipiens. There was no significant difference between the performances of the two diffusers for each species. PMID:23092689

Revay, Edita E; Junnila, Amy; Xue, Rui-De; Kline, Daniel L; Bernier, Ulrich R; Kravchenko, Vasiliy D; Qualls, Whitney A; Ghattas, Nina; Müller, Günter C

2013-02-01

300

Plasmodium knowlesi in humans, macaques and mosquitoes in peninsular Malaysia  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Since a large focus of human infection with Plasmodium knowlesi, a simian malaria parasite naturally found in long-tailed and pig tailed macaques, was reported in Sarawak, Malaysian Borneo, it was pertinent to study the situation in peninsular Malaysia. A study was thus initiated to screen human cases of Plasmodium malariae using molecular techniques, to determine the presence of P. knowlesi in non- human primates and to elucidate its vectors. Methods Nested polymerase chain reaction (PCR was used to identify all Plasmodium species present in the human blood samples sent to the Parasitology laboratory of Institute for Medical Research. At the same time, non-human primates were also screened for malaria parasites and nested PCR was carried out to determine the presence of P. knowlesi. Mosquitoes were collected from Pahang by human landing collection and monkey-baited-traps situated on three different levels. All mosquitoes were identified and salivary glands and midguts of anopheline mosquitoes were dissected to determine the presence of malaria parasites and nested PCR was carried out on positive glands. Sequencing of the csp genes were carried on P. knowlesi samples from humans, monkeys and mosquitoes, positive by PCR. Results and Discussion Plasmodium knowlesi was detected in 77 (69.37% of the 111 human samples, 10 (6.90% of the 145 monkey blood and in 2 (1.7% Anopheles cracens. Sequence of the csp gene clustered with other P. knowlesi isolates. Conclusion Human infection with Plasmodium knowlesi is occurring in most states of peninsular Malaysia. An. cracens is the main vector. Economic exploitation of the forest is perhaps bringing monkeys, mosquitoes and humans into increased contact. A single bite from a mosquito infected with P. knowlesi is sufficient to introduce the parasite to humans. Thus, this zoonotic transmission has to be considered in the future planning of malaria control.

NorParina Ismail

2008-08-01

 
 
 
 
301

The origin and evolution of mosquito APE retroposons.  

Science.gov (United States)

The detection of horizontal transfer is important to understanding the origin and spread of transposable elements and in assessing their impact on genetic diversity. The occurrence of the phenomenon is not in doubt for two of the three major groups of elements, but is disputed for retroposons, largely on the grounds of data paucity and overreliance on divergence estimates between host species. We present here the most wide-ranging retroposon data set assembled to date for a species group, the mosquitoes. The results provide no evidence for horizontal transfer events and show conclusively that four previously reported events, involving Juan-A, Juan-C, T1, and Q, did not occur. We propose that the origin of all known mosquito retroposons can be attributed to vertical inheritance and that retroposons have therefore been a persistent source of genetic diversity in mosquito genomes since the emergence of the taxon. Furthermore, the data confirm that the unprecedented levels of retroposon diversity previously reported in Anopheles gambiae extends to at least seven other species representing five genera and all three mosquito subfamilies. Most notably, this included the L1 elements, which are not known in other insects. A number of novel well-defined monophyletic groups were also identified, particularly, JM2 and JM3 within the Jockey clade, which included sequences from seven and five mosquito species, respectively. As JM3 does not contain an Anopheles element, this represents a good example of stochastic loss and the best out of at least four found in this study. This exceptionally diverse data set when compared with the wealth of data available for the many unrelated species with which mosquitoes have intimate contact through blood feeding ought to be fertile ground for the discovery of horizontal transfer events. The absence of positive results therefore supports the view that retroposon horizontal transfer does not occur or is far more exceptional than for other types of transposable elements. PMID:16033989

Crainey, James L; Garvey, Clare F; Malcolm, Colin A

2005-11-01

302

Potassium Channels Mediate Killing by Human Natural Killer Cells  

Science.gov (United States)

Human natural killer (NK) cells in peripheral blood spontaneously recognize and kill a wide variety of target cells. It has been suggested that ion channels are involved in the killing process because there is a Ca-dependent stage and because killing by presensitized cytotoxic T lymphocytes, which in many respects resembles NK killing, is associated with changes in K and Na transport in the target cell. However, no direct evidence exists for ion channels in NK cells or in their target cells. Using the whole-cell variation of the patch-clamp technique, we found a voltage-dependent potassium (K+) current in NK cells. The K+ current was reduced in a dose-dependent manner by the K-channel blockers 4-aminopyridine and quinidine and by the traditional Ca-channel blockers verapamil and Cd2+. We tested the effects of ion-channel blockers on killing of two commonly used target cell lines: K562, which is derived from a human myeloid leukemia, and U937, which is derived from a human histiocytic leukemia. Killing of K562 target cells, determined in a standard 51Cr-release assay, was inhibited in a dose-dependent manner by verapamil, quinidine, Cd2+, and 4-aminopyridine at concentrations comparable to those that blocked the K+ current in NK cells. In K562 target cells only a voltage-dependent Na+ current was found and it was blocked by concentrations of tetrodotoxin that had no effect on killing. Killing of U937 target cells was also inhibited by the two ion-channel blockers tested, quinidine and verapamil. In this cell line only a small K+ current was found that was similar to the one in NK cells. We could not find any evidence of a Ca2+ current in target cells or in NK cells; therefore, our results cannot explain the Ca dependence of killing. Our findings show that there are K channels in NK cells and that these channels play a necessary role in the killing process. In contrast, the endogenous channel type in the target cell is probably not a factor in determining target cell sensitivity to natural killing.

Schlichter, Lyanne; Sidell, Neil; Hagiwara, Susumu

1986-01-01

303

Olfaction-based anthropophily in a mosquito-specialist predator  

Science.gov (United States)

Evarcha culicivora is an unusual salticid spider because it feeds indirectly on vertebrate blood by choosing blood-carrying mosquitoes as preferred prey. Its preferred mosquitoes are Anopheles, the genus to which all human malaria vectors belong. Here, we show that human odour, which is known to be salient to malaria vectors, is also salient to the adults and juveniles of E. culicivora. Test spiders spent more time in the vicinity of a source of human odour (previously worn socks) when the alternative was unworn socks.

Cross, Fiona R.; Jackson, Robert R.

2011-01-01

304

"Licence to kill" : problem pravnosti in legtimnosti dovoljenja za ubijanje  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In the thesis we will try to present the covert operation of three world’s major Intelligence services and their interference with human rights. In short, we will investigate whether "Licence to Kill" exist’s. On which basis of a legal act can Intelligence services and Military service perform assasination. We checked these facts in three cases: »Alexander Litvinenko was killed with radioactive isotope 210Po. This endangered the lives of thousands of others, because the murderer?...

2013-01-01

305

The role of special conformal Killing tensors in general relativity  

International Nuclear Information System (INIS)

Special conformal Killing tensors have a number of interesting properties, an overview of which is given in the Riemannian case. Some of these properties remain valid in pseudo-Riemannian manifolds. Presently, we are investigating the latter problem, where, in order to obtain a better insight, we first examine some specific cases, such as special conformal Killing tensors in conformally flat or Petrov type D space-times.

2011-09-22

306

Special Killing forms on toric Sasaki-Einstein manifolds  

CERN Document Server

In this paper we study the interplay between complex coordinates of the Calabi-Yau metric cone and the special Killing forms on the toric Sasaki-Einstein manifold. In the general case we give a procedure to locally construct the special Killing forms. In the final part we exemplify the general scheme in the case of the 5-dimensional $Y^{p,q}$ spaces.

Slesar, Vladimir; Vilcu, Gabriel Eduard

2014-01-01

307

Roles of antibodies and complement in phagocytic killing of enterococci.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The contributions of complement and antibodies to polymorphonuclear leukocyte (PMN)-mediated killing of enterococci were investigated with pooled normal human serum (PNHS) or immune human sera (IHS) from patients with serious enterococcal infections. Each IHS containing antienterococcal antibodies demonstrated by enzyme-linked immunosorbent assay and Western blotting (immunoblotting) was examined with the enterococcus strain isolated from the same patient. PNHS promoted PMN-mediated killing o...

Arduino, R. C.; Murray, B. E.; Rakita, R. M.

1994-01-01

308

Pseudomonas aeruginosa PAO1 Kills Caenorhabditis elegans by Cyanide Poisoning  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this report we describe experiments to investigate a simple virulence model in which Pseudomonas aeruginosa PAO1 rapidly paralyzes and kills the nematode Caenorhabditis elegans. Our results imply that hydrogen cyanide is the sole or primary toxic factor produced by P. aeruginosa that is responsible for killing of the nematode. Four lines of evidence support this conclusion. First, a transposon insertion mutation in a gene encoding a subunit of hydrogen cyanide synthase (hcnC) eliminated ne...

Gallagher, Larry A.; Manoil, Colin

2001-01-01

309

Anaerobic Killing of Oral Streptococci by Reduced, Transition Metal Cations  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Reduced, transition metal cations commonly enhance oxidative damage to cells caused by hydroperoxides formed as a result of oxygen metabolism or added externally. As expected, the cations Fe2+ and Cu+ enhanced killing of Streptococcus mutans GS-5 by hydroperoxides. However, unexpectedly, they also induced lethal damage under fully anaerobic conditions in a glove box with no exposure to O2 or hydroperoxides from initial treatment with the cations. Sensitivities to anaerobic killing by Fe2+ var...

Dunning, J. C.; Ma, Y.; Marquis, R. E.

1998-01-01

310

Aeromonas salmonicida resistance to complement-mediated killing.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The resistance of Aeromonas salmonicida to complement-mediated killing was investigated by using different strains and their isogenic mutants that had been previously characterized for their surface components. We found that the classical complement pathway is involved in serum killing of susceptible A. salmonicida strains, while the alternative complement pathway seems not to be involved. All of the A. salmonicida strains are able to activate complement, but the smooth strains (with or witho...

Merino, S.; Alberti?, S.; Toma?s, J. M.

1994-01-01

311

Role of nitric oxide and superoxide in Giardia lamblia killing  

Directory of Open Access Journals (Sweden)

Full Text Available Giardia lamblia trophozoites were incubated for 2 h with activated murine macrophages, nitric oxide (NO donors or a superoxide anion generator (20 mU/ml xanthine oxidase plus 1 mM xanthine. Activated macrophages were cytotoxic to Giardia trophozoites (~60% dead trophozoites. This effect was inhibited (>90% by an NO synthase inhibitor (200 µM and unaffected by superoxide dismutase (SOD, 300 U/ml. Giardia trophozoites were killed by the NO donors, S-nitroso-acetyl-penicillamine (SNAP and sodium nitroprusside (SNP in a dose-dependent manner (LD50 300 and 50 µM, respectively. A dual NO-superoxide anion donor, 3-morpholino-sydnonimine hydrochloride (SIN-1, did not have a killing effect in concentrations up to 1 mM. However, when SOD (300 U/ml was added simultaneously with SIN-1 to Giardia, a significant trophozoite-killing effect was observed (~35% dead trophozoites at 1 mM. The mixture of SNAP or SNP with superoxide anion, which yields peroxynitrite, abolished the trophozoite killing induced by NO donors. Authentic peroxynitrite only killed trophozoites at very high concentrations (3 mM. These results indicate that NO accounts for Giardia trophozoite killing and this effect is not mediated by peroxynitrite

Fernandes P.D.

1997-01-01

312

Role of nitric oxide and superoxide in Giardia lamblia killing  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Giardia lamblia trophozoites were incubated for 2 h with activated murine macrophages, nitric oxide (NO) donors or a superoxide anion generator (20 mU/ml xanthine oxidase plus 1 mM xanthine). Activated macrophages were cytotoxic to Giardia trophozoites (~60% dead trophozoites). This effect was inhib [...] ited (>90%) by an NO synthase inhibitor (200 µM) and unaffected by superoxide dismutase (SOD, 300 U/ml). Giardia trophozoites were killed by the NO donors, S-nitroso-acetyl-penicillamine (SNAP) and sodium nitroprusside (SNP) in a dose-dependent manner (LD50 300 and 50 µM, respectively). A dual NO-superoxide anion donor, 3-morpholino-sydnonimine hydrochloride (SIN-1), did not have a killing effect in concentrations up to 1 mM. However, when SOD (300 U/ml) was added simultaneously with SIN-1 to Giardia, a significant trophozoite-killing effect was observed (~35% dead trophozoites at 1 mM). The mixture of SNAP or SNP with superoxide anion, which yields peroxynitrite, abolished the trophozoite killing induced by NO donors. Authentic peroxynitrite only killed trophozoites at very high concentrations (3 mM). These results indicate that NO accounts for Giardia trophozoite killing and this effect is not mediated by peroxynitrite

P.D., Fernandes; J., Assreuy.

313

On conformal Killing symmetric tensor fields on Riemannian manifolds  

CERN Document Server

A vector field on a Riemannian manifold is called conformal Killing if it generates one-parameter group of conformal transformations. The class of conformal Killing symmetric tensor fields of an arbitrary rank is a natural generalization of the class of conformal Killing vector fields, and appears in different geometric and physical problems. A symmetric tensor field is a trace-free field if the contraction of the field with the metric tensor is identically equal to zero. On a Riemannian manifold of dimension at least three, the space of trace-free conformal Killing symmetric tensor fields of arbitrary rank is of a finite dimension. On a two-dimensional manifold, the space can be of infinite dimension. Nevertheless, on a connected manifold of any dimension, a trace-free conformal Killing tensor field is uniquely determined by its $C^\\infty$-jet at any point. We prove the statement: On a connected manifold, a trace-free conformal Killing tensor field is identically equal to zero if it vanishes on some hypersur...

Dairbekov, Nurlan S

2011-01-01

314

Effects of Haulm Killing on Seed Potato Quality  

Directory of Open Access Journals (Sweden)

Full Text Available In Northern Finland (65º40'N, haulm killing is used in seed potato production primarily to regulate tuber size. The most common haulm killing method is mechanical-chemical. We studied the effects of mechanical and mechanical-chemical haulm killing methods on seed potato quality, comparing to natural haulm senescence (control. The timing of haulm killing (when no more than 5% of the crop tubers were over 50 mm in size and the time between destruction and harvest (21–26 days were similar to practices followed in seed-potato production. Matilda was the cultivar used. In this study, haulm killing clearly increased plant disease pressure, as black scurf (Rhizoctonia solani could be seen in tubers whose haulm had been destroyed. Black scurf was also observed in mechanical haulm killing. The yield from naturally senesced haulms had less black scurf than the other treatments. In addition, when haulm senescence occurred naturally, crop yield and starch content were highest compared to other treatments.

E. Virtanen

2014-02-01

315

Controle de vetores utilizando mosquitos geneticamente modificados / Control of vector populations using genetically modified mosquitoes / Control de vectores utilizando mosquitos genéticamente modificados  

Scientific Electronic Library Online (English)

Full Text Available SciELO Public Health | Language: Portuguese Abstract in portuguese Formas químicas de controle de mosquitos vetores são ineficazes, levando ao desenvolvimento de novas estratégias. Assim, foi realizada revisão das estratégias de controle genético de populações de mosquitos vetores baseada na técnica do inseto estéril. Uma delas consiste na liberação de machos ester [...] ilizados por radiação, a outra, na integração de um gene letal dominante associado a um promotor específico de fêmeas imaturas. Entre as vantagens sobre outras técnicas biológicas e químicas de controle de vetores estão: alta especificidade, não prejudicial ao meio ambiente, baixo custo de produção e alta eficácia. O uso desta técnica de modificação genética pode vir a ser uma importante ferramenta do manejo integrado de vetores. Abstract in spanish Formas químicas de control de mosquitos vectores son ineficaces, llevando al desarrollo de nuevas estrategias. Así, fue realizada revisión de las estrategias de control genético de poblaciones de mosquitos vectores basada en la técnica del insecto estéril. Una de ellas consiste en la liberación de m [...] achos esterilizados por radiación, la otra, en la integración de un gen letal dominante asociado a un promotor específico de hembras inmaduras. Entre las ventajas sobre otras técnicas biológicas y químicas de control de vectores están: la alta especificidad, no prejudicial al ambiente, bajo costo de producción y alta eficiencia. El uso de esta técnica de modificación genética puede ser una importante herramienta del manejo integrado de vectores. Abstract in english The ineffectiveness of current strategies for chemical control of mosquito vectors raises the need for developing novel approaches. Thus, we carried out a literature review of strategies for genetic control of mosquito populations based on the sterile insect technique. One of these strategies consis [...] ts of releasing radiation-sterilized males into the population; another, of integrating a dominant lethal gene under the control of a specific promoter into immature females. Advantages of these approaches over other biological and chemical control strategies include: highly species-specific, environmentally safety, low production cost, and high efficacy. The use of this genetic modification technique will constitute an important tool for integrated vector management.

André Barreto Bruno, Wilke; Almério de Castro, Gomes; Delsio, Natal; Mauro Toledo, Marrelli.

316

Controle de vetores utilizando mosquitos geneticamente modificados / Control of vector populations using genetically modified mosquitoes / Control de vectores utilizando mosquitos genéticamente modificados  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Formas químicas de controle de mosquitos vetores são ineficazes, levando ao desenvolvimento de novas estratégias. Assim, foi realizada revisão das estratégias de controle genético de populações de mosquitos vetores baseada na técnica do inseto estéril. Uma delas consiste na liberação de machos ester [...] ilizados por radiação, a outra, na integração de um gene letal dominante associado a um promotor específico de fêmeas imaturas. Entre as vantagens sobre outras técnicas biológicas e químicas de controle de vetores estão: alta especificidade, não prejudicial ao meio ambiente, baixo custo de produção e alta eficácia. O uso desta técnica de modificação genética pode vir a ser uma importante ferramenta do manejo integrado de vetores. Abstract in spanish Formas químicas de control de mosquitos vectores son ineficaces, llevando al desarrollo de nuevas estrategias. Así, fue realizada revisión de las estrategias de control genético de poblaciones de mosquitos vectores basada en la técnica del insecto estéril. Una de ellas consiste en la liberación de m [...] achos esterilizados por radiación, la otra, en la integración de un gen letal dominante asociado a un promotor específico de hembras inmaduras. Entre las ventajas sobre otras técnicas biológicas y químicas de control de vectores están: la alta especificidad, no prejudicial al ambiente, bajo costo de producción y alta eficiencia. El uso de esta técnica de modificación genética puede ser una importante herramienta del manejo integrado de vectores. Abstract in english The ineffectiveness of current strategies for chemical control of mosquito vectors raises the need for developing novel approaches. Thus, we carried out a literature review of strategies for genetic control of mosquito populations based on the sterile insect technique. One of these strategies consis [...] ts of releasing radiation-sterilized males into the population; another, of integrating a dominant lethal gene under the control of a specific promoter into immature females. Advantages of these approaches over other biological and chemical control strategies include: highly species-specific, environmentally safety, low production cost, and high efficacy. The use of this genetic modification technique will constitute an important tool for integrated vector management.

André Barreto Bruno, Wilke; Almério de Castro, Gomes; Delsio, Natal; Mauro Toledo, Marrelli.

317

Controle de vetores utilizando mosquitos geneticamente modificados Control de vectores utilizando mosquitos genéticamente modificados Control of vector populations using genetically modified mosquitoes  

Directory of Open Access Journals (Sweden)

Full Text Available Formas químicas de controle de mosquitos vetores são ineficazes, levando ao desenvolvimento de novas estratégias. Assim, foi realizada revisão das estratégias de controle genético de populações de mosquitos vetores baseada na técnica do inseto estéril. Uma delas consiste na liberação de machos esterilizados por radiação, a outra, na integração de um gene letal dominante associado a um promotor específico de fêmeas imaturas. Entre as vantagens sobre outras técnicas biológicas e químicas de controle de vetores estão: alta especificidade, não prejudicial ao meio ambiente, baixo custo de produção e alta eficácia. O uso desta técnica de modificação genética pode vir a ser uma importante ferramenta do manejo integrado de vetores.Formas químicas de control de mosquitos vectores son ineficaces, llevando al desarrollo de nuevas estrategias. Así, fue realizada revisión de las estrategias de control genético de poblaciones de mosquitos vectores basada en la técnica del insecto estéril. Una de ellas consiste en la liberación de machos esterilizados por radiación, la otra, en la integración de un gen letal dominante asociado a un promotor específico de hembras inmaduras. Entre las ventajas sobre otras técnicas biológicas y químicas de control de vectores están: la alta especificidad, no prejudicial al ambiente, bajo costo de producción y alta eficiencia. El uso de esta técnica de modificación genética puede ser una importante herramienta del manejo integrado de vectores.The ineffectiveness of current strategies for chemical control of mosquito vectors raises the need for developing novel approaches. Thus, we carried out a literature review of strategies for genetic control of mosquito populations based on the sterile insect technique. One of these strategies consists of releasing radiation-sterilized males into the population; another, of integrating a dominant lethal gene under the control of a specific promoter into immature females. Advantages of these approaches over other biological and chemical control strategies include: highly species-specific, environmentally safety, low production cost, and high efficacy. The use of this genetic modification technique will constitute an important tool for integrated vector management.

André Barreto Bruno Wilke

2009-10-01

318

Eastern equine encephalitis virus in mosquitoes and their role as bridge vectors.  

Science.gov (United States)

Eastern equine encephalitis virus (EEEV) is maintained in an enzootic cycle involving Culiseta melanura mosquitoes and avian hosts. Other mosquito species that feed opportunistically on mammals have been incriminated as bridge vectors to humans and horses. To evaluate the capacity of these mosquitoes to acquire, replicate, and potentially transmit EEEV, we estimated the infection prevalence and virus titers in mosquitoes collected in Connecticut, USA, by cell culture, plaque titration, and quantitative reverse transcription-PCR. Cs. melanura mosquitoes were the predominant source of EEEV (83 [68%] of 122 virus isolations) and the only species to support consistently high virus titers required for efficient transmission. Our findings suggest that Cs. melanura mosquitoes are primary enzootic and epidemic vectors of EEEV in this region, which may explain the relative paucity of human cases. This study emphasizes the need for evaluating virus titers from field-collected mosquitoes to help assess their role as vectors. PMID:21122215

Armstrong, Philip M; Andreadis, Theodore G

2010-12-01

319

Eastern Equine Encephalitis Virus in Mosquitoes and Their Role as Bridge Vectors  

Science.gov (United States)

Eastern equine encephalitis virus (EEEV) is maintained in an enzootic cycle involving Culiseta melanura mosquitoes and avian hosts. Other mosquito species that feed opportunistically on mammals have been incriminated as bridge vectors to humans and horses. To evaluate the capacity of these mosquitoes to acquire, replicate, and potentially transmit EEEV, we estimated the infection prevalence and virus titers in mosquitoes collected in Connecticut, USA, by cell culture, plaque titration, and quantitative reverse transcription–PCR. Cs. melanura mosquitoes were the predominant source of EEEV (83 [68%] of 122 virus isolations) and the only species to support consistently high virus titers required for efficient transmission. Our findings suggest that Cs. melanura mosquitoes are primary enzootic and epidemic vectors of EEEV in this region, which may explain the relative paucity of human cases. This study emphasizes the need for evaluating virus titers from field-collected mosquitoes to help assess their role as vectors.

Andreadis, Theodore G.

2010-01-01

320

Larval habitats of mosquito fauna in Osogbo metropolis, Southwestern Nigeria  

Science.gov (United States)

Objective To determine the larval habitats of mosquito fauna and possible impact of land use/ land cover changes on the epidemiology of mosquito-borne diseases in Osogbo metropolis, Southwestern, Nigeria. Methods All accessible larval habitats were surveyed between May and September, 2011 in Osogbo metropolis while Land Use/ Land cover of the city was analyzed using 2 Lansat Multispectral Scanner satellite imagery of SPOT 1986 and LANDSAT TM 2009. Results A total of six species namely, Aedes aegypti, Aedes albopictus, Aedes vittatus, Anopheles gambiae complex, Culex quinquefasciatus and Eretmapodite chrysogaster were encountered during the study. The occurrence and contribution of disused tyres was significantly higher (Pseptic tanks/ drums, ground pools/open drains and discarded containers to the breeding of mosquitoes (P>0.05). The accessible land use/ land covered of the study area between 1986 and 2009 showed that the wet land coverage and settlement area increased from 0.19 to 9.09 hectare and 1.00 to 2.01 hectare respectively while the forest area decreased from 60.18 to 50.14 hectare. Conclusion The contribution of the habitats coupled with the increasing rate of flooded environment which could provide ample breeding sites for mosquitoes call for sustained environmental sanitation and management in Osogbo metropolis.

Adeleke, Monsuru Adebayo; Adebimpe, Wasiu Olalekan; Hassan, AbdulWasiu Oladele; Oladejo, Sunday Olukayode; Olaoye, Ismail; Olatunde, Ganiyu Olatunji; Adewole, Taiwo

2013-01-01

 
 
 
 
321

Filarial susceptibility and effects of Wolbachia in Aedes pseudoscutellaris mosquitoes.  

Science.gov (United States)

The mosquito Aedes pseudoscutellaris (Theobald), a member of the Aedes (Stegomyia) scutellaris complex (Diptera: Culicidae), is an important vector of subperiodic Wuchereria bancrofti (Cobbold) (Spirurida: Onchocercidae), causing human lymphatic filariasis, on South Pacific islands. Maternal inheritance of filarial susceptibility in the complex has previously been asserted, and larval tetracycline treatment reduced susceptibility; the maternally inherited Wolbachia in these mosquitoes were suggested to be responsible. To investigate the relationship of these two factors, we eliminated Wolbachia from a strain of Ae. pseudoscutellaris by tetracycline treatment, and tested filarial susceptibility of the adult female mosquitoes using Brugia pahangi (Edeson & Buckley). Filarial susceptibility was not significantly different in Wolbachia-free and infected lines of Ae. pseudoscutellaris, suggesting that the Wolbachia in these mosquitoes do not influence vector competence. Crosses between Wolbachia-infected males and uninfected females of Ae. pseudoscutellaris showed cytoplasmic incompatibility (CI), i.e. no eggs hatched, unaffected by larval crowding or restricted nutrient availability, whereas these factors are known to affect CI in Drosophila simulans. Reciprocal crosses between Ae. pseudoscutellaris and Ae. katherinensis Woodhill produced no progeny, even when both parents were Wolbachia-free, suggesting that nuclear factors are responsible for this interspecific sterility. PMID:15752178

Dutton, T J; Sinkins, S P

2005-03-01

322

The suitability of clay pots for indoor sampling of mosquitoes in an arid area in northern Tanzania  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Water storage clay pots have been recently explored as method for outdoor mosquito sampling and as novel device for administrating insect-pathogenic fungi to mosquitoes. Their suitability for indoor mosquito sampling in natural conditions is unknown. We tested clay pots as indoor resting sites alongside catches by CDC light trap in an area of low malaria endemicity in northern Tanzania. Mosquitoes were caught by clay pots although the rate of female Anopheles mosquito catches was 22.64 (95% C...

Bijllaardt, W.; Braak, R.; Shekalaghe, S.; Otieno, S.; Mahande, A.; Sauerwein, R.; Takken, W.; Bousema, T.

2009-01-01

323

Risk Factors for Mosquito House Entry in the Lao PDR  

Science.gov (United States)

Background Construction of the Nam Theun 2 hydroelectric project and flooding of a 450 km2 area of mountain plateau in south-central Lao PDR resulted in the resettlement of 6,300 people to newly built homes. We examined whether new houses would have altered risk of house entry by mosquitoes compared with traditional homes built from poorer construction materials. Methodology/Principal Findings Surveys were carried out in the Nam Theun 2 resettlement area and a nearby traditional rice farming area in 2010. Mosquitoes were sampled in bedrooms using CDC light traps in 96 resettlement houses and 96 traditional houses and potential risk factors for mosquito house entry were recorded. Risk of mosquito house entry was more than twice as high in traditional bamboo houses compared with those newly constructed from wood (Putative Japanese Encephalitis (JE) vector incidence rate ratio (IRR)?=?2.26, 95% CI 1.38–3.70, P?=?0.001; Anopheline IRR?=?2.35, 95% CI: 1.30–4.23, P?=?0.005). Anophelines were more common in homes with cattle compared against those without (IRR?=?2.32, 95% CI: 1.29–4.17, P?=?0.005).Wood smoke from cooking fires located under the house or indoors was found to be protective against house entry by both groups of mosquito, compared with cooking in a separate room beside the house (Putative JE vector IRR?=?0.43, 95% CI: 0.26–0.73, P?=?0.002; Anopheline IRR?=?0.22, 95% CI: 0.10–0.51, P<0.001). Conclusions/Significance Construction of modern wooden homes should help reduce human-mosquito contact in the Lao PDR. Reduced mosquito contact rates could lead to reduced transmission of diseases such as JE and malaria. Cattle ownership was associated with increased anopheline house entry, so zooprophylaxis for malaria control is not recommended in this area. Whilst wood smoke was protective against putative JE vector and anopheline house entry we do not recommend indoor cooking since smoke inhalation can enhance respiratory disease.

Hiscox, Alexandra; Khammanithong, Phasouk; Kaul, Surinder; Sananikhom, Pany; Luthi, Ruedi; Brey, Paul T.; Lindsay, Steve W.

2013-01-01

324

Efficacy of an insecticide paint against insecticide-susceptible and resistant mosquitoes - Part 1: Laboratory evaluation  

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Full Text Available Abstract Background The main malaria vector Anopheles gambiae and the urban pest nuisance Culex quinquefasciatus are increasingly resistant to pyrethroids in many African countries. There is a need for new products and strategies. Insecticide paint Inesfly 5A IGR™, containing two organophosphates (OPs, chlorpyrifos and diazinon, and insect growth regulator (IGR, pyriproxyfen, was tested under laboratory conditions for 12 months following WHOPES Phase I procedures. Methods Mosquitoes used were laboratory strains of Cx. quinquefasciatus susceptible and resistant to OPs. The paint was applied at two different doses (1 kg/6 m2 and 1 kg/12 m2 on different commonly used surfaces: porous (cement and stucco and non-porous (softwood and hard plastic. Insecticide efficacy was studied in terms of delayed mortality using 30-minute WHO bioassay cones. IGR efficacy on fecundity, fertility and larval development was studied on OP-resistant females exposed for 30 minutes to cement treated and control surfaces. Results After treatment, delayed mortality was high (87-100% even against OP-resistant females on all surfaces except cement treated at 1 kg/12 m2. Remarkably, one year after treatment delayed mortality was 93-100% against OP-resistant females on non-porous surfaces at both doses. On cement, death rates were low 12 months after treatment regardless of the dose and the resistance status. Fecundity, fertility and adult emergence were reduced after treatment even at the lower dose (p -3. A reduction in fecundity was still observed nine months after treatment at both doses (p -3 and adult emergence was reduced at the higher dose (p -3. Conclusions High mortality rates were observed against laboratory strains of the pest mosquito Cx. quinquefasciatus susceptible and resistant to insecticides. Long-term killing remained equally important on non-porous surfaces regardless the resistance status for over 12 months. The paint's effect on fecundity, fertility and adult emergence may continue to provide an additional angle of attack in reducing overall population densities when the lethal effect of OPs diminishes over time. Some options on how to deal with porous materials are given. Implications in vector control are discussed.

Carnevale Pierre

2010-11-01

325

Midgut Microbial Community of Culex quinquefasciatus Mosquito Populations from India  

Science.gov (United States)

The mosquito Culex quinquefasciatus is a ubiquitous species that serves as a major vector for west nile virus and lymphatic filariasis. Ingestion of bloodmeal by females triggers a series of physiological processes in the midgut and also exposes them to infection by these pathogens. The bacteria normally harbored in the midgut are known to influence physiology and can also alter the response to various pathogens. The midgut bacteria in female Cx. quinquefasciatus mosquitoes collected over a large geographical area from India was studied. Examination of 16S ribosomal DNA amplicons from culturable microflora revealed the presence of 83 bacterial species belonging to 31 bacterial genera. All of these species belong to three phyla i.e. Proteobacteria, Firmicutes and Actinobacteria. Phylum Proteobacteria was the most dominant phylum (37 species), followed by Firmicutes (33 species) and Actinobacteria (13 species). Phylum Proteobacteria, was dominated by members of ?-proteobacteria class. The genus Staphylococcus was the largest genus represented by 11 species whereas Enterobacter was the most prevalent genus and recovered from all the field stations except Leh. Highest bacterial prevalence was observed from Bhuj (22 species) followed by Nagrota (18 species), Masimpur (18 species) and Hathigarh (16 species). Whereas, least species were observed from Leh (8 species). It has been observed that individual mosquito harbor extremely diverse gut bacteria and have very small overlap bacterial taxa in their gut. This variation in midgut microbiota may be one of the factors responsible for variation in disease transmission rates or vector competence within mosquito population. The present data strongly encourage further investigations to verify the potential role of the detected bacteria in mosquito for the transmission of lymphatic filariasis and west nile virus. To the best of our knowledge this is the first study on midgut microbiota of wild Cx. quinquefasciatus from over a large geographical area.

Chandel, Kshitij; Mendki, Murlidhar J.; Parikh, Rasesh Y.; Kulkarni, Girish; Tikar, Sachin N.; Sukumaran, Devanathan; Prakash, Shri; Parashar, Brahma D.; Shouche, Yogesh S.; Veer, Vijay

2013-01-01

326

Genetic methods for control of mosquitoes and biting flies  

International Nuclear Information System (INIS)

The earliest research efforts on using genetic methods for the control of mosquitoes and biting flies concentrated on the evaluation of the sterile insect technique (SIT). Several successful, but generally small scale, research efforts with mosquitoes clearly documented that either chemosterilized or radiation sterilized males were effective in causing a level of genetic load that would be sufficient for the reduction or eradication of natural populations of several species. Genetic sexing strains of several species of mosquitoes have been assembled, and this aspect of breeding specialty strains is not a limiting factor in the implementation of SIT. In the largest field experiment, conducted with Anopheles albimanus in El Salvador during the 1970s, a genetic sexing strain was used operationally in a factory that produced one million sterile males per day over a one year period. Technical problems that would require extensive research of a practical nature before the implementation of SIT for mosquito control involve primarily better means for the rearing, sterilization and distribution of the insects. A successful experiment was conducted to eliminate the stable fly on the island of St. Croix, the United States Virgin Islands, and since this work in the 1970s, genetic sexing strains have been developed. A considerable amount of effort was expended on the synthesis of chromosome aberrations for the control of mosquitoes. Although the results of experimental trials indicated that aberration bearing insects could effectively inject a genetic load into the natural population, no large scale tests have ever been conducted to evaluate fully the real effectiveness of induced chromosomal aberrations. More recently, most of the research work in genetic control has been aimed at the use of recombinant DNA techniques for the development of new technology. All of these topics and an assessment of their value are discussed. (author). 30 refs

1987-11-16

327

Limitation of using synthetic human odours to test mosquito repellents  

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Full Text Available Abstract Background Gold-standard tests of mosquito repellents involve exposing human volunteers to host-seeking mosquitoes, to assess the protective efficacy of the repellents. These techniques are not exposure-free and cannot be performed prior to toxicological evaluation. It is postulated that synthetic lures could provide a useful assay that mimics in-vivo conditions for use in high-throughput screening for mosquito repellents. Methods This paper reports on a semi-field evaluation of repellents using a synthetic blend of human derived attractants for the malaria vector, Anopheles gambiae sensu stricto Different concentrations of known repellents, N, N diethyl-3-methylbenzamide (deet and Para-methane-3, 8, diol (PMD were added into traps baited with the synthetic blend, and resulting changes in mosquito catches were measured. Results All test concentrations of deet (0.001% to 100% reduced the attractiveness of the synthetic blend. However, PMD was repellent only at 0.25%. Above this concentration, it significantly increased the attractiveness of the blend. There was no relationship between the repellent concentrations and the change in mosquito catches when either deet (r2 = 0.033, P = 0.302 or PMD (r2 = 0.020, P = 0.578 was used. Conclusion It is concluded that while some repellents may reduce the attractiveness of synthetic human odours, others may instead increase their attractiveness. Such inconsistencies indicate that even though the synthetic attractants may provide exposure-free and consistent test media for repellents, careful selection and multiple-repellent tests are necessary to ascertain their suitability for use in repellent screening. The synthetic odour blend tested here is not yet sufficiently refined to serve as replacement for humans in repellent testing, but may be developed further and evaluated in different formats for exposure free repellent testing purposes.

Mbeyela Edgar

2009-07-01

328

KILLING IN THE NAME OF HONOUR AND TRADITION  

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Full Text Available Honour killing is the oppression and murder carried out in the name of culture, tradition, or religion, and the consequential confusion many Indians experience in the name of social familial honour. 'Honour killing' also known as 'customary killing' is the murder of a family or clan member by one or more family members where the murderers, essentially the community at wider scope thinks that the victim through his/her actions has brought disgrace to the family honour. This concept of honour is so deeply rooted in the traditional society that it acquires importance larger than the life of the family member itself. It is a crime which originates from the culture or race or one might even call it a cultural tradition.1 Indeed, recent research has made it amply clear that crimes committed to uphold honour are fairly widely spread not only across India but also in the entire Asian subcontinent. The phenomenon is unbelievable that in the 21st century, where India takes pride over its largest democracy, families murder their kith and kin for allegedly saving their honor. This paper is an attempt to highlight: 1The concept of honour killing; 2 honour killing in India, how it took its shape, and why its so hard to tackle with it 3the present legal system that stands to swipe this menace, and the views of Honorable courts on the subject.

PREETI MALIK

2013-06-01

329

Radiosensitizers as probes of DNA damage and cell killing  

International Nuclear Information System (INIS)

Effects have been compared of a series of hypoxic cell radiosensitizers on radiation-induced DNA damage and mammalian cell killing, in order to ascertain the nature of the critical radiation target site(s) involved. Sensitizer efficacy is determined by the ability to oxidize the radiation target and is found to increase exponentially with increasing electron affinity. The threshold redox potential, below which no sensitization occurs, corresponds to the oxidation potential of the target bioradical involved, and is characteristic, and useful in identification, of the particular radiation target. Model product analysis studies of DNA base damage, inorganic phosphate release, single-strand breaks and incorporation of radioactively labelled sensitizer into DNA show a correspondence between the electronic-affinic radiosensitization of DNA damage and cell killing. Comparison of the radiosensitization of different DNA sites and cell killing indicates that the sugar-phosphate backbone of DNA, not the heterocyclic bases, is the DNA target site which mimics cell killing in its threshold redox potential and overall radiosensitization response. These results suggest that the enhancement by electron-affinic drugs of radiation damage to the DNA backbone (strand breaks) correlates strongly with, and is the most likely cause of, the radiosensitization of hypoxic cell killing. (author)

1985-11-01

330

Potential impacts of climate change on the ecology of dengue and its mosquito vector the Asian tiger mosquito (Aedes albopictus)  

Science.gov (United States)

Shifts in temperature and precipitation patterns caused by global climate change may have profound impacts on the ecology of certain infectious diseases. We examine the potential impacts of climate change on the transmission and maintenance dynamics of dengue, a resurging mosquito-vectored infectious disease. In particular, we project changes in dengue season length for three cities: Atlanta, GA; Chicago, IL and Lubbock, TX. These cities are located on the edges of the range of the Asian tiger mosquito within the United States of America and were chosen as test cases. We use a disease model that explicitly incorporates mosquito population dynamics and high-resolution climate projections. Based on projected changes under the Special Report on Emissions Scenarios (SRES) A1fi (higher) and B1 (lower) emission scenarios as simulated by four global climate models, we found that the projected warming shortened mosquito lifespan, which in turn decreased the potential dengue season. These results illustrate the difficulty in predicting how climate change may alter complex systems.

Erickson, R. A.; Hayhoe, K.; Presley, S. M.; Allen, L. J. S.; Long, K. R.; Cox, S. B.

2012-09-01

331

Almost-Killing conserved currents: A general mass function  

Science.gov (United States)

A new class of conserved currents, describing nongravitational energy-momentum density, is presented. The proposed currents do not require the existence of a (timelike) Killing vector, and are not restricted to spherically symmetric spacetimes (or similar ones, in which the Kodama vector can be defined). They are based instead on almost-Killing vectors, which could in principle be defined on generic spacetimes. We provide local arguments, based on energy density profiles in highly simplified (stationary, rigidly rotating) star models, which confirm the physical interest of these almost-Killing currents. A mass function is defined in this way for the spherical case, qualitatively different from the Hernández-Misner mass function. An elliptic equation determining the new mass function is derived for the Tolman-Bondi spherically symmetric dust metrics, including a simple solution for the Oppenheimer-Snyder collapse. The equations for the nonsymmetric case are shown to be of a mixed elliptic-hyperbolic nature.

Ruiz, Milton; Palenzuela, Carlos; Bona, Carles

2014-01-01

332

Aeromonas salmonicida resistance to complement-mediated killing.  

Science.gov (United States)

The resistance of Aeromonas salmonicida to complement-mediated killing was investigated by using different strains and their isogenic mutants that had been previously characterized for their surface components. We found that the classical complement pathway is involved in serum killing of susceptible A. salmonicida strains, while the alternative complement pathway seems not to be involved. All of the A. salmonicida strains are able to activate complement, but the smooth strains (with or without the A-layer) are resistant to complement-mediated killing. The reasons for this resistance are that C3b may be bound far from the cell membrane and that it is rapidly degraded; therefore, the lytic final complex C5b-9 (membrane attack complex) is not formed. Isogenic rough mutants are serum sensitive because they bind more C3b than the smooth strains, and if C3b is not completely degraded, then the lytic complex (C5b-9) is formed. Images

Merino, S; Alberti, S; Tomas, J M

1994-01-01

333

Generalized killing equations and symmetries of spinning space  

International Nuclear Information System (INIS)

The authors derive a set of general conditions for the isometrics of d-dimensional spinning space. These equations constitute a Grassmann-valued extension of the Killing equations for ordinary space. They are realized as invariances of spinning-particle actions. Some general solutions for the extended Killing equations in arbitrary curved space are presented. Thus the spinning particle in d-dimensions can be shown to possess new types of (super-)symmetries, which transform the commuting and anti-commuting co-ordinates (X"?, ?"a) not only linearly, but also non-linearly. The authors present the algebra of these non-linear transformations. They give a complete solution of the generalized Killing-equations for flat spinning space and construct an infinite set of conserved charges. (author). 11 refs

1989-01-01

334

Reoxidation behavior in Al killed steel during casting; Al killed hagane ikomiji no yoko saisanka kyodo  

Energy Technology Data Exchange (ETDEWEB)

The kinetics of reoxidation of Al killed steel with slag and air were investigated in laboratory experiments using tammann furnace and in plant experiments using commercial 85 x 10{sup 3} kg tundish. Experimental results were discussed by the coupled reaction model. Observed apparent rate constants of [sol.Al] decreased with increasing (CaO)/(SiO{sub 2}) ratio in laboratory experiments and showed a good agreement with calculated ones. Flow rate of air leak at steady state was evaluated to be 3.0 x 10{sup -5} and 4.0 x 10{sup -4} m{sup 3}/s inside and outside of immersion tube in commercial tundish, respectively and was estimated to have little influence on reoxidation. Mass transfer coefficient in metal was estimated to be 6.0 x 10{sup -5} m/s based on the tundish mixing model and the coupled reaction model. Observed [sol.Al] in tundish decreased with increasing (%FeO) + (%MnO) value in ladle slag and showed a good agreement with calculated one by considering reoxidation in ladle and air leak at unsteady state. (author)

Higuchi, Y.; Tago, Y.; Fukagawa, S.; Kanai, T.; Muto, A. [Sumitomo Metal Industries, Ltd., Osaka (Japan)

1999-05-01

335

Small-stature emergent macrophytes and crepuscular sprinkler disturbance reduce mosquito abundance in wetland mesocosms.  

Science.gov (United States)

The impact of emergent macrophyte species and crepuscular sprinkler disturbance on mosquito abundance over a 2-year period was measured in wetland mesocosms. Mosquito oviposition and abundance of immature mosquitoes and aquatic invertebrates were monitored in monotypic plots of small-stature (height of mature stands 2 m) California bulrush (Schoenoplectus californicus) without or with daily sprinkler showers to deter mosquito egg laying. Relative to wetlands without operational sprinklers, oviposition by culicine mosquitoes was reduced by > 99% and immature mosquito abundance was reduced by > 90% by crepuscular sprinkler applications. Mosquito abundance or distribution in wetlands did not differ between the two bulrush species subjected to the sprinkler treatment. Alkali bulrush wetlands without daily sprinkler treatments contained more egg rafts but significantly fewer mosquito larvae than did California bulrush wetlands. Predaceous damselfly naiads were 3-5 times more abundant in alkali bulrush than in California bulrush. Stem density, rate of spread, and autumnal mortality of alkali bulrush were higher than for California bulrush. Replacement of large emergent macrophytes by smaller species may enhance the efficacy of integrated mosquito management programs to reduce mosquito-transmitted disease cycles associated with multipurpose constructed wetlands used worldwide for water reclamation and habitat restoration. PMID:24581369

Popko, David A; Walton, William E

2013-12-01

336

Adult survivorship of the dengue mosquito Aedes aegypti varies seasonally in central Vietnam.  

Science.gov (United States)

The survival characteristics of the mosquito Aedes aegypti affect transmission rates of dengue because transmission requires infected mosquitoes to survive long enough for the virus to infect the salivary glands. Mosquito survival is assumed to be high in tropical, dengue endemic, countries like Vietnam. However, the survival rates of wild populations of mosquitoes are seldom measured due the difficulty of predicting mosquito age. Hon Mieu Island in central Vietnam is the site of a pilot release of Ae. aegypti infected with a strain of Wolbachia pipientis bacteria (wMelPop) that induces virus interference and mosquito life-shortening. We used the most accurate mosquito age grading approach, transcriptional profiling, to establish the survival patterns of the mosquito population from the population age structure. Furthermore, estimations were validated on mosquitoes released into a large semi-field environment consisting of an enclosed house, garden and yard to incorporate natural environmental variability. Mosquito survival was highest during the dry/cool (January-April) and dry/hot (May-August) seasons, when 92 and 64% of Hon Mieu mosquitoes had survived to an age that they were able to transmit dengue (12 d), respectively. This was reduced to 29% during the wet/cool season from September to December. The presence of Ae. aegypti older than 12 d during each season is likely to facilitate the observed continuity of dengue transmission in the region. We provide season specific Ae. aegypti survival models for improved dengue epidemiology and evaluation of mosquito control strategies that aim to reduce mosquito survival to break the dengue transmission cycle. PMID:24551251

Hugo, Leon E; Jeffery, Jason A L; Trewin, Brendan J; Wockner, Leesa F; Nguyen, Thi Yen; Nguyen, Hoang Le; Nghia, Le Trung; Hine, Emma; Ryan, Peter A; Kay, Brian H

2014-02-01

337

The Risk of a Mosquito-Borne Infectionin a Heterogeneous Environment  

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Full Text Available A common assumption about malaria, dengue, and other mosquito-borne infections is that the two main components of the risk of human infection-the rate at which people are bitten (human biting rate and the proportion of mosquitoes that are infectious-are positively correlated. In fact, these two risk factors are generated by different processes and may be negatively correlated across space and time in heterogeneous environments. Uneven distribution of blood-meal hosts and larval habitat creates a spatial mosaic of demograPhic sources and sinks. Moreover, mosquito populations fluctuate temporally, forced by environmental variables such as rainfall, temperature, and humidity. These sources of spatial and temporal heterogeneity in the distribution of mosquito populations generate variability in the human biting rate, in the proportion of mosquitoes that are infectious, and in the risk of human infection. To understand how heterogeneity affects the epidemiology of mosquito-borne infections, we developed a set of simple models that incorporate heterogeneity in a stepwise fashion. These models predict that the human biting rate is highest shortly after the mosquito densities peak, near breeding sites where adult mosquitoes emerge, and around the edges of areas where humans are aggregated. In contrast, the proportion of mosquitoes that are infectious reflects the age structure of mosquito populations; it peaks where old mosquitoes are found, far from mosquito breeding habitat, and when mosquito population density is declining. Finally, we show that estimates for the average risk of infection that are based on the average entomological inoculation rate are strongly biased in heterogeneous environments.

Smith David L

2004-01-01

338

Adult Survivorship of the Dengue Mosquito Aedes aegypti Varies Seasonally in Central Vietnam  

Science.gov (United States)

The survival characteristics of the mosquito Aedes aegypti affect transmission rates of dengue because transmission requires infected mosquitoes to survive long enough for the virus to infect the salivary glands. Mosquito survival is assumed to be high in tropical, dengue endemic, countries like Vietnam. However, the survival rates of wild populations of mosquitoes are seldom measured due the difficulty of predicting mosquito age. Hon Mieu Island in central Vietnam is the site of a pilot release of Ae. aegypti infected with a strain of Wolbachia pipientis bacteria (wMelPop) that induces virus interference and mosquito life-shortening. We used the most accurate mosquito age grading approach, transcriptional profiling, to establish the survival patterns of the mosquito population from the population age structure. Furthermore, estimations were validated on mosquitoes released into a large semi-field environment consisting of an enclosed house, garden and yard to incorporate natural environmental variability. Mosquito survival was highest during the dry/cool (January-April) and dry/hot (May-August) seasons, when 92 and 64% of Hon Mieu mosquitoes had survived to an age that they were able to transmit dengue (12 d), respectively. This was reduced to 29% during the wet/cool season from September to December. The presence of Ae. aegypti older than 12 d during each season is likely to facilitate the observed continuity of dengue transmission in the region. We provide season specific Ae. aegypti survival models for improved dengue epidemiology and evaluation of mosquito control strategies that aim to reduce mosquito survival to break the dengue transmission cycle.

Hugo, Leon E.; Jeffery, Jason A. L.; Trewin, Brendan J.; Wockner, Leesa F.; Thi Yen, Nguyen; Le, Nguyen Hoang; Nghia, Le Trung; Hine, Emma; Ryan, Peter A.; Kay, Brian H.

2014-01-01

339

Role of copper oxides in contact killing of bacteria.  

Science.gov (United States)

The potential of metallic copper as an intrinsically antibacterial material is gaining increasing attention in the face of growing antibiotics resistance of bacteria. However, the mechanism of the so-called "contact killing" of bacteria by copper surfaces is poorly understood and requires further investigation. In particular, the influences of bacteria-metal interaction, media composition, and copper surface chemistry on contact killing are not fully understood. In this study, copper oxide formation on copper during standard antimicrobial testing was measured in situ by spectroscopic ellipsometry. In parallel, contact killing under these conditions was assessed with bacteria in phosphate buffered saline (PBS) or Tris-Cl. For comparison, defined Cu2O and CuO layers were thermally generated and characterized by grazing incidence X-ray diffraction. The antibacterial properties of these copper oxides were tested under the conditions used above. Finally, copper ion release was recorded for both buffer systems by inductively coupled plasma atomic absorption spectroscopy, and exposed copper samples were analyzed for topographical surface alterations. It was found that there was a fairly even growth of CuO under wet plating conditions, reaching 4-10 nm in 300 min, but no measurable Cu2O was formed during this time. CuO was found to significantly inhibit contact killing, compared to pure copper. In contrast, thermally generated Cu2O was essentially as effective in contact killing as pure copper. Copper ion release from the different surfaces roughly correlated with their antibacterial efficacy and was highest for pure copper, followed by Cu2O and CuO. Tris-Cl induced a 10-50-fold faster copper ion release compared to PBS. Since the Cu2O that primarily forms on copper under ambient conditions is as active in contact killing as pure copper, antimicrobial objects will retain their antimicrobial properties even after oxide formation. PMID:24344971

Hans, Michael; Erbe, Andreas; Mathews, Salima; Chen, Ying; Solioz, Marc; Mücklich, Frank

2013-12-31

340

Humane killing of animals for disease control purposes.  

Science.gov (United States)

Killing for disease control purposes is an emotional issue for everyone concerned. Large-scale euthanasia or depopulation of animals may be necessary for the emergency control or eradication of animal diseases, to remove animals from a compromised situation (e.g. following flood, storm, fire, drought or a feed contamination event), to effect welfare depopulation when there is an oversupply due to a dysfunctional or closed marketing channel, or to depopulate and dispose of animals with minimal handling to decrease the risk of a zoonotic disease infecting humans. The World Organisation for Animal Health (OIE) developed international standards to provide advice on humane killing for various species and situations. Some fundamental issues are defined, such as competency of animal handling and implementation of humane killing techniques. Some of these methods have been used for many years, but novel approaches for the mass killing of particular species are being explored. Novel vaccines and new diagnostic techniques that differentiate between vaccinated and infected animals will save many animals from being killed as part of biosecurity response measures. Unfortunately, the destruction of affected livestock will still be required to control diseases whilst vaccination programmes are activated or where effective vaccines are not available. This paper reviews the principles of humane destruction and depopulation and explores available techniques with their associated advantages and disadvantages. It also identifies some current issues that merit consideration, such as legislative conflicts (emergency disease legislation versus animal welfare legislation, occupational health and safety), media issues, opinions on the future approaches to killing for disease control, and animal welfare. PMID:25000803

Thornber, P M; Rubira, R J; Styles, D K

2014-04-01

 
 
 
 
341

How Moist Heat Kills Spores of Bacillus subtilis?  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Populations of Bacillus subtilis spores in which 90 to 99.9% of the spores had been killed by moist heat gave only two fractions on equilibrium density gradient centrifugation: a fraction comprised of less dense spores that had lost their dipicolinic acid (DPA), undergone significant protein denaturation, and were all dead and a fraction with the same higher density as that of unheated spores. The latter fraction from heat-killed spore populations retained all of its DPA, but ?98% of the sp...

Coleman, William H.; Chen, De; Li, Yong-qing; Cowan, Ann E.; Setlow, Peter

2007-01-01

342

Radiolabel release microassay for phagocytic killing of Candida albicans  

Energy Technology Data Exchange (ETDEWEB)

The chromium-51 release technique for quantifying intracellular killing of radiolabelled Candida albicans particles was exploited in a microassay in which murine and human phagocytes acted as effectors under peculiarly simple conditions. At appropriate effector: target ratios and with a 4 h incubation, up to 50% specific chromium release could be detected in the supernatant with no need for opsonization or lysis of phagocytes. This simple microassay permits easy-to-perform, simultaneous testing of a variety of different phagocytes even if only available in limited amounts, and provides an objective measurement of intracellular killing of Candida albicans.

Bistoni, F.; Baccarini, M.; Blasi, E.; Marconi, P. (Perugia Univ. (Italy). Inst. of Microbiology); Puccetti, P. (Perugia Univ. (Italy). Inst. of Pharmacology)

1982-08-13

343

A radiolabel release microassay for phagocytic killing of Candida albicans  

International Nuclear Information System (INIS)

The chromium-51 release technique for quantifying intracellular killing of radiolabelled Candida albicans particles was exploited in a microassay in which murine and human phagocytes acted as effectors under peculiarly simple conditions. At appropriate effector: target ratios and with a 4 h incubation, up to 50% specific chromium release could be detected in the supernatant with no need for opsonization or lysis of phagocytes. This simple microassay permits easy-to-perform, simultaneous testing of a variety of different phagocytes even if only available in limited amounts, and provides an objective measurement of intracellular killing of Candida albicans. (Auth.)

1982-08-13

344

Class of spherically symmetric solutions with conformal killing vectors  

Energy Technology Data Exchange (ETDEWEB)

Spherically symmetric solutions with a conformal Killing vector in the (r,t) surface allow the null geodesics to be found with relative ease. Knowledge of the null geodesics is essential to calculating the optical properties of a solution via the optical scalar equations. Solutions of this type may be useful for the treatment of the optical properties of an inhomogeneous universe. The authors first address the question of whether the large class of spherically symmetric solutions found by McVitte possess conformal symmetry. They also investigate the potential for using conformal Killing vectors to aid in the solution of Einstein's Field Equations.

Dyer, C.C.; McVittie, G.C.; Oattes, L.M.

1987-09-01

345

Registros de mayor altitud para mosquitos (Diptera: Culicidae en Venezuela  

Directory of Open Access Journals (Sweden)

Full Text Available Los mosquitos (Diptera: Culicidae son insectos holometábolos con estadios inmaduros acuáticos que utilizan una amplia variedad de hábitats larvales, desde cuerpos de agua en el suelo hasta Fitotelmata (depósitos de agua en las plantas y depósitos artificiales. La disponibilidad de sitios de reproducción a menudo determina el límite superior del ámbito de los mosquitos. Nosotros construimos una base de datos de 9 607 registros, 432 localidades, 19 géneros y 254 especies. La coordillera Andina posee el 77% de los registros con mayor altitud incluyendo Aedes euris con un registro a 3 300 m, seguido por tres especies de Anopheles -subgénero Kerteszia- con una altitud máxima de 2 680 m. Wyeomyia bicornis y Culex daumastocampa a 2 550 m fueron los registros de mayor altitud en la cordillera Costera- Central, mientras que el record más alto en Pantepui fue Wyeomyia zinzala a 2 252 m. El 60% de los registros de máxima altitud están representados por especies asociadas con fitotelmata (Bromeliaceae y Sarraceniaceae. Los límites superiores de Culex quinquefasciatus y Anopheles (Kerteszia podría representar el límite teórico para la transmisión de filariasis o arbovirus, por Culex y malaria por Anopheles (Kerteszia en Venezuela. Del mismo modo, un vector del dengue, Aedes aegypti, no ha sido registrado por encima de 2 000 m.Highest mosquito records (Diptera: Culicidae in Venezuela. Mosquitoes (Diptera: Culicidae are holometabolous insects with aquatic immature stages, which use a broad variety of larval habitats, from ground water bodies to Phytothelmata (water deposits in plants and artificial deposits. The availability of breeding sites often determines the upper limits of mosquito ranges. We built a database with 9 607 records with 432 localities, 19 genera and 254 species. The Andean mountains have 77% of the highest mosquito records including Aedes euris with record at 3 133 m, followed by three species of Anopheles -subgenera Kerteszia- with the upper limit of 2 680 m. Wyeomyia bicornis and Culex daumastocampa at 2 550 m were the highest records in the Central- Coastal cordillera, while the highest record in Pantepui was Wyeomyia zinzala at 2 252 m. The species associated with phytothelmata (Bromeliaceae and Sarraceniaceae represent 60% of the records. The upper limits of Culex quinquefasciatus and Anopheles (Kerteszia species could represent the theoretical limit for transmission of filariasis or arboviruses, by Culex, and malaria by Anopheles (Kerteszia in Venezuela. Similarly, a vector of Dengue, Aedes aegypti, has not been not recorded above 2 000 m. Rev. Biol. Trop. 58 (1: 245-254. Epub 2010 March 01.

Juan-Carlos Navarro

2010-03-01

346

Transcriptome of the adult female malaria mosquito vector Anopheles albimanus  

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Full Text Available Abstract Background Human Malaria is transmitted by mosquitoes of the genus Anopheles. Transmission is a complex phenomenon involving biological and environmental factors of humans, parasites and mosquitoes. Among more than 500 anopheline species, only a few species from different branches of the mosquito evolutionary tree transmit malaria, suggesting that their vectorial capacity has evolved independently. Anopheles albimanus (subgenus Nyssorhynchus is an important malaria vector in the Americas. The divergence time between Anopheles gambiae, the main malaria vector in Africa, and the Neotropical vectors has been estimated to be 100 My. To better understand the biological basis of malaria transmission and to develop novel and effective means of vector control, there is a need to explore the mosquito biology beyond the An. gambiae complex. Results We sequenced the transcriptome of the An. albimanus adult female. By combining Sanger, 454 and Illumina sequences from cDNA libraries derived from the midgut, cuticular fat body, dorsal vessel, salivary gland and whole body, we generated a single, high-quality assembly containing 16,669 transcripts, 92% of which mapped to the An. darlingi genome and covered 90% of the core eukaryotic genome. Bidirectional comparisons between the An. gambiae, An. darlingi and An. albimanus predicted proteomes allowed the identification of 3,772 putative orthologs. More than half of the transcripts had a match to proteins in other insect vectors and had an InterPro annotation. We identified several protein families that may be relevant to the study of Plasmodium-mosquito interaction. An open source transcript annotation browser called GDAV (Genome-Delinked Annotation Viewer was developed to facilitate public access to the data generated by this and future transcriptome projects. Conclusions We have explored the adult female transcriptome of one important New World malaria vector, An. albimanus. We identified protein-coding transcripts involved in biological processes that may be relevant to the Plasmodium lifecycle and can serve as the starting point for searching targets for novel control strategies. Our data increase the available genomic information regarding An. albimanus several hundred-fold, and will facilitate molecular research in medical entomology, evolutionary biology, genomics and proteomics of anopheline mosquito vectors. The data reported in this manuscript is accessible to the community via the VectorBase website (http://www.vectorbase.org/Other/AdditionalOrganisms/.

Martínez-Barnetche Jesús

2012-05-01

347

Registros de mayor altitud para mosquitos (Diptera: Culicidae) en Venezuela  

Scientific Electronic Library Online (English)

Full Text Available SciELO Costa Rica | Language: Spanish Abstract in spanish Los mosquitos (Diptera: Culicidae) son insectos holometábolos con estadios inmaduros acuáticos que utilizan una amplia variedad de hábitats larvales, desde cuerpos de agua en el suelo hasta Fitotelmata (depósitos de agua en las plantas) y depósitos artificiales. La disponibilidad de sitios de reprod [...] ucción a menudo determina el límite superior del ámbito de los mosquitos. Nosotros construimos una base de datos de 9 607 registros, 432 localidades, 19 géneros y 254 especies. La coordillera Andina posee el 77% de los registros con mayor altitud incluyendo Aedes euris con un registro a 3 300 m, seguido por tres especies de Anopheles -subgénero Kerteszia- con una altitud máxima de 2 680 m. Wyeomyia bicornis y Culex daumastocampa a 2 550 m fueron los registros de mayor altitud en la cordillera Costera- Central, mientras que el record más alto en Pantepui fue Wyeomyia zinzala a 2 252 m. El 60% de los registros de máxima altitud están representados por especies asociadas con fitotelmata (Bromeliaceae y Sarraceniaceae). Los límites superiores de Culex quinquefasciatus y Anopheles (Kerteszia) podría representar el límite teórico para la transmisión de filariasis o arbovirus, por Culex y malaria por Anopheles (Kerteszia) en Venezuela. Del mismo modo, un vector del dengue, Aedes aegypti, no ha sido registrado por encima de 2 000 m. Abstract in english Highest mosquito records (Diptera: Culicidae) in Venezuela. Mosquitoes (Diptera: Culicidae) are holometabolous insects with aquatic immature stages, which use a broad variety of larval habitats, from ground water bodies to Phytothelmata (water deposits in plants) and artificial deposits. The availab [...] ility of breeding sites often determines the upper limits of mosquito ranges. We built a database with 9 607 records with 432 localities, 19 genera and 254 species. The Andean mountains have 77% of the highest mosquito records including Aedes euris with record at 3 133 m, followed by three species of Anopheles -subgenera Kerteszia- with the upper limit of 2 680 m. Wyeomyia bicornis and Culex daumastocampa at 2 550 m were the highest records in the Central- Coastal cordillera, while the highest record in Pantepui was Wyeomyia zinzala at 2 252 m. The species associated with phytothelmata (Bromeliaceae and Sarraceniaceae) represent 60% of the records. The upper limits of Culex quinquefasciatus and Anopheles (Kerteszia) species could represent the theoretical limit for transmission of filariasis or arboviruses, by Culex, and malaria by Anopheles (Kerteszia) in Venezuela. Similarly, a vector of Dengue, Aedes aegypti, has not been not recorded above 2 000 m. Rev. Biol. Trop. 58 (1): 245-254. Epub 2010 March 01.

Juan-Carlos, Navarro; Fabiola, Del Ventura; Adriana, Zorrilla; Jonathan, Liria.

348

[A mosquito net for everyone in 2010].  

Science.gov (United States)

At less than two hundred days of the 2010 deadline for the "Roll Back Malaria" initiative which committed itself to reduce by half, before that date, mortality due to malaria in the world and relying on the latest WHO reports pointing out, in Africa, major shortcomings concerning the accessibility to treatment combinations consisting of artemisinin and on the acknowledged fact that an insufficient number of pregnant women receive an intermittent treatment, the author notes that a coverage, so-called universal, with the use of long action insecticide treated mosquito nets has become the Grail of the battle against malaria, with the perverse effects entailed, namely that of blinding realities or throwing discredit on other types of possible interventions that are not consistent with an accounting logic. He also notes that the average figure of estimated deaths due to malaria was at a quasi stagnation in 2008 and that the lives of 34,000 African children of less than 5 years of age saved between 2006 and 2008 was achieved in the context of the reduction in infant mortality resulting from a series of causes among which it is impossible to individualise malaria with certainty. He finally points out that Eritrea, Rwanda, Zambia, São Tome y Principe and the Tanzanian island of Zanzibar which quite regularly serve as showcases to RBM and UNICEF and which report spectacular progress in the field of prevention of malaria accompanied by a parallel reduction in its mortality, are, for different reasons, far from being representative of the totality of African countries and that they should be considered as exceptions rather than examples to be exploited without restraint. On the other hand, the author considers that deluding the grand public into thinking that a few watchwords, slogans and simple, even simplistic, ideas would enable eradicating malaria given that large sums of money are made available, is not quite honest and may finally prove to be dangerous. He warns against the false hopes concerning the impact of coming discoveries on the antimalarial battle often conjured up to take over today's actions, by recalling that a century of scientific, technological and medical progress has not positively translated into any decisive progress in the prevention or treatment of this disease, in spite of the issue of scientific publications on the subject at every 20 minute interval since more than thirty years. Although the author willingly agrees that huge financial means are essential and for a long time to come, he however believes that they would not suffice to enable, in countries with high rates of transmission, the elimination of a disease that is not solely linked to biological, ecological and entomological parameters, but that is also anchored to the economic, societal, social and cultural contexts that are quite often forgotten and on which it is difficult, but essential, to act in order to obtain long lasting results. He recalls, on this occasion, that man, as an individual in relationship with his surroundings, should also be at the heart of the battle on the same footing as the anopheles and the plasmodium, even if this, at times, leads to clashes between medical logic and native social, traditional, popular, scholarly or religious logics. He regrets, similarly and within the spirit of the Abuja declaration, that the educational systems of African countries having a high transmission rate do not play the role they had to assume in the battle against malaria and are not mobilised much better than they are, by including, for example, in the primary and secondary curriculum of public and private schools, on the same footing as the learning of the alphabet or of the multiplication tables, a compulsory adapted instruction in malaria, so that children not only become victims but also "actors in the battle against malaria". The author finally underlines the absolute necessity to rapidly strengthen health care facilities of the most affected countries, particularly in the rural area, and plead that this intens

Pays, J-F

2010-10-01

349

Altitudinal distribution of mosquitoes in mountainous area of Garhwal region : Part–I  

Directory of Open Access Journals (Sweden)

Full Text Available Background & objectives : Mosquito fauna diversity in mountainous areas of Garhwal region wasstudied during November 2000 to October 2002 to correlate the altitudinal vegetation and distributionof mosquitoes.Methods : Adult mosquitoes and mosquito immatures were collected using WHO methods and identifiedusing standard keys and catalogues. Altitude of mosquito habitat was measured using portablealtimeter and also by GPS.Results : Altogether 34 species in five genera — Aedes, Anopheles, Armigeres, Culex and Uranotaeniawere encountered in the present study in the altitude range of 300 to 2000 m. Majority of themosquitoes were found in between 300 to 900 m altitude except Culex vagus and Anopheles maculatus,which were found throughout the range.Interpretation & conclusion : The mosquitoes were categorised into six groups based on their altitudinaldistribution. The areas at lowest elevation were having the greatest number of species but notthe corresponding greater number of specimens in the present study.

N. Pemola Devi , R.K. Jauhari

2004-03-01

350

Transmission of malaria to mosquitoes blocked by bumped kinase inhibitors.  

Science.gov (United States)

Effective control and eradication of malaria will require new tools to prevent transmission. Current antimalarial therapies targeting the asexual stage of Plasmodium do not prevent transmission of circulating gametocytes from infected humans to mosquitoes. Here, we describe a new class of transmission-blocking compounds, bumped kinase inhibitors (BKIs), which inhibit microgametocyte exflagellation. Oocyst formation and sporozoite production, necessary for transmission to mammals, were inhibited in mosquitoes fed on either BKI-1-treated human blood or mice treated with BKI-1. BKIs are hypothesized to act via inhibition of Plasmodium calcium-dependent protein kinase 4 and predicted to have little activity against mammalian kinases. Our data show that BKIs do not inhibit proliferation of mammalian cell lines and are well tolerated in mice. Used in combination with drugs active against asexual stages of Plasmodium, BKIs could prove an important tool for malaria control and eradication. PMID:22565309

Ojo, Kayode K; Pfander, Claudia; Mueller, Natascha R; Burstroem, Charlotte; Larson, Eric T; Bryan, Cassie M; Fox, Anna M W; Reid, Molly C; Johnson, Steven M; Murphy, Ryan C; Kennedy, Mark; Mann, Henning; Leibly, David J; Hewitt, Stephen N; Verlinde, Christophe L M J; Kappe, Stefan; Merritt, Ethan A; Maly, Dustin J; Billker, Oliver; Van Voorhis, Wesley C

2012-06-01

351

Illustrated keys to the anopheline mosquitoes of Myanmar.  

Science.gov (United States)

In the newly revised and illustrated keys to 4th instar larvae and adult female mosquitoes, the following 36 Anopheles species from Myanmar are included: Anopheles aconitus, An. aitkenii, An. annularis, An. argyropus, An. barbirostris, An. bengalensis, An. culicifacies, An. dirus, An. fluviatilis, An. gigas, An. insulaeflorum, An. jamesii, An. jeyporensis, An. karwari, An. kochi, An. kyondawensis, An. lindesayi, An. maculatus, An. majidi, An. minimus, An. nigerrimus, An. nitidus, An. pallidus, An. peditaeniatus, An. philippinensis, An. pseudojamesii, An. sinensis, An. splendidus, An. stephensi, An. subpictus, An. sundaicus, An. tessellatus, An. theobaldi, An. vagus, An. varuna, and An. willmori. The new keys presented in this paper will enable public health workers to rapidly identify mosquito vectors of malaria and to distinguish them from other species in the same genera. PMID:16859085

Oo, Thin Thin; Kaiser, Achim; Becker, Norbert

2006-06-01

352

Larvicidal activity of neem oil (Azadirachta indica) formulation against mosquitoes  

Science.gov (United States)

Background Mosquitoes transmit serious human diseases, causing millions of deaths every year. Use of synthetic insecticides to control vector mosquitoes has caused physiological resistance and adverse environmental effects in addition to high operational cost. Insecticides of botanical origin have been reported as useful for control of mosquitoes. Azadirachta indica (Meliaceae) and its derived products have shown a variety of insecticidal properties. The present paper discusses the larvicidal activity of neem-based biopesticide for the control of mosquitoes. Methods Larvicidal efficacy of an emulsified concentrate of neem oil formulation (neem oil with polyoxyethylene ether, sorbitan dioleate and epichlorohydrin) developed by BMR & Company, Pune, India, was evaluated against late 3rd and early 4th instar larvae of different genera of mosquitoes. The larvae were exposed to different concentrations (0.5–5.0 ppm) of the formulation along with untreated control. Larvicidal activity of the formulation was also evaluated in field against Anopheles, Culex, and Aedes mosquitoes. The formulation was diluted with equal volumes of water and applied @ 140 mg a.i./m2 to different mosquito breeding sites with the help of pre calibrated knapsack sprayer. Larval density was determined at pre and post application of the formulation using a standard dipper. Results Median lethal concentration (LC50) of the formulation against Anopheles stephensi, Culex quinquefasciatus and Aedes aegypti was found to be 1.6, 1.8 and 1.7 ppm respectively. LC50 values of the formulation stored at 26°C, 40°C and 45°C for 48 hours against Ae. aegypti were 1.7, 1.7, 1.8 ppm while LC90 values were 3.7, 3.7 and 3.8 ppm respectively. Further no significant difference in LC50 and LC90 values of the formulation was observed against Ae. aegypti during 18 months storage period at room temperature. An application of the formulation at the rate of 140 mg a.i./m2 in different breeding sites under natural field conditions provided 98.1% reduction of Anopheles larvae on day 1; thereafter 100% reduction was recorded up to week 1 and more than 80% reduction up to week 3, while percent reduction against Culex larvae was 95.5% on day 1, and thereafter 80% reduction was achieved up to week 3. The formulation also showed 95.1% and, 99.7% reduction of Aedes larvae on day 1 and day 2 respectively; thereafter 100% larval control was observed up to day 7. Conclusion The neem oil formulation was found effective in controlling mosquito larvae in different breeding sites under natural field conditions. As neem trees are widely distributed in India, their formulations may prove to be an effective and eco-friendly larvicide, which could be used as an alternative for malaria control.

Dua, Virendra K; Pandey, Akhilesh C; Raghavendra, Kamaraju; Gupta, Ashish; Sharma, Trilochan; Dash, Aditya P

2009-01-01

353

Larvicidal activity of neem oil (Azadirachta indica formulation against mosquitoes  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Mosquitoes transmit serious human diseases, causing millions of deaths every year. Use of synthetic insecticides to control vector mosquitoes has caused physiological resistance and adverse environmental effects in addition to high operational cost. Insecticides of botanical origin have been reported as useful for control of mosquitoes. Azadirachta indica (Meliaceae and its derived products have shown a variety of insecticidal properties. The present paper discusses the larvicidal activity of neem-based biopesticide for the control of mosquitoes. Methods Larvicidal efficacy of an emulsified concentrate of neem oil formulation (neem oil with polyoxyethylene ether, sorbitan dioleate and epichlorohydrin developed by BMR & Company, Pune, India, was evaluated against late 3rd and early 4th instar larvae of different genera of mosquitoes. The larvae were exposed to different concentrations (0.5–5.0 ppm of the formulation along with untreated control. Larvicidal activity of the formulation was also evaluated in field against Anopheles, Culex, and Aedes mosquitoes. The formulation was diluted with equal volumes of water and applied @ 140 mg a.i./m2 to different mosquito breeding sites with the help of pre calibrated knapsack sprayer. Larval density was determined at pre and post application of the formulation using a standard dipper. Results Median lethal concentration (LC50 of the formulation against Anopheles stephensi, Culex quinquefasciatus and Aedes aegypti was found to be 1.6, 1.8 and 1.7 ppm respectively. LC50 values of the formulation stored at 26°C, 40°C and 45°C for 48 hours against Ae. aegypti were 1.7, 1.7, 1.8 ppm while LC90 values were 3.7, 3.7 and 3.8 ppm respectively. Further no significant difference in LC50 and LC90 values of the formulation was observed against Ae. aegypti during 18 months storage period at room temperature. An application of the formulation at the rate of 140 mg a.i./m2 in different breeding sites under natural field conditions provided 98.1% reduction of Anopheles larvae on day 1; thereafter 100% reduction was recorded up to week 1 and more than 80% reduction up to week 3, while percent reduction against Culex larvae was 95.5% on day 1, and thereafter 80% reduction was achieved up to week 3. The formulation also showed 95.1% and, 99.7% reduction of Aedes larvae on day 1 and day 2 respectively; thereafter 100% larval control was observed up to day 7. Conclusion The neem oil formulation was found effective in controlling mosquito larvae in different breeding sites under natural field conditions. As neem trees are widely distributed in India, their formulations may prove to be an effective and eco-friendly larvicide, which could be used as an alternative for malaria control.

Dua Virendra K

2009-06-01

354

BIOACTIVIDAD DE ACEITES ESENCIALES DE Minthostachys mollis CONTRA MOSQUITOS  

Directory of Open Access Journals (Sweden)

Full Text Available El control químico de vectores es una herramienta principal de prevención de enfermedades transmitidas por mosquitos. Los aceites esenciales (AE de plantas pueden ser una alternativa a los compuestos sintéticos. Se extrajeron por arrastre con vapor AE de Minthostachys mollis y se evaluó su actividad insecticida contra larvas, pupas y adultos de mosquitos, según protocolos estándar de la Organización Mundial de la Salud. Se evaluaron concentraciones entre 10 y 160 ppm del AE y se registró la mortalidad a las 1, 2, 3 y 24 h de exposición. La dosis de 160 ppm mostró una clara actividad insecticida en larvas y adultos, pero no en pupas. Los resultados sugieren que este aceite puede tener potencial como insecticida y merita mayores estudios.

Julio A. Zygadlo

2007-01-01

355

Killing-Yano tensors and multi-hermitian structures  

CERN Document Server

We show that the Euclidean Kerr-NUT-(A)dS metric in $2m$ dimensions locally admits $2^m$ hermitian complex structures. These are derived from the existence of a non-degenerate closed conformal Killing-Yano tensor with distinct eigenvalues. More generally, a conformal Killing-Yano tensor, provided its exterior derivative satisfies a certain condition, algebraically determines $2^m$ almost complex structures that turn out to be integrable as a consequence of the conformal Killing-Yano equations. In the complexification, these lead to $2^m$ maximal isotropic foliations of the manifold and, in Lorentz signature, these lead to two congruences of null geodesics. These are not shear-free, but satisfy a weaker condition that also generalizes the shear-free condition from 4-dimensions to higher-dimensions. In odd dimensions, a conformal Killing-Yano tensor leads to similar integrable distributions in the complexification. We show that the recently discovered 5-dimensional solution of Lu, Mei and Pope also admits such ...

Mason, Lionel

2008-01-01

356

Requirements Comparison Hit-To-Kill vs Warhead for TMD.  

Science.gov (United States)

There has been recent interest in usage of conventional blast fragmentation warheads in a TMD role. This interest implies a perception that this approach would be easier to accomplish than Hit-To-Kill (HTK), and would yield comparable lethality. The first...

A. Sleiman J. L. Harris

1999-01-01

357

Killing spinors according to O. Hijazi and applications  

International Nuclear Information System (INIS)

A survey on the Killing spinors, mainly connected with the results of Hijazi concerning the lower bound for the absolute values of the eigenvalues of the Dirac operator of a compact spin manifold in terms of conformal geometry, as well as some of the author's results are given. 17 refs

1988-01-01

358

Seeking authority to kill poultry during bird flu ... - ARCHIVE: Defra  

would be impracticable to use another permitted method of killing in the \\individual ..... House height. 4m. Est. house volume m3 (length x width x height). \\18.3 x 61 .... health and there are no alternative that we can use in this case, VSD \\should.

359

Killing for Girls: Predation Play and Female Empowerment  

Science.gov (United States)

Predation games--games in which the player is actively encouraged and often required to hunt and kill in order to survive--have historically been the purview of male players. Females, though now much more involved in digital games than before, generally play games that stress traditionally feminine values such as socializing with others, shopping,…

Bertozzi, Elena

2012-01-01

360

Type-D space-times with a Killing tensor  

International Nuclear Information System (INIS)

Conditions under which a vacuum type-D space-time admits a regular S_2 separability structure are investigated. It is shown that all vacuum type-D space-times without acceleration admit such a structure. It turns out that the structure is completely determined by the Killing tensor and the metric. (author)

1981-01-01

 
 
 
 
361

Szekeres's space-time have no killing vectors  

International Nuclear Information System (INIS)

Szekeres (Commun. Math. Phys.; 41:55 (1975), Phys. Rev. D.; 12:2941 (1975)) obtained some exact solutions of Einstein's equations for dust which have applications in cosmology, in the theory of collapse, and in the study of gravitational radiation. It is shown that in their most general form these space-times have no Killing vectors. (author)

1977-01-01

362

Heat shock proteins contribute to mosquito dehydration tolerance  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This study examines the responses of heat shock protein transcripts, Hsp70 and Hsp90, to dehydration stress in three mosquito species, Aedes aegypti, Anopheles gambiae and Culex pipiens. We first defined the water balance attributes of adult females of each species, monitored expression of the hsp transcripts in response to dehydration, and then knocked down expression of the transcripts using RNA interference (RNAi) to evaluate potential functions of the Hsps in maintenance of water balance....

Benoit, Joshua B.; Lopez-martinez, Giancarlo; Phillips, Zachary P.; Patrick, Kevin R.; Denlinger, David L.

2010-01-01

363

Genome of Invertebrate Iridescent Virus Type 3 (Mosquito Iridescent Virus)  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Iridoviruses (IVs) are classified into five genera: Iridovirus and Chloriridovirus, whose members infect invertebrates, and Ranavirus, Lymphocystivirus, and Megalocytivirus, whose members infect vertebrates. Until now, Chloriridovirus was the only IV genus for which a representative and complete genomic sequence was not available. Here, we report the genome sequence and comparative analysis of a field isolate of Invertebrate iridescent virus type 3 (IIV-3), also known as mosquito iridescent v...

Delhon, Gustavo; Tulman, Edan R.; Afonso, Claudio L.; Lu, Zhiqiang; Becnel, James J.; Moser, Bettina A.; Kutish, Gerald F.; Rock, Daniel L.

2006-01-01

364

Brazilian dengue virus type 1 replication in mosquito cell cultures  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The development of dengue viruses type 1 obtained from accute human sera and inoculated into mosquito cell cultures, was observed by standard transmission electron microscopy and cytochemical staining. It follows the trans-type mechanism already estabilished of other dengue types. Directed passage of single virus particles across the cell membrane seems to be a pathway of entry and exit in dengue-1 infected cells. The nature of numerous electron translucent vesicles and tubules, produced simm...

Ortrud Monika Barth; Schatzmayr, Hermann G.

1992-01-01

365

An improved trap to capture adult container-inhabiting mosquitoes.  

Science.gov (United States)

Although dengue viruses are thought to be transmitted by Aedes aegypti in Puerto Rico, Aedes mediovittatus, the Caribbean tree hole mosquito, is also a potential vector. This species is native to the Greater Antilles and has been shown to be a competent vector of dengue viruses in the laboratory. Consequently, it has been suggested that Ae. mediovittatus could be acting as a secondary vector or virus reservoir. This study was part of an ongoing investigation into this, and it aimed to determine whether BG-Sentinel traps (BGS traps) could be used to collect adults of this mosquito and could be modified to increase the number of captures of this species in the field. We conducted experiments to test the relative attractiveness of BGS traps to Ae. mediovittatus and Ae. aegypti and explored the effects of chemical lures (BG-Lure, CO2, octenol) and optical properties (color, size) on the capture rates of BGS traps in a large, outdoor cage in San Juan city, Puerto Rico. We also conducted field tests to compare modified BGS traps with the original traps in a rural community in Patillas municipality, Puerto Rico. Results obtained from the large, outdoor cage experiments indicated that trap captures of both mosquito species could be significantly enhanced by using black instead of white BGS traps combined with BG-Lure. Field experiments revealed that the modified traps captured a significantly greater number of Ae. aegypti, Ae. mediovittatus, and Culex quinquefasciatus, with greater sensitivity for the latter 2 species, and also captured a larger number of mosquito species and a smaller ratio of Ae. aegypti to Ae. mediovittatus, with greater than expected species co-occurrences. PMID:24551969

Barrera, Roberto; Mackay, Andrew J; Amador, Manuel

2013-12-01

366

Vector Competence of Australian Mosquitoes for Yellow Fever Virus  

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The vector competence of Australian mosquitoes for yellow fever virus (YFV) was evaluated. Infection and transmission rates in Cairns and Townsville populations of Aedes aegypti and a Brisbane strain of Ae. notoscriptus were not significantly different from a well-characterized YFV-susceptible strain of Ae. aegypti. After exposure to 107.2 tissue culture infectious dose (TCID50)/mL of an African strain of YFV, > 70% of Ae. aegypti and Ae. notoscriptus became infected, and > 50% transmitted th...

Den Hurk, Andrew F.; Mcelroy, Kate; Pyke, Alyssa T.; Mcgee, Charles E.; Hall-mendelin, Sonja; Day, Andrew; Ryan, Peter A.; Ritchie, Scott A.; Vanlandingham, Dana L.; Higgs, Stephen

2011-01-01

367

Biting behavior of Anopheles mosquitoes in Costa Marques, Rondonia, Brazil  

Directory of Open Access Journals (Sweden)

Full Text Available Mosquito collections were made in and near Costa Marques, Rondonia, Brazil, to determine anopheline anthropophilic/zoophilic behavior. Collections from a non-illuminated, bovine-baited trap and indoor and outdoor human-bait collections were compared. Anopheles darlingi and Anopheles deaneorum were more anthropophilic than the other anophelines collected. The remainder of the Anopheles species were collected much morefrequently in bovine-baited traps than in human-bait collections. Anopheles darlingi and An. deaneorum were more frequently collected inside houses than the other anopheline species. But, when collections were made in a house with numerous openings in the walls, there were few differences in the percentages of each species biting man indoors versus outdoors. Anopheles darlingi was the predominant mosquito collected, both inside and outside houses, and had the strongest anthropophilic feeding behavior of the anophelines present.Para determinar o comportamento antropofilico e zoofilico dos anofelinos, foram capturados mosquitos na periferia e na zona urbana de Costa Marques, Rondônia, Brasil. Foram comparadas as capturas feitas à noite, com iscas bovinas e humanas, dentro efora de casa. O Anopheles darlingi e o Anopheles deaneorumforam mais antropojilicos do que os outros anofelinos capturados. O restante das espécies anofelinas foi capturado mais freqüentemente nas iscas bovinas do que nas humanas. Anopheles darlingi e Anopheles deaneorumforam capturados dentro de casa com mais freqüência do que as outras espécies anofelinas. Porém, quando a captura foi feita em casas com muitas aberturas nas paredes houve pouca diferença nas porcentagens de cada espécie sugadora de humanos dentro efora de casa. Anopheles darlingi foi o mosquito capturado com mais freqüência, dentro e fora de casa, e apresentava maior antropofilia em relação aos outros anofelinos presentes.

Terry A. Klein

1991-03-01

368

Biting behavior of Anopheles mosquitoes in Costa Marques, Rondonia, Brazil  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Mosquito collections were made in and near Costa Marques, Rondonia, Brazil, to determine anopheline anthropophilic/zoophilic behavior. Collections from a non-illuminated, bovine-baited trap and indoor and outdoor human-bait collections were compared. Anopheles darlingi and Anopheles deaneorum were more anthropophilic than the other anophelines collected. The remainder of the Anopheles species were collected much morefrequently in bovine-baited traps than in human-bait collections. Anopheles d...

1991-01-01

369

High Wolbachia density in insecticide-resistant mosquitoes.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Wolbachia symbionts are responsible for various alterations in host reproduction. The effects of the host genome on endosymbiont levels have often been suggested, but rarely described. Here, we show that Wolbachia density is strongly modified by the presence of insecticide-resistant genes in the common house mosquito, Culex pipiens. The Wolbachia density was estimated using a real-time quantitative PCR assay. Strains harbouring different genes conferring resistance were more infected than a s...

Berticat, Claire; Rousset, Franc?ois; Raymond, Michel; Berthomieu, Arnaud; Weill, Myle?ne

2002-01-01

370

Malaria Infection Increases Attractiveness of Humans to Mosquitoes  

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Do malaria parasites enhance the attractiveness of humans to the parasite's vector? As such manipulation would have important implications for the epidemiology of the disease, the question has been debated for many years. To investigate the issue in a semi-natural situation, we assayed the attractiveness of 12 groups of three western Kenyan children to the main African malaria vector, the mosquito Anopheles gambiae. In each group, one child was uninfected, one was naturally infected with the ...

Lacroix, Renaud; Mukabana, Wolfgang R.; Gouagna, Louis Clement; Koella, Jacob C.

2005-01-01

371

Chromosome end elongation by recombination in the mosquito Anopheles gambiae.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

One of the functions of telomeres is to counteract the terminal nucleotide loss associated with DNA replication. While the vast majority of eukaryotic organisms maintain their chromosome ends via telomerase, an enzyme system that generates short, tandem repeats on the ends of chromosomes, other mechanisms such as the transposition of retrotransposons or recombination can also be used in some species. Chromosome end regression and extension were studied in a medically important mosquito, the m...

Roth, C. W.; Kobeski, F.; Walter, M. F.; Biessmann, H.

1997-01-01

372

Late-acting dominant lethal genetic systems and mosquito control  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Background Reduction or elimination of vector populations will tend to reduce or eliminate transmission of vector-borne diseases. One potential method for environmentally-friendly, species-specific population control is the Sterile Insect Technique (SIT). SIT has not been widely used against insect disease vectors such as mosquitoes, in part because of various practical difficulties in rearing, sterilization and distribution. Additionally, vector populations with str...

2007-01-01

373

Blood feeding patterns of mosquitoes: random or structured?  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background The foraging behavior of blood-sucking arthropods is the defining biological event shaping the transmission cycle of vector-borne parasites. It is also a phenomenon that pertains to the realm of community ecology, since blood-feeding patterns of vectors can occur across a community of vertebrate hosts. Although great advances in knowledge of the genetic basis for blood-feeding choices have been reported for selected vector species, little is known about the role of community composition of vertebrate hosts in determining such patterns. Methods & Results Here, we present an analysis of feeding patterns of vectors across a variety of locations, looking at foraging patterns of communities of mosquitoes, across communities of hosts primarily comprised of mammals and birds. Using null models of species co-occurrence, which do not require ancillary information about host abundance, we found that blood-feeding patterns were aggregated in studies from multiple sites, but random in studies from a single site. This combination of results supports the idea that mosquito species in a community may rely primarily on host availability in a given landscape, and that contacts with specific hosts will be influenced more by the presence/absence of hosts than by innate mosquito choices. This observation stresses the importance of blood-feeding plasticity as a key trait explaining the emergence of many zoonotic mosquito transmitted diseases. Discussion From an epidemiological perspective our observations support the idea that phenomena promoting synchronization of vectors and hosts can promote the emergence of vector-borne zoonotic diseases, as suggested by observations on the linkages between deforestation and the emergence of several human diseases.

Nguyen Andy M

2010-01-01

374

Diversity of Bacterial Communities in Container Habitats of Mosquitoes  

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We investigated the bacterial diversity of microbial communities in water-filled, human-made and natural container habitats of the mosquitoes Aedes aegypti and Aedes albopictus in suburban landscapes of New Orleans, Louisiana in 2003. We collected water samples from three classes of containers, including tires (n=12), cemetery urns (n=23), and miscellaneous containers that included two tree holes (n=19). Total genomic DNA was extracted from water samples, and 16S ribosomal DNA fragments (oper...

2008-01-01

375

Organization and developmental expression of the mosquito vitellogenin receptor gene.  

Science.gov (United States)

Vitellogenin is a precursor of the major yolk protein, vitellin. It is internalized by developing oocytes via receptor-mediated endocytosis. Previously, we characterized the vitellogenin receptor (VgR) from oocytes of the mosquito Aedes aegypti [Sappington, T.W., Kokoza,V.A., Cho,W.L. and Raikhel,A.S. (1996) Molecular characterization of the mosquito vitellogenin receptor reveals unexpected high homology to the Drosophila yolk protein receptor. Proc Natl Acad Sci USA 93: 8934-8939]. The VgR receptor has a unique structure with two putative ligand-binding domains. In order to understand the regulation of this important molecule, we characterized the VgR gene structure and its expression during vitellogenesis in the mosquito A. aegypti. We report here that the VgR gene was separated by five introns that have an average length of 60 bp, except for the second intron which was more than 20 kb long. Most introns were located within the coding regions of the first protein domain. We isolated two allelic variations of the VgR gene, VgR1 and VgR2, the nucleotide sequences of which differing only in their 5'-flanking regions. Considering their frequency in the mosquito genome, VgR2 appeared to be a major allele. The expression of VgR mRNA was studied by the Northern blot analysis and in situ hybridization. The level of the VgR transcript started to rise in the ovary one day post-eclosion. It continued its dramatic rise during the vitellogenic period, reaching its peak at 24 h PBM. The VgR transcript was present exclusively in ovaries where it was seen in oocytes and nurse cells of primary follicles and germ-line cells of the germarium. PMID:11881811

Cho, K H; Raikhel, A S

2001-10-01

376

Detection of mosquito-only flaviviruses in Europe  

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The genus Flavivirus, family Flaviviridae, includes a number of important arthropod-transmitted human pathogens such as dengue viruses, West Nile virus, Japanese encephalitis virus and yellow fever virus. In addition, the genus includes flaviviruses without a known vertebrate reservoir, which have been detected only in insects, particularly in mosquitoes, such as cell fusing agent virus, Kamiti River virus, Culex flavivirus, Aedes flavivirus, Quang Binh virus, Nakiwogo virus and Calbertado vi...

Calzolari, M.; Ze?-ze?, L.; Ru? Z? Ek, D.; Va?zquez, A.; Jeffries, C.; Defilippo, F.; Oso?rio, H. C.; Kilian, P.; Rui?z, S.; Fooks, A. R.; Amaro, F.; Tlusty?, M.; Maioli, G.; Figuerola, Jordi; Medlock, J. M.

2012-01-01

377

Transmission of malaria to mosquitoes blocked by bumped kinase inhibitors  

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Effective control and eradication of malaria will require new tools to prevent transmission. Current antimalarial therapies targeting the asexual stage of Plasmodium do not prevent transmission of circulating gametocytes from infected humans to mosquitoes. Here, we describe a new class of transmission-blocking compounds, bumped kinase inhibitors (BKIs), which inhibit microgametocyte exflagellation. Oocyst formation and sporozoite production, necessary for transmission to mammals, were inhibit...

2012-01-01

378

Historical applications of induced sterilisation in field populations of mosquitoes  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Research on sterile mosquito technology from 1955 to the 1980s provided a substantial body of knowledge on propagation and release of sterile mosquitoes. Radiation sterilisation and chemosterilisation have been used effectively to induce dominant lethality and thereby sterilise important mosquito vectors in the laboratory. Experimental releases of chemosterilised males provided complete control of Anopheles albimanus in a small breeding population (14-15 sq km in El Salvador. Releases of radiation sterilised males failed to control either Aedes aegypti or Anopheles quadrimaculatus in the USA. Releases of radiation-sterilised and chemosterilised male Culex quinquefasciatus in the USA and India were successful in some instances. Development of genetic sexing systems for Anopheles and improved physical separation methods for Culex have made it possible to rear and release males almost exclusively (> 99% minimizing the release of potential vectors, the females. Factors that affected efficacy in some field programmes included reduction of competitiveness by radiation, immigration of fertilized females from outside the release zones, and inability of laboratory-bred males to perform in the wild. Despite significant progress, institutional commitments to carry the process further were generally lacking in the late 1970s and until recently. Now, with renewed interest and support for further assessment of this technology, this paper summarizes the current knowledge base, prioritizes some areas of investigation, and challenges scientists and administrators to maintain an awareness of progress, remain realistic about the interpretation of new findings, and make decisions about the sterile insect technique on the basis of informed scientific documentation. Areas recommended for priority research status include the establishment of genetic sexing mechanisms that can be transferred to other mosquito species, re-examination of radiation sterilisation, aerial release technology and mass rearing.

Knols Bart GJ

2009-11-01

379

Aerial and Tidal Transport of Mosquito Control Pesticides into the Florida Keys National Marine Sanctuary  

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This project was undertaken as the initial monitoring program to determine if mosquito adulticides applied along the Florida Keys cause adverse ecological effects in the Florida Keys National Marine Sanctuary (FKNMS).The study monitored the distribution and persistence of two mosquito adulticides,permethrin and dibrom (naled),during three separate routine applications by the Florida Keys Mosquito Control District.The approach was to determine if toxic concentrations of the pesticides entered ...

Pierce, R. H.; Henry, M. S.; Blum, T. C.; Mueller, E. M.

2005-01-01

380

Dynamic Gut Microbiome across Life History of the Malaria Mosquito Anopheles gambiae in Kenya  

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The mosquito gut represents an ecosystem that accommodates a complex, intimately associated microbiome. It is increasingly clear that the gut microbiome influences a wide variety of host traits, such as fitness and immunity. Understanding the microbial community structure and its dynamics across mosquito life is a prerequisite for comprehending the symbiotic relationship between the mosquito and its gut microbial residents. Here we characterized gut bacterial communities across larvae, pupae ...

Wang, Ying; Gilbreath, Thomas M.; Kukutla, Phanidhar; Yan, Guiyun; Xu, Jiannong

2011-01-01

 
 
 
 
381

A synthetic homing endonuclease-based gene drive system in the human malaria mosquito  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Genetic methods of manipulating or eradicating disease vector populations have long been discussed as an attractive alternative to existing control measures because of their potential advantages in terms of effectiveness and species specificity1–3. The development of genetically engineered malaria-resistant mosquitoes has shown, as a proof-of-principle, the possibility of targeting the mosquito’s ability to serve as a disease vector4–7. The translation of these achievements into control...

Windbichler, Nikolai; Menichelli, Miriam; Papathanos, Philippos Aris; Thyme, Summer B.; Li, Hui; Ulge, Umut Y.; Hovde, Blake T.; Baker, David; Monnat, Raymond J.; Burt, Austin; Crisanti, Andrea

2011-01-01

382

Identification of mosquito repellent odours from Ocimum forskolei  

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Abstract Background Native mosquito repellent plants have a good potential for integrated mosquito control in local settings. Ocimum forskolei, Lamiaceae, is used in Eritrea as a spatial mosquito repellent inside houses, either through crushing fresh plants or burning dry plants. We verified whether active repellent compounds could be identified using gas-chromatography coupled electroantennogram recordings (GC-EAD) with headspace extracts of crushed plants. R...

Dekker Teun; Ignell Rickard; Ghebru Maedot; Glinwood Robert; Hopkins Richard

2011-01-01

383

Dengue Virus Type 2 Infections of Aedes aegypti Are Modulated by the Mosquito's RNA Interference Pathway  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A number of studies have shown that both innate and adaptive immune defense mechanisms greatly influence the course of human dengue virus (DENV) infections, but little is known about the innate immune response of the mosquito vector Aedes aegypti to arbovirus infection. We present evidence here that a major component of the mosquito innate immune response, RNA interference (RNAi), is an important modulator of mosquito infections. The RNAi response is triggered by double-stranded RNA (dsRNA), ...

Sa?nchez-vargas, Irma; Scott, Jaclyn C.; Poole-smith, B. Katherine; Franz, Alexander W. E.; Barbosa-solomieu, Vale?rie; Wilusz, Jeffrey; Olson, Ken E.; Blair, Carol D.

2009-01-01

384

Wolbachia Infection Reduces Blood-Feeding Success in the Dengue Fever Mosquito, Aedes aegypti  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The primary mosquito vector of dengue virus, Aedes aegypti, has recently been artificially infected with a symbiotic bacterium called Wolbachia pipientis. This bacterium occurs naturally inside the cells of ?66% of insect species. The Wolbachia used to infect A. aegypti shortens the insect's lifespan. Because only old mosquitoes are capable of transmitting dengue virus, the Wolbachia infection could theoretically reduce dengue virus transmission if infected mosquitoes were released into the...

Turley, Andrew P.; Moreira, Luciano A.; O Neill, Scott L.; Mcgraw, Elizabeth A.

2009-01-01

385

Integrated mosquito larval source management reduces larval numbers in two highland villages in western Kenya  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Background: In western Kenya, malaria remains one of the major health problems and its control remains an important public health measure. Malaria control is by either use of drugs to treat patients infected with malaria parasites or by controlling the vectors. Vector control may target the free living adult or aquatic (larval) stages of mosquito. The most commonly applied control strategies target indoor resting mosquitoes. However, because mosquitoes spend a considerable time in water, targ...

Imbahale, S. S.; Githeko, A.; Mukabana, W. R.; Takken, W.

2012-01-01

386

Prevalence of Dirofilaria immitis (Nematoda: Filarioidea) in mosquitoes from northeast Arkansas, the United States.  

Science.gov (United States)

A mosquito survey was conducted to identify which species of mosquitoes carry Dirofilaria immitis (Leidy) (Nematoda: Filarioidea), dog heartworm, in northeast Arkansas. Using polymerase chain reaction, mosquitoes were analyzed for D. immitis, Dirofilaria repens Railliet & Henry, and Acanthocheilonema dracunculoides Cobbold. Mosquitoes were collected from April to October 2009 using black light ultraviolet traps baited with dry ice. Sixteen mosquito species were identified. D. immitis was identified in nine mosquito species, which included Aedes vexans (Meigen), Anopheles quadrimaculatus Say, Anopheles punctipennis (Say), Culex pipiens quinquefasciatus Say, Culex erraticus (Dyer & Knab), Culiseta inornata (Williston), Psorophora columbiae (Dyer & Knab), Psorophora ferox (Humboldt), and Psorophora howardii Coquillett. No D. repens or A. dracunculoides DNA was amplified. Of the 1,212 mosquito pools tested, 7.3% were positive for D. immitis. Frequency of D. immitis infections from six collection sites ranged from 2.1 to 19.4%. Ae. vexans and An. quadrimaculatus were the two most abundant species, composing 58.7 and 23.7% of the total mosquitoes collected, with 9.6 and 6.9% of pools positive for D. immitis, respectively. To investigate localized vector infection rates of D. immitis, mosquitoes were collected from inside the kennel of a heartworm-positive dog. Of the 114 mosquitoes collected, 84 (73.7%) were positive for D. immitis. The frequency of D. immitis-infected mosquitoes collected near a heartworm-positive dog was considerably higher than in the original six collection sites, suggesting a single heartworm-positive dog potentially increases infection pressure on susceptible animals sharing mosquito exposure. PMID:23926787

Mckay, Tanja; Bianco, T; Rhodes, L; Barnett, S

2013-07-01

387

Insecticide-Treated Nets Can Reduce Malaria Transmission by Mosquitoes Which Feed Outdoors  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Insecticide treated nets (ITNs) represent a powerful means for controlling malaria in Africa because the mosquito vectors feed primarily indoors at night. The proportion of human exposure that occurs indoors, when people are asleep and can conveniently use ITNs, is therefore very high. Recent evidence suggests behavioral changes by malaria mosquito populations to avoid contact with ITNs by feeding outdoors in the early evening. We adapt an established mathematical model of mosquito behavior a...

2010-01-01

388

Examining Landscape Factors Influencing Relative Distribution of Mosquito Genera and Frequency of Virus Infection  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Mosquito-borne infections cause some of the most debilitating human diseases, including yellow fever and malaria, yet we lack an understanding of how disease risk scales with human-driven habitat changes. We present an approach to study variation in mosquito distribution and concomitant viral infections on the landscape level. In a pilot study we analyzed mosquito distribution along a 10-km transect of a West African rainforest area, which included primary forest, secondary forest, plantation...

Junglen, S.; Kurth, A.; Kuehl, H.; Quan, P. L.; Ellerbrok, H.; Pauli, G.; Nitsche, A.; Nunn, Charles Lindsay; Rich, S. M.; Lipkin, W. I.; Briese, T.; Leendertz, F. H.

2009-01-01

389

Examining Landscape Factors Influencing Relative Distribution of Mosquito Genera and Frequency of Virus Infection  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Mosquito-borne infections cause some of the most debilitating human diseases, including yellow fever and malaria, yet we lack an understanding of how disease risk scales with human-driven habitat changes. We present an approach to study variation in mosquito distribution and concomitant viral infections on the landscape level. In a pilot study we analyzed mosquito distribution along a 10-km transect of a West African rainforest area, which included primary forest, secondary forest, planta...

Junglen, Sandra; Kurth, Andreas; Kuehl, H.; Quan, Phenix-lan; Ellerbrok, Heinz; Pauli, Georg; Nitsche, Andreas; Nunn, Charles L.; Rich, S. M.; Briese, Thomas; Leendertz, Fabian

2009-01-01

390

IDENTIFICATION OF MOSQUITO AVIAN-DERIVED BLOOD MEALS BY POLYMERASE CHAIN REACTION-HETERODUPLEX ANALYSIS  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A polymerase chain reaction (PCR) heteroduplex assay (HDA) was developed to identify avian derived mosquito blood meals to the species level. The assay used primers amplifying a fragment of the cytochrome B gene from vertebrate but not invertebrate species. In Culex tarsalis fed on quail, PCR products derived from the quail cytochrome B gene were detected seven days post-engorgement. In an analysis of wild-caught mosquitoes, 85% of blood-fed mosquitoes produced detectable PCR products. Hetero...

Lee, Joon Hak; Hassan, Hassan; Hill, Geoff; Cupp, Eddie W.; Higazi, Tarig B.; Mitchell, Carl J.; Godsey, Marvin S.; Unnasch, Thomas R.

2002-01-01

391

Open Release of Male Mosquitoes Infected with a Wolbachia Biopesticide: Field Performance and Infection Containment  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Additional tools are required to mitigate mosquito borne disease in the South Pacific, including human lymphatic filariasis (LF). Wolbachia are obligate intracellular bacteria that occur in a majority of insect species and that cause a form of conditional sterility in mosquitoes. Prior work demonstrates that male Aedes polynesiensis mosquitoes, which are artificially infected with Wolbachia (i.e., transinfected) can effectively sterilize wild type females in the laboratory, suggesting the pot...

O Connor, Linda; Plichart, Catherine; Sang, Ayo Cheong; Brelsfoard, Corey L.; Bossin, Herve? C.; Dobson, Stephen L.

2012-01-01

392

Nature, Nurture and Evolution of Intra-Species Variation in Mosquito Arbovirus Transmission Competence  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Mosquitoes vary in their competence or ability to transmit arthropod-borne viruses (arboviruses). Many arboviruses cause disease in humans and animals. Identifying the environmental and genetic causes of variation in mosquito competence for arboviruses is one of the great challenges in public health. Progress identifying genetic (nature) and environmental (nurture) factors influencing mosquito competence for arboviruses is reviewed. There is great complexity in the various traits that compris...

Tabachnick, Walter J.

2013-01-01

393

Preliminary Analysis of Several Attractants and Spatial Repellents for the Mosquito, Aedes albopictus using an Olfactometer  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Mosquito attractants and spatial repellents hold great promise in controlling mosquito pests. In assessing the effectiveness of mosquito attractants and repellents, a good olfactometer system, and optimized testing conditions, are essential. In this research, we demonstrated the usefulness of an olfactometer system, and optimized testing conditions for Aedes albopictus (Diptera: Culicidae). We found no significant difference in the biting activity of the insect between 8:00 and 22:00. Further...

Hao, Huiling; Sun, Jingcheng; Dai, Jianqing

2012-01-01

394

Ingested Human Insulin Inhibits the Mosquito NF-?B-Dependent Immune Response to Plasmodium falciparum  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We showed previously that ingested human insulin activates the insulin/IGF-1 signaling pathway in Anopheles stephensi and increases the susceptibility of these mosquitoes to Plasmodium falciparum. In other organisms, insulin can alter immune responsiveness through regulation of NF-?B transcription factors, critical elements for innate immunity that are also central to mosquito immunity. We show here that insulin signaling decreased expression of NF-?B-regulated immune genes in mosquito cell...

Pakpour, Nazzy; Corby-harris, Vanessa; Green, Gabriel P.; Smithers, Hannah M.; Cheung, Kong W.; Riehle, Michael A.; Luckhart, Shirley

2012-01-01

395

Comprehensive Genetic Dissection of the Hemocyte Immune Response in the Malaria Mosquito Anopheles gambiae  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Reverse genetics in the mosquito Anopheles gambiae by RNAi mediated gene silencing has led in recent years to an advanced understanding of the mosquito immune response against infections with bacteria and malaria parasites. We developed RNAi screens in An. gambiae hemocyte-like cells using a library of double-stranded RNAs targeting 109 genes expressed highly or specifically in mosquito hemocytes to identify novel regulators of the hemocyte immune response. Assays included phagocytosis of bac...

Lombardo, F.; Ghani, Y.; Kafatos, F. C.; Christophides, G. K.

2013-01-01

396

Enterobacter-Activated Mosquito Immune Responses to Plasmodium Involve Activation of SRPN6 in Anopheles stephensi  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Successful development of Plasmodium in the mosquito is essential for the transmission of malaria. A major bottleneck in parasite numbers occurs during midgut invasion, partly as a consequence of the complex interactions between the endogenous microbiota and the mosquito immune response. We previously identified SRPN6 as an immune component which restricts Plasmodium berghei development in the mosquito. Here we demonstrate that SRPN6 is differentially activated by bacteria in Anopheles stephe...

Eappen, Abraham G.; Smith, Ryan C.; Jacobs-lorena, Marcelo

2013-01-01

397

Aedes triseriatus females transovarially-infected with La Crosse virus mate more efficiently than uninfected mosquitoes  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The mating efficiencies of field-collected and laboratory-colonized Aedes triseriatus (Say) (Diptera: Culicidae) female mosquitoes transovarially-infected or uninfected with La Crosse virus (LACV) were compared. The females were placed in cages with age-matched males, and the insemination rates were determined daily by detection of sperm in the spermathecae. LACV-infected mosquitoes typically mated more quickly than uninfected mosquitoes. LACV load was not correlated with increased insemination.

Reese, Sara M.; Beaty, Meaghan K.; Gabitzsch, Elizabeth S.; Blair, Carol D.; Beaty, Barry J.

2009-01-01

398

Larval ecology of mosquitoes in sylvatic arbovirus foci in southeastern Senegal  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Background Although adult mosquito vectors of sylvatic arbovirus [yellow fever (YFV), dengue-2 (DENV-2) and chikungunya (CHIKV)] have been studied for the past 40 years in southeastern Senegal, data are still lacking on the ecology of larval mosquitoes in this area. In this study, we investigated the larval habitats of mosquitoes and characterized their seasonal and spatial dynamics in arbovirus foci. Methods We searched for wet microhabitats, classifie...

2012-01-01

399

Perspectives of people in Mali toward genetically-modified mosquitoes for malaria control  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Background Genetically-modified (GM) mosquitoes have been proposed as part of an integrated vector control strategy for malaria control. Public acceptance is essential prior to field trials, particularly since mosquitoes are a vector of human disease and genetically modified organisms (GMOs) face strong scepticism in developed and developing nations. Despite this, in sub-Saharan Africa, where the GM mosquito effort is primarily directed, very little data is available...

Marshall John M; Touré Mahamoudou B; Traore Mohamed M; Famenini Shannon; Taylor Charles E

2010-01-01

400

Some environmental and biological factors influencing the activity of entomopathogenic Bacillus on mosquito larvae in Brazil  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The influence of environmental and biological factors on the efficacy of Bacillus thuringiensis serovar israelensis and B. sphaericus as mosquito larvicides are reviewed. The importance of strain dependence, cultivating media/methods, mosquito species/specificity, formulations and their relation to mosquito feeding habits, as well as temperature, solar exposure, larval density and concomitant presence of other aquatic organisms are addressed with reference to the present status of knowledge i...

1995-01-01

 
 
 
 
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Some environmental and biological factors influencing the activity of entomopathogenic Bacillus on mosquito larvae in Brazil  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english The influence of environmental and biological factors on the efficacy of Bacillus thuringiensis serovar israelensis and B. sphaericus as mosquito larvicides are reviewed. The importance of strain dependence, cultivating media/methods, mosquito species/specificity, formulations and their relation to [...] mosquito feeding habits, as well as temperature, solar exposure, larval density and concomitant presence of other aquatic organisms are addressed with reference to the present status of knowledge in Brazil.

R. A. G. B, Consoli; C. J, Carvalho-Pinto; M. A, Oliveira; B. S, Santos; M. A, Lamounier; R. S. A, Alves; C. M. B, Silva; L, Rabinovitch.

402

Some environmental and biological factors influencing the activity of entomopathogenic Bacillus on mosquito larvae in Brazil  

Directory of Open Access Journals (Sweden)

Full Text Available The influence of environmental and biological factors on the efficacy of Bacillus thuringiensis serovar israelensis and B. sphaericus as mosquito larvicides are reviewed. The importance of strain dependence, cultivating media/methods, mosquito species/specificity, formulations and their relation to mosquito feeding habits, as well as temperature, solar exposure, larval density and concomitant presence of other aquatic organisms are addressed with reference to the present status of knowledge in Brazil.

R. A. G. B Consoli

1995-02-01

403

Integrated mosquito larval source management reduces larval numbers in two highland villages in western Kenya  

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Abstract Background In western Kenya, malaria remains one of the major health problems and its control remains an important public health measure. Malaria control is by either use of drugs to treat patients infected with malaria parasites or by controlling the vectors. Vector control may target the free living adult or aquatic (larval) stages of mosquito. The most commonly applied control strategies target indoor resting mosquitoes. However, because mosquitoes spend a conside...

2012-01-01

404

The Transcriptome Profile of the Mosquito Culex quinquefasciatus following Permethrin Selection  

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To gain valuable insights into the gene interaction and the complex regulation system involved in the development of insecticide resistance in mosquitoes Culex quinquefasciatus, we conducted a whole transcriptome analysis of Culex mosquitoes following permethrin selection. Gene expression profiles for the lower resistant parental mosquito strain HAmCqG0 and their permethrin-selected high resistant offspring HAmCqG8 were compared and a total of 367 and 3982 genes were found to be up- and down-...

Reid, William R.; Zhang, Lee; Liu, Feng; Liu, Nannan

2012-01-01

405

Larvicidal Activity of Sterol Carrier Protein-2 Inhibitor in Four Species of Mosquitoes  

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A previous report has shown that mosquito sterol carrier protein-2 inhibitors (SCPIs) are larvicidal to larvae of the yellowfever mosquito, Aedes aegypti (L.) (J. Lipid Res. 46: 650–657, 2005). In the current study, we tested SCPI-1 in an additional four mosquito species for larvicidal activities: Culex pipiens pipiens, Anopheles gambiae, Culex restuans, and Aedes vexans. Cholesterol accumulation in SCPI-treated Ae. aegypti fourth instars was examined. SCPI-1 is lethal to all tested mosquit...

Larson, Ryan T.; Wessely, Vilena; Jiang, Zhisheng; Lan, Que

2008-01-01

406

Trapping mosquitoes using milk products as odour baits in western Kenya  

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Abstract Background Ample evidence has shown that blood seeking mosquitoes locate their hosts by following odours produced by the hosts. Odour baited traps would therefore, provide a solution in controlling diseases spread by mosquitoes. Comparative studies were undertaken to determine the relative efficacies of two odour baits i.e. Limburger cheese and African traditional milk cream in trapping mosquitoes in the field in western Kenya. Method Comparative effica...

2010-01-01