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

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Full Text Available 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 device, named the 'Ifakara Odor-baited Station' (Ifakara OBS, is a 4 m3 hut-shaped canvas box with seven openings, two of which may be fitted with interception traps to catch exiting mosquitoes. It is baited with synthetic human odors and may be augmented with contaminants including toxic insecticides or biological agents. Results In field trials where panels of fabric were soaked in 1% pirimiphos-methyl solution and suspended inside the Ifakara OBS, at least 73.6% of Anopheles arabiensis, 78.7% of Culex and 60% of Mansonia mosquitoes sampled while exiting the OBS, died within 24 hours. When used simply as a trap and evaluated against two existing outdoor traps, Ifakara Tent trap and Mosquito Magnet-X®, the OBS proved more efficacious than the Ifakara Tent trap in catching all mosquito species found (P ®, it was equally efficacious in catching An. arabiensis (P = 0.969, but was less efficacious against Culex (P Mansonia species (P Conclusion The Ifakara OBS is efficacious against disease-carrying mosquitoes including the malaria vector, An. arabiensis and Culicine vectors of filarial worms and arboviruses. It can be used simultaneously as a trap and as a contamination or killing station, meaning most mosquitoes which escape trapping would leave when already contaminated and die shortly afterwards. This technique has potential to complement current vector control methods, by targeting mosquitoes in places other than human dwellings, but its effectiveness in the field will require cheap, long-lasting and easy-to-use mosquito lures.

John Alex N

2010-03-01

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Photoacoustically-guided photothermal killing of mosquitoes targeted by nanoparticles.  

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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. 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. appendiculata, peaking in intensity in the final 24 h prior to pupation, as observed for Toxorhynchites spp. Attack sites identified from videotaped encounters with mosquito prey were divided among head, thorax, abdomen, and siphon. Consumed mosquito larvae (n = 70) were attacked primarily on the head (46%) or siphon (34%), but surplus-killed prey (n = 30) were attacked predominantly on the thorax (83%). Despite its independent evolution among different insect species in aquatic container habitats, the functional significance of prepupal surplus killing remains unclear. PMID:19081802

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

2008-03-01

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Tolypocladium terricola sp. N., a new mosquito-killing species of the genus Tolypocladium Gams (Hyphomycetes).  

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A new entomopathogenic species of the genus Tolypocladium, T. terricola is described from a soil sample from Finalnd. From other known Tolypocladium species, T. terricola differs in morphology, production of secondary metabolites and possession of relatively strong mosquitocidal activity. The fungus is characterized by broad oval conidia (2.5 x 2 microns) with one pointed end which are produced in grape-like clusters, and are not firmly adherent. When treated with T. terricola, mosquito larvae show typical features of intoxication characterized by the concentration of larvae in the centre of cup, hanging by their siphons on the surface. PMID:1688023

Weiser, J; Matha, V; Jegorov, A

1991-01-01

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What does not kill them makes them stronger: larval environment and infectious dose alter mosquito potential to transmit filarial worms.  

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For organisms with complex life cycles, larval environments can modify adult phenotypes. For mosquitoes and other vectors, when physiological impacts of stressors acting on larvae carry over into the adult stage they may interact with infectious dose of a vector-borne pathogen, producing a range of phenotypes for vector potential. Investigation of impacts of a common source of stress, larval crowding and intraspecific competition, on adult vector interactions with pathogens may increase our understanding of the dynamics of pathogen transmission by mosquito vectors. Using Aedes aegypti and the nematode parasite Brugia pahangi, we demonstrate dose dependency of fitness effects of B. pahangi infection on the mosquito, as well as interactions between competitive stress among larvae and infectious dose for resulting adults that affect the physiological and functional ability of mosquitoes to act as vectors. Contrary to results from studies on mosquito-arbovirus interactions, our results suggest that adults from crowded larvae may limit infection better than do adults from uncrowded controls, and that mosquitoes from high-quality larval environments are more physiologically and functionally capable vectors of B. pahangi. Our results provide another example of how the larval environment can have profound effects on vector potential of resulting adults. PMID:24827444

Breaux, Jennifer A; Schumacher, Molly K; Juliano, Steven A

2014-07-01

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Towards mosquito sterile insect technique programmes: exploring genetic, molecular, mechanical and behavioural methods of sex separation in mosquitoes.  

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When considering a mosquito release programme, one of the first issues to be addressed is how to eliminate/separate the females. The greatest number of options might eventually be available for those who can use transgenic mosquitoes, but the inherent characteristics of the target species may also provide possibilities for interim measures until more efficient methods can be developed. Differences in intrinsic size, in behaviour and in development rate between females and males are often available and useful for sexing. Efficient species-specific systems for eliminating females at the embryo stage have been developed, but most have since been discarded due to lack of use. Ideal systems specifically kill female embryos using some treatment that can be manipulated during production. Such killing systems are far more efficient than using intrinsic sexual differences, but they systems require selectable genetic markers and sex-linkage created by rare random chromosomal rearrangements. While intrinsic sexual differences should not be considered as long-term candidates for the development of robust and efficient sexing approaches, in the absence of these, the accessibility and integration of less efficient systems can provide a stop-gap measure that allows rapid start up with a minimum of investment. The International Atomic Energy Agency is funding over a 5 year period (2013-2018) a new Coordinated Research Project on "Exploring Genetic, Molecular, Mechanical and Behavioural Methods of Sex Separation in Mosquitoes" to network researchers and to address the critical need of genetic sexing strains for the implementation of the sterile insect technique (using radiation-sterilised or transgenic male mosquitoes) and for insect incompatibility technique programmes against disease-transmitting mosquitoes. PMID:23994521

Gilles, Jeremie R L; Schetelig, Marc F; Scolari, Francesca; Marec, František; Capurro, Margareth L; Franz, Gerald; Bourtzis, Kostas

2014-04-01

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Mosquito Control  

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... Environmental Protection Agency Search Search Contact Us Mosquito Control About Mosquitoes General Information Life Cycle Information on ... is Right for You DEET Pesticides for Mosquito Control Larvicides Adulticides Misting Systems Getting Help with Mosquito ...

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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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Mosquito Modifications: New Approaches to Controlling Malaria  

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This article from the November 2007 issue of BioScience examines the historical and current methods to control Malaria.Malaria kills about one million people each year, but efforts to destroy disease-carrying mosquitoes have succeeded only in breeding tougher bugs. Researchers have begun to look for ways to create malaria-resistant mosquitoes. One approach is to bioengineer transgenic mosquitoes that, when released into the wild, would lead to a new race of malaria-proof young. Another approach uses mosquitoes' natural resistance to Plasmodium infection.

Sharon Levy (;)

2007-11-01

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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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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.

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

2014-08-01

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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.

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

2014-04-29

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Do traditional mosquito repellent plants work as mosquito larvicides?  

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Plant derived larvicides were evaluated in Kamhororo, an area of Zimbabwe. Twenty five third and fourth instar An. gambiae s.s mosquito larvae were used per test according to the method of WHO. All larvicides were effective against the An. gambiae s.s mosquito larvae and were comparable to studies done in Tanzania using Orange peel extracts. The extracts of the plant Ocimum canum (LC50 = 54, 94 x 10(3) ug/ml) were more effective in killing the larvae than Lippia javanica (LC50 = 125,34mg x 10(3) ug/ml). These concentrations are higher when considering commercial larvicides. PMID:7859271

Lukwa, N

1994-11-01

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Climatic factors driving invasion of the tiger mosquito (Aedes albopictus) into new areas of Trentino, Northern Italy  

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Background:The tiger mosquito (Aedes albopictus), vector of several emerging diseases, is expanding into more northerly latitudes as well as into higher altitudes in northern Italy. Changes in the pattern of distribution of the tiger mosquito may affect the potential spread of infectious diseases transmitted by this species in Europe. Therefore, predicting suitable areas of future establishment and spread is essential for planning early prevention and control strategies.Methodology/Principal ...

Roiz, David; Neteler, Markus; Castellani, Cristina; Arnoldi, Daniele; Rizzoli, Annapaola

2011-01-01

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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...

Ming Tang, I.; Surapol Naowarat

2013-01-01

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European risk assessment guidance for infectious diseases transmitted on aircraft--the RAGIDA project.  

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In order to assist national public health authorities in the European Union to assess the risks associated with the transmission of infectious agents on board aircrafts, the European Centre for Disease Prevention and Control initiated in 2007 the RAGIDA project (Risk Assessment Guidance for Infectious Diseases transmitted on Aircraft). RAGIDA consists of two parts: the production of a systematic review and a series of disease-specific guidance documents. The systematic review covered over 3,700 peer-reviewed articles and grey literature for the following diseases: tuberculosis, influenza, severe acute respiratory syndrome (SARS), invasive meningococcal disease, measles, rubella, diphtheria, Ebola and Marburg haemorrhagic fevers, Lassa fever, smallpox and anthrax. In addition, general guidelines on risk assessment and management from international aviation boards and national and international public health agencies were systematically searched. Experts were interviewed on case-based events by standardised questionnaires. Disease-specific guidance documents on tuberculosis, SARS, meningococcal infections, measles, rubella, Ebola and Marburg haemorrhagic fevers, Lassa fever, smallpox and anthrax were the result of consultations of disease-specific expert panels. Factors that influence the risk assessment of infectious disease transmission on board aircrafts and decision making for contact tracing are outlined. PMID:21527131

Leitmeyer, K

2011-01-01

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Mosquito species geographical distribution in Iraq 2009  

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Full Text Available Background & objectives: Mosquitoes transmit diseases to >700 million people annually. Malaria kills threemillion persons every year, including one child every 30 sec. Worldwide there are >3000 mosquito species.In Iraq, 37 species have been identified in different surveys over several decades. We conducted an entomologicalsurvey to determine the mosquito species and their distribution in Iraq in 2009.Methods: Between January 20 and December 31, 2009, mosquitoes in houses in 12 Iraqi provinces werecollected and speciated. Five to 10 villages were selected randomly in each province and in each village 10houses were selected randomly to collect mosquitoes and the density of mosquitoes per room was calculated.Kits for entomological investigation were used and the collected mosquitoes were sent to the vector bornedisease section laboratory for classification using the Naval Medical Research Unit 3 standard classificationkey.Results: A total of 29,156 mosquitoes were collected, representing two genera: Anopheles (n=13,268, or 46%of the total collected and Culex (n=15,888, or 54% of the total collected. Four Anopheles (An. pulcherrimus,An. stephensi, An. superpictus, and An. sacharovi and one Culex (Cx. pipiens species were identified. Anophelespulcherrimus was found in 11 provinces, An. stephensi in 7, An. superpictus in 2 and An. sacharovi in oneprovince, while Cx. pipiens was found in all the 12 provinces. Two peaks of mosquito density were found: thefirst from April–June and the other from September–October.Interpretation & conclusion: There are clear differences in Anopheles mosquito species geographical distributionand density among Iraqi provinces, while Cx. pipiens mosquitoes are distributed all over Iraq. All mosquitogenera show clear seasonal density variation. The study highlights that the manual mosquito classification isnot enough to identify all the species of mosquitoes in Iraq

Haidar A. Hantosh, Hameeda M. Hassan, Bushra Ahma & Ali Al-fatlawy

2012-03-01

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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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[Mosquito allergy].  

Science.gov (United States)

Althought serious illnesses can be transmitted by mosquitoes, the most frequent manifestations are due to the contact with saliva of mosquitoes during the blood meal. Culex and Aedes are meeting in countries with moderate climates. Clinical signs vary according to the immunoallergical response, from simple pruritic wheals to immediate and/or delayed allergic reactions. Some reactions can provoke confusion with an infectious cellulitis and an inappropriate antibiotherapy. The natural history of insect bite reactions in an individual tends to progress through 5 stages until immunizing tolerance settles down. Skin prick testing or Serum specific IgE of whole body extracts are lacking sensibility and specificity. Actually, they must be reserved for the most invalidating or severe cases. The recombinant allergens of the saliva of mosquitoes should allow to improve diagnosis and to envisage immunotherapy. PMID:24954785

Haas, H; Tran, A

2014-08-01

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Mosquito diapause.  

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Diapause, a dominant feature in the life history of many mosquito species, offers a mechanism for bridging unfavorable seasons in both temperate and tropical environments and serves to synchronize development within populations, thus directly affecting disease transmission cycles. The trait appears to have evolved independently numerous times within the Culicidae, as exemplified by the diverse developmental stages of diapause in closely related species. Its impact is pervasive, not only influencing the arrested stage, but also frequently altering physiological processes both before and after diapause. How the diapause response can be molded evolutionarily is critical for understanding potential range expansions of native and newly introduced species. The study of hormonal regulation of mosquito diapause has focused primarily on adult diapause, with little current information available on larval diapause or the intriguing maternal effects that regulate egg diapause. Recent quantitative trait locus, transcriptome, and RNA interference studies hold promise for interpreting the complex suite of genes that subserve the diapause phenotype. PMID:24160427

Denlinger, David L; Armbruster, Peter A

2014-01-01

 
 
 
 
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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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With Toxic Crystals, Bacterium Targets - and Takes out - Nematodes  

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... kill crop-killing caterpillars and beetles, and disease-transmitting black flies and mosquitoes ... consistent with the mechanism of crystal toxin action in insects," leading them to question whether ...

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Mycoplasma gallisepticum infection in house finches (Carpodacus mexicanus) affects mosquito blood feeding patterns.  

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Disease-induced lethargy can diminish host capacity to repel or kill biting mosquitoes. We exposed house finches (Carpodacus mexicanus) to mosquitoes (Culex pipiens pipiens), repeated the experiment after inoculating finches with Mycoplasma gallisepticum, and then repeated the experiment with the same birds after curing their infections. We videotaped avian behaviors before and during mosquito exposure, identifying hosts through blood meal DNA fingerprinting. Results revealed heterogeneity in mosquito preference regardless of infection. Mosquitoes choosing between two healthy finches were more likely to feed upon the same individual bird consistently. When one bird was sick, mosquitoes exhibited no preference. Sick birds made fewer total defensive behaviors than healthy birds, but only foot stomps were associated with reduced mosquito feeding success. Our results suggest that Mycoplasma and other avian infections that alter bird defensive behavior may influence mosquito feeding patterns and transmission of arthropod-borne pathogens such as West Nile virus. PMID:17827365

Darbro, Jonathan M; Dhondt, André A; Vermeylen, Françoise M; Harrington, Laura C

2007-09-01

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An entomopathogenic fungus for control of adult African malaria mosquitoes.  

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Biological control of malaria mosquitoes in Africa has rarely been used in vector control programs. Recent developments in this field show that certain fungi are virulent to adult Anopheles mosquitoes. Practical delivery of an entomopathogenic fungus that infected and killed adult Anopheles gambiae, Africa's main malaria vector, was achieved in rural African village houses. An entomological inoculation rate model suggests that implementation of this vector control method, even at the observed...

2005-01-01

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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 ...

Moore Sarah J; Chitnis Nakul; Killeen Gerry F; 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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Use of Expanded Polystyrene (EPS) and Shredded Waste Polystyrene (SWAP) Beads for Control of Mosquitoes  

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Background: Mosquitoes transmit several diseases to human. There are several measures for control of larvae. As part of Integrated Vector Management (IVM) program, the utility of floating layers of polystyrene beads (EPS) is a po­ten­tial alternative in habitats of mosquito larva. EPS beads prevent oviposition of mosquito as well as killing the im­ma­ture stages by forming a tick layer on the water surface.  They are cheap, environmentally safe and do ...

Soltani, A.; Vatandoost, H.; Jabbari, H.; Ar, Mesdaghinia; Ah, Mahvi; Younesian, M.; Aa, Hanafi-bojd; Bozorgzadeh, S.; MR Abai; Pakari, A.; Shabkhiz, H.

2008-01-01

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

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Full Text Available 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 mosquitoes to non-users rather than killing them outright. Methods A process-explicit model of malaria transmission is described which captures the sequential interaction between deterrent and toxic actions of vector control pesticides and accounts for the distinctive impacts of toxic activities which kill mosquitoes before or after they have fed upon the occupant of a covered house or sleeping space. Results Increasing deterrency increases personal protection but consistently reduces communal protection because deterrent sub-lethal exposure inevitably reduces the proportion subsequently exposed to higher lethal doses. If the high coverage targets of the World Health Organization are achieved, purely toxic products with no deterrence are predicted to generally provide superior protection to non-users and even users, especially where vectors feed exclusively on humans and a substantial amount of transmission occurs outdoors. Remarkably, this is even the case if that product confers no personal protection and only kills mosquitoes after they have fed. Conclusions Products with purely mosquito-toxic profiles may, therefore, be preferable for programmes with universal coverage targets, rather than those with equivalent toxicity but which also have higher deterrence. However, if purely mosquito-toxic products confer little personal protection because they do not deter mosquitoes and only kill them after they have fed, then they will require aggressive "catch up" campaigns, with behaviour change communication strategies that emphasize the communal nature of protection, to achieve high coverage rapidly.

Moore Sarah J

2011-07-01

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The role of volatile semiochemicals in mediating host location and selection by nuisance and disease-transmitting cattle flies.  

Science.gov (United States)

The role of volatile semiochemicals in mediating the location and selection within herds of Holstein-Friesian heifers by nuisance and disease-transmitting cattle flies was investigated using coupled gas chromatography-electrophysiology (GC-EAG), coupled gas chromatography-mass spectrometry (GC-MS), electrophysiology (EAG), laboratory behaviour and field studies. Using volatile extracts collected by air entrainment from heifers in the Netherlands, a number of active peaks were located by coupled GC-EAG for Musca autumnalis (de Geer) (Diptera: Muscidae) and Haematobia irritans (L.) (Diptera: Muscidae). Volatile samples were also collected from two heifers in Denmark shown in previous counting experiments to differ significantly in their fly loads. Coupled GC-EAG using Ha. irritans antennae revealed differences in the EAG response to the samples, with additional EAG activity in the sample collected from the heifer with the lower fly load. To identify more EAG active compounds, volatiles were also collected from 48-h-old urine by air entrainment. In total, 23 compounds were located and identified by coupled GC-EAG and GC-MS. Further electrophysiological testing of these compounds with five fly species [M. autumnalis, Ha. irritans, Hydrotaea irritans (L.) (Diptera: Muscidae), Stomoxys calcitrans (L.) (Diptera: Musicidae) and Wohlfahrtia magnifica (Schiner) (Diptera: Sarcophagidae)] showed that only some of the compounds were physiologically active across the range of flies tested. These included 1-octen-3-ol, 6-methyl-5-hepten-2-one, (Z)-3-hexen-1-ol, naphthalene, and all EAG active compounds identified from urine. Compounds showing significant EAG activity were tested for behavioural activity using a wind-tunnel designed for measuring upwind flight behaviour. At certain concentrations, 1-octen-3-ol, 6-methyl-5-hepten-2-one and 3-octanol increased upwind flight, whereas naphthalene, propyl butanoate and linalool reduced upwind flight. In field studies using small herds of heifers ranked according to their fly load, individual slow-release formulations of 1-octen-3-ol and 6-methyl-5-hepten-2-one, when applied to low and high fly loading heifers, reduced fly loads on these individuals. This study provides evidence for the hypothesis that the natural differential attractiveness within herds of Holstein-Freisian heifers, i.e. a single host species, for cattle flies is partly due to differences in volatile semiochemicals emitted from the host. It is suggested that this phenomenon applies to other vertebrate host species and their associated insect pests. PMID:15641996

Birkett, M A; Agelopoulos, N; Jensen, K-M V; Jespersen, J B; Pickett, J A; Prijs, H J; Thomas, G; Trapman, J J; Wadhams, L J; Woodcock, C M

2004-12-01

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Olfaction in mosquitoes  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Female mosquitoes are vectors of diseases, affecting both livestock and humans. The host-seeking and identification behaviors of mosquitoes are mediated mainly by olfactory cues. The peripheral olfactory organs of mosquitoes which perceive olfactory cues are the antennae and maxillary palps. These appendages bear numerous hair shaped structures, sensilla, in which olfactory receptor neurons (ORNs) are housed. The ORNs detect and discriminate various odorant molecules and send information rega...

Ghaninia, Majid

2007-01-01

32

Malaria mosquitoes attracted by fatal fungus.  

Science.gov (United States)

Insect-killing fungi such as Beauveria bassiana are being evaluated as possible active ingredients for use in novel biopesticides against mosquito vectors that transmit malaria. Fungal pathogens infect through contact and so applications of spores to surfaces such as walls, nets, or other resting sites provide possible routes to infect mosquitoes in and around domestic dwellings. However, some insects can detect and actively avoid fungal spores to reduce infection risk. If true for mosquitoes, such behavior could render the biopesticide approach ineffective. Here we find that the spores of B. bassiana are highly attractive to females of Anopheles stephensi, a major anopheline mosquito vector of human malaria in Asia. We further find that An. stephensi females are preferentially attracted to dead and dying caterpillars infected with B. bassiana, landing on them and subsequently becoming infected with the fungus. Females are also preferentially attracted to cloth sprayed with oil-formulated B. bassiana spores, with 95% of the attracted females becoming infected after a one-minute visit on the cloth. This is the first report of an insect being attracted to a lethal fungal pathogen. The exact mechanisms involved in this behavior remain unclear. Nonetheless, our results indicate that biopesticidal formulations comprising B. bassiana spores will be conducive to attraction and on-source visitation by malaria vectors. PMID:23658757

George, Justin; Jenkins, Nina E; Blanford, Simon; Thomas, Matthew B; Baker, Thomas C

2013-01-01

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Persistence of Viral RNA in Chikungunya Virus-Infected Aedes aegypti (Diptera: Culicidae) Mosquitoes after Prolonged Storage at 28°C  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Experiments were conducted to determine the persistence of chikungunya viral (CHIKV) RNA in experimentally infected Aedes aegypti mosquitoes stored for prolonged periods at 28°C. Intra-thoracically inoculated mosquitoes with confirmed positivity were killed by quick freezing at -80°C, applied to sticky tape, and stored at 28°C with 80 ± 5% relative humidity (RH). At weekly intervals, five mosquitoes were removed from the tape randomly and assayed individually for detection of viral RNA by...

Mavale, Mangala; Sudeep, Anakkathil; Gokhale, Mangesh; Hundekar, Supriya; Parashar, Deepti; Ghodke, Youwaraj; Arankalle, Vidya; Mishra, Akhilesh Chandra

2012-01-01

34

Mosquito, egg raft (image)  

Science.gov (United States)

Mosquitoes of the Culex species lay their eggs in the form of egg rafts that float in still or stagnant water. The mosquito lays the eggs one at a time sticking them together in the shape of a raft. An egg raft ...

35

Natural and engineered mosquito immunity.  

Science.gov (United States)

A recent paper in BMC Microbiology shows how suppression of mosquito innate immunity against a virus that the mosquito can normally tolerate increases mosquito mortality. This is just one of several approaches that may soon bring genetics-based mosquito control methods from the laboratory into the field. PMID:19439051

Alphey, Luke

2009-01-01

36

Killing Forms and Applications  

Directory of Open Access Journals (Sweden)

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

37

[Novel approach toward infectious diseases--combating malaria by using genetically engineered mosquitoes].  

Science.gov (United States)

Malaria is a devastating disease that kills millions of people every year, yet there has been little progress in controlling this disease. Mosquitoes are obligatory vectors for the disease and this part of the parasite cycle represents a potential weak link in transmission. Therefore, control of parasite development in the mosquito has considerable promise as a new approach in the fight against malaria. In recent year, methods for the genetic modification of mosquitoes have been developed, and effector genes whose products interfere with Plasmodium development in the mosquito are beginning to be identified. Here we review strategies to alter mosquito vector competence and consider issues related to translating this knowledge to field applications. PMID:17877001

Yoshida, Shigeto; Shimada, Yohei; Watanabe, Hiroyuki

2007-09-01

38

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

39

Suppression of RNA interference increases alphavirus replication and virus-associated mortality in Aedes aegypti mosquitoes  

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Full Text Available Abstract Background Arthropod-borne viruses (arboviruses can persistently infect and cause limited damage to mosquito vectors. RNA interference (RNAi is a mosquito antiviral response important in restricting RNA virus replication and has been shown to be active against some arboviruses. The goal of this study was to use a recombinant Sindbis virus (SINV; family Togaviridae; genus Alphavirus that expresses B2 protein of Flock House virus (FHV; family Nodaviridae; genus Alphanodavirus, a protein that inhibits RNAi, to determine the effects of linking arbovirus infection with RNAi inhibition. Results B2 protein expression from SINV (TE/3'2J inhibited the accumulation of non-specific small RNAs in Aedes aegypti mosquito cell culture and virus-specific small RNAs both in infected cell culture and Ae. aegypti mosquitoes. More viral genomic and subgenomic RNA accumulated in cells and mosquitoes infected with TE/3'2J virus expressing B2 (TE/3'2J/B2 compared to TE/3'2J and TE/3'2J virus expressing GFP. TE/3'2J/B2 exhibited increased infection rates, dissemination rates, and infectious virus titers in mosquitoes following oral bloodmeal. Following infectious oral bloodmeal, significantly more mosquitoes died when TE/3'2J/B2 was ingested. The virus was 100% lethal following intrathoracic inoculation of multiple mosquito species and lethality was dose-dependent in Ae. aegypti. Conclusion We show that RNAi is active in Ae. aegypti cell culture and that B2 protein inhibits RNAi in mosquito cells when expressed by a recombinant SINV. Also, SINV more efficiently replicates in mosquito cells when RNAi is inhibited. Finally, TE/3'2J/B2 kills mosquitoes in a dose-dependent manner independent of infection route and mosquito species.

Geiss Brian J

2009-03-01

40

Ultra-prolonged activation of CO2-sensing neurons disorients mosquitoes.  

Science.gov (United States)

Carbon dioxide (CO(2)) present in exhaled air is the most important sensory cue for female blood-feeding mosquitoes, causing activation of long-distance host-seeking flight, navigation towards the vertebrate host and, in the case of Aedes aegypti, increased sensitivity to skin odours. The CO(2) detection machinery is therefore an ideal target to disrupt host seeking. Here we use electrophysiological assays to identify a volatile odorant that causes an unusual, ultra-prolonged activation of CO(2)-detecting neurons in three major disease-transmitting mosquitoes: Anopheles gambiae, Culex quinquefasciatus and A. aegypti. Importantly, ultra-prolonged activation of these neurons severely compromises their ability subsequently to detect CO(2) for several minutes. We also identify odours that strongly inhibit CO(2)-sensitive neurons as candidates for use in disruption of host-seeking behaviour, as well as an odour that evokes CO(2)-like activity and thus has potential use as a lure in trapping devices. Analysis of responses to panels of structurally related odours across the three mosquitoes and Drosophila, which have related CO(2)-receptor proteins, reveals a pattern of inhibition that is often conserved. We use video tracking in wind-tunnel experiments to demonstrate that the novel ultra-prolonged activators can completely disrupt CO(2)-mediated activation as well as source-finding behaviour in Aedes mosquitoes, even after the odour is no longer present. Lastly, semi-field studies demonstrate that use of ultra-prolonged activators disrupts CO(2)-mediated hut entry behaviour of Culex mosquitoes. The three classes of CO(2)-response-modifying odours offer powerful instruments for developing new generations of insect repellents and lures, which even in small quantities can interfere with the ability of mosquitoes to seek humans. PMID:21637258

Turner, Stephanie Lynn; Li, Nan; Guda, Tom; Githure, John; Cardé, Ring T; Ray, Anandasankar

2011-06-01

 
 
 
 
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Assessing the efficacy of candidate mosquito repellents against the background of an attractive source that mimics a human host.  

Science.gov (United States)

Mosquito repellents are used around the globe to protect against nuisance biting and disease-transmitting mosquitoes. Recently, there has been renewed interest in the development of repellents as tools to control the transmission of mosquito-borne diseases. We present a new bioassay for the accurate assessment of candidate repellent compounds, using a synthetic odour that mimics the odour blend released by human skin. Using DEET (N,N-diethyl-meta-toluamide) and PMD (p-menthane-3,8-diol) as reference compounds, nine candidate repellents were tested, of which five showed significant repellency to the malaria mosquito Anopheles gambiae sensu stricto (Diptera: Culicidae). These included: 2-nonanone; 6-methyl-5-hepten-2-one; linalool; ?-decalactone, and ?-undecalactone. The lactones were also tested on the yellow fever mosquito Aedes aegypti (Stegomyia aegypti) (Diptera: Culicidae), against which they showed similar degrees of repellency. We conclude that the lactones are highly promising repellents, particularly because these compounds are pleasant-smelling, natural products that are also present in human food sources. PMID:24797537

Menger, D J; VAN Loon, J J A; Takken, W

2014-12-01

42

Flavivirus-Mosquito Interactions  

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Full Text Available The Flavivirus genus is in the family Flaviviridae and is comprised of more than 70 viruses. These viruses have a broad geographic range, circulating on every continent except Antarctica. Mosquito-borne flaviviruses, such as yellow fever virus, dengue virus serotypes 1–4, Japanese encephalitis virus, and West Nile virus are responsible for significant human morbidity and mortality in affected regions. This review focuses on what is known about flavivirus-mosquito interactions and presents key data collected from the field and laboratory-based molecular and ultrastructural evaluations.

Yan-Jang S. Huang

2014-11-01

43

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

44

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.

2007-06-01

45

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

Directory of Open Access Journals (Sweden)

Full Text Available 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, are 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

2007-06-01

46

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

Science.gov (United States)

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, are 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. PMID:17612761

Sperança, Márcia Aparecida; Capurro, Margareth Lara

2007-06-01

47

Mosquito glutathione transferases.  

Science.gov (United States)

The glutathione transferases (glutathione S-transferases, GSTs) are a diverse family of enzymes involved in a wide range of biological processes, many of which involve the conjugation of the tripeptide glutathione to an electrophilic substrate. Relatively little is known about the endogenous substrates of mosquito GSTs, and most studies have focused on their role in insecticide metabolism, because elevated levels of GST activity have been associated with resistance to all the major classes of insecticides. In addition, there is growing interest in the role of this enzyme family in maintaining the redox status of the mosquito cell, particularly in relation to vectorial capacity. Most GSTs are cytosolic dimeric proteins, although a smaller class of microsomal GSTs exists in insects, mammals, and plants. Each GST subunit has a G site that binds glutathione and a substrate-binding site or H site. There are more than 30 GST genes in mosquitoes. Additional diversity is contributed by alternative splicing to produce GSTs with differing substrate specificities. In this review, we first discuss the diversity of insect GST enzymes and their mode of action before focusing on the various functions that have been attributed to specific mosquito GSTs. PMID:16399389

Ranson, Hilary; Hemingway, Janet

2005-01-01

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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

49

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

Science.gov (United States)

... false Newtown Creek, Dutch Kills, English Kills and their tributaries. 117...801 Newtown Creek, Dutch Kills, English Kills and their tributaries. (a...bridges across Newtown Creek, Dutch Kills, English Kills, and their tributaries:...

2010-07-01

50

Maximum Equilibrium Prevalence of Mosquito-Borne Microparasite Infections in Humans  

Science.gov (United States)

To determine the maximum equilibrium prevalence of mosquito-borne microparasitic infections, this paper proposes a general model for vector-borne infections which is flexible enough to comprise the dynamics of a great number of the known diseases transmitted by arthropods. From equilibrium analysis, we determined the number of infected vectors as an explicit function of the model's parameters and the prevalence of infection in the hosts. From the analysis, it is also possible to derive the basic reproduction number and the equilibrium force of infection as a function of those parameters and variables. From the force of infection, we were able to conclude that, depending on the disease's structure and the model's parameters, there is a maximum value of equilibrium prevalence for each of the mosquito-borne microparasitic infections. The analysis is exemplified by the cases of malaria and dengue fever. With the values of the parameters chosen to illustrate those calculations, the maximum equilibrium prevalence found was 31% and 0.02% for malaria and dengue, respectively. The equilibrium analysis demonstrated that there is a maximum prevalence for the mosquito-borne microparasitic infections. PMID:24454539

Burattini, Marcelo Nascimento; Coutinho, Francisco Antonio Bezerra; Lopez, Luis Fernandez; Massad, Eduardo

2013-01-01

51

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

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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.

Surapol Naowarat

2013-01-01

52

Anopheles arabiensis egg treatment with dieldrin for sex separation leaves residues in male adult mosquitoes that can bioaccumulate in goldfish (Carassius auratus auratus).  

Science.gov (United States)

The sterile insect technique (SIT) is a biological control tactic that is used as a component of area-wide integrated pest management (AW-IPM) programs. The SIT can only be applied against disease-transmitting mosquitoes when only sterile male mosquitoes are released, and the blood-sucking and potentially disease-transmitting females are eliminated from the production line. For Anopheles arabiensis, a potent vector of malaria, a genetic sexing strain was developed whereby females can be eliminated by treating the eggs or larvae with the insecticide dieldrin. To evaluate the presence of dieldrin residues in male mosquitoes designated for SIT releases, a simple, sensitive, and accurate gas chromatography-electron capture detector (GC-ECD) method was developed. In addition, bioaccumulation and food chain transfer of these residues to fish after feeding with treated mosquitoes was demonstrated. The overall recovery from method validation studies was 77.3?±?2.2% (mean?±?relative standard deviation [RSD]) for the mosquitoes, and 99.1?±?4.4% (mean?±?RSD) for the fish. The average dieldrin concentration found in adult male An. arabiensis was 28.1?±?2.9?µg/kg (mean?±?standard deviation [SD]). A range of 23.9?±?1.1?µg/kg to 73.9?±?5.2?µg/kg (mean?±?SD) of dieldrin was found in the fish samples. These findings indicate the need to reassess the environmental and health implications of control operations with a SIT component against An. arabiensis that involves using persistent organochlorines in the sexing process. PMID:23983078

Yamada, Hanano; Jandric, Zora; Chhem-Kieth, Sorivan; Vreysen, Marc J B; Rathor, Mohammad N; Gilles, Jeremie R L; Cannavan, Andrew

2013-12-01

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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

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Effect of triethylamine on the recovery of selected South American alphaviruses, flaviviruses, and bunyaviruses from mosquito (Diptera: Culicidae) pools.  

Science.gov (United States)

We evaluated the effect of triethylamine (TEA) on the recovery of infectious virus from pools of mosquitoes for two South American alphaviruses (eastern equine encephalomyelitis and Venezuelan equine encephalomyelitis subtypes IIIC and ID), one flavivirus (Ilheus) and two bunyaviruses (Mirim [Guama group] and Itaqui [group C]). Mosquitoes were inoculated intrathoracically with virus, held for 7-10 d at 26 degrees C, and handled under one of four regimens before testing for the presence of virus by plaque assay. Mosquitoes were killed by freezing at - 70 degrees C for 3 min and tested immediately for the presence of virus; killed by freezing at -70 degrees C for 3 min and then held at room temperature for 1 h before testing for the presence of virus; anesthetized with TEA and assayed immediately for the presence of virus; or anesthetized with TEA and then held at room temperature for 1 h before being assayed for the presence of virus. For each of the viruses tested, viral titers in mosquitoes anesthetized with TEA were similar to those in mosquitoes killed by freezing at-70 degrees C. Likewise, there was no significant difference in viral titers in mosquitoes anesthetized with TEA and held at room temperature for 1 h or in mosquitoes frozen at -70 degrees C and held at room temperature for 1 h before being processed for virus by isolation. Triethylamine is advantageous for the handling of mosquitoes in a field environment. The elimination of the need for a cold chain, without compromising virus recovery, increases the feasibility of conducting research projects requiring the isolation of live virus from mosquitoes in remote tropical environments. PMID:12349865

O'Guinn, Monica L; Turell, Michael J

2002-09-01

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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

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Charged Conformal Killing Spinors  

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We study the twistor equation on pseudo-Riemannian $Spin^c-$manifolds whose solutions we call charged conformal Killing spinors (CCKS). We derive several integrability conditions for the existence of CCKS and study their relations to spinor bilinears. A construction principle for Lorentzian manifolds admitting CCKS with nontrivial charge starting from CR-geometry is presented. We obtain a partial classification result in the Lorentzian case under the additional assumption th...

Lischewski, Andree

2014-01-01

57

Delayed action insecticides and their role in mosquito and malaria control.  

Science.gov (United States)

There is considerable interest in the management of insecticide resistance in mosquitoes. One possible approach to slowing down the evolution of resistance is to use late-life-acting (LLA) insecticides that selectively kill only the old mosquitoes that transmit malaria, thereby reducing selection pressure favoring resistance. In this paper we consider an age-structured compartmental model for malaria with two mosquito strains that differ in resistance to insecticide, using an SEI approach to model malaria in the mosquitoes and thereby incorporating the parasite developmental times for the two strains. The human population is modeled using an SEI approach. We consider both conventional insecticides that target all adult mosquitoes, and LLA insecticides that target only old mosquitoes. According to linearised theory the potency of the insecticide affects mainly the speed of evolution of resistance. Mutations that confer resistance can also affect other parameters such as mean adult life span and parasite developmental time. For both conventional and LLA insecticides the stability of the malaria-free equilibrium, with only the resistant mosquito strain present, depends mainly on these other parameters. This suggests that the main long term role of an insecticide could be to induce genetic changes that have a desirable effect on a vital parameter such as adult life span. However, when this equilibrium is unstable, numerical simulations suggest that a potent LLA insecticide can slow down the spread of malaria in humans but that the timing of its action is very important. PMID:23274406

Wang, Chuncheng; Gourley, Stephen A; Liu, Rongsong

2014-01-01

58

Development of briquettes from natural products for knockdown of mosquitoes  

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Full Text Available Malaria is a major death cause in many parts of the world. This necessitates the development of alternative ways of curbing the problem. This study focused on the development of briquettes that would knockdown (KD mosquitoes in the course of burning. The briquettes were developed using jatropha seed husks (source of energy, cow dung (binder and pyrethrin (insecticide, which were then tested for their ability to knockdown and kill mosquitoes at Kenya Pyrethrum Board laboratory. The results were analysed using the analysis-of-variance (ANOVA tool. The results showed that a hand pressed mixture of jatropha seed husks, pyrethrin and cow dung (binder in the ratio of 3 g: 0.5 ml: 2 g respectively can cause a 100 % mosquito knockdown within 10 min. and mortality of 97.50 % within 24 hr when burnt indoors. The percentage mosquito knockdown and percentage mortality rate were found to vary significantly with the amount of pyrethrin used. It is expected that the findings of this study will generate new knowledge on briquette development and also contribute to waste management. The research findings will also contribute towards reducing the death rate resulting from malaria.

Thuku L. Nyakeru

2012-05-01

59

Wolbachia surface protein induces innate immune responses in mosquito cells  

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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

60

Bacteria expressing single-chain immunotoxin inhibit malaria parasite development in mosquitoes.  

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Single-chain immunotoxins are ideal tools to selectively kill infectious agents. In applying this technology to block transmission of malaria parasites in the mosquito vector, we have constructed a single-chain immunotoxin composed of a single-chain antibody fragment (scFv) directed to Pbs2l on the surface of Plasmodium berghei ookinetes linked to a lytic peptide, Shiva-1. The single-chain immunotoxin was expressed in Escherichia coli, and the protein was purified by a Ni-NTA column. The single-chain immunotoxin was initially shown to exhibit greater killing properties for P. berghei ookinetes in vitro compared with the scFv or synthetic Shiva-1 peptide alone. In an attempt to block malaria transmission by genetically engineered bacteria, recombinant E. coli harboring the single-chain immunotoxin gene were introduced into the mosquito midgut by membrane feeding. The number of infected mosquitoes and their oocyst densities were significantly reduced when the mosquitoes were subsequently allowed to feed on P. berghei-infected mice. These results indicate not only that a single-chain immunotoxin with enhanced parasiticidal activity could form a basis for the development of more effective malaria therapeutic agents, but also that introduction of genetically engineered bacteria into anopheline mosquitoes may offer a practical approach to the regulation of malaria transmission. PMID:11254957

Yoshida, S; Ioka, D; Matsuoka, H; Endo, H; Ishii, A

2001-03-01

 
 
 
 
61

Eliciting renal failure in mosquitoes with a small-molecule inhibitor of inward-rectifying potassium channels.  

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Mosquito-borne diseases such as malaria and dengue fever take a large toll on global health. The primary chemical agents used for controlling mosquitoes are insecticides that target the nervous system. However, the emergence of resistance in mosquito populations is reducing the efficacy of available insecticides. The development of new insecticides is therefore urgent. Here we show that VU573, a small-molecule inhibitor of mammalian inward-rectifying potassium (Kir) channels, inhibits a Kir channel cloned from the renal (Malpighian) tubules of Aedes aegypti (AeKir1). Injection of VU573 into the hemolymph of adult female mosquitoes (Ae. aegypti) disrupts the production and excretion of urine in a manner consistent with channel block of AeKir1 and renders the mosquitoes incapacitated (flightless or dead) within 24 hours. Moreover, the toxicity of VU573 in mosquitoes (Ae. aegypti) is exacerbated when hemolymph potassium levels are elevated, suggesting that Kir channels are essential for maintenance of whole-animal potassium homeostasis. Our study demonstrates that renal failure is a promising mechanism of action for killing mosquitoes, and motivates the discovery of selective small-molecule inhibitors of mosquito Kir channels for use as insecticides. PMID:23734226

Raphemot, Rene; Rouhier, Matthew F; Hopkins, Corey R; Gogliotti, Rocco D; Lovell, Kimberly M; Hine, Rebecca M; Ghosalkar, Dhairyasheel; Longo, Anthony; Beyenbach, Klaus W; Denton, Jerod S; Piermarini, Peter M

2013-01-01

62

What Killed Substantial Form?  

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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

63

How to kill creativity.  

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In today's knowledge economy, creativity is more important than ever. But many companies unwittingly employ managerial practices that kill it. How? By crushing their employees' intrinsic motivation--the strong internal desire to do something based on interests and passions. Managers don't kill creativity on purpose. Yet in the pursuit of productivity, efficiency, and control--all worthy business imperatives--they undermine creativity. It doesn't have to be that way, says Teresa Amabile. Business imperatives can comfortably coexist with creativity. But managers will have to change their thinking first. Specifically, managers will need to understand that creativity has three parts: expertise, the ability to think flexibly and imaginatively, and motivation. Managers can influence the first two, but doing so is costly and slow. It would be far more effective to increase employees' intrinsic motivation. To that end, managers have five levers to pull: the amount of challenge they give employees, the degree of freedom they grant around process, the way they design work groups, the level of encouragement they give, and the nature of organizational support. Take challenge as an example. Intrinsic motivation is high when employees feel challenged but not overwhelmed by their work. The task for managers, therefore, becomes matching people to the right assignments. Consider also freedom. Intrinsic motivation--and thus creativity--soars when managers let people decide how to achieve goals, not what goals to achieve. Managers can make a difference when it comes to employee creativity. The result can be truly innovative companies in which creativity doesn't just survive but actually thrives. PMID:10185433

Amabile, T M

1998-01-01

64

Botanicals as Mosquito Larvicides  

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Full Text Available Methanol extracts of 19 indigenous plants were evaluated as mosquito larvicide. Among these, pericarp of Zanthoxylum limonella was found to have the most promising larvicidal properties against Aedes(s albopictus and Culex quinquefasciatus with LC90 values at 0.47 ppm and 0.73 ppm, respectively. The extract of Piper nigrum was also found very effective (LC90 on the larvae of both the species at 6.8 ppm and 8.4 ppm, respectively. The extracts of the remaining plant parts showed LC90 values at above 100 ppm concentration. Extract of Calotropis gigantea was found to be the least effective ( LC90 values at 962.8 ppm and 1091.8 ppm against the larvae of both the species. However, plant extracts were found more effective against Aedes(s albopictus larvae than against Culex quinquefasciatus larvae.

D.R. Nath

2006-10-01

65

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

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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

66

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

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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

67

Larvicidal activities of some organotin compounds on mosquito larvae: a QSAR study.  

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Mosquitoes are not only the cause of nuisance by their bites but also transmit deadly diseases like malaria, filariasis, yellow fever, dengue, and Japanese encephalitis. In this paper, nine QSAR models were developed using different series of organotins with respect to their larvicidal activities against Aedes aegypti and Anopheles stephensi mosquito larvae. Internal [cross-validation (LOO-q(2)), quality factor (Q), Fischer statistics (F), and Y-randomization] and external validation tests have validated all these QSAR models. QSAR results suggest that the two most important determinants for the toxicity are the hydrophobic (pi) and Hammett electronic (sigma(+)) parameters of the substituents, and the kill mechanism is different for these two species of mosquito larvae. On the basis of QSAR (6), nine compounds 4a-4i are suggested as potential synthetic targets. PMID:18423942

Hansch, Corwin; Verma, Rajeshwar P

2009-01-01

68

Larvicidal Activity of Tephrosia vogelii Crude Extracts on Mosquito Larval Stages  

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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

69

Mosquito Infection Responses to Developing Filarial Worms  

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Human lymphatic filariasis is a mosquito-vectored disease caused by the nematode parasites Wuchereria bancrofti, Brugia malayi and Brugia timori. These are relatively large roundworms that can cause considerable damage in compatible mosquito vectors. In order to assess how mosquitoes respond to infection in compatible mosquito-filarial worm associations, microarray analysis was used to evaluate transcriptome changes in Aedes aegypti at various times during B. malayi development. Changes in tr...

Erickson, Sara M.; Xi, Zhiyong; Mayhew, George F.; Ramirez, Jose L.; Aliota, Matthew T.; Christensen, Bruce M.; Dimopoulos, George

2009-01-01

70

Evaluation of plant-mediated synthesized silver nanoparticles against vector mosquitoes.  

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Diseases transmitted by blood-feeding mosquitoes, such as dengue fever, dengue hemorrhagic fever, Japanese encephalitis, malaria, and filariasis, are increasing in prevalence, particularly in tropical and subtropical zones. To control mosquitoes and mosquito-borne diseases, which have worldwide health and economic impacts, synthetic insecticide-based interventions are still necessary, particularly in situations of epidemic outbreak and sudden increases of adult mosquitoes. Green nanoparticle synthesis has been achieved using environmentally acceptable plant extract and eco-friendly reducing and capping agents. In view of the recently increased interest in developing plant origin insecticides as an alternative to chemical insecticide, in the present study, the adulticidal activity of silver nanoparticles (AgNPs) synthesized using Heliotropium indicum plant leaf extract against adults of Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus was determined. Adult mosquitoes were exposed to varying concentrations of aqueous extract of H. indicum and synthesized AgNPs for 24 h. AgNPs were rapidly synthesized using the leaf extract of H. indicum, and the formation of nanoparticles was observed within 6 h. The results recorded from UV-vis spectrum, Fourier transform infrared, X-ray diffraction, scanning electron microscopy, and transmission electron microscopy support the biosynthesis and characterization of AgNPs. The maximum efficacy was observed in synthesized AgNPs against the adult of A. stephensi (lethal dose (LD)50?=?26.712 ?g/mL; LD90?=?49.061 ?g/mL), A. aegypti (LD50?=?29.626 ?g/mL; LD90?=?54.269 ?g/mL), and C. quinquefasciatus (LD50?=?32.077 ?g/mL; LD90?=?58.426 ?g/mL), respectively. No mortality was observed in the control. These results suggest that the leaf aqueous extracts of H.indicum and green synthesis of AgNPs have the potential to be used as an ideal eco-friendly approach for the control of the A. stephensi, A. aegypti, and C. quinquefasciatus. This is the first report on the adulticidal activity of the plant extracts and AgNPs. PMID:25300419

Veerakumar, Kaliyan; Govindarajan, Marimuthu; Hoti, S L

2014-12-01

71

Exploiting mosquito sugar feeding to detect mosquito-borne pathogens.  

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Arthropod-borne viruses (arboviruses) represent a global public health problem, with dengue viruses causing millions of infections annually, while emerging arboviruses, such as West Nile, Japanese encephalitis, and chikungunya viruses have dramatically expanded their geographical ranges. Surveillance of arboviruses provides vital data regarding their prevalence and distribution that may be utilized for biosecurity measures and the implementation of disease control strategies. However, current surveillance methods that involve detection of virus in mosquito populations or sero-conversion in vertebrate hosts are laborious, expensive, and logistically problematic. We report a unique arbovirus surveillance system to detect arboviruses that exploits the process whereby mosquitoes expectorate virus in their saliva during sugar feeding. In this system, infected mosquitoes captured by CO(2)-baited updraft box traps are allowed to feed on honey-soaked nucleic acid preservation cards within the trap. The cards are then analyzed for expectorated virus using real-time reverse transcription-PCR. In field trials, this system detected the presence of Ross River and Barmah Forest viruses in multiple traps deployed at two locations in Australia. Viral RNA was preserved for at least seven days on the cards, allowing for long-term placement of traps and continuous collection of data documenting virus presence in mosquito populations. Furthermore no mosquito handling or processing was required and cards were conveniently shipped to the laboratory overnight. The simplicity and efficacy of this approach has the potential to transform current approaches to vector-borne disease surveillance by streamlining the monitoring of pathogens in vector populations. PMID:20534559

Hall-Mendelin, Sonja; Ritchie, Scott A; Johansen, Cheryl A; Zborowski, Paul; Cortis, Giles; Dandridge, Scott; Hall, Roy A; van den Hurk, Andrew F

2010-06-22

72

Insecticide-resistant mosquitoes and malaria control.  

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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

73

Rural buyers' perception about mosquito repellants  

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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

74

Mosquito control by larvivorous fish.  

Science.gov (United States)

There is growing of the effects of insecticide used controlling the vectors of human diseases. Manipulating or introducing an auto-reproducing predator into the ecosystem may provide sustained biological control of pest populations. The selection of a biological agent should be based on its self-replicating capacity, preference for the target pest population in the presence of alternate natural prey, adaptability to the introduced environment, and overall interaction with indigenous organisms. In order to achieve an acceptable range of control, a sound knowledge of various attributes of interactions between the pest population and the predator to be introduced is desirable. Biological larviciding for the control of mosquito borne diseases is feasible and effective only when breeding sites are relatively few or are easily identified and treated. Larval control appears to be promising in urban areas, given that the density of humans needing protection is higher than the limited number of breeding sites. Since 1937, fish have been employed for controlling mosquito larvae. Different types of fish have been used so far in this operational technique. However, use of fish of indigenous origin is found to be more appropriate in this operation. This review presents information on different larvivorous fish species and the present status of their use in mosquito control and provides a ready reference for workers involved and interested in mosquito research. PMID:18316849

Chandra, G; Bhattacharjee, I; Chatterjee, S N; Ghosh, A

2008-01-01

75

Pharmacological validation of an inward-rectifier potassium (Kir) channel as an insecticide target in the yellow fever mosquito Aedes aegypti.  

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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. PMID:24959745

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

2014-01-01

76

Fish Kills 1969-1987  

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A total of 66 fish kills were reported to the Regional Fisheries Boards in 1986 and 122 in 1987. Effluents from agriculture and agriculture-based industries accounted for 56 of the kills in 1986 and 95 in 1987. When the two periods, 1969-74 and 1980-87 are compared, it can be seen that the numbers caused by sewage and industrial wastes have not changed significantly, but the damage from agriculture has risen at an alarming rate. The fact that problems from sewage and industry remained at a lo...

Mccarthy, D. T.

1988-01-01

77

Evaluation of indoor residual spraying with the pyrrole insecticide chlorfenapyr against pyrethroid-susceptible Anopheles arabiensis and pyrethroid-resistant Culex quinquefasciatus mosquitoes.  

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Chlorfenapyr is a pyrrole insecticide with a unique non-neurological mode of action. Laboratory bioassays of chlorfenapyr comparing the mortality of pyrethroid-susceptible and -resistant Anopheles gambiae s.s. and Culex quinquefasciatus mosquitoes indicated that operational cross-resistance is unlikely to occur (resistance ratio ranged between 0 and 2.1). Three trials of chlorfenapyr indoor residual spraying were undertaken in experimental huts in an area of rice irrigation in northern Tanzania that supports breeding of A. arabiensis. Daily mosquito collections were undertaken to assess product performance primarily in terms of mortality. In the second trial, 250mg/m(2) and 500mg/m(2) chlorfenapyr were tested for residual efficacy over 6 months. Both dosages killed 54% of C. quinquefasciatus, whilst for A. arabiensis 250mg/m(2) killed 48% compared with 41% for 500mg/m(2); mortality was as high at the end of the trial as at the beginning. In the third trial, 250mg/m(2) chlorfenapyr was compared with the pyrethroid alpha-cypermethrin dosed at 30mg/m(2). Chlorfenapyr performance was equivalent to the pyrethroid against A. arabiensis, with both insecticides killing 50% of mosquitoes. Chlorfenapyr killed a significantly higher proportion of pyrethroid-resistant C. quinquefasciatus (56%) compared with alpha-cypermethrin (17%). Chlorfenapyr has the potential to be an important addition to the limited arsenal of public health insecticides for indoor residual control of A. arabiensis and pyrethroid-resistant species of mosquito. PMID:20850003

Oxborough, R M; Kitau, J; Matowo, J; Mndeme, R; Feston, E; Boko, P; Odjo, A; Metonnou, C G; Irish, S; N'guessan, R; Mosha, F W; Rowland, M W

2010-10-01

78

Human Neutrophils Kill Bacillus anthracis.  

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Full Text Available Bacillus anthracis spores cause natural infections and are used as biological weapons. Inhalation infection with B. anthracis, the etiological agent of anthrax, is almost always lethal, yet cutaneous infections usually remain localized and resolve spontaneously. Neutrophils are typically recruited to cutaneous but seldom to other forms of anthrax infections, raising the possibility that neutrophils kill B. anthracis. In this study we infected human neutrophils with either spores or vegetative bacteria of a wild-type strain, or strains, expressing only one of the two major virulence factors. The human neutrophils engulfed B. anthracis spores, which germinated intracellularly and were then efficiently killed. Interestingly, neutrophil killing was independent of reactive oxygen species production. We fractionated a human neutrophil granule extract by high-performance liquid chromatography and identified alpha-defensins as the component responsible for B. anthracis killing. These data suggest that the timely recruitment of neutrophils can control cutaneous infections and possibly other forms of B. anthracis infections, and that alpha-defensins play an important role in the potent anti-B. anthracis activity of neutrophils.

2005-11-01

79

The unexpected importance of mosquito oviposition behaviour for malaria: non-productive larval habitats can be sources for malaria transmission  

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Full Text Available Abstract Background Mosquitoes commute between blood-meal hosts and water. Thus, heterogeneity in human biting reflects underlying spatial heterogeneity in the distribution and suitability of larval habitat as well as inherent differences in the attractiveness, suitability and distribution of blood-meal hosts. One of the possible strategies of malaria control is to identify local vector species and then attack water bodies that contain their larvae. Methods Biting and host seeking, not oviposition, have been the focus of most previous studies of mosquitoes and malaria transmission. This study presents a mathematical model that incorporates mosquito oviposition behaviour. Results The model demonstrates that oviposition is one potential factor explaining heterogeneous biting and vector distribution in a landscape with a heterogeneous distribution of larval habitat. Adult female mosquitoes tend to aggregate around places where they oviposit, thereby increasing the risk of malaria, regardless of the suitability of the habitat for larval development. Thus, a water body may be unsuitable for adult mosquito emergence, but simultaneously, be a source for human malaria. Conclusion Larval density may be a misleading indicator of a habitat's importance for malaria control. Even if mosquitoes could be lured to oviposit in sprayed larval habitats, this would not necessarily mitigate – and might aggravate – the risk of malaria transmission. Forcing mosquitoes to fly away from humans in search of larval habitat may be a more efficient way to reduce the risk of malaria than killing larvae. Thus, draining, fouling, or filling standing water where mosquitoes oviposit can be more effective than applying larvicide.

Flahault Antoine

2005-05-01

80

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, Roxanne; O'Connell, Sheila M.; Berg, Joe; Sakolsky-Hoopes, Gabrielle E.; Laderman, Aimlee D.

2012-01-01

 
 
 
 
81

North American Wetlands and Mosquito Control  

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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

82

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

83

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

84

Mosquitoes (Diptera: Culicidae) of metropolitan Hamburg, Germany.  

Science.gov (United States)

In Europe, mosquito-related public health concerns are growing due to the increasing spread of invasive mosquito species and the recent emergence of mosquito-borne arboviruses. A vital backbone in the assessment of these issues is detailed knowledge of the mosquito fauna, i.e. regional mosquito inventories. It was therefore decided to intensify nationwide investigations on the occurrence and distribution of mosquitoes in Germany in order to update old records and to detect possible faunal changes. This paper is focussing on a densely populated metropolitan region, the federal state of Hamburg and its adjacent environs, taking two historical baseline inventories into consideration, spanning almost 100 years of mosquito research in Hamburg. In the period between 2010 and 2014, more than 10,000 juvenile, neonate and adult mosquito specimens were sampled and trapped at 105 sites in Hamburg and its environs, of which about 60% have been identified to species level, resulting in a total of 33 recorded species. Of these, Anopheles algeriensis, Culex modestus, Ochlerotatus caspius, Ochlerotatus nigrinus and Ochlerotatus sticticus are new to the area. The most common species in Hamburg are Culex pipiens/torrentium and Ochlerotatus annulipes/cantans. In contrast, two previously common species, Anopheles atroparvus and Ochlerotatus excrucians, were not detected. Despite substantial environmental changes due to reconstruction, urbanisation and renaturation in the Hamburg metropolitan region in recent decades, there has been remarkably little change within the mosquito fauna during the last century. PMID:24870250

Krüger, A; Börstler, J; Badusche, M; Lühken, R; Garms, R; Tannich, E

2014-08-01

85

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

86

Biocontrol efficiency of odonate nymphs against larvae of the mosquito, Culex quinquefasciatus Say, 1823.  

Science.gov (United States)

An estimation of the predatory efficiency of the nymphs of five coexisting odonate species Aeshna flavifrons, Coenagrion kashmirum, Ischnura forcipata, Rhinocypha ignipennis and Sympetrum durum using the fourth-instar larvae of Culex quinquefasciatus as prey, was made under laboratory and semi-field conditions. The daily feeding rate varied among the odonate species, at laboratory conditions. The mean number of IV instars Cx. quinquefasciatus larvae killed per day, ranged between 14 and 64 (64 mosquito larvae for I. forcipata, 57 for A. flavifrons, 45 for R. ignipennis, 25 for S. durum and 14 for C. kashmirum). The prey consumption was linearly related to the number of predators and prey available but inversely related with space. It was also noted that the feeding rates varied significantly between dark and light conditions, in all the odonate species. The presence of nymphs in semi-field conditions significantly lowered the mosquito larval density in dipper samples after 15 days from the introduction, followed by a significant increase of larval mosquito density after 15 days from the withdrawal of the nymphs. The results of the present observations are suggestive of the use of odonate nymphs in temporary pools or larger habitats where they can be a potential biological resource in regulating the larval population of the vector and pest mosquitoes. PMID:18378207

Mandal, S K; Ghosh, A; Bhattacharjee, I; Chandra, G

2008-05-01

87

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 Culex mosquito species, Ochlero...

2012-01-01

88

WOMEN'S RIGHTS VIOLATION: HONOUR KILLINGS  

Directory of Open Access Journals (Sweden)

Full Text Available In this study I have presented the domestic violence concept and the situation regarding the observing of woman’s rights in Syria. We have also evidenced the juridical aspects regarding the honor killing directed against women after the modification of the article 548 from the Penal Code changed by the President al-Asad on July the 1st 2009. The data offered by NGOs have been of great help for the elaboration of the study as also the statistic data presented in Thara E-Magazine regarding the cities where had been done the honor killings and their number, the instrument of the murder, the age of the victim, and the motives for the murders. It must be noticed that, lately, the Government fought for the observing of the woman’s rights and promoted he gender equality by appointing women in leading positions, including the vice-president one.

CRISTINA OTOVESCU FRASIE

2011-04-01

89

Tumour necrosis factor-dependent parasite-killing effects during paroxysms in non-immune Plasmodium vivax malaria patients.  

Science.gov (United States)

Plasmodium vivax malaria infections in non-immune individuals manifest as periodic clinical episodes of fever with chills and rigors known as paroxysms. We have demonstrated that in non-immune patients the period of paroxysm is associated with the transient presence of plasma factors which kill gametocytes, the intra-erythrocytic sexual stages of the malaria parasite which transmit the infection from humans to mosquito, rendering them non-infectious to mosquitoes. Gametocyte killing in paroxysm plasma is mediated by tumour necrosis factor (TNF) acting in conjunction with other essential serum factor(s). Plasma TNF levels were elevated during a paroxysm. In semi-immune individuals from a P. vivax-endemic area clinical symptoms of malaria are mild and the parasite killing factors are not induced during paroxysm. Serum TNF levels were correspondingly lower in endemic patients during a paroxysm. Human peripheral blood mononuclear cells (PBMC) can be stimulated in vitro by extracts of P. vivax blood stage parasites to produce TNF and associated parasite killing factor(s), thus simulating in vitro the events that occur during a paroxysm, this being the release of parasite exo-antigens by rupturing schizonts and the subsequent induction of PBMC to produce TNF and other parasite-killing factors. We were able to show that convalescent serum from P. vivax semi-immune individuals block the induction of TNF and parasite-killing factors by malaria antigens in vitro, presumably through antibodies that neutralize parasite exo-antigens. Thus, individuals living in malaria-endemic areas appear to acquire clinical immunity to malaria by avoiding their induction during infection; we have shown that one such mechanism is the neutralization of parasite exo-antigens that induce the production of parasite killing factors. PMID:1351432

Karunaweera, N D; Carter, R; Grau, G E; Kwiatkowski, D; Del Giudice, G; Mendis, K N

1992-06-01

90

Women who kill their mates.  

Science.gov (United States)

Spousal homicide perpetrators are much more likely to be men than women. Accordingly, little research has focused on delineating characteristics of women who have committed spousal homicide. A retrospective clinical review of coroners' files containing all cases of spousal homicide occurring in Quebec over a 20-year period was carried out. A total of 276 spousal homicides occurred between 1991 and 2010, with 42 homicides by female spouses and 234 homicides by male spouses. Differences between homicides committed by female offenders and male offenders are discussed, and findings on spousal homicide committed by women are compared with those of previous studies. Findings regarding offenses perpetrated by females in the context of mental illness, domestic violence, and homicide-suicide are explored. The finding that only 28% of the female offenders in the Quebec sample had previously been subjected to violence by their victim is in contrast to the popular belief and reports that indicate that most female-perpetrated spousal homicide occurs in self-defense or in reaction to long-term abuse. In fact, women rarely gave a warning before killing their mates. Most did not suffer from a mental illness, although one-fifth were acutely intoxicated at the time of the killing. In the vast majority of cases of women who killed their mates, there were very few indicators that might have signaled the risk and helped predict the violent lethal behavior. PMID:23015414

Bourget, Dominique; Gagné, Pierre

2012-01-01

91

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 energyt source of energy

92

Mosquito Surveillance Revealed Lagged Effects of Mosquito Abundance on Mosquito-Borne Disease Transmission: A Retrospective Study in Zhejiang, China  

Science.gov (United States)

Mosquito-borne diseases (MBDs) are still threats to public health in Zhejiang. In this study, the associations between the time-lagged mosquito capture data and MBDs incidence over five years were used to examine the potential effects of mosquito abundance on patterns of MBDs epidemiology in Zhejiang during 2008–2012. Light traps were used to collect adult mosquitoes at 11 cities. Correlation tests with and without time lag were performed to investigate the correlations between MBDs incidence rates and mosquito abundance by month. Selected MBDs consisted of Japanese encephalitis (JE), dengue fever (DF) and malaria. A Poisson regression analysis was performed by using a generalized estimating equations (GEE) approach, and the most parsimonious model was selected based on the quasi-likelihood based information criterion (QICu). We identified five mosquito species and the constituent ratio of Culex pipiens pallens, Culex tritaeniorhynchus, Aedes albopictus, Anopheles sinensis and Armigeres subalbatus was 66.73%, 21.47%, 6.72%, 2.83% and 2.25%, respectively. The correlation analysis without and with time lag showed that Culex mosquito abundance at a lag of 0 or 1 month was positively correlated with JE incidence during 2008–2012, Ae. albopictus abundance at a lag of 1 month was positively correlated with DF incidence in 2009, and An. sinensis abundance at a lag of 0–2 months was positively correlated with malaria incidence during 2008–2010. The Poisson regression analysis showed each 0.1 rise of monthly mosquito abundance corresponded to a positive increase of MBD cases for the period of 2008–2012. The rise of mosquito abundance with a lag of 0–2 months increased the risk of human MBDs infection in Zhejiang. Our study provides evidence that mosquito monitoring could be a useful early warning tool for the occurrence and transmission of MBDs. PMID:25393834

Guo, Song; Ling, Feng; Hou, Juan; Wang, Jinna; Fu, Guiming; Gong, Zhenyu

2014-01-01

93

Green synthesis of silver nanoparticles for the control of mosquito vectors of malaria, filariasis, and dengue.  

Science.gov (United States)

A biological method was used to synthesize stable silver nanoparticles that were tested as mosquito larvicides against Aedes aegypti, Anopheles stephensi, and Culex quinquefasciatus. Annona squamosa leaf broth (5%) reduced aqueous 1?mM AgNO? to stable silver nanoparticles with an average size of 450?nm. The structure and percentage of synthesized nanoparticles was characterized by using ultraviolet spectrophotometry, X-Ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy methods. The median lethal concentrations (LC??) of silver nanoparticles that killed fourth instars of Ae. aegypti, Cx. quinquefasciatus, and An. stephensi were 0.30, 0.41, and 2.12 ppm, respectively. Adult longevity (days) in male and female mosquitoes exposed as larvae to 0.1 ppm silver nanoparticles was reduced by ~30% (p<0.05), whereas the number of eggs laid by females exposed as larvae to 0.1 ppm silver nanoparticles decreased by 36% (p<0.05). PMID:22022807

Arjunan, Naresh Kumar; Murugan, Kadarkarai; Rejeeth, Chandrababu; Madhiyazhagan, Pari; Barnard, Donald R

2012-03-01

94

Free flight of the mosquito Aedes aegypti  

CERN Document Server

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

95

Killing-Yano tensors in spaces admitting a hypersurface orthogonal Killing vector  

CERN Document Server

Methods are presented for finding Killing-Yano tensors, conformal Killing-Yano tensors, and conformal Killing vectors in spacetimes with a hypersurface orthogonal Killing vector. These methods are similar to a method developed by the authors for finding Killing tensors. In all cases one decomposes both the tensor and the equation it satisfies into pieces along the Killing vector and pieces orthogonal to the Killing vector. Solving the separate equations that result from this decomposition requires less computing than integrating the original equation. In each case, examples are given to illustrate the method.

Garfinkle, David

2013-01-01

96

Enhanced UV Resistance and Improved Killing of Malaria Mosquitoes by Photolyase Transgenic Entomopathogenic Fungi  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The low survival of microbial pest control agents exposed to UV is the major environmental factor limiting their effectiveness. Using gene disruption we demonstrated that the insect pathogenic fungus Metarhizium robertsii uses photolyases to remove UV-induced cyclobutane pyrimidine dimers (CPD) and pyrimidine (6-4) photoproducts [(6-4)PPs] from its DNA. However, this photorepair is insufficient to fix CPD lesions and prevent the loss of viability caused by seven hours of solar radiation. Expr...

Fang, Weiguo; St Leger, Raymond J.

2012-01-01

97

Estudio de un brote de enfermedades trasmitidas por alimentos en una instalación hotelera. Municipio Varadero. 2009 / Study of an outbreak of diseases transmitted by food in a hotel. Varadero, 2009  

Scientific Electronic Library Online (English)

Full Text Available SciELO Cuba | Language: Spanish Abstract in spanish Las enfermedades transmitidas por alimentos constituyen un problema cada vez más importante a nivel internacional. Según la Organización Mundial de la Salud, entre un 70 y un 80 % de los casos de diarrea que se producen se deben a la ingestión de agua y alimentos contaminados, constituyendo actualme [...] nte un desafío, puesto que se desconoce su real incidencia. Motivados por la necesidad de incrementar la vigilancia de los brotes de estas enfermedades y de realizar un adecuado estudios de los mismos, se realizó una investigación epidemiológica observacional descriptiva de un brote de enfermedades transmitidas por alimentos, ocurrido en una instalación hotelera en Varadero, en agosto de 2009. La muestra estuvo constituida por 58 turistas: 29 sanos e igual número de enfermos, a los que se le aplicó la encuesta validada para estudiar estos eventos; de ella se obtuvo la información. Se calculó la Mediana para determinar período de incubación, haciéndolo corresponder con el posible agente etiológico. Se halló la tasa de ataque específica, la cual indicó el alimento sospechoso. Se realizó estudios de laboratorio a muestras de alimentos, especímenes y a manipuladores de alimentos. Se demostró que la no aplicación de las buenas prácticas de manufactura de los alimentos, unido al deterioro del cuadro higiénico de la instalación, fue la causa directa del brote; el agente causal la Samonella D, aislada en el revoltillo y en los especímenes. Abstract in english The diseases transmitted by food are a more and more important problem at the international level. According to the World Health Organization, between the 70 and the 80 % of the diarrheic cases are due to the ingestion of contaminated water and food, being a challenge nowadays, because its real inci [...] dence is unknown. Motivated for the necessity of increasing the surveillance of these diseases outbreaks and adequately studying them, we carried out the descriptive, observational, epidemiologic survey of an outbreak of diseases transmitted by foods that took place in a hotel in Varadero, in August 2009. The sample was formed by 59 tourists: 28 healthy and the same number of sick. They applied a survey validated to study these events; the information was taken from it. The media was calculated to determine the incubation period, making it correspond with the possible etiologic agent. We calculated the specific attack rate, indicating the suspecting food. We made laboratory studies of food samples, specimens and food manipulators. It was showed that not applying good practices of food elaboration, together with the worsening of the health situation of the installation, was the direct cause of the outbreak; the causal agent was the Salmonella D, isolated in the scrambled eggs and the specimens.

Milvian, Morales Cardona; Dayami, Núñez González; Beatriz, Guerra González; Tamara, Parra Rodríguez; Osvaldo, Morales Hernández.

2011-02-01

98

Estudio de un brote de enfermedades trasmitidas por alimentos en una instalación hotelera. Municipio Varadero. 2009 / Study of an outbreak of diseases transmitted by food in a hotel. Varadero, 2009  

Scientific Electronic Library Online (English)

Full Text Available SciELO Cuba | Language: Spanish Abstract in spanish Las enfermedades transmitidas por alimentos constituyen un problema cada vez más importante a nivel internacional. Según la Organización Mundial de la Salud, entre un 70 y un 80 % de los casos de diarrea que se producen se deben a la ingestión de agua y alimentos contaminados, constituyendo actualme [...] nte un desafío, puesto que se desconoce su real incidencia. Motivados por la necesidad de incrementar la vigilancia de los brotes de estas enfermedades y de realizar un adecuado estudios de los mismos, se realizó una investigación epidemiológica observacional descriptiva de un brote de enfermedades transmitidas por alimentos, ocurrido en una instalación hotelera en Varadero, en agosto de 2009. La muestra estuvo constituida por 58 turistas: 29 sanos e igual número de enfermos, a los que se le aplicó la encuesta validada para estudiar estos eventos; de ella se obtuvo la información. Se calculó la Mediana para determinar período de incubación, haciéndolo corresponder con el posible agente etiológico. Se halló la tasa de ataque específica, la cual indicó el alimento sospechoso. Se realizó estudios de laboratorio a muestras de alimentos, especímenes y a manipuladores de alimentos. Se demostró que la no aplicación de las buenas prácticas de manufactura de los alimentos, unido al deterioro del cuadro higiénico de la instalación, fue la causa directa del brote; el agente causal la Samonella D, aislada en el revoltillo y en los especímenes. Abstract in english The diseases transmitted by food are a more and more important problem at the international level. According to the World Health Organization, between the 70 and the 80 % of the diarrheic cases are due to the ingestion of contaminated water and food, being a challenge nowadays, because its real inci [...] dence is unknown. Motivated for the necessity of increasing the surveillance of these diseases outbreaks and adequately studying them, we carried out the descriptive, observational, epidemiologic survey of an outbreak of diseases transmitted by foods that took place in a hotel in Varadero, in August 2009. The sample was formed by 59 tourists: 28 healthy and the same number of sick. They applied a survey validated to study these events; the information was taken from it. The media was calculated to determine the incubation period, making it correspond with the possible etiologic agent. We calculated the specific attack rate, indicating the suspecting food. We made laboratory studies of food samples, specimens and food manipulators. It was showed that not applying good practices of food elaboration, together with the worsening of the health situation of the installation, was the direct cause of the outbreak; the causal agent was the Salmonella D, isolated in the scrambled eggs and the specimens.

Milvian, Morales Cardona; Dayami, Núñez González; Beatriz, Guerra González; Tamara, Parra Rodríguez; Osvaldo, Morales Hernández.

99

Field evaluation of mosquito control devices in southern Louisiana.  

Science.gov (United States)

The effect of 2 mosquito traps and 2 repellent systems on the catch of adult mosquitoes in American Biophysics Corporation (ABC) light traps was evaluated over a 14-month period at 3 locations in Louisiana. Devices evaluated included 1) ABC Mosquito Magnet with dry ice and octanol; 2) the BioSensory 500 cc Dragonfly Biting Insect Trap with CO2, octenol, and Mosquito Cognito, which uses Conceal inhibitor; 3) the SC Johnson OFF! Mosquito Lantern; and 4) the ThermaCell cordless mosquito repellent system. The number of adult mosquitoes caught in the ABC light traps, at the SC Johnson OFF! Mosquito Lantern, and ThermaCell cordless mosquito repellent treatment sites was significantly lower than the number collected at the ABC Mosquito Magnet or the Dragonfly/Mosquito Cognito trap system sites. When the 2 repellent devices were placed in combination with the ABC traps, mosquito numbers were significantly reduced when compared with sites with ABC traps alone. These data indicate that the SC Johnson OFF! Mosquito Lantern and ThermaCell cordless mosquito system may reduce attack from biting mosquitoes due to the reduction in their numbers. In the same study, the mosquito counts of the trapping devices also were reported. PMID:17067044

Collier, Brett W; Perich, Michael J; Boquin, Gerardo J; Harrington, Scott R; Francis, Mike J

2006-09-01

100

WOMEN'S RIGHTS VIOLATION: HONOUR KILLINGS  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this study I have presented the domestic violence concept and the situation regarding the observing of woman’s rights in Syria. We have also evidenced the juridical aspects regarding the honor killing directed against women after the modification of the article 548 from the Penal Code changed by the President al-Asad on July the 1st 2009. The data offered by NGOs have been of great help for the elaboration of the study as also the statistic data presented in Thara E-Magazine regarding th...

CRISTINA OTOVESCU FRASIE

2011-01-01

 
 
 
 
101

Green Nanoparticles for Mosquito Control  

Science.gov (United States)

Here, we have used the green method for synthesis of silver and gold nanoparticles. In the present study the silver (Ag) and gold (Au) nanoparticles (NPs) were synthesized by using the aqueous bark extract of Indian spice dalchini (Cinnamomum zeylanicum) (C. zyelanicum or C. verum J. Presl). Additionally, we have used these synthesized nanoparticles for mosquito control. The larvicidal activity has been tested against the malaria vector Anopheles stephensi and filariasis vector Culex quinquefasciatus. The results were obtained using UV-visible spectrophotometer and the images were recorded with a transmission electron microscope (TEM). The efficacy tests were then performed at different concentrations and varying numbers of hours by probit analysis. The synthesized AgNPs were in spherical shape and average sizes (11.77?nm AgNPs and 46.48?nm AuNPs). The larvae of An. stephensi were found highly susceptible to the synthesized AgNPs and AuNPs than the Cx. quinquefasciatus. These results suggest that the C. zeylanicum synthesized silver and gold nanoparticles have the potential to be used as an ideal ecofriendly approach for the control of mosquito. PMID:25243210

Soni, Namita; Prakash, Soam

2014-01-01

102

Green nanoparticles for mosquito control.  

Science.gov (United States)

Here, we have used the green method for synthesis of silver and gold nanoparticles. In the present study the silver (Ag) and gold (Au) nanoparticles (NPs) were synthesized by using the aqueous bark extract of Indian spice dalchini (Cinnamomum zeylanicum) (C. zyelanicum or C. verum J. Presl). Additionally, we have used these synthesized nanoparticles for mosquito control. The larvicidal activity has been tested against the malaria vector Anopheles stephensi and filariasis vector Culex quinquefasciatus. The results were obtained using UV-visible spectrophotometer and the images were recorded with a transmission electron microscope (TEM). The efficacy tests were then performed at different concentrations and varying numbers of hours by probit analysis. The synthesized AgNPs were in spherical shape and average sizes (11.77 nm AgNPs and 46.48 nm AuNPs). The larvae of An. stephensi were found highly susceptible to the synthesized AgNPs and AuNPs than the Cx. quinquefasciatus. These results suggest that the C. zeylanicum synthesized silver and gold nanoparticles have the potential to be used as an ideal ecofriendly approach for the control of mosquito. PMID:25243210

Soni, Namita; Prakash, Soam

2014-01-01

103

9 CFR 113.201 - Canine Distemper Vaccine, Killed Virus.  

Science.gov (United States)

...2010-01-01 2010-01-01 false Canine Distemper Vaccine, Killed Virus. 113.201 Section...Killed Virus Vaccines § 113.201 Canine Distemper Vaccine, Killed Virus. Canine Distemper Vaccine, Killed Virus, shall be...

2010-01-01

104

9 CFR 113.201 - Canine Distemper Vaccine, Killed Virus.  

Science.gov (United States)

... 2010-01-01 2010-01-01 false Canine Distemper Vaccine, Killed Virus. 113...REQUIREMENTS Killed Virus Vaccines § 113.201 Canine Distemper Vaccine, Killed Virus. Canine Distemper Vaccine, Killed Virus,...

2010-01-01

105

Plant extracts as potential mosquito larvicides.  

Science.gov (United States)

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 and adverse effects on environmental quality and non target organisms including human health. Application of active toxic agents from plant extracts as an alternative mosquito control strategy was available from ancient times. These are non-toxic, easily available at affordable prices, biodegradable and show broad-spectrum target-specific activities against different species of vector mosquitoes. In this article, the current state of knowledge on phytochemical sources and mosquitocidal activity, their mechanism of action on target population, variation of their larvicidal activity according to mosquito species, instar specificity, polarity of solvents used during extraction, nature of active ingredient and promising advances made in biological control of mosquitoes by plant derived secondary metabolites have been reviewed. PMID:22771587

Ghosh, Anupam; Chowdhury, Nandita; Chandra, Goutam

2012-05-01

106

Fish kill from underwater explosions  

Science.gov (United States)

The U.S. Geological Survey has used 23 different shotpoints during two seasons of field work in our seismic study of crustal structure in western United States. Without exception, it has been found that under-water shotpoints result in a more efficient conversion of explosive energy into seismic energy than do drilled-hole shotpoints. This experience, together with elimination of drilling costs, has led to the use of underwater shotpoints wherever possible. Three of the 23 shotpoints were in the Pacific Ocean, and for these we have no detailed information on the fish kill. Another six shotpoints were located in inland bodies of water. These are: * Soda Lake near Fallon, Nevada * Mono Lake near Lee Vining, California * Lake Mead near Boulder City, Nevada * Shasta Lake near Redding, California * C.J. Strike Reservoir near Bruneau, Idaho * Lucky Peak Reservoir near Boise, Idaho The 22 high-explosive charges, weighing a total of 95,100 pounds, that were fired in lakes containing fish life resulted in the known death of 2,413 game fish with a total weight of 759 pounds. The average mortality was 110 game fish or 34.5 pounds of game fish killed per average shot of 4,325 pounds of high-explosives.

Stuart, David J.

1962-01-01

107

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

108

Can mosquitoes fly in the rain?  

CERN Document Server

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

109

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...

Roiz, David; Roussel, Marion; Mun?oz, Joaqui?n; Ruiz, Santiago; Soriguer, Ramo?n C.; Figuerola, Jordi

2012-01-01

110

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

111

Models for dynamic kill of blowouts  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

Ravndal, Maiken

2011-01-01

112

Male-killing in African butterflies  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

113

Mosquito transcriptome changes and filarial worm resistance in Armigeres subalbatus  

Directory of Open Access Journals (Sweden)

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

114

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

115

Isolated Horizon, Killing Horizon and Event Horizon  

CERN Document Server

We consider space-times which in addition to admitting an isolated horizon also admit Killing horizons with or without an event horizon. We show that an isolated horizon is a Killing horizon provided either (1) it admits a stationary neighbourhood or (2) it admits a neighbourhood with two independent, commuting Killing vectors. A Killing horizon is always an isolated horizon. For the case when an event horizon is definable, all conceivable relative locations of isolated horizon and event horizons are possible. Corresponding conditions are given.

Date, G

2001-01-01

116

Slow Death by Many Mosquito Bites  

CERN Document Server

We study the dynamics of a single diffusing particle (a "man") with diffusivity $D_M$ that is attacked by another diffusing particle (a "mosquito") with fixed diffusivity $D_m$. Each time the mosquito meets and bites the man, the diffusivity of the man is reduced by a fixed amount, while the diffusivity of the mosquito is unchanged. The mosquito is also displaced by a small distance $\\pm a$ with respect to the man after each encounter. The man is defined as dead when $D_M$ reaches zero. At the moment when the man dies, his probability distribution of displacements $x$ is given by a Cauchy form, which asymptotically decays as $x^{-2}$, while the distribution of times $t$ when the man dies asymptotically decays as $t^{-3/2}$, which has the same form as the one-dimensional first-passage probability.

Redner, S

2014-01-01

117

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

118

MODELING AND BIOLOGICAL CONTROL OF MOSQUITOES  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Models can be useful at many different levels when considering complex issues such as biological control of mosquitoes. At an early stage, exploratory models are valuable in exploring the characteristics of an ideal biological control agent and for guidance in data collection. When more data are available, models can be used to explore alternative control strategies and the likelihood of success. There are few modeling studies that explicitly consider biological control in mosquitoes; however...

Lord, Cynthia C.

2007-01-01

119

Mosquitoes infected with dengue viruses in Brazil  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Dengue epidemics have been reported in Brazil since 1985. The scenery has worsened in the last decade because several serotypes are circulating and producing a hyper-endemic situation, with an increase of DHF/DSS cases as well as the number of fatalities. Herein, we report dengue virus surveillance in mosquitoes using a Flavivirus genus-specific RT-Hemi-Nested-PCR assay. The mosquitoes (Culicidae, n = 1700) collected in the Northeast, Southeast and South o...

2010-01-01

120

Techniques of Mosquitoes Collecting and Laboratory Rearing  

Directory of Open Access Journals (Sweden)

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

 
 
 
 
121

75 FR 62469 - Drawbridge Operation Regulations; Newtown Creek, Dutch Kills, English Kills, and Their...  

Science.gov (United States)

...Coast Guard 33 CFR Part 117 [Docket No. USCG-2010-0907] Drawbridge Operation Regulations; Newtown Creek, Dutch Kills, English Kills, and Their Tributaries, NY, Maintenance AGENCY: Coast Guard, DHS. ACTION: Notice of temporary deviation from...

2010-10-12

122

75 FR 30299 - Drawbridge Operation Regulations; Newtown Creek, Dutch Kills, English Kills, and Their...  

Science.gov (United States)

...Coast Guard 33 CFR Part 117 [Docket No. USCG-2010-0355] Drawbridge Operation Regulations; Newtown Creek, Dutch Kills, English Kills, and Their Tributaries, NY, Maintenance AGENCY: Coast Guard, DHS. ACTION: Notice of temporary deviation from...

2010-06-01

123

Loss of protection with insecticide-treated nets against pyrethroid-resistant Culex quinquefasciatus mosquitoes once nets become holed: an experimental hut study  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background An important advantage of pyrethroid-treated nets over untreated nets is that once nets become worn or holed a pyrethroid treatment will normally restore protection. The capacity of pyrethroids to kill or irritate any mosquito that comes into contact with the net and prevent penetration of holes or feeding through the sides are the main reasons why treated nets continue to provide protection despite their condition deteriorating over time. Pyrethroid resistance is a growing problem among Anopheline and Culicine mosquitoes in many parts of Africa. When mosquitoes become resistant the capacity of treated nets to provide protection might be diminished, particularly when holed. An experimental hut trial against pyrethroid-resistant Culex quinquefasciatus was therefore undertaken in southern Benin using a series of intact and holed nets, both untreated and treated, to assess any loss of protection as nets deteriorate with use and time. Results There was loss of protection when untreated nets became holed; the proportion of mosquitoes blood feeding increased from 36.2% when nets were intact to between 59.7% and 68.5% when nets were holed to differing extents. The proportion of mosquitoes blood feeding when treated nets were intact was 29.4% which increased to 43.6–57.4% when nets were holed. The greater the number of holes the greater the loss of protection regardless of whether nets were untreated or treated. Mosquito mortality in huts with untreated nets was 12.9–13.6%; treatment induced mortality was less than 12%. The exiting rate of mosquitoes into the verandas was higher in huts with intact nets. Conclusion As nets deteriorate with use and become increasingly holed the capacity of pyrethroid treatments to restore protection is greatly diminished against resistant Culex quinquefasciatus mosquitoes.

Irish SR

2008-06-01

124

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.

2013-03-01

125

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.

126

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

Science.gov (United States)

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 plus thorax with different abdomens. Depending on the experiment, lures were either moving or motionless. Findings from the lure experiments suggested that, for E. culicivora, seeing a blood-fed female mosquito's abdomen on a lure was a necessary, but not sufficient, cue by which preferred prey was identified, as cues from the abdomen needed to be paired with cues from the head and thorax of a mosquito. Conversely, when abdomens were not visible or were identical, spiders based their decisions on the appearance of the head plus thorax of mosquitoes, choosing prey with female characteristics. Findings from a subsequent experiment using animated 3D virtual mosquitoes suggest that it is specifically the mosquito's antennae that influence E. culicivora's prey-choice decisions. Our results show that E. culicivora uses a complex process for prey classification. PMID:22675186

Nelson, Ximena J; Jackson, Robert R

2012-07-01

127

Approximate Killing Vectors on S^2  

CERN Document Server

We present a new method for computing the best approximation to a Killing vector on closed 2-surfaces that are topologically S^2. When solutions of Killing's equation do not exist, this method is shown to yield results superior to those produced by existing methods. In addition, this method appears to provide a new tool for studying the horizon geometry of distorted black holes.

Cook, Gregory B

2007-01-01

128

Indoor use of plastic sheeting impregnated with carbamate combined with long-lasting insecticidal mosquito nets for the control of pyrethroid-resistant malaria vectors.  

Science.gov (United States)

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 (~70% for LLIN + CTPS and LLIN + IRS). Blood feeding by An. gambiae was uninhibited by IRS and CTPS compared with LLIN (43%), LLIN + CTPS (58%), and LLIN + IRS (56%). No evidence for selection of the kdr and ace-1(R) alleles was observed with the combinations, whereas a survival advantage of mosquitoes bearing the ace-1(R) mutation was observed with IRS and CTPS. The results suggest that the combination of the two interventions constitutes a potential tool for vector-resistance management. PMID:20682865

Djènontin, Armel; Chandre, Fabrice; Dabiré, K Roch; Chabi, Joseph; N'guessan, Raphael; Baldet, Thierry; Akogbéto, Martin; Corbel, Vincent

2010-08-01

129

Germ killing by ultraviolet radiation  

International Nuclear Information System (INIS)

Short-wave UV radiation, in particular the range about 250 nm, has a high germ reducing effect. Corresponding UV burners which above all emit radiation at the line of 254 nm can therefore be used effectively in all cases where the least possible content of germs in the air is aimed at. Apart from this it is also possible to reduce by this process the germs on surfaces and liquids. Especially in the most various ranges of pharmaceutical production one is steadily striving for efficient and last not least economic procedures by which it is possible to reduce the germs present in the air of a room. Numerous scientific investigations have sufficiently proved that short-wave UV radiation is extremely well appropriate for such purposes. Absolutely germ-free air in a room can only be obtained under laboratory conditions. In practice, however, the aim is not to achieve a 100 per cent killing of the germs present in a room but to make sure that the germ rate in certain rooms is constantly reduced to the lowest possible level. If in this connection it is referred to a germ reduction of 100 or 99 per cent this is but theory. (orig.)

130

Optimization and synthesis of silver nanoparticles using Isaria fumosorosea against human vector mosquitoes.  

Science.gov (United States)

The efficacy of silver generated larvicide with the help of entomopathogenic fungi, Isaria fumosorosea (Ifr) against major vector mosquitoes Culex quinquefasciatus and Aedes aegypti. The Ifr-silver nanoparticles (AgNPs) were characterized structurally and functionally using UV-visible spectrophotometer followed by scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) spectroscopy and Fourier transform infrared (FTIR) spectra. The optimum pH (alkaline), temperature (30 °C) and agitation (150 rpm) for AgNP synthesis and its stability were confirmed through colour change. Ae. aegypti larvae (I-IV instars) were found highly susceptible to synthesized AgNPs than the larvae of Cx. quinquefasciatus. However, the mortality rate was indirectly proportional to the larval instar and the concentration. The lethal concentration that kills 50% of the exposed larvae (LC50) and lethal concentration that kills 90% of the exposed larvae (LC90) values of the tested concentration are 0.240, 0 0.075.337, 0.430, 0.652 and 1.219, 2.210, 2.453, 2.916; 0.065, 0.075, 0.098, 0.137 and 0.558, 0.709, 0.949, 1.278 ppm with respect to 0.03 to 1.00 ppm of Ifr-AgNPs against first, second, third and fourth instars of Cx. quinquefasciatus and Ae. aegypti, respectively. This is the first report for synthesis of AgNPs using Ifr against human vector mosquitoes. Hence, Ifr-AgNPs would be significantly used as a potent mosquito larvicide. PMID:25085201

Banu, A Najitha; Balasubramanian, C

2014-10-01

131

Vaccine Shows Promise Against Mosquito-Borne Virus  

Science.gov (United States)

... enable JavaScript. Vaccine Shows Promise Against Mosquito-Borne Virus Volunteers developed antibodies to chikungunya in first human ... to protect people from the mosquito-borne chikungunya virus has shown promise in its first human trial. " ...

132

The trial detection of malaria sporozoit in field-collected mosquito by immunoradiometric assay in Thailand  

International Nuclear Information System (INIS)

The sporozoite rate, species of parasite and vector are important in the epidemiology of malaria. The investigation of sporozoite by dissection and examination under a microscope is time-consuming and it could be done only on freshly killed mosquitoes. Immunoradiometric assay (IRMA) that can detect, identify and quantify malaria sporozoite (Zavala et al., 1982) was therefore applied to detect sporozoite in laboratory-maintained Anopheles dirus and wild-caught mosquitoes. Study on P. falciparum-infected An. dirus showed that the circumsporozoite (CS) antigen was first found in the abdomen on the 10th day post-infection, whilst the sporozoites were examined in salivary glands from day 15 onwards. The malaria infection in wild-caught mosquitoes were investigated in Anopheles spp collected by human baites from three endemic areas in Thailand. Since the sporozoite rate refers to the presence of sporozoite in the salivary gland, then only head-thorax part of the specimens were detected by IRMA to prevent an exaggeration over the true results. It was found that none of mosquitoes collected from Phrae was positive for malaria. Four out of 1243 An. dirus among eight species collected from Chantaburi were positive for P. falciparum with sporozoites ranged from 270 to 3875. Of all ten species collected from Kanchanaburi, two and one out of 3123 An. minimus were positive for P. falciparum and P. vivax with sporozoites found in head-thorax portions were 1880, 2380 and 1026 respectively. It is evident that the IRMA is suitable for the investigation of malaria sporozoites in this region. The application of this technique in the further epidemiological study is in progress

133

Insecticide resistance in vector mosquitoes in China.  

Science.gov (United States)

Because of their special behaviour, physiology and close relationship with humans, mosquitoes act as one of the most important vectors of human diseases, such as filariasis, Japanese encephalitis, dengue and malaria. The major vector mosquitoes are members of the Culex, Aedes and Anopheles genera. Insecticides play important roles in agricultural production and public health, especially in a country with a huge human population, like China. Large quantities of four classes of insecticides, organochlorines, organophosphates, carbamates and pyrethroids, are applied annually to fields or indoors in China, directly or indirectly bringing heavy selection pressure on vector populations. The seven major species of vector mosquito in China are the Culex pipiens L. complex, C. tritaeniorhynchus Giles, Anopheles sinensis Wied., A. minimus Theobald, A. anthropophagus Xu & Feng, Aedes albopictus (Skuse) and Ae. aegypti L., and all have evolved resistance to all the above types of insecticide except the carbamates. The degree of resistance varies among mosquito species, insecticide classes and regions. This review summarizes the resistance status of these important vector mosquitoes, according to data reported since the 1990s, in order to improve resistance management and epidemic disease control, and to communicate this information from China to the wider community. PMID:16953491

Cui, Feng; Raymond, Michel; Qiao, Chuan-Ling

2006-11-01

134

Field performance of engineered male mosquitoes.  

Science.gov (United States)

Dengue is the most medically important arthropod-borne viral disease, with 50-100 million cases reported annually worldwide. As no licensed vaccine or dedicated therapy exists for dengue, the most promising strategies to control the disease involve targeting the predominant mosquito vector, Aedes aegypti. However, the current methods to do this are inadequate. Various approaches involving genetically engineered mosquitoes have been proposed, including the release of transgenic sterile males. However, the ability of laboratory-reared, engineered male mosquitoes to effectively compete with wild males in terms of finding and mating with wild females, which is critical to the success of these strategies, has remained untested. We report data from the first open-field trial involving a strain of engineered mosquito. We demonstrated that genetically modified male mosquitoes, released across 10 hectares for a 4-week period, mated successfully with wild females and fertilized their eggs. These findings suggest the feasibility of this technology to control dengue by suppressing field populations of A. aegypti. PMID:22037376

Harris, Angela F; Nimmo, Derric; McKemey, Andrew R; Kelly, Nick; Scaife, Sarah; Donnelly, Christl A; Beech, Camilla; Petrie, William D; Alphey, Luke

2011-11-01

135

Toxic activity of Bacillus sphaericus SSII-1 for mosquito larvae.  

Science.gov (United States)

Using larvae of the mosquito Culex pipiens var. quinquefasciatus as a bioassay system, we have verified an earlier proposal that pathogenicity of Bacillus sphaericus SSII-1 is a toxin-mediated rather than an infectious process. Chloroform or ultraviolet-light treatments that decreased the viable count of SSII-1 cells by 4 or 5 logs did not significantly alter the ability of the bacterial cells to kill larvae. Three lines of evidence indicated that toxic activity was not related to sporulation: (i) cells grown in either a complex or a defined medium were toxic at all ages; (ii) when supplemental Mn2+ was excluded from a complex medium, the culture yielded few spores but was of equal toxicity to a culture containing many spores; and (iii) several early blocked oligosporogenous mutants were isolated that had toxic activities comparable to that of the parent. The toxin was shown to be relatively unstable because activity was destroyed by heat and decreased by refrigeration, a freeze-thaw cycle, or two methods of cell breakage. Thin sections of SSII-1 cells did not reveal the presence of any inclusion body that might be related to toxicity. Images PMID:640722

Myers, P; Yousten, A A

1978-01-01

136

Mosquito (Diptera: Culicidae) Fauna of Qom Province, Iran  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 usi...

Saghafipour, A.; MR Abai; Farzinnia, B.; Nafar, R.; Ladonni, H.; Azari-hamidian, S.

2012-01-01

137

Transstadial Transmission of Francisella tularensis holarctica in Mosquitoes, Sweden  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In Sweden, human cases of tularemia caused by Francisella tularensis holarctica are assumed to be transmitted by mosquitoes, but how mosquito vectors acquire and transmit the bacterium is not clear. To determine how transmission of this bacterium occurs, mosquito larvae were collected in an area where tularemia is endemic, brought to the laboratory, and reared to adults in their original pond water. Screening of adult mosquitoes by real-time PCR demonstrated F. tularensis lpnA sequences...

Lundstro?m, Jan O.; Andersson, Ann-christin; Ba?ckman, Stina; Scha?fer, Martina L.; Forsman, Mats; Thelaus, Johanna

2011-01-01

138

Next-generation site-directed transgenesis in the malaria vector mosquito Anopheles gambiae: self-docking strains expressing germline-specific phiC31 integrase.  

Science.gov (United States)

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, thus overcoming many limitations due to size constraints and random integration associated with transposon-mediated transformation. Using this technology, we previously published the first site-directed transformation of Anopheles gambiae, the principal vector of human malaria. Mosquitoes were initially engineered to incorporate the phiC31 docking site at a defined genomic location. A second phase of genetic modification then achieved site-directed integration of an anti-malarial effector gene. In the current publication we report improved efficiency and utility of the phiC31 integrase system following the generation of Anopheles gambiae self-docking strains. Four independent strains, with docking sites at known locations on three different chromosome arms, were engineered to express integrase under control of the regulatory regions of the nanos gene from Anopheles gambiae. The resulting protein accumulates in the posterior oocyte to provide integrase activity at the site of germline development. Two self-docking strains, exhibiting significantly different levels of integrase expression, were assessed for site-directed transgene integration and found to demonstrate greatly improved survival and efficiency of transformation. In the fight against malaria, it is imperative to establish a broad repertoire of both anti-malarial effector genes and tissue-specific promoters to regulate their expression, enabling those offering maximum effect with minimum fitness cost to be identified. The improved technology we describe here will facilitate comparative studies of effector transgenes, allowing informed choices to be made that potentially lead to transmission blockade. PMID:23516619

Meredith, Janet M; Underhill, Ann; McArthur, Clare C; Eggleston, Paul

2013-01-01

139

The Killing : Urban topographies of a crime  

DEFF Research Database (Denmark)

This article tracks the uncanny locations of The Killing (2007–2012), relating them to place, space and atmosphere, putting bits and pieces from the topographic puzzle together with cues from the symbolic space in order to see how they fit into the overall pattern of Nordic Noir. In The Killing, the abstract level of space and atmosphere meets the concrete level of place, both influencing the notion of location. This meeting, I suggest, has contributed towards the simultaneous domestic and international appeal of The Killing.

Agger, Gunhild

2013-01-01

140

Monster storms mainly kill the poor  

... Monster storms mainly kill the poor Climate & Capitalism An ecosocialist journal Home About Ecosocialist Notebook Book Reviews Archives Articles By Subject Articles ...Press MRzine Economist’s Travelogue You are here: Home / 2012 / November / 05 / East and west, monster storms mainly kill the poor Posted on November 5, 2012 ...East and west, monster storms mainly kill the poor In every country, the ravages of climate change fall overwhelming on the poor. ...Tumblr Related articleshellip; (auto-generated) Frankenstorms and climate change: How the 1% created a monster (posted on October 29, 2012) Cyclone Nargis and ...

 
 
 
 
141

Wolbachia and the biological control of mosquito-borne disease  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Mosquito-borne diseases are an increasing problem in many regions of the world, and control options are limited. Mosquito infection with the endosymbiotic bacteria Wolbachia—which reduces lifespan, affects mosquito reproduction and interferes with pathogen replication—is a promising new biocontrol strategy.

Iturbe-ormaetxe, In?aki; Walker, Thomas; O Neill, Scott L.

2011-01-01

142

9 CFR 113.214 - Parvovirus Vaccine, Killed Virus (Canine).  

Science.gov (United States)

... Parvovirus Vaccine, Killed Virus (Canine). 113.214 Section 113.214 ...Parvovirus Vaccine, Killed Virus (Canine). Parvovirus Vaccine, Killed...tested for neutralizing antibody against canine parvovirus to determine...

2010-01-01

143

9 CFR 113.209 - Rabies Vaccine, Killed Virus.  

Science.gov (United States)

...2010-01-01 false Rabies Vaccine, Killed Virus. 113.209 Section...DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS...PRODUCTS; ORGANISMS AND VECTORS STANDARD REQUIREMENTS Killed Virus Vaccines § 113.209 Rabies Vaccine, Killed...

2010-01-01

144

Molecular Perspectives on the Genetics of Mosquitoes  

International Nuclear Information System (INIS)

Mosquitoes have been a focus of scientific study since the turn of the century, when they were first linked with human diseases. This review concentrates on the three most intensely studied genera, Anopheles, Culex, and Aedes. These genera include the principal vectors of three major groups of human pathogens: malaria parasites of the genus Plasmodium, filarial worms of the genera Wuchereria and Brugia, and numerous arboviruses. Anophelines are the only mosquitoes known to transmit human malaria parasites, a group of organisms that may be responsible for more morbidity and mortality worldwide than any other human pathogen. Anophelines also transmit filarial worms, as do Culex and Aedes species. Among the 14 or more different mosquito genera known to harbor arboviruses (Mattingly, 1973), the most important are Culex and Aedes, which include the principal vectors of yellow fever, dengue, and most encephalitis-causing arboviruses.

145

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

146

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

147

Homefucking is Killing Prostitution / Taavi Eelmaa  

Index Scriptorium Estoniae

Mis jääb vaatajale teatrietendusest meelde? Ilmus Kris Moori raamat "Homefucking is Killing Prostitution". Raamat sisaldab tekste ja Erki Lauri fotosid Von Krahli Teatri samanimelisest etendusest, mida kordagi ei mängitud

Eelmaa, Taavi, 1971-

2008-01-01

148

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

149

Tip-Over Furniture Can Kill Kids  

Science.gov (United States)

... on this page, please enable JavaScript. Tip-Over Furniture Can Kill Kids Experts share childproofing advice (*this ... computer monitor and gets critically injured when the furniture tips over. "Every parent or guardian of a ...

150

Heat and Drought Kills Trees in Southwest  

Science.gov (United States)

... br/>Press Release 05-182Heat and Drought Kills Trees in Southwest Study sheds light on how quickly ... of Arizona. "Beetles don't get trees unless the trees are really water-stressed" and unable to make ...

151

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

152

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...

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

2011-01-01

153

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

154

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.

155

Mosquito larvicidal activity of thymol from essential oil of Coleus aromaticus Benth. against Culex tritaeniorhynchus, Aedes albopictus, and Anopheles subpictus (Diptera: Culicidae).  

Science.gov (United States)

Diseases transmitted by blood-feeding mosquitoes, such as dengue fever, dengue hemorrhagic fever, Japanese encephalitis, malaria, and filariasis, are increasing in prevalence, particularly in tropical and subtropical zones. To control mosquitoes and mosquito-borne diseases, which have a worldwide health and economic impacts, synthetic insecticide-based interventions are still necessary, particularly in situations of epidemic outbreak and sudden increases of adult mosquitoes. However, the indiscriminate use of conventional insecticides is fostering multifarious problems like widespread development of insecticide resistance, toxic hazards to mammals, undesirable effects on nontarget organisms, and environmental pollution. The aim of this research was to evaluate the toxicity of mosquito larvicidal activity of essential oil from Coleus aromaticus and its pure isolated constituent thymol against larvae of Culex tritaeniorhynchus, Aedes albopictus, and Anopheles subpictus. The chemical composition of the essential oil was analyzed using gas chromatography-mass spectroscopy. A total of 14 components of the essential oil of C. aromaticus were identified. The major chemical components identified were thymol (82.68%), terpinen-4-ol (3.2%), and trans-Caryophyllene (3.18%). Twenty-five early third instar larvae of C. tritaeniorhynchus, A. albopictus, and A. subpictus were exposed and assayed in the laboratory. Thymol and essential oil were tested in concentrations of 10, 20, 30, 40, and 50 and 30, 60, 90, 120, and 150 ppm, respectively. The larval mortality was observed after 24 h of treatment. The thymol had a significant toxic effect against early third-stage larvae of C. tritaeniorhynchus, A. albopictus, and A. subpictus with an LC50 values of 28.19, 24.83, and 22.06 ?g/mL respectively, whereas the essential oil of C. aromaticus had an LC50 values of 72.70, 67.98, and 60.31 ?g/mL, respectively. No mortality was observed in controls. The Chi-square values were significant at p larvae and could be useful in search of newer, safer, and more effective natural compounds as larvicides. PMID:23933878

Govindarajan, Marimuthu; Sivakumar, Rajamohan; Rajeswary, Mohan; Veerakumar, Kaliyan

2013-11-01

156

Killing-Yano tensors, rank-2 Killing tensors, and conserved quantities in higher dimensions  

International Nuclear Information System (INIS)

From the metric and one Killing-Yano tensor of rank D-2 in any D-dimensional spacetime with such a principal Killing-Yano tensor, we show how to generate k = [(D+1)/2] Killing-Yano tensors, of rank D-2j for all 0 ? j ? k-1, and k rank-2 Killing tensors, giving k constants of geodesic motion that are in involution. For the example of the Kerr-NUT-AdS spacetime (hep-th/0604125) with its principal Killing-Yano tensor (gr-qc/0610144), these constants and the constants from the k Killing vectors give D independent constants in involution, making the geodesic motion completely integrable (hep-th/0611083). The constants of motion are also related to the constants recently obtained in the separation of the Hamilton-Jacobi and Klein-Gordon equations (hep-th/0611245)

157

Killing-Yano Tensors, Rank-2 Killing Tensors, and Conserved Quantities in Higher Dimensions  

CERN Document Server

From the metric and one Killing-Yano tensor of rank D-2 in any D-dimensional spacetime with such a principal Killing-Yano tensor, we show how to generate k=[(D+1)/2] Killing-Yano tensors, of rank D-2j for all j=0,...,k-1, and k rank-2 Killing tensors, giving k constants of geodesic motion that are in involution. For the example of the Kerr-NUT-AdS spacetime (hep-th/0604125) with its principal Killing-Yano tensor (gr-qc/0610144), these constants and the constants from the k Killing vectors give D independent constants in involution, making the geodesic motion completely integrable (hep-th/0611083). The constants of motion are also related to the constants recently obtained in the separation of the Hamilton-Jacobi and Klein-Gordon equations (hep-th/0611245).

Krtous, P; Kubiznak, D; Page, D N; Frolov, Valeri P.; Krtous, Pavel; Kubiznak, David; Page, Don N.

2007-01-01

158

Selection of cyanobacteria isolated from mosquito breeding sites as a potential food source for mosquito larvae.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

One way to increase the persistence of larvicidal toxins in mosquito breeding sites is to clone the corresponding genes in microorganisms, such as cyanobacteria, which could serve as a source of food for the larvae. We isolated and cultured 10 strains of cyanobacteria from three mosquito breeding sites along the French Mediterranean coast. Most of the strains were tolerant to a relatively wide range of salt concentrations, and all of them were totally or partially resistant to at least four o...

Thiery, I.; Nicolas, L.; Rippka, R.; Tandeau Marsac, N.

1991-01-01

159

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

160

Larvicidal and phytochemical properties of Callistemon rigidus R. Br. (Myrtaceae leaf solvent extracts against three vector mosquitoes  

Directory of Open Access Journals (Sweden)

Full Text Available Background & objectives: Due to ever-growing insecticide resistance in mosquito vectors and environmental contamination by synthetic insecticides, plants may be a source of alternative agents for mosquito control. Therefore, the present investigation involved the determination of larvicidal and phytochemical properties of Callistemon rigidus leaf extracts against Anopheles gambiae, Aedes aegypti and Culex quinquefasciatus. Methods: The standard protocol of WHO was used for larval tests. Twenty five IV instar larvae were exposed to various concentrations from 125-1000 ppm for methanol crude extract (MCE, hexane (HF, chloroform (CF, ethyl acetate (EAF and methanol (MF fractions, from 250-2000 ppm for aqueous extract (AE and 2500 ppm for Diclorvos. The mortality was observed 24 h post-exposure. The LC50 and LC90 values were determined by Probit analysis. Results: The phytochemical analysis revealed that the presence of alkaloids, steroids, saponins, terpenoids, tannins and phenolic compounds, lipids, fats and fixed oils in MCE; terpenoids, steroids, lipids, fats and fixed oils in HF; terpenoids in CF; tannins and phenolic compounds in EAF and alkaloids, tannins, saponins and phenolic compounds in MF. Against Ae. aegypti, HF was the most active fraction with LC50 of 56.25 ppm. Against An. gambiae, HF demonstrated its potential mosquito larvicide killing relatively all exposed larvae at all concentrations with LC50 of 17.11 ppm. Against Cx. quinquefasciatus, only MCE and HF exhibited larvicidal activity with LC50 of 447.38 and 721.95 ppm, respectively. Interpretation & conclusion: Callistemon rigidus exhibited some promising larvicidal activity against medically important vector mosquitoes. Studies are indicated to identify the active compounds from this plant for developing mosquito larvicides

Danga Yinyang Simon Pierre

2014-08-01

 
 
 
 
161

Selection of cyanobacteria isolated from mosquito breeding sites as a potential food source for mosquito larvae.  

Science.gov (United States)

One way to increase the persistence of larvicidal toxins in mosquito breeding sites is to clone the corresponding genes in microorganisms, such as cyanobacteria, which could serve as a source of food for the larvae. We isolated and cultured 10 strains of cyanobacteria from three mosquito breeding sites along the French Mediterranean coast. Most of the strains were tolerant to a relatively wide range of salt concentrations, and all of them were totally or partially resistant to at least four of the five biological or chemical larvicides used in the local mosquito control program. Six unicellular strains from these habitats and Synechococcus strain PCC 7942, a strain maintained for more than 10 years under laboratory conditions, were assessed for ingestion and digestion by larvae Culex pipiens and Anopheles gambiae mosquitoes. The numbers of cells ingested and digested were dependent on the cyanobacterial strain and varied with the mosquito species. Three of the new isolates, Synechococcus strain PCC 8905 and Synechocystis strains PCC 8906 and PCC 8912, were ingested and digested rapidly by larvae of both mosquito species. Since these strains are also tolerant to larvicides and relatively resistant to elevated salt concentrations, they meet the basic requirements for potential recipients of bacterial genes that encode endotoxins. PMID:1677241

Thiery, I; Nicolas, L; Rippka, R; Tandeau de Marsac, N

1991-01-01

162

Musings on Sketches, Artists, and Mosquito Nets  

Centers for Disease Control (CDC) Podcasts

Byron Breedlove reads his essay Musings on Sketches, Artists, and Mosquito Nets about the art of James Whistler and the transmission of vector borne diseases.  Created: 9/23/2014 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 10/20/2014.

2014-09-23

163

Workbook on the Identification of Mosquito Larvae.  

Science.gov (United States)

This self-instructional booklet is designed to enable public health workers identify larvae of some important North American mosquito species. The morphological features of larvae of the various genera and species are illustrated in a programed booklet, which also contains illustrated taxonomic keys to the larvae of 11 North American genera and to…

Pratt, Harry D.; And Others

164

Chemically enhanced sunlight for killing bacteria  

International Nuclear Information System (INIS)

Solar ultraviolet (UV) photocatalyzed oxidation of chemicals with titanium dioxide (TiO2) has received considerable attention. Much less recognized, however, is the ability of the same system to destroy bacteria. This study examined this phenomenon and the conditions that affect it. Bacteria in aqueous solution were given solar exposure with titanium dioxide and their survival with time was determined. Lamps with a predominantly solar ultraviolet spectrum were also used in the experiments. Without exposure to UV light, TiO2 had no deleterious effect on the bacteria. However, several common bacteria on solar exposure in the presence of TiO2 were killed in just a few minutes, whereas without TiO2 it took over an hour to destroy them. A concentration of 0.01% TiO2 was most effective in killing bacteria and 10-fold concentrations lower or higher were successively less effective. Inorganic and organic compounds in solution, even in small amounts, interfered with the efficiency of killing. Alkaline solution also reduced the bactericidal activity. Circulation and agitation provided by stirring to keep the TiO2 particles suspended reduced the time necessary to kill the bacteria. Time-intensity curves for killing bacteria were the same general shape with or without TiO2, indicating that TiO2 served merely as a catalyst to increase the rate of the reaction but that the mechanism of action was not changed. The shape of the curves show that the organisms are sensitized with a minimum intensity of radiation and that an increase doesn't greatly increase the rate of kill. Below this critical intensity, however, the time required for killing markedly increases as the intensity is decreased

165

Cambio climático en España y riesgo de enfermedades infecciosas y parasitarias transmitidas por artrópodos y roedores / Climate Change in Spain and Risk of Infectious and Parasitic Diseases Transmitted by Arthropods and Rodents  

Scientific Electronic Library Online (English)

Full Text Available SciELO Public Health | Language: Spanish Abstract in spanish Por la proximidad con el continente africano, siendo lugar de tránsito obligado de aves migratorias y personas, y por las condiciones climáticas, cercanas a las de zonas donde hay transmisión de enfermedades vectoriales, España es un país en el que este tipo de enfermedades podrían verse potenciadas [...] por el cambio climático. El posible riesgo vendría por extensión geográfica de vectores ya establecidos o por la importación e instalación de vectores sub-tropicales adaptados a sobrevivir en climas menos cálidos y más secos. Hipotéticamente, las enfermedades vectoriales susceptibles de ser influidas por el cambio climático en España serían aquellas transmitidas por dípteros como dengue, encefalitis del Nilo occidental, fiebre del valle del Rift, malaria y leishmaniosis; las transmitidas por garrapatas como la fiebre de Congo Crimea, encefalitis por garrapata, enfermedad de Lyme, fiebre botonosa y fiebre recurrente endémica; y las transmitidas por roedores. Pero la mayor y más factible amenaza sería la instauración del mosquito Aedes albopictus, que sería capaz de transmitir enfermedades virales como la del Nilo occidental o el dengue. Pero para el establecimiento de auténticas áreas de endemia se necesitaría la conjunción de otros factores, tales como el aflujo masivo y simultáneo de reservorios animales o humanos y el deterioro de las condiciones socio-sanitarias y de los servicios de Salud Pública. Abstract in english Due to Spain's being located near Africa, being a stopping-off point for migrating birds and individuals and due to its climate conditions, nearing those of areas where there are vector-borne diseases, this is a country where this type of diseases could taken on greater importance due to the climate [...] change. The possible risk would result from the geographical spread of already established vectors or due to subtropical vectors adapted to surviving in cooler, dried climates being imported and taking up residence. Hypothetically, the vector-borne diseases subject to be influenced by the climate change in Spain would be those transmitted by dipterans, such as dengue fever, West Nile encephalitis, Rift Valley fever, malaria and leishmaniasis; tick-transmitted diseases, such as Crimean-Congo hemorrhagic fever, tick-borne encephalitis, Lyme disease, spotted fever and endemic relapsing fever; and rodent-transmitted diseases. But the greatest, most viable threat would be the Aedes albopictus mosquito, which would be capable of transmitting viral diseases such as West Nile encephalitis or dengue fever, taking up residence. But, for actual areas of endemia being established, a combination of other factors, such as the massive, simultaneous influx of animal or human reservoirs and the deterioration of the social healthcare conditions and of the Public Health services.

Rogelio, López-Vélez; Ricardo, Molina Moreno.

2005-04-01

166

Cambio climático en España y riesgo de enfermedades infecciosas y parasitarias transmitidas por artrópodos y roedores / Climate Change in Spain and Risk of Infectious and Parasitic Diseases Transmitted by Arthropods and Rodents  

Scientific Electronic Library Online (English)

Full Text Available SciELO Spain | Language: Spanish Abstract in spanish Por la proximidad con el continente africano, siendo lugar de tránsito obligado de aves migratorias y personas, y por las condiciones climáticas, cercanas a las de zonas donde hay transmisión de enfermedades vectoriales, España es un país en el que este tipo de enfermedades podrían verse potenciadas [...] por el cambio climático. El posible riesgo vendría por extensión geográfica de vectores ya establecidos o por la importación e instalación de vectores sub-tropicales adaptados a sobrevivir en climas menos cálidos y más secos. Hipotéticamente, las enfermedades vectoriales susceptibles de ser influidas por el cambio climático en España serían aquellas transmitidas por dípteros como dengue, encefalitis del Nilo occidental, fiebre del valle del Rift, malaria y leishmaniosis; las transmitidas por garrapatas como la fiebre de Congo Crimea, encefalitis por garrapata, enfermedad de Lyme, fiebre botonosa y fiebre recurrente endémica; y las transmitidas por roedores. Pero la mayor y más factible amenaza sería la instauración del mosquito Aedes albopictus, que sería capaz de transmitir enfermedades virales como la del Nilo occidental o el dengue. Pero para el establecimiento de auténticas áreas de endemia se necesitaría la conjunción de otros factores, tales como el aflujo masivo y simultáneo de reservorios animales o humanos y el deterioro de las condiciones socio-sanitarias y de los servicios de Salud Pública. Abstract in english Due to Spain's being located near Africa, being a stopping-off point for migrating birds and individuals and due to its climate conditions, nearing those of areas where there are vector-borne diseases, this is a country where this type of diseases could taken on greater importance due to the climate [...] change. The possible risk would result from the geographical spread of already established vectors or due to subtropical vectors adapted to surviving in cooler, dried climates being imported and taking up residence. Hypothetically, the vector-borne diseases subject to be influenced by the climate change in Spain would be those transmitted by dipterans, such as dengue fever, West Nile encephalitis, Rift Valley fever, malaria and leishmaniasis; tick-transmitted diseases, such as Crimean-Congo hemorrhagic fever, tick-borne encephalitis, Lyme disease, spotted fever and endemic relapsing fever; and rodent-transmitted diseases. But the greatest, most viable threat would be the Aedes albopictus mosquito, which would be capable of transmitting viral diseases such as West Nile encephalitis or dengue fever, taking up residence. But, for actual areas of endemia being established, a combination of other factors, such as the massive, simultaneous influx of animal or human reservoirs and the deterioration of the social healthcare conditions and of the Public Health services.

Rogelio, López-Vélez; Ricardo, Molina Moreno.

2005-04-01

167

Killing-Yano equations and G structures  

International Nuclear Information System (INIS)

We solve the Killing-Yano equation on manifolds with a G structure for G = SO(n), U(n), SU(n), Sp(n) . Sp(1), Sp(n), G2 and Spin(7). Solutions include nearly-Kaehler, weak holonomy G2, balanced SU(n) and holonomy G manifolds. As an application, we find that particle probes on AdS4 x X compactifications of type IIA and 11-dimensional supergravity admit a W type of symmetry generated by the fundamental forms. We also explore the W symmetries of string and particle actions in heterotic and common sector supersymmetric backgrounds. In the heterotic case, the generators of the W symmetries completely characterize the solutions of the gravitino Killing spinor equation, and the structure constants of the cal W symmetry algebra depend on the solution of the dilatino Killing spinor equation

168

Super Killing equation and supersymmetry transformation  

International Nuclear Information System (INIS)

In super space (x,theta), as the metric tensor field G/sup A/B (x,theta) is given, we calculate the Riemann curvature tensor R/sup D//sub A/BC of the fourth rank and its generalized cyclicity. The equation that must be satisfied by isometry in the super space, i.e., super Killing equation: xi/sub A/;B+eta/sub a/bxi/sub B/;A = 0, is deduced. In flat super space with zero curvature tensor, we have obtained the general solutions of the super Killing equation and the commutation relations of the corresponding generators. In the case of constant curvature, we have obtained a special solution of the super Killing equation

169

Timelike Killing fields and relativistic statistical mechanics  

Science.gov (United States)

For spacetimes with timelike Killing fields, we introduce a 'Fermi Walker Killing' coordinate system and use it to prove a Liouville theorem for an appropriate volume element of phase space for a statistical mechanical system of particles. We derive an exact relativistic formula for the Helmholtz free energy of an ideal gas and compare it, for a class of spacetimes, to its Newtonian analog, derived both independently and as the Newtonian limit of our formula. We also find the relativistic thermodynamic equation of state. Specific examples are given in Kerr spacetime.

Klein, David; Collas, Peter

2009-02-01

170

Timelike Killing Fields and Relativistic Statistical Mechanics  

CERN Document Server

For spacetimes with timelike Killing fields, we introduce a "Fermi-Walker-Killing" coordinate system and use it to prove a Liouville Theorem for an appropriate volume element of phase space for a statistical mechanical system of particles. We derive an exact relativistic formula for the Helmholtz free energy of an ideal gas and compare it, for a class of spacetimes, to its Newtonian analog, derived both independently and as the Newtonian limit of our formula. We also find the relativistic thermodynamic equation of state. Specific examples are given in Kerr spacetime.

Klein, David

2008-01-01

171

Timelike Killing fields and relativistic statistical mechanics  

Energy Technology Data Exchange (ETDEWEB)

For spacetimes with timelike Killing fields, we introduce a 'Fermi-Walker-Killing' coordinate system and use it to prove a Liouville theorem for an appropriate volume element of phase space for a statistical mechanical system of particles. We derive an exact relativistic formula for the Helmholtz free energy of an ideal gas and compare it, for a class of spacetimes, to its Newtonian analog, derived both independently and as the Newtonian limit of our formula. We also find the relativistic thermodynamic equation of state. Specific examples are given in Kerr spacetime.

Klein, David [Department of Mathematics, California State University, Northridge, Northridge, CA 91330-8313 (United States); Collas, Peter, E-mail: david.klein@csun.ed, E-mail: peter.collas@csun.ed [Department of Physics and Astronomy, California State University, Northridge, Northridge, CA 91330-8268 (United States)

2009-02-21

172

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.

173

Cell killing by ultrasoft x-rays  

International Nuclear Information System (INIS)

The experimental results of cell killing by ultrasoft x-rays (0.28 and 1.5 keV) is presented. Cell lines V79, 10 T 1/2 and human skin fibroblasts that have different cellular dimensions due to difference in their attachment properties were used in these studies. Cellular dimensions at the time of exposure to ultrasoft x-rays were carefully measured by optical and electron microscopy. The results indicate that the differences in cell killing by ultrasoft x-rays and hard x-rays may be dependent on nuclear configurations of cells. The implications of these results to theories of radiation action are discussed

174

Fish Kills in Ireland in 1993  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The pattern of fish kills in 1993 showed a dramatic change from that of the previous ten years. The number of incidents showed a very welcome reduction to a total of 33, the lowest since systematic records began to be kept in 1982. Only one case of damage caused by silage effluent was reported and two from farm effluents - in the recent past these were the most frequent and serious sources. However, fish kills provisionally attributed to 'enrichment' attained a record total of 16, most of the...

Moriarty, C.

1994-01-01

175

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

176

Approximate Killing Fields as an Eigenvalue Problem  

CERN Document Server

Approximate Killing vector fields are expected to help define physically meaningful spins for non-symmetric black holes in general relativity. However, it is not obvious how such fields should be defined geometrically. This paper relates a definition suggested recently by Cook and Whiting to an older proposal by Matzner, which seems to have been overlooked in the recent literature. It also describes how to calculate approximate Killing fields based on these proposals using an efficient scheme that could be of immediate practical use in numerical relativity.

Beetle, Christopher

2008-01-01

177

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

178

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

179

Isolation and characterization of larvicidal components against mosquito larvae (Aedes aegypti Linn. from calodendrum capense Thunb  

Directory of Open Access Journals (Sweden)

Full Text Available Chromatographic analysis of air-dried root barks and seeds of Calodendrum capense Thunb led to the isolation of calodendrolide (1, limonin (2 and limonin diosphenol (3 whose structures were elucidated using physical and spectroscopic techniques. The compounds and the crude extract were then tested against mosquito 2nd instar larvae of the species Aedes aegypti Linn senso stricto, a yellow fever vector at concentrations of 25, 50, 75, and 100 ppm. Calodendrolide (1 was the most toxic as it killed all the larvae even at the lower concentration of 25 ppm. In addition, concentrations of 15, 10, 5 and 1 ppm of this compound retained moderate efficacy. Calodendrolide (1, C. capense root bark crude, limonin (2, and limonin diosphenol (3 had LC50 values of 13.1, 29.2, 71.6 and 217.1 ppm, respectively.

A.K. Kiprop

2005-06-01

180

Progress in mapping the yellow fever mosquito genome.  

Science.gov (United States)

Mosquito-borne diseases cause significant problems for the human health. For this reason, the genomes of three most dangerous species of mosquitoes, including the yellow fever mosquito Aedes aegypti, were sequenced in last decade. The efficient vector of arboviruses. Ae. aegypti, is also a convenient model for laboratory research. The intensive genetic mapping of morphological and molecular markers conducted for this mosquito in the past was very successful. This mapping was also used as a tool to localize a number of quantitative trait loci related to the mosquito's ability to transmit various pathogens. However, physical mapping of the Ae. aegypti genome is difficult due to the lack of high-quality polytene chromosomes. Here, we review different mapping approaches that help improving genome sequence assembly and also integrate linkage, chromocome and genome maps the yellow fever mosquito. PMID:23875456

Sharakhova, M V; Sharakhov, I V

2013-01-01

 
 
 
 
181

The cell biology of mosquito vitellogenesis  

Directory of Open Access Journals (Sweden)

Full Text Available Insect vitellogenesis involves coordinated activities of the fat body and oocytes. We have studied these activities at the cellular level in the mosquito. During each vitellogenic cycle, the fat body undergoes three successive stages: 1 proliferation of biosynthetic organelles, 2 vitellogenin synthesis, 3 termination of vitellogenin synthesis and degradation of biosynthetic organelles by lysosomes. Analysis with monoclonal antibodies and radiolabelling demonstrated that the mosquito yolk protein consists of two subunits (200-kDa and 65-kDa. Both subunits are glycosylated, their carbohydrate moieties are composed of high-mannose oligosaccharides. The yolk protein subunits are derived from a single 220 kDa precursor detected by an in vitro translation. Oocytes become competent to internalize proteins as a result of juvenile hormone-mediated biogenesis of endocytotic organelles. The yolk protein is then accumulated by receptor-mediated endocytosis. A pathway of the yold protein and factors determining its routing in the oocyte have been studied.

Alexander S. Raikhel

1987-01-01

182

Sensory physiological basis for attraction in mosquitoes.  

Science.gov (United States)

Hematophagous insects use air-borne chemical cues to guide them to resources such as blood-meal hosts, plants, and oviposition sites. Research that combines behavioral and electrophysiological approaches to the study of how insects find these resources can result in useful information about what chemical signals a mosquito can detect and at what airborne concentrations such compounds are effective. Such studies have helped clarify the role of lactic acid, ammonia, carbon dioxide, octenol, phenols, temperature, and humidity in the attraction of mosquitoes, tsetse flies, and ticks to blood-meal hosts. Egg raft pheromone, indoles, cresols, methyl cyclohexanol, 2-butoxy ethanol, and fatty acid esters have been examined with respect to oviposition site location and selection. Plant volatiles have received less attention but electrophysiological responses to terpenes and green plant volatiles have been observed. Information from studies of this type can be useful in the design of both attractants and more effective repellents. PMID:8965085

Davis, E E; Bowen, M F

1994-06-01

183

Efficacy of Lagenidium giganteum metabolites on mosquito larvae with reference to nontarget organisms.  

Science.gov (United States)

Lagenidium giganteum is a water mold and an effective mosquito control agent with limited use due to poor survival and contamination during storage. Invert extracellular metabolites of L. giganteum is easy to produce, long shelf life, and a potential candidate in tropical climates. This fungus was grown in PYG broth in the laboratory at 25 +/- 2 degrees C, and relative humidity was maintained at 75 +/- 5% for 15 +/- 2 days. Filtration process of metabolites was done using Whatman filter paper, column chromatograph, and range syringe filters techniques. Then 5-ml fractions were collected and used to assay larvicidal efficacies. Larvicidal efficacies were performed against Culex quinquefasciatus, Anopheles stephensi, and Aedes aegypti at five different concentrations, viz. 1.68, 1.99, 2.17, 2.30, and 2.40 ppm. And also, filtrates were assessed against four species of nontarget organisms named Daphnia pulex, Cyclopes, Lymnea auriculeta, and tadpoles of Rana tigrina with different concentrations. The mortality values were subjected by the Probit analysis. The complete mortalities that resulted from applying filtrates dosage on all instars of mosquitoes persisted for a period of 24, 48, and 72 h, respectively. The efficacies in killing instar of three important vectors and safer for nontarget organisms with good biological stability of extracellular metabolites make this a promising alternative to mycelium and conidial-based larvicides. It could be regarded as fungal-based natural larvicide for the use of vector control. PMID:17334944

Vyas, Neetu; Dua, K K; Prakash, Soam

2007-07-01

184

Changes in local mosquito fauna following beaver (Castor canadensis) activity--an update.  

Science.gov (United States)

Drastic reduction of populations of univoltine temporary pool mosquitoes followed impoundment of breeding areas by beavers. Mosquito populations persist at very low levels over a 10-year period with no evidence of mosquito development in the impoundment. PMID:1357092

Butts, W L

1992-09-01

185

School Shootings; Standards Kill Students and Society  

Science.gov (United States)

School shootings have been in the news of late. People ponder what occurs in classrooms today. Why would a young person wish to take a life? Within educational institutions, the killings are a concern. In our dire attempt to teach the children and ensure student success, it seems many of our offspring are lost. Some students feel separate from…

Angert, Betsy L.

2008-01-01

186

Red Tide Kills Fish, Fouls Gulf Coast  

Science.gov (United States)

This CBS news article reports a toxic algae bloom that spread along the Texas Gulf coast in 2000, killing millions of fish and fouling beaches with their remains. The article explains how red tide affects fish and describes health threats to humans.

News, Cbs

187

Crab Hole Mosquito Bluesâ??The Story  

Centers for Disease Control (CDC) Podcasts

This podcast reports on a humorous song that takes a look at a very serious human and equine disease. Written and performed by the MARU Health Angels Band, Bill Dietz, director of the Division of Nutrition, Physical Activity and Obesity at CDC, talks about the song, "Crab Hole Mosquito Blues", and the history behind it.  Created: 5/12/2011 by National Center for Emerging Zoonotic and Infectious Diseases (NCEZID).   Date Released: 5/23/2011.

2011-05-12

188

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 ...

N G Das, I. Baruah

2003-01-01

189

Predictors of mosquito net use in Ghana  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 rai...

2011-01-01

190

Nonlinear auditory mechanism enhances female sounds for male mosquitoes  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Sound plays an important role in the life history of mosquitoes. Male mosquitoes detect females by the sound generated by their wingbeat. Because female wings are weak acoustic radiators, males have been driven by sexual selection to evolve sensitive acoustic sensors. Mosquito antennae are very sensitive acoustic receivers, featuring up to 16,000 sensory cells, a number comparable with that contained in the human cochlea. The antennal sound receiver exhibits frequency selectivity, input ampli...

Jackson, Joseph C.; Robert, Daniel

2006-01-01

191

Mosquitoes infected with dengue viruses in Brazil  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Dengue epidemics have been reported in Brazil since 1985. The scenery has worsened in the last decade because several serotypes are circulating and producing a hyper-endemic situation, with an increase of DHF/DSS cases as well as the number of fatalities. Herein, we report dengue virus surveillance in mosquitoes using a Flavivirus genus-specific RT-Hemi-Nested-PCR assay. The mosquitoes (Culicidae, n = 1700 collected in the Northeast, Southeast and South of Brazil, between 1999 and 2005, were grouped into 154 pools. Putative genomes of DENV-1, -2 and -3 were detected in 6 mosquito pools (3.8%. One amplicon of putative DENV-1 was detected in a pool of Haemagogus leucocelaenus suggesting that this virus could be involved in a sylvatic cycle. DENV-3 was found infecting 3 pools of larvae of Aedes albopictus and the nucleotide sequence of one of these viruses was identified as DENV-3 of genotype III, phylogenetically related to other DENV-3 isolated in Brazil. This is the first report of a nucleotide sequence of DENV-3 from larvae of Aedes albopictus.

Durigon Edison L

2010-07-01

192

Genetic elimination of dengue vector mosquitoes.  

Science.gov (United States)

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-only releases, and permits the release of eggs instead of adult mosquitoes. OX3604C males introduced weekly into large laboratory cages containing stable target mosquito populations at initial ratios of 8.5-101 OX3604Ctarget eliminated the populations within 10-20 weeks. These data support the further testing of this strain in contained or confined field trials to evaluate mating competitiveness and environmental and other effects. Successful completion of the field trials should facilitate incorporation of this approach into area-wide dengue control or elimination efforts as a component of an integrated vector management strategy. PMID:21383140

Wise de Valdez, Megan R; Nimmo, Derric; Betz, John; Gong, Hong-Fei; James, Anthony A; Alphey, Luke; Black, William C

2011-03-22

193

Manipulating insulin signaling to enhance mosquito reproduction  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Backgrond In the mosquito Aedes aegypti the insulin/insulin growth factor I signaling (IIS cascade is a key regulator of many physiological processes, including reproduction. Two important reproductive events, steroidogenesis in the ovary and yolk synthesis in the fat body, are regulated by the IIS cascade in mosquitoes. The signaling molecule phosphatase and tensin homolog (PTEN is a key inhibitor of the IIS cascade that helps modulate the activity of the IIS cascade. In Ae. aegypti, six unique splice variants of AaegPTEN were previously identified, but the role of these splice variants, particularly AaegPTEN3 and 6, were unknown. Results Knockdown of AaegPTEN or its specific splice variant AaegPTEN6 (the splice variant thought to regulate reproduction in the ovary and fat body using RNAi led to a 15–63% increase in egg production with no adverse effects on egg viability during the first reproductive cycle. Knockdown of AaegPTEN3, expressed predominantly in the head, had no effect on reproduction. We also characterized the protein expression patterns of these two splice variants during development and in various tissues during a reproductive cycle. Conclusion Previous studies in a range of organisms, including Drosophila melanogaster and Caenorhabditis elegans, have demonstrated that disruption of the IIS cascade leads to decreased reproduction or sterility. In this study we demonstrate that knockdown of the IIS inhibitor PTEN can actually increase reproduction in the mosquito, at least during the first reproductive cycle.

Rasgon Jason L

2009-08-01

194

Biocontrol from a mosquito control director's point of view.  

Science.gov (United States)

Two principal mosquito breeding problems that occur in Florida are discussed from the standpoint of a manager of a mosquito abatement district: 1) mosquitoes that breed in standing or permanent water, and 2) mosquitoes that breed in temporary habitats such as floodwater pools. The efficacies of several different types of biological control agents are discussed for each type of problem. Fish are used in permanent water sites, and several other organisms are being evaluated. No programs are based exclusively on biological control agents. Biological control is generally not used in temporary sites. Relative costs of chemical and biological control are discussed. PMID:7595458

Beidler, E J

1995-06-01

195

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.

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

2013-06-01

196

Venereal Transmission of Chikungunya Virus by Aedes aegypti Mosquitoes (Diptera: Culicidae)  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Experiments were conducted to demonstrate the role of male Aedes aegypti mosquitoes in the maintenance and transmission of chikungunya virus (CHIKV) to female mosquitoes. We demonstrated that infected male mosquitoes are capable of infecting females during mating. The infection rate in female mosquitoes was 11% when virgin female mosquitoes were allowed to coinhabit with infected males. The body suspension of venereally infected female mosquitoes induced illness in infant Swiss albino mice, w...

Mavale, Mangala; Parashar, Deepti; Sudeep, Anakkathil; Gokhale, Mangesh; Ghodke, Youwaraj; Geevarghese, Geevarghese; Arankalle, Vidya; Mishra, Akhilesh Chandra

2010-01-01

197

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

198

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

199

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

200

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 dis...

Christensen Jamie; Harrison Stanley; Birney Ian; Wilkerson Richard C; Foley Desmond H; Rueda Leopoldo M

2010-01-01

 
 
 
 
201

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

202

Genetic Control of Mosquitoes: population suppression strategies Controle genético de mosquitos: estratégias de supressão de populações  

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Full Text Available 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.Ao longo das duas últimas décadas, morbidade e mortalidade da malária e dengue e outros patógenos tem se tornado cada vez mais um problema de Saúde Pública. O aumento na distribuição geográfica de seus respectivos vetores é acompanhada pela emergência de doenças em novas áreas. Não estão disponíveis drogas específicas suficientes e não há vacinas específicas para imunizar as populações alvo. As medidas de controle de mosquitos atuais falharam em atingir os objetivos propostos, principalmente devido à grande capacidade reprodutiva dos mosquitos e alta flexibilidade genômica. O controle químico se torna cada vez mais restrito devido a sua potencial toxicidade aos seres humanos, mortalidade de organismos não alvos, resistência a inseticida além de outros impactos ambientais. Novas estratégias de controle são necessárias. A técnica do inseto estéril (SIT é um método de supressão populacional espécie específico e ambientalmente amigável, baseia-se na criação em massa, esterilização mediante irradiação e liberação de um grande número de insetos machos. Liberar insetos carregando um gene letal dominante (RIDL oferece uma solução a muitas limitações impostas pela técnica do inseto estéril (SIT que limitaram sua aplicação em mosquitos e ainda assim mantém suas características de ambientalmente amigável e espécie específica. A natureza auto-limitante de mosquitos estéreis tende a deixar alguns empecilhos para uso no campo, de certa forma, menos desafiadores quando comparados a sistemas auto-propagação, característicos de estratégias de substituição de população. Sistemas auto-limitantes estão mais próximos para uso no campo, portanto pode ser apropriado considerá-lo primeiro. A perspectiva de métodos de controle genéticos contra mosquitos vetores de doenças que acometem humanos está rapidamente se tornando uma realidade, muitas decisões terão de ser tomadas em âmbito nacional, regional e internacional com relação a aspectos étnicos, sociais, culturais e de biossegurança para o uso e liberação

André Barretto Bruno Wilke

2012-10-01

203

Genetic Control of Mosquitoes: population suppression strategies / Controle genético de mosquitos: estratégias de supressão de populações  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Ao longo das duas últimas décadas, morbidade e mortalidade da malária e dengue e outros patógenos tem se tornado cada vez mais um problema de Saúde Pública. O aumento na distribuição geográfica de seus respectivos vetores é acompanhada pela emergência de doenças em novas áreas. Não estão disponíveis [...] drogas específicas suficientes e não há vacinas específicas para imunizar as populações alvo. As medidas de controle de mosquitos atuais falharam em atingir os objetivos propostos, principalmente devido à grande capacidade reprodutiva dos mosquitos e alta flexibilidade genômica. O controle químico se torna cada vez mais restrito devido a sua potencial toxicidade aos seres humanos, mortalidade de organismos não alvos, resistência a inseticida além de outros impactos ambientais. Novas estratégias de controle são necessárias. A técnica do inseto estéril (SIT) é um método de supressão populacional espécie específico e ambientalmente amigável, baseia-se na criação em massa, esterilização mediante irradiação e liberação de um grande número de insetos machos. Liberar insetos carregando um gene letal dominante (RIDL) oferece uma solução a muitas limitações impostas pela técnica do inseto estéril (SIT) que limitaram sua aplicação em mosquitos e ainda assim mantém suas características de ambientalmente amigável e espécie específica. A natureza auto-limitante de mosquitos estéreis tende a deixar alguns empecilhos para uso no campo, de certa forma, menos desafiadores quando comparados a sistemas auto-propagação, característicos de estratégias de substituição de população. Sistemas auto-limitantes estão mais próximos para uso no campo, portanto pode ser apropriado considerá-lo primeiro. A perspectiva de métodos de controle genéticos contra mosquitos vetores de doenças que acometem humanos está rapidamente se tornando uma realidade, muitas decisões terão de ser tomadas em âmbito nacional, regional e internacional com relação a aspectos étnicos, sociais, culturais e de biossegurança para o uso e liberação destes métodos de controle de vetores. Abstract in english 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 intern

André Barretto Bruno, Wilke; Mauro Toledo, Marrelli.

2012-10-01

204

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

205

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

206

Otters Lutra lutra killing Mountain Hares Lepus timidus  

Digital Repository Infrastructure Vision for European Research (DRIVER)

During the winter, otter Lutra lutra were found to kill mountain hares Lepus timidus in the Scottish highlands. The possible method of killing is discussed. Hares and other mammals are an important part of otter' diet during winter.

Conroy J.; Calder J.

2000-01-01

207

9 CFR 113.205 - Newcastle Disease Vaccine, Killed Virus.  

Science.gov (United States)

...205 Newcastle Disease Vaccine, Killed Virus. Newcastle Disease Vaccine (Killed...from embryonated chicken eggs or cell...10 unvaccinated chickens that have been...virulent strain of Newcastle disease virus...

2010-01-01

208

9 CFR 113.213 - Pseudorabies Vaccine, Killed Virus.  

Science.gov (United States)

... false Pseudorabies Vaccine, Killed Virus. 113.213 Section 113.213 Animals...INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS...VECTORS STANDARD REQUIREMENTS Killed Virus Vaccines § 113.213...

2010-01-01

209

9 CFR 113.201 - Canine Distemper Vaccine, Killed Virus.  

Science.gov (United States)

...false Canine Distemper Vaccine, Killed Virus. 113.201 Section 113.201 Animals...INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS...VECTORS STANDARD REQUIREMENTS Killed Virus Vaccines § 113.201 Canine...

2010-01-01

210

9 CFR 113.206 - Wart Vaccine, Killed Virus.  

Science.gov (United States)

...2010-01-01 false Wart Vaccine, Killed Virus. 113.206 Section 113.206 Animals...INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS...VECTORS STANDARD REQUIREMENTS Killed Virus Vaccines § 113.206 Wart...

2010-01-01

211

9 CFR 113.205 - Newcastle Disease Vaccine, Killed Virus.  

Science.gov (United States)

...false Newcastle Disease Vaccine, Killed Virus. 113.205 Section 113.205 Animals...INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS...VECTORS STANDARD REQUIREMENTS Killed Virus Vaccines § 113.205 Newcastle...

2010-01-01

212

9 CFR 113.203 - Feline Panleukopenia Vaccine, Killed Virus.  

Science.gov (United States)

... Feline Panleukopenia Vaccine, Killed Virus. 113.203 Section 113.203 Animals...INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS...VECTORS STANDARD REQUIREMENTS Killed Virus Vaccines § 113.203 Feline...

2010-01-01

213

9 CFR 113.209 - Rabies Vaccine, Killed Virus.  

Science.gov (United States)

...2010-01-01 false Rabies Vaccine, Killed Virus. 113.209 Section 113.209 Animals...INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS...VECTORS STANDARD REQUIREMENTS Killed Virus Vaccines § 113.209 Rabies...

2010-01-01

214

9 CFR 113.204 - Mink Enteritis Vaccine, Killed Virus.  

Science.gov (United States)

...false Mink Enteritis Vaccine, Killed Virus. 113.204 Section 113.204 Animals...INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS...VECTORS STANDARD REQUIREMENTS Killed Virus Vaccines § 113.204 Mink...

2010-01-01

215

9 CFR 113.212 - Bursal Disease Vaccine, Killed Virus.  

Science.gov (United States)

...false Bursal Disease Vaccine, Killed Virus. 113.212 Section 113.212 Animals...INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS...VECTORS STANDARD REQUIREMENTS Killed Virus Vaccines § 113.212 Bursal...

2010-01-01

216

9 CFR 113.210 - Feline Calicivirus Vaccine, Killed Virus.  

Science.gov (United States)

... Feline Calicivirus Vaccine, Killed Virus. 113.210 Section 113.210 Animals...INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS...VECTORS STANDARD REQUIREMENTS Killed Virus Vaccines § 113.210 Feline...

2010-01-01

217

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.

218

Euler obstruction and Lipschitz-Killing curvatures  

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Applying a local Gauss-Bonnet formula for closed subanalytic sets to the complex analytic case, we obtain characterizations of the Euler obstruction of a complex analytic germ in terms of the Lipschitz-Killing curvatures and the Chern forms of its regular part. We also prove analogous results for the global Euler obstruction. As a corollary, we give a positive answer to a question of Fu on the Euler obstruction and the Gauss-Bonnet measure.

Dutertre, Nicolas

2014-01-01

219

Mosquito bisection as a variable in estimates of PCR-derived malaria sporozoite rates  

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Full Text Available Abstract Background Highly sensitive polymerase chain reaction (PCR methods offer an alternative to the light microscopy examination of mosquito salivary glands for the determination of malaria sporozoite rates in wild caught female Anopheles. Removal of mosquito abdomens is assumed to eliminate false positives caused by malaria oocyst DNA in the midgut. This assumption has not been tested with current gold standard PCR assays, and for the variety of conditions that specimens could encounter in the laboratory and field. Methods Laboratory Anopheles stephensi were used that had been infected with Plasmodium falciparum 6–7 days and 14 days post infection (p.i., when oocysts only and oocysts + sporozoites, respectively, are developed. Mosquitoes were killed and immediately frozen, air dried before being frozen, or stored under humid conditions overnight before being frozen, to simulate a range of conditions in the field. Additionally, abdomens were removed anterior to, at, or posterior to the junction of the abdomen and thorax, and both portions were processed using a standard nested PCR of the small sub-unit nuclear ribosomal genes (ssrDNA with products visualized on agarose gels. Results Overall, 4.1 % (4/97 of head + thorax samples that were 6–7 days p.i. gave apparent false positives for sporozoites, compared to 9.3 % (9/97 that were positive for abdomens. No positives (0/52 were obtained when similar specimens were bisected anterior to the junction of the thorax and abdomen, compared to 21.2 % (11/52 that were positive for posterior portions. Multiple bands were noted for positives from the ‘Frozen’ treatment and the rate of false negatives due to DNA degradation appears higher under the ‘Humid’ treatment. Reproducibility of results for the ‘Frozen’ treatment was 90 %. Conclusions Despite the importance of specimen condition and the bisection step in determining sporozoite rates, little attention has been paid to them in the literature. Recommendations from this study are that: 1 care needs to be taken to reduce DNA degradation in the field; 2 mosquito abdomens be separated anterior to the junction of the thorax and abdomen; and 3 DNA sequencing of a subsample of positive results should be undertaken if possible.

Foley Desmond H

2012-05-01

220

The Knowledge and Experience of Dengue Mosquitoes among Housewives.  

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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

 
 
 
 
221

Changes in local mosquito fauna following beaver (Castor canadensis) activity.  

Science.gov (United States)

A marked decrease in anthropophilic temporary water mosquito populations subsequent to impoundment of extensive areas of larval development by beavers is documented. Absence to date of development of other mosquito species in the permanent water thus established is noted and discussed relative to current characteristics of the site. PMID:2906976

Butts, W L

1986-09-01

222

Analysing the generality of spatially predictive mosquito habitat models.  

Science.gov (United States)

The increasing spread of multi-drug resistant malaria in African highlands has highlighted the importance of malaria suppression through vector control. Its historical success has meant that larval control has been proposed as part of an integrated malaria vector control program. Due to high operation costs, larval control activities would benefit greatly if the locations of mosquito habitats could be identified quickly and easily, allowing for focal habitat source suppression. Several mosquito habitat models have been developed to predict the location of mosquito habitats. However, to what extent these models can be generalised across time and space to predict the distribution of dynamic mosquito habitats remains largely unexplored. This study used mosquito habitat data collected in six different time periods and four different modelling approaches to establish 24 mosquito habitat models. We systematically tested the generality of these 24 mosquito habitat models. We found that although habitat--environment relationships change temporally, a modest level of performance was attained when validating the models using data collected from different time periods. We also describe flexible approaches to the predictive modelling of mosquito habitats, that provide novel modelling architecture for future research efforts. PMID:21527240

Li, Li; Bian, Ling; Yakob, Laith; Zhou, Guofa; Yan, Guiyun

2011-07-01

223

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

224

Mosquito transmission of the rodent malaria parasite Plasmodium chabaudi  

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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

225

Effects of rice straw and water management on riceland mosquitoes.  

Science.gov (United States)

Rice fields are important sources of mosquitoes in many regions, and rice (Oryza spp.) growing practices can affect mosquito populations. Rice straw incorporation and winter flooding have become common methods to prepare seedbeds, largely replacing burning of straw. These methods increase nutrients during the growing season. We sampled mosquito larvae during 1999-2001 in 16 0.72-ha plots where straw was either burned or incorporated into soil after the previous growing season; these treatments were crossed with either winter flooding or no winter flooding. In 2000, all fields were drained mid-season for an application of herbicide, and then they were reflooded. Mosquitoes responded positively to straw incorporation and winter flooding, especially in combination. The mid-season reflood in year 2 was associated with an order of magnitude increase in Culex tarsalis Coquillett larvae. Results confirm that rice straw and water management can strongly influence mosquito populations. PMID:17017215

Lawler, Sharon P; Dritz, Deborah A

2006-09-01

226

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)

227

New records of mosquitoes from northwestern Argentina.  

Science.gov (United States)

Eleven mosquito species, namely Aedes hastatus, Ae. fulvus, Coquillettidia albicosta, Cq. juxtamansonia, Culex aliciae, Cx. delpontei, Cx. oedipus, Cx. pedroi, Mansonia flaveola, Uranotaenia leucoptera, and Wyeomyia oblita, are recorded for the first time from northwestern Argentina. In addition, 3 species, Cx. brethesi, Limatus durhami, and Ur. nataliae, are reported for the first time from Salta Province. These records extend the geographical distribution of these 3 species to Salta Province. This study also extends the geographical distributions of Cq. nigricans, Cx. chidesteri, and Ma. humeralis to Jujuy Province and of Ae. meprai, Ae. milleri, Ae. oligopistus, Cx. brethesi, Cx. fernandezi, and Cx. tatoi to Tucumán Province. PMID:22894121

Dantur Juri, María J; Stein, Marina; Rossi, Gustavo C; Navarro, Juan Carlos; Zaidenberg, Mario; Sallum, María A Mureb

2012-06-01

228

Novel acetylcholinesterase target site for malaria mosquito control.  

Science.gov (United States)

Current anticholinesterase pesticides were developed during World War II and are toxic to mammals because they target a catalytic serine residue of acetylcholinesterases (AChEs) in insects and in mammals. A sequence analysis of AChEs from 73 species and a three-dimensional model of a malaria-carrying mosquito (Anopheles gambiae) AChE (AgAChE) reported here show that C286 and R339 of AgAChE are conserved at the opening of the active site of AChEs in 17 invertebrate and four insect species, respectively. Both residues are absent in the active site of AChEs of human, monkey, dog, cat, cattle, rabbit, rat, and mouse. The 17 invertebrates include house mosquito, Japanese encephalitis mosquito, African malaria mosquito, German cockroach, Florida lancelet, rice leaf beetle, African bollworm, beet armyworm, codling moth, diamondback moth, domestic silkworm, honey bee, oat or wheat aphid, the greenbug, melon or cotton aphid, green peach aphid, and English grain aphid. The four insects are house mosquito, Japanese encephalitis mosquito, African malaria mosquito, and German cockroach. The discovery of the two invertebrate-specific residues enables the development of effective and safer pesticides that target the residues present only in mosquito AChEs rather than the ubiquitous serine residue, thus potentially offering an effective control of mosquito-borne malaria. Anti-AgAChE pesticides can be designed to interact with R339 and subsequently covalently bond to C286. Such pesticides would be toxic to mosquitoes but not to mammals. PMID:17183688

Pang, Yuan-Ping

2006-01-01

229

Larvicidal activity of mosquito sterol carrier protein-2 inhibitors to the insecticide-resistant mosquito Culex quinquefasciatus (Diptera: Culicidae).  

Science.gov (United States)

AeSCP-2 inhibitors (SCPIs) compete with cholesterol for binding to a mosquito sterol carrier protein-2 (AeSCP-2) known to aid in the uptake of cholesterol in mosquito cells. The larvicidal activities of AeSCP-2 inhibitor-1 (SCPI-1) and inhibitor-2 (SCPI-2) against Culex quinquefasciatus Say (Diptera: Culicidae) were therefore examined in insecticide-resistant Culex mosquitoes HAmCq(G9), MAmCq(G2), and BAmCq(G0). All of the resistant Culex mosquito strains exhibited similar sensitivity to SCPI-1 and SCPI-2 inhibitors compared with a susceptible S-Lab strain. When an AeSCP-2 inhibitor was applied simultaneously with permethrin, the toxicity of permethrin to the second-instar larvae of all four strains of Culex mosquitoes increased, suggesting a synergistic effect of AeSCP-2 inhibitors on the toxicity of permethrin against Culex mosquitoes. Both SCPI-1 and SCPI-2 inhibitors caused a 2.4- to 3-fold reduction in the level of permethrin resistance in the highly resistant strain HAmCq(G9). This result suggests that the mode of action of the AeSCP-2 inhibitors, which reduces the uptake of cholesterol by inhibiting the function of AeSCP-2 in mosquito cells, may interfere with the mechanisms or ability that govern permethrin resistance in the HAmCq(G9) mosquito strain. PMID:19960692

Li, Ting; Lan, Que; Liu, Nannan

2009-11-01

230

The conformal Killing equation on forms -- prolongations and applications  

CERN Document Server

We construct a conformally invariant vector bundle connection such that its equation of parallel transport is a first order system that gives a prolongation of the conformal Killing equation on differential forms. Parallel sections of this connection are related bijectively to solutions of the conformal Killing equation. We construct other conformally invariant connections, also giving prolongations of the conformal Killing equation, that bijectively relate solutions of the conformal Killing equation on $k$-forms to a twisting of the conformal Killing equation on (k - l)-forms for various integers l. These tools are used to develop a helicity raising and lowering construction in the general setting and on conformally Einstein manifolds.

Gover, A R; Silhan, Josef

2006-01-01

231

The cell biology of mosquito vitellogenesis  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Insect vitellogenesis involves coordinated activities of the fat body and oocytes. We have studied these activities at the cellular level in the mosquito. During each vitellogenic cycle, the fat body undergoes three successive stages: 1) proliferation of biosynthetic organelles, 2) vitellogenin synt [...] hesis, 3) termination of vitellogenin synthesis and degradation of biosynthetic organelles by lysosomes. Analysis with monoclonal antibodies and radiolabelling demonstrated that the mosquito yolk protein consists of two subunits (200-kDa and 65-kDa). Both subunits are glycosylated, their carbohydrate moieties are composed of high-mannose oligosaccharides. The yolk protein subunits are derived from a single 220 kDa precursor detected by an in vitro translation. Oocytes become competent to internalize proteins as a result of juvenile hormone-mediated biogenesis of endocytotic organelles. The yolk protein is then accumulated by receptor-mediated endocytosis. A pathway of the yold protein and factors determining its routing in the oocyte have been studied.

Alexander S., Raikhel.

232

What Killed The Dinosaurs?: The Great Mystery  

Science.gov (United States)

This site presents theories about why the dinosaurs became extinct. The first page provides background information covering not only the "great dying" at the K-T boundary but also the mass extinction at the end of the Paleozoic Era. The author covers six factors that complicate the study of mass extinction including time resolution, the Signor-Lipps Effect, and falsifiability. A link then takes the reader to a second page where invalid extinction hypotheses are explained. These range from "hay fever killed the dinosaurs" to "the dinosaurs just faded away," (no causation implied). The final link leads us to current thinking about extinction including volcanism, plate tectonics, and the Alvarez Hypothesis.

Hutchinson, John

233

Fish Kills in Ireland 1991-1992  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The numbers of fish kills were below the average for the ten years since the systematic recording of incidents began in 1983. Totals were 60 and 51 for 1991 and 1992 respectively. Both years therefore represent a continuation of the downward trend which began after the peak of 122 incidents in 1987. An important factor in the improved situation was the reduction in the number of silage discharges which had been the most serious problem for a number of years. Untreated sewage and industrial ef...

Moriarty, C.

1993-01-01

234

Towards the genetic manipulation of mosquito disease vectors  

International Nuclear Information System (INIS)

Our research is aimed at developing the technologies necessary to undertake the genetic manipulation of insect vector genomes. In the longer term, we wish to explore the potential that this technology may have for developing novel strategies for the control of vector-borne diseases. The focus of our current research has been to: i) identify and characterise endogenous transposable elements in the genomes of mosquito vectors -research has focussed on identifying both Class I and Class 11 elements and determining their structure and distribution within mosquito genomes; ii) develop and use transfection systems for mosquito cells in culture as a test bed for transformation vectors and promoters - transfection techniques, vector constructs and different promoters driving reporter genes have been utilised to optimise the transformation of both Aedes aegypti and Anopheles gambiae cells in culture; iii) identify putative promoter sequences which are induced in the female mosquito midgut when it takes a blood meal - the Anopheles gambiae trypsin gene locus has been cloned and sequenced and the intergenic regions assessed for their ability to induce reporter gene expression in mosquito gut cells. The progress we have made in each of these areas will be described and discussed in the context of our longer term aim which is to introduce genes coding for antiparasitic agents into mosquito genomes in such a way that they are expressed in the mosquito midgut and disrupt transmission of the malaria parasite. (author)

235

Culicinae mosquitoes in Sanandaj county, Kurdistan province, western Iran  

Directory of Open Access Journals (Sweden)

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

236

Plasmodium infection decreases fecundity and increases survival of mosquitoes.  

Science.gov (United States)

Long-lived mosquitoes maximize the chances of Plasmodium transmission. Yet, in spite of decades of research, the effect of Plasmodium parasites on mosquito longevity remains highly controversial. On the one hand, many studies report shorter lifespans in infected mosquitoes. On the other hand, parallel (but separate) studies show that Plasmodium reduces fecundity and imply that this is an adaptive strategy of the parasite aimed at redirecting resources towards longevity. No study till date has, however, investigated fecundity and longevity in the same individuals to see whether this prediction holds. In this study, we follow for both fecundity and longevity in Plasmodium-infected and uninfected mosquitoes using a novel, albeit natural, experimental system. We also explore whether the genetic variations that arise through the evolution of insecticide resistance modulate the effect of Plasmodium on these two life-history traits. We show that (i) a reduction in fecundity in Plasmodium-infected mosquitoes is accompanied by an increase in longevity; (ii) this increase in longevity arises through a trade-off between reproduction and survival; and (iii) in insecticide-resistant mosquitoes, the slope of this trade-off is steeper when the mosquito is infected by Plasmodium (cost of insecticide resistance). PMID:22859589

Vézilier, J; Nicot, A; Gandon, S; Rivero, A

2012-10-01

237

British container breeding mosquitoes: the impact of urbanisation and climate change on community composition and phenology  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The proliferation of artificial container habitats in urban areas has benefitted urban adaptable mosquito species globally. In areas where mosquitoes transmit viruses and parasites, it can promote vector population productivity and fuel mosquito-borne disease outbreaks. In Britain, storage of water in garden water butts is increasing, potentially expanding mosquito larval habitats and influencing population dynamics and mosquito-human contact. Here we show that the community composition, abun...

Townroe, Susannah; Callaghan, Amanda

2014-01-01

238

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

239

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

240

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

 
 
 
 
241

Blocking malaria parasite invasion of mosquito salivary glands.  

Science.gov (United States)

Release of genetically engineered mosquitoes resistant to parasite infections has been proposed as a novel way to control malaria transmission, and several important advances have been made in anticipation of testing this approach. In particular, the development of synthetic effector genes that block parasite development in mosquito hosts has exploited a number of different mechanisms that result in parasite-resistant phenotypes, and those that target specifically the sporozoites are reviewed here. The use of a number of synthetic genes based on different mechanisms in transgenic mosquitoes will make the selection of resistant parasites unlikely. PMID:14506217

James, Anthony A

2003-11-01

242

Genetically engineered resistance to dengue-2 virus transmission in mosquitoes.  

Science.gov (United States)

The control of arthropod-borne virus diseases such as dengue may ultimately require the genetic manipulation of mosquito vectors to disrupt virus transmission to human populations. To reduce the ability of mosquitoes to transmit dengue viruses, a recombinant Sindbis virus was used to transduce female Aedes aegypti with a 567-base antisense RNA targeted to the premembrane coding region of dengue type 2 (DEN-2) virus. The transduced mosquitoes were unable to support replication of DEN-2 virus in their salivary glands and therefore were not able to transmit the virus. PMID:8629025

Olson, K E; Higgs, S; Gaines, P J; Powers, A M; Davis, B S; Kamrud, K I; Carlson, J O; Blair, C D; Beaty, B J

1996-05-10

243

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

244

Xenodiagnosis: use of mosquitoes for the diagnosis of arboviral infections  

Directory of Open Access Journals (Sweden)

Full Text Available The arboviruses have a worldwide distribution and, mosquitoes and ticks contribute principally intheir transmission. In the last two decades, arboviral diseases have been recognised due to theirresurgence and spread in newer geographic areas. Surveys to determine the prevalence of arbovirusesin any region largely depend on the isolation attempts from the arthropods along with the serosurveys.Xenodiagnosis means use of insects for the diagnosis of infectious diseases affecting humanbeing. The present communication discusses the application of mosquitoes for propagation and assaysof arboviruses, the technique of mosquito inoculation and importance of xenodiagnosis.

D.T. Mourya, M.D. Gokhale , R. Kumar

2007-12-01

245

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

246

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

247

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

Directory of Open Access Journals (Sweden)

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

248

Field evaluation of CDC and Mosquito Magnet X traps baited with dry ice, CO2 sachet, and octenol against mosquitoes.  

Science.gov (United States)

The Centers for Disease Control and Prevention (CDC) light traps and Mosquito Magnet X (MMX) traps baited with dry ice, octenol, and a new formulation (granular) of carbon dioxide (CO2) were evaluated against adult mosquitoes in the field. The results showed that the MMX traps (68.6%) baited with dry ice collected more mosquitoes compared to the CDC light traps (32.4%) only. The CDC traps baited with dry ice (64%) collected significantly more mosquitoes than traps baited with CO2 sachets (11%) or octenol (23%). The MMX traps baited with dry ice (85.5%) collected significantly more mosquitoes than traps baited with CO2 sachets (6.5%) or octenol (9%). The CDC traps baited with the formulations of normal and slow release CO2 sachets collected more mosquitoes than the formulation of fast release sachets. The CDC traps baited with fresh sachets and 24-h-exposed sachets collected significantly more mosquitoes than the traps baited with 48-h- and 72-h-exposed sachets. PMID:18666533

Xue, Rui-De; Doyle, Melissa A; Kline, Daniel L

2008-06-01

249

Malaria and the Anopheles mosquitoes of Tajikistan.  

Science.gov (United States)

Surveys of Anopheles mosquitoes were conducted in urban, rural, and natural areas of Tajikistan to obtain updated information on their distributions, especially in southern districts of the country where malaria is a prevalent disease. Nine species of Anopheles are found in Tajikistan. Anopheles superpictus, An. claviger, An. hyrcanus, and An. pulcherrimus are the most widespread and abundant species. Investigations in northern Tajikistan confirmed the presence of An. artemievi and the absence of An. martinius, both members of the An. maculipennis complex of malaria vectors. Anopheles barianensis, An. lindesayi, and An. marteri sogdianus, species previously recorded in the country, were not encountered during our surveys. The history of Anopheles and malaria research in Tajikistan is reviewed and bionomical and distributional information is provided for each of the nine species. PMID:23181867

Habirov, Zamonidin; Kadamov, Dilshod; Iskandarov, Firuz; Komilova, Saodat; Cook, Shelley; McAlister, Erica; Harbach, Ralph E

2012-12-01

250

A SIMPLE METHOD FOR DETERMINING ARBOVIRUS TRANSMISSION IN MOSQUITOES  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We present a simplified method for the collection of mosquito saliva to determine Culex pipiens quinquefasciatus transmission of West Nile virus that can be used for experiments requiring large sample sizes.

Anderson, Sheri L.; Richards, Stephanie L.; Smartt, Chelsea T.

2010-01-01

251

Oviposition and olfaction responses of Aedes aegypti mosquitoes to insecticides.  

Science.gov (United States)

Insecticide applications are not particularly effective on Aedes aegypti mosquitoes which has been attributed to their 'closet' behaviour, or ability to rest in places that remain unexposed to insecticides. Some researchers have suggested that insecticides repel mosquitoes, which would result in less exposure and increased dispersal. If repellence due to insecticides is a fact, acquiring a vector-borne disease, such as dengue, could legitimately be attributed to local vector control efforts and this would lead to restitution claims. This study thus investigated the effect of insecticide presence on mosquito behaviour indirectly via oviposition and directly via olfactory response. In all experiments, oviposition in each insecticide compared to its water and ethanol controls was not significantly different. This indicates that Ae. aegypti mosquitoes are not affected by insecticide presence and that increased dispersal is unlikely to be caused by vector control spraying. PMID:24522139

Canyon, D V; Muller, R

2013-12-01

252

Simple intervention to reduce mosquito breeding in waste stabilisation ponds.  

Science.gov (United States)

Waste stabilisation ponds (WSP) are the preferred method for treatment of urban wastewater in low-income countries but, especially in arid regions, the pond systems can be important breeding sites for mosquitoes of medical importance. In a WSP system in Faisalabad, Pakistan, we assessed the impact of simple environmental interventions on mosquito occurrence and abundance. Reducing the amount of floating matter in the ponds, eliminating emergent vegetation and repairing cracks in the cement structure reduced the number of mosquito-positive samples in the intervention ponds to almost zero, whereas the control ponds had a significant number of positive samples. This suggests that a combination of simple low-cost interventions is a feasible environmental management strategy for vector control in WSP systems that are located in areas where medically important mosquitoes may breed in the shallow ponds. PMID:17825333

Ensink, Jeroen H J; Mukhtar, Muhammad; van der Hoek, Wim; Konradsen, Flemming

2007-11-01

253

Toxicity of Organophosphate and Carbamate Insecticide Against Aedes aegypti Mosquitoes  

Directory of Open Access Journals (Sweden)

Full Text Available Aedes aegypti mosquito is increasing problem of public health, being the vector responsible for Dengue and Chikungunya. Chlorpirifos (Organofosfat and Metonil (Carbamate were known to posses insecticide activity against insect. The study was aimed to examine effectiveness of Chlorpirifos and Metonil as insectiside against Ae. aegypti mos-quito Chlorpirifos a significantly higher insecticide activity against Ae. aegypti than Metonil. The mosquito mortality was observed after 24 h exposure. The LC50 value of Chlorpirifos and Metonil were 0.64 mg/lt and 0,802 mg/lt, against Ae. aegypti mosquito. The mixed of both insecticide was LC50 value 108.04 mg/lt, this result prove that mixed of both insecticede not sinergism. The result of this study suggested that Chlorpirifos more effective insecticide against Ae.aegypti than Metonil.

Endang Puji Astuti

2010-12-01

254

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

255

Mosquitoes actively remove drops deposited by fog and dew.  

Science.gov (United States)

We report mosquito behaviors for removing accumulated drops of water which would otherwise increase the energy expended during takeoff and free flight. These techniques take advantage of the insect's small size and great structural strength. To dry their wings before takeoff, mosquitoes employ a flutter stroke, at double the wingbeat frequency of normal flight, generating nearly 2500 gravities of acceleration. Mosquitoes may also remove drops by the respective accelerations associated with takeoff and collision with the ground. We correlate the accelerations and size of drops ejected using a simple model involving the drop's inertial force and surface tension. We note mosquitoes may use similar techniques to remove synthetic drops, making our observations applicable for understanding the resistance of insects to insecticides. PMID:24876192

Dickerson, Andrew K; Hu, David L

2014-12-01

256

Boosting the sterile insect technique to control mosquitoes.  

Science.gov (United States)

Mosquitoes are vectors of major diseases. Auto-dissemination recently proved very efficient to control Aedes species, using adult females contaminated with dissemination stations of juvenile hormone to treat breeding habitats, but cannot be used at large scales. Here we propose to combine it to the Sterile Insect Technique (SIT) to create a new control concept, named 'boosted SIT' that might enable the area-wide eradication of mosquitoes and many other vectors and insect pests. PMID:24746400

Bouyer, Jérémy; Lefrançois, Thierry

2014-06-01

257

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...

Cross, Fiona R.; Jackson, Robert R.

2011-01-01

258

MULTIPLICATION OF DENGUE AND CHIKUNGUNYA VIRUSES IN AEDES MOSQUITOES  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 show...

Soedarto Soekiman

2012-01-01

259

Mosquito repellent activity of oils from Vitex negundo Linn. leaves.  

Science.gov (United States)

Oil obtained from stream distillate of V. negundo leaves was fractionated by column chromatography. Mosquito repellence activity, as evaluated against Aedes aegypti was mainly confined to the most polar fractions. The protection period against mosquito bites by polar fractions ranged between 1-3 h. However, the mean protection period values of these fractions did not show significant increase in the subsequent subfractions. PMID:1398810

Hebbalkar, D S; Hebbalkar, G D; Sharma, R N; Joshi, V S; Bhat, V S

1992-07-01

260

EFFICACY OF AGERATUM CONYZOIDES AGAINST THE CONTROL OF MOSQUITOES  

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Mosquitoes transmit serious human diseases causing millions of deaths every year. Phytochemistry has proven that there are potential mosquito control agents and also alternatives to synthetic insecticides. The present paper reports Ageratum conyzoides commonly known as Kubhi in Hindi of family Astereacae. The plant after proper identification was collected shade dried and powdered to the fine mesh size. 5 different concentrations were used against IInd and IVth instar of Anapheles stephensi. ...

Neetu Arya et al.

2011-01-01

 
 
 
 
261

Fungal infection counters insecticide resistance in African malaria mosquitoes  

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The evolution of insecticide resistance in mosquitoes is threatening the effectiveness and sustainability of malaria control programs in various parts of the world. Through their unique mode of action, entomopathogenic fungi provide promising alternatives to chemical control. However, potential interactions between fungal infection and insecticide resistance, such as cross-resistance, have not been investigated. We show that insecticide-resistant Anopheles mosquitoes remain susceptible to inf...

2009-01-01

262

BIOACTIVIDAD DE ACEITES ESENCIALES DE Minthostachys mollis CONTRA MOSQUITOS  

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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...

Zygadlo, Julio A.; Bonino, Mari?a A.; Gleiser, Raquel M.

2007-01-01

263

Fighting malaria with engineered symbiotic bacteria from vector mosquitoes  

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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...

Wang, Sibao; Ghosh, Anil K.; Bongio, Nicholas; Stebbings, Kevin A.; Lampe, David J.; Jacobs-lorena, Marcelo

2012-01-01

264

Type-IIB Killing spinors and calibrations  

International Nuclear Information System (INIS)

In this paper we derive the full set of differential equations and some algebraic relations for p-forms constructed from type IIB Killing spinors. These equations are valid for the most general type IIB supersymmetric backgrounds which have a non-zero NS-NS 3-form field strength, H, and non-zero R-R field strengths, G(1), G(3) and G(5). Our motivation is to use these equations to obtain generalised calibrations for branes in supersymmetric backgrounds. In particular, we consider giant gravitons in AdS5xS5. These non-static branes have an interesting construction via holomorphic surfaces in C1,2xC3. We construct the p-forms corresponding to these branes and show that they satisfy the correct differential equations. Moreover, we interpret the equations as calibration conditions and derive the calibration bound. We find that giant gravitons minimise 'energy minus momentum'. (author)

265

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

266

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

267

9 CFR 113.214 - Parvovirus Vaccine, Killed Virus (Canine).  

Science.gov (United States)

...AND VECTORS STANDARD REQUIREMENTS Killed Virus...applicable general requirements prescribed in...accordance with the Outline of Production... (5) An Outline of Production... (c) Test requirements for...

2010-01-01

268

Mosquito (Diptera: Culicidae Fauna of Qom Province, Iran  

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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

269

Mosquito (Diptera: Culicidae Fauna of Qom Province, Iran  

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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

270

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

271

Fungal infection counters insecticide resistance in African malaria mosquitoes.  

Science.gov (United States)

The evolution of insecticide resistance in mosquitoes is threatening the effectiveness and sustainability of malaria control programs in various parts of the world. Through their unique mode of action, entomopathogenic fungi provide promising alternatives to chemical control. However, potential interactions between fungal infection and insecticide resistance, such as cross-resistance, have not been investigated. We show that insecticide-resistant Anopheles mosquitoes remain susceptible to infection with the fungus Beauveria bassiana. Four different mosquito strains with high resistance levels against pyrethroids, organochlorines, or carbamates were equally susceptible to B. bassiana infection as their baseline counterparts, showing significantly reduced mosquito survival. Moreover, fungal infection reduced the expression of resistance to the key public health insecticides permethrin and dichlorodiphenyltrichloroethane. Mosquitoes preinfected with B. bassiana or Metarhizium anisopliae showed a significant increase in mortality after insecticide exposure compared with uninfected control mosquitoes. Our results show a high potential utility of fungal biopesticides for complementing existing vector control measures and provide products for use in resistance management strategies. PMID:19805146

Farenhorst, Marit; Mouatcho, Joel C; Kikankie, Christophe K; Brooke, Basil D; Hunt, Richard H; Thomas, Matthew B; Koekemoer, Lizette L; Knols, Bart G J; Coetzee, Maureen

2009-10-13

272

Species Composition and Relative Abundance of Mosquitoes in Swat, Pakistan  

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Full Text Available A comprehensive survey of mosquitoes (Diptera: Culicidae was conducted in Swat Pakistan, from April to September during 2000. The survey involved the sampling of both, adult and immature stages of mosquitoes, and recovered a total of 21 species in five genera. Sampling of adult mosquitoes involved Pyrethrum spray collections, Man-biting collections, and Animal-biting collection. Immature stages of mosquitoes were collected from variety of habitats including springs, irrigation channels, rice fields, marshes, temporary pools, construction pools, agriculture pools, river margins, ditches, waste water drains, wells and tree holes. During the study most of the species built up their populations in June, July and August, while a few increased their populations in September. During the survey of immature stages, from a total of 138 samples taken, Cx. quinquefasciatus showed maximum frequency of occurrence (recovered from 48 samples followed by An. maculatus (17 samples, Cx. pseudovishnui (14 samples, An. annularis and An. stephensi (13 samples each, Cx. bitaeniorhynchus (11 samples, An. splendidus (5 samples and Cx. theileri (4 samples. The rest of the species occurred infrequently. The observations on habitat specificity of different species of mosquitoes showed the rice fields as the most favorable site for mosquito breeding (harboring 12 species followed by river margins (five species and temporary pools and springs (four species each. During this study Ae. aegypti was recovered from tyres in Mingora; it was not reported earlier from Swat.

Ikram Ilahi

2013-04-01

273

Effects of dairy wastewater on mosquitoes in southern California.  

Science.gov (United States)

The effect of dairy pond water quality on mosquito biology was studied under laboratory conditions during 2004. Due to high turbidity and larval toxicity of raw water samples from dairy ponds with no mosquito breeding, water samples from both mosquito breeding and non-breeding ponds were filtered and diluted 5X with distilled water prior to being tested for sublethal effects on mosquito development. The diluted pond waters showed no significant deleterious effects on the overall development of Culex quiquefasciatus Say at 23.9 degrees and 26.6 degrees C. However, the 3rd and 4th instar larvae were significantly shorter and lighter in weight when reared in diluted water samples from mosquito non-breeding ponds. Similar effects were found on the developmental stages of Cx. tarsalis Coquillette. Data on water quality parameters of filtered pond waters showed higher levels of hexavalent chromium (4X), nitrites (10X), nitrates (2X), sulfates (5X), and salinity (2X) in water samples from non-breeding ponds. Based on these data, the presence of high levels of hexavalent chromium and sulfate appear to be responsible for the absence of mosquito breeding in some dairy ponds. PMID:17249348

Mian, Lal S

2006-12-01

274

Evaluation of octenol and Lurex as baits in Mosquito Magnet Pro traps to collect vector mosquitoes in China.  

Science.gov (United States)

The effectiveness of the attractants 1-octen-3-ol (octenol) and L-lactic acid (Lurex) on the collection of Aedes albopictus, Culex tritaeniorhynchus, Cx. pipiens pallens, and Anopheles sinensis was first evaluated in Mosquito Magnet Pro traps in Yamenkou and Badachu residential areas, Beijing City, and Lishui area, Zhejiang Province, China. The Mosquito Magnet Pro traps baited with octenol collected significantly more Ae. albopictus, Cx. tritaeniorhynchus, and An. sinensis, but fewer Cx. pipiens pallens than collection by the traps alone. There were no significant differences in the numbers of Cx. pipiens pallens, Cx. tritaeniorhynchus, and An. sinensis collected by Mosquito Magnet Pro traps baited with Lurex compared to the traps alone, but the Mosquito Magnet Pro traps baited with Lurex collected significantly more Ae. albopictus than the number collected by the traps alone at 2 areas in Beijing. PMID:21290944

Li, Chun-Xiao; Dong, Yan-De; Zhang, Xiao-Long; Chen, Chen; Song, Shi-Pei; Deng, Bin; Zhao, Tong-Yan; Xue, Rui-De

2010-12-01

275

Killing of gram-negative bacteria by neutrophils: role of O2-independent system in intracellular killing and evidence of O2-dependent extracellular killing.  

Science.gov (United States)

For many strains of these two bacterial species, ingested bacteria are efficiently killed by O2-independent mechanisms. Intracellular killing depends not on 2de novo generation of toxic products of the respiratory burst but rather on intracellular delivery to pre-existing cytotoxic proteins. The principal O2- independent bactericidal system toward these bacteria appears to be BPI which rapidly binds to ingested bacteria and whose discrete action closely resembles the initial lesions produced by the intact neutrophil. In addition, at least for one strain of E. coli (S15), extracellular bacteria can be killed in an O2- dependent fashion. PMID:3898755

Weiss, J; Victor, M; Kao, L; Elsbach, P

1985-01-01

276

Experimental hut comparisons of nets treated with carbamate or pyrethroid insecticides, washed or unwashed, against pyrethroid-resistant mosquitoes.  

Science.gov (United States)

The efficacy against mosquitoes (Diptera: Culicidae) of a bednet treated with carbamate insecticide [carbosulfan capsule suspension (CS) 200 mg/m(2)] was compared with four types of pyrethroid-treated nets in veranda-trap huts at Yaokoffikro near Bouaké, Côte d'Ivoire, where the malaria vector Anopheles gambiae Giles carries the kdr gene (conferring pyrethroid resistance) at high frequency and Culex quinquefasciatus Say is also pyrethroid resistant. Pyrethroids compared were lambdacyhalothrin CS 18 mg/m(2), alphacypermethrin water dispersible granules (WG) 20 mg/m(2), deltamethrin 50 mg/m(2) (Permanet) and permethrin emulsifiable concentrate (EC) 500 mg/m(2). Insecticidal power and personal protection from mosquito bites were assessed before and after the nets were used for 8 months and hand washed five times in cold soapy water. Before washing, all treatments except permethrin significantly reduced blood-feeding and all had significant insecticidal activity against An. gambiae. The carbosulfan net gave significantly higher killing of An. gambiae than all pyrethroid treatments except the Permanet. Against Culex spp., carbosulfan was more insecticidal and gave a significantly better protective effect than any of the pyrethroid treatments. After washing, treated nets retained various degrees of efficacy against both mosquito genera - but least for the carbosulfan net. Washed nets with three types of pyrethroid treatment (alphacypermethrin, lambdacyhalothrin, permethrin) gave significantly higher mortality rates of Culex than in huts with the same pyrethroid-treated nets before washing. After five washes, the Permanet, which is sold as a long-lasting insecticidal product, performed no better than the other nets in our experimental conditions. PMID:15189238

Asidi, A N; N'Guessan, R; Hutchinson, R A; Traoré-Lamizana, M; Carnevale, P; Curtis, C F

2004-06-01

277

Mosquito larvicidal and ovicidal activity of puffer fish extracts against Anopheles stephensi, Culex quinquefasciatus and Aedes aegypti (Diptera: Culicidae).  

Science.gov (United States)

The extracts of liver (LE), ovary (OE), skin (SE) and muscle (ME) tissues of four species of puffer fishes viz., Arothron hispidus, Lagocephalus inermis, Lagocephalus scleratus and Chelonodon patoca were evaluated against larvae and eggs of three mosquito vectors, Anopheles stephensi, Culex quinquefasciatus and Aedes aegypti. The LC50 values were 1194.26, 1382.73 (LE); 1421.42, 1982.73 (OE); 7116.86, 15038.98 (ME) and 10817.8 ppm (SE) for An. stephensi and Cx. quinquefasciatus respectively for A. hispidus. In the case of L. inermis, the LC50 values were 1163.83, 1556.1 and 2426.38 (LE); 1653.53, 2734.74 (OE); 6067.47 (ME) and 10283.04 ppm (SE) for An. stephensi, Cx. quinquefasciatus and Ae. aegypti respectively. The LC50 values were 1509.98, 1608.69 (LE) and 1414.9, 2278.69 ppm (OE) for An. stephensi and Cx. quinquefasciatus respectively for the extracts of L. scleratus. In the case C. patoca extracts the LC50 values were 1182.29, 1543.00, 2441.03 (LE) and 1076.13, 2582.11 ppm (OE) for An. stephensi, Cx. quinquefasciatus and Ae. aegypti respectively. OE and LE of all puffer fishes exhibited zero percent egg hatchability from 600 to 1000 ppm against eggs of An. stephensi and Cx. quinquefasciatus. This study shows that puffer toxins are effective in killing the larvae and eggs of mosquitoes. PMID:23665705

Samidurai, Kaliyaperumal; Mathew, Nisha

2013-03-01

278

Effects of Post Ingestion and Physical Conditions on PCR Amplification of Host Blood Meal DNA in Mosquitoes  

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Full Text Available Identification of host blood meal in haematophagous arthropods is an important element in their rule in transmission of vector borne diseases. The effects of post ingestion and physical conditions that killed mosquitoes are stored on the success of detecting blood meal DNA of Anopheles stephensi and Culex quinquefasiatus was investigated by polymerase chain reaction (PCR amplification at the human mitochondrial DNA cytochromeB (CytB gene. Host DNA extracted from the blood meal up to 33 h post ingestion in both species acts as an efficient template for PCR amplification. However more DNA concentration needs for meals digested longer time. Successful PCR amplification among meals digested for 36 h dropping to a faint band. There were no differences between PCR success rate for sampled stored at +4° C or -20° C, but less successful products were observed in samples kept at 4° C for periods longer than 30 h digestion. The results of this study is important in malaria epidemiological studies to provide valuable information about the degree of contact between human hosts and mosquito vectors, impact of vectors controls such bed nets and repellents, and the transmission dynamics of human malaria and other vector-borne diseases.

MA Oshaghi

2005-08-01

279

Mosquito Surveillance for Prevention and Control of Emerging Mosquito-Borne Diseases in Portugal — 2008–2014  

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Full Text Available Mosquito surveillance in Europe is essential for early detection of invasive species with public health importance and prevention and control of emerging pathogens. In Portugal, a vector surveillance national program—REVIVE (REde de VIgilância de VEctores—has been operating since 2008 under the custody of Portuguese Ministry of Health. The REVIVE is responsible for the nationwide surveillance of hematophagous arthropods. Surveillance for West Nile virus (WNV and other flaviviruses in adult mosquitoes is continuously performed. Adult mosquitoes—collected mainly with Centre for Disease Control light traps baited with CO2—and larvae were systematically collected from a wide range of habitats in 20 subregions (NUTS III. Around 500,000 mosquitoes were trapped in more than 3,000 trap nights and 3,500 positive larvae surveys, in which 24 species were recorded. The viral activity detected in mosquito populations in these years has been limited to insect specific flaviviruses (ISFs non-pathogenic to humans. Rather than emergency response, REVIVE allows timely detection of changes in abundance and species diversity providing valuable knowledge to health authorities, which may take control measures of vector populations reducing its impact on public health. This work aims to present the REVIVE operation and to expose data regarding mosquito species composition and detected ISFs.

Hugo C. Osório

2014-11-01

280

Mosquito surveillance for prevention and control of emerging mosquito-borne diseases in portugal - 2008-2014.  

Science.gov (United States)

Mosquito surveillance in Europe is essential for early detection of invasive species with public health importance and prevention and control of emerging pathogens. In Portugal, a vector surveillance national program-REVIVE (REde de VIgilância de VEctores)-has been operating since 2008 under the custody of Portuguese Ministry of Health. The REVIVE is responsible for the nationwide surveillance of hematophagous arthropods. Surveillance for West Nile virus (WNV) and other flaviviruses in adult mosquitoes is continuously performed. Adult mosquitoes-collected mainly with Centre for Disease Control light traps baited with CO2-and larvae were systematically collected from a wide range of habitats in 20 subregions (NUTS III). Around 500,000 mosquitoes were trapped in more than 3,000 trap nights and 3,500 positive larvae surveys, in which 24 species were recorded. The viral activity detected in mosquito populations in these years has been limited to insect specific flaviviruses (ISFs) non-pathogenic to humans. Rather than emergency response, REVIVE allows timely detection of changes in abundance and species diversity providing valuable knowledge to health authorities, which may take control measures of vector populations reducing its impact on public health. This work aims to present the REVIVE operation and to expose data regarding mosquito species composition and detected ISFs. PMID:25396768

Osório, Hugo C; Zé-Zé, Líbia; Amaro, Fátima; Alves, Maria J

2014-01-01

 
 
 
 
281

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  

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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

282

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 contactt

283

A review of mixed malaria species infections in anopheline mosquitoes  

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Full Text Available Abstract Background In patients with malaria mixed species infections are common and under reported. In PCR studies conducted in Asia mixed infection rates often exceed 20%. In South-East Asia, approximately one third of patients treated for falciparum malaria experience a subsequent Plasmodium vivax infection with a time interval suggesting relapse. It is uncertain whether the two infections are acquired simultaneously or separately. To determine whether mixed species infections in humans are derived from mainly from simultaneous or separate mosquito inoculations the literature on malaria species infection in wild captured anopheline mosquitoes was reviewed. Methods The biomedical literature was searched for studies of malaria infection and species identification in trapped wild mosquitoes and artificially infected mosquitoes. The study location and year, collection methods, mosquito species, number of specimens, parasite stage examined (oocysts or sporozoites, and the methods of parasite detection and speciation were tabulated. The entomological results in South East Asia were compared with mixed infection rates documented in patients in clinical studies. Results In total 63 studies were identified. Individual anopheline mosquitoes were examined for different malaria species in 28 of these. There were 14 studies from Africa; four with species evaluations in individual captured mosquitoes (SEICM. One study, from Ghana, identified a single mixed infection. No mixed infections were identified in Central and South America (seven studies, two SEICM. 42 studies were conducted in Asia and Oceania (11 from Thailand; 27 SEICM. The proportion of anophelines infected with Plasmodium falciparum parasites only was 0.51% (95% CI: 0.44 to 0.57%, for P. vivax only was 0.26% (95% CI: 0.21 to 0.30%, and for mixed P. falciparum and P. vivax infections was 0.036% (95% CI: 0.016 to 0.056%. The proportion of mixed infections in mosquitoes was significantly higher than expected by chance (P Conclusions There are relatively few data on mixed infection rates in mosquitoes from Africa. Mixed species malaria infections may be acquired by simultaneous inoculation of sporozoites from multiply infected anopheline mosquitoes but this is relatively unusual. In South East Asia, where P. vivax infection follows P. falciparum malaria in one third of cases, the available entomological information suggests that the majority of these mixed species malaria infections are acquired from separate inoculations.

Day Nicholas PJ

2011-08-01

284

Design of Targeted B Cell Killing Agents  

Science.gov (United States)

B cells play an important role in the pathogenesis of both systemic and organ-specific autoimmune diseases. Autoreactive B cells not only produce autoantibodies, but also are capable to efficiently present specific autoantigens to T cells. Furthermore, B cells can secrete proinflammatory cytokines and amplify the vicious process of self-destruction. B cell-directed therapy is a potentially important approach for treatment of various autoimmune diseases. The depletion of B cells by anti-CD20/19 monoclonal antibody Retuximab® used in autoimmune diseases therapy leads to systemic side effects and should be significantly improved. In this study we designed a repertoire of genetically engineered B cell killers that specifically affected one kind of cells carrying a respective B cell receptor. We constructed immunotoxins (ITs), fused with c-myc epitope as a model targeting sequence, based on barnase, Pseudomonas toxin, Shiga-like toxin E.coli and Fc domain of human antibody IgG?1. C-MYC hybridoma cell line producing anti-c-myc IgG was chosen as a model for targeted cell depletion. C-myc sequence fused with toxins provided addressed delivery of the toxic agent to the target cells. We demonstrated functional activity of designed ITs in vitro and showed recognition of the fusion molecules by antibodies produced by targeted hybridoma. To study specificity of the proposed B cells killing molecules, we tested a set of created ITs ex vivo, using C-MYC and irrelevant hybridoma cell lines. Pseudomonas-containing IT showed one of the highest cytotoxic effects on the model cells, however, possessed promiscuous specificity. Shiga-like toxin construct demonstrated mild both cytotoxicity and specificity. Barnase and Fc-containing ITs revealed excellent balance between their legibility and toxic properties. Moreover, barnase and Fc molecules fused with c-myc epitope were able to selectively deplete c-myc-specific B cells and decrease production of anti-c-myc antibodies in culture of native splenocytes, suggesting their highest therapeutic potential as targeted B cell killing agents. PMID:21677771

Ponomarenko, Natalia A.; Stremovskiy, Oleg A.; Kozlov, Leonid V.; Bichucher, Anna M.; Dmitriev, Sergey E.; Smirnov, Ivan V.; Shamborant, Olga G.; Balabashin, Dmitry S.; Sashchenko, Lidia P.; Tonevitsky, Alexander G.; Friboulet, Alain; Gabibov, Alexander G.; Deyev, Sergey M.

2011-01-01

285

Otters Lutra lutra killing Mountain Hares Lepus timidus  

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Full Text Available During the winter, otter Lutra lutra were found to kill mountain hares Lepus timidus in the Scottish highlands. The possible method of killing is discussed. Hares and other mammals are an important part of otter' diet during winter.

Conroy J.

2000-04-01

286

Killing of bacteria during solar eclipse and its biological implications.  

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Enhanced killing of bacteria was obtained by radiation reaching the earth during total solar eclipse (February 16, 1980) than during the corresponding time of a normal day (February 26, 1980). The killing was not due to the formation of sunlight induced photoproducts of tryptophan. The damage to the bacteria exposed to sunlight could be repaired by photoreactivation. PMID:6359236

Banerjee, S K; Chatterjee, S N

1983-01-01

287

Response of the mosquito protein interaction network to dengue infection  

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Full Text Available Abstract Background Two fifths of the world's population is at risk from dengue. The absence of effective drugs and vaccines leaves vector control as the primary intervention tool. Understanding dengue virus (DENV host interactions is essential for the development of novel control strategies. The availability of genome sequences for both human and mosquito host greatly facilitates genome-wide studies of DENV-host interactions. Results We developed the first draft of the mosquito protein interaction network using a computational approach. The weighted network includes 4,214 Aedes aegypti proteins with 10,209 interactions, among which 3,500 proteins are connected into an interconnected scale-free network. We demonstrated the application of this network for the further annotation of mosquito proteins and dissection of pathway crosstalk. Using three datasets based on physical interaction assays, genome-wide RNA interference (RNAi screens and microarray assays, we identified 714 putative DENV-associated mosquito proteins. An integrated analysis of these proteins in the network highlighted four regions consisting of highly interconnected proteins with closely related functions in each of replication/transcription/translation (RTT, immunity, transport and metabolism. Putative DENV-associated proteins were further selected for validation by RNAi-mediated gene silencing, and dengue viral titer in mosquito midguts was significantly reduced for five out of ten (50.0% randomly selected genes. Conclusions Our results indicate the presence of common host requirements for DENV in mosquitoes and humans. We discuss the significance of our findings for pharmacological intervention and genetic modification of mosquitoes for blocking dengue transmission.

Pike Andrew D

2010-06-01

288

Zika Virus Emergence in Mosquitoes in Southeastern Senegal, 2011  

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Background Zika virus (ZIKV; genus Flavivirus, family Flaviviridae) is maintained in a zoonotic cycle between arboreal Aedes spp. mosquitoes and nonhuman primates in African and Asian forests. Spillover into humans has been documented in both regions and the virus is currently responsible for a large outbreak in French Polynesia. ZIKV amplifications are frequent in southeastern Senegal but little is known about their seasonal and spatial dynamics. The aim of this paper is to describe the spatio-temporal patterns of the 2011 ZIKV amplification in southeastern Senegal. Methodology/Findings Mosquitoes were collected monthly from April to December 2011 except during July. Each evening from 18?00 to 21?00 hrs landing collections were performed by teams of 3 persons working simultaneously in forest (canopy and ground), savannah, agriculture, village (indoor and outdoor) and barren land cover sites. Mosquitoes were tested for virus infection by virus isolation and RT-PCR. ZIKV was detected in 31 of the 1,700 mosquito pools (11,247 mosquitoes) tested: Ae. furcifer (5), Ae. luteocephalus (5), Ae. africanus (5), Ae. vittatus (3), Ae. taylori, Ae. dalzieli, Ae. hirsutus and Ae. metallicus (2 each) and Ae. aegypti, Ae. unilinaetus, Ma. uniformis, Cx. perfuscus and An. coustani (1 pool each) collected in June (3), September (10), October (11), November (6) and December (1). ZIKV was detected from mosquitoes collected in all land cover classes except indoor locations within villages. The virus was detected in only one of the ten villages investigated. Conclusions/Significance This ZIKV amplification was widespread in the Kédougou area, involved several mosquito species as probable vectors, and encompassed all investigated land cover classes except indoor locations within villages. Aedes furcifer males and Aedes vittatus were found infected within a village, thus these species are probably involved in the transmission of Zika virus to humans in this environment. PMID:25310102

Diallo, Diawo; Sall, Amadou A.; Diagne, Cheikh T.; Faye, Oumar; Faye, Ousmane; Ba, Yamar; Hanley, Kathryn A.; Buenemann, Michaela; Weaver, Scott C.; Diallo, Mawlouth

2014-01-01

289

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. PMID:24827460

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

2014-01-01

290

Mechanisms of Dendritic Cell Lysosomal Killing of Cryptococcus  

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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

291

Optimization of weapon-target pairings based on kill probabilities.  

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In this paper, we present a novel optimization algorithm for assigning weapons to targets based on desired kill probabilities. For the given weapons, targets, and desired kill probabilities, our optimization algorithm assigns weapons to targets that satisfy the desired kill probabilities and minimize the overkill. The minimization of overkill assures that any proper subset of the weapons assigned to a target results in a kill probability that is less than the desired kill probability on such a target. Computational results for up to 120 weapons and 120 targets indicate that the performance of this algorithm yields an average improvement in quality of solutions of 26.8% over the greedy algorithms, whereas execution times remained on the order of milliseconds. PMID:24273148

Bogdanowicz, Zbigniew R; Tolano, Antony; Patel, Ketula; Coleman, Norman P

2013-12-01

292

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

293

European Surveillance for West Nile Virus in Mosquito Populations  

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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. PMID:24157510

Engler, Olivier; Savini, Giovanni; Papa, Anna; Figuerola, Jordi; Groschup, Martin H.; Kampen, Helge; Medlock, Jolyon; Vaux, Alexander; Wilson, Anthony J.; Werner, Doreen; Jost, Hanna; Goffredo, Maria; Capelli, Gioia; Federici, Valentina; Tonolla, Mauro; Patocchi, Nicola; Flacio, Eleonora; Portmann, Jasmine; Rossi-Pedruzzi, Anya; Mourelatos, Spiros; Ruiz, Santiago; Vazquez, Ana; Calzolari, Mattia; Bonilauri, Paolo; Dottori, Michele; Schaffner, Francis; Mathis, Alexander; Johnson, Nicholas

2013-01-01

294

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

295

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, Mohammad Rahim; Shariff, Nadiah Syariani; Nurfarliza, Siti; Othman, Azizah; Ismail, Khaidzir H; Mat Saat, Geshina Ayu

2014-04-01

296

[The mosquito fauna of Smolensk and Kaluga provinces].  

Science.gov (United States)

The mosquitos collected in Smolensk and Kaluga provinces in 1985 by the expedition team of the D. I. Ivanovski? Institute of Virology were identified by V. N. Danilov in 1986. Among the females of mosquitos collected in Smolensk Province four genera and 16 species were recorded; two genera (Culiseta, Mansonia) and 9 species were new ones for this region. Taking in account the reference data (excluding Anopheles hircanus and Aedes behningi, the presence of which here is doubtful) there 22 species of mosquitos of five genera (Anopheles--3, Aedes--16, Mansonia, Culiseta, Culex--one of each) are recently known in Smolensk Province. Among the females of mosquitos collected in Kaluga Province, two genera and 8 species were found including one genus (Mansonia) and three species being a new ones for this region. Together with the reference data, there 17 species of mosquitos of four genera (Anopheles--2, Aedes--13, Mansonia, Culex--one of each) are known now for Kaluga Province. PMID:10862400

Gornostaeva, R M

2000-01-01

297

Silica nanoparticle: a potential new insecticide for mosquito vector control.  

Science.gov (United States)

Presently, there is a need for increased efforts to develop newer and effective methods to control mosquito vectors as the existing chemical and biological methods are not as effective as in earlier period owing to different technical and operational reasons. The use of nanomaterial products in various sectors of science including health increased during the last decade. We tested three types of nanosilica, namely lipophilic, hydrophilic and hydrophobic, to assess their larvicidal, pupicidal and growth inhibitor properties and also their influence on oviposition behaviour (attraction/deterrence) of mosquito species that transmit human diseases, namely malaria (Anopheles), yellow fever, chickungunya and dengue (Aedes), lymphatic filariasis and encephalitis (Culex and Aedes). Application of hydrophobic nanosilica at 112.5 ppm was found effective against mosquito species tested. The larvicidal effect of hydrophobic nanosilica on mosquito species tested was in the order of Anopheles stephensi > Aedes aegypti > Culex quinquefasciatus, and the pupicidal effect was in the order of A. stephensi > C. quinquefasciatus > Ae. aegypti. Results of combined treatment of hydrophobic nanosilica with temephos in larvicidal test indicated independent toxic action without any additive effect. This is probably the first report that demonstrated that nanoparticles particularly nanosilica could be used in mosquito vector control. PMID:22565400

Barik, Tapan K; Kamaraju, Raghavendra; Gowswami, Arunava

2012-09-01

298

REPELLENCY OF LANTANA CAMARA LEAVES SMOKE AGAINST FEMALE ANOPHELES MOSQUITOES  

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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

299

Fighting malaria with engineered symbiotic bacteria from vector mosquitoes.  

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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 mosquito symbiotic bacterium. These engineered P. agglomerans strains inhibited development of the human malaria parasite Plasmodium falciparum and rodent malaria parasite Plasmodium berghei by up to 98%. Significantly, the proportion of mosquitoes carrying parasites (prevalence) decreased by up to 84% for two of the effector molecules, scorpine, a potent antiplasmodial peptide and (EPIP)(4), four copies of Plasmodium enolase-plasminogen interaction peptide that prevents plasminogen binding to the ookinete surface. We demonstrate the use of an engineered symbiotic bacterium to interfere with the development of P. falciparum in the mosquito. These findings provide the foundation for the use of genetically modified symbiotic bacteria as a powerful tool to combat malaria. PMID:22802646

Wang, Sibao; Ghosh, Anil K; Bongio, Nicholas; Stebbings, Kevin A; Lampe, David J; Jacobs-Lorena, Marcelo

2012-07-31

300

Malaria Mosquitoes Host-Locate and Feed upon Caterpillars.  

Science.gov (United States)

Adult female mosquitoes need blood to develop their eggs and both sexes use nectar and honeydew as carbohydrate resources for flight, survival and to enhance reproduction. However, there are also a few reports in the literature of mosquitoes feeding on haemolymph of soft-bodied insects such as caterpillars. The frequency and significance of this entomophagous behavior is not well understood, but is thought to be a vestige of ancestral feeding behavior or an opportunistic behavior that has evolved over time. In our current paper we investigated the extent to which the malaria mosquito, Anopheles stephensi, is attracted to, and can successfully feed on, larvae of two common moth species, Manduca sexta and Heliothis subflexa. Using y-tube olfactometer assays we found that female An. stephensi readily flew upwind to and landed on the caterpillars of both moth species. The nature of the volatile cues used in host location remains unclear but respirometer studies suggest a possible role of CO2. Laboratory cage assays further showed that the female mosquitoes were able to actively feed on moth larvae and gain sufficient nutritional benefit to influence survival. The extent to which such an opportunistic behavior occurs in the field has yet to be explored but our results suggest that this haemolymph feeding behavior could play a role in malaria mosquito life history and could provide a novel mechanism for horizontal transmission of pathogens and other micro-organisms between hosts. PMID:25372720

George, Justin; Blanford, Simon; Thomas, Matthew B; Baker, Thomas C

2014-01-01

 
 
 
 
301

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

302

Mosquito Saliva Causes Enhancement of West Nile Virus Infection in Mice ?  

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West Nile virus (WNV) is transmitted to vertebrate hosts primarily by infected Culex mosquitoes. Transmission of arboviruses by the bite of infected mosquitoes can potentiate infection in hosts compared to viral infection by needle inoculation. Here we examined the effect of mosquito transmission on WNV infection and systematically investigated multiple factors that differ between mosquito infection and needle inoculation of WNV. We found that mice infected with WNV through the bite of a sing...

Styer, Linda M.; Lim, Pei-yin; Louie, Karen L.; Albright, Rebecca G.; Kramer, Laura D.; Bernard, Kristen A.

2011-01-01

303

Awareness and practice about preventive method against mosquito bite in Gujarat  

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Mosquito borne diseases are major public health problems in India. Gujarat is endemic for malaria and other mosquito borne diseases. Anopheles, Aedes and Culex are commonly seen in Gujarat. Therefore the efforts have been consistently made to educate the citizens of State on danger of mosquito bites. The present study was conducted to assess the awareness and practices of mosquito bite prevention methods among households of Central Gujarat district Vadodara. Total 311 families have p...

Niraj Pandit; Yogesh Patel; Bharat Bhavsar

2010-01-01

304

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

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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; Juliano, Steven A.

2007-01-01

305

Behavioural and insecticidal effects of organophosphate-, carbamate- and pyrethroid-treated mosquito nets against African malaria vectors.  

Science.gov (United States)

Three insecticides - the pyrethroid deltamethrin, the carbamate carbosulfan and the organophosphate chlorpyrifos-methyl - were tested on mosquito nets in experimental huts to determine their potential for introduction as malaria control measures. Their behavioural effects and efficacy were examined in Anopheles gambiae Giles s.s. (Diptera: Culicidae) and Anopheles funestus Giles s.s. in Muheza, Tanzania, and in Anopheles arabiensis Patton and Culex quinquefasciatus Say in Moshi, Tanzania. A standardized dosage of 25 mg/m(2) plus high dosages of carbosulfan (50 mg/m(2), 100 mg/m(2) and 200 mg/m(2)) and chlorpyrifos-methyl (100 mg/m(2)) were used to compare the three types of insecticide. At 25 mg/m(2), the rank order of the insecticides for insecticide-induced mortality in wild An. gambiae and An. funestus was, respectively, carbosulfan (88%, 86%) > deltamethrin (79%, 78%) > chlorpyrifos-methyl (35%, 53%). The rank order of the insecticides for blood-feeding inhibition (reduction in the number of blood-fed mosquitoes compared with control) in wild An. gambiae and An. funestus was deltamethrin > chlorpyrifos-methyl > carbosulfan. Carbosulfan was particularly toxic to endophilic anophelines at 200 mg/m(2), killing 100% of An. gambiae and 98% of An. funestus that entered the huts. It was less effective against the more exophilic An. arabiensis (67% mortality) and carbamate-resistant Cx quinquefasciatus (36% mortality). Carbosulfan deterred anophelines from entering huts, but did not deter carbamate-resistant Cx quinquefasciatus. Deltamethrin reduced the proportion of insects engaged in blood-feeding, probably as a consequence of contact irritancy, whereas carbosulfan seemed to provide personal protection through deterred entry or perhaps a spatial repellent action. Any deployment of carbosulfan as an individual treatment on nets should be carried out on a large scale to reduce the risk of diverting mosquitoes to unprotected individuals. Chlorpyrifos-methyl was inferior to deltamethrin in terms of mortality and blood-feeding inhibition and would be better deployed on a net in combination with a pyrethroid to control insecticide-resistant mosquitoes. PMID:19941597

Malima, R C; Oxborough, R M; Tungu, P K; Maxwell, C; Lyimo, I; Mwingira, V; Mosha, F W; Matowo, J; Magesa, S M; Rowland, M W

2009-12-01

306

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.

307

Can nanomedicines kill cancer stem cells?  

Science.gov (United States)

Most tumors are heterogeneous and many cancers contain small population of highly tumorigenic and intrinsically drug resistant cancer stem cells (CSCs). Like normal stem cell, CSCs have the ability to self-renew and differentiate to other tumor cell types. They are believed to be a source for drug resistance, tumor recurrence and metastasis. CSCs often overexpress drug efflux transporters, spend most of their time in non-dividing G0 cell cycle state, and therefore, can escape the conventional chemotherapies. Thus, targeting CSCs is essential for developing novel therapies to prevent cancer relapse and emerging of drug resistance. Nanocarrier-based therapeutic agents (nanomedicines) have been used to achieve longer circulation times, better stability and bioavailability over current therapeutics. Recently, some groups have successfully applied nanomedicines to target CSCs to eliminate the tumor and prevent its recurrence. These approaches include 1) delivery of therapeutic agents (small molecules, siRNA, antibodies) that affect embryonic signaling pathways implicated in self-renewal and differentiation in CSCs, 2) inhibiting drug efflux transporters in an attempt to sensitize CSCs to therapy, 3) targeting metabolism in CSCs through nanoformulated chemicals and field-responsive magnetic nanoparticles and carbon nanotubes, and 4) disruption of multiple pathways in drug resistant cells using combination of chemotherapeutic drugs with amphiphilic Pluronic block copolymers. Despite clear progress of these studies the challenges of targeting CSCs by nanomedicines still exist and leave plenty of room for improvement and development. This review summarizes biological processes that are related to CSCs, overviews the current state of anti-CSCs therapies, and discusses state-of-the-art nanomedicine approaches developed to kill CSCs. PMID:24120657

Zhao, Yi; Alakhova, Daria Y; Kabanov, Alexander V

2013-11-01

308

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...

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

2009-01-01

309

La Prevention Contre les Moustiques dans les Terres Irriguees (Mosquito Prevention on Irrigated Farms).  

Science.gov (United States)

This book tells what measures to take to control mosquitos. The nature and extent of the problem is discussed, its socio-economic and public health aspects are given. The mosquitos' biology and habitat, and problems of reconciling mosquito control with ot...

1969-01-01

310

Surveillance of Zoonotic Infectious Disease Transmitted by Small Companion Animals  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The One Health paradigm for global health recognizes that most new human infectious diseases will emerge from animal reservoirs. Little consideration has been given to the known and potential zoonotic infectious diseases of small companion animals. Cats and dogs closely share the domestic environment with humans and have the potential to act as sources and sentinels of a wide spectrum of zoonotic infections. This report highlights the lack of a coordinated global surveillance scheme that moni...

Day, Michael J.; Breitschwerdt, Edward; Cleaveland, Sarah; Karkare, Umesh; Khanna, Chand; Kirpensteijn, Jolle; Kuiken, Thijs; Lappin, Michael R.; Mcquiston, Jennifer; Mumford, Elizabeth; Myers, Tanya; Palatnik-de-sousa, Clarisa B.; Rubin, Carol; Takashima, Gregg; Thiermann, Alex

2012-01-01

311

Control of mosquito vectors of tropical infectious diseases: (1) bioefficacy of mosquito coils containing several pyrethroids and a synergist.  

Science.gov (United States)

The bioefficacy of mosquito coils containing several pyrethroids were tested in a 25 m3 room against Culex pipiens quinquefasciatus, Aedes aegypti and Anopheles dirus. The test results were compared with tests against Culex pipiens pallens in Japan. Based on the KT50 values (the 50% knockdown time) of mosquito coils containing dl, d-T80-allethrin, d, d-T-prallethrin and methoxymethyl-tetrafluorobenzyl tetramethyl-cyclopropanecarboxylate (K-3050) at doses of 0.05-0.5% (w/w) with or without a synergist, the pyrethroid susceptibility of the four mosquito species was as follows: Cx. p. quinquefasciatus was several times more tolerant to pyrethroids than Cx. p. pallens, Ae. aegypti was a further several times more tolerant than Cx. p. quinquefasciatus, and An. dirus was more susceptible than Cx. p. pallens (KT50 value: about half of Cx. p. pallens). The order of their susceptibilities is common for pyrethroids. Mosquito coils containing d, d-T-prallethrin and K-3050 at doses of 0.05-0.2% (w/w) and N-(2-ethylhexyl)bicycle-[2,2,1]-hept-5-ene-2,3-dicarboxyimide as a synergist at a ratio of 2 times the active ingredient were highly effective against Ae. aegypti, the most important mosquito vector for dengue fever. PMID:18567443

Katsuda, Yoshio; Leemingsawat, Somjai; Thongrungkiat, Supatra; Komalamisara, Narumon; Kanzaki, Tsutomu; Watanabe, Tomoe; Kahara, Tomoko

2008-01-01

312

Statics and dynamics of malaria infection in Anopheles mosquitoes  

Directory of Open Access Journals (Sweden)

Full Text Available 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 reformulates a simple dynamic model for the proportion of infected humans. The classic formulae are related to formulae from cyclical feeding models, and some inconsistencies are noted. The classic formulae are used to to illustrate how malaria control reduces malaria transmission and show that increased mosquito mortality has an effect even larger than was proposed by Macdonald in the 1950's.

Ellis McKenzie F

2004-06-01

313

Conjugation by mosquito pathogenic strains of Bacillus sphaericus.  

Science.gov (United States)

A mosquito pathogenic strain of Bacillus sphaericus carried out the conjugal transfer of plasmid pAM beta 1 to other strains of its own and two other serotypes. However, it was unable to conjugate with mosquito pathogens from three other serotypes, with B. sphaericus of other DNA homology groups or with three other species of Bacillus. Conjugation frequency was highest with a strain having an altered surface layer (S layer). Conjugal transfer of pAM beta 1 was not detected in mosquito larval cadavers. B. sphaericus 2362 was unable to mobilize pUB110 for transfer to strains that had served as recipients of pAM beta 1. These observations suggest that it is unlikely that genetically engineered B. sphaericus carrying a recombinant plasmid could pass that plasmid to other bacteria. PMID:9332611

Correa, M; Yousten, A A

1997-01-01

314

Gene drive systems in mosquitoes: rules of the road.  

Science.gov (United States)

Population replacement strategies for controlling transmission of mosquito-borne diseases call for the introgression of antipathogen effector genes into vector populations. It is anticipated that these genes, if present at high enough frequencies, will impede transmission of the target pathogens and result in reduced human morbidity and mortality. Recent laboratory successes in the development of virus- and protozoan-resistant mosquito strains make urgent research of gene drive systems capable of moving effector genes into wild populations. A systematic approach to developing safe and effective gene drive systems that includes defining the requirements of the system, identifying naturally occurring or synthetic genetic mechanisms for gene spread upon which drive systems can be based and the successful adaptation of a mechanism to a drive system, should mitigate concerns about using genetically engineered mosquitoes for disease control. PMID:15664528

James, Anthony A

2005-02-01

315

Mosquito midgut glycoproteins and recognition sites for malaria parasites.  

Science.gov (United States)

Midgut glycoproteins of the malaria vector Anopheles tessellatus were partially characterised by gel electrophoresis and lectin binding. Specific binding to wheat germ agglutinin (WGA) and Concanavalin A (Con A) indicated the presence of N-linked core oligosaccharides in many proteins. Rabbit antibodies were produced against wheat germ agglutinin binding proteins (WGABP). These antibodies also recognised distinct proteins in the peritrophic membrane which is secreted into the midgut to enclose a bloodmeal. Rabbit anti-WGABP antibodies ingested in a bloodmeal containing infective gametocytes of the human malaria parasites Plasmodium falciparum and P. vivax tended to reduce infectivity of the parasites to vector mosquitoes. Chitotriose added to a bloodmeal also inhibited parasite development in the mosquito. The results are consistent with a hypothesis that N-acetyl glucosamine residues in mosquito midgut glycoproteins and/or midgut chitin and proteoglycan function as recognition sites for malaria parasites. PMID:9247095

Ramasamy, R; Wanniarachchi, I C; Srikrishnaraj, K A; Ramasamy, M S

1997-07-10

316

Periodic dynamic systems for infected hosts and mosquitoes  

Directory of Open Access Journals (Sweden)

Full Text Available A mathematical model for the purpose of analysing the dynamic of the populations of infected hosts anf infected mosquitoes when the populations of mosquitoes are periodic in time is here presented. By the computation of a parameter lambda (the spectral radius of a certain monodromy matrix one can state that either the infection peters out naturally (lambda 1 the infection becomes endemic. The model generalizes previous models for malaria by considering the case of periodic coefficients; it is also a variation of that for gonorrhea. The main motivation for the consideration of this present model was the recent studies on mosquitoes at an experimental rice irrigation system, in the South-Eastern region of Brazil.

Oliva W. M.

1996-01-01

317

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

318

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

319

Fish Kills in Ireland in 1994 and 1995  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In 1994, the downward trend in numbers of fish kills continued, the total for the year being 32. However, in 1995 a long spell of dry weather greatly reduced the flow in rivers in all parts of Ireland and the number of fish kills rose to 84, the highest since 1989. In 1994, farmyard effluents, silage and slurry together accounted for one third of the fish kills. Industrial effluents and enrichment both caused 19% of the total. Storm water runoff and cement spillage in building operations w...

Moriarty, C.

1996-01-01

320

Factors Affecting Zebra Mussel Kill by the Bacterium Pseudomonas fluorescens  

Energy Technology Data Exchange (ETDEWEB)

The specific purpose of this research project was to identify factors that affect zebra mussel kill by the bacterium Pseudomonas fluorescens. Test results obtained during this three-year project identified the following key variables as affecting mussel kill: treatment concentration, treatment duration, mussel siphoning activity, dissolved oxygen concentration, water temperature, and naturally suspended particle load. Using this latter information, the project culminated in a series of pipe tests which achieved high mussel kill inside power plants under once-through conditions using service water in artificial pipes.

Daniel P. Molloy

2004-02-24

 
 
 
 
321

HIV transcription is induced with some forms of cell killing  

Energy Technology Data Exchange (ETDEWEB)

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. {Gamma} rays were the only cell-killing agent which did not induce HIV transcription; this can be attributed to the fact that {gamma}-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.

Woloschak, G.E. [Argonne National Lab., IL (United States); Schreck, S. [Argonne National Lab., IL (United States)][South Carolina Univ., Columbia, SC (United States). Dept. of Chemistry; Panozzo, J. [Loyola Univ. Medical Center, Maywood, IL (United States); Chang-Liu, C.-M. [Argonne National Lab., IL (United States); Libertin, C.R. [Loyola Univ. Medical Center, Maywood, IL (United States)

1996-11-01

322

Survey of the mosquitoes (Diptera: Culicidae) of Mayotte.  

Science.gov (United States)

A transversal survey of immature mosquitoes was conducted on Mayotte Island (France) in the Comoros Archipelago, western Indian Ocean, with the aim to inventory the Culicidae and to document inter-species relationships in different habitats. In total 420 habitats were sampled for larvae and/or pupae mosquitoes, resulting in more than 6,000 specimens. Forty species belonging to 15 genera were collected, with eight taxa integrated for the first time to the Mayotte mosquito list. The most frequently recorded species were Stegomyia aegypti, St. albopicta, Anopheles gambiae and Eretmapodites subsimplicipes, the first three species being known vectors of viruses and parasites transmitted to humans. Mean species richness in habitats ranged from 1.00 to 3.29, with notable differences between habitats. For example, water-filled axils of banana leaves, tree-holes and crab-holes had low species richness, while cut bamboo, water pools, abandoned tires and marsh and swamp water had notably higher species richness. Twenty-seven mosquito species belonging to 12 genera were routinely collected (in ?20% of at least one type of larval habitat) suggesting that multiple species play a role in the biocenosis of these aquatic habitats. Multispecies association was observed in 52% of the habitats. The co-occurrence of up to six species belonging to five genera was recorded in a single habitat. The mosquitoes of Mayotte show notable biogeographical affinities to those of Madagascar, as compared to the African continent. These two potential source areas are nearly equidistant from Mayotte, which in turn indicates biased dispersal from east to west. Our findings suggest that with relatively short-term intensive sampling in different habitats, it is possible to approach exhaustive species inventories based on collection of larvae. Mayotte, with its modest elevation range and land surface, has a notable species richness of mosquitoes with 45 well-documented species belonging to 15 genera. PMID:25004163

Le Goff, Gilbert; Goodman, Steven M; Elguero, Eric; Robert, Vincent

2014-01-01

323

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

324

Mosquito repellency of the seeds of celery (Apium graveolens L.).  

Science.gov (United States)

When the mosquito repellencies of four fractions of Apium graveolens seeds (one hexane, two dichloromethane and one methanolic) were investigated in the laboratory, all four were found to offer human volunteers some protection against female, adult Aedes aegypti. The hexane fraction, however, was found to exhibit the highest repellency in the laboratory, with median effective doses (ED50) and ED95 of 0.41 and 2.93 mg/cm2 skin, respectively. Only this fraction, which was also found to provide protection against mosquito bites for 3.5 h when applied, in the laboratory, at a concentration of 250 mg/ml, was then investigated for its repellency in the field and its stability. In storage, it was found to retain its repellency for at least 2 months, although significant reductions in its repellency were observed (in terms of shortened complete-protection times) after 3 months, whatever the temperature of storage (-20 degrees C, 4 degrees C, or room temperature). When applied to the skin of volunteers under field conditions, the hexane fraction showed strong repellent activity against a wide range of mosquito species belonging to various genera (Ae. gardnerii, Ae. lineatopennis, Armigeres subalbatus, Culex tritaeniorhynchus, Cx. vishnui group, Cx. quinquefasciatus and Mansonia uniformis). It appeared not to cause dermal irritation or any other adverse effect, either during 6 months of use or in the following 3 months of follow-up. Mosquito repellents based on extracts of Ap. graveolens seeds could be developed commercially, as an effective personal-protection measure against mosquito bites and the diseases caused by mosquito-borne pathogens. PMID:15228722

Tuetun, B; Choochote, W; Rattanachanpichai, E; Chaithong, U; Jitpakdi, A; Tippawangkosol, P; Riyong, D; Pitasawat, B

2004-06-01

325

40 CFR 180.1163 - Killed Myrothecium verrucaria; exemption from the requirement of a tolerance.  

Science.gov (United States)

...2010-07-01 false Killed Myrothecium verrucaria; exemption from the...Tolerances § 180.1163 Killed Myrothecium verrucaria; exemption from...requirement of a tolerance. Killed Myrothecium verrucaria is...

2010-07-01

326

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. PMID:21325304

Cross, Fiona R.; Jackson, Robert R.

2011-01-01

327

Morphological sexual dimorphism in three species of anopheline mosquito larvae.  

Science.gov (United States)

Sexual separation at the larval stage in anopheline mosquitoes with the naked eye is difficult. We have identified distinguishing spots visible to the naked eye on the 6th abdominal segment of 3rd and 4th instars of Anopheles stephensi, An. culicifacies, and An. subpictus. Based on this feature, male and female larvae can be differentiated morphologically at 3rd and 4th instars of these species. This is the first report on these characteristic spots that may have a wide application for larval sexing in mosquito taxonomy, physiology, toxicology, genetics, and control. PMID:18666540

Suman, Devi S; Parashar, B D; Prakash, Shri

2008-06-01

328

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

329

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.

330

9 CFR 113.213 - Pseudorabies Vaccine, Killed Virus.  

Science.gov (United States)

...AND VECTORS STANDARD REQUIREMENTS Killed Virus...applicable general requirements prescribed in...accordance with the Outline of Production...provided in the Outline of Production. (c) Test requirements for...

2010-01-01

331

9 CFR 113.201 - Canine Distemper Vaccine, Killed Virus.  

Science.gov (United States)

...AND VECTORS STANDARD REQUIREMENTS Killed Virus...applicable general requirements prescribed in...accordance with the Outline of Production...specified in the Outline of Production... (c) Test requirements for...

2010-01-01

332

9 CFR 113.211 - Feline Rhinotracheitis Vaccine, Killed Virus.  

Science.gov (United States)

...AND VECTORS STANDARD REQUIREMENTS Killed Virus...applicable general requirements prescribed in...accordance with the Outline of Production...specified in the Outline of Production. (d) Test requirements for...

2010-01-01

333

9 CFR 113.212 - Bursal Disease Vaccine, Killed Virus.  

Science.gov (United States)

...AND VECTORS STANDARD REQUIREMENTS Killed Virus...the applicable requirements prescribed in...accordance with the Outline of Production...specified in the Outline of Production... (d) Test requirements for...

2010-01-01

334

9 CFR 113.210 - Feline Calicivirus Vaccine, Killed Virus.  

Science.gov (United States)

...AND VECTORS STANDARD REQUIREMENTS Killed Virus...applicable general requirements prescribed in...accordance with the Outline of Production...specified in the Outline of Production. (d) Test requirements for...

2010-01-01

335

9 CFR 113.209 - Rabies Vaccine, Killed Virus.  

Science.gov (United States)

...AND VECTORS STANDARD REQUIREMENTS Killed Virus...the applicable requirements prescribed in § 113.200 and the requirements prescribed in...prescribed in the Outline of Production...accordance with the standard NIH test for...

2010-01-01

336

9 CFR 113.216 - Bovine Rhinotracheitis Vaccine, Killed Virus.  

Science.gov (United States)

...AND VECTORS STANDARD REQUIREMENTS Killed Virus...200 and the requirements of this section...accordance with the Outline of Production...provided in the Outline of Production. (c) Test requirements for...

2010-01-01

337

Prevent Tipping Furniture from Injuring or Killing Young Children  

Science.gov (United States)

... a child — killed by a piece of a furniture, appliance or a television falling on them. “It ... to Prevent Injuries of Fatalities: Properly secure all furniture (especially with shelves, drawers and doors) to walls ...

338

The Variety of Integrable Killing Tensors on the 3-Sphere  

CERN Document Server

Integrable Killing tensors are used to classify orthogonal coordinates in which the classical Hamilton-Jacobi equation can be solved by a separation of variables. We completely solve the Nijenhuis integrability conditions for Killing tensors on the sphere S^3 and give a set of isometry invariants for the integrability of a Killing tensor. We describe explicitly the space of solutions as well as its quotient under isometries as projective varieties and interpret their algebro-geometric properties in terms of Killing tensors. Furthermore, we identify all St\\"ackel systems in these varieties. This allows us to recover the known list of separation coordinates on S^3 in a simple and purely algebraic way. In particular, we prove that their moduli space is homeomorphic to the associahedron K_4.

Schöbel, Konrad

2012-01-01

339

Hidden symmetries and Killing tensors on curved spaces  

CERN Document Server

Higher order symmetries corresponding to Killing tensors are investigated. The intimate relation between Killing-Yano tensors and non-standard supersymmetries is pointed out. In the Dirac theory on curved spaces, Killing-Yano tensors generate Dirac type operators involved in interesting algebraic structures as dynamical algebras or even infinite dimensional algebras or superalgebras. The general results are applied to space-times which appear in modern studies. One presents the infinite dimensional superalgebra of Dirac type operators on the 4-dimensional Euclidean Taub-NUT space that can be seen as a twisted loop algebra. The existence of the conformal Killing-Yano tensors is investigated for some spaces with mixed Sasakian structures.

Ianus, Stere; Vilcu, Gabriel-Eduard

2008-01-01

340

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

 
 
 
 
341

Conformal Killing vector fields and a virial theorem  

CERN Document Server

The virial theorem is formulated both intrinsically and in local coordinates for a Lagrangian system of mechanical type on a Riemann manifold. An import case studied in this paper is that of an affine virial function associated to a vector field on the configuration manifold. The special cases of a virial function associated to a Killing, a homothetic and a conformal Killing vector field are considered and the corresponding virial theorems are established for this type of functions.

Cariñena, José F; Martínez, Eduardo; Santos, Patrícia

2014-01-01

342

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

343

Conformal Killing vector fields and a virial theorem  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The virial theorem is formulated both intrinsically and in local coordinates for a Lagrangian system of mechanical type on a Riemann manifold. An import case studied in this paper is that of an affine virial function associated to a vector field on the configuration manifold. The special cases of a virial function associated to a Killing, a homothetic and a conformal Killing vector field are considered and the corresponding virial theorems are established for this type of fu...

Carin?ena, Jose? F.; Gheorghiu, Irina; Marti?nez, Eduardo; Santos, Patri?cia

2014-01-01

344

Flat deformation of a spacetime admitting two commuting Killing fields  

International Nuclear Information System (INIS)

It is shown that, given an analytic Lorentzian metric on a 4-manifold, gab, which admits two Killing vector fields, there exists a local deformation law ?ab = a gab + b Hab, where Hab is a two-dimensional projector, such that ?ab is flat and admits the same Killing vectors. We also characterize the particular case when the projector Hab coincides with the quotient metric. We apply some of our results to general stationary axisymmetric spacetimes.

345

STJ X-ray detectors with killed electrode  

International Nuclear Information System (INIS)

Tunnel junctions Al(0)/Nb/Al(1)/AlOx/Al(2)/Nb/NbN with bottom electrode Al(0)/Nb/Al(1) as a killed electrode were studied at temperatures 1.35 and 0.3 K. It was found that at T=0.3 K tunneling from the killed electrode, absent at T=1.35 K, appeared. It increases the detector signal and broadens the spectrum

346

El control de mosquitos (Diptera: Culicidae utilizando métodos biomatemáticos en la provincia Villa Clara - Control of mosquitoes (Diptera: Culicidae using biomathematical methods in Villa Clara province  

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Full Text Available ResumenObjetivo: evaluar la eficacia de dos especies de peces fluviales conjuntamente con la modelación matemática en función del control de las larvas de mosquitos en la provincia Villa Clara.AbstractThe aim is to evaluate the efficiency of two species of freshwater fish and also use the mathematical modelling in function of the control of the mosquito’s larvas in Villa Clara province.

Fimia Duarte, Rigoberto

2012-03-01

347

Mosquito ingestion of antibodies against mosquito midgut microbiota improves conversion of ookinetes to oocysts for Plasmodium falciparum, but not P. yoelii  

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The mosquito midgut is a site of complex interactions between the mosquito, the malaria parasite and the resident bacterial flora. In laboratory experiments, we observed significant enhancement of Plasmodium falciparum oocyst production when Anopheles gambiae (Diptera: Culicidae) mosquitoes were membrane-fed on infected blood containing gametocytes from in vitro cultures mixed with sera from rabbits immunized with A. gambiae midguts. To identify specific mechanisms, we evaluated whether the i...

Noden, Bruce H.; Vaughan, Jefferson A.; Pumpuni, Charles B.; Beier, John C.

2011-01-01

348

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.

349

Effects of Haulm Killing on Seed Potato Quality  

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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

350

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.

1997-01-01

351

Cultured skin microbiota attracts malaria mosquitoes  

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Full Text Available Abstract Background Host-seeking of the African malaria mosquito, Anopheles gambiae sensu stricto, is guided by human odours. The precise nature of the odours, and the composition of attractive blends of volatiles, remains largely unknown. Skin microbiota plays an important role in the production of human body odours. It is hypothesized that host attractiveness and selection of An. gambiae is affected by the species composition, density, and metabolic activity of the skin microbiota. A study is presented in which the production and constituency of volatile organic compounds (VOCs by human skin microbiota is examined and the behavioural responses of An. gambiae to VOCs from skin microbiota are investigated. Methods Blood agar plates incubated with skin microbiota from human feet or with a reference strain of Staphylococcus epidermidis were tested for their attractiveness to An. gambiae in olfactometer bioassays and indoor trapping experiments. Entrained air collected from blood agar plates incubated with natural skin microbiota or with S. epidermidis were analysed using GC-MS. A synthetic blend of the compounds identified was tested for its attractiveness to An. gambiae. Behavioural data were analysed by a ?2-test and GLM. GC-MS results were analysed by fitting an exponential regression line to test the effect of the concentration of bacteria. Results More An. gambiae were caught with blood agar plates incubated with skin bacteria than with sterile blood agar plates, with a significant effect of incubation time and dilution of the skin microbiota. When bacteria from the feet of four other volunteers were tested, similar effects were found. Fourteen putative attractants were found in the headspace of the skin bacteria. A synthetic blend of 10 of these was attractive to An. gambiae. Conclusions The discovery that volatiles produced by human skin microorganisms in vitro mediate An. gambiae host-seeking behaviour creates new opportunities for the development of odour-baited trapping systems. Additionally, identification of bacterial volatiles provides a new method to develop synthetic blends, attractive to An. gambiae and possibly other anthropophilic disease vectors.

Takken Willem

2009-12-01

352

[Mosquito complex (Diptera, Culicidae) in a West Nile fever focus in the Volgograd Region. II. Host-feeding patterns of mosquitoes in different habitats].  

Science.gov (United States)

Host preference of the mosquitoes collected in the urban and rural habitats of Volgograd and its suburbs was studied by the precipitation reaction test. Human and avian blood was detected in Cx. pipiens, Cx. modestus, Ae. vexans, Ae. behningi, Ae. caspius, Ae. sticticus, and females of the Anopheles maculipennis. The proportion of the mosquitoes fed on birds was similar in the urban and rural biotopes whereas that of the mosquitoes feeding on humans was significantly higher in Volgograd than in its environs. The increase in the number of human blood-fed mosquitoes in the city resulted mainly from the females collected in its multi-storied buildings. PMID:17657957

Platonova, O V; Fedorova, M V; Lopatina, Iu V; Bezzhonova, O V; Bulgakova, T V; Platonov, A E

2007-01-01

353

Isolation and titration of dengue viruses by the mosquito inoculation technique.  

Science.gov (United States)

Mosquito inoculation is a highly sensitive technique for isolation and titration of dengue virus (DENV) from sera, human tissues, wild animals, or mosquitoes. It has been under utilized since it was described 40 years ago because most dengue laboratories do not have access to an insectary to rear mosquitoes. This technique requires good eye-hand coordination while doing manipulation under a stereoscopic microscope, and extensive practice is needed to become proficient at inoculating mosquitoes. Following inoculation, mosquitoes are held for 10 days to allow dengue virus to replicate and disseminate to tissues throughout the mosquitoes. They are then harvested and examined for the presence of viral antigens in head tissue by either immunofluorescence assay (IFA) or PCR (polymerase chain reaction). The mosquito infectious dose 50 (MID50) is calculated using the method of Reed and Muench to quantitate the virus. This method can be used for other arboviruses as well as for dengue. PMID:24696328

Choy, Milly M; Gubler, Duane J

2014-01-01

354

Evaluation of compounds for insecticidal activity on adult mosquitos*  

Science.gov (United States)

N-methylcarbamates derived from thiophenols possess negligible insecticidal activity against the mosquitos Anopheles stephensi and Aedes aegypti. The probable basic reason for the inactivity is that these compounds are much less efficient inhibitors of cholinesterase than the oxygen analogues. PMID:4392937

Hadaway, A. B.; Barlow, F.; Grose, J. E. H.; Turner, C. R.; Flower, L. S.

1970-01-01

355

Vector competence of Egyptian mosquitoes for Rift Valley fever virus.  

Science.gov (United States)

Reintroduction of Rift Valley fever (RVF) into Egypt in 1993 raised concerns about the potential for Egyptian mosquitoes to transmit the virus. We evaluated the ability of Aedes caspius, Culex pipiens, Cx. antennatus, Cx. perexiguus, Cx. poicilipes, and Anopheles pharoensis collected in the Aswan area and Cx. pipiens collected in the Nile Delta to transmit RVF virus. All mosquito species tested were susceptible to RVF virus infection, with An. pharoensis and Ae. caspius being the most sensitive to infection. However, none of 12 An. pharoensis, including 10 with a disseminated infection, transmitted RVF virus by bite. In contrast, nearly all Cx. pipiens (87%, n = 15) and Cx. perexiguus (90%, n = 10) with a disseminated infection transmitted virus. Overall transmission rates for mosquitoes exposed to hamsters with a viremia > or = 10(7) plaque-forming units/ml were Ae. caspius, 20% (n = 5); Cx. pipiens, 7% (n = 102); Cx. antennatus, 7% (n = 30); Cx. perexiguus, 11% (n = 9); and An. pharoensis, 0% (n = 7). Based on abundance, susceptibility to infection, ability to transmit virus, and feeding behavior, Ae. caspius appeared to be the most efficient vector of the Egyptian mosquitoes evaluated. While less susceptible than Ae. caspius, Cx. pipiens, Cx. antennatus, and Cx. perexiguus were also potential vectors during this RVF outbreak in Egypt. PMID:8619436

Turell, M J; Presley, S M; Gad, A M; Cope, S E; Dohm, D J; Morrill, J C; Arthur, R R

1996-02-01

356

Malaria-induced changes in host odors enhance mosquito attraction.  

Science.gov (United States)

Vector-borne pathogens may alter traits of their primary hosts in ways that influence the frequency and nature of interactions between hosts and vectors. Previous work has reported enhanced mosquito attraction to host organisms infected with malaria parasites but did not address the mechanisms underlying such effects. Here we document malaria-induced changes in the odor profiles of infected mice (relative to healthy individuals) over the course of infection, as well as effects on the attractiveness of infected hosts to mosquito vectors. We observed enhanced mosquito attraction to infected mice during a key period after the subsidence of acute malaria symptoms, but during which mice remained highly infectious. This attraction corresponded to an overall elevation in the volatile emissions of infected mice observed during this period. Furthermore, data analyses--using discriminant analysis of principal components and random forest approaches--revealed clear differences in the composition of the volatile blends of infected and healthy individuals. Experimental manipulation of individual compounds that exhibited altered emission levels during the period when differential vector attraction was observed also elicited enhanced mosquito attraction, indicating that compounds being influenced by malaria infection status also mediate vector host-seeking behavior. These findings provide important insights into the cues that mediate vector attraction to hosts infected with transmissible stages of malaria parasites, as well as documenting characteristic changes in the odors of infected individuals that may have potential value as diagnostic biomarkers of infection. PMID:24982164

De Moraes, Consuelo M; Stanczyk, Nina M; Betz, Heike S; Pulido, Hannier; Sim, Derek G; Read, Andrew F; Mescher, Mark C

2014-07-29

357

Formulas of components of citronella oil against mosquitoes (Aedes aegypti).  

Science.gov (United States)

The mosquito Aedes aegypti is an epidemic vector of several diseases such as dengue fever and yellow fever. Several pesticides are used to control the mosquito population. Because of their frequent use, some mosquitoes have developed resistance. In this study, we used the Y-tube olfactometer to test essential oils of Cymbopogon species and screened specific formulas of components as repellents against Ae. aegypti. At 400 ?L, the extracted oil of citronella grass (Cymbopogon nardus) and myrcene produced a low-active response by inhibiting mosquito host-seeking activity. Citronella grass, lemon grass (Cymbopogon citratus), citral and myrcene also produced a low-treatment response to repellents, for more potential to affect host-seeking behavior. Furthermore, the mixture of citral, myrcene, and citronellal oil (C:M:Ci = 6:4:1) greatly affected and inhibited host-seeking behavior (76% active response; 26% treatment response with 40 ?L; 42.5%, 18% with 400 ?L; and 19%, 23% with 1000 ?L). As compared with the result for N,N-diethyl-3-methylbenzamide (DEET; 44%, 22% with 400 ?L), adjusting the composition formulas of citronella oil had a synergistic effect, for more effective repellent against Ae. aegypti. PMID:23998314

Hsu, Wey-Shin; Yen, Jui-Hung; Wang, Yei-Shung

2013-01-01

358

DEVICE FOR FISH ADDITIONAL FEEDING ON MOSQUITO LARVAE ?????????? ??? ????????? ???? ????????? ???????  

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Full Text Available The electro optical transducer with changeable emission color depending on air temperature, which is destined for fish additional feeding with mosquito larvae, has been designed. It is the effective device of electrotechnics of ecological fish additional feeding with live feed

Gazalov V. S.

2013-03-01

359

New Zealand's northern mosquito survey, 1988-89.  

Science.gov (United States)

The latest mosquito survey of the warmer regions of New Zealand (NZ) sampled 2,304 larval mosquito habitats of all major categories. While revealing no evidence of new establishments of exotic mosquitoes, it produced important data revealing the underutilization of types of habitats that could be invaded now or in the future (especially if the "greenhouse effect" eventually causes even quite small rises in average temperatures and sea levels). Although long feared additions of malaria vectors to a fauna still lacking any species of Anopheles, or of essentially tropical arbovirus vectors from neighboring countries to the north and northeast, may not materialize failing climatic amelioration, a new danger appeared at the beginning of the 1988-89 Northern Mosquito Survey when Aedes albopictus was reported for the first time from Fiji. This vector of dengue hemorrhagic fever and Ross River virus has since been spreading widely on the archipelago's main island, Viti Levu, whence much air and sea traffic reaches NZ. Information presented and discussed herein strongly supports the continuance and improvement of international aircraft disinsection and other insect quarantine measures. PMID:1973449

Laird, M

1990-06-01

360

Effects of the mosquito larvicide GB-1111 on bird eggs  

International Nuclear Information System (INIS)

survival or development of bobwhite embryos but is potentially toxic to mallard embryos under conditions of larvicide drift or spray overlap. - Mosquito larvicide GB-1111 is unlikely to harm bobwhite embryos when applied according to product label guidance, but could pose a potential risk to mallard embryos under conditions of larvicide drift or spray overlap

 
 
 
 
361

Nectar feeding by the early-spring mosquito Aedes provocans.  

Science.gov (United States)

Nectar feeding by males and females of the mosquito Aedes provocans was studied at a site near Belleville, Ontario, Canada. Canada plum, Prunus nigra, and especially pin cherry, P. pensylvanica, bloomed contemporaneously with the emergence of Ae. provocans and were important nectar sources for adult mosquitoes during their first week of life. Blossoms of P. pensylvanica shielded for 24 h from foragers produced an average of 0.14 mg of sugar (approximately 2.3J). This nectar was avidly sought by both sexes of Ae. provocans; > 97% of the blossoms were visited by mosquitoes in the first few days of blooming. Young adult mosquitoes were found on blossoms at all hours of the day and night; feeding on P. nigra was strongly eocrepuscular, whereas on P. pensylvanica feeding was much less strongly periodic. Adults foraged for nectar in an energy-conserving, pedestrian strategy, devoting 56% (females) and 68% (males) of their time on blossoms to nectar feeding during foraging bouts that lasted a median of 5.3 min. Both sexes sought nectar soon after emergence--males before they had completed hypopygial rotation or swarmed, and females before mating or host seeking. Female Ae. provocans sought nectar in all stages of oogenesis, but primarily at the initiation of a gonotrophic cycle. Energy stores in the crop averaged 18J per female, with a distribution that depended on gonotrophic age and parity. PMID:7949310

Smith, S M; Gadawski, R M

1994-07-01

362

Insecticide mixtures for mosquito net impregnation against malaria vectors.  

Science.gov (United States)

Insecticides belonging to the pyrethroid family are the only compounds currently available for the treatment of mosquito nets. Unfortunately, some malaria vector species have developed resistance to pyrethroids and the lack of alternative chemical categories is a great concern. One strategy for resistance management would be to treat mosquito nets with a mixture associating two insecticides having different modes of action. This study presents the results obtained with insecticide mixtures containing several proportions of bifenthrin (a pyrethroid insecticide) and carbosulfan (a carbamate insecticide). The mixtures were sprayed on mosquito net samples and their efficacy were tested against a susceptible strain of Anopheles gambiae, the major malaria vector in Africa. A significant synergism was observed with a mixture containing 25 mg/m2 of bifenthrin (half the recommended dosage for treated nets) and 6.25 mg/m2 of carbosulfan (about 2% of the recommended dosage). The observed mortality was significantly more than expected in the absence of any interaction (80% vs 41%) and the knock-down effect was maintained, providing an effective barrier against susceptible mosquitoes. PMID:12375369

Corbel, V; Darriet, F; Chandre, F; Hougard, J M

2002-09-01

363

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

364

Energetic cost of insecticide resistance in Culex pipiens mosquitoes.  

Science.gov (United States)

The extensive use of insecticides to control vector populations has lead to the widespread development of different mechanisms of insecticide resistance. Mutations that confer insecticide resistance are often associated to fitness costs that prevent them from spreading to fixation. In vectors, such fitness costs include reductions in preimaginal survival, adult size, longevity, and fecundity. The most commonly invoked explanation for the nature of such pleiotropic effects of insecticide resistance is the existence of resource-based trade-offs. According to this hypothesis, insecticide resistance would deplete the energetic stores of vectors, reducing the energy available for other biological functions and generating trade-offs between insecticide resistance and key life history traits. Here we test this hypothesis by quantifying the energetic resources (lipids, glycogen, and glucose) of larvae and adult females of the mosquito Culex pipiens L. resistant to insecticides through two different mechanisms: esterase overproduction and acetylcholinesterase modification. We find that, as expected from trade-off theory, insecticide resistant mosquitoes through the overproduction of esterases contain on average 30% less energetic reserves than their susceptible counterparts. Acetylcholinesterase-modified mosquitoes, however, also showed a significant reduction in energetic resources (20% less). We suggest that, in acetylcholinesterase-modified mosquitoes, resource depletion may not be the result of resource-based trade-offs but a consequence of the hyperactivation of the nervous system. We argue that these results not only provide a mechanistic explanation for the negative pleiotropic effects of insecticide resistance on mosquito life history traits but also can have a direct effect on the development of parasites that depend on the vector's energetic reserves to fulfil their own metabolic needs. PMID:21661333

Rivero, A; Magaud, A; Nicot, A; Vézilier, J

2011-05-01

365

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 indigh 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

366

Detection of Quang Binh virus from mosquitoes in China.  

Science.gov (United States)

Flaviviruses present a wide range of genetic diversity and exhibit diverse host relationships. Mosquito-borne flaviviruses have recently been isolated and characterized worldwide. Yunnan Province of China is one of the richest areas of species diversity and is the center of multi-species evolution in mainland Asia, which supports the circulation of numerous arthropod-borne viruses (arboviruses). In a screening program of arboviruses, mosquitoes were collected during the mosquito activity season in the Yunnan Province from 2007 to 2010. Eleven flavivirus strains, named Yunnan Culex flaviviruses (YNCxFVs), were obtained from Culex tritaeniorhynchus and Anopheles sinensis specimens. Sequence analyses based on partial nonstructural protein (NS) 5 gene indicated that the YNCxFVs shared 92.8-99.6% nucleotide identity with each other and were similar to the Culex-related flaviviruses. The complete genome of one representative isolate, LSFlaviV-A20-09, was sequenced. The genome was 10,865 nucleotides long and contained a single, long open reading frame (ORF) of 10,080 nucleotides that encoded a 3360-aa polyprotein. This genome was most closely related to the Quang Binh virus (QBV) VN180 strain, an insect-specific flavivirus isolated from Culex mosquitoes in Vietnam, but only had 83.0% nucleotide and 93.8% amino acid identities for the ORF sequence. The genome has approximately 66.3%-68.5% nucleotide sequence and 69.3-73.3% amino acid sequence identities to other Culex flaviviruses, and only has 47.9-57.9% nucleotide sequence and 38.7-55.1% amino acid sequence identities to Coquillettidia-related, Mansonia-related and Aedes-related flaviviruses. Phylogenetic analyses revealed that the LSFlaviV-A20-09 fell into the Culex-related flavivirus clade. Our discoveries provide more information regarding the heterogeneity of viruses that infect mosquitoes. PMID:24342141

Zuo, Shuqing; Zhao, Qiumin; Guo, Xiaofang; Zhou, Hongning; Cao, Wuchun; Zhang, Jiusong

2014-02-13

367

Honor killing attitudes amongst adolescents in Amman, Jordan.  

Science.gov (United States)

The present study examines attitudes towards honor crimes amongst a sample of 856 ninth grade students (mean age?=?14.6, SD?=?0.56) from 14 schools in Amman, Jordan. Descriptive findings suggest that about 40% of boys and 20% of girls believe that killing a daughter, sister, or wife who has dishonored the family can be justified. A number of theoretically meaningful predictors were examined: Findings suggest that attitudes in support of honor killings are more likely amongst adolescents who have collectivist and patriarchal world views, believe in the importance of female chastity amongst adolescents, and morally neutralize aggressive behavior in general. Findings for parental harsh discipline are mixed: While the father's harsh discipline is predictive of honor killing attitudes, the mother's behavior is not. Furthermore, support for honor killing is stronger amongst male adolescents and adolescents for low education backgrounds. After controlling for other factors religion and the intensity of religious beliefs are not associated with support for honor killings. Models were tested separately for male and female respondents and suggested no systematic differences in predictors. Limitations and implications are discussed. PMID:23744567

Eisner, Manuel; Ghuneim, Lana

2013-01-01

368

KILLING IN THE NAME OF HONOUR AND TRADITION  

Directory of Open Access Journals (Sweden)

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

369

Identification of Swedish mosquitoes based on molecular barcoding of the COI gene and SNP analysis.  

Science.gov (United States)

Mosquito-borne infectious diseases are emerging in many regions of the world. Consequently, surveillance of mosquitoes and concomitant infectious agents is of great importance for prediction and prevention of mosquito-borne infectious diseases. Currently, morphological identification of mosquitoes is the traditional procedure. However, sequencing of specified genes or standard genomic regions, DNA barcoding, has recently been suggested as a global standard for identification and classification of many different species. Our aim was to develop a genetic method to identify mosquitoes and to study their relationship. Mosquitoes were captured at collection sites in northern Sweden and identified morphologically before the cytochrome c oxidase subunit I (COI) gene sequences of 14 of the most common mosquito species were determined. The sequences obtained were then used for phylogenetic placement, for validation and benchmarking of phenetic classifications and finally to develop a hierarchical PCR-based typing scheme based on single nucleotide polymorphism sites (SNPs) to enable rapid genetic identification, circumventing the need for morphological characterization. The results showed that exact phylogenetic relationships between mosquito taxa were preserved at shorter evolutionary distances, but at deeper levels, they could not be inferred with confidence using COI gene sequence data alone. Fourteen of the most common mosquito species in Sweden were identified by the SNP/PCR-based typing scheme, demonstrating that genetic typing using SNPs of the COI gene is a useful method for identification of mosquitoes with potential for worldwide application. PMID:24215491

Engdahl, Cecilia; Larsson, Pär; Näslund, Jonas; Bravo, Mayra; Evander, Magnus; Lundström, Jan O; Ahlm, Clas; Bucht, Göran

2014-05-01

370

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

371

Characterization of aquatic mosquito habitat, natural enemies, and immature mosquitoes in the Artibonite Valley, Haiti.  

Science.gov (United States)

This paper characterizes water body types harboring immature mosquitoes in a low-lying area of Haiti and investigates the relationship between immature Anopheles albimanus abundance and aquatic predator presence. Larval An. albimanus were found in permanent and semi-permanent groundwater habitats including (in order of greatest abundance) hoof/footprints, ditches, rice fields, and ground pools. High levels of species co-occurrence were observed in habitats. Among water bodies positive for immature Anopheles, 42.9% also contained immature Culex species. Significant association between An. albimanus abundance and the absence of fish predators was detected. Results from the multivariate negative binomial regression suggest that the interactive effect of increasing distance from the Artibonite River and elevation are positively associated with the abundance of immature An. albimanus. The presence of fish predators was not associated with the abundance of An. albimanus larvae in habitats while controlling for habitat distance and elevation. The results of this study provide baseline entomological information to inform vector control programs in the country. PMID:18697323

Caillouët, Kevin A; Keating, Joseph; Eisele, Thomas P

2008-06-01

372

Olfactory search-image use by a mosquito-eating predator.  

Science.gov (United States)

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 prey odour or mate odour (control: not primed with odour), spiders were transferred to an olfactometer designed to test ability to find a prey-odour or mate-odour source that was either 'cryptic' (i.e. accompanied by a masking odour source, Lantana camara) or 'conspicuous' (no L. camara odour). When tested with conspicuous odour, the identity of the priming odour had no significant effect on how many spiders found the odour source. However, when tested with cryptic odour, significantly more spiders found the odour source when primed with congruent odour and significantly fewer spiders found the odour source when primed with incongruent odour. PMID:20504813

Cross, Fiona R; Jackson, Robert R

2010-10-22

373

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.

2010-03-01

374

QFT on homothetic Killing twist deformed curved spacetimes  

CERN Document Server

We study the quantum field theory (QFT) of a free, real and massless scalar field on self-similar symmetric spacetimes, which are deformed by an abelian Drinfel'd twist constructed from a Killing and a homothetic Killing vector field. In contrast to deformations solely by Killing vector fields, such as the Moyal-Weyl Minkowski spacetime, the equation of motion and Green's operators are deformed. We show that there is a *-algebra isomorphism between the QFT on the deformed and the formal power series extension of the QFT on the undeformed spacetime. We study the convergent implementation of our deformations for toy-models. For these models it is found that there is a *-isomorphism between the deformed Weyl algebra and a reduced undeformed Weyl algebra, where certain strongly localized observables are excluded. Thus, our models realize the intuitive physical picture that noncommutative geometry prevents arbitrary localization in spacetime.

Schenkel, Alexander

2010-01-01

375

QFT on homothetic Killing twist deformed curved spacetimes  

Science.gov (United States)

We study the quantum field theory (QFT) of a free, real, massless and curvature coupled scalar field on self-similar symmetric spacetimes, which are deformed by an abelian Drinfel'd twist constructed from a Killing and a homothetic Killing vector field. In contrast to deformations solely by Killing vector fields, such as the Moyal-Weyl Minkowski spacetime, the equation of motion and Green's operators are deformed. We show that there is a *-algebra isomorphism between the QFT on the deformed and the formal power series extension of the QFT on the undeformed spacetime. We study the convergent implementation of our deformations for toy-models. For these models it is found that there is a *-isomorphism between the deformed Weyl algebra and a reduced undeformed Weyl algebra, where certain strongly localized observables are excluded. Thus, our models realize the intuitive physical picture that noncommutative geometry prevents arbitrary localization in spacetime.

Schenkel, Alexander

2011-10-01

376

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

377

Killing and Noether Symmetries of Plane Symmetric Spacetime  

Science.gov (United States)

This paper is devoted to investigate the Killing and Noether symmetries of static plane symmetric spacetime. For this purpose, five different cases have been discussed. The Killing and Noether symmetries of Minkowski spacetime in cartesian coordinates are calculated as a special case and it is found that Lie algebra of the Lagrangian is 10 and 17 dimensional respectively. The symmetries of Taub's universe, anti-deSitter universe, self similar solutions of infinite kind for parallel perfect fluid case and self similar solutions of infinite kind for parallel dust case are also explored. In all the cases, the Noether generators are calculated in the presence of gauge term. All these examples justify the conjecture that Killing symmetries form a subalgebra of Noether symmetries (Bokhari et al. in Int. J. Theor. Phys. 45:1063, 2006).

Shamir, M. Farasat; Jhangeer, Adil; Bhatti, Akhlaq Ahmad

2013-09-01

378

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

379

Adenosine receptor antagonists effect on plasma-enhanced killing.  

Science.gov (United States)

Previous studies demonstrated that naive plasma has inherent capabilities to enhance bacterial opsonization and phagocyte killing, but not all plasma is equally effective. This raised the question of whether plasma constituents other than opsonins may play a role. Adenosine receptor antagonists have been shown to modulate cytokine response and survival in mice after a bacterial challenge. We investigated whether selective adenosine receptor blockade would influence the ability of naive plasma to effectively control bacterial growth. Colonic bacteria- and thioglycollate-elicited peritoneal macrophages and neutrophils were obtained from naive mice. Stock murine plasma from naive was purchased and categorized as having high plasma-enhanced bacterial killing capacity using our previously described methods. Bacteria and plasma were incubated to allow for opsonization and then added to macrophages previously exposed to selected adenosine receptor antagonists: ZM 241385: A2A, MRS1754: A2B, DPCPX: A1, and MRS1220: A3. The final mixture was plated on blood agar plates in aerobic and anaerobic conditions and bacterial colony-forming units quantified after 24 h. This study demonstrated that exogenous adenosine was able to significantly decrease phagocyte killing of cecal bacteria. Blocking adenosine receptors with selective antagonists altered the bacterial killing capacity of plasma. Selectively blocking the A1, A2A, or A2B receptors proved most beneficial at reversing the effect of adenosine. Consistent with previous work, only macrophage killing of bacteria could be modulated by adenosine receptor blockade because neutrophils were unaffected. These data demonstrate that adenosine decreases macrophage killing of enteric bacteria and that this effect is mediated through the adenosine receptors. PMID:24089004

Bauzá, Gustavo; Moitra, Rituparna; Remick, Daniel

2014-01-01

380

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

 
 
 
 
381

Apparent influence of the stage of blood meal digestion on the efficacy of ground applied ULV aerosols for the control of urban Culex mosquitoes. II. Laboratory evidence.  

Science.gov (United States)

The susceptibility of adult Culex pipiens s.l., Culiseta melanura and Aedes aegypti to insecticide aerosols in wind tunnel exposures varied with time, depending on the stage of blood meal digestion. Greater than 2-fold differences were observed in the concentrations of malathion and synergized resmethrin required to kill test mosquitoes, depending on whether they had been given a blood meal and, if they had, the length of time following the blood meal. The period of lowest susceptibility varied from 24 h after feeding in Ae. aegypti to 72 h in Cs. melanura. The greatest variability occurred during the period when undigested blood was present. Data from tests with a malathion-tolerant strain of Cx. pipiens s.l. suggested little change in susceptibility regardless of blood feeding and the associated weight changes that occur from ingestion of blood. PMID:2230763

Eliason, D A; Campos, E G; Moore, C G; Reiter, P

1990-09-01

382

Geometric Properties of Stationary and Axisymmetric Killing Horizons  

CERN Document Server

We study some geometric properties of Killing horizons in 4-dimensional stationary and axisymmetric space-times with electromagnetic field and cosmological constant. Using a $(1+1+2)$ space-time split, we construct relations between the space-time Riemann tensor components and components of the Riemann tensor corresponding to the horizon surface. The Einstein equations allow to derive the space-time scalar curvature invariants, Kretschmann, Chern-Pontryagin, and Euler, on the 2-dimensional spacelike horizon surface. The derived relations generalize the relations known for Killing horizons of static and axisymmetric 4-dimensional space-times. We also present the generalization of Hartle's curvature formula.

Shoom, Andrey A

2014-01-01

383

Effects of extract of soapnut Sapindus emarginatus on esterases and phosphatases of the vector mosquito, Aedes aegypti (Diptera: Culicidae).  

Science.gov (United States)

Our earlier investigations with kernels from the soapnut Sapindus emarginatus revealed it as a new source of botanical biocide with potent antimosquito activity, as evident from the proven unique ability of the aqueous kernel extract to kill all the developmental stages of three important vector mosquito species, Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus. This extract was also found to be safe for two non-target aquatic insects. As a sequel to these findings, we have further examined quantitative and qualitative changes in total proteins, esterases, and phosphatases in whole body homogenates of fourth instar larvae and pupae of A. aegypti exposed to this extract at an appropriate threshold time for its lethal effect to gain insights into the impact of the botanical biocide on biochemical characteristics of the target vector mosquito at two distinct developmental stages. The profiles of proteins, esterases (acetylcholinesterse, ?- and ?-carboxylesterases), and phosphatases (acid and alkaline) exhibited distinct patterns of variation during normal development of fourth instar larvae and pupae, indicating intrinsic difference in biochemical features between these two developmental stages of A. aegypti. Upon exposure of the larvae to the extract, significant reduction in the activities of acetylcholinesterse, ?-carboxylesterase, and acid phosphatases were recorded, whereas the total proteins, ?-carboxylesterase and alkaline phosphatase activities were unaffected. By contrast, only alkaline phosphatase activity was significantly affected in pupae exposed to the extract. Analysis of these enzymes in native PAGE revealed that they exist in isoforms in both the larvae and pupae. The alterations in the levels of enzymatic activities observed from the quantitative assays of various enzymes were reflected by the respective zymograms with perceptible differences in the intensity and the number of bands detected especially with ?-carboxylesterase, acid and alkaline phosphatase activity between the control and exposed test organisms. Despite the fact that the soapnut kernel extract causes mortality of both the larvae and pupae of A. aegypti, the findings of this study demonstrate that the impact of this extract is most pronounced in various enzyme profiles of the larvae rather than the pupae. Such discrepancy implicates the presence of unique biochemical mechanisms in the pupae of mosquito for detoxification of botanical biocides. PMID:21251906

Koodalingam, Arunagirinathan; Mullainadhan, Periasamy; Arumugam, Munusamy

2011-04-01

384

[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

385

[Physico-chemical signals involved in host localization and in the induction of mosquito bites].  

Science.gov (United States)

Disease vector female mosquitoes respond to physic-chemical signals to localize vertebrate hosts for blood meals. Zoophylic mosquitoes preferentially respond to CO2 and octenol released in the breath and bodily fluids, while anthropophylic mosquitoes respond to lactic acid and a variety of sweat compounds. These compounds are modified by saprophytic microorganisms in the skin sebaceous glands. Other factors present in human dwellings contribute to the integration of microsystems with characteristic odors that have different attraction for mosquitoes, explaining the focalization of malaria transmission in few households in endemic areas. The identification of the chemical attractants and their molecular receptors could be used to complement new methods to attract mosquitoes to traps during epidemiological surveys, to increase their contact with insecticides in control interventions, and for genetic manipulation to divert mosquito bites towards other animal populations. The English version of this paper is available at:http://www.insp.mx/salud/index.html. PMID:14974294

Torres-Estrada, José Luis; Rodríguez, Mario H

2003-01-01

386

Mosquito infection studies with Aotus monkeys and humans infected with the Chesson strain of Plasmodiun vivax.  

Science.gov (United States)

Oocyst counts were compared between mosquitoes that fed on humans versus mosquitoes that fed on Aotus monkeys, both of which were infected with the Chesson strain of Plasmodium vivax. Oocyst counts obtained from mosquitoes fed on humans were almost 10-fold higher in number. Mosquitoes were more likely to be infected and with a higher rate of infection when they fed on monkeys before the peak in the asexual parasite count. Mosquitoes that fed on humans were more likely to be more heavily infected when fed after the peak in the asexual count. Of several species of owl monkeys, Aotus vociferans was infected at a higher frequency. On the basis of oocyst counts, Anopheles dirus were the most susceptible and An. maculatus were the least susceptible of the mosquito species tested. PMID:22403307

Collins, William E; Sullivan, JoAnn S; Jeffery, Geoffrey M; Nace, Douglas; Williams, Tyrone; Galland, G Gale; Williams, Allison; Barnwell, John W

2012-03-01

387

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

388

Reciprocal Trophic Interactions and Transmission of Blood Parasites between Mosquitoes and Frogs  

Directory of Open Access Journals (Sweden)

Full Text Available The relationship between mosquitoes and their amphibian hosts is a unique, reciprocal trophic interaction. Instead of a one-way, predator-prey relationship, there is a cyclical dance of avoidance and attraction. This has prompted spatial and temporal synchrony between organisms, reflected in emergence time of mosquitoes in the spring and choice of habitat for oviposition. Frog-feeding mosquitoes also possess different sensory apparatuses than do their mammal-feeding counterparts. The reciprocal nature of this relationship is exploited by various blood parasites that use mechanical, salivary or trophic transmission to pass from mosquitoes to frogs. It is important to investigate the involvement of mosquitoes, frogs and parasites in this interaction in order to understand the consequences of anthropogenic actions, such as implementing biocontrol efforts against mosquitoes, and to determine potential causes of the global decline of amphibian species.

Todd G. Smith

2012-04-01

389

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

390

BIOACTIVIDAD DE ACEITES ESENCIALES DE Minthostachys mollis CONTRA MOSQUITOS  

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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.

Raquel M. Gleiser

2007-01-01

391

High Wolbachia density in insecticide-resistant mosquitoes.  

Science.gov (United States)

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 susceptible strain with the same genetic background. We show that this interaction also operates in natural populations. We propose that mosquitoes may control Wolbachia density less efficiently when they carry an insecticide-resistant gene, i.e. when they suffer from a physiological resistance cost. PMID:12079666

Berticat, Claire; Rousset, François; Raymond, Michel; Berthomieu, Arnaud; We