WorldWideScience
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Attracting, Trapping and killing Disease-Transmitting Mosquitoes Using Odor-Baited Stations - The Ifakara Odor-Baited Stations.  

OpenAIRE

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

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

2010-01-01

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

Directory of Open Access Journals (Sweden)

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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A Geographical Location Model for Targeted Implementation of Lure-and-Kill Strategies Against Disease-Transmitting Mosquitoes in Rural Areas  

OpenAIRE

Outdoor devices for luring and killing disease-transmitting mosquitoes have been proposed as potential com- plementary interventions alongside existing intra-domiciliary methods namely insecticide treated nets and house spraying with residual insecticides. To enhance effectiveness of such outdoor interventions, it is essential to optimally locate them in such a way that they target most of the outdoor mosquitoes. Using odour-baited lure and kill stations (OBS) as an example, we describe a map...

Sumaye, Robert D.; Lwetoijera, Dickson W.; Madumla, Edith P.; Okumu, Fredros O.

2012-01-01

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A modified experimental hut design for studying responses of disease-transmitting mosquitoes to indoor interventions: the Ifakara experimental huts.  

Science.gov (United States)

Differences between individual human houses can confound results of studies aimed at evaluating indoor vector control interventions such as insecticide treated nets (ITNs) and indoor residual insecticide spraying (IRS). Specially designed and standardised experimental huts have historically provided a solution to this challenge, with an added advantage that they can be fitted with special interception traps to sample entering or exiting mosquitoes. However, many of these experimental hut designs have a number of limitations, for example: 1) inability to sample mosquitoes on all sides of huts, 2) increased likelihood of live mosquitoes flying out of the huts, leaving mainly dead ones, 3) difficulties of cleaning the huts when a new insecticide is to be tested, and 4) the generally small size of the experimental huts, which can misrepresent actual local house sizes or airflow dynamics in the local houses. Here, we describe a modified experimental hut design - The Ifakara Experimental Huts- and explain how these huts can be used to more realistically monitor behavioural and physiological responses of wild, free-flying disease-transmitting mosquitoes, including the African malaria vectors of the species complexes Anopheles gambiae and Anopheles funestus, to indoor vector control-technologies including ITNs and IRS. Important characteristics of the Ifakara experimental huts include: 1) interception traps fitted onto eave spaces and windows, 2) use of eave baffles (panels that direct mosquito movement) to control exit of live mosquitoes through the eave spaces, 3) use of replaceable wall panels and ceilings, which allow safe insecticide disposal and reuse of the huts to test different insecticides in successive periods, 4) the kit format of the huts allowing portability and 5) an improved suite of entomological procedures to maximise data quality. PMID:22347415

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

2012-01-01

5

A modified experimental hut design for studying responses of disease-transmitting mosquitoes to indoor interventions: the Ifakara experimental huts.  

OpenAIRE

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

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

2012-01-01

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Photoacoustically-guided photothermal killing of mosquitoes targeted by nanoparticles.  

Science.gov (United States)

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

Science.gov (United States)

Haemoproteus parasites (Haemosporida, Haemoproteidae) are widespread; some species cause severe diseases in avian hosts. Heavy Haemoproteus infections are often lethal for biting midges (Ceratopogonidae), which transmit avian haemoproteids, but there is no information regarding detrimental effect on other blood-sucking insects. We examined effects of Haemoproteus tartakovskyi (lineage hSISKIN1), Haemoproteus lanii (lineages hRB1and hRBS2) and Haemoproteus balmorali (lineage hCOLL3) on the survival of Ochlerotatus cantans, a widespread Eurasian mosquito. Wild-caught females were infected by allowing them to feed on naturally infected birds with light (0.01%) and high (3.0-9.6%) parasitaemia. Mosquitoes fed on uninfected birds were used as controls. Both experimental and control groups were maintained under the same laboratory conditions until 20 days post-exposure (dpe). Dead insects were counted daily and used for parasitological examination and PCR-based testing. No difference was discernible in the survival rate of control mosquitoes and those fed on meal with light parasitaemia. There was a highly significant difference in the survival rate between the control group and all groups fed on meals with high parasitaemia, with the greatest mortality reported 1-3 dpe. For 4 dpe, the percentage of survived control mosquitoes (88%) was 2.2-, 3.6- and 4-fold greater than that of groups fed on meals with high parasitaemia of H. balmorali, H. tartakovskyi and H. lanii, respectively. Numerous ookinetes were observed in the gut area and adjacent tissues located in the head, thorax and abdomen of infected insects 0.5-1 dpe. The migrating parasites damage organs throughout the entire body of mosquitoes; that is the main reason of mortality. To the end of this study, 46% of mosquitoes survived in control group, but the survival rates of experimental mosquitoes fed on meals with high parasitaemia were between 2.6- and 5.8-fold lower. This study indicates that widespread Haemoproteus infections are markedly virulent for bird-biting mosquitoes, which rapidly die after feeding on heavily infected blood meals. PMID:24337545

Valki?nas, Gediminas; Kazlauskien?, Rita; Bernotien?, Rasa; Bukauskait?, Dovil?; Palinauskas, Vaidas; Iezhova, Tatjana A

2014-03-01

8

Assessment of laboratory and field assays of sunlight-induced killing of mosquito larvae by photosensitizers.  

Science.gov (United States)

The effectiveness of light-induced killing of mosquito larvae in the presence of photosensitizers was studied with larvae of Aedes aegypti (L.), Anopheles stephensi (Liston), and Culex quinquefasciatus Say grown in the laboratory and of Cx. quinquefasciatus grown under field conditions. Tested photosensitizers included xanthene, chlorin, and porphyrin derivatives. All the larvae were treated at the fourth instar. Preliminary laboratory experiments showed a light-induced lethal effect of Rose Bengal (RB) on three species of mosquito larvae. Compared with other photosensitizers, RB seemed to be more efficient at even lower concentration than chlorin (e6) and chlorophyllin on Ae. aegypti larvae. Among the four porphyrin derivatives, i.e., chloroquinoline tetraphenyl propioamidoporphine, tetraphenyl porphine tetrasulfonate, hematoporphyrin (HP), and tetraphenylporphinepropionic acid porphine, HP was the only effective photosensitizer on Ae. aegypti larvae. The best conditions for field tests using RB were conducted on Cx. quinquefasciatus in Bobo-Dioulasso, Burkina Faso. The mortality induced by RB varied from 80 to 96% obtained with unfiltered cesspit water to 0.4 to 6.7% in cesspits with a heavy load of organic materials, thus providing the basis for further developments of this technique under field conditions. PMID:16119556

Dondji, Blaise; Duchon, Stephane; Diabate, Abdoulaye; Herve, Jean Pierre; Corbel, Vincent; Hougard, Jean-Marc; Santus, Rene; Schrevel, Joseph

2005-07-01

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Two mosquito LRR proteins function as complement control factors in the TEP1-mediated killing of Plasmodium.  

Science.gov (United States)

Plasmodium development within Anopheles mosquitoes is a vulnerable step in the parasite transmission cycle, and targeting this step represents a promising strategy for malaria control. The thioester-containing complement-like protein TEP1 and two leucine-rich repeat (LRR) proteins, LRIM1 and APL1, have been identified as major mosquito factors that regulate parasite loads. Here, we show that LRIM1 and APL1 are required for binding of TEP1 to parasites. RNAi silencing of the LRR-encoding genes results in deposition of TEP1 on Anopheles tissues, thereby depleting TEP1 from circulation in the hemolymph and impeding its binding to Plasmodium. LRIM1 and APL1 not only stabilize circulating TEP1, they also stabilize each other prior to their interaction with TEP1. Our results indicate that three major antiparasitic factors in mosquitoes jointly function as a complement-like system in parasite killing, and they reveal a role for LRR proteins as complement control factors. PMID:19286136

Fraiture, Malou; Baxter, Richard H G; Steinert, Stefanie; Chelliah, Yogarany; Frolet, Cécile; Quispe-Tintaya, Wilber; Hoffmann, Jules A; Blandin, Stéphanie A; Levashina, Elena A

2009-03-19

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

Science.gov (United States)

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  

Science.gov (United States)

... Share Facebook Twitter Google+ Pinterest 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 ...

12

Development and Field Evaluation of a Synthetic Mosquito Lure That Is More Attractive than Humans  

OpenAIRE

BACKGROUND Disease transmitting mosquitoes locate humans and other blood hosts by identifying their characteristic odor profiles. Using their olfactory organs, the mosquitoes detect compounds present in human breath, sweat and skins, and use these as cues to locate and obtain blood from the humans. These odor compounds can be synthesized in vitro, then formulated to mimic humans. While some synthetic mosquito lures already exist, evidence supporting their utility is limited to laboratory ...

Okumu, Fredros O.; Killeen, Gerry F.; Ogoma, Sheila; Biswaro, Lubandwa; Smallegange, Renate C.; Mbeyela, Edgar; Titus, Emmanuel; Munk, Cristina; Ngonyani, Hassan; Takken, Willem; Mshinda, Hassan; Mukabana, Wolfgang R.; Moore, Sarah J.

2010-01-01

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

Directory of Open Access Journals (Sweden)

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

M. Zimba

2013-04-01

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

OpenAIRE

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

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

2013-01-01

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Malaria Mosquitoes Attracted by Fatal Fungus  

OpenAIRE

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...

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

2013-01-01

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

OpenAIRE

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

Klowden, M. J.; Bulla, L. A.

1984-01-01

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Using a New Odour-Baited Device to Explore Options for Luring and Killing Outdoor-Biting Malaria Vectors: A Report on Design and Field Evaluation of the Mosquito Landing Box.  

OpenAIRE

Mosquitoes that bite people outdoors can sustain malaria transmission even where effective indoor interventions such as bednets or indoor residual spraying are already widely used. Outdoor tools may therefore complement current indoor measures and improve control. We developed and evaluated a prototype mosquito control device, the 'Mosquito Landing Box' (MLB), which is baited with human odours and treated with mosquitocidal agents. The findings are used to explore technical options and challe...

Matowo, Nancy S.; Moore, Jason; Mapua, Salum; Madumla, Edith P.; Moshi, Irene R.; Kaindoa, Emanuel W.; Mwangungulu, Stephen P.; Kavishe, Deogratius R.; Sumaye, Robert D.; Lwetoijera, Dickson W.; Okumu, Fredros O.

2013-01-01

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Entomopathogenic fungi for mosquito control: A review  

Directory of Open Access Journals (Sweden)

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

21

Phagocytosis in mosquito immune responses.  

Science.gov (United States)

Anopheles mosquitoes are the only vectors of human malaria parasites. Mosquito-parasite interactions are critical for disease transmission and therefore are a potential target for malaria control strategies. Mosquitoes mount potent immune responses that efficiently limit proliferation of a variety of infectious agents, including microbial pathogens and malaria parasites. The recent completion of the Anopheles gambiae genome sequencing project combined with the development of the powerful RNA interference-based gene silencing helped to identify major players of the immune defenses and uncovered evolutionarily conserved mechanisms in the anti-bacterial and anti-Plasmodium responses. The anti-bacterial responses are based on phagocytosis at early steps of infections, followed, several hours later, by the synthesis of anti-microbial peptides. The principal regulators of anti-parasitic responses are predominantly synthesized by the mosquito blood cells; however, the exact molecular mechanisms of parasite killing remain unclear. Several regulators of phagocytosis are also required for efficient parasite killing. Here, we summarize our current knowledge of the anti-bacterial and anti-parasitic responses, with the particular emphasis on the role of phagocytosis in mosquito immunity. PMID:17850478

Blandin, Stephanie A; Levashina, Elena A

2007-10-01

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Selective and Irreversible Inhibitors of Mosquito Acetylcholinesterases for Controlling Malaria and Other Mosquito-Borne Diseases  

OpenAIRE

New insecticides are urgently needed because resistance to current insecticides allows resurgence of disease-transmitting mosquitoes while concerns for human toxicity from current compounds are growing. We previously reported the finding of a free cysteine (Cys) residue at the entrance of the active site of acetylcholinesterase (AChE) in some insects but not in mammals, birds, and fish. These insects have two AChE genes (AP and AO), and only AP-AChE carries the Cys residue. Most of these inse...

Pang, Yuan-ping; Ekstro?m, Fredrik; Polsinelli, Gregory A.; Gao, Yang; Rana, Sandeep; Hua, Duy H.; Andersson, Bjo?rn; Andersson, Per Ola; Peng, Lei; Singh, Sanjay K.; Mishra, Rajesh K.; Zhu, Kun Yan; Fallon, Ann M.; Ragsdale, David W.; Brimijoin, Stephen

2009-01-01

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HERBAL CONTROL OF MOSQUITO LARVAE  

Directory of Open Access Journals (Sweden)

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

24

Killing Tensors and Conformal Killing Tensors from Conformal Killing Vectors  

OpenAIRE

Koutras has proposed some methods to construct reducible proper conformal Killing tensors and Killing tensors (which are, in general, irreducible) when a pair of orthogonal conformal Killing vectors exist in a given space. We give the completely general result demonstrating that this severe restriction of orthogonality is unnecessary. In addition we correct and extend some results concerning Killing tensors constructed from a single conformal Killing vector. A number of exam...

Rani, Raffaele; Edgar, S. Brian; Barnes, Alan

2003-01-01

25

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

Directory of Open Access Journals (Sweden)

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

Amul B. Patel

2011-04-01

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

OpenAIRE

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

27

Virtual mosquito  

Science.gov (United States)

3D virtual image of a mosquito (Family Culicidae). This movie is also available as a Virtual Reality Modeling Language (VRML) model. The VRML models are more interactive than the QuickTime versions, but special software may need to be downloaded to open them (read the ÃÂHelpÃÂ page for details). Those people using public computers may be limited from fully accessing the resource. Mozilla Firefox users can view the VRML files directly in their browsers by downloading the Cortona extension (http://www.parallelgraphics.com/products/cortona/download/netscape/). This website is an excellent educational resource for all ages. The Virtual Insects home page (http://www.ento.vt.edu/~sharov/3d/3dinsect.html) has a basic explanation of how virtual reality works, including the Virtual Reality Modeling Language. The "Virtual Images" link takes you to a list of insects that can be viewed as 3D digital reconstructions. The image files would make excellent additions to teaching lectures for introductory classes. Visit the "How to Build Virtual Insects" page to read about how the images were created and how the original models were made more biologically accurate. Also be sure to read the page on how to view the cyber-insects inside a virtual reality "cave".

0002-11-30

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

Directory of Open Access Journals (Sweden)

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

29

Olfaction in mosquitoes  

OpenAIRE

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

30

Killing Tensors and Symmetries  

CERN Document Server

A new method is presented for finding Killing tensors in spacetimes with symmetries. The method is used to find all the Killing tensors of Melvin's magnetic universe and the Schwarzschild vacuum. We show that they are all trivial. The method requires less computation than solving the full Killing tensor equations directly, and it can be used even when the spacetime is not algebraically special.

Garfinkle, Professor David

2010-01-01

31

Killing tensors and symmetries  

International Nuclear Information System (INIS)

A new method is presented for finding Killing tensors in spacetimes with symmetries. The method is used to find all the Killing tensors of Melvin's magnetic universe and the Schwarzschild vacuum. We show that they are all trivial. The method requires less computation than solving the full Killing tensor equations directly, and it can be used even when the spacetime is not algebraically special.

32

Irreducible Killing Tensors from Third Rank Killing-Yano Tensors  

OpenAIRE

We investigate higher rank Killing-Yano tensors showing that third rank Killing-Yano tensors are not always trivial objects being possible to construct irreducible Killing tensors from them. We give as an example the Kimura IIC metric were from two rank Killing-Yano tensors we obtain a reducible Killing tensor and from third rank Killing-Yano tensors we obtain three Killing tensors, one reducible and two irreducible.

Popa, Florian Catalin; Tintareanu-mircea, Ovidiu

2006-01-01

33

Play the Mosquito Game  

Science.gov (United States)

... of Nobel Prizes and Laureates All Educational Productions Physics Prize Related Chemistry Prize Related Medicine Prize Related ... and Work Teachers' Questionnaire Malaria Play the Mosquito Game Play the Parasite Game About the games Malaria ...

34

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

35

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

OpenAIRE

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

Klowden, M. J.; Held, G. A.; Bulla, L. A.

1983-01-01

36

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

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background This study was initiated to establish whether any South African ethnomedicinal plants (indigenous or exotic, that have been reported to be used traditionally to repel or kill mosquitoes, exhibit effective mosquito 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

37

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

Directory of Open Access Journals (Sweden)

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

38

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

39

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

40

Flavivirus-mosquito interactions.  

Science.gov (United States)

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. PMID:25421894

Huang, Yan-Jang S; Higgs, Stephen; Horne, Kate McElroy; Vanlandingham, Dana L

2014-11-01

41

Flavivirus-Mosquito Interactions  

Directory of Open Access Journals (Sweden)

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

42

How Mosquitoes Detect People  

Science.gov (United States)

... video): http://www.youtube.com/watch?v=7wijX9WZUpc Malaria Vaccine Found Safe and Protective: http://www.nih.gov/researchmatters/august2013/08192013malaria.htm Infection Makes Mosquitoes Immune to Malaria Parasites: http://www.nih.gov/researchmatters/may2013/05202013malaria. ...

43

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

44

Skew Killing spinors  

CERN Document Server

In this paper, we study the existence of a skew Killing spinor (see the definition below) on 2 and 3-dimensional Riemannian spin manifolds. We establish the integrability conditions and prove that these spinor fields correspond to twistor spinors in the two dimensional case while, up to a conformal change of the metric, they correspond to parallel spinors in the three dimensional case.

Habib, Georges

2011-01-01

45

A Visit to Florida's Mosquito Man  

Science.gov (United States)

This radio broadcast features an interview with George O'Meara, the world's foremost expert on mosquitoes, who studies mosquito biology and dispenses fun facts (such as: only female mosquitoes bite). There are descriptions of the most aggressive mosquito species, how to tell female mosquitoes from males, and a discussion of landing rates of mosquitoes in the Everglades National Park. The clip is 5 minutes and 30 seconds in length.

46

Wolbachia surface protein induces innate immune responses in mosquito cells  

Directory of Open Access Journals (Sweden)

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

Pinto Sofia B

2012-01-01

47

Development of briquettes from natural products for knockdown of mosquitoes  

Directory of Open Access Journals (Sweden)

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

48

Mosquito repellents in frog skin.  

Science.gov (United States)

The search for novel insect repellents has been driven by health concerns over established synthetic compounds such as diethyl-m-toluamide (DEET). Given the diversity of compounds known from frog skin and records of mosquito bite and ectoparasite infestation, the presence of mosquito repellents in frogs seemed plausible. We investigated frog skin secretions to confirm the existence of mosquito repellent properties. Litoria caerulea secretions were assessed for mosquito repellency by topical application on mice. The secretions provided protection against host-seeking Culex annulirostris mosquitoes. Olfactometer tests using aqueous washes of skin secretions from L. caerulea and four other frog species were conducted to determine whether volatile components were responsible for repellency. Volatiles from Litoria rubella and Uperoleia mjobergi secretions were repellent to C. annulirostris, albeit not as repellent as a DEET control. The demonstration of endogenous insect repellents in amphibians is novel, and demonstrates that many aspects of frog chemical ecology remain unexplored. PMID:17148373

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

2006-06-22

49

Modelling prey-predator cycles using hemipteran predators of mosquito larvae for reducing world-wide mosquito-borne disease incidence.  

Science.gov (United States)

Diplonychus indicus is an aquatic hemipterous bug known to be a voracious predator of dipteran larvae, among others, and to show a selective predation for mosquito larvae when exposed to a mixed prey diet. A datum consisted of the percentage of the fourth instar of (25) culicine mosquitoes killed by the bug. Data around the clock, published earlier (from starved adult males of this bug), reanalyzed by single cosinor, reveal a circasemidian rhythm (p = 0.004). This result prompts the recommendation of studying the time structure of prey-predator cycles further to evaluate the merits or demerits of introducing the bug in the field with the aim of reducing worldwide mosquito-borne disease incidence. PMID:2880698

Venkatesan, P; Cornélissen, G; Halberg, F

1986-01-01

50

What Killed Substantial Form?  

Directory of Open Access Journals (Sweden)

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

David Banach

2007-01-01

51

How to kill creativity.  

Science.gov (United States)

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

52

"The Killing Fields" of Innovation : How to Kill Ideas  

DEFF Research Database (Denmark)

This paper points to seemingly contradicted processes of framing innovation, idea generation and killing ideas. It reports from a yearlong innovation project, where health care professionals explored problems and tested ideas for solutions, regarding a future downsizing of the case hospital. Theories in various ways describe the opening and closing phases of innovation. Exploration and idea generation opens a field of interest, which is then closed by making choices of ideas to further explore in the next opening phase. These choices deliberately kill a lot of ideas. In the innovation project, however, substantial amounts of relevant ideas got killed during opening phases, where the purpose of activities was framed as idea generation. These ideas were either verbally or silently killed, and some in rather contradicted ways: The design and facilitation of brain storming processes lead to clustering of ideas, a design strategy which seemed to kill unique ideas. The reframing of innovation as a radical endeavor killed learning from others for being not innovative. The findings of this paper supplement theories of deliberate killing of ideas by suggesting framing, design and facilitation of innovation as more subtle ways of killing ideas during opening phases.

Ingerslev, Karen

2014-01-01

53

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

OpenAIRE

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...

Dje?nontin, Armel; Chandre, Fabrice; Dabire?, K. Roch; Chabi, Joseph; N Guessan, Raphael; Baldet, Thierry; Akogbe?to, Martin; Corbel, Vincent

2010-01-01

54

Mosquito age and dengue transmission  

Science.gov (United States)

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

The Grand Challenges in Global Health Initiative

55

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

Directory of Open Access Journals (Sweden)

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

Rider Mark A

2012-06-01

56

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

OpenAIRE

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

N Guessan, R.; Boko, P.; Odjo, A.; Knols, B. G. J.; Akogbeto, M.; Rowland, M.

2009-01-01

57

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

OpenAIRE

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

Walther, C. J.; Couche, G. A.; Pfannenstiel, M. A.; Egan, S. E.; Bivin, L. A.; Nickerson, K. W.

1986-01-01

58

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

OpenAIRE

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 inciden...

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

2014-01-01

59

Protocol for Mosquito Rearing (A. gambiae)  

OpenAIRE

This protocol describes mosquito rearing in the insectary. The insectary rooms are maintained at 28°C and ~80% humidity, with a 12 hr. day/night cycle. For this procedure, you'll need mosquito cages, 10% sterile sucrose solution, paper towels, beaker, whatman filter paper, glass feeders, human blood and serum, water bath, parafilm, distilled water, clean plastic trays, mosquito food (described below), mosquito net to cover the trays, vacuum, and a collection chamber to collect...

Das, Suchismita; Garver, Lindsey; Dimopoulos, George

2007-01-01

60

Inhibition of malaria parasite development in mosquitoes by anti-mosquito-midgut antibodies.  

OpenAIRE

The mosquito midgut plays a central role in the development and subsequent transmission of malaria parasites. Using a rodent malaria parasite, Plasmodium berghei, and the mosquito vector Anopheles stephensi, we investigated the effect of anti-mosquito-midgut antibodies on the development of malaria parasites in the mosquito. In agreement with previous studies, we found that mosquitoes that ingested antimidgut antibodies along with infectious parasites had significantly fewer oocysts than mosq...

Lal, A. A.; Schriefer, M. E.; Sacci, J. B.; Goldman, I. F.; Louis-wileman, V.; Collins, W. E.; Azad, A. F.

1994-01-01

61

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

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 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)???=?26.712 ?g/mL; LD???=?49.061 ?g/mL), A. aegypti (LD???=?29.626 ?g/mL; LD???=?54.269 ?g/mL), and C. quinquefasciatus (LD???=?32.077 ?g/mL; LD???=?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

62

Spacetimes foliated by Killing horizons  

International Nuclear Information System (INIS)

It seems to be expected that a horizon of a quasi-local type, such as a Killing or an isolated horizon, by analogy with a globally defined event horizon, should be unique in some open neighbourhood in the spacetime, provided the vacuum Einstein or the Einstein-Maxwell equations are satisfied. The aim of our paper is to verify whether that intuition is correct. If one can extend a so-called Kundt metric, in such a way that its null, shear-free surfaces have spherical spacetime sections, the resulting spacetime is foliated by so-called non-expanding horizons. The obstacle is Kundt's constraint induced at the surfaces by the Einstein or the Einstein-Maxwell equations, and the requirement that a solution be globally defined on the sphere. We derived a transformation (reflection) that creates a solution to Kundt's constraint out of data defining an extremal isolated horizon. Using that transformation, we derived a class of exact solutions to the Einstein or Einstein-Maxwell equations of very special properties. Each spacetime we construct is foliated by a family of the Killing horizons. Moreover, it admits another, transversal Killing horizon. The intrinsic and extrinsic geometries of the transversal Killing horizon coincide with the one defined on the event horizon of the extremal Kerr-Newman solution. However, the Killing horizon in our example admits yet another Killing vector tangent to and null at it. The geometries of the leaves are given by the reflectionves are given by the reflection

63

Insecticide-resistant mosquitoes and malaria control.  

Science.gov (United States)

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

Blayneh, Kbenesh W; Mohammed-Awel, Jemal

2014-06-01

64

Rural buyers' perception about mosquito repellants  

Directory of Open Access Journals (Sweden)

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

D. MEHTA

2010-06-01

65

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

Science.gov (United States)

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

66

Fish Kills 1969-1987  

OpenAIRE

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

67

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

Directory of Open Access Journals (Sweden)

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

68

Improvised microinjection technique for mosquito vectors  

Science.gov (United States)

Background & objectives: Bio-manipulation technique is of primary importance during the development of transgenic mosquitoes. The study describes the variable factors that influence the viability of medically important mosquito vectors during microinjection. Methods: Three mosquito vectors belonging to the genus Aedes, Anopheles and Culex were microinjected at different developmental stages of their life cycle viz., egg, larvae, pupae and adult. Results: The improvisations revealed an increased survivability of biomanipulated mosquitoes during the embryonic and adult microinjection. The study of injecting larvae and pupae resulted in poor survivability. Interpretation & conclusions: The microinjection protocol was successfully tested on three important mosquito vectors. The critical period after biomanipulation which contributes heavily for the survivability factor was evaluated. The results provide a common protocol for biomanipulation of three mosquito vectors with enhanced survivability. PMID:23391792

Sampath, Kumar S.; Puttaraju, H. P.

2012-01-01

69

North American Wetlands and Mosquito Control  

Directory of Open Access Journals (Sweden)

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

Gabrielle E. Sakolsky-Hoopes

2012-12-01

70

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

71

Wolbachia-a foe for mosquitoes  

OpenAIRE

Mosquitoes act as vectors for a wide range of viral and parasitic infectious diseases such as malaria, dengue, Chickungunya, lymphatic filariasis, Japanese encephalitis and West Nile virus in humans as well as in animals. Although a wide range of insecticides are used to control mosquitoes, it has only resulted in development of resistance to such insecticides. The evolution of insecticide resistance and lack of vaccines for many mosquito-borne diseases have made these arthropods highly harmf...

Guruprasad, Nadipinayakanahalli Munikrishnappa; Jalali, Sushil Kumar; Puttaraju, Hosagavi Puttegowda

2014-01-01

72

Chemical odorant of colonial seabird repels mosquitoes.  

Science.gov (United States)

The crested auklet, Aethia cristatella, emits a class of aldehydes shown to be potent invertebrate repellents when used by heteropterans against their predators. Our aim was to determine the efficacy of these aldehydes against mosquitoes in the laboratory. Synthetic analogues of the auklet odorant were strongly repellent to mosquitoes in controlled laboratory trials. Furthermore, the efficacy was similar to previous reports for commercial mosquito repellents. These results, in combination with a previously published study, show that constituents of the aldehyde odorant are broad spectrum in efficacy against ectoparasitic arthropods of birds. Our report is the first empirical evidence for an endogenous mosquito repellent in birds. PMID:16119555

Douglas, H D; Co, J E; Jones, T H; Conner, W E; Day, J F

2005-07-01

73

Measurement of landing mosquito density on humans.  

Science.gov (United States)

In traditional vector surveillance systems, adult mosquito density and the rate of mosquito-human host contact are estimated from the mosquito numbers captured in mechanical traps. But the design of the traps, their placement in the habitat and operating time, microclimate, and other environmental factors bias mosquito responses such that trapped mosquito numbers may be at variance with the numbers actually making human contact. As an alternative to mechanical traps, direct measurement of landing mosquito density enables real-time estimation of the mosquito-human-host-contact parameter. Based on this paradigm, we studied methods to measure mosquito landing responses to a human host. Our results showed: (a) an 18% difference (Pnumber of female Aedes albopictus (Skuse) making initial contact with the skin (9.11±0.74min(-1)) compared with the number remaining on the skin for 5s (7.42±0.69min(-1)); (b) an increase (P0.55) in the average number of Ae. albopictus landing on the arm (8.6±1.6min(-1)) compared with the leg (9.2±2.5min(-1)) of the same human subject; (d) differences among day-to-day landing patterns for the mosquito species we studied but measurable periodicity (P<0.05) in each case when daily patterns were averaged for four or more diel periods; and (e) an effect on landing mosquito density from air temperature (P<0.0001) for Ae. albopictus and Cx. nigripalpus and dew point temperature (P<0.0001) for Cx. quinquefasciatus. Results from this study were used to develop a procedure for safely and accurately measuring mosquito landing density on a human subject. PMID:24769003

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

2014-08-01

74

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

75

Distinct biological effects of golgicide a derivatives on larval and adult mosquitoes.  

Science.gov (United States)

A collection of Golgicide A (GCA) analogs has been synthesized and evaluated in larval and adult mosquito assays. Commercially available GCA is a mixture of four compounds. One enantiomer (GCA-2) of the major diastereomer in this mixture was shown to be responsible for the unique activity of GCA. Structure-activity studies (SAR) of the GCA architecture suggested that the pyridine ring was most easily manipulated without loss or gain in new activity. Eighteen GCA analogs were synthesized of which five displayed distinct behavior between larval and adult mosquitos, resulting in complete mortality of both Aedes aegypti and Anopheles stephensi larvae. Two analogs from the collection were shown to be distinct from the rest in displaying high selectivity and efficiency in killing An. stephensi larvae. PMID:22818079

Mack, Daniel J; Isoe, Jun; Miesfeld, Roger L; Njardarson, Jon T

2012-08-15

76

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

77

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

78

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

79

Mosquito coil emissions and health implications.  

Science.gov (United States)

Burning mosquito coils indoors generates smoke that can control mosquitoes effectively. This practice is currently used in numerous households in Asia, Africa, and South America. However, the smoke may contain pollutants of health concern. We conducted the present study to characterize the emissions from four common brands of mosquito coils from China and two common brands from Malaysia. We used mass balance equations to determine emission rates of fine particles (particulate matter pollutant concentrations resulting from burning mosquito coils could substantially exceed health-based air quality standards or guidelines. Under the same combustion conditions, the tested Malaysian mosquito coils generated more measured pollutants than did the tested Chinese mosquito coils. We also identified a large suite of volatile organic compounds, including carcinogens and suspected carcinogens, in the coil smoke. In a set of experiments conducted in a room, we examined the size distribution of particulate matter contained in the coil smoke and found that the particles were ultrafine and fine. The findings from the present study suggest that exposure to the smoke of mosquito coils similar to the tested ones can pose significant acute and chronic health risks. For example, burning one mosquito coil would release the same amount of PM(2.5) mass as burning 75-137 cigarettes. The emission of formaldehyde from burning one coil can be as high as that released from burning 51 cigarettes. PMID:12948883

Liu, Weili; Zhang, Junfeng; Hashim, Jamal H; Jalaludin, Juliana; Hashim, Zailina; Goldstein, Bernard D

2003-09-01

80

9 CFR 113.206 - Wart Vaccine, Killed Virus.  

Science.gov (United States)

... 1 2010-01-01 2010-01-01 false Wart Vaccine, Killed Virus. 113.206 Section 113...REQUIREMENTS Killed Virus Vaccines § 113.206 Wart Vaccine, Killed Virus. Wart Vaccine, Killed Virus, shall be prepared...

2010-01-01

81

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

OpenAIRE

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

82

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

83

Wolbachia-a foe for mosquitoes  

Science.gov (United States)

Mosquitoes act as vectors for a wide range of viral and parasitic infectious diseases such as malaria, dengue, Chickungunya, lymphatic filariasis, Japanese encephalitis and West Nile virus in humans as well as in animals. Although a wide range of insecticides are used to control mosquitoes, it has only resulted in development of resistance to such insecticides. The evolution of insecticide resistance and lack of vaccines for many mosquito-borne diseases have made these arthropods highly harmful vectors. Recently, a novel approach to control mosquitoes by transinfection of life shortening maternally transmitted endo-symbiont Wolbachia wMelPop strain from fruitfly Drosophila into mosquito population has been developed by researchers. The wMelPop strain up-regulated the immune gene expression in mosquitoes thereby reducing the dengue and Chickungunya viral replication in Aedes aegypti, and also it significantly reduced the Plasmodium level in Anopheles gambiae. Here, we discuss the strategy of using Wolbachia in control of vector-borne diseases of mosquitoes.

Guruprasad, Nadipinayakanahalli Munikrishnappa; Jalali, Sushil Kumar; Puttaraju, Hosagavi Puttegowda

2014-01-01

84

Influence of climate change on mosquito development and mosquito-borne diseases in Europe.  

Science.gov (United States)

Mass occurrence of mosquitoes can have an immense impact on the quality of life in areas such as the Upper Rhine Valley. Therefore, biological and environmental measures are applied to prevent mass development in many regions of Europe. Despite successful prevention measures, the risk of contracting mosquito-borne viral diseases, such as West Nile fever, should be discounted in Central Europe. The transport of mosquitoes (e.g., through tire trade or within containers) into Germany has to be prevented. Individuals (tourists and immigrants) infected with imported vector-borne pathogens and parasites must be diagnosed and treated immediately. Mosquitoes and mosquito-borne diseases know no borders, and their spread is also a consequence of high mobility and globalization. Therefore, mosquito control requires international cooperation. People's increased mobility and international trade play a more important role in the dissemination of the vectors and their pathogens/parasites than increasing temperatures. PMID:19030883

Becker, Norbert

2008-12-01

85

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

86

Integrability conditions for Killing-Yano tensors and conformal Killing-Yano tensors  

Science.gov (United States)

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

Batista, Carlos

2015-01-01

87

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

88

Mosquito immune defenses against Plasmodium infection.  

Science.gov (United States)

The causative agent of malaria, Plasmodium, has to undergo complex developmental transitions and survive attacks from the mosquito's innate immune system to achieve transmission from one host to another through the vector. Here we discuss recent findings on the role of the mosquito's innate immune signaling pathways in preventing infection by the Plasmodium parasite, the identification and mechanistic description of novel anti-parasite molecules, the role that natural bacteria harbored in the mosquito midgut might play in this immune defense and the crucial parasite and vector molecules that mediate midgut infection. PMID:20026176

Cirimotich, Chris M; Dong, Yuemei; Garver, Lindsey S; Sim, Shuzhen; Dimopoulos, George

2010-04-01

89

The entomopathogenic fungus Beauveria bassiana reduces instantaneous blood feeding in wild multi-insecticide-resistant Culex quinquefasciatus mosquitoes in Benin, West Africa  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Mosquito-borne diseases are still a major health risk in many developing countries, and the emergence of multi-insecticide-resistant mosquitoes is threatening the future of vector control. Therefore, new tools that can manage resistant mosquitoes are required. Laboratory studies show that entomopathogenic fungi can kill insecticide-resistant malaria vectors but this needs to be verified in the field. Methods The present study investigated whether these fungi will be effective at infecting, killing and/or modifying the behaviour of wild multi-insecticide-resistant West African mosquitoes. The entomopathogenic fungi Metarhizium anisopliae and Beauveria bassiana were separately applied to white polyester window netting and used in combination with either a permethrin-treated or untreated bednet in an experimental hut trial. Untreated nets were used because we wanted to test the effect of fungus alone and in combination with an insecticide to examine any potential additive or synergistic effects. Results In total, 1125 female mosquitoes were collected during the hut trial, mainly Culex quinquefasciatus Say. Unfortunately, not enough wild Anopheles gambiae Giles were collected to allow the effect the fungi may have on this malaria vector to be analysed. None of the treatment combinations caused significantly increased mortality of Cx. quinquefasciatus when compared to the control hut. The only significant behaviour modification found was a reduction in blood feeding by Cx. quinquefasciatus, caused by the permethrin and B. bassiana treatments, although no additive effect was seen in the B. bassiana and permethrin combination treatment. Beauveria bassiana did not repel blood foraging mosquitoes either in the laboratory or field. Conclusions This is the first time that an entomopathogenic fungus has been shown to reduce blood feeding of wild mosquitoes. This behaviour modification indicates that B. bassiana could potentially be a new mosquito control tool effective at reducing disease transmission, although further field work in areas with filariasis transmission should be carried out to verify this. In addition, work targeting malaria vector mosquitoes should be carried out to see if these mosquitoes manifest the same behaviour modification after infection with B. bassiana conidia.

Howard Annabel FV

2010-09-01

90

Killing-Yano tensors and some applications  

OpenAIRE

The role of Killing and Killing-Yano tensors for studying the geodesic motion of the particle and the superparticle in a curved background is reviewed. Additionally the Papadopoulos list [74] for Killing-Yano tensors in G structures is reproduced by studying the torsion types these structures admit. The Papadopoulos list deals with groups G appearing in the Berger classification, and we enlarge the list by considering additional G structures which are not of the Berger type....

Santillan, O. P.

2011-01-01

91

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

92

MODELING AND BIOLOGICAL CONTROL OF MOSQUITOES  

OpenAIRE

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

93

Mosquito immune defenses against Plasmodium infection  

OpenAIRE

The causative agent of malaria, Plasmodium, has to undergo complex developmental transitions and survive attacks from the mosquito's innate immune system to achieve transmission from one host to another through the vector. Here we discuss recent findings on the role of the mosquito's innate immune signaling pathways in preventing infection by the Plasmodium parasite, the identification and mechanistic description of novel anti-parasite molecules, the role that natural bacteria harbored in the...

Cirimotich, Chris M.; Dong, Yuemei; Garver, Lindsey S.; Sim, Shuzhen; Dimopoulos, George

2010-01-01

94

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

95

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

96

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

97

Repelentes electrónicos contra mosquitos: propaganda y realidad  

Directory of Open Access Journals (Sweden)

Full Text Available Se presenta una revisión bibliográfica acerca del uso de dispositivos electroacústicos con supuesta acción repelente sobre las hembras de diferentes especies de mosquitos hematófagos. Se dan 15 referencias directas y 2 indirectas, en todas se concluye que estos dispositivos no protegen a quienes los portan de las picadas de los mosquitos. Se dan los nombres de 9 de los dispositivos probados, así como de 16 de las principales especies de mosquitos presentes en las pruebas de campo. Estas pruebas de campo se han realizado en condiciones ecológicas muy diferentes, que van desde alaska hasta el África Ecuatorial. También se menciona el efecto potencialmente dañino al hombre de los dispositivos que emiten frecuencias a alta intensidad.A bibliographic review about the use of electroacustic devices with a supposed repellent action on the females of different species of hematophagous mosquitoes is presented. 15 direct references and 2 indirect ones are given, in which it is concluded that these devices do not protect those who have them from the stings of mosquitoes. The names of 9 of the tested devices as well as of 16 of the main species of mosquitoes present in the field tests are mentioned. These tests have been carried out in very different ecological conditions from Alaska to Equatorial Africa. It is also stressed that the high intensity ultrasonic frequencies emitted by these devices produces a potentially harmful effect on man.

Frank Coro

1998-08-01

98

Repelentes electrónicos contra mosquitos: propaganda y realidad  

Scientific Electronic Library Online (English)

Full Text Available SciELO Cuba | Language: Spanish Abstract in spanish Se presenta una revisión bibliográfica acerca del uso de dispositivos electroacústicos con supuesta acción repelente sobre las hembras de diferentes especies de mosquitos hematófagos. Se dan 15 referencias directas y 2 indirectas, en todas se concluye que estos dispositivos no protegen a quienes los [...] portan de las picadas de los mosquitos. Se dan los nombres de 9 de los dispositivos probados, así como de 16 de las principales especies de mosquitos presentes en las pruebas de campo. Estas pruebas de campo se han realizado en condiciones ecológicas muy diferentes, que van desde alaska hasta el África Ecuatorial. También se menciona el efecto potencialmente dañino al hombre de los dispositivos que emiten frecuencias a alta intensidad. Abstract in english A bibliographic review about the use of electroacustic devices with a supposed repellent action on the females of different species of hematophagous mosquitoes is presented. 15 direct references and 2 indirect ones are given, in which it is concluded that these devices do not protect those who have [...] them from the stings of mosquitoes. The names of 9 of the tested devices as well as of 16 of the main species of mosquitoes present in the field tests are mentioned. These tests have been carried out in very different ecological conditions from Alaska to Equatorial Africa. It is also stressed that the high intensity ultrasonic frequencies emitted by these devices produces a potentially harmful effect on man.

Frank, Coro; Silvia, Suárez.

1998-08-01

99

Hypersurface homogeneous Killing spinor space-times  

CERN Document Server

I present a complete list of hypersurface homogeneous space-times admitting a non-null valence two Killing spinor, including a new class admitting only exceptional Killing tensors. A connection is established with the classification of locally rotationally symmetric or boost symmetric space-times.

Bergh, Norbert Van den

2014-01-01

100

The Lie Algebra of Local Killing Fields  

CERN Document Server

We present an algebraic procedure that finds the Lie algebra of the local Killing fields of a smooth metric. In particular, we determine the number of independent local Killing fields about a given point on the manifold. Metrics of constant curvature, locally symmetric spaces and surfaces are also discussed.

Atkins, Richard

2008-01-01

101

Repellent, Irritant and Toxic Effects of 20 Plant Extracts on Adults of the Malaria Vector Anopheles gambiae Mosquito  

Science.gov (United States)

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

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

2013-01-01

102

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

Science.gov (United States)

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

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

2013-01-01

103

Raised houses reduce mosquito bites.  

Science.gov (United States)

BACKGROUND: In many parts of continental Africa house construction does not appear to impede entry of malaria vectors and, given their generally late biting cycle, the great majority of transmission takes place indoors. In contrast, many houses in São Tomé, 140 km off the coast of Gabon, are raised on stilts and built of wooden planks. Building on stilts is a time-honoured, but largely untested, way of avoiding mosquito bites. Exposure may also be affected by mosquito activity times and age composition of host-seeking females. A study was therefore undertaken on the island of São Tomé to determine if exposure to Anopheles gambiae, the only vector on the island, varied with house construction or time of the night. METHODS: A series of all-night landing collections were undertaken out of doors at ground level, inside houses at ground level, on the verandas of, and inside houses built on stilts. The gonotrophic age of an unselected sample of insects from the first three hours of landing collection (18:00-21:00) was determined by dissection. In addition, 1,149 miniature light-trap collections were obtained from 125 houses in the study area. Numbers collected were related to house construction. RESULTS: Biting of An. gambiae took place primarily outside at ground level. Less than one third of biting occurred inside houses. Houses built on stilts had half the number of An. gambiae in them compared to those built at ground level. Conversely houses with an eaves gap had more An. gambiae in them than houses without such a gap. Gonotrophic age did not affect house entry rates in An. gambiae. House construction affected Culex quinquefasciatus less than An. gambiae. Mean density per house, derived from a series of 1,490 randomly assigned light-trap collections, was over-dispersed with 18% of houses having 70% of the vectors. CONCLUSION: House construction plays an important role in determining exposure to malaria vectors in São Tomé. Neighbours can have very different exposure levels. Recommendations for improvement in control are given. PMID:14667242

Charlwood, J Derek; Pinto, Joao; Ferrara, Patrica R; Sousa, Carla A; Ferreira, Conceicao; Gil, Vilfrido; Do Rosário, Virgillo E

2003-12-10

104

Raised houses reduce mosquito bites  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background In many parts of continental Africa house construction does not appear to impede entry of malaria vectors and, given their generally late biting cycle, the great majority of transmission takes place indoors. In contrast, many houses in São Tomé, 140 km off the coast of Gabon, are raised on stilts and built of wooden planks. Building on stilts is a time-honoured, but largely untested, way of avoiding mosquito bites. Exposure may also be affected by mosquito activity times and age composition of host-seeking females. A study was therefore undertaken on the island of São Tomé to determine if exposure to Anopheles gambiae, the only vector on the island, varied with house construction or time of the night. Methods A series of all-night landing collections were undertaken out of doors at ground level, inside houses at ground level, on the verandas of, and inside houses built on stilts. The gonotrophic age of an unselected sample of insects from the first three hours of landing collection (18:00–21:00 was determined by dissection. In addition, 1,149 miniature light-trap collections were obtained from 125 houses in the study area. Numbers collected were related to house construction. Results Biting of An. gambiae took place primarily outside at ground level. Less than one third of biting occurred inside houses. Houses built on stilts had half the number of An. gambiae in them compared to those built at ground level. Conversely houses with an eaves gap had more An. gambiae in them than houses without such a gap. Gonotrophic age did not affect house entry rates in An. gambiae. House construction affected Culex quinquefasciatus less than An. gambiae. Mean density per house, derived from a series of 1,490 randomly assigned light-trap collections, was over-dispersed with 18% of houses having 70% of the vectors. Conclusion House construction plays an important role in determining exposure to malaria vectors in São Tomé. Neighbours can have very different exposure levels. Recommendations for improvement in control are given.

Gil Vilfrido

2003-12-01

105

Mount Unzen kills three volcanologists  

Science.gov (United States)

Three AGU members were among 37 people killed June 3 when Mount Unzen, a volcano in Nagasaki prefecture, Japan, erupted. Unzen last erupted in 1792. The first signs of renewed activity appeared in mid-1990, with increases in seismicity and the first volcanic tremor since observations began in 1966. The three volcanologists, Harry Glicken and Maurice and Katia Krafft, had traveled to Mount Unzen to monitor the increased seismic activity. Glicken, 33, was a visiting scientist at Tokyo Metropolitan University and an assistant researcher in geological sciences at the University of California, Santa Barbara. He worked for the U.S. Geological Survey until 1989, and narrowly escaped death in the 1980 eruption of Mount St. Helens in Washington.Glicken had been an AGU member since 1980 and was known for his work in debris avalanches. Maurice, 45, and Katia Krafft, 44, of Cernay, France, were professional volcanologists known for their extensive work in publishing books and films on volcanology for the general public. Both Kraffts joined AGU in 1975.

DeVito, M. Catherine

106

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

OpenAIRE

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

107

[Killing of cattle via electrical stunning].  

Science.gov (United States)

For disease control in the case of epidemics killing of cattle via electrical stunning is a method of choice. The official veterinarian is responsible for monitoring the adhesion to animal welfare principles during electrical stunning and killing. This requires specialised knowledge and experience as the symptoms of effective stunning are quite variable in cattle. Signs of effective and ineffective stunning are described below. In addition to suitable technical equipment, restraint of the animals and correct use of the equipment, neurophysiological processes have to be considered. Calm handling of the animals avoiding stress is a prerequisite for ensuring animal welfare and minimising pain especially when killing cattle using electrical methods. PMID:17484500

Maurer, B; Forster, S

2007-04-01

108

9 CFR 113.216 - Bovine Rhinotracheitis Vaccine, Killed Virus.  

Science.gov (United States)

...2010-01-01 2010-01-01 false Bovine Rhinotracheitis Vaccine, Killed Virus... Killed Virus Vaccines § 113.216 Bovine Rhinotracheitis Vaccine, Killed Virus. Infectious Bovine Rhinotracheitis Vaccine,...

2010-01-01

109

9 CFR 113.205 - Newcastle Disease Vaccine, Killed Virus.  

Science.gov (United States)

...2010-01-01 false Newcastle Disease Vaccine, Killed Virus. 113.205 Section...Disease Vaccine, Killed Virus. Newcastle Disease Vaccine (Killed Virus...a virulent strain of Newcastle disease virus supplied by or...

2010-01-01

110

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

Science.gov (United States)

...2010-01-01 2010-01-01 false Parvovirus Vaccine, Killed Virus (Canine). 113.214 Section 113...Virus Vaccines § 113.214 Parvovirus Vaccine, Killed Virus (Canine). Parvovirus Vaccine, Killed Virus,...

2010-01-01

111

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 < 0.05 level. The result indicated that the essential oil of C. aromaticus and the isolated constituent have a potential for use in control of C. tritaeniorhynchus, A. albopictus, and A. subpictus 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

112

Esbiothrin-impregnated ropes as mosquito repellent.  

Science.gov (United States)

Esbiothrin [(+/-)-3-allyl-2-methyl-4-oxocylopent-2-enyl-(+)-trans- chrysanthemate] is an improved isomeric composition of allethrin series and consists essentially of esters of chrysanthemic acid and allethrolone. Jute rope was impregnated with esbiothrin and the smoke from smouldering ropes was evaluated as mosquito repellent in human dwellings and cattlesheds with open doors and windows at different dosages. Esbiothrin-impregranted (500 ppm) ropes prevented the entry of more than 95% An. culicifacles and other anophelines, 90.9-88.8% Culex quinquefasciatus and 96-95.1% total mosquitoes in open rooms of houses and cattlesheds respectively. The impact of ropes was more pronounced on the biting rate of mosquitoes. Indoors and outdoors human baits seated at a distance of about 3 m from smouldering esbiothrin ropes experienced no bite at all from An. culicifacies. An iron mesh around the rope prevents fire hazards. PMID:1291341

Ansari, M A; Sharma, V P; Razdan, R K

1992-12-01

113

Evaluation of botanicals as repellents against mosquitoes.  

Science.gov (United States)

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

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

2003-01-01

114

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

115

The Geometry of D=11 Killing Spinors  

CERN Document Server

We propose a way to classify all supersymmetric configurations of D=11 supergravity using the G-structures defined by the Killing spinors. We show that the most general bosonic geometries admitting a Killing spinor have at least an SU(5) or an (Spin(7)\\ltimes R^8)x R structure, depending on whether the Killing vector constructed from the Killing spinor is timelike or null, respectively. In the former case we determine what kind of SU(5) structure is present and show that almost all of the form of the geometry is determined by the structure. We also deduce what further conditions must be imposed in order that the equations of motion are satisfied. We illustrate the formalism with some known solutions and also present some new solutions including a rotating generalisation of the resolved membrane solutions and generalisations of the recently constructed D=11 Godel solution.

Gauntlett, J P; Gauntlett, Jerome P.; Pakis, Stathis

2003-01-01

116

Male-killing in African butterflies  

Directory of Open Access Journals (Sweden)

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

Sami Saeed M. Hassan

2013-02-01

117

Cryptococcus neoformans modulates extracellular killing by neutrophils  

Directory of Open Access Journals (Sweden)

Full Text Available We recently established a key role for host sphingomyelin synthase (SMS in the regulation of the killing activity of neutrophils against Cryptococcus neoformans. In this work, we studied the effect of C. neoformans on the killing activity of neutrophils and whether SMS would still be a player against C. neoformans in immunocompromised mice lacking T and NK cells (Tg?26 mice. To this end, we analyzed whether C. neoformans would have any effect on neutrophil survival and killing in vitro and in vivo. We show that unlike C. albicans, neither the presence nor the capsule size of C. neoformans cells have any effect on neutrophil viability. Interestingly, melanized C. neoformans cells totally abrogated the killing activity of neutrophils. Next, we monitored how exposure of neutrophils to C. neoformans cells would interfere with any further killing activity of the medium and found that pre-incubation with live but not “heat-killed” fungal cells significantly inhibits further killing activity of the medium. We next studied whether activation of SMS at the site of C. neoformans infection is dependent on T and NK cells. Using matrix-assisted laser desorption-ionization (MALDI tissue imaging in infected lung we found that similarly to previous observations in the isogenic wild type CBA/J mice, SM 16:0 levels are significantly elevated at the site of infection in mice lacking T and NK cells but only at early time points. This study highlights that C. neoformans may negatively regulate the killing activity of neutrophils and that SMS activation in neutrophils appears to be partially independent of T and/or NK cells.

AsfiaQureshi

2011-09-01

118

Killing spinors for the bosonic string  

Science.gov (United States)

We obtain the effective action for the bosonic string with arbitrary Yang-Mills fields, up to the ?' order, in general dimensions. The form of the action is determined by the requirement that the action admit well-defined Killing spinor equations, whose projected integrability conditions give rise to the full set of equations of motion. The success of the construction suggests that the hidden "pseudo-supersymmetry" associated with the Killing spinor equations may be a property of the bosonic string itself.

Lü, H.; Wang, Zhao-Long

2012-03-01

119

Killing Spinors for the Bosonic String  

OpenAIRE

We obtain the effective action for the bosonic string with arbitrary Yang-Mills fields, up to the \\alpha' order, in general dimensions. The form of the action is determined by the requirement that the action admit well-defined Killing spinor equations, whose projected integrability conditions give rise to the full set of equations of motion. The success of the construction suggests that the hidden "pseudo-supersymmetry" associated with the Killing spinor equations may be a p...

Lu, H.; Wang, Zhao-long

2011-01-01

120

Modelling releases of sterile mosquitoes with different strategies.  

Science.gov (United States)

To prevent the transmissions of malaria, dengue fever, or other mosquito-borne diseases, one effective weapon is the sterile insect technique in which sterile mosquitoes are released to reduce or eradicate the wild mosquito population. To study the impact of the sterile insect technique on disease transmission, we formulate discrete-time mathematical models, based on difference equations, for the interactive dynamics of the wild and sterile mosquitoes, incorporating different strategies in releasing sterile mosquitoes. We investigate the model dynamics and compare the impact of the different release strategies. Numerical examples are given to demonstrate rich dynamical features of the models. PMID:25377433

Li, Jia; Yuan, Zhiling

2015-01-01

121

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

122

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

123

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

124

Biological assay methods for mosquito repellents.  

Science.gov (United States)

Three biological assay procedures for repellents are currently documented in the literature: 1) ASTM E951-94, Laboratory testing of non-commercial repellent formulations on the skin. 2) ASTM E939-94, Field testing topical applications of compounds as repellents for medically important and pest arthropods. 1. Mosquitoes. 3) WHO/CTD/WHOPES/IC/96.1, Report of WHOPES informal consultation on the evaluation and testing of insecticides. One public draft set of repellent-testing guidelines is available on the internet: 4) USEPA OPPTS 810.3700, Product performance test guidelines. Insect repellents for human skin and outdoor premises. In practice, the outcome of a repellent bioassay using any of these procedures is affected by the absorption, penetration, and chemical modification of repellent on skin and by evaporation, abrasion, and perspiration. Other abiotic factors that influence mosquito responses to repellent stimuli are light, temperature, humidity, repellent dose, exposure time, and test-cage shape and size. Biotic variables in repellent bioassays are larval nutrition, carbohydrate availability for adult mosquitoes, age and parity of females, and differences in the innate attraction/ repellency of test subjects. Geographic location and seasonal and diel activity cycles in mosquitoes determine when and where repellents can be tested in the field. Critical knowledge of these sources of variation can be converted to improved precision and accuracy in repellent bioassays and the resulting information used to efficiently select new repellent compounds for toxicological evaluation and field testing. PMID:16921678

Barnard, Donald R

2005-12-01

125

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

Science.gov (United States)

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

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

2013-04-01

126

Spatiotemporal monitoring of floodwater mosquito dispersal in Osijek, Croatia.  

Science.gov (United States)

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

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

2007-06-01

127

Integration without integration: New Killing spinor spacetimes  

Science.gov (United States)

Non-conformally flat spacetimes admitting a non-null two-index Killing spinor are investigated by means of the Geroch-Held-Penrose formalism. Claims appearing in the literature that such spacetimes are all explicitly known are incorrect. This was shown in [5] for the family where, in the canonical frame, the spin coefficients ? or ?, vanish. Here the general case with non-vanishing ?, ?, ? and ? is re-considered. It is shown that the construction in [4] hinges on the tacit assumption that certain integrability conditions hold, implying two algebraic relations for the spin coefficients and the components of the Ricci spinor. All (conformal classes of) spacetimes, in which one of these conditions is violated, are obtained by invariant integration. The resulting classes are each other's Sachs transform and are characterised by one free function. They admit in general no Killing vectors, but still admit a conformal gauge (different from the trivial unitary gauge) in which a Killing tensor exists.

Van den Bergh, Norbert

2010-05-01

128

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

129

Killing Yano equations and G structures  

Science.gov (United States)

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

Papadopoulos, G.

2008-05-01

130

Extracellular killing of inhaled pneumococci in rats  

Energy Technology Data Exchange (ETDEWEB)

Early clearance of inhaled Staphylococcus aureus is believed to be caused by phagocytosis by alveolar macrophages. In murine models inhaled pneumococci are cleared even more rapidly than S. aureus. Conventional opsonins appear to play no role in this clearance, and recently it has been shown that murine alveolar lining material contains free fatty acids and other soluble factors that are directly bactericidal for pneumococci. To determine whether non-phagocytic factors are involved in pneumococcal clearance, we compared the site of killing of inhaled pneumococci and S. aureus in rats using histologic methods and bronchoalveolar lavage. Spontaneous lysis of pneumococci was prevented by use of autolysin-defective pneumococci or by substitution of ethanolamine for choline in the cell wall. Histologic studies showed that the percent of inhaled staphylococci associated with alveolar macrophages always exceeded the percent of staphylococci cleared, whereas there was little association of pneumococci with macrophages during clearance. Analysis of the intracellular or extracellular location of iron 59 in bronchoalveolar lavage fluid of rats that had inhaled aerosols of /sup 59/Fe-labeled bacteria suggested that staphylococci were killed predominantly in macrophages and pneumococci in the extracellular space. When /sup 59/Fe-labeled pneumococci or staphylococci were ingested and killed by macrophages in vitro, the /sup 59/Fe remained with the macrophages, suggesting that the extracellular location of /sup 59/Fe during pneumococcal killing in vivo was not caused by rapid turnover of /sup 59/Fe in macrophages. Studies of the site of killing of inhaled type 25 pneumococci labeled exclusively in the cell wall with carbon 14-ethanolamine confirmed the results obtained with /sup 59/Fe-labeled pneumococci. Thus, early killing of inhaled pneumococci, unlike staphylococci, appears to take place outside of macrophages.

Coonrod, J.D.; Marple, S.; Holmes, G.P.; Rehm, S.R.

1987-12-01

131

Extracellular killing of inhaled pneumococci in rats  

International Nuclear Information System (INIS)

Early clearance of inhaled Staphylococcus aureus is believed to be caused by phagocytosis by alveolar macrophages. In murine models inhaled pneumococci are cleared even more rapidly than S. aureus. Conventional opsonins appear to play no role in this clearance, and recently it has been shown that murine alveolar lining material contains free fatty acids and other soluble factors that are directly bactericidal for pneumococci. To determine whether non-phagocytic factors are involved in pneumococcal clearance, we compared the site of killing of inhaled pneumococci and S. aureus in rats using histologic methods and bronchoalveolar lavage. Spontaneous lysis of pneumococci was prevented by use of autolysin-defective pneumococci or by substitution of ethanolamine for choline in the cell wall. Histologic studies showed that the percent of inhaled staphylococci associated with alveolar macrophages always exceeded the percent of staphylococci cleared, whereas there was little association of pneumococci with macrophages during clearance. Analysis of the intracellular or extracellular location of iron 59 in bronchoalveolar lavage fluid of rats that had inhaled aerosols of 59Fe-labeled bacteria suggested that staphylococci were killed predominantly in macrophages and pneumococci in the extracellular space. When 59Fe-labeled pneumococci or staphylococci were ingested and killed by macrophages in vitro, the 59Fe remained with the macrophages, suggesp>Fe remained with the macrophages, suggesting that the extracellular location of 59Fe during pneumococcal killing in vivo was not caused by rapid turnover of 59Fe in macrophages. Studies of the site of killing of inhaled type 25 pneumococci labeled exclusively in the cell wall with carbon 14-ethanolamine confirmed the results obtained with 59Fe-labeled pneumococci. Thus, early killing of inhaled pneumococci, unlike staphylococci, appears to take place outside of macrophages

132

Conformal Killing Tensors and covariant Hamiltonian Dynamics  

CERN Document Server

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

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

2014-01-01

133

Killing spinors in supergravity with 4-fluxes  

International Nuclear Information System (INIS)

We study the spinorial Killing equation of supergravity involving a torsion 3-form T as well as a flux 4-form F. In dimension seven, we construct explicit families of compact solutions out of 3-Sasakian geometries, nearly parallel G2-geometries and on the homogeneous Aloff-Wallach space. The constraint F · ? = 0 defines a non-empty subfamily of solutions. We investigate the constraint T · ? = 0 , too, and show that it singles out a very special choice of numerical parameters in the Killing equation, which can also be justified geometrically

134

Killing spinors in supergravity with 4-fluxes  

Energy Technology Data Exchange (ETDEWEB)

We study the spinorial Killing equation of supergravity involving a torsion 3-form T as well as a flux 4-form F. In dimension seven, we construct explicit families of compact solutions out of 3-Sasakian geometries, nearly parallel G{sub 2}-geometries and on the homogeneous Aloff-Wallach space. The constraint F {center_dot} {psi} = 0 defines a non-empty subfamily of solutions. We investigate the constraint T {center_dot} {psi} = 0 , too, and show that it singles out a very special choice of numerical parameters in the Killing equation, which can also be justified geometrically.

Agricola, Ilka; Friedrich, Thomas [Institut fuer Mathematik, Humboldt-Universitaet zu Berlin, Sitz: WBC Adlershof, D-10099 Berlin (Germany)

2003-11-07

135

Killing spinors in supergravity with 4-fluxes  

CERN Document Server

We study the spinorial Killing equation of supergravity involving a torsion 3-form $\\T$ as well as a flux 4-form $\\F$. In dimension seven, we construct explicit families of compact solutions out of 3-Sasakian geometries, nearly parallel $\\G_2$-geometries and on the homogeneous Aloff-Wallach space. The constraint $\\F \\cdot \\Psi = 0$ defines a non empty subfamily of solutions. We investigate the constraint $\\T \\cdot \\Psi = 0$, too, and show that it singles out a very special choice of numerical parameters in the Killing equation, which can also be justified geometrically.

Agricola, I; Agricola, Ilka; Friedrich, Thomas

2003-01-01

136

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

137

Killing Spinors for the Bosonic String  

CERN Document Server

We obtain the effective action for the bosonic string with arbitrary Yang-Mills fields, up to the \\alpha' order, in general dimensions. The form of the action is determined by the requirement that the action admit well-defined Killing spinor equations, whose projected integrability conditions give rise to the full set of equations of motion. The success of the construction suggests that the hidden "pseudo-supersymmetry" associated with the Killing spinor equations may be a property of the bosonic string itself.

Lu, H

2011-01-01

138

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

139

HIV transcription is induced with cell killing  

Energy Technology Data Exchange (ETDEWEB)

In this report, we demonstrate that this induction of HIV-LTR transcription occurs when stably transfected HeLa cells are exposed to agents which mediate cell killing, such as UV radiation, electroporation of sucrose buffer, prolonged heating, and low and high pH. Cells cultured following UV exposure demonstrated a peak in CAT expression that is evident in viable (but not necessarily cell division-competent) cells 24 h after exposure; this inductive response continued until at least 72 h after exposure. HIV-LTR induction was dose-dependent, and the amount of CAT transcription induced was correlated with the amount of cell killing that occurred in the culture.

Woloschak, G.E.; Schreck, S.; Chang-Liu, Chin-Mei [Argonne National Lab., IL (United States); Panozzo, J.; Libertin, C.R. [Loyola Univ. Medical Center, Maywood, IL (United States)

1993-11-01

140

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

Directory of Open Access Journals (Sweden)

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

Maharaj Rajendra

2012-09-01

141

Evaluation of larvicidal activity of Pongamia pinnata extracts against three mosquito vectors  

Science.gov (United States)

Objective To evaluate the mosquito larvicidal activity of Pongamia pinnata (P. pinnata) extracts against three mosquito vectors. Methods The methanol and hydroalcohol extracts of bark part of P. pinnata L were tested against fourth instar larvae of Culex quinquefasciatus, Aedes aegypti and Anopheles stephensi. The mortality was observed 24 h and 48 h after treatment, data was subjected to probit analysis to determine lethal concentration (LC50 and LC90) to kill 50 and 90 percent of treated larvae of tested species. Results The larval mortality was found in both methanol and hydroalcohol extracts of P. pinnata against Culex quinquefasciatus, Aedes aegypti and Anopheles stephensi with LC50 values of 84.8, 118.2 and 151.7 ppm; 97.7, 128.3 and 513 ppm. The highest larval mortality was found in methanol extract of P. pinnata when comparable to the hydroalcohol extract. Conclusions These results suggest that both methanol and hyrdoalcohol extracts have the potential to be used as an ideal ecofriendly approach for the control of disease vectors. This could lead to isolation of novel natural larvicidal compounds.

Kolli, Guna Ranjan; Balakrishnan; Vijayan; Sundararajan, Raja

2013-01-01

142

Infection of the malaria mosquito, Anopheles gambiae, with two species of entomopathogenic fungi: effects of concentration, co-formulation, exposure time and persistence  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Entomopathogenic fungi Metarhizium anisopliae and Beauveria bassiana isolates have been shown to infect and reduce the survival of mosquito vectors. Methods Here four different bioassays were conducted to study the effect of conidia concentration, co-formulation, exposure time and persistence of the isolates M. anisopliae ICIPE-30 and B. bassiana I93-925 on infection and survival rates of female Anopheles gambiae sensu stricto. Test concentrations and exposure times ranged between 1 × 107 - 4 × 1010 conidia m-2 and 15 min - 6 h. In co-formulations, 2 × 1010 conidia m-2 of both fungus isolates were mixed at ratios of 4:1, 2:1, 1:1,1:0, 0:1, 1:2 and 1:4. To determine persistence, mosquitoes were exposed to surfaces treated 1, 14 or 28 d previously, with conidia concentrations of 2 × 109, 2 × 1010 or 4 × 1010. Results Mosquito survival varied with conidia concentration; 2 × 1010 conidia m-2 was the concentration above which no further reductions in survival were detectable for both isolates of fungus. The survival of mosquitoes exposed to single and co-formulated treatments was similar and no synergistic or additive effects were observed. Mosquitoes were infected within 30 min and longer exposure times did not result in a more rapid killing effect. Fifteen min exposure still achieved considerable mortality rates (100% mortality by 14 d of mosquitoes, but at lower speed than with 30 min exposure (100% mortality by 9 d. Conidia remained infective up to 28 d post-application but higher concentrations did not increase persistence. Conclusion Both fungus isolates are effective and persistent at low concentrations and short exposure times.

Lwetoijera Dickson W

2009-12-01

143

Potential of medicinal plants in mosquito control.  

Science.gov (United States)

Medicinal plants have long history as important components in traditional medicine, and food of humans since ancient Egyptians and Chinese. Naturally occurring botanical compounds contain a broad range of chemical active ingredients can intervene in all biological processes of the mosquito, thus interrupt its life cycle and dispersal and reduce harms to humans and animals. Many medicinal plants were tested for their pesticide and repellent potential, as crude material, essential oils or individual active ingredients. This article reviewed studies on the efficacy of many well known and commonly used safe medicinal plants or their products in controlling the mosquitoes; Aedes aegypti, Anopheles gambiae, An. stephensi and Culex quinquefasciatus and the ticks, Dermacentor variabilis, Amblyomma americanum, Ixodes scapularis and I. ricinus. Promising and encouraging results were obtained against these arthropod-vectors of zoonotic diseases. PMID:20503582

Fallatah, Sahar A B; Khater, Emad I M

2010-04-01

144

Ord River arboviruses--isolations from mosquitoes.  

Science.gov (United States)

One hundred and thirty presumptive viruses have been isolated from 485 pools made from 23,872 mosquitoes collected in the Ord River area of North-West Australia. One hundred and eleven of the virus isolates isolates came from pools of Culex annulirostis, the dominant mosquito species caught in the vicinity of Kununurra. Forty-five of the viruses pathogenic for newborn mice have been further characterized-19 as Flaviviruses, 1 Alphavirus, 9 Koongol, 1 Mapputta and 15 non-haemagglutinating viruses of which 6 are Corripata. Thirty-seven isolates were from Culex annulirostis, 7 from Aedomyia catasticta and 1 from aedes tremulus. All Corriparta isolates were from Aedomyia catasticta. The Flaviviruses comprised 13 Kunjin and 6 MVE isolates. PMID:14613

Liehne, C G; Leivers, S; Stanley, N F; Alpers, M P; Paul, S; Liehne, P F; Chan, K H

1976-10-01

145

Novel Flaviviruses Detected in Different Species of Mosquitoes in Spain  

OpenAIRE

We report the characterization of three novel flaviviruses isolated in Spain. Marisma Mosquito virus, a novel mosquito borne virus, was isolated from Ochlerotatus caspius mosquitoes; Spanish Ochlerotatus flavivirus and Spanish Culex flavivirus, two novel insect flaviviruses, were isolated from Oc. caspius and Culex pipiens, re- spectively. During this investigation, we designed a sensitive RT-nested polymerase chain reaction method that amplifies a 1019bp fragmen...

Va?zquez, Ana; Sa?nchez-seco, Mari?a-paz; Palacios, Gustavo; Molero, Francisca; Reyes, Noelia; Ruiz, Santiago; Aranda, Carles; Marque?s, Eduard; Escosa, Raul; Moreno, Juana; Figuerola, Jordi; Tenorio, Antonio

2012-01-01

146

Cues of mosquito host finding and oviposition site selection  

OpenAIRE

The aim of this work was to study odor cues that affect mosquito host seeking and oviposition behavior. Due to the vastness (and sometimes contradictions) of mosquito oviposition cues available in literature, I started by reviewing these cues, their source in nature, and their role in mosquito oviposition. Then, I tested the oviposition response of Aedes aegypti towards the contradictory oviposition odor p-cresol and its isomer m-cresol in different situations. p-cresol showed an ...

Afify, Ali

2014-01-01

147

Vector Competence of New Zealand Mosquitoes for Selected Arboviruses  

OpenAIRE

New Zealand (NZ) historically has been free of arboviral activity with the exception of Whataroa virus (Togaviridae: Alphavirus), which is established in bird populations and is transmitted by local mosquitoes. This naive situation is threatened by global warming, invasive mosquitoes, and tourism. To determine the threat of selected medically important arboviruses to NZ, vector competence assays were conducted using field collected endemic and introduced mosquito species. Four alphaviruses (T...

Kramer, Laura D.; Chin, Pam; Cane, Rachel P.; Kauffman, Elizabeth B.; Mackereth, Graham

2011-01-01

148

A role for endosomal proteins in alphavirus dissemination in mosquitoes  

OpenAIRE

Little is known about endosomal pathway proteins involved in arthropod-borne virus (arbovirus) assembly and cell-to-cell spread in vector mosquitoes. UNC93A and Synaptic vesicle-2 (SV2) proteins are involved in intracellular transport in mammals. They show amino acid sequence conservation from mosquitoes to humans, and their transcripts are highly-enriched in Aedes aegypti during arbovirus infection. Transient gene silencing of SV2 or UNC93A in mosquitoes infected with the recombinant alphavi...

Campbell, Corey L.; Lehmann, Christopher J.; Gill, Sargeet S.; Dunn, W. A.; James, Anthony A.; Foy, Brian D.

2011-01-01

149

Advances in methods for colour marking of mosquitoes  

OpenAIRE

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

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

2013-01-01

150

Wolbachia-Associated Bacterial Protection in the Mosquito Aedes aegypti  

OpenAIRE

Wolbachia is a commonly occurring bacterium or symbiont that lives inside the cells of insects. Recently, Wolbachia was artificially introduced into the mosquito vector dengue virus that was naturally Wolbachia-free. Wolbachia limits the growth of a range of pathogens transmitted to humans, including viruses, bacteria and parasites inside the mosquito. This “pathogen protection” forms the basis of field trials to determine if releasing Wolbachia into wild mosquito populations could reduce...

Ye, Yixin H.; Woolfit, Megan; Rance?s, Edwige; O Neill, Scott L.; Mcgraw, Elizabeth A.

2013-01-01

151

Limitation of using synthetic human odours to test mosquito repellents  

OpenAIRE

Abstract Background Gold-standard tests of mosquito repellents involve exposing human volunteers to host-seeking mosquitoes, to assess the protective efficacy of the repellents. These techniques are not exposure-free and cannot be performed prior to toxicological evaluation. It is postulated that synthetic lures could provide a useful assay that mimics in-vivo conditions for use in high-throughput screening for mosquito repellents. Methods This paper re...

Mbeyela Edgar; Titus Emmanuel; Okumu Fredros O; Killeen Gerry F; Moore Sarah J

2009-01-01

152

Killing Hitler: A Writer's Journey and Angst.  

Science.gov (United States)

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

Thaler, Paul

2002-01-01

153

Can Vet Schools Teach without Killing Animals?  

Science.gov (United States)

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

Mangan, Katherine S.

2000-01-01

154

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

155

Distribution of anopheline mosquitoes in Eritrea.  

Science.gov (United States)

The spatial distribution of anopheline mosquito species was studied throughout Eritrea during the 1999-2001 malaria transmission seasons from October to December for the highlands and western lowlands and February to April for the coastal region. Of the 302 villages sampled, 59 were visited in both the first and second year. Overall, 13 anopheline species were identified, with the Anopheles gambiae complex predominating during the first year (75.6%, n = 861) and the second year (91.9%, n = 1,262). Intrazonal variation accounted for 90% of the total variation in mosquito distribution. Polymerase chain reaction results indicated that 99% (n = 1,309) of the An. gambiae s.l. specimens were An. arabiensis, indicating that this was the only member of the gambiae complex present. There was a high degree of aggregation of anophelines within zones and villages, with more than 80% of the total anophelines being collected from less than 20% of the villages and from only 10% of the houses sampled. At least 80% of the anopheline mosquitoes were collected from grass-thatched Agudo-type housing. Vector abundance showed an inverse relationship with elevation, with highest densities in the low-lying western lowlands. Multiple regression analysis of log-transformed mean density of An. arabiensis with rainfall and the normalized difference vegetation index (NDVI) (average NDVI, minimum NDVI, and maximum NDVI) showed that these independent variables were not significantly associated with mosquito densities (R2 = 0.058). Our study contributes to the basic understanding of the ecology and distribution of malaria vectors with respect to species composition and spatial heterogeneities both that could be used to guide vector control operations in Eritrea. PMID:14628947

Shililu, Josephat; Ghebremeskel, Tewolde; Mengistu, Solomon; Fekadu, Helen; Zerom, Mehari; Mbogo, Charles; Githure, John; Gu, Weidong; Novak, Robert; Beier, John C

2003-09-01

156

Cultured skin microbiota attracts malaria mosquitoes  

OpenAIRE

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 activi...

Takken Willem; Gj, Knols Bart; Beijleveld Hans; Verhulst Niels O; Schraa Gosse; Bouwmeester Harro J; Smallegange Renate C

2009-01-01

157

Avian malaria associations with British mosquitoes  

OpenAIRE

Avian malaria (Plasmodium spp.) is a popular model system to study the ecology and evolution of parasite-host-vector interactions in the wild. These studies have historically focused mostly on the avian hosts and the malaria parasites. Knowledge regarding the role of vectors is essential to our understanding of these wild systems, but has only very recently started to accumulate. This thesis aimed to contribute to this field by assessing mosquito-malaria-host associations for Britis...

Alves, R. O. N.; Sheldon, B. C.; Wood, M. J.

2012-01-01

158

Larval habitats and species composition of mosquitoes in Darjeeling Himalayas, India  

OpenAIRE

Background & objectives: A preliminary survey of larval mosquito habitats and temporal variationin mosquito diversity in the hill town of Darjeeling, India was made during 2003, for a qualitativeand quantitative assessment of mosquito distribution.Methods: The possible larval habitats of mosquitoes were surveyed and the species diversity in thesites positive for mosquito larvae was noted. Bi-weekly sampling from a particular habitat wascarried out to reveal the temporal variation in mosquito ...

Gautam Aditya, B.

2006-01-01

159

Lista dos mosquitos da Bolívia: (Diptera, Culicidae  

Directory of Open Access Journals (Sweden)

Full Text Available Em quinze gêneros, cento e vinte e seis espécies de mosquitos foram constatadas no material capturado pelo Servicio de Fiebre Amarilla desde 1933 até 1942. Êste número, três vezes mais elevado do que o existente na literatura para o país, seria ainda maior se possível fôsse identificar sem o auxílio de machos inúmeras fêmeas das espécies de Culex. Tôdas as espécies estudadas apresentavam suas distribuições geográficas nos departamentos e províncias onde casos de Febre Amarela foram observados. Algumas cosiderações foram feitas em torno de espécies que não correspondiam exatamente com as descrições existentes, assim como descrições de outras foram dadas, cujos sexos opostos apenas eram conhecidos.One hundred and twenty-six species of mosquitoes, corresponding fifteen genera, have been found in material collected by the Bolivian Yellow Fever Service between 1933 and 1942. This number is three times that given for the country in existing literature and would be even largar if it were possible to identify a consierable group of Culex mosquitoes composed principally of female specimens. All species studied come from Departmetns and Provinces where cases of yellow fever have been found. Consideration has been given to certain species which do not agree exactly with existing descriptions, and supplementary descriptions have been made for the male or female of two additional species for which only description of the opposite sex had existed.

N. L. Cerqueira

1943-08-01

160

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

161

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

162

[Mosquitoes as vectors for exotic pathogens in Germany].  

Science.gov (United States)

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

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

2014-05-01

163

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

164

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

165

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

166

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

Directory of Open Access Journals (Sweden)

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

167

9 CFR 113.206 - Wart Vaccine, Killed Virus.  

Science.gov (United States)

...Vaccine, Killed Virus. Wart Vaccine, Killed Virus, shall...efficacy. The efficacy of wart vaccine has been demonstrated to...product precludes the possible development of serial to serial potency...Provided, That, (1) The vaccine shall be a tissue...

2010-01-01

168

9 CFR 113.204 - Mink Enteritis Vaccine, Killed Virus.  

Science.gov (United States)

...Mink Enteritis Vaccine, Killed Virus. 113.204 Section 113...Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS...STANDARD REQUIREMENTS Killed Virus Vaccines § 113.204...

2010-01-01

169

9 CFR 113.205 - Newcastle Disease Vaccine, Killed Virus.  

Science.gov (United States)

...Newcastle Disease Vaccine, Killed Virus. 113.205 Section 113...Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS...STANDARD REQUIREMENTS Killed Virus Vaccines § 113.205...

2010-01-01

170

9 CFR 113.203 - Feline Panleukopenia Vaccine, Killed Virus.  

Science.gov (United States)

...Panleukopenia Vaccine, Killed Virus. 113.203 Section 113...Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS...STANDARD REQUIREMENTS Killed Virus Vaccines § 113.203...

2010-01-01

171

9 CFR 113.208 - Avian Encephalomyelitis Vaccine, Killed Virus.  

Science.gov (United States)

...Encephalomyelitis Vaccine, Killed Virus. 113.208 Section 113...Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS...STANDARD REQUIREMENTS Killed Virus Vaccines § 113.208...

2010-01-01

172

9 CFR 113.206 - Wart Vaccine, Killed Virus.  

Science.gov (United States)

...false Wart Vaccine, Killed Virus. 113.206 Section 113...Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS...STANDARD REQUIREMENTS Killed Virus Vaccines § 113.206...

2010-01-01

173

Underground blowout killed with quick snubbing operation  

Energy Technology Data Exchange (ETDEWEB)

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

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

1993-10-18

174

Heterotic supergravity on manifolds with Killing spinors  

International Nuclear Information System (INIS)

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 R4-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 Rp, 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 instns 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 G2, 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 G2. 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.

175

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.

176

Emotion, gender and genre : Investigating The Killing  

DEFF Research Database (Denmark)

Traditionally, Scandinavian TV crime fiction has been regarded as a public arena for critical exhibition of and debate about salient features in contemporary social development. To explain the acknowledged impact of this kind of crime fiction, it is necessary to involve the notions of emotion and gender in combination with the mixing of genres, as especially the thriller and the melodrama have invaded the police procedural. This is demonstrated in an analysis of The Killing.

Agger, Gunhild

2011-01-01

177

Bacterial Killing by Dry Metallic Copper Surfaces?  

OpenAIRE

Metallic copper surfaces rapidly and efficiently kill bacteria. Cells exposed to copper surfaces accumulated large amounts of copper ions, and this copper uptake was faster from dry copper than from moist copper. Cells suffered extensive membrane damage within minutes of exposure to dry copper. Further, cells removed from copper showed loss of cell integrity. Acute contact with metallic copper surfaces did not result in increased mutation rates or DNA lesions. These findings are important fir...

Santo, Christophe Espi?rito; Lam, Ee Wen; Elowsky, Christian G.; Quaranta, Davide; Domaille, Dylan W.; Chang, Christopher J.; Grass, Gregor

2011-01-01

178

Generalized Korn's inequality and conformal Killing vectors  

OpenAIRE

Korn's inequality plays an important role in linear elasticity theory. This inequality bounds the norm of the derivatives of the displacement vector by the norm of the linearized strain tensor. The kernel of the linearized strain tensor are the infinitesimal rigid-body translations and rotations (Killing vectors). We generalize this inequality by replacing the linearized strain tensor by its trace free part. That is, we obtain a stronger inequality in which the kernel of the...

Dain, Sergio

2005-01-01

179

Generalized Killing spinors in dimension 5  

OpenAIRE

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

Conti, Diego; Salamon, Simon

2005-01-01

180

Methionine: a new biopesticide for use in mosquito management  

Science.gov (United States)

Mosquito larvicides are an effective means of source reduction, controlling the population size so that the number of adult females that are present to bite and potentially spread pathogenic organisms is decreased. Currently utilized mosquito larvicides include insect growth regulators, organophosph...

181

Statics and dynamics of malaria infection in Anopheles mosquitoes  

OpenAIRE

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...

Ellis McKenzie F; Smith David L

2004-01-01

182

Protocol for RNAi Assays in Adult Mosquitoes (A. gambiae)  

OpenAIRE

Reverse genetic approaches have proven extremely useful for determining which genes underly resistance to vector pathogens in mosquitoes. This video protocol illustrates a method used by the Dimopoulos lab to inject dsRNA into Anopheles gambiae mosquitoes, which harbor the malaria parasite. The technique manipulating the injection setup and injecting dsRNA into the thorax is illustrated.

Garver, Lindsey; Dimopoulos, George

2007-01-01

183

The Knowledge and Experience of Dengue Mosquitoes among Housewives.  

Directory of Open Access Journals (Sweden)

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

Atik Triratnawati

2011-06-01

184

Aspirator modification for the removal of mosquitoes from tight spaces.  

Science.gov (United States)

An insect aspirator was modified to remove mosquitoes that entered an animal-baited experimental cage within a cage. The modified aspirator is easy to maneuver inside tight spaces, powerful enough to aspirate mosquitoes but not remove scales or fluorescent marking powders, and will run continuously for at least 45 min. PMID:18240528

Kobylinski, Kevin C; Allan, Sandra A; Connelly, C Roxanne

2007-12-01

185

Integration without integration: New Killing spinor spacetimes  

Energy Technology Data Exchange (ETDEWEB)

Non-conformally flat spacetimes admitting a non-null two-index Killing spinor are investigated by means of the Geroch-Held-Penrose formalism. Claims appearing in the literature that such spacetimes are all explicitly known are incorrect. This was shown in [5] for the family where, in the canonical frame, the spin coefficients {rho} or {mu}, vanish. Here the general case with non-vanishing {rho}, {mu}, {pi} and {tau} is re-considered. It is shown that the construction in [4] hinges on the tacit assumption that certain integrability conditions hold, implying two algebraic relations for the spin coefficients and the components of the Ricci spinor. All (conformal classes of) spacetimes, in which one of these conditions is violated, are obtained by invariant integration. The resulting classes are each other's Sachs transform and are characterised by one free function. They admit in general no Killing vectors, but still admit a conformal gauge (different from the trivial unitary gauge) in which a Killing tensor exists.

Van den Bergh, Norbert, E-mail: norbert.vandenbergh@ugent.b [Department of Mathematical Analysis TW16, University of Ghent, Galglaan 2, Ghent (Belgium)

2010-05-01

186

Enhanced gentamicin killing of Escherichia coli by tet gene expression.  

OpenAIRE

Time-kill studies were performed to determine the effect of tetracycline resistance (tet) gene expression on gentamicin killing of Escherichia coli. Expression of tet increased gentamicin killing in laboratory strains and clinical isolates. A role for tetracycline in inducing tet expression and increasing the bactericidal activity of aminoglycosides is suggested.

Merlin, T. L.; Corvo, D. L.; Gill, J. H.; Griffith, J. K.

1989-01-01

187

UV light and urban pollution: Bad cocktail for mosquitoes?  

International Nuclear Information System (INIS)

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

188

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

189

Mosquito attractant blends to trap host seeking Aedes aegypti.  

Science.gov (United States)

Aedes aegypti is the key vector of three important arboviral diseases -dengue, yellow fever and chikungunya. To identify volatile chemicals which could be used in odour based traps for Aedes mosquito surveillance, a few synthetic compounds and compound blends have been evaluated in an indigenously designed olfactometer. A total of 24 compounds and seven compound blends were screened against unfed adult female Ae. aegypti mosquitoes for attraction and compared with control group. The attractancy or repellency index of the test material to mosquitoes was calculated and rated them as class-1, class-2 and class-3 with rating values ranging 1-15, 16-33 and 34-100 respectively. Out of the 24 compounds tested, six were showing significant attractancy (P?compounds showed significant repellency (P?repellent action against Ae. aegypti. All the seven blends showed significant mosquito attractancy (P?mosquito attractancy. PMID:23306388

Mathew, Nisha; Ayyanar, Elango; Shanmugavelu, Sabesan; Muthuswamy, Kalyanasundaram

2013-03-01

190

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)

191

Mosquito transmission of the rodent malaria parasite Plasmodium chabaudi  

Directory of Open Access Journals (Sweden)

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

Spence Philip J

2012-12-01

192

Field evaluation of herbal mosquito repellents.  

Science.gov (United States)

Repellent properties of Zanthoxylum armatum DC. Syn. Z. alatum Roxb. (Timur), Curcuma aromatica (Jungli haldi) and Azadirachta indica (Neem) oils were evaluated against mosquitoes in mustard (Brassica sp.) and coconut (Cocos sp.) oil base and compared with synthetic repellent. Dimethyl phthalate (DMP) as standard. Timur and jungli haldi afforded better protection in the both the base at all the concentrations. Tepellents in mustard oil gave longer protection time than those in coconut oil. At 0.57 mg/cm2 concentration timur oil gave significantly higher protection both in mustard (445 min) as well as coconut oil (404 min) than the other repellents and DMP. PMID:10937301

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

1999-12-01

193

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

194

Protocol for Plasmodium falciparum Infections in Mosquitoes and Infection Phenotype Determination  

OpenAIRE

Once a gene is identified as potentially refractory for malaria, it must be evaluated for its role in preventing Plasmodium infections within the mosquito. This protocol illustrates how the extent of plasmodium infections of mosquitoes can be assayed. The techniques for preparing the gametocyte culture, membrane feeding mosquitoes human blood, and assaying viral titers in the mosquito midgut are demonstrated.

Xi, Zhiyong; Das, Suchismita; Garver, Lindsey; Dimopoulos, George

2007-01-01

195

9 CFR 113.215 - Bovine Virus Diarrhea Vaccine, Killed Virus.  

Science.gov (United States)

... 2010-01-01 2010-01-01 false Bovine Virus Diarrhea Vaccine, Killed Virus. ...REQUIREMENTS Killed Virus Vaccines § 113.215 Bovine Virus Diarrhea Vaccine, Killed Virus. Bovine Virus Diarrhea Vaccine, Killed...

2010-01-01

196

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

197

Identification of mosquito repellent odours from Ocimum forskolei  

Directory of Open Access Journals (Sweden)

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

Glinwood Robert

2011-09-01

198

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)

199

Lorentzian Manifolds having the Killing Property  

Science.gov (United States)

We deal with a Lorentzian n-dimensional manifold M carrying two skew-symmetric Killing null vector fields ?1 and ?n. They define a commutative left invariant pairing. The (n - 2)-dimensional spatial distribution orthogonal to ?1 and ?n is involutive and its leaves are totally geodesic and pseudo-isotropic. If n = 4, then it is shown that the general space-time M is of type D in Petrov's classification and the spatial surfaces which foliate M are totally geodesic and pseudo-isotropic. Properties of the congruence of Debever are pointed-out.

Mihai, Adela

2012-06-01

200

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

201

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

OpenAIRE

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

202

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

OpenAIRE

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 rele...

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

2014-01-01

203

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

OpenAIRE

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

Ogoma Sheila B; Moore Sarah J; Maia Marta F

2012-01-01

204

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

205

Mosquito genomics. Highly evolvable malaria vectors: the genomes of 16 Anopheles mosquitoes.  

Science.gov (United States)

Variation in vectorial capacity for human malaria among Anopheles mosquito species is determined by many factors, including behavior, immunity, and life history. To investigate the genomic basis of vectorial capacity and explore new avenues for vector control, we sequenced the genomes of 16 anopheline mosquito species from diverse locations spanning ~100 million years of evolution. Comparative analyses show faster rates of gene gain and loss, elevated gene shuffling on the X chromosome, and more intron losses, relative to Drosophila. Some determinants of vectorial capacity, such as chemosensory genes, do not show elevated turnover but instead diversify through protein-sequence changes. This dynamism of anopheline genes and genomes may contribute to their flexible capacity to take advantage of new ecological niches, including adapting to humans as primary hosts. PMID:25554792

Neafsey, Daniel E; Waterhouse, Robert M; Abai, Mohammad R; Aganezov, Sergey S; Alekseyev, Max A; Allen, James E; Amon, James; Arcà, Bruno; Arensburger, Peter; Artemov, Gleb; Assour, Lauren A; Basseri, Hamidreza; Berlin, Aaron; Birren, Bruce W; Blandin, Stephanie A; Brockman, Andrew I; Burkot, Thomas R; Burt, Austin; Chan, Clara S; Chauve, Cedric; Chiu, Joanna C; Christensen, Mikkel; Costantini, Carlo; Davidson, Victoria L M; Deligianni, Elena; Dottorini, Tania; Dritsou, Vicky; Gabriel, Stacey B; Guelbeogo, Wamdaogo M; Hall, Andrew B; Han, Mira V; Hlaing, Thaung; Hughes, Daniel S T; Jenkins, Adam M; Jiang, Xiaofang; Jungreis, Irwin; Kakani, Evdoxia G; Kamali, Maryam; Kemppainen, Petri; Kennedy, Ryan C; Kirmitzoglou, Ioannis K; Koekemoer, Lizette L; Laban, Njoroge; Langridge, Nicholas; Lawniczak, Mara K N; Lirakis, Manolis; Lobo, Neil F; Lowy, Ernesto; MacCallum, Robert M; Mao, Chunhong; Maslen, Gareth; Mbogo, Charles; McCarthy, Jenny; Michel, Kristin; Mitchell, Sara N; Moore, Wendy; Murphy, Katherine A; Naumenko, Anastasia N; Nolan, Tony; Novoa, Eva M; O'Loughlin, Samantha; Oringanje, Chioma; Oshaghi, Mohammad A; Pakpour, Nazzy; Papathanos, Philippos A; Peery, Ashley N; Povelones, Michael; Prakash, Anil; Price, David P; Rajaraman, Ashok; Reimer, Lisa J; Rinker, David C; Rokas, Antonis; Russell, Tanya L; Sagnon, N'Fale; Sharakhova, Maria V; Shea, Terrance; Simão, Felipe A; Simard, Frederic; Slotman, Michel A; Somboon, Pradya; Stegniy, Vladimir; Struchiner, Claudio J; Thomas, Gregg W C; Tojo, Marta; Topalis, Pantelis; Tubio, José M C; Unger, Maria F; Vontas, John; Walton, Catherine; Wilding, Craig S; Willis, Judith H; Wu, Yi-Chieh; Yan, Guiyun; Zdobnov, Evgeny M; Zhou, Xiaofan; Catteruccia, Flaminia; Christophides, George K; Collins, Frank H; Cornman, Robert S; Crisanti, Andrea; Donnelly, Martin J; Emrich, Scott J; Fontaine, Michael C; Gelbart, William; Hahn, Matthew W; Hansen, Immo A; Howell, Paul I; Kafatos, Fotis C; Kellis, Manolis; Lawson, Daniel; Louis, Christos; Luckhart, Shirley; Muskavitch, Marc A T; Ribeiro, José M; Riehle, Michael A; Sharakhov, Igor V; Tu, Zhijian; Zwiebel, Laurence J; Besansky, Nora J

2015-01-01

206

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

207

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

208

New Brane Solutions from Killing Spinor Equations  

CERN Document Server

In a recent paper, we have pointed out a relation between the Killing spinor and Einstein equations. Using this relation, new brane solutions of D=11 and D=10 type IIB supergravity theories are constructed. It is shown that in a brane solution, the flat world-volume directions, the smeared transverse directions and the sphere located at a fixed radial distance can be replaced with any Lorentzian Ricci flat, Euclidean Ricci flat and Einstein manifolds, respectively. The solution obtained in this fashion is supersymmetric when the Ricci flat and Einstein manifolds have Killing spinors. We generalize intersecting brane solutions, in which M5, M2 and D3-branes also wrap over the cycles determined by the K\\"{a}hler forms of Ricci flat K\\"{a}hler manifolds. New, singular, Ricci flat manifolds as (generalized) cones over the U(1) bundles over Ricci flat K\\"{a}hler spaces are constructed. These manifolds have covariantly constant spinors and give rise to new, supersymmetric, Ricci flat compactifications of non-gauged...

Kaya, A

2000-01-01

209

New brane solutions from Killing spinor equations  

Science.gov (United States)

In a recent paper, we have pointed out a relation between the Killing spinor and Einstein equations. Using this relation, new brane solutions of D=11 and D=10 type IIB supergravity theories are constructed. It is shown that in a brane solution, the flat world-volume directions, the smeared transverse directions and the sphere located at a fixed radial distance can be replaced with any Lorentzian Ricci flat, Euclidean Ricci flat and Einstein manifolds, respectively. The solution obtained in this fashion is supersymmetric when the Ricci flat and Einstein manifolds have Killing spinors. We generalize intersecting brane solutions, in which M5-, M2- and D3-branes also wrap over the cycles determined by the Kähler forms of Ricci flat Kähler manifolds. New, singular, Ricci flat manifolds as (generalized) cones over the U(1) bundles over Ricci flat Kähler spaces are constructed. These manifolds have covariantly constant spinors and give rise to new, supersymmetric, Ricci flat compactifications of non-gauged supergravity theories. We find M2- and D3-brane solutions, which asymptotically approach these singular vacua.

Kaya, Ali

2000-09-01

210

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

Science.gov (United States)

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

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

2013-01-01

211

Novel flaviviruses detected in different species of mosquitoes in Spain.  

Science.gov (United States)

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

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

2012-03-01

212

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

213

Comparative repellency of 38 essential oils against mosquito bites.  

Science.gov (United States)

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

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

2005-04-01

214

Why Are Bad Products So Hard to Kill?  

OpenAIRE

It is puzzling that firms often continue to invest in product development projects when they should know that demand will be low. We argue that bad products are hard to kill because firms face an inherent conflict when designing managers' incentives. Rewarding success encourages managers to forge ahead even when demand is low. To avoid investing in low-demand products, the firm must also reward decisions to kill products. However, rewarding managers for killing products effectively undermines...

Simester, Duncan; Zhang, Juanjuan

2009-01-01

215

Murine Macrophages Kill the Vegetative Form of Bacillus anthracis  

Science.gov (United States)

Anti-protective antigen antibody was reported to enhance macrophage killing of ingested Bacillus anthracis spores, but it was unclear whether the antibody-mediated macrophage killing mechanism was directed against the spore itself or the vegetative form emerging from the ingested and germinating spore. To address this question, we compared the killing of germination-proficient (gp) and germination-deficient (?gerH) Sterne 34F2 strain spores by murine peritoneal macrophages. While macrophages similarly ingested both spores, only gp Sterne was killed at 5 h (0.37 log kill). Pretreatment of macrophages with gamma interferon (IFN-?) or opsonization with immunoglobulin G (IgG) isolated from a subject immunized with an anthrax vaccine enhanced the killing of Sterne to 0.49 and 0.73 log, respectively, but the combination of IFN-? and IgG was no better than either treatment alone. Under no condition was there killing of ?gerH spores. To examine the ability of the exosporium to protect spores from macrophages, we compared the macrophage-mediated killing of nonsonicated (exosporium+) and sonicated (exosporium?) Sterne 34F2 spores. More sonicated spores than nonsonicated spores were killed at 5 h (0.98 versus 0.37 log kill, respectively). Pretreatment with IFN-? increased the sonicated spore killing to 1.39 log. However, the opsonization with IgG was no better than no treatment or pretreatment with IFN-?. We conclude that macrophages appear unable to kill the spore form of B. anthracis and that the exosporium may play a role in the protection of spores from macrophages. PMID:16239551

Kang, Tae Jin; Fenton, Matthew J.; Weiner, Matthew A.; Hibbs, Stephen; Basu, Subhendu; Baillie, Les; Cross, Alan S.

2005-01-01

216

Targeted killing, unmanned aerial vehicles and EU policy  

OpenAIRE

This paper collects 7 expert memoranda prepared for the Global Governance Program's High-Level Policy Seminar on Targeted Killing, Unmanned Aerial Vehicles and EU Policy. In these memoranda, noted experts address the legality of the US policy of targeted killings under the international law of self-defence, international humanitarian law and international human rights law. Also addressed is the comparative example of Israel, and its legal framework regulating targeted killing. The concluding ...

Bhuta, Nehal; Kreß, Claus; Seiderman, Ian; Heyns, Christof; Melzer, Nils; Scheinin, Martin; Benvenisti, Eyal; Dworkin, Anthony

2013-01-01

217

Killing Symmetries in $\\mathcal{H}$-Spaces with $\\Lambda$  

CERN Document Server

All Killing symmetries in complex $\\mathcal{H}$-spaces with $\\Lambda$ in terms of the Pleba\\'nski - Robinson - Finley coordinate system are found. All $\\mathcal{H}$-metrics with $\\Lambda$ admitting a null Killing vector are explicitly given. It is shown that the problem of non-null Killing vector reduces to looking for solution of the Boyer - Finley - Pleba\\'nski (Toda field) equation

Chudecki, Adam

2013-01-01

218

Hidden symmetries and Killing tensors on curved spaces  

OpenAIRE

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 ...

Ianus, Stere; Visinescu, Mihai; Vilcu, Gabriel-eduard

2008-01-01

219

Alphavirus Transducing System: Tools for Visualizing Infection in Mosquito Vectors  

OpenAIRE

Alphavirus transducing systems (ATSs) are important tools for expressing genes of interest (GOI) during infection. ATSs are derived from cDNA clones of mosquito-borne RNA viruses (genus Alphavirus; family Togaviridae). The Alphavirus genus contains about 30 different mosquito-borne virus species. Alphaviruses are enveloped viruses and contain single-stranded RNA genomes (~11.7 Kb). Alphaviruses transcribe a subgenomic mRNA that encodes the structural proteins of the virus required for encap...

Phillips, Aaron; Mossel, Eric; Sanchez-vargas, Irma; Foy, Brian; Olson, Ken

2010-01-01

220

Semliki Forest virus strongly reduces mosquito host defence signaling  

OpenAIRE

The Alphavirus genus within the Togaviridae family contains several important mosquito-borne arboviruses. Other than the antiviral activity of RNAi, relatively little is known about alphavirus interactions with insect cell defences. Here we show that Semliki Forest virus (SFV) infection of Aedes albopictus-derived U4.4 mosquito cells reduces cellular gene expression. Activation prior to SFV infection of pathways involving STAT/IMD, but not Toll signaling reduced subseq...

Fragkoudis, R.; Siu, Rw; Chi, Y.; Barry, G.; Attarzadeh-yazdi, G.; Nash, Aa; Kohl, A.; Fazakerley, Jk; Merits, A.

2008-01-01

221

Composition of Human Skin Microbiota Affects Attractiveness to Malaria Mosquitoes  

OpenAIRE

The African malaria mosquito Anopheles gambiae sensu stricto continues to play an important role in malaria transmission, which is aggravated by its high degree of anthropophily, making it among the foremost vectors of this disease. In the current study we set out to unravel the strong association between this mosquito species and human beings, as it is determined by odorant cues derived from the human skin. Microbial communities on the skin play key roles in the production of human body odou...

Verhulst, N. O.; Qiu, Y. T.; Beijleveld, H.; Maliepaard, C. A.; Knights, D.; Schulz, S.; Berg-lyons, D.; Lauber, C. L.; Verduijn, W.; Haasnoot, G. W.; Mumm, R.; Bouwmeester, H. J.; Claas, F. H. J.; Dicke, M.; Loon, J. J. A.

2011-01-01

222

Malaria Mosquitoes Host-Locate and Feed upon Caterpillars  

OpenAIRE

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 evo...

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

2014-01-01

223

EFFICACY OF AGERATUM CONYZOIDES AGAINST THE CONTROL OF MOSQUITOES  

OpenAIRE

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

224

Wolbachia surface protein induces innate immune responses in mosquito cells  

OpenAIRE

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 na...

Pinto, Sb; Mariconti, M.; Bazzocchi, C.; Bandi, C.; Sinkins, Sp

2012-01-01

225

Hemocyte Differentiation Mediates Innate Immune Memory in Anopheles gambiae Mosquitoes  

OpenAIRE

Mosquito midgut invasion by ookinetes of the malaria parasite Plasmodium disrupts the barriers that normally prevent the gut microbiota from coming in direct contact with epithelial cells. This triggers a long-lived response characterized by increased abundance of granulocytes, a subpopulation of hemocytes, circulating in the insect’s hemocoel, and enhanced immunity to bacteria that indirectly reduces survival of Plasmodium parasites upon reinfection. In mosquitoes, differentiation of hemoc...

Rodrigues, Janneth; Brayner, Fa?bio Andre?; Alves, Luiz Carlos; Dixit, Rajnikant; Barillas-mury, Carolina

2010-01-01

226

Pesticides and public health: integrated methods of mosquito management.  

OpenAIRE

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

Rose, R. I.

2001-01-01

227

Taxis assays measure directional movement of mosquitoes to olfactory cues  

OpenAIRE

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

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

2013-01-01

228

Mosquitoes of Grand Teton National Park, Teton County, Wyoming, USA.  

Science.gov (United States)

An inventory of the mosquitoes of Grand Teton National Park and the John D. Rockefeller, Jr. Memorial Parkway was conducted during 1998 and 2000. Twenty-five culicid species belonging to 3 genera and 5 subgenera were recorded. This is the 1st substantive effort to record the mosquito fauna of this national park since its establishment in 1929. Collection of specimens of Ochlerotatus communis and Ochlerotatus nevadensis from the same larval site supports the species status of Oc. nevadensis. PMID:11804462

Moore, J P

2001-12-01

229

The Knowledge and Experience of Dengue Mosquitoes among Housewives.  

OpenAIRE

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 Sendan...

Atik Triratnawati; Aryani Pujiyanti

2011-01-01

230

Factors Influencing Stakeholders Attitudes Toward Genetically Modified Aedes Mosquito.  

Science.gov (United States)

Dengue fever is a debilitating and infectious disease that could be life-threatening. It is caused by the dengue virus which affects millions of people in the tropical area. Currently, there is no cure for the disease as there is no vaccine available. Thus, prevention of the vector population using conventional methods is by far the main strategy but has been found ineffective. A genetically modified (GM) mosquito is among the favoured alternatives to curb dengue fever in Malaysia. Past studies have shown that development and diffusion of gene technology products depends heavily upon public acceptance. The purpose of this study is to identify the relevant factors influencing stakeholders' attitudes toward the GM Aedes mosquito and to analyse the relationships between all the factors using the structural equation model. A survey was carried out on 509 respondents from various stakeholder groups in the Klang Valley region of Malaysia. Results of the survey have confirmed that public perception towards complex issues such as gene technology should be seen as a multi-faceted process. The perceived benefit-perceived risk balance is very important in determining the most predominant predictor of attitudes toward a GM mosquito. In this study the stakeholders perceived the benefit of the GM mosquito as outweighing its risk, translating perceived benefit as the most important direct predictor of attitudes toward the GM mosquito. Trust in key players has a direct influence on attitudes toward the GM mosquito while moral concern exhibited an indirect influence through perceived benefits. Other factors such as attitudes toward technology and nature were also indirect predictors of attitudes toward the GM mosquito while religiosity and engagement did not exhibited any significant roles. The research findings serve as a useful database to understand public acceptance and the social construct of public attitudes towards the GM mosquito to combat dengue. PMID:24906652

Amin, Latifah; Hashim, Hasrizul

2014-06-01

231

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

232

Mosquito (Diptera: Culicidae Fauna of Qom Province, Iran  

Directory of Open Access Journals (Sweden)

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

A Saghafipour

2012-06-01

233

Insecticide resistance in mosquitoes: impact, mechanisms, and research directions.  

Science.gov (United States)

Mosquito-borne diseases, the most well known of which is malaria, are among the leading causes of human deaths worldwide. Vector control is a very important part of the global strategy for management of mosquito-associated diseases, and insecticide application is the most important component in this effort. However, mosquito-borne diseases are now resurgent, largely because of the insecticide resistance that has developed in mosquito vectors and the drug resistance of pathogens. A large number of studies have shown that multiple, complex resistance mechanisms-in particular, increased metabolic detoxification of insecticides and decreased sensitivity of the target proteins-or genes are likely responsible for insecticide resistance. Gene overexpression and amplification, and mutations in protein-coding-gene regions, have frequently been implicated as well. However, no comprehensive understanding of the resistance mechanisms or regulation involved has yet been developed. This article reviews current knowledge of the molecular mechanisms, genes, gene interactions, and gene regulation governing the development of insecticide resistance in mosquitoes and discusses the potential impact of the latest research findings on the basic and practical aspects of mosquito resistance research. PMID:25564745

Liu, Nannan

2015-01-01

234

Discovery of Mosquito Saliva MicroRNAs during CHIKV Infection.  

Science.gov (United States)

Mosquito borne pathogens are transmitted to humans via saliva during blood feeding. Mosquito saliva is a complex concoction of many secretory factors that modulate the feeding foci to enhance pathogen infection and establishment. Multiple salivary proteins/factors have been identified/characterized that enhance pathogen infection. Here, we describe, for the first time, the identification of exogenous microRNAs from mosquito saliva. MicroRNAs are short, 18-24 nucleotide, non-coding RNAs that regulate gene expression, and are generally intracellular. However, circulating miRNAs have been described from serum and saliva of humans. Exogenous miRNAs have not been reported from hematophagous arthropod saliva. We sought to identify miRNAs in the mosquito saliva and their role in Chikungunya virus (CHIKV) infection. Next generation sequencing was utilized to identify 103 exogenous miRNAs in mosquito saliva of which 31 miRNAs were previously unidentified and were designated novel. Several miRNAs that we have identified are expressed only in the CHIKV infected mosquitoes. Five of the saliva miRNAs were tested for their potential to regulated CHIKV infection, and our results demonstrate their functional role in the transmission and establishment of infection during blood feeding on the host. PMID:25612225

Maharaj, Payal D; Widen, Steven G; Huang, Jing; Wood, Thomas G; Thangamani, Saravanan

2015-01-01

235

Species Composition and Relative Abundance of Mosquitoes in Swat, Pakistan  

Directory of Open Access Journals (Sweden)

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

236

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

237

Crustacean biodiversity as an important factor for mosquito larval control.  

Science.gov (United States)

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

Kroeger, Iris; Duquesne, Sabine; Liess, Matthias

2013-12-01

238

Discovery of Mosquito Saliva MicroRNAs during CHIKV Infection  

Science.gov (United States)

Mosquito borne pathogens are transmitted to humans via saliva during blood feeding. Mosquito saliva is a complex concoction of many secretory factors that modulate the feeding foci to enhance pathogen infection and establishment. Multiple salivary proteins/factors have been identified/characterized that enhance pathogen infection. Here, we describe, for the first time, the identification of exogenous microRNAs from mosquito saliva. MicroRNAs are short, 18–24 nucleotide, non-coding RNAs that regulate gene expression, and are generally intracellular. However, circulating miRNAs have been described from serum and saliva of humans. Exogenous miRNAs have not been reported from hematophagous arthropod saliva. We sought to identify miRNAs in the mosquito saliva and their role in Chikungunya virus (CHIKV) infection. Next generation sequencing was utilized to identify 103 exogenous miRNAs in mosquito saliva of which 31 miRNAs were previously unidentified and were designated novel. Several miRNAs that we have identified are expressed only in the CHIKV infected mosquitoes. Five of the saliva miRNAs were tested for their potential to regulated CHIKV infection, and our results demonstrate their functional role in the transmission and establishment of infection during blood feeding on the host. PMID:25612225

Maharaj, Payal D.; Widen, Steven G.; Huang, Jing; Wood, Thomas G.; Thangamani, Saravanan

2015-01-01

239

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

Directory of Open Access Journals (Sweden)

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

Harris Anthony

2007-01-01

240

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

Directory of Open Access Journals (Sweden)

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

Raúl Ernesto Campos

2003-03-01

241

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

Scientific Electronic Library Online (English)

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

Raúl, Ernesto Campos; Victoria Elena, Sy.

2003-03-01

242

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

243

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

244

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

245

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

246

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

2014-11-01

247

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

248

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

249

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

Energy Technology Data Exchange (ETDEWEB)

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 /sup 3/H-thymidine and the unassociated bacteria removed by two centrifugations through a density interface. Both cell-associated radioactivity and cell-associated viable bacteria, determined as colony forming units after sonication of the cell pellet, increased with time of incubation. However, the specific viability of these bacteria, expressed as the ratio of number of viable bacteria per unit radioactivity declined with time, as an approximate inverse exponential, after a lag period of 2.9 +/- 0.8 min. Evidence is given that other possible causes for this decline in specific viability, other than death of the bacteria, such as preferential ingestion of dead Listeria, clumping of bacteria, variations in autolytic activity, or release of Listericidins are unlikely. I conclude therefore that activated macrophages kill Listeria approximately 3 min after the cell and the bacterium first make contact.

Davies, W.A.

1983-08-01

250

Mosquito immune responses and compatibility between Plasmodium parasites and anopheline mosquitoes  

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Full Text Available Abstract Background Functional screens based on dsRNA-mediated gene silencing identified several Anopheles gambiae genes that limit Plasmodium berghei infection. However, some of the genes identified in these screens have no effect on the human malaria parasite Plasmodium falciparum; raising the question of whether different mosquito effector genes mediate anti-parasitic responses to different Plasmodium species. Results Four new An. gambiae (G3 genes were identified that, when silenced, have a different effect on P. berghei (Anka 2.34 and P. falciparum (3D7 infections. Orthologs of these genes, as well as LRIM1 and CTL4, were also silenced in An. stephensi (Nijmegen Sda500 females infected with P. yoelii (17XNL. For five of the six genes tested, silencing had the same effect on infection in the P. falciparum-An. gambiae and P. yoelii-An. stephensi parasite-vector combinations. Although silencing LRIM1 or CTL4 has no effect in An. stephensi females infected with P. yoelii, when An. gambiae is infected with the same parasite, silencing these genes has a dramatic effect. In An. gambiae (G3, TEP1, LRIM1 or LRIM2 silencing reverts lysis and melanization of P. yoelii, while CTL4 silencing enhances melanization. Conclusion There is a broad spectrum of compatibility, the extent to which the mosquito immune system limits infection, between different Plasmodium strains and particular mosquito strains that is mediated by TEP1/LRIM1 activation. The interactions between highly compatible animal models of malaria, such as P. yoelii (17XNL-An. stephensi (Nijmegen Sda500, is more similar to that of P. falciparum (3D7-An. gambiae (G3.

Molina-Cruz Alvaro

2009-07-01

251

7 CFR 29.1018 - Fire-killed.  

Science.gov (United States)

...2010-01-01 2010-01-01 false Fire-killed. 29.1018 Section 29.1018 Agriculture Regulations of the Department of Agriculture...Types 11, 12, 13, 14 and Foreign Type 92) § 29.1018 Fire-killed. Any leaf of which 5...

2010-01-01

252

Phagocytosis and Killing of Francisella tularensis by Human Polymorphonuclear Leukocytes  

OpenAIRE

Bacteria of a wild strain of Francisella tularensis were less efficiently killed by human polymorphonuclear leukocytes than were bacteria of an attenuated strain. This finding was explained to some extent by a less efficient phagocytosis, but bacteria of the wild strain also seemed to be more resistant to killing after ingestion.

Lo?fgren, Sture; Ta?rnvik, Arne; Bloom, Gunnar D.; Sjo?berg, Wigert

1983-01-01

253

Control of Influenza and Poliomyelitis with Killed Virus Vaccines  

Science.gov (United States)

Discusses control of poliomyelitis and influenza by live and killed virus vaccines. Considered are the etiological agents, pathogenic mechanisms and epidemiology of each disease. Reviews recent scientific studies of the diseases. Recommends use of killed virus vaccines in controlling both diseases. (CS)

Salk, Jonas; Salk, Darrell

1977-01-01

254

Microwave irradiation for rapid killing and fixing of plant tissue  

Energy Technology Data Exchange (ETDEWEB)

Irradiation by microwaves allows for rapid killing and fixing of plant tissue, with excellent cellular integrity for histological examination. One or two exposures to microwaves for three seconds in formalin/acetic acid/alcohol gave good preservation of nuclei, chloroplasts, and other plant structures. The microwave method offers a considerable saving of time over traditional methods for killing and fixing plant tissue.

Walsh, G.E.; Bohannon, P.M.; Wessinger-Duvall, P.B.

1989-01-01

255

Killing of Bacteria by Copper Surfaces Involves Dissolved Copper?  

OpenAIRE

Bacteria are rapidly killed on copper surfaces. However, the mechanism of this process remains unclear. Using Enterococcus hirae, the effect of inactivation of copper homeostatic genes and of medium compositions on survival and copper dissolution was tested. The results support a role for dissolved copper ions in killing.

Molteni, Cristina; Abicht, Helge K.; Solioz, Marc

2010-01-01

256

Potency of killed plague vaccines prepared from avirulent Yersinia pestis*  

OpenAIRE

Killed plague vaccines prepared from avirulent strains A1122 and EV76S of Yersinia pestis were more effective in mouse potency tests than samples of Plague Vaccine, USP, prepared from killed Y. pestis of the virulent strain 195/P. Manufacture of vaccine from avirulent Y. pestis would obviate requirements for the large containment facilities that are currently needed for producing Plague Vaccine, USP.

Williams, James E.; Altieri, Patricia L.; Berman, Sanford; Lowenthal, Joseph P.; Cavanaugh, Dan C.

1980-01-01

257

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

OpenAIRE

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

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

2012-01-01

258

Mechanisms of Dendritic Cell Lysosomal Killing of Cryptococcus  

Science.gov (United States)

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

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

2012-10-01

259

Surveillance of Zoonotic Infectious Disease Transmitted by Small Companion Animals  

OpenAIRE

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

260

Is Creutzfeldt-Jakob disease transmitted in blood?  

OpenAIRE

Creutzfeldt-Jakob disease (CJD) has been considered infectious since the mid-1960s, but its transmissibility through the transfusion of blood or blood products is controversial. The causative agent's novel undefined nature and resistance to standard decontamination, the absence of a screening test, and the recognition that even rare cases of transmission may be unacceptable have led to the revision of policies and procedures worldwide affecting all facets of blood product manufacturing from b...

Ricketts, M. N.; Cashman, N. R.; Stratton, E. E.; Elsaadany, S.

1997-01-01

261

Checklist of Iranian mosquitoes (Diptera: Culicidae).  

Science.gov (United States)

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

Azari-Hamidian, Shahyad

2007-12-01

262

Novel innate cancer killing activity in humans  

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

Lovato James

2011-08-01

263

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

Science.gov (United States)

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

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

2013-01-01

264

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

265

Identification of Belgian mosquito species (Diptera: Culicidae) by DNA barcoding.  

Science.gov (United States)

Since its introduction in 2003, DNA barcoding has proven to be a promising method for the identification of many taxa, including mosquitoes (Diptera: Culicidae). Many mosquito species are potential vectors of pathogens, and correct identification in all life stages is essential for effective mosquito monitoring and control. To use DNA barcoding for species identification, a reliable and comprehensive reference database of verified DNA sequences is required. Hence, DNA sequence diversity of mosquitoes in Belgium was assessed using a 658 bp fragment of the mitochondrial cytochrome oxidase I (COI) gene, and a reference data set was established. Most species appeared as well-supported clusters. Intraspecific Kimura 2-parameter (K2P) distances averaged 0.7%, and the maximum observed K2P distance was 6.2% for Aedes koreicus. A small overlap between intra- and interspecific K2P distances for congeneric sequences was observed. Overall, the identification success using best match and the best close match criteria were high, that is above 98%. No clear genetic division was found between the closely related species Aedes annulipes and Aedes cantans, which can be confused using morphological identification only. The members of the Anopheles maculipennis complex, that is Anopheles maculipennis s.s. and An. messeae, were weakly supported as monophyletic taxa. This study showed that DNA barcoding offers a reliable framework for mosquito species identification in Belgium except for some closely related species. PMID:25143182

Versteirt, V; Nagy, Z T; Roelants, P; Denis, L; Breman, F C; Damiens, D; Dekoninck, W; Backeljau, T; Coosemans, M; Van Bortel, W

2015-03-01

266

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

OpenAIRE

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

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

2012-01-01

267

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

OpenAIRE

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

Churcher, Thomas S.; Bousema, Teun; Walker, Martin; Drakeley, Chris; Schneider, Petra; Oue?draogo, Andre? Lin; Basa?n?ez, Mari?a-gloria

2013-01-01

268

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

269

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.

270

Biosynthesis of 130-kilodalton mosquito larvicide in the cyanobacterium Agmenellum quadruplicatum PR-6.  

OpenAIRE

The 130-kilodalton mosquito larvicidal gene, cloned from Bacillus thuringiensis var. israelensis, was introduced into the cyanobacterium Agmenellum quadruplicatum PR-6 by plasmid transformation. Transformed cells synthesized 130-kilodalton delta-endotoxin protein and showed mosquito larvicidal activity. Results demonstrate a potential use of a cyanobacterium for biological control of mosquitoes.

Angsuthanasombat, C.; Panyim, S.

1989-01-01

271

Biosynthesis of 130-kilodalton mosquito larvicide in the cyanobacterium Agmenellum quadruplicatum PR-6.  

Science.gov (United States)

The 130-kilodalton mosquito larvicidal gene, cloned from Bacillus thuringiensis var. israelensis, was introduced into the cyanobacterium Agmenellum quadruplicatum PR-6 by plasmid transformation. Transformed cells synthesized 130-kilodalton delta-endotoxin protein and showed mosquito larvicidal activity. Results demonstrate a potential use of a cyanobacterium for biological control of mosquitoes. PMID:2552921

Angsuthanasombat, C; Panyim, S

1989-09-01

272

Potassium channels mediate killing by human natural killer cells  

International Nuclear Information System (INIS)

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. Using the whole-cell variation of the patch-clamp technique, the authors 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+. They 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 wo 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. The findings show that there are K channels in NK cells and that these channels play a necessary role in the killing process

273

Did Vertigo Kill America's Forgotten Astronaut?  

Science.gov (United States)

On November 15, 1967, U.S. Air Force test pilot Major Michael J. Adams was killed while flying the X-15 rocket-propelled research vehicle in a parabolic spaceflight profile. This flight was part of a joint effort with NASA. An electrical short in one of the experiments aboard the vehicle caused electrical transients, resulting in excessive workload by the pilot. At altitude Major Adams inappropriately initiated a flat spin that led to a series of unusual aircraft attitudes upon atmospheric re-entry, ultimately causing structural failure of the airframe. Major Adams was known to experience vertigo (i.e. spatial disorientation) while flying the X-15, but all X-15 pilots most likely experienced vertigo (i.e. somatogravic, or "Pitch-Up", illusion) as a normal physiologic response to the accelerative forces involved. Major Adams probably experienced vertigo to a greater degree than did others, since prior aeromedical testing for astronaut selection at Brooks AFB revealed that he had an unusually high degree of labyrinthine sensitivity. Subsequent analysis reveals that after engine burnout, and through the zenith of the flight profile, he likely experienced the oculoagravic ("Elevator") illusion. Nonetheless, painstaking investigation after the mishap revealed that spatial disorientation (Type II, Recognized) was NOT the cause, but rather, a contributing factor. The cause was in fact the misinterpretation of a dual-use flight instrument (i.e. Loss of Mode Awareness), resulting in confusion between yaw and roll indications, with subsequent flight control input that was inappropriate. Because of the altitude achieved on this flight, Major Adams was awarded Astronaut wings posthumously. Understanding the potential for spatial disorientation, particularly the oculoagravic illusion, associated with parabolic spaceflight profiles, and understanding the importance of maintaining mode awareness in the context of automated cockpit design, are two lessons that have direct application to the commercial space industry today.

Bendrick, Gregg A.; Merlin, Peter W.

2007-01-01

274

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

275

Control of mosquito breeding through Gambusia affinis in rice fields.  

Science.gov (United States)

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

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

1993-06-01

276

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

277

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

278

Special Killing forms on toric Sasaki–Einstein manifolds  

Science.gov (United States)

In this paper we study the interplay between complex coordinates on the Calabi–Yau metric cone and the special Killing forms on the toric Sasaki–Einstein manifold. First, we give a procedure to locally construct the special Killing forms. Finally, we exemplify the general scheme in the case of the five-dimensional {{Y}p,q} spaces, identifying the additional special Killing 2-forms which were previously obtained using a different method by Visinescu (2012 Mod. Phys. Lett. A 27 1250217).

Slesar, Vladimir; Visinescu, Mihai; Vîlcu, Gabriel Eduard

2014-12-01

279

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

280

9 CFR 113.200 - General requirements for killed virus vaccines.  

Science.gov (United States)

...General requirements for killed virus vaccines. 113.200 Section 113.200 ...STANDARD REQUIREMENTS Killed Virus Vaccines § 113.200 General requirements for killed virus vaccines. When prescribed in an...

2010-01-01

281

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

282

Native microbiome impedes vertical transmission of Wolbachia in Anopheles mosquitoes.  

Science.gov (United States)

Over evolutionary time, Wolbachia has been repeatedly transferred between host species contributing to the widespread distribution of the symbiont in arthropods. For novel infections to be maintained, Wolbachia must infect the female germ line after being acquired by horizontal transfer. Although mechanistic examples of horizontal transfer exist, there is a poor understanding of factors that lead to successful vertical maintenance of the acquired infection. Using Anopheles mosquitoes (which are naturally uninfected by Wolbachia) we demonstrate that the native mosquito microbiota is a major barrier to vertical transmission of a horizontally acquired Wolbachia infection. After injection into adult Anopheles gambiae, some strains of Wolbachia invade the germ line, but are poorly transmitted to the next generation. In Anopheles stephensi, Wolbachia infection elicited massive blood meal-induced mortality, preventing development of progeny. Manipulation of the mosquito microbiota by antibiotic treatment resulted in perfect maternal transmission at significantly elevated titers of the wAlbB Wolbachia strain in A. gambiae, and alleviated blood meal-induced mortality in A. stephensi enabling production of Wolbachia-infected offspring. Microbiome analysis using high-throughput sequencing identified that the bacterium Asaia was significantly reduced by antibiotic treatment in both mosquito species. Supplementation of an antibiotic-resistant mutant of Asaia to antibiotic-treated mosquitoes completely inhibited Wolbachia transmission and partly contributed to blood meal-induced mortality. These data suggest that the components of the native mosquito microbiota can impede Wolbachia transmission in Anopheles. Incompatibility between the microbiota and Wolbachia may in part explain why some hosts are uninfected by this endosymbiont in nature. PMID:25114252

Hughes, Grant L; Dodson, Brittany L; Johnson, Rebecca M; Murdock, Courtney C; Tsujimoto, Hitoshi; Suzuki, Yasutsugu; Patt, Alyssa A; Cui, Long; Nossa, Carlos W; Barry, Rhiannon M; Sakamoto, Joyce M; Hornett, Emily A; Rasgon, Jason L

2014-08-26

283

Plasmodium knowlesi in humans, macaques and mosquitoes in peninsular Malaysia  

Directory of Open Access Journals (Sweden)

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

NorParina Ismail

2008-08-01

284

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

285

Laser-diffraction characterization of flat-fan nozzles used to develop aerosol clouds of aerially applied mosquito adulticides.  

Science.gov (United States)

The importance of appropriate drop size and density for successful mosquito adulticide applications mandates the necessity for accurate determination of drop spectra of a particular nozzle. There is considerable disparity between mass median diameter (MMD) determinations for flat-fan nozzles relative to the horizontal or vertical orientation of the microscope slide used to collect the drops. To remove this ambiguity, the definitive MMDs of flat-fan nozzles used in aerially applied mosquito control adulticides were determined by laser-diffraction-based characterization and analysis. These data were compared with previous data, and the impact of these data on aerial adult mosquito control was discussed. At The Florida Wind Tunnel for Mosquito Control, the Malvern Spraytec Spray Particle Analysis System was used to characterize the entire aerosol plume of the nozzles. Nozzle characterizations were carried out at aircraft operational wind speeds and pressures with nozzles mounted at 135 degrees relative to the direction of air flow. The mean drop-diameter volumes (Dv) Dv(0.1), Dv(0.5), and Dv(0.9) with 95% confidence intervals for each scenario were determined. Characterizations of flat-fan nozzles of 80005 to 8005 for Orchex 796, Dibrom and a Permanone:Orchex 796 mix (1:1) resulted in no Dv(0.5) less than 50 microm and a maximum of 133 microm. The Dv(0.1) was greater than 25 min for 52% of the nozzles and ranged from 14 to 42 microm. The Dv(0.9) ranged from 130 to 296 microm. There was a decrease in drop-diameter values (Dv(0.1), Dv(0.5), Dv(0.9)) relative to increased wind speed and/or pressure for any particular nozzle. Relative to characterizations with Orchex 796, drop-diameter values for Dibrom varied from the same to slightly larger, whereas the Permanone:Orchex 796 mix values were larger except for 2. Relative to the goal of creating an aerosol cloud efficient in controlling adult mosquitoes, none of the nozzles were capable of producing a Dv(0.5) of less than 50 microm. Fifty percent of the spray was capable of causing visible damage to a car's finish. The concept that droplets larger than 25 microm are wasteful because they contain more malathion than required for kill suggests that for 52% of the nozzle configurations, those with Dv(0.1) greater than 25 microm, 90% of the spray is of little use in controlling mosquitoes. None of the flat-fan nozzle regimes tested will satisfy new label requirements of a Dv(0.5) and Dv(0.9) of around 50 and 100 microm, respectively, because of their high Dv(0.9). PMID:17304940

Hornby, Jonathan A; Robinson, Jim; Opp, William; Sterling, Milton

2006-12-01

286

On the Lie subalgebra of Killing-Milne and Killing-Cartan vector fields in Newtonian space-time  

CERN Document Server

The Galilean (and more generally Milne) invariance of Newtonian theory allows for Killing vector fields of a general kind, whereby the Lie derivative of a field is not required to vanish but only to be cancellable by some infinitesimal Galilean (respectively Milne) gauge transformation. In this paper, it is shown that both the Killing-Milne vector fields, which preserve the background Newtonian space-time structure, and the Killing-Cartan vector fields, which in addition preserve the gravitational field, form a Lie subalgebra.

Chamel, N

2014-01-01

287

Surface structure influences contact killing of bacteria by copper.  

Science.gov (United States)

Copper kills bacteria rapidly by a mechanism that is not yet fully resolved. The antibacterial property of copper has raised interest in its use in hospitals, in place of plastic or stainless steel. On the latter surfaces, bacteria can survive for days or even weeks. Copper surfaces could thus provide a powerful accessory measure to curb nosocomial infections. We here investigated the effect of the copper surface structure on the efficiency of contact killing of Escherichia coli, an aspect which so far has received very little attention. It was shown that electroplated copper surfaces killed bacteria more rapidly than either polished copper or native rolled copper. The release of ionic copper was also more rapid from electroplated copper compared to the other materials. Scanning electron microscopy revealed that the bacteria nudged into the grooves between the copper grains of deposited copper. The findings suggest that, in terms of contact killing, more efficient copper surfaces can be engineered. PMID:24740976

Zeiger, Marco; Solioz, Marc; Edongué, Hervais; Arzt, Eduard; Schneider, Andreas S

2014-06-01

288

9 CFR 113.216 - Bovine Rhinotracheitis Vaccine, Killed Virus.  

Science.gov (United States)

...Rhinotracheitis Vaccine, Killed Virus. 113.216 Section...Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE...DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS...bovine rhinotracheitis virus furnished or approved by the Animal and Plant Health Inspection...

2010-01-01

289

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

Science.gov (United States)

...Parvovirus Vaccine, Killed Virus (Canine). 113...Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE...DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS...50 to 300 TCID50 of virus shall be used. Dogs...acceptable to Animal and Plant Health Inspection...

2010-01-01

290

9 CFR 113.212 - Bursal Disease Vaccine, Killed Virus.  

Science.gov (United States)

...Disease Vaccine, Killed Virus. 113.212 Section...Products ANIMAL AND PLANT HEALTH INSPECTION...DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS...infectious bursal disease virus furnished or approved by Animal and Plant Health...

2010-01-01

291

9 CFR 113.211 - Feline Rhinotracheitis Vaccine, Killed Virus.  

Science.gov (United States)

...Rhinotracheitis Vaccine, Killed Virus. 113.211 Section...Products ANIMAL AND PLANT HEALTH INSPECTION...DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS...feline rhinotracheitis virus furnished or approved by Animal and Plant Health...

2010-01-01

292

9 CFR 113.213 - Pseudorabies Vaccine, Killed Virus.  

Science.gov (United States)

...Pseudorabies Vaccine, Killed Virus. 113.213 Section...Products ANIMAL AND PLANT HEALTH INSPECTION...DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS...virulent pseudorabies virus furnished or approved by Animal and Plant Health...

2010-01-01

293

Scratch from Pet Rat Kills Child; CDC Warns of Risk  

Science.gov (United States)

... please enable JavaScript. Scratch From Pet Rat Kills Child; CDC Warns of Risk 'Rat-bite fever' also ... 18 issue of the CDC journal Morbidity and Mortality Weekly Report . SOURCE: Morbidity and Mortality Weekly Report , ...

294

Killing superalgebra deformations of ten-dimensional supergravity backgrounds  

International Nuclear Information System (INIS)

We explore Lie superalgebra deformations of the Killing superalgebras of some ten-dimensional supergravity backgrounds. We prove the rigidity of the Poincare superalgebras in types I, IIA and IIB, as well as of the Killing superalgebra of the Freund-Rubin vacuum of type IIB supergravity. We also prove rigidity of the Killing superalgebras of the NS5-, D0-, D3-, D4- and D5-branes, whereas we exhibit the possible deformations of the D1-, D2-, D6- and D7-brane Killing superalgebras, as well as of that of the type II fundamental string solutions. We relate the superalgebra deformations of the D2- and D6-branes to those of the (delocalized) M2-brane and the Kaluza-Klein monopole, respectively. The good behaviour under Kaluza-Klein reduction suggests that the deformed superalgebras ought to have a geometric interpretation

295

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

296

The Variety of Integrable Killing Tensors on the 3-Sphere  

Science.gov (United States)

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 Stäckel 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

2014-07-01

297

Mosquito larvicidal activity of active constituent derived from Chamaecyparis obtusa leaves against 3 mosquito species.  

Science.gov (United States)

Mosqutio larvicidal activity of Chamaecyparis obtusa leaf-derived materials against the 4th-stage larvae of Aedes aegypti (L.), Ochlerotatus togoi (Theobald), and Culex pipiens pallens (Coquillett) was examined in the laboratory. A crude methanol extract of C. obtusa leaves was found to be active (percent mortality rough) against the 3 species larvae; the hexane fraction of the methanol extract showed a strong larvicidal activity (100% mortality) at 100 ppm. The bioactive component in the C. obtusa leaf extract was characterized as beta-thujaplicin by spectroscopic analyses. The LC50 value of beta-thujaplicin was 2.91, 2.60, and 1.33 ppm against Ae. aegypti, Oc. togoi, and Cx. pipiens pallens larvae. This naturally occurring C. obtusa leaves-derived compound merits further study as a potential mosquito larval control agent or lead compound. PMID:16506565

Jang, Young-Su; Jeon, Ju-Hyun; Lee, Hoi-Seon

2005-12-01

298

Diphtheria toxin mutant selectively kills cerebellar Purkinje neurons.  

OpenAIRE

CRM107 (crossreacting material 107), a double point mutant of diphtheria toxin that lacks receptor-binding activity, specifically kills cerebellar Purkinje cells in vivo. After injection into guinea pig cerebrospinal fluid, CRM107 (0.9 micrograms) and CRM107-monoclonal antibody conjugates (10 micrograms) kill up to 90% of the total Purkinje cell population with no detectable toxicity to other neurons. Animals exhibit ataxia, tremor, and abnormalities of posture and tone. Native diphtheria tox...

Riedel, C. J.; Muraszko, K. M.; Youle, R. J.

1990-01-01

299

Locally convex surfaces immersed in a Killing submersion  

CERN Document Server

We generalize Hadamard-Stoker-Currier Theorems for surfaces immersed in a Killing submersion over a strictly Hadamard surface whose fibers are the trajectories of a unit Killing field. We prove that every complete surface whose principal curvatures are greater than a certain function (depending on the ambient manifold) at each point, must be properly embedded, homeomorphic to the sphere or to the plane and, in the latter case, we study the behavior of the end.

Espinar, Jose M

2010-01-01

300

The Killing-Yano equation on Lie groups  

Science.gov (United States)

In this paper we study 2-forms which are solutions of the Killing-Yano equation on Lie groups endowed with a left invariant metric having various curvature properties. We prove a general result for 2-step nilpotent Lie groups and as a corollary we obtain a nondegenerate solution of the Killing-Yano equation on the Iwasawa manifold with its half-flat metric.

Barberis, M. L.; Dotti, I. G.; Santillán, O.

2012-03-01

301

The Killing-Yano equation on Lie groups  

International Nuclear Information System (INIS)

In this paper we study 2-forms which are solutions of the Killing-Yano equation on Lie groups endowed with a left invariant metric having various curvature properties. We prove a general result for 2-step nilpotent Lie groups and as a corollary we obtain a nondegenerate solution of the Killing-Yano equation on the Iwasawa manifold with its half-flat metric. (paper)

302

On Killing vectors and harmonic vectors at quantization of gravitation  

International Nuclear Information System (INIS)

Attention is paid to two shortcomings occuring at quantization in the curved spacetime: mathematical shortcoming consisting in the killing vector absence in arbitrary Riemann space and physical one consisting in absence of energy-momentum tensor of the gravitational field. It is shown, that both shortcomings may be removed, if the killing vectors are replaced by harmonic vectors corresponding to shift generators of the Poincare group existing in arbitrary Riemann space

303

Anaerobic Killing of Oral Streptococci by Reduced, Transition Metal Cations  

OpenAIRE

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

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

1998-01-01

304

Monocytes in inflammatory bowel disease: phagocytosis and intracellular killing.  

OpenAIRE

The ability of peripheral blood monocytes from patients with ulcerative colitis and Crohn's disease to phagocytose and kill a standard strain of Staphyloccus aureus has been studied. Using lysostaphin, a rapidly acting muralytic enzyme, phagocytosis could be accurately differentiated from intracellular killing. When compared with normal healthy individuals and patients with gastrointestinal diseases not thought to be immunologically mediated, monocytes from patients with inflammatory bowel di...

Mee, As; Szawatakowski, M.; Jewell, Dp

1980-01-01

305

Population dynamics of tree-killing bark beetles  

OpenAIRE

During outbreak periods, the European spruce bark beetle and the North American mountain pine beetle are able to kill millions of coniferous trees. Throughout the 20th century, six outbreaks have occurred in Sweden and four in British Columbia, with about 20-year intervals in both regions. The outbreaks of the mountain pine beetles seem to grow much larger and last longer compared to the outbreaks of the spruce bark beetles. Over the years, the mountain pine beetle has killed about 60 million...

Ka?rvemo, Simon

2010-01-01

306

Snail-Killing Effects of Streptomyces 218 Powder  

OpenAIRE

This study is aimed at finding out the snail-killing effects of Streptomyces 218 powder on Oncomelania hupensis snails which are the vectors or intermediate host of Schiltosoma Japonicum (intestinal schistosomiasis) in china the tests were carried out in the laboratory and on the field. The snail-killing effects of Streptomyces218 powder, isolated from snail habitat at Anchang Village of Anxiang country in China was tested using the immersion and spraying methods. The tests on the Oncomelania...

Aina, V. O.; Adewumi, A. A. J.; Yao, C. O.; Shi, M. Z.; Hu, D. Y.; Chai, W. H.

2012-01-01

307

Does Japanese encephalitis virus share the same cellular receptor with other mosquito-borne flaviviruses on the C6/36 mosquito cells?  

OpenAIRE

Abstract Japanese encephalitis virus (JEV) is a member of mosquito-borne Flaviviridae. To date, the mechanisms of the early events of JEV infection remain poorly understood, and the cellular receptors are unidentified. There are evidences that the structure of the virus attachment proteins (VAP), envelope glycoprotein of mosquito-borne flaviviruses is very similar, and the vector-virus interaction of mosquito-borne flaviviruses is also very similar. Based on the studies pre...

Song Jianhua; Zhang Wei; Ding Tianbing; Ren Junping; Ma Wenyu

2007-01-01

308

Optimización de un procedimiento de extracción de ADN para mosquitos anofelinos Optimization of a DNA extraction procedure for anopheline mosquitoes  

OpenAIRE

Se optimizó un protocolo para la extracción de ADN a partir de mosquitos anofelinos, evaluando varios tiempos de incubación de la muestra con el acetato de potasio (AcK). Los resultados evidenciaron que la mayor concentración de ADN y frecuencia de amplificación se obtuvieron al utilizar el tratamiento de 1 h, lo que sugiere que es posible reducir el tiempo de incubación con AcK sin afectar la cantidad y calidad del ADN extraído.A DNA extraction protocol for anopheline mosquitoes w...

Rosero, Doris A.; Gutie?rrez, Lina A.; Cienfuegos, Astrid V.; Jaramillo, Luz M.; Correa, Margarita M.

2010-01-01

309

Role of nitric oxide and superoxide in Giardia lamblia killing  

Directory of Open Access Journals (Sweden)

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

P.D. Fernandes

1997-01-01

310

Spinorial geometry and Killing spinor equations of 6D supergravity  

Science.gov (United States)

We solve the Killing spinor equations of six-dimensional (1, 0)-supergravity coupled to any number of tensor, vector and scalar multiplets in all cases. The isotropy groups of Killing spinors are Sp(1)\\cdot Sp(1)\\ltimes {\\bb H}(1), U(1)\\cdot Sp(1)\\ltimes {\\bb H}(2), Sp(1)\\ltimes {\\bb H}(3,4), Sp(1)(2), U(1)(4) and {1}(8), where in parenthesis is the number of supersymmetries preserved in each case. If the isotropy group is non-compact, the spacetime admits a parallel null 1-form with respect to a connection with torsion given by the 3-form field strength of the gravitational multiplet. The associated vector field is Killing and the 3-form is determined in terms of the geometry of spacetime. The Sp(1)\\ltimes {\\bb H} case admits a descendant solution preserving three out of four supersymmetries due to the hyperini Killing spinor equation. If the isotropy group is compact, the spacetime admits a natural frame constructed from 1-form spinor bi-linears. In the Sp(1) and U(1) cases, the spacetime admits three and four parallel 1-forms with respect to the connection with torsion, respectively. The associated vector fields are Killing and under some additional restrictions the spacetime is a principal bundle with fibre a Lorentzian Lie group. The conditions imposed by the Killing spinor equations on all other fields are also determined.

Akyol, M.; Papadopoulos, G.

2011-05-01

311

Francisella tularensis subspecies holarctica occurs in Swedish mosquitoes, persists through the developmental stages of laboratory-infected mosquitoes and is transmissible during blood feeding.  

Science.gov (United States)

In Sweden, mosquitoes are considered the major vectors of the bacterium Francisella tularensis subsp. holarctica, which causes tularaemia. The aim of this study was to investigate whether mosquitoes acquire the bacterium as aquatic larvae and transmit the disease as adults. Mosquitoes sampled in a Swedish area where tularaemia is endemic (Örebro) were positive for the presence of F. tularensis deoxyribonucleic acid throughout the summer. Presence of the clinically relevant F. tularensis subsp. holarctica was confirmed in 11 out of the 14 mosquito species sampled. Experiments performed using laboratory-reared Aedes aegypti confirmed that F. tularensis subsp. holarctica was transstadially maintained from orally infected larvae to adult mosquitoes and that 25% of the adults exposed as larvae were positive for the presence of F. tularensis-specific sequences for at least 2 weeks. In addition, we found that F. tularensis subsp. holarctica was transmitted to 58% of the adult mosquitoes feeding on diseased mice. In a small-scale in vivo transmission experiment with F. tularensis subsp. holarctica-positive adult mosquitoes and susceptible mice, none of the animals developed tularaemia. However, we confirmed that there was transmission of the bacterium to blood vials by mosquitoes that had been exposed to the bacterium in the larval stage. Taken together, these results provide evidence that mosquitoes play a role in disease transmission in part of Sweden where tularaemia recurs. PMID:24057273

Thelaus, J; Andersson, A; Broman, T; Bäckman, S; Granberg, M; Karlsson, L; Kuoppa, K; Larsson, E; Lundmark, E; Lundström, J O; Mathisen, P; Näslund, J; Schäfer, M; Wahab, T; Forsman, M

2014-01-01

312

Wolbachia infection does not alter attraction of the mosquito Aedes (Stegomyia) aegypti to human odours.  

Science.gov (United States)

The insect endosymbiont Wolbachia pipientis (Rickettsiales: Rickettsiaceae) is undergoing field trials around the world to determine if it can reduce transmission of dengue virus from the mosquito Stegomyia aegypti to humans. Two different Wolbachia strains have been released to date. The primary effect of the wMel strain is pathogen protection whereby infection with the symbiont limits replication of dengue virus inside the mosquito. A second strain, wMelPop, induces pathogen protection, reduces the adult mosquito lifespan and decreases blood feeding success in mosquitoes after 15 days of age. Here we test whether Wolbachia infection affects mosquito attraction to host odours in adults aged 5 and 15 days. We found no evidence of reduced odour attraction of mosquitoes, even for those infected with the more virulent wMelPop. This bodes well for fitness and competitiveness in the field given that the mosquitoes must find hosts to reproduce for the biocontrol method to succeed. PMID:24797695

Turley, A P; Smallegange, R C; Takken, W; Zalucki, M P; O'Neill, S L; McGraw, E A

2014-12-01

313

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

314

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

315

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

316

Japanese encephalitis on Saipan: a survey of suspected mosquito vectors.  

Science.gov (United States)

An outbreak of Japanese encephalitis (JE) occurred on Saipan, Commonwealth of Northern Mariana Islands, in October 1990. Adult and larval mosquitoes were collected during September-October 1991 to retrospectively determine the probable mosquito vector(s). Virus was not isolated from 119 mosquito pools composed of 7,250 adult specimens as follows: Aedes vexans nocturnis (14%), Culex tritaeniorhynchus (39%), Cx. sitiens group (11%), Culex (Culex) species (35%), and Anopheles indefinitus, Ae. neopandani, and Cx. quinquefasciatus. Among the vectors of JE incriminated in other areas, Cx. tritaeniorhynchus was the predominant species in our collections and the principal species feeding on swine. This is the first published record of the occurrence of this species on Saipan. Culex tritaeniorhynchus is abundant and widely distributed on the southern half of Saipan where human JE cases occurred in 1990, and where swine seroconversions were detected. Although the identity of the mosquito vector(s) responsible for the 1990 outbreak cannot be established with certainty, our results suggest that Cx. tritaeniorhychus was probably involved. PMID:8386909

Mitchell, C J; Savage, H M; Smith, G C; Flood, S P; Castro, L T; Roppul, M

1993-04-01

317

New protective battle-dress impregnated against mosquito vector bites  

OpenAIRE

Abstract Background Mixing repellent and organophosphate (OP) insecticides to better control pyrethroid resistant mosquito vectors is a promising strategy developed for bed net impregnation. Here, we investigated the opportunity to adapt this strategy to personal protection in the form of impregnated clothes. Methods We compared standard permethrin impregnated uniforms with uniforms manually impregnated with the repellent KBR3023 alone and in combination with an...

Pennetier Cédric; Chabi Joseph; Martin Thibaud; Chandre Fabrice; Rogier Christophe; Hougard Jean-Marc; Pages Frédéric

2010-01-01

318

An incident of fenthion mosquito control and subsequent avian mortality  

Science.gov (United States)

Mass mortality among migratory birds at Grand Forks, North Dakota, was attributed to a mosquito control operation employing the insecticide fenthion. The factors involved may have included the toxicity of the pesticide for birds, the method of application and coincidence with the peak of the spring warbler migration.

Seabloom, R.W.; Pearson, G.L.; Oring, L.W.; Reilly, J.R.

1973-01-01

319

Murine complement reduces infectivity of Plasmodium yoelii to mosquitoes.  

OpenAIRE

The alternative pathway of complement in the mouse serum significantly reduced, but did not eliminate, the infectivity of Plasmodium yoelii to Anopheles stephensi. The reduction of the infectivity is mainly due to the inability of the zygote to transform into the ookinete in the mosquito midgut.

Tsuboi, T.; Cao, Y. M.; Torii, M.; Hitsumoto, Y.; Kanbara, H.

1995-01-01

320

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

Directory of Open Access Journals (Sweden)

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

321

Limitation of using synthetic human odours to test mosquito repellents  

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

Mbeyela Edgar

2009-07-01

322

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

323

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

International Nuclear Information System (INIS)

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

324

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

Science.gov (United States)

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

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

2012-09-01

325

The Risk of a Mosquito-Borne Infectionin a Heterogeneous Environment  

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

Smith David L

2004-01-01

326

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

327

It’s Not Just Conflict That Motivates Killing of Orangutans  

OpenAIRE

We investigated why orangutans are being killed in Kalimantan, Indonesia, and the role of conflict in these killings. Based on an analysis of interview data from over 5,000 respondents in over 450 villages, we also assessed the socio-ecological factors associated with conflict and non-conflict killings. Most respondents never kill orangutans. Those who reported having personally killed an orangutan primarily did so for non-conflict reasons; for example, 56% of these respondents said that the ...

Davis, Jacqueline T.; Mengersen, Kerrie; Abram, Nicola K.; Ancrenaz, Marc; Wells, Jessie A.; Meijaard, Erik

2013-01-01

328

Transcriptome of the adult female malaria mosquito vector Anopheles albimanus  

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

Martínez-Barnetche Jesús

2012-05-01

329

Inflatable kill packers used in working over Kuwaiti wells  

International Nuclear Information System (INIS)

This paper reports on inflatable packers which are being used with great success in post-well capping workover operations in Kuwait oil fields. In mid-January, about one kill packer was being run per day. Use is expected to increase in March when a second post-capping crew arrives. Of several thousand unconventional ideas submitted to Kuwait Oil Co. (KOC) for controlling the well fires left in the aftermath of lst year's Gulf War, only about a dozen were actually used. Inflatable kill packers, designed and manufactured by Baker Service Tools and marketed by Baker Oil Tools, were one of the ideas that proved effective. The kill packers are modifications of Baker's inflatable packers that have successfully been used in capping producers on many blowouts throughout the world, including the Piper Alpha disaster in the North Sea and the Saga blowout offshore Norway

330

Immune killing of newborn Trichinella larvae by human leucocytes.  

Science.gov (United States)

The capacity of human leucocytes from normal donors to kill the newborn larvae of the nematode Trichinella spiralis in vitro, in the presence of serum from infected individuals, was studied using newborn larvae (NBL) less than 2 h of age or NBL that had been maintained in culture at 37 degrees C for 20 h. Neutrophils and monocytes attached to newborn Trichinella larvae and killed them, regardless of their age. When eosinophils were used, 20 h old NBL were killed whereas 2 h old NBL were not. Complement was essential in the cytotoxic effect of leucocytes. These results indicate that host defence against T. spiralis in humans may be a complex mechanism in which different cell types can be involved. They also show that the age of maturation of the NBL is of paramount importance in the antibody-dependent cellular cytotoxicity reaction. PMID:7877832

Venturiello, S M; Giambartolomei, G H; Costantino, S N

1993-10-01

331

[Effect of niclosamide spreading oil on killing schistosome cercariae].  

Science.gov (United States)

Dechlorinated water (100 ml, 30 degrees C) was put into a plate (diameter 15 cm), and 1% niclosamide spreading oil 5 microl was added, then a ring of Schistosoma japonicum cercariae were picked up to the plate. The time of killing all the cercariae was observed at three time points (immediately, 24, 48 h), and the dechlorinated water was used as control. The results showed that schistosome cercariae were all killed in three minutes by 1% niclosamide spreading oil at the three time points. The cercaria-killing effects of each time point were not significantly different (F = 0.062, P > 0.05). The cercariae were alive in the control in 48 h. PMID:23012973

Peng, Guo-Hua; Hu, Zhu-Hua; Bao, Zi-Ping; Zhou, Yi-Sheng; Xiong, Zhi-Wei; Chen, Hai-Ying'; Guo, Jia-Gang

2012-06-01

332

Killing-Yano equations and G-structures  

CERN Document Server

We solve the Killing-Yano equation on manifolds with a $G$-structure for $G=SO(n), U(n), SU(n), Sp(n)\\cdot Sp(1), Sp(n), G_2$ and $Spin(7)$. Solutions include nearly-K\\"ahler, weak holonomy $G_2$, balanced SU(n) and holonomy $G$ manifolds. As an application, we find that particle probes on $AdS_4\\times X$ compactifications of type IIA and 11-dimensional supergravity admit a ${\\cal W}$-type of symmetry generated by the fundamental forms. We also explore the ${\\cal W}$-symmetries of string and particle actions in heterotic and common sector supersymmetric backgrounds. In the heterotic case, the generators of the ${\\cal W}$-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.

Papadopoulos, G

2007-01-01

333

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

334

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

335

From conformal Killing vector fields to boost-rotational symmetry  

Scientific Electronic Library Online (English)

Full Text Available SciELO Mexico | Language: English Abstract in spanish Se discute la conexión entre variedades Riemannianas (?,) de dimension tres que admiten un campo vectorial de Killing conforme ? y espacios- tiempo estáticos asociados a sistemas en el vacío o no-vacío. Cualquiera de estas variedades [...] (?,) generan un espacio-tiempo (M, g) e igual generan un espacio-tiempo (M, g,?), donde (g, ?) satisfacen las ecuaciones para el campo escalar asociadas a los sistemas de Einstein-Klein-Gordon con acoplamiento mínimo o conforme. Los espacios-tiempo asociados resultantes admiten cuatro campos vectoriales de Killing o una simetría de "boost" y rotacional. Se argumenta como esta conexión va mas allá de los sistemas en el vacío o de los sistemas de campos escalares y esto puede ser visto como un mecanismo para generar soluciones de las ecuaciones de Einstein, que admitan un campo vectorial de Killing ortogonal a una hipersuperficie. Abstract in english We discuss a connection between three-dimensional Riemannian manifolds (?,) admitting a special conformal Killing vector field ? and static vacuum or non-vacuum spacetimes. Any such (?,[...] mf/v53s2/a5s2.jpg">) generates a vacuum spacetime (M,g) but it also generates a spacetime (M, g, ?), where (g, ?) satisfies the Einstein-Klein-Gordon massless minimally coupled gravity equations, or the Einstein-Conformal scalar field equations. The resulting spacetimes either admit four Killing vector fields or possess boost and rotational symmetry. We argue that this connection goes beyond the vacuum or Einstein-scalar field system and it should be viewed as a mechanism of generating solutions for the Einstein equations, admitting a hypersurface orthogonal Killing vector field.

J, Estevez-Delgado; T, Zannias.

2007-02-01

336

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

337

A radiolabel release microassay for phagocytic killing of Candida albicans  

International Nuclear Information System (INIS)

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

338

How Moist Heat Kills Spores of Bacillus subtilis?  

OpenAIRE

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

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

2007-01-01

339

Perturbative stability of the approximate Killing field eigenvalue problem  

Science.gov (United States)

An approximate Killing field may be defined on a compact, Riemannian geometry by solving an eigenvalue problem for a certain elliptic operator. This paper studies the effect of small perturbations in the Riemannian metric on the resulting vector field. It shows that small metric perturbations, as measured using a Sobolev-type supremum norm on the space of Riemannian geometries on a fixed manifold, yield small perturbations in the approximate Killing field, as measured using a Hilbert-type square integral norm. It also discusses applications to the problem of computing the spin of a generic black hole in general relativity.

Beetle, Christopher; Wilder, Shawn

2014-04-01

340

Perturbative stability of the approximate Killing field eigenvalue problem  

CERN Document Server

An approximate Killing field may be defined on a compact, Riemannian geometry by solving an eigenvalue problem for a certain elliptic operator. This paper studies the effect of small perturbations in the Riemannian metric on the resulting vector field. It shows that small metric perturbations, as measured using a Sobolev-type supremum norm on the space of Riemannian geometries on a fixed manifold, yield small perturbations in the approximate Killing field, as measured using a Hilbert-type square integral norm. It also discusses applications to the problem of computing the spin of a generic black hole in general relativity.

Beetle, Christopher

2014-01-01

341

Species composition and temporal distribution of mosquito populations in Ibadan, Southwestern Nigeria  

Science.gov (United States)

Nigeria has a high burden of vector borne diseases such as malaria and lymphatic filariasis (LF). This study aimed to determine the species composition of mosquitoes in Ibadan, Southwest Nigeria as well as determine their role in malaria and LF transmission. Adult mosquitoes were collected by Pyrethrum Spray Catch (PSC) and identified and graded according to their abdominal conditions. The mosquitoes were dissected to determine the parity status and to check for microfilariae of Wuchereria bancrofti. The presence of circumsporozoite protein of Plasmodium falciparum was examined using ELISA. A total of 1600 mosquitoes were collected of which 31 (1.9%) were Anopheles gambiae s.l. while 1756 (98%) were Culex sp. None of the mosquitoes examined was positive for Plasmodium falciparum and Wuchereria bancrofti. The lack of adequate sanitary conditions in the area could be responsible for the large number of mosquitoes collected. Health education could help in sensitizing the inhabitants. PMID:25520960

Okorie, Patricia N.; Popoola, K.O.K.; Awobifa, Olayemi M.; Ibrahim, Kolade T.; Ademowo, George O.

2014-01-01

342

Studies on mid gut microbiota of wild caught Culex (Culex quinquefasciatus mosquitoes from Barasat (North 24 Parganas of West Bengal.  

Directory of Open Access Journals (Sweden)

Full Text Available Mosquitoes are haematophagous insects that serve as obligate intermediate host for numerous diseases like Filaria, Malaria, Dengue, etc. Mosquitoes can be considered as a holobiont units in which host (mosquitoes and its gut microbiota are involved in a complex reciprocal interaction. The naturally acquired microbiota can modulate mosquitos’ vectorial capacity by inhibiting the development of pathogens. But, enough care has not been taken in West Bengal to investigate on the midgut microbiota of Culex mosquitoes. Therefore, a preliminary attempt has been undertaken to study the morphology, growth pattern and antibiotic susceptibility of midgut microbiota of Culex (Culex quinquefasciatus mosquitoes collected from Barasat areas (North 24 Parganas of West Bengal..

Abhishek Pal

2014-06-01

343

Larvicidal activity of neem oil (Azadirachta indica formulation against mosquitoes  

Directory of Open Access Journals (Sweden)

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

Dua Virendra K

2009-06-01

344

Screening of Rubiaceae and Apocynaceae extracts for mosquito larvicidal potential.  

Science.gov (United States)

Rubiaceae and Apocynaceae families are well known for the expression of cyclotides having insecticidal properties. Leaves and flowers extracts of plants from the families Rubiaceae (Ixora coccinea) and Apocynaceae (Allamanda violacea) were evaluated for mosquito larvicidal effect against early IVth instars of Aedes aegypti and Anopheles stephensi. Two forms of plant extracts, one untreated and the other treated with heat and proteolytic enzyme were used for assay. After primary assay, the extract showing more than 50% inhibition was further used for quantification purpose. LC50 and LC90 values of all the extracts were found to be reduced with the treated form. Phytochemical analysis of plant extracts was performed. Primary confirmation for the presence of cyclotides was done by Lowry test, thin layer chromatography and haemolytic assay. This novel approach merits use of plant extracts in mosquito control programmes. PMID:25317964

Suryawanshi, Rahul; Patil, Chandrashekhar; Borase, Hemant; Narkhede, Chandrakant; Patil, Satish

2015-01-01

345

Bioassays for Culex (Diptera: Culicidae) mosquito oviposition attractants and stimulants.  

Science.gov (United States)

Bioassay methods for mosquito oviposition attractants and stimulants were developed and compared, using Culex tarsalis Coq. gravid females as test insects, and distilled water, dyed water, or Bermuda grass infusions as the test stimuli. Bioassays with sticky screens covering jars containing volatile test stimuli or with colorless and odorless Triton X100 surfactant in the aqueous oviposition medium demonstrated that gravid mosquitoes were attracted to distilled water, with the attraction increased by the addition of dye, grass infusion, or the steam distillate of grass infusion to the water. A variation of the sticky screen bioassay was used to demonstrate that the grass infusion also contained oviposition stimulants. A forced oviposition bioassay was minimally useful, because it failed to discriminate between a solution known to contain oviposition stimulants and a distilled-water control. Overall, the bioassays developed can be used to distinguish between oviposition attractants and stimulants, a distinction that cannot be made by simply counting egg rafts. PMID:7650709

Isoe, J; Millar, J G; Beehler, J W

1995-07-01

346

Transmission of malaria to mosquitoes blocked by bumped kinase inhibitors  

Science.gov (United States)

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

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

2012-01-01

347

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

OpenAIRE

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

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

2005-01-01

348

Occurrence of Japanese Encephalitis Virus Mosquito Vectors in Relation to Urban Pig Holdings  

OpenAIRE

Japanese encephalitis virus (JEV) is transmitted to humans from pigs or birds by mosquitoes. In this study, the association between urban pig keeping and mosquito vectors was analyzed. A total of 7, 419 mosquitoes were collected overnight in urban households with and without pigs in Can Tho City, Vietnam. The most prevalent vectors were Culex tritaeniorhynchus (36%), Cx. gelidus (24%), and Cx. quinquefasciatus (15%), which were present in all parts of the city. Pigs were associated with incre...

Lindahl, Johanna; Chirico, Jan; Boqvist, Sofia; Thu, Ho Thi Viet; Magnusson, Ulf

2012-01-01

349

Trapping mosquitoes using milk products as odour baits in western Kenya  

OpenAIRE

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

Owino Eunice A

2010-01-01

350

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

OpenAIRE

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

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

2010-01-01

351

Relation between HLA genes, human skin volatiles and attractiveness of humans to malaria mosquitoes  

OpenAIRE

Chemical cues are considered to be the most important cues for mosquitoes to find their hosts and humans can be ranked for attractiveness to mosquitoes based on the chemical cues they emit. Human leukocyte antigen (HLA) genes are considered to be involved in the regulation of human body odor and may therefore affect human attractiveness to mosquitoes, and hence, affect the force of malaria transmission. In the present study the correlations between HLA profiles, human skin volatiles and human...

Verhulst, N. O.; Beijleveld, H.; Qiu, Y. T.; Maliepaard, C. A.; Verduyn, W.; Haasnoot, G. W.; Claas, F. H. J.; Mumm, R.; Bouwmeester, H. J.; Takken, W.; Loon, J. J. A.; Smallegange, R. C.

2013-01-01

352

Effects of inducing or inhibiting apoptosis on Sindbis virus replication in mosquito cells  

OpenAIRE

Sindbis virus (SINV) is a mosquito-borne virus in the genus Alphavirus, family Togaviridae. Like most alphaviruses, SINVs exhibit lytic infection (apoptosis) in many mammalian cell types, but are generally thought to cause persistent infection with only moderate cytopathic effects in mosquito cells. However, there have been several reports of apoptotic-like cell death in mosquitoes infected with alphaviruses or flaviviruses. Given that apoptosis has been shown to be an antiviral response in o...

Wang, Hua; Blair, Carol D.; Olson, Ken E.; Clem, Rollie J.

2008-01-01

353

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

Directory of Open Access Journals (Sweden)

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

R. A. G. B Consoli

1995-02-01

354

Insectos acuáticos biorreguladores de larvas de mosquito presentes en los "Pantanos de Villa", Lima, Perú  

OpenAIRE

Se colectaron y determinaron los principales insectos acuáticos biorreguladores de larvas de mosquito presentes en distintos reservorios en los "Pantanos de Villa", Lima, Perú, donde encontramos larvas y pupas de mosquito de las especies Culex quinquefasciatus Say y Aedes scapularis Rondani, en acuatorios donde no observamos insectos acuáticos. En aquéllos donde estaban presentes estos efectivos biorreguladores de larvas de mosquito como fueron Ischnura ramburri (Selys), Ceratura capreola...

ISRAEL GARCÍA ÁVILA; RONALD VIVAR GUZMÁN; JAIME QUEZADA MÁRQUEZ; PEDRO HUAMÁN MAYTA

1996-01-01

355

Limited Dengue Virus Replication in Field-Collected Aedes aegypti Mosquitoes Infected with Wolbachia  

OpenAIRE

Almost half of the world's population is at risk of contracting dengue virus, particularly in the tropics and sub-tropics. The virus is transmitted by the mosquito Aedes aegypti, a cosmopolitan species that has proved difficult to control using traditional methods. A new biocontrol strategy has been developed involving the release of mosquitoes infected with Wolbachia bacteria. Mosquitoes with the wMel strain of Wolbachia show dramatically reduced replication and transmission of dengue virus ...

Frentiu, Francesca D.; Zakir, Tasnim; Walker, Thomas; Popovici, Jean; Pyke, Alyssa T.; Den Hurk, Andrew; Mcgraw, Elizabeth A.; O Neill, Scott L.

2014-01-01

356

Wolbachia Enhances West Nile Virus (WNV) Infection in the Mosquito Culex tarsalis  

OpenAIRE

Novel strategies are required to control mosquitoes and the pathogens they transmit. One attractive approach involves maternally inherited endosymbiotic Wolbachia bacteria. After artificial infection with Wolbachia, many mosquitoes become refractory to infection and transmission of diverse pathogens. We evaluated the effects of Wolbachia (wAlbB strain) on infection, dissemination and transmission of West Nile virus (WNV) in the naturally uninfected mosquito Culex tarsalis, which is an importa...

Dodson, Brittany L.; Hughes, Grant L.; Paul, Oluwatobi; Matacchiero, Amy C.; Kramer, Laura D.; Rasgon, Jason L.

2014-01-01

357

The roles of kairomones, synomones and pheromones in the chemically-mediated behaviour of male mosquitoes.  

Science.gov (United States)

Despite decades of intensive study of the chemical ecology of female mosquitoes, relatively little is known about the chemical ecology of males. This short review summarizes the current state of knowledge of the chemicals that mediate male mosquito behaviour. Various trophic interactions including insect-plant, insect-host, and insect-insect responses are emphasized. The relevance of the chemical ecology of male mosquitoes in the context of vector control programmes is discussed. PMID:24055544

Pitts, R Jason; Moz?raitis, Raimondas; Gauvin-Bialecki, Anne; Lempérière, Guy

2014-04-01

358

Molecular Genetic Analysis of Midgut Serine Proteases in Aedes aegypti Mosquitoes  

OpenAIRE

Digestion of blood meal proteins by midgut proteases provides anautogenous mosquitoes with the nutrients required to complete the gonotrophic cycle. Inhibition of protein digestion in the midgut of blood feeding mosquitoes could therefore provide a strategy for population control. Based on recent reports indicating that the mechanism and regulation of protein digestion in blood fed female Aedes aegypti mosquitoes is more complex than previously thought, we used a robust RNAi knockdown method ...

Isoe, Jun; Rasco?n, Alberto A.; Kunz, Susan; Miesfeld, Roger L.

2009-01-01

359

Mosquito immatures in bamboo internodes in eastern Santa Catarina State, South Brazil (Diptera: Culicidae)  

OpenAIRE

Since mosquito immatures had been previously reported found in bamboo internodes in the Brazilian state of Santa Catarina, a study was conducted from January to March 2011 to evaluate the mosquito fauna associated with artificially drilled bamboos in eight localities in the eastern region of this state. Ninety-one mosquitoes of the following species were recorded: Aedes albopictus (Skuse, 1894) (1.1%), Culex soperi Antunes & Lane, 1937 (11.0%), Onirium personatum (Lutz, 1904) (6.6%), Sabethes...

Gerson Azulim Müller; Marco Jacometto Marchi; Carlos Brisola Marcondes

2014-01-01

360

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

OpenAIRE

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

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

2012-01-01

361

Protocol for Dengue Infections in Mosquitoes (A. aegypti) and Infection Phenotype Determination  

OpenAIRE

The purpose of this procedure is to infect the Aedes mosquito with dengue virus in a laboratory condition and examine the infection level and dynamic of the virus in the mosquito tissues. This protocol is routinely used for studying mosquito-virus interactions, especially for identification of novel host factors that are able to determine vector competence. The entire experiment must be conducted in a BSL2 laboratory. Similar to Plasmodium falciparum infections, proper attire including gloves...

Das, Suchismita; Garver, Lindsey; Ramirez, Jose Ruiz; Xi, Zhiyong; Dimopoulos, George

2007-01-01

362

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

OpenAIRE

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

Govella, Nicodem J.; Okumu, Fredros O.; Killeen, Gerry F.

2010-01-01

363

Metofluthrin: a potent new synthetic pyrethroid with high vapor activity against mosquitoes.  

Science.gov (United States)

(1R)-trans-Norchrysanthemic acid fluorobenzyl esters are synthesized and their structure-activity relationships are discussed. These esters show outstanding insecticidal activity against mosquitoes. In particular, the 2,3,5,6-tetrafluoro-4-methoxymethylbenzyl analog (metofluthrin) exhibits the highest potency, being approximately forty times as potent as d-allethrin in a mosquito coil formulation when tested against southern house mosquitoes (Culex quinquefasciatus). Metofluthrin also exhibits a significant vapor action at room temperature. PMID:14745180

Ujihara, Kazuya; Mori, Tatsuya; Iwasaki, Tomonori; Sugano, Masayo; Shono, Yoshinori; Matsuo, Noritada

2004-01-01

364

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

Scientific Electronic Library Online (English)

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

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

1995-02-01

365

The Transcriptome Profile of the Mosquito Culex quinquefasciatus following Permethrin Selection  

OpenAIRE

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

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

2012-01-01

366

Detection of Porcine Circovirus Type 2 (PCV2) in Mosquitoes from Pig Farms by PCR  

OpenAIRE

To investigate, whether mosquitoes could be potential vectors that maintain or transmit PCV2, 59 mosquito samples were collected from suspicious PCV2-infected pig farms in Hubei and Anhui province, China. Total DNA from these mosquitoes was extracted and then tested for presence of PCV2 nucleic acid by PCR. Four (6.78%) samples showed the positive result. Subsequently, the positive PCR product was cloned into pEASY-T1 vector and sequenced. Sequence analysis displayed that homology between the...

Xiaohong Yang, Lidan Hou

2012-01-01

367

Native Argentinean cyclopoids (Crustacea: Copepoda) as predators of Aedes aegypti and Culex pipiens (Diptera: Culicidae) mosquitoes  

OpenAIRE

Copepods from La Plata, Argentina were investigated to characterize the local community of larvivorous copepods inhabiting mosquito breeding sites and to identify new predator species of the mosquitoes which occur in artificial containers, Aedes aegypti and Culex pipiens. Diversity of larvivorous cyclopoids was highest in permanent pools. Predation by sex and age, selectivity on mosquito species, and daily predation rate during five days were studied for Acanthocyclops robustus, Diacyclops ur...

Tranchida, Mari?a C.; Micieli, Mari?a V.; Arnaldo Maciá; Garci?a, Juan J.

2009-01-01

368

[New findings of Anopheles mosquitoes in artificial containers].  

Science.gov (United States)

New findings of Anopheles mosquitoes in artificial containers are reported. In one, a plastic container served as a breeding place for Anopheles bellator larvae and, in another, four instar larvae of An. albitarsis s.l. were found in an abandoned toilet basin. Reflections are offered as to the selective pressure represented by the production, of an ever increasing scale, of disposable objects. PMID:10349154

Forattini, O P; Kakitani, I; Marques, G R; de Brito, M

1998-12-01

369

Mosquitoes smell and avoid the insect repellent DEET.  

Science.gov (United States)

The insect repellent DEET is effective against a variety of medically important pests, but its mode of action still draws considerable debate. The widely accepted hypothesis that DEET interferes with the detection of lactic acid has been challenged by demonstrated DEET-induced repellency in the absence of lactic acid. The most recent hypothesis suggests that DEET masks or jams the olfactory system by attenuating electrophysiological responses to 1-octen-3-ol. Our research shows that mosquitoes smell DEET directly and avoid it. We performed single-unit recordings from all functional ORNs on the antenna and maxillary palps of Culex quinquefasciatus and found an ORN in a short trichoid sensillum responding to DEET in a dose-dependent manner. The same ORN responded with higher sensitivity to terpenoid compounds. SPME and GC analysis showed that odorants were trapped in conventional stimulus cartridges upon addition of a DEET-impregnated filter paper strip thus leading to the observed reduced electrophysiological responses, as reported elsewhere. With a new stimulus delivery method releasing equal amounts of 1-octen-3-ol alone or in combination with DEET we found no difference in neuronal responses. When applied to human skin, DEET altered the chemical profile of emanations by a "fixative" effect that may also contribute to repellency. However, the main mode of action is the direct detection of DEET as indicated by the evidence that mosquitoes are endowed with DEET-detecting ORNs and corroborated by behavioral bioassays. In a sugar-feeding assay, both female and male mosquitoes avoided DEET. In addition, mosquitoes responding only to physical stimuli avoided DEET. PMID:18711137

Syed, Zainulabeuddin; Leal, Walter S

2008-09-01

370

Terpenoid mosquito repellents: a combined DFT and QSAR study.  

Science.gov (United States)

Interactions between low-toxicity terpenoid mosquito repellents and lactic acid are studied at the HF and B3LYP level. The subsequent QSAR study shows that not only the structure of repellents but also the repellent-lactic acid complexes may play an important role. It suggests that further study on interactions between repellents and characteristic compounds from human host may be required in order to understand the repelling mechanism. PMID:23375229

Song, Jie; Wang, Zongde; Findlater, Alexander; Han, Zhaojiu; Jiang, Zhikuan; Chen, Jinzhu; Zheng, Weiqing; Hyde, Sarah

2013-03-01

371

Historical applications of induced sterilisation in field populations of mosquitoes  

Directory of Open Access Journals (Sweden)

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

Knols Bart GJ

2009-11-01

372

Malaria parasite chitinase and penetration of the mosquito peritrophic membrane.  

OpenAIRE

Malaria parasites (ookinetes) appear to digest the peritrophic membrane in the mosquito midgut during penetration. Previous studies demonstrated that lectins specific for N-acetylglucosamine bind to the peritrophic membrane and proposed that the membrane contains chitin [Rudin, W. & Hecker, H. (1989) Parasitol. Res. 75, 268-279]. In the present study, we show that the peritrophic membrane is digested by Serratia marcescens chitinase (EC 3.2.1.14), leading to the release of N-acetylglucosamine...

Huber, M.; Cabib, E.; Miller, L. H.

1991-01-01

373

Identification of Wolbachia Strains in Mosquito Disease Vectors  

OpenAIRE

Wolbachia bacteria are common endosymbionts of insects, and some strains are known to protect their hosts against RNA viruses and other parasites. This has led to the suggestion that releasing Wolbachia-infected mosquitoes could prevent the transmission of arboviruses and other human parasites. We have identified Wolbachia in Kenyan populations of the yellow fever vector Aedes bromeliae and its relative Aedes metallicus, and in Mansonia uniformis and Mansonia africana, which are vectors of ly...

Osei-poku, Jewelna; Han, Calvin; Mbogo, Charles M.; Jiggins, Francis M.

2012-01-01

374

Mosquito odorant receptor for DEET and methyl jasmonate  

OpenAIRE

DEET (N,N-diethyl-3-methylbenzamide) has intrigued medical entomologists, neurobiologists, insect physiologists, and chemical ecologists for decades, and hitherto it was not known how and why it works. We have discovered an odorant receptor in the southern house mosquito, which is essential for repellency, thus unravelling how DEET works. Additionally, we have identified a link between this synthetic repellent and methyl jasmonate, thus suggesting that DEET might work by mimicking defensive c...

Xu, Pingxi; Choo, Young-moo; La Rosa, Alyssa; Leal, Walter S.

2014-01-01

375

Challenges and Approaches for Mosquito Targeted Malaria Control  

OpenAIRE

Malaria is one of today’s most serious diseases with an enormous socioeconomic impact. While anti-malarial drugs have existed for some time and vaccines development may be underway, the most successful malaria eradication programs have thus far relied on attacking the mosquito vector that spreads the disease causing agent Plasmodium. Here we will review past, current and future perspectives of malaria vector control strategies and how these approaches have taken a promising turn thanks rece...

Ramirez, Jose? L.; Garver, Lindsey S.; Dimopoulos, George

2009-01-01

376

Complex environmental drivers of immunity and resistance in malaria mosquitoes  

OpenAIRE

Considerable research effort has been directed at understanding the genetic and molecular basis of mosquito innate immune mechanisms. Whether environmental factors interact with these mechanisms to shape overall resistance remains largely unexplored. Here, we examine how changes in mean ambient temperature, diurnal temperature fluctuation and time of day of infection affected the immunity and resistance of Anopheles stephensi to infection with Escherichia coli. We used quantitative PCR to est...

Murdock, Courtney C.; Moller-jacobs, Lillian L.; Thomas, Matthew B.

2013-01-01

377

Detection of mosquito-only flaviviruses in Europe  

OpenAIRE

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

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

2012-01-01

378

Chromosome end elongation by recombination in the mosquito Anopheles gambiae.  

OpenAIRE

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

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

1997-01-01

379

Reappraisal on anopheline mosquitoes of Garhwal region, Uttarakhand, India  

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Full Text Available Background & objectives: The study examines occurrence of anopheline mosquitoes in seven districts— Dehradun, Pauri, New Tehri, Hardwar, Rudraprayag, Chamoli and Uttarkashi of Garhwal region in Uttarakhand state, India. Methods: The methodological approach comprised sampling and processing of adult/immature mosquitoes, data compilation, meteorological information and parasitological survey.Results: A total of 87 localities covering 24 tehsils/blocks were surveyed during January 2000 to December 2005 for mosquito sampling. The study encountered 18 species of anophelines including three malaria vectors namely Anopheles culicifacies, An. fluviatilis and An. stephensi collected from Kalsi, Dehradun City, Sahaspur, Hardwar town, Roorkee, New Tehri town and Kotdwar localities. An. pallidus has been recorded for the first time from the Garhwal region. All the collected species have been presented with particular reference to their both adult and immature distribution, brief account of bionomics and some ecological notes.Interpretation & conclusion: Out of 18 collected anopheline species, 15 were non-vectors and they were found to create nuisance to the inhabitants. As far as the species distribution was concerned the diversity was more at elevation between 150 and 1000 m above the mean sea level, while the immature of some species were not recovered from those localities where their adults were collected. Certain species of Anopheles were climate determined and their distribution was localized while some others were cosmopolitan.

N. Pemola Devi

2008-05-01

380

Mosquitoes of eastern Amazonian Ecuador: biodiversity, bionomics and barcodes  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Two snapshot surveys to establish the diversity and ecological preferences of mosquitoes (Diptera: Culicidae) in the terra firme primary rain forest surrounding the Tiputini Biodiversity Station in the UNESCO Yasuní Biosphere Reserve of eastern Amazonian Ecuador were carried out in November 1998 and [...] May 1999. The mosquito fauna of this region is poorly known; the focus of this study was to obtain high quality link-reared specimens that could be used to unequivocally confirm species level diversity through integrated systematic study of all life stages and DNA sequences. A total of 2,284 specimens were preserved; 1,671 specimens were link-reared with associated immature exuviae, all but 108 of which are slide mounted. This study identified 68 unique taxa belonging to 17 genera and 27 subgenera. Of these, 12 are new to science and 37 comprise new country records. DNA barcodes [658-bp of the mtDNA cytochrome c oxidase ( COI ) I gene] are presented for 58 individuals representing 20 species and nine genera. DNA barcoding proved useful in uncovering and confirming new species and we advocate an integrated systematics approach to biodiversity studies in future. Associated bionomics of all species collected are discussed. An updated systematic checklist of the mosquitoes of Ecuador (n = 179) is presented for the first time in 60 years.

Yvonne-Marie, Linton; James E, Pecor; Charles H, Porter; Luke Brett, Mitchell; Andres, Garzon-Moreno; Desmond H, Foley; David Brooks, Pecor; Richard C, Wilkerson.

381

Mosquito embryos and eggs: polarity and terminology of chorionic layers.  

Science.gov (United States)

The development of genetically modified vectors refractory to parasites is seen as a promising strategy in the future control of endemic diseases such as malaria. Nevertheless, knowledge of mosquito embryogenesis, a pre-requisite to the establishment of transgenic individuals, has been presently neglected. We have here studied the eggs from two neotropical malaria vectors. Eggs from Anopheles (Nyssorhynchus) albitarsis and Anopheles (Nyssorhynchus) aquasalis were analyzed by laser scanning microscopy and scanning electron microscopy and compared to those of Drosophila melanogaster. We verified basic conflicting data such as mosquito egg polarity and ultrastructure of eggshell layers. A 180 degrees rotation movement of the mosquito embryo along its longitudinal axis, a phenomenon not conserved among all Diptera, was confirmed. This early event is not taken into account by several present groups, leading to a non-consensual assignment of eggshell dorsal and ventral poles. Since embryo and egg polarities, defined during oogenesis, are the same, we propose to consider the flattened egg side as the dorsal one. The structure of Anopheles eggshell was also examined. Embryos are covered by a smooth endochorion or inner chorion layer. Outside this coat lies the compound exochorion or outer chorion layer, assembled by a thin basal lamellar layer and external tubercles. The terminology related to eggshell layers is discussed. PMID:12770300

Valle, D; Monnerat, A T.; Soares, M J.; Rosa-Freitas, M G.; Pelajo-Machado, M; Vale, B S.; Lenzi, H L.; Galler, R; Lima, J B.P.

1999-08-01

382

A rationale to design longer lasting mosquito repellents.  

Science.gov (United States)

Mosquito repellents represent a cleaner and safer alternative for population control and reduce the diseases they carry in large areas of the world. Recently, research has been focused on repellents of natural origins, both crude essential oils and their main constituents. We have observed that, although a large number of compounds can be efficiently used as mosquito repellents, their efficacy is never higher than those of commercial products DEET and Icaridin. Reasoning that probably specific and exceptionally active repellents might not exist, we focused our research on products that could provide longer protection times with respect to current commercial formulations while being used at lower concentrations. Based on the structure of menthone, a moderate natural repellent, we designed and synthesised some cyclic ketals that, because of their reduced volatility, could be effective for longer periods. In particular, a 1% solution of one of such derivatives can still reduce mosquito bites by 90% after 2 h, while DEET provides the same performance only for 15 min, when used at the same concentration. The approach we illustrate can be applied to other compounds and other systems and offers the additional advantage that derivatives of reduced volatility are also endowed with weaker odours. PMID:24599300

Iovinella, Immacolata; Pelosi, Paolo; Conti, Barbara

2014-05-01

383

Multiple activities of insect repellents on odorant receptors in mosquitoes.  

Science.gov (United States)

Several lines of evidence suggest that insect repellent molecules reduce mosquito-host contacts by interacting with odorants and odorant receptors (ORs), thereby ultimately affecting olfactory-driven behaviours. We describe the molecular effects of 10 insect repellents and a pyrethroid insecticide with known repellent activity on two highly specific Aedes aegypti (Diptera: Culicidae) ORs, AaOR2 + AaOR7 and AaOR8 + AaOR7, exquisitely sensitive to key mosquito attractants indole and (R)-(-)-1-octen-3-ol, expressed in oocytes of Xenopus (Anura: Pipidae). Our study demonstrates that insect repellents can both inhibit odorant-evoked currents mediated by ORs and independently elicit currents in the absence of odorants. All of the repellents had effects on one or both ORs; most of these compounds were selective inhibitors and showed a high degree of specificity in their capacity to activate the two ORs. These results show that a range of insect repellents belonging to structurally diverse chemical classes modulate the function of mosquito ORs through multiple molecular mechanisms. PMID:21395633

Bohbot, J D; Fu, L; LE, T C; Chauhan, K R; Cantrell, C L; Dickens, J C

2011-12-01

384

Plasmodium ookinetes coopt mammalian plasminogen to invade the mosquito midgut  

DEFF Research Database (Denmark)

Ookinete invasion of the mosquito midgut is an essential step for the development of the malaria parasite in the mosquito. Invasion involves recognition between a presumed mosquito midgut receptor and an ookinete ligand. Here, we show that enolase lines the ookinete surface. An antienolase antibody inhibits oocyst development of both Plasmodium berghei and Plasmodium falciparum, suggesting that enolase may act as an invasion ligand. Importantly, we demonstrate that surface enolase captures plasminogen from the mammalian blood meal via its lysine motif (DKSLVK) and that this interaction is essential for midgut invasion, because plasminogen depletion leads to a strong inhibition of oocyst formation. Although addition of recombinant WT plasminogen to depleted serum rescues oocyst formation, recombinant inactive plasminogen does not, thus emphasizing the importance of plasmin proteolytic activity for ookinete invasion. The results support the hypothesis that enolase on the surface of Plasmodium ookinetes plays a dual role in midgut invasion: by acting as a ligand that interacts with the midgut epithelium and, further, by capturing plasminogen, whose conversion to active plasmin promotes the invasion process.

Ghosh, Anil K; Coppens, Isabelle

2011-01-01

385

Susceptibility of adult mosquitoes to insecticides in aqueous sucrose baits.  

Science.gov (United States)

Mosquitoes characteristically feed on plant-derived carbohydrates and honeydew just after emergence and intermittently during their lives. Development of toxic baits focusing on this carbohydrate-seeking behavior may potentially contribute to localized control. In the present study, ten insecticides were fed to female Culex quinquefasciatus, Anopheles quadrimaculatus, and Aedes taeniorhynchus in a 10% sucrose solution. Active ingredients representative of five classes of insecticides (pyrethroids, phenylpyroles, pyrroles, neonicotinoids, and macrocyclic lactones) were selected for comparison with commercial formulations used to facilitate incorporation of active ingredients into aqueous sucrose solutions. Sucrose as a phagostimulant significantly enhanced mortality to toxicants. In general, the most effective active ingredients were fipronil, deltamethrin and imidacloprid, followed by spinosad, thiamethoxam, bifenthrin, permethrin, and cyfluthrin. The least effective ingredients were chlorfenapyr and ivermectin. For some of the ingredients tested, Cx. quinquefasciatus was the least susceptible species. One-day-old male Cx. quinquefasciatus were more susceptible than females; however, no differences existed between one- and seven-day-old mosquitoes. There were no differences in susceptibility between unfed and gravid ten-day-old female Cx. quinquefasciatus to bifenthrin. In conclusion, several pesticides from different classes of compounds have potential for use in development of toxic baits for mosquitoes. PMID:21635642

Allan, Sandra A

2011-06-01

386

Evaluation of the control of mosquitoes with insect growth regulators.  

Science.gov (United States)

In this study, the effectiveness of eight insect growth regulators (IGRs) (chlorfluazuron, diflubenzuron, EL-494, flufenoxuron, teflubenzuron, juglone, plumbagin and methoprene) against five mosquito vectors (Armigeres subalbatus, Aedes albopictus, Aedes aegypti, Culex tritaeniorhynchus, and Culex quinquefasciatus) was investigated in the laboratory. The EC50s of chlorfluazuron, diflubenzuron, EL-494, flufenoxuron, teflubenzuron, and methoprene against the five mosquitoes ranged from 0.0001 to 0.3 ppm and those of juglone and plumbagin from 3-25 ppm. The five mosquito species had similar tolerances to the test IGRs. At pH 5 to 9, the effectiveness of the first five chemicals was very stable. After ultraviolet irradiation or heat management (45 degrees C-60 degrees C), diflubenzuron and flufenoxuron were very stable. EL-494 was not stable when exposed to ultraviolet irradiation or heat. Under 0.1 ppm, teflubenzuron was not stable upon exposure to heat and chlorfluazuron and methoprene were not stable when exposed to ultraviolet irradiation. Piperonyl butoxide reduces the effectiveness of the five IGRs. Administration of diflubenzuron (1-5 ppm), flufenoxuron (0.025 ppm), and teflubenzuron (1-5 ppm) reduced Culex quinquefasciatus larvae in ditches by 40-90%. The administration of diflubenzuron (0.5 ppm) to containers reduced 97% of the Aedes albopictus larvae. PMID:2402025

Ho, C M; Wu, S H; Wu, C C

1990-07-01

387

Evidence of mosquito-transmitted flavivirus circulation in Piedmont, north-western Italy  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Flavivirus is a highly heterogeneous viral genus that includes important human pathogens and several viral strains with unknown zoonotic potential. Mosquito-borne flaviviruses have been isolated and characterized in Northern Italy: West Nile virus and Usutu virus were detected in mosquitoes and in different host species and recent studies provided evidence about the circulation of “insect Flavivirus” strains. Methods In order to clarify the diffusion and the distribution of the mosquito-transmitted flaviviruses in Italy, we analyzed Culex and Ochlerotatus mosquitoes collected in 2009 and 2010 in an area divided evenly between hills and plains and where the landscape is dominated by mixed agricultural patches, rice fields, deciduous tree forests, and urban environments. Each mosquito pool was tested for the presence of Flavivirus strains and we characterized positive samples by genetic sequencing. Results Positive mosquito pools revealed low infection prevalence, but suggested a continuous circulation of both Usutu virus and insect Flavivirus. Interestingly, phylogenetic analyses based on NS5 gene partial sequences showed a closer relationship among new Usutu virus strains from Piedmont and the reference sequences from the Eastern Europe, with respect to Italian samples characterized so far. Moreover, NS5 gene phylogeny suggested that mosquito flaviviruses found in Italy could belong to different lineages. Conclusions Our results contribute to a wider point of view on the heterogeneity of viruses infecting mosquitoes suggesting a taxonomical revision of the Mosquito-borne Flavivirus group.

Cerutti Francesco

2012-05-01

388

Immune activation by life-shortening Wolbachia and reduced filarial competence in mosquitoes  

OpenAIRE

Wolbachia strain wMelPop reduces the longevity of its Drosophila melanogaster host and, when introduced into the mosquito Aedes aegypti, halves its life span. We show that wMelPop induces up-regulation of the mosquito's innate immune system and that its presence inhibits the development of filarial nematodes in the mosquito. These data suggest that wMelPop could be used in the global effort to eliminate lymphatic filariasis and possibly for the control of other mosquito-borne parasites where ...

Kambris, Z.; Cook, Pe; Phuc, Hk; Sinkins, Sp

2009-01-01

389

Immune activation by life-shortening Wolbachia and reduced filarial competence in mosquitoes.  

Science.gov (United States)

Wolbachia strain wMelPop reduces the longevity of its Drosophila melanogaster host and, when introduced into the mosquito Aedes aegypti, halves its life span. We show that wMelPop induces up-regulation of the mosquito's innate immune system and that its presence inhibits the development of filarial nematodes in the mosquito. These data suggest that wMelPop could be used in the global effort to eliminate lymphatic filariasis and possibly for the control of other mosquito-borne parasites where immune preactivation inhibits their development. The cost of constitutive immune up-regulation may contribute to the life-shortening phenotype. PMID:19797660

Kambris, Zakaria; Cook, Peter E; Phuc, Hoang K; Sinkins, Steven P

2009-10-01

390

Temporal abundance of Aedes aegypti in Manaus, Brazil, measured by two trap types for adult mosquitoes.  

Science.gov (United States)

A longitudinal study was conducted in Manaus, Brazil, to monitor changes of adult Aedes aegypti (L.) abundance. The objectives were to compare mosquito collections of two trap types, to characterise temporal changes of the mosquito population, to investigate the influence of meteorological variables on mosquito collections and to analyse the association between mosquito collections and dengue incidence. Mosquito monitoring was performed fortnightly using MosquiTRAPs (MQT) and BG-Sentinel (BGS) traps between December 2008-June 2010. The two traps revealed opposing temporal infestation patterns, with highest mosquito collections of MQTs during the dry season and highest collections of BGS during the rainy seasons. Several meteorological variables were significant predictors of mosquito collections in the BGS. The best predictor was the relative humidity, lagged two weeks (in a positive relationship). For MQT, only the number of rainy days in the previous week was significant (in a negative relationship). The correlation between monthly dengue incidence and mosquito abundance in BGS and MQT was moderately positive and negative, respectively. Catches of BGS traps reflected better the dynamic of dengue incidence. The findings help to understand the effects of meteorological variables on mosquito infestation indices of two different traps for adult dengue vectors in Manaus. PMID:25494470

Degener, Carolin Marlen; Ázara, Tatiana Mingote Ferreira de; Roque, Rosemary Aparecida; Codeço, Cláudia Torres; Nobre, Aline Araújo; Ohly, Jörg Johannes; Geier, Martin; Eiras, Álvaro Eduardo

2014-12-01

391

Temporal abundance of Aedes aegypti in Manaus, Brazil, measured by two trap types for adult mosquitoes  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english A longitudinal study was conducted in Manaus, Brazil, to monitor changes of adult Aedes aegypti (L.) abundance. The objectives were to compare mosquito collections of two trap types, to characterise temporal changes of the mosquito popu [...] lation, to investigate the influence of meteorological variables on mosquito collections and to analyse the association between mosquito collections and dengue incidence. Mosquito monitoring was performed fortnightly using MosquiTRAPs (MQT) and BG-Sentinel (BGS) traps between December 2008-June 2010. The two traps revealed opposing temporal infestation patterns, with highest mosquito collections of MQTs during the dry season and highest collections of BGS during the rainy seasons. Several meteorological variables were significant predictors of mosquito collections in the BGS. The best predictor was the relative humidity, lagged two weeks (in a positive relationship). For MQT, only the number of rainy days in the previous week was significant (in a negative relationship). The correlation between monthly dengue incidence and mosquito abundance in BGS and MQT was moderately positive and negative, respectively. Catches of BGS traps reflected better the dynamic of dengue incidence. The findings help to understand the effects of meteorological variables on mosquito infestation indices of two different traps for adult dengue vectors in Manaus.

Carolin Marlen, Degener; Tatiana Mingote Ferreira de, Ázara; Rosemary Aparecida, Roque; Cláudia Torres, Codeço; Aline Araújo, Nobre; Jörg Johannes, Ohly; Martin, Geier; Álvaro Eduardo, Eiras.

1030-10-01

392

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

Directory of Open Access Journals (Sweden)

Full Text Available Mosquitoes vary in their competence or ability to transmit arthropod-borne viruses (arboviruses. Many arboviruses cause disease in humans and animals. Identifying the environmental and genetic causes of variation in mosquito competence for arboviruses is one of the great challenges in public health. Progress identifying genetic (nature and environmental (nurture factors influencing mosquito competence for arboviruses is reviewed. There is great complexity in the various traits that comprise mosquito competence. The complex interactions between environmental and genetic factors controlling these traits and the factors shaping variation in Nature are largely unknown. The norms of reaction of specific genes influencing competence, their distributions in natural populations and the effects of genetic polymorphism on phenotypic variation need to be determined. Mechanisms influencing competence are not likely due to natural selection because of the direct effects of the arbovirus on mosquito fitness. More likely the traits for mosquito competence for arboviruses are the effects of adaptations for other functions of these competence mechanisms. Determining these other functions is essential to understand the evolution and distributions of competence for arboviruses. This information is needed to assess risk from mosquito-borne disease, predict new mosquito-arbovirus systems, and provide novel strategies to mitigate mosquito-borne arbovirus transmission.

Walter J. Tabachnick

2013-01-01

393

Killing for Girls: Predation Play and Female Empowerment  

Science.gov (United States)

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

Bertozzi, Elena

2012-01-01

394

9 CFR 113.210 - Feline Calicivirus Vaccine, Killed Virus.  

Science.gov (United States)

...Calicivirus Vaccine, Killed Virus. 113.210 Section...Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE...DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS...swabs are negative for virus isolation and all serums...approved by Animal and Plant Health Inspection...

2010-01-01

395

Partner Killing by Men in Cohabiting and Marital Relationships  

Science.gov (United States)

Using a national-level U.S. database, T. K. Shackelford (2001) calculated rates of uxoricide (the murder of a woman by her romantic partner) by relationship type (cohabiting or marital), by ages of the partners, and by the age difference between partners. Women in cohabiting relationships were 9 times more likely to be killed by their partner than…

Shackelford, Todd K.; Mouzos, Jenny

2005-01-01

396

Fish Kill in the Philippines—Déjà Vu  

OpenAIRE

Almost ten years ago today, the country woke up toscreaming headlines— “Massive Fish Kill inPangasinan” or something akin to that. The fish killphenomenon, familiar to fishers in freshwater andcoastal bodies of water where fish farming was beingpursued, was suddenly manifested at a scale that hadheretofore not been experienced.

Gil Jacinto

2011-01-01

397

Fish Kill in the Philippines—Déjà Vu  

Directory of Open Access Journals (Sweden)

Full Text Available Almost ten years ago today, the country woke up toscreaming headlines— “Massive Fish Kill inPangasinan” or something akin to that. The fish killphenomenon, familiar to fishers in freshwater andcoastal bodies of water where fish farming was beingpursued, was suddenly manifested at a scale that hadheretofore not been experienced.

Gil Jacinto

2011-12-01

398

The algebra of Killing vectors in five-dimensional space  

International Nuclear Information System (INIS)

This paper presents algebras which are formed by the found earlier Killing vectors in the space with linear element ds. Under some conditions, an explicit dependence of r is given for the functions entering in linear element ds. The curvature two-forms are described. 7 refs

399

Super-energy and Killing-Yano tensors  

OpenAIRE

In this paper we investigate a class of basic super-energy tensors, namely those constructed from Killing-Yano tensors, and give a generalization of super-energy tensors for cases when we start not with a single tensor, but with a pair of tensors.

Tintareanu-mircea, Ovidiu; Popa, Florian Catalin

2004-01-01

400

Optimización de un procedimiento de extracción de ADN para mosquitos anofelinos / Optimization of a DNA extraction procedure for anopheline mosquitoes  

Scientific Electronic Library Online (English)

Full Text Available SciELO Colombia | Language: Spanish Abstract in spanish Se optimizó un protocolo para la extracción de ADN a partir de mosquitos anofelinos, evaluando varios tiempos de incubación de la muestra con el acetato de potasio (AcK). Los resultados evidenciaron que la mayor concentración de ADN y frecuencia de amplificación se obtuvieron al utilizar el tratamie [...] nto de 1 h, lo que sugiere que es posible reducir el tiempo de incubación con AcK sin afectar la cantidad y calidad del ADN extraído. Abstract in english A DNA extraction protocol for anopheline mosquitoes was optimized by the evaluation of various incubation times of the sample with Potassium acetate (KAc). The results showed that the highest DNA concentration and amplification frequency were obtained with the 1 h treatment, which suggests that is p [...] ossible to reduce the incubation time with KAc without affecting the amount and quality of the DNA extracted.

DORIS A, ROSERO; LINA A, GUTIÉRREZ; ASTRID V, CIENFUEGOS; LUZ M, JARAMILLO; MARGARITA M, CORREA.

2010-12-01

401

Optimización de un procedimiento de extracción de ADN para mosquitos anofelinos Optimization of a DNA extraction procedure for anopheline mosquitoes  

Directory of Open Access Journals (Sweden)

Full Text Available Se optimizó un protocolo para la extracción de ADN a partir de mosquitos anofelinos, evaluando varios tiempos de incubación de la muestra con el acetato de potasio (AcK. Los resultados evidenciaron que la mayor concentración de ADN y frecuencia de amplificación se obtuvieron al utilizar el tratamiento de 1 h, lo que sugiere que es posible reducir el tiempo de incubación con AcK sin afectar la cantidad y calidad del ADN extraído.A DNA extraction protocol for anopheline mosquitoes was optimized by the evaluation of various incubation times of the sample with Potassium acetate (KAc. The results showed that the highest DNA concentration and amplification frequency were obtained with the 1 h treatment, which suggests that is possible to reduce the incubation time with KAc without affecting the amount and quality of the DNA extracted.

DORIS A ROSERO

2010-12-01

402

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Este estudo observou a dinâmica populacional dos mosquitos em açude eutrofizado na área rural de Paraíba do Sul, Estado do Rio de Janeiro. Foram realizadas 12 coletas mensais de mosquitos imaturos pelo método da conchada em 9 m de borda, divididos em três postos (P1, P2 e P3), com 3 m de extensão ca [...] da. O posto P1 difere por não ter vegetação (capim, mato) na margem, alcançando ou penetrando e promovendo alguma sombra na água. Larvas L3, L4 e pupas foram isoladas para a obtenção dos adultos e identificação. Foram identificados 217 espécimes adultos de quatro espécies, com as seguintes constâncias e frequências: Culex quinquefasciatus (Say, 1823) (83% e 40,6%), Anopheles (Nyssorhynchus) evansae (Brèthes, 1926) (92% e 26,7%), Anopheles (Nyssorhynchus) rangeli (Gabaldon, Cova Garcia e Lopez, 1940) (83% e 14,3%) e Culex nigripalpus (Theobald, 1901) (33% e 18,4%), com maiores frequências nos trimestres nov./dez./jan. (85,7%), maio/jun./jul. (75%), ago./set./out. (29,4%), ago./set./out. (23,5%) e, nos meses dezembro (88,4%), setembro (48,94), (38,3) e agosto (47,62), respectivamente. A presença do Culex quinquefasciatus (40%) e a elevada incidência de Daphinia sp., juntamente com os níveis de Nitrogênio orgânico (0,28 mg/L) e de Fósforo total (0,02 mg/L), indicam a eutrofização do açude. Houve diferença comparando os totais de anofelinos (A. avansae + A. rangeli) com os totais de culicini (C. quinquefasciatus + C. nigripalpis) entre P1 e P2 (?² = 0,0097), e entre P1 para P3 (?² = 0,0005), mas não entre P2 e P3 (?² = 0,2045). A elevada frequência e a constância de C. quinquefasciatus confirmam esta ser uma boa espécie bioindicadora para ambientes eutrofizados e A. evansae apresentou boa potencialidade nesse nível trófico. A vegetação pode influir na dinâmica populacional dos anofelinos também em ambientes eutróficos. Abstract in english This study observed the mosquito population in a rural eutrophised dam. Larvae of L3 and L4 stages and pupae were dipped out during twelve month collections and the reared to the adult stage for identification. The collections were done along nine metres from the edge of the dam divided in three par [...] ts (P1, P2 and P3), each part being 3 m long. P1 did not have vegetation (grass) along its edge,which would reach or sink into the water to promote some shade on the marginal water. A total of 217 adults of four species was identified with the following constancies and frequencies: Culex quinquefasciatus (Say, 1823) (83% and 40.6%), Anopheles (Nyssorhynchus) evansae (Brèthes, 1926) (92% and 26.7%), Anopheles (Nyssorhynchus) rangeli (Gabaldon, Cova Garcia and Lopez, 1940) (83% and 14.3%) and Culex nigripalpus (Theobald, 1901) (33% and 18.4%). C. quinquefasciatus, A. evansae, A. rangeli and C. nigripalpus were more frequent in the quarters Nov./Dec./Jan. (85.7%), May/June/July (75%), Aug./Sept./Oct. (29.4%) and Aug./Sept./Oct. (23.5%) particularly in the months of December (88.4%) Sept.tember (48.94), (38.3) and August (47.62) respectively. The presence of C. quinquefasciatus and the high incidence of Daphinia sp. and also the levels of Organic Nitrogen (0.28 mg/L) and of total Phosphorus (0.02 mg/L) are indications of the eutrophication of the dam. There was a difference regarding the total of Anopheles (A. avansae + A. rangeli) and Culex species (C. quinquefasciatus + C. nigripalpis) between P1 and P2 (?² = 0.0097), P1 and P3 (?² = 0.0005), but not between P2 and P3 (?² = 0.2045).The high C. quinquefasciatus constancy and frequency were confirmed to be a good biological indicator for a eutrophised environment and A. evansae showed a good potential for this environment. Vegetation can be an important factor for anopheline population dynamic also in eutrophic breeding sites.

ED., Wermelinger; CV., Benigno; RNM., Machado; PH., Cabello; AM., Meira; AP., Ferreira; JC., Zanuncio.

2012-11-01

403

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

Directory of Open Access Journals (Sweden)

Full Text Available This study observed the mosquito population in a rural eutrophised dam. Larvae of L3 and L4 stages and pupae were dipped out during twelve month collections and the reared to the adult stage for identification. The collections were done along nine metres from the edge of the dam divided in three parts (P1, P2 and P3, each part being 3 m long. P1 did not have vegetation (grass along its edge,which would reach or sink into the water to promote some shade on the marginal water. A total of 217 adults of four species was identified with the following constancies and frequencies: Culex quinquefasciatus (Say, 1823 (83% and 40.6%, Anopheles (Nyssorhynchus evansae (Brèthes, 1926 (92% and 26.7%, Anopheles (Nyssorhynchus rangeli (Gabaldon, Cova Garcia and Lopez, 1940 (83% and 14.3% and Culex nigripalpus (Theobald, 1901 (33% and 18.4%. C. quinquefasciatus, A. evansae, A. rangeli and C. nigripalpus were more frequent in the quarters Nov./Dec./Jan. (85.7%, May/June/July (75%, Aug./Sept./Oct. (29.4% and Aug./Sept./Oct. (23.5% particularly in the months of December (88.4% Sept.tember (48.94, (38.3 and August (47.62 respectively. The presence of C. quinquefasciatus and the high incidence of Daphinia sp. and also the levels of Organic Nitrogen (0.28 mg/L and of total Phosphorus (0.02 mg/L are indications of the eutrophication of the dam. There was a difference regarding the total of Anopheles (A. avansae + A. rangeli and Culex species (C. quinquefasciatus + C. nigripalpis between P1 and P2 (?² = 0.0097, P1 and P3 (?² = 0.0005, but not between P2 and P3 (?² = 0.2045.The high C. quinquefasciatus constancy and frequency were confirmed to be a good biological indicator for a eutrophised environment and A. evansae showed a good potential for this environment. Vegetation can be an important factor for anopheline population dynamic also in eutrophic breeding sites.Este estudo observou a dinâmica populacional dos mosquitos em açude eutrofizado na área rural de Paraíba do Sul, Estado do Rio de Janeiro. Foram realizadas 12 coletas mensais de mosquitos imaturos pelo método da conchada em 9 m de borda, divididos em três postos (P1, P2 e P3, com 3 m de extensão cada. O posto P1 difere por não ter vegetação (capim, mato na margem, alcançando ou penetrando e promovendo alguma sombra na água. Larvas L3, L4 e pupas foram isoladas para a obtenção dos adultos e identificação. Foram identificados 217 espécimes adultos de quatro espécies, com as seguintes constâncias e frequências: Culex quinquefasciatus (Say, 1823 (83% e 40,6%, Anopheles (Nyssorhynchus evansae (Brèthes, 1926 (92% e 26,7%, Anopheles (Nyssorhynchus rangeli (Gabaldon, Cova Garcia e Lopez, 1940 (83% e 14,3% e Culex nigripalpus (Theobald, 1901 (33% e 18,4%, com maiores frequências nos trimestres nov./dez./jan. (85,7%, maio/jun./jul. (75%, ago./set./out. (29,4%, ago./set./out. (23,5% e, nos meses dezembro (88,4%, setembro (48,94, (38,3 e agosto (47,62, respectivamente. A presen?a do Culex quinquefasciatus (40% e a elevada incidência de Daphinia sp., juntamente com os níveis de Nitrogênio orgânico (0,28 mg/L e de Fósforo total (0,02 mg/L, indicam a eutrofização do açude. Houve diferença comparando os totais de anofelinos (A. avansae + A. rangeli com os totais de culicini (C. quinquefasciatus + C. nigripalpis entre P1 e P2 (?² = 0,0097, e entre P1 para P3 (?² = 0,0005, mas não entre P2 e P3 (?² = 0,2045. A elevada frequência e a constância de C. quinquefasciatus confirmam esta ser uma boa espécie bioindicadora para ambientes eutrofizados e A. evansae apresentou boa potencialidade nesse nível trófico. A vegetação pode influir na dinâmica populacional dos anofelinos também em ambientes eutróficos.

ED. Wermelinger

2012-11-01

404

Evaluation of PermaNet 3.0 a deltamethrin-PBO combination net against Anopheles gambiae and pyrethroid resistant Culex quinquefasciatus mosquitoes: an experimental hut trial in Tanzania  

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Full Text Available Abstract Background Combination mosquito nets incorporating two unrelated insecticides or insecticide plus synergist are designed to control insecticide resistant mosquitoes. PermaNet 3.0 is a long-lasting combination net incorporating deltamethrin on the side panels and a mixture of deltamethrin and synergist piperonyl butoxide (PBO on the top panel. PBO is an inhibitor of mixed function oxidases implicated in pyrethroid resistance. Method An experimental hut trial comparing PermaNet 3.0, PermaNet 2.0 and a conventional deltamethrin-treated net was conducted in NE Tanzania using standard WHOPES procedures. The PermaNet arms included unwashed nets and nets washed 20 times. PermaNet 2.0 is a long-lasting insecticidal net incorporating deltamethrin as a single active. Results Against pyrethroid susceptible Anopheles gambiae the unwashed PermaNet 3.0 showed no difference to unwashed PermaNet 2.0 in terms of mortality (95% killed, but showed differences in blood-feeding rate (3% blood-fed with PermaNet 3.0 versus 10% with PermaNet 2.0. After 20 washes the two products showed no difference in feeding rate (10% with 3.0 and 9% with 2.0 but showed small differences in mortality (95% with 3.0 and 87% with 2.0. Against pyrethroid resistant Culex quinquefasciatus, mediated by elevated oxidase and kdr mechanisms, the unwashed PermaNet 3.0 killed 48% and PermaNet 2.0 killed 32% but after 20 washes there was no significant difference in mortality between the two products (32% killed by 3.0 and 30% by 2.0. For protecting against Culex PermaNet 3.0 showed no difference to PermaNet 2.0 when either unwashed or after 20 washes; both products were highly protective against biting. Laboratory tunnel bioassays confirmed the loss of biological activity of the PBO/deltamethrin-treated panel after washing. Conclusion Both PermaNet products were highly effective against susceptible Anopheles gambiae. As a long-lasting net to control or protect against pyrethroid resistant mosquitoes PermaNet 3.0 showed limited improvement over PermaNet 2.0 against Culex quinquefasciatus.

Malima Robert

2010-01-01

405

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

OpenAIRE

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 a...

Oso?rio, Hugo C.; Líbia Zé-Zé; Fátima Amaro; Alves, Maria J.

2014-01-01

406

Mosquitoes Put the Brake on Arbovirus Evolution: Experimental Evolution Reveals Slower Mutation Accumulation in Mosquito Than Vertebrate Cells  

OpenAIRE

Like other arthropod-borne viruses (arboviruses), mosquito-borne dengue virus (DENV) is maintained in an alternating cycle of replication in arthropod and vertebrate hosts. The trade-off hypothesis suggests that this alternation constrains DENV evolution because a fitness increase in one host usually diminishes fitness in the other. Moreover, the hypothesis predicts that releasing DENV from host alternation should facilitate adaptation. To test this prediction, DENV was serially passaged in e...

Vasilakis, Nikos; Deardorff, Eleanor R.; Kenney, Joan L.; Rossi, Shannan L.; Hanley, Kathryn A.; Weaver, Scott C.

2009-01-01

407

Reduction of mosquito biting-pressure: spatial repellents or mosquito traps? A field comparison of seven commercially available products in Israel.  

Science.gov (United States)

The present study assessed the personal protection efficiency of seven commercially available mosquito control devices (MCD) under field conditions in Israel. Trials were performed in a high biting-pressure area inhabited by large populations of mosquito and biting midge species, using human volunteers as bait in landing catch experiments. Results show that under minimal air-movement, three spatial repellent based products (ThermaCELL(®) Patio Lantern, OFF!(®) PowerPad lamp, and Terminix(®) ALLCLEAR Tabletop Mosquito Repeller) significantly reduced the biting-pressure (t-test - Prepelled significantly more mosquitoes then the Terminix ALLCLEAR Tabletop Mosquito Repeller (t-test, P<0.05). In contrast, mosquito traps using attracting cues to bait mosquitoes (Dynatrap(®), Vortex(®) Electronic Insect Trap, Blue Rhino(®) SV3100) either significantly increased or had no effect on the biting-pressure at short distances compared with the unprotected control. Trials conducted over large areas showed that only the Blue Rhino trap was able to significantly reduce the biting-pressure (40.1% reduction), but this was only when operating four units at the corners of an intermediate sized area. PMID:23545129

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

2013-07-01

408

Community Knowledge and Experience of Mosquitoes and Personal Prevention and Control Practices in Lhasa, Tibet  

Directory of Open Access Journals (Sweden)

Full Text Available Since 2009, great public attention has been paid in Lhasa City (Tibet, China to mosquito bites and accompanying inflammatory complications. However, the potential contribution of knowledge levels, experiences, disease control and preventive practices (KEP towards mosquitoes has not received much attention. To investigate community KEP concerning mosquitoes in Lhasa, a cross-sectional survey was undertaken in four sub-districts of urban Lhasa in 2012. Questionnaires were designed to collect information regarding socio-demographics and KEP concerning the harmful effects of mosquitoes on participants. The scoring for KEP was developed after consultation of literature. A total of 591 eligible questionnaires were examined. The majority of respondents were female (61.8% with a mean age of 46 years. Nearly all of the respondents were of Tibetan nationality (97.4% and living in registered native households (92.7%, who have less than primary school education. The averages of overall score, knowledge score, experience score, and practice score were 9.23, 4.53, 1.80, 2.90, respectively. The registered household with the highest overall score, knowledge score and practice score was non-native. Female subjects with monthly incomes between 1000 and 3000 RMB had higher experience scores. The correlation analysis revealed that significant positive linear correlations existed between knowledge and experience, knowledge and practices, and experience and practices towards mosquitoes. Past experiences with mosquitoes can result in a better knowledge of effective mosquito control practices in the present and the future. Though the average of overall scores related to mosquitoes is high among the participants in Lhasa, however, the knowledge about the ecological habits of mosquitoes should be strengthened. The findings in this study may help to develop strategies and measures of mosquito and mosquito-borne diseases in the future, not only in Lhasa, but also in similar altitude, latitude and longitude regions worldwide.

Xiaobo Liu

2014-09-01

409

Laboratory evaluation of Mesocyclops annulatus (Wierzejski, 1892 (Copepoda: Cyclopidea as a predator of container-breeding mosquitoes in Argentina  

Directory of Open Access Journals (Sweden)

Full Text Available In laboratory bioassays we tested the predatory capacity of the copepod Mesocyclops annulatus on Aedes aegypti and Culex pipiens larvae. A single adult female of M. annulatus caused 51.6% and 52.3% mortality of 50 first instar larvae of Ae. aegypti and Cx. pipiens respectively, in a 72 h test period. When alternative food was added to the containers, mortality rates declined to 16% and 10.3% for Ae. aegypti and Cx. pipiens respectively. When 50 first instar larvae of each of the two mosquito species tested were placed together with a single adult female of M. annulatus, mortality rates were 75.5% for Ae. aegypti larvae and 23.5% for Cx. pipiens larvae in a three day test period. Different density of adult females of M. annulatus ranged from 5 to 25 females produced mortality rates of Ae. aegypti first instar larvae from 50% to 100% respectively. When a single adult female of M. annulatus was exposed to an increasing number of first-instar Ae. aegypti larvae ranging from 10 to 100, 100% mortality was recorded from 1 to 25 larvae, then mortality declined to 30% with 100 larvae. The average larvae killed per 24 h period by a single copepod were 29.

María V Micieli

2002-09-01

410

Feasible Introgression of an Anti-pathogen Transgene into an Urban Mosquito Population without Using Gene-Drive  

OpenAIRE

Dengue is transmitted by the Aedes aegypti mosquito. Releases of genetically sterile males have been shown to reduce wild mosquito numbers. An alternative approach is to release mosquitoes carrying genes blocking dengue transmission. It is often assumed that spreading such genes in mosquito populations requires using selfish genetic elements (SGEs - genes that are inherited at higher rates than other genes in the genome). Absent such techniques, the release numbers required to transform mosqu...

Okamoto, Kenichi W.; Robert, Michael A.; Gould, Fred; Lloyd, Alun L.

2014-01-01

411

Inhibition of luciferase expression in transgenic Aedes aegypti mosquitoes by Sindbis virus expression of antisense luciferase RNA  

OpenAIRE

A rapid and reproducible method of inhibiting the expression of specific genes in mosquitoes should further our understanding of gene function and may lead to the identification of mosquito genes that determine vector competence or are involved in pathogen transmission. We hypothesized that the virus expression system based on the mosquito-borne Alphavirus, Sindbis (Togaviridae), may efficiently transcribe effector RNAs that inhibit expression of a targeted mosquito gene. To test this hypothe...

Johnson, Barbara W.; Olson, Ken E.; Allen-miura, Tanya; Rayms-keller, Alfredo; Carlson, Jonathan O.; Coates, Craig J.; Jasinskiene, Nijole; James, Anthony A.; Beaty, Barry J.; Higgs, Stephen

1999-01-01

412

Detection of Francisella tularensis in Alaskan Mosquitoes (Diptera: Culicidae) and Assessment of a Laboratory Model for Transmission  

OpenAIRE

Tularemia is a zoonotic disease caused by the Category A bioterrorism agent Francisella tularensis. In Scandinavia, tularemia transmission by mosquitoes has been widely cited in the literature. We tested >2,500 mosquitoes captured in Alaska and found Francisella DNA in 30% of pooled samples. To examine the potential for transmission of Francisella by mosquitoes, we developed a mosquito model of Francisella infection. Larvae of Anopheles gambiae Giles and Aedes aegypti (L.) readily ingest F. t...

Triebenbach, Alison N.; Vogl, Sigrid J.; Lotspeich-cole, Leda; Sikes, Derek S.; Happ, George M.; Hueffer, Karsten

2010-01-01

413

Larvicidal Activity of Trigonella foenum and Nerium oleander Leaves Against Mosquito Larvae Found in Vellore City, India  

OpenAIRE

The aim of this study is to evaluate larvicidal activityof Trigonella foenum and Nerium oleanderagainst mosquito and to test their activity in combination with each other. Mosquito, the primary vector formalaria, dengue and other severe infectious diseases are the major problem in Vellore city. Survey on theprevalence of mosquitoes present in Vellore city and the larvicidal activity of Trigonella foenum and Neriumoleander leaf extracts on the different mosquito larvae were studied. Further we...

Sundar, K.

2010-01-01

414

9 CFR 113.207 - Encephalomyelitis Vaccine, Eastern, Western, and Venezuelan, Killed Virus.  

Science.gov (United States)

...Western, and Venezuelan, Killed Virus. 113.207 Section 113...Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS...STANDARD REQUIREMENTS Killed Virus Vaccines § 113.207...

2010-01-01

415

9 CFR 113.200 - General requirements for killed virus vaccines.  

Science.gov (United States)

...General requirements for killed virus vaccines. 113.200 Section...Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS...STANDARD REQUIREMENTS Killed Virus Vaccines § 113.200...

2010-01-01

416

Conformal Yano-Killing tensors for the Taub-NUT metric  

OpenAIRE

Symmetric conformal Killing tensors and (skew-symmetric) conformal Yano-Killing tensors for Euclidean Taub-NUT metric are given in explicit form. Relations between Yano and CYK tensors in terms of conformal rescaling are discussed.

Jezierski, Jacek; ?ukasik, Maciej

2006-01-01

417

Comparison of mosquito control programs in seven urban sites in Africa, the Middle East, and the Americas.  

Science.gov (United States)

Mosquito control programs at seven urban sites in Kenya, Egypt, Israel, Costa Rica, and Trinidad are described and compared. Site-specific urban and disease characteristics, organizational diagrams, and strengths, weaknesses, obstacles and threats (SWOT) analysis tools are used to provide a descriptive assessment of each mosquito control program, and provide a comparison of the factors affecting mosquito abatement. The information for SWOT analysis is collected from surveys, focus-group discussions, and personal communication. SWOT analysis identified various issues affecting the efficiency and sustainability of mosquito control operations. The main outcome of our work was the description and comparison of mosquito control operations within the context of each study site's biological, social, political, management, and economic conditions. The issues identified in this study ranged from lack of inter-sector collaboration to operational issues of mosquito control efforts. A lack of sustainable funding for mosquito control was a common problem for most sites. Many unique problems were also identified, which included lack of mosquito surveillance, lack of law enforcement, and negative consequences of human behavior. Identifying common virtues and shortcomings of mosquito control operations is useful in identifying "best practices" for mosquito control operations, thus leading to better control of mosquito biting and mosquito-borne disease transmission. PMID:17316882

Impoinvil, Daniel E; Ahmad, Sajjad; Troyo, Adriana; Keating, Joseph; Githeko, Andrew K; Mbogo, Charles M; Kibe, Lydiah; Githure, John I; Gad, Adel M; Hassan, Ali N; Orshan, Laor; Warburg, Alon; Calderón-Arguedas, Olger; Sánchez-Loría, Victoria M; Velit-Suarez, Rosanna; Chadee, Dave D; Novak, Robert J; Beier, John C

2007-10-01

418

BOOK CHAPTER: BIOMETRICS AND BEHAVIOR IN MOSQUITO REPELLENT ASSAY. FOR: INSECT REPELLENTS: PRINCIPLES, METHODS, AND USE. CRC PRESS, BOCA RATON.  

Science.gov (United States)

The discovery and evaluation of mosquito repellents is made using a process called biological assay (bioassay). The identification of mosquito repellent activity in bioassays is complicated because many types of bioassay systems are used and because the methods for rearing and manipulating mosquito...

419

Infectivity of Plasmodium berghei Sporozoites Delivered by Intravenous Inoculation versus Mosquito Bite: Implications for Sporozoite Vaccine Trials  

OpenAIRE

Plasmodium berghei sporozoites delivered by mosquito bite were more infectious to outbred CD-1 mice than were sporozoites delivered by intravenous inoculation. The route of challenge also affected vaccine efficacy. In view of these findings and the fact that mosquito bites are the natural mode of sporozoite delivery, infectious mosquito bites should be considered the challenge protocol of choice for sporozoite vaccine efficacy trials.

Vaughan, Jefferson A.; Scheller, Libia F.; Wirtz, Robert A.; Azad, Abdu F.

1999-01-01

420

Duplication, concerted evolution and purifying selection drive the evolution of mosquito vitellogenin genes  

OpenAIRE

Abstract Background Mosquito vitellogenin (Vtg) genes belong to a small multiple gene family that encodes the major yolk protein precursors required for egg production. Multiple Vtg genes have been cloned and characterized from several mosquito species, but their origin and molecular evolution are poorly understood. Results Here we used in silico and molecular cloning techniques to identify and characterize the evolution of the Vtg...

Sakamoto Joyce M; Provost-Javier Katie N; Armistead Jennifer S; Chen Song; Rasgon Jason L

2010-01-01

421

Awareness and practice about preventive method against mosquito bite in Gujarat  

Directory of Open Access Journals (Sweden)

Full Text Available 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 participated in the study from UHTC area of the Medical college. Door to door visit was conducted to visit the all households. The study was conducted in the month of June 2009, which is observed as Anti-Malaria month in Gujarat. The pilot pre-tested structure questionnaire was used to collect the data. Study respondents were 57% male and 43% female. Almost 99% had knowledge about breeding places of mosquito, but poor knowledge about biting time (20%. 71% of participants knew that mosquito bite causes malaria. 39% 0f households were using mosquito net as protection against the bite, but only 10% were using insecticide treated bed net. There is need of increasing use of insecticide treated bed nets and continuous updating of knowledge about various aspects of mosquito bite.

Niraj Pandit

2010-07-01

422

Using green fluorescent malaria parasites to screen for permissive vector mosquitoes  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background The Plasmodium species that infect rodents, particularly Plasmodium berghei and Plasmodium yoelii, are useful to investigate host-parasite interactions. The mosquito species that act as vectors of human plasmodia in South East Asia, Africa and South America show different susceptibilities to infection by rodent Plasmodium species. P. berghei and P. yoelii infect both Anopheles gambiae and Anopheles stephensi, which are found mainly in Africa and Asia, respectively. However, it was reported that P. yoelii can infect the South American mosquito, Anopheles albimanus, while P. berghei cannot. Methods P. berghei lines that express the green fluorescent protein were used to screen for mosquitoes that are susceptible to infection by P. berghei. Live mosquitoes were examined and screened for the presence of a fluorescent signal in the abdomen. Infected mosquitoes were then examined by time-lapse microscopy to reveal the dynamic behaviour of sporozoites in haemolymph and extracted salivary glands. Results A single fluorescent oocyst can be detected in live mosquitoes and P. berghei can infect A. albimanus. As in other mosquitoes, P. berghei sporozoites can float through the haemolymph and invade A. albimanus salivary glands and they are infectious in mice after subcutaneous injection. Conclusion Fluorescent Plasmodium parasites can be used to rapidly screen susceptible mosquitoes. These results open the way to develop a laboratory model in countries where importation of A. gambiae and A. stephensi is not allowed.

Martin Beatrice

2006-03-01

423

Insectos acuáticos biorreguladores de larvas de mosquito presentes en los "Pantanos de Villa", Lima, Perú  

Scientific Electronic Library Online (English)

Full Text Available SciELO Cuba | Language: Spanish Abstract in spanish Se colectaron y determinaron los principales insectos acuáticos biorreguladores de larvas de mosquito presentes en distintos reservorios en los "Pantanos de Villa", Lima, Perú, donde encontramos larvas y pupas de mosquito de las especies Culex quinquefasciatus Say y Aedes scapularis Rondani, en acua [...] torios donde no observamos insectos acuáticos. En aquéllos donde estaban presentes estos efectivos biorreguladores de larvas de mosquito como fueron Ischnura ramburri (Selys), Ceratura capreola (Hagen), Erithrodiplax cleopatra Ris, Aeschna elsia Calvert, Tropisternus dorsalis Brullé, Thermonectes circunscripta Latr, Belostoma asiaticum (Mayr) y Buenoa absidata Truxal, no encontramos larvas de mosquito. Se muestran las especies de insectos acuáticos colectados y las variables físico-químicas del agua en los reservorios investigados. Abstract in english The main aquatic insects bioregulators of mosquitoe larvae living in different reservoirs at the "Pantanos de Villa", Lima, Perú, were collected and determined. Mosquitoe larvae and pupas of the Culex quinquefasciatus Say and Aedes scapularis Rondani species were found in water reservoirs where aqua [...] tic insects are not observed. In those where there were these effective bioregulators of mosquitoe larvae such as Ischnura ramburii (Selys), Ceratura capreola (Hagen), Erithrodoplax cleopatra Ris, Aschna elsia Calvert, Tropisternus dorsalis Brullé, Thermonectes circunscripta Lart, Belostoma asiaticum (Mayr), and Buenos absidata Truxal, no mosquitoe larvae were found. The species of the aquatic insects collected in the reservoirs as well as the physical and chemical variables of the water are shown.

ISRAEL, GARCÍA ÁVILA; RONALD, VIVAR GUZMÁN; JAIME, QUEZADA MÁRQUEZ; PEDRO, HUAMÁN MAYTA.

1996-12-01

424

Wolbachia enhances West Nile virus (WNV) infection in the mosquito Culex tarsalis.  

Science.gov (United States)

Novel strategies are required to control mosquitoes and the pathogens they transmit. One attractive approach involves maternally inherited endosymbiotic Wolbachia bacteria. After artificial infection with Wolbachia, many mosquitoes become refractory to infection and transmission of diverse pathogens. We evaluated the effects of Wolbachia (wAlbB strain) on infection, dissemination and transmission of West Nile virus (WNV) in the naturally uninfected mosquito Culex tarsalis, which is an important WNV vector in North America. After inoculation into adult female mosquitoes, Wolbachia reached high titers and disseminated widely to numerous tissues including the head, thoracic flight muscles, fat body and ovarian follicles. Contrary to other systems, Wolbachia did not inhibit WNV in this mosquito. Rather, WNV infection rate was significantly higher in Wolbachia-infected mosquitoes compared to controls. Quantitative PCR of selected innate immune genes indicated that REL1 (the activator of the antiviral Toll immune pathway) was down regulated in Wolbachia-infected relative to control mosquitoes. This is the first observation of Wolbachia-induced enhancement of a human pathogen in mosquitoes, suggesting that caution should be applied before releasing Wolbachia-infected insects as part of a vector-borne disease control program. PMID:25010200

Dodson, Brittany L; Hughes, Grant L; Paul, Oluwatobi; Matacchiero, Amy C; Kramer, Laura D; Rasgon, Jason L

2014-07-01

425

Insectos acuáticos biorreguladores de larvas de mosquito presentes en los "Pantanos de Villa", Lima, Perú  

Directory of Open Access Journals (Sweden)

Full Text Available Se colectaron y determinaron los principales insectos acuáticos biorreguladores de larvas de mosquito presentes en distintos reservorios en los "Pantanos de Villa", Lima, Perú, donde encontramos larvas y pupas de mosquito de las especies Culex quinquefasciatus Say y Aedes scapularis Rondani, en acuatorios donde no observamos insectos acuáticos. En aquéllos donde estaban presentes estos efectivos biorreguladores de larvas de mosquito como fueron Ischnura ramburri (Selys, Ceratura capreola (Hagen, Erithrodiplax cleopatra Ris, Aeschna elsia Calvert, Tropisternus dorsalis Brullé, Thermonectes circunscripta Latr, Belostoma asiaticum (Mayr y Buenoa absidata Truxal, no encontramos larvas de mosquito. Se muestran las especies de insectos acuáticos colectados y las variables físico-químicas del agua en los reservorios investigados.The main aquatic insects bioregulators of mosquitoe larvae living in different reservoirs at the "Pantanos de Villa", Lima, Perú, were collected and determined. Mosquitoe larvae and pupas of the Culex quinquefasciatus Say and Aedes scapularis Rondani species were found in water reservoirs where aquatic insects are not observed. In those where there were these effective bioregulators of mosquitoe larvae such as Ischnura ramburii (Selys, Ceratura capreola (Hagen, Erithrodoplax cleopatra Ris, Aschna elsia Calvert, Tropisternus dorsalis Brullé, Thermonectes circunscripta Lart, Belostoma asiaticum (Mayr, and Buenos absidata Truxal, no mosquitoe larvae were found. The species of the aquatic insects collected in the reservoirs as well as the physical and chemical variables of the water are shown.

ISRAEL GARCÍA ÁVILA

1996-12-01

426

Mosquitoes infected with West Nile virus in the Florida Keys, Monroe County, Florida, USA.  

Science.gov (United States)

More than 30,000 mosquitoes in 22 species or species groups were collected from the Florida Keys, Monroe County, FL, USA, in dry ice-baited light and gravid traps. Dry ice-baited traps collected more mosquitoes than did gravid traps. West Nile virus was detected in pools of Anopheles atropos Dyar & Knab, Deinocerites cancer Theobald, and Ochlerotatus taeniorhynchus (Wiedemann). PMID:12943117

Hribar, Lawrence J; Vlach, Joshua J; Demay, David J; Stark, Lillian M; Stoner, Robin L; Godsey, Marvin S; Burkhalter, Kristin L; Spoto, Michael C; James, Shannon S; Smith, Jennifer M; Fussell, Edsel M

2003-05-01

427

Zoonotic Dirofilaria repens (Nematoda: Filarioidea) in Aedes vexans mosquitoes, Czech Republic.  

Science.gov (United States)

The surveillance of vectors for arthropod-borne pathogens is nowadays an important tool in surveillance programmes throughout Europe. Whereas many studies have been performed to screen arthropods for viruses or bacterial pathogens, only limited information is available concerning the geographical distribution and vector range of pathogenic filariae in Central Europe. To consider the prevalence of filarial parasites in mosquito vectors, we performed a molecular survey of mosquitoes for filarial DNA. Mosquito collection was conducted at six study sites in the South Moravian region (Czech Republic) close to the borders with Slovakia and Austria from 2009 to 2011. Molecular screening of mosquitoes was conducted using conventional PCR with primers designed to amplify the mitochondrial cytochromoxidase subunit I gene as well as the partial 5.8S ribosomal RNA gene. A total of 13,222 mosquitoes belonging to six species were captured and distributed into 237 pools with different numbers of individuals. Overall, four pools were positive for Dirofilaria repens (a minimum infection rate 0.03%) at two study sites (both natural and urban). Another filarial parasite detected during a study into Aedes vexans mosquitoes revealed the closest homology to Setaria spp. We detected specific D. repens DNA in Ae. vexans mosquitoes for the first time in the Czech Republic and confirmed the circulation of Dirofilaria spp. in a natural focus of infection providing an epidemiological link between autochthonous canine cases and mosquito vectors in the area studied. PMID:25346197

Rudolf, Ivo; Šebesta, Old?ich; Mendel, Jan; Betášová, Lenka; Bocková, Eva; Jedli?ková, Petra; Venclíková, Kristýna; Blažejová, Hana; Šikutová, Silvie; Hubálek, Zden?k

2014-12-01

428

Don't Let the Bugs Bite: Preventing Dengue and Other Diseases Spread by Mosquitoes  

Centers for Disease Control (CDC) Podcasts

This year (2007) CDC is receiving a great many reports of cases of Dengue fever, which is spread by mosquitoes. This podcast discusses ways travelers to the tropics can protect themselves from mosquito bites.  Created: 12/10/2007 by National Center for the Prevention, Detection and Control of Infectious Diseases (NCPDCID).   Date Released: 12/10/2007.

2007-12-10

429

Vector competence of Aedes aegypti mosquitoes for filarial nematodes is affected by age and nutrient limitation.  

Science.gov (United States)

Mosquitoes are one of the most important vectors of human disease. The ability of mosquitoes to transmit disease is dependent on the age structure of the population, as mosquitoes must survive long enough for the parasites to complete their development and infect another human. Age could have additional effects due to mortality rates and vector competence changing as mosquitoes senesce, but these are comparatively poorly understood. We have investigated these factors using the mosquito Aedes aegypti and the filarial nematode Brugia malayi. Rather than observing any effects of immune senescence, we found that older mosquitoes were more resistant, but this only occurred if they had previously been maintained on a nutrient-poor diet of fructose. Constant blood feeding reversed this decline in vector competence, meaning that the number of parasites remained relatively unchanged as mosquitoes aged. Old females that had been maintained on fructose also experienced a sharp spike in mortality after an infected blood meal ("refeeding syndrome") and few survived long enough for the parasite to develop. Again, this effect was prevented by frequent blood meals. Our results indicate that old mosquitoes may be inefficient vectors due to low vector competence and high mortality, but that frequent blood meals can prevent these effects of age. PMID:25446985

Ariani, Cristina V; Juneja, Punita; Smith, Sophia; Tinsley, Matthew C; Jiggins, Francis M

2015-01-01

430

Reconstructing the flight kinematics of swarming and mating behavior in wild mosquitoes  

Science.gov (United States)

We describe a tracking system for reconstructing three-dimensional tracks of individual mosquitoes in wild swarms and present the results of validating the system by filming swarms and mating events of the malaria mosquito Anopheles gambiae in Mali. The tracking system is designed to address noisy, ...

431

Native Argentinean cyclopoids (Crustacea: Copepoda) as predators of Aedes aegypti and Culex pipiens (Diptera: Culicidae) mosquitoes  

Scientific Electronic Library Online (English)

Full Text Available SciELO Costa Rica | Language: English Abstract in spanish Se hizo una prospección de copépodos en La Plata, Argentina, con los objetivos de caracterizar la comunidad local de copépodos larvívoros en sitios de cría de mosquitos, e identificar nuevas especies depredadoras de los mosquitos de contenedores artificiales Aedes aegypti y Culex pipiens. La diversi [...] dad de ciclopoides larvívoros fue máxima en charcos permanentes. Se examinó la depredación por sexos y edad, la selectividad por especies de mosquito, y la tasa de depredación diaria durante cinco días en Acanthocyclops robustus, Diacyclops uruguayensis, Macrocyclops albidus y Mesocyclops longisetus. Los copépodos hembra presentaron la capacidad depredadora más alta. No se encontró preferencia por alguna especie de mosquito. De acuerdo al potencial de depredación en general, los copépodos se ordenan así: D. uruguayensis Abstract in english Copepods from La Plata, Argentina were investigated to characterize the local community of larvivorous copepods inhabiting mosquito breeding sites and to identify new predator species of the mosquitoes which occur in artificial containers, Aedes aegypti and Culex pipiens. Diversity of larvivorous cy [...] clopoids was highest in permanent pools. Predation by sex and age, selectivity on mosquito species, and daily predation rate during five days were studied for Acanthocyclops robustus, Diacyclops uruguayensis, Macrocyclops albidus and Mesocyclops longisetus. Female copepods presented the highest predatory capacity. No predatory preference for mosquito species was found. According to overall predation potential, copepods were ranked as follows: D. uruguayensis

María C, Tranchida; María V, Micieli; Arnaldo, Maciá; Juan J, García.

1059-10-01

432

Secondary Kill Effect of Deltamethrin on Triatoma infestans  

Science.gov (United States)

Control of the Chagas disease vector, Triatoma infestans, relies on the application of pyrethroid insecticides, especially deltamethrin. We performed laboratory studies to determine whether a T. infestans nymph that comes into contact with a deltamethrin-treated surface horizontally transfers the insecticide to subsequent triatomines. We found that a triatomine that walks on a deltamethrin-treated surface for a short period of time has the ability to transport the insecticide in concentrations sufficient to kill other triatomines with which it comes into contact. The effect was limited to high-density environments, and mortality as a result of secondary exposure was greater among second-instar nymphs compared with fifth-instar nymphs. Our results suggest that deltamethrin could be killing triatomines through both direct and indirect contact, although it remains unclear whether the phenomenon occurs in natural conditions. PMID:21845956

MALONEY, KATHLEEN M.; ANCCA-JUAREZ, JENNY; SALAZAR, RENZO; BORRINI-MAYORI, KATTY; PAMO-TITO, DANITZA; KEATING, JOSEPH A.; LEVY, MICHAEL Z.

2012-01-01

433

Stochastic quantisation and killing symmetries of random systems  

International Nuclear Information System (INIS)

Recent results about the supersymmetries of random systems governed by stochastic differential equations have classical analogues in terms of geometrical symmetries in the configuration space of commuting variables. The related results are: (1) The reversible drift velocity of a stationary stochastic process in a Killing vector of the diffusion metric; (2) the irreversible drift velocity is a geodesic tangent vector; (3) the stationary current conservation equation is a special case of the general result that scalar products of Killing vectors with geodesic tangent vectors are constants of the motion. The physical postulate is that microscopic reversibility is to the normality of time translation generators what time reversal invariance is to the hermiticity of hamiltonians. (orig.)

434

An evaluation of Sex-Age-Kill (SAK) model performance  

Science.gov (United States)

The sex-age-kill (SAK) model is widely used to estimate abundance of harvested large mammals, including white-tailed deer (Odocoileus virginianus). Despite a long history of use, few formal evaluations of SAK performance exist. We investigated how violations of the stable age distribution and stationary population assumption, changes to male or female harvest, stochastic effects (i.e., random fluctuations in recruitment and survival), and sampling efforts influenced SAK estimation. When the simulated population had a stable age distribution and ?? > 1, the SAK model underestimated abundance. Conversely, when ?? Sex-age-kill estimates may be precise at large spatial scales, such as the state level, but less so at the individual management unit level. Alternative models, such as statistical age-at-harvest models, which require similar data types, might allow for more robust, broad-scale demographic assessments.

Millspaugh, J.J.; Skalski, J.R.; Townsend, R.L.; Diefenbach, D.R.; Boyce, M.S.; Hansen, L.P.; Kammermeyer, K.

2009-01-01

435

A Research for Massive Fish Kills in Lake Bafa (Turkey  

Directory of Open Access Journals (Sweden)

Full Text Available As there were massive fish kills in Lake Bafa which is a lagoon situated in Southwestern Turkey in October, 2006, water and fish samples were taken from the region. Water samples were analysed physicochemically, toxicologically and microbiologically and fish samples were subjected to toxicological analysis. The analyses of lake water revealed on oxygen value of approximately 5.0 mg/L, salinity 16.2 ?, nitrogen from ammonia 0.1 mg/L, nitrogen nitrite 0.013 mg/L, and total organic carbon 13 mg/L. Total coliform count was 1100 MPN/100 ml and faecal coliform count was 28 MPN/100 ml. There was no detection of any pesticide residues in fish and water samples. Massive fish kills are thought to be due to the decrease in water quality.

Murat Yabanl?

2011-06-01

436

Scientific projection paper for mutagenesis, transformation and cell killing  

International Nuclear Information System (INIS)

Our knowledge about mutagenesis, transformation, and cell killing by ionizing radiation consists of large bodies of data, which are potentially useful in terms of application to human risk assessment and to the constructive use of radiation, as in cancer treatment. The three end-points discussed above are united by at least five significant concepts in radiation research strategy: (1) The inter-relationships among the important end-points, mutation, carcinogenesis, and cell killing. Research on one is meaningful only in the context of information about the other two. (2) The interaction of radiations with other agents in producing these end-points. (3) The mechanisms of action of other environmental mutagenic, carcinogenic, and cytotoxic agents. (4) The use of repair deficient human mutant cells. (5) The study of radiation damage mechanisms. There is no better way to extrapolate laboratory data to the clinical and public worlds than to understand the underlying biological mechanisms that produced the data

437

Are U.S drone targeted killings within the confines of the law?  

OpenAIRE

Equally discomforting is the PlayStation mentality that surrounds drone killings. Young military personnel raised on a diet of video games now kill real people remotely using joysticks. Far removed from the human consequences of their actions, how will this generation of fighters value the right to life? How will commanders and policy makers keep themselves immune from the deceptively antiseptic nature of drone killings? Will killing be a more attractive option than capture? Wi...

Chengeta, Thompson

2011-01-01

438