WorldWideScience

Sample records for water-based insecticidal aerosols

  1. Effectiveness and acceptance of total release insecticidal aerosol cans as a control measure in reducing dengue vectors.

    Science.gov (United States)

    Pai, Hsiu-Hua; Hsu, Err-Lieh

    2014-01-01

    The effectiveness of regular application of insecticidal fogging in reducing dengue is questionable, since delays occur between peak time of outbreak and insecticide administrations. Moreover, many residents do not accept indoor application because of concern about insecticide contamination of household items. The study described in this article was designed to evaluate the effectiveness and acceptance of insecticidal aerosol cans to reduce dengue vectors inside and outside of homes. Residents in Kaohsiung City of South Taiwan were provided with two formulations of aerosol cans (permethrin 3.75% weight/weight [w/w] and cypermethrin 1.716% w/w) and were requested to use these aerosol cans. Although the indoor ovitrap index of the permethrin group returned to the original level in week 3, the index of the cypermethrin group decreased 60% to 20%. The residents accepted the insecticidal aerosol cans but complained of unfavorable effects caused by traditional insecticidal fogging. Results indicate that the insecticidal aerosol cans may serve as a supplementary household control measure for dengue vectors during the time period between the peak of outbreak and the administration of government-organized insecticide fogging.

  2. An examination of the effect of aerosolized permanone insecticide on zebra finch susceptibility to West Nile virus

    Science.gov (United States)

    Jankowski, Mark D.; Murray, E. Moore; Hofmeister, Erik K.

    2017-01-01

    West Nile virus is primarily maintained cryptically primarily in avian (Passerine) populations where it is transmitted by Culex spp. mosquitoes. Mosquito control measures currently include physical activities to reduce mosquito breeding sites, the application of mosquito larvicides, or aerosolized insecticides to kill adults (adulticides) when arboviral diseases such as West Nile virus (WNV) or Zika virus are detected in mosquito populations. Organochlorine, organohosphorus, carbamate and pyrethroid insecticides are often used. Previous work suggests an effect of pyrethroids on the immune system in a variety of vertebrates. We examined the effects of exposure to aerosolized Permanone® 30:30 insecticide (permethrin and piperonyl butoxide in soy oil vehicle) at ∼103−106x potential environmental concentrations on the response of captive zebra finches (Taeniopygia guttata) to experimental challenge with WNV. Compared to vehicle control birds, WNV outcome was unchanged (65% of birds produced a viremia) in the ‘low’ exposure (9.52 mg/m3±3.13 SD permethrin) group, but reduced in the ‘high’ exposure (mean 376.5 mg/m3±27.9 SD permethrin) group (30% were viremic) (p < 0.05). After clearing WNV infection, birds treated with Permanone regained less body mass than vehicle treated birds (p < 0.001). Our study suggests that exposure to aerosolized Permanone insecticide at levels exceeding typical application rates has the potential to not change or mildly enhance a bird's resistance to WNV.

  3. An examination of the effect of aerosolized Permanone insecticide on zebra finch susceptibility to West Nile virus.

    Science.gov (United States)

    Jankowski, Mark D; Moore, Murray E; Hofmeister, Erik K

    2017-12-01

    West Nile virus (WNV) is maintained cryptically primarily in avian (passerine) populations, where it is transmitted by Culex spp. mosquitoes. Mosquito-control measures currently include physical activities to reduce mosquito-breeding sites and the application of mosquito larvicides or aerosolized insecticides to kill adults (adulticides) when arboviral diseases such as WNV or Zika virus are detected in mosquito populations. Organochlorine, organophosphorus, carbamate, and pyrethroid insecticides are often used. Previous work suggests an effect of pyrethroids on the immune system in a variety of vertebrates. We examined the effects of exposure to aerosolized Permanone® 30:30 insecticide (permethrin and piperonyl butoxide in soy oil vehicle) at approximately 10 3 to 10 6 times potential environmental concentrations on the response of captive zebra finches (Taeniopygia guttata) to experimental challenge with WNV. Compared to vehicle control birds, WNV outcome was unchanged (65% of birds produced a viremia) in the "low" exposure (9.52 ± 3.13 mg/m 3 standard deviation [SD] permethrin) group but reduced in the "high" exposure (mean 376.5 ± 27.9 mg/m 3 SD permethrin) group (30% were viremic; p < 0.05). After clearing WNV infection, birds treated with Permanone regained less body mass than vehicle-treated birds (p < 0.001). The present study suggests that exposure to aerosolized Permanone insecticide at levels exceeding typical application rates has the potential to not change or to mildly enhance a bird's resistance to WNV. Environ Toxicol Chem 2017;36:3376-3386. Published 2017 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America. Published 2017 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.

  4. Droplet sampling of an oil-based and two water-based antievaporant ultra-low volume insecticide formulations using Teflon- and magnesium oxide-coated slides.

    Science.gov (United States)

    Chaskopoulou, Alexandra; Latham, Mark D; Pereira, Roberto M; Koehler, Philip G

    2013-06-01

    We estimated the diameters below which 50% and 90% of the volume of droplets exist (Dv50 and Dv90, respectively) of 1 oil-based (Permanone 30-30) and 2 water-based (AquaReslin, Aqua-K-Othrine) antievaporant aerosols (with the Film Forming Aqueous Spray Technology [FFAST]) using Teflon- and magnesium oxide (MgO)-coated slides and determined whether the aging of the droplets on the slides (up to 60 min) exhibited any significant effect on Dv50 and Dv90 calculations. There were no significant differences in either Dv50 or Dv90 estimates on MgO-coated slides at 0 min and 60 min for all 3 products tested. On Teflon-coated slides, the only product that showed significant difference between 0 min and 60 min in both Dv50 and Dv90 estimates was Aqua-K-Othrine, perhaps due to a difference in formulation components. Specifically, both values corresponding to Dv50 and Dv90 at 60 min decreased by approximately 50% when compared to the values at 0 min. For the other 2 products, AquaReslin and Permanone, aging of droplets on Teflon up to 60 min did not have any significant effect on Dv50 and Dv90 values. To further investigate the behavior of Aqua-K-Othrine droplets on Teflon-coated slides we observed the droplets immediately after spraying and at 10-min intervals under different conditions of temperature and humidity. The majority of the shrinkage occurred within the 1st 10 min after impaction on the slides under all conditions tested. So in most field situations where slides are read several hours or days after collection, this shrinkage would not be observed. The MgO-coated slides should be the preferred field method for sampling droplets of Aqua-K-Othirne with the FFAST antievaporant technology.

  5. Aerosol insecticide distribution inside a flour mill: Assessment using droplet measurements and bioassays

    Science.gov (United States)

    The distribution of aerosol applications of pyrethrin+methoprene, generated from a mechanical fogger, and pyrethrin+pyriproxyfen, dispensed from a pressurized cylinder, were characterized inside a pilot-scale flour mill using measurements of particle size and concentration and effects on adult confu...

  6. Collection of Viable Aerosolized Influenza Virus and Other Respiratory Viruses in a Student Health Care Center through Water-Based Condensation Growth.

    Science.gov (United States)

    Pan, Maohua; Bonny, Tania S; Loeb, Julia; Jiang, Xiao; Lednicky, John A; Eiguren-Fernandez, Arantzazu; Hering, Susanne; Fan, Z Hugh; Wu, Chang-Yu

    2017-01-01

    The dynamics and significance of aerosol transmission of respiratory viruses are still controversial, for the major reasons that virus aerosols are inefficiently collected by commonly used air samplers and that the collected viruses are inactivated by the collection method. Without knowledge of virus viability, infection risk analyses lack accuracy. This pilot study was performed to (i) determine whether infectious (viable) respiratory viruses in aerosols could be collected from air in a real world environment by the viable virus aerosol sampler (VIVAS), (ii) compare and contrast the efficacy of the standard bioaerosol sampler, the BioSampler, with that of the VIVAS for the collection of airborne viruses in a real world environment, and (iii) gain insights for the use of the VIVAS for respiratory virus sampling. The VIVAS operates via a water vapor condensation process to enlarge aerosolized virus particles to facilitate their capture. A variety of viable human respiratory viruses, including influenza A H1N1 and H3N2 viruses and influenza B viruses, were collected by the VIVAS located at least 2 m from seated patients, during a late-onset 2016 influenza virus outbreak. Whereas the BioSampler when operated following our optimized parameters also collected virus aerosols, it was nevertheless overall less successful based on a lower frequency of virus isolation in most cases. This side-by-side comparison highlights some limitations of past studies based on impingement-based sampling, which may have generated false-negative results due to either poor collection efficiency and/or virus inactivation due to the collection process. IMPORTANCE The significance of virus aerosols in the natural transmission of respiratory diseases has been a contentious issue, primarily because it is difficult to collect or sample virus aerosols using currently available air sampling devices. We tested a new air sampler based on water vapor condensation for efficient sampling of viable

  7. DESCRIPTIVE ANALYSIS OF HOUSEHOLD INSECTICIDE IN COMMUNITY

    Directory of Open Access Journals (Sweden)

    Aram Sih Joharina

    2014-06-01

    Full Text Available The most popular and effective vector control is the use of insecticides. Surveywas done in the houses and some supermarket to know many kind of insecticides usedby people. The formulation, active ingredients, and concentration were recorded andanalyzed. Based on the results of the survey, household insecticides formulated invarious formulations such as liquid, mosquito coils, aerosol, mat and liquid vaporizer,chalk and paper burn. In addition to formulation, active ingredients and concentrationalso vary. Almost all household insecticide products on the market using the syntheticpyrethroid. Selection of household insecticides should be adapted to the type of insectpests because each type of active ingredients and formulations have advantages anddisadvantages. Efficacy of various active ingredients in various formulations has beenstudied and the results vary widely. Insecticide efficacy is influenced by the type ofactive ingredient, dosage, concentration, formulation, and the susceptibility of insectspecies, temperature, sunlight, wind, and application method.Key word: household insecticide, insecticides formulation, active ingredientsABSTRAKPengendalian serangga vektor penyakit yang paling efektif dan populer adalahpenggunaan insektisida. Survei dilakukan di masyarakat dan supermarket untuk mengetahuijcnis-jenis insektisida yang digunakan oleh masyarakat. Berdasarkan hasil survei, insektisidarumah tangga terkemas dalam berbagai formulasi antara lain liquid, mosquito coil, aerosol, mat& liquid vaporizer, kapur serangga dan kertas bakar. Disamping formulasi, bahan aktif dankonsentrasi yang digunakan juga bermacam-macam. Hampir semua produk insektisida rumahtangga di pasaran menggunakan bahan aktif golongan piretroid sintetik. Pemilihan insektisidarumah tangga hendaknya disesuaikan dengan jenis serangga sasaran karena tiap jenis bahan aktifdan formulasi memiliki kelcbihan dan kekurangan. Efikasi berbagai bahan aktif dalam berbagaiformulasi telah

  8. Insecticide Exposure in Parkinsonism

    National Research Council Canada - National Science Library

    Bloomquist, Jeffrey

    2003-01-01

    Behavioral, neurochemical, and immunocytochemical studies are characterizing the possible role of insecticide exposure in the etiology of Parkinson's disease as it may relate to Gulf War Syndrome. Chlorpyrifos (CP) and/or permethrin (PM...

  9. Insecticide Exposure in Parkinsonism

    National Research Council Canada - National Science Library

    Bloomquist, Jeffrey

    2001-01-01

    Behavioral, neurochemical, and immunocytochemical studies characterized the possible role of insecticide exposure in the etiology of Parkinson's disease as it may relate to Gulf War Syndrome. Chlorpyrifos (CP) and permethrin (PM...

  10. Insecticide Exposure in Parkinsonism

    National Research Council Canada - National Science Library

    Bloomquist, Jeffrey

    2002-01-01

    Behavioral, neurochemical, and immunocytochemical studies characterized the possible role of insecticide exposure in the etiology of Parkinson's disease as it may relate to Gulf War Syndrome. Chlorpyrifos (CP) and permethrin (PM...

  11. More about Insecticides

    Directory of Open Access Journals (Sweden)

    E.K. Hartwig

    1980-09-01

    Full Text Available An insecticide is a chemical used to kill insects. Insect control can also include other materials such as repellents, oils, antifeedants and attractants. Ideally, an insecticide would effectively control any target insect exposed to it and would be harmless to man and his domestic animals. It would also be readily available in necessary quantitie s , s table chemically, noninflammable, easily prepared and applied, noncorrosive, non-staining, and would have no undesirable odour.

  12. Insecticide resistance in bedbugs in Thailand and laboratory evaluation of insecticides for the control of Cimex hemipterus and Cimex lectularius (Hemiptera: Cimicidae).

    Science.gov (United States)

    Tawatsin, Apiwat; Thavara, Usavadee; Chompoosri, Jakkrawarn; Phusup, Yutthana; Jonjang, Nisarat; Khumsawads, Chayada; Bhakdeenuan, Payu; Sawanpanyalert, Pathom; Asavadachanukorn, Preecha; Mulla, Mir S; Siriyasatien, Padet; Debboun, Mustapha

    2011-09-01

    Bedbugs are found in many countries around the world, and in some regions they are resistant to numerous insecticides. This study surveyed bedbugs in Thailand and determined their resistance to insecticides. The surveys were carried out in six provinces that attract large numbers of foreign tourists: Bangkok, Chonburi, Chiang Mai, Ubon Ratchathani, Phuket, and Krabi. Bedbugs were collected from hotels and colonized in the laboratory to evaluate their resistance to insecticides. Cimex hemipterus (F.) was found in some hotels in Bangkok, Chonburi, Phuket, and Krabi, whereas Cimex lectularius L. was found only in hotels in Chiang Mai. No bedbugs were found in Ubon Ratchathani. The colonized bedbugs showed resistance to groups of insecticides, including organochlorines (dichlorodiphenyl trichloroethane, dieldrin), carbamates (bendiocarb, propoxur), organophosphates (malathion, fenitrothion), and pyrethroids (cyfluthrin, deltamethrin, permethrin, lambda-cyhalothrin, etofenprox) in tests using World Health Organization insecticide-impregnated papers. The new insecticides imidacloprid (neonicotinoid group), chlorfenapyr (pyrrole group), and fipronil (phenylpyrazole group) were effective against the bedbugs; however, organophosphate (diazinon), carbamates (fenobucarb, propoxur), and pyrethroids (bifenthrin, cypermethrin, esfenvalerate, etofenprox) were ineffective. Aerosols containing various pyrethroid insecticides with two to four different active ingredients were effective against the bedbugs. The results obtained from this study suggested that both species of bedbugs in Thailand have developed marked resistance to various groups of insecticides, especially those in the pyrethroid group, which are the most common insecticides used for pest control. Therefore, an integrated pest management should be implemented for managing bedbugs in Thailand.

  13. Botanical Insecticides in Plant Protection

    OpenAIRE

    Martina Grdiša; Kristina Gršić

    2013-01-01

    Botanical insecticides are natural compounds with insecticidal properties and their use in crop protection is as old as agricultural practice. Although they have been in use for over one hundred years, the advent of synthetic insecticides has unfortunately displaced their use today. Due to fast action, low cost, easy application and efficiency against a wide range of harmful species, synthetic insecticides have become an important part of pest management in modern agricultural systems....

  14. Microbial Metabolites with Insecticidal Properties

    Science.gov (United States)

    Cole, M.; Rolinson, G. N.

    1972-01-01

    A screen of fungi for insecticidal activity revealed the ability of Aspergillus versicolor to make versimide, methyl-α-(methylsuccinimido)acrylate, a novel contact insecticide. The larvicidal activities of Alternaria tenuis and Fusarium lateritium were found to be due to tenuazonic acid and diacetoxyscirpenol, respectively. Thiolutin, cycloheximide, rubratoxin, patulin, trichothecin, an actinomycin, and scirpene-producing fungi also had insecticidal activity. PMID:4628800

  15. Microbial metabolites with insecticidal properties.

    Science.gov (United States)

    Cole, M; Rolinson, G N

    1972-10-01

    A screen of fungi for insecticidal activity revealed the ability of Aspergillus versicolor to make versimide, methyl-alpha-(methylsuccinimido)acrylate, a novel contact insecticide. The larvicidal activities of Alternaria tenuis and Fusarium lateritium were found to be due to tenuazonic acid and diacetoxyscirpenol, respectively. Thiolutin, cycloheximide, rubratoxin, patulin, trichothecin, an actinomycin, and scirpene-producing fungi also had insecticidal activity.

  16. Organic aerosols

    Energy Technology Data Exchange (ETDEWEB)

    Penner, J.E.

    1994-01-01

    Organic aerosols scatter solar radiation. They may also either enhance or decrease concentrations of cloud condensation nuclei. This paper summarizes observed concentrations of aerosols in remote continental and marine locations and provides estimates for the sources of organic aerosol matter. The anthropogenic sources of organic aerosols may be as large as the anthropogenic sources of sulfate aerosols, implying a similar magnitude of direct forcing of climate. The source estimates are highly uncertain and subject to revision in the future. A slow secondary source of organic aerosols of unknown origin may contribute to the observed oceanic concentrations. The role of organic aerosols acting as cloud condensation nuclei (CCN) is described and it is concluded that they may either enhance or decrease the ability of anthropogenic sulfate aerosols to act as CCN.

  17. Effects of the insecticide

    Directory of Open Access Journals (Sweden)

    VESELA YANCHEVA

    2012-01-01

    Full Text Available The main goal of the present work is to study the effects of the new neonicotinoid insecticide „Actara 25 WG" on the intensity of expression of glycogen in the liver of common carp (Cyprinus carpio L. by using PAS-reaction on cryosections. Common carp is an economically important fish species, which is widely used as a bioindicator for the health of freshwater basins since it could also survive at very contaminated sites. We have used 6.6 mg/L, 10 mg/L and 20 mg/L of the test chemical under laboratory conditions. The results demonstrated that the intensity of staining of the PAS-reaction is directly proportional to the increasing concentration of the insecticide. In addition, this indicates that the amount of glycogen in hepatocytes also increased. Conglomerates of accumulated glycogen in certain hepatocytes were found at the highest concentration of the insecticide. Therefore, we consider that under the influence of „Actara 25 WG" the process of glyconeogenesis in the liver of the studied fish accelerates.

  18. Alternative insecticides: an urgent need.

    Science.gov (United States)

    Zaim, Morteza; Guillet, Pierre

    2002-04-01

    Most insecticides used against pests and vectors of human disease (e.g. fleas, flies and mosquitoes) are spin-offs from agrochemical research and development. The arsenal of safe and cost-effective public health insecticides is being depleted by restrictions for various reasons (e.g. insecticide resistance, unacceptable side effects and non re-registration) and the number of new products launched is dwindling. Mobilizing public resources and establishment of partnerships to support research and development of public health insecticides is crucial in the post-DDT and post-pyrethroid era.

  19. Deposition from Ultra-low Volume Application of Public Health Insecticides in a Hot Desert Environment

    Science.gov (United States)

    2015-06-01

    Shaffer KR, Hester PG. 1990. Effects of pressure and flow rate CythionH droplet size produced by three different ground ULV aerosol generators. J Am Mosq...sand flies to selected insecticides in North Africa and the Middle East. J Am Mosq Control Assoc 17:23–27. Tietze NS, Hester PG, Shaffer KR. 1994. Mass

  20. Environmental fate model for ultra-low-volume insecticide applications used for adult mosquito management

    Science.gov (United States)

    Schleier, Jerome J.; Peterson, Robert K.D.; Irvine, Kathryn M.; Marshall, Lucy M.; Weaver, David K.; Preftakes, Collin J.

    2012-01-01

    One of the more effective ways of managing high densities of adult mosquitoes that vector human and animal pathogens is ultra-low-volume (ULV) aerosol applications of insecticides. The U.S. Environmental Protection Agency uses models that are not validated for ULV insecticide applications and exposure assumptions to perform their human and ecological risk assessments. Currently, there is no validated model that can accurately predict deposition of insecticides applied using ULV technology for adult mosquito management. In addition, little is known about the deposition and drift of small droplets like those used under conditions encountered during ULV applications. The objective of this study was to perform field studies to measure environmental concentrations of insecticides and to develop a validated model to predict the deposition of ULV insecticides. The final regression model was selected by minimizing the Bayesian Information Criterion and its prediction performance was evaluated using k-fold cross validation. Density of the formulation and the density and CMD interaction coefficients were the largest in the model. The results showed that as density of the formulation decreases, deposition increases. The interaction of density and CMD showed that higher density formulations and larger droplets resulted in greater deposition. These results are supported by the aerosol physics literature. A k-fold cross validation demonstrated that the mean square error of the selected regression model is not biased, and the mean square error and mean square prediction error indicated good predictive ability.

  1. Toxicology of insecticides to mammals.

    Science.gov (United States)

    Marrs, Timothy C

    2012-10-01

    Many insecticides target structures or functions in non-target species, including mammals. This is particularly true of those that target the insect nervous system, such as the organochlorines, anticholinesterases and GABA antagonists. Another group of insecticides target structures or functions not present in mammals, and this group of insecticides has considerable target species specificity, but there are often potential targets in mammals. Octopamine is closely related to adrenaline and amitraz (an octopamine receptor agonist) and acts in mammals at α2-adrenergic receptors. Although there are potential targets in mammals for juvenile hormone mimics and ecdysone receptor agonists, there is no evidence that the mammalian toxicity of either group is related to their insecticidal activity. Nor do chitin synthesis inhibitors have high mammalian toxicity. Copyright © 2012 Society of Chemical Industry.

  2. Neurotoxicology of insecticides and pheromones

    National Research Council Canada - National Science Library

    Narahashi, Toshio

    1979-01-01

    The purpose of this symposium was to provide a forum where a variety of scientists who were interested in the interactions of insecticides and pheromones with the nervous system got together to exchange their views...

  3. Diatomaceous Earths - Natural Insecticides

    Directory of Open Access Journals (Sweden)

    Zlatko Korunić

    2013-01-01

    Full Text Available The regulatory issues for diatomaceous earth (DE cover three fields: consumer safety,worker safety, and proof of efficacy against pests. For consumer safety, regulatory issuesare similar to those for other additives, and a principal benefit of DEs is their removal bynormal processing methods. For worker safety, regulatory issues are similar to those forother dusts, such as lime. The proof of potential insecticide values of DE may be assessedby using the analysis of physical and chemical properties of DE and its effect on grainproperties and the proof of efficacy may be regulated by bioassay of standard design.Integrated pest management (IPM, a knowledge-based system, is rapidly providing aframework to reduce dependence on synthetic chemical pesticides. The main principleof post-harvest IPM is to prevent problems rather than to react to them. The specificcurative measures using synthetic pesticides should be applied only when infestationoccurs. DE and enhanced diatomaceous earth (EDE formulations hold significant promiseto increase the effectiveness and broaden the adoption of IPM strategies, thereby reducingthe need for synthetic pesticides. By incorporating DE in an effective IPM program,grain is protected against infestation, loss caused by insects is prevented and grain qualityis maintained until the grain is processed. Cases study data on the use of DE for commodityand structural treatment show that DE is already a practical alternative to syntheticpesticides in some applications.

  4. Health Benefits of Water-based Exercise

    Science.gov (United States)

    ... Pools Operating Public Hot Tubs/Spas Recommendations for Hydrotherapy Tanks Preventing Pool Chemical-Associated Health Events Chloramines & ... arthritis have more health improvements after participating in hydrotherapy than with other activities 8 . Water-based exercise ...

  5. Tropospheric Aerosols

    Science.gov (United States)

    Buseck, P. R.; Schwartz, S. E.

    2003-12-01

    It is widely believed that "On a clear day you can see forever," as proclaimed in the 1965 Broadway musical of the same name. While an admittedly beautiful thought, we all know that this concept is only figurative. Aside from Earth's curvature and Rayleigh scattering by air molecules, aerosols - colloidal suspensions of solid or liquid particles in a gas - limit our vision. Even on the clearest day, there are billions of aerosol particles per cubic meter of air.Atmospheric aerosols are commonly referred to as smoke, dust, haze, and smog, terms that are loosely reflective of their origin and composition. Aerosol particles have arisen naturally for eons from sea spray, volcanic emissions, wind entrainment of mineral dust, wildfires, and gas-to-particle conversion of hydrocarbons from plants and dimethylsulfide from the oceans. However, over the industrial period, the natural background aerosol has been greatly augmented by anthropogenic contributions, i.e., those produced by human activities. One manifestation of this impact is reduced visibility (Figure 1). Thus, perhaps more than in other realms of geochemistry, when considering the composition of the troposphere one must consider the effects of these activities. The atmosphere has become a reservoir for vast quantities of anthropogenic emissions that exert important perturbations on it and on the planetary ecosystem in general. Consequently, much recent research focuses on the effects of human activities on the atmosphere and, through them, on the environment and Earth's climate. For these reasons consideration of the geochemistry of the atmosphere, and of atmospheric aerosols in particular, must include the effects of human activities. (201K)Figure 1. Impairment of visibility by aerosols. Photographs at Yosemite National Park, California, USA. (a) Low aerosol concentration (particulate matter of aerodynamic diameter less than 2.5 μm, PM2.5=0.3 μg m-3; particulate matter of aerodynamic diameter less than 10

  6. Efficacy of an Esfenvalerate plus Methoprene Aerosol for the Control of Eggs and Fifth Instars of the Plodia interpunctella (Lepidoptera: Pyralidae)

    Science.gov (United States)

    Aerosol insecticides may provide an alternative to fumigants for control of the Indianmeal moth, Plodia interpunctella (Hübner), a major insect pest of stored processed food. In this study, eggs and larvae (5th instars) of P. interpunctella were exposed to aerosol applications of the pyrethroid esf...

  7. TOMS Absorbing Aerosol Index

    Data.gov (United States)

    Washington University St Louis — TOMS_AI_G is an aerosol related dataset derived from the Total Ozone Monitoring Satellite (TOMS) Sensor. The TOMS aerosol index arises from absorbing aerosols such...

  8. Tunable Water-based Microwave Metasurface

    DEFF Research Database (Denmark)

    Kapitanova, Polina; Odit, Mikhail; Dobrykh, Dmitry

    2017-01-01

    A water-based dynamically tunable microwave metasurface is developed and experimentally investigated. A simple approach to tune the metasurface properties by changing the shape of water-based unit cells by gravitation force is proposed. The transmission spectra of the metasurface for linear...... and circular polarizations of the incident wave are numerically simulated and experimentally measured under the metasurface rotation around a horizontal axis. The measured changes of the transmission coefficient magnitude up to 8 dB at 1.25 GHz are reported while rotating the metasurface by the 90 degrees...... angle. The proposed approach can be used to design cheap metasurfaces for electromagnetic wave control in the microwave frequency range....

  9. Insecticide Exposures on Commercial Aircraft: A Literature Review and Screening Level Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Maddalena, Randy I.; McKone, Thomas E.

    2008-10-01

    The objective of this project was to provide initial estimates of the relationship between insecticide use on passenger aircraft and exposure levels present in the cabin environment. The work was initially divided into three tasks including 1) a review of insecticide application practices in commercial aircraft, 2) exploratory measurements of insecticide concentrations in treated aircraft and 3) screening level exposure modeling. Task 1 gathered information that is needed to assess the time-concentration history of insecticides in the airline cabin. The literature review focused on application practices, information about the cabin environment and existing measurements of exposure concentrations following treatment. Information from the airlines was not available for estimating insecticide application rates in the U.S. domestic fleet or for understanding how frequently equipment rotate into domestic routes following insecticide treatment. However, the World Health Organization (WHO) recommends several methods for treating aircraft with insecticide. Although there is evidence that these WHO guidelines may not always be followed, and that practices vary by airline, destination, and/or applicator company, the guidelines in combination with information related to other indoor environments provides a plausible basis for estimating insecticide loading rates on aircraft. The review also found that while measurements of exposure concentrations following simulated aerosol applications are available, measurements following residual treatment of aircraft or applications in domestic aircraft are lacking. Task 2 focused on developing an approach to monitor exposure concentrations in aircraft using a combination of active and passive sampling methods. An existing active sampling approach was intended to provide data immediately following treatment while a passive sampler was developed to provide wider coverage of the fleet over longer sampling periods. The passive sampler, based

  10. CADDIS Volume 2. Sources, Stressors and Responses: Insecticides - Detailed Conceptual Diagram

    Science.gov (United States)

    Introduction to the insecticides module, when to list insecticides as a candidate cause, ways to measure insecticides, simple and detailed conceptual diagrams for insecticides, insecticides module references and literature reviews.

  11. CADDIS Volume 2. Sources, Stressors and Responses: Insecticides - Simple Conceptual Diagram

    Science.gov (United States)

    Introduction to the insecticides module, when to list insecticides as a candidate cause, ways to measure insecticides, simple and detailed conceptual diagrams for insecticides, insecticides module references and literature reviews.

  12. Preliminary assessment of insecticidal activity of Moroccan ...

    African Journals Online (AJOL)

    Microbial insecticides are considered as the most sustainable and ecologically acceptable means of crop protection. Here we report the ability of some Moroccan actinobacteria isolates to produce larvicidal compounds against the Medfly (Ceratitis capitata Wied.). Thus, actinobacteria isolates were tested for their insecticidal ...

  13. Insecticide Resistance Reducing Effectiveness of Malaria Control

    Centers for Disease Control (CDC) Podcasts

    2007-01-24

    Malaria prevention is increasingly insecticide based. Dr. John Gimnig, an entomologist with the Division of Parasitic Diseases, CDC, discusses evidence that mosquito resistance to insecticides, which is measured in the laboratory, could compromise malaria prevention in the field.  Created: 1/24/2007 by Emerging Infectious Diseases.   Date Released: 3/13/2007.

  14. Aerosol gels

    Science.gov (United States)

    Sorensen, Christopher M. (Inventor); Chakrabarti, Amitabha (Inventor); Dhaubhadel, Rajan (Inventor); Gerving, Corey (Inventor)

    2010-01-01

    An improved process for the production of ultralow density, high specific surface area gel products is provided which comprises providing, in an enclosed chamber, a mixture made up of small particles of material suspended in gas; the particles are then caused to aggregate in the chamber to form ramified fractal aggregate gels. The particles should have a radius (a) of up to about 50 nm and the aerosol should have a volume fraction (f.sub.v) of at least 10.sup.-4. In preferred practice, the mixture is created by a spark-induced explosion of a precursor material (e.g., a hydrocarbon) and oxygen within the chamber. New compositions of matter are disclosed having densities below 3.0 mg/cc.

  15. Aerosol typing - key information from aerosol studies

    Science.gov (United States)

    Mona, Lucia; Kahn, Ralph; Papagiannopoulos, Nikolaos; Holzer-Popp, Thomas; Pappalardo, Gelsomina

    2016-04-01

    Aerosol typing is a key source of aerosol information from ground-based and satellite-borne instruments. Depending on the specific measurement technique, aerosol typing can be used as input for retrievals or represents an output for other applications. Typically aerosol retrievals require some a priori or external aerosol type information. The accuracy of the derived aerosol products strongly depends on the reliability of these assumptions. Different sensors can make use of different aerosol type inputs. A critical review and harmonization of these procedures could significantly reduce related uncertainties. On the other hand, satellite measurements in recent years are providing valuable information about the global distribution of aerosol types, showing for example the main source regions and typical transport paths. Climatological studies of aerosol load at global and regional scales often rely on inferred aerosol type. There is still a high degree of inhomogeneity among satellite aerosol typing schemes, which makes the use different sensor datasets in a consistent way difficult. Knowledge of the 4d aerosol type distribution at these scales is essential for understanding the impact of different aerosol sources on climate, precipitation and air quality. All this information is needed for planning upcoming aerosol emissions policies. The exchange of expertise and the communication among satellite and ground-based measurement communities is fundamental for improving long-term dataset consistency, and for reducing aerosol type distribution uncertainties. Aerosol typing has been recognized as one of its high-priority activities of the AEROSAT (International Satellite Aerosol Science Network, http://aero-sat.org/) initiative. In the AEROSAT framework, a first critical review of aerosol typing procedures has been carried out. The review underlines the high heterogeneity in many aspects: approach, nomenclature, assumed number of components and parameters used for the

  16. Sea Spray Aerosols

    DEFF Research Database (Denmark)

    Butcher, Andrew Charles

    Aerosols are important climactically. Their specific emissions are key to reducing the uncertainty in global climate models. Marine aerosols make up the largest source of primary aerosols to the Earth's atmosphere. Uncertainty in marine aerosol mass and number flux lies in separating primary emis...... with decreasing temperature. Unique surface images of bubble size distributions allow the investigation of temperature, bubble size, and particle production......Aerosols are important climactically. Their specific emissions are key to reducing the uncertainty in global climate models. Marine aerosols make up the largest source of primary aerosols to the Earth's atmosphere. Uncertainty in marine aerosol mass and number flux lies in separating primary...... entrainment may account for the large discrepancy in energy input for the two systems. In the third study, the temperature dependence of sea spray aerosol production is probed with the use of a highly stable temperature controlled plunging jet. Similar to previous studies, particle production increases...

  17. Which came first: insecticides or resistance?

    Science.gov (United States)

    Ffrench-Constant, Richard H

    2007-01-01

    Mutations that confer resistance to insecticides are well documented. However, so far, we have been unable to determine whether these mutations arose before or after the introduction of insecticides. Recently, a landmark study showed that resistance to Malathion can be detected in pinned specimens of Australian sheep blowflies that were collected before the introduction of the insecticide. This finding has numerous implications for our understanding of the prevalence of resistance to new compounds. It also indicates that pre-existing resistance alleles might not carry the fitness cost that is associated with new mutations.

  18. Aerosol mobility size spectrometer

    Science.gov (United States)

    Wang, Jian; Kulkarni, Pramod

    2007-11-20

    A device for measuring aerosol size distribution within a sample containing aerosol particles. The device generally includes a spectrometer housing defining an interior chamber and a camera for recording aerosol size streams exiting the chamber. The housing includes an inlet for introducing a flow medium into the chamber in a flow direction, an aerosol injection port adjacent the inlet for introducing a charged aerosol sample into the chamber, a separation section for applying an electric field to the aerosol sample across the flow direction and an outlet opposite the inlet. In the separation section, the aerosol sample becomes entrained in the flow medium and the aerosol particles within the aerosol sample are separated by size into a plurality of aerosol flow streams under the influence of the electric field. The camera is disposed adjacent the housing outlet for optically detecting a relative position of at least one aerosol flow stream exiting the outlet and for optically detecting the number of aerosol particles within the at least one aerosol flow stream.

  19. Transformation of the insecticide teflubenzuron by microorganisms

    NARCIS (Netherlands)

    Finkelstein, Z.I.; Baskunov, B.P.; Rietjens, I.M.C.M.; Boersma, M.G.; Vervoort, J.; Golovleva, L.A.

    2001-01-01

    Transformation of teflubenzuron, the active component in the insecticide commercialized as Nomolt, by soil microorganisms was studied. It was shown that microorganisms, belonging to Bacillus, Alcaligenes, Pseudomonas and Acinetobacter genera are capable to perform the hydrolytic cleavage of the

  20. Aerosols and Climate

    Indian Academy of Sciences (India)

    How do Aerosols Influence Climate? Although making up only one part in a billion of the mass of the atmosphere, aerosols have the potential to significantly influ- ence the climate. The global impact of aerosol is assessed as the change imposed on planetary radiation measured in Wm-2, which alters the global temperature ...

  1. Aerosols and Climate

    Indian Academy of Sciences (India)

    Aerosols and Climate · Slide 2 · Slide 3 · Slide 4 · Slide 5 · Slide 6 · Principal efforts in improving the understanding of Climate impact of aerosols - · Slide 8 · Observations of Aerosol – from space (Spatial variation) · AOD around Indian region from AVHRR · Dust absorption efficiency over Great Indian Desert from Satellite ...

  2. Aerosol distribution apparatus

    Science.gov (United States)

    Hanson, W.D.

    An apparatus for uniformly distributing an aerosol to a plurality of filters mounted in a plenum, wherein the aerosol and air are forced through a manifold system by means of a jet pump and released into the plenum through orifices in the manifold. The apparatus allows for the simultaneous aerosol-testing of all the filters in the plenum.

  3. Methoprene and synergized pyrethrins as an aerosol treatment to control Plodia interpunctella (Hubner), the Indian meal moth (Lepidoptera: Pyralidae)

    Science.gov (United States)

    Aerosol insecticides (also known as ULV or fogging treatments) delivered through an ultra-low volume application system, are available commercially to control insect pests such as Plodia interpunctella Hübner, the Indianmeal moth. However, little is known about the susceptibility of eggs of P. inter...

  4. Water-based Tourism - A Strategic Vision for Galway

    OpenAIRE

    Institute, Marine

    2002-01-01

    Water-based Tourism – A Strategic Vision for Galway is a report commissioned by a consortium of Agencies in collaboration with Ireland West Tourism. The terms of reference were to undertake a study which would: - evaluate the potential to develop the water-based tourism and leisure resource in Galway City and County; - identify the potential and provide a development strategy for at least six pilot water-based tourism and leisure initiatives in selected geographic locations throughout Galway;...

  5. Imaging aerosol viscosity

    Science.gov (United States)

    Pope, Francis; Athanasiadis, Thanos; Botchway, Stan; Davdison, Nicholas; Fitzgerald, Clare; Gallimore, Peter; Hosny, Neveen; Kalberer, Markus; Kuimova, Marina; Vysniauskas, Aurimas; Ward, Andy

    2017-04-01

    Organic aerosol particles play major roles in atmospheric chemistry, climate, and public health. Aerosol particle viscosity is important since it can determine the ability of chemical species such as oxidants, organics or water to diffuse into the particle bulk. Recent measurements indicate that OA may be present in highly viscous states; however, diffusion rates of small molecules such as water appear not to be limited by these high viscosities. We have developed a technique for measuring viscosity that allows for the imaging of aerosol viscosity in micron sized aerosols through use of fluorescence lifetime imaging of viscosity sensitive dyes which are also known as 'molecular rotors'. These rotors can be introduced into laboratory generated aerosol by adding minute quantities of the rotor to aerosol precursor prior to aerosolization. Real world aerosols can also be studied by doping them in situ with the rotors. The doping is achieved through generation of ultrafine aerosol particles that contain the rotors; the ultrafine aerosol particles deliver the rotors to the aerosol of interest via impaction and coagulation. This work has been conducted both on aerosols deposited on microscope coverslips and on particles that are levitated in their true aerosol phase through the use of a bespoke optical trap developed at the Central Laser Facility. The technique allows for the direct observation of kinetic barriers caused by high viscosity and low diffusivity in aerosol particles. The technique is non-destructive thereby allowing for multiple experiments to be carried out on the same sample. It can dynamically quantify and track viscosity changes during atmospherically relevant processes such oxidation and hygroscopic growth (1). This presentation will focus on the oxidation of aerosol particles composed of unsaturated and saturated organic species. It will discuss how the type of oxidant, oxidation rate and the composition of the oxidized products affect the time

  6. Insecticide susceptibility of Anopheles stephensi to DDT and current insecticides in an elimination area in Iran

    Directory of Open Access Journals (Sweden)

    Mehdi Zare

    2016-11-01

    Full Text Available Abstract Background Iran has recently initiated a malaria elimination program with emphasis on vector control strategies which are heavily reliant on indoor residual spraying and long-lasting insecticidal nets. Insecticide resistance seriously threatens the efficacy of vector control strategies. This study was conducted to determine the insecticide susceptibility of Anopheles stephensi to DDT and current insecticides in Jask county as an active malaria focus in southeastern Iran. Methods In this study, the anopheline larvae were collected from different aquatic habitats in Jask county and transported to insectarium, fed with sugar and then 3-day-old adults were used for susceptibility tests. WHO insecticide susceptibility tests were performed with DDT (4 %, malathion (5 %, lambda-cyhalothrin (0.05 %, deltamethrin (0.05 % and permethrin (0.75 %. Results The field strain of An. stephensi was found resistant to DDT and lambda-cyhalothrin. The LT50 values for DDT and lambda-cyhalothrin in this species were 130.25, and 37.71 min, respectively. Moreover, An. stephensi was completely susceptible to malathion and permethrin and tolerant to deltamethrin. Conclusion The present study results confirm the resistance of the major malaria vector, An. stephensi, to DDT and lambda-cyhalothrin, and tolerance to deltamethrin, which could gradually increase and spread into other malaria endemic areas. Thus, there is a need for regular monitoring of insecticide resistance in order to select suitable insecticides for vector control interventions towards malaria elimination.

  7. Electronic structure of pesticides: 1. Organochlorine insecticides

    Energy Technology Data Exchange (ETDEWEB)

    Novak, Igor, E-mail: inovak@csu.edu.au [Charles Sturt University, POB 883, Orange, NSW 2800 (Australia); Kovac, Branka [Physical Chemistry Division, ' R. Boskovic' Institute, HR-10000 Zagreb (Croatia)

    2011-11-15

    Highlights: {yields} Electronic structure of several organochlorine insecticides has been determined by UV photoelectron spectroscopy and high-level ab initio calculations. {yields} The electronic structure obtained from spectra has been related to their biological activity. {yields} The molecular modes of binding to appropriate receptors are rationalized in view of the molecule's electronic structure and conformational flexibility. - Abstract: The electronic structures of six organochlorine insecticides: {gamma}-lindane (I), aldrin (II), dieldrin (III), DDD (IV), DDE (V) and DDT (VI) have been investigated by UV photoelectron spectroscopy (UPS), quantum chemical calculations and comparison with molecular modelling studies. Their electronic and molecular structures are discussed in order to rationalize their biological activity. In this work we relate the biological activity of these insecticides to their experimentally observed electronic and molecular structures.

  8. Insecticide Groups and Their Effects in Aquatic Environment

    OpenAIRE

    Kayhan, Figen Esin; KAYMAK, Güllü; Yön, Nazan Deniz

    2014-01-01

    Over the past decade aquatic environments have become more contaminated by insecticides. Insecticides have a toxic effect on aquatic organisms and they become a part of the food chain by accumulation. Therefore it is very important to study the effects of subchronic exposure to environmental concentrations of insecticides on aquatic organisms. The aim of this review is to investigate different effects of insecticide groups on aquatic organisms in aquatic environment. 

  9. Aerosols Science and Technology

    CERN Document Server

    Agranovski, Igor

    2011-01-01

    This self-contained handbook and ready reference examines aerosol science and technology in depth, providing a detailed insight into this progressive field. As such, it covers fundamental concepts, experimental methods, and a wide variety of applications, ranging from aerosol filtration to biological aerosols, and from the synthesis of carbon nanotubes to aerosol reactors.Written by a host of internationally renowned experts in the field, this is an essential resource for chemists and engineers in the chemical and materials disciplines across multiple industries, as well as ideal supplementary

  10. Microbes as interesting source of novel insecticides: A review ...

    African Journals Online (AJOL)

    Since these versatile organisms are amenable for genetic engineering, strains with good insecticidal properties can be identified, evaluated and utilized for pest control. This paper reviews the insecticidal properties of microbes and their potential utility in pest management. Keywords: Microbes, insecticides, metabolites, ...

  11. treated bednets compared with insecticide house spraying in ...

    African Journals Online (AJOL)

    Objectives_ The objective of this study was to produce data indicating whether insecticide-treated bednets should replac insecticide house spraying as a malaria control method in. South Africa_ We report 2 years of preliminary data on malaria incidence comparing areas receiving insecticide- treated bednets and those ...

  12. Insecticide susceptibility status of human biting mosquitoes in ...

    African Journals Online (AJOL)

    Background: There has been a rapid emergence in insecticide resistance among mosquito population to commonly used public health insecticides. This situation presents a challenge to chemicals that are currently used to control mosquitoes in sub-Saharan African. Furthermore, there is limited information on insecticide ...

  13. Effectiveness of a Reduced-Risk Insecticide Based Bed Bug Management Program in Low-Income Housing

    Directory of Open Access Journals (Sweden)

    Narinderpal Singh

    2013-11-01

    Full Text Available Bed bug (Cimex lectularius L. infestations are becoming increasingly common in low-income communities. Once they are introduced, elimination is very difficult. As part of the efforts to develop effective and safe bed bug management programs, we conducted a laboratory study evaluating the efficacy of a reduced-risk insecticide—Alpine aerosol (0.5% dinotefuran. We then conducted a field evaluation of a reduced-risk insecticide based integrated pest management (IPM program in low-income family apartments with young children. In laboratory evaluations, direct spray and 5 min exposure to dry Alpine aerosol residue caused 100.0 ± 0.0 and 91.7 ± 8.3% mortality to bed bug nymphs, respectively. Direct Alpine aerosol spray killed 91.3 ± 4.3% of the eggs. The IPM program included education, steam, bagging infested linens, placing intercepting devices under furniture legs and corners of rooms, applying Alpine aerosol and Alpine dust (0.25% dinotefuran, 95% diatomaceous earth dust, and regularly scheduled monitoring and re-treatment. Nine apartments ranging from 1–1,428 (median: 29 bed bugs based on visual inspection and Climbup interceptor counts were included. Over a 6-month period, an average 172 g insecticide (Alpine aerosol + Alpine dust was used in each apartment, a 96% reduction in pesticide usage compared to chemical only treatment reported in a similar environment. The IPM program resulted in an average of 96.8 ± 2.2% reduction in the number of bed bugs. However, elimination of bed bugs was only achieved in three lightly infested apartments (<30 bed bugs at the beginning. Elimination success was closely correlated with the level of bed bug populations.

  14. molluscidial, insecticidal and piscicidal activities of barringtonia ...

    African Journals Online (AJOL)

    MOLLUSCIDIAL, INSECTICIDAL AND PISCICIDAL ACTIVITIES OF BARRINGTONIA RACEMOSA. ... The rank order of toxicity for the pericarp extracts tested was for the snails: CHCl3 extract 367.3 ppm >Ethyl acetate extract 390.3 ppm. > methanol extract 530.4 ppm > petroleum ether extract 704.27 ppm. The larvicidal ...

  15. (AJST) INSECTICIDAL ACTIVITY OF EXTRACTS DERIVED FROM ...

    African Journals Online (AJOL)

    opiyo

    Science and Engineering Series Vol. 2, No. 2, pp. .... wide range of activities, for example extracts from the the ... processing and application of the product inexpensive. In ... From time immemorial poles of ... the insecticidal activity of the mangrove R. mucronata ... (29) and regression analysis (30) to determine the LC50's of.

  16. Protectant, insecticidal and antimicrobial potentials of Dalbergia ...

    African Journals Online (AJOL)

    PRECIOUS

    2009-12-01

    Dec 1, 2009 ... 2Department of Biological Sciences, University of Abuja, Gwagwalada, Abuja, Nigeria. Accepted 30 October, 2009. The protectant, insecticidal and ... properties demonstrate the great potentials of D. saxatilis for use in agriculture and medicine. The relevance of bioassay-guided fractionation in ensuring ...

  17. Surveillance and insecticide susceptibility status of Culicine ...

    African Journals Online (AJOL)

    Vector control programs in Nigeria are mostly targeted towards reducing the burden of malaria with less emphasis placed on other debilitating vector borne diseases such as dengue, yellow fever and filariasis. This study assessed the indoor resting densities and insecticide susceptibility status of Culex and Aedes ...

  18. Storage crambe seed treated with insecticides

    Directory of Open Access Journals (Sweden)

    Geraldo Cabral e Souza

    2014-02-01

    Full Text Available The use of low quality seeds with a lower physiological reflects one of the major causes of low productivity. Thus the storage conditions of seed must be taken into consideration. This research aimed to evaluate the influence of natural and synthetic insecticides on emergence and seed storage of crambe, as these substances are essential to prevent infestation of seeds of other species by harmful organisms. The experimental design was a randomized block in factorial 3 x 8 ( 8 substances and 3 storage times with 4 replications. We assessed the following natural insecticides: saffron, lime, ash, neem, diatomaceous earth, and synthetic: chlorpyrifos and deltamethrin; besides the control consisting of seeds without any treatment. We evaluated the percentage of emergence, speed of emergence index and time to reach 50 % of emergency. In all characteristics, it was found that no influence of neem on seed vigor. There are disadvantages in the application of the insecticides chlorpyrifos and diatomaceous earth, which interfered with the emergence rate of seeds of crambe. The seeds treated with other insecticides had different behavior of untreated seeds after 120 days of storage to assess the time that they take to reach 50 % germination.

  19. Radical Scavenging, Antimicrobial and Insecticidal Efficacy of ...

    African Journals Online (AJOL)

    Lichens are self-supporting symbiotic association of mycobiont and photobiont. The present study was conducted to investigate antimicrobial, insecticidal and radical scavenging potential of methanol extract of two macrolichens viz. Parmotrema cristiferum (Taylor) Hale and Dirinaria applanata (Fée) D.D. Awasthi.

  20. Insecticides for Suppression of Nylanderia fulva

    Directory of Open Access Journals (Sweden)

    Dawn Calibeo

    2017-08-01

    Full Text Available Nylanderia fulva (Mayr is an invasive ant that is a serious pest in the southern United States. Pest control operators and homeowners are challenged to manage pest populations below acceptable thresholds. Contact and bait insecticides are key components of an Integrated Pest Management (IPM strategy, however, little is known about their efficacy. In repellency and efficacy bioassays, N. fulva were not completely repelled by any insecticide tested, although fewer ants crossed a surface treated with Temprid®. Few insecticides provided rapid control. Termidor® and Temprid® were the best performing with mean mortality of 100% in 13.4 and 19.0 days, respectively. In no-choice bait acceptance studies, it was shown that N. fulva generally had greater acceptance of carbohydrate-based ant baits (Advion®, InTiceTM (gel, and InTiceTM (granular. However, mortality was low for the InTiceTM baits in a 7-day bioassay. Maxforce® Ant Killer Bait Gel and Advance® 375A in the spring and Maxforce® Complete in the summer and fall required the fewest days to reach 100% mortality. Bait active ingredients that resulted in the highest mortality were hydramethylnon and fipronil. These data on the efficacy of commercially available contact and bait insecticides provide valuable information to manage this invasive pest.

  1. Preliminary assessment of insecticidal activity of Moroccan ...

    African Journals Online (AJOL)

    aghomotsegin

    2015-03-11

    Mar 11, 2015 ... Microbial insecticides are considered as the most sustainable and ecologically acceptable means of crop protection. Here we report the ability of some Moroccan actinobacteria isolates to produce larvicidal compounds against the Medfly (Ceratitis capitata Wied.). Thus, actinobacteria isolates were.

  2. Fungicide and insecticide residues in rice grains

    Directory of Open Access Journals (Sweden)

    Gustavo Mack Teló

    2017-01-01

    Full Text Available The objective of this study was to analyse residues of fungicides and insecticides in rice grains that were subjected to different forms of processing. Field work was conducted during three crop seasons, and fungicides and insecticides were applied at different crop growth stages on the aerial portion of the rice plants. Azoxystrobin, difenoconazole, propiconazole, tebuconazole, and trifloxystrobin fungicides were sprayed only once at the R2 growth stage or twice at the R2 and R4 growth stages; cypermethrin, lambda-cyhalothrin, permethrin, and thiamethoxam insecticides were sprayed at the R2 growth stage; and permethrin was sprayed at 5-day intervals from the R4 growth stage up to one day prior to harvest. Pesticide residues were analysed in uncooked, cooked, parboiled, polished and brown rice grains as well as rice hulls during the three crop seasons, for a total of 1458 samples. The samples were analysed by gas chromatography with electron capture detection (GC-ECD using modified QuEChERS as the extraction method. No fungicide or insecticide residues were detected in rice grain samples; however, azoxystrobin and cypermethrin residues were detected in rice hull samples.

  3. Pharmacognostic standardization and insecticidal activity of the ...

    African Journals Online (AJOL)

    Lamiaceae have traditionally been used in developing countries for their insecticidal and repellant properties against several insect species. Hyptis suaveolens has been reported to repel mosquitoes and other insects effectively when burnt overnight in rooms. This study was aimed at establishing the Pharmacognostic ...

  4. Water-based Tourism and Leisure Product Audit 2006

    OpenAIRE

    Huskyes, E.; O?connor, K.

    2006-01-01

    In consultation with key agencies and stakeholders, the Marine Institute is drafting a Development Strategy for the marine/water-based tourism and leisure sector for the period 2007-2013. Preparation and research for this has involved the completion of a Water-based Tourism and Leisure Product Audit. The Institute worked in collaboration with Royal Haskoning, spatial planning consultants, and Kevin O’Connor, Donegal County Council, to complete the audit. The objective of the audit is to syste...

  5. Sensitivity of aerosol direct radiative forcing to aerosol vertical profile

    Directory of Open Access Journals (Sweden)

    Jung-Ok Choi

    2014-05-01

    Full Text Available Aerosol vertical profile significantly affects the aerosol direct radiative forcing at the TOA level. The degree to which the aerosol profile impacts the aerosol forcing depends on many factors such as presence of cloud, surface albedo and aerosol single scattering albedo (SSA. Using a radiation model, we show that for absorbing aerosols (with an SSA of 0.7–0.8 whether aerosols are located above cloud or below induces at least one order of magnitude larger changes of the aerosol forcing than how aerosols are vertically distributed in clear skies, above cloud or below cloud. To see if this finding also holds for the global average aerosol direct radiative effect, we use realistic AOD distribution by integrating MODIS, MISR and AERONET observations, SSA from AERONET and cloud data from various satellite observations. It is found that whether aerosols are above cloud or below controls about 70–80% of the effect of aerosol vertical profile on the global aerosol radiative effect. Aerosols below cloud contribute as much to the global aerosol radiative effect as aerosols above cloud.

  6. Atmosphere aerosol satellite project Aerosol-UA

    Science.gov (United States)

    Milinevsky, Gennadi; Yatskiv, Yaroslav; Syniavskyi, Ivan; Bovchaliuk, Andrii; Degtyaryov, Oleksandr; Sosonkin, Mikhail; Mishchenko, Michael; Danylevsky, Vassyl; Ivanov, Yury; Oberemok, Yevgeny; Masley, Volodymyr; Rosenbush, Vera; Moskalev, Sergii

    2017-04-01

    The experiment Aerosol-UA is Ukrainian space mission aimed to the terrestrial atmospheric aerosol spatial distribution and microphysics investigations. The experiment concept is based on idea of Glory/APS mission of precise orbital measurements of polarization and intensity of the sunlight scattered by the atmosphere, aerosol and the surface the multichannel Scanning Polarimeter (ScanPol) with narrow field-of-view. ScanPol measurements will be accompanied by the wide-angle MultiSpectral Imager-Polarimeter (MSIP). The ScanPol is designed to measure Stokes parameters I, Q, U within the spectral range from the UV to the SWIR in a wide range of phase angles along satellite ground path. Expected ScanPol polarimetric accuracy is 0.15%. A high accuracy measurement of the degree of linear polarization is provided by on-board calibration of the ScanPol polarimeter. On-board calibration is performed for each scan of the mirror scanning system. A set of calibrators is viewed during the part of the scan range when the ScanPol polarimeter looks in the direction opposite to the Earth's surface. These reference assemblies provide calibration of the zero of the polarimetric scale (unpolarized reference assembly) and the scale factor for the polarimetric scale (polarized reference assembly). The zero of the radiometric scale is provided by the dark reference assembly.The spectral channels of the ScanPol are used to estimate the tropospheric aerosol absorption, the aerosol over the ocean and the land surface, the signals from cirrus clouds, stratospheric aerosols caused by major volcanic eruptions, and the contribution of the Earth's surface. The imager-polarimeter MSIP will collect 60°x60° field-of-view images on the state of the atmosphere and surface in the area, where the ScanPol polarimeter will measure, to retrieve aerosol optical depth and polarization properties of aerosol by registration of three Stokes parameters simultaneously in three spectral channels. The two more

  7. DARE : Dedicated Aerosols Retrieval Experiment

    NARCIS (Netherlands)

    Smorenburg, K.; Courrèges-Lacoste, G.B.; Decae, R.; Court, A.J.; Leeuw, G. de; Visser, H.

    2004-01-01

    At present there is an increasing interest in remote sensing of aerosols from space because of the large impact of aerosols on climate, earth observation and health. TNO has performed a study aimed at improving aerosol characterisation using a space based instrument and state-of-the-art aerosol

  8. The activity of the pyrrole insecticide chlorfenapyr in mosquito bioassay: towards a more rational testing and screening of non-neurotoxic insecticides for malaria vector control

    National Research Council Canada - National Science Library

    Oxborough, Richard M; N'Guessan, Raphael; Jones, Rebecca; Kitau, Jovin; Ngufor, Corine; Malone, David; Mosha, Franklin W; Rowland, Mark W

    2015-01-01

    .... Chlorfenapyr is a pyrrole insecticide which shows no cross resistance to insecticide classes normally used for vector control and is effective on mosquito nets under experimental hut conditions...

  9. Neem (Azadirachta indica): towards the ideal insecticide?

    Science.gov (United States)

    Benelli, Giovanni; Canale, Angelo; Toniolo, Chiara; Higuchi, Akon; Murugan, Kadarkarai; Pavela, Roman; Nicoletti, Marcello

    2017-02-01

    Pesticide resistance is going to change rapidly our antibiotics and insecticides arsenal. In this scenario, plant-derived natural products are considered valuable candidates to reverse this negative trend. Growing research attention is focused on neem (Azadirachta indica, Meliaceae), exploring the utility of its products as insecticides and antibiotics. In this review, we summarised the knowledge on neem oil and neem cake by-products in arthropod pest control, with special reference to mosquito vectors of public health importance. To the best of our knowledge, neem-borne products currently showed effective and eco-friendly features, including little non-target effects, multiple mechanisms of action, low cost, easy production in countries with limited industrial facilities. In particular, the potentiality of neem cake as ideal and affordable source of mosquitocidal compounds in anopheline and aedine control programmes is outlined. Overall, we propose the employ of neem-based products as an advantageous alternative to build newer and safer arthropod control tools.

  10. A global analysis on water-based fire extinguishing agent

    Science.gov (United States)

    WANG, Shuai

    2017-04-01

    Due to the superiority of the attribute of water, water-based fire extinguishing agent is considered as one of most effectively fire extinguishing agents. NFPA has developed two standards regarding to water-based fire extinguishing agents. ISO technical committee working group is also preparing for developing a standard about the subject fire extinguishing agent. China also has its own national GB standard about water-based standard. This paper aims at to elaborate standard requirements and methods in different technical documents and standards currently available around the world with a view to summarize the main concern in different standards, and trying to find out valuable information for readers in future research and development.

  11. Aerosols from biomass combustion

    Energy Technology Data Exchange (ETDEWEB)

    Nussbaumer, T.

    2001-07-01

    This report is the proceedings of a seminar on biomass combustion and aerosol production organised jointly by the International Energy Agency's (IEA) Task 32 on bio energy and the Swiss Federal Office of Energy (SFOE). This collection of 16 papers discusses the production of aerosols and fine particles by the burning of biomass and their effects. Expert knowledge on the environmental impact of aerosols, formation mechanisms, measurement technologies, methods of analysis and measures to be taken to reduce such emissions is presented. The seminar, visited by 50 participants from 11 countries, shows, according to the authors, that the reduction of aerosol emissions resulting from biomass combustion will remain a challenge for the future.

  12. Emergency Protection from Aerosols

    Energy Technology Data Exchange (ETDEWEB)

    Cristy, G.A.

    2001-11-13

    Expedient methods were developed that could be used by an average person, using only materials readily available, to protect himself and his family from injury by toxic (e.g., radioactive) aerosols. The most effective means of protection was the use of a household vacuum cleaner to maintain a small positive pressure on a closed house during passage of the aerosol cloud. Protection factors of 800 and above were achieved.

  13. Marine Aerosols and Clouds.

    Science.gov (United States)

    Brooks, Sarah D; Thornton, Daniel C O

    2017-10-13

    The role of marine bioaerosols in cloud formation and climate is currently so uncertain that even the sign of the climate forcing is unclear. Marine aerosols form through direct emissions and through the conversion of gasphase emissions to aerosols in the atmosphere. The composition and size of aerosols determine how effective they are in catalyzing the formation of water droplets and ice crystals in clouds by acting as cloud condensation nuclei and ice nucleating particles, respectively. Marine organic aerosols may be sourced both from recent regional phytoplankton blooms that add labile organic matter to the surface ocean and from long-term global processes, such as the upwelling of old refractory dissolved organic matter from the deep ocean. Understanding the formation of marine aerosols and their propensity to catalyze cloud formation processes are challenges that must be addressed given the major uncertainties associated with aerosols in climate models. Expected final online publication date for the Annual Review of Marine Science Volume 10 is January 3, 2018. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

  14. Multiple insecticide resistance: an impediment to insecticide-based malaria vector control program.

    Science.gov (United States)

    Yewhalaw, Delenasaw; Wassie, Fantahun; Steurbaut, Walter; Spanoghe, Pieter; Van Bortel, Wim; Denis, Leen; Tessema, Dejene A; Getachew, Yehenew; Coosemans, Marc; Duchateau, Luc; Speybroeck, Niko

    2011-01-12

    Indoor Residual Spraying (IRS), insecticide-treated nets (ITNs) and long-lasting insecticidal nets (LLINs) are key components in malaria prevention and control strategy. However, the development of resistance by mosquitoes to insecticides recommended for IRS and/or ITNs/LLINs would affect insecticide-based malaria vector control. We assessed the susceptibility levels of Anopheles arabiensis to insecticides used in malaria control, characterized basic mechanisms underlying resistance, and evaluated the role of public health use of insecticides in resistance selection. Susceptibility status of An. arabiensis was assessed using WHO bioassay tests to DDT, permethrin, deltamethrin, malathion and propoxur in Ethiopia from August to September 2009. Mosquito specimens were screened for knockdown resistance (kdr) and insensitive acetylcholinesterase (ace-1(R)) mutations using AS-PCR and PCR-RFLP, respectively. DDT residues level in soil from human dwellings and the surrounding environment were determined by Gas Chromatography with Electron Capture Detector. An. arabiensis was resistant to DDT, permethrin, deltamethrin and malathion, but susceptible to propoxur. The West African kdr allele was found in 280 specimens out of 284 with a frequency ranged from 95% to 100%. Ace-1(R) mutation was not detected in all specimens scored for the allele. Moreover, DDT residues were found in soil samples from human dwellings but not in the surrounding environment. The observed multiple-resistance coupled with the occurrence of high kdr frequency in populations of An. arabiensis could profoundly affect the malaria vector control programme in Ethiopia. This needs an urgent call for implementing rational resistance management strategies and integrated vector control intervention.

  15. Multiple insecticide resistance: an impediment to insecticide-based malaria vector control program.

    Directory of Open Access Journals (Sweden)

    Delenasaw Yewhalaw

    Full Text Available BACKGROUND: Indoor Residual Spraying (IRS, insecticide-treated nets (ITNs and long-lasting insecticidal nets (LLINs are key components in malaria prevention and control strategy. However, the development of resistance by mosquitoes to insecticides recommended for IRS and/or ITNs/LLINs would affect insecticide-based malaria vector control. We assessed the susceptibility levels of Anopheles arabiensis to insecticides used in malaria control, characterized basic mechanisms underlying resistance, and evaluated the role of public health use of insecticides in resistance selection. METHODOLOGY/PRINCIPAL FINDINGS: Susceptibility status of An. arabiensis was assessed using WHO bioassay tests to DDT, permethrin, deltamethrin, malathion and propoxur in Ethiopia from August to September 2009. Mosquito specimens were screened for knockdown resistance (kdr and insensitive acetylcholinesterase (ace-1(R mutations using AS-PCR and PCR-RFLP, respectively. DDT residues level in soil from human dwellings and the surrounding environment were determined by Gas Chromatography with Electron Capture Detector. An. arabiensis was resistant to DDT, permethrin, deltamethrin and malathion, but susceptible to propoxur. The West African kdr allele was found in 280 specimens out of 284 with a frequency ranged from 95% to 100%. Ace-1(R mutation was not detected in all specimens scored for the allele. Moreover, DDT residues were found in soil samples from human dwellings but not in the surrounding environment. CONCLUSION: The observed multiple-resistance coupled with the occurrence of high kdr frequency in populations of An. arabiensis could profoundly affect the malaria vector control programme in Ethiopia. This needs an urgent call for implementing rational resistance management strategies and integrated vector control intervention.

  16. Insecticide resistance in the bed bug comes with a cost

    OpenAIRE

    Jennifer R. Gordon; Potter, Michael F.; Haynes, Kenneth F

    2015-01-01

    Adaptation to new environmental stress is often associated with an alteration of one or more life history parameters. Insecticide resistant populations of insects often have reduced fitness relative to susceptible populations in insecticide free environments. Our previous work showed that three populations of bed bugs, Cimex lectularius L., evolved significantly increased levels of resistance to one product containing both ?-cyfluthrin and imidacloprid insecticides with only one generation of...

  17. Comparative toxicities of organophosphate and pyrethroid insecticides to aquatic macroarthropods

    OpenAIRE

    Halstead, Neal T.; Civitello, David J.; Rohr, Jason R.

    2015-01-01

    As agricultural expansion and intensification increase to meet the growing global food demand, so too will insecticide use and thus the risk of non-target effects. Insecticide pollution poses a particular threat to aquatic macroarthropods, which play important functional roles in freshwater ecosystems. Thus, understanding the relative toxicities of insecticides to non-target functional groups is critical for predicting effects on ecosystem functions. We exposed two common macroarthropod preda...

  18. Comparative toxicity of insecticides to Choristoneura species (Lepidoptera: Tortricidae)

    Science.gov (United States)

    Jacqueline L. Robertson; Nancy L. Gillette; Barbara A. Lucas; Robert M. Russell; N.E. Savin

    1978-01-01

    Selected carbamate, chlorinated hydrocarbon, organophosphorous, and pyrethroid insecticides were tested on six Choristoneura species: conflictana (Walker), fumiferana (Clemens), lambertiana ponderosana Obraztsov, occidentalis Freeman, pinus Freeman, and...

  19. Physical metrology of aerosols; Metrologie physique des aerosols

    Energy Technology Data Exchange (ETDEWEB)

    Boulaud, D.; Vendel, J. [CEA Saclay, 91 - Gif-sur-Yvette (France). Inst. de Protection et de Surete Nucleaire

    1996-12-31

    The various detection and measuring methods for aerosols are presented, and their selection is related to aerosol characteristics (size range, concentration or mass range), thermo-hydraulic conditions (carrier fluid temperature, pressure and flow rate) and to the measuring system conditions (measuring frequency, data collection speed, cost...). Methods based on aerosol dynamic properties (inertial, diffusional and electrical methods) and aerosol optical properties (localized and integral methods) are described and their performances and applications are compared

  20. Insecticide susceptibility status of malaria vectors in India: A review.

    Directory of Open Access Journals (Sweden)

    Raj Kumar Singh

    2014-03-01

    Full Text Available Malaria is a disease caused by the biting of the Anopheline mosquito vectors. Vector control is the major component of the strategy for malaria control which aims to prevent parasite transmission through interventions targeting adult malaria vectors. For this, chemical, biological and mechanical methods are applied. In chemical approach of controlling malarial mosquitoes, insecticides have been used extensively for larviciding, indoor residual spraying and impregnation of bed nets in the last few decades. As a result of this, vector resistance to these insecticides have been recorded in various parts of the country and mosquitoes have developed wide spread resistance to some of these insecticides. There is need for countrywide and regular surveys for monitoring the insecticide susceptibility status of major vectors and assessing their implications on vector control activities. In India, most of the studies revealed that resistance against DDT is prevalent in most of the malaria vector species. Bye and large, An. culicifacies and An. stephensi are resistant to malathion also and resistance against synthetic pyrethroid is developing. Moreover, An. fluviatilis, An. minimus and An. annularis are susceptible to malathion and deltamethrin. As the chemical molecules available for the role of insecticide are very few and invention of new molecules takes time, this is the need of time that increasing trend of resistance status of mosquitoes against the insecticides used in the vector control programme have to be minimized. There are only a few reports on the susceptibility status of the mosquitoes against various insecticides and thus more emphasis on these studies should be given. Again the appropriate use of the insecticides like rationale use with rotation of insecticides and insecticide combinations can be an effective strategy to combat this insecticide resistance.

  1. Insecticide-Treated Nets and Protection against Insecticide-Resistant Malaria Vectors in Western Kenya.

    Science.gov (United States)

    Ochomo, Eric; Chahilu, Mercy; Cook, Jackie; Kinyari, Teresa; Bayoh, Nabie M; West, Philippa; Kamau, Luna; Osangale, Aggrey; Ombok, Maurice; Njagi, Kiambo; Mathenge, Evan; Muthami, Lawrence; Subramaniam, Krishanthi; Knox, Tessa; Mnavaza, Abraham; Donnelly, Martin James; Kleinschmidt, Immo; Mbogo, Charles

    2017-05-01

    Insecticide resistance might reduce the efficacy of malaria vector control. In 2013 and 2014, malaria vectors from 50 villages, of varying pyrethroid resistance, in western Kenya were assayed for resistance to deltamethrin. Long-lasting insecticide-treated nets (LLIN) were distributed to households at universal coverage. Children were recruited into 2 cohorts, cleared of malaria-causing parasites, and tested every 2 weeks for reinfection. Infection incidence rates for the 2 cohorts were 2.2 (95% CI 1.9-2.5) infections/person-year and 2.8 (95% CI 2.5-3.0) infections/person-year. LLIN users had lower infection rates than non-LLIN users in both low-resistance (rate ratio 0.61, 95% CI 0.42-0.88) and high-resistance (rate ratio 0.55, 95% CI 0.35-0.87) villages (p = 0.63). The association between insecticide resistance and infection incidence was not significant (p = 0.99). Although the incidence of infection was high among net users, LLINs provided significant protection (p = 0.01) against infection with malaria parasite regardless of vector insecticide resistance.

  2. BACILLUS THURINGIENSIS ELASTASES WITH INSECTICIDE ACTIVITY

    Directory of Open Access Journals (Sweden)

    E. V. Matseliukh

    2015-10-01

    Full Text Available The purpose of the research was a screening of proteases with elastase activity among Bacillus thuringiensis strains, their isolation, partially purification, study of physicochemical properties and insecticide activity in relation to the larvae of the Colorado beetle. The objects of the investigation were 18 strains of B. thuringiensis, isolated from different sources: sea water, dry biological product "Bitoksibatsillin" and also from natural populations of Colorado beetles of the Crimea, Kherson, Odesa, Mykolaiv and Zaporizhiia regions of Ukraine. Purification of enzymes with elastase activity isolated from above mentioned strains was performed by gel-chromatography and insecticide activity was studied on the 3–4 larvae instar of Colorado beetle. The ability of a number of B. thuringiensis strains to synthesize the proteases with elastase activity has been established. The most active were enzymes obtained from strains IMV B-7465, IMV B-7324 isolated from sea water, and strains 9, 902, Bt-H and 0-239 isolated from Colorado beetles. The study of the physicochemical properties of the partially purified proteases of these strains showed that they belonged to enzymes of the serine type. Peptidases of a number of B. thuringiensis strains (IMV B-7324, IMV B-7465, 902, 0-239, 9 are metal-dependent enzymes. Optimal conditions of action of all tested enzymes are the neutral and alkaline рН values and the temperatures of 30–40 °С. The studies of influence of the complex enzyme preparations and partially purified ones of B. thuringiensis strains on the larvae instar of Colorado beetles indicated that enzymes with elastase activity could be responsible for insecticide action of the tested strains.

  3. Aerosol deposition on plant leaves

    Science.gov (United States)

    James B. Wedding; Roger W. Carlson; James J. Stukel; Fakhri A. Bazzaz

    1976-01-01

    An aerosol generator and wind tunnel system designed for use in aerosol deposition is described. Gross deposition on rough pubescent leaves was nearly 7 times greater than on smooth, waxy leaves. Results suggest that aerosol deposition, on a per unit area basis, for single horizontal streamlining leaves is similar to that for arrays of leaves under similar flow...

  4. Effects of insecticide spray application on insect pest infestation and ...

    African Journals Online (AJOL)

    Field studies were conducted during the 2008 - 2009 cropping season to determine the minimal insecticide application which can reduce cowpea yield losses on the field due to insect pest infestations in the Transkei region of South Africa. Treatments consisted of five cowpea varieties and four regimes of insecticide spray ...

  5. Ecdysone Agonist: New Insecticides with Novel Mode of Action

    Directory of Open Access Journals (Sweden)

    Y. Andi Trisyono

    2002-12-01

    Full Text Available Development of insect resistance to insecticide has been the major driving force for the development of new insecticides. Awareness and demand from public for more environmentally friendly insecticides have contributed in shifting the trend from using broad spectrum to selective insecticides. As a result, scientists have looked for new target sites beyond the nervous system. Insect growth regulators (IGRs are more selective insecticides than conventional insecticides, and ecdysone agonists are the newest IGRs being commercialized, e.g. tebufenozide, methoxyfenozide, and halofenozide. Ecdysone agonists bind to the ecdysteroid receptors, and they act similarly to the molting hormone 20-hydroxyecdysone. The binding provides larvae or nymphs with a signal to enter a premature and lethal molting cycle. In addition, the ecdysone agonists cause a reduction in the number of eggs laid by female insects. The ecdysone agonists are being developed as selective biorational insecticides. Tebufenozide and methoxyfenozide are used to control lepidopteran insect pests, whereas halofenozide is being used to control coleopteran insect pests. Their selectivity is due to differences in the binding affinity between these compounds to the receptors in insects from different orders. The selectivity of these compounds makes them candidates to be used in combinations with other control strategies to develop integrated pest management programs in agricultural ecosystems. Key words: new insecticides, selectivity, ecdysone agonists

  6. Mechanistic modeling of insecticide risks to breeding birds in ...

    Science.gov (United States)

    Insecticide usage in the United States is ubiquitous in urban, suburban, and rural environments. In evaluating data for an insecticide registration application and for registration review, scientists at the United States Environmental Protection Agency (USEPA) assess the fate of the insecticide and the risk the insecticide poses to the environment and non-target wildlife. At the present time, current USEPA risk assessments do not include population-level endpoints. In this paper, we present a new mechanistic model, which allows risk assessors to estimate the effects of insecticide exposure on the survival and seasonal productivity of birds known to use agricultural fields during their breeding season. The new model was created from two existing USEPA avian risk assessment models, the Terrestrial Investigation Model (TIM v.3.0) and the Markov Chain Nest Productivity model (MCnest). The integrated TIM/MCnest model has been applied to assess the relative risk of 12 insecticides used to control corn pests on a suite of 31 avian species known to use cornfields in midwestern agroecosystems. The 12 insecticides that were assessed in this study are all used to treat major pests of corn (corn root worm borer, cutworm, and armyworm). After running the integrated TIM/MCnest model, we found extensive differences in risk to birds among insecticides, with chlorpyrifos and malathion (organophosphates) generally posing the greatest risk, and bifenthrin and ë-cyhalothrin (

  7. Effect of Insecticidal Plant Materials, Lantana camara L. and

    African Journals Online (AJOL)

    Effect of Insecticidal Plant Materials, Lantana camara L. and Tephrosia vogelii Hook, on the Quality Parameters of Stored Maize Grains. ... product treatments suitable for post-harvest grain protection and as sustainable alternatives to synthetic insecticides in the control of the maize weevil, Sitophilus zeamais Motschulsky.

  8. Control of emerald ash borer adults and larvae with insecticides

    Science.gov (United States)

    Deborah G. McCullough; David Cappaert; Therese Poland; David R. Smitley

    2003-01-01

    Virtually no information is available from Asia regarding the ability of insecticide products and application methods to protect ash trees from emerald ash borer. Many landscapers in the Core infestation in southeastern Michigan have promoted various treatments to their customers, but there has been no objective evaluation of these products. Insecticides may also be...

  9. influence des traitements insecticides sur les populations de ...

    African Journals Online (AJOL)

    INFLUENCE OF INSECTICIDE TREA TMENTS ON DAMAGING TERMITE POPULATIONS OF R/CE AND MAIZE CROPS. IN SA VANNA (LAMTO ... tennite damages and évaluate the efficiency Of insecticide treatments on termite populations. Thé abundance of ..... TEM = tension ; PRO = prosibam 480 ; REGA = Régent A ;.

  10. Standard Protocol for Screening Conventional Insecticides at the ...

    African Journals Online (AJOL)

    Mirids, (Sachlbergella singularis Hagl, and Distantiella theobroma (Dist), are the most important insect pests of cocoa in West Africa and their current control relies primarily on conventional insecticides. Insecticides have, for over six decades, had very beneficial effects on cocoa cultivation in Ghana. The success of mired ...

  11. Insecticidal activity of bioproducts on Ceratitis capitata Wiedemann ...

    African Journals Online (AJOL)

    The aim of this study was to evaluate the insecticidal activity of the bioproducts proagrim, essential oil from fennel and orange oil, on the mortality of Ceratitis capitata Wiedemann (Diptera: Tephritidae). The study was divided into three parts: the first assay studied the insecticidal activity of the products on infested fruit; ...

  12. Larvicidal activities of Biostop Moustiques ® , a botanical insecticide ...

    African Journals Online (AJOL)

    Larvicidal activities of Biostop Moustiques ® , a botanical insecticide on field collected malaria mosquito Anopheles gambiae sensu lato in Togo. ... In general, this study showed that the botanical insecticide tested has almost the same larvicidal effect no matter the strains of Anopheles gambiae used. Keywords: Biostop ...

  13. Identification and cloning of two insecticidal protein genes from ...

    African Journals Online (AJOL)

    SAM

    2014-06-18

    Jun 18, 2014 ... 2State Key Laboratory of Biology for Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of ... Different insecticidal crystal proteins of Bt have different bioactivity ... Key words: Bacillus thuringiensis, peptide mess fingerprint, identification, clone, insecticidal crystal protein.

  14. Effectiveness and profitability of insecticide formulations used for ...

    African Journals Online (AJOL)

    To identify optimal pest control with lower economic risks to farmers, we investigated the effectiveness and profitability of different insecticides and insecticide formulations against bean fly (Ophiomyia spp.) and bean flower thrips (Megalurothrips sjostedtii). Two separate experiments were conducted during 2009 to 2012.

  15. Expression of melanin and insecticidal protein from Rhodotorula ...

    African Journals Online (AJOL)

    Both the salmon/red melanin and the insecticidal producing genes of Rhodotorula glutinis was successfully expressed in Escherichia coli using plasmid pZErO-1. This work suggests that in Rhodotorula species melanin and insecticidal toxin are co-expressed and therefore possibly co-evolved. Keywords: Rhodotorula ...

  16. Levels of organochlorine insecticide residues in cowpea grains and ...

    African Journals Online (AJOL)

    Qualitative and quantitative analysis of the insecticides after clean-up on silica gel adsorbent were carried out using Gas Chromatography equipped with Electron Capture Detector (GC-ECD). Organochlorine insecticide residues were detected in all the samples of cowpea and dried yam chips analysed with highest mean ...

  17. Insecticide susceptibility status of human biting mosquitoes in ...

    African Journals Online (AJOL)

    Matowo Pc

    commonly used insecticides in the most common mosquito vectors of human diseases in north-eastern. Tanzania. The findings of the present study call for integrated vector control interventions. Keywords: insecticide resistance, mosquitoes, Tanzania. Introduction. Mosquito-borne diseases such as dengue, Rift Valley fever, ...

  18. Effects of carbamate and pyrethroid insecticides on cowpea ...

    African Journals Online (AJOL)

    The effects of two insecticides, Lannate (n carbamate) and karate (a pyrethoid) on nitrogen fix::.tion by c:owpeas { Jligna ungtticulata) were evaluated after establishing the toxic effects of these insecticides on the microsymbiont bradyrihobia itl vitro. In this (in vitro) experiment conducted in modified Le.onard jars (LJ), ...

  19. Effects of pirimiphos-methyl (an organophosphate insecticide) on ...

    African Journals Online (AJOL)

    Effects of pirimiphos-methyl (an organophosphate insecticide) on the fertility of adult male rats. ... African Health Sciences ... Background: Organophosphate insecticides represent one of the most widely used classes of pesticides with high potential for human exposure in both rural and residential environments. Objective: In ...

  20. Cloning and characterization of an insecticidal crystal protein gene ...

    Indian Academy of Sciences (India)

    Unknown

    characterization of an insecticidal crystal protein gene from Bacillus thuringiensis subspecies kenyae. J. Genet. 81, 5–11]. Introduction. Subspecies of Bacillus thuringiensis, a sporulating bac- terium, produce a wide range of insecticidal crystal proteins. These have been grouped on the basis of their toxicity spectrum for a ...

  1. Identification and cloning of two insecticidal protein genes from ...

    African Journals Online (AJOL)

    Bacillus thuringiensis (Bt) is the most widely applied type of microbial pesticide due to its high specificity and environmental safety. The activity of Bt is largely attributed to the insecticidal crystal protein encoded by the cry genes. Different insecticidal crystal proteins of Bt have different bioactivity against distinct agricultural ...

  2. Effects of the numbers of foliar insecticide applications on the ...

    African Journals Online (AJOL)

    ... define an economically beneficial foliar insecticide application frequency to manage insect pests on the oleaginous C. lanatus in a woodland savannah zone of Côte d'Ivoire. Zero (control) to four sprays of a foliar carbamate-based insecticide (Cypercal EC 50) were applied at four plant growth stages (seedling emergence ...

  3. Insecticidal, brine shrimp cytotoxicity, antifungal and nitric oxide free ...

    African Journals Online (AJOL)

    The crude methanolic extract and various fractions derived from the aerial parts of Myrsine africana were screened in vitro for possible insecticidal, antifungal, brine shrimp lethality and nitric oxide free radical scavenging activities. Low insecticidal activity (20 %) was shown by chloroform (CHCl3) and aqueous fractions ...

  4. Arctic Aerosols and Sources

    DEFF Research Database (Denmark)

    Nielsen, Ingeborg Elbæk

    2017-01-01

    Since the Industrial Revolution, the anthropogenic emission of greenhouse gases has been increasing, leading to a rise in the global temperature. Particularly in the Arctic, climate change is having serious impact where the average temperature has increased almost twice as much as the global during...... aerosol contribution from wood combustion will not be sufficient. Arctic aerosols were investigated during several time periods with different instruments and time resolutions. Two years of weekly measurements of black carbon and sulfate at the Villum Research Station showed elevated concentrations during...

  5. An Operational Framework for Insecticide Resistance Management Planning.

    Science.gov (United States)

    Chanda, Emmanuel; Thomsen, Edward K; Musapa, Mulenga; Kamuliwo, Mulakwa; Brogdon, William G; Norris, Douglas E; Masaninga, Freddie; Wirtz, Robert; Sikaala, Chadwick H; Muleba, Mbanga; Craig, Allen; Govere, John M; Ranson, Hilary; Hemingway, Janet; Seyoum, Aklilu; Macdonald, Michael B; Coleman, Michael

    2016-05-01

    Arthropod vectors transmit organisms that cause many emerging and reemerging diseases, and their control is reliant mainly on the use of chemical insecticides. Only a few classes of insecticides are available for public health use, and the increased spread of insecticide resistance is a major threat to sustainable disease control. The primary strategy for mitigating the detrimental effects of insecticide resistance is the development of an insecticide resistance management plan. However, few examples exist to show how to implement such plans programmatically. We describe the formulation and implementation of a resistance management plan for mosquito vectors of human disease in Zambia. We also discuss challenges, steps taken to address the challenges, and directions for the future.

  6. Production of Insecticide Degradates in Juices: Implications for Risk Assessment.

    Science.gov (United States)

    Radford, Samantha A; Panuwet, Parinya; Hunter, Ronald E; Barr, Dana Boyd; Ryan, P Barry

    2016-06-08

    This study was designed to observe the production of degradates of two organophosphorus insecticides and one pyrethroid insecticide in beverages. Purified water, white grape juice, apple juice, and red grape juice were fortified with 500 ng/g malathion, chlorpyrifos, and permethrin, and aliquots were extracted for malathion dicarboxylic acid (MDA), 3,5,6-trichloro-2-pyridinol (TCPy), and 3-phenoxybenzoic acid (3-PBA) several times over a 15 day period of being stored in the dark at 2.5 °C. Overall, first-order kinetics were observed for production of MDA, and statistically significant production of TCPy was also observed. Statistically significant production of 3-phenoxybenzoic acid was not observed. Results indicate that insecticides degrade in food and beverages, and this degradation may lead to preexisting insecticide metabolites in the beverages. Therefore, it is suggested that caution should be exercised when using urinary insecticide metabolites to assess exposure and risk.

  7. Flow properties of water-based drilling fluids

    OpenAIRE

    Kristensen, Aleksander

    2013-01-01

    The objective of this master thesis was to investigate the flow properties of water based drilling fluids, utilizing measurements in both the micro and macro scale. The research was performed on two realistic drilling fluids by the use of a viscometer, a rheometer and a realistic flow loop, where the latter represents the macro scale. The research outcome could possibly improve the understanding of flow behavior in wellbores, and remove uncertainties associated with annular friction. The two...

  8. Modified model of convective drying of water-based Caramic ...

    African Journals Online (AJOL)

    Modified model of convective drying of water-based Caramic suspension for tape casting. Y T Puyate. Abstract. No Abstract. Global Journal of Engineering Research Vol. 5 (1&2) 2006: pp. 67-72. http://dx.doi.org/10.4314/gjer.v5i1.18970 · AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians ...

  9. GRIP LANGLEY AEROSOL RESEARCH GROUP EXPERIMENT (LARGE) V1

    Data.gov (United States)

    National Aeronautics and Space Administration — Langley Aerosol Research Group Experiment (LARGE) measures ultrafine aerosol number density, total and non-volatile aerosol number density, dry aerosol size...

  10. Aerosol can puncture device operational test plan

    Energy Technology Data Exchange (ETDEWEB)

    Leist, K.J.

    1994-05-03

    Puncturing of aerosol cans is performed in the Waste Receiving and Processing Facility Module 1 (WRAP 1) process as a requirement of the waste disposal acceptance criteria for both transuranic (TRU) waste and low-level waste (LLW). These cans have contained such things as paints, lubricating oils, paint removers, insecticides, and cleaning supplies which were used in radioactive facilities. Due to Westinghouse Hanford Company (WHC) Fire Protection concerns of the baseline system`s fire/explosion proof characteristics, a study was undertaken to compare the baseline system`s design to commercially available puncturing devices. While the study found no areas which might indicate a risk of fire or explosion, WHC Fire Protection determined that the puncturing system must have a demonstrated record of safe operation. This could be obtained either by testing the baseline design by an independent laboratory, or by substituting a commercially available device. As a result of these efforts, the commercially available Aerosolv can puncturing device was chosen to replace the baseline design. Two concerns were raised with the system. Premature blinding of the coalescing/carbon filter, due to its proximity to the puncture and draining operation; and overpressurization of the collection bottle due to its small volume and by blinding of the filter assembly. As a result of these concerns, testing was deemed necessary. The objective of this report is to outline test procedures for the Aerosolv.

  11. [Anti-infective aerosols].

    Science.gov (United States)

    Diot, P; Dequin, P F; Rivoire, B; Gagnadoux, F; Faurisson, F; Diot, E; Boissinot, E; Lemarié, E

    1999-06-01

    Anti-infectious agents such as pentamidine, antibiotics (mainly colistine and aminoglycosides) and amphotericin B can be administered by aerosol. This route of administration is not officially approved and it constitutes an empirical approach which has benefited from recent research which is summarized hereafter. The most fundamental question is related to the potentially deleterious effects of nebulization processes, especially ultrasound, on the anti infectious properties of the drugs. Colimycin, which was chosen as a reference because its polypeptide structure makes it unstable a priori, proved to be resistant to high frequency ultrasound, which is encouraging for other molecules such as aminoglycosides or betalactamins. The nebulizer characteristics have also to be taken into account. An aerosol can be produced from an amphotericin B suspension and from colistine using both an ultrasonic nebulizer and a jet nebulizer. Distinction between good and bad nebulizers does not depend upon the physical process involved to nebulize the drug, but on the intrinsic characteristics of the device and its performance with a known drug. The inhaled mass of an aerosol in the respirable range must be high and dosimetric nebulizers represent a significant progress. Finally, adminnistration of anti infectious aerosols requires a new pharmacological approach to monitor treatment and urinary assays are promising.

  12. AEROSOL DISSEMINATION ASSESSMENT.

    Science.gov (United States)

    Basic performance requirements are given for a chamber assessment aerosol system to be designed, developed and fabricated for evaluating the...automated assessment system. These include light scattering particle counters and mathematical treatment of decay curves for analysis of size properties

  13. Water-based exercise for adults with asthma.

    Science.gov (United States)

    Grande, Antonio Jose; Silva, Valter; Andriolo, Brenda N G; Riera, Rachel; Parra, Sergio A; Peccin, Maria S

    2014-07-17

    Asthma is a common condition characterised by airway inflammation and airway narrowing, which can result in intermittent symptoms of wheezing, coughing and chest tightness, possibly limiting activities of daily life. Water-based exercise is believed to offer benefits for people with asthma through pollen-free air, humidity and effects of exercise on physical function. To evaluate the effectiveness and safety of water-based exercise for adults with asthma. We searched the Cochrane Airways Group Specialised Register of Trials (CAGR), the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, the Cumulative Index to Nursing and Allied Health Literature (CINAHL), the Allied and Complementary Medicine Database (AMED), PsycINFO, the Latin American and Caribbean Health Science Information Database (LILACS), the Physiotherapy Evidence Database (PEDro), the System for Information on Grey Literature in Europe (SIGLE) and Google Scholar on 13 May 2014. We handsearched ongoing clinical trial registers and meeting abstracts of the American Thoracic Society (ATS), the European Respiratory Society (ERS) and the British Thoracic Society (BTS). We included all randomised controlled trials (RCTs) of adults with asthma comparing a water-based exercise group versus one or more of the following groups: usual care, land-based exercise, non-exercise. Two review authors (AJG, VS) independently extracted data from the primary studies using a standard form developed for this purpose, which includes methods, participants, interventions and outcomes. We contacted trial authors to request additional data. Data were input by one review author and were double-checked by a second review author. In this systematic review, we provide a narrative synthesis of available evidence from three small studies including 136 adult participants. The studies were at high risk of bias. No meta-analysis was possible because of methodological and interventional heterogeneity between included

  14. How to make evolution-proof insecticides for malaria control.

    Science.gov (United States)

    Read, Andrew F; Lynch, Penelope A; Thomas, Matthew B

    2009-04-07

    Insecticides are one of the cheapest, most effective, and best proven methods of controlling malaria, but mosquitoes can rapidly evolve resistance. Such evolution, first seen in the 1950s in areas of widespread DDT use, is a major challenge because attempts to comprehensively control and even eliminate malaria rely heavily on indoor house spraying and insecticide-treated bed nets. Current strategies for dealing with resistance evolution are expensive and open ended, and their sustainability has yet to be demonstrated. Here we show that if insecticides targeted old mosquitoes, and ideally old malaria-infected mosquitoes, they could provide effective malaria control while only weakly selecting for resistance. This alone would greatly enhance the useful life span of an insecticide. However,such weak selection for resistance can easily be overwhelmed if resistance is associated with fitness costs. In that case, late-life-acting insecticides would never be undermined by mosquito evolution.We discuss a number of practical ways to achieve this, including different use of existing chemical insecticides,biopesticides, and novel chemistry. Done right, a one-off investment in a single insecticide would solve the problem of mosquito resistance forever.

  15. How to make evolution-proof insecticides for malaria control.

    Directory of Open Access Journals (Sweden)

    Andrew F Read

    2009-04-01

    Full Text Available Insecticides are one of the cheapest, most effective, and best proven methods of controlling malaria, but mosquitoes can rapidly evolve resistance. Such evolution, first seen in the 1950s in areas of widespread DDT use, is a major challenge because attempts to comprehensively control and even eliminate malaria rely heavily on indoor house spraying and insecticide-treated bed nets. Current strategies for dealing with resistance evolution are expensive and open ended, and their sustainability has yet to be demonstrated. Here we show that if insecticides targeted old mosquitoes, and ideally old malaria-infected mosquitoes, they could provide effective malaria control while only weakly selecting for resistance. This alone would greatly enhance the useful life span of an insecticide. However,such weak selection for resistance can easily be overwhelmed if resistance is associated with fitness costs. In that case, late-life-acting insecticides would never be undermined by mosquito evolution.We discuss a number of practical ways to achieve this, including different use of existing chemical insecticides,biopesticides, and novel chemistry. Done right, a one-off investment in a single insecticide would solve the problem of mosquito resistance forever.

  16. RUMEN BACTERIAL AND PROTOZOAL RESPONSES TO INSECTICIDE SUBSTRATES.

    Science.gov (United States)

    WILLIAMS, P P; ROBBINS, J D; GUTIERREZ, J; DAVIS, R E

    1963-11-01

    Insecticides containing organophosphate, chlorinated hydrocarbon, and carbamate were tested with bovine ruminal ingesta fractions. Rumen bacteria exposed to insecticide levels of 0 to 500 ppm in rumen fluid for 4 hr were inoculated into rumen fluid-starch feed extract medium. No apparent significant bacterial count inhibitions were noted. Also, when insecticides were used as carbon sources at concentrations of 500 ppm in carbohydrate-limited media, no increases in bacterial counts were indicated. Warburg manometric data showed that paraffin oil-Triton X-155 preparations of dimethoate, Diazinon, lindane, Thiodan and Sevin stimulated gas production in holotrich protozoa. Entodinium simplex, an oligotrich, produced less gas with insecticide substrates per unit of dry weight than did an Isotricha sp. Rumen bacteria and plant debris fractions from ruminal ingesta provided with insecticides did not give increased manometric responses over the endogenous control vessels. Washed suspensions of I. intestinalis produced volatile fatty acids in excess of the endogenous suspensions when provided insecticide substrates. Thiodan dissimilation by I. intestinalis was followed colorimetrically with 15% loss in substrate in 1 hr of incubation at 39 C. Diazinon-C(14) substrate uptake was demonstrated with suspensions of E. simplex and I. intestinalis. Rumen ciliates are suggested as a possible means for screening out useful insecticides susceptible to microbial dissimilation for use on forage and other cattle-feed crops.

  17. Insecticides induced biochemical changes in freshwater microalga Chlamydomonas mexicana.

    Science.gov (United States)

    Kumar, Muthukannan Satheesh; Kabra, Akhil N; Min, Booki; El-Dalatony, Marwa M; Xiong, Jiuqiang; Thajuddin, Nooruddin; Lee, Dae Sung; Jeon, Byong-Hun

    2016-01-01

    The effect of insecticides (acephate and imidacloprid) on a freshwater microalga Chlamydomonas mexicana was investigated with respect to photosynthetic pigments, carbohydrate and protein contents, fatty acids composition and induction of stress indicators including proline, superoxide dismutase (SOD) and catalase (CAT). C. mexicana was cultivated with 1, 5, 10, 15, 20 and 25 mg L(-1) of acephate and imidacloprid. The microalga growth increased with increasing concentrations of both insecticides up to 15 mg L(-1), beyond which the growth declined compared to control condition (without insecticides). C. mexicana cultivated with 15 mg L(-1) of both insecticides for 12 days was used for further analysis. The accumulation of photosynthetic pigments (chlorophyll and carotenoids), carbohydrates and protein was decreased in the presence of both insecticides. Acephate and imidacloprid induced the activities of superoxide dismutase (SOD) and catalase (CAT) and increased the concentration of proline in the microalga, which play a defensive role against various environmental stresses. Fatty acid analysis revealed that the fraction of polyunsaturated fatty acids decreased on exposure to both insecticides. C. mexicana also promoted 25 and 21% removal of acephate and imidacloprid, respectively. The biochemical changes in C. mexicana on exposure to acephate and imidacloprid indicate that the microalga undergoes an adaptive change in response to the insecticide-induced oxidative stress.

  18. Neonicotinoid insecticide toxicology: mechanisms of selective action.

    Science.gov (United States)

    Tomizawa, Motohiro; Casida, John E

    2005-01-01

    The neonicotinoids, the newest major class of insecticides, have outstanding potency and systemic action for crop protection against piercing-sucking pests, and they are highly effective for flea control on cats and dogs. Their common names are acetamiprid, clothianidin, dinotefuran, imidacloprid, nitenpyram, thiacloprid, and thiamethoxam. They generally have low toxicity to mammals (acute and chronic), birds, and fish. Biotransformations involve some activation reactions but largely detoxification mechanisms. In contrast to nicotine, epibatidine, and other ammonium or iminium nicotinoids, which are mostly protonated at physiological pH, the neonicotinoids are not protonated and have an electronegative nitro or cyano pharmacophore. Agonist recognition by the nicotinic receptor involves cation-pi interaction for nicotinoids in mammals and possibly a cationic subsite for interaction with the nitro or cyano substituent of neonicotinoids in insects. The low affinity of neonicotinoids for vertebrate relative to insect nicotinic receptors is a major factor in their favorable toxicological profile.

  19. Teppeki, selective insecticide about Bombus terrestris.

    Science.gov (United States)

    Fanigliulo, Angela; Filì, Vittorio; Pacella, Rosa; Comes, Soccorsa; Crescenzi, Aniello

    2009-01-01

    At a time when a highly controversial debate about the causes of the widespread deaths of bees is taking place all over Europe, which accused the agriculture and its practices with particular reference to the harmful effects of some insecticides, it seems important to point out as another insecticide, the Teppeki, can be selective about bumble and have a good compatibility with the activity of the apiaries. This insecticide has the active ingredient flonicamid (500 g/kg) belonging to a new chemical class, called pyridinecarboxamides: the product works systemic and is known as having a long lasting efficacy against all important aphid species. Bioagritest test facility of Pignola (PZ, Italy) has conducted in two successive production cycles an experimental trial on a tomato hydroponic cultivation within the Agricola Bonsai farm in Sibari (CS, Italy), whose objective was to measure the selectivity of flonicamid on Bombus terrestris, insects playing an important role in the pollination of certain species grown in greenhouse such as Tomato, Eggplant, Pepper and Cucumber. On the pollinated flower B. terrestris leaves some trace of its visit, a typical dark trademark: on the detection of the marking of flowers was based the testing program conducted by Bioagritest. Two thesis were compared: A, standard) treatment with a foliar insecticide, the neonicotinoide acetamiprid, normally used for control of aphids and whiteflies (unlike other neonicotinoides--imidacloprid and thiametoxam--quite selective about B. terrestris) and B, Teppeki) foliar treatment with Teppeki, to the maximum dose indicated on the label. The experimental design included the use of randomized blocks with 4 repetitions (4 plots/thesis with 100 plants each). In every thesis six B. terrestris hives were placed 2 days before treatment: the respective holes remained closed during the treatment and the 12 following hours. In order to verify the pollination, by the detection of the flower marking, 2 flowers

  20. Insecticidal Constituents from Buddlej aalbiflora Hemsl.

    Science.gov (United States)

    Zhang, Xiu-Yun; Shen, Jing; Zhou, Yu; Wei, Zhi-Ping; Gao, Jin-Ming

    2017-06-01

    Eleven known compounds, deoxymikanolide (1), 1,3-dihydroxyxanthone (2), kumatakenin (3), apigenin (4), chrysin (5), kaempferol (6), Iso-kaempferol (7), luteolin (8), luteolin-3',4'-dimethylether-7-O-β-glucoside (9), luteolin-7-O-β-glucoside (10) and quercetin (11) were identified in MeOH extract of Buddleja albiflora Hemsl (Oleaceae). These compounds (each, 1, 0.5 and 0.25 mg mL -1 ) were tested for insecticidal activity against 3rd and 4th-instar larvae of Plutella xylostella, 3rd-instar larvae of Mythimna separata and 3rd-instar larvae of Macrosiphoniella sanborni. The lowest 50% anti-feedant concentration (AFC 50 ) against P. xylostella and 50% lethal concentration (LC 50 ) against P. xylostella and M. sanborni were observed as 0.0058, 0.0046 and 3.4048 mg L -1 , respectively.

  1. Insecticidal Effects of Insecticide, Fungicide, Complex Fertilizer and Wetting Agent Combinations Depending on Water Hardness

    Directory of Open Access Journals (Sweden)

    Slavica Vuković

    2009-01-01

    Full Text Available Simultaneous occurrence of different harmful species in agricultural practice necessitates that different plant protection chemicals be applied at the same time (tank mix. Mix components differ in purpose, mode of action and/or formulation, while addition of nonpesticide components (complex fertilizers, adjuvants and wetting agents is widely practiced today. However, data concerning the effects of water quality used for preparation of working liquids on the biological effects of pesticides is still scarce. Therefore, the objective of this study was to determine insecticidal effects as depending on components used in mixes and water hardness. The effects of mixtures of thiametoxam (Actara 25-WG 0,07kg/ha with azoxystrobin (Quadris 0.75 l/ha, mancozeb (Dithane M-70 2.5 kg/ha, a complex fertilizer (Mortonijc plus 3 kg/ha and a wetting agent (Silwet L-77, depending on the components and water hardness(slightly hard (15.4 d° - tap water from Novi Sad, and very hard (34.7 d° - well water from Adica, a Novi Sad suburb, were determined in a bioassay based on adult mortality rate of the first generation of Colorado potato beetle (Leptinotarsa decemlineata Say. The mixtures were applied by a flooding method. The trial was set up to include four replications. Insecticidal effects were determined 24 h and 48 h after exposure. Thiametoxam effectiveness 24 h and 48 h after application in slightly hard water was 100% when the insecticide was applied alone and in double and triple mixes with the fungicides, complex fertilizer and wetting agent, showing no dependency on mix components.The tested adult population of Colorado potato beetle demonstrated high susmceptibility to thiametoxam, while the other components had no impact in slightly hard water. In very hard water, 24 h after application, the insecticidal effect had the same level of significance to thiametoxam in double and triple mixes, with an exception of thiametoxam+mancozeb+Mortonijc plus and

  2. Subscale Water Based Phase Change Material Heat Exchanger Development

    Science.gov (United States)

    Sheth, Rubik; Hansen, Scott

    2016-01-01

    Supplemental heat rejection devices are required in many spacecraft as the radiators are not sized to meet the full heat rejection demand. One means of obtaining additional heat rejection is through the use of phase change material heat exchangers (PCM HX's). PCM HX's utilize phase change to store energy in unfavorable thermal environments (melting) and reject the energy in favorable environments (freezing). Traditionally, wax has been used as a PCM on spacecraft. However, water is an attractive alternative because it is capable of storing about 40% more energy per unit mass due to its higher latent heat of fusion. The significant problem in using water as a PCM is its expansion while freezing, leading to structural integrity concerns when housed in an enclosed heat exchanger volume. Significant investigation and development has taken place over the past five years to understand and overcome the problems associated with water PCM HX's. This paper reports on the final efforts by Johnson Space Center's Thermal Systems Branch to develop a water based PCM HX. The test article developed and reported on is a subscale version of the full-scale water-based PCM HX's constructed by Mezzo Technologies. The subscale unit was designed by applying prior research on freeze front propagation and previous full-scale water PCM HX development. Design modifications to the subscale unit included use of urethane bladder, decreased aspect ratio, perforated protection sheet, and use of additional mid-plates. Testing of the subscale unit was successful and 150 cycles were completed without fail.

  3. Reclamation and disposal of water-based machining coolants

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, P.A.

    1982-01-01

    The Oak Ridge Y-12 Plant, which is operated by the Union Carbide Corporation, Nuclear Division for the Department of Energy under US government contract W-7405-eng-26, currently uses about 10{sup 6} L/yr (260,000 gal/yr) of water-based coolants in its machining operations. These coolants are disposed of in a 110,000-L (29,000-gal) activated sludge reactor. The reactor has oxidized an average of 38.6 kg of total organic carbon (TOC) per day with an overall efficiency of 90%. The predominant bacteria in the reactor have been identified once each year for the past three years. Six primary types of water-based coolants are currently used in the machine shops. In order to reduce the coolant usage rate, efforts are being made to introduce one universal coolant into the shops. By using a biocide to limit bacterial deterioration and using a filter and centrifuge system to remove dirt and tramp oils from the coolant, the coolant discard rate can be greatly reduced. 1 tab.

  4. Aerosol characterization during project POLINAT

    Energy Technology Data Exchange (ETDEWEB)

    Hagen, D.E.; Hopkins, A.R.; Paladino, J.D.; Whitefield, P.D. [Missouri Univ., Rolla, MO (United States). Cloud and Aerosol Sciences Lab.; Lilenfeld, H.V. [McDonnell Douglas Aerospace-East, St. Louis, MO (United States)

    1997-12-31

    The objectives of the aerosol/particulate characterization measurements of project POLINAT (POLlution from aircraft emissions In the North ATlantic flight corridor) are: to search for aerosol/particulate signatures of air traffic emissions in the region of the North Atlantic Flight Corridor; to search for the aerosol/particulate component of large scale enhancement (`corridor effects`) of air traffic related species in the North Atlantic region; to determine the effective emission indices for the aerosol/particulate component of engine exhaust in both the near and far field of aircraft exhaust plumes; to measure the dispersion and transformation of the aerosol/particulate component of aircraft emissions as a function of ambient condition; to characterize background levels of aerosol/particulate concentrations in the North Atlantic Region; and to determine effective emission indices for engine exhaust particulates for regimes beyond the jet phase of plume expansion. (author) 10 refs.

  5. Aerosol Observing System (AOS) Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Jefferson, A

    2011-01-17

    The Aerosol Observing System (AOS) is a suite of in situ surface measurements of aerosol optical and cloud-forming properties. The instruments measure aerosol properties that influence the earth’s radiative balance. The primary optical measurements are those of the aerosol scattering and absorption coefficients as a function of particle size and radiation wavelength and cloud condensation nuclei (CCN) measurements as a function of percent supersaturation. Additional measurements include those of the particle number concentration and scattering hygroscopic growth. Aerosol optical measurements are useful for calculating parameters used in radiative forcing calculations such as the aerosol single-scattering albedo, asymmetry parameter, mass scattering efficiency, and hygroscopic growth. CCN measurements are important in cloud microphysical models to predict droplet formation.

  6. Photothermal spectroscopy of aerosols

    Energy Technology Data Exchange (ETDEWEB)

    Campillo, A.J.; Lin, H.B.

    1981-04-01

    In situ aerosol absorption spectroscopy was performed using two novel photothermal detection schemes. The first, based on a photorefractive effect and coherent detection, called phase fluctuation optical heterodyne (PFLOH) spectroscopy, could, depending on the geometry employed, yield particle specific or particle and gas absorption data. Single particles of graphite as small as 1 ..mu..m were detected in the particle specific mode. In another geometrical configuration, the total absorption (both gas and particle) of submicron sized aerosols of ammonium sulfate particles in equilibrium with gaseous ammonia and water vapor were measured at varying CO/sub 2/ laser frequencies. The specific absorption coefficient for the sulfate ion was measured to be 0.5 m/sup 2//g at 1087 cm/sup -1/. The absorption coefficient sensitivity of this scheme was less than or equal to 10/sup -8/ cm/sup -1/. The second scheme is a hybrid visible Mie scattering scheme incorporating photothermal modulation. Particle specific data on ammonium sulfate droplets were obtained. For chemically identical species, the relative absorption spectrum versus laser frequency can be obtained for polydisperse aerosol distributions directly from the data without the need for complex inverse scattering calculations.

  7. Effects of an inorganic insecticide (boric acid) against Blattella ...

    African Journals Online (AJOL)

    ufuoma

    2013-05-01

    May 1, 2013 ... Effects of an inorganic insecticide (boric acid) against. Blattella germanica: ..... originate in the brain and ovaries, which can be influenced by the .... (2004). Water solutions of boric acid and sugar for management of. German ...

  8. Neurotoxicological effects and the mode of action of pyrethroid insecticides

    NARCIS (Netherlands)

    Vijverberg, H.P.M.; Bercken, Joep van den

    1990-01-01

    Neuroexcitatory symptoms of acute poisoning of vertebrates by pyrethroids are related to the ability of these insecticides to modify electrical activity in various parts of the nervous system. Repetitive nerve activity, particularly in the sensory nervous system, membrane depolarization, and

  9. Use of insecticide treated nets among caregivers of children under ...

    African Journals Online (AJOL)

    Use of insecticide treated nets among caregivers of children under five years in Makueni ... in addressing malaria problem among young children and pregnant women. ... Scaling up proper use of ITNs along with other initiatives can contribute ...

  10. PRN 73-4: Residual Insecticides in Food Handling Establishments

    Science.gov (United States)

    This notice provides a copy of a Federal Register notice published July 6, 1973, regarding certain insecticides used in food-handling establishments. It establishes certain definitions and requirements related to approval for crack and crevice treatment.

  11. Design, Synthesis and Insecticidal Activity of Novel Phenylurea Derivatives

    Directory of Open Access Journals (Sweden)

    Jialong Sun

    2015-03-01

    Full Text Available A series of novel phenylurea derivatives were designed and synthesized according to the method of active groups linkage and the principle of aromatic groups bioisosterism in this study. The structures of the novel phenylurea derivatives were confirmed based on ESI-MS, IR and 1H-NMR spectral data. All of the compounds were evaluated for the insecticidal activity against the third instars larvae of Spodoptera exigua Hiibner, Plutella xyllostella Linnaeus, Helicoverpa armigera Hubner and Pieris rapae Linne respectively, at the concentration of 10 mg/L. The results showed that all of the derivatives displayed strong insecticidal activity. Most of the compounds presented higher insecticidal activity against S. exigua than the reference compounds tebufenozide, chlorbenzuron and metaflumizone. Among the synthesized compounds, 3b, 3d, 3f, 4b and 4g displayed broad spectrum insecticidal activity.

  12. Bio-evaluation of South African plants for insecticidal properties

    CSIR Research Space (South Africa)

    Maharaj, R

    2006-02-01

    Full Text Available Malaria is a serious health problem in South Africa affecting the lives of approximately 4 million people. Resistance to the principal vector, Anopheles arabiensis, has initiated a search for new plant-derived insecticides. Plants were selected...

  13. Federal Insecticide, Fungicide, and Rodenticide Act Section 18 Database

    Data.gov (United States)

    U.S. Environmental Protection Agency — Section 18 of Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) authorizes EPA to allow an unregistered use of a pesticide for a limited time if EPA...

  14. Dry Live Aerosol Anthrax Vaccine

    Science.gov (United States)

    In preparing the dry live aerosol anthrax vaccine the use of a spore culture of the STI-1 single vaccine strain and culturing of the latter on a...to 10 billion spores in 1 mm of wash. Dry live aerosol anthrax vaccine is suitable for aerosol immunization if the calculated aspiration dose, when...the viable spores in dry live aerosol anthrax vaccine, it is necessary to store it under deep vacuum (in the range of 100-150 microns) and at temperatures not exceeding +10 degrees.

  15. Aerosol Data Assimilation at GMAO

    Science.gov (United States)

    da Silva, Arlindo M.; Buchard, Virginie

    2017-01-01

    This presentation presents an overview of the aerosol data assimilation work performed at GMAO. The GMAO Forward Processing system and the biomass burning emissions from QFED are first presented. Then, the current assimilation of Aerosol Optical Depth (AOD), performed by means of the analysis splitting method is briefly described, followed by some results on the quality control of observations using a Neural Network trained using AERONET AOD. Some applications are shown such as the Mount Pinatubo eruption in 1991 using the MERRA-2 aerosol dataset. Finally preliminary results on the EnKF implementation for aerosol assimilation are presented.

  16. Topics in current aerosol research

    CERN Document Server

    Hidy, G M

    1971-01-01

    Topics in Current Aerosol Research deals with the fundamental aspects of aerosol science, with emphasis on experiment and theory describing highly dispersed aerosols (HDAs) as well as the dynamics of charged suspensions. Topics covered range from the basic properties of HDAs to their formation and methods of generation; sources of electric charges; interactions between fluid and aerosol particles; and one-dimensional motion of charged cloud of particles. This volume is comprised of 13 chapters and begins with an introduction to the basic properties of HDAs, followed by a discussion on the form

  17. Mechanism of Insect Resistance to the Microbial Insecticide Bacillus thuringiensis

    Science.gov (United States)

    van Rie, J.; McGaughey, W. H.; Johnson, D. E.; Barnett, B. D.; van Mellaert, H.

    1990-01-01

    Receptor binding studies show that resistance of a laboratory-selected Plodia interpunctella strain to a Bacillus thuringiensis insecticidal crystal protein (ICP) is correlated with a 50-fold reduction in affinity of the membrane receptor for this protein. The strain is sensitive to a second type of ICP that apparently recognizes a different receptor. Understanding the mechanism of resistance will provide strategies to prevent or delay resistance and hence prolong the usefulness of B. thuringiensis ICPs as environmentally safe insecticides.

  18. Flupyradifurone: a brief profile of a new butenolide insecticide

    OpenAIRE

    Nauen, Ralf; Jeschke, Peter; Velten, Robert; Beck, Michael E; Ebbinghaus-Kintscher, Ulrich; Thielert, Wolfgang; W?lfel, Katharina; Haas, Matthias; Kunz, Klaus; Raupach, Georg

    2014-01-01

    BACKGROUND The development and commercialisation of new chemical classes of insecticides for efficient crop protection measures against destructive invertebrate pests is of utmost importance to overcome resistance issues and to secure sustainable crop yields. Flupyradifurone introduced here is the first representative of the novel butenolide class of insecticides active against various sucking pests and showing an excellent safety profile. RESULTS The discovery of flupyradifurone was inspired...

  19. Online characterization of nano-aerosols released by commercial spray products using SMPS–ICPMS coupling

    Energy Technology Data Exchange (ETDEWEB)

    Losert, Sabrina; Hess, Adrian [Empa Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Analytical Chemistry (Switzerland); Ilari, Gabriele [Empa Swiss Federal Laboratories for Materials Science and Technology, Electron Microscopy Center (Switzerland); Goetz, Natalie von, E-mail: natalie.von.goetz@chem.ethz.ch; Hungerbuehler, Konrad [ETH Zürich Swiss Federal Institute of Technology Zürich, Institute for Chemical and Bioengineering (Switzerland)

    2015-07-15

    Nanoparticle-containing sprays are a critical class of consumer products, since human exposure may occur by inhalation of nanoparticles (NP) in the generated aerosols. In this work, the suspension and the released aerosol of six different commercially available consumer spray products were analyzed. Next to a broad spectrum of analytical methods for the characterization of the suspension, a standardized setup for the analysis of aerosol has been used. In addition, a new online coupling technique (SMPS–ICPMS) for the simultaneous analysis of particle size and elemental composition of aerosol particles has been applied. Results obtained with this new method were confirmed by other well-established techniques. Comparison of particles in the original suspensions and in the generated aerosol showed that during spraying single particles of size less than 20 nm had been formed, even though in none of the suspensions particles of size less than 280 nm were present (Aerosol size range scanned: 7–300 nm). Both pump sprays and propellant gas sprays were analyzed and both released particles in the nm size range. Also, both water-based and organic solvent-based sprays released NP. However, a trend was observed that spraying an aqueous suspension contained in a pump spray dispenser after drying resulted in bigger agglomerates than spraying organic suspensions in propellant gas dispensers.

  20. TRP Channels in Insect Stretch Receptors as Insecticide Targets.

    Science.gov (United States)

    Nesterov, Alexandre; Spalthoff, Christian; Kandasamy, Ramani; Katana, Radoslav; Rankl, Nancy B; Andrés, Marta; Jähde, Philipp; Dorsch, John A; Stam, Lynn F; Braun, Franz-Josef; Warren, Ben; Salgado, Vincent L; Göpfert, Martin C

    2015-05-06

    Defining the molecular targets of insecticides is crucial for assessing their selectivity and potential impact on environment and health. Two commercial insecticides are now shown to target a transient receptor potential (TRP) ion channel complex that is unique to insect stretch receptor cells. Pymetrozine and pyrifluquinazon disturbed Drosophila coordination and hearing by acting on chordotonal stretch receptor neurons. This action required the two TRPs Nanchung (Nan) and Inactive (Iav), which co-occur exclusively within these cells. Nan and Iav together sufficed to confer cellular insecticide responses in vivo and in vitro, and the two insecticides were identified as specific agonists of Nan-Iav complexes that, by promoting cellular calcium influx, silence the stretch receptor cells. This establishes TRPs as insecticide targets and defines specific agonists of insect TRPs. It also shows that TRPs can render insecticides cell-type selective and puts forward TRP targets to reduce side effects on non-target species. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Susceptibility and resistance to insecticides of Chagas disease vectors.

    Science.gov (United States)

    Zerba, E N

    1999-01-01

    Chemical control of Chagas disease vectors appears to be the best practical way to reduce the incidence of the disease. DDT was initially tested in the 1950s for the campaigns of control of Chagas disease vectors. Its low level of effectiveness against triatomine caused the failure of these control actions. HCH was then introduced in the southern cone and Dieldrin in the north of Latinoamerica. Starting in the late 1960s anticholinesterasic organophosphorus and carbamate compounds were introduced in the control of Chagas vectors. The use of pyrethroid compounds began in 1980. This family of insecticides is now the most important tool in triatomines control because of its favorable toxicological properties. Other types of insecticides also studied for Chagas vector control were the insect growth regulators and the antifeeding compounds. Because of the mode of action of these insecticides they are now considered just a potential complement of neurotoxic insecticides for integrated programmes of Triatomines control. Innovative formulations such as fumigant canister and insecticidal paints have been successfully developed in Latinoamerica with the World Health Organization support. Resistance to insecticides of triatomines is not yet a great problem in Chagas vectors. However, some resistant strains to pyrethroids have been found in Rhodnius prolixus from Venezuela and in Triatoma infestans from Brazil. Some cases of T. infestans incipient resistance to deltamethrin have been detected in Argentina. According to the control tools now available it is possible to expect the interruption of vector transmission of Chagas disease in the near future.

  2. Male mosquitoes as vehicles for insecticide.

    Directory of Open Access Journals (Sweden)

    James W Mains

    2015-01-01

    Full Text Available The auto-dissemination approach has been shown effective at treating cryptic refugia that remain unaffected by existing mosquito control methods. This approach relies on adult mosquito behavior to spread larvicide to breeding sites at levels that are lethal to immature mosquitoes. Prior studies demonstrate that 'dissemination stations,' deployed in mosquito-infested areas, can contaminate adult mosquitoes, which subsequently deliver the larvicide to breeding sites. In some situations, however, preventative measures are needed, e.g., to mitigate seasonal population increases. Here we examine a novel approach that combines elements of autocidal and auto-dissemination strategies by releasing artificially reared, male mosquitoes that are contaminated with an insecticide.Laboratory and field experiments examine for model-predicted impacts of pyriproxyfen (PPF directly applied to adult male Aedes albopictus, including (1 the ability of PPF-treated males to cross-contaminate females and to (2 deliver PPF to breeding sites.Similar survivorship was observed in comparisons of PPF-treated and untreated males. Males contaminated both female adults and oviposition containers in field cage tests, at levels that eliminated immature survivorship. Field trials demonstrate an ability of PPF-treated males to transmit lethal doses to introduced oviposition containers, both in the presence and absence of indigenous females. A decline in the Ae. albopictus population was observed following the introduction of PPF-treated males, which was not observed in two untreated field sites.The results demonstrate that, in cage and open field trials, adult male Ae. albopictus can tolerate PPF and contaminate, either directly or indirectly, adult females and immature breeding sites. The results support additional development of the proposed approach, in which male mosquitoes act as vehicles for insecticide delivery, including exploration of the approach with additional medically

  3. Aerosol absorption and radiative forcing

    Directory of Open Access Journals (Sweden)

    P. Stier

    2007-10-01

    Full Text Available We present a comprehensive examination of aerosol absorption with a focus on evaluating the sensitivity of the global distribution of aerosol absorption to key uncertainties in the process representation. For this purpose we extended the comprehensive aerosol-climate model ECHAM5-HAM by effective medium approximations for the calculation of aerosol effective refractive indices, updated black carbon refractive indices, new cloud radiative properties considering the effect of aerosol inclusions, as well as by modules for the calculation of long-wave aerosol radiative properties and instantaneous aerosol forcing. The evaluation of the simulated aerosol absorption optical depth with the AERONET sun-photometer network shows a good agreement in the large scale global patterns. On a regional basis it becomes evident that the update of the BC refractive indices to Bond and Bergstrom (2006 significantly improves the previous underestimation of the aerosol absorption optical depth. In the global annual-mean, absorption acts to reduce the short-wave anthropogenic aerosol top-of-atmosphere (TOA radiative forcing clear-sky from −0.79 to −0.53 W m−2 (33% and all-sky from −0.47 to −0.13 W m−2 (72%. Our results confirm that basic assumptions about the BC refractive index play a key role for aerosol absorption and radiative forcing. The effect of the usage of more accurate effective medium approximations is comparably small. We demonstrate that the diversity in the AeroCom land-surface albedo fields contributes to the uncertainty in the simulated anthropogenic aerosol radiative forcings: the usage of an upper versus lower bound of the AeroCom land albedos introduces a global annual-mean TOA forcing range of 0.19 W m−2 (36% clear-sky and of 0.12 W m−2 (92% all-sky. The consideration of black carbon inclusions on cloud radiative properties results in a small global annual-mean all-sky absorption of 0.05 W

  4. Safety Cultures in Water-Based Outdoor Activities in Denmark

    DEFF Research Database (Denmark)

    Andkjær, Søren; Arvidsen, Jan

    2015-01-01

    water-based outdoor activities: small boat fishing, sea kayaking, and kite surfing. The theoretical framework used was cultural analysis and the methodological approach was mixed methods using case studies with survey and qualitative interviews. The study indicates that safety is a complex matter...... and that safety culture can be understood as the sum and interaction among six categories. The safety culture is closely related to the activity and differs widely among activities. We suggest a broad perspective be taken on risk management wherein risk and safety can be managed at different levels. Small boat...... fishing is a critical example with obvious critical points according to risk management. We also present suggestions for improving safety in small boat fishing....

  5. Coalescence Sampling and Analysis of Aerosols using Aerosol Optical Tweezers.

    Science.gov (United States)

    Haddrell, Allen E; Miles, Rachael E H; Bzdek, Bryan R; Reid, Jonathan P; Hopkins, Rebecca J; Walker, Jim S

    2017-02-21

    We present a first exploratory study to assess the use of aerosol optical tweezers as an instrument for sampling and detecting accumulation- and coarse-mode aerosol. A subpicoliter aqueous aerosol droplet is captured in the optical trap and used as a sampling volume, accreting mass from a free-flowing aerosol generated by a medical nebulizer or atomizer. Real-time measurements of the initial stability in size, refractive index, and composition of the sampling droplet inferred from Raman spectroscopy confirm that these quantities can be measured with high accuracy and low noise. Typical standard deviations in size and refractive index of the sampling droplet over a period of 200 s are droplet as discrete coalescence events. With accumulation-mode aerosol, we show that fluxes as low as 0.068 pg s -1 can be detected over a 50 s period, equivalent to ∼3 pg of sampled material.

  6. Insecticide mixtures could enhance the toxicity of insecticides in a resistant dairy population of Musca domestica L [corrected].

    Directory of Open Access Journals (Sweden)

    Hafiz Azhar Ali Khan

    Full Text Available House flies, Musca domestica L., are important pests of dairy operations worldwide, with the ability to adapt wide range of environmental conditions. There are a number of insecticides used for their management, but development of resistance is a serious problem. Insecticide mixtures could enhance the toxicity of insecticides in resistant insect pests, thus resulting as a potential resistance management tool. The toxicity of bifenthrin, cypermethrin, deltamethrin, chlorpyrifos, profenofos, emamectin benzoate and fipronil were assessed separately, and in mixtures against house flies. A field-collected population was significantly resistant to all the insecticides under investigation when compared with a laboratory susceptible strain. Most of the insecticide mixtures like one pyrethroid with other compounds evaluated under two conditions (1∶1-"A" and LC50: LC50-"B" significantly increased the toxicity of pyrethroids in the field population. Under both conditions, the combination indices of pyrethroids with other compounds, in most of the cases, were significantly below 1, suggesting synergism. The enzyme inhibitors, PBO and DEF, when used in combination with insecticides against the resistant population, toxicities of bifenthrin, cypermethrin, deltamethrin and emamectin were significantly increased, suggesting esterase and monooxygenase based resistance mechanism. The toxicities of bifenthrin, cypermethrin and deltamethrin in the resistant population of house flies could be enhanced by the combination with chlorpyrifos, profenofos, emamectin and fipronil. The findings of the present study might have practical significance for resistance management in house flies.

  7. AEROSOL VARIABILITY OBSERVED WITH RPAS

    Directory of Open Access Journals (Sweden)

    B. Altstädter

    2013-08-01

    Full Text Available To observe the origin, vertical and horizontal distribution and variability of aerosol particles, and especially ultrafine particles recently formed, we plan to employ the remotely piloted aircraft system (RPAS Carolo-P360 "ALADINA" of TU Braunschweig. The goal of the presented project is to investigate the vertical and horizontal distribution, transport and small-scale variability of aerosol particles in the atmospheric boundary layer using RPAS. Two additional RPAS of type MASC of Tübingen University equipped with turbulence instrumentation add the opportunity to study the interaction of the aerosol concentration with turbulent transport and exchange processes of the surface and the atmosphere. The combination of different flight patterns of the three RPAS allows new insights in atmospheric boundary layer processes. Currently, the different aerosol sensors are miniaturized at the Leibniz Institute for Tropospheric Research, Leipzig and together with the TU Braunschweig adapted to fit into the RPAS. Moreover, an additional meteorological payload for measuring temperature, humidity and turbulence properties is constructed by Tübingen University. Two condensation particle counters determine the total aerosol number with a different lower detection threshold in order to investigate the horizontal and vertical aerosol variability and new particle formation (aerosol particles of some nm diameter. Further the aerosol size distribution in the range from about 0.300 to ~5 μm is given by an optical particle counter.

  8. Aerosol dynamics in porous media

    NARCIS (Netherlands)

    Ghazaryan, L.

    2014-01-01

    In this thesis, a computational model was developed for the simulation of aerosol formation through nucleation, followed by condensation and evaporation and filtration by porous material. Understanding aerosol dynamics in porous media can help improving engineering models that are used in various

  9. Aerosol therapy in young children

    NARCIS (Netherlands)

    H.M. Janssens (Hettie)

    2001-01-01

    textabstractInhalation of aerosolized drugs has become an established means for treatment of pulmonary diseases in the last fifiy years. The majoriry of aerosol therapy in childhood concerns inhaled corticosteroids and bronchodilators in the management of asthma. Administration of drugs via the

  10. Aerosol Variability Observed with Rpas

    Science.gov (United States)

    Altstädter, B.; Lampert, A.; Scholtz, A.; Bange, J.; Platis, A.; Hermann, M.; Wehner, B.

    2013-08-01

    To observe the origin, vertical and horizontal distribution and variability of aerosol particles, and especially ultrafine particles recently formed, we plan to employ the remotely piloted aircraft system (RPAS) Carolo-P360 "ALADINA" of TU Braunschweig. The goal of the presented project is to investigate the vertical and horizontal distribution, transport and small-scale variability of aerosol particles in the atmospheric boundary layer using RPAS. Two additional RPAS of type MASC of Tübingen University equipped with turbulence instrumentation add the opportunity to study the interaction of the aerosol concentration with turbulent transport and exchange processes of the surface and the atmosphere. The combination of different flight patterns of the three RPAS allows new insights in atmospheric boundary layer processes. Currently, the different aerosol sensors are miniaturized at the Leibniz Institute for Tropospheric Research, Leipzig and together with the TU Braunschweig adapted to fit into the RPAS. Moreover, an additional meteorological payload for measuring temperature, humidity and turbulence properties is constructed by Tübingen University. Two condensation particle counters determine the total aerosol number with a different lower detection threshold in order to investigate the horizontal and vertical aerosol variability and new particle formation (aerosol particles of some nm diameter). Further the aerosol size distribution in the range from about 0.300 to ~5 μm is given by an optical particle counter.

  11. How can the fipronil insecticide access phloem?

    Science.gov (United States)

    Aajoud, Asmae; Raveton, Muriel; Azrou-Isghi, Dalila; Tissut, Michel; Ravanel, Patrick

    2008-05-28

    Seeds of sunflower plants coated with the fipronil (14)C-insecticide were allowed to grow in the greenhouse. The distribution of the (14)C-compounds was studied in each part of the plant after three months. After 83 days of culture small amounts of (14)C-compounds were found in the inflorescence (0.6 per thousand of the seed deposit) which were fipronil itself or its lipophilic or hydrophilic metabolites. The (14)C-compounds were found in each part of the inflorescence (bracts, ray and disk florets containing pollen, akenes). The (14)C-concentration in the xylem sap evaluated at this stage was much too low to explain the accumulated amount in the inflorescence. Under controlled conditions in a culture chamber, it was then demonstrated that a net phloem transfer of (14)C-fipronil occurred from developed leaves to growing organs. This allowed us to suppose that a similar (14)C-fipronil phloem transfer could occur toward the inflorescence during its formation. A quantitative evaluation suggests that most of the labeled compounds at this stage were not coming from the leaves but from the roots and stem where storage compounds were hydrolyzed for sustaining inflorescence development.

  12. Federal chemist reports on insecticide dangers

    Science.gov (United States)

    DeWitt, J.B.

    1957-01-01

    There's been much discussion, and considerable argument, in recent years regarding the effects of crop dusting on game populations. In an attempt to get some of the answers, the U. S. Fish and Wildlife Service has been conducting a series of experiments, using captive quail? and pheasants.....By. feeding. specified amounts??of various insecticides, they found how 'much it would take to kill outright all test birds, how much to produce partIal kill, and how much would have relatively little effect. An interesting result? of the experiments was the proof that even non-fatal doses would stunt growth and reduce egg fertility, and that birds were unable to reproduce at all after two generations of exposure to these poisons....Of the cheriricals tested, aldrin and endrin were the most poisonous to the birds. If aldrin were applied at the rate of one pound per acre, each square? foot of ground would have enough poison? to kill two adult quail or 20 two-week-old birds.

  13. Insecticidal activity of menthol derivatives against mosquitoes.

    Science.gov (United States)

    Samarasekera, Radhika; Weerasinghe, Indira S; Hemalal, Kd Patrick

    2008-03-01

    The insecticidal activity of essential oil of Mentha piperita L. emend. Huds. against local mosquitoes as disease vectors was recognized and found to be due to the presence of menthol, which is the major aroma compound of the oil. The minor compounds of the oil, i.e. menthone, beta-caryophyllene, menthyl acetate, limonene, alpha-pinene and pulegone, showed either less or no activity against the mosquitoes tested. L-Menthol derivatives were synthesized and their knockdown effect and mortality were evaluated against local mosquitoes of Culex quinquefasciatus Say, Aedes aegypti L. and Anopheles tessellatus Theobald as disease vectors. This is the first report of mosquitocidal activity of menthol and its derivatives against Cx. quinquefasciatus, Ae. aegypti and An. tessellatus. Derivative synthesis followed by structure-activity relationship studies identified several derivatives, i.e. menthyl chloroacetate, menthyl dichloroacetate, menthyl cinnamate, menthone glyceryl acetal, thymol, alpha-terpineol and mugetanol, with enhanced mosquitocidal activity against Cx. quinquefasciatus, Ae. aegypti and An. tessellatus relative to the parent compound L-menthone. In ester derivatives of L-menthol the optimum activity is dependent on the size and shape of the ester group and the presence of chlorine atoms in the ester group. In structurally related derivatives of L-menthol the optimum activity is dependent on the aromaticity, the degree of unsaturation, the position of the hydroxy group and the type of functional group. (c) 2007 Society of Chemical Industry.

  14. The Climatology of Australian Aerosol

    Science.gov (United States)

    Mitchell, Ross M.; Forgan, Bruce W.; Campbell, Susan K.

    2017-04-01

    Airborne particles or aerosols have long been recognised for their major contribution to uncertainty in climate change. In addition, aerosol amounts must be known for accurate atmospheric correction of remotely sensed images, and are required to accurately gauge the available solar resource. However, despite great advances in surface networks and satellite retrievals over recent years, long-term continental-scale aerosol data sets are lacking. Here we present an aerosol assessment over Australia based on combined sun photometer measurements from the Bureau of Meteorology Radiation Network and CSIRO/AeroSpan. The measurements are continental in coverage, comprising 22 stations, and generally decadal in timescale, totalling 207 station-years. Monthly climatologies are given at all stations. Spectral decomposition shows that the time series can be represented as a weighted sum of sinusoids with periods of 12, 6 and 4 months, corresponding to the annual cycle and its second and third harmonics. Their relative amplitudes and phase relationships lead to sawtooth-like waveforms sharply rising to an austral spring peak, with a slower decline often including a secondary peak during the summer. The amplitude and phase of these periodic components show significant regional change across the continent. Fits based on this harmonic analysis are used to separate the periodic and episodic components of the aerosol time series. An exploratory classification of the aerosol types is undertaken based on (a) the relative periodic amplitudes of the Ångström exponent and aerosol optical depth, (b) the relative amplitudes of the 6- and 4-month harmonic components of the aerosol optical depth, and (c) the ratio of episodic to periodic variation in aerosol optical depth. It is shown that Australian aerosol can be broadly grouped into three classes: tropical, arid and temperate. Statistically significant decadal trends are found at 4 of the 22 stations. Despite the apparently small

  15. Azobenzene Modified Imidacloprid Derivatives as Photoswitchable Insecticides: Steering Molecular Activity in a Controllable Manner

    Science.gov (United States)

    Xu, Zhiping; Shi, Lina; Jiang, Danping; Cheng, Jiagao; Shao, Xusheng; Li, Zhong

    2015-10-01

    Incorporating the photoisomerizable azobenzene into imidacloprid produced a photoswitchable insecticidal molecule as the first neonicotinoid example of remote control insecticide performance with spatiotemporal resolution. The designed photoswitchable insecticides showed distinguishable activity against Musca both in vivo and in vitro upon irradiation. Molecular docking study further suggested the binding difference of the two photoisomers. The generation of these photomediated insecticides provides novel insight into the insecticidal activity facilitating further investigation on the functions of insect nicotinic acetylcholine receptors and opens a novel way to control and study insect behavior on insecticide poisoning using light.

  16. Atmospheric and aerosol chemistry

    Energy Technology Data Exchange (ETDEWEB)

    McNeill, V. Faye [Columbia Univ., New York, NY (United States). Dept. of Chemical Engineering; Ariya, Parisa A. (ed.) [McGill Univ. Montreal, QC (Canada). Dept. of Chemistry; McGill Univ. Montreal, QC (Canada). Dept. of Atmospheric and Oceanic Sciences

    2014-09-01

    This series presents critical reviews of the present position and future trends in modern chemical research. Short and concise reports on chemistry, each written by the world renowned experts. Still valid and useful after 5 or 10 years. More information as well as the electronic version of the whole content available at: springerlink.com. Christian George, Barbara D'Anna, Hartmut Herrmann, Christian Weller, Veronica Vaida, D. J. Donaldson, Thorsten Bartels-Rausch, Markus Ammann Emerging Areas in Atmospheric Photochemistry. Lisa Whalley, Daniel Stone, Dwayne Heard New Insights into the Tropospheric Oxidation of Isoprene: Combining Field Measurements, Laboratory Studies, Chemical Modelling and Quantum Theory. Neil M. Donahue, Allen L. Robinson, Erica R. Trump, Ilona Riipinen, Jesse H. Kroll Volatility and Aging of Atmospheric Organic Aerosol. P. A. Ariya, G. Kos, R. Mortazavi, E. D. Hudson, V. Kanthasamy, N. Eltouny, J. Sun, C. Wilde Bio-Organic Materials in the Atmosphere and Snow: Measurement and Characterization V. Faye McNeill, Neha Sareen, Allison N. Schwier Surface-Active Organics in Atmospheric Aerosols.

  17. DSMC multicomponent aerosol dynamics: Sampling algorithms and aerosol processes

    Science.gov (United States)

    Palaniswaamy, Geethpriya

    The post-accident nuclear reactor primary and containment environments can be characterized by high temperatures and pressures, and fission products and nuclear aerosols. These aerosols evolve via natural transport processes as well as under the influence of engineered safety features. These aerosols can be hazardous and may pose risk to the public if released into the environment. Computations of their evolution, movement and distribution involve the study of various processes such as coagulation, deposition, condensation, etc., and are influenced by factors such as particle shape, charge, radioactivity and spatial inhomogeneity. These many factors make the numerical study of nuclear aerosol evolution computationally very complicated. The focus of this research is on the use of the Direct Simulation Monte Carlo (DSMC) technique to elucidate the role of various phenomena that influence the nuclear aerosol evolution. In this research, several aerosol processes such as coagulation, deposition, condensation, and source reinforcement are explored for a multi-component, aerosol dynamics problem in a spatially homogeneous medium. Among the various sampling algorithms explored the Metropolis sampling algorithm was found to be effective and fast. Several test problems and test cases are simulated using the DSMC technique. The DSMC results obtained are verified against the analytical and sectional results for appropriate test problems. Results show that the assumption of a single mean density is not appropriate due to the complicated effect of component densities on the aerosol processes. The methods developed and the insights gained will also be helpful in future research on the challenges associated with the description of fission product and aerosol releases.

  18. Storm Aerosol Environments and Aerosol Sources in Subtropical South America

    Science.gov (United States)

    Cancelada, M.; Salio, P. V.; Nesbitt, S. W.

    2016-12-01

    Several studies have shown a strong interaction in the subtropical area of Southeastern South America (SESA) between deep moist convection and the presence of the South American low level jet (SALLJ), which advects humidity and heat from tropical latitudes creating ideal conditions in the environment for convective activity. Moreover, the SALLJ is considered an important mechanism for transport of gases and particulate matter emitted in tropical South America. Biomass burning season associated with deforestation and land clearing for agricultural use is observed in these regions principally from August to October. Past studies have shown, through modeling and in-situ measurements, an increase in optical depth and Angstrom exponent during SALLJ events. Evidence of an increase in aerosol loading during burning biomass season, along with favorable conditions for deep moist convection activity, supports the hypothesis of an indirect effect from aerosols in convective development in SESA. The objective of this work is to characterize aerosol environments in SESA associated with the presence of mesoscale convective system development. High aerosol concentration events during biomass burning season from 2002 to 2015 were detected using corrected aerosol optical depth (CAOD) with 10-km horizontal resolution from Moderate Resolution Imaging Spectroradiometer (MODIS) Aerosol Products. Environmental variables from NCEP Climate Forecast System Reanalysis (CFSR) were examined to detect SALLJ events and deep moist convection development was observed through infrared channel from GOES. This combination of aerosol data and SALLJ presence determined a data-set for polluted and non-polluted environments. A remarkable correlation between higher values of CAOD in central Argentina and SALLJ was found. A case of study with evidence of SALLJ, high CAOD values and strong convection development was examined. A Weather Research and Forecasting (WRF) simulation has been performed in order

  19. Current status of insecticide resistance among malaria vectors in Kenya.

    Science.gov (United States)

    Ondeto, Benyl M; Nyundo, Christopher; Kamau, Luna; Muriu, Simon M; Mwangangi, Joseph M; Njagi, Kiambo; Mathenge, Evan M; Ochanda, Horace; Mbogo, Charles M

    2017-09-19

    Insecticide resistance has emerged as one of the major challenges facing National Malaria Control Programmes in Africa. A well-coordinated national database on insecticide resistance (IRBase) can facilitate the development of effective strategies for managing insecticide resistance and sustaining the effectiveness of chemical-based vector control measures. The aim of this study was to assemble a database on the current status of insecticide resistance among malaria vectors in Kenya. Data was obtained from published literature through PubMed, HINARI and Google Scholar searches and unpublished literature from government reports, research institutions reports and malaria control programme reports. Each data source was assigned a unique identification code and entered into Microsoft Excel 2010 datasheets. Base maps on the distribution of insecticide resistance and resistance mechanisms among malaria vectors in Kenya were generated using ArcGIS Desktop 10.1 (ESRI, Redlands, CA, USA). Insecticide resistance status among the major malaria vectors in Kenya was reported in all the four classes of insecticides including pyrethroids, carbamates, organochlorines and organophosphates. Resistance to pyrethroids has been detected in Anopheles gambiae (s.s.), An. arabiensis and An. funestus (s.s.) while resistance to carbamates was limited to An. gambiae (s.s.) and An. arabiensis. Resistance to the organochlorine was reported in An. gambiae (s.s.) and An. funestus (s.s.) while resistance to organophosphates was reported in An. gambiae (s.l.) only. The mechanisms of insecticide resistance among malaria vectors reported include the kdr mutations (L 1014S and L 1014F) and elevated activity in carboxylesterase, glutathione S-transferases (GST) and monooxygenases. The kdr mutations L 1014S and L 1014F were detected in An. gambiae (s.s.) and An. arabiensis populations. Elevated activity of monooxygenases has been detected in both An. arabiensis and An. gambiae (s.s.) populations while

  20. Underpinning sustainable vector control through informed insecticide resistance management.

    Science.gov (United States)

    Thomsen, Edward K; Strode, Clare; Hemmings, Kay; Hughes, Angela J; Chanda, Emmanuel; Musapa, Mulenga; Kamuliwo, Mulakwa; Phiri, Faustina N; Muzia, Lucy; Chanda, Javan; Kandyata, Alister; Chirwa, Brian; Poer, Kathleen; Hemingway, Janet; Wondji, Charles S; Ranson, Hilary; Coleman, Michael

    2014-01-01

    There has been rapid scale-up of malaria vector control in the last ten years. Both of the primary control strategies, long-lasting pyrethroid treated nets and indoor residual spraying, rely on the use of a limited number of insecticides. Insecticide resistance, as measured by bioassay, has rapidly increased in prevalence and has come to the forefront as an issue that needs to be addressed to maintain the sustainability of malaria control and the drive to elimination. Zambia's programme reported high levels of resistance to the insecticides it used in 2010, and, as a result, increased its investment in resistance monitoring to support informed resistance management decisions. A country-wide survey on insecticide resistance in Zambian malaria vectors was performed using WHO bioassays to detect resistant phenotypes. Molecular techniques were used to detect target-site mutations and microarray to detect metabolic resistance mechanisms. Anopheles gambiae s.s. was resistant to pyrethroids, DDT and carbamates, with potential organophosphate resistance in one population. The resistant phenotypes were conferred by both target-site and metabolic mechanisms. Anopheles funestus s.s. was largely resistant to pyrethroids and carbamates, with potential resistance to DDT in two locations. The resistant phenotypes were conferred by elevated levels of cytochrome p450s. Currently, the Zambia National Malaria Control Centre is using these results to inform their vector control strategy. The methods employed here can serve as a template to all malaria-endemic countries striving to create a sustainable insecticide resistance management plan.

  1. Susceptibility of Grapholita molesta to insecticides in Brazil

    Directory of Open Access Journals (Sweden)

    Oscar Arnaldo Batista Neto e Silva

    2017-12-01

    Full Text Available ABSTRACT: The use of insecticides has been the main tool for Grapholita molesta (Busck control in Brazil, which is considered one of the most important pests in apple and peach orchards. In order to implement an Insect Resistance Management (IRM program, studies were conducted to characterize the baseline susceptibility of G. molesta to major insecticides for its control. Then, we conducted an insecticide susceptibility monitoring in thirteen field-collected populations of the pest. Neonates (0-24h old were exposed to insecticides applied on surface of artificial diet. A high susceptibility was verified when neonates of the Laboratory population of G. molesta were exposed to insecticides with LC50 values (µg a.i./cm2 of 0.1 (spinetoram, 1.0 (metaflumizone, 1.2 (chlorantraniliprole, 4.8 (novaluron, 5.1 (tebufenozide, 11.3 (phosmet and 222.5 (pyriproxyfen. Based on the LC99 (µg a.i./cm2, the diagnostic concentrations of 0.6 (spinetoram, 5.5 (metaflumizone, 5.6 (chlorantraniliprole, 19.6 (tebufenozide, 37.4 (phosmet, 37.8 (novaluron and 2011 pyriproxyfen caused high mortality (>95% of neonates from field populations. These diagnostic concentrations will be used in resistance monitoring programs of G. molesta in Brazil.

  2. Insecticide resistance in the bed bug comes with a cost.

    Science.gov (United States)

    Gordon, Jennifer R; Potter, Michael F; Haynes, Kenneth F

    2015-06-03

    Adaptation to new environmental stress is often associated with an alteration of one or more life history parameters. Insecticide resistant populations of insects often have reduced fitness relative to susceptible populations in insecticide free environments. Our previous work showed that three populations of bed bugs, Cimex lectularius L., evolved significantly increased levels of resistance to one product containing both β-cyfluthrin and imidacloprid insecticides with only one generation of selection, which gave us an opportunity to explore potential tradeoffs between life history parameters and resistance using susceptible and resistant strains of the same populations. Life history tables were compiled by collecting weekly data on mortality and fecundity of bugs from each strain and treatment throughout their lives. Selection led to a male-biased sex ratio, shortened oviposition period, and decreased life-time reproductive rate. Generation time was shortened by selection, a change that represents a benefit rather than a cost. Using these life history characteristics we calculated that there would be a 90% return to pre-selection levels of susceptibility within 2- 6.5 generations depending on strain. The significant fitness costs associated with resistance suggest that insecticide rotation or utilization of non-insecticidal control tactics could be part of an effective resistance management strategy.

  3. An insecticidal toxin from Nephila clavata spider venom.

    Science.gov (United States)

    Jin, Lin; Fang, Mingqian; Chen, Mengrou; Zhou, Chunling; Ombati, Rose; Hakim, Md Abdul; Mo, Guoxiang; Lai, Ren; Yan, Xiuwen; Wang, Yumin; Yang, Shilong

    2017-07-01

    Spiders are the most successful insect predators given that they use their venom containing insecticidal peptides as biochemical weapons for preying. Due to the high specificity and potency of peptidic toxins, discoveries of insecticidal toxins from spider venom have provided an opportunity to obtain natural compounds for agricultural applications without affecting human health. In this study, a novel insecticidal toxin (μ-NPTX-Nc1a) was identified and characterized from the venom of Nephila clavata. Its primary sequence is GCNPDCTGIQCGWPRCPGGQNPVMDKCVSCCPFCPPKSAQG which was determined by automated Edman degradation, cDNA cloning, and MS/MS analysis. BLAST search indicated that Nc1a shows no similarity with known peptides or proteins, indicating that Nc1a belongs to a novel family of insecticidal peptide. Nc1a displayed inhibitory effects on Na V and K V channels in cockroach dorsal unpaired median neurons. The median lethal dose (LD50) of Nc1a on cockroach was 573 ng/g. Herein, a study that identifies a novel insecticidal toxin, which can be a potential candidate and/or template for the development of bioinsecticides, is presented.

  4. Plant compounds insecticide activity against Coleoptera pests of stored products

    Energy Technology Data Exchange (ETDEWEB)

    Moreira, Marcio Dionizio; Picanco, Marcelo Coutinho; Guedes, Raul Narciso Carvalho; Campos, Mateus Ribeiro de; Silva, Gerson Adriano; Martins, Julio Claudio [Universidade Federal de Vicosa (UFV), MG (Brazil). Dept. de Biologia Animal]. E-mail: marcio.dionizio@gmail.com; picanco@ufv.br; guedes@ufv.br; mateusc3@yahoo.com.br; agronomiasilva@yahoo.com.br

    2007-07-15

    The objective of this work was to screen plants with insecticide activity, in order to isolate, identify and assess the bioactivity of insecticide compounds present in these plants, against Coleoptera pests of stored products: Oryzaephilus surinamensis L. (Silvanidae), Rhyzopertha dominica F. (Bostrichidae) and Sitophilus zeamais Mots. (Curculionidae). The plant species used were: basil (Ocimum selloi Benth.), rue (Ruta graveolens L.), lion's ear (Leonotis nepetifolia (L.) R.Br.), jimson weed (Datura stramonium L.), baleeira herb (Cordia verbenacea L.), mint (Mentha piperita L.), wild balsam apple (Mormodica charantia L.), and billy goat weed or mentrasto (Ageratum conyzoides L.). The insecticide activity of hexane and ethanol extracts from those plants on R. dominica was evaluated. Among them, only hexane extract of A. conyzoides showed insecticide activity; the hexane extract of this species was successively fractionated by silica gel column chromatography, for isolation and purification of the active compounds. Compounds 5,6,7,8,3',4',5'-heptamethoxyflavone; 5,6,7,8,3'-pentamethoxy-4',5'-methilenedioxyflavone and coumarin were identified. However, only coumarin showed insecticide activity against three insect pests (LD{sub 50} from 2.72 to 39.71 mg g{sup -1} a.i.). The increasing order of insects susceptibility to coumarin was R. dominica, S. zeamais and O. surinamensis. (author)

  5. Continued Water-Based Phase Change Material Heat Exchanger Development

    Science.gov (United States)

    Hansen, Scott W.; Sheth, Rubik B.; Poynot, Joe; Giglio, Tony; Ungar, Gene K.

    2015-01-01

    In a cyclical heat load environment such as low Lunar orbit, a spacecraft's radiators are not sized to meet the full heat rejection demands. Traditionally, a supplemental heat rejection device (SHReD) such as an evaporator or sublimator is used to act as a "topper" to meet the additional heat rejection demands. Utilizing a Phase Change Material (PCM) heat exchanger (HX) as a SHReD provides an attractive alternative to evaporators and sublimators as PCM HX's do not use a consumable, thereby leading to reduced launch mass and volume requirements. In continued pursuit of water PCM HX development two full-scale, Orion sized water-based PCM HX's were constructed by Mezzo Technologies. These HX's were designed by applying prior research on freeze front propagation to a full-scale design. Design options considered included bladder restraint and clamping mechanisms, bladder manufacturing, tube patterns, fill/drain methods, manifold dimensions, weight optimization, and midplate designs. Two units, Units A and B, were constructed and differed only in their midplate design. Both units failed multiple times during testing. This report highlights learning outcomes from these tests and are applied to a final sub-scale PCM HX which is slated to be tested on the ISS in early 2017.

  6. Performance of Water-Based Liquid Scintillator: An Independent Analysis

    Directory of Open Access Journals (Sweden)

    D. Beznosko

    2014-01-01

    Full Text Available The water-based liquid scintillator (WbLS is a new material currently under development. It is based on the idea of dissolving the organic scintillator in water using special surfactants. This material strives to achieve the novel detection techniques by combining the Cerenkov rings and scintillation light, as well as the total cost reduction compared to pure liquid scintillator (LS. The independent light yield measurement analysis for the light yield measurements using three different proton beam energies (210 MeV, 475 MeV, and 2000 MeV for water, two different WbLS formulations (0.4% and 0.99%, and pure LS conducted at Brookhaven National Laboratory, USA, is presented. The results show that a goal of ~100 optical photons/MeV, indicated by the simulation to be an optimal light yield for observing both the Cerenkov ring and the scintillation light from the proton decay in a large water detector, has been achieved.

  7. Progress Report on Computational Analyses of Water-Based NSTF

    Energy Technology Data Exchange (ETDEWEB)

    Lv, Q. [Argonne National Lab. (ANL), Argonne, IL (United States); Kraus, A. [Argonne National Lab. (ANL), Argonne, IL (United States); Hu, R. [Argonne National Lab. (ANL), Argonne, IL (United States); Bucknor, M. [Argonne National Lab. (ANL), Argonne, IL (United States); Lisowski, D. [Argonne National Lab. (ANL), Argonne, IL (United States); Nunez, D. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2017-08-01

    CFD analysis has been focused on important component-level phenomena using STARCCM+ to supplement the system analysis of integral system behavior. A notable area of interest was the cavity region. This area is of particular interest for CFD analysis due to the multi-dimensional flow and complex heat transfer (thermal radiation heat transfer and natural convection), which are not simulated directly by RELAP5. CFD simulations allow for the estimation of the boundary heat flux distribution along the riser tubes, which is needed in the RELAP5 simulations. The CFD results can also provide additional data to help establish what level of modeling detail is necessary in RELAP5. It was found that the flow profiles in the cavity region are simpler for the water-based concept than for the air-cooled concept. The local heat flux noticeably increases axially, and is higher in the fins than in the riser tubes. These results were utilized in RELAP5 simulations as boundary conditions, to provide better temperature predictions in the system level analyses. It was also determined that temperatures were higher in the fins than the riser tubes, but within design limits for thermal stresses. Higher temperature predictions were identified in the edge fins, in part due to additional thermal radiation from the side cavity walls.

  8. Experimental stability analysis of different water-based nanofluids

    Directory of Open Access Journals (Sweden)

    Barison Simona

    2011-01-01

    Full Text Available Abstract In the recent years, great interest has been devoted to the unique properties of nanofluids. The dispersion process and the nanoparticle suspension stability have been found to be critical points in the development of these new fluids. For this reason, an experimental study on the stability of water-based dispersions containing different nanoparticles, i.e. single wall carbon nanohorns (SWCNHs, titanium dioxide (TiO2 and copper oxide (CuO, has been developed in this study. The aim of this study is to provide stable nanofluids for selecting suitable fluids with enhanced thermal characteristics. Different dispersion techniques were considered in this study, including sonication, ball milling and high-pressure homogenization. Both the dispersion process and the use of some dispersants were investigated as a function of the nanoparticle concentration. The high-pressure homogenization was found to be the best method, and the addition of n-dodecyl sulphate and polyethylene glycol as dispersants, respectively in SWCNHs-water and TiO2-water nanofluids, improved the nanofluid stability.

  9. The GRAPE aerosol retrieval algorithm

    Directory of Open Access Journals (Sweden)

    G. E. Thomas

    2009-11-01

    Full Text Available The aerosol component of the Oxford-Rutherford Aerosol and Cloud (ORAC combined cloud and aerosol retrieval scheme is described and the theoretical performance of the algorithm is analysed. ORAC is an optimal estimation retrieval scheme for deriving cloud and aerosol properties from measurements made by imaging satellite radiometers and, when applied to cloud free radiances, provides estimates of aerosol optical depth at a wavelength of 550 nm, aerosol effective radius and surface reflectance at 550 nm. The aerosol retrieval component of ORAC has several incarnations – this paper addresses the version which operates in conjunction with the cloud retrieval component of ORAC (described by Watts et al., 1998, as applied in producing the Global Retrieval of ATSR Cloud Parameters and Evaluation (GRAPE data-set.

    The algorithm is described in detail and its performance examined. This includes a discussion of errors resulting from the formulation of the forward model, sensitivity of the retrieval to the measurements and a priori constraints, and errors resulting from assumptions made about the atmospheric/surface state.

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

    Directory of Open Access Journals (Sweden)

    Carnevale Pierre

    2010-11-01

    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

  11. Insecticidal action of synthetic girgensohnine analogues and essential oils on Rhodnius prolixus (Hemiptera: Reduviidae

    Directory of Open Access Journals (Sweden)

    Juliana Cuadros

    2017-03-01

    Conclusion: Synthetic girgensohnine analogues, and C. flexuosus and C. sinensis essential oils showed insecticidal activity in R. prolixus. Analogue 3 showed the greatest insecticidal activity among all molecules and oils evaluated under our laboratory conditions.

  12. Instrumentation for tropospheric aerosol characterization

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Z.; Young, S.E.; Becker, C.H.; Coggiola, M.J. [SRI International, Menlo Park, CA (United States); Wollnik, H. [Giessen Univ. (Germany)

    1997-12-31

    A new instrument has been developed that determines the abundance, size distribution, and chemical composition of tropospheric and lower stratospheric aerosols with diameters down to 0.2 {mu}m. In addition to aerosol characterization, the instrument also monitors the chemical composition of the ambient gas. More than 25.000 aerosol particle mass spectra were recorded during the NASA-sponsored Subsonic Aircraft: Contrail and Cloud Effects Special Study (SUCCESS) field program using NASA`s DC-8 research aircraft. (author) 7 refs.

  13. eDPS Aerosol Collection

    Energy Technology Data Exchange (ETDEWEB)

    Venzie, J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-10-13

    The eDPS Aerosol Collection project studies the fundamental physics of electrostatic aerosol collection for national security applications. The interpretation of aerosol data requires understanding and correcting for biases introduced from particle genesis through collection and analysis. The research and development undertaken in this project provides the basis for both the statistical correction of existing equipment and techniques; as well as, the development of new collectors and analytical techniques designed to minimize unwanted biases while improving the efficiency of locating and measuring individual particles of interest.

  14. Insecticide-treated nets provide protection against malaria to children in an area of insecticide resistance in Southern Benin.

    Science.gov (United States)

    Bradley, John; Ogouyèmi-Hounto, Aurore; Cornélie, Sylvie; Fassinou, Jacob; de Tove, Yolande Sissinto Savi; Adéothy, Adicath Adéola; Tokponnon, Filémon T; Makoutode, Patrick; Adechoubou, Alioun; Legba, Thibaut; Houansou, Telesphore; Kinde-Gazard, Dorothée; Akogbeto, Martin C; Massougbodji, Achille; Knox, Tessa Bellamy; Donnelly, Martin; Kleinschmidt, Immo

    2017-05-26

    Malaria control is heavily reliant on insecticides, especially pyrethroids. Resistance of mosquitoes to insecticides may threaten the effectiveness of insecticide-based vector control and lead to a resurgence of malaria in Africa. In 21 villages in Southern Benin with high levels of insecticide resistance, the resistance status of local vectors was measured at the same time as the prevalence of malaria infection in resident children. Children who used LLINs had lower levels of malaria infection [odds ratio = 0.76 (95% CI 0.59, 0.98, p = 0.033)]. There was no evidence that the effectiveness of nets was different in high and low resistance locations (p = 0.513). There was no association between village level resistance and village level malaria prevalence (p = 0.999). LLINs continue to offer individual protection against malaria infection in an area of high resistance. Insecticide resistance is not a reason to stop efforts to increase coverage of LLINs in Africa.

  15. Insecticide resistance in Bemisia tabaci (Homoptera: Aleyrodidae) populations from Crete.

    Science.gov (United States)

    Roditakis, Emmanouil; Roditakis, Nikos E; Tsagkarakou, Anastasia

    2005-06-01

    The resistance levels to alpha-cypermethrin, bifenthrin, pirimiphos-methyl, endosulfan and imidacloprid were determined in Bemisia tabaci (Gennadius) from Crete. Five B tabaci populations collected from greenhouse and outdoor crops were bioassayed and compared with a reference susceptible strain. Bemisia tabaci collected in a floriculture greenhouse exhibited the highest resistance against all insecticides: at LC50, resistance factors were 23-fold for bifenthrin, 80-fold for alpha-cypermethrin, 18-fold for pirimiphos-methyl, 58-fold for endosulfan and 730-fold for imidacloprid. A population collected on outdoor melons was more susceptible than the reference strain against all insecticides tested, suggesting the occurrence of local highly susceptible B tabaci populations in 'refugia'. In pairwise comparisons of resistance levels, correlation was observed between the LC50 values of the pyrethroid insecticides bifenthrin and alpha-cypermethrin.

  16. A comparative study of insecticide toxicity among seven cladoceran species.

    Science.gov (United States)

    Mano, Hiroyuki; Sakamoto, Masaki; Tanaka, Yoshinari

    2010-11-01

    The sensitivities of seven cladoceran species (Ceriodaphnia reticulata, Chydorus sphaericus, Daphnia galeata, Diaphanosoma brachyurum, Moina macrocopa, Scapholeberis kingi, and Simocephalus vetulus) to carbamate insecticides (carbaryl and methomyl) were investigated by acute toxicity tests. The sensitivities to carbaryl and methomyl were highly correlated among the tested organisms, but the co-tolerance level varied markedly among species. C. reticulata showed the highest sensitivity, whereas M. macrocopa and S. kingi showed the lowest sensitivities to the two insecticides. These results indicate that the degree of chemical impacts on natural communities can vary depending on cladoceran species composition. The highly positive correlation between the EC(50) values for both insecticides indicates that the two chemicals have a shared mode of action on cladoceran species. Unlike previous reports, acute toxicity was not correlated with body size. The results are discussed in relation to community-level experiments, the functions of freshwater ecosystems, and ecological risk assessment.

  17. Aerosol Transmission of Filoviruses

    Directory of Open Access Journals (Sweden)

    Berhanu Mekibib

    2016-05-01

    Full Text Available Filoviruses have become a worldwide public health concern because of their potential for introductions into non-endemic countries through international travel and the international transport of infected animals or animal products. Since it was first identified in 1976, in the Democratic Republic of Congo (formerly Zaire and Sudan, the 2013–2015 western African Ebola virus disease (EVD outbreak is the largest, both by number of cases and geographical extension, and deadliest, recorded so far in medical history. The source of ebolaviruses for human index case(s in most outbreaks is presumptively associated with handling of bush meat or contact with fruit bats. Transmission among humans occurs easily when a person comes in contact with contaminated body fluids of patients, but our understanding of other transmission routes is still fragmentary. This review deals with the controversial issue of aerosol transmission of filoviruses.

  18. Aerosol Transmission of Filoviruses.

    Science.gov (United States)

    Mekibib, Berhanu; Ariën, Kevin K

    2016-05-23

    Filoviruses have become a worldwide public health concern because of their potential for introductions into non-endemic countries through international travel and the international transport of infected animals or animal products. Since it was first identified in 1976, in the Democratic Republic of Congo (formerly Zaire) and Sudan, the 2013-2015 western African Ebola virus disease (EVD) outbreak is the largest, both by number of cases and geographical extension, and deadliest, recorded so far in medical history. The source of ebolaviruses for human index case(s) in most outbreaks is presumptively associated with handling of bush meat or contact with fruit bats. Transmission among humans occurs easily when a person comes in contact with contaminated body fluids of patients, but our understanding of other transmission routes is still fragmentary. This review deals with the controversial issue of aerosol transmission of filoviruses.

  19. Stratospheric aerosol geoengineering

    Energy Technology Data Exchange (ETDEWEB)

    Robock, Alan [Department of Environmental Sciences, Rutgers University, 14 College Farm Road, New Brunswick, NJ 08901 (United States)

    2015-03-30

    The Geoengineering Model Intercomparison Project, conducting climate model experiments with standard stratospheric aerosol injection scenarios, has found that insolation reduction could keep the global average temperature constant, but global average precipitation would reduce, particularly in summer monsoon regions around the world. Temperature changes would also not be uniform; the tropics would cool, but high latitudes would warm, with continuing, but reduced sea ice and ice sheet melting. Temperature extremes would still increase, but not as much as without geoengineering. If geoengineering were halted all at once, there would be rapid temperature and precipitation increases at 5–10 times the rates from gradual global warming. The prospect of geoengineering working may reduce the current drive toward reducing greenhouse gas emissions, and there are concerns about commercial or military control. Because geoengineering cannot safely address climate change, global efforts to reduce greenhouse gas emissions and to adapt are crucial to address anthropogenic global warming.

  20. Insecticide resistance status of malaria vectors in Lao PDR.

    Science.gov (United States)

    Marcombe, Sébastien; Bobichon, Julie; Somphong, Boutsady; Phommavan, Nothasin; Maithaviphet, Santi; Nambanya, Simone; Corbel, Vincent; Brey, Paul T

    2017-01-01

    Knowledge on insecticide resistance in Anopheles species is a basic requirement to guide malaria vector control programs. In Lao PDR, vector control relies on insecticide residual spraying (IRS) and impregnated bed-nets (ITNs) with the use of pyrethroids. Here, the susceptibility of Anopheles species, including several malaria vectors (An. maculatus and An. minimus), to various insecticides was investigated in ten provinces of Lao PDR through a north-south transect. Bioassays were performed on field caught female mosquitoes using the standard WHO susceptibility tests with DDT (4%), deltamethrin (0.05%) and permethrin (0.75%). In addition, the DIIS6 region of the para-type sodium channel gene was amplified and sequenced to identify knockdown resistance mutations (kdr). Resistance to DDT and permethrin was detected in suspected malaria vectors, such as An. nivipes and An. philippinensis in Lao PDR. Resistance to the formerly used DDT was found in a population of An. maculatus s.l. from Luang Prabang province. No resistance to pyrethroids was found in primary vectors, indicating that these insecticides are still adequate for malaria vector control. However, high resistance levels to pyrethroids was found in-vector species and reduced susceptibility to permethrin in An. minimus and An. maculatus was reported in specific localities which raises concerns for pyrethroid-based control in the future. No kdr mutation was found in any of the resistant populations tested hence suggesting a probable role detoxification enzymes in resistance. This study highlights the necessity to continue the monitoring of insecticide susceptibility to early detect potential occurrence and/or migration of insecticide resistance in malaria vectors in Lao PDR.

  1. Insecticide resistance status of malaria vectors in Lao PDR.

    Directory of Open Access Journals (Sweden)

    Sébastien Marcombe

    Full Text Available Knowledge on insecticide resistance in Anopheles species is a basic requirement to guide malaria vector control programs. In Lao PDR, vector control relies on insecticide residual spraying (IRS and impregnated bed-nets (ITNs with the use of pyrethroids. Here, the susceptibility of Anopheles species, including several malaria vectors (An. maculatus and An. minimus, to various insecticides was investigated in ten provinces of Lao PDR through a north-south transect. Bioassays were performed on field caught female mosquitoes using the standard WHO susceptibility tests with DDT (4%, deltamethrin (0.05% and permethrin (0.75%. In addition, the DIIS6 region of the para-type sodium channel gene was amplified and sequenced to identify knockdown resistance mutations (kdr. Resistance to DDT and permethrin was detected in suspected malaria vectors, such as An. nivipes and An. philippinensis in Lao PDR. Resistance to the formerly used DDT was found in a population of An. maculatus s.l. from Luang Prabang province. No resistance to pyrethroids was found in primary vectors, indicating that these insecticides are still adequate for malaria vector control. However, high resistance levels to pyrethroids was found in-vector species and reduced susceptibility to permethrin in An. minimus and An. maculatus was reported in specific localities which raises concerns for pyrethroid-based control in the future. No kdr mutation was found in any of the resistant populations tested hence suggesting a probable role detoxification enzymes in resistance. This study highlights the necessity to continue the monitoring of insecticide susceptibility to early detect potential occurrence and/or migration of insecticide resistance in malaria vectors in Lao PDR.

  2. Insecticide resistance status in Anopheles gambiae in southern Benin

    Directory of Open Access Journals (Sweden)

    Corbel Vincent

    2010-03-01

    Full Text Available Abstract Background The emergence of pyrethroid resistance in Anopheles gambiae has become a serious concern to the future success of malaria control. In Benin, the National Malaria Control Programme has recently planned to scaling up long-lasting insecticidal nets (LLINs and indoor residual spraying (IRS for malaria prevention. It is, therefore, crucial to monitor the level and type of insecticide resistance in An. gambiae, particularly in southern Benin where reduced efficacy of insecticide-treated nets (ITNs and IRS has previously been reported. Methods The protocol was based on mosquito collection during both dry and rainy seasons across forty districts selected in southern Benin. Bioassay were performed on adults collected from the field to assess the susceptibility of malaria vectors to insecticide-impregnated papers (permethrin 0.75%, delthamethrin 0.05%, DDT 4%, and bendiocarb 0.1% following WHOPES guidelines. The species within An. gambiae complex, molecular form and presence of kdr and ace-1 mutations were determined by PCR. Results Strong resistance to permethrin and DDT was found in An. gambiae populations from southern Benin, except in Aglangandan where mosquitoes were fully susceptible (mortality 100% to all insecticides tested. PCR showed the presence of two sub-species of An. gambiae, namely An. gambiae s.s, and Anopheles melas, with a predominance for An. gambiae s.s (98%. The molecular M form of An. gambiae was predominant in southern Benin (97%. The kdr mutation was detected in all districts at various frequency (1% to 95% whereas the Ace-1 mutation was found at a very low frequency (≤ 5%. Conclusion This study showed a widespread resistance to permethrin in An. gambiae populations from southern Benin, with a significant increase of kdr frequency compared to what was observed previously in Benin. The low frequency of Ace-1 recorded in all populations is encouraging for the use of bendiocarb as an alternative insecticide to

  3. Chlorfenapyr: irritant effect compared to other insecticides and its intrinsic toxicity in multiple-insecticide-susceptible and -resistant Anopheles stephensi (Diptera: Culicidae).

    Science.gov (United States)

    Verma, Vaishali; Elamathi, N; Velamuri, Poonam S; Sreehari, U; Agrawal, O P; Raghavendra, K

    2015-03-01

    For effective management of vector resistance there is a need for new insecticide molecules with novel modes of action. For desired toxic effect of an insecticide, apart from other behavioural aspects, toxicity and chemical nature of the molecule are important that may cause irritability in the mosquito to the insecticide affecting the uptake. In this study, a pyrrole class insecticide, chlorfenapyr (a late acting insecticide) was tested for its irritability against multiple-insecticide-susceptible and -resistant strains of Anopheles stephensi Liston 1901 (Diptera: Culicidae). Studies were conducted to assess the irritability due to chlorfenapyr, DDT, malathion, deltamethrin and permethrin and intrinsic toxicity of chlorfenapyr in multiple-insecticide-susceptible and -resistant laboratory strains of An. stephensi following standard WHO methods. Chlorfenapyr molecule has shown least irritant effect against susceptible and resistant strains among all the insecticides tested allowing more landing time to the vector species on the impregnated surfaces to pick-up lethal dose. Chlorfenapyr could be an ideal insecticide for management of multiple-insecticide-resistance including pyrethroids.

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

    Science.gov (United States)

    2010-01-01

    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 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. PMID:21108819

  5. Insecticide applications to soil contribute to the development of Burkholderia mediating insecticide resistance in stinkbugs.

    Science.gov (United States)

    Tago, Kanako; Kikuchi, Yoshitomo; Nakaoka, Sinji; Katsuyama, Chie; Hayatsu, Masahito

    2015-07-01

    Some soil Burkholderia strains are capable of degrading the organophosphorus insecticide, fenitrothion, and establish symbiosis with stinkbugs, making the host insects fenitrothion-resistant. However, the ecology of the symbiotic degrading Burkholderia adapting to fenitrothion in the free-living environment is unknown. We hypothesized that fenitrothion applications affect the dynamics of fenitrothion-degrading Burkholderia, thereby controlling the transmission of symbiotic degrading Burkholderia from the soil to stinkbugs. We investigated changes in the density and diversity of culturable Burkholderia (i.e. symbiotic and nonsymbiotic fenitrothion degraders and nondegraders) in fenitrothion-treated soil using microcosms. During the incubation with five applications of pesticide, the density of the degraders increased from less than the detection limit to around 10(6)/g of soil. The number of dominant species among the degraders declined with the increasing density of degraders; eventually, one species predominated. This process can be explained according to the competitive exclusion principle using V(max) and K(m) values for fenitrothion metabolism by the degraders. We performed a phylogenetic analysis of representative strains isolated from the microcosms and evaluated their ability to establish symbiosis with the stinkbug Riptortus pedestris. The strains that established symbiosis with R. pedestris were assigned to a cluster including symbionts commonly isolated from stinkbugs. The strains outside the cluster could not necessarily associate with the host. The degraders in the cluster predominated during the initial phase of degrader dynamics in the soil. Therefore, only a few applications of fenitrothion could allow symbiotic degraders to associate with their hosts and may cause the emergence of symbiont-mediated insecticide resistance. © 2015 John Wiley & Sons Ltd.

  6. Insecticide susceptibility of Aedes aegypti and Aedes albopictus across Thailand.

    Science.gov (United States)

    Ponlawat, Alongkot; Scott, Jeffrey G; Harrington, Laura C

    2005-09-01

    Aedes aegypti (L.) and Aedes albopictus (Skuse), two important vectors of dengue fever and dengue hemorrhagic fever, were collected from Mae Sot, Nakhon Sawan, Nakhon Ratchasima, Surat Thani, and Phatthalung, Thailand, from July 2003 to April 2004. The patterns of insecticide susceptibility to temephos, malathion, and permethrin of both Ae. aegypti and Ae. albopictus larvae were determined. Ae. aegypti from all study sites were resistant to permethrin, they but were susceptible to malathion. Resistance to temephos was detected in all strains of Ae. aegypti, except those from Nakhon Ratchasima. Ae. albopictus larvae had low levels of resistance to all three insecticides, except Mae Sot and Phatthalung strains, which were resistant to permethrin.

  7. Willingness to Pay For Insecticide-Treated Nets in Berehet District ...

    African Journals Online (AJOL)

    Nearly 68.5% persons had willingness to buy Insecticide-Treated Nets if they have access to these Nets. The median maximum price a person is willingness to pay for blue rectangular Insecticide-Treated Net was 20 ETB. People had willingness to pay 30 ETB for blue and white conical insecticide-treated nets. Working on ...

  8. Field and Laboratory Evaluations of Insecticides for Southern Pine Beetle Control

    Science.gov (United States)

    Felton L. Hastings; Jack E. Coster; [Editors

    1981-01-01

    Reports results of laboratory screenings and field studies of insecticides for use against the southern pine beetle. Preventive as webas remedial efficacywere observed, along with phytotoxicity to pine and understory hardwood species, effects of insecticides on soil microbial and mesofaunal populations, and degradation of insecticides by selected soil microbes.

  9. Maternal use of insecticide-treated nets in the prevention of Malaria ...

    African Journals Online (AJOL)

    Background: Insecticide treated nets (ITNs) have been proved as one of the most effective ways of reducing malaria morbidity and mortality in children and pregnant women. Proper use and care of insecticide treated nets reduce malaria health risk to children. Objective: To determine maternal use of insecticide treated nets ...

  10. A study under semi-field conditions on the efficacy of insecticides against Meligethes aeneus F

    DEFF Research Database (Denmark)

    Kaiser, Caroline; Bormann, Inga; Ahlemann, Martin

    2014-01-01

    statements of the reactions of the beetles to insecticides under realistic field conditions. The method is implemented to study the efficacy of insecticides with different mode of actions. Pollen beetle populations were collected from untreated fields in Saxony-Anhalt, Germany. Six insecticides...

  11. Do insecticide-treated bednets have an effect on malaria vectors?

    NARCIS (Netherlands)

    Takken, W.

    2002-01-01

    The use of insecticide-treated bednets (ITNs) has been widely adopted as an important method for malaria control. Few data exist on effects of ITNs on mosquito biology and ecology, other than the development of insecticide resistance against the insecticides used. There is no hard evidence that the

  12. Aerosol Size Distributions In Auckland.

    Czech Academy of Sciences Publication Activity Database

    Coulson, G.; Olivares, G.; Talbot, Nicholas

    2016-01-01

    Roč. 50, č. 1 (2016), s. 23-28 E-ISSN 1836-5876 Institutional support: RVO:67985858 Keywords : aerosol size distribution * particle number concentration * roadside Subject RIV: CF - Physical ; Theoretical Chemistry

  13. Earth Observatory Aerosol Optical Depth

    Data.gov (United States)

    National Aeronautics and Space Administration — Tiny solid and liquid particles suspended in the atmosphere are called aerosols. Windblown dust, sea salts, volcanic ash, smoke from wildfires, and pollution from...

  14. Eulerian modeling of aerosol dynamics

    NARCIS (Netherlands)

    Frederix, E.M.A.

    2016-01-01

    We explore the feasibility and applicability of the Eulerian approach in the mathematical modeling of aerosol dynamics including droplet nucleation, condensation, drift, diffusion and deposition. Both the methodology as well as a number of illustrating applications are contained, establishing the

  15. Hygroscopic organic aerosols during BRAVO?

    Science.gov (United States)

    Lowenthal, Douglas H; Kumar, Naresh; Hand, Jenny; Day, Derek; Kreidenweis, Sonia; Collett, Jeffrey; Lee, Taehyoung; Ashbaugh, Lowell

    2003-10-01

    The hygroscopic properties of the organic fraction of aerosols are poorly understood. The ability of organic aerosols to absorb water as a function of relative humidity (RH) was examined using data collected during the 1999 Big Bend Regional Aerosol and Visibility Observational Study (BRAVO). (On average, organics accounted for 22% of fine particulate matter with an aerodynamic diameter less than 2.5 microm (PM2.5) mass). Hourly RH exceeded 80% only 3.5% of the time and averaged 44%. BRAVO aerosol chemical composition and dry particle size distributions were used to estimate PM2.5 light scattering (Bsp) at low and high ambient RH. Liquid water growth associated with inorganic species was sufficient to account for measured Bsp for RH between 70 and 95%.

  16. Aerosol Inlet Characterization Experiment Report

    Energy Technology Data Exchange (ETDEWEB)

    Bullard, Robert L. [Brookhaven National Lab. (BNL), Upton, NY (United States); Kuang, Chongai [Brookhaven National Lab. (BNL), Upton, NY (United States); Uin, Janek [Brookhaven National Lab. (BNL), Upton, NY (United States); Smith, Scott [Brookhaven National Lab. (BNL), Upton, NY (United States); Springston, Stephen R. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2017-05-01

    The U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility Aerosol Observation System inlet stack was characterized for particle penetration efficiency from 10 nm to 20 μm in diameter using duplicate scanning mobility particle sizers (10 nm-450 nm), ultra-high-sensitivity aerosol spectrometers (60 nm-μm), and aerodynamic particle sizers (0.5 μm-20 μm). Results show good model-measurement agreement and unit transmission efficiency of aerosols from 10 nm to 4 μm in diameter. Large uncertainties in the measured transmission efficiency exist above 4 μm due to low ambient aerosol signal in that size range.

  17. Background stratospheric aerosol reference model

    Science.gov (United States)

    Mccormick, M. P.; Wang, P.

    1989-01-01

    In this analysis, a reference background stratospheric aerosol optical model is developed based on the nearly global SAGE 1 satellite observations in the non-volcanic period from March 1979 to February 1980. Zonally averaged profiles of the 1.0 micron aerosol extinction for the tropics and the mid- and high-altitudes for both hemispheres are obtained and presented in graphical and tabulated form for the different seasons. In addition, analytic expressions for these seasonal global zonal means, as well as the yearly global mean, are determined according to a third order polynomial fit to the vertical profile data set. This proposed background stratospheric aerosol model can be useful in modeling studies of stratospheric aerosols and for simulations of atmospheric radiative transfer and radiance calculations in atmospheric remote sensing.

  18. Modeling urban and regional aerosols

    Science.gov (United States)

    Sun, Qing

    Aerosol particles in Earth's atmosphere have long been associated with adverse human health effects. They also play an important role in visibility reduction and global climate change. Atmospheric formation and removal of particles are governed by a number of complex dynamic processes which make the aerosol modeling a far more challenging task than the modeling of gas-phase species. Wexler et al. (1994) identified and analyzed the atmospheric aerosol processes that govern particulate mass concentrations and estimated the relative importance of each term using typical atmospheric conditions. In this thesis I start from the general dynamic equation resulted from their analysis and develop a working and optimized aerosol model that can be incorporated into a host Eulerian air quality model to simulate particulate pollution on an urban or a regional scale. Chapter 1 presents the background of the model and highlights the important issues that need to be addressed. Chapter 2 presents the mathematical representation of the aerosol model and introduces an acid equilibrium assumption, that is, when the aerosol particles are close to acid neutral the aerosol hydrogen ion concentration can be assumed to be in equilibrium with the gas-phase acidity. This assumption greatly reduced the CPU requirement of the aerosol model and hence enable us to complete the simulation of an particulate pollution episode in a reasonable time. In Chapter 3 the aerosol model IS incorporated into the Urban Airshed Model to predict the size and composition distribution of particulate matter (PM) during the June 24-25 1987 SCAQS episode. The predicted size distribution is compared to available SCAQS measurement data. In Chapter 4 the aerosol model is further optimized and incorporated into MCNC's Multiscale Air Quality Simulation Platform (MAQSIP) to investigate the particulate pollution in eastern United States using a July 9-13 1995 episode. A cloud model is modified for the sectional

  19. The MERRA-2 Aerosol Reanalysis

    Science.gov (United States)

    da Silva, A.; Randles, C. A.; Buchard, V.; Darmenov, A.; Colarco, P. R.

    2015-12-01

    MERRA-2 is NASA's latest reanalysis for the satellite era (1980-present) using GEOS-5 earth system model. This project focuses on historical analyses of the hydrological cycle on a broad range of weather and climate time scales, and includes interactive aerosols for the entire period. MERRA-2 provides several improvements over its predecessor MERRA reanalysis, including: 1) modern satellite observing systems not available with MERRA, 2) reduction in discontinuities associated with a changing observing system, and 3) reduced biases and imbalances in the hydrologic cycle. As another step towards an integrated Earth System Analysis (IESA), MERRA-2 includes for the first time aerosols in a reanalysis, improves the representation of stratospheric ozone, and better characterizes cryospheric processes. In this talk we will present results relating to the introduction of aerosols in MERRA-2. The assimilation of Aerosol Optical Depth (AOD) in GEOS-5 involves very careful cloud screening and homogenization of the observing system by means of a Neural Net scheme that translates MODIS and AVHRR radiances into AERONET calibrated AOD. The system also assimilates MISR and AERONET AOD observations. For the EOS period (2000-present) GEOS-5 is driven by daily biomass burning emissions derived from MODIS fire radiative power retrievals using the so-called QFED emissions. Historical emissions are calibrated as to minimize discontinuities the EOS/pre-EOS boundaries. MERRA-2 aerosols are also driven by historical anthropogenic and volcanic emissions. We will present a summary of our efforts to validate the MERRA-2 aerosols. The GEOS-5 assimilated aerosol fields are first validated by comparison to independent in-situ measurements. In order to assess aerosol absorption on a global scale, we perform a detailed radiative transfer calculation to simulate the UV aerosol index, comparing our results to OMI measurements. By simulating aerosol-attenuated backscatter, we use CALIPSO measurements

  20. Optical Properties of Biological Aerosols

    Science.gov (United States)

    2006-01-01

    biologi al aerosols, i.e. aerosols omposed of biologi al sporesand other organi ompounds, presents unique diÆ ulties both on the experimental and on...thetheoreti al side. On the experimental side, we ite, as an example, the fa t that all organi materials,both spores and organi ompounds present a...ORGANIZATION NAME(S) AND ADDRESS(ES) Universita di Messina Dipartimento di Fisica Della Materia e TEcnologie Fische Avanzate, Salita Sperone, 31

  1. Devices and methods for generating an aerosol

    KAUST Repository

    Bisetti, Fabrizio

    2016-03-03

    Aerosol generators and methods of generating aerosols are provided. The aerosol can be generated at a stagnation interface between a hot, wet stream and a cold, dry stream. The aerosol has the benefit that the properties of the aerosol can be precisely controlled. The stagnation interface can be generated, for example, by the opposed flow of the hot stream and the cold stream. The aerosol generator and the aerosol generation methods are capable of producing aerosols with precise particle sizes and a narrow size distribution. The properties of the aerosol can be controlled by controlling one or more of the stream temperatures, the saturation level of the hot stream, and the flow times of the streams.

  2. Gas/Aerosol partitioning: a simplified method for global modeling

    NARCIS (Netherlands)

    Metzger, S.M.

    2000-01-01

    The main focus of this thesis is the development of a simplified method to routinely calculate gas/aerosol partitioning of multicomponent aerosols and aerosol associated water within global atmospheric chemistry and climate models. Atmospheric aerosols are usually multicomponent mixtures,

  3. Are anthropogenic aerosols affecting rainfall?

    Science.gov (United States)

    Junkermann, Wolfgang; Hacker, Jorg

    2013-04-01

    Modification of cloud microphysics by anthropogenic aerosols is well known since several decades. Whether the underlying processes leads to changes in precipitation is by far less confirmed. Several different factors affect the production of rain in a way that a causality between increasing aerosol load in the atmosphere and a change of annual rainfall is very difficult to confirm. What would be expected as an effect of additional cloud condensation nuclei is a shift in the spatial and temporal rainfall distribution towards a lower number of days with low rain intensity and more frequent or more vigorous single events. In fact such a shift has been observed in several locations worldwide and has been suggested to be caused by increasing aerosol load, however, without further specification of the nature and number of the aerosols involved. Measurements of aerosols which might be important for cloud properties are extremely sparse and no long term monitoring data sets are available up to now. The problem of missing long term aerosol data that could be compared to available long term meteorological data sets can possibly be resolved in certain areas where well characterized large anthropogenic aerosol sources were installed in otherwise pristine areas without significant changes in land use over several decades. We investigated aerosol sources and current aerosol number, size and spatial distributions with airborne measurements in the planetary boundary layer over two regions in Australia that are reported to suffer from extensive drought despite the fact that local to regional scale water vapor in the atmosphere is slowly and constantly increasing. Such an increase of the total water in the planetary boundary layer would imply also an increase in annual precipitation as observed in many other locations elsewhere. The observed decline of rainfall in these areas thus requires a local to regional scale physical process modifying cloud properties in a way that rain

  4. Ability of systemic insecticide dimethoate to prevent aphid ...

    African Journals Online (AJOL)

    C. Elsevier,. Amsterdam, pp. 225-266. Blackman, RH. and Eastop, V.P., 1984. Aphids on the world Crops: An Identification and Information Guide. John Wiley and Sons, NewYork, 466 pp. Broadbent, L. (1957). Insecticidal control of the spread of plant viruses. Annual Review of Entomology 2: 339-. 353. Burton, W.G., 1966.

  5. Effect of insecticide application on pests of late maturing pigeonpea ...

    African Journals Online (AJOL)

    Journal of Technology and Education in Nigeria ... The effect of insecticide application on the incidence of pests of late maturing pigeonpea cultivar in intercrops with maize, yam, cassava, and cocoyam was carried out at the Department of Crop Science, University of Nigeria, Nsukka agro-ecological zone in 2000/2001 ...

  6. Potency of Traditional Insecticide Materials against Stored Bean ...

    African Journals Online (AJOL)

    The bean weevil, Acanthoscelides obtectus is a major insect pest of stored common bean, Phaseolus vulgaris an important source of plant protein in many parts of the world, Tanzania inclusive. In rural Tanzania, most smallholder farmers apply traditional insecticide materials in the protection of bean from insect pests.

  7. Chemical composition and insecticidal properties of essential oil ...

    African Journals Online (AJOL)

    Purpose: To determine the insecticidal properties of essential oil from Mosla soochowensis aerial parts against two insect pests, Sitophilus zeamais and Tribolium castaneum. Methods: Hydro-distillation of M. soochowensis was used to extract the essential oil. Gas chromatography/mass spectrometry (GC/MS) analysis was ...

  8. Identification of Compounds and Insecticidal Activity of the Root of ...

    African Journals Online (AJOL)

    ADOWIE PERE

    Correspondence: E-mail: osayemwenre.erharuyi@uniben.edu,. JASEM ISSN 1119-8362. All rights reserved. J. Appl. Sci. Environ. Manage. April. 2017. Vol. 21 (2) 281-287. Full-text Available Online at www.ajol.info and www.bioline.org.br/ja. Identification of Compounds and Insecticidal Activity of the Root of Pride of ...

  9. Larvicidal and insecticidal properties of some marine sponges ...

    African Journals Online (AJOL)

    SERVER

    2008-01-18

    Jan 18, 2008 ... The ocean environment is massively complex, consisting of extreme variations in pressure, salinity, temperature, and biologi- cal habitats. Among the .... of these invented novel products in mosquito control instead of synthetic insecticides could reduce the envi- ronmental pollution. The present results may ...

  10. Phytotoxic, insecticidal and leishmanicidal activities of aerial parts of ...

    African Journals Online (AJOL)

    STORAGESEVER

    2010-02-22

    Feb 22, 2010 ... The aim of the present study was to explore the aerial parts of the Polygonatum verticillatum for various biological activities such as phytotoxic, insecticidal and leishmanicidal properties. Outstanding phytotoxicity was observed for the crude extract and its subsequent solvent fractions against Lemna.

  11. Paraoxonase 1 (PON1) Status and Risk of Insecticide Exposure

    Energy Technology Data Exchange (ETDEWEB)

    Furlong, Clement E.; Cole, Toby B.; Walter, Betsy J.; Shih, Diana M.; Tward, Aaron; Lusis, Aldons J.; Timchalk, Chuck; Richter, Rebecca J.; Costa, Lucio G.

    2005-06-23

    Paraoxonase 1 (PON1) is an HDL associated enzyme that catalyzes a number of different reactions including the hydrolysis of the toxic oxon metabolites of the insecticides diazinon and chlorpyrifos. PON1 has also been implicated in the detoxication of oxidized lipids and the metabolism of a number of drugs, activating some, while inactivating others. There are two common PON1 coding region polymorphisms (L55M and Q192R). The latter determines the catalytic efficiency of hydrolysis of a number of substrates including chlorpyrifos oxon, but not diazoxon. Evidence for the physiological importance of PON1 in modulating exposures to these two insecticides comes from several different studies. Early studies noted that species with high levels of PON1 were much more resistant to certain organophosphorus (OP) insecticides than were species with low levels. Another early study by Main demonstrated that injected rabbit paraoxonase protected rats from paraoxon toxicity. Our research group began the development of a mouse model system for examining the importance of PON1 in the detoxication of OP insecticides.

  12. Toxicity of selected insecticides applied to western spruce budworm

    Science.gov (United States)

    Jacqueline L. Robertson; Nancy L. Gillette; Melvin Look; Barbara A. Lucas; Robert L. Lyon

    1975-01-01

    The contact toxicity of 100 insecticides to last stage larvae of Choristoneura occidentalis Freeman was tested by topical application in a 10-yr series of screening experiments. Pyrethroids were generally the most toxic group of chemicals tested. Compounds more toxic than the standard, mexacarbate, at Ld50 were:...

  13. Contact toxicity of twenty insecticides applied to Symmerista canicosta

    Science.gov (United States)

    Jacqueline L. Robertson; Robert L. Lyon; Fay L. Shon; Nancy L. Gillette

    1972-01-01

    Twenty insecticides were tested by topical application on mixed groups of 4th- and 5th -stage larvae of Symmerista canicosta Franclemont. Four exceeded DDT in toxicity at LD50 but only resmethrin was significantly mor toxic. Most of the compounds showed unusually high toxicities. Twelve, listed in decreasing order of toxicity...

  14. Factors Influencing the Usage of Insecticide Treated Mosquito Nets ...

    African Journals Online (AJOL)

    Purpose: Malaria in Sudan is a leading cause of morbidity and mortality. Incidence remains very high especially among pregnant women and children under five. study was conducted to determine the factors influencing the usage of insecticide treated mosquito nets (ITNs) for prevention of malaria among pregnant women.

  15. Utilization of insecticide treated nets in Arbaminch Town and the ...

    African Journals Online (AJOL)

    Introduction: Malaria causes an overwhelmingly large number of cases and deaths round the globe every year. Insecticide treated nets (ITNs) have become important tools that provide a simple, but effective means of preventing malaria in highly endemic areas. Methods: A community-based cross-sectional study design ...

  16. Evaluation of four local plant species for insecticidal activity against ...

    African Journals Online (AJOL)

    Les propriétés insecticides de quatre plantes médicinales locales: Ricinus communis Linn. (haricot de ricin), Jatropha curcas Linn. (noix de purge/corail), Anacardium occidentale Linn. (noix de cajou), et Erythrophleum sauveolens (le mançone) étaient étudiées sous les conditions de laboratoire contre deux ravageurs de ...

  17. Insecticidal properties of materials used by resource- limited farmers ...

    African Journals Online (AJOL)

    Moyo S

    2013-04-03

    Apr 3, 2013 ... Fleas are obligate blood feeders that infest free-range chickens, thereby impeding their productivity. Commercial insecticides used in controlling fleas are expensive and inaccessible, hence making farmers to resort to low cost and easily available alternatives. The study was conducted to assess the.

  18. 1 Characterization of Anopheles gambiae s.l. and insecticide ...

    African Journals Online (AJOL)

    Economic Entomology 18, 265-267. Achonduh, O.A. (2005) Insecticide resistance in Anopheles gambiae s.l. Giles (Diptera: Culicidae) in cabbage growing areas associated with pyrethroid and organophosphate use in. Accra, Ghana. MPhil Entomology Thesis, University of Ghana, Legon. Adasi, K., Wilson, M.D. & Boakye, ...

  19. Impact of insecticide treated mosquito nets and low dose monthly ...

    African Journals Online (AJOL)

    Lymphatic filariasis (LF) is among the poverty related neglected tropical diseases earmarked for elimination using mass drug administration (MDA) strategy. Additional use of insecticide treated mosquito nets (ITNs) might enhance elimination of LF infection. Between August 1998 and July 1999, all individuals aged ≥ 8 ...

  20. Effect of natural and chemical insecticides on Hyalopterus pruni and ...

    African Journals Online (AJOL)

    Experiments were carried out to evaluate the effect of water extracts of Fagonia arabica, Salix alba and Anthmis pseudocotula and their mixtures with chemical insecticide (Malathion) on growth of. Hyalopterus pruni and characters of Armeniaca vulgaris plants and their soils. The data revealed that F.arabica extract at 20% ...

  1. Flupyradifurone: a brief profile of a new butenolide insecticide

    Science.gov (United States)

    Nauen, Ralf; Jeschke, Peter; Velten, Robert; Beck, Michael E; Ebbinghaus-Kintscher, Ulrich; Thielert, Wolfgang; Wölfel, Katharina; Haas, Matthias; Kunz, Klaus; Raupach, Georg

    2015-01-01

    BACKGROUND The development and commercialisation of new chemical classes of insecticides for efficient crop protection measures against destructive invertebrate pests is of utmost importance to overcome resistance issues and to secure sustainable crop yields. Flupyradifurone introduced here is the first representative of the novel butenolide class of insecticides active against various sucking pests and showing an excellent safety profile. RESULTS The discovery of flupyradifurone was inspired by the butenolide scaffold in naturally occurring stemofoline. Flupyradifurone acts reversibly as an agonist on insect nicotinic acetylcholine receptors but is structurally different from known agonists, as shown by chemical similarity analysis. It shows a fast action on a broad range of sucking pests, as demonstrated in laboratory bioassays, and exhibits excellent field efficacy on a number of crops with different application methods, including foliar, soil, seed treatment and drip irrigation. It is readily taken up by plants and translocated in the xylem, as demonstrated by phosphor imaging analysis. Flupyradifurone is active on resistant pests, including cotton whiteflies, and is not metabolised by recombinantly expressed CYP6CM1, a cytochrome P450 conferring metabolic resistance to neonicotinoids and pymetrozine. CONCLUSION The novel butenolide insecticide flupyradifurone shows unique properties and will become a new tool for integrated pest management around the globe, as demonstrated by its insecticidal, ecotoxicological and safety profile. © 2014 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. PMID:25351824

  2. Comparative essential oils composition and insecticidal effect of ...

    African Journals Online (AJOL)

    Comparative essential oils composition and insecticidal effect of different tissues of Piper capense L., Piper guineense Schum. et Thonn., Piper nigrum L. and Piper ... The essential oil obtained from the leaves of P. capense was largely composed of a-pinene (12.8%), -pinene (50.1%) and b-caryophyllene (12.4%). The most ...

  3. Insecticidal Activity of Essential Oil of Cinnamomum cassia and its ...

    African Journals Online (AJOL)

    Purpose: To investigate the insecticidal activity of the essential oil of Cinnamomum cassis and its main constituent compound, trans-cinnamaldehyde, against the booklice, Liposcelis bostrychophila. Methods: Steam distillation of C. cassis twigs was carried out using a Clavenger apparatus in order to obtain the volatile oils.

  4. Insecticidal activity of extracts derived from different parts of the ...

    African Journals Online (AJOL)

    The insecticidal and antifeedant activity of extracts derived from different parts of the mangrove tree Rhizophora mucronata (Rhizophoraceae) Lam. is reported. The 70% ethanol extracts of leaves, bark, stem wood and pith were tested for toxicity against adults of the desert locust Schistocerca gregaria (Forskal), the 2nd ...

  5. Pesticidal and insecticidal effect of Campsis grandiflora (Thumb ...

    African Journals Online (AJOL)

    Campsis grandiflora (Thunb.), the Indian trumpet creeper, is commonly grown for ornament. In the present study, the aqueous extract of the leaves of the climber was evaluated for its pesticidal and insecticidal activities. A direct relationship was observed between the dose and the percentage larval mortality. Dosage values ...

  6. Utilization of insecticide treated nets among pregnant women in ...

    African Journals Online (AJOL)

    Conclusion: The use of ITNs is poor among pregnant women in Enugu, but associated with favorable maternal and feto-neonatal outcome. Future measures to increase its use should consider improvement in educational level and social class of our women. Key words: Insecticide treated nets, Malaria, Nigeria, pregnancy ...

  7. Pyrethroid insecticides in urban salmon streams of the Pacific Northwest

    Energy Technology Data Exchange (ETDEWEB)

    Weston, D.P., E-mail: dweston@berkeley.edu [Department of Integrative Biology, University of California, 3060 Valley Life Sciences Bldg., Berkeley, CA 94720-3140 (United States); Asbell, A.M., E-mail: aasbell@berkeley.edu [Department of Integrative Biology, University of California, 3060 Valley Life Sciences Bldg., Berkeley, CA 94720-3140 (United States); Hecht, S.A., E-mail: scott.hecht@noaa.gov [NOAA Fisheries, Office of Protected Resources, 510 Desmond Drive S.E., Lacey, WA 98503 (United States); Scholz, N.L., E-mail: nathaniel.scholz@noaa.gov [NOAA Fisheries, Northwest Fisheries Science Center, 2725 Montlake Blvd. E., Seattle, WA 98112 (United States); Lydy, M.J., E-mail: mlydy@siu.edu [Fisheries and Illinois Aquaculture Center and Department of Zoology, Southern Illinois University, 171 Life Sciences II, Carbondale, IL 62901 (United States)

    2011-10-15

    Urban streams of the Pacific Northwest provide spawning and rearing habitat for a variety of salmon species, and food availability for developing salmon could be adversely affected by pesticide residues in these waterbodies. Sediments from Oregon and Washington streams were sampled to determine if current-use pyrethroid insecticides from residential neighborhoods were reaching aquatic habitats, and if they were at concentrations acutely toxic to sensitive invertebrates. Approximately one-third of the 35 sediment samples contained measurable pyrethroids. Bifenthrin was the pyrethroid of greatest concern with regards to aquatic life toxicity, consistent with prior studies elsewhere. Toxicity to Hyalella azteca and/or Chironomus dilutus was found in two sediment samples at standard testing temperature (23 deg. C), and in one additional sample at a more environmentally realistic temperature (13 deg. C). Given the temperature dependency of pyrethroid toxicity, low temperatures typical of northwest streams can increase the potential for toxicity above that indicated by standard testing protocols. - Highlights: > Salmon-bearing creeks can be adversely impacted by insecticides from urban runoff. > Pyrethroid insecticides were found in one-third of the creeks in Washington and Oregon. > Two creeks contained concentrations acutely lethal to sensitive invertebrates. > Bifenthrin was of greatest concern, though less than in prior studies. > Standard toxicity testing underestimates the ecological risk of pyrethroids. - Pyrethroid insecticides are present in sediments of urban creeks of Oregon and Washington, though less commonly than in studies elsewhere in the U.S.

  8. Larvicidal, pupicidal and insecticidal activities of Cosmos bipinnatus ...

    African Journals Online (AJOL)

    Purpose: To evaluate the larvicidal, pupicidal and insecticidal activities of Cosmos bipinnatus,. Foenuculum vulgare and Tagetes minuta leaf extracts against Culex quinquefasciatus mosquitoes. Methods: The leaves of the plants were extracted with distilled water, ethanol (95 %), and hexane and the extracts screened for ...

  9. Utilisation of insecticide treated nets among pregnant women in Gulu

    African Journals Online (AJOL)

    EB

    Abstract. Background: Malaria during pregnancy causes severe anaemia, placental malaria or death to the mother while the fetus may be aborted or stillborn. Objective: To establish the prevalence and factors associated with Insecticide Treated Net (ITN) utilisation among pregnant women in a post conflict Internally ...

  10. Identification of Compounds and Insecticidal Activity of the Root of ...

    African Journals Online (AJOL)

    Caesalpinia pulcherrima (Caesalpiniaceae) is an ornamental plant with several ethnomedicinal uses. The present study was designed to investigate the brine shrimp cytotoxicity and insecticidal activity of oil obtained from C. pulcherrima root. The powdered root was extracted with methanol and then defatted with petroleum ...

  11. Biological efficacy of the ecotoxically favourable insecticides and ...

    African Journals Online (AJOL)

    Administrator

    2011-05-30

    May 30, 2011 ... ingredient: Spores and protein-crystals of the bacterium Bacillus thuringiensis ssp. kurstaki) are most widely used pesticides for the .... insecticide was applied on synthetic or natural food of the target insect species in the ... and Alverde® 240 SC (active ingredient - metaflumizone) are modern chemical ...

  12. Resistance to organophosphate and carbamate insecticides in Anopheles atroparvus.

    Science.gov (United States)

    Hemingway, J; Davidson, G

    1983-04-01

    Adult Anopheles atroparvus, from Cadiz, Spain (strain AT SPA) were resistant to several organophosphorus and carbamate insecticides. Separate lines of the AT SPA strain selected with propoxur, fenitrothion, fenthion and malathion were cross-resistant to these insecticides as well as chlorphoxim and bendiocarb. Lack of synergism between malathion and triphenyl phosphate (TPP), a carboxylesterase inhibitor and between fenitrothion and piperonyl butoxide (PB), a multi-function oxidase inhibitor, against the selected lines suggests that resistance to these insecticides may be non-metabolic. Lack of synergism of propoxur after 2 h exposure with PB, sensamex and SV1 (which all inhibit multi-function oxidases), may suggest that the same mechanism is involved here. However, all three synergists were effective in conjunction with 6 h exposure to propoxur. The postulated mechanisms are: a non-metabolic resistance, possibly an altered site of action, responsible for the non-synergizable resistance to organophosphorus insecticides and to a lesser extent the carbamates and a multi-function oxidase inhibitor-suppressed mechanism conferring resistance to propoxur.

  13. Effects of an inorganic insecticide (boric acid) against Blattella ...

    African Journals Online (AJOL)

    ufuoma

    2013-05-01

    May 1, 2013 ... Conventional insecticides, such as the organophosphates, carbamates, and pyrethroids, have been used widely to control cockroach ... mode of action of boric acid, which has not been satisfactorily established, a biometric and biochemical study of the ovaries was done following the toxicity assays after ...

  14. insecticide handling in cocoa production in four regions in ghana

    African Journals Online (AJOL)

    Management of insect pests of cocoa (Theobroma cacao L.) using insecticides began in 1950 and has since gone through various programmes with concomitant challenges and successes. Presently Imidacloprid (Confidor®), Bifenthrin (Akatemaster®) and Thiamethoxam (Actara®) are recommended by Ghana Cocoa ...

  15. Material gain: bednets treated with insecticides improve the lives of ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2011-07-15

    Jul 15, 2011 ... PSI uses commercial marketing techniques to meet public health objectives, known as social marketing. The kit is one of the key elements of PSI's Social Marketing of Insecticide-Treated Nets (SMITN) project in Tanzania, launched in 1998. This project, funded by the UK's Department for International ...

  16. Ecological risks of pesticides in freshwater ecosystems; Part 2: insecticides

    NARCIS (Netherlands)

    Brock, T.C.M.; Wijngaarden, van R.P.A.; Geest, van G.J.

    2000-01-01

    A literature review of freshwater model ecosystem studies with insecticides was performed to assess the NOEC ecosystem for individual compounds, to compare these threshold levels with water quality standards, and to evaluate the ecological consequences of exceeding these standards. Studies were

  17. Seed coating with a neonicotinoid insecticide negatively affects wild bees.

    Science.gov (United States)

    Rundlöf, Maj; Andersson, Georg K S; Bommarco, Riccardo; Fries, Ingemar; Hederström, Veronica; Herbertsson, Lina; Jonsson, Ove; Klatt, Björn K; Pedersen, Thorsten R; Yourstone, Johanna; Smith, Henrik G

    2015-05-07

    Understanding the effects of neonicotinoid insecticides on bees is vital because of reported declines in bee diversity and distribution and the crucial role bees have as pollinators in ecosystems and agriculture. Neonicotinoids are suspected to pose an unacceptable risk to bees, partly because of their systemic uptake in plants, and the European Union has therefore introduced a moratorium on three neonicotinoids as seed coatings in flowering crops that attract bees. The moratorium has been criticized for being based on weak evidence, particularly because effects have mostly been measured on bees that have been artificially fed neonicotinoids. Thus, the key question is how neonicotinoids influence bees, and wild bees in particular, in real-world agricultural landscapes. Here we show that a commonly used insecticide seed coating in a flowering crop can have serious consequences for wild bees. In a study with replicated and matched landscapes, we found that seed coating with Elado, an insecticide containing a combination of the neonicotinoid clothianidin and the non-systemic pyrethroid β-cyfluthrin, applied to oilseed rape seeds, reduced wild bee density, solitary bee nesting, and bumblebee colony growth and reproduction under field conditions. Hence, such insecticidal use can pose a substantial risk to wild bees in agricultural landscapes, and the contribution of pesticides to the global decline of wild bees may have been underestimated. The lack of a significant response in honeybee colonies suggests that reported pesticide effects on honeybees cannot always be extrapolated to wild bees.

  18. Proprietes insecticides de l'huile essentielle d' Aeollanthus ...

    African Journals Online (AJOL)

    Proprietes insecticides de l'huile essentielle d'Aeollanthus Pubescens benth. Sur les chenilles de deux lepidopteres: Selepa docilsi butler (noctuidae,/i>) et scrobipalpa ergassima mayr. (geleduidae). K Koba, WP Poutouli, C Raynaud, P Yaka, K Sanda ...

  19. Larvicidal, pupicidal and insecticidal activities of Cosmos bipinnatus ...

    African Journals Online (AJOL)

    Purpose: To evaluate the larvicidal, pupicidal and insecticidal activities of Cosmos bipinnatus, Foenuculum vulgare and Tagetes minuta leaf extracts against Culex quinquefasciatus mosquitoes. Methods: The leaves of the plants were extracted with distilled water, ethanol (95 %), and hexane and the extracts screened for ...

  20. Evaluation of the Insecticidal Potentials of Some Indigeneous ...

    African Journals Online (AJOL)

    Pulverized plant materials of Eugenia aromatica (Baill) (seeds), Aristolochia ringes (Varl) (roots), Zanthoxylum xanthoxyloides (Lam.) Waterman (roots) and Azadirachta indica A. Juss (stem bark) were evaluated for their insecticidal activities against the warehouse moth, Ephestia cautella (Walker) reared on cocoa beans.

  1. Insecticidal activity of four medicinal plant extracts against Tribolium ...

    African Journals Online (AJOL)

    Administrator

    2006-05-16

    May 16, 2006 ... Nascimento IR, Murata AT, Bortoli SA, Lopes LM (2004). Insecticidal activity of chemical constituents from Aristolochia pubescens against. Aticarsia gemmatalis larvae. Pest Manag. Sci. 60: 413-6. Papachristos DP, Stamopoulos DC (2002). Repellent, toxic and reproduction inhibitory effects of essential oil ...

  2. Insecticide resistance testing in malaria vectors in Tanzania ...

    African Journals Online (AJOL)

    Control Programme, has been conducting annual insecticide resistance surveillance since 1999, aimed at early detection of ... Key words: Malaria, Anopheles gambiae complex, larvae, fabric, resistance, susceptibility, Tanzania. Introduction ..... Both authors worked on literature review and hereafter,. BE set the first draft of ...

  3. Insecticide assays against the brown stink bug feeding on pecan

    Science.gov (United States)

    The brown stink bug, Euschistus servus (Say) (Hemiptera: Pentatomidae), is an economic pest of pecan, Carya illinoinensis (Wangenh) K. Koch (Juglandaceae), and other agronomic crops across the southeastern U.S. Management of this pest is mainly via insecticides. Many commercial products indicate o...

  4. Ethnobotany of plants used as insecticides, repellents and ...

    African Journals Online (AJOL)

    Eight medicinal plants were found to be used as insecticides and insect repellents and 11 species as anti-malarial. Informants' consensus showed that 65.7 percent of the informants used Lepidium sativum for medicinal purposes followed by Croton macrostachyus (61.4 percent). The paired comparison showed that Allium ...

  5. Risk of transmission of viral haemorrhagic fevers and the insecticide ...

    African Journals Online (AJOL)

    Aedes mosquitoes were found to be resistant to DDT, deltamethrin and lamdacyhalothrin, but susceptible to permethrin. Funding: This study was supported in part by Japan Initiative for Global Research Network on Infectious Diseases (J-Grid). Keywords: Mosquitoes, Aedes aegypti, insecticide, risk, VHF transmission, ...

  6. Malaria vectors resistance to commonly used insecticides in the ...

    African Journals Online (AJOL)

    This study was carried out in 2015 to assess the level of resistance of sibling species of Anopheles gambiae complex the principal malaria vector from Bichi in Kano state to three classes of insecticides; (DDT, Permethrin and Bendiocarb) approved by World Health Organization (WHO) for vector control with the aim of ...

  7. Chemical Composition and Insecticidal Activity of the Essential Oil of ...

    African Journals Online (AJOL)

    Purpose: To investigate the chemical composition and insecticidal activity of the essential oil of the aerial parts of Ostericum grosseserratum against the maize weevil, Sitophilus zeamaisD. Methods: Steam distillation of the aerial parts of O. grosseserratum during the flowering stage was carried out using a Clavenger ...

  8. Insecticidal activity of essential oil of Cinnamomum cassia and its ...

    African Journals Online (AJOL)

    Purpose: To investigate the insecticidal activity of the essential oil of Cinnamomum cassis and its main constituent compound, trans-cinnamaldehyde, against the booklice, Liposcelis bostrychophila. Methods: Steam distillation of C. cassis twigs was carried out using a Clavenger apparatus in order to obtain the volatile oils.

  9. Knowledge and utilization of long lasting insecticide treated nets ...

    African Journals Online (AJOL)

    Background: Long Lasting Insecticide Treated Nets (LLITNs) are a form of personal protection that have been shown to reduce malaria illness in endemic regions. They form a protective barrier around people sleeping under them particularly the vulnerable group such as pregnant women and under - fives. Methods: A cross ...

  10. Insecticide resistance testing in malaria vectors in Tanzania ...

    African Journals Online (AJOL)

    Improvised heater of charcoal stoves and humidifier of wet fabric such as “Kanga” and “Kitenge” were also used. Results and conclusion: There was 90% larval survival, adult mosquito survived much better and the scientists had a total of 467 mosquitoes to run the insecticide susceptibility tests. Innovative ways are ...

  11. Insecticide use and practices among cotton farmers in northern ...

    African Journals Online (AJOL)

    Cotton (Gossypium hirsutum L.) is an important cash crop in Uganda. Insecticide application practices among cotton growers in northern Uganda were examined to determine the pests targeted and the compliance of control measures with the standards recommended by the Uganda's Cotton Development Organization ...

  12. Insecticidal activity of four medicinal plant powders and extracts ...

    African Journals Online (AJOL)

    Powders and extracts prepared from Capsicum frutescens, Cymbopogon citratus, Moringa oleifera, Anacardium occidentale were tested for their insecticidal potential against Angoumois grain moth, Sitotroga cerealella. The powder of C. frutescens had the highest mortality rate of 100% after 2 days of application at all tested ...

  13. Domains of Bacillus thuringiensis crystal proteins involved in insecticidal activity

    NARCIS (Netherlands)

    Bosch, H.J.; Schipper, B.; Kleij, van der H.; Maagd, de R.A.; Stiekema, W.J.

    1994-01-01

    The expected increase in application of Bacillus thuringiensis (Bt) in crop protection makes it necessary to anticipate the development of Bt-resistant insects. To safeguard the long-term use of Bt-based insecticides, we studied the mode of action of Bt crystal proteins. CryIA(b), CryIC and CryIE

  14. Effects of the numbers of foliar insecticide applications on the ...

    African Journals Online (AJOL)

    of cucumeropsis mannii Naudin, its impact on plant yield and some aspects of the biology of. Dacus bivitattus (Diptera: Tephritidae). Afr J. Agric Res 3 (5): 363-370. Foster R.E., & Brust G.E., 1995. Effects of insecticides applied to control cucumber beetles (Coleoptera: Chrysomelidae) on watermelon yields Crop Prot 14: ...

  15. Insecticidal effect of kaolin powder flavoured with essential oils of ...

    African Journals Online (AJOL)

    Insecticidal effect of kaolin powder flavoured with essential oils of Lantana camara L. (Verbenaceae) and Annona senegalensis Pers. (Annonaceae) on ... Purified and pulverized kaolin was flavoured with essential oils of A. Senegalensis Pers. and L. camara (Lam) obtained through vapour distillation. Adults C. serratus ...

  16. Scepticism towards insecticide treated mosquito nets for malaria ...

    African Journals Online (AJOL)

    The study explores reasons for scepticism and low uptake of insecticide treated mosquito nets (ITNs) that were promoted through social marketing strategy for malaria control prior to the introduction of long lasting nets (LLN). The paper breaks from traditional approach that tend to study low uptake of health interventions in ...

  17. 1 Scepticism towards insecticide treated mosquito nets for malaria ...

    African Journals Online (AJOL)

    The study explores reasons for scepticism and low uptake of insecticide treated mosquito nets (ITNs) that were promoted through social marketing strategy for malaria control prior to the introduction of long lasting nets (LLN). The paper breaks from traditional approach that tend to study low uptake of health interventions in ...

  18. Insecticide Use Practices in Cocoa Production in Four Regions in ...

    African Journals Online (AJOL)

    Most of the insecticides used are classified as class II under WHO Hazard category, and the farmers used very minimal protective clothing during pesticides application. The results of this study show that there is the need to intensify education on safe handling and use of pesticides to reduce pesticide abuse, especially by ...

  19. Timing of insecticidal application in vigna unguiculata (l.) Walp, cv ...

    African Journals Online (AJOL)

    The proper timing of insecticidal application in cowpea cultivar, IT84S-2246-4 using the synthetic pyrethroid, Lamdacyhyhalothrin applied at 25g a.i./ha was investigated in the Calabar area during two late seasons. In the 1990 planting, there was no significant difference in yield of treated and untreated plants (P = 0.05), but ...

  20. Insecticide resistance and glutathione S-transferases in mosquitoes ...

    African Journals Online (AJOL)

    Mosquito glutathione S-transferases (GSTs) have received considerable attention in the last 20 years because of their role in insecticide metabolism producing resistance. Many different compounds, including toxic xenobiotics and reactive products of intracellular processes such as lipid peroxidation, act as GST substrates.

  1. Utilization of insecticide treated nets among pregnant women and ...

    African Journals Online (AJOL)

    The possibility of provision of steady light supply through the use of solar power in the homes by those who can afford it can be explored as a remedy for promoting consistent use of ITN by pregnant women and under five children in this community. Keywords: Insecticide treated nets, pregnant women, mothers, Ikot Omin, ...

  2. Water based microwave assisted extraction of thiamethoxam residues from vegetables and soil for determination by HPLC.

    Science.gov (United States)

    Karmakar, Rajib; Singh, Shashi Bala; Kulshrestha, Gita

    2012-02-01

    A microwave assisted extraction (MAE) method for determination of thiamethoxam residues in vegetable and soil samples was standardized. Insecticide spiked vegetable and soil samples were extracted by MAE using water as an extraction solvent, cleaned up by solid phase extraction and analysed by high performance liquid chromatography on photodiode array detector. The recoveries of the insecticide from various vegetable (tomato, radish, brinjal, okra, French been, sugarbeet) and soil (sandy loam, silty clay loam, sandy clay loam, loamy sand) samples at 0.1 and 0.5 μg g(-1) spiking levels ranged from 79.8% to 86.2% and from 82.1% to 87.0%, respectively. The recoveries by MAE were comparable to those obtained by the conventional blender and shake-flask extraction techniques. The precision of the MAE method was demonstrated by relative standard deviations of <3% for the insecticide.

  3. AERONET - Aerosol Climatology From Megalopolis Aerosol Source Regions

    Science.gov (United States)

    Holben, B. N.; Eck, T. F.; Dubovik, O.; Smirnov, A.; Slutsker, I.; Artaxo, P.; Leyva, A.; Lu, D.; Sano, I.; Singh, R. P.; Quel, E.; Tanre, D.; Zibordi, G.

    2002-05-01

    AERONET is a globally distributed network of ~170 identical sun and sky scanning spectral radiometers expanded by federation with collaborating investigators that contribute to the AERONET public domain data-base. We will detail the current distribution and plans for expanded collaboration. Recent products available through the project database are important for assessment of human health as well as climate forcing issues. We will illustrate a summary of aerosol optical properties measured in Indian, East Asian, North American, South American and European megalopolis source regions. We will present monthly mean fine and coarse particle aerosol optical depth, particle size distributions and single scattering albedos. Each region represents a population in excess of 10 million inhabitants within a 200 km radius of the observation site that dictate the anthropogenic aerosol sources contributing to significantly diverse aerosol properties as a function of economic development and seasonally dependent meteorological processes. The diversity of the measured optical properties of urban aerosols illustrates the need for long-term regional monitoring that contribute to comparative assessments for health and climate change investigations.

  4. Analysis of Insecticides in Dead Wild Birds in Korea from 2010 to 2013.

    Science.gov (United States)

    Kim, Soohee; Park, Mi-Young; Kim, Hyo-Jin; Shin, Jin Young; Ko, Kyung Yuk; Kim, Dong-Gyu; Kim, MeeKyung; Kang, Hwan-Goo; So, ByungJae; Park, Sung-Won

    2016-01-01

    Wild birds are exposed to insecticides in a variety of ways, at different dose levels and via multiple routes, including ingestion of contaminated food items, and dermal, inhalation, preening, and embryonic exposure. Most poisoning by insecticides occurs as a result of misuse or accidental exposure, but intentional killing of unwanted animals also occurs. In this study, we investigated insecticides in the gastric contents of dead wild birds that were suspected to have died from insecticide poisoning based on necropsy. The wild birds were found dead in various regions and locations such as in mountains, and agricultural and urban areas. A total of 182 dead wild birds of 27 species were analyzed in this study, and insecticide residue levels were determined in 60.4% of the total samples analyzed. Monocrotophos and phosphamidon were the most common insecticides identified at rates of 50.0% and 30.7% of the insecticide-positive samples, respectively. Other insecticides identified in dead wild birds included organophosphorous, organochlorine and carbamate insecticides. However, there was limited evidence to conclusively establish the cause of death related to insecticides in this study. Nevertheless, considering the level of insecticide exposure, it is speculated that the exposure was mainly a result of accidental or intentional killing, and not from environmental residue.

  5. Novel and viable acetylcholinesterase target site for developing effective and environmentally safe insecticides.

    Science.gov (United States)

    Pang, Yuan-Ping; Brimijoin, Stephen; Ragsdale, David W; Zhu, Kun Yan; Suranyi, Robert

    2012-04-01

    Insect pests are responsible for human suffering and financial losses worldwide. New and environmentally safe insecticides are urgently needed to cope with these serious problems. Resistance to current insecticides has resulted in a resurgence of insect pests, and growing concerns about insecticide toxicity to humans discourage the use of insecticides for pest control. The small market for insecticides has hampered insecticide development; however, advances in genomics and structural genomics offer new opportunities to develop insecticides that are less dependent on the insecticide market. This review summarizes the literature data that support the hypothesis that an insect-specific cysteine residue located at the opening of the acetylcholinesterase active site is a promising target site for developing new insecticides with reduced off-target toxicity and low propensity for insect resistance. These data are used to discuss the differences between targeting the insect-specific cysteine residue and targeting the ubiquitous catalytic serine residue of acetylcholinesterase from the perspective of reducing off-target toxicity and insect resistance. Also discussed is the prospect of developing cysteine-targeting anticholinesterases as effective and environmentally safe insecticides for control of disease vectors, crop damage, and residential insect pests within the financial confines of the present insecticide market.

  6. Changes in insecticide resistance of the rice striped stem borer (Lepidoptera: Crambidae).

    Science.gov (United States)

    Su, Jianya; Zhang, Zhenzhen; Wu, Min; Gao, Congfen

    2014-02-01

    Application of insecticides is the most important method to control Chilo suppressalis (Walker) (Lepidoptera: Crambidae), and continuous use of individual insecticides has driven the rapid development of insecticide resistance in C. suppressalis during the past 30 yr. Monitoring insecticide resistance provides information essential for integrated pest management. Insecticide resistance of field populations to monosultap, triazophos, chlorpyrifos, and abamectin in China was examined in 2010 and 2011. The results indicated that the resistance levels of 14 field populations to four insecticides were significantly different. Four populations showed moderate resistance, and other populations possessed low-level resistance or were susceptible to monosultap. Nine populations displayed an extremely high or a high level of resistance to triazophos, whereas four populations were sensitive to this agent. Five populations exhibited a low level of resistance to abamectin, while the others remained sensitive. When compared with historical data, resistance to monosultap and triazophos decreased significantly, and the percentage of populations with high-level or extremely high-level resistance was obviously reduced. By contrast, the resistance to abamectin increased slightly. The increasing and decreasing resistance levels reported in this study highlight the different evolutionary patterns of insecticide resistance in C. suppressalis. An overreliance on one or two insecticides may promote rapid development of resistance. Slow development of resistance to abamectin, which was used mainly in mixtures with other insecticides, implies that the use of insecticide mixtures may be an effective method to delay the evolution of resistance to insecticides.

  7. Ground-based aerosol climatology of China: aerosol optical depths from the China Aerosol Remote Sensing Network 2002-2013

    National Research Council Canada - National Science Library

    Che, H; Zhang, X.-Y; Xia, X; Goloub, P; Holben, B; Zhao, H; Wang, Y; Zhang, X.-C; Wang, H; Blarel, L; Damiri, B; Zhang, R; Deng, X; Ma, Y; Wang, T; Geng, F; Qi, B; Zhu, J; Yu, J; Chen, Q; Shi, G

    2015-01-01

      Long-term measurements of aerosol optical depths (AODs) at 440 nm and Ångström exponents (AE) between 440 and 870 nm made for CARSNET were compiled into a climatology of aerosol optical properties for China...

  8. Underpinning sustainable vector control through informed insecticide resistance management.

    Directory of Open Access Journals (Sweden)

    Edward K Thomsen

    Full Text Available There has been rapid scale-up of malaria vector control in the last ten years. Both of the primary control strategies, long-lasting pyrethroid treated nets and indoor residual spraying, rely on the use of a limited number of insecticides. Insecticide resistance, as measured by bioassay, has rapidly increased in prevalence and has come to the forefront as an issue that needs to be addressed to maintain the sustainability of malaria control and the drive to elimination. Zambia's programme reported high levels of resistance to the insecticides it used in 2010, and, as a result, increased its investment in resistance monitoring to support informed resistance management decisions.A country-wide survey on insecticide resistance in Zambian malaria vectors was performed using WHO bioassays to detect resistant phenotypes. Molecular techniques were used to detect target-site mutations and microarray to detect metabolic resistance mechanisms. Anopheles gambiae s.s. was resistant to pyrethroids, DDT and carbamates, with potential organophosphate resistance in one population. The resistant phenotypes were conferred by both target-site and metabolic mechanisms. Anopheles funestus s.s. was largely resistant to pyrethroids and carbamates, with potential resistance to DDT in two locations. The resistant phenotypes were conferred by elevated levels of cytochrome p450s.Currently, the Zambia National Malaria Control Centre is using these results to inform their vector control strategy. The methods employed here can serve as a template to all malaria-endemic countries striving to create a sustainable insecticide resistance management plan.

  9. Agricultural insecticides threaten surface waters at the global scale.

    Science.gov (United States)

    Stehle, Sebastian; Schulz, Ralf

    2015-05-05

    Compared with nutrient levels and habitat degradation, the importance of agricultural pesticides in surface water may have been underestimated due to a lack of comprehensive quantitative analysis. Increasing pesticide contamination results in decreasing regional aquatic biodiversity, i.e., macroinvertebrate family richness is reduced by ∼30% at pesticide concentrations equaling the legally accepted regulatory threshold levels (RTLs). This study provides a comprehensive metaanalysis of 838 peer-reviewed studies (>2,500 sites in 73 countries) that evaluates, for the first time to our knowledge on a global scale, the exposure of surface waters to particularly toxic agricultural insecticides. We tested whether measured insecticide concentrations (MICs; i.e., quantified insecticide concentrations) exceed their RTLs and how risks depend on insecticide development over time and stringency of environmental regulation. Our analysis reveals that MICs occur rarely (i.e., an estimated 97.4% of analyses conducted found no MICs) and there is a complete lack of scientific monitoring data for ∼90% of global cropland. Most importantly, of the 11,300 MICs, 52.4% (5,915 cases; 68.5% of the sites) exceeded the RTL for either surface water (RTLSW) or sediments. Thus, the biological integrity of global water resources is at a substantial risk. RTLSW exceedances depend on the catchment size, sampling regime, and sampling date; are significantly higher for newer-generation insecticides (i.e., pyrethroids); and are high even in countries with stringent environmental regulations. These results suggest the need for worldwide improvements to current pesticide regulations and agricultural pesticide application practices and for intensified research efforts on the presence and effects of pesticides under real-world conditions.

  10. Toxicity of some insecticides to the haemocytes of giant honeybee, Apis dorsata F. under laboratory conditions

    Directory of Open Access Journals (Sweden)

    Nighat Perveen

    2017-07-01

    Full Text Available Quantitative studies concerning total and differential haemocyte counts and abnormalities were performed under laboratory conditions for larvae, pupae and adults collected from a wild Apis dorsata colony. Haemolymph samples were observed immediately, thirty and sixty minutes after field recommended concentration exposure of five different insecticides. Total haemocyte counts were significantly higher for larvae and pupae but less for adult bees, however, differential haemocyte counts insignificantly different. Exposure of insecticides showed variable response for tested insecticides with immediate increased change with ethofenprox, diafenthiuron and imidacloprid but decreased for all tested insecticides after sixty minutes. For differential haemocyte counts, plasmatocytes and granulocytes increased with exposure of insecticides. Immune response of haemocytes against insecticides showed different degrees of abnormalities like agglutination, denucleation and cell shape distortion. Such studies may help in possible identification of insect defense mechanisms against their exposure to external hazards for instance insecticide exposure.

  11. Specificity determinants for Cry insecticidal proteins: Insights from their mode of action.

    Science.gov (United States)

    Jurat-Fuentes, Juan Luis; Crickmore, Neil

    2017-01-01

    Insecticidal proteins from the bacterium Bacillus thuringiensis (Bt) are used as active components of biopesticides and as plant incorporated protectants in transgenic crops. One of the most relevant attributes of these Bt protein-based insecticidal technologies is their high specificity, which assures lack of detrimental effects on non-target insects, vertebrates and the environment. The identification of specificity determinants in Bt insecticidal proteins could guide risk assessment for novel insecticidal proteins currently considered for commercialization. In this work we review the available data on specificity determinants of crystal (Cry) insecticidal proteins as the Bt toxins most well characterized and used in transgenic crops. The multi-step mode of action of the Cry insecticidal proteins allows various factors to potentially affect specificity determination and here we define seven levels that could influence specificity. The relative relevance of each of these determinants on efficacy of transgenic crops producing Cry insecticidal proteins is also discussed. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Classifying aerosol type using in situ surface spectral aerosol optical properties

    Science.gov (United States)

    Schmeisser, Lauren; Andrews, Elisabeth; Ogren, John A.; Sheridan, Patrick; Jefferson, Anne; Sharma, Sangeeta; Kim, Jeong Eun; Sherman, James P.; Sorribas, Mar; Kalapov, Ivo; Arsov, Todor; Angelov, Christo; Mayol-Bracero, Olga L.; Labuschagne, Casper; Kim, Sang-Woo; Hoffer, András; Lin, Neng-Huei; Chia, Hao-Ping; Bergin, Michael; Sun, Junying; Liu, Peng; Wu, Hao

    2017-10-01

    Knowledge of aerosol size and composition is important for determining radiative forcing effects of aerosols, identifying aerosol sources and improving aerosol satellite retrieval algorithms. The ability to extrapolate aerosol size and composition, or type, from intensive aerosol optical properties can help expand the current knowledge of spatiotemporal variability in aerosol type globally, particularly where chemical composition measurements do not exist concurrently with optical property measurements. This study uses medians of the scattering Ångström exponent (SAE), absorption Ångström exponent (AAE) and single scattering albedo (SSA) from 24 stations within the NOAA/ESRL Federated Aerosol Monitoring Network to infer aerosol type using previously published aerosol classification schemes.Three methods are implemented to obtain a best estimate of dominant aerosol type at each station using aerosol optical properties. The first method plots station medians into an AAE vs. SAE plot space, so that a unique combination of intensive properties corresponds with an aerosol type. The second typing method expands on the first by introducing a multivariate cluster analysis, which aims to group stations with similar optical characteristics and thus similar dominant aerosol type. The third and final classification method pairs 3-day backward air mass trajectories with median aerosol optical properties to explore the relationship between trajectory origin (proxy for likely aerosol type) and aerosol intensive parameters, while allowing for multiple dominant aerosol types at each station.The three aerosol classification methods have some common, and thus robust, results. In general, estimating dominant aerosol type using optical properties is best suited for site locations with a stable and homogenous aerosol population, particularly continental polluted (carbonaceous aerosol), marine polluted (carbonaceous aerosol mixed with sea salt) and continental dust/biomass sites

  13. Classifying aerosol type using in situ surface spectral aerosol optical properties

    Directory of Open Access Journals (Sweden)

    L. Schmeisser

    2017-10-01

    Full Text Available Knowledge of aerosol size and composition is important for determining radiative forcing effects of aerosols, identifying aerosol sources and improving aerosol satellite retrieval algorithms. The ability to extrapolate aerosol size and composition, or type, from intensive aerosol optical properties can help expand the current knowledge of spatiotemporal variability in aerosol type globally, particularly where chemical composition measurements do not exist concurrently with optical property measurements. This study uses medians of the scattering Ångström exponent (SAE, absorption Ångström exponent (AAE and single scattering albedo (SSA from 24 stations within the NOAA/ESRL Federated Aerosol Monitoring Network to infer aerosol type using previously published aerosol classification schemes.Three methods are implemented to obtain a best estimate of dominant aerosol type at each station using aerosol optical properties. The first method plots station medians into an AAE vs. SAE plot space, so that a unique combination of intensive properties corresponds with an aerosol type. The second typing method expands on the first by introducing a multivariate cluster analysis, which aims to group stations with similar optical characteristics and thus similar dominant aerosol type. The third and final classification method pairs 3-day backward air mass trajectories with median aerosol optical properties to explore the relationship between trajectory origin (proxy for likely aerosol type and aerosol intensive parameters, while allowing for multiple dominant aerosol types at each station.The three aerosol classification methods have some common, and thus robust, results. In general, estimating dominant aerosol type using optical properties is best suited for site locations with a stable and homogenous aerosol population, particularly continental polluted (carbonaceous aerosol, marine polluted (carbonaceous aerosol mixed with sea salt and continental dust

  14. Evaluation of some vanillin-modified polyoxyethylene surfactants as additives for water based mud

    Directory of Open Access Journals (Sweden)

    M.M.A. El-Sukkary

    2014-03-01

    Full Text Available Water-based drilling fluids are increasingly being used for oil and gas exploration and are generally considered to be more environmentally acceptable than oil-based or synthetic-based fluids. In this study, new types of vanillin-modified polyoxyethylene surfactants were evaluated as additives in water-based mud. Their rheological properties in water-based mud were investigated which included the apparent viscosity, the plastic viscosity, the yield point, the gel strength, the thixotropy as well as the filtration properties. Also, the effect of high temperature on the rheology of the formulated water based mud was studied. The tested ethoxylated non-ionic surfactants showed good results when utilized in the formulation of water-based mud.

  15. Factors Affecting Aerosol Radiative Forcing

    Science.gov (United States)

    Wang, J.; Lin, J.; Ni, R.

    2016-12-01

    Rapid industrial and economic growth has meant large amount of aerosols in the atmosphere with strong radiative forcing (RF) upon the climate system. Over parts of the globe, the negative forcing of aerosols has overcompensated for the positive forcing of greenhouse gases. Aerosol RF is determined by emissions and various chemical-transport-radiative processes in the atmosphere, a multi-factor problem whose individual contributors have not been well quantified. In this study, we analyze the major factors affecting RF of secondary inorganic aerosols (SIOAs, including sulfate, nitrate and ammonium), primary organic aerosol (POA), and black carbon (BC). We analyze the RFof aerosols produced by 11 major regions across the globe, including but not limited to East Asia, Southeast Asia, South Asia, North America, and Western Europe. Factors analyzed include population size, per capita gross domestic production (GDP), emission intensity (i.e., emissionsper unit GDP), chemical efficiency (i.e., mass per unit emissions) and radiative efficiency (i.e., RF per unit mass). We find that among the 11 regions, East Asia produces the largest emissions and aerosol RF, due to relatively high emission intensity and a tremendous population size.South Asia produce the second largest RF of SIOA and BC and the highest RF of POA, in part due to its highest chemical efficiency among all regions. Although Southeast Asia also has large emissions,its aerosol RF is alleviated by its lowest chemical efficiency.The chemical efficiency and radiative efficiency of BC produced by the Middle East-North Africa are the highest across the regions, whereas its RF is loweredbyasmall per capita GDP.Both North America and Western Europe have low emission intensity, compensating for the effects on RF of large population sizes and per capita GDP. There has been a momentum to transfer industries to Southeast Asia and South Asia, and such transition is expected to continue in the coming years. The resulting

  16. Aerosol Emission during Human Speech

    Science.gov (United States)

    Asadi, Sima; Ristenpart, William

    2016-11-01

    The traditional emphasis for airborne disease transmission has been on coughing and sneezing, which are dramatic expiratory events that yield easily visible droplets. Recent research suggests that normal speech can release even larger quantities of aerosols that are too small to see with the naked eye, but are nonetheless large enough to carry a variety of pathogens (e.g., influenza A). This observation raises an important question: what types of speech emit the most aerosols? Here we show that the concentration of aerosols emitted during healthy human speech is positively correlated with both the amplitude (loudness) and fundamental frequency (pitch) of the vocalization. Experimental measurements with an aerodynamic particle sizer (APS) indicate that speaking in a loud voice (95 decibels) yields up to fifty times more aerosols than in a quiet voice (75 decibels), and that sounds associated with certain phonemes (e.g., [a] or [o]) release more aerosols than others. We interpret these results in terms of the egressive airflow rate associated with each phoneme and the corresponding fundamental frequency, which is known to vary significantly with gender and age. The results suggest that individual speech patterns could affect the probability of airborne disease transmission.

  17. CATS Aerosol Typing and Future Directions

    Science.gov (United States)

    McGill, Matt; Yorks, John; Scott, Stan; Palm, Stephen; Hlavka, Dennis; Hart, William; Nowottnick, Ed; Selmer, Patrick; Kupchock, Andrew; Midzak, Natalie; hide

    2016-01-01

    The Cloud Aerosol Transport System (CATS), launched in January of 2015, is a lidar remote sensing instrument that will provide range-resolved profile measurements of atmospheric aerosols and clouds from the International Space Station (ISS). CATS is intended to operate on-orbit for at least six months, and up to three years. Status of CATS Level 2 and Plans for the Future:Version. 1. Aerosol Typing (ongoing): Mode 1: L1B data released later this summer; L2 data released shortly after; Identify algorithm biases (ex. striping, FOV (field of view) biases). Mode 2: Processed Released Currently working on correcting algorithm issues. Version 2 Aerosol Typing (Fall, 2016): Implementation of version 1 modifications Integrate GEOS-5 aerosols for typing guidance for non spherical aerosols. Version 3 Aerosol Typing (2017): Implementation of 1-D Var Assimilation into GEOS-5 Dynamic lidar ratio that will evolve in conjunction with simulated aerosol mixtures.

  18. Miniature Sensor for Aerosol Mass Measurements Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR project seeks to develop a miniature sensor for mass measurement of size-classified aerosols. A cascade impactor will be used to classify aerosol sample...

  19. Aerosol Chemical Speciation Monitor (ACSM) Instrument Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Watson, Thomas B. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2017-08-15

    The Aerodyne Aerosol Chemical Speciation Monitor (ACSM) measures particle mass loading and chemical composition in real time for non-refractory sub-micron aerosol particles. The ACSM is designed for long-term unattended deployment and routine monitoring applications.

  20. MISR Aerosol Climatology Product V001

    Data.gov (United States)

    National Aeronautics and Space Administration — MISR Aerosol Climatology Product is 1) the microphysical and scattering characteristics of pure aerosol upon which routine retrievals are based; 2) mixtures of pure...

  1. Origins of atmospheric aerosols. Basic concepts on aerosol main physical properties; L`aerosol atmospherique: ses origines quelques notions sur les principales proprietes physiques des aerosols

    Energy Technology Data Exchange (ETDEWEB)

    Renoux, A. [Paris-12 Univ., 94 - Creteil (France). Laboratoire de Physique des aerosols et de transferts des contaminations

    1996-12-31

    Natural and anthropogenic sources of atmospheric aerosols are reviewed and indications of their concentrations and granulometry are given. Calculation of the lifetime of an atmospheric aerosol of a certain size is presented and the various modes of aerosol granulometry and their relations with photochemical and physico-chemical processes in the atmosphere are discussed. The main physical, electrical and optical properties of aerosols are also presented: diffusion coefficient, dynamic mobility and relaxation time, Stokes number, limit rate of fall, electrical mobility, optical diffraction

  2. Aerosol retrieval experiments in the ESA Aerosol_cci project

    Directory of Open Access Journals (Sweden)

    T. Holzer-Popp

    2013-08-01

    Full Text Available Within the ESA Climate Change Initiative (CCI project Aerosol_cci (2010–2013, algorithms for the production of long-term total column aerosol optical depth (AOD datasets from European Earth Observation sensors are developed. Starting with eight existing pre-cursor algorithms three analysis steps are conducted to improve and qualify the algorithms: (1 a series of experiments applied to one month of global data to understand several major sensitivities to assumptions needed due to the ill-posed nature of the underlying inversion problem, (2 a round robin exercise of "best" versions of each of these algorithms (defined using the step 1 outcome applied to four months of global data to identify mature algorithms, and (3 a comprehensive validation exercise applied to one complete year of global data produced by the algorithms selected as mature based on the round robin exercise. The algorithms tested included four using AATSR, three using MERIS and one using PARASOL. This paper summarizes the first step. Three experiments were conducted to assess the potential impact of major assumptions in the various aerosol retrieval algorithms. In the first experiment a common set of four aerosol components was used to provide all algorithms with the same assumptions. The second experiment introduced an aerosol property climatology, derived from a combination of model and sun photometer observations, as a priori information in the retrievals on the occurrence of the common aerosol components. The third experiment assessed the impact of using a common nadir cloud mask for AATSR and MERIS algorithms in order to characterize the sensitivity to remaining cloud contamination in the retrievals against the baseline dataset versions. The impact of the algorithm changes was assessed for one month (September 2008 of data: qualitatively by inspection of monthly mean AOD maps and quantitatively by comparing daily gridded satellite data against daily averaged AERONET sun

  3. Optical trapping of gold aerosols

    DEFF Research Database (Denmark)

    Schmitt, Regina K.; Pedersen, Liselotte Jauffred; Taheri, S. M.

    2015-01-01

    Aerosol trapping has proven challenging and was only recently demonstrated.1 This was accomplished by utilizing an air chamber designed to have a minimum of turbulence and a laser beam with a minimum of aberration. Individual gold nano-particles with diameters between 80 nm and 200 nm were trapped...... in air using a 1064 nm laser. The positions visited by the trapped gold nano-particle were quantified using a quadrant photo diode placed in the back focal plane. The time traces were analyzed and the trapping stiffness characterizing gold aerosol trapping determined and compared to aerosol trapping...... of nanometer sized silica and polystyrene particles. Based on our analysis, we concluded that gold nano-particles trap more strongly in air than similarly sized polystyrene and silica particles. We found that, in a certain power range, the trapping strength of polystyrene particles is linearly decreasing...

  4. A mathematical model of aerosol holding chambers

    DEFF Research Database (Denmark)

    Zak, M; Madsen, J; Berg, E

    1999-01-01

    A mathematical model of aerosol delivery from holding chambers (spacers) was developed incorporating tidal volume (VT), chamber volume (Vch), apparatus dead space (VD), effect of valve insufficiency and other leaks, loss of aerosol by immediate impact on the chamber wall, and fallout of aerosol...

  5. Aerosol processes relevant for the Netherlands

    NARCIS (Netherlands)

    Brugh, Aan de J.M.J.

    2013-01-01

    Particulate matter (or aerosols) are particles suspended in the atmosphere. Aerosols are believed to be the most important pollutant associated with increased human mortality and morbidity. Therefore, it is important to investigate the relationship between sources of aerosols (such as industry) and

  6. DARE: a dedicated aerosols retrieval instrument

    NARCIS (Netherlands)

    Court, A.J.; Smorenburg, K.; Courrèges-Lacoste, G.B.; Visser, H.; Leeuw, G. de; Decae, R.

    2004-01-01

    Satellite remote sensing of aerosols is a largely unresolved problem. A dedicated instrument aimed at aerosols would be able to reduce the large uncertainties connected to this kind of remote sensing. TNO is performing a study of a space based instrument for aerosol measurements, together with the

  7. Aerosol Transport Over Equatorial Africa

    Science.gov (United States)

    Gatebe, C. K.; Tyson, P. D.; Annegarn, H. J.; Kinyua, A. M.; Piketh, S.; King, M.; Helas, G.

    1999-01-01

    Long-range and inter-hemispheric transport of atmospheric aerosols over equatorial Africa has received little attention so far. Most aerosol studies in the region have focussed on emissions from rain forest and savanna (both natural and biomass burning) and were carried out in the framework of programs such as DECAFE (Dynamique et Chimie Atmospherique en Foret Equatoriale) and FOS (Fires of Savanna). Considering the importance of this topic, aerosols samples were measured in different seasons at 4420 meters on Mt Kenya and on the equator. The study is based on continuous aerosol sampling on a two stage (fine and coarse) streaker sampler and elemental analysis by Particle Induced X-ray Emission. Continuous samples were collected for two seasons coinciding with late austral winter and early austral spring of 1997 and austral summer of 1998. Source area identification is by trajectory analysis and sources types by statistical techniques. Major meridional transports of material are observed with fine-fraction silicon (31 to 68 %) in aeolian dust and anthropogenic sulfur (9 to 18 %) being the major constituents of the total aerosol loading for the two seasons. Marine aerosol chlorine (4 to 6 %), potassium (3 to 5 %) and iron (1 to 2 %) make up the important components of the total material transport over Kenya. Minimum sulfur fluxes are associated with recirculation of sulfur-free air over equatorial Africa, while maximum sulfur concentrations are observed following passage over the industrial heartland of South Africa or transport over the Zambian/Congo Copperbelt. Chlorine is advected from the ocean and is accompanied by aeolian dust recirculating back to land from mid-oceanic regions. Biomass burning products are transported from the horn of Africa. Mineral dust from the Sahara is transported towards the Far East and then transported back within equatorial easterlies to Mt Kenya. This was observed during austral summer and coincided with the dying phase of 1997/98 El

  8. High Concentration Standard Aerosol Generator.

    Science.gov (United States)

    1985-07-31

    through entrances (1) and (3) so as to attain an anular flow of aerosol. The merging flow is then accelerated by the narrowing cross-section of the duct...tration (if a lower flow or a wider size distribution is acceptable and 2) precautions and suggestions for use of different aerosol materials. Additional...particles of interest. The flow split in both VPI and VP2 is 10% so that 4 slpm exits through the token flow Q2T of VP2. A venturi is utilized to

  9. Insecticide-tolerant and plant-growth-promoting Rhizobium improves the growth of lentil (Lens esculentus) in insecticide-stressed soils.

    Science.gov (United States)

    Ahemad, Munees; Khan, Mohammad S

    2011-04-01

    Application of insecticides in modern agriculture in order to enhance legume production has led to their accumulation in soils to levels that adversely affect soil microflora such as rhizobia and exert a negative impact on the physiological activities associated with them. This study was therefore designed to identify rhizobial strains expressing higher tolerance to insecticides fipronil and pyriproxyfen and synthesising plant growth regulators even amid insecticide stress. The fipronil- and pyriproxyfen-tolerant Rhizobium sp. strain MRL3 produced plant-growth-promoting substances in substantial amounts, both in the presence and in the absence of the insecticides. In general, both insecticides at recommended and higher rates reduced plant dry biomass, symbiotic properties, nutrient uptake and seed yield of lentil plants. Interestingly, when applied with any concentration of the two insecticides, Rhizobium sp. strain MRL3 significantly increased the measured parameters compared with plants grown in soils treated solely with the same concentration of each insecticide but without inoculant. This study suggests that Rhizobium strain MRL3 may be exploited as a bioinoculant to augment the efficiency of lentil exposed to insecticide-stressed soils. Copyright © 2010 Society of Chemical Industry.

  10. Insecticide-mediated shift in ecological dominance between two competing species of grain beetles.

    Directory of Open Access Journals (Sweden)

    Erick Maurício G Cordeiro

    Full Text Available Competition is a driving force regulating communities often considered an intermittent phenomenon, difficult to verify and potentially driven by environmental disturbances. Insecticides are agents of environmental disturbance that can potentially change ecological relationships and competitive outcomes, but this subject has seldom been examined. As the co-existing cereal grain beetle species Sitophilus zeamais Motschulsky and Rhyzopertha dominica F. share a common realized niche, directly competing for the same resources, they were used as models in our study. Intraspecific competition experiments were performed with increasing insect densities and insecticide doses in additive and replacement series using various density combinations of both beetle species maintained on insecticide-free or -sprayed grains. Insecticide-mediated release from competitive stress was not observed in our study of intraspecific competition in grain beetles. The insecticide enhanced the effect of insect density, particularly for the maize weevil S. zeamais, further impairing population growth at high densities. Therefore, insecticide susceptibility increased with intraspecific competition favoring insecticide efficacy. However, the effect of insecticide exposure on competitive interaction extends beyond intraspecific competition, affecting interspecific competition as well. Sitophilus zeamais was the dominant species when in interspecific competition prevailing in natural conditions (without insecticide exposure, but the dominance and species prevalence shifted from S. zeamais to R. dominica under insecticide exposure. Therefore, high conspecific densities favored insecticide efficacy, but the strength of the relationship differs with the species. In addition, the insecticide mediated a shift in species dominance and competition outcome indicating that insecticides are relevant mediators of species interaction, potentially influencing community composition and raising

  11. [Preparation and characterization of a polyvinylpyrrolidone water-based magnetic fluid].

    Science.gov (United States)

    Xie, Jian-feng; Zhang, Yang-de; Zeng, Zhao-wu; Wang, Xiao-li; Liu, Xing-yan; Zhou, Wei-hua

    2008-03-01

    To prepare a stable water-based magnetic fluid. A water-based magnetic fluid was prepared by addition of polyvinylpyrrolidone (PVP) as the coating agent for the magnetic particles. After preparation of Fe3O4 by co-precipitation method, PVP was added for its coating, followed by ultrasonic agitation and purification. The magnetic nanoparticles of homogeneously small size and water-based magnetic fluid were obtained, which had good dispersion in water with strong magnetism. PVP can be used as a surfactant to stabilize the magnetic fluid.

  12. Insecticide resistance in the western flower thrips, Frankliniella occidentalis

    DEFF Research Database (Denmark)

    Jensen, Sten Erik

    to insecticides. Since F. occidentulis spread to become a worldwide pest in 1980’es, resistance to a number of different insecticides has been shown in many populations of F. occidentalis. This flower thrips has the potential of fast development of resistance owing to the short generation time, high fecundity...... (piperonyl butoxide, a cytochrome P450- monooxygenase inhibitor, and S,S,S-tributylphosphorotrithioate, an esterase inhibitor), assays in vitro of activity of detoxification enzymes (general esterases and glutathione S-transferases) toward model substrates, and assays in vitro of insensitivity and activity...... of acetylcholinesterase, the target site enzyme for methiocarb. The results from bioassays with synergists included indicated involvement of cytochrome P450- monooxygenases and esterases in methiocarb resistance in the most resistant populations. Selection with methiocarb on one of the populations to increase the level...

  13. Resistance is not Futile: It Shapes Insecticide Discovery

    Directory of Open Access Journals (Sweden)

    Margaret C. Hardy

    2014-01-01

    Full Text Available Conventional chemical control compounds used for the management of insect pests have been much maligned, but still serve a critical role in protecting people and agricultural products from insect pests, as well as conserving biodiversity by eradicating invasive species. Although biological control can be an effective option for area-wide management of established pests, chemical control methods are important for use in integrated pest management (IPM programs, as well as in export treatments, eradicating recently arrived invasive species, and minimizing population explosions of vectors of human disease. Cogitated research and development programs have continued the innovation of insecticides, with a particular focus on combating insecticide resistance. Recent developments in the fields of human health, protecting the global food supply, and biosecurity will be highlighted.

  14. [INSECTICIDE RESISTANCE IN MAJOR MALARIA VECTORS IN UZBEKISTAN].

    Science.gov (United States)

    Zhakhongirov, Sh M; Saifiev, Sh T; Abidov, Z I

    2016-01-01

    The resistance of Anopheles artemievi to DDT (26.7%) and propoxur (80.0%) was established in the kishlak of Chubat, Bulungursky District, Samarkand Viloyati and that in the kishlak of Rastguzar, Uichinsky District, Namangan Viloyati, was 45.0 and 22.5%, respectively. In the kishlak of Navruz, Kanlikulsky District, Republic of Karakalpakstan, there was reduced propoxur susceptibil- ity (90.0% An. superpictus death); in other human settle- ments, An. artemievi was susceptible--100% death in the use of the test insecticides. An. superpictus proved to be susceptive to 7 test insecticides (other than propoxur). In Uzbekistan, the resistance of An. artemievi was noted only in a small area. Among the major malaria vectors, An. superpictus remained susceptible to pyrethroid insec- ticides.

  15. CHROMOSOME CHANGES AND INSECTICIDE RESISTANCE IN ANOPHELES QUADRIMACULATUS.

    Science.gov (United States)

    MASON, G F; BROWN, A W

    1963-01-01

    Certain insecticide-resistant strains of anopheline mosquitos found in the field or developed in the laboratory are known to contain a high proportion of heterozygotes for chromosomal inversions, but up till now it has not been clear how this could be causally related to resistance. In the present investigation, 2 resistant strains and 2 susceptible strains of Anopheles quadrimaculatus, and the hybrids between them, were examined for the frequency of inversions. It was found that neither the resistant nor the susceptible strains were characterized by inversion buckles. Moreover, no new inversions appeared in the hybrids between them. It was therefore concluded that where heterozygosity for inversions has been observed in anophelines, it is a characteristic of hybrids due to parental differences resulting from geographic separation, and has no relation to specific insecticide resistance.

  16. Chromosome changes and insecticide-resistance in Anopheles quadrimaculatus

    Science.gov (United States)

    Mason, G. F.; Brown, A. W. A.

    1963-01-01

    Certain insecticide-resistant strains of anopheline mosquitos found in the field or developed in the laboratory are known to contain a high proportion of heterozygotes for chromosomal inversions, but up till now it has not been clear how this could be causally related to resistance. In the present investigation, 2 resistant strains and 2 susceptible strains of Anopheles quadrimaculatus, and the hybrids between them, were examined for the frequency of inversions. It was found that neither the resistant nor the susceptible strains were characterized by inversion buckles. Moreover, no new inversions appeared in the hybrids between them. It was therefore concluded that where heterozygosity for inversions has been observed in anophelines, it is a characteristic of hybrids due to parental differences resulting from geographic separation, and has no relation to specific insecticide resistance. ImagesFIG. 2FIG. 3 PMID:14166989

  17. A mathematical model of aerosol holding chambers

    DEFF Research Database (Denmark)

    Zak, M; Madsen, J; Berg, E

    1999-01-01

    A mathematical model of aerosol delivery from holding chambers (spacers) was developed incorporating tidal volume (VT), chamber volume (Vch), apparatus dead space (VD), effect of valve insufficiency and other leaks, loss of aerosol by immediate impact on the chamber wall, and fallout of aerosol...... in the chamber with time. Four different spacers were connected via filters to a mechanical lung model, and aerosol delivery during "breathing" was determined from drug recovery from the filters. The formula correctly predicted the delivery of budesonide aerosol from the AeroChamber (Trudell Medical, London...

  18. A critical review of neonicotinoid insecticides for developmental neurotoxicity

    Science.gov (United States)

    Sheets, Larry P.; Li, Abby A.; Minnema, Daniel J.; Collier, Richard H.; Creek, Moire R.; Peffer, Richard C.

    2016-01-01

    Abstract A comprehensive review of published and previously unpublished studies was performed to evaluate the neonicotinoid insecticides for evidence of developmental neurotoxicity (DNT). These insecticides have favorable safety profiles, due to their preferential affinity for nicotinic receptor (nAChR) subtypes in insects, poor penetration of the mammalian blood–brain barrier, and low application rates. Nevertheless, examination of this issue is warranted, due to their insecticidal mode of action and potential exposure with agricultural and residential uses. This review identified in vitro, in vivo, and epidemiology studies in the literature and studies performed in rats in accordance with GLP standards and EPA guidelines with imidacloprid, acetamiprid, thiacloprid, clothianidin, thiamethoxam, and dinotefuran, which are all the neonicotinoids currently registered in major markets. For the guideline-based studies, treatment was administered via the diet or gavage to primiparous female rats at three dose levels, plus a vehicle control (≥20/dose level), from gestation day 0 or 6 to lactation day 21. F1 males and females were evaluated using measures of motor activity, acoustic startle response, cognition, brain morphometry, and neuropathology. The principal effects in F1 animals were associated with decreased body weight (delayed sexual maturation, decreased brain weight, and morphometric measurements) and acute toxicity (decreased activity during exposure) at high doses, without neuropathology or impaired cognition. No common effects were identified among the neonicotinoids that were consistent with DNT or the neurodevelopmental effects associated with nicotine. Findings at high doses were associated with evidence of systemic toxicity, which indicates that these insecticides do not selectively affect the developing nervous system. PMID:26513508

  19. A critical review of neonicotinoid insecticides for developmental neurotoxicity.

    Science.gov (United States)

    Sheets, Larry P; Li, Abby A; Minnema, Daniel J; Collier, Richard H; Creek, Moire R; Peffer, Richard C

    2016-02-01

    A comprehensive review of published and previously unpublished studies was performed to evaluate the neonicotinoid insecticides for evidence of developmental neurotoxicity (DNT). These insecticides have favorable safety profiles, due to their preferential affinity for nicotinic receptor (nAChR) subtypes in insects, poor penetration of the mammalian blood-brain barrier, and low application rates. Nevertheless, examination of this issue is warranted, due to their insecticidal mode of action and potential exposure with agricultural and residential uses. This review identified in vitro, in vivo, and epidemiology studies in the literature and studies performed in rats in accordance with GLP standards and EPA guidelines with imidacloprid, acetamiprid, thiacloprid, clothianidin, thiamethoxam, and dinotefuran, which are all the neonicotinoids currently registered in major markets. For the guideline-based studies, treatment was administered via the diet or gavage to primiparous female rats at three dose levels, plus a vehicle control (≥20/dose level), from gestation day 0 or 6 to lactation day 21. F1 males and females were evaluated using measures of motor activity, acoustic startle response, cognition, brain morphometry, and neuropathology. The principal effects in F1 animals were associated with decreased body weight (delayed sexual maturation, decreased brain weight, and morphometric measurements) and acute toxicity (decreased activity during exposure) at high doses, without neuropathology or impaired cognition. No common effects were identified among the neonicotinoids that were consistent with DNT or the neurodevelopmental effects associated with nicotine. Findings at high doses were associated with evidence of systemic toxicity, which indicates that these insecticides do not selectively affect the developing nervous system.

  20. A Primer for Using Transgenic Insecticidal Cotton in Developing Countries

    OpenAIRE

    Showalter, Ann M.; Heuberger, Shannon; Tabashnik, Bruce E.; Carrière, Yves

    2009-01-01

    Many developing countries face the decision of whether to approve the testing and commercial use of insecticidal transgenic cotton and the task of developing adequate regulations for its use. In this review, we outline concepts and provide information to assist farmers, regulators and scientists in making decisions concerning this technology. We address seven critical topics: 1) molecular and breeding techniques used for the development of transgenic cotton cultivars, 2) properties of transge...

  1. "Phosphorous Insecticides Residues in Mazandaran River Waters, Iran (2000)"

    OpenAIRE

    Shayeghi, M.; SJ Shahtaheri; M Selsele

    2001-01-01

    In order to study the residues of phosphorous insecticides in Mazandaran district of Iran, Ethion, Azinphosmethyl, Diazinon and Malathion four most used pesticides were chosen and river water samples were collected in April to Sept. 2000, throughout the Mazandaran state. Thin layer chromatography was used, since it was the best applicable method in area with reasonably high level of sensitivity up to 0-01 ppm and acceptable recovery of 80% . Four hundred eighty samples were collected and test...

  2. Insecticide residues cross-contamination of oilseeds during storage

    Directory of Open Access Journals (Sweden)

    Dauguet Sylvie

    2007-11-01

    Full Text Available Pesticide residues are found in oilseeds and crude oils: they are mainly organophosphate insecticides (pirimiphos-methyl, dichlorvos, malathion used in empty storage facilities and for application to stored cereal grains. Even if pests are found in stored oilseeds, French regulation does not permit use of these insecticides on stored oilseeds, as they have affinity for these lipophilic subtances. These residues arise from cross-contamination during mechanical contact with storage bins and grain handling equipment, and not from illegal use. This uptake of insecticide residues from their storage environment by oilseeds can lead to levels that exceed regulatory limits. An investigation of 11 grain storage companies allowed us to follow the course of 27 sunflower seeds batches, from reception at the storage facilities to outloading. Samples from each of these batches, made at outloading, were analysed content for insecticide residues. Traceability of sunflower seeds established by storers allowed us to identify the origine of observed cross-contamination cases. Substances discovered were dichlorvos, pirimiphos-methyl and malathion (and chlorpyriphos-methyl in a single case. Pirimiphos-methyl was most commonly detected, but most cases of non-accordance with regulatory levels were observed with dichlorvos and malathion. Main cross-contamination hazard resulted from treatment of cereals at outloading, just before sunflower seeds were outloaded, especially when these cereals treatments were frequent on that elevator. Other situations led to cross-contaminations, but generally of lower levels: outloading of sunflower seeds after outloading of cereal that was treated at the reception, several weeks or months before; sunflower seeds stored in bin that contained previously treated cereal; empty bins and handling equipment treated before receipt of sunflower seeds.

  3. Insecticidal Activities of Jatropha curcas L. against Callosobruchus ...

    African Journals Online (AJOL)

    The aim of the experiment was to determine the insecticidal activities of Jatropha curcas L. seed oil against cowpea seed bruchid, Callosobruchus maculatus (F.) in storage under prevailing temperature (27±2ºC) and relative humidity (68±3%). The seed oil was applied at the rates of 0.2, 0.3, 0.5, and 1.0 ml/50 g cowpea ...

  4. Lead, cadmium, mercury and insecticide residue control of fresh vegetables.

    Science.gov (United States)

    Köck, M; Sixl, W; Möse, J R

    1989-01-01

    Comparative investigations were carried out for heavy metals and heptenophos the sole used insecticide in used water, soil samples and harvest vegetables of a fresh cultivation region and of supplies of large plants. If one compares the recommended levels given with the levels found in the different types of vegetables investigated (cucumber, green pepper, tomatoes) then the values found lie far below the recommended levels.

  5. Insecticide resistance evolution with mixtures and sequences: a model-based explanation.

    Science.gov (United States)

    South, Andy; Hastings, Ian M

    2018-02-15

    Insecticide resistance threatens effective vector control, especially for mosquitoes and malaria. To manage resistance, recommended insecticide use strategies include mixtures, sequences and rotations. New insecticides are being developed and there is an opportunity to develop use strategies that limit the evolution of further resistance in the short term. A 2013 review of modelling and empirical studies of resistance points to the advantages of mixtures. However, there is limited recent, accessible modelling work addressing the evolution of resistance under different operational strategies. There is an opportunity to improve the level of mechanistic understanding within the operational community of how insecticide resistance can be expected to evolve in response to different strategies. This paper provides a concise, accessible description of a flexible model of the evolution of insecticide resistance. The model is used to develop a mechanistic picture of the evolution of insecticide resistance and how it is likely to respond to potential insecticide use strategies. The aim is to reach an audience unlikely to read a more detailed modelling paper. The model itself, as described here, represents two independent genes coding for resistance to two insecticides. This allows the representation of the use of insecticides in isolation, sequence and mixtures. The model is used to demonstrate the evolution of resistance under different scenarios and how this fits with intuitive reasoning about selection pressure. Using an insecticide in a mixture, relative to alone, always prompts slower evolution of resistance to that insecticide. However, when resistance to both insecticides is considered, resistance thresholds may be reached later for a sequence relative to a mixture. Increasing the ability of insecticides to kill susceptible mosquitoes (effectiveness), has the most influence on favouring a mixture over a sequence because one highly effective insecticide provides more

  6. Complexation of insecticide chlorantraniliprole with human serum albumin: Biophysical aspects

    Energy Technology Data Exchange (ETDEWEB)

    Ding Fei [Department of Chemistry, China Agricultural University, No. 2 Yuanmingyuan Xi Road, Haidian District, Beijing 100193 (China); Liu Wei [College of Economics and Management, China Agricultural University, Beijing 100083 (China); Diao Jianxiong [Department of Chemistry, China Agricultural University, No. 2 Yuanmingyuan Xi Road, Haidian District, Beijing 100193 (China); Yin Bin [Key Laboratory of Pesticide Chemistry and Application Technology, Ministry of Agriculture, Department of Applied Chemistry, China Agricultural University, Beijing 100193 (China); Zhang Li, E-mail: zhli.work@gmail.co [Key Laboratory of Pesticide Chemistry and Application Technology, Ministry of Agriculture, Department of Applied Chemistry, China Agricultural University, Beijing 100193 (China); Sun Ying, E-mail: sunying@cau.edu.c [Department of Chemistry, China Agricultural University, No. 2 Yuanmingyuan Xi Road, Haidian District, Beijing 100193 (China)

    2011-07-15

    Chlorantraniliprole is a novel insecticide belonging to the diamide class of selective ryanodine receptor agonists. A biophysical study on the binding interaction of a novel diamide insecticide, chlorantraniliprole, with staple in vivo transporter, human serum albumin (HSA) has been investigated utilizing a combination of steady-state and time-resolved fluorescence, circular dichroism (CD), and molecular modeling methods. The interaction of chlorantraniliprole with HSA gives rise to fluorescence quenching through static mechanism, this corroborates the fluorescence lifetime outcomes that the ground state complex formation and the predominant forces in the HSA-chlorantraniliprole conjugate are van der Waals forces and hydrogen bonds, as derived from thermodynamic analysis. The definite binding site of chlorantraniliprole in HSA has been identified from the denaturation of protein, competitive ligand binding, and molecular modeling, subdomain IIIA (Sudlow's site II) was designated to possess high-affinity binding site for chlorantraniliprole. Moreover, using synchronous fluorescence, CD, and three-dimensional fluorescence we testified some degree of HSA structure unfolding upon chlorantraniliprole binding. - Highlights: {yields} Our study highlights for the first time how binding dynamics can predominate for the new diamide insecticide, chlorantraniliprole. {yields} Chlorantraniliprole is situated within subdomain IIIA, Sudlow's site II, which is the same as that of indole-benzodiazepine site. {yields} Biophysical and molecular modeling approaches are useful to resolve the ligand interaction with biomacromolecule. {yields} It serves as a protective device in binding and in inactivating potential toxic compounds to which the body is exposed.

  7. Pro-insecticidal approach towards increasing in planta activity.

    Science.gov (United States)

    Creemer, Lawrence C; Giampietro, Natalie C; Lambert, William; Yap, Maurice C; deBoer, Gerrit J; Adelfinskaya, Yelena; Castetter, Scott; Wessels, Frank J

    2017-04-01

    The adrenergic mode of action was investigated for the development of potential new insecticides. Clonidine-related analogs were tested against Myzus persicae (Sulzer) and Bemisia tabaci (Gennadius). Clonidine analogs lack translation owing to a possible vacuole-trapping mechanism. Physical property modulation via a prodrug approach was attempted to overcome this mechanism. Clonidine showed insecticidal activity against M. persicae and B. tabaci. A prodrug of a known open-chain analog of clonidine was developed. While the prodrug had decreased pKa and increased lipophilicity and displayed good activity against M. persicae B. tabaci, the activity did not translate to cotton. Metabolic studies showed that the prodrug was quickly metabolized to the parent compound, and was further metabolized to a known vacuole-trapped oxazoline analog. Adrenergic active compounds, such as clonidine analogs, show potential as insecticides; however, a designed prodrug approach did not overcome the lack of translation in this case. Studies confirmed that the synthesized prodrug analog metabolized in planta to the proposed vacuole-trapped compound. One possible explanation for the failure of this approach is that the rate of metabolism and vacuole trapping is faster than translaminar flow, and therefore the released pesticide is not biologically available to the target organism. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  8. Neonicotinoid insecticides can serve as inadvertent insect contraceptives.

    Science.gov (United States)

    Straub, Lars; Villamar-Bouza, Laura; Bruckner, Selina; Chantawannakul, Panuwan; Gauthier, Laurent; Khongphinitbunjong, Kitiphong; Retschnig, Gina; Troxler, Aline; Vidondo, Beatriz; Neumann, Peter; Williams, Geoffrey R

    2016-07-27

    There is clear evidence for sublethal effects of neonicotinoid insecticides on non-target ecosystem service-providing insects. However, their possible impact on male insect reproduction is currently unknown, despite the key role of sex. Here, we show that two neonicotinoids (4.5 ppb thiamethoxam and 1.5 ppb clothianidin) significantly reduce the reproductive capacity of male honeybees (drones), Apis mellifera Drones were obtained from colonies exposed to the neonicotinoid insecticides or controls, and subsequently maintained in laboratory cages until they reached sexual maturity. While no significant effects were observed for male teneral (newly emerged adult) body mass and sperm quantity, the data clearly showed reduced drone lifespan, as well as reduced sperm viability (percentage living versus dead) and living sperm quantity by 39%. Our results demonstrate for the first time that neonicotinoid insecticides can negatively affect male insect reproductive capacity, and provide a possible mechanistic explanation for managed honeybee queen failure and wild insect pollinator decline. The widespread prophylactic use of neonicotinoids may have previously overlooked inadvertent contraceptive effects on non-target insects, thereby limiting conservation efforts. © 2016 The Authors.

  9. Potent Insecticidal Secondary Metabolites from the Medicinal Plant Acanthus montanus

    Directory of Open Access Journals (Sweden)

    Elham Amin

    2012-03-01

    Full Text Available Acanthus montanus (Nees T. Anders. (Family: Acanthaceae is a small shrub with sparse branches and soft stems, widespread in Africa, the Balkans, Romania, Greece and Eastern Mediterranean. Documented evidence showed that the leaves of the plant possess spasmolytic, analgesic, anti-inflammatory and antipyretic activities. In our ongoing research project; aimed at identifying new natural compounds with insecticidal activity, the alcohol extract of the aerial parts of A. montanus exhibited a significant activity against adult Aedes aegypti. Phytochemical study of the plant has resulted in isolation of nine compounds, eight of which exhibit variable degrees of insecticidal activity. β-sitosterol-3-O- β –D-glucoside (1 exhibited potent mosquitocidal activity (100% mortality against adult Aedes aegypti at 1.25 μg/mg concentration, followed by palmitic acid (2 (90%, linaroside (3 (80%, and acetoside (9 (70% respectively. It is noteworthy that this is the first report of insecticidal activity of β-sitosterol-3-O- β –D-glucoside, linaroside and acetoside.

  10. Mdr65 decreases toxicity of multiple insecticides in Drosophila melanogaster.

    Science.gov (United States)

    Sun, Haina; Buchon, Nicolas; Scott, Jeffrey G

    2017-10-01

    ABC transporters are ubiquitous membrane-bound proteins, present in both prokaryotes and eukaryotes. The major function of eukaryotic ABC transporters is to mediate the efflux of a variety of substrates (including xenobiotics) out of cells. ABC transporters have been widely investigated in humans, particularly for their involvement in multidrug resistance (MDR). Considerably less is known about their roles in transport and/or excretion in insects. ABC transporters are only known to function as exporters in insects. Drosophila melanogaster has 56 ABC transporter genes, including eight which are phylogenetically most similar to the human Mdr genes (ABCB1 clade). We investigated the role of ABC transporters in the ABCB1 clade in modulating the susceptibility to insecticides. We took advantage of the GAL4/UAS system in D. melanogaster to knockdown the expression levels of Mdr65, Mdr50, Mdr49 and ABCB6 using transgenic UAS-RNAi lines and conditional driver lines. The most notable effects were increased sensitivities to nine different insecticides by silencing of Mdr65. Furthermore, a null mutation of Mdr65 decreased the malathion, malaoxon and fipronil LC50 values by a factor of 1.9, 2.1 and 3.9, respectively. Altogether, this data demonstrates the critical role of ABC transporters, particularly Mdr65, in altering the toxicity of specific, structurally diverse, insecticides in D. melanogaster. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Climatic impacts of anthropogenic aerosols

    Energy Technology Data Exchange (ETDEWEB)

    Iversen, T. [Oslo Univ. (Norway)

    1996-03-01

    This paper was read at the workshop ``The Norwegian Climate and Ozone Research Programme`` held on 11-12 March 1996. Anthropogenic production of aerosols is mainly connected with combustion of fossil fuel. Measured by particulate mass, the anthropogenic sulphate production is the dominating source of aerosols in the Northern Hemisphere. Particles emitted in mechanical processes, fly ash etc. are less important because of their shorter atmospheric residence time. Possible climatological effects of anthropogenic aerosols are usually classified in two groups: direct and indirect. Direct effects are alterations of the radiative heating budget due to the aerosol particles in clear air. Indirect effects involve the interaction between particles and cloud processes. A simplified one-layer radiation model gave cooling in the most polluted mid-latitude areas and heating due to soot absorption in the Arctic. This differential trend in heating rates may have significant effects on atmospheric meridional circulations, which is important for the atmosphere as a thermodynamic system. Recently the description of sulphur chemistry in the hemispheric scale dispersion model has been improved and will be used in a model for Mie scattering and absorption

  12. NASA's Aerosol Sampling Experiment Summary

    Science.gov (United States)

    Meyer, Marit E.

    2016-01-01

    In a spacecraft cabin environment, the size range of indoor aerosols is much larger and they persist longer than on Earth because they are not removed by gravitational settling. A previous aerosol experiment in 1991 documented that over 90 of the mass concentration of particles in the NASA Space Shuttle air were between 10 m and 100 m based on measurements with a multi-stage virtual impactor and a nephelometer (Liu et al. 1991). While the now-retired Space Shuttle had short duration missions (less than two weeks), the International Space Station (ISS) has been continually inhabited by astronauts for over a decade. High concentrations of inhalable particles on ISS are potentially responsible for crew complaints of respiratory and eye irritation and comments about 'dusty' air. Air filtration is the current control strategy for airborne particles on the ISS, and filtration modeling, performed for engineering and design validation of the air revitalization system in ISS, predicted that PM requirements would be met. However, aerosol monitoring has never been performed on the ISS to verify PM levels. A flight experiment is in preparation which will provide data on particulate matter in ISS ambient air. Particles will be collected with a thermophoretic sampler as well as with passive samplers which will extend the particle size range of sampling. Samples will be returned to Earth for chemical and microscopic analyses, providing the first aerosol data for ISS ambient air.

  13. Near UV Aerosol Group Report

    Science.gov (United States)

    Torres, Omar

    2013-01-01

    2012-13 Report of research on aerosol and cloud remote sensing using UV observations. The document was presented at the 2013 AEROCENTER Annual Meeting held at the GSFC Visitors Center, May 31, 2013. The Organizers of the meeting are posting the talks to the public Aerocentr website, after the meeting.

  14. Aerosol and monsoon climate interactions over Asia: AEROSOL AND MONSOON CLIMATE INTERACTIONS

    Energy Technology Data Exchange (ETDEWEB)

    Li, Zhanqing [State Key Laboratory of Earth Surface Processes and Resource Ecology and College of Global Change and Earth System Science, Beijing Normal University, Beijing China; Department of Atmospheric and Oceanic Science and ESSIC, University of Maryland, College Park Maryland USA; Lau, W. K. -M. [Department of Atmospheric and Oceanic Science and ESSIC, University of Maryland, College Park Maryland USA; Ramanathan, V. [Department of Atmospheric and Climate Sciences, University of California, San Diego California USA; Wu, G. [Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing China; Ding, Y. [National Climate Center, China Meteorological Administration, Beijing China; Manoj, M. G. [Department of Atmospheric and Oceanic Science and ESSIC, University of Maryland, College Park Maryland USA; Liu, J. [Department of Atmospheric and Oceanic Science and ESSIC, University of Maryland, College Park Maryland USA; Qian, Y. [Pacific Northwest National Laboratory, Richland Washington USA; Li, J. [State Key Laboratory of Earth Surface Processes and Resource Ecology and College of Global Change and Earth System Science, Beijing Normal University, Beijing China; Zhou, T. [Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing China; Fan, J. [Pacific Northwest National Laboratory, Richland Washington USA; Rosenfeld, D. [Institute of Earth Sciences, Hebrew University, Jerusalem Israel; Ming, Y. [Geophysical Fluid Dynamic Laboratory, NOAA, Princeton New Jersey USA; Wang, Y. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena California USA; Huang, J. [College of Atmospheric Sciences, Lanzhou University, Lanzhou China; Wang, B. [Department of Atmospheric Sciences, University of Hawaii, Honolulu Hawaii USA; School of Atmospheric Physics, Nanjing University of Information Science and Technology, Nanjing China; Xu, X. [Chinese Academy of Meteorological Sciences, Beijing China; Lee, S. -S. [Department of Atmospheric and Oceanic Science and ESSIC, University of Maryland, College Park Maryland USA; Cribb, M. [Department of Atmospheric and Oceanic Science and ESSIC, University of Maryland, College Park Maryland USA; Zhang, F. [State Key Laboratory of Earth Surface Processes and Resource Ecology and College of Global Change and Earth System Science, Beijing Normal University, Beijing China; Yang, X. [State Key Laboratory of Earth Surface Processes and Resource Ecology and College of Global Change and Earth System Science, Beijing Normal University, Beijing China; Zhao, C. [State Key Laboratory of Earth Surface Processes and Resource Ecology and College of Global Change and Earth System Science, Beijing Normal University, Beijing China; Takemura, T. [Research Institute for Applied Mechanics, Kyushu University, Fukuoka Japan; Wang, K. [State Key Laboratory of Earth Surface Processes and Resource Ecology and College of Global Change and Earth System Science, Beijing Normal University, Beijing China; Xia, X. [Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing China; Yin, Y. [School of Atmospheric Physics, Nanjing University of Information Science and Technology, Nanjing China; Zhang, H. [National Climate Center, China Meteorological Administration, Beijing China; Guo, J. [Chinese Academy of Meteorological Sciences, Beijing China; Zhai, P. M. [Chinese Academy of Meteorological Sciences, Beijing China; Sugimoto, N. [National Institute for Environmental Studies, Tsukuba Japan; Babu, S. S. [Space Physics Laboratory, Vikram Sarabhai Space Centre, Thiruvananthapuram India; Brasseur, G. P. [Max Planck Institute for Meteorology, Hamburg Germany

    2016-11-15

    Asian monsoons and aerosols have been studied extensively which are intertwined in influencing the climate of Asia. This paper provides a comprehensive review of ample studies on Asian aerosol, monsoon and their interactions. The region is the primary source of aerosol emissions of varies species, influenced by distinct weather and climatic regimes. On continental scale, aerosols reduce surface insolation and weaken the land-ocean thermal contrast, thus inhibiting the development of monsoons. Locally, aerosol radiative effects alter the thermodynamic stability and convective potential of the lower atmosphere leading to reduced temperatures, increased atmospheric stability, and weakened wind and atmospheric circulation. The atmospheric thermodynamic state may also be altered by the aerosol serving as cloud condensation nuclei or ice nuclei. Many mechanisms have been put forth regarding how aerosols modulate the amplitude, frequency, intensity, and phase of numerous monsoon climate variables. A wide range of theoretical, observational, and modeling findings on the Asian monsoon, aerosols, and their interactions are synthesized. A new paradigm is proposed on investigating aerosol-monsoon interactions, in which natural aerosols such as desert dust, black carbon from biomass burning, and biogenic aerosols from vegetation are considered integral components of an intrinsic aerosol-monsoon climate system, subject to external forcings of global warming, anthropogenic aerosols, and land use and change. Future research on aerosol-monsoon interactions calls for an integrated approach and international collaborations based on long-term sustained observations, process measurements, and improved models, as well as using observations to constrain model simulations and projections.

  15. Viscosity Prediction of Different Ethylene Glycol/Water Based Nanofluids Using a RBF Neural Network

    National Research Council Canada - National Science Library

    Ningbo Zhao; Zhiming Li

    2017-01-01

    In this study, a radial basis function (RBF) neural network with three-layer feed forward architecture was developed to effectively predict the viscosity ratio of different ethylene glycol/water based nanofluids...

  16. Aerosol Absorption Measurements in MILAGRO.

    Science.gov (United States)

    Gaffney, J. S.; Marley, N. A.; Arnott, W. P.; Paredes-Miranda, L.; Barnard, J. C.

    2007-12-01

    During the month of March 2006, a number of instruments were used to determine the absorption characteristics of aerosols found in the Mexico City Megacity and nearby Valley of Mexico. These measurements were taken as part of the Department of Energy's Megacity Aerosol Experiment - Mexico City (MAX-Mex) that was carried out in collaboration with the Megacity Interactions: Local and Global Research Observations (MILAGRO) campaign. MILAGRO was a joint effort between the DOE, NSF, NASA, and Mexican agencies aimed at understanding the impacts of a megacity on the urban and regional scale. A super-site was operated at the Instituto Mexicano de Petroleo in Mexico City (designated T-0) and at the Universidad Technologica de Tecamac (designated T-1) that was located about 35 km to the north east of the T-0 site in the State of Mexico. A third site was located at a private rancho in the State of Hidalgo approximately another 35 km to the northeast (designated T-2). Aerosol absorption measurements were taken in real time using a number of instruments at the T-0 and T-1 sites. These included a seven wavelength aethalometer, a multi-angle absorption photometer (MAAP), and a photo-acoustic spectrometer. Aerosol absorption was also derived from spectral radiometers including a multi-filter rotating band spectral radiometer (MFRSR). The results clearly indicate that there is significant aerosol absorption by the aerosols in the Mexico City megacity region. The absorption can lead to single scattering albedo reduction leading to values below 0.5 under some circumstances. The absorption is also found to deviate from that expected for a "well-behaved" soot anticipated from diesel engine emissions, i.e. from a simple 1/lambda wavelength dependence for absorption. Indeed, enhanced absorption is seen in the region of 300-450 nm in many cases, particularly in the afternoon periods indicating that secondary organic aerosols are contributing to the aerosol absorption. This is likely due

  17. Preparation of a Novel Water-based Acrylic Multi-Thermal Insulation Coating

    OpenAIRE

    Xiufang YE; Dongchu CHEN; Chang, Menglei; Youtian MO; Wang, Qingxiang

    2017-01-01

    To efficiently improve the thermal insulation effect of coatings, a novel water-based acrylic multi-thermal insulation coating (multi-WATIC) combined with thermal obstruction, echo, and radiation was prepared. The category and ratio of thermal insulation functional fillers are crucial. First, water-based acrylic thermal insulation coating (WATIC) with single thermal insulation functional fillers was prepared, and the thermal insulation property tests were done. Thereafter, a novel multi-WATIC...

  18. Chlorfenapyr: a new insecticide with novel mode of action can control pyrethroid resistant malaria vectors

    OpenAIRE

    Srivastava Harish C; Bhatt Rajendra M; Sharma Poonam; Barik Tapan K; Raghavendra Kamaraju; Sreehari Uragayala; Dash Aditya P

    2011-01-01

    Abstract Background Malaria vectors have acquired widespread resistance to many of the currently used insecticides, including synthetic pyrethroids. Hence, there is an urgent need to develop alternative insecticides for effective management of insecticide resistance in malaria vectors. In the present study, chlorfenapyr was evaluated against Anopheles culicifacies and Anopheles stephensi for its possible use in vector control. Methods Efficacy of chlorfenapyr against An. culicifacies and An. ...

  19. Mechanism of action of sodium channel blocker insecticides (SCBIs) on insect sodium channels

    OpenAIRE

    Silver, Kristopher S.; Song, Weizhong; NOMURA, Yoshiko; Salgado, Vincent L.; Dong, Ke

    2009-01-01

    Sodium channel blocker insecticides (SCBIs) are a relatively new class of insecticides, with a mechanism of action different from those of other classes of insecticides that target voltage-gated sodium channels. These compounds have no effect at hyperpolarized membrane potentials, but cause a voltage-dependent, nearly irreversible block as the membrane potential is depolarized. The mechanism of action of SCBIs is similar to that of local anesthetics (LAs), class I anticonvulsants and class I ...

  20. Specificity determinants for Cry insecticidal proteins: insights from their mode of action

    OpenAIRE

    Jurat-Fuentes, Juan Luis; Crickmore, Neil

    2017-01-01

    Insecticidal proteins from the bacterium Bacillus thuringiensis (Bt) are used as active components of biopesticides and as plant incorporated protectants in transgenic crops. One of the most relevant attributes of these Bt protein-based insecticidal technologies is their high specificity, which assures lack of detrimental effects on non-target insects, vertebrates and the environment. The identification of specificity determinants in Bt insecticidal proteins could guide risk assessment for no...

  1. A Standardized Lepidopteran Bioassay to Investigate the Bioactivity of Insecticidal Proteins Produced in Transgenic Crops.

    Science.gov (United States)

    Graser, Gerson; Walters, Frederick S

    2016-01-01

    Insecticidal bioassays are the only reliable method to investigate the biological activity of an insecticidal protein and therefore provide an essential toolkit for the characterization and potency determination of these proteins. Here we present a standardized method for a lepidopteran larval bioassay, which is optimized to specifically estimate activity of insecticidal proteins produced in transgenic plants. The treatment can be either applied to the surface of the artificial diet, or blended into the diet.

  2. Novel water-based antiseptic lotion demonstrates rapid, broad-spectrum kill compared with alcohol antiseptic.

    Science.gov (United States)

    Czerwinski, Steven E; Cozean, Jesse; Cozean, Colette

    2014-01-01

    A novel alcohol-based antiseptic and a novel water-based antiseptic lotion, both with a synergistic combination of antimicrobial ingredients containing 0.2% benzethonium chloride, were evaluated using the standard time-kill method against 25 FDA-specified challenge microorganisms. The purpose of the testing was to determine whether a non-alcohol product could have equivalent rapid and broad-spectrum kill to a traditional alcohol sanitizer. Both the alcohol- and water-based products showed rapid and broad-spectrum antimicrobial activity. The average 15-s kill was 99.999% of the challenge organism for the alcohol-based antiseptic and 99.971% for the water-based antiseptic. The alcohol-based product demonstrated 100% of peak efficacy (60s) within the first 15s, whereas the water-based product showed 99.97%. The novel alcohol-based antiseptic reduced concentrations of 100% of organisms by 99.999%, whereas the water-based antiseptic lotion showed the same reduction for 96% of organisms. A novel water-based antiseptic product demonstrated equivalent rapid, broad-spectrum antimicrobial activity to an alcohol-based sanitizer and provided additional benefits of reduced irritation, persistent effect, and greater efficacy against common viruses. The combination of rapid, broad-spectrum immediate kill and persistent efficacy against pathogens may have significant clinical benefit in limiting the spread of disease. Copyright © 2014 King Saud Bin Abdulaziz University for Health Sciences. Published by Elsevier Ltd. All rights reserved.

  3. Impact and Selectivity of Insecticides to Predators and Parasitoids

    Directory of Open Access Journals (Sweden)

    Flávio Lemes Fernandes

    2010-04-01

    Full Text Available Problems with the use of insecticides has brought losses, such as, negative impact on natural enemies. When these beneficial insects reduce cause the eruption of pests and resurgence it’s more common. Thus principles of conservation these arthropods are extremely important in the biological natural control of pests, so that these enemies may present a high performance. Because of the negative impacts caused by insecticides on agriculture and their harmful effects on natural enemies, the objective of this article is to approach two important subjects, divided into three parts. Part I relates to the description of the main crop pests and their natural enemies; Part II involves the impact of insecticides on predators and parasitoids and Part III focuses on the selectivity of several groups of insecticides to natural enemies. Before spraying insecticides, it is necessary to choose a product that is efficient to pests and selective to natural enemies. So, it is indispensable to identify correctly the groups and species of natural enemies, since insecticides have an impact on their survival, growth, development, reproduction (sexual ratio, fecundity, longevity and fertility, and behavior (motility, orientation, feeding, oviposition and learning of insects. The mechanisms of toxicity and selectivity of insecticides are related to the properties of higher or lower solubility and molecular weight. Besides, characteristics of the cuticular composition of the integument of natural enemies are extremely important in the selectivity of a product or the tolerance of a certain predator or parasitoid to this molecules.Impacto e Seletividade de Inseticidas para Predadores e ParasitóidesResumo.Dentre os problemas advindos do uso de inseticidas, a destruição de inimigos naturais é fator importante. Estes insetos benéficos podem reduzir problemas de erupção de pragas secundárias, ressurgência de pragas e manter a praga abaixo do nível de dano econ

  4. Does multigenerational exposure to hormetic concentrations of imidacloprid precondition aphids for increased insecticide tolerance?

    Science.gov (United States)

    Rix, Rachel R; Cutler, G Christopher

    2018-02-01

    Hormetic preconditioning, whereby exposure to mild stress primes an organism to better tolerate subsequent stress, is well documented. It is unknown if exposure to hormetic concentrations of insecticide can trans-generationally prime insects to better tolerate insecticide exposure, or whether exposure to hormetic concentrations of insecticide can induce mutations in genes responsible for insecticide resistance. Using the aphid Myzus persicae (Sulzer) and the insecticide imidacloprid as a model, we examined if exposure to mildly toxic and hormetic concentrations of imidacloprid reduced aphid susceptibility to insecticides across four generations, and whether such exposures induced mutations in the imidacloprid binding site in post-synaptic nicotinic acetylcholine receptors. Chronic, multigenerational exposure of aphids to hormetic concentrations of imidacloprid primed offspring to better survive exposure to certain concentrations of imidacloprid, but not exposure to spirotetramat, an insecticide with a different mode of action. Exposure to hormetic and mildly toxic concentrations of imidacloprid did not result in mutations in any of the examined nicotinic acetylcholine receptor subunits. Our findings demonstrate that exposure to hormetic concentrations of insecticide can prime insects to better withstand subsequent chemical stress, but this is dependent upon the insecticide exposure scenario, and may be subtle over generations. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  5. Degradation of Organophosphorus and Pyrethroid Insecticides in Beverages: Implications for Risk Assessment

    Directory of Open Access Journals (Sweden)

    Samantha A. Radford

    2018-02-01

    Full Text Available Since urinary insecticide metabolites are commonly used as biomarkers of exposure, it is important that we quantify whether insecticides degrade in food and beverages in order to better perform risk assessment. This study was designed to quantify degradation of organophosphorus and pyrethroid insecticides in beverages. Purified water, white grape juice, orange juice, and red wine were fortified with 500 ng/mL diazinon, malathion, chlorpyrifos, permethrin, cyfluthrin, cypermethrin, and deltamethrin, and aliquots were extracted several times over a 15-day storage period at 2.5 °C. Overall, statistically significant loss of at least one insecticide was observed in each matrix, and at least five out of seven insecticides demonstrated a statistically significant loss in all matrices except orange juice. An investigation of an alternative mechanism of insecticide loss—adsorption onto the glass surface of the storage jars—was carried out, which indicated that this mechanism of loss is insignificant. Results of this work suggest that insecticides degrade in these beverages, and this degradation may lead to pre-existing insecticide degradates in the beverages, suggesting that caution should be exercised when using urinary insecticide metabolites to assess exposure and risk.

  6. Current Perspectives on Plague Vector Control in Madagascar: Susceptibility Status of Xenopsylla cheopis to 12 Insecticides.

    Directory of Open Access Journals (Sweden)

    Adélaïde Miarinjara

    2016-02-01

    Full Text Available Plague is a rodent disease transmissible to humans by infected flea bites, and Madagascar is one of the countries with the highest plague incidence in the world. This study reports the susceptibility of the main plague vector Xenopsylla cheopis to 12 different insecticides belonging to 4 insecticide families (carbamates, organophosphates, pyrethroids and organochlorines. Eight populations from different geographical regions of Madagascar previously resistant to deltamethrin were tested with a World Health Organization standard bioassay. Insecticide susceptibility varied amongst populations, but all of them were resistant to six insecticides belonging to pyrethroid and carbamate insecticides (alphacypermethrin, lambdacyhalothrin, etofenprox, deltamethrin, bendiocarb and propoxur. Only one insecticide (dieldrin was an efficient pulicide for all flea populations. Cross resistances were suspected. This study proposes at least three alternative insecticides (malathion, fenitrothion and cyfluthrin to replace deltamethrin during plague epidemic responses, but the most efficient insecticide may be different for each population studied. We highlight the importance of continuous insecticide susceptibility surveillance in the areas of high plague risk in Madagascar.

  7. Protective effect and economic impact of insecticide application methods on barley

    Directory of Open Access Journals (Sweden)

    Alfred Stoetzer

    2014-03-01

    Full Text Available The objective of this work was to evaluate the protective effect of different forms of insecticide application on the transmission of yellow dwarf disease in barley cultivars, as well as to determine the production costs and the net profit of these managements. The experiments were carried out during 2011 and 2012 growing seasons, using the following managements at main plots: T1, seed treatment with insecticide (ST + insecticide on shoots at 15-day interval; T2, just ST; T3, insecticide applied on shoots, when aphid control level (CL was reached; T4, without insecticide; and T5, ST + insecticide on shoots when CL was reached. Different barley cultivars - BRS Cauê, BRS Brau and MN 6021 - were arranged in the subplots. Insecticides lambda cyhalothrin (pyrethroid and thiamethoxam (neonicotinoid were used. There were differences on yellow dwarf disease index in both seasons for the different treatments, while damage to grain yield was influenced by year and aphid population. Production costs and net profit were different among treatments. Seed treatment with insecticide is sufficient to reduce the transmission of yellow dwarf disease in years with low aphid population pressure, while in years with larger populations, the application of insecticide on shoots is also required.

  8. Current Perspectives on Plague Vector Control in Madagascar: Susceptibility Status of Xenopsylla cheopis to 12 Insecticides.

    Science.gov (United States)

    Miarinjara, Adélaïde; Boyer, Sébastien

    2016-02-01

    Plague is a rodent disease transmissible to humans by infected flea bites, and Madagascar is one of the countries with the highest plague incidence in the world. This study reports the susceptibility of the main plague vector Xenopsylla cheopis to 12 different insecticides belonging to 4 insecticide families (carbamates, organophosphates, pyrethroids and organochlorines). Eight populations from different geographical regions of Madagascar previously resistant to deltamethrin were tested with a World Health Organization standard bioassay. Insecticide susceptibility varied amongst populations, but all of them were resistant to six insecticides belonging to pyrethroid and carbamate insecticides (alphacypermethrin, lambdacyhalothrin, etofenprox, deltamethrin, bendiocarb and propoxur). Only one insecticide (dieldrin) was an efficient pulicide for all flea populations. Cross resistances were suspected. This study proposes at least three alternative insecticides (malathion, fenitrothion and cyfluthrin) to replace deltamethrin during plague epidemic responses, but the most efficient insecticide may be different for each population studied. We highlight the importance of continuous insecticide susceptibility surveillance in the areas of high plague risk in Madagascar.

  9. Effects of persistent insecticides on beneficial soil arthropod in conventional fields compared to organic fields, puducherry.

    Science.gov (United States)

    Anbarashan, Padmavathy; Gopalswamy, Poyyamoli

    2013-07-15

    The usage of synthetic fertilizers/insecticides in conventional farming has dramatically increased over the past decades. The aim of the study was to compare the effects of bio-pesticides and insecticides/pesticides on selected beneficial non targeted arthropods. Orders Collembola, Arachinida/Opiliones, Oribatida and Coleoptera were the main groups of arthropods found in the organic fields and Coleoptera, Oribatida, Gamasida and Collembola in conventional fields. Pesticides/insecticides had a significant effect on non-targeted arthropods order- Collembola, Arachinida/Opiliones, Hymenoptera and Thysonoptera were suppressed after pesticides/insecticides spraying. Bio-insecticides in organic fields had a non-significant effect on non targeted species and they started to increase in abundance after 7 days of spraying, whereas insecticide treatment in conventional fields had a significant long-term effect on non targeted arthropods and short term effect on pests/insects, it started to increase after 21 days of the spraying. These results indicate that insecticide treatment kept non targeted arthropods at low abundance. In conclusion, organic farming does not significantly affected the beneficial-non targeted arthropods biodiversity, whereas preventive insecticide application in conventional fields had significant negative effects on beneficial non targeted arthropods. Therefore, conventional farmers should restrict insecticide applications, unless pest densities reach the thresholds and more desirably can switch to organic farming practices.

  10. Aerosol and monsoon climate interactions over Asia

    Science.gov (United States)

    Li, Zhanqing; Lau, W. K.-M.; Ramanathan, V.; Wu, G.; Ding, Y.; Manoj, M. G.; Liu, J.; Qian, Y.; Li, J.; Zhou, T.; Fan, J.; Rosenfeld, D.; Ming, Y.; Wang, Y.; Huang, J.; Wang, B.; Xu, X.; Lee, S.-S.; Cribb, M.; Zhang, F.; Yang, X.; Zhao, C.; Takemura, T.; Wang, K.; Xia, X.; Yin, Y.; Zhang, H.; Guo, J.; Zhai, P. M.; Sugimoto, N.; Babu, S. S.; Brasseur, G. P.

    2016-12-01

    The increasing severity of droughts/floods and worsening air quality from increasing aerosols in Asia monsoon regions are the two gravest threats facing over 60% of the world population living in Asian monsoon regions. These dual threats have fueled a large body of research in the last decade on the roles of aerosols in impacting Asian monsoon weather and climate. This paper provides a comprehensive review of studies on Asian aerosols, monsoons, and their interactions. The Asian monsoon region is a primary source of emissions of diverse species of aerosols from both anthropogenic and natural origins. The distributions of aerosol loading are strongly influenced by distinct weather and climatic regimes, which are, in turn, modulated by aerosol effects. On a continental scale, aerosols reduce surface insolation and weaken the land-ocean thermal contrast, thus inhibiting the development of monsoons. Locally, aerosol radiative effects alter the thermodynamic stability and convective potential of the lower atmosphere leading to reduced temperatures, increased atmospheric stability, and weakened wind and atmospheric circulations. The atmospheric thermodynamic state, which determines the formation of clouds, convection, and precipitation, may also be altered by aerosols serving as cloud condensation nuclei or ice nuclei. Absorbing aerosols such as black carbon and desert dust in Asian monsoon regions may also induce dynamical feedback processes, leading to a strengthening of the early monsoon and affecting the subsequent evolution of the monsoon. Many mechanisms have been put forth regarding how aerosols modulate the amplitude, frequency, intensity, and phase of different monsoon climate variables. A wide range of theoretical, observational, and modeling findings on the Asian monsoon, aerosols, and their interactions are synthesized. A new paradigm is proposed on investigating aerosol-monsoon interactions, in which natural aerosols such as desert dust, black carbon from

  11. Insecticide Resistance and Metabolic Mechanisms Involved in Larval and Adult Stages of Aedes aegypti Insecticide-Resistant Reference Strains from Cuba.

    Science.gov (United States)

    Bisset, Juan Andrés; Rodríguez, María Magdalena; French, Leydis; Severson, David W; Gutiérrez, Gladys; Hurtado, Daymi; Fuentes, Ilario

    2014-12-01

    Studies were conducted to compare levels of insecticide resistance and to determine the metabolic resistance mechanisms in larval and adult stages of Aedes aegypti from Cuba. Three insecticide-resistant reference strains of Ae. aegypti from Cuba were examined. These strains were derived from a Santiago de Cuba strain isolated in 1997; it was previously subjected to a strong selection for resistance to temephos (SAN-F6), deltamethrin (SAN-F12), and propoxur (SAN-F13) and routinely maintained in the laboratory under selection pressure up to the present time, when the study was carried out. In addition, an insecticide-susceptible strain was used for comparison. The insecticide resistance in larvae and adults was determined using standard World Health Organization methodologies. Insecticide resistance mechanisms were determined by biochemical assays. The esterases (α EST and β EST) and mixed function oxidase (MFO) activities were significantly higher in adults than in the larvae of the three resistant strains studied. The association of resistance level with the biochemical mechanism for each insecticide was established for each stage. The observed differences between larval and adult stages of Ae. aegypti in their levels of insecticide resistance and the biochemical mechanisms involved should be included as part of monitoring and surveillance activities in Ae. aegypti vector control programs.

  12. Toxicity of atmospheric aerosols on marine phytoplankton.

    Science.gov (United States)

    Paytan, Adina; Mackey, Katherine R M; Chen, Ying; Lima, Ivan D; Doney, Scott C; Mahowald, Natalie; Labiosa, Rochelle; Post, Anton F

    2009-03-24

    Atmospheric aerosol deposition is an important source of nutrients and trace metals to the open ocean that can enhance ocean productivity and carbon sequestration and thus influence atmospheric carbon dioxide concentrations and climate. Using aerosol samples from different back trajectories in incubation experiments with natural communities, we demonstrate that the response of phytoplankton growth to aerosol additions depends on specific components in aerosols and differs across phytoplankton species. Aerosol additions enhanced growth by releasing nitrogen and phosphorus, but not all aerosols stimulated growth. Toxic effects were observed with some aerosols, where the toxicity affected picoeukaryotes and Synechococcus but not Prochlorococcus. We suggest that the toxicity could be due to high copper concentrations in these aerosols and support this by laboratory copper toxicity tests preformed with Synechococcus cultures. However, it is possible that other elements present in the aerosols or unknown synergistic effects between these elements could have also contributed to the toxic effect. Anthropogenic emissions are increasing atmospheric copper deposition sharply, and based on coupled atmosphere-ocean calculations, we show that this deposition can potentially alter patterns of marine primary production and community structure in high aerosol, low chlorophyll areas, particularly in the Bay of Bengal and downwind of South and East Asia.

  13. Aerosol optical absorption measurements with photoacoustic spectroscopy

    Science.gov (United States)

    Liu, Kun; Wang, Lei; Liu, Qiang; Wang, Guishi; Tan, Tu; Zhang, Weijun; Chen, Weidong; Gao, Xiaoming

    2015-04-01

    Many parameters related to radiative forcing in climate research are known only with large uncertainties. And one of the largest uncertainties in global radiative forcing is the contribution from aerosols. Aerosols can scatter or absorb the electromagnetic radiation, thus may have negative or positive effects on the radiative forcing of the atmosphere, respectively [1]. And the magnitude of the effect is directly related to the quantity of light absorbed by aerosols [2,3]. Thus, sensitivity and precision measurement of aerosol optical absorption is crucial for climate research. Photoacoustic spectroscopy (PAS) is commonly recognized as one of the best candidates to measure the light absorption of aerosols [4]. A PAS based sensor for aerosol optical absorption measurement was developed. A 532 nm semiconductor laser with an effective power of 160 mW was used as a light source of the PAS sensor. The PAS sensor was calibrated by using known concentration NO2. The minimum detectable optical absorption coefficient (OAC) of aerosol was determined to be 1 Mm-1. 24 hours continues measurement of OAC of aerosol in the ambient air was carried out. And a novel three wavelength PAS aerosol OAC sensor is in development for analysis of aerosol wavelength-dependent absorption Angstrom coefficient. Reference [1] U. Lohmann and J. Feichter, Global indirect aerosol effects: a review, Atmos. Chem. Phys. 5, 715-737 (2005) [2] M. Z. Jacobson, Strong radiative heating due to the mixing state of black carbon in atmospheric aerosols, Nature 409, 695-697 (2001) [3] V. Ramanathan and G. Carmichae, Global and regional climate changes due to black carbon, nature geoscience 1, 221-227 (2008) [4] W.P Arnott, H. Moosmuller, C. F. Rogers, T. Jin, and R. Bruch, Photoacoustic spectrometer for measuring light absorption by aerosol: instrument description. Atmos. Environ. 33, 2845-2852 (1999).

  14. On the implications of aerosol liquid water and phase separation for organic aerosol mass

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset contains data presented in the figures of the paper "On the implications of aerosol liquid water and phase separation for organic aerosol mass"...

  15. Beschrijving van een verdampings-condensatie aerosol generator voor de produktie van submicron aerosol

    NARCIS (Netherlands)

    Feijt; A.*; Meulen; A.van der

    1985-01-01

    Dit rapport is een handleiding voor een bedrijfszeker, routinematig gebruik van een zgn. Evaporation-Condensation aerosol Conditioner. Met deze aerosol generatie apparatuur kunnen op stabiele, reproduceerbare manier zeer hoge concentraties (tot 1 miljoen deeltjes per cc) monodispers submicron

  16. Gut Microbiota Mediate Insecticide Resistance in the Diamondback Moth, Plutella xylostella (L.

    Directory of Open Access Journals (Sweden)

    Xiaofeng Xia

    2018-01-01

    Full Text Available The development of insecticide resistance in insect pests is a worldwide concern and elucidating the underlying mechanisms is critical for effective crop protection. Recent studies have indicated potential links between insect gut microbiota and insecticide resistance and these may apply to the diamondback moth, Plutella xylostella (L., a globally and economically important pest of cruciferous crops. We isolated Enterococcus sp. (Firmicutes, Enterobacter sp. (Proteobacteria, and Serratia sp. (Proteobacteria from the guts of P. xylostella and analyzed the effects on, and underlying mechanisms of insecticide resistance. Enterococcus sp. enhanced resistance to the widely used insecticide, chlorpyrifos, in P. xylostella, while in contrast, Serratia sp. decreased resistance and Enterobacter sp. and all strains of heat-killed bacteria had no effect. Importantly, the direct degradation of chlorpyrifos in vitro was consistent among the three strains of bacteria. We found that Enterococcus sp., vitamin C, and acetylsalicylic acid enhanced insecticide resistance in P. xylostella and had similar effects on expression of P. xylostella antimicrobial peptides. Expression of cecropin was down-regulated by the two compounds, while gloverin was up-regulated. Bacteria that were not associated with insecticide resistance induced contrasting gene expression profiles to Enterococcus sp. and the compounds. Our studies confirmed that gut bacteria play an important role in P. xylostella insecticide resistance, but the main mechanism is not direct detoxification of insecticides by gut bacteria. We also suggest that the influence of gut bacteria on insecticide resistance may depend on effects on the immune system. Our work advances understanding of the evolution of insecticide resistance in this key pest and highlights directions for research into insecticide resistance in other insect pest species.

  17. Highly Resolved Paleoclimatic Aerosol Records

    DEFF Research Database (Denmark)

    Kettner, Ernesto

    with frequently changing signs are preserved. Therefore, these aerosol records can be used for dating by annual layer counting. However, with increasing depth the annual layer thicknesses decreases due to pressure and ice flow and accurate dating is possible only as long as the rapid variations can be resolved...... soluble aerosols can be analysed for concentration changes only, insoluble aeolian dust can reveal additional information on its atmospheric residence time via changes in the mean grain sizes. Volumes of particulate matter in ice cores are most reliably determined with Coulter counters, but since...... a Coulter counter performs measurements on discrete samples, it cannot be connected to a CFA system. Attenuation sensors, on the other hand, can be integrated into a CFA set-up, but are known to yield poor dust size records. The dilemma between high quality sizing and high depth resolution was found...

  18. OSIRIS Measurements of Stratospheric Aerosol

    Science.gov (United States)

    Bourassa, Adam; Degenstein, Doug; Llewellyn, Edward J.

    The Canadian built OSIRIS instrument, currently in operation on the Swedish Odin satel-lite, has collected over nine years of limb radiance spectra at UV, visible and near infrared wavelengths. These measurements are used to retrieve vertical profiles of stratospheric aerosol extinction. The relatively high horizontal sampling of the limb scatter technique, which pro-vides nearly global coverage, combined with the almost decade long duration of the mission, makes this an increasingly useful and important data set. This work shows comparisons with coincident measurements and highlights the features of the OSIRIS stratospheric aerosol data product including the potential for studies of long term trends, stratospheric dynamics, and the effect of recent volcanic eruptions on climate.

  19. Biogeochemical Recycling on Aerosol Particles

    Science.gov (United States)

    Arimoto, R.; Stewart, B.; Khaing, H.; Tatro, D. P.

    2006-12-01

    Trace elements are recycled on sea-salt particles that are produced and later re-deposited in the surface ocean. This recycling process involves aluminum, iron, and other elements commonly associated with mineral dust. Non-crustal Al can amount to as much as ~ 30% of the total aerosol Al at Bermuda, but this occurs only during a few months of the year when the dust concentrations and deposition rates are low. Simple model calculations suggest that ~15 to 20% of the total Al dry deposition during December and January can be attributed to recycled sea salt, but when dust concentrations are higher, recycling accounts for only ~ 1% of the Al dry deposition. Non-crustal/non-sea salt (NC/NSS) sources account for > 70% of the aerosol Sb, Se, V, and Zn, but differences in the dry deposition velocities for particles of different sizes are such that the amount of Sb and Se recycled on sea spray approaches or exceeds their new inputs to the open ocean from dust and the NC/NSS sources. More recently, recycling on aerosol particles has been found to occur in other environments, including the deserts in the southwestern USA. In this case, the recycling of radionuclides released during nuclear weapons tests many years ago occurs via the resuspension of contaminated soil particles. Studies conducted near Carlsbad, NM have shown that the temporal variability in ^{239,240}Pu and ^{241}Am activities tracks that of Al, a mineral dust indictor, in aerosol samples. Analyses of soil samples from various sites have shown that plutonium is released from the particles by chemical procedures developed for removing iron oxides from mineral particles; this implies that the dust/plutonium relationship is mediated by iron oxides.

  20. Ice-condenser aerosol tests

    Energy Technology Data Exchange (ETDEWEB)

    Ligotke, M.W.; Eschbach, E.J.; Winegardner, W.K. (Pacific Northwest Lab., Richland, WA (United States))

    1991-09-01

    This report presents the results of an experimental investigation of aerosol particle transport and capture using a full-scale height and reduced-scale cross section test facility based on the design of the ice compartment of a pressurized water reactor (PWR) ice-condenser containment system. Results of 38 tests included thermal-hydraulic as well as aerosol particle data. Particle retention in the test section was greatly influenced by thermal-hydraulic and aerosol test parameters. Test-average decontamination factor (DF) ranged between 1.0 and 36 (retentions between {approximately}0 and 97.2%). The measured test-average particle retentions for tests without and with ice and steam ranged between DF = 1.0 and 2.2 and DF = 2.4 and 36, respectively. In order to apparent importance, parameters that caused particle retention in the test section in the presence of ice were steam mole fraction (SMF), noncondensible gas flow rate (residence time), particle solubility, and inlet particle size. Ice-basket section noncondensible flows greater than 0.1 m{sup 3}/s resulted in stable thermal stratification whereas flows less than 0.1 m{sup 3}/s resulted in thermal behavior termed meandering with frequent temperature crossovers between flow channels. 10 refs., 66 figs., 16 tabs.

  1. Characterization of Aerosols Containing Microcystin

    Directory of Open Access Journals (Sweden)

    Lorraine C. Backer

    2007-10-01

    Full Text Available Toxic blooms of cyanobacteria are ubiquitous in both freshwater and brackishwater sources throughout the world. One class of cyanobacterial toxins, calledmicrocystins, is cyclic peptides. In addition to ingestion and dermal, inhalation is a likelyroute of human exposure. A significant increase in reporting of minor symptoms,particularly respiratory symptoms was associated with exposure to higher levels ofcyanobacteria during recreational activities. Algae cells, bacteria, and waterborne toxinscan be aerosolized by a bubble-bursting process with a wind-driven white-capped wavemechanism. The purposes of this study were to: evaluate sampling and analysis techniquesfor microcystin aerosol, produce aerosol droplets containing microcystin in the laboratory,and deploy the sampling instruments in field studies. A high-volume impactor and an IOMfilter sampler were tried first in the laboratory to collect droplets containing microcystins.Samples were extracted and analyzed for microcystin using an ELISA method. Thelaboratory study showed that cyanotoxins in water could be transferred to air via a bubble-bursting process. The droplets containing microcystins showed a bimodal size distributionwith the mass median aerodynamic diameter (MMAD of 1.4 and 27.8 μm. The samplingand analysis methods were successfully used in a pilot field study to measure microcystinaerosol in situ.

  2. Nebulizer delivery of micafungin aerosols.

    Science.gov (United States)

    Alexander, Barbara D; Winkler, Thomas P; Shi, Shuai; Ashley, Elizabeth S Dodds; Hickey, Anthony J

    2011-01-01

    To determine the optimal nebulization system for aerosolizing micafungin and to further assess the physiochemical properties of aerosolized micafungin. In vitro experiment. University research center. NEBULIZERS: Pari LC Star, Hudson Updraft, Small Volume Nebulizer, and Aeroclipse II. Using a commercially available cascade impactor, the four nebulizers were tested for their ability to deliver micafungin to the lungs. Mass median aerodynamic diameter (MMAD) and fine particle fraction (FPF) percent less than 3.3 μm (FPF(3.3)) and less than 5.8 μm (FPF(5.8)) were determined during two sampling periods for each of three trials of all nebulizers. The mean ± standard error of the mean MMAD for the nebulizers ranged from 1.93 ± 0.09 to 2.49 ± 0.25 μm; FPF(3.3) and FPF(5.8) were approximately 50% and 90%, respectively, for all nebulizers. Although all nebulizers appeared acceptable to deliver micafungin to the lungs, the Pari LC Star had the smallest MMAD and highest FPF(3.3) and FPF(5.8). These properties of the Pari LC Star should result in greater delivery of the aerosol to the lungs. Additional research on pulmonary delivery and clinical tolerability is warranted.

  3. Insecticide resistance and the future of malaria control in Zambia.

    Science.gov (United States)

    Chanda, Emmanuel; Hemingway, Janet; Kleinschmidt, Immo; Rehman, Andrea M; Ramdeen, Varsha; Phiri, Faustina N; Coetzer, Sarel; Mthembu, David; Shinondo, Cecilia J; Chizema-Kawesha, Elizabeth; Kamuliwo, Mulakwa; Mukonka, Victor; Baboo, Kumar S; Coleman, Michael

    2011-01-01

    In line with the Global trend to improve malaria control efforts a major campaign of insecticide treated net distribution was initiated in 1999 and indoor residual spraying with DDT or pyrethroids was reintroduced in 2000 in Zambia. In 2006, these efforts were strengthened by the President's Malaria Initiative. This manuscript reports on the monitoring and evaluation of these activities and the potential impact of emerging insecticide resistance on disease transmission. Mosquitoes were captured daily through a series of 108 window exit traps located at 18 sentinel sites. Specimens were identified to species and analyzed for sporozoites. Adult Anopheles mosquitoes were collected resting indoors and larva collected in breeding sites were reared to F1 and F0 generations in the lab and tested for insecticide resistance following the standard WHO susceptibility assay protocol. Annual cross sectional household parasite surveys were carried out to monitor the impact of the control programme on prevalence of Plasmodium falciparum in children aged 1 to 14 years. A total of 619 Anopheles gambiae s.l. and 228 Anopheles funestus s.l. were captured from window exit traps throughout the period, of which 203 were An. gambiae malaria vectors and 14 An. funestus s.s.. In 2010 resistance to DDT and the pyrethroids deltamethrin, lambda-cyhalothrin and permethrin was detected in both An. gambiae s.s. and An. funestus s.s.. No sporozoites were detected in either species. Prevalence of P. falciparum in the sentinel sites remained below 10% throughout the study period. Both An. gambiae s.s. and An. funestus s.s. were controlled effectively with the ITN and IRS programme in Zambia, maintaining a reduced disease transmission and burden. However, the discovery of DDT and pyrethroid resistance in the country threatens the sustainability of the vector control programme.

  4. Insecticide resistance and the future of malaria control in Zambia.

    Directory of Open Access Journals (Sweden)

    Emmanuel Chanda

    Full Text Available In line with the Global trend to improve malaria control efforts a major campaign of insecticide treated net distribution was initiated in 1999 and indoor residual spraying with DDT or pyrethroids was reintroduced in 2000 in Zambia. In 2006, these efforts were strengthened by the President's Malaria Initiative. This manuscript reports on the monitoring and evaluation of these activities and the potential impact of emerging insecticide resistance on disease transmission.Mosquitoes were captured daily through a series of 108 window exit traps located at 18 sentinel sites. Specimens were identified to species and analyzed for sporozoites. Adult Anopheles mosquitoes were collected resting indoors and larva collected in breeding sites were reared to F1 and F0 generations in the lab and tested for insecticide resistance following the standard WHO susceptibility assay protocol. Annual cross sectional household parasite surveys were carried out to monitor the impact of the control programme on prevalence of Plasmodium falciparum in children aged 1 to 14 years.A total of 619 Anopheles gambiae s.l. and 228 Anopheles funestus s.l. were captured from window exit traps throughout the period, of which 203 were An. gambiae malaria vectors and 14 An. funestus s.s.. In 2010 resistance to DDT and the pyrethroids deltamethrin, lambda-cyhalothrin and permethrin was detected in both An. gambiae s.s. and An. funestus s.s.. No sporozoites were detected in either species. Prevalence of P. falciparum in the sentinel sites remained below 10% throughout the study period.Both An. gambiae s.s. and An. funestus s.s. were controlled effectively with the ITN and IRS programme in Zambia, maintaining a reduced disease transmission and burden. However, the discovery of DDT and pyrethroid resistance in the country threatens the sustainability of the vector control programme.

  5. Aerosol from Organic Nitrogen in the Southeast United States

    Science.gov (United States)

    Biogenic volatile organic compounds (BVOCs) contribute significantly to organic aerosol in the southeastern United States. During the Southern Oxidant and Aerosol Study (SOAS), a portion of ambient organic aerosol was attributed to isoprene oxidation and organic nitrogen from BVO...

  6. AEROSOL INDUSTRY SUCCESS IN REDUCING CFC PROPELLANT USAGE

    Science.gov (United States)

    Part I of this report discusses the U.S. aerosol industry's experience in converting from chlorofluorocarbon (CFC) propellants to alternative aerosol formulations. Detailed examples of non-CFC formulations are provided for 28 categories of aerosol products. ydrocarbon propellants...

  7. Synergy in efficacy of fungal entomopathogens and permethrin against West African insecticide-resistant Anopheles gambiae mosquitoes

    NARCIS (Netherlands)

    Farenhorst, Marit; Knols, Bart G. J.; Thomas, Matthew B.; Howard, Annabel F. V.; Takken, Willem; Rowland, Mark; N'Guessan, Raphael

    2010-01-01

    Increasing incidences of insecticide resistance in malaria vectors are threatening the sustainable use of contemporary chemical vector control measures. Fungal entomopathogens provide a possible additional tool for the control of insecticide-resistant malaria mosquitoes. This study investigated the

  8. Synergy in Efficacy of Fungal Entomopathogens and Permethrin against West African Insecticide-Resistant Anopheles gambiae Mosquitoes

    NARCIS (Netherlands)

    Farenhorst, M.; Knols, B.G.J.; Thomas, M.B.; Howard, A.F.V.; Takken, W.; Rowland, M.; N'Guessan, R.

    2010-01-01

    Background: Increasing incidences of insecticide resistance in malaria vectors are threatening the sustainable use of contemporary chemical vector control measures. Fungal entomopathogens provide a possible additional tool for the control of insecticide-resistant malaria mosquitoes. This study

  9. Synergy in efficacy of fungal entomopathogens and permethrin against West African insecticide-resistant Anopheles gambiae mosquitoes

    NARCIS (Netherlands)

    Farenhorst, M.; Knols, B.G.J.; Thomas, M.B.; Howard, A.F.V.; Takken, W.; Rowland, M.; N'Guessan, R.

    2010-01-01

    Background Increasing incidences of insecticide resistance in malaria vectors are threatening the sustainable use of contemporary chemical vector control measures. Fungal entomopathogens provide a possible additional tool for the control of insecticide-resistant malaria mosquitoes. This study

  10. Topics in current aerosol research (part2)

    CERN Document Server

    Hidy, G M

    1972-01-01

    Topics in Current Aerosol Research, Part 2 contains some selected articles in the field of aerosol study. The chosen topics deal extensively with the theory of diffusiophoresis and thermophoresis. Also covered in the book is the mathematical treatment of integrodifferential equations originating from the theory of aerosol coagulation. The book is the third volume of the series entitled International Reviews in Aerosol Physics and Chemistry. The text offers significant understanding of the methods employed to develop a theory for thermophoretic and diffusiophoretic forces acting on spheres in t

  11. Electronic cigarette solutions and resultant aerosol profiles.

    Science.gov (United States)

    Herrington, Jason S; Myers, Colton

    2015-10-30

    Electronic cigarettes (e-cigarettes) are growing in popularity exponentially. Despite their ever-growing acceptance, their aerosol has not been fully characterized. The current study focused on evaluating e-cigarette solutions and their resultant aerosol for potential differences. A simple sampling device was developed to draw e-cigarette aerosol into a multi-sorbent thermal desorption (TD) tube, which was then thermally extracted and analyzed via a gas chromatography (GC) mass spectrometry (GC-MS) method. This novel application provided detectable levels of over one hundred fifteen volatile organic compounds (VOCs) and semivolatile organic compounds (SVOCs) from a single 40mL puff. The aerosol profiles from four commercially available e-cigarettes were compared to their respective solution profiles with the same GC-MS method. Solution profiles produced upwards of sixty four unidentified and identified (some only tentatively) constituents and aerosol profiles produced upwards of eighty two compounds. Results demonstrated distinct analyte profiles between liquid and aerosol samples. Most notably, formaldehyde, acetaldehyde, acrolein, and siloxanes were found in the aerosol profiles; however, these compounds were never present in the solutions. These results implicate the aerosolization process in the formation of compounds not found in solutions; have potential implications for human health; and stress the need for an emphasis on electronic cigarette aerosol testing. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

  12. SMEX02 Atmospheric Aerosol Optical Properties Data

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set consists of observations of atmospheric parameters including spectral aerosol optical depths, precipitable water, sky radiance distributions and...

  13. The Aerosol/Cloud/Ecosystems Mission (ACE)

    Science.gov (United States)

    Schoeberl, Mark

    2008-01-01

    The goals and measurement strategy of the Aerosol/Cloud/Ecosystems Mission (ACE) are described. ACE will help to answer fundamental science questions associated with aerosols, clouds, air quality and global ocean ecosystems. Specifically, the goals of ACE are: 1) to quantify aerosol-cloud interactions and to assess the impact of aerosols on the hydrological cycle and 2) determine Ocean Carbon Cycling and other ocean biological processes. It is expected that ACE will: narrow the uncertainty in aerosol-cloud-precipitation interaction and quantify the role of aerosols in climate change; measure the ocean ecosystem changes and precisely quantify ocean carbon uptake; and, improve air quality forecasting by determining the height and type of aerosols being transported long distances. Overviews are provided of the aerosol-cloud community measurement strategy, aerosol and cloud observations over South Asia, and ocean biology research goals. Instruments used in the measurement strategy of the ACE mission are also highlighted, including: multi-beam lidar, multiwavelength high spectra resolution lidar, the ocean color instrument (ORCA)--a spectroradiometer for ocean remote sensing, dual frequency cloud radar and high- and low-frequency micron-wave radiometer. Future steps for the ACE mission include refining measurement requirements and carrying out additional instrument and payload studies.

  14. Aerosol composition of the tropical upper troposphere

    Directory of Open Access Journals (Sweden)

    K. D. Froyd

    2009-07-01

    Full Text Available Aerosol composition was measured by the NOAA single-particle mass spectrometer (PALMS aboard the NASA WB-57 high altitude aircraft platform during two Aura Validation Experiment (AVE campaigns based in Costa Rica in 2004 and 2006. These studies yielded the most complete set of aerosol composition measurements to date throughout the tropical tropopause layer (TTL and tropical lower stratosphere. We describe the aerosol properties of the tropical atmosphere and use composition tracers to examine particle sources, the role of recent convection, and cirrus-forming potential in the TTL. Tropical dynamics and regional air sources played principal roles in dictating tropospheric aerosol properties. There was a sharp change in aerosol chemical composition at about 12 km altitude coincident with a change in convective influence. Below this level, maritime convection lofted condensable material that generated acidic, sulfate-rich aerosol. These particles contained significant amounts of methanesulfonic acid (MSA and showed evidence of cloud processes. In contrast, continental convection injected particles and precursors directly into the TTL, yielding a population of neutralized, organic-rich aerosol. The organics were often highly oxidized and particles with oxidized organics also contained nitrate. Above the tropopause, chemical composition gradually changed toward sulfuric acid particles but neutralized particles were still abundant 2 km above the tropopause. Deep continental convection, though sporadic and geographically localized, may strongly influence TTL aerosol properties on a global scale. The abundance of organic-rich aerosol may inhibit ice nucleation and formation of tropopause level cirrus.

  15. A global aerosol classification algorithm incorporating multiple satellite data sets of aerosol and trace gas abundances

    Science.gov (United States)

    Penning de Vries, M. J. M.; Beirle, S.; Hörmann, C.; Kaiser, J. W.; Stammes, P.; Tilstra, L. G.; Tuinder, O. N. E.; Wagner, T.

    2015-09-01

    Detecting the optical properties of aerosols using passive satellite-borne measurements alone is a difficult task due to the broadband effect of aerosols on the measured spectra and the influences of surface and cloud reflection. We present another approach to determine aerosol type, namely by studying the relationship of aerosol optical depth (AOD) with trace gas abundance, aerosol absorption, and mean aerosol size. Our new Global Aerosol Classification Algorithm, GACA, examines relationships between aerosol properties (AOD and extinction Ångström exponent from the Moderate Resolution Imaging Spectroradiometer (MODIS), UV Aerosol Index from the second Global Ozone Monitoring Experiment, GOME-2) and trace gas column densities (NO2, HCHO, SO2 from GOME-2, and CO from MOPITT, the Measurements of Pollution in the Troposphere instrument) on a monthly mean basis. First, aerosol types are separated based on size (Ångström exponent) and absorption (UV Aerosol Index), then the dominating sources are identified based on mean trace gas columns and their correlation with AOD. In this way, global maps of dominant aerosol type and main source type are constructed for each season and compared with maps of aerosol composition from the global MACC (Monitoring Atmospheric Composition and Climate) model. Although GACA cannot correctly characterize transported or mixed aerosols, GACA and MACC show good agreement regarding the global seasonal cycle, particularly for urban/industrial aerosols. The seasonal cycles of both aerosol type and source are also studied in more detail for selected 5° × 5° regions. Again, good agreement between GACA and MACC is found for all regions, but some systematic differences become apparent: the variability of aerosol composition (yearly and/or seasonal) is often not well captured by MACC, the amount of mineral dust outside of the dust belt appears to be overestimated, and the abundance of secondary organic aerosols is underestimated in comparison

  16. A global aerosol classification algorithm incorporating multiple satellite data sets of aerosol and trace gas abundances

    Directory of Open Access Journals (Sweden)

    M. J. M. Penning de Vries

    2015-09-01

    Full Text Available Detecting the optical properties of aerosols using passive satellite-borne measurements alone is a difficult task due to the broadband effect of aerosols on the measured spectra and the influences of surface and cloud reflection. We present another approach to determine aerosol type, namely by studying the relationship of aerosol optical depth (AOD with trace gas abundance, aerosol absorption, and mean aerosol size. Our new Global Aerosol Classification Algorithm, GACA, examines relationships between aerosol properties (AOD and extinction Ångström exponent from the Moderate Resolution Imaging Spectroradiometer (MODIS, UV Aerosol Index from the second Global Ozone Monitoring Experiment, GOME-2 and trace gas column densities (NO2, HCHO, SO2 from GOME-2, and CO from MOPITT, the Measurements of Pollution in the Troposphere instrument on a monthly mean basis. First, aerosol types are separated based on size (Ångström exponent and absorption (UV Aerosol Index, then the dominating sources are identified based on mean trace gas columns and their correlation with AOD. In this way, global maps of dominant aerosol type and main source type are constructed for each season and compared with maps of aerosol composition from the global MACC (Monitoring Atmospheric Composition and Climate model. Although GACA cannot correctly characterize transported or mixed aerosols, GACA and MACC show good agreement regarding the global seasonal cycle, particularly for urban/industrial aerosols. The seasonal cycles of both aerosol type and source are also studied in more detail for selected 5° × 5° regions. Again, good agreement between GACA and MACC is found for all regions, but some systematic differences become apparent: the variability of aerosol composition (yearly and/or seasonal is often not well captured by MACC, the amount of mineral dust outside of the dust belt appears to be overestimated, and the abundance of secondary organic aerosols is underestimated in

  17. Toxicology of the newer neonicotinoid insecticides: imidacloprid poisoning in a human.

    Science.gov (United States)

    David, Deepu; George, Ige Abraham; Peter, John Victor

    2007-01-01

    Imidacloprid, a potent neonicotinoid insecticide, is currently one of the best selling insecticides. We report a patient with clinical toxicity due to the ingestion of imidacloprid in a deliberate suicide attempt. The structure and mode of action of imidacloprid are discussed.

  18. Insecticide susceptibility status of invasive Aedes albopictus across dengue endemic districts of Odisha, India.

    Science.gov (United States)

    Rath, Animesha; Mohanty, Ipsita; Hazra, Rupenangshu K

    2017-12-14

    Aedes albopictus is currently the most invasive mosquito species in the world. Keeping in view the wide emergence of insecticide resistance, it is imperative to focus on the current susceptibility status for various insecticides in Ae. albopictus. The present study is focused on understanding the insecticide resistance mechanism of Ae. albopictus collected from dengue endemic districts of Odisha. Insecticide resistance was evaluated by using standardized bioassay kits (WHO) and biochemical analysis. Larval bioassays revealed the highest level of resistance from JP population with RR50 of 15.3 and LC50 of 1.177ppm compared to LC50 of 0.077 for the susceptible strain LabS. Results indicated the presence of DDT resistance in the majority of adult populations. Elevated activity of non specific esterases and P450s MFO indicated probable resistance to organophosphates and pyrethroids. Molecular screening for common insecticide target-site mutations confirmed the absence of the "knock down resistance" response for pyrethroid insecticide in Ae. albopictus population suggesting its continual effectiveness as the major insecticide of significant importance in future vector control programmes. This is the first report of a kdr mutation in Ae. albopictus in India and highlights the need for intensive research on other unexplored target site mutations that might also contribute to pyrethroid resistance. Effective management and sustainable use of insecticides can be implemented by understanding resistance mechanisms and development of appropriate diagnostic tools. This article is protected by copyright. All rights reserved.

  19. GC-MS Analysis of Insecticidal Leaf Essential Oil of Pyrenacantha ...

    African Journals Online (AJOL)

    Purpose: Insecticides have been known to cause serious toxicological and environmental problems. Hence, the insecticidal activity and chemical composition of a local medicinal plant was investigated. Methods: Steam distillation of P.staudtii leaves was carried out using a Clavenger apparatus in order to obtain the volatile ...

  20. Efficacy of insecticides through contact and oral uptake towards four Agriotes wireworm species under controlled conditions

    NARCIS (Netherlands)

    Rozen, van K.; Huiting, H.F.; Wilhelm, R.; Heger, M.; Ester, A.

    2013-01-01

    Wireworms of Agriotes lineatus, A. obscurus, A. sputator and A. sordidus were exposed to insecticide treated soil using two different control methods. One method consisted of a spray application of insecticides at doses of 50, 100, 200, and 300 g a.i. per ha. The other method consisted of a bait

  1. Risks of large-scale use of systemic insecticides to ecosystem functioning and services

    NARCIS (Netherlands)

    Chagnon, M.; Kreutzweiser, D.; Mitchell, E.A.D.; Morrissey, C.A.; Noome, D.A.; van der Sluijs, J.P.|info:eu-repo/dai/nl/073427489

    2015-01-01

    Large-scale use of the persistent and potent neonicotinoid and fipronil insecticides has raised concerns about risks to ecosystem functions provided by a wide range of species and environments affected by these insecticides. The concept of ecosystem services is widely used in decision making in the

  2. Influence on sensitivity to insecticides: a case study of a settled area ...

    African Journals Online (AJOL)

    The closeness of the two ecosystems has an impact on biology of mosquitoes of the area, such as susceptibility to insecticides. Susceptibility to insecticide was determined using knockdown bioassays. The mosquito, Anopheles gambiae, was exposed to 0.05% deltamethrin and 0.75 % permethrin giving LT 50 and LT 90.

  3. Current insecticide susceptibility status of Malaysian Anopheles maculatus Theobald to malathion, permethrin, DDT and deltamethrin.

    Science.gov (United States)

    Rohani, A; Aziz, I; Zurainee, M N; Rohana, S H; Zamree, I; Lee, H L

    2014-03-01

    Chemical insecticides are still considered as important control agents for malaria vector control. However, prolonged use of these chemicals may select mosquito vectors for resistance. In this study, susceptibility status of adult Anopheles maculatus collected from 9 localities in peninsular Malaysia, viz., Jeli, Temerloh, Pos Banun, Senderut, Jeram Kedah, Segamat, Kota Tinggi, Kluang and Pos Lenjang were determined using the standard WHO bioassay method in which the adult mosquitoes were exposed to standard insecticide impregnated papers malathion, permethrin, DDT and deltamethrin--at pre-determined diagnostic dosage. Deltamethrin was most effective insecticide among the four insecticides tested, with the LT50 of 29.53 min, compared to malathion (31.67 min), DDT (47.76 min) and permethrin (48.01 min). The effect of all insecticides on the laboratory strain was greater (with all insecticides demonstrated LT50 < 1 hour) than the field strains (deltamethrin 32.7, malathion 53.0, permethrin 62.0, DDT 67.4 min). An. maculatus exhibited low degree of resistance to all test insecticides, indicating that these chemical insecticides are still effective in the control of malaria vector.

  4. Sublethal effects of some botanical and chemical insecticides on the cotton whitefly, Bemisia tabaci (Hem: Aleyrodidae

    Directory of Open Access Journals (Sweden)

    Fatemeh Jafarbeigi

    2014-09-01

    Full Text Available In addition to direct mortalities caused by acute concentrations of insecticides, some biological traits of target pests may be also affected by sublethal doses. The cotton whitefly, Bemisia tabaci (Hem: Aleyrodidae is an important pest of a wide variety of agricultural crops across the world. The control of B. tabaci largely relies on wide application of chemical insecticides. In this study, we analyzed the life table parameters to evaluate the sublethal effect of three plant-derived insecticides (Fumaria parviflora (Fumariaceae, Teucrium polium (Lamiaceae, and Thymus vulgaris (Lamiaceae and two chemical insecticides (pymetrozin and neemarin on B. tabaci. The whiteflies were allowed to oviposit on plants infected with each of the five insecticides using leaf-dip method. The data were analyzed using the age-stage two-sex life table. We found significant differences in the gross reproductive rate (GRR, the net reproductive rat (R0, the intrinsic rate of increase (r and the finite rate of increase (λ of treated whiteflies compared to control. Our results showed that some biological traits of B. tabaci are affected by sub-lethal doses of the plant-derived extracts and that these effects are comparable to those of chemical insecticides. Given the detrimental effects of chemical insecticides on human, environment and non-target organisms, plant-derived insecticides may provide valuable environmentally friendly tools for pest management programs.

  5. Fate of the insecticide lambda-cyhalothrin in ditch enclosures differing in vegetation density

    NARCIS (Netherlands)

    Leistra, M.; Zweers, A.J.; Warinton, J.S.; Crum, S.J.H.; Hand, L.H.; Beltman, W.H.J.; Maund, S.J.

    2004-01-01

    Use of the insecticide lambda-cyhalothrin in agriculture may result in the contamination of water bodies, for example by spray drift. Therefore, the possible exposure of aquatic organisms to this insecticide needs to be evaluated. The exposure of the organisms may be reduced by the strong sorption

  6. Resistance: a threat to the insecticidal crystal proteins of Bacillus thuringiensis

    Science.gov (United States)

    Leah S. Bauer

    1995-01-01

    Insecticidal crystal proteins (also known as d-endotoxins) synthesized by the bacterium Bacillus thuringiensis Berliner (Bt) are the active ingredient of various environmentally friendly insecticides that are 1) highly compatible with natural enemies and other nontarget organisms due to narrow host specificity, 2) harmless to vertebrates, 3) biodegradable in the...

  7. Fate and effects of the insecticide chlorpyrifos in outdoor plankton-dominated microcosms in Thailand.

    NARCIS (Netherlands)

    Daam, M.A.; Crum, S.J.H.; Brink, van den P.J.; Nogueira, A.J.A.

    2008-01-01

    The fate and effects of the insecticide chlorpyrifos were studied in plankton-dominated, freshwater microcosms in Thailand. Disappearance rates of chlorpyrifos from the water column in the present study were similar to those in temperate regions. Insecticide accumulation in the sediment was

  8. Global Trends in the Use of Insecticides to Control Vector-Borne Diseases

    NARCIS (Netherlands)

    Berg, van den H.; Zaim, M.; Yadav, R.S.; Soares, A.; Ameneshewa, B.; Mnzava, A.; Hii, J.; Dash, A.P.; Ejov, M.

    2012-01-01

    Background: Data on insecticide use for vector control are essential for guiding pesticide management systems on judicious and appropriate use, resistance management, and reduction of risks to human health and the environment. Objective: We studied the global use and trends of insecticide use for

  9. Liquid-Liquid Extraction of Insecticides from Juice: An Analytical Chemistry Laboratory Experiment

    Science.gov (United States)

    Radford, Samantha A.; Hunter, Ronald E., Jr.; Barr, Dana Boyd; Ryan, P. Barry

    2013-01-01

    A laboratory experiment was developed to target analytical chemistry students and to teach them about insecticides in food, sample extraction, and cleanup. Micro concentrations (sub-microgram/mL levels) of 12 insecticides spiked into apple juice samples are extracted using liquid-liquid extraction and cleaned up using either a primary-secondary…

  10. Effect of insecticide treated nets fence in protect- ing cattle against ...

    African Journals Online (AJOL)

    A field trial was carried out to assess the effect of insecticide treated net in pro- tecting cattle from tsetse and other flies. A total of 35 pens were constructed, out of which 30 of them were fenced with insecticide treated net which served as treatment group and the remaining 5 pens were untreated controls. The fly populations ...

  11. Effects of insecticides with different modes of action in the control of ...

    African Journals Online (AJOL)

    The aim of the study was to evaluate the use of insecticides with different modes of action on banana borer weevil. Insecticides with different modes of action were administered to banana weevils (Cosmopolites sordidus) in small containers (1 litre by volume) with perforated lids and monitored in the laboratory at room ...

  12. Managing fall armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae), with Bt maize and insecticides in southern Brazil.

    Science.gov (United States)

    Burtet, Leonardo M; Bernardi, Oderlei; Melo, Adriano A; Pes, Maiquel P; Strahl, Thiago T; Guedes, Jerson Vc

    2017-12-01

    Maize plants expressing insecticidal proteins of Bacillus thuringiensis are valuable options for managing fall armyworm (FAW), Spodoptera frugiperda, in Brazil. However, control failures were reported, and therefore insecticides have been used to control this species. Based on these, we evaluated the use of Bt maize and its integration with insecticides against FAW in southern Brazil. Early-planted Agrisure TL, Herculex, Optimum Intrasect and non-Bt maize plants were severely damaged by FAW and required up to three insecticidal sprays. In contrast, YieldGard VT Pro, YieldGard VT Pro 3, PowerCore, Agrisure Viptera and Agrisure Viptera 3 showed little damage and did not require insecticides. Late-planted Bt maize plants showed significant damage by FAW and required up to four sprays, with the exceptions of Agrisure Viptera and Agrisure Viptera 3. Exalt (first and second sprays); Lannate + Premio (first spray) and Avatar (second spray); and Karate + Match (first spray) and Ampligo (second spray) were the most effective insecticides against FAW larvae in Bt and non-Bt maize. Maize plants expressing Cry proteins exhibited FAW control failures in southern Brazil, necessitating insecticidal sprays. In contrast, Bt maize containing the Vip3Aa20 protein remained effective against FAW. However, regardless of the insecticide used against FAW surviving on Bt maize, grain yields were similar. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  13. Estimating aerosol emissions by assimilating observed aerosol optical depth in a global aerosol model

    Directory of Open Access Journals (Sweden)

    N. Huneeus

    2012-05-01

    Full Text Available This study estimates the emission fluxes of a range of aerosol species and one aerosol precursor at the global scale. These fluxes are estimated by assimilating daily total and fine mode aerosol optical depth (AOD at 550 nm from the Moderate Resolution Imaging Spectroradiometer (MODIS into a global aerosol model of intermediate complexity. Monthly emissions are fitted homogenously for each species over a set of predefined regions. The performance of the assimilation is evaluated by comparing the AOD after assimilation against the MODIS observations and against independent observations. The system is effective in forcing the model towards the observations, for both total and fine mode AOD. Significant improvements for the root mean square error and correlation coefficient against both the assimilated and independent datasets are observed as well as a significant decrease in the mean bias against the assimilated observations. These improvements are larger over land than over ocean. The impact of the assimilation of fine mode AOD over ocean demonstrates potential for further improvement by including fine mode AOD observations over continents. The Angström exponent is also improved in African, European and dusty stations. The estimated emission flux for black carbon is 15 Tg yr−1, 119 Tg yr−1 for particulate organic matter, 17 Pg yr−1 for sea salt, 83 TgS yr−1 for SO2 and 1383 Tg yr−1 for desert dust. They represent a difference of +45 %, +40 %, +26 %, +13 % and −39 % respectively, with respect to the a priori values. The initial errors attributed to the emission fluxes are reduced for all estimated species.

  14. Measuring and Classifying Land-Based and Water-Based Daily Living Activities Using Inertial Sensors

    Directory of Open Access Journals (Sweden)

    Koichi Kaneda

    2018-02-01

    Full Text Available This study classified motions of typical daily activities in both environments using inertial sensors attached at the chest and thigh to determine the optimal site to attach the sensors. Walking, chair standing and sitting, and step climbing were conducted both in water and on land. A mean, variance and skewness for acceleration data was calculated. A Neural Network and Decision Tree algorithm was applied for classifying each motion in both environments. In total, 126 and 144 samples of thigh and chest data sets were obtained for analysis in each condition. For the chest data, the algorithm correctly classified 80% of the water-based activities, and 90% of the land-based. Whilst the thigh sensor correctly classified 97% of water-based and 100% of land-based activities. The inertial sensor placed on the thigh provided the most appropriate protocol for classifying motions for land-based and water-based typical daily life activities.

  15. Potential exposure of pollinators to neonicotinoid insecticides from the use of insecticide seed treatments in the mid-southern United States.

    Science.gov (United States)

    Stewart, Scott D; Lorenz, Gus M; Catchot, Angus L; Gore, Jeff; Cook, Don; Skinner, John; Mueller, Thomas C; Johnson, Donald R; Zawislak, Jon; Barber, Jonathan

    2014-08-19

    Research was done during 2012 to evaluate the potential exposure of pollinators to neonicotinoid insecticides used as seed treatments on corn, cotton, and soybean. Samples were collected from small plot evaluations of seed treatments and from commercial fields in agricultural production areas in Arkansas, Mississippi, and Tennessee. In total, 560 samples were analyzed for concentrations of clothianidin, imidacloprid, thiamethoxam, and their metabolites. These included pollen from corn and cotton, nectar from cotton, flowers from soybean, honey bees, Apis mellifera L., and pollen carried by foragers returning to hives, preplanting and in-season soil samples, and wild flowers adjacent to recently planted fields. Neonicotinoid insecticides were detected at a level of 1 ng/g or above in 23% of wild flower samples around recently planted fields, with an average detection level of about 10 ng/g. We detected neonicotinoid insecticides in the soil of production fields prior to planting at an average concentration of about 10 ng/g, and over 80% of the samples having some insecticide present. Only 5% of foraging honey bees tested positive for the presence of neonicotinoid insecticides, and there was only one trace detection (flowers, cotton pollen, and cotton nectar contained little or no neonicotinoids resulting from insecticide seed treatments. Average levels of neonicotinoid insecticides in corn pollen ranged from less than 1 to 6 ng/g. The highest neonicotinoid concentrations were found in soil collected during early flowering from insecticide seed treatment trials. However, these levels were generally not well correlated with neonicotinoid concentrations in flowers, pollen, or nectar. Concentrations in flowering structures were well below defined levels of concern thought to cause acute mortality in honey bees. The potential implications of our findings are discussed.

  16. Insecticide resistance profiles can be misleading in predicting the survival of Myzus persicae genotypes on potato crops following the application of different insecticide classes.

    Science.gov (United States)

    van Toor, Ron F; Malloch, Gaynor L; Anderson, Eric A; Dawson, Greg; Fenton, Brian

    2013-01-01

    The accuracy of predicting the survival of insecticide-resistant aphids following the application of commonly used insecticides from the carbamate, the pyrethroid, a mix of the two or the neonicotinoid chemical classes was evaluated in a potato field in Scotland. Equal proportions of five genotypes of the peach-potato aphid, Myzus persicae (Sulzer), with none, resistance to dimethyl-carbamates, resistance to pyrethroids or combinations conferring resistance to both chemical classes were released into potato field plots. The insecticides were sprayed separately onto these plots, the aphid populations were analysed after 6-8 days and the process repeated. For each assessment after the three separate spray events, plots treated with the carbamate had 48, 147 and 28%, those treated with pyrethroid 53, 210 and 89%, those treated with carbamate/pyrethroid 28, 108 and 64% and those treated with neonicotinoid 43, 55 and 11% of the numbers of M. persicae by comparison with untreated controls. Only the proportions of surviving aphids from the genotype containing no insecticide resistance traits and the genotype containing elevated carboxylesterases matched ratios predicted from the selective advantage afforded by the resistance traits alone. Survival of aphids from the other three genotypes that carried 1-3 of the insecticide resistance traits differed from expectations in all cases, possibly owing to physiological differences, including their vulnerability to predators and hymenopterous parasitoids present at the site and/or their carrying unknown insecticide resistance mechanisms. Control strategies based on knowledge of the genetically determined insecticide resistance profile of an M. persicae population alone are insufficient. Hence, other important factors contributing to aphid survival under insecticide pressure need to be considered. Copyright © 2012 Society of Chemical Industry.

  17. Insecticide treated curtains and residual insecticide treatment to control Aedes aegypti: An acceptability study in Santiago de Cuba.

    Directory of Open Access Journals (Sweden)

    Dennis Pérez

    2018-01-01

    Full Text Available Within the context of a field trial conducted by the Cuban vector control program (AaCP, we assessed acceptability of insecticide-treated curtains (ITCs and residual insecticide treatment (RIT with deltamethrin by the community. We also assessed the potential influence of interviewees' risk perceptions for getting dengue and disease severity.We embedded a qualitative study using in-depth interviews in a cluster randomized trial (CRT testing the effectiveness of ITCs and RIT in Santiago de Cuba. In-depth interviews (N = 38 were conducted four and twelve months after deployment of the tools with people who accepted the tools, who stopped using them and who did not accept the tools. Data analysis was deductive. Main reasons for accepting ITCs at the start of the trial were perceived efficacy and not being harmful to health. Constraints linked to manufacturer instructions were the main reason for not using ITCs. People stopped using the ITCs due to perceived allergy, toxicity and low efficacy. Few heads of households refused RIT despite the noting reasons for rejection, such as allergy, health hazard and toxicity. Positive opinions of the vector control program influenced acceptability of both tools. However, frequent insecticide fogging as part of routine AaCP vector control actions diminished perceived efficacy of both tools and, therefore, acceptability. Fifty percent of interviewees did feel at risk for getting dengue and considered dengue a severe disease. However, this did not appear to influence acceptability of ITCs or RIT.Acceptability of ITCs and RIT was linked to acceptability of AaCP routine vector control activities. However, uptake and use were not always an indication of acceptability. Factors leading to acceptability may be best identified using qualitative methods, but more research is needed on the concept of acceptability and its measurement.

  18. Insecticide treated curtains and residual insecticide treatment to control Aedes aegypti: An acceptability study in Santiago de Cuba.

    Science.gov (United States)

    Pérez, Dennis; Van der Stuyft, Patrick; Toledo, María Eugenia; Ceballos, Enrique; Fabré, Francisco; Lefèvre, Pierre

    2018-01-01

    Within the context of a field trial conducted by the Cuban vector control program (AaCP), we assessed acceptability of insecticide-treated curtains (ITCs) and residual insecticide treatment (RIT) with deltamethrin by the community. We also assessed the potential influence of interviewees' risk perceptions for getting dengue and disease severity. We embedded a qualitative study using in-depth interviews in a cluster randomized trial (CRT) testing the effectiveness of ITCs and RIT in Santiago de Cuba. In-depth interviews (N = 38) were conducted four and twelve months after deployment of the tools with people who accepted the tools, who stopped using them and who did not accept the tools. Data analysis was deductive. Main reasons for accepting ITCs at the start of the trial were perceived efficacy and not being harmful to health. Constraints linked to manufacturer instructions were the main reason for not using ITCs. People stopped using the ITCs due to perceived allergy, toxicity and low efficacy. Few heads of households refused RIT despite the noting reasons for rejection, such as allergy, health hazard and toxicity. Positive opinions of the vector control program influenced acceptability of both tools. However, frequent insecticide fogging as part of routine AaCP vector control actions diminished perceived efficacy of both tools and, therefore, acceptability. Fifty percent of interviewees did feel at risk for getting dengue and considered dengue a severe disease. However, this did not appear to influence acceptability of ITCs or RIT. Acceptability of ITCs and RIT was linked to acceptability of AaCP routine vector control activities. However, uptake and use were not always an indication of acceptability. Factors leading to acceptability may be best identified using qualitative methods, but more research is needed on the concept of acceptability and its measurement.

  19. GRIP LANGLEY AEROSOL RESEARCH GROUP EXPERIMENT (LARGE) V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The GRIP Langley Aerosol Research Group Experiment (LARGE) dataset was collected by the Langley Aerosol Research Group Experiment (LARGE), which measures ultrafine...

  20. NAMMA LANGLEY AEROSOL RESEARCH GROUP EXPERIMENT (LARGE) V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The NAMMA Langley Aerosol Research Group Experiment (LARGE) dataset is data collected from in situ aerosol sensors: condensation nuclei counters, optical particle...

  1. NAMMA LANGLEY AEROSOL RESEARCH GROUP EXPERIMENT (LARGE) V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The NAMMA Langley Aerosol Research Group Experiment (LARGE) dataset contains data collected from the following in situ aerosol sensors: condensation nuclei counters,...

  2. Sublethal effects of some synthetic and botanical insecticides on Bemisia tabaci (Hemiptera: Aleyrodidae

    Directory of Open Access Journals (Sweden)

    Esmaeily Saeideh

    2014-07-01

    Full Text Available In addition to direct mortality caused by insecticides, some biological traits of insects may also be affected by sublethal insecticide doses. In this study, we used the age-stage, two-sex life table method to evaluate the sublethal effects of the four synthetic insecticides: abamectin, imidacloprid, diazinon, and pymetrozin as well as the botanical insecticide taken from Calotropis procera (Asclepiadaceae extract, on eggs of the cotton whitefly, Bemisia tabaci (Hem.: Aleyrodidae. The lowest and highest survival rates and oviposition periods were observed in whiteflies treated by diazinon and imidacloprid, respectively. We found significant differences in the net reproductive rate (R0, the intrinsic rate of increase (r, the finite rate of increase (?, and the gross reproductive rate (GRR among different insecticides. Altogether, our results showed that pymetrozin and C. procera induced the most sublethal effects, thus they may be suitable candidates for use in integrated pest management programs of B. tabaci.

  3. Molecular Descriptors Family on Structure Activity Relationships 2. Insecticidal Activity of Neonicotinoid Compounds

    Directory of Open Access Journals (Sweden)

    Sorana BOLBOACĂ

    2005-01-01

    Full Text Available The neonicotinoids are the newest major class of insecticides modeled after the basic nicotine molecule having improved insecticide activity and generally low toxicity. The insecticidal activities of neonicotinoids were previous studied using 3D and standard partial least squares regression models. The paper describes the ability of the MDF SAR methodology in prediction of insecticidal activities of neonicotinoid compounds. The best MDF SAR bi-varied model was validated on training and test sets and its ability on prediction of insecticidal activity was compared with previous reported models. Even if the MDF SAR methodology is complex and time consuming the results worth the effort because they are statistical significant better then previous reported results.

  4. Life-stage variation in insecticide resistance of the western flower thrips (Thysanoptera: Thripidae).

    Science.gov (United States)

    Contreras, J; Espinosa, P J; Quinto, V; Abellán, J; Grávalos, C; Fernández, E; Bielza, P

    2010-12-01

    The life-stage variations in insecticide resistance of western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), to selective insecticides (acrinathrin, formetanate, and methiocarb) were studied using resistant laboratory strains. In each strain, the second-instar larva was less susceptible to the insecticides tested than the adults. The lower the resistance level of the adults, the higher the difference between larva and adult susceptibility: 32-fold to methiocarb, 15.4-fold to formetanate, and 180-fold to acrinathrin in the reference strain. In laboratory-selected resistant strains, these differences were much lower: 5.8-fold to methiocarb, 4.8-fold to formetanate, and 2.0-fold to acrinathrin. In selected strains, higher resistance levels for each insecticide were found, both for larvae and adults, compared with the reference strain. These results show that after insecticide resistance selection in adults, the resistance is carried over to the larvae, but at lower levels.

  5. Efficacy of ULV and thermal aerosols of deltamethrin for control of Aedes albopictus in Nice, France

    Directory of Open Access Journals (Sweden)

    Saïd C Boubidi

    2016-11-01

    Full Text Available Abstract Background Ultra-low volume (ULV insecticidal aerosols dispensed from vehicle-mounted cold-foggers are widely considered the method of choice for control of Aedes aegypti and Ae. albopictus during outbreaks of dengue and chikungunya and, more recently, Zika. Nevertheless, their effectiveness has been poorly studied, particularly in Europe. Nearly all published studies of ULV efficacy are bio-assays based on the mortality of caged mosquitoes. In our study we preferred to monitor the direct impact of treatments on the wild mosquito populations. This study was undertaken to evaluate the efficiency of the two widely used space spraying methods to control Ae. albopictus and Ae. aegypti. Methods We determined the susceptibility of local Ae. albopictus to deltamethrin by two methods: topical application and the “WHO Tube Test”. We used ovitraps baited with hay infusion and adult traps (B-G Sentinel baited with a patented attractant to monitor the mosquitoes in four residential areas in Nice, southern France. The impact of deltamethrin applied from vehicle-mounted ULV fogging-machines was assessed by comparing trap results in treated vs untreated areas for 5 days before and 5 days after treatment. Four trials were conducted at the maximum permitted application rate (1 g.ha-1. We also made two small-scale tests of the impact of the same insecticide dispensed from a hand-held thermal fogger. Results Susceptibility to the insecticide was high but there was no discernable change in the oviposition rate or the catch of adult female mosquitoes, nor was there any change in the parous rate. In contrast, hand-held thermal foggers were highly effective, with more than 90% reduction of both laid eggs and females. Conclusions We believe that direct monitoring of the wild mosquito populations gives a realistic assessment of the impact of treatments and suggest that the lack of efficacy is due to lack of interaction between the target mosquitoes and

  6. Efficacy of ULV and thermal aerosols of deltamethrin for control of Aedes albopictus in nice, France.

    Science.gov (United States)

    Boubidi, Saïd C; Roiz, David; Rossignol, Marie; Chandre, Fabrice; Benoit, Romain; Raselli, Marc; Tizon, Charles; Cadiou, Bernard; Tounsi, Reda; Lagneau, Christophe; Fontenille, Didier; Reiter, Paul

    2016-11-23

    Ultra-low volume (ULV) insecticidal aerosols dispensed from vehicle-mounted cold-foggers are widely considered the method of choice for control of Aedes aegypti and Ae. albopictus during outbreaks of dengue and chikungunya and, more recently, Zika. Nevertheless, their effectiveness has been poorly studied, particularly in Europe. Nearly all published studies of ULV efficacy are bio-assays based on the mortality of caged mosquitoes. In our study we preferred to monitor the direct impact of treatments on the wild mosquito populations. This study was undertaken to evaluate the efficiency of the two widely used space spraying methods to control Ae. albopictus and Ae. aegypti. We determined the susceptibility of local Ae. albopictus to deltamethrin by two methods: topical application and the "WHO Tube Test". We used ovitraps baited with hay infusion and adult traps (B-G Sentinel) baited with a patented attractant to monitor the mosquitoes in four residential areas in Nice, southern France. The impact of deltamethrin applied from vehicle-mounted ULV fogging-machines was assessed by comparing trap results in treated vs untreated areas for 5 days before and 5 days after treatment. Four trials were conducted at the maximum permitted application rate (1 g.ha-1). We also made two small-scale tests of the impact of the same insecticide dispensed from a hand-held thermal fogger. Susceptibility to the insecticide was high but there was no discernable change in the oviposition rate or the catch of adult female mosquitoes, nor was there any change in the parous rate. In contrast, hand-held thermal foggers were highly effective, with more than 90% reduction of both laid eggs and females. We believe that direct monitoring of the wild mosquito populations gives a realistic assessment of the impact of treatments and suggest that the lack of efficacy is due to lack of interaction between the target mosquitoes and the ULV aerosol. We discuss the factors that influence the

  7. Nucleophilic stabilization of water-based reactive ink for titania-based thin film inkjet printing

    DEFF Research Database (Denmark)

    Gadea, Christophe; Marani, Debora; Esposito, Vincenzo

    2017-01-01

    Drop on demand deposition (DoD) of titanium oxide thin films (<500 nm) is performed via a novel titanium-alkoxide-based solution that is tailored as a reactive ink for inkjet printing. The ink is developed as water-based solution by a combined use of titanium isopropoxide and n-methyldiethanolami......Drop on demand deposition (DoD) of titanium oxide thin films (printing. The ink is developed as water-based solution by a combined use of titanium isopropoxide and n...

  8. Investigation into the Use of Water Based Brake Fluid for Light Loads

    Directory of Open Access Journals (Sweden)

    W. A. Akpan

    2012-12-01

    Full Text Available This paper addresses the possibility of using water based fluid as a brake fluid for light loads. Characterization of both standard and water based braked fluids formulated was carried out. The properties of the latter were compared with that of a standard commercial brake fluid. The actual test of the formulated brake fluid was carried out with a Nissan Sunny vehicle model 1.5 within the speed range of 20km/hr to 80km/hr at the permanent campus of University of Uyo and the braking efficiency obtained attest to its suitability for light loads.

  9. Captures in methyl eugenol and cue-lure detection traps with and without insecticides and with a Farma Tech solid lure and insecticide dispenser.

    Science.gov (United States)

    Vargas, Roger I; Burns, R E; Mau, Ronald F L; Stark, John D; Cook, Peter; Piñero, Jaime C

    2009-04-01

    Methyl eugenol (ME) and cue-lure (C-L) traps to detect tephritid flies on the U.S. mainland were tested with and without insecticides under Hawaiian weather conditions against small populations of oriental fruit fly, Bactrocera dorsalis (Hendel) and melon fly, Bactrocera cucurbitae (Coquillett), respectively. In comparative tests, standard Jackson traps with naled and the Hawaii fruit fly areawide pest management (AWPM) trap with 2,2-dichorovinyl dimethyl phosphate (DDVP) insecticidal strips outperformed traps without an insecticide. Addition of the reduced risk insecticide spinosad did not increase trap capture significantly compared with Jackson traps without an insecticide. Captures in AWPM traps with DDVP compared favorably with those for the Jackson trap with liquid naled (the Florida standard). In subsequent tests, captures with solid Farma Tech wafer dispensers with ME or C-L and DDVP placed inside Jackson and AWPM traps were equal to those for a Jackson trap with naled, currently used for detection of ME and C-L responding fruit flies in Florida. Farma Tech ME and C-L wafers with DDVP would be more convenient and safer to handle than current liquid insecticide formulations (e.g., naled) used for detection programs in Florida.

  10. Effect of aerosol subgrid variability on aerosol optical depth and cloud condensation nuclei: Implications for global aerosol modelling

    NARCIS (Netherlands)

    Weigum, Natalie; Schutgens, Nick; Stier, Philip

    2016-01-01

    A fundamental limitation of grid-based models is their inability to resolve variability on scales smaller than a grid box. Past research has shown that significant aerosol variability exists on scales smaller than these grid-boxes, which can lead to discrepancies in simulated aerosol climate effects

  11. Measurements of Aerosol Hygroscopic Growth From Eight Different Regions and Aerosol Types

    Science.gov (United States)

    Jefferson, A.; Ogren, J.

    2007-12-01

    The change in the aerosol scattering coefficient with relative humidity has been measured at eight regions across the Earth over a time period of a few months to eight years. The measurement sites include the Arctic, Northeastern North America, Central US, Northwestern US, the Korean Peninsula, Indian Ocean, African Sahel and Central Europe. The aerosol types in these studies include mixtures of dust, smoke, pollution and marine aerosol. The covariance in the aerosol hygroscopic growth factor with other aerosol properties and source regions will be discussed as well as implications for direct and indirect radiative forcing.

  12. Heterogeneous Chemistry: Understanding Aerosol/Oxidant Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Joyce E. Penner

    2005-03-14

    Global radiative forcing of nitrate and ammonium aerosols has mostly been estimated from aerosol concentrations calculated at thermodynamic equilibrium or using approximate treatments for their uptake by aerosols. In this study, a more accurate hybrid dynamical approach (DYN) was used to simulate the uptake of nitrate and ammonium by aerosols and the interaction with tropospheric reactive nitrogen chemistry in a three-dimensional global aerosol and chemistry model, IMPACT, which also treats sulfate, sea salt and mineral dust aerosol. 43% of the global annual average nitrate aerosol burden, 0.16 TgN, and 92% of the global annual average ammonium aerosol burden, 0.29 TgN, exist in the fine mode (D<1.25 {micro}m) that scatters most efficiently. Results from an equilibrium calculation differ significantly from those of DYN since the fraction of fine-mode nitrate to total nitrate (gas plus aerosol) is 9.8%, compared to 13% in DYN. Our results suggest that the estimates of aerosol forcing from equilibrium concentrations will be underestimated. We also show that two common approaches used to treat nitrate and ammonium in aerosol in global models, including the first-order gas-to-particle approximation based on uptake coefficients (UPTAKE) and a hybrid method that combines the former with an equilibrium model (HYB), significantly overpredict the nitrate uptake by aerosols especially that by coarse particles, resulting in total nitrate aerosol burdens higher than that in DYN by +106% and +47%, respectively. Thus, nitrate aerosol in the coarse mode calculated by HYB is 0.18 Tg N, a factor of 2 more than that in DYN (0.086 Tg N). Excessive formation of the coarse-mode nitrate in HYB leads to near surface nitrate concentrations in the fine mode lower than that in DYN by up to 50% over continents. In addition, near-surface HNO{sub 3} and NO{sub x} concentrations are underpredicted by HYB by up to 90% and 5%, respectively. UPTAKE overpredicts the NO{sub x} burden by 56% and near

  13. Aerosol Blanket Likely Thinned During 1990s

    Science.gov (United States)

    2007-01-01

    Each day, a blanket of tiny particles drifting through the Earth's atmosphere filters out some of the sunlight headed for the planet's surface. These aerosols, including dust, smoke, and human-produced pollution, can reflect incoming light or absorb it, directly affecting the Earth's energy balance and climate. Aerosols also influence the climate indirectly, by affecting the brightness and amount of clouds. Research by NASA scientists on global aerosol patterns since the 1990s indicate the global aerosol blanket has likely thinned, allowing more sunlight to reach the Earth's surface over the past decade. The thinning of the blanket is shown by this trio of images based on satellite observations of aerosol optical thickness, a measurement that scientists use to describe how much the aerosols filter the incoming sunlight. Higher optical thickness (orange and red) means more sunlight blocking. The globes show average aerosol optical thickness for 1988-1991 (top), 2002-2005 (middle), and the change between the two time periods (bottom). Overall, the 1988-1991 image appears redder, a sign that aerosols were blocking more incoming sunlight; the 2002-2005 image has more light yellow areas. In the bottom image, small pockets of red (increased aerosol optical thickness), mostly near land masses in the Northern Hemisphere, are far outnumbered by blue areas (decreased aerosol optical thickness). Because they block incoming sunlight from reaching Earth's surface, aerosols may counterbalance greenhouse gas warming. The decline in the dimming power of aerosols over the past decade may have made the greenhouse warming trend more evident in the past decade than in previous decades. The scientists describe their results as a 'likely' trend because the National Oceanic and Atmospheric Administration satellite sensors they used in their analysis were not specifically designed to observe aerosols, and may contain some errors. However, specific, major aerosol events, such as large

  14. Characterization of aerosols produced by surgical procedures

    Energy Technology Data Exchange (ETDEWEB)

    Yeh, H.C.; Muggenburg, B.A.; Lundgren, D.L.; Guilmette, R.A.; Snipes, M.B.; Jones, R.K. [Inhalation Toxicology Research Institute, Albuquerque, NM (United States); Turner, R.S. [Lovelace Health Systems, Albuquerque, NM (United States)

    1994-07-01

    In many surgeries, especially orthopedic procedures, power tools such as saws and drills are used. These tools may produce aerosolized blood and other biological material from bone and soft tissues. Surgical lasers and electrocautery tools can also produce aerosols when tissues are vaporized and condensed. Studies have been reported in the literature concerning production of aerosols during surgery, and some of these aerosols may contain infectious material. Garden et al. (1988) reported the presence of papilloma virus DNA in the fumes produced from laser surgery, but the infectivity of the aerosol was not assessed. Moon and Nininger (1989) measured the size distribution and production rate of emissions from laser surgery and found that particles were generally less than 0.5 {mu}m diameter. More recently there has been concern expressed over the production of aerosolized blood during surgical procedures that require power tools. In an in vitro study, the production of an aerosol containing the human immunodeficiency virus (HIV) was reported when power tools were used to cut tissues with blood infected with HIV. Another study measured the size distribution of blood aerosols produced by surgical power tools and found blood-containing particles in a number of size ranges. Health care workers are anxious and concerned about whether surgically produced aerosols are inspirable and can contain viable pathogens such as HIV. Other pathogens such as hepatitis B virus (HBV) are also of concern. The Occupational Safety and Health funded a project at the National Institute for Inhalation Toxicology Research Institute to assess the extent of aerosolization of blood and other tissues during surgical procedures. This document reports details of the experimental and sampling approach, methods, analyses, and results on potential production of blood-associated aerosols from surgical procedures in the laboratory and in the hospital surgical suite.

  15. Synthesis and Insecticidal Activity of an Oxabicyclolactone and Novel Pyrethroids

    Directory of Open Access Journals (Sweden)

    Elson S. de Alvarenga

    2012-11-01

    Full Text Available Deltamethrin, a member of the pyrethroids, one of the safest classes of pesticides, is among some of the most popular and widely used insecticides in the World. Our objective was to synthesize an oxabicyclolactone 6 and five novel pyrethroids 8–12 from readily available furfural and D-mannitol, respectively, and evaluate their biological activity against four insect species of economic importance namely A. obtectus, S. zeamais, A. monuste orseis, and P. americana. A concise and novel synthesis of 6,6-dimethyl-3-oxabicyclo[3.1.0]hexan-2-one (6 from furfural is described. Photochemical addition of isopropyl alcohol to furan-2(5H-one afforded 4-(1'-hydroxy-1'-methylethyltetrahydro-furan-2-one (3. The alcohol 3 was directly converted into 4-(1'-bromo-1'-methylethyl-tetrahydrofuran-2-one (5 in 50% yield by reaction with PBr3 and SiO2. The final step was performed by cyclization of 5 with potassium tert-butoxide in 40% yield. The novel pyrethroids 8–12 were prepared from methyl (1S,3S-3-formyl-2,2-dimethylcyclopropane-1-carboxylate (7a by reaction with five different aromatic phosphorous ylides. Compounds 6–12 presented high insecticidal activity, with 6 and 11 being the most active. Compound 6 killed 90% of S. zeamais and 100% of all the other insects evaluated. Compound 11 killed 100% of all insects tested.

  16. Phthalides as promising insecticides against Tuta absoluta (Lepidoptera: Gelechiidae).

    Science.gov (United States)

    Farias, Elizeu S; Silva, Eliete M P; Teixeira, Milena G; Ferreira, Jhulyana S; Alvarenga, Elson S; Picanço, Marcelo C

    2018-01-02

    In this study, the insecticide potential of eight phthalides derived from furan-2(5H)-one was evaluated against Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) larvae. The potency of the most active phthalides and the susceptibility of six different T. absoluta populations to these compounds were determined. The toxicity of these molecules to two non-target species (Solenopsis saevissima Smith and Tetragonisca angustula Latreille) was also evaluated. Two phthalides (3 and 4) presented insecticide potential against T. absoluta. Phthalide 4 was as toxic as piperine (positive control) and both phthalides exhibited rapid action (LT 50 < 2 hours). The variation in the susceptibility of T. absoluta populations to the phthalides 3 and 4 was low. Neither phthalide presented physiological selectivity for non-target species. Therefore, the phthalides 3 and 4 are promising molecules, or at least, a starting point for a chemical optimization program leading to formulations for the management of the tomato leafminer. The application of such products should be conducted according to the principles of ecological selectivity.

  17. Delivering insecticide-treated nets for malaria prevention: innovative strategies

    Directory of Open Access Journals (Sweden)

    Krezanoski PJ

    2016-09-01

    Full Text Available Paul J Krezanoski1–3 1Department of Medicine, 2Department of Pediatrics, Massachusetts General Hospital, 3Medicine and Pedatrics, Harvard Medical School, Boston, MA, USA Abstract: The wide-scale adoption of insecticide-treated nets (ITNs has led to significant reductions in malaria morbidity and mortality worldwide. Delivery of ITNs to the 3.2 billion people at risk of malaria requires multiple steps in diverse settings. The effectiveness of the delivery of ITNs in order to prevent malaria relies on activities that include ITN manufacturing and design, integration into national and international malaria prevention policies, supplying and distributing ITNs to households and individuals, and, finally, programs focused on spurring demand for and use of ITNs by individuals at risk. This paper reviews some recent innovative strategies for ITN delivery across these four domains, places these innovations within the context of the history of ITN deployment, and identifies opportunities to further improve the effectiveness of this ubiquitous public health tool. Keywords: malaria, insecticide-treated bed nets, prevention, access, ownership, use, policies

  18. Actions of insecticides on the insect GABA receptor complex

    Energy Technology Data Exchange (ETDEWEB)

    Bermudez, I.; Hawkins, C.A.; Taylor, A.M.; Beadle, D.J. (School of Biological and Molecular Sciences, Oxford Polytechnic, Headington, Oxford (England))

    1991-01-01

    The actions of insecticides on the insect gamma-aminobutyric acid (GABA) receptor were investigated using (35S)t-butylbicyclophosphorothionate (( 35S)TBPS) binding and voltage-clamp techniques. Specific binding of (35S)TBPS to a membrane homogenate derived from the brain of Locusta migratoria locusts is characterised by a Kd value of 79.3 {plus minus} 2.9 nM and a Bmax value of 1770 {plus minus} 40 fmol/mg protein. (35S)TBPS binding is inhibited by mM concentrations of barbiturates and benzodiazepines. In contrast dieldrin, ivermectin, lindane, picrotoxin and TBPS are inhibitors of (35S)TBPS binding at the nanomolar range. Bicuculline, baclofen and pyrethroid insecticides have no effect on (35S)TBPS binding. These results are similar to those obtained in electrophysiological studies of the current elicited by GABA in both Locusta and Periplaneta americana central neurones. Noise analysis of the effects of lindane, TBPS, dieldrin and picrotoxin on the cockroach GABA responses reveals that these compounds decrease the variance of the GABA-induced current but have no effect on its mean open time. All these compounds, with the exception of dieldrin, significantly decrease the conductance of GABA-evoked single current.

  19. Chronic toxicity to quail and pheasants of some chlorinated insecticides

    Science.gov (United States)

    DeWitt, J.B.

    1956-01-01

    Quantitative report of tests. 'Inclusion of 1 p.p.m, of aldrin, dieldrin, or endrin in diets fed growing quail resulted in high mortality rates, but the birds survived on diets containing 100 p.p.m, of DDT or 50 p.p.m. of strobane. Young pheasants survived on diets containing 50 p.p.m, of DDT or strobane, but failed to survive on diets containing 5 p.p.m, of aldrin, dieldrin, or endrin. No ill effects were noted when quail were fed winter diets containing 50 p.p.m, of strobane, or 1 p.p.m, of dieldrin or endrin, but nearly all birds died when fed diets containing 0.5 p.p.m, of aldrin. Mortality rates among pheasants fed 50 p.p.m, and of quail fed 100 p.p.m. of DDT were higher than for birds receiving normal diets, but none of the birds displayed symptoms characteristic of DDT poisoning. Egg production, fertility, and hatchability were relatively unaffected by inclusion of insecticides in diets fed breeding quail, but chicks from these matings showed high mortality rates even when reared on insecticide-free diets. Lowered viability of quail chicks was most pronounced in groups receiving DDT and strobane in the reproduction diets. Hatchability of pheasant eggs and viability of chicks were adversely affected by inclusion of aldrin, dieldrin, or endrin in the reproduction diets.'

  20. Insecticide Resistance Mechanisms in the Green Peach Aphid Myzus persicae (Hemiptera: Aphididae) I: A Transcriptomic Survey

    Science.gov (United States)

    Silva, Andrea X.; Jander, Georg; Samaniego, Horacio; Ramsey, John S; Figueroa, Christian C.

    2012-01-01

    Background Insecticide resistance is one of the best examples of rapid micro-evolution found in nature. Since the development of the first synthetic insecticide in 1939, humans have invested considerable effort to stay ahead of resistance phenotypes that repeatedly develop in insects. Aphids are a group of insects that have become global pests in agriculture and frequently exhibit insecticide resistance. The green peach aphid, Myzus persicae, has developed resistance to at least seventy different synthetic compounds, and different insecticide resistance mechanisms have been reported worldwide. Methodology/Principal Findings To further characterize this resistance, we analyzed genome-wide transcriptional responses in three genotypes of M. persicae, each exhibiting different resistance mechanisms, in response to an anti-cholinesterase insecticide. The sensitive genotype (exhibiting no resistance mechanism) responded to the insecticide by up-regulating 183 genes primarily ones related to energy metabolism, detoxifying enzymes, proteins of extracellular transport, peptidases and cuticular proteins. The second genotype (resistant through a kdr sodium channel mutation), up-regulated 17 genes coding for detoxifying enzymes, peptidase and cuticular proteins. Finally, a multiply resistant genotype (carrying kdr and a modified acetylcholinesterase), up-regulated only 7 genes, appears not to require induced insecticide detoxification, and instead down-regulated many genes. Conclusions/Significance This study suggests strongly that insecticide resistance in M. persicae is more complex that has been described, with the participation of a broad array of resistance mechanisms. The sensitive genotype exhibited the highest transcriptional plasticity, accounting for the wide range of potential adaptations to insecticides that this species can evolve. In contrast, the multiply resistant genotype exhibited a low transcriptional plasticity, even for the expression of genes encoding

  1. Insecticide resistance mechanisms in the green peach aphid Myzus persicae (Hemiptera: Aphididae I: A transcriptomic survey.

    Directory of Open Access Journals (Sweden)

    Andrea X Silva

    Full Text Available BACKGROUND: Insecticide resistance is one of the best examples of rapid micro-evolution found in nature. Since the development of the first synthetic insecticide in 1939, humans have invested considerable effort to stay ahead of resistance phenotypes that repeatedly develop in insects. Aphids are a group of insects that have become global pests in agriculture and frequently exhibit insecticide resistance. The green peach aphid, Myzus persicae, has developed resistance to at least seventy different synthetic compounds, and different insecticide resistance mechanisms have been reported worldwide. METHODOLOGY/PRINCIPAL FINDINGS: To further characterize this resistance, we analyzed genome-wide transcriptional responses in three genotypes of M. persicae, each exhibiting different resistance mechanisms, in response to an anti-cholinesterase insecticide. The sensitive genotype (exhibiting no resistance mechanism responded to the insecticide by up-regulating 183 genes primarily ones related to energy metabolism, detoxifying enzymes, proteins of extracellular transport, peptidases and cuticular proteins. The second genotype (resistant through a kdr sodium channel mutation, up-regulated 17 genes coding for detoxifying enzymes, peptidase and cuticular proteins. Finally, a multiply resistant genotype (carrying kdr and a modified acetylcholinesterase, up-regulated only 7 genes, appears not to require induced insecticide detoxification, and instead down-regulated many genes. CONCLUSIONS/SIGNIFICANCE: This study suggests strongly that insecticide resistance in M. persicae is more complex that has been described, with the participation of a broad array of resistance mechanisms. The sensitive genotype exhibited the highest transcriptional plasticity, accounting for the wide range of potential adaptations to insecticides that this species can evolve. In contrast, the multiply resistant genotype exhibited a low transcriptional plasticity, even for the expression

  2. Aerosol Therapy: Nebulizer vs Metered Dose Inhaler

    National Research Council Canada - National Science Library

    Newhouse, M; Dolovich, M

    1987-01-01

    ... aerosol generation using metered-dose inhalers. Previously, aerosol delivery by means of intermittent positive pressure breathing devices attached to nebulizers enjoyed unwarranted popularity for decades, only to be abandoned when convincing evidence became available that they were no better than nebulizers alone for administering bronchodilato...

  3. Aerosol feed direct methanol fuel cell

    Science.gov (United States)

    Kindler, Andrew (Inventor); Narayanan, Sekharipuram R. (Inventor); Valdez, Thomas I. (Inventor)

    2002-01-01

    Improvements to fuel cells include introduction of the fuel as an aerosol of liquid fuel droplets suspended in a gas. The particle size of the liquid fuel droplets may be controlled for optimal fuel cell performance by selection of different aerosol generators or by separating droplets based upon size using a particle size conditioner.

  4. Atmospheric aerosol light scattering and polarization peculiarities

    CERN Document Server

    Patlashenko, Zh I

    2015-01-01

    This paper considers environmental problems of natural and anthropogenic atmospheric aerosol pollution and its global and regional monitoring. Efficient aerosol investigations may be achieved by spectropolarimetric measurements. Specifically second and fourth Stokes parameters spectral dependencies carry information on averaged refraction and absorption indexes and on particles size distribution functions characteristics.

  5. Evaluation of MERRAero (MERRA Aerosol Reanalysis)

    Science.gov (United States)

    Buchard, Virginie; da Silva, Arlindo; Randles, Cynthia; Colarco, Peter; Darmenov, Anton; Govindaraju, Ravi

    2016-01-01

    This presentation focuses on MERRA Aerosol Reanalysis (MERRAero) which is the first aerosol reanalysis produced at GMAO. This presentation involve an overview of MERRAero. The evaluation of MERRAero absorption and the evaluation of MERRAero Surface PM 2.5 will also be discussed.

  6. Impact of aerosols on ice crystal size

    Directory of Open Access Journals (Sweden)

    B. Zhao

    2018-01-01

    Full Text Available The interactions between aerosols and ice clouds represent one of the largest uncertainties in global radiative forcing from pre-industrial time to the present. In particular, the impact of aerosols on ice crystal effective radius (Rei, which is a key parameter determining ice clouds' net radiative effect, is highly uncertain due to limited and conflicting observational evidence. Here we investigate the effects of aerosols on Rei under different meteorological conditions using 9-year satellite observations. We find that the responses of Rei to aerosol loadings are modulated by water vapor amount in conjunction with several other meteorological parameters. While there is a significant negative correlation between Rei and aerosol loading in moist conditions, consistent with the "Twomey effect" for liquid clouds, a strong positive correlation between the two occurs in dry conditions. Simulations based on a cloud parcel model suggest that water vapor modulates the relative importance of different ice nucleation modes, leading to the opposite aerosol impacts between moist and dry conditions. When ice clouds are decomposed into those generated from deep convection and formed in situ, the water vapor modulation remains in effect for both ice cloud types, although the sensitivities of Rei to aerosols differ noticeably between them due to distinct formation mechanisms. The water vapor modulation can largely explain the difference in the responses of Rei to aerosol loadings in various seasons. A proper representation of the water vapor modulation is essential for an accurate estimate of aerosol–cloud radiative forcing produced by ice clouds.

  7. Optical manipulation of aerosol particle arrays

    Science.gov (United States)

    Reid, J. P.; Haddrell, A. E.; Walker, J. S.; Power, R.; Bones, D. L.; Davies, J. F.

    2011-10-01

    Aerosols play a crucial role in many areas of science, ranging from atmospheric chemistry and physics, to drug delivery to the lungs, combustion science and spray drying. The development of new methods to characterise the properties and dynamics of aerosol particles is of crucial importance if the complex role that particles play is to be more fully understood. Optical tweezers provide a valuable new tool to address fundamental questions in aerosol science. Single or multiple particles 1-15 μm in diameter can be manipulated over indefinite timescales using optical tweezing. Linear and non-linear Raman and fluorescence spectroscopies can be used to probe a particle's composition and size. In this paper we will report on the latest developments in the use of holographic optical trapping (HOT) to study aerosols. Although widely used to trap and manipulate arrays of particles in the condensed phase, the application of HOT to aerosols is still in its infancy. We will explore the opportunities provided by the formation of complex optical landscapes for controlling aerosol flow, for comparing the properties of multiple particles, for performing the first ever digital microfluidic operations in the aerosol phase and for examining interparticle interactions that can lead to coalescence/coagulation. Although aerosol coagulation is the primary process driving the evolution of particle size distributions, it remains very poorly understood. Using HOT, we can resolve the time-dependent motion of trapped particles and the light scattering from particles during the coalescence process.

  8. Physical properties of aerosols at Maitri, Antarctica

    Indian Academy of Sciences (India)

    Measurements of the submicron aerosol size distribution made at the Indian Antarctic station, Maitri (70° 45′S, 11° 44′E) from January 10th to February 24th, 1997, are reported. Total aerosol concentrations normally range from 800 to 1200 particles cm-3 which are typical values for the coastal stations at Antarctica in ...

  9. What Aerosol Water do Organic Compounds See?

    Science.gov (United States)

    Large amounts of aerosol water are associated with inorganic salts such as ammonium sulfate with generally smaller but important contributions from hydrophilic organics. Ambient aerosols can be externally or internally mixed in addition to containing one or multiple phases. The d...

  10. Aerosol light-scattering in the Netherlands

    NARCIS (Netherlands)

    Brink, H.M. ten; Veefkind, J.P.; Waijers-IJpelaan, A.; Hage, J.C. van der

    1996-01-01

    The relation between the (midday) aerosol light-scattering and the concentrations of nitrate and sulfate has been assessed at a site near the coast of the North Sea in The Netherlands. Midday was selected for the measurements because this is the time at which the aerosol is most effective in the

  11. Size segregated aerosol mass concentration measurements over ...

    Indian Academy of Sciences (India)

    Mass concentration and mass size distribution of total (composite) aerosols near the surface are essential inputs needed in developing aerosol models for radiative forcing estimation as well as to infer the environment and air quality. Using extensive measurements onboard the oceanographic research vessel, Sagar Kanya ...

  12. Estimating marine aerosol particle volume and number from Maritime Aerosol Network data

    Directory of Open Access Journals (Sweden)

    A. M. Sayer

    2012-09-01

    Full Text Available As well as spectral aerosol optical depth (AOD, aerosol composition and concentration (number, volume, or mass are of interest for a variety of applications. However, remote sensing of these quantities is more difficult than for AOD, as it is more sensitive to assumptions relating to aerosol composition. This study uses spectral AOD measured on Maritime Aerosol Network (MAN cruises, with the additional constraint of a microphysical model for unpolluted maritime aerosol based on analysis of Aerosol Robotic Network (AERONET inversions, to estimate these quantities over open ocean. When the MAN data are subset to those likely to be comprised of maritime aerosol, number and volume concentrations obtained are physically reasonable. Attempts to estimate surface concentration from columnar abundance, however, are shown to be limited by uncertainties in vertical distribution. Columnar AOD at 550 nm and aerosol number for unpolluted maritime cases are also compared with Moderate Resolution Imaging Spectroradiometer (MODIS data, for both the present Collection 5.1 and forthcoming Collection 6. MODIS provides a best-fitting retrieval solution, as well as the average for several different solutions, with different aerosol microphysical models. The "average solution" MODIS dataset agrees more closely with MAN than the "best solution" dataset. Terra tends to retrieve lower aerosol number than MAN, and Aqua higher, linked with differences in the aerosol models commonly chosen. Collection 6 AOD is likely to agree more closely with MAN over open ocean than Collection 5.1. In situations where spectral AOD is measured accurately, and aerosol microphysical properties are reasonably well-constrained, estimates of aerosol number and volume using MAN or similar data would provide for a greater variety of potential comparisons with aerosol properties derived from satellite or chemistry transport model data. However, without accurate AOD data and prior knowledge of

  13. The activity of the pyrrole insecticide chlorfenapyr in mosquito bioassay: towards a more rational testing and screening of non-neurotoxic insecticides for malaria vector control.

    Science.gov (United States)

    Oxborough, Richard M; N'Guessan, Raphael; Jones, Rebecca; Kitau, Jovin; Ngufor, Corine; Malone, David; Mosha, Franklin W; Rowland, Mark W

    2015-03-24

    The rapid selection of pyrethroid resistance throughout sub-Saharan Africa is a serious threat to malaria vector control. Chlorfenapyr is a pyrrole insecticide which shows no cross resistance to insecticide classes normally used for vector control and is effective on mosquito nets under experimental hut conditions. Unlike neurotoxic insecticides, chlorfenapyr owes its toxicity to disruption of metabolic pathways in mitochondria that enable cellular respiration. A series of experiments explored whether standard World Health Organization (WHO) guidelines for evaluation of long-lasting insecticidal nets, developed through testing of pyrethroid insecticides, are suitable for evaluation of non-neurotoxic insecticides. The efficacy of WHO recommended cone, cylinder and tunnel tests was compared for pyrethroids and chlorfenapyr. To establish bioassay exposure times predictive of insecticide-treated net (ITN) efficacy in experimental hut trials, standard three-minute bioassays of pyrethroid and chlorfenapyr ITNs were compared with longer exposures. Mosquito behaviour and response to chlorfenapyr ITN in bioassays conducted at night were compared to day and across a range of temperatures representative of highland and lowland transmission. Standard three-minute bioassay of chlorfenapyr produced extremely low levels of mortality compared to pyrethroids. Thirty-minute day-time bioassay produced mortality closer to hut efficacy of chlorfenapyr ITN but still fell short of the WHO threshold. Overnight tunnel test with chlorfenapyr produced 100% mortality and exceeded the WHO threshold of 80%. The endogenous circadian activity rhythm of anophelines results in inactivity by day and raised metabolism and flight activity by night. A model which explains improved toxicity of chlorfenapyr ITN when tested at night, and during the day at higher ambient temperature, is that activation of chlorfenapyr and disruption of respiratory pathways is enhanced when the insect is more metabolically

  14. AEROSOL PARTICLE COLLECTOR DESIGN STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S; Richard Dimenna, R

    2007-09-27

    A computational evaluation of a particle collector design was performed to evaluate the behavior of aerosol particles in a fast flowing gas stream. The objective of the work was to improve the collection efficiency of the device while maintaining a minimum specified air throughput, nominal collector size, and minimal power requirements. The impact of a range of parameters was considered subject to constraints on gas flow rate, overall collector dimensions, and power limitations. Potential improvements were identified, some of which have already been implemented. Other more complex changes were identified and are described here for further consideration. In addition, fruitful areas for further study are proposed.

  15. Characterization of Cooking-Related Aerosols

    Science.gov (United States)

    Niedziela, R. F.; Blanc, L. E.

    2010-12-01

    The temperatures at which food is cooked are usually high enough to drive oils and other organic compounds out of materials which are being prepared for consumption. As these compounds move away from the hot cooking surface and into the atmosphere, they can participate in chemical reactions or condense to form particles. Given the high concentration of cooking in urban areas, cooking-related aerosols likely contribute to the overall amount of particulate matter on a local scale. Reported here are results for the mid-infrared optical characterization of aerosols formed during the cooking of several meat and vegetable samples in an inert atmosphere. The samples were heated in a novel aerosol generator that is designed to collect particles formed immediately above the cooking surface and inject them into a laminar aerosol flow cell. Preliminary results for the chemical processing of cooking-related aerosols in synthetic air will also be presented.

  16. Enhanced thermal conductivity of nano-SiC dispersed water based ...

    Indian Academy of Sciences (India)

    Abstract. Silicon carbide (SiC) nanoparticle dispersed water based nanofluids were prepared using up to 0·1 vol% of nanoparticles. Use of suitable stirring routine ensured uniformity and stability of dispersion. Thermal conduc- tivity ratio of nanofluid measured using transient hot wire device shows a significant increase of ...

  17. Land- and water-based exercises in rheumatoid arthritis patients: a ...

    African Journals Online (AJOL)

    Objective. To compare the effects of a 3-month land- and waterbased exercise programme among rheumatoid arthritis (RA) sufferers. Methods. Patients with RA Functional Class I and II (N=10) were randomly assigned to a land-based exercise group (Group L) (N=4), water-based exercise group (Group W) (N=4) or a ...

  18. Boundary lubrication of bearing steel in water-based lubricants with functional additives

    NARCIS (Netherlands)

    Wu, Y.

    2017-01-01

    This thesis focuses on the effect of additives on boundary lubrication of bearing steel for water-based lubrication systems. The oil-in-water (O/W) emulsion and the water-glycol based liquid were selected as the base fluids for research. Sulfur compounds, nitrogen heterocycles and graphene

  19. Water-based exercise and quality of life in women: the role of depressive symptoms.

    Science.gov (United States)

    Schuch, Felipe Barreto; Pinto, Stephanie Santana; Bagatini, Natália Carvalho; Zaffari, Paula; Alberton, Cristine Lima; Cadore, Eduardo Lusa; Silva, Rodrigo Ferrari; Kruel, Luiz Fernando Martins

    2014-01-01

    Several studieshave evaluated the relation of exercise to quality of life (QoL). To our knowledge, no study has evaluated the relation of water-based exercise to depressive symptoms and QoL, or the association between improvement in QoL and depressive symptoms in healthy women. The purpose of this study was to evaluate the association of water-based exercise with changes in QoL. Forty-seven women performed water-based combined exercise for 12 weeks. All participants improved in the physical and psychological domains of QoL. Decreases in depressive symptoms and improvements in maximal strength and aerobic capacity were found for all participants. A regression model revealed that depressive symptoms were associated with improvements in physical and psychological domains of QoL. The results showed that moderate intensity, water-based exercise improved physical and psychological domains of QoL, depressive symptoms, aerobic capacity, and muscular strength of women. Furthermore, the improvement in physical and psychological domains of QoL appeared to be mediated by the antidepressant effects of exercise, but not by changes in aerobic capacity or muscular strength.

  20. Presence and sources of anthropogenic perfluorinated alkyl acids in tap-water based beverages

    NARCIS (Netherlands)

    Eschauzier, C.; Hoppe, M.; Schlummer, M.; de Voogt, P.

    2013-01-01

    This study investigates the presence and sources of perfluorinated alkyl acids (PFAAs) in tap water and corresponding tap-water based beverages such as coffee and cola collected in the city of Amsterdam, The Netherlands. Exposure pathways studies have shown that low concentrations of PFAA in tap

  1. Moisture diffusion coefficients determination of furan bonded sands and water based foundry coatings

    DEFF Research Database (Denmark)

    Di Muoio, Giovanni Luca; Tiedje, Niels Skat

    2016-01-01

    Moisture content in furan bonded sand and water based coatings can be one of the main causes for gas related defects in large cast iron parts. Moisture diffusion coefficients for these materials are needed to precisely predict the possible moisture levels in foundry moulds. In this study, we firs...

  2. Research of water-base nano-PU paint for heat insulation

    Science.gov (United States)

    Jwo, Ching-Song; Jeng, Lung-Yue; Cheng, Ho; Chen, Sih-Li

    2008-12-01

    The purpose of this study is to research and produce water-base nano-PU paint with energy conservation, environmental consciousness and high efficiency of heat insulation, which can be enhance the traditional PU paint for performance improvement of heat insulation and range of application. In this study, research will be held on the two-stage synthesis method. The SiO2 nanoparticles are added into the water-base PU paint to improve the properties of traditional PU paint. Next, the fundamental properties of this paint, including water resistance, weather rsistance, weak acid solvent resistance, and heat insulation rate, will be measured and analyzed, and the performance of heat insulation will be evaluated in order to confirm the performance and practicability of the heat insulation of water-base nano-PU paint in this study. The experimental results show that for the SiO2/W-PU composite nanopaint prepared by two-stage synthesis method, the dispersion of SiO2 powder in the water-base PU (W-PU) paint is even. For the SiO2/W-PU nanocomposite paint prepared by adding SiO2 powder at 8% wt. to the marketed water-base PU, the water absorption of its experimental sample is enhanced by around 10.1 times, whereas its weak acid dissolve erosion rate is increased by 3.3 times. However, the average heat insulation rate in the thermal properties is also increased, increasing around 24.22% for the W-PU paint without SiO2 powder. Through the multilayered coating construction, the water-base nano-PU paint added with SiO2 powder can be used on any facility of heat insulation, including vehicle, safety helmet, umbrella, drapes, and outer wall of building. The newly developed water-base nano-PU paint with high thermal resistance is especially suitable for application to the shell coating of air conditioner and cooling tower,. Due to the better thermal resistance of this nanopaint, the problems of poor heat transfer and temperature rise of cooling water caused by direct sunlight can be

  3. Postexercise hypotension during different water-based concurrent training intrasession sequences in young women.

    Science.gov (United States)

    Pinto, Stephanie Santana; Umpierre, Daniel; Ferreira, Hector Kerchirne; Nunes, Gabriela Neves; Ferrari, Rodrigo; Alberton, Cristine Lima

    2017-10-01

    The purpose of the study was to compare the acute effects of water-based resistance-aerobic (RA) and aerobic-resistance (AR) sequences on systolic blood pressure, diastolic blood pressure (DBP), and mean blood pressure (MBP) in young women. Thirteen active women participated in four sessions: (1) exercises familiarization, (2) aquatic maximal test to determine the heart rate (HR) corresponding to the anaerobic threshold (HRAT), (3) concurrent protocol RA, and (4) concurrent protocol AR. Both protocols were initiated with the blood pressure measurements at rest in supine position. After that, either RA or AR concurrent protocol was performed. At the end of both protocols, blood pressure was measured throughout 60 minutes (every 10 minutes). The water-based resistance protocol was made up by exercises at maximal velocity, and the water-based aerobic protocol was performed at ±5 bpm of HRAT continuously. Two-way analysis of variance with repeated measures was used to analyze the data (α = 0.05). There was no hypotensive effect on systolic blood pressure among the time points (P = .235) in both water-based intrasession exercise sequences (P = .423). Regarding the DBP and MBP, both intrasession exercise sequences presented similar (DBP: P = .980; MBP: P = .796) hypotensive effects in the first 10 minutes (DBP: P = .003; MBP: P = .008) at the end of RA and AR sessions (DBP: -4 vs. -13 mm Hg; MBP: -3 vs. -10 mm Hg). It was concluded that both RA and AR water-based concurrent training sessions resulted in postexercise hypotension (DBP and MBP) in normotensive young women. Copyright © 2017 American Society of Hypertension. Published by Elsevier Inc. All rights reserved.

  4. Consequences of co-applying insecticides and fungicides for managing Thrips tabaci (Thysanoptera: Thripidae) on onion.

    Science.gov (United States)

    Nault, Brian A; Hsu, Cynthia L; Hoepting, Christine A

    2013-07-01

    Insecticides and fungicides are commonly co-applied in a tank mix to protect onions from onion thrips, Thrips tabaci Lindeman, and foliar pathogens. Co-applications reduce production costs, but past research shows that an insecticide's performance can be reduced when co-applied with a fungicide. An evaluation was made of the effects of co-applying spinetoram, abamectin and spirotetramat with commonly used fungicides, with and without the addition of a penetrating surfactant, on onion thrips control in onion fields. Co-applications of insecticides with chlorothalonil fungicides reduced thrips control by 25-48% compared with control levels provided by the insecticides alone in three of five trials. Inclusion of a penetrating surfactant at recommended rates with the insecticide and chlorothalonil fungicide did not consistently overcome this problem. Co-applications of insecticides with other fungicides did not interfere with thrips control. Co-applications of pesticides targeting multiple organisms should be examined closely to ensure that control of each organism is not compromised. To manage onion thrips in onion most effectively, insecticides should be applied with a penetrating surfactant, and should be applied separately from chlorothalonil fungicides. © 2012 Society of Chemical Industry.

  5. Impact of five insecticides on chickpea (Cicer arietinum L. nodulation, yield and nitrogen fixing rhizospheric bacteria

    Directory of Open Access Journals (Sweden)

    H. Khan

    2009-05-01

    Full Text Available A field experiment was conducted to study the effect of five insecticides i.e. Lorsban (40% EC, Decis (25% EC, Pyrifos (40% EC, Karate (25% EC, and Ripcord (10% EC on the survival of rhizosphere N2-fixing microorganisms, nodulation, pod damage (by pod borer, and grain yield of chickpea (Cicer arietinum L. crop. The study revealed that Pyrifos suppressed nodulation in chickpea and specific rhizobial counts in the crop rhizosphere, indicating that this insecticide was harmful to rhizobial population in rhizosphere. All the other tested insecticides were safe as they did not affect nodulation of the crop and the specific rhizobial counts in the rhizosphere. The results also revealed that all the tested insecticides except Lorsban (40% EC suppressed Azotobacter population in the rhizospheric soil indicating that Lorsban was harmless to Azotobacter while all other tested insecticides were harmful to the survival of this important nitrogen fixing bacterium. Pyrifos proved to be the most effective insecticide in controlling the pod borer damage and also in increasing the grain yield significantly as compared to other tested insecticides.

  6. Environmental risk assessment of registered insecticides in Iran using Environmental Impact Quotient (EIQ index

    Directory of Open Access Journals (Sweden)

    S. Moinoddini

    2016-05-01

    Full Text Available In the last decades, pesticides have been used extensively, in order to control pests and plant diseases, but negative impacts of pesticides caused several environmental problems and put human health in danger. In order to decrease environmental hazards of pesticide, risk of pesticide application should be measured briefly and precisely. In this study environmental impacts of registered insecticides in Iran which applied in 2001-2002, 2003-2004, 2004-2005, are considered using environmental impact quotient (EIQ index. Results showed that among considered insecticides, Imidacloprid, Fipronil and Tiodicarb, potentially (EIQ were the most hazardous insecticides, respectively. Taking rate of application and active ingredient of insecticide in to account, environmental impact (practical toxicity per cultivated hectare (EIQ Field of each provinces were investigated. In this regard, among different province of Iran, Kerman, Mazandaran and Golestan were in danger more than the others, respectively. Besides, considering the amount of agricultural production in provinces, environmental impact per ton of production were calculated for each provinces which three northern provinces of Mazandaran, Golestan and Guilan, respectively endure the most environmental impact per ton of production. Eventually based on environmental impact quotient, results demonstrated that majority of environmental impacts of insecticide in Iran were due to inadequate knowledge and also overuse of a few number of insecticides. Therefore, by improving knowledge about environmental impact of pesticides and also developing environmental friendly and ecological based methods, negative environmental impacts of insecticides will be reduced significantly.

  7. Insecticide resistance, control failure likelihood and the First Law of Geography.

    Science.gov (United States)

    Guedes, Raul Narciso C

    2017-03-01

    Insecticide resistance is a broadly recognized ecological backlash resulting from insecticide use and is widely reported among arthropod pest species with well-recognized underlying mechanisms and consequences. Nonetheless, insecticide resistance is the subject of evolving conceptual views that introduces a different concept useful if recognized in its own right - the risk or likelihood of control failure. Here we suggest an experimental approach to assess the likelihood of control failure of an insecticide allowing for consistent decision-making regarding management of insecticide resistance. We also challenge the current emphasis on limited spatial sampling of arthropod populations for resistance diagnosis in favor of comprehensive spatial sampling. This necessarily requires larger population sampling - aiming to use spatial analysis in area-wide surveys - to recognize focal points of insecticide resistance and/or control failure that will better direct management efforts. The continuous geographical scale of such surveys will depend on the arthropod pest species, the pattern of insecticide use and many other potential factors. Regardless, distance dependence among sampling sites should still hold, following the maxim that the closer two things are, the more they resemble each other, which is the basis of Tobler's First Law of Geography. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  8. Synergism studies with binary mixtures of pyrethroid, carbamate and organophosphate insecticides on Frankliniella occidentalis (Pergande).

    Science.gov (United States)

    Bielza, Pablo; Espinosa, Pedro J; Quinto, Vicente; Abellán, Jaime; Contreras, Josefina

    2007-01-01

    The major mechanism of resistance to most insecticides in Frankliniella occidentalis (Pergande) is metabolic, piperonyl butoxide (PBO) suppressible, mediated by cytochrome-P450 monooxygenases and conferring cross-resistance among insecticide classes. The efficacy of insecticide mixtures of acrinathrin, methiocarb, formetanate and chlorpyrifos was studied by topical exposure in strains of F. occidentalis selected for resistance to each insecticide. The method consisted in combining increasing concentrations of one insecticide with a constant low rate of the second one as synergist. Acrinathrin activity against F. occidentalis was enhanced by carbamate insecticides, methiocarb being a much better synergist than formetanate. Monooxygenase action on the carbamates would prevent degradation of the pyrethroid, hence providing a level of synergism by competitive substrate inhibition. However, the number of insecticides registered for control of F. occidentalis is very limited, and they are needed for antiresistance strategies such as mosaics and rotations. Therefore, a study was made of the synergist effect of other carbamates not used against thrips, such as carbofuran and carbosulfan, against a susceptible strain and a field strain. Neither carbamate showed synergism to acrinathrin in the susceptible strain, but both did in the field strain, carbosulfan being a better synergist than carbofuran. The data obtained indicate that low rates of carbamates could be used as synergists to restore some pyrethroid susceptibility in F. occidentalis. Copyright (c) 2006 Society of Chemical Industry.

  9. Evaluation of leaching potential of three systemic neonicotinoid insecticides in vineyard soil

    Science.gov (United States)

    Kurwadkar, Sudarshan; Wheat, Remington; McGahan, Donald G.; Mitchell, Forrest

    2014-12-01

    Dinotefuran (DNT), imidacloprid (IMD), and thiamethoxam (THM) are commonly used neonicotinoid insecticides in a variety of agriculture operations. Although these insecticides help growers control pest infestation, the residual environmental occurrence of insecticides may cause unintended adverse ecological consequences to non-target species. In this study, the leaching behavior of DNT, IMD, and THM was investigated in soils collected from an active AgriLife Research Extension Center (AREC) vineyard. A series of column experiments were conducted to evaluate the leaching potential of insecticides under two experimental scenarios: a) individual pulse mode, and b) mixed pulse mode. In both scenarios, the breakthrough pattern of the insecticides in the mostly acidic to neutral vineyard soil clearly demonstrates medium to high leachability. Of the three insecticides studied for leaching, DNT has exhibited high leaching potential and exited the column with fewer pore volumes, whereas IMD was retained for longer, indicating lower leachability. Relative differences in leaching behavior of neonicotinoids could be attributed to their solubility with the leaching pattern IMD neonicotinoid insecticides based on the leachability indices such as groundwater ubiquity score, relative leaching potential, and partitioning between different environmental matrices through a fugacity-based equilibrium criterion model clearly indicates that DNT may pose a greater threat to aquatic resources compared to IMD and THM.

  10. Decaleside: a new class of natural insecticide targeting tarsal gustatory sites

    Science.gov (United States)

    Rajashekar, Yallappa; Rao, Lingamallu J. M.; Shivanandappa, Thimmappa

    2012-10-01

    Natural sources for novel insecticide molecules hold promise in view of their eco-friendly nature, selectivity, and mammalian safety. Recent progress in understanding the biology of insect olfaction and taste offers new strategies for developing selective pest control agents. We have isolated two natural insecticidal molecules from edible roots of Decalepis hamiltonii named Decalesides I and II, which are novel trisaccharides, highly toxic to household insect pests and stored-product insects. We have experimentally shown that insecticidal activity requires contact with tarsi on the legs but is not toxic orally. The insecticidal activity of molecules is lost by hydrolysis, and various sugars modify toxic response, showing that the insecticidal activity is via gustatory sites on the tarsi. Selective toxicity to insects by virtue of their gustatory site of action and the mammalian safety of the new insecticides is inherent in their chemical structure with 1-4 or 1-1 α linkage that is easily hydrolyzed by digestive enzymes of mammals. Decalesides represent a new chemical class of natural insecticides with a unique mode of action targeting tarsal chemosensory/gustatory system of insects.

  11. Metabolic mechanisms of insecticide resistance in the western flower thrips, Frankliniella occidentalis (Pergande).

    Science.gov (United States)

    Espinosa, Pedro J; Contreras, Josefina; Quinto, Vicente; Grávalos, Carolina; Fernández, Esther; Bielza, Pablo

    2005-10-01

    The interactions between six insecticides (methiocarb, formetanate, acrinathrin, deltamethrin, methamidophos and endosulfan) and three potential synergists (piperonyl butoxide (PBO), S,S,S-tributyl phosphorotrithioate (DEF) and diethyl maleate (DEM)) were studied by topical exposure in strains selected for resistance to each insecticide, and in a susceptible strain of Frankliniella occidentalis (Pergande). In the susceptible strain PBO produced appreciable synergism only of formetanate, methiocarb and methamidophos. Except for endosulfan, PBO synergized all the insecticides to varying degrees in the resistant strains. A very high level of synergism by PBO was found with acrinathrin, which reduced the resistance level from 3344- to 36-fold. PBO slightly synergized the carbamates formetanate (4.6-fold) and methiocarb (3.3-fold). PBO also produced a high synergism of deltamethrin (12.5-fold) and methamidophos (14.3-fold) and completely restored susceptibility to both insecticides. DEF did not produce synergism with any insecticide in the resistant strains and DEM was slightly synergistic to endosulfan (3-fold). These studies indicate that an enhanced detoxification, mediated by cytochrome P-450 monooxygenases, is the major mechanism imparting resistance to different insecticides in F occidentalis. Implications of different mechanisms in insecticide resistance in F occidentalis are discussed. Copyright (c) 2005 Society of Chemical Industry.

  12. Effect of an aerosol- reduction device on spreading infected aerosols during ultrasonic scaling

    Directory of Open Access Journals (Sweden)

    Ghalyani Isfahani P. Assistant Professor"

    2003-07-01

    Full Text Available Statement of Problem: Ultrasonic Scaling is one of the main sources of producing infected aerosols in dentistry. These aerosols are able to spread pathogens such as microorganisms associated with tuberculosis, conjunctivitis, influenza and other respiratory diseases, herpetic and other skin diseases, ADIS and hepatitis B."nPurpose: The aim of this study was to investigate the clinical effectiveness of an aerosol- reduction device attaching to ultrasonic scaler handpiece."nMaterials and Methods: In this experimental study 18 patients participated. Randomly, mandibular and maxillary quadrants of one side, in each subject, were scaled using an ultrasonic scaler with aerosol-reduction device for 5 minutes. After 30 minutes, another quadrant was scaled by ultrasonic scaler without aerosol- reduction device. In order to determine the effectiveness of aerosol- reduction device, blood agar plates attached to the surgical mask of the operator, 30 cm far from the patient's mouth, were incubated in 37°c for three days and the colonies were counted. Median, Interquartile eange and Wilcoxon test, at the 0.05 level of significance, were used to analyze the data."nResults: The median and interquartile range for the number of colony forming units (CFUS without aerosol- reduction device was 17.5 (8, 24, while the median for the number of CFUS when using aerosol-reduction device was 0 (0, 1, indicating significant statistical difference (PO.001 Conclusion: The aerosol- reduction device significantly reduces the amount of aerosols produced during ultrasonic scaling.

  13. Filter-based Aerosol Measurement Experiments using Spherical Aerosol Particles under High Temperature and High Pressure

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jong Chan; Jung, Woo Young; Lee, Hyun Chul; Lee, Doo Young [FNC TECH., Yongin (Korea, Republic of)

    2016-05-15

    Optical Particle Counter (OPC) is used to provide real-time measurement of aerosol concentration and size distribution. Glass fiber membrane filter also be used to measure average mass concentration. Three tests (MTA-1, 2 and 3) have been conducted to study thermal-hydraulic effect, a filtering tendency at given SiO{sub 2} particles. Based on the experimental results, the experiment will be carried out further with a main carrier gas of steam and different aerosol size. The test results will provide representative behavior of the aerosols under various conditions. The aim of the tests, MTA 1, 2 and 3, are to be able to 1) establish the test manuals for aerosol generation, mixing, sampling and measurement system, which defines aerosol preparation, calibration, operating and evaluation method under high pressure and high temperature 2) develop commercial aerosol test modules applicable to the thermal power plant, environmental industry, automobile exhaust gas, chemical plant, HVAC system including nuclear power plant. Based on the test results, sampled aerosol particles in the filter indicate that important parameters affecting aerosol behavior aerosols are 1) system temperature to keep above a evaporation temperature of ethanol and 2) aerosol losses due to the settling by ethanol liquid droplet.

  14. Quantitative comparison of aerosol optical depth (AOD) and aerosol indirect effects in three polluted Asian cities

    Science.gov (United States)

    Das, B.; Ahn, C.; Torres, O.; Durbin, P.

    2008-12-01

    Advances in satellite technology and ground based measurement techniques have resulted in vast amount of data on aerosol and cloud parameters. Aerosol indirect effects are characterized by the effects of aerosol on cloud radiative properties. This being a subject of significant interest for climate change and human health effects, many computational and satellite data analysis studies have been made to understand this mechanism. However, most of the studies are made on understanding the global effects. In this work we attempt to understand the local effects by making quantitative analysis of aerosol and its indirect effects in three polluted Asian cities. We analyze aerosol optical depth (AOD) data from MODIS (Moderate Resolution Imaging Spectroradiometer) and MISR (Multiangle Imaging SpectroRadiometer), aerosol extinction optical depth, absorption optical depth, and aerosol index (AI) data from OMI (Ozone Monitoring Instrument) and compare with AOD data of AERONET (Aerosol Robotic Network) at Beijing, China; Dalanzadgad, Mongolia; and Kanpur, India. Cloud parameters from MODIS data are correlated with aerosol optical depth. Seasonal variation of aerosol optical depth and its effect on cloud radiative properties are discussed. Large differences in AOD are observed in the measurements by different instruments. The differences in the results of indirect effects indicate considerable influence of local environment.

  15. Contemporary status of insecticide resistance in the major Aedes vectors of arboviruses infecting humans

    Science.gov (United States)

    Vontas, John; Martins, Ademir J.; Ng, Lee Ching; Koou, Sin Ying; Dusfour, Isabelle; Raghavendra, Kamaraju; Pinto, João; Corbel, Vincent; David, Jean-Philippe; Weetman, David

    2017-01-01

    Both Aedes aegytpi and Ae. albopictus are major vectors of 5 important arboviruses (namely chikungunya virus, dengue virus, Rift Valley fever virus, yellow fever virus, and Zika virus), making these mosquitoes an important factor in the worldwide burden of infectious disease. Vector control using insecticides coupled with larval source reduction is critical to control the transmission of these viruses to humans but is threatened by the emergence of insecticide resistance. Here, we review the available evidence for the geographical distribution of insecticide resistance in these 2 major vectors worldwide and map the data collated for the 4 main classes of neurotoxic insecticide (carbamates, organochlorines, organophosphates, and pyrethroids). Emerging resistance to all 4 of these insecticide classes has been detected in the Americas, Africa, and Asia. Target-site mutations and increased insecticide detoxification have both been linked to resistance in Ae. aegypti and Ae. albopictus but more work is required to further elucidate metabolic mechanisms and develop robust diagnostic assays. Geographical distributions are provided for the mechanisms that have been shown to be important to date. Estimating insecticide resistance in unsampled locations is hampered by a lack of standardisation in the diagnostic tools used and by a lack of data in a number of regions for both resistance phenotypes and genotypes. The need for increased sampling using standard methods is critical to tackle the issue of emerging insecticide resistance threatening human health. Specifically, diagnostic doses and well-characterised susceptible strains are needed for the full range of insecticides used to control Ae. aegypti and Ae. albopictus to standardise measurement of the resistant phenotype, and calibrated diagnostic assays are needed for the major mechanisms of resistance. PMID:28727779

  16. Neonicotinoid insecticides alter induced defenses and increase susceptibility to spider mites in distantly related crop plants.

    Directory of Open Access Journals (Sweden)

    Adrianna Szczepaniec

    Full Text Available Chemical suppression of arthropod herbivores is the most common approach to plant protection. Insecticides, however, can cause unintended, adverse consequences for non-target organisms. Previous studies focused on the effects of pesticides on target and non-target pests, predatory arthropods, and concomitant ecological disruptions. Little research, however, has focused on the direct effects of insecticides on plants. Here we demonstrate that applications of neonicotinoid insecticides, one of the most important insecticide classes worldwide, suppress expression of important plant defense genes, alter levels of phytohormones involved in plant defense, and decrease plant resistance to unsusceptible herbivores, spider mites Tetranychus urticae (Acari: Tetranychidae, in multiple, distantly related crop plants.Using cotton (Gossypium hirsutum, corn (Zea mays and tomato (Solanum lycopersicum plants, we show that transcription of phenylalanine ammonia lyase, coenzyme A ligase, trypsin protease inhibitor and chitinase are suppressed and concentrations of the phytohormone OPDA and salicylic acid were altered by neonicotinoid insecticides. Consequently, the population growth of spider mites increased from 30% to over 100% on neonicotinoid-treated plants in the greenhouse and by nearly 200% in the field experiment.Our findings are important because applications of neonicotinoid insecticides have been associated with outbreaks of spider mites in several unrelated plant species. More importantly, this is the first study to document insecticide-mediated disruption of plant defenses and link it to increased population growth of a non-target herbivore. This study adds to growing evidence that bioactive agrochemicals can have unanticipated ecological effects and suggests that the direct effects of insecticides on plant defenses should be considered when the ecological costs of insecticides are evaluated.

  17. Contemporary status of insecticide resistance in the major Aedes vectors of arboviruses infecting humans.

    Directory of Open Access Journals (Sweden)

    Catherine L Moyes

    2017-07-01

    Full Text Available Both Aedes aegytpi and Ae. albopictus are major vectors of 5 important arboviruses (namely chikungunya virus, dengue virus, Rift Valley fever virus, yellow fever virus, and Zika virus, making these mosquitoes an important factor in the worldwide burden of infectious disease. Vector control using insecticides coupled with larval source reduction is critical to control the transmission of these viruses to humans but is threatened by the emergence of insecticide resistance. Here, we review the available evidence for the geographical distribution of insecticide resistance in these 2 major vectors worldwide and map the data collated for the 4 main classes of neurotoxic insecticide (carbamates, organochlorines, organophosphates, and pyrethroids. Emerging resistance to all 4 of these insecticide classes has been detected in the Americas, Africa, and Asia. Target-site mutations and increased insecticide detoxification have both been linked to resistance in Ae. aegypti and Ae. albopictus but more work is required to further elucidate metabolic mechanisms and develop robust diagnostic assays. Geographical distributions are provided for the mechanisms that have been shown to be important to date. Estimating insecticide resistance in unsampled locations is hampered by a lack of standardisation in the diagnostic tools used and by a lack of data in a number of regions for both resistance phenotypes and genotypes. The need for increased sampling using standard methods is critical to tackle the issue of emerging insecticide resistance threatening human health. Specifically, diagnostic doses and well-characterised susceptible strains are needed for the full range of insecticides used to control Ae. aegypti and Ae. albopictus to standardise measurement of the resistant phenotype, and calibrated diagnostic assays are needed for the major mechanisms of resistance.

  18. Neonicotinoid insecticides alter induced defenses and increase susceptibility to spider mites in distantly related crop plants.

    Science.gov (United States)

    Szczepaniec, Adrianna; Raupp, Michael J; Parker, Roy D; Kerns, David; Eubanks, Micky D

    2013-01-01

    Chemical suppression of arthropod herbivores is the most common approach to plant protection. Insecticides, however, can cause unintended, adverse consequences for non-target organisms. Previous studies focused on the effects of pesticides on target and non-target pests, predatory arthropods, and concomitant ecological disruptions. Little research, however, has focused on the direct effects of insecticides on plants. Here we demonstrate that applications of neonicotinoid insecticides, one of the most important insecticide classes worldwide, suppress expression of important plant defense genes, alter levels of phytohormones involved in plant defense, and decrease plant resistance to unsusceptible herbivores, spider mites Tetranychus urticae (Acari: Tetranychidae), in multiple, distantly related crop plants. Using cotton (Gossypium hirsutum), corn (Zea mays) and tomato (Solanum lycopersicum) plants, we show that transcription of phenylalanine ammonia lyase, coenzyme A ligase, trypsin protease inhibitor and chitinase are suppressed and concentrations of the phytohormone OPDA and salicylic acid were altered by neonicotinoid insecticides. Consequently, the population growth of spider mites increased from 30% to over 100% on neonicotinoid-treated plants in the greenhouse and by nearly 200% in the field experiment. Our findings are important because applications of neonicotinoid insecticides have been associated with outbreaks of spider mites in several unrelated plant species. More importantly, this is the first study to document insecticide-mediated disruption of plant defenses and link it to increased population growth of a non-target herbivore. This study adds to growing evidence that bioactive agrochemicals can have unanticipated ecological effects and suggests that the direct effects of insecticides on plant defenses should be considered when the ecological costs of insecticides are evaluated.

  19. Characterization of Florida red tide aerosol and the temporal profile of aerosol concentration.

    Science.gov (United States)

    Cheng, Yung Sung; Zhou, Yue; Pierce, Richard H; Henry, Mike; Baden, Daniel G

    2010-05-01

    Red tide aerosols containing aerosolized brevetoxins are produced during the red tide bloom and transported by wind to coastal areas of Florida. This study reports the characterization of Florida red tide aerosols in human volunteer studies, in which an asthma cohort spent 1h on Siesta Beach (Sarasota, Florida) during aerosolized red tide events and non-exposure periods. Aerosol concentrations, brevetoxin levels, and particle size distribution were measured. Hourly filter samples were taken and analyzed for brevetoxin and NaCl concentrations. In addition, the aerosol mass concentration was monitored in real time. The results indicated that during a non-exposure period in October 2004, no brevetoxin was detected in the water, resulting in non-detectable levels of brevetoxin in the aerosol. In March 2005, the time-averaged concentrations of brevetoxins in water samples were moderate, in the range of 5-10 microg/L, and the corresponding brevetoxin level of Florida red tide aerosol ranged between 21 and 39 ng/m(3). The temporal profiles of red tide aerosol concentration in terms of mass, NaCl, and brevetoxin were in good agreement, indicating that NaCl and brevetoxins are components of the red tide aerosol. By continuously monitoring the marine aerosol and wind direction at Siesta Beach, we observed that the marine aerosol concentration varied as the wind direction changed. The temporal profile of the Florida red tide aerosol during a sampling period could be explained generally with the variation of wind direction. Copyright 2009 Elsevier Ltd. All rights reserved.

  20. An aerosol climatology for a rapidly growing arid region (southern Arizona): Major aerosol species and remotely sensed aerosol properties.

    Science.gov (United States)

    Sorooshian, Armin; Wonaschütz, Anna; Jarjour, Elias G; Hashimoto, Bryce I; Schichtel, Bret A; Betterton, Eric A

    2011-10-01

    This study reports a comprehensive characterization of atmospheric aerosol particle properties in relation to meteorological and back trajectory data in the southern Arizona region, which includes two of the fastest growing metropolitan areas in the United States (Phoenix and Tucson). Multiple data sets (MODIS, AERONET, OMI/TOMS, MISR, GOCART, ground-based aerosol measurements) are used to examine monthly trends in aerosol composition, aerosol optical depth (AOD), and aerosol size. Fine soil, sulfate, and organics dominate PM2.5 mass in the region. Dust strongly influences the region between March and July owing to the dry and hot meteorological conditions and back trajectory patterns. Because monsoon precipitation begins typically in July, dust levels decrease, while AOD, sulfate, and organic aerosol reach their maximum levels because of summertime photochemistry and monsoon moisture. Evidence points to biogenic volatile organic compounds being a significant source of secondary organic aerosol in this region. Biomass burning also is shown to be a major contributor to the carbonaceous aerosol budget in the region, leading to enhanced organic and elemental carbon levels aloft at a sky-island site north of Tucson (Mt. Lemmon). Phoenix exhibits different monthly trends for aerosol components in comparison with the other sites owing to the strong influence of fossil carbon and anthropogenic dust. Trend analyses between 1988 and 2009 indicate that the strongest statistically significant trends are reductions in sulfate, elemental carbon, and organic carbon, and increases in fine soil during the spring (March-May) at select sites. These results can be explained by population growth, land-use changes, and improved source controls.

  1. Quantitative assessment of surf-produced sea spray aerosol

    NARCIS (Netherlands)

    Neele, F.P.; De Leeuw, G.; Jansen, M.; Stive, M.J.F.

    1998-01-01

    The first results are presented from a quantitative model describing the aerosol production in the surf zone. A comparison is made with aerosol produced in the surf zone as measured during EOPACE experiments in La Jolla and Monterey. The surf aerosol production was derived from aerosol concentration

  2. Poisoning in Industrial Workers by the Insecticide Aldrin

    Science.gov (United States)

    Kazantzis, G.; McLaughlin, A. I. G.; Prior, Pamela F.

    1964-01-01

    A 23-year-old worker in a formulating plant developed epileptiform convulsions after a short period of heavy exposure to the chlorinated hydrocarbon insecticide aldrin. He was found to have a high concentration in body fat of hexachloro-epoxy-octahydro-dimethanonaphthalene(H.E.O.D.), the principal metabolite of aldrin, and transient electroencephalographic abnormalities. Nine exposed workers from the same factory were examined, and two of these had symptoms suggestive of aldrin poisoning. At a later date one of these two men and one other man developed convulsions associated with abnormalities of the electroencephalogram and high concentrations of H.E.O.D. in body fat. The concentrations of H.E.O.D. in body fat and also in blood and the electroencephalogram were found to be useful in diagnosis, and their value is discussed. PMID:14106135

  3. Environmental risks and challenges associated with neonicotinoid insecticides

    Science.gov (United States)

    Hladik, Michelle L.; Main, Anson; Goulson, Dave

    2018-01-01

    Neonicotinoid use has increased rapidly in recent years, with a global shift towards insecticide applications as seed coatings rather than aerial spraying. While the use of seed coatings can lessen the amount of overspray and drift, the near universal and prophylactic use of neonicotinoid seed coatings on major agricultural crops has led to widespread detections in the environment (pollen, soil, water, honey). Pollinators and aquatic insects appear to be especially susceptible to the effects of neonicotinoids with current research suggesting that chronic sub-lethal effects are more prevalent than acute toxicity. Meanwhile, evidence of clear and consistent yield benefits from the use of neonicotinoids remains elusive for most crops. Future decisions on neonicotinoid use will benefit from weighing crop yield benefits versus environmental impacts to non-target organisms and considering whether there are more environmentally benign alternatives.

  4. Toxicity of a neonicotinoid insecticide, guadipyr, in earthworm (Eisenia fetida).

    Science.gov (United States)

    Wang, Kai; Mu, Xiyan; Qi, Suzhen; Chai, Tingting; Pang, Sen; Yang, Yang; Wang, Chengju; Jiang, Jiazhen

    2015-04-01

    Neonicotinoid insecticides are new class of pesticides and it is very meaningful to evaluate the toxicity of guadipyr to earthworm (Eisenia fetida). In the present study, effects of guadipyr on reproduction, growth, catalase(CAT), superoxide dismutase (SOD), acetylcholinesterase (AChE) and DNA damage in earthworm were assessed using an artificial soil medium. Guadipyr showed low toxicity to earthworms and did not elicit an effect on earthworm reproduction or growth in artificial soils at concentrations earthworm increased and then decreased to control level. AChE activity decreased at day 3 at 50 and 100mg/kg and then increased to control level. Our data indicate that guadipyr did not induce DNA damage in earthworms at concentration of <100mg/kg. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. Vegetative growth and yield of tomato (Lycopersicum esculentum Mill.) in response to the systemic insecticide phorate

    OpenAIRE

    Raul N. C. Guedes; Guedes,Nelsa M. P.; Picanço,Marcelo

    1998-01-01

    The effect of the systemic insecticide phorate on vegetative growth and yield of tomato (Lycopersicum esculentum Mill.) was studied in the greenhouse. Three dosages of phorate (1.5, 7.5, and 13.5 mg a.i./ 1.5 L pot) were applied along with a control (without insecticide application). The plants were harvested at 17, 32, 51, 69, and 90 days after tilling. Regression analysis did not show any significant effect of insecticide dosages in plant and root length. However, an overall negative effect...

  6. Degradation of insecticides used for indoor spraying in malaria control and possible solutions

    Directory of Open Access Journals (Sweden)

    Massinga Pedro

    2011-10-01

    Full Text Available Abstract Background The insecticide dichloro-diphenyl-trichloroethane (DDT is widely used in indoor residual spraying (IRS for malaria control owing to its longer residual efficacy in the field compared to other World Health Organization (WHO alternatives. Suitable stabilization to render these alternative insecticides longer lasting could provide a less controversial and more acceptable and effective alternative insecticide formulations than DDT. Methods This study sought to investigate the reasons behind the often reported longer lasting behaviour of DDT by exposing all the WHO approved insecticides to high temperature, high humidity and ultra-violet light. Interactions between the insecticides and some mineral powders in the presence of an aqueous medium were also tested. Simple insecticidal paints were made using slurries of these mineral powders whilst some insecticides were dispersed into a conventional acrylic paint binder. These formulations were then spray painted on neat and manure coated mud plaques, representative of the material typically used in rural mud houses, at twice the upper limit of the WHO recommended dosage range. DDT was applied directly onto mud plaques at four times the WHO recommended concentration and on manure plaques at twice WHO recommended concentration. All plaques were subjected to accelerated ageing conditions of 40°C and a relative humidity of 90%. Results The pyrethroids insecticides outperformed the carbamates and DDT in the accelerated ageing tests. Thus UV exposure, high temperature oxidation and high humidity per se were ruled out as the main causes of failure of the alternative insecticides. Gas chromatography (GC spectrograms showed that phosphogypsum stabilised the insecticides the most against alkaline degradation (i.e., hydrolysis. Bioassay testing showed that the period of efficacy of some of these formulations was comparable to that of DDT when sprayed on mud surfaces or cattle manure coated

  7. Degradation of insecticides used for indoor spraying in malaria control and possible solutions.

    Science.gov (United States)

    Sibanda, Mthokozisi M; Focke, Walter W; Labuschagne, Frederick J W J; Moyo, Lumbidzani; Nhlapo, Nontete S; Maity, Arjun; Muiambo, Herminio; Massinga, Pedro; Crowther, Nico A S; Coetzee, Maureen; Brindley, Gordon W A

    2011-10-18

    The insecticide dichloro-diphenyl-trichloroethane (DDT) is widely used in indoor residual spraying (IRS) for malaria control owing to its longer residual efficacy in the field compared to other World Health Organization (WHO) alternatives. Suitable stabilization to render these alternative insecticides longer lasting could provide a less controversial and more acceptable and effective alternative insecticide formulations than DDT. This study sought to investigate the reasons behind the often reported longer lasting behaviour of DDT by exposing all the WHO approved insecticides to high temperature, high humidity and ultra-violet light. Interactions between the insecticides and some mineral powders in the presence of an aqueous medium were also tested. Simple insecticidal paints were made using slurries of these mineral powders whilst some insecticides were dispersed into a conventional acrylic paint binder. These formulations were then spray painted on neat and manure coated mud plaques, representative of the material typically used in rural mud houses, at twice the upper limit of the WHO recommended dosage range. DDT was applied directly onto mud plaques at four times the WHO recommended concentration and on manure plaques at twice WHO recommended concentration. All plaques were subjected to accelerated ageing conditions of 40°C and a relative humidity of 90%. The pyrethroids insecticides outperformed the carbamates and DDT in the accelerated ageing tests. Thus UV exposure, high temperature oxidation and high humidity per se were ruled out as the main causes of failure of the alternative insecticides. Gas chromatography (GC) spectrograms showed that phosphogypsum stabilised the insecticides the most against alkaline degradation (i.e., hydrolysis). Bioassay testing showed that the period of efficacy of some of these formulations was comparable to that of DDT when sprayed on mud surfaces or cattle manure coated surfaces. Bioassay experiments indicated that

  8. Insecticidal heterolignans--tubuline polymerization inhibitors with activity against chewing pests.

    Science.gov (United States)

    Frackenpohl, Jens; Adelt, Isabelle; Antonicek, Horst; Arnold, Christian; Behrmann, Patricia; Blaha, Nicole; Böhmer, Jutta; Gutbrod, Oliver; Hanke, Roman; Hohmann, Sabine; van Houtdreve, Marc; Lösel, Peter; Malsam, Olga; Melchers, Martin; Neufert, Valentina; Peschel, Elisabeth; Reckmann, Udo; Schenke, Thomas; Thiesen, Hans-Peter; Velten, Robert; Vogelsang, Kathrin; Weiss, Hans-Christoph

    2009-06-15

    Starting from natural product podophyllotoxin 1 substituted heterolignans were identified with promising insecticidal in vivo activity. The impact of substitution in each segment of the core structure was investigated in a detailed SAR study, and variation of substituents in both aromatic moieties afforded derivatives 5 and 43 with broad insecticidal activity against lepidopteran and coleopteran species. In vitro measurements supported by modeling studies indicate that heterolignans 3-134 act as tubuline polymerization inhibitors interacting with the colchicine-binding site. Insect specific structure-activity effects were observed showing that the insecticidal SAR described herein differs from reported cytotoxicity studies.

  9. Intervalos entre tratamentos inseticidas Interval between insecticide treatments

    Directory of Open Access Journals (Sweden)

    Luiz O. T. Mendes

    1959-01-01

    Full Text Available Admitindo que as populações de insetos crescem segundo a lei logística, o autor, partindo de uma equação que a descreve, apresenta uma fórmula que permite estabelecer o intervalo de tempo que deve decorrer entre os tratamentos inseticidas, para que a infestação por uma praga não exceda um limite pré-estabelecido. O valor de t (intervalo, expresso em número de gerações do inseto depende do potencial biótico da espécie, da eficiência do inseticida e do nível de infestação que se estabelecer como máximo permissível. Os resultados teóricos são discutidos e mostram a possibilidade de sua comprovação por meio de populações de insetos mantidas em laboratório, como fase preliminar à sua aplicação no campo.Based on the assumption that the growth of insect populations follows the logistic law, the author developed an equation for the determination of the time interval between insecticide treatments: t= {lpg [100-Po (1-E / (1 - E (100 -Po]} / log p where t = time interval between treatments expressed in number of generations of the species; Po = maximum percentage of infestation, that must not be surpassed (from 0,00 to 100,00; E = efficiency of the insecticide (from 0,00 to 1,00; p = reproduction potential of the species. The theoretical results are discussed.

  10. Smoke and Pollution Aerosol Effect on Cloud Cover

    Science.gov (United States)

    Kaufman, Yoram J.; Koren, Ilan

    2006-01-01

    Pollution and smoke aerosols can increase or decrease the cloud cover. This duality in the effects of aerosols forms one of the largest uncertainties in climate research. Using solar measurements from Aerosol Robotic Network sites around the globe, we show an increase in cloud cover with an increase in the aerosol column concentration and an inverse dependence on the aerosol absorption of sunlight. The emerging rule appears to be independent of geographical location or aerosol type, thus increasing our confidence in the understanding of these aerosol effects on the clouds and climate. Preliminary estimates suggest an increase of 5% in cloud cover.

  11. Photochemistry on Pluto - I. Hydrocarbons and aerosols

    Science.gov (United States)

    Luspay-Kuti, Adrienn; Mandt, Kathleen; Jessup, Kandis-Lea; Kammer, Joshua; Hue, Vincent; Hamel, Mark; Filwett, Rachael

    2017-11-01

    In light of the recent New Horizons flyby measurements, we present a coupled ion-neutral-photochemistry model developed for simulating the atmosphere of Pluto. Our model results closely match the observed density profiles of CH4, N2 and the C2 hydrocarbons in the altitude range where available New Horizons measurements are most accurate (above ∼100-200 km). We found a high eddy coefficient of 106 cm2 s-1 from the surface to an altitude of 150 km, and 3 × 106 cm2 s-1 above 150 km for Pluto's atmosphere. Our results demonstrate that C2 hydrocarbons must stick to and be removed by aerosol particles in order to reproduce the C2 profiles observed by New Horizons. Incorporation into aerosols in Pluto's atmosphere is a significantly more effective process than condensation, and we found that condensation alone cannot account for the observed shape of the vertical profiles. We empirically determined the sticking efficiency of C2 hydrocarbons to aerosol particles as a function of altitude, and found that the sticking efficiency of C2 hydrocarbons is inversely related to the aerosol surface area. Aerosols must harden and become less sticky as they age in Pluto's atmosphere. Such hardening with ageing is both necessary and sufficient to explain the vertical profiles of C2 hydrocarbons in Pluto's atmosphere. This result is in agreement with the fundamental idea of aerosols hardening as they age, as proposed for Titan's aerosols.

  12. Aerosol Angstrom Absorption Coefficient Comparisons during MILAGRO.

    Science.gov (United States)

    Marley, N. A.; Marchany-Rivera, A.; Kelley, K. L.; Mangu, A.; Gaffney, J. S.

    2007-12-01

    Measurements of aerosol absorption were obtained as part of the MAX-Mex component of the MILAGRO field campaign at site T0 (Instituto Mexicano de Petroleo in Mexico City) by using a 7-channel aethalometer (Thermo- Anderson) during the month of March, 2006. The absorption measurements obtained in the field at 370, 470, 520, 590, 660, 880, and 950 nm were used to determine the aerosol Angstrom absorption exponents by linear regression. Since, unlike other absorbing aerosol species (e.g. humic like substances, nitrated PAHs), black carbon absorption is relatively constant from the ultraviolet to the infrared with an Angstrom absorption exponent of -1 (1), a comparison of the Angstrom exponents can indicate the presence of aerosol components with an enhanced UV absorption over that expected from BC content alone. The Angstrom exponents determined from the aerosol absorption measurements obtained in the field varied from - 0.7 to - 1.3 during the study and was generally lower in the afternoon than the morning hours, indicating an increase in secondary aerosol formation and photochemically generated UV absorbing species in the afternoon. Twelve-hour integrated samples of fine atmospheric aerosols (Petroleo (IMP) and CENICA.

  13. Condensing Organic Aerosols in a Microphysical Model

    Science.gov (United States)

    Gao, Y.; Tsigaridis, K.; Bauer, S.

    2015-12-01

    The condensation of organic aerosols is represented in a newly developed box-model scheme, where its effect on the growth and composition of particles are examined. We implemented the volatility-basis set (VBS) framework into the aerosol mixing state resolving microphysical scheme Multiconfiguration Aerosol TRacker of mIXing state (MATRIX). This new scheme is unique and advances the representation of organic aerosols in models in that, contrary to the traditional treatment of organic aerosols as non-volatile in most climate models and in the original version of MATRIX, this new scheme treats them as semi-volatile. Such treatment is important because low-volatility organics contribute significantly to the growth of particles. The new scheme includes several classes of semi-volatile organic compounds from the VBS framework that can partition among aerosol populations in MATRIX, thus representing the growth of particles via condensation of low volatility organic vapors. Results from test cases representing Mexico City and a Finish forrest condistions show good representation of the time evolutions of concentration for VBS species in the gas phase and in the condensed particulate phase. Emitted semi-volatile primary organic aerosols evaporate almost completely in the high volatile range, and they condense more efficiently in the low volatility range.

  14. In Situ Measurement of Aerosol Extinction

    Science.gov (United States)

    Strawa, Anthony W.; Castaneda, R.; Owano, T. G.; Bear, D.; Gore, Warren J. (Technical Monitor)

    2001-01-01

    Aerosols are important contributors to the radiative forcing in the atmosphere. Much of the uncertainty in our knowledge of climate forcing is due to uncertainties in the radiative forcing due to aerosols as illustrated in the IPCC reports of the last ten years. Improved measurement of aerosol optical properties, therefore, is critical to an improved understanding of atmospheric radiative forcing. Additionally, attempts to reconcile in situ and remote measurements of aerosol radiative properties have generally not been successful. This is due in part to the fact that it has been impossible to measure aerosol extinction in situ in the past. In this presentation we introduce a new instrument that employs the techniques used in cavity ringdown spectroscopy to measure the aerosol extinction and scattering coefficients in situ. A prototype instrument has been designed and tested in the lab and the field. It is capable of measuring aerosol extinction coefficient to 2x10(exp -6) per meter. This prototype instrument is described and results are presented.

  15. Effect of aerosol vertical distribution on aerosol-radiation interaction: A theoretical prospect.

    Science.gov (United States)

    Mishra, Amit Kumar; Koren, Ilan; Rudich, Yinon

    2015-10-01

    This study presents a theoretical investigation of the effect of the aerosol vertical distribution on the aerosol radiative effect (ARE). Four aerosol composition models (dust, polluted dust, pollution and pure scattering aerosols) with varying aerosol vertical profiles are incorporated into a radiative transfer model. The simulations show interesting spectral dependence of the ARE on the aerosol layer height. ARE increases with the aerosol layer height in the ultraviolet (UV: 0.25-0.42 μm) and thermal-infrared (TH-IR: 4.0-20.0 μm) regions, whereas it decreases in the visible-near infrared (VIS-NIR: 0.42-4.0 μm) region. Changes in the ARE with aerosol layer height are associated with different dominant processes for each spectral region. The combination of molecular (Rayleigh) scattering and aerosol absorption is the key process in the UV region, whereas aerosol (Mie) scattering and atmospheric gaseous absorption are key players in the VIS-NIR region. The longwave emission fluxes are controlled by the environmental temperature at the aerosol layer level. ARE shows maximum sensitivity to the aerosol layer height in the TH-IR region, followed by the UV and VIS-NIR regions. These changes are significant even in relatively low aerosol loading cases (aerosol optical depth ∼0.2-0.3). Dust aerosols are the most sensitive to altitude followed by polluted dust and pollution in all three different wavelength regions. Differences in the sensitivity of the aerosol type are explained by the relative strength of their spectral absorption/scattering properties. The role of surface reflectivity on the overall altitude dependency is shown to be important in the VIS-NIR and UV regions, whereas it is insensitive in the TH-IR region. Our results indicate that the vertical distribution of water vapor with respect to the aerosol layer is an important factor in the ARE estimations. Therefore, improved estimations of the water vapor profiles are needed for the further reduction in

  16. Effect of aerosol vertical distribution on aerosol-radiation interaction: A theoretical prospect

    Directory of Open Access Journals (Sweden)

    Amit Kumar Mishra

    2015-10-01

    Full Text Available This study presents a theoretical investigation of the effect of the aerosol vertical distribution on the aerosol radiative effect (ARE. Four aerosol composition models (dust, polluted dust, pollution and pure scattering aerosols with varying aerosol vertical profiles are incorporated into a radiative transfer model. The simulations show interesting spectral dependence of the ARE on the aerosol layer height. ARE increases with the aerosol layer height in the ultraviolet (UV: 0.25–0.42 μm and thermal-infrared (TH-IR: 4.0–20.0 μm regions, whereas it decreases in the visible-near infrared (VIS-NIR: 0.42–4.0 μm region. Changes in the ARE with aerosol layer height are associated with different dominant processes for each spectral region. The combination of molecular (Rayleigh scattering and aerosol absorption is the key process in the UV region, whereas aerosol (Mie scattering and atmospheric gaseous absorption are key players in the VIS-NIR region. The longwave emission fluxes are controlled by the environmental temperature at the aerosol layer level. ARE shows maximum sensitivity to the aerosol layer height in the TH-IR region, followed by the UV and VIS-NIR regions. These changes are significant even in relatively low aerosol loading cases (aerosol optical depth ∼0.2–0.3. Dust aerosols are the most sensitive to altitude followed by polluted dust and pollution in all three different wavelength regions. Differences in the sensitivity of the aerosol type are explained by the relative strength of their spectral absorption/scattering properties. The role of surface reflectivity on the overall altitude dependency is shown to be important in the VIS-NIR and UV regions, whereas it is insensitive in the TH-IR region. Our results indicate that the vertical distribution of water vapor with respect to the aerosol layer is an important factor in the ARE estimations. Therefore, improved estimations of the water vapor profiles are needed for the

  17. Comparison of aerosol lidar retrieval methods for boundary layer height detection using ceilometer aerosol backscatter data

    Science.gov (United States)

    Caicedo, Vanessa; Rappenglück, Bernhard; Lefer, Barry; Morris, Gary; Toledo, Daniel; Delgado, Ruben

    2017-04-01

    Three algorithms for estimating the boundary layer heights are assessed: an aerosol gradient method, a cluster analysis method, and a Haar wavelet method. Over 40 daytime clear-sky radiosonde profiles are used to compare aerosol backscatter boundary layer heights retrieved by a Vaisala CL31 ceilometer. Overall good agreement between radiosonde- and aerosol-derived boundary layer heights was found for all methods. The cluster method was found to be particularly sensitive to noise in ceilometer signals and lofted aerosol layers (48.8 % of comparisons), while the gradient method showed limitations in low-aerosol-backscatter conditions. The Haar wavelet method was demonstrated to be the most robust, only showing limitations in 22.5 % of all observations. Occasional differences between thermodynamically and aerosol-derived boundary layer heights were observed.

  18. Secondary organic aerosols: Formation potential and ambient data

    DEFF Research Database (Denmark)

    Barthelmie, R.J.; Pryor, S.C.

    1997-01-01

    Organic aerosols comprise a significant fraction of the total atmospheric particle loading and are associated with radiative forcing and health impacts. Ambient organic aerosol concentrations contain both a primary and secondary component. Herein, fractional aerosol coefficients (FAC) are used...... in conjunction with measurements of volatile organic compounds (VOC) to predict the formation potential of secondary organic aerosols (SOA) in the Lower Fraser Valley (LEV) of British Columbia. The predicted concentrations of SOA show reasonable accord with ambient aerosol measurements and indicate considerable...

  19. CARES: Carbonaceous Aerosol and Radiative Effects Study Science Plan

    Energy Technology Data Exchange (ETDEWEB)

    Zaveri, RA; Shaw, WJ; Cziczo, DJ

    2010-05-27

    Carbonaceous aerosol components, which include black carbon (BC), urban primary organic aerosols (POA), biomass burning aerosols, and secondary organic aerosols (SOA) from both urban and biogenic precursors, have been previously shown to play a major role in the direct and indirect radiative forcing of climate. The primary objective of the CARES 2010 intensive field study is to investigate the evolution of carbonaceous aerosols of different types and their effects on optical and cloud formation properties.

  20. Air aerosol pollution and lidar measurements

    Science.gov (United States)

    Yegorov, Alexander D.; Kopp, Ilia Z.; Perelman, Anri Y.

    1995-09-01

    The means and techniques of lidar sounding are nowadays widely used to obtain the data on the aerosol pollution of the atmosphere, including the industrial emissions and atmospheric characteristics around highways. To add to that scope, pioneering unconventional lidar sounding of optical and microphysical aerosol characteristics was organized during the recent field programs: CLE (Leningrad, 1984), Soviet-American AUTOEX experiment (Leningrad, 1988), Leningrad experiment (1991). The paper presents lidar data obtained from these programs. The problem of interpreting lidar measurements data is discussed. The relationships between optical and microphysical aerosol characteristics are analysed.

  1. Capstone Depleted Uranium Aerosols: Generation and Characterization

    Energy Technology Data Exchange (ETDEWEB)

    Parkhurst, MaryAnn; Szrom, Fran; Guilmette, Ray; Holmes, Tom; Cheng, Yung-Sung; Kenoyer, Judson L.; Collins, John W.; Sanderson, T. Ellory; Fliszar, Richard W.; Gold, Kenneth; Beckman, John C.; Long, Julie

    2004-10-19

    In a study designed to provide an improved scientific basis for assessing possible health effects from inhaling depleted uranium (DU) aerosols, a series of DU penetrators was fired at an Abrams tank and a Bradley fighting vehicle. A robust sampling system was designed to collect aerosols in this difficult environment and continuously monitor the sampler flow rates. Aerosols collected were analyzed for uranium concentration and particle size distribution as a function of time. They were also analyzed for uranium oxide phases, particle morphology, and dissolution in vitro. The resulting data provide input useful in human health risk assessments.

  2. Implementation of bin scheme into sulfate aerosol module in aerosol climate model

    Science.gov (United States)

    Yamaguchi, Y.; Takemura, T.; Suzuki, K.; Goto, D.

    2012-12-01

    Atmospheric aerosols are known for inducing climate change, but uncertainty still remains about the assessment of aerosol climate impact. More accurate evaluation of their effects on climate system requires to reduce uncertainty of estimation of the entire climate change. Thus we are implementing a bin scheme into an aerosol transport-climate model, SPRINTARS, which is coupled with an AORI/NIES/JAMSTEC climate model, MIROC [Takemura et al., 2000, 2002, 2005, 2009] to refine the representation of interactions between aerosol particles and cloud droplets as well as the aerosol-radiation interaction. The scheme can represent the aerosol size distribution explicitly by segregating to a finite number of bins incorporating aerosol nucleation, condensation, and coagulation processes in detail. Nucleation of sulfuric acid is parameterized using Gong et al. [2003]. Based on a single column model [Suzuki et al., 2006, 2010], the condensation of sulfuric acid on pre-existing aerosol particles and the coagulation of sulfate aerosol particles are parameterized by the methods proposed by Bott [1989] and Bott [1997], respectively. The radii of sulfate aerosols range from 0.01μm to 1.0μm and are split into 20 bins. Implementation of the bin scheme into the aerosol model resulted in characteristic aerosol size distribution and indicated possibilities of representation of microphysical and optical properties in more detail. We will report the results of comparison between the original and the improved SPRINTARS. This work is supported by the Funding Program for Next Generation World-Leading Researchers (GR079).

  3. Natural Radionuclides and Isotopic Signatures for Determining Carbonaceous Aerosol Sources, Aerosol Lifetimes, and Washout Processes

    Energy Technology Data Exchange (ETDEWEB)

    Gaffney, Jeffrey [Univ. of Arkansas, Little Rock, AR (United States)

    2012-12-12

    This is the final technical report. The project description is as follows: to determine the role of aerosol radiative forcing on climate, the processes that control their atmospheric concentrations must be understood, and aerosol sources need to be determined for mitigation. Measurements of naturally occurring radionuclides and stable isotopic signatures allow the sources, removal and transport processes, as well as atmospheric lifetimes of fine carbonaceous aerosols, to be evaluated.

  4. The Two‐Column Aerosol Project: Phase I—Overview and impact of elevated aerosol layers on aerosol optical depth

    National Research Council Canada - National Science Library

    Berg, Larry K; Fast, Jerome D; Barnard, James C; Burton, Sharon P; Cairns, Brian; Chand, Duli; Comstock, Jennifer M; Dunagan, Stephen; Ferrare, Richard A; Flynn, Connor J; Hair, Johnathan W; Hostetler, Chris A; Hubbe, John; Jefferson, Anne; Johnson, Roy; Kassianov, Evgueni I; Kluzek, Celine D; Kollias, Pavlos; Lamer, Katia; Lantz, Kathleen; Mei, Fan; Miller, Mark A; Michalsky, Joseph; Ortega, Ivan; Pekour, Mikhail; Rogers, Ray R; Russell, Philip B; Redemann, Jens; Sedlacek, Arthur J; Segal‐Rosenheimer, Michal; Schmid, Beat; Shilling, John E; Shinozuka, Yohei; Springston, Stephen R; Tomlinson, Jason M; Tyrrell, Megan; Wilson, Jacqueline M; Volkamer, Rainer; Zelenyuk, Alla; Berkowitz, Carl M

    2016-01-01

    The Two‐Column Aerosol Project (TCAP), conducted from June 2012 through June 2013, was a unique study designed to provide a comprehensive data set that can be used to investigate a number of important climate science questions, including...

  5. Preparation of a Novel Water-based Acrylic Multi-Thermal Insulation Coating

    Directory of Open Access Journals (Sweden)

    Xiufang YE

    2017-08-01

    Full Text Available To efficiently improve the thermal insulation effect of coatings, a novel water-based acrylic multi-thermal insulation coating (multi-WATIC combined with thermal obstruction, echo, and radiation was prepared. The category and ratio of thermal insulation functional fillers are crucial. First, water-based acrylic thermal insulation coating (WATIC with single thermal insulation functional fillers was prepared, and the thermal insulation property tests were done. Thereafter, a novel multi-WATIC was prepared combined with the 3 thermal insulation functional fillers together, and the formula of the novel multi-WATIC was optimized based on single factor experiments by response surface methodology (RSM. Test results showed that multi-WATIC has excellent thermal insulation property, and the fitting result obtained by RSM is in good agreement with test data.DOI: http://dx.doi.org/10.5755/j01.ms.23.2.16090

  6. Production of Natural Rubber Grafted Styrene Copolymer Latex as Water Base Coatings

    Directory of Open Access Journals (Sweden)

    M Utama

    2006-07-01

    Full Text Available Twelve kinds formulation of natural rubber grafted copolymer styrene (NR-g-S prepared by gamma radiation co-polymerization technique has been carried out. The characteristic of NR-g-S and its water base coating such as molecular structure, particle size, and the properties of latex and its film were evaluated. The results showed that the NR-g-S latex as a water base coating has low viscosity, height strength, good grease resistance, good flexibility, good aging and corrosion resistance on concrete cement and metal. The average particle size is between 270-300 nm, and the bonding between poly-isoprene of NRL and styrene molecules were grafted copolymer

  7. The Two-Column Aerosol Project: Phase I - Overview and Impact of Elevated Aerosol Layers on Aerosol Optical Depth

    Science.gov (United States)

    Berg, Larry K.; Fast, Jerome D.; Barnard, James C.; Burton, Sharon P.; Cairns, Brian; Chand, Duli; Comstock, Jennifer M.; Dunagan, Stephen; Ferrare, Richard A.; Flynn, Connor J.; hide

    2015-01-01

    The Two-Column Aerosol Project (TCAP), conducted from June 2012 through June 2013, was a unique study designed to provide a comprehensive data set that can be used to investigate a number of important climate science questions, including those related to aerosol mixing state and aerosol radiative forcing. The study was designed to sample the atmosphere be tween and within two atmospheric columns; one fixed near the coast of North America (over Cape Cod, MA) and a second moveable column over the Atlantic Ocean several hundred kilometers from the coast. The U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Mobile Facility (AMF) was deployed at the base of the Cape Cod column, and the ARM Aerial Facility was utilized for the summer and winter intensive observation periods. One important finding from TCAP is that four of six nearly cloud-free flight days had aerosol layers aloft in both the Cape Cod and maritime columns that were detected using the nadir pointing second-generation NASA high-spectral resolution lidar (HSRL-2).These layer s contributed up to 60 of the total observed aerosol optical depth (AOD). Many of these layers were also intercepted by the aircraft configured for in situ sampling, and the aerosol in the layers was found to have increased amounts of biomass burning material and nitrate compared to aerosol found near the surface. In addition, while there was a great deal of spatial and day-to-day variability in the aerosol chemical composition and optical properties, no systematic differences between the two columns were observed.

  8. The Two-Column Aerosol Project: Phase I - Overview and Impact of Elevated Aerosol Layers on Aerosol Optical Depth

    Energy Technology Data Exchange (ETDEWEB)

    Berg, Larry K.; Fast, Jerome D.; Barnard, James C.; Burton, Sharon; Cairns, Brian; Chand, Duli; Comstock, Jennifer M.; Dunagan, Stephen; Ferrare, Richard A.; Flynn, Connor J.; Hair, John; Hostetler, Chris A.; Hubbe, John M.; Jefferson, Anne; Johnson, Roy; Kassianov, Evgueni I.; Kluzek, Celine D.; Kollias, Pavlos; Lamer, Katia; Lantz, K.; Mei, Fan; Miller, Mark A.; Michalsky, Joseph; Ortega, Ivan; Pekour, Mikhail S.; Rogers, Ray; Russell, P.; Redemann, Jens; Sedlacek, Art; Segal Rozenhaimer, Michal; Schmid, Beat; Shilling, John E.; Shinozuka, Yohei; Springston, Stephen R.; Tomlinson, Jason M.; Tyrrell, Megan; Wilson, Jacqueline; Volkamer, Rainer M.; Zelenyuk, Alla; Berkowitz, Carl M.

    2016-01-08

    The Two-Column Aerosol Project (TCAP), which was conducted from June 2012 through June 2013, was a unique field study that was designed to provide a comprehensive data set that can be used to investigate a number of important climate science questions, including those related to aerosol mixing state and aerosol radiative forcing. The study was designed to sample the atmosphere at a number of altitudes, from near the surface to as high as 8 km, within two atmospheric columns; one located near the coast of North America (over Cape Cod, MA) and a second over the Atlantic Ocean several hundred kilometers from the coast. TCAP included the yearlong deployment of the U.S. Department of Energy’s (DOE) Atmospheric Radiation Measurement (ARM) Mobile Facility (AMF) that was located at the base of the Cape Cod column, as well as summer and winter aircraft intensive observation periods of the ARM Aerial Facility. One important finding from TCAP is the relatively common occurrence (on four of six nearly cloud-free flights) of elevated aerosol layers in both the Cape Cod and maritime columns that were detected using the nadir pointing second-generation NASA high-spectral resolution lidar (HSRL-2). These layers contributed up to 60% of the total aerosol optical depth (AOD) observed in the column. Many of these layers were also intercepted by the aircraft configured for in situ sampling, and the aerosol in the layers was found to have increased amounts of biomass burning aerosol and nitrate compared to the aerosol found near the surface.

  9. Aerosols Produced by Cosmic Rays

    DEFF Research Database (Denmark)

    Enghoff, Martin Andreas Bødker

    , it will be possible to develop the experiment to cover additional processes involved in the route to cloud droplet formation. The experiment will be conducted at the Danish National Space Center where a clean room facility has been provided. It comprises a 7 m3 reaction chamber across which an electric field......Satellite observations have shown that the Earth’s cloud cover is strongly correlated with the galactic cosmic ray flux. While this correlation is indicative of a possible physical connection, there is currently no confirmation that a physical mechanism exists. We are therefore setting up...... mechanism linking cosmic rays to clouds and climate is currently speculative, there have been various suggestions of the role atmospheric ions may play; these involve any one of a number of processes from the nucleation of aerosols up to the collection processes of cloud droplets. We have chosen to start...

  10. Southern Hemisphere tropospheric aerosol microphysics

    Science.gov (United States)

    Gras, John L.

    1991-01-01

    Aerosol particle-size distribution data have been obtained in the Southern Hemisphere from approximately 4-deg S to 44-deg S and between ground level and 5 km, in the vicinity of eastern Australia. The relative shape of the free-tropospheric size distribution for particles with radii larger than approximately 0.04 micron was found to be remarkably stable with time, altitude, and location for the autumn-winter periods considered. This was despite some large concentration changes, which were found to be typical of the southeastern Australian coastal region. The majority of free-troposphere large particles were found to have sulfuric acid or lightly ammoniated sulfate morphology. Large particles in the boundary layer almost exclusively had a sea-salt morphology.

  11. Outcome of Patients with Cholinergic Insecticide Poisoning Treated with Gastric Lavage: A Prospective Observational Cohort Study

    Directory of Open Access Journals (Sweden)

    Mekkattukunnel Andrews

    2014-12-01

    Conclusion: Number or timing of GL does not show any association with mortality while multiple GL had protective effect against development of late RF and IMS. Hence, GL might be beneficial in cholinergic insecticide poisoning.

  12. HPLC-MS/MS method for the measurement of insecticide degradates in baby food.

    Science.gov (United States)

    Radford, Samantha A; Panuwet, Parinya; Hunter, Ronald E; Barr, Dana Boyd; Ryan, P Barry

    2014-07-23

    A solid phase extraction method was developed to isolate four insecticide degradates from baby food that were measured subsequently using high-performance liquid chromatography-tandem mass spectrometry. The degradates [parent insecticide] measured were malathion dicarboxylic acid [malathion], 3,5,6-trichloro-2-pyridinol [chlorpyrifos, chlorpyrifos methyl] (TCPy), cis/trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid [permethrin, cypermethrin, cyfluthrin], and 3-phenoxybenzoic acid [general pyrethroid]. All degradates produced recoveries between 80 and 120% except TCPy in fruit (122% recovery), and all relative standard deviations were foods frequently purchased in the United States, supporting the need for this method. These data will assist in differentiating whether biomarker levels of insecticide metabolites are the result of exposures to the toxic insecticide or its preformed degradate.

  13. Control of sugar beet pests at early season by seed treatment with insecticides

    Directory of Open Access Journals (Sweden)

    Kereši Tatjana

    2006-01-01

    Full Text Available In the period 2001-2004, experiments were conducted in the region of Bačka (northern Serbia to assess the efficiency of insecticide treatment of sugar beet seeds in controlling soil pests (larvae of Elateridae family and reducing the damage caused by beet weevil (Bothynoderes punctiventris G e r m and flea beetle (Chaetocnema tibialis I l l i g. Several insecticides mostly systemic ones (carbofuran, thiamethoxam, fipronil, imidacloprid and clothianidin, and their combinations with pyrethroids in different doses were tested in field conditions. Stand density, percentages of plants damaged by B. punctiventris and C. tibialis, injury level and weight of juvenile plants served as parameters for evaluation of insecticide efficiency. Most of the insecticides applied to seeds provided a significantly better stand density compared with the untreated control. Because of their systemic action, imidacloprid, thiamethoxam and their mixtures with pyrethroids provided very good protection of juvenile plants from C. tibialis and in some cases from B. punctiventris.

  14. ENANTIOSELECTIVE MICROBIAL TRANSFORMATION OF THE PHENYLPYRAZOLE INSECTICIDE FIPRONIL IN ANOXIC SEDIMENTS

    Science.gov (United States)

    Fipronil, a chiral insecticide, was biotransformed initially to fipronil sulfide in anoxic sediment slurries following a short lag period. Sediment slurries characterized as either sulfidogenic or methanogenic transformed fipronil with half-lives of approximately 35 and 40 days, ...

  15. Application of nanotechnology for the encapsulation of botanical insecticides for sustainable agriculture: prospects and promises.

    Science.gov (United States)

    de Oliveira, Jhones Luiz; Campos, Estefânia Vangelie Ramos; Bakshi, Mansi; Abhilash, P C; Fraceto, Leonardo Fernandes

    2014-12-01

    This review article discusses the use of nanotechnology in combination with botanical insecticides in order to develop systems for pest control in agriculture. The main types of botanical insecticides are described, together with different carrier systems and their potential uses. The botanical insecticides include those based on active principles isolated from plant extracts, as well as essential oils derived from certain plants. The advantages offered by the systems are highlighted, together with the main technological challenges that must be resolved prior to future implementation of the systems for agricultural pest control. The use of botanical insecticides associated with nanotechnology offers considerable potential for increasing agricultural productivity, while at the same time reducing impacts on the environment and human health.

  16. Monitoring changes in bemisia tabaci susceptibility to neonicotinoid insecticides in Arizona and California

    Science.gov (United States)

    Laboratory bioassays were carried out on field-collected and laboratory strains of Bemisia tabaci to evaluate relative toxicities of four neonicotinoid insecticides: acetamiprid, dinotefuran, imidacloprid and thiamethoxam. Susceptibility to all four neonicotinoids in leaf-uptake bioassays varied co...

  17. Passive dosing of pyrethroid insecticides to Daphnia magna: Expressing excess toxicity by chemical activity

    DEFF Research Database (Denmark)

    Nørgaard Schmidt, Stine; Gan, Jay; Kretschmann, A. C.

    2015-01-01

    Pyrethroid insecticides are nerve poisons and used as active ingredients in pesticide mixtures available for household and agriculture. The compounds are hydrophobic, and their strong sorption to organic material may result in decreasing exposure levels during toxicity tests and consequent...

  18. STATUS OF INSECTICIDE RESISTANCE IN THE COTTON BOLLWORM, HELICOVERPA ARMIGERA (HUBNER

    Directory of Open Access Journals (Sweden)

    INDIRA CHATURVEDI

    2001-09-01

    Full Text Available The status of insecticide resistance in some fi eld populations of Helicoverpa armigera (Hubner from the main cotton growing regions of central and south India was determined during the cropping seasons of 2001-2005. Seven insecticides viz. endosulfan, methomyl, monocrotophos, quinalphos, chlorpyriphos, fenvalerate and cypermethrin were tested against second-, third- and fi fth-instar Helicoverpa armigera larvae. Dose-mortality regressions, LD50s and their fi ducial limits were computed by probit analysis. Resistance factors (RF were estimated at the LD50 level as RF=LD50 fi eld strain/LD50 susceptible strain. The Helicoverpa armigera (Hubner exhibited widespread resistance (RF=48-919 to cypermethrin. Insecticide resistance to chlorpyriphos was low to moderate in the majority of the strains tested. A substantial inter-strain variation in insecticide resistance was evident.

  19. Effects of insecticidal treatment on the Yield and Control of major ...

    African Journals Online (AJOL)

    DAP) in all the insecticidal treatments were the defoliators, Monolepta duplicata Sahl and Ootheca mutabilis Sahl while the stink bugs, Nezara viridula Linnaeus and Aspavia armigera Fabricius attacked soybean from 56DAP to 86DAP, ...

  20. Insecticide Resistance in Eggs and First Instars of the Bed Bug, Cimex lectularius (Hemiptera: Cimicidae)

    National Research Council Canada - National Science Library

    Brittany E Campbell; Dini M Miller

    2015-01-01

      Two strains of the common bed bug, Cimex lectularius L., eggs and first instars collected from pyrethroid-resistant adults were evaluated for insecticide resistance and compared to a susceptible strain...

  1. Theoretical impact of insecticide-impregnated school uniforms on dengue incidence in Thai children

    National Research Council Canada - National Science Library

    Massad, Eduardo; Amaku, Marcos; Coutinho, Francisco Antonio Bezerra; Kittayapong, Pattamaporn; Wilder-Smith, Annelies

    2013-01-01

    ...; hence strategies that reduce human-mosquito contact to protect against the day-biting habits of Aedes mosquitoes at schools, such as insecticide-impregnated uniforms, could be an effective prevention strategy...

  2. Interaction of insecticide and media moisture on ambrosia beetle (Coleoptera: Curculionidae) attacks on ornamental trees

    Science.gov (United States)

    Exotic ambrosia beetles, particularly Xylosandrus crassiusculus (Motschulsky) and Xylosandrus germanus (Blandford), are among the most economically damaging pests of ornamental trees in nurseries. Growers have had few tactics besides insecticide applications to reduce ambrosia beetle attacks but rec...

  3. Water-based exercise for patients with chronic arm lymphedema: a randomized controlled pilot trial.

    Science.gov (United States)

    Johansson, Karin; Hayes, Sandi; Speck, Rebecca M; Schmitz, Kathryn H

    2013-04-01

    The aim of this study was to evaluate the feasibility and effect of a water-based exercise program on lymphedema status and shoulder range of motion among women with breast cancer-related lymphedema. This was a single-blinded, randomized controlled pilot trial. Twenty-nine eligible breast cancer survivors (median, 10 yrs after surgery) with arm lymphedema (median, 21% interlimb difference) were included and randomized into the intervention (n = 15) or control (n = 14) group. Twenty-five participants completed the study. The intervention was at least twice-weekly water-based exercise for 8 wks, initially supervised but performed independently during the study period. Outcomes of interest were feasibility as measured by retention and adherence; lymphedema status as measured by optoelectronic perometry, bioimpedance spectroscopy, and tissue dielectric constant; and shoulder range of motion as measured by goniometer. Four participants were not measured at postintervention and were not included in the analysis (retention). Four participants in the intervention group did not perform the minimum water-based exercise criteria set (adherence). No effect was found on lymphedema status. Compared with the control group, median range of motion change for flexion was 6 (1-10) degrees (P < 0.001) and 6 (0-15.5) degrees (P = 0.07) for external rotation.A clinically relevant increase in the intervention group was found for 36% in flexion (P ≤ 0.05) and 57% in external rotation (P ≤ 0.05) compared with controls. This study shows that water-based exercise is feasible for breast cancer survivors with arm lymphedema and that shoulder range of motion can be improved years after cancer treatment has been completed.

  4. Standard Test Method for Preparing Aircraft Cleaning Compounds, Liquid Type, Water Base, for Storage Stability Testing

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2002-01-01

    1.1 This test method covers the determination of the stability in storage, of liquid, water-base chemical cleaning compounds, used to clean the exterior surfaces of aircraft. 1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  5. Water-Based Assembly and Purification of Plasmon-Coupled Gold Nanoparticle Dimers and Trimers

    Directory of Open Access Journals (Sweden)

    Sébastien Bidault

    2012-01-01

    Full Text Available We describe a simple one-pot water-based scheme to produce gold nanoparticle groupings with short interparticle spacings. This approach combines a cross-linking molecule and a hydrophilic passivation layer to control the level of induced aggregation. Suspensions of dimers and trimers are readily obtained using a single electrophoretic purification step. The final interparticle spacings allow efficient coupling of the particle plasmon modes as verified in extinction spectroscopy.

  6. Smallest worthwhile effect of land-based and water-based pulmonary rehabilitation for COPD

    Directory of Open Access Journals (Sweden)

    Renae J. McNamara

    2015-06-01

    Full Text Available This study aimed to determine the smallest worthwhile effect of land-based and water-based pulmonary rehabilitation on 6-min walk distance among people with chronic obstructive pulmonary disease (COPD. Using a benefit–harm trade-off method, people with COPD who had completed two baseline 6-min walk tests at the commencement of outpatient pulmonary rehabilitation were presented with two scenarios: 8 weeks of land-based and 8 weeks of water-based pulmonary rehabilitation. Participants were guided through an iterative process allowing them to progressively refine their estimates of the smallest improvement due to each form of rehabilitation that would outweigh the associated costs, risks and inconvenience presented in the scenario. 100 people with COPD participated (mean±sd age 72±9 years, forced expiratory volume in 1 s 54±16% predicted and baseline 6-min walk distance 377±101 m. For land-based pulmonary rehabilitation, the median smallest worthwhile effect was 20 m (95% CI 15–37 m. For water-based pulmonary rehabilitation, the median smallest worthwhile effect was 26 m (95% CI 15–33 m. These estimates did not differ significantly (p=0.10. People with COPD typically perceive that pulmonary rehabilitation would be worthwhile if it increased the 6-min walk distance by about 6%. The smallest worthwhile effects of land- and water-based pulmonary rehabilitation were similar.

  7. Papers of the 14. french congress on aerosols CFA 98; Actes du 14. congres francais sur les aerosols CFA 98

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    This french congress on the aerosols took place in Paris the 8 and 9 december 1998. It was presented in four main themes: the aerosols in the environment; the bio-aerosols, filtering and purifying; the aerosols metrology; the aerosols physic and application. Seven papers have been analyzed in INIS data base for their specific interest in nuclear industry. Eight other ones are analyzed in ETDE data base. (A.L.B.)

  8. Evaluating the efficacy of biological and conventional insecticides with the new 'MCD bottle' bioassay.

    Science.gov (United States)

    Sternberg, Eleanore D; Waite, Jessica L; Thomas, Matthew B

    2014-12-16

    Control of mosquitoes requires the ability to evaluate new insecticides and to monitor resistance to existing insecticides. Monitoring tools should be flexible and low cost so that they can be deployed in remote, resource poor areas. Ideally, a bioassay should be able to simulate transient contact between mosquitoes and insecticides, and it should allow for excito-repellency and avoidance behaviour in mosquitoes. Presented here is a new bioassay, which has been designed to meet these criteria. This bioassay was developed as part of the Mosquito Contamination Device (MCD) project and, therefore, is referred to as the MCD bottle bioassay. Presented here are two experiments that serve as a proof-of-concept for the MCD bottle bioassay. The experiments used four insecticide products, ranging from fast-acting, permethrin-treated, long-lasting insecticide nets (LLINs) that are already widely used for malaria vector control, to the slower acting entomopathogenic fungus, Beauveria bassiana, that is currently being evaluated as a prospective biological insecticide. The first experiment used the MCD bottle to test the effect of four different insecticides on Anopheles stephensi with a range of exposure times (1 minute, 3 minutes, 1 hour). The second experiment is a direct comparison of the MCD bottle and World Health Organization (WHO) cone bioassay that tests a subset of the insecticides (a piece of LLIN and a piece of netting coated with B. bassiana spores) and a further reduced exposure time (5 seconds) against both An. stephensi and Anopheles gambiae. Immediate knockdown and mortality after 24 hours were assessed using logistic regression and daily survival was assessed using Cox proportional hazards models. Across both experiments, fungus performed much more consistently than the chemical insecticides but measuring the effect of fungus required monitoring of mosquito mortality over several days to a week. Qualitatively, the MCD bottle and WHO cone performed comparably

  9. DIRProt: a computational approach for discriminating insecticide resistant proteins from non-resistant proteins.

    Science.gov (United States)

    Meher, Prabina Kumar; Sahu, Tanmaya Kumar; Banchariya, Anjali; Rao, Atmakuri Ramakrishna

    2017-03-24

    Insecticide resistance is a major challenge for the control program of insect pests in the fields of crop protection, human and animal health etc. Resistance to different insecticides is conferred by the proteins encoded from certain class of genes of the insects. To distinguish the insecticide resistant proteins from non-resistant proteins, no computational tool is available till date. Thus, development of such a computational tool will be helpful in predicting the insecticide resistant proteins, which can be targeted for developing appropriate insecticides. Five different sets of feature viz., amino acid composition (AAC), di-peptide composition (DPC), pseudo amino acid composition (PAAC), composition-transition-distribution (CTD) and auto-correlation function (ACF) were used to map the protein sequences into numeric feature vectors. The encoded numeric vectors were then used as input in support vector machine (SVM) for classification of insecticide resistant and non-resistant proteins. Higher accuracies were obtained under RBF kernel than that of other kernels. Further, accuracies were observed to be higher for DPC feature set as compared to others. The proposed approach achieved an overall accuracy of >90% in discriminating resistant from non-resistant proteins. Further, the two classes of resistant proteins i.e., detoxification-based and target-based were discriminated from non-resistant proteins with >95% accuracy. Besides, >95% accuracy was also observed for discrimination of proteins involved in detoxification- and target-based resistance mechanisms. The proposed approach not only outperformed Blastp, PSI-Blast and Delta-Blast algorithms, but also achieved >92% accuracy while assessed using an independent dataset of 75 insecticide resistant proteins. This paper presents the first computational approach for discriminating the insecticide resistant proteins from non-resistant proteins. Based on the proposed approach, an online prediction server DIRProt has

  10. Comparison of water-based foam and carbon dioxide gas emergency depopulation methods of turkeys.

    Science.gov (United States)

    Rankin, M K; Alphin, R L; Benson, E R; Johnson, A L; Hougentogler, D P; Mohankumar, P

    2013-12-01

    Recommended response strategies for outbreaks of avian influenza and other highly contagious poultry diseases include surveillance, quarantine, depopulation, disposal, and decontamination. The best methods of emergency mass depopulation should maximize human health and safety while minimizing disease spread and animal welfare concerns. The goal of this project was to evaluate the effectiveness of 2 mass depopulation methods on adult tom turkeys. The methods tested were carbon dioxide gassing and water-based foam. The time to unconsciousness, motion cessation, brain death, and altered terminal cardiac activity were recorded for each bird through the use of an electroencephalogram, accelerometer, and electrocardiogram. Critical times for physiological events were extracted from sensor data and compiled in a spreadsheet for statistical analysis. A statistically significant difference was observed in time to brain death, with water-based foam resulting in faster brain death (µ = 190 s) than CO2 gas (µ = 242 s). Though not statistically significant, differences were found comparing the time to unconsciousness (foam: µ = 64 s; CO2 gas: µ = 90 s), motion cessation (foam: µ = 182 s; CO2 gas: µ = 153 s), and altered terminal cardiac activity (foam: µ = 208 s; CO2 gas µ = 242 s) between foam and CO2 depopulation treatments. The results of this study demonstrate that water-based foam can be used to effectively depopulate market size male turkeys.

  11. Characterization of bis-[triethoxysilylpropyl] tetrasulfide layers on aluminum based on water-based silanization solution

    Energy Technology Data Exchange (ETDEWEB)

    Wang Minghao [College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082 (China); He Deliang, E-mail: delianghe@163.com [College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082 (China); Xie Hui; Fu Liqun; Yu Yan [College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082 (China); Zhang Quan [College of Civil Engineering, Hunan University, Changsha, 410082 (China)

    2012-06-30

    In this work, a water-based silanization solution was prepared using a biphasic hydrolysis system composed of 85% (V/V) water and 15% (V/V) bis-[triethoxysilylpropyl] tetrasulfide (BTESPT)/n-heptane/ethanol mixture for efficiently coating aluminum with silane layer against corrosion. The BTESPT-based coatings on several pretreated aluminum samples were characterized by scanning electron microscopy and X-ray energy dispersive spectroscopy, and their electrochemical behaviors were assessed in 0.1 M NaCl neutral solution by means of electrochemical impedance spectroscopy and Tafel polarization. The BTESPT-based coating of about 180 nm thick was found to be uniform and compact, and the maximum corrosion resistance of 10{sup 6} Ohm-Sign of the BTESPT-treated aluminum samples was observed, which is larger than that of bare aluminum by two orders of magnitude. Durability tests in NaCl solution demonstrated that the BTESPT coating can provide superior protection of alumina substrate from corrosion for 10-day immersion in the corrosive media. - Highlights: Black-Right-Pointing-Pointer Water-based silanization solution prepared using a biphasic hydrolysis system. Black-Right-Pointing-Pointer Silane layers with thickness of about 180 nm were uniform and compact. Black-Right-Pointing-Pointer Water-based silane layers as alternative to anticorrosion chromate coatings for Al. Black-Right-Pointing-Pointer Excellent anticorrosion protection observed after 10-day immersion in corrosive medium.

  12. Improved thermal conductivity of Ag decorated carbon nanotubes water based nanofluids

    Energy Technology Data Exchange (ETDEWEB)

    Farbod, Mansoor, E-mail: farbod_m@scu.ac.ir; Ahangarpour, Ameneh

    2016-12-16

    The effect of Ag decoration of carbon nanotubes on thermal conductivity enhancement of Ag decorated MWCNTs water based nanofluids has been investigated. The pristine and functionalized MWCNTs were decorated with Ag nanoparticles by mass ratios of 1%, 2% and 4% and used to prepare water based nanofluids with 0.1 vol.%. An enhancement of 1–20.4 percent in thermal conductivity was observed. It was found that the decoration of functionalized MWCNTs can increase the thermal conductivity about 0.16–8.02 percent compared to the undecorated ones. The maximum enhancement of 20.4% was measured for the sample containing 4 wt.% Ag at 40 °C. - Highlights: • MWCNTs were decorated with Ag nanoparticles by the mass ratios of 1, 2 and 4%. • The decorated CNTs were used to prepare water based nanofluids with 0.1 Vol.%. • 1–20.4% increase was observed in thermal conductivity (TC) compared to pure water. • Ag decorated CNTs increased TC of nanofluid up to 8% compared to CNTs nanofluid.

  13. Application of cellulose nanofibers to remove water-based flexographic inks from wastewaters.

    Science.gov (United States)

    Balea, Ana; Monte, M Concepción; de la Fuente, Elena; Negro, Carlos; Blanco, Ángeles

    2017-02-01

    Water-based or flexographic inks in paper and plastic industries are more environmentally favourable than organic solvent-based inks. However, their use also creates new challenges because they remain dissolved in water and alter the recycling process. Conventional deinking technologies such as flotation processes do not effectively remove them. Adsorption, coagulation/flocculation, biological and membrane processes are either expensive or have negative health impacts, making the development of alternative methods necessary. Cellulose nanofibers (CNF) are biodegradable, and their structural and mechanical properties are useful for wastewater treatment. TEMPO-oxidised CNF have been evaluated for the decolourisation of wastewaters that contained copper phthalocyanine blue, carbon black and diarlyide yellow pigments. CNF in combination with a cationic polyacrylamide (cPAM) has also been tested. Jar-test methodology was used to evaluate the efficiency of the different treatments and cationic/anionic demand, turbidity and ink concentration in waters were measured. Results show that dual-component system for ink removal has a high potential as an alternative bio-based adsorbent for the removal of water-based inks. In addition, experiments varying CNF and cPAM concentrations were performed to optimise the ink-removal process. Ink concentration reductions of 100%, 87.5% and 83.3% were achieved for copper phthalocyanine blue, carbon black and diarlyide yellow pigments, respectively. Flocculation studies carried out show the decolourisation mechanism during the dual-component treatment of wastewaters containing water-based inks.

  14. Effects of Water-Based Training on Static and Dynamic Balance of Older Women.

    Science.gov (United States)

    Bento, Paulo Cesar Barauce; Lopes, Maria de Fátima A; Cebolla, Elaine Cristine; Wolf, Renata; Rodacki, André L F

    2015-08-01

    The aim of this study was to evaluate the effects of a water-based exercise program on static and dynamic balance. Thirty-six older women were randomly assigned to a water-based training (3 days/week for 12 weeks) or control group. Water level was kept at the level of the xiphoid process and temperature at ∼28-30°C. Each session included aerobic activities and lower limb strength exercises. The medial-lateral, the anterior-posterior amplitude, and displacement of the center of pressure (CP-D) were measured in a quiet standing position (60 sec eyes opened and closed). The dynamic balance and 8-Foot Up-and-Go tests were also applied. Group comparisons were made using two-way analysis of variance (ANOVA) with repeated measures. No differences were found in the center of pressure variables; however, the WBT group showed better performance in the 8 Foot Up-and-Go Test after training (5.61±0.76 vs. 5.18±0.42; p<0.01). The water-based training was effective in improving dynamic balance, but not static balance.

  15. Preparation and evaluation of cationic bolaform surfactants for water-based drilling

    Directory of Open Access Journals (Sweden)

    M.M. Dardir

    2017-03-01

    Full Text Available Three cationic bolaform surfactants with different spacer lengths were prepared from the reaction of two moles of triisopropanolamine with one mole of each of the following 1,4-dibromobutane, 1,5-dibromopentane and 1,6-dibromohexane. The chemical structures of the prepared compounds were confirmed via: FTIR spectroscopy, 1H NMR and elemental microanalysis. The surface activity of these bolaform surfactants was studied. The prepared cationic bolaform surfactants were evaluated as viscosifier additives for water-based drilling fluids. The evaluation includes the study of rheological properties of the formulated mud (apparent viscosity, plastic viscosity and yield point, gel strength and thixotropy, effect of temperature on the rheological properties and also, the study of mineralogical properties of the water-based before and after treatment with the prepared surfactants using: X-ray diffraction (XRD, scanning electron microscope (SEM and transmission electron microscope (TEM. The results of the evaluation were compared to the water-based mud formulated from commercial grade bentonite.

  16. The Wiggle Index: An Open Source Bioassay to Assess Sub-Lethal Insecticide Response in Drosophila melanogaster.

    Science.gov (United States)

    Denecke, Shane; Nowell, Cameron J; Fournier-Level, Alexandre; Perry, Trent; Batterham, Phil

    2015-01-01

    Toxicological assays measuring mortality are routinely used to describe insecticide response, but sub-lethal exposures to insecticides can select for resistance and yield additional biological information describing the ways in which an insecticide impacts the insect. Here we present the Wiggle Index (WI), a high-throughput method to quantify insecticide response by measuring the reduction in motility during sub-lethal exposures in larvae of the vinegar fly Drosophila melanogaster. A susceptible wild type strain was exposed to the insecticides chlorantraniliprole, imidacloprid, spinosad, and ivermectin. Each insecticide reduced larval motility, but response times and profiles differed among insecticides. Two sets of target site mutants previously identified in mortality studies on the basis of imidacloprid or spinosad resistance phenotypes were tested. In each case the resistant mutant responded significantly less than the control. The WI was also able to detect a spinosad response in the absence of the primary spinosad target site. This response was not detected in mortality assays suggesting that spinosad, like many other insecticides, may have secondary targets affecting behaviour. The ability of the WI to detect changes in insecticide metabolism was confirmed by overexpressing the imidacloprid metabolizing Cyp6g1 gene in digestive tissues or the central nervous system. The data presented here validate the WI as an inexpensive, generic, sub-lethal assay that can complement information gained from mortality assays, extending our understanding of the genetic basis of insecticide response in D. melanogaster.

  17. Multivariate analysis of elution parameters for RP-HPLC with charged aerosol detection of sucrose caprate regioisomers

    DEFF Research Database (Denmark)

    Lie, Aleksander; Pedersen, Lars Haastrup

    2012-01-01

    and Environmental Engineering, Aalborg University, Denmark Sugar fatty acid monoesters have been shown to possess antibiotic and insecticidal properties. The physical and chemical properties of sugar fatty acid esters depend on the saccharide moiety, fatty acid chain length, and both position and degree....... Nevertheless, preparative purification is often a necessary downstream processing step to obtain regioisomer pure products. In the present work we have investigated the use of step-down gradient elution profiles to improve regioisomer separation as part of the development of a quantitative HPLC analysis method...... for sucrose caprate regioisomers. As a sensitive method based on mass detection, charged aerosol detection was used. The investigation was conducted using design-of-experiments (DOE) methodology for development and prediction of elution strategies. The elution profiles were described by a number of important...

  18. Country-level operational implementation of the Global Plan for Insecticide Resistance Management.

    Science.gov (United States)

    Hemingway, Janet; Vontas, John; Poupardin, Rodolphe; Raman, Jaishree; Lines, Jo; Schwabe, Chris; Matias, Abrahan; Kleinschmidt, Immo

    2013-06-04

    Malaria control is reliant on the use of long-lasting pyrethroid-impregnated nets and/or indoor residual spraying (IRS) of insecticide. The rapid selection and spread of operationally significant pyrethroid resistance in African malaria vectors threatens our ability to sustain malaria control. Establishing whether resistance is operationally significant is technically challenging. Routine monitoring by bioassay is inadequate, and there are limited data linking resistance selection with changes in disease transmission. The default is to switch insecticides when resistance is detected, but limited insecticide options and resistance to multiple insecticides in numerous locations make this approach unsustainable. Detailed analysis of the resistance situation in Anopheles gambiae on Bioko Island after pyrethroid resistance was detected in this species in 2004, and the IRS program switched to carbamate bendiocarb, has now been undertaken. The pyrethroid resistance selected is a target-site knock-down resistance kdr-form, on a background of generally elevated metabolic activity, compared with insecticide-susceptible A. gambiae, but the major cytochrome P450-based metabolic pyrethroid resistance mechanisms are not present. The available evidence from bioassays and infection data suggests that the pyrethroid resistance mechanisms in Bioko malaria vectors are not operationally significant, and on this basis, a different, long-lasting pyrethroid formulation is now being reintroduced for IRS in a rotational insecticide resistance management program. This will allow control efforts to be sustained in a cost-effective manner while reducing the selection pressure for resistance to nonpyrethroid insecticides. The methods used provide a template for evidence-based insecticide resistance management by malaria control programs.

  19. Phytotoxic effects of fungicides, insecticides and nonpesticidal components on pepper depending on water quality

    OpenAIRE

    Slavica Vuković; Dušanka Inđić; Sonja Gvozdenac

    2014-01-01

    Modern agriculture relies on simultaneous application of fungicides, insecticides, fertilizers and adjuvants. The selection of compounds for tank-mixes has been rarely studied and it presents a risk in the application of pesticides but the quality of water should also be considered. The aim of this study was to assess the phytotoxic effects of several fungicides, insecticides, a complex fertilizer, an adjuvant and their mixtures on pepper (Capsicum annuum L...

  20. Comparison of the insecticide susceptibilities of laboratory strains of Aedes aegypti and Aedes albopictus

    OpenAIRE

    Andrea Gómez; Emilia Seccacini; Eduardo Zerba; Susana Licastro

    2011-01-01

    A susceptible strain of Aedes albopictus derived from the Gainesville strain (Florida, USA) was established in our laboratory. The larvicidal efficacies of the neurotoxic insecticides temephos, permethrin and the pure cis and trans-permethrin isomers and the microbial insecticide Bacillus thuringiensis israelensis (Bti) against Ae. albopictus were estimated and compared to a susceptible strain of Aedes aegypti. The larvicidal effect of insect growth regulator pyriproxyfen was also evaluated i...