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Sample records for classical biological control

  1. INTEGRATED MANAGEMENT OF CHROMOLAENA ODORATA EMPHASIZING THE CLASSICAL BIOLOGICAL CONTROL

    Directory of Open Access Journals (Sweden)

    SOEKISMAN TJITROSEMITO

    1998-01-01

    Full Text Available Chromolaena odorata, Siam weed, a very important weed of Java Island (Indonesia is native to Central and South America. In the laboratory it showed rapid growth (1.15 g/g/week in the first 8 weeks of its growth. The biomass was mainly as leaves (LAR : 317.50 cm'/g total weight. It slowed down in the following month as the biomass was utilized for stem and branch formation. This behavior supported the growth of C. odorata into a very dense stand. It flowered, fruited during the dry season, and senesced following maturation of seeds from inflorescence branches. These branches dried out, but soon the stem resumed aggressive growth following the wet season. Leaf biomass was affected by the size of the stem in its early phase of regrowth, but later on it was more affected by the number of branches. The introduction of Pareuchaetes pseudoinsulata to Indonesia, was successful only in North Sumatera. In Java it has not been reported to establish succesfully. The introduction of another biological control agent, Procecidochares conneca to Indonesia was shown to be sp ecific and upon release in West Java it established immediately. It spread exponentia lly in the first 6 months of its release. Field monitoring continues to eval uate the impact of the agents. Other biocontrol agents (Actmole anteas and Conotrachelus wilt be introduced to Indonesia in 1997 through ACIAR Project on the Biological Control of Chromolaena odorata in Indonesia and Papua New Guinea.

  2. Current levels of suppression of waterhyacinth in Florida by classical biological control agents

    Science.gov (United States)

    Waterhyacinth, Eichhornia crassipes, has been a global target for classical biological control efforts for decades. In Florida, herbicides are the primary tactic employed, usually without regard for the activities of the three biological control agents introduced intentionally during the 1970's, na...

  3. Guiding Classical Biological Control of an Invasive Mealybug Using Integrative Taxonomy.

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    Aleixandre Beltrà

    Full Text Available Delottococcus aberiae De Lotto (Hemiptera: Pseudococcidae is a mealybug of Southern African origin that has recently been introduced into Eastern Spain. It causes severe distortions on young citrus fruits and represents a growing threat to Mediterranean citrus production. So far, biological control has proven unsatisfactory due to the absence of efficient natural enemies in Spain. Hence, the management of this pest currently relies only on chemical control. The introduction of natural enemies of D. aberiae from the native area of the pest represents a sustainable and economically viable alternative to reduce the risks linked to pesticide applications. Since biological control of mealybugs has been traditionally challenged by taxonomic misidentification, an intensive survey of Delottococcus spp. and their associated parasitoids in South Africa was required as a first step towards a classical biological control programme. Combining morphological and molecular characterization (integrative taxonomy a total of nine mealybug species were identified in this study, including three species of Delottococcus. Different populations of D. aberiae were found on wild olive trees, in citrus orchards and on plants of Chrysanthemoides monilifera, showing intra-specific divergences according to their host plants. Interestingly, the invasive mealybug populations from Spanish orchards clustered together with the population on citrus from Limpopo Province (South Africa, sharing COI haplotypes. This result pointed to an optimum location to collect natural enemies against the invasive mealybug. A total of 14 parasitoid species were recovered from Delottococcus spp. and identified to genus and species level, by integrating morphological and molecular data. A parasitoid belonging to the genus Anagyrus, collected from D. aberiae in citrus orchards in Limpopo, is proposed here as a good biological control agent to be introduced into Spain.

  4. Guiding Classical Biological Control of an Invasive Mealybug Using Integrative Taxonomy

    Science.gov (United States)

    Beltrà, Aleixandre; Addison, Pia; Ávalos, Juan Antonio; Crochard, Didier; Garcia-Marí, Ferran; Guerrieri, Emilio; Giliomee, Jan H.; Malausa, Thibaut; Navarro-Campos, Cristina; Palero, Ferran; Soto, Antonia

    2015-01-01

    Delottococcus aberiae De Lotto (Hemiptera: Pseudococcidae) is a mealybug of Southern African origin that has recently been introduced into Eastern Spain. It causes severe distortions on young citrus fruits and represents a growing threat to Mediterranean citrus production. So far, biological control has proven unsatisfactory due to the absence of efficient natural enemies in Spain. Hence, the management of this pest currently relies only on chemical control. The introduction of natural enemies of D. aberiae from the native area of the pest represents a sustainable and economically viable alternative to reduce the risks linked to pesticide applications. Since biological control of mealybugs has been traditionally challenged by taxonomic misidentification, an intensive survey of Delottococcus spp. and their associated parasitoids in South Africa was required as a first step towards a classical biological control programme. Combining morphological and molecular characterization (integrative taxonomy) a total of nine mealybug species were identified in this study, including three species of Delottococcus. Different populations of D. aberiae were found on wild olive trees, in citrus orchards and on plants of Chrysanthemoides monilifera, showing intra-specific divergences according to their host plants. Interestingly, the invasive mealybug populations from Spanish orchards clustered together with the population on citrus from Limpopo Province (South Africa), sharing COI haplotypes. This result pointed to an optimum location to collect natural enemies against the invasive mealybug. A total of 14 parasitoid species were recovered from Delottococcus spp. and identified to genus and species level, by integrating morphological and molecular data. A parasitoid belonging to the genus Anagyrus, collected from D. aberiae in citrus orchards in Limpopo, is proposed here as a good biological control agent to be introduced into Spain. PMID:26047349

  5. Rationale for classical biological control of cattle fever ticks and proposed methods for field collection of natural enemies

    Science.gov (United States)

    Classical biological control using specialist parasitoids, predators and/or nematodes from the native ranges of cattle fever ticks Rhipicephalus microplus and Rhipicephalus annulatus could complement existing control strategies for this livestock pest in the transboundary region between Mexico and T...

  6. Recent progress in a classical biological control program for olive fruit fly in California

    Science.gov (United States)

    The olive fruit fly, Bactrocera oleae (Diptera: Tephritidae), causes severe damage to olive production worldwide. Control of olive fruit fly typically relies on pesticides, and under such conditions the impact of natural enemies is relatively low. About 15 years ago, the USDA-ARS European Biologic...

  7. Factors affecting the flight capacity of Tetrastichus planipennisi (Hymenoptera: Eulophidae), a classical biological control agent of Agrilus planipennis (Coleoptera: Buprestidae).

    Science.gov (United States)

    Fahrner, Samuel J; Lelito, Jonathan P; Blaedow, Karen; Heimpel, George E; Aukema, Brian H

    2014-12-01

    The dispersal characteristics of a biological control agent can have direct implications on the ability of that agent to control populations of a target host. Tetrastichus planipennisi Yang (Hymenoptera: Eulophidae) is a parasitic wasp native to eastern Asia that has been introduced into the United States as part of a classical biological control program against the emerald ash borer Agrilus planipennis Fairmaire (Coleoptera: Buprestidae). We used computer-monitored flight mills to investigate the role of age, feeding status, mating status, and size on the flight capacity of female T. planipennisi over a 24-h period. We also compared flight capacity between sexes. Flight distance of female T. planipennisi representative of populations released in the biological control program averaged 1.26 km in 24 h with a maximum flight of just over 7 km. Median flight distance, however, was 422 m. The flight capacity of females fed a honey-water solution was 41× that of females provided only water, who flew very little. Larger females were capable of flying farther distances, but age did not affect the flight capacity of females up to 70 d posteclosion. Females dispersed 6× farther than did their smaller, male counterparts. The implications of our findings to host-parasitoid interactions and release protocols for distributing T. planipennisi are discussed.

  8. Molecular comparison of cattle fever ticks from native and introduced ranges with insights into optimal search areas for classical biological control agents

    Science.gov (United States)

    Classical biological control using specialist parasitoids, predators and/or nematodes from the native ranges of cattle fever ticks could complement existing control strategies for this livestock pest in the transboundary region between Mexico and Texas. DNA fingerprinting tools were used to compare ...

  9. Classical biological control of an invasive forest pest: a world perspective of the management of Sirex noctilio using the parasitoid Ibalia leucospoides (Hymenoptera: Ibaliidae).

    Science.gov (United States)

    Fischbein, D; Corley, J C

    2015-02-01

    Classical biological control is a key method for managing populations of pests in long-lived crops such as plantation forestry. The execution of biological control programmes in general, as the evaluation of potential natural enemies remains, to a large extent, an empirical endeavour. Thus, characterizing specific cases to determine patterns that may lead to more accurate predictions of success is an important goal of the much applied ecological research. We review the history of introduction, ecology and behaviour of the parasitoid Ibalia leucospoides. The species is a natural enemy of Sirex noctilio, one of the most important pests of pine afforestation worldwide. We use an invasion ecology perspective given the analogy between the main stages involved in classical biological control and the biological invasion processes. We conclude that success in the establishment, a common reason of failure in biocontrol, is not a limiting factor of success by I. leucospoides. A mismatch between the spread capacity of the parasitoid and that of its host could nevertheless affect control at a regional scale. In addition, we suggest that given its known life history traits, this natural enemy may be a better regulator than suppressor of the host population. Moreover, spatial and temporal refuges of the host population that may favour the local persistence of the interaction probably reduce the degree to which S. noctilio population is suppressed by the parasitoid. We emphasize the fact that some of the biological attributes that promote establishment may negatively affect suppression levels achieved. Studies on established non-native pest-parasitoid interactions may contribute to defining selection criteria for classical biological control which may prove especially useful in integrated pest management IPM programmes of invasive forest insects.

  10. Classical Biological Control of Invasive Legacy Crop Pests: New Technologies Offer Opportunities to Revisit Old Pest Problems in Perennial Tree Crops

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    Mark S. Hoddle

    2014-12-01

    Full Text Available Advances in scientific disciplines that support classical biological control have provided “new tools” that could have important applications for biocontrol programs for some long-established invasive arthropod pests. We suggest that these previously unavailable tools should be used in biological control programs targeting “legacy pests”, even if they have been targets of previously unsuccessful biocontrol projects. Examples of “new tools” include molecular analyses to verify species identities and likely geographic area of origin, climate matching and ecological niche modeling, preservation of natural enemy genetic diversity in quarantine, the use of theory from invasion biology to maximize establishment likelihoods for natural enemies, and improved understanding of the interactions between natural enemy and target pest microbiomes. This review suggests that opportunities exist for revisiting old pest problems and funding research programs using “new tools” for developing biological control programs for “legacy pests” could provide permanent suppression of some seemingly intractable pest problems. As a case study, we use citricola scale, Coccus pseudomagnoliarum, an invasive legacy pest of California citrus, to demonstrate the potential of new tools to support a new classical biological control program targeting this insect.

  11. Classical Biological Control of Invasive Legacy Crop Pests: New Technologies Offer Opportunities to Revisit Old Pest Problems in Perennial Tree Crops.

    Science.gov (United States)

    Hoddle, Mark S; Warner, Keith; Steggall, John; Jetter, Karen M

    2014-12-23

    Advances in scientific disciplines that support classical biological control have provided "new tools" that could have important applications for biocontrol programs for some long-established invasive arthropod pests. We suggest that these previously unavailable tools should be used in biological control programs targeting "legacy pests", even if they have been targets of previously unsuccessful biocontrol projects. Examples of "new tools" include molecular analyses to verify species identities and likely geographic area of origin, climate matching and ecological niche modeling, preservation of natural enemy genetic diversity in quarantine, the use of theory from invasion biology to maximize establishment likelihoods for natural enemies, and improved understanding of the interactions between natural enemy and target pest microbiomes. This review suggests that opportunities exist for revisiting old pest problems and funding research programs using "new tools" for developing biological control programs for "legacy pests" could provide permanent suppression of some seemingly intractable pest problems. As a case study, we use citricola scale, Coccus pseudomagnoliarum, an invasive legacy pest of California citrus, to demonstrate the potential of new tools to support a new classical biological control program targeting this insect.

  12. Endophytic fungi associated with Fallopia japonica (Polygonaceae) in Japan and their interactions with Puccinia polygoni-amphibii var. tovariae, a candidate for classical biological control.

    Science.gov (United States)

    Kurose, Daisuke; Furuya, Naruto; Tsuchiya, Kenichi; Tsushima, Seiya; Evans, Harry C

    2012-07-01

    Fallopia japonica (Polygonaceae), or Japanese knotweed, is now spreading globally, causing serious problems in Europe and North America in both natural and urban habitats. There is an urgent need for alternative management solutions, and classical biological control, using coevolved natural enemies found in the native range, is currently being investigated. Here, we isolated fungal endophytes from F. japonica in Japan, its natural habitat, to find endophytes that might increase the virulence of a coevolved rust pathogen, Puccinia polygoni-amphibii var. tovariae. A total of 1581 fungal endophytes were recovered from F. japonica and classified into 15 taxa. Five genera (Colletotrichum, Pestalotiopsis, Phoma, Phomopsis, and Alternaria) were dominant as endophytes in F. japonica. A greenhouse study of the dominant endophyte-pathogen interactions revealed three types of reactions: suppressive, synergistic, and neutral. In particular, one Phomopsis isolate--closely related to Diaporthe medusaea, based on ITS sequences--promoted the pathogenic aggressiveness of P. polygoni-amphibii var. tovariae and, therefore, this interaction is potentially useful to increase the effectiveness of the rust fungus as a biological control agent of F. japonica in its invasive range.

  13. Mass Trapping and Classical Biological Control of Rhynchophorus palmarum L. 1794 (Coleoptera: Curculionidae. A hypothesis based in morphological evidences.

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    Flávio Miguens

    2011-07-01

    Resumo. Coleópteros têm sido descritos como pragas e vetores de nematódeos causadores de Anel Vermelho em diversas palmeiras da família Arecaceae. Rhynchophorus palmarum L (Coleoptera: Curculionidae é uma praga que afeta a cocoicultura e outras palmeiras; e, vetor de Bursaphelencus cocophilus (Cobb Baujard (Nematoda, agente etiológico de Anel Vermelho e de outros nematódeos. Atualmente, recomenda-se o emprego de inimigos naturais e parasitas no manejo integrado de pragas; dentre elas, Rhynchophorinae. Armadilhas de coleta massal são recomendadas no manejo integrado de pragas. Nosso estudo relata, na cocoicultura, a eficiência de armadilhas artesanais de baixo custo e a utilização cariomônios (toletes de cana-de-açúcar e cariômonios mais feromônios (toletes de cana-de-açúcar e machos adultos de R. palmarum como atrativos nas armadilhas. Ácaros ectoparasitas foram identificados nestes coleópteros, por microscopia, que podem ser propostos como parte do manejo integrado desta praga. Armadilhas de coleta massal com cariômonios foram eficientes na captura de R. palmarum e outros Curculionidae. No entanto, armadilhas de coleta massal com cariômonios e feromônios aumentaram a atratividade, em relação às primeiras, para este Coleoptera e Cosmopolites sordidus (Germar (Coleoptera: Curculionidae. Eventualmente, exemplares de R. palmarum apresentavam infecção fúngica. Ácaros ectoparasitas infestavam mais de 50% dos exemplares de R. palmarum. A microanatomia destes ácaros e sua interação com R. palmarum foi preliminarmente descrita. Todos os estágios do ciclo de vida destes ácaros foram identificados no compartimento dos élitros. As evidências morfológicas suportam a hipótese de que estes ácaros podem ser empregados no controle biológico de R. palmarum em um programa de manejo integrado.

  14. Are we ready to move beyond the reductionist approach of classical synergy control?. Comment on "Hand synergies: Integration of robotics and neuroscience for understanding the control of biological and artificial hands" by Marco Santello et al.

    Science.gov (United States)

    Lacquaniti, Francesco; Ivanenko, Yuri P.; Zago, Myrka

    2016-07-01

    Starting from the classical concepts introduced by Sherrington [1] and considerably elaborated by Bernstein [2], much has been learned about motor synergies in the last several years. The contributions of the group funded by the European project ;The Hand Embodied; are remarkable in the field of biological and robotic control of the hand based on synergies, and they are reflected in this enjoyable review [3]. There, Santello et al. adopt Bernstein's definition of motor synergies as multiple elements working together towards a common goal, with the result that multiple degrees of freedom are controlled within a lower-dimensional space than the available number of dimensions.

  15. Biological control and sustainable food production

    NARCIS (Netherlands)

    Bale, J.S.; Lenteren, van J.C.; Bigler, F.

    2008-01-01

    The use of biological control for the management of pest insects pre-dates the modern pesticide era. The first major successes in biological control occurred with exotic pests controlled by natural enemy species collected from the country or area of origin of the pest (classical control). Augmentati

  16. Biological pest control in Mexico.

    Science.gov (United States)

    Williams, Trevor; Arredondo-Bernal, Hugo C; Rodríguez-del-Bosque, Luis A

    2013-01-01

    Mexico is a megadiverse country that forms part of the Mesoamerican biological corridor that connects North and South America. Mexico's biogeographical situation places it at risk from invasive exotic insect pests that enter from the United States, Central America, or the Caribbean. In this review we analyze the factors that contributed to some highly successful past programs involving classical biological control and/or the sterile insect technique (SIT). The present situation is then examined with reference to biological control, including SIT programs, targeted at seven major pests, with varying degrees of success. Finally, we analyze the current threats facing Mexico's agriculture industry from invasive pests that have recently entered the country or are about to do so. We conclude that despite a number of shortcomings, Mexico is better set to develop biological control-based pest control programs, particularly on an area-wide basis, than many other Latin American countries are. Classical and augmentative biological control and SIT-based programs are likely to provide effective and sustainable options for control of native and exotic pests, particularly when integrated into technology packages that meet farmers' needs across the great diversity of production systems in Mexico.

  17. Model predictive control classical, robust and stochastic

    CERN Document Server

    Kouvaritakis, Basil

    2016-01-01

    For the first time, a textbook that brings together classical predictive control with treatment of up-to-date robust and stochastic techniques. Model Predictive Control describes the development of tractable algorithms for uncertain, stochastic, constrained systems. The starting point is classical predictive control and the appropriate formulation of performance objectives and constraints to provide guarantees of closed-loop stability and performance. Moving on to robust predictive control, the text explains how similar guarantees may be obtained for cases in which the model describing the system dynamics is subject to additive disturbances and parametric uncertainties. Open- and closed-loop optimization are considered and the state of the art in computationally tractable methods based on uncertainty tubes presented for systems with additive model uncertainty. Finally, the tube framework is also applied to model predictive control problems involving hard or probabilistic constraints for the cases of multiplic...

  18. Classical and spatial stochastic processes with applications to biology

    CERN Document Server

    Schinazi, Rinaldo B

    2014-01-01

    The revised and expanded edition of this textbook presents the concepts and applications of random processes with the same illuminating simplicity as its first edition, but with the notable addition of substantial modern material on biological modeling. While still treating many important problems in fields such as engineering and mathematical physics, the book also focuses on the highly relevant topics of cancerous mutations, influenza evolution, drug resistance, and immune response. The models used elegantly apply various classical stochastic models presented earlier in the text, and exercises are included throughout to reinforce essential concepts. The second edition of Classical and Spatial Stochastic Processes is suitable as a textbook for courses in stochastic processes at the advanced-undergraduate and graduate levels, or as a self-study resource for researchers and practitioners in mathematics, engineering, physics, and mathematical biology. Reviews of the first edition: An appetizing textbook for a f...

  19. Insecticides and Biological Control

    Science.gov (United States)

    Furness, G. O.

    1972-01-01

    Use of insecticides has been questioned due to their harmful effects on edible items. Biological control of insects along with other effective practices for checking spread of parasites on crops are discussed. (PS)

  20. Classical investigation of long-range coherence in biological systems

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    Preto, Jordane

    2016-12-01

    Almost five decades ago, H. Fröhlich [H. Fröhlich, "Long-range coherence and energy storage in biological systems," Int. J. Quantum Chem. 2(5), 641-649 (1968)] reported, on a theoretical basis, that the excitation of quantum modes of vibration in contact with a thermal reservoir may lead to steady states, where under high enough rate of energy supply, only specific low-frequency modes of vibration are strongly excited. This nonlinear phenomenon was predicted to occur in biomolecular systems, which are known to exhibit complex vibrational spectral properties, especially in the terahertz frequency domain. However, since the effects of terahertz or lower-frequency modes are mainly classical at physiological temperatures, there are serious doubts that Fröhlich's quantum description can be applied to predict such a coherent behavior in a biological environment, as suggested by the author. In addition, a quantum formalism makes the phenomenon hard to investigate using realistic molecular dynamics simulations (MD) as they are usually based on the classical principles. In the current paper, we provide a general classical Hamiltonian description of a nonlinear open system composed of many degrees of freedom (biomolecular structure) excited by an external energy source. It is shown that a coherent behaviour similar to Fröhlich's effect is to be expected in the classical case for a given range of parameter values. Thus, the supplied energy is not completely thermalized but stored in a highly ordered fashion. The connection between our Hamiltonian description, carried out in the space of normal modes, and a more standard treatment in the physical space is emphasized in order to facilitate the prediction of the effect from MD simulations. It is shown how such a coherent phenomenon may induce long-range resonance effects that could be of critical importance at the biomolecular level. The present work is motivated by recent experimental evidences of long-lived excited low

  1. Commercializing Biological Control

    Science.gov (United States)

    LeLeu, K. L.; Young, M. A.

    1973-01-01

    Describes the only commercial establishment involved in biological control in Australia. The wasp Aphitis melinus, which parasitizes the insect Red Scale, is bred in large numbers and released in the citrus groves where Red Scale is causing damage to the fruit. (JR)

  2. Bioterrorism and Biological Warfare, from Past to the Present: A classic review

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    Majid Zare Bidaki

    2015-10-01

    Full Text Available Bioterrorism is defined as any terrorist action of intentional release or dissemination of highly pathogenic biological agents, including a variety of microorganisms or biological toxins. With the growing threat of terrorism, is necessary that the potential danger of various microorganisms – as a powerful tool of aggression and threat- to be taken seriously. This review tries to explain the concept of biological weapons and their historical development process with an emphasis on efforts to control the proliferation of these types of weapons over the last century. Potential impact of infectious diseases on people and armed forces was known from since 600 BC. Using the victims of the plague as a weapon in medieval warfare and spread of smallpox as a weapon during the war against the Indians when initially America was discovered, the development of biological weapons during the World War I, World War II and the Cold War, and even since the beginning of the third millennium, all show the strategic importance of pathogenic microorganisms as a deterrent power for the superiority of some governments and cults. Historical attempts to use infectious diseases as biological weapons reveal that the distinction between a natural outbreak of an infectious disease and that of a deliberate biological attack is very difficult. Abusing this characteristic of infectious diseases has made it possible for the purposes of superiority. International agreements to control the development of biological weapons, such as “the 1925 Geneva Protocol” and “the Convention on the Prohibition of the Development, Production and Stockpiling of Biological and Toxic Weapons” have not been able to control the development and using of biological warfare.  The current paper is a classic review (Overview article aiming at increasing the knowledge and awareness of people especially of health authorities and government officials.

  3. Biological control of ticks

    Science.gov (United States)

    Samish, M.; Ginsberg, H.; Glazer, I.; Bowman, A.S.; Nuttall, P.

    2004-01-01

    Ticks have numerous natural enemies, but only a few species have been evaluated as tick biocontrol agents (BCAs). Some laboratory results suggest that several bacteria are pathogenic to ticks, but their mode of action and their potential value as biocontrol agents remain to be determined. The most promising entomopathogenic fungi appear to be Metarhizium anisopliae and Beauveria bassiana, strains of which are already commercially available for the control of some pests. Development of effective formulations is critical for tick management. Entomopathogenic nematodes that are pathogenic to ticks can potentially control ticks, but improved formulations and selection of novel nematode strains are needed. Parasitoid wasps of the genus Ixodiphagus do not typically control ticks under natural conditions, but inundative releases show potential value. Most predators of ticks are generalists, with a limited potential for tick management (one possible exception is oxpeckers in Africa). Biological control is likely to play a substantial role in future IPM programmes for ticks because of the diversity of taxa that show high potential as tick BCAs. Considerable research is required to select appropriate strains, develop them as BCAs, establish their effectiveness, and devise production strategies to bring them to practical use.

  4. BIOLOGICAL CONTROL OF WEEDS BY MEANS OF PLANT PATHOGENS

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    Marija Ravlić

    2014-06-01

    Full Text Available Biological control is the use of live beneficial organisms and products of their metabolism in the pests control. Plant pathogens can be used for weed control in three different ways: as classical, conservation and augmentative (inoculative and inundated biological control. Inundated biological control involves the use of bioherbicides (mycoherbicides or artificial breeding of pathogens and application in specific stages of crops and weeds. Biological control of weeds can be used where chemical herbicides are not allowed, if resistant weed species are present or in the integrated pest management against weeds with reduced herbicides doses and other non-chemical measures, but it has certain limitations and disadvantages.

  5. An Exercise in Biological Control.

    Science.gov (United States)

    Lennox, John; Duke, Michael

    1997-01-01

    Discusses the history of the use of pesticides and biological control. Introduces the concept of biological control as illustrated in the use of the entomopathogenic bacterium Bacillus thuringiensis and highlights laboratory demonstrations of Koch's postulates. Includes an exercise that offers the student and teacher several integrated learning…

  6. Unified analysis of terminal-time control in classical and quantum systems

    CERN Document Server

    Pechen, Alexander; 10.1209/0295-5075/91/60005

    2010-01-01

    Many phenomena in physics, chemistry, and biology involve seeking an optimal control to maximize an objective for a classical or quantum system which is open and interacting with its environment. The complexity of finding an optimal control for maximizing an objective is strongly affected by the possible existence of sub-optimal maxima. Within a unified framework under specified conditions, control objectives for maximizing at a terminal time physical observables of open classical and quantum systems are shown to be inherently free of sub-optimal maxima. This attractive feature is of central importance for enabling the discovery of controls in a seamless fashion in a wide range of phenomena transcending the quantum and classical regimes.

  7. Experimental proposal for testing the Emergence of Environment Induced (EIN) Classical Selection rules with Biological Systems

    CERN Document Server

    Durt, Thomas

    2010-01-01

    According to the so-called Quantum Darwinist approach, the emergence of "classical islands" from a quantum background is assumed to obey a (selection) principle of maximal information. We illustrate this idea by considering the coupling of two oscillators (modes). As our approach suggests that the classical limit could have emerged throughout a long and progressive Evolution mechanism, it is likely that primitive living organisms behave in a "more quantum", "less classical" way than more evolved ones. This brings us to seriously consider the possibility to measure departures from classicality exhibited by biological systems. We describe an experimental proposal the aimed at revealing the presence of entanglement in the biophotonic radiation emitted by biological sources.

  8. Comparison Analysis of Model Predictive Controller with Classical PID Controller For pH Control Process

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    V. Balaji

    2016-12-01

    Full Text Available pH control plays a important role in any chemical plant and process industries. For the past four decades the classical PID controller has been occupied by the industries. Due to the faster computing   technology in the industry demands a tighter advanced control strategy. To fulfill the needs and requirements Model Predictive Control (MPC is the best among all the advanced control algorithms available in the present scenario. The study and analysis has been done for First Order plus Delay Time (FOPDT model controlled by Proportional Integral Derivative (PID and MPC using the Matlab software. This paper explores the capability of the MPC strategy, analyze and compare the control effects with conventional control strategy in pH control. A comparison results between the PID and MPC is plotted using the software. The results clearly show that MPC provide better performance than the classical controller.

  9. Herbivory, Predation, and Biological Control.

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    Murphy, Terence M.; And Others

    1992-01-01

    Authors describe a set of controlled ecosystems that can be used to demonstrate the effects of herbivory on the health and growth of a plant population and of predation on the growth of a primary consumer population. The system also shows the effectiveness of biological pest control measures in a dramatic way. The construction of the ecosystems is…

  10. The cactus moth, Cactoblastis cactorum: Lessons in Biological Control

    Science.gov (United States)

    The cactus moth was one of the success stories in classical biological control. In the 1920s, the prickly pear cactus was a serious pest in Australia. The cactus moth was imported from its native habitat in South America and proved so successful in controlling cactus that it was mass reared and exp...

  11. Optimal tuning for a classical wind turbine controller

    DEFF Research Database (Denmark)

    Tibaldi, Carlo; Hansen, Morten Hartvig; Henriksen, Lars Christian

    2012-01-01

    Fine tuning of controllers for pitch-torque regulated wind turbines is an opportunity to improve the wind turbine performances and reduce the cost of energy without applying any changes to the design. For this purpose, a method for automatically tune a classical controller based on numerical opti...... tuning that improves the wind turbine performances. For the case study selected in this work, a 2% cost of energy reduction is achieved with seven iterations.......Fine tuning of controllers for pitch-torque regulated wind turbines is an opportunity to improve the wind turbine performances and reduce the cost of energy without applying any changes to the design. For this purpose, a method for automatically tune a classical controller based on numerical...... optimization is developed and tested. To have a better understanding of the problem a parametric analysis of the wind turbine performances due to changes in the controller parameters is rst performed. Thereafter results obtained with the automatic tuning show that is possible to identify a ner controller...

  12. Optimal tuning for a classical wind turbine controller

    DEFF Research Database (Denmark)

    Tibaldi, Carlo; Hansen, Morten Hartvig; Henriksen, Lars Christian

    2014-01-01

    Fine tuning of controllers for pitch-torque regulated wind turbines is an opportunity to improve the wind turbine performances and reduce the cost of energy without applying any changes to the design. For this purpose, a method for automatically tune a classical controller based on numerical opti...... tuning that improves the wind turbine performances. For the case study selected in this work, a 2% cost function reduction is achieved with seven iterations.......Fine tuning of controllers for pitch-torque regulated wind turbines is an opportunity to improve the wind turbine performances and reduce the cost of energy without applying any changes to the design. For this purpose, a method for automatically tune a classical controller based on numerical...... optimization is developed and tested. To have a better understanding of the problem a parametric analysis of the wind turbine performances due to changes in the controller parameters is first performed. Thereafter results obtained with the automatic tuning show that is possible to identify a finer controller...

  13. Control theory meets synthetic biology.

    Science.gov (United States)

    Del Vecchio, Domitilla; Dy, Aaron J; Qian, Yili

    2016-07-01

    The past several years have witnessed an increased presence of control theoretic concepts in synthetic biology. This review presents an organized summary of how these control design concepts have been applied to tackle a variety of problems faced when building synthetic biomolecular circuits in living cells. In particular, we describe success stories that demonstrate how simple or more elaborate control design methods can be used to make the behaviour of synthetic genetic circuits within a single cell or across a cell population more reliable, predictable and robust to perturbations. The description especially highlights technical challenges that uniquely arise from the need to implement control designs within a new hardware setting, along with implemented or proposed solutions. Some engineering solutions employing complex feedback control schemes are also described, which, however, still require a deeper theoretical analysis of stability, performance and robustness properties. Overall, this paper should help synthetic biologists become familiar with feedback control concepts as they can be used in their application area. At the same time, it should provide some domain knowledge to control theorists who wish to enter the rising and exciting field of synthetic biology.

  14. An abundant biological control agent does not provide a significant predator subsidy

    Science.gov (United States)

    Classical weed biological control agents, regardless of their effectiveness, may provide subsidies to predators and parasites. The chemically defended weevil Oxyops vitiosa Pascoe is a successful agent that was introduced to control the invasive tree Melaleuca quinquenervia. Two consecutive small ...

  15. Intestinal nematodes: biology and control.

    Science.gov (United States)

    Epe, Christian

    2009-11-01

    A variety of nematodes occur in dogs and cats. Several nematode species inhabit the small and large intestines. Important species that live in the small intestine are roundworms of the genus Toxocara (T canis, T cati) and Toxascaris (ie, T leonina), and hookworms of the genus Ancylostoma (A caninum, A braziliense, A tubaeforme) or Uncinaria (U stenocephala). Parasites of the large intestine are nematodes of the genus Trichuris (ie, whipworms, T vulpis). After a comprehensive description of their life cycle and biology, which are indispensable for understanding and justifying their control, current recommendations for nematode control are presented and discussed thereafter.

  16. Feedback Control Of Dynamical Instabilities In Classical Lasers And Fels

    CERN Document Server

    Bielawski, S; Szwaj, C

    2005-01-01

    Dynamical instabilities lead to unwanted full-scale power oscillations in many classical lasers and FEL oscillators. For a long time, applications requiring stable operation were typically performed by working outside the problematic parameter regions. A breakthrough occurred in the nineties [1], when emphasis was made on the practical importance of unstable states (stationary or periodic) that coexist with unwanted oscillatory states. Indeed, although not observable in usual experiments, unstable states can be stabilized, using a feedback control involving arbitrarily small perturbations of a parameter. This observation stimulated a set of works leading to successful suppression of dynamical instabilities (initially chaos) in lasers, sometimes with surprisingly simple feedback devices [2]. We will review a set of key results, including in particular the recent works on the stabilization of mode-locked lasers, and of the super-ACO, ELETTRA and UVSOR FELs [3].

  17. "Protected biological control"- Biological pest management in the greenhouse industry

    NARCIS (Netherlands)

    Pilkington, L.J.; Messelink, G.J.; Lenteren, van J.C.; Mottee, Le K.

    2010-01-01

    This paper briefly describes the foundations and characteristics of biological control in protected cropping and what drivers are behind adoption of this management system within this industry. Examining a brief history of biological control in greenhouses and what makes it a successful management s

  18. The control of classical swine fever in wild boar

    Directory of Open Access Journals (Sweden)

    Volker eMoennig

    2015-11-01

    Full Text Available Classical swine fever (CSF is a viral disease with severe economic consequences for domestic pigs. Natural hosts for the CSF virus (CSFV are members of the family Suidae, i.e. Eurasian wild boar (sus scrofa are also susceptible. CSF in wild boar poses a serious threat to domestic pigs. CSFV is an enveloped RNA virus belonging to the pestivirus genus of the Flaviviridae family. Transmission of the infection is usually by direct contact or by feeding of contaminated meat products. In recent decades CSF has been successfully eradicated from Australia, North America, and the European Union. In areas with dense wild boar populations CSF tends to become endemic whereas it is often self-limiting in small, less dense populations. In recent decades eradication strategies of CSF in wild boar have been improved considerably. The reduction of the number of susceptible animals to a threshold level where the basic reproductive number is R0<1 is the major goal of all control efforts. Depending on the epidemiological situation, hunting measures combined with strict hygiene may be effective in areas with a relatively low density of wild boar. Oral immunization was shown to be highly effective in endemic situations in areas with a high density of wild boar.

  19. Biological and spatial structure of an early classic period cemetery at Charco Redondo, Oaxaca.

    Science.gov (United States)

    Paul, Kathleen S; Stojanowski, Christopher M; Butler, Michelle M

    2013-10-01

    This article presents an analysis of biological and spatial patterning of an Early Classic (A.D. 250-500) Chatino cemetery at the archaeological site of Charco Redondo, located in the lower Río Verde Valley, Oaxaca, Mexico. The Early Classic was a time of political instability positioned between two phases of state-level centralization within the coastal valley. The communal cemetery at Charco Redondo adds significantly to the inventory of excavated graves from this time period and provides novel data on mortuary practices during a critical phase in the development of state level polities in the region. Cluster analysis of mortuary data is combined with intracemetery biodistance approaches to reconstruct how the Charco Redondo cemetery was organized with respect to biological relationships. Cluster analysis of mortuary data identified three groupings of burials. Multidimensional scaling of Euclidean distances and Gower coefficients based on 45 odontometric and 13 dental morphological variables suggests a strong relationship between grave characteristics and locations and phenotypic variation. In other words, the cemetery at Charco Redondo appears biologically kin-structured. The communal nature of the cemetery conflicts with the assumed "household" burial model for this time period. We propose the observed combination of features represents a transitional practice in which aspects of community, kin, and individual identity were signaled simultaneously within the funerary environment during a time of political transition in the Valley. This article highlights the utility of intracemetery biodistance analyses for examining dimensions of kinship, "house," and community throughout Mesoamerica where overarching models often mask regional variability.

  20. Biology and Water Pollution Control.

    Science.gov (United States)

    Warren, Charles E.

    Within this text, the reader is attuned to the role biology can and should play in combating the alarming increase in water pollution. Both the urgency of the problem and the biological techniques that are being developed to cope with the water pollution crisis are scrutinized; what is and is not known about the problem is explained; past,…

  1. Quantum interferences and their classical limit in laser driven coherent control scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Franco, Ignacio, E-mail: ifranco@chem.northwestern.edu [Chemical Physics Theory Group, Department of Chemistry, Center for Quantum Information and Quantum Control, University of Toronto, Toronto, ON, M5S 3H6 (Canada); Spanner, Michael; Brumer, Paul [Chemical Physics Theory Group, Department of Chemistry, Center for Quantum Information and Quantum Control, University of Toronto, Toronto, ON, M5S 3H6 (Canada)

    2010-05-12

    Graphical abstract: The analogy between Young's double-slit experiment with matter and laser driven coherent control schemes is investigated, and shown to be limited. To do so, a general decomposition of observables in the Heisenberg picture into direct terms and interference contributions is introduced, and formal quantum-classical correspondence arguments in the Heisenberg picture are employed to define classical analogs of quantum interference terms. While the classical interference contributions in the double-slit experiment are shown to be zero, they can be nonzero in laser driven coherent control schemes and lead to laser control in the classical limit. This classical limit is interpreted in terms of nonlinear response theory arguments. - Abstract: The analogy between Young's double-slit experiment with matter and laser driven coherent control schemes is investigated, and shown to be limited. To do so, a general decomposition of observables in the Heisenberg picture into direct terms and interference contributions is introduced, and formal quantum-classical correspondence arguments in the Heisenberg picture are employed to define classical analogs of quantum interference terms. While the classical interference contributions in the double-slit experiment are shown to be zero, they can be nonzero in laser driven coherent control schemes and lead to laser control in the classical limit. This classical limit is interpreted in terms of nonlinear response theory arguments.

  2. Biology, host specificity tests, and risk assessment of the sawfly Heteroperreyia hubrichi, a potential biological control agent of Schinus terebinthifolius in Hawaii

    Science.gov (United States)

    Abstract. Heteroperreyia hubrichi Malaise (Hymenoptera: Pergidae), a foliage feeding sawfly of Schinus terebinthifolius Raddi (Sapindales: Anacardiaceae), was studied to assess its suitability as a classical biological control agent of this invasive weed in Hawaii. Nochoice host-specificity tests we...

  3. The biological control of disease vectors.

    Science.gov (United States)

    Okamoto, Kenichi W; Amarasekare, Priyanga

    2012-09-21

    Vector-borne diseases are common in nature and can have a large impact on humans, livestock and crops. Biological control of vectors using natural enemies or competitors can reduce vector density and hence disease transmission. However, the indirect interactions inherent in host-vector disease systems make it difficult to use traditional pest control theory to guide biological control of disease vectors. This necessitates a conceptual framework that explicitly considers a range of indirect interactions between the host-vector disease system and the vector's biological control agent. Here we conduct a comparative analysis of the efficacy of different types of biological control agents in controlling vector-borne diseases. We report three key findings. First, highly efficient predators and parasitoids of the vector prove to be effective biological control agents, but highly virulent pathogens of the vector also require a high transmission rate to be effective. Second, biocontrol agents can successfully reduce long-term host disease incidence even though they may fail to reduce long-term vector densities. Third, inundating a host-vector disease system with a natural enemy of the vector has little or no effect on reducing disease incidence, but inundating the system with a competitor of the vector has a large effect on reducing disease incidence. The comparative framework yields predictions that are useful in developing biological control strategies for vector-borne diseases. We discuss how these predictions can inform ongoing biological control efforts for host-vector disease systems.

  4. Biology-Inspired Autonomous Control

    Science.gov (United States)

    2011-08-31

    of, and perhaps will not be tolerated in, manmade critical systems. Although this paper does not directly address questions of ethics associated...political, ethical , and moral issues associated with the use of autonomous systems in warfare will be debated long after the technology hurdles to...accessible discussion on the interplay of biochemistry, genetics and embryology in animal evolution; Wagner, 2005 describes biological concepts of

  5. Biological Control of Mosquitoes with Mermithids

    OpenAIRE

    Platzer, E. G.

    1981-01-01

    Mermithid nematodes parasitizing mosquitoes have substantial potential for vector control. Studies on the physiological ecology of Romanomermis culicivorax have defined some of the general requirements of mermithid nematodes and produced general guidelines for the experimental release of mermithids in biological control. Experimental field studies have established the biological control potential of R. culicivorax, but further development and ulilization of this parasite will require a substa...

  6. Economic value of biological control in integrated pest management of managed plant systems.

    Science.gov (United States)

    Naranjo, Steven E; Ellsworth, Peter C; Frisvold, George B

    2015-01-07

    Biological control is an underlying pillar of integrated pest management, yet little focus has been placed on assigning economic value to this key ecosystem service. Setting biological control on a firm economic foundation would help to broaden its utility and adoption for sustainable crop protection. Here we discuss approaches and methods available for valuation of biological control of arthropod pests by arthropod natural enemies and summarize economic evaluations in classical, augmentative, and conservation biological control. Emphasis is placed on valuation of conservation biological control, which has received little attention. We identify some of the challenges of and opportunities for applying economics to biological control to advance integrated pest management. Interaction among diverse scientists and stakeholders will be required to measure the direct and indirect costs and benefits of biological control that will allow farmers and others to internalize the benefits that incentivize and accelerate adoption for private and public good.

  7. Conserving and enhancing biological control of nematodes.

    Science.gov (United States)

    Timper, Patricia

    2014-06-01

    Conservation biological control is the modification of the environment or existing practices to protect and enhance antagonistic organisms to reduce damage from pests. This approach to biological control has received insufficient attention compared with inundative applications of microbial antagonists to control nematodes. This review provides examples of how production practices can enhance or diminish biological control of plant-parasitic nematodes and other soilborne pests. Antagonists of nematodes can be enhanced by providing supplementary food sources such as occurs when organic amendments are applied to soil. However, some organic amendments (e.g., manures and plants containing allelopathic compounds) can also be detrimental to nematode antagonists. Plant species and genotype can strongly influence the outcome of biological control. For instance, the susceptibility of the plant to the nematode can determine the effectiveness of control; good hosts will require greater levels of suppression than poor hosts. Plant genotype can also influence the degree of rhizosphere colonization and antibiotic production by antagonists, as well the expression of induced resistance by plants. Production practices such as crop rotation, fallow periods, tillage, and pesticide applications can directly disrupt populations of antagonistic organisms. These practices can also indirectly affect antagonists by reducing their primary nematode host. One of the challenges of conservation biological control is that practices intended to protect or enhance suppression of nematodes may not be effective in all field sites because they are dependent on indigenous antagonists. Ultimately, indicators will need to be identified, such as the presence of particular antagonists, which can guide decisions on where it is practical to use conservation biological control. Antagonists can also be applied to field sites in conjunction with conservation practices to improve the consistency, efficacy, and

  8. Global Asymptotic Stability of the Classical PID Controller by Considering Saturation Effects in Industrial Robots

    Directory of Open Access Journals (Sweden)

    Antonio Yarza

    2011-09-01

    Full Text Available An unsolved ancient problem in position control of robot manipulators is to find a stability analysis that proves global asymptotic stability of the classical PID control in closed loop with robot manipulators. The practical evidence suggests that in fact the classical PID in industrial robots is a global regulator. The main goal of the present paper is theoretically to show why in the practice such a fact is achieved. We show that considering the natural saturations of every control stage in practical robots, the classical PID becomes a type of saturated nonlinear PID controller. In this work such a nonlinear PID controller with bounded torques for robot manipulators is proposed. This controller, unlike other saturated nonlinear PID controllers previously proposed, uses a single saturation for the three terms of the controller. Global asymptotical stability is proved via Lyapunov stability theory. Experimental results are presented in order to observe the performance of the proposed controller.

  9. TREG Cells in Cancer: Beyond Classical Immunological Control.

    Science.gov (United States)

    Bos, Paula D

    2016-10-19

    A prerequisite for tumor evolution toward a malignant state is the establishment of cell intrinsic and extrinsic mechanisms of immune suppression (Hanahan and Weinberg, 2000, 2011; Schreiber, Old, and Smyth, 2011). Widespread recruitment of Foxp3(+) regulatory T cells (TREG) is a prevailing means to dampen antitumor immunity. Advances in the characterization of TREG cell heterogeneity and physiological function of tissue resident TREG cells unfold new possibilities for nontraditional tumor-promoting functions of intratumoral TREG cells. This review will focus on the nonclassical function of TREG cells and their implicancies for cancer biology and treatment.

  10. Controlled ecological life support system - biological problems

    Science.gov (United States)

    Moore, B., III (Editor); Macelroy, R. D. (Editor)

    1982-01-01

    The general processes and controls associated with two distinct experimental paradigms are examined. Specific areas for research related to biotic production (food production) and biotic decomposition (waste management) are explored. The workshop discussions were directed toward Elemental cycles and the biological factors that affect the transformations of nutrients into food, of food material into waste, and of waste into nutrients were discussed. To focus on biological issues, the discussion assumed that (1) food production would be by biological means (thus excluding chemical synthesis), (2) energy would not be a limiting factor, and (3) engineering capacity for composition and leak rate would be adequate.

  11. Moving constraints as stabilizing controls in classical mechanics

    CERN Document Server

    Bressan, A

    2008-01-01

    The paper analyzes a Lagrangian system which is controlled by directly assigning some of the coordinates as functions of time, by means of frictionless constraints. In a natural system of coordinates, the equations of motions contain terms which are linear or quadratic w.r.t.time derivatives of the control functions. After reviewing the basic equations, we explain the significance of the quadratic terms, related to geodesics orthogonal to a given foliation. We then study the problem of stabilization of the system to a given point, by means of oscillating controls. This problem is first reduced to the weak stability for a related convex-valued differential inclusion, then studied by Lyapunov functions methods. In the last sections, we illustrate the results by means of various mechanical examples.

  12. Moving Constraints as Stabilizing Controls in Classical Mechanics

    Science.gov (United States)

    Bressan, Alberto; Rampazzo, Franco

    2010-04-01

    The paper analyzes a Lagrangian system which is controlled by directly assigning some of the coordinates as functions of time, by means of frictionless constraints. In a natural system of coordinates, the equations of motion contain terms which are linear or quadratic with respect to time derivatives of the control functions. After reviewing the basic equations, we explain the significance of the quadratic terms related to geodesics orthogonal to a given foliation. We then study the problem of stabilization of the system to a given point by means of oscillating controls. This problem is first reduced to theweak stability for a related convex-valued differential inclusion, then studied by Lyapunov functions methods. In the last sections, we illustrate the results by means of various mechanical examples.

  13. Lie Algebroids in Classical Mechanics and Optimal Control

    Directory of Open Access Journals (Sweden)

    Eduardo Martínez

    2007-03-01

    Full Text Available We review some recent results on the theory of Lagrangian systems on Lie algebroids. In particular we consider the symplectic and variational formalism and we study reduction. Finally we also consider optimal control systems on Lie algebroids and we show how to reduce Pontryagin maximum principle.

  14. Real-time adaption of the classical Riccati-Controller; Echtzeitanpassung des klassischen Riccati-Reglers

    Energy Technology Data Exchange (ETDEWEB)

    Bueskens, Christof [Bremen Univ. (Germany). AG Optimierung und Optimale Steuerung

    2009-07-01

    Optimal controllers, like the classical Linear Quadratic Regulator closed-loop controller (LQR), have proved to be a powerful tool in many applications and to be robust enough to compensate most differences between simulation and reality. Nevertheless these controllers are not optimal if disturbances or perturbations in the system data occur. For this purpose, a numerical method based on the parametric sensitivity analysis of nonlinear optimization problems is suggested to calculate higher order approximations of the feedback control law in real-time. The method is illustrated by the classical inverted pendulum. (orig.)

  15. Discrepant epidemiological patterns between classical and atypical scrapie in sheep flocks under French TSE control measures.

    Science.gov (United States)

    Fediaevsky, Alexandre; Gasqui, Patrick; Calavas, Didier; Ducrot, Christian

    2010-09-01

    The occurrence of secondary cases of atypical and classical scrapie was examined in 340 outbreaks of atypical and 296 of classical sheep scrapie detected in France during active surveillance programmes between 2002 and 2007. The prevalence of atypical scrapie in these flocks was 0.05% under selective culling and 0.07% under intensified monitoring i.e. not significantly different from that detected during active surveillance of the general population (P>0.5), whereas these figures were much higher for classical scrapie (3.67% and 0.25%, respectively, P<10(-5)). In addition the number of atypical scrapie cases per outbreak did not indicate clustering. The results suggest that atypical scrapie occurs spontaneously or is not particularly contagious, and that the control measures in force allowed appropriate control of classical scrapie but were not more efficient than active surveillance in detecting cases of atypical scrapie.

  16. The Biological Control of the Malaria Vector

    Directory of Open Access Journals (Sweden)

    Layla Kamareddine

    2012-09-01

    Full Text Available The call for malaria control, over the last century, marked a new epoch in the history of this disease. Many control strategies targeting either the Plasmodium parasite or the Anopheles vector were shown to be effective. Yet, the emergence of drug resistant parasites and insecticide resistant mosquito strains, along with numerous health, environmental, and ecological side effects of many chemical agents, highlighted the need to develop alternative tools that either complement or substitute conventional malaria control approaches. The use of biological means is considered a fundamental part of the recently launched malaria eradication program and has so far shown promising results, although this approach is still in its infancy. This review presents an overview of the most promising biological control tools for malaria eradication, namely fungi, bacteria, larvivorous fish, parasites, viruses and nematodes.

  17. Ecology and biological control of Verticillium dahliae

    NARCIS (Netherlands)

    Soesanto, L.

    2000-01-01

    The dynamics of Verticillium dahliae , the causal agent of wilt disease in many crops including potato, cotton, and olive, were investigated. Its biological control with Talaromyces flavus with or without additional Pseudomonas fluorescens was attempted. Arabidopsis thaliana was selected as a bioass

  18. Biological Control of Nematodes with Bacteria

    Science.gov (United States)

    Biological control of nematodes is receiving increased attention as environmental considerations with the use of nematicides have increased in importance and their high cost prohibits use on many crops. In addition, nematode resistant cultivars are not available for many crops and resistance that i...

  19. Fuzzy logic controller versus classical logic controller for residential hybrid solar-wind-storage energy system

    Science.gov (United States)

    Derrouazin, A.; Aillerie, M.; Mekkakia-Maaza, N.; Charles, J. P.

    2016-07-01

    Several researches for management of diverse hybrid energy systems and many techniques have been proposed for robustness, savings and environmental purpose. In this work we aim to make a comparative study between two supervision and control techniques: fuzzy and classic logics to manage the hybrid energy system applied for typical housing fed by solar and wind power, with rack of batteries for storage. The system is assisted by the electric grid during energy drop moments. A hydrogen production device is integrated into the system to retrieve surplus energy production from renewable sources for the household purposes, intending the maximum exploitation of these sources over years. The models have been achieved and generated signals for electronic switches command of proposed both techniques are presented and discussed in this paper.

  20. Beyond the Classical Performance Limitations Controlling Uncertain MIMO Systems: UAV Applications

    Science.gov (United States)

    2008-05-01

    filtering and control, Springer, London, 1997. [18]. I. Horowitz, Synthesis of feedback systems, Academic Press, New York, 1963. [19]. Robert Shorten...and P. J. Enright , Classical feedback control with MATLAB, Marcel Dekker, New York, 2000. [28]. J. W. Glass and M. A. Franchek, “Frequency-based

  1. MicroRNA-regulated networks: the perfect storm for classical molecular biology, the ideal scenario for systems biology.

    Science.gov (United States)

    Vera, Julio; Lai, Xin; Schmitz, Ulf; Wolkenhauer, Olaf

    2013-01-01

    MicroRNAs (miRNAs) are involved in many regulatory pathways some of which are complex networks enriched in regulatory motifs like positive or negative feedback loops or coherent and incoherent feedforward loops. Their complexity makes the understanding of their regulation difficult and the interpretation of experimental data cumbersome. In this book chapter we claim that systems biology is the appropriate approach to investigate the regulation of these miRNA-regulated networks. Systems biology is an interdisciplinary approach by which biomedical questions on biochemical networks are addressed by integrating experiments with mathematical modelling and simulation. We here introduce the foundations of the systems biology approach, the basic theoretical and computational tools used to perform model-based analyses of miRNA-regulated networks and review the scientific literature in systems biology of miRNA regulation, with a focus on cancer.

  2. Biological control of aflatoxin contamination of crops

    Institute of Scientific and Technical Information of China (English)

    Yan-ni YIN; Lei-yan YAN; Jin-hua JIANG; Zhong-hua MA

    2008-01-01

    Aflatoxins produced primarily by two closely related fungi, Aspergillus flavus and Aspergillus parasiticus, are mutagenic and carcinogenic in animals and humans. Of many approaches investigated to manage aflatoxin contamination, biological control method has shown great promise. Numerous organisms, including bacteria, yeasts and nontoxigenic fungal strains of A.flavus and A. parasiticus, have been tested for their ability in controlling aflatoxin contamination. Great successes in reducing aflatoxin contamination have been achieved by application of nontoxigenic strains of A. flavus and A. parasiticus in fields of cotton, peanut, maize and pistachio. The nontoxigenic strains applied to soil occupy the same niches as the natural occurring toxigenic strains. They, therefore, are capable of competing and displacing toxigenic strains. In this paper, we review recent development in biological control of aflatoxin contamination.

  3. Diapause in Abrostola asclepiadis (Lepidoptera: Noctuidae) may make for an ineffective weed biological control agent

    Science.gov (United States)

    Pale and black swallow-wort (Vincetoxicum rossicum and V. nigrum; Apocynaceae, subfamily Asclepiadoideae) are perennial vines from Europe that are invasive in various terrestrial habitats in the northeastern USA and southeastern Canada. A classical weed biological control program has been in develop...

  4. Status of biological control projects on terrestrial invasive alien weeds in California

    Science.gov (United States)

    In cooperation with foreign scientists, we are currently developing new classical biological control agents for five species of invasive alien terrestrial weeds. Cape-Ivy. A gall-forming fly, Parafreutreta regalis, and a stem-boring moth, Digitivalva delaireae, have been favorably reviewed by TAG...

  5. From classical genetics to quantitative genetics to systems biology: modeling epistasis.

    Directory of Open Access Journals (Sweden)

    David L Aylor

    2008-03-01

    Full Text Available Gene expression data has been used in lieu of phenotype in both classical and quantitative genetic settings. These two disciplines have separate approaches to measuring and interpreting epistasis, which is the interaction between alleles at different loci. We propose a framework for estimating and interpreting epistasis from a classical experiment that combines the strengths of each approach. A regression analysis step accommodates the quantitative nature of expression measurements by estimating the effect of gene deletions plus any interaction. Effects are selected by significance such that a reduced model describes each expression trait. We show how the resulting models correspond to specific hierarchical relationships between two regulator genes and a target gene. These relationships are the basic units of genetic pathways and genomic system diagrams. Our approach can be extended to analyze data from a variety of experiments, multiple loci, and multiple environments.

  6. Learning in a simple biological system: a pilot study of classical conditioning of human macrophages in vitro

    Directory of Open Access Journals (Sweden)

    Nilsonne Gustav

    2011-11-01

    Full Text Available Abstract Recent advances in cell biology and gene regulation suggest mechanisms whereby associative learning could be performed by single cells. Therefore, we explored a model of classical conditioning in human macrophages in vitro. In macrophage cultures, bacterial lipopolysaccharide (LPS; unconditioned stimulus was paired once with streptomycin (conditioned stimulus. Secretion of interleukin-6 (IL-6 was used as response measure. At evocation, conditioning was not observed. Levels of IL-6 were higher only in those cultures that had been exposed to LPS in the learning phase (p's However, habituation was evident, with a 62% loss of the IL-6 response after three LPS presentations (p

  7. Experimental demonstration of a classical approach for flexible space structure control: NASA CSI testbeds

    Science.gov (United States)

    Bond, Wie

    1991-01-01

    The results of active control experiments performed for the Mini-Mast truss structure are presented. The primary research objectives were: (1) to develop active structural control concepts and/or techniques; (2) to verify the concept of robust non-minimum-phase compensation for a certain class of non-colocated structural control problems through ground experiments; (3) to verify a 'dipole' concept for persistent disturbance rejection control of flexible structures; and (4) to identify CSI (Control Structure Interaction) issues and areas of emphasis for the next generation of large flexible spacecraft. The classical SISO (Single Input and Single Output) control design approach was employed.

  8. Onchocerciasis control: biological research is still needed

    Directory of Open Access Journals (Sweden)

    Boussinesq M.

    2008-09-01

    Full Text Available Achievements obtained by the onchocerciasis control programmes should not lead to a relaxation in the biological research on Onchocerca volvulus. Issues such as the Loa loa-related postivermectin serious adverse events, the uncertainties as to whether onchocerciasis can be eliminated by ivermectin treatments, and the possible emergence of ivermectin-resistant O. volvulus populations should be addressed proactively. Doxycycline, moxidectin and emodepside appear to be promising as alternative drugs against onchocerciasis but support to researches in immunology and genomics should also be increased to develop new control tools, including both vaccines and macrofilaricidal drugs.

  9. Quantum and classical control of single photon states via a mechanical resonator

    Science.gov (United States)

    Basiri-Esfahani, Sahar; Myers, Casey R.; Combes, Joshua; Milburn, G. J.

    2016-06-01

    Optomechanical systems typically use light to control the quantum state of a mechanical resonator. In this paper, we propose a scheme for controlling the quantum state of light using the mechanical degree of freedom as a controlled beam splitter. Preparing the mechanical resonator in non-classical states enables an optomechanical Stern-Gerlach interferometer. When the mechanical resonator has a small coherent amplitude it acts as a quantum control, entangling the optical and mechanical degrees of freedom. As the coherent amplitude of the resonator increases, we recover single photon and two-photon interference via a classically controlled beam splitter. The visibility of the two-photon interference is particularly sensitive to coherent excitations in the mechanical resonator and this could form the basis of an optically transduced weak-force sensor.

  10. Economic aspects of antiviral agents to control Classical Swine Fever epidemics

    NARCIS (Netherlands)

    Bergevoet, R.H.M.; Asseldonk, van M.A.P.M.; Backer, J.A.

    2012-01-01

    Outbreaks of contagious animal diseases such as Classical Swine Fever have detrimental effects on the livestock sector in an affected country as well as on society at large. The development of antiviral agents to control these epidemics can reduce the consequences of such outbreaks. The economic imp

  11. Functional Basis for Efficient Physical Layer Classical Control in Quantum Processors

    Science.gov (United States)

    Ball, Harrison; Nguyen, Trung; Leong, Philip H. W.; Biercuk, Michael J.

    2016-12-01

    The rapid progress seen in the development of quantum-coherent devices for information processing has motivated serious consideration of quantum computer architecture and organization. One topic which remains open for investigation and optimization relates to the design of the classical-quantum interface, where control operations on individual qubits are applied according to higher-level algorithms; accommodating competing demands on performance and scalability remains a major outstanding challenge. In this work, we present a resource-efficient, scalable framework for the implementation of embedded physical layer classical controllers for quantum-information systems. Design drivers and key functionalities are introduced, leading to the selection of Walsh functions as an effective functional basis for both programing and controller hardware implementation. This approach leverages the simplicity of real-time Walsh-function generation in classical digital hardware, and the fact that a wide variety of physical layer controls, such as dynamic error suppression, are known to fall within the Walsh family. We experimentally implement a real-time field-programmable-gate-array-based Walsh controller producing Walsh timing signals and Walsh-synthesized analog waveforms appropriate for critical tasks in error-resistant quantum control and noise characterization. These demonstrations represent the first step towards a unified framework for the realization of physical layer controls compatible with large-scale quantum-information processing.

  12. Sensory prediction or motor control? Application of marr-albus type models of cerebellar function to classical conditioning.

    Science.gov (United States)

    Lepora, Nathan F; Porrill, John; Yeo, Christopher H; Dean, Paul

    2010-01-01

    Marr-Albus adaptive filter models of the cerebellum have been applied successfully to a range of sensory and motor control problems. Here we analyze their properties when applied to classical conditioning of the nictitating membrane response in rabbits. We consider a system-level model of eyeblink conditioning based on the anatomy of the eyeblink circuitry, comprising an adaptive filter model of the cerebellum, a comparator model of the inferior olive and a linear dynamic model of the nictitating membrane plant. To our knowledge, this is the first model that explicitly includes all these principal components, in particular the motor plant that is vital for shaping and timing the behavioral response. Model assumptions and parameters were systematically investigated to disambiguate basic computational capacities of the model from features requiring tuning of properties and parameter values. Without such tuning, the model robustly reproduced a range of behaviors related to sensory prediction, by displaying appropriate trial-level associative learning effects for both single and multiple stimuli, including blocking and conditioned inhibition. In contrast, successful reproduction of the real-time motor behavior depended on appropriate specification of the plant, cerebellum and comparator models. Although some of these properties appear consistent with the system biology, fundamental questions remain about how the biological parameters are chosen if the cerebellar microcircuit applies a common computation to many distinct behavioral tasks. It is possible that the response profiles in classical conditioning of the eyeblink depend upon operant contingencies that have previously prevailed, for example in naturally occurring avoidance movements.

  13. Rotating Biological Contractors (RBC's). Instructor's Guide. Biological Treatment Process Control.

    Science.gov (United States)

    Zickefoose, Charles S.

    This two-lesson unit on rotating biological contactors (RBC's) is designed to be used with students who have had some experience in wastewater treatment and a basic understanding of biological treatment. The first lesson provides information on the concepts and components of RBC treatment systems. The second lesson focuses on design operation and…

  14. Control of quantum localization and classical diffusion in laser-kicked molecular rotors

    Science.gov (United States)

    Bitter, M.; Milner, V.

    2017-01-01

    We experimentally study a system of quantum kicked rotors—an ensemble of diatomic molecules exposed to a periodic sequence of ultrashort laser pulses. In the regime where the underlying classical dynamics is chaotic, we investigate the quantum phenomenon of dynamical localization by means of state-resolved coherent Raman spectroscopy. We examine the dependence of the exponentially localized angular momentum distribution and of the total rotational energy on the time period between the pulses and their amplitude. The former parameter is shown to provide control over the localization center, whereas the latter one controls the localization length. Similar control of the center and width of a nonlocalized rotational distribution is demonstrated in the limit of classical diffusion, established by adding noise to the periodic pulse sequence.

  15. Biological control with Trichogramma pretiosum increases organic maize productivity by 19.4%

    OpenAIRE

    de Lourdes Corrêa Figueiredo, Maria; Cruz, Ivan; da Silva, Rafael Braga; Foster, John Edward

    2015-01-01

    International audience; AbstractSpodoptera frugiperda is a major pest causing maize yield loss in Brazil. There is therefore a need for control methods, notably for organic farming because classical pesticides are not allowed. A potential solution for organic maize is to apply the biological control agent Trichogramma pretiosum to reduce S. frugiperda populations. Here, we tested the application of one, two, or three releases of T. pretiosum. We measured plant damage ratings, egg masses paras...

  16. Models for integrated pest control and their biological implications.

    Science.gov (United States)

    Tang, Sanyi; Cheke, Robert A

    2008-09-01

    Successful integrated pest management (IPM) control programmes depend on many factors which include host-parasitoid ratios, starting densities, timings of parasitoid releases, dosages and timings of insecticide applications and levels of host-feeding and parasitism. Mathematical models can help us to clarify and predict the effects of such factors on the stability of host-parasitoid systems, which we illustrate here by extending the classical continuous and discrete host-parasitoid models to include an IPM control programme. The results indicate that one of three control methods can maintain the host level below the economic threshold (ET) in relation to different ET levels, initial densities of host and parasitoid populations and host-parasitoid ratios. The effects of host intrinsic growth rate and parasitoid searching efficiency on host mean outbreak period can be calculated numerically from the models presented. The instantaneous pest killing rate of an insecticide application is also estimated from the models. The results imply that the modelling methods described can help in the design of appropriate control strategies and assist management decision-making. The results also indicate that a high initial density of parasitoids (such as in inundative releases) and high parasitoid inter-generational survival rates will lead to more frequent host outbreaks and, therefore, greater economic damage. The biological implications of this counter intuitive result are discussed.

  17. Design and control strategies for CELSS - Integrating mechanistic paradigms and biological complexities

    Science.gov (United States)

    Moore, B., III; Kaufmann, R.; Reinhold, C.

    1981-01-01

    Systems analysis and control theory consideration are given to simulations of both individual components and total systems, in order to develop a reliable control strategy for a Controlled Ecological Life Support System (CELSS) which includes complex biological components. Because of the numerous nonlinearities and tight coupling within the biological component, classical control theory may be inadequate and the statistical analysis of factorial experiments more useful. The range in control characteristics of particular species may simplify the overall task by providing an appropriate balance of stability and controllability to match species function in the overall design. The ultimate goal of this research is the coordination of biological and mechanical subsystems in order to achieve a self-supporting environment.

  18. Classical-Wigner Phase Space Approximation to Cumulative Matrix Elements in Coherent Control

    OpenAIRE

    McQuarrie, B. R.; Abrashkevich, Dmitri G.; Brumer, Paul

    2003-01-01

    The classical limit of the Wigner-Weyl representation is used to approximate products of bound-continuum matrix elements that are fundamental to many coherent control computations. The range of utility of the method is quantified through an examination of model problems, single-channel Na_2 dissociation and multi-arrangement channel photodissociation of CH_2IBr. Very good agreement with the exact quantum results is found for a wide range of system parameters.

  19. Chemical Biology Strategies for Biofilm Control.

    Science.gov (United States)

    Yang, Liang; Givskov, Michael

    2015-08-01

    Microbes live as densely populated multicellular surface-attached biofilm communities embedded in self-generated, extracellular polymeric substances (EPSs). EPSs serve as a scaffold for cross-linking biofilm cells and support development of biofilm architecture and functions. Biofilms can have a clear negative impact on humans, where biofilms are a common denominator in many chronic diseases in which they prime development of destructive inflammatory conditions and the failure of our immune system to efficiently cope with them. Our current assortment of antimicrobial agents cannot efficiently eradicate biofilms. For industrial applications, the removal of biofilms within production machinery in the paper and hygienic food packaging industry, cooling water circuits, and drinking water manufacturing systems can be critical for the safety and efficacy of those processes. Biofilm formation is a dynamic process that involves microbial cell migration, cell-to-cell signaling and interactions, EPS synthesis, and cell-EPS interactions. Recent progress of fundamental biofilm research has shed light on novel chemical biology strategies for biofilm control. In this article, chemical biology strategies targeting the bacterial intercellular and intracellular signaling pathways will be discussed.

  20. Programmable temperature control system for biological materials

    Science.gov (United States)

    Anselmo, V. J.; Harrison, R. G.; Rinfret, A. P.

    1982-01-01

    A system was constructed which allows programmable temperature-time control for a 5 cu cm sample volume of arbitrary biological material. The system also measures the parameters necessary for the determination of the sample volume specific heat and thermal conductivity as a function of temperature, and provides a detailed measurement of the temperature during phase change and a means of calculating the heat of the phase change. Steady-state and dynamic temperature control is obtained by supplying heat to the sample volume through resistive elements constructed as an integral part of the sample container. For cooling purposes, this container is totally immersed into a cold heat sink. Using a mixture of dry ice and alcohol at 79 C, the sample volume can be controlled from +40 to -60 C at rates from steady state to + or - 65 C/min. Steady-state temperature precision is better than 0.2 C, while the dynamic capability depends on the temperature rate of change as well as the mass of both the sample and the container.

  1. Classic yin and yang tonic formula for osteopenia: study protocol for a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Holz Jonathan D

    2011-08-01

    Full Text Available Abstract Background Osteoporosis is a growing worldwide problem, with the greatest burden resulting from fractures. Nevertheless, the majority of fractures in adults occur in those with "osteopenia" (bone mineral density (BMD only moderately lower than young normal individuals. Since long-term drug therapy is an expensive option with uncertain consequences and side effects, natural herbal therapy offers an attractive alternative. The purpose of this study is to evaluate the effect on BMD and safety of the Classic Yin and Yang Tonic Formula for treatment of osteopenia and to investigate the mechanism by which this efficacy is achieved. Methods/design We propose a multicenter double-blind randomized placebo-controlled trial to evaluate the efficacy and safety of the Classic Yin and Yang Tonic Formula for the treatment of osteopenia. Participants aged 55 to 75 with low bone mineral density (T-score between -1 and -2.5 and kidney deficiency in TCM will be included and randomly allocated into two groups: treatment group and control group. Participants in the treatment group will be treated with Classic Yin and Yang Tonic Granule, while the controlled group will receive placebo. Primary outcome measure will be BMD of the lumbar spine and proximal femur using dual-energy X-ray absorptiometry. Secondary outcomes will include pain intensity measured with visual analogue scales, quality of life, serum markers of bone metabolism, indices of Neuro-endocrino-immune network and safety. Discussion If the Classic Yin and Yang Tonic Formula can increase bone mass without adverse effects, it may be a novel strategy for the treatment of osteoporosis. Furthermore, the mechanism of the Chinese medical formula for osteoporosis will be partially elucidated. Trial registration This study is registered at ClinicalTrials.gov, NCT01271647.

  2. Fatty acid synthase - Modern tumor cell biology insights into a classical oncology target.

    Science.gov (United States)

    Buckley, Douglas; Duke, Gregory; Heuer, Timothy S; O'Farrell, Marie; Wagman, Allan S; McCulloch, William; Kemble, George

    2017-02-12

    Decades of preclinical and natural history studies have highlighted the potential of fatty acid synthase (FASN) as a bona fide drug target for oncology. This review will highlight the foundational concepts upon which this perspective is built. Published studies have shown that high levels of FASN in patient tumor tissues are present at later stages of disease and this overexpression predicts poor prognosis. Preclinical studies have shown that experimental overexpression of FASN in previously normal cells leads to changes that are critical for establishing a tumor phenotype. Once the tumor phenotype is established, FASN elicits several changes to the tumor cell and becomes intertwined with its survival. The product of FASN, palmitate, changes the biophysical nature of the tumor cell membrane; membrane microdomains enable the efficient assembly of signaling complexes required for continued tumor cell proliferation and survival. Membranes densely packed with phospholipids containing saturated fatty acids become resistant to the action of other chemotherapeutic agents. Inhibiting FASN leads to tumor cell death while sparing normal cells, which do not have the dependence of this enzyme for normal functions, and restores membrane architecture to more normal properties thereby resensitizing tumors to killing by chemotherapies. One compound has recently reached clinical studies in solid tumor patients and highlights the need for continued evaluation of the role of FASN in tumor cell biology. Significant advances have been made and much remains to be done to optimally apply this class of pharmacological agents for the treatment of specific cancers.

  3. Rotating Biological Contactors (RBC's). Student Manual. Biological Treatment Process Control.

    Science.gov (United States)

    Zickefoose, Charles S.

    This student manual provides the textual material for a unit on rotating biological contactors (RBC's). Topic areas considered include: (1) flow patterns of water through RBC installations; (2) basic concepts (shaft and stage); (3) characteristics of biomass; (4) mechanical features (bearings, mechanical drive systems, and air drive systems); (5)…

  4. Responses of an idiobiont ectoparasitoid, Spathius galinae, to host larvae parasitized by the koinobiont endoparasitoid Tetrastichus planipennisi: implications for biological control of emerald ash borer

    Science.gov (United States)

    Understanding interspecific competition among insect parasitoids is important in designing classical biological control programs that involve multiple species introductions. Spathius galinae, a new idiobiont ectoparasitoid from the Russian Far East, is currently being considered for introduction to ...

  5. Revisiting classic water erosion models in drylands: The strong impact of biological soil crusts

    Science.gov (United States)

    Bowker, M.A.; Belnap, J.; Bala, Chaudhary V.; Johnson, N.C.

    2008-01-01

    Soil erosion and subsequent degradation has been a contributor to societal collapse in the past and is one of the major expressions of desertification in arid regions. The revised universal soil loss equation (RUSLE) models soil lost to water erosion as a function of climate erosivity (the degree to which rainfall can result in erosion), topography, soil erodibility, and land use/management. The soil erodibility factor (K) is primarily based upon inherent soil properties (those which change slowly or not at all) such as soil texture and organic matter content, while the cover/management factor (C) is based on several parameters including biological soil crust (BSC) cover. We examined the effect of two more precise indicators of BSC development, chlorophyll a and exopolysaccharides (EPS), upon soil stability, which is closely inversely related to soil loss in an erosion event. To examine the relative influence of these elements of the C factor to the K factor, we conducted our investigation across eight strongly differing soils in the 0.8 million ha Grand Staircase-Escalante National Monument. We found that within every soil group, chlorophyll a was a moderate to excellent predictor of soil stability (R2 = 0.21-0.75), and consistently better than EPS. Using a simple structural equation model, we explained over half of the variance in soil stability and determined that the direct effect of chlorophyll a was 3?? more important than soil group in determining soil stability. Our results suggest that, holding the intensity of erosive forces constant, the acceleration or reduction of soil erosion in arid landscapes will primarily be an outcome of management practices. This is because the factor which is most influential to soil erosion, BSC development, is also among the most manageable, implying that water erosion in drylands has a solution. ?? 2008 Elsevier Ltd.

  6. Biologically inspired control of humanoid robot arms robust and adaptive approaches

    CERN Document Server

    Spiers, Adam; Herrmann, Guido

    2016-01-01

    This book investigates a biologically inspired method of robot arm control, developed with the objective of synthesising human-like motion dynamically, using nonlinear, robust and adaptive control techniques in practical robot systems. The control method caters to a rising interest in humanoid robots and the need for appropriate control schemes to match these systems. Unlike the classic kinematic schemes used in industrial manipulators, the dynamic approaches proposed here promote human-like motion with better exploitation of the robot’s physical structure. This also benefits human-robot interaction. The control schemes proposed in this book are inspired by a wealth of human-motion literature that indicates the drivers of motion to be dynamic, model-based and optimal. Such considerations lend themselves nicely to achievement via nonlinear control techniques without the necessity for extensive and complex biological models. The operational-space method of robot control forms the basis of many of the techniqu...

  7. Ecological Compatibility of GM Crops and Biological Control

    Science.gov (United States)

    Insect-resistant and herbicide-tolerant genetically modified (GM) crops pervade many modern cropping systems, and present challenges and opportunities for developing biologically-based pest management programs. Interactions between biological control agents (insect predators, parasitoids, and pathog...

  8. An embodied biologically constrained model of foraging: from classical and operant conditioning to adaptive real-world behavior in DAC-X.

    Science.gov (United States)

    Maffei, Giovanni; Santos-Pata, Diogo; Marcos, Encarni; Sánchez-Fibla, Marti; Verschure, Paul F M J

    2015-12-01

    Animals successfully forage within new environments by learning, simulating and adapting to their surroundings. The functions behind such goal-oriented behavior can be decomposed into 5 top-level objectives: 'how', 'why', 'what', 'where', 'when' (H4W). The paradigms of classical and operant conditioning describe some of the behavioral aspects found in foraging. However, it remains unclear how the organization of their underlying neural principles account for these complex behaviors. We address this problem from the perspective of the Distributed Adaptive Control theory of mind and brain (DAC) that interprets these two paradigms as expressing properties of core functional subsystems of a layered architecture. In particular, we propose DAC-X, a novel cognitive architecture that unifies the theoretical principles of DAC with biologically constrained computational models of several areas of the mammalian brain. DAC-X supports complex foraging strategies through the progressive acquisition, retention and expression of task-dependent information and associated shaping of action, from exploration to goal-oriented deliberation. We benchmark DAC-X using a robot-based hoarding task including the main perceptual and cognitive aspects of animal foraging. We show that efficient goal-oriented behavior results from the interaction of parallel learning mechanisms accounting for motor adaptation, spatial encoding and decision-making. Together, our results suggest that the H4W problem can be solved by DAC-X building on the insights from the study of classical and operant conditioning. Finally, we discuss the advantages and limitations of the proposed biologically constrained and embodied approach towards the study of cognition and the relation of DAC-X to other cognitive architectures.

  9. The Use and Exchange of Biological Control Agents for Food and Agriculture

    Institute of Scientific and Technical Information of China (English)

    J.C.van; Lenteren; M.J.W.Cock; J.Brodeur; B.Barratt; F.Bigler; K.Bolckmans; F.Haas; P.G.Mason; J.R.P.Parra

    2010-01-01

    The report sets out to summarize the past and current situation regarding the practice of biologicalcontrol inrelationtothe use and exchange of genetic resources relevant for BCAs.It considers the twomain categories of biological control:classical and augmentative.Allowing access to BCAs for use inanother country imposes no risk of liability to the source country.Local scientific knowledge abouthabitats,fauna andflora,can be helpful

  10. Sensory prediction or motor control? Application of Marr-Albus type models of cerebellar function to classical conditioning

    Directory of Open Access Journals (Sweden)

    Nathan F Lepora

    2010-10-01

    Full Text Available Marr-Albus adaptive filter models of the cerebellum have been applied successfully to a range of sensory and motor control problems. Here we analyze their properties when applied to classical conditioning of the nictitating membrane response in rabbits. We consider a system-level model of eyeblink conditioning based on the anatomy of the eyeblink circuitry, comprising an adaptive filter model of the cerebellum, a comparator model of the inferior olive and a linear dynamic model of the nictitating membrane plant. To our knowledge, this is the first model that explicitly includes all these principal components, in particular the motor plant that is vital for shaping and timing the behavioral response. Model assumptions and parameters were systematically investigated to disambiguate basic computational capacities of the model from features requiring tuning of properties and parameter values. Without such tuning, the model robustly reproduced a range of behaviors related to sensory prediction, by displaying appropriate trial-level associative learning effects for both single and multiple stimuli, including blocking and conditioned inhibition. In contrast, successful reproduction of the real-time motor behavior depended on appropriate specification of the plant, cerebellum and comparator models. Although some of these properties appear consistent with the system biology, fundamental questions remain about how the biological parameters are chosen if the cerebellar microcircuit applies a common computation to many distinct behavioral tasks. It is possible that the response profiles in classical conditioning of the eyeblink depend upon operant contingencies that have previously prevailed, for example in naturally occurring avoidance movements.

  11. Complexity, Analysis and Control of Singular Biological Systems

    CERN Document Server

    Zhang, Qingling; Zhang, Xue

    2012-01-01

    Complexity, Analysis and Control of Singular Biological Systems follows the control of real-world biological systems at both ecological and phyisological levels concentrating on the application of now-extensively-investigated singular system theory. Much effort has recently been dedicated to the modelling and analysis of developing bioeconomic systems and the text establishes singular examples of these, showing how proper control can help to maintain sustainable economic development of biological resources. The book begins from the essentials of singular systems theory and bifurcations before tackling  the use of various forms of control in singular biological systems using examples including predator-prey relationships and viral vaccination and quarantine control. Researchers and graduate students studying the control of complex biological systems are shown how a variety of methods can be brought to bear and practitioners working with the economics of biological systems and their control will also find the ...

  12. Maternal feeding controls fetal biological clock.

    Directory of Open Access Journals (Sweden)

    Hidenobu Ohta

    Full Text Available BACKGROUND: It is widely accepted that circadian physiological rhythms of the fetus are affected by oscillators in the maternal brain that are coupled to the environmental light-dark (LD cycle. METHODOLOGY/PRINCIPAL FINDINGS: To study the link between fetal and maternal biological clocks, we investigated the effects of cycles of maternal food availability on the rhythms of Per1 gene expression in the fetal suprachiasmatic nucleus (SCN and liver using a transgenic rat model whose tissues express luciferase in vitro. Although the maternal SCN remained phase-locked to the LD cycle, maternal restricted feeding phase-advanced the fetal SCN and liver by 5 and 7 hours respectively within the 22-day pregnancy. CONCLUSIONS/SIGNIFICANCE: Our results demonstrate that maternal feeding entrains the fetal SCN and liver independently of both the maternal SCN and the LD cycle. This indicates that maternal-feeding signals can be more influential for the fetal SCN and particular organ oscillators than hormonal signals controlled by the maternal SCN, suggesting the importance of a regular maternal feeding schedule for appropriate fetal molecular clockwork during pregnancy.

  13. Optically controlled collisions of biological objects

    Science.gov (United States)

    Davies, Benjamin J.; Kishore, Rani; Mammen, Mathai; Helmerson, Kristian; Choi, Seok-Ki; Phillips, William D.; Whitesides, George M.

    1998-04-01

    We have developed a new assay in which two mesoscale particles are caused to collide using two independently controlled optical tweezers. This assay involves the measurement of the adhesion probability following a collision. Since the relative orientation, impact parameter (i.e., distance of closest approach), and collision velocity of the particles, as well as the components of the solution, are all under the user's control, this assay can mimic a wide range of biologically relevant collisions. We illustrate the utility of our assay by evaluating the adhesion probability of a single erythrocyte (red blood cell) to an influenza virus-coated microsphere, in the presence of sialic acid-bearing inhibitors of adhesion. This probability as a function of inhibitor concentration yields a measure of the effectiveness of the inhibitor for blocking viral adhesion. Most of the inhibition constants obtained using the tweezers agree well with those obtained from other techniques, although the inhibition constants for the best of the inhibitors were beyond the limited resolution of conventional assays. They were readily evaluated using our tweezers-based assay, however, and prove to be the most potent inhibitors of adhesion between influenza virus and erythrocytes ever measured. Further studies are underway to investigate the effect of collision velocity on the adhesion probability, with the eventual goal of understanding the various mechanisms of inhibition (direct competition for viral binding sites versus steric stabilization). Analysis of these data also provide evidence that the density of binding sites may be a crucial parameter in the application of this assay and polymeric inhibition in general.

  14. A Coherence Preservation Control Strategy in Cavity QED Based on Classical Quantum Feedback

    Directory of Open Access Journals (Sweden)

    Ming Li

    2013-01-01

    Full Text Available For eliminating the unexpected decoherence effect in cavity quantum electrodynamics (cavity QED, the transfer function of Rabi oscillation is derived theoretically using optical Bloch equations. In particular, the decoherence in cavity QED from the atomic spontaneous emission is especially considered. A feedback control strategy is proposed to preserve the coherence through Rabi oscillation stabilization. In the scheme, a classical quantum feedback channel for the quantum information acquisition is constructed via the quantum tomography technology, and a compensation system based on the root locus theory is put forward to suppress the atomic spontaneous emission and the associated decoherence. The simulation results have proved its effectiveness and superiority for the coherence preservation.

  15. Will the Convention on Biological Diversity put an end to biological control?

    Directory of Open Access Journals (Sweden)

    Joop C. van Lenteren

    2011-03-01

    Full Text Available Will the Convention on Biological Diversity put an end to biological control? Under the Convention on Biological Diversity countries have sovereign rights over their genetic resources. Agreements governing the access to these resources and the sharing of the benefits arising from their use need to be established between involved parties. This also applies to species collected for potential use in biological control. Recent applications of access and benefit sharing principles have already made it difficult or impossible to collect and export natural enemies for biological control research in several countries. If such an approach is widely applied it would impede this very successful and environmentally safe pest management method based on the use of biological diversity. The International Organization for Biological Control of Noxious Animals and Plants has, therefore, created the "Commission on Biological Control and Access and Benefit Sharing". This commission is carrying out national and international activities to make clear how a benefit sharing regime might seriously frustrate the future of biological control. In addition, the IOBC Commission members published information on current regulations and perceptions concerning exploration for natural enemies and drafted some 30 case studies selected to illustrate a variety of points relevant to access and benefit sharing. In this article, we summarize our concern about the effects of access and benefit sharing systems on the future of biological control.

  16. Multicriteria Evaluation of Classical Swine Fever Control Strategies Using the Choquet Integral.

    Science.gov (United States)

    Brosig, J; Traulsen, I; Krieter, J

    2016-02-01

    An outbreak of the highly contagious animal disease classical swine fever (CSF) requires the selection of an optimal control strategy. The choice of a control strategy is a decision process depending on different aspects. Besides epidemiology, economic and ethical/social aspects must be taken into account. In this study, multicriteria decision-making (MCDM) was used to evaluate six control strategies for two regions with different farm densities. A strategy including only the minimum EU control measures and the traditional control strategy based on preventive culling were compared to alternative control strategies using emergency vaccination and/or rapid PCR testing ('emergency vaccination', 'test to slaughter', 'test to control' and 'vaccination in conjunction with rapid testing'). The MACBETH approach was used in order to assess the three main criteria (epidemiology, economics and ethical/social aspects). Subcriteria with both quantitative and qualitative performance levels were translated into a normalized scale. The Choquet integral approach was adopted to obtain a ranking of the six CSF control strategies based on the three main criteria, taking interactions into account. Three different rankings of the importance of the main criteria, which were to reflect the potential perceptions of stakeholders, were examined. Both the region under investigation and the ranking of the main criteria had an influence on the 'best' choice. Alternative control strategies were favourable to the minimum EU control and the traditional control measures independent of the farm density. Because the choice of the 'best' control strategy does not solely depend on the epidemiological efficiency, MCDM can help to find the best solution. Both MACBETH and the Choquet integral approach are feasible MCDM approaches. MACBETH only needs a qualitative evaluation and is therefore a comparatively intuitive approach. The Choquet integral does not only take the importance of the criteria into

  17. New Biologic Drug Tackles Hard-To-Control Asthma

    Science.gov (United States)

    ... html New Biologic Drug Tackles Hard-to-Control Asthma Benralizumab significantly cuts respiratory attacks, two trials show ... drug reduces flare-ups in patients with severe asthma that is not controlled by steroid inhalers alone, ...

  18. Dynamical Systems and Control Theory Inspired by Molecular Biology

    Science.gov (United States)

    2014-10-02

    in both bacterial and eukaryotic signaling pathways. A common theme in the systems biology literature is that certain systems whose output variables...AFRL-OSR-VA-TR-2014-0282 DYNAMICAL SYSTEMS AND CONTROL THEORY INSPIRED BY MOLECULAR BIOLOGY Eduardo Sontag RUTGERS THE STATE UNIVERSITY OF NEW JERSEY...Standard Form 298 (Re . 8-98) v Prescribed by ANSI Std. Z39.18 DYNAMICAL SYSTEMS AND CONTROL THEORY INSPIRED BY MOLECULAR BIOLOGY AFOSR FA9550-11-1-0247

  19. Parasitoids as biological control agents of thrips pests

    NARCIS (Netherlands)

    Loomans, A.J.M.

    2003-01-01

    Keywords: Thysanoptera, Frankliniella occidentalis, Hymenoptera, Ceranisus menes, Ceranisus americensis, biological controlThe thesis presented here is the result of a joint European Research project "Biological Control of Thrips Pests". Specific aims of the project were to collect, evaluate, mass p

  20. Damage control surgery--new concept or reenacting of a classical idea?

    Science.gov (United States)

    Beuran, Mircea; Iordache, Florin-Mihail

    2008-01-01

    Damage-control surgery is an example of a paradigm shift. The term is borrowed from naval teminology and means gaining the initial control of a damaged ship. Because of the lethal triad the polytrauma patient is at a grave risk. The classical concept of surgically solving all the patient's injuries in the first moment was even theoretically incorrect as a multiple injured patient is a critical patient with depleted reserves. As such, complex procedures were doomed from this point of view. The concept of damage-control surgery emerged in 1992. The core idea was that as minimal as possible had to be done in these critical patients in the first phase, meaning temporary control of a hemorrhage and simple measures for stopping contamination. After 24-48 hours in the ICU, in which time the physiological disturbances were corrected, a further intervention is perfomed for definitively treating the injuries. Further refinements consider five stages and not three in damage-control surgery. The bright side of the concept is an up to 70% survivability rate but with a higher risk of complications, mostly due to the policy of temporary closing the abdomen and sepsis.

  1. Damage control surgery–new concept or reenacting of a classical ideea?

    Science.gov (United States)

    Iordache, FM

    2008-01-01

    Damage–control surgery is an example of a paradigm shift. The term is borrowed from naval terminology and means gaining the initial control of a damaged ship. Because of the lethal triad the polytrauma patient is at a grave risk. The classical concept of surgically solving all the patient's injuries in the first moment was even theoretically incorrect as a multiple injured patient is a critical patient with depleted reserves. As such, complex procedures were doomed from this point of view. The concept of damage–control surgery emerged in 1992. The core idea was that as minimal as possible had to be done in these critical patients in the first phase, meaning temporary control of a hemorrhage and simple measures for stopping contamination. After 24–48 hours in the ICU, in which time the physiological disturbances were corrected, a further intervention is performed for definitively treating the injuries. Further refinements consider five stages and not three in damage–control surgery. The bright side of the concept is an up to 70% survivability rate but with a higher risk of complications, mostly due to the policy of temporary closing the abdomen and sepsis. PMID:20108501

  2. The potential of antiviral agents to control classical swine fever: a modelling study.

    Science.gov (United States)

    Backer, Jantien A; Vrancken, Robert; Neyts, Johan; Goris, Nesya

    2013-09-01

    Classical swine fever (CSF) represents a continuous threat to pig populations that are free of disease without vaccination. When CSF virus is introduced, the minimal control strategy imposed by the EU is often insufficient to mitigate the epidemic. Additional measures such as preemptive culling encounter ethical objections, whereas emergency vaccination leads to prolonged export restrictions. Antiviral agents, however, provide instantaneous protection without inducing an antibody response. The use of antiviral agents to contain CSF epidemics is studied with a model describing within- and between-herd virus transmission. Epidemics are simulated in a densely populated livestock area in The Netherlands, with farms of varying sizes and pig types (finishers, piglets and sows). Our results show that vaccination and/or antiviral treatment in a 2 km radius around an infected herd is more effective than preemptive culling in a 1 km radius. However, the instantaneous but temporary protection provided by antiviral treatment is slightly less effective than the delayed but long-lasting protection offered by vaccination. Therefore, the most effective control strategy is to vaccinate animals when allowed (finishers and piglets) and to treat with antiviral agents when vaccination is prohibited (sows). As independent control measure, antiviral treatment in a 1 km radius presents an elevated risk of epidemics running out of control. A 2 km control radius largely eliminates this risk.

  3. The challenges of classical swine fever control: modified live and E2 subunit vaccines.

    Science.gov (United States)

    Huang, Yu-Liang; Deng, Ming-Chung; Wang, Fun-In; Huang, Chin-Cheng; Chang, Chia-Yi

    2014-01-22

    Classical swine fever (CSF) is an economically important, highly contagious disease of swine worldwide. CSF is caused by classical swine fever virus (CSFV), and domestic pigs and wild boars are its only natural hosts. The two main strategies used to control CSF epidemic are systematic prophylactic vaccination and a non-vaccination stamping-out policy. This review compares the protective efficacy of the routinely used modified live vaccine (MLV) and E2 subunit vaccines and summarizes the factors that influence the efficacy of the vaccines and the challenges that both vaccines face to CSF control. Although MLV provide earlier and more complete protection than E2 subunit vaccines, it has the drawback of not allowing differentiation between infected and vaccinated animals (DIVA). The marker vaccine of E2 protein with companion discriminatory test to detect antibodies against E(rns) allows DIVA and is a promising strategy for future control and eradication of CSF. Maternal derived antibody (MDA) is the critical factor in impairing the efficacy of both MLV and E2 subunit vaccines, so the well-designed vaccination programs of sows and piglets should be considered together. Because of the antigen variation among various genotypes of CSFV, antibodies raised by either MLV or subunit vaccine neutralize genotypically homologous strains better than heterologous ones. However, although this is not a major concern for MLV as the induced immune responses can protect pigs against the challenge of various genotypes of CSFVs, it is critical for E2 subunit vaccines. It is thus necessary to evaluate whether the E2 subunit vaccine can completely protect against the current prevalent strains in the field. An ideal new generation of vaccine should be able to maintain the high protective efficiency of MLV and overcome the problem of antigenic variations while allowing for DIVA.

  4. Biological control of the terrestrial carbon sink

    Science.gov (United States)

    Schulze, E.-D.

    2006-03-01

    This lecture reviews the past (since 1964 when the International Biological Program began) and the future of our understanding of terrestrial carbon fluxes with focus on photosynthesis, respiration, primary-, ecosystem-, and biome-productivity. Photosynthetic capacity is related to the nitrogen concentration of leaves, but the capacity is only rarely reached under field conditions. Average rates of photosynthesis and stomatal conductance are closely correlated and operate near 50% of their maximal rate, with light being the limiting factor in humid regions and air humidity and soil water the limiting factor in arid climates. Leaf area is the main factor to extrapolate from leaves to canopies, with maximum surface conductance being dependent on leaf level stomatal conductance. Additionally, gas exchange depends also on rooting depth which determines the water and nutrient availability and on mycorrhizae which regulate the nutrient status. An important anthropogenic disturbance is the nitrogen uptake from air pollutants, which is not balanced by cation uptake from roots and this may lead to damage and breakdown of the plant cover. Photosynthesis is the main carbon input into ecosystems, but it alone does not represent the ecosystem carbon balance, which is determined by respiration of various kinds. Plant respiration and photosynthesis determine growth (net primary production) and microbial respiration balances the net ecosystem flux. In a spruce forest, 30% of the assimilatory carbon gain is used for respiration of needles, 20% is used for respiration in stems. Soil respiration is about 50% the carbon gain, half of which is root respiration, half is microbial respiration. In addition, disturbances lead to carbon losses, where fire, harvest and grazing bypass the chain of respiration. In total, the carbon balance at the biome level is only about 1% of the photosynthetic carbon input, or may indeed become negative. The recent observed increase in plant growth has

  5. Biological control of the terrestrial carbon sink

    Directory of Open Access Journals (Sweden)

    E.-D. Schulze

    2006-01-01

    Full Text Available This lecture reviews the past (since 1964 when the International Biological Program began and the future of our understanding of terrestrial carbon fluxes with focus on photosynthesis, respiration, primary-, ecosystem-, and biome-productivity. Photosynthetic capacity is related to the nitrogen concentration of leaves, but the capacity is only rarely reached under field conditions. Average rates of photosynthesis and stomatal conductance are closely correlated and operate near 50% of their maximal rate, with light being the limiting factor in humid regions and air humidity and soil water the limiting factor in arid climates. Leaf area is the main factor to extrapolate from leaves to canopies, with maximum surface conductance being dependent on leaf level stomatal conductance. Additionally, gas exchange depends also on rooting depth which determines the water and nutrient availability and on mycorrhizae which regulate the nutrient status. An important anthropogenic disturbance is the nitrogen uptake from air pollutants, which is not balanced by cation uptake from roots and this may lead to damage and breakdown of the plant cover. Photosynthesis is the main carbon input into ecosystems, but it alone does not represent the ecosystem carbon balance, which is determined by respiration of various kinds. Plant respiration and photosynthesis determine growth (net primary production and microbial respiration balances the net ecosystem flux. In a spruce forest, 30% of the assimilatory carbon gain is used for respiration of needles, 20% is used for respiration in stems. Soil respiration is about 50% the carbon gain, half of which is root respiration, half is microbial respiration. In addition, disturbances lead to carbon losses, where fire, harvest and grazing bypass the chain of respiration. In total, the carbon balance at the biome level is only about 1% of the photosynthetic carbon input, or may indeed become negative. The recent observed increase in

  6. Biological control and nutrition: food for thought

    Science.gov (United States)

    Chemical pesticides are used frequently to combat arthropod pests that plague crops; however, these compounds come with potential risks to the environment and human health. Research efforts have focused on using natural agents as an alternative to these chemical insecticides. These biological contro...

  7. Biologic

    CERN Document Server

    Kauffman, L H

    2002-01-01

    In this paper we explore the boundary between biology and the study of formal systems (logic). In the end, we arrive at a summary formalism, a chapter in "boundary mathematics" where there are not only containers but also extainers ><, entities open to interaction and distinguishing the space that they are not. The boundary algebra of containers and extainers is to biologic what boolean algebra is to classical logic. We show how this formalism encompasses significant parts of the logic of DNA replication, the Dirac formalism for quantum mechanics, formalisms for protein folding and the basic structure of the Temperley Lieb algebra at the foundations of topological invariants of knots and links.

  8. Classical mechanics with calculus of variations and optimal control an intuitive introduction

    CERN Document Server

    Levi, Mark

    2014-01-01

    This is an intuitively motivated presentation of many topics in classical mechanics and related areas of control theory and calculus of variations. All topics throughout the book are treated with zero tolerance for unrevealing definitions and for proofs which leave the reader in the dark. Some areas of particular interest are: an extremely short derivation of the ellipticity of planetary orbits; a statement and an explanation of the "tennis racket paradox"; a heuristic explanation (and a rigorous treatment) of the gyroscopic effect; a revealing equivalence between the dynamics of a particle and statics of a spring; a short geometrical explanation of Pontryagin's Maximum Principle, and more. In the last chapter, aimed at more advanced readers, the Hamiltonian and the momentum are compared to forces in a certain static problem. This gives a palpable physical meaning to some seemingly abstract concepts and theorems. With minimal prerequisites consisting of basic calculus and basic undergraduate physics, this boo...

  9. A Reconfigurable Cryogenic Platform for the Classical Control of Scalable Quantum Computers

    CERN Document Server

    Homulle, Harald; Patra, Bishnu; Ferrari, Giorgio; Prati, Enrico; Sebastiano, Fabio; Charbon, Edoardo

    2016-01-01

    Recent advances in solid-state qubit technology are paving the way to fault-tolerant quantum computing systems. However, qubit technology is limited by qubit coherence time and by the complexity of coupling the quantum system with a classical electronic infrastructure. We propose an infrastructure, enabling to read and control qubits, that is implemented on a field-programmable gate array (FPGA). The FPGA platform supports functionality required by several qubit technologies and can operate physically close to the qubits over a temperature range from 4K to 300K. Extensive characterization of the platform over this temperature range revealed all major components (such as LUTs, MMCM, PLL, BRAM, IDELAY2) operate correctly and the logic speed is very stable. The stability is finally concretized by operating an integrated ADC with relatively stable performance over temperature.

  10. Biology and control of Varroa destructor.

    Science.gov (United States)

    Rosenkranz, Peter; Aumeier, Pia; Ziegelmann, Bettina

    2010-01-01

    The ectoparasitic honey bee mite Varroa destructor was originally confined to the Eastern honey bee Apis cerana. After a shift to the new host Apis mellifera during the first half of the last century, the parasite dispersed world wide and is currently considered the major threat for apiculture. The damage caused by Varroosis is thought to be a crucial driver for the periodical colony losses in Europe and the USA and regular Varroa treatments are essential in these countries. Therefore, Varroa research not only deals with a fascinating host-parasite relationship but also has a responsibility to find sustainable solutions for the beekeeping. This review provides a survey of the current knowledge in the main fields of Varroa research including the biology of the mite, damage to the host, host tolerance, tolerance breeding and Varroa treatment. We first present a general view on the functional morphology and on the biology of the Varroa mite with special emphasis on host-parasite interactions during reproduction of the female mite. The pathology section describes host damage at the individual and colony level including the problem of transmission of secondary infections by the mite. Knowledge of both the biology and the pathology of Varroa mites is essential for understanding possible tolerance mechanisms in the honey bee host. We comment on the few examples of natural tolerance in A. mellifera and evaluate recent approaches to the selection of Varroa tolerant honey bees. Finally, an extensive listing and critical evaluation of chemical and biological methods of Varroa treatments is given. This compilation of present-day knowledge on Varroa honey bee interactions emphasizes that we are still far from a solution for Varroa infestation and that, therefore, further research on mite biology, tolerance breeding, and Varroa treatment is urgently needed.

  11. Encyrtid parasitoids of soft scale insects: biology, behavior, and their use in biological control.

    Science.gov (United States)

    Kapranas, Apostolos; Tena, Alejandro

    2015-01-07

    Parasitoids of the hymenopterous family Encyrtidae are one of the most important groups of natural enemies of soft scale insects and have been used extensively in biological control. We summarize existing knowledge of the biology, ecology, and behavior of these parasitoids and how it relates to biological control. Soft scale stage/size and phenology are important determinants of host range and host utilization, which are key aspects in understanding how control by these parasitoids is exerted. Furthermore, the nutritional ecology of encyrtids and their physiological interactions with their hosts affect soft scale insect population dynamics. Lastly, the interactions among encyrtids, heteronomous parasitoids, and ants shape parasitoid species complexes and consequently have a direct impact on the biological control of soft scale insects.

  12. Insect pathogens as biological control agents: Back to the future.

    Science.gov (United States)

    Lacey, L A; Grzywacz, D; Shapiro-Ilan, D I; Frutos, R; Brownbridge, M; Goettel, M S

    2015-11-01

    The development and use of entomopathogens as classical, conservation and augmentative biological control agents have included a number of successes and some setbacks in the past 1years. In this forum paper we present current information on development, use and future directions of insect-specific viruses, bacteria, fungi and nematodes as components of integrated pest management strategies for control of arthropod pests of crops, forests, urban habitats, and insects of medical and veterinary importance. Insect pathogenic viruses are a fruitful source of microbial control agents (MCAs), particularly for the control of lepidopteran pests. Most research is focused on the baculoviruses, important pathogens of some globally important pests for which control has become difficult due to either pesticide resistance or pressure to reduce pesticide residues. Baculoviruses are accepted as safe, readily mass produced, highly pathogenic and easily formulated and applied control agents. New baculovirus products are appearing in many countries and gaining an increased market share. However, the absence of a practical in vitro mass production system, generally higher production costs, limited post application persistence, slow rate of kill and high host specificity currently contribute to restricted use in pest control. Overcoming these limitations are key research areas for which progress could open up use of insect viruses to much larger markets. A small number of entomopathogenic bacteria have been commercially developed for control of insect pests. These include several Bacillus thuringiensis sub-species, Lysinibacillus (Bacillus) sphaericus, Paenibacillus spp. and Serratia entomophila. B. thuringiensis sub-species kurstaki is the most widely used for control of pest insects of crops and forests, and B. thuringiensis sub-species israelensis and L. sphaericus are the primary pathogens used for control of medically important pests including dipteran vectors. These pathogens

  13. Project Summary: Biology-Inspired Autonomous Control

    Science.gov (United States)

    2011-02-01

    relative high performance predictability currently associated with automated machines. Anyone who has walked a normally well behaved male dog in the...possibilities as well. Attitude control systems normally include proportional and integral control on sensed attitude, with damping and robustness provided...attacking predators. Some examples include red-wing black bird nest defense [1], meerkat predator mobbing [2], and predator identification in guppy schools

  14. Biological control of weeds release sites : Kulm Wetland Management District

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Table of release sites of insects for biological control of invasive plants at Kulm Wetland Management District (WMD). Insects were released on Kulm WMD to...

  15. Arms Control: US and International efforts to ban biological weapons

    Energy Technology Data Exchange (ETDEWEB)

    1992-12-01

    The Bacteriological (Biological) and Toxin Weapons Convention, the treaty that bans the development, production, and stockpiling and acquisition of biological weapons was opened for signature in 1972 and came into force in 1975 after being ratified by 22 governments, including the depository nations of the USA, the United Kingdom, and the former Soviet Union. In support of the Convention, the USA later established export controls on items used to make biological weapons. Further, in accordance with the 1990 President`s Enhanced Proliferation Control Initiative, actions were taken to redefine and expand US export controls, as well as to encourage multilateral controls through the Australia Group. Thus far, the Convention has not been effective in stopping the development of biological weapons. The principal findings as to the reasons of the failures of the Convention are found to be: the Convention lacks universality, compliance measures are effective, advantage of verification may outweigh disadvantages. Recommendations for mitigating these failures are outlined in this report.

  16. Approach to the classical radiation biology. Ionizing radiation effects and repair mechanism of DNA double strand breaks

    Energy Technology Data Exchange (ETDEWEB)

    Utsumi, Hiroshi [Kyoto Univ., Kumatori, Osaka (Japan). Research Reactor Inst

    2000-09-01

    Split-dose recovery has been observed under a variety of experimental conditions in many cell systems and believed to be the recovery of sublethal damage (SLD). It is considered to be one of the most widespread and important cellular responses in clinical radiotherapy. To study the molecular mechanism of this recovery, we analyzed the knockout mutants KU70{sup -/-}, RAD54{sup -/-}, and KU70{sup -/-}/ RAD54{sup -/-} of the chicken B-cell line, DT40. Rad54 participates in the homologous recombinational (HR) repair of DNA double-strand breaks (DSB), while Ku proteins are involved in non-homologous end-joining (NHEJ). Split-dose recovery was observed in the parent DT40 and KU70{sup -/-} cells. Moreover the split-dose survival enhancement had all of the characteristics of SLD recovery that had been demonstrated earlier: e.g., the reappearance of the shoulder of the survival curve with dose fractionation; repair at 25degC; and inhibition by the antibiotic actinomycin D. These results strongly suggest that SLD recovery is due to DSB repair via or mediated by HR, and that these breaks constitute SLD. The tonicity-sensitive potentially lethal damage (PLD) recovery was also found only in DT40 and KU70 {sup -/-} cells. Delayed-plating PLD recovery may be controlled by NHEJ repair that works through the cell cycle. These results lead to the conclusion that the repair of DSBs could explain the classical operational recovery phenomena. We have also investigated RBE/LET using those mutants. (author)

  17. Biological control of tortricids and aphids in strawberries

    DEFF Research Database (Denmark)

    Sigsgaard, Lene; Enkegaard, Annie; Eilenberg, Jørgen;

    Cropping practice and biological control can contribute to reduced pesticide use in strawberries. Organic strawberries are less attacked by strawberry tortricid and buckwheat flower strips can augment its natural enemies. Against shallot aphid the two-spot ladybird is promising.......Cropping practice and biological control can contribute to reduced pesticide use in strawberries. Organic strawberries are less attacked by strawberry tortricid and buckwheat flower strips can augment its natural enemies. Against shallot aphid the two-spot ladybird is promising....

  18. Effects of gain-scheduling methods in a classical wind turbine controller on wind turbine aeroservoelastic modes and loads

    DEFF Research Database (Denmark)

    Tibaldi, Carlo; Henriksen, Lars Christian; Hansen, Morten Hartvig

    2014-01-01

    The eects of dierent gain-scheduling methods for a classical wind turbine controller, operating in full load region, on the wind turbine aeroservoelastic modes and loads are investigated in this work. The dierent techniques are derived looking at the physical problem to take into account the chan......The eects of dierent gain-scheduling methods for a classical wind turbine controller, operating in full load region, on the wind turbine aeroservoelastic modes and loads are investigated in this work. The dierent techniques are derived looking at the physical problem to take into account...

  19. Controllability and observability of Boolean networks arising from biology.

    Science.gov (United States)

    Li, Rui; Yang, Meng; Chu, Tianguang

    2015-02-01

    Boolean networks are currently receiving considerable attention as a computational scheme for system level analysis and modeling of biological systems. Studying control-related problems in Boolean networks may reveal new insights into the intrinsic control in complex biological systems and enable us to develop strategies for manipulating biological systems using exogenous inputs. This paper considers controllability and observability of Boolean biological networks. We propose a new approach, which draws from the rich theory of symbolic computation, to solve the problems. Consequently, simple necessary and sufficient conditions for reachability, controllability, and observability are obtained, and algorithmic tests for controllability and observability which are based on the Gröbner basis method are presented. As practical applications, we apply the proposed approach to several different biological systems, namely, the mammalian cell-cycle network, the T-cell activation network, the large granular lymphocyte survival signaling network, and the Drosophila segment polarity network, gaining novel insights into the control and/or monitoring of the specific biological systems.

  20. Optimal Control through Biologically-Inspired Pursuit

    Science.gov (United States)

    2004-01-01

    Transactions on Automatic Control 48, 988– 1001. Roumeliotis, S.I. and G.A. Bekey (2002). Distributed multi-robot localization. IEEE Transactions on Robotics and...1999). Distributed covering by ant- robots using evaporating traces. IEEE Transactions on Robotics and Automation 15(5), 918–933.

  1. Biological effect of penetration controlled irradiation with ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Atsushi; Shimizu, Takashi; Kikuchi, Masahiro; Kobayashi, Yasuhiko; Watanabe, Hiroshi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Yamashita, Takao

    1997-03-01

    To investigate the effect of local irradiation with ion beams on biological systems, technique for penetration controlled irradiation has been established. The range in a target was controlled by changing the distance from beam window in the atmosphere, and could be controlled linearly up to about 31 {mu}m in biological material. In addition, the effects of the penetration controlled irradiations with 1.5 MeV/u C and He ions were examined using tobacco pollen. The increased frequency of leaky pollen produced by ion beams suggests that the efficient pollen envelope damages would be induced at the range-end of ion beams. (author)

  2. Augmentative Biological Control Using Parasitoids for Fruit Fly Management in Brazil

    Directory of Open Access Journals (Sweden)

    Flávio R. M. Garcia

    2012-12-01

    Full Text Available The history of classical biological control of fruit flies in Brazil includes two reported attempts in the past 70 years. The first occurred in 1937 when an African species of parasitoid larvae (Tetrastichus giffardianus was introduced to control the Mediterranean fruit fly, Ceratitis capitata and other tephritids. The second occurred in September 1994 when the exotic parasitoid Diachasmimorpha longicaudata, originally from Gainesville, Florida, was introduced by a Brazilian agricultural corporation (EMBRAPA to evaluate the parasitoid’s potential for the biological control of Anastrepha spp. and Ceratitis capitata. Although there are numerous native Brazilian fruit fly parasitoids, mass rearing of these native species is difficult. Thus, D. longicaudata was chosen due to its specificity for the family Tephritidae and its ease of laboratory rearing. In this paper we review the literature on Brazilian fruit fly biological control and suggest that those tactics can be used on a large scale, together creating a biological barrier to the introduction of new fruit fly populations, reducing the source of outbreaks and the risk of species spread, while decreasing the use of insecticides on fruit destined for domestic and foreign markets.

  3. Augmentative Biological Control Using Parasitoids for Fruit Fly Management in Brazil.

    Science.gov (United States)

    Garcia, Flávio R M; Ricalde, Marcelo P

    2012-12-21

    The history of classical biological control of fruit flies in Brazil includes two reported attempts in the past 70 years. The first occurred in 1937 when an African species of parasitoid larvae (Tetrastichus giffardianus) was introduced to control the Mediterranean fruit fly, Ceratitis capitata and other tephritids. The second occurred in September 1994 when the exotic parasitoid Diachasmimorpha longicaudata, originally from Gainesville, Florida, was introduced by a Brazilian agricultural corporation (EMBRAPA) to evaluate the parasitoid's potential for the biological control of Anastrepha spp. and Ceratitis capitata. Although there are numerous native Brazilian fruit fly parasitoids, mass rearing of these native species is difficult. Thus, D. longicaudata was chosen due to its specificity for the family Tephritidae and its ease of laboratory rearing. In this paper we review the literature on Brazilian fruit fly biological control and suggest that those tactics can be used on a large scale, together creating a biological barrier to the introduction of new fruit fly populations, reducing the source of outbreaks and the risk of species spread, while decreasing the use of insecticides on fruit destined for domestic and foreign markets.

  4. Autonomic control of heart rate and blood pressure in spontaneously hypertensive rats during aversive classical conditioning.

    Science.gov (United States)

    Hatton, D C; Buchholz, R A; Fitzgerald, R D

    1981-12-01

    An examination was made of the heart rate (HR) and blood pressure (BP) responses of 7-9-wk-old spontaneously hypertensive rats (SHR) and genetical control Wistar/Kyoto (WKY) rats during aversive classical conditioning. Subsequent to the development of conditioned responding (CRs), assessments were made of the effects of selective autonomic blockade by methyl atropine (10 mg/kg), phentolamine (2 mg/kg), and propranolol (2 mg/kg). The CR complex in the two strains consisted of pressor BP CRs in conjunction with vagally mediated decelerative HR CRs in the SHR strain and sympathetically mediated accelerative HR CRs in the WKY strain. The decelerative SHR HR CR did not appear to be secondary to baroreceptor reflex activity, although such activity did appear to be involved in the pressor BP and decelerative HR orienting response (OR) and unconditioned response (UR) complex of the SHRs on the initial application of the CS and the US, respectively. Augmented pressor BP ORs, CRs, and URs in the SHRs relative to the WKYs and differential drug effects on BP and HR baselines of the two strains suggested the presence of enhanced sympathetic activity in the SHRs that was not reflected in the SHR decelerative HR CR. Phentolamine unmasked evidence of reflex beta 2-vasodilation deficiency in the SHRs that could have contributed to the enhancement of their BP OR and CR.

  5. Evaluation of control and surveillance strategies for classical swine fever using a simulation model.

    Science.gov (United States)

    Dürr, S; Zu Dohna, H; Di Labio, E; Carpenter, T E; Doherr, M G

    2013-01-01

    Classical swine fever (CSF) outbreaks can cause enormous losses in naïve pig populations. How to best minimize the economic damage and number of culled animals caused by CSF is therefore an important research area. The baseline CSF control strategy in the European Union and Switzerland consists of culling all animals in infected herds, movement restrictions for animals, material and people within a given distance to the infected herd and epidemiological tracing of transmission contacts. Additional disease control measures such as pre-emptive culling or vaccination have been recommended based on the results from several simulation models; however, these models were parameterized for areas with high animal densities. The objective of this study was to explore whether pre-emptive culling and emergency vaccination should also be recommended in low- to moderate-density areas such as Switzerland. Additionally, we studied the influence of initial outbreak conditions on outbreak severity to improve the efficiency of disease prevention and surveillance. A spatial, stochastic, individual-animal-based simulation model using all registered Swiss pig premises in 2009 (n=9770) was implemented to quantify these relationships. The model simulates within-herd and between-herd transmission (direct and indirect contacts and local area spread). By varying the four parameters (a) control measures, (b) index herd type (breeding, fattening, weaning or mixed herd), (c) detection delay for secondary cases during an outbreak and (d) contact tracing probability, 112 distinct scenarios were simulated. To assess the impact of scenarios on outbreak severity, daily transmission rates were compared between scenarios. Compared with the baseline strategy (stamping out and movement restrictions) vaccination and pre-emptive culling neither reduced outbreak size nor duration. Outbreaks starting in a herd with weaning piglets or fattening pigs caused higher losses regarding to the number of culled

  6. Anti-tick biological control agents: assessment and future perspectives

    Science.gov (United States)

    Samish, M.; Ginsberg, H.S.; Glazer, I.; Bowman, Alan. S.; Nuttall, Patricia A.

    2008-01-01

    Widespread and increasing resistance to most available acaracides threatens both global livestock industries and public health. This necessitates better understanding of ticks and the diseases they transmit in the development of new control strategies. Ticks: Biology, Disease and Control is written by an international collection of experts and covers in-depth information on aspects of the biology of the ticks themselves, various veterinary and medical tick-borne pathogens, and aspects of traditional and potential new control methods. A valuable resource for graduate students, academic researchers and professionals, the book covers the whole gamut of ticks and tick-borne diseases from microsatellites to satellite imagery and from exploiting tick saliva for therapeutic drugs to developing drugs to control tick populations. It encompasses the variety of interconnected fields impinging on the economically important and biologically fascinating phenomenon of ticks, the diseases they transmit and methods of their control.

  7. New developments in classical microscopy; what can be expected for the official control?

    Directory of Open Access Journals (Sweden)

    van Raamsdonk, L.

    2011-01-01

    Full Text Available The official control of animal proteins in feed is focused on the prevention of Bovine Spongiform Encephalopathy (mad cow disease. The current legislation of the European Union is planned to avoid the feeding of animal by-products to the same species as its origin (ban of cannibalism, or species-to-species ban. With respect to the official control, the circumscription of the term species in legislation should be defined, and species-specific markers should be available. Markers will include primer sets, antibodies, near-infrared profiles or visual characteristics. The method of classical light microscopy is currently the only accepted method in the framework of the official detection of animal proteins. Besides the necessary development of complementary methods, either as stand alone methods or in combination, the visual characteristics used for a microscopic examination of meat and bone meal particles should be fully explored. Multivariate analysis of a range of characteristics of lacunae in bone fragments revealed that discrimination is possible between mammalian and avian bone fragments. Translation to features for every day practical use should be carried out very carefully, and only comprehensively collected information on a range of features will give a first indication of the source. Characteristics of hairs and feather filaments can be used to identify the origin of animal particles. An in situ identification method has been developed for antibody conjugation with troponin I in muscle fibers on a microscopic slide. A proof of principle is presented. Interlaboratory transferability and validation have still to be achieved. The development and testing of light microscopy markers in the framework of the SAFEED-PAP project revealed that a fine tuning of existing microscopic characteristics appears to be possible.

  8. Using a Classic Paper by I. E. Lawton and N. B. Schwartz to Consider the Array of Factors that Control Luteinizing Hormone Production

    Science.gov (United States)

    Bauer-Dantoin, Angela C.; Hanke, Craig J.

    2007-01-01

    Two significant benefits derived from reading and discussing classic scientific papers in undergraduate biology courses are 1) providing students with the realistic perspective that science is an ongoing process (rather than a set of inarguable facts) and 2) deepening the students' understanding of physiological processes. A classic paper that is…

  9. A brief overview of current relationships of geography, statistics, and taxonomy with the classical integrated control concept

    Science.gov (United States)

    A classic paper on the integrated control concept appeared in the later part of the 1950’s, led by Vernon Stern, Ray Smith, Robert van den Bosch, and Kenneth Hagen. Numerous concepts and definitions were formulated at that time. In this presentation, a short philosophical summary will be presented...

  10. Exogenous control of biological and ecological systems through evolutionary modelling

    Directory of Open Access Journals (Sweden)

    Alessandro Ferrarini

    2013-09-01

    Full Text Available The controllability of network-like systems is a topical issue in ecology and biology. It relies on the ability to lead a system's behaviour towards the desired state through the appropriate handling of input variables. Up to now, controllability of networks is based on the permanent control of a set of driver nodes that can guide the system's dynamics. This assumption seems motivated by real-world networks observation, where a decentralized control is often applied only to part of the nodes. While in a previous paper I showed that ecological and biological networks can be efficaciously controlled from the inside, here I further introduce a new framework for network controllability based on the employment of exogenous controllers and evolutionary modelling, and provide an exemplification of its application.

  11. Augmentative biological control of arthropods in Latin America

    NARCIS (Netherlands)

    Lenteren, van J.C.; Bueno, V.H.P.

    2003-01-01

    Augmentative forms of biological control, where natural enemies are periodically introduced, are applied over large areas in various cropping systems in Latin America. About 25% of the world area under augmentative control is situated in this region. Well-known examples are the use of species of the

  12. EFSA Panel on Biological Hazards (BIOHAZ); Scientific Opinion on the risk of transmission of classical scrapie via in vivo derived embryo transfer in ovine animals

    DEFF Research Database (Denmark)

    Hald, Tine; Baggesen, Dorte Lau

    impact of PrP genotype of the embryo and/or of the ram and donor ewe on this risk was also assessed. The new data made available over the last three years further reinforce the view that classical scrapie could be vertically transmitted in sheep. Since the possibility of such vertical transmission....... Under natural exposure conditions, animals that are heterozygous or homozygous A136R154R171 display respectively a low or negligible risk of being infected. The genetic control of the susceptibility to classical scrapie is also likely to impact on the risk of transmitting the disease via embryo transfer...

  13. Cell biology. Metabolic control of cell death.

    Science.gov (United States)

    Green, Douglas R; Galluzzi, Lorenzo; Kroemer, Guido

    2014-09-19

    Beyond their contribution to basic metabolism, the major cellular organelles, in particular mitochondria, can determine whether cells respond to stress in an adaptive or suicidal manner. Thus, mitochondria can continuously adapt their shape to changing bioenergetic demands as they are subjected to quality control by autophagy, or they can undergo a lethal permeabilization process that initiates apoptosis. Along similar lines, multiple proteins involved in metabolic circuitries, including oxidative phosphorylation and transport of metabolites across membranes, may participate in the regulated or catastrophic dismantling of organelles. Many factors that were initially characterized as cell death regulators are now known to physically or functionally interact with metabolic enzymes. Thus, several metabolic cues regulate the propensity of cells to activate self-destructive programs, in part by acting on nutrient sensors. This suggests the existence of "metabolic checkpoints" that dictate cell fate in response to metabolic fluctuations. Here, we discuss recent insights into the intersection between metabolism and cell death regulation that have major implications for the comprehension and manipulation of unwarranted cell loss.

  14. Implementation of integral feedback control in biological systems.

    Science.gov (United States)

    Somvanshi, Pramod R; Patel, Anilkumar K; Bhartiya, Sharad; Venkatesh, K V

    2015-01-01

    Integral control design ensures that a key variable in a system is tightly maintained within acceptable levels. This approach has been widely used in engineering systems to ensure offset free operation in the presence of perturbations. Several biological systems employ such an integral control design to regulate cellular processes. An integral control design motif requires a negative feedback and an integrating process in the network loop. This review describes several biological systems, ranging from bacteria to higher organisms in which the presence of integral control principle has been hypothesized. The review highlights that in addition to the negative feedback, occurrence of zero-order kinetics in the process is a key element to realize the integral control strategy. Although the integral control motif is common to these systems, the mechanisms involved in achieving it are highly specific and can be incorporated at the level of signaling, metabolism, or at the phenotypic levels.

  15. Citrus growers vary in their adoption of biological control

    OpenAIRE

    Grogan, Kelly A.; Goodhue, Rachael E.

    2012-01-01

    In a spring 2010 survey, we investigated the characteristics that influenced whether California growers controlled major citrus pests with beneficial insects. We also performed statistical analysis of growers' reliance on Aphytus melinus, a predatory wasp, to control California red scale. The survey results suggest that growers with greater citrus acreage and more education are more likely to use biological control. Marketing outlets, ethnicity and primary information sources also influenced ...

  16. Biological Control of the Invasive Dryocosmus kuriphilus (Hymenoptera: Cynipidae) - an Overview and the First Trials in Croatia

    OpenAIRE

    2014-01-01

    Background and Purpose: Dryocosmus kuriphilus is a globally invasive insect pest, spreading very quickly in new habitats and making serious damage to sweet chestnut forests in Croatia and in several other European countries. Indigenous parasitoid species trophically associated with oak gallwasps have adapted to this new host but cannot effectively regulate its population density. Classical biological control using parasitoid Torymus sinensis has been proven to be the only effective method of ...

  17. Biology and host range of Tecmessa elegans (Lepidoptera:Notodontidae) a leaf-feeding moth evaluated as a potential biological control agent for Schinus terebinthifolius (Sapindales: Anacardiaceae) in the USA

    Science.gov (United States)

    During surveys for natural enemies that could potentially be used as classical biological control agents of Schinus terebinthifolius Raddi (Brazilian pepper) which is invasive in the USA, the caterpillar, Tecmessa elegans Schaus (Lepidoptera: Notodontidae), was recorded feeding on the leaves of the ...

  18. Economic welfare analysis of simulated control strategies for classical swine fever epidemics

    NARCIS (Netherlands)

    Mangen, M.J.J.

    2002-01-01

     Keywords: Classical swine fever; contagious disease; epidemiological model; sector-level market and trade model; simulation; economic welfare analysis; densely and sparsely populated areas; supplementary animal welfare measure

  19. Synthetic biology and therapeutic strategies for the degenerating brain: Synthetic biology approaches can transform classical cell and gene therapies, to provide new cures for neurodegenerative diseases.

    Science.gov (United States)

    Agustín-Pavón, Carmen; Isalan, Mark

    2014-10-01

    Synthetic biology is an emerging engineering discipline that attempts to design and rewire biological components, so as to achieve new functions in a robust and predictable manner. The new tools and strategies provided by synthetic biology have the potential to improve therapeutics for neurodegenerative diseases. In particular, synthetic biology will help design small molecules, proteins, gene networks, and vectors to target disease-related genes. Ultimately, new intelligent delivery systems will provide targeted and sustained therapeutic benefits. New treatments will arise from combining 'protect and repair' strategies: the use of drug treatments, the promotion of neurotrophic factor synthesis, and gene targeting. Going beyond RNAi and artificial transcription factors, site-specific genome modification is likely to play an increasing role, especially with newly available gene editing tools such as CRISPR/Cas9 systems. Taken together, these advances will help develop safe and long-term therapies for many brain diseases in human patients.

  20. Total cross sections for ionizing processes induced by proton impact on molecules of biological interest: A classical trajectory Monte Carlo approach

    Energy Technology Data Exchange (ETDEWEB)

    Lekadir, H.; Abbas, I.; Champion, C. [Universite Paul Verlaine Metz, Laboratoire de Physique Moleculaire et des Collisions, Institut J. Barriol FR CNRS 2843, 1 Bd Arago, 57078 Metz Cedex3 (France); Hanssen, J. [Universite Paul Verlaine Metz, Laboratoire de Physique Moleculaire et des Collisions, Institut J. Barriol FR CNRS 2843, 1 Bd Arago, 57078 Metz Cedex3 (France)], E-mail: jocelyn@univ-metz.fr

    2009-03-15

    In the current work, we present a study of ionizing interactions between protons and molecular targets of biological interest like water vapour and DNA bases. Total cross sections for single and multiple ionizing processes are calculated in the independent electron model and compared to existing theoretical and experimental results for impact energies ranging from 10 keV/amu to 10 MeV/amu. The theoretical approach combines some characteristics of the classical trajectory Monte Carlo method with the classical over-barrier framework. In this 'mixed' approach, all the particles are described in a classical way by assuming that the target electrons are involved in the collision only when their binding energy is greater than the maximum of the potential energy of the system projectile-target. We test our theoretical approach on the water molecule and the obtained results are compared to a large set of data and a reasonable agreement is generally observed specially for impact energies greater than 100 keV, except for the double ionization process for which large discrepancies are reported. Considering the DNA bases, the obtained results are given without any comparison since the literature is till now very poor in terms of cross section measurements.

  1. Methylene Diphosphonate Chemical and Biological control of MDP complex

    CERN Document Server

    Aungurarat, A

    2000-01-01

    Technetium-9 sup 9 sup m MDP easy prepared from MDP kits which different sources such as OAP (In house), SIGMA. The resulting Tc 9 sup 9 sup m -MDP preparations were controlled in chemical and biological tests to compare the different results in these cases: radiochemical purity, the quantity of starting material and biodistribution result.

  2. Successful biological control of tropical soda apple in Florida

    Science.gov (United States)

    Tropical soda apple, Solanum viarum, is a small shrub native to tropical regions of Brazil, Paraguay, and Argentina. This weed was first found in Florida in 1988. In May 2003, a leaf feeding beetle, Gratiana boliviana, from South America was released in Florida as a biological control agent of tro...

  3. Conditional lethality strains for the biological control of Anastrepha species

    Science.gov (United States)

    Pro-apoptotic cell death genes are promising candidates for biologically-based autocidal control of pest insects as demonstrated by tetracycline (tet)-suppressible systems for conditional embryonic lethality in Drosophila melanogaster (Dm) and the medfly, Ceratitis capitata (Cc). However, for medfly...

  4. Identification and evaluation of Trichogramma parasitoids for biological pest control

    NARCIS (Netherlands)

    Silva, I.M.M.S.

    1999-01-01

    Egg parasitoids of the genus Trichogramma are used as biological control agents against lepidopterous pests. From the 180 species described world-wide, only 5 have large scale application. The development of better methods to select other Trichogramma species/strains is necessary for a more effectiv

  5. Integrating Biological Systems in the Process Dynamics and Control Curriculum

    Science.gov (United States)

    Parker, Robert S.; Doyle, Francis J.; Henson, Michael A.

    2006-01-01

    The evolution of the chemical engineering discipline motivates a re-evaluation of the process dynamics and control curriculum. A key requirement of future courses will be the introduction of theoretical concepts and application examples relevant to emerging areas, notably complex biological systems. We outline the critical concepts required to…

  6. Control and Transfer of Entanglement between Two Atoms Driven by Classical Fields under Dressed-State Representation

    Science.gov (United States)

    Liao, Qing-Hong; Zhang, Qi; Xu, Juan; Yan, Qiu-Rong; Liu, Ye; Chen, An

    2016-06-01

    We have studied the dynamics and transfer of the entanglement of the two identical atoms simultaneously interacting with vacuum field by employing the dressed-state representation. The two atoms are driven by classical fields. The influence of the initial entanglement degree of two atoms, the coupling strength between the atom and the classical field and the detuning between the atomic transition frequency and the frequency of classical field on the entanglement and atomic linear entropy is discussed. The initial entanglement of the two atoms can be transferred into the entanglement between the atom and cavity field when the dissipation is neglected. The maximally entangled state between the atoms and cavity field can be obtained under some certain conditions. The time of disentanglement of two atoms can be controlled and manipulated by adjusting the detuning and classical driving fields. Moreover, the larger the cavity decay rate is, the more quickly the entanglement of the two atoms decays. Supported by National Natural Science Foundation of China under Grant Nos. 11247213, 61368002, 11304010, 11264030, 61168001, China Postdoctoral Science Foundation under Grant No. 2013M531558, Jiangxi Postdoctoral Research Project under Grant No. 2013KY33, the Natural Science Foundation of Jiangxi Province under Grant No. 20142BAB217001, the Foundation for Young Scientists of Jiangxi Province (Jinggang Star) under Grant No. 20122BCB23002, the Research Foundation of the Education Department of Jiangxi Province under Grant Nos. GJJ13051, GJJ13057, and the Graduate Innovation Special Fund of Nanchang University under Grant No. cx2015137

  7. Economic Benefit for Cuban Laurel Thrips Biological Control.

    Science.gov (United States)

    Shogren, C; Paine, T D

    2016-02-01

    The Cuban laurel thrips, Gynaikothrips ficorum Marchal (Thysanoptera: Phlaeothripidae), is a critical insect pest of Ficus microcarpa in California urban landscapes and production nurseries. Female thrips feed and oviposit on young Ficus leaves, causing the expanding leaves to fold or curl into a discolored leaf gall. There have been attempts to establish specialist predator natural enemies of the thrips, but no success has been reported. We resampled the same areas in 2013-2014 where we had released Montandoniola confusa (= morguesi) Streito and Matocq (Hemiptera: Anthocoridae) in southern California in 1995 but had been unable to recover individuals in 1997-1998. Thrips galls were significantly reduced in all three of the locations in the recent samples compared with the earlier samples. M. confusa was present in all locations and appears to be providing successful biological control. The value of the biological control, the difference between street trees in good foliage condition and trees with poor foliage, was $58,766,166. If thrips damage reduced the foliage to very poor condition, the value of biological control was $73,402,683. Total cost for the project was $61,830. The benefit accrued for every dollar spent on the biological control of the thrips ranged from $950, if the foliage was in poor condition, to $1,187, if the foliage was in very poor condition. The value of urban forest is often underappreciated. Economic analyses that clearly demonstrate the very substantial rates of return on investment in successful biological control in urban forests provide compelling arguments for supporting future efforts.

  8. On Feeling in Control: A Biological Theory for Individual Differences in Control Perception

    Science.gov (United States)

    Declerck, Carolyn H.; Boone, Christophe; De Brabander, Bert

    2006-01-01

    This review aims to create a cross-disciplinary framework for understanding the perception of control. Although, the personality trait locus of control, the most common measure of control perception, has traditionally been regarded as a product of social learning, it may have biological antecedents as well. It is suggested that control perception…

  9. Epigenetics and Why Biological Networks are More Controllable than Expected

    Science.gov (United States)

    Motter, Adilson

    2013-03-01

    A fundamental property of networks is that perturbations to one node can affect other nodes, potentially causing the entire system to change behavior or fail. In this talk, I will show that it is possible to exploit this same principle to control network behavior. This approach takes advantage of the nonlinear dynamics inherent to real networks, and allows bringing the system to a desired target state even when this state is not directly accessible or the linear counterpart is not controllable. Applications show that this framework permits both reprogramming a network to a desired task as well as rescuing networks from the brink of failure, which I will illustrate through various biological problems. I will also briefly review the progress our group has made over the past 5 years on related control of complex networks in non-biological domains.

  10. A theoretical approach on controlling agricultural pest by biological controls.

    Science.gov (United States)

    Mondal, Prasanta Kumar; Jana, Soovoojeet; Kar, T K

    2014-03-01

    In this paper we propose and analyze a prey-predator type dynamical system for pest control where prey population is treated as the pest. We consider two classes for the pest namely susceptible pest and infected pest and the predator population is the natural enemy of the pest. We also consider average delay for both the predation rate i.e. predation to the susceptible pest and infected pest. Considering a subsystem of original system in the absence of infection, we analyze the existence of all possible non-negative equilibria and their stability criteria for both the subsystem as well as the original system. We present the conditions for transcritical bifurcation and Hopf bifurcation in the disease free system. The theoretical evaluations are demonstrated through numerical simulations.

  11. Biologically Inspired Self-Stabilizing Control for Bipedal Robots

    Directory of Open Access Journals (Sweden)

    Woosung Yang

    2013-02-01

    Full Text Available Despite recent major advances in computational power and control algorithms, the stable and robust control of a bipedal robot is still a challenging issue due to the complexity and high nonlinearity of robot dynamics. To address the issue an efficient and powerful alternative based on a biologically inspired control framework employing neural oscillators is proposed and tested. In a numerical test the virtual force controller combined with the neural oscillator of a humanoid robot generated rhythmic control signals and stable bipedal locomotion when coupled with proper impedance components. The entrainment nature inherent to neural oscillators also achieved stable and robust walking even in the presence of unexpected disturbances, in that the centre of mass (COM was successfully kept in phase with the zero moment point (ZMP input trajectory. The efficiency of the proposed control scheme is discussed alongside simulation results.

  12. Ecological Complexity and the Success of Fungal Biological Control Agents

    Directory of Open Access Journals (Sweden)

    Guy R. Knudsen

    2014-01-01

    Full Text Available Fungal biological control agents against plant pathogens, especially those in soil, operate within physically, biologically, and spatially complex systems by means of a variety of trophic and nontrophic interspecific interactions. However, the biocontrol agents themselves are also subject to the same types of interactions, which may reduce or in some cases enhance their efficacy against target plant pathogens. Characterization of these ecologically complex systems is challenging, but a number of tools are available to help unravel this complexity. Several of these tools are described here, including the use of molecular biology to generate biocontrol agents with useful marker genes and then to quantify these agents in natural systems, epifluorescence and confocal laser scanning microscopy to observe their presence and activity in situ, and spatial statistics and computer simulation modeling to evaluate and predict these activities in heterogeneous soil habitats.

  13. Controlled biological and biomimetic systems for landmine detection.

    Science.gov (United States)

    Habib, Maki K

    2007-08-30

    Humanitarian demining requires to accurately detect, locate and deactivate every single landmine and other buried mine-like objects as safely and as quickly as possible, and in the most non-invasive manner. The quality of landmine detection affects directly the efficiency and safety of this process. Most of the available methods to detect explosives and landmines are limited by their sensitivity and/or operational complexities. All landmines leak with time small amounts of their explosives that can be found on surrounding ground and plant life. Hence, explosive signatures represent the robust primary indicator of landmines. Accordingly, developing innovative technologies and efficient techniques to identify in real-time explosives residue in mined areas represents an attractive and promising approach. Biological and biologically inspired detection technology has the potential to compete with or be used in conjunction with other artificial technology to complement performance strengths. Biological systems are sensitive to many different scents concurrently, a property that has proven difficult to replicate artificially. Understanding biological systems presents unique opportunities for developing new capabilities through direct use of trained bio-systems, integration of living and non-living components, or inspiring new design by mimicking biological capabilities. It is expected that controlled bio-systems, biotechnology and microbial techniques will contribute to the advancement of mine detection and other application domains. This paper provides directions, evaluation and analysis on the progress of controlled biological and biomimetic systems for landmine detection. It introduces and discusses different approaches developed, underlining their relative advantages and limitations, and highlighting trends, safety and ecology concern, and possible future directions.

  14. Assessing non-target effects and host feeding of the exotic parasitoid Apanteles taragamae, a potential biological control agent of the cowpea pod borer Maruca vitrata

    NARCIS (Netherlands)

    Dannon, A.E.; Tamo, M.; Huis, van A.; Dicke, M.

    2012-01-01

    Apanteles taragamae Viereck is a larval parasitoid introduced in Benin for classical biological control of the cowpea pod borer Maruca vitrata Fabricius. In the laboratory, we evaluated the effects of A. taragamae on non-target herbivore species, and on another parasitoid of M. vitrata, i.e. the egg

  15. [Classical Swine Fever in wild boar in Rhineland-Palatinate: evaluation of the official control measures from 2005-2011].

    Science.gov (United States)

    Romelt, Maria; Klingelhefer, Irene; Konig, Astrid; Braun, Bettina; Reiner, Gerald

    2015-01-01

    The present study describes the control strategy for fighting Classical Swine Fever in wild boar in Rhineland-Palatinate from 2005 to 2011 and evaluates its effectiveness. The official control measures were based on the following three main pillars:--Serological and virological monitoring: By means of serological monitoring Classical Swine Fever outbreaks could be detected very early. Increasing antibody prevalences indicated an imminent Classical Swine Fever outbreak. This could be confirmed by the virological investigations. The geographical evaluations of the virological investigations showed that the outbreaks occurred only in localized areas and a spreading of the virus had not taken place yet or could be prevented.--Oral immunization: After virological detection of Classical Swine Fever Virus oral immunization was started immediately. This oral immunization achieved antibody prevalence rates of 57% on an average. The analysis of the distribution of the antibodies in the vaccination areas concerning the different age groups in the vaccination areas showed that 41% of the young animals, 66% of animals from one to two years and 77% of the adult animals were immunized.--Hunting measures: For the reduction of the wild boar population an all-year, intensive hunt with special attention to the young animals and the female animals was carried out. The hunting bag increased on more than 80 000 wild boar per hunting season. Out of the total 108,772 hunted wild boar were 47% of young animals, 40% of animals from one to two years and 13% of adult animals. Concerning the gender distribution on an average 53% female and 47% male animals were shot. in summary, the current control strategy was effective because there had been no further proof of Classical Swine Fever in wild boar in Rhineland-Palatinate since 2009. Nevertheless, the fight strategy can be optimized even further. For an optimum monitoring the development of a marker vaccine which allows a differentiation of

  16. Biological Control of Olive Green Mold in Agaricus bisporus Cultivation.

    Science.gov (United States)

    Tautorus, T E; Townsley, P M

    1983-02-01

    Successful methods to control the damaging weed mold Chaetomium olivaceum (olive green mold) in mushroom beds are not presently known. An attempt was made to control C. olivaceum by biological means. A thermophilic Bacillus sp. which showed dramatic activity against C. olivaceum on Trypticase soy agar (BBL Microbiology Systems)-0.4% yeast extract agar plates was isolated from commercial mushroom compost (phase I). When inoculated into conventional and hydroponic mushroom beds, the bacillus not only provided a significant degree of protection from C. olivaceum, but also increased yields of Agaricus bisporus.

  17. Decentralized control of ecological and biological networks through Evolutionary Network Control

    Directory of Open Access Journals (Sweden)

    Alessandro Ferrarini

    2016-09-01

    Full Text Available Evolutionary Network Control (ENC has been recently introduced to allow the control of any kind of ecological and biological networks, with an arbitrary number of nodes and links, acting from inside and/or outside. To date, ENC has been applied using a centralized approach where an arbitrary number of network nodes and links could be tamed. This approach has shown to be effective in the control of ecological and biological networks. However a decentralized control, where only one node and the correspondent input/output links are controlled, could be more economic from a computational viewpoint, in particular when the network is very large (i.e. big data. In this view, ENC is upgraded here to realize the decentralized control of ecological and biological nets.

  18. Active control on high-order coherence and statistic characterization on random phase fluctuation of two classical point sources.

    Science.gov (United States)

    Hong, Peilong; Li, Liming; Liu, Jianji; Zhang, Guoquan

    2016-03-29

    Young's double-slit or two-beam interference is of fundamental importance to understand various interference effects, in which the stationary phase difference between two beams plays the key role in the first-order coherence. Different from the case of first-order coherence, in the high-order optical coherence the statistic behavior of the optical phase will play the key role. In this article, by employing a fundamental interfering configuration with two classical point sources, we showed that the high- order optical coherence between two classical point sources can be actively designed by controlling the statistic behavior of the relative phase difference between two point sources. Synchronous position Nth-order subwavelength interference with an effective wavelength of λ/M was demonstrated, in which λ is the wavelength of point sources and M is an integer not larger than N. Interestingly, we found that the synchronous position Nth-order interference fringe fingerprints the statistic trace of random phase fluctuation of two classical point sources, therefore, it provides an effective way to characterize the statistic properties of phase fluctuation for incoherent light sources.

  19. Acute effect of scapular proprioceptive neuromuscular facilitation (PNF) techniques and classic exercises in adhesive capsulitis: a randomized controlled trial.

    Science.gov (United States)

    Balcı, Nilay Comuk; Yuruk, Zeliha Ozlem; Zeybek, Aslican; Gulsen, Mustafa; Tekindal, Mustafa Agah

    2016-04-01

    [Purpose] The aim of our study was to compare the initial effects of scapular proprioceptive neuromuscular facilitation techniques and classic exercise interventions with physiotherapy modalities on pain, scapular dyskinesis, range of motion, and function in adhesive capsulitis. [Subjects and Methods] Fifty-three subjects were allocated to 3 groups: scapular proprioceptive neuromuscular facilitation exercies and physiotherapy modalities, classic exercise and physiotherapy modalities, and only physiotherapy modalities. The intervention was applied in a single session. The Visual Analog Scale, Lateral Scapular Slide Test, range of motion and Simple Shoulder Test were evaluated before and just after the one-hour intervention in the same session (all in one session). [Results] All of the groups showed significant differences in shoulder flexion and abduction range of motion and Simple Shoulder Test scores. There were statistically significant differences in Visual Analog Scale scores in the proprioceptive neuromuscular facilitation and control groups, and no treatment method had significant effect on the Lateral Scapular Slide Test results. There were no statistically significant differences between the groups before and after the intervention. [Conclusion] Proprioceptive neuromuscular facilitation, classic exercise, and physiotherapy modalities had immediate effects on adhesive capsulitis in our study. However, there was no additional benefit of exercises in one session over physiotherapy modalities. Also, an effective treatment regimen for shoulder rehabilitation of adhesive capsulitis patients should include scapular exercises.

  20. Classical antiparticles

    Energy Technology Data Exchange (ETDEWEB)

    Costella, J.P.; McKellar, B.H.J.; Rawlinson, A.A.

    1997-03-01

    We review how antiparticles may be introduced in classical relativistic mechanics, and emphasize that many of their paradoxical properties can be more transparently understood in the classical than in the quantum domain. (authors). 13 refs., 1 tab.

  1. Classical antiparticles

    CERN Document Server

    Costella, J P; Rawlinson, A A; Costella, John P.; Kellar, Bruce H. J. Mc; Rawlinson, Andrew A.

    1997-01-01

    We review how antiparticles may be introduced in classical relativistic mechanics, and emphasize that many of their paradoxical properties can be more transparently understood in the classical than in the quantum domain.

  2. Self-Organized Biological Dynamics and Nonlinear Control

    Science.gov (United States)

    Walleczek, Jan

    2006-04-01

    The frontiers and challenges of biodynamics research Jan Walleczek; Part I. Nonlinear Dynamics in Biology and Response to Stimuli: 1. External signals and internal oscillation dynamics - principal aspects and response of stimulated rhythmic processes Friedemann Kaiser; 2. Nonlinear dynamics in biochemical and biophysical systems: from enzyme kinetics to epilepsy Raima Larter, Robert Worth and Brent Speelman; 3. Fractal mechanisms in neural control: human heartbeat and gait dynamics in health and disease Chung-Kang Peng, Jeffrey M. Hausdorff and Ary L. Goldberger; 4. Self-organising dynamics in human coordination and perception Mingzhou Ding, Yanqing Chen, J. A. Scott Kelso and Betty Tuller; 5. Signal processing in biochemical reaction networks Adam P. Arkin; Part II. Nonlinear Sensitivity of Biological Systems to Electromagnetic Stimuli: 6. Electrical signal detection and noise in systems with long-range coherence Paul C. Gailey; 7. Oscillatory signals in migrating neutrophils: effects of time-varying chemical and electrical fields Howard R. Petty; 8. Enzyme kinetics and nonlinear biochemical amplification in response to static and oscillating magnetic fields Jan Walleczek and Clemens F. Eichwald; 9. Magnetic field sensitivity in the hippocampus Stefan Engström, Suzanne Bawin and W. Ross Adey; Part III. Stochastic Noise-Induced Dynamics and Transport in Biological Systems: 10. Stochastic resonance: looking forward Frank Moss; 11. Stochastic resonance and small-amplitude signal transduction in voltage-gated ion channels Sergey M. Bezrukov and Igor Vodyanoy; 12. Ratchets, rectifiers and demons: the constructive role of noise in free energy and signal transduction R. Dean Astumian; 13. Cellular transduction of periodic and stochastic energy signals by electroconformational coupling Tian Y. Tsong; Part IV. Nonlinear Control of Biological and Other Excitable Systems: 14. Controlling chaos in dynamical systems Kenneth Showalter; 15. Electromagnetic fields and biological

  3. Adaptive Fuzzy-Lyapunov Controller Using Biologically Inspired Swarm Intelligence

    Directory of Open Access Journals (Sweden)

    Alejandro Carrasco Elizalde

    2008-01-01

    Full Text Available The collective behaviour of swarms produces smarter actions than those achieved by a single individual. Colonies of ants, flocks of birds and fish schools are examples of swarms interacting with their environment to achieve a common goal. This cooperative biological intelligence is the inspiration for an adaptive fuzzy controller developed in this paper. Swarm intelligence is used to adjust the parameters of the membership functions used in the adaptive fuzzy controller. The rules of the controller are designed using a computing-with-words approach called Fuzzy-Lyapunov synthesis to improve the stability and robustness of an adaptive fuzzy controller. Computing-with-words provides a powerful tool to manipulate numbers and symbols, like words in a natural language.

  4. Biopesticides: An option for the biological pest control

    Directory of Open Access Journals (Sweden)

    Eusebio Nava Pérez

    2012-09-01

    Full Text Available The indiscriminate use of synthetic pesticides and the problems that its cause to human health, agriculture and the environment is comment, this paper also present general aspects about of biopesticides, and their uses in the biological pest control. By the nature these can be safely used in a sustainable agriculture. An example is the use of botanical pesticides whose active ingredient are the terpenes, alkaloids and phenolics, these have insecticide effects for many agriculture pests; also its are less expensive, are biodegradable and safe for humans and the environment, however havelittle residuality. Microbial pesticides are being introduced successfully to pests control in important crops such as; coffee, sugar cane, beans and corn. These products contain bacteria, fungi, viruses or nematodes. However, few entomopathogenic agents have been developed as effective biocontrol agents, one of them is the bacterium Bacillus thuringiensis (Berlinier for control of armyworm Spodoptera frugiperda (J.E Smith covering about 74% of the market,fungus 10% , viruses 5% and 11% others. Other upstanding case is the use of the fungus Beauveria bassiana (Balsamoagainst bean weevil Acanthoscelides obtectus (Say. Biopesticides have shown that when are used properly in the biological pest control its favor the practice of a sustainable agriculture, with less dependence of chemical insecticides.

  5. Biological Stability of Drinking Water: Controlling Factors, Methods, and Challenges

    KAUST Repository

    Prest, Emmanuelle I.

    2016-02-01

    Biological stability of drinking water refers to the concept of providing consumers with drinking water of same microbial quality at the tap as produced at the water treatment facility. However, uncontrolled growth of bacteria can occur during distribution in water mains and premise plumbing, and can lead to hygienic (e.g., development of opportunistic pathogens), aesthetic (e.g., deterioration of taste, odor, color) or operational (e.g., fouling or biocorrosion of pipes) problems. Drinking water contains diverse microorganisms competing for limited available nutrients for growth. Bacterial growth and interactions are regulated by factors, such as (i) type and concentration of available organic and inorganic nutrients, (ii) type and concentration of residual disinfectant, (iii) presence of predators, such as protozoa and invertebrates, (iv) environmental conditions, such as water temperature, and (v) spatial location of microorganisms (bulk water, sediment, or biofilm). Water treatment and distribution conditions in water mains and premise plumbing affect each of these factors and shape bacterial community characteristics (abundance, composition, viability) in distribution systems. Improved understanding of bacterial interactions in distribution systems and of environmental conditions impact is needed for better control of bacterial communities during drinking water production and distribution. This article reviews (i) existing knowledge on biological stability controlling factors and (ii) how these factors are affected by drinking water production and distribution conditions. In addition, (iii) the concept of biological stability is discussed in light of experience with well-established and new analytical methods, enabling high throughput analysis and in-depth characterization of bacterial communities in drinking water. We discussed, how knowledge gained from novel techniques will improve design and monitoring of water treatment and distribution systems in order

  6. Biological stability of drinking water: controlling factors, methods and challenges

    Directory of Open Access Journals (Sweden)

    Emmanuelle ePrest

    2016-02-01

    Full Text Available Biological stability of drinking water refers to the concept of providing consumers with drinking water of same microbial quality at the tap as produced at the water treatment facility. However, uncontrolled growth of bacteria can occur during distribution in water mains and premise plumbing, and can lead to hygienic (e.g. development of opportunistic pathogens, aesthetic (e.g. deterioration of taste, odour, colour or operational (e.g. fouling or biocorrosion of pipes problems. Drinking water contains diverse microorganisms competing for limited available nutrients for growth. Bacterial growth and interactions are regulated by factors such as (i type and concentration of available organic and inorganic nutrients, (ii type and concentration of residual disinfectant, (iii presence of predators such as protozoa and invertebrates, (iv environmental conditions such as water temperature, and (v spatial location of microorganisms (bulk water, sediment or biofilm. Water treatment and distribution conditions in water mains and premise plumbing affect each of these factors and shape bacterial community characteristics (abundance, composition, viability in distribution systems. Improved understanding of bacterial interactions in distribution systems and of environmental conditions impact is needed for better control of bacterial communities during drinking water production and distribution. This article reviews (i existing knowledge on biological stability controlling factors and (ii how these factors are affected by drinking water production and distribution conditions. In addition, (iii the concept of biological stability is discussed in light of experience with well-established and new analytical methods, enabling high throughput analysis and in-depth characterization of bacterial communities in drinking water. We discuss how knowledge gained from novel techniques will improve design and monitoring of water treatment and distribution systems in order to

  7. Biological Stability of Drinking Water: Controlling Factors, Methods, and Challenges

    Science.gov (United States)

    Prest, Emmanuelle I.; Hammes, Frederik; van Loosdrecht, Mark C. M.; Vrouwenvelder, Johannes S.

    2016-01-01

    Biological stability of drinking water refers to the concept of providing consumers with drinking water of same microbial quality at the tap as produced at the water treatment facility. However, uncontrolled growth of bacteria can occur during distribution in water mains and premise plumbing, and can lead to hygienic (e.g., development of opportunistic pathogens), aesthetic (e.g., deterioration of taste, odor, color) or operational (e.g., fouling or biocorrosion of pipes) problems. Drinking water contains diverse microorganisms competing for limited available nutrients for growth. Bacterial growth and interactions are regulated by factors, such as (i) type and concentration of available organic and inorganic nutrients, (ii) type and concentration of residual disinfectant, (iii) presence of predators, such as protozoa and invertebrates, (iv) environmental conditions, such as water temperature, and (v) spatial location of microorganisms (bulk water, sediment, or biofilm). Water treatment and distribution conditions in water mains and premise plumbing affect each of these factors and shape bacterial community characteristics (abundance, composition, viability) in distribution systems. Improved understanding of bacterial interactions in distribution systems and of environmental conditions impact is needed for better control of bacterial communities during drinking water production and distribution. This article reviews (i) existing knowledge on biological stability controlling factors and (ii) how these factors are affected by drinking water production and distribution conditions. In addition, (iii) the concept of biological stability is discussed in light of experience with well-established and new analytical methods, enabling high throughput analysis and in-depth characterization of bacterial communities in drinking water. We discussed, how knowledge gained from novel techniques will improve design and monitoring of water treatment and distribution systems in order

  8. Biological Stability of Drinking Water: Controlling Factors, Methods, and Challenges.

    Science.gov (United States)

    Prest, Emmanuelle I; Hammes, Frederik; van Loosdrecht, Mark C M; Vrouwenvelder, Johannes S

    2016-01-01

    Biological stability of drinking water refers to the concept of providing consumers with drinking water of same microbial quality at the tap as produced at the water treatment facility. However, uncontrolled growth of bacteria can occur during distribution in water mains and premise plumbing, and can lead to hygienic (e.g., development of opportunistic pathogens), aesthetic (e.g., deterioration of taste, odor, color) or operational (e.g., fouling or biocorrosion of pipes) problems. Drinking water contains diverse microorganisms competing for limited available nutrients for growth. Bacterial growth and interactions are regulated by factors, such as (i) type and concentration of available organic and inorganic nutrients, (ii) type and concentration of residual disinfectant, (iii) presence of predators, such as protozoa and invertebrates, (iv) environmental conditions, such as water temperature, and (v) spatial location of microorganisms (bulk water, sediment, or biofilm). Water treatment and distribution conditions in water mains and premise plumbing affect each of these factors and shape bacterial community characteristics (abundance, composition, viability) in distribution systems. Improved understanding of bacterial interactions in distribution systems and of environmental conditions impact is needed for better control of bacterial communities during drinking water production and distribution. This article reviews (i) existing knowledge on biological stability controlling factors and (ii) how these factors are affected by drinking water production and distribution conditions. In addition, (iii) the concept of biological stability is discussed in light of experience with well-established and new analytical methods, enabling high throughput analysis and in-depth characterization of bacterial communities in drinking water. We discussed, how knowledge gained from novel techniques will improve design and monitoring of water treatment and distribution systems in order

  9. Analysis of classical Fourier, SPL and DPL heat transfer model in biological tissues in presence of metabolic and external heat source

    Science.gov (United States)

    Kumar, Dinesh; Singh, Surjan; Rai, K. N.

    2016-06-01

    In this paper, the temperature distribution in a finite biological tissue in presence of metabolic and external heat source when the surface subjected to different type of boundary conditions is studied. Classical Fourier, single-phase-lag (SPL) and dual-phase-lag (DPL) models were developed for bio-heat transfer in biological tissues. The analytical solution obtained for all the three models using Laplace transform technique and results are compared. The effect of the variability of different parameters such as relaxation time, metabolic heat source, spatial heat source, different type boundary conditions on temperature distribution in different type of the tissues like muscle, tumor, fat, dermis and subcutaneous based on three models are analyzed and discussed in detail. The result obtained in three models is compared with experimental observation of Stolwijk and Hardy (Pflug Arch 291:129-162, 1966). It has been observe that the DPL bio-heat transfer model provides better result in comparison of other two models. The value of metabolic and spatial heat source in boundary condition of first, second and third kind for different type of thermal therapies are evaluated.

  10. Classical and adaptive control of ex vivo skeletal muscle contractions using Functional Electrical Stimulation (FES)

    Science.gov (United States)

    Shoemaker, Adam; Grange, Robert W.; Abaid, Nicole; Leonessa, Alexander

    2017-01-01

    Functional Electrical Stimulation is a promising approach to treat patients by stimulating the peripheral nerves and their corresponding motor neurons using electrical current. This technique helps maintain muscle mass and promote blood flow in the absence of a functioning nervous system. The goal of this work is to control muscle contractions from FES via three different algorithms and assess the most appropriate controller providing effective stimulation of the muscle. An open-loop system and a closed-loop system with three types of model-free feedback controllers were assessed for tracking control of skeletal muscle contractions: a Proportional-Integral (PI) controller, a Model Reference Adaptive Control algorithm, and an Adaptive Augmented PI system. Furthermore, a mathematical model of a muscle-mass-spring system was implemented in simulation to test the open-loop case and closed-loop controllers. These simulations were carried out and then validated through experiments ex vivo. The experiments included muscle contractions following four distinct trajectories: a step, sine, ramp, and square wave. Overall, the closed-loop controllers followed the stimulation trajectories set for all the simulated and tested muscles. When comparing the experimental outcomes of each controller, we concluded that the Adaptive Augmented PI algorithm provided the best closed-loop performance for speed of convergence and disturbance rejection. PMID:28273101

  11. Magnetically Controlled Accretion on the Classical T Tauri Stars GQ Lupi and TW Hydrae

    CERN Document Server

    Johns-Krull, C M; Valenti, J A; Jeffers, S V; Piskunov, N E; Kuchukhov, O; Makaganiuk, V; Stempels, H C; Snik, F; Keller, C; Rodenhuis, M

    2013-01-01

    We present high spectral resolution ($R\\approx108,000$) Stokes $V$ polarimetry of the Classical T Tauri stars (CTTSs) GQ Lup and TW Hya obtained with the polarimetric upgrade to the HARPS spectrometer on the ESO 3.6 m telescope. We present data on both photospheric lines and emission lines, concentrating our discussion on the polarization properties of the \\ion{He}{1} emission lines at 5876 \\AA\\ and 6678 \\AA. The \\ion{He}{1} lines in these CTTSs contain both narrow emission cores, believed to come from near the accretion shock region on these stars, and broad emission components which may come from either a wind or the large scale magnetospheric accretion flow. We detect strong polarization in the narrow component of the two \\ion{He}{1} emission lines in both stars. We observe a maximum implied field strength of $6.05 \\pm 0.24$ kG in the 5876 \\AA\\ line of GQ Lup, making it the star with the highest field strength measured in this line for a CTTS. We find field strengths in the two \\ion{He}{1} lines that are c...

  12. Synthetic biology and regulatory networks: where metabolic systems biology meets control engineering.

    Science.gov (United States)

    He, Fei; Murabito, Ettore; Westerhoff, Hans V

    2016-04-01

    Metabolic pathways can be engineered to maximize the synthesis of various products of interest. With the advent of computational systems biology, this endeavour is usually carried out through in silico theoretical studies with the aim to guide and complement further in vitro and in vivo experimental efforts. Clearly, what counts is the result in vivo, not only in terms of maximal productivity but also robustness against environmental perturbations. Engineering an organism towards an increased production flux, however, often compromises that robustness. In this contribution, we review and investigate how various analytical approaches used in metabolic engineering and synthetic biology are related to concepts developed by systems and control engineering. While trade-offs between production optimality and cellular robustness have already been studied diagnostically and statically, the dynamics also matter. Integration of the dynamic design aspects of control engineering with the more diagnostic aspects of metabolic, hierarchical control and regulation analysis is leading to the new, conceptual and operational framework required for the design of robust and productive dynamic pathways.

  13. Study on Biological Control Of Rhizoctonia solani via Trichoderma

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Strain T02-25 was selected from approximately 30 rhizosphere isolates of Trichoderma species isolated from roots of crops. Its biological activity against Rhizoctonia solani was determined for the control efficacy to pepper seedling blight caused by R. solani in the field. The assay methods were treating R. solani sclerotia by Trichoderma conidial suspension (106cfu ml-1) and scattering Thichoderma rice bran over the pepper root medium. The results showed that T02-25 was active against R. solani in both ways, and its control efficacy was 82.7% and 78.0%, respectively. In addition to comparison of the efficacy of the two application methods, the relationship of different factors in the control efficacy of Trichoderma against R. solani was discussed.

  14. Deciphering endophyte behaviour: the link between endophyte biology and efficacious biological control agents.

    Science.gov (United States)

    Card, Stuart; Johnson, Linda; Teasdale, Suliana; Caradus, John

    2016-08-01

    Endophytes associate with the majority of plant species found in natural and managed ecosystems. They are regarded as extremely important plant partners that provide improved stress tolerance to the host compared with plants that lack this symbiosis. Fossil records of endophytes date back more than 400 million years, implicating these microorganisms in host plant adaptation to habitat transitions. However, it is only recently that endophytes, and their bioactive products, have received meaningful attention from the scientific community. The benefits some endophytes can confer on their hosts include plant growth promotion and survival through the inhibition of pathogenic microorganisms and invertebrate pests, the removal of soil contaminants, improved tolerance of low fertility soils, and increased tolerance of extreme temperatures and low water availability. Endophytes are extremely diverse and can exhibit many different biological behaviours. Not all endophyte technologies have been successfully commercialised. Of interest in the development of the next generation of plant protection products is how much of this is due to the biology of the particular endophytic microorganism. In this review, we highlight selected case studies of endophytes and discuss their lifestyles and behavioural traits, and discuss how these factors contribute towards their effectiveness as biological control agents.

  15. Indoor biology pollution control based on system-based humidity priority control strategy

    Institute of Scientific and Technical Information of China (English)

    刘亚昱; 谢慧; 石博强

    2009-01-01

    Indoor biological contamination and HVAC system secondary contamination problems caused wide public concerns. Biological contamination control will be the next step to achieve better IAQ. The most efficient and safe way to control biological contamination was to limit relative humidity in HVAC system and conditioned environment in the range that is more unsuitable for microorganism to survive. In this paper,by referring to bio-clean project experiences,a system-based humidity priority control manner came into being by lowering outdoor air humidity ratio to eliminate all indoor latent load and using self recirculation units to bear indoor sensible load. Based on the whole-course residue humidity contaminant control concept,dynamic step models for coil and conditioned zone were developed to describe mass and energy conservation and transformation processes. Then,HVAC system and conditioned zone dynamic models were established on LabVIEW+Matlab platform to investigate optimized regulation types,input signatures and control logics. Decoupling between cooling and dehumidification processes can be achieved and a more simplified and stable control system can be acquired by the system-based humidity priority control strategy. Therefore,it was a promising way for controlling biological pollution in buildings in order to achieve better IAQ.

  16. Biological control of surface temperature in the Arabian Sea

    Science.gov (United States)

    Sathyendranath, Shubha; Gouveia, Albert D.; Shetye, Satish R.; Ravindran, P.; Platt, Trevor

    1991-01-01

    In the Arabian Sea, the southwest monsoon promotes seasonal upwelling of deep water, which supplies nutrients to the surface layer and leads to a marked increase in phytoplankton growth. Remotely sensed data on ocean color are used here to show that the resulting distribution of phytoplankton exerts a controlling influence on the seasonal evolution of sea surface temperature. This results in a corresponding modification of ocean-atmosphere heat exchange on regional and seasonal scales. It is shown that this biological mechanism may provide an important regulating influence on ocean-atmosphere interactions.

  17. Microstructure synthesis control of biological polyhydroxyalkanoates with mass spectrometry

    Science.gov (United States)

    Pederson, Erik Norman

    Polyhydroxyalkanoates (PHA's) are a class of biologically produced polymers, or plastic, that is synthesized by various microorganisms. PHA's are made from biorenewable resources and are fully biodegradable and biocompatible, making them an environmentally friendly green polymer. A method of incorporating polymer microstructure into the PHA synthesized in Ralstonia eutropha was developed. These microstructures were synthesized with polyhydroxybutyrate (PHB) and poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) as the polymer domains. To synthesize the PHB V copolymer, the additional presence of valerate was required. To control valerate substrate additions to the bioreactor, an off-gas mass spectrometry (MS) feedback control system was developed. Important process information including the cell physiology, growth kinetics, and product formation kinetics in the bioreactor was obtained with MS and used to control microstructure synthesis. The two polymer microstructures synthesized were core-shell granules and block copolymers. Block copolymers control the structure of the individual polymer chains while core-shell granules control the organization of many polymer chains. Both these microstructures result in properties unattainable by blending the two polymers together. The core-shell structures were synthesized with controlled domain thickness based on a developed model. Different block copolymers compositions were synthesized by varying the switching time of the substrate pulses responsible for block copolymer synthesis. The block copolymers were tested to determine their chemical properties and cast into films to determine the materials properties. These block copolymer films possessed new properties not achieved by copolymers or blends of the two polymers.

  18. Exploring the Altered Dynamics of Mammalian Central Carbon Metabolic Pathway in Cancer Cells: A Classical Control Theoretic Approach.

    Directory of Open Access Journals (Sweden)

    Debjyoti Paul

    Full Text Available In contrast with normal cells, most of the cancer cells depend on aerobic glycolysis for energy production in the form of adenosine triphosphate (ATP bypassing mitochondrial oxidative phosphorylation. Moreover, compared to normal cells, cancer cells exhibit higher consumption of glucose with higher production of lactate. Again, higher rate of glycolysis provides the necessary glycolytic intermediary precursors for DNA, protein and lipid synthesis to maintain high active proliferation of the tumor cells. In this scenario, classical control theory based approach may be useful to explore the altered dynamics of the cancer cells. Since the dynamics of the cancer cells is different from that of the normal cells, understanding their dynamics may lead to development of novel therapeutic strategies.We have developed a model based on the state space equations of classical control theory along with an order reduction technique to mimic the actual dynamic behavior of mammalian central carbon metabolic (CCM pathway in normal cells. Here, we have modified Michaelis Menten kinetic equation to incorporate feedback mechanism along with perturbations and cross talks associated with a metabolic pathway. Furthermore, we have perturbed the proposed model to reduce the mitochondrial oxidative phosphorylation. Thereafter, we have connected proportional-integral (PI controller(s with the model for tuning it to behave like the CCM pathway of a cancer cell. This methodology allows one to track the altered dynamics mediated by different enzymes.The proposed model successfully mimics all the probable dynamics of the CCM pathway in normal cells. Moreover, experimental results demonstrate that in cancer cells, a coordination among enzymes catalyzing pentose phosphate pathway and intermediate glycolytic enzymes along with switching of pyruvate kinase (M2 isoform plays an important role to maintain their altered dynamics.

  19. Biological Characteristics and Control of Orobanche Crenata Forsk., a Review

    Directory of Open Access Journals (Sweden)

    Giuseppe Restuccia

    2011-02-01

    Full Text Available Orobanche crenata is a holoparasitic phanerogam which is particularly noxious to legumes, such as faba bean (Vicia faba L., pea (Pisum sativum L., chickpea (Cicer arietinum L., lentil (Lens culinaris Medik., etc., and commonly considered one of the major causes which has contributed to re-rizing the area designed to their cultivation. After a few brief references on the origin and diffusion of O. crenata, in this work summarises the results of research into biological aspects and control of this species. The information obtained especially concerns seed production, seed viability, seed longevity and dormancy, seed conditioning and germination, parasitism phases, the effects of parasite attacks on host plants and the means of control.

  20. Compact and controlled microfluidic mixing and biological particle capture

    Science.gov (United States)

    Ballard, Matthew; Owen, Drew; Mills, Zachary Grant; Hesketh, Peter J.; Alexeev, Alexander

    2016-11-01

    We use three-dimensional simulations and experiments to develop a multifunctional microfluidic device that performs rapid and controllable microfluidic mixing and specific particle capture. Our device uses a compact microfluidic channel decorated with magnetic features. A rotating magnetic field precisely controls individual magnetic microbeads orbiting around the features, enabling effective continuous-flow mixing of fluid streams over a compact mixing region. We use computer simulations to elucidate the underlying physical mechanisms that lead to effective mixing and compare them with experimental mixing results. We study the effect of various system parameters on microfluidic mixing to design an efficient micromixer. We also experimentally and numerically demonstrate that orbiting microbeads can effectively capture particles transported by the fluid, which has major implications in pre-concentration and detection of biological particles including various cells and bacteria, with applications in areas such as point-of-care diagnostics, biohazard detection, and food safety. Support from NSF and USDA is gratefully acknowledged.

  1. Viable spore counts in biological controls pre-sterilization.

    Science.gov (United States)

    Brusca, María I; Bernat, María I; Turcot, Liliana; Nastri, Natalia; Nastri, Maria; Rosa, Alcira

    2005-01-01

    The aim of the present study was to evaluate the total count of viable spores in standardized inoculated carriers pre-sterilization. Samples of "Bacterial Spore Sterilization Strip" (R Biological Laboratories) (well before their expiry date) were divided into Group A (B. subtilis) and Group B (B. stearothermophylus). Twenty-four strips were tested per group. The strips were minced in groups of three, placed in chilled sterile water and vortexed for 5 minutes to obtain a homogenous suspension. Ten ml of the homogenous suspension were transferred to two sterile jars, i.e. one jar per group. The samples were then heated in a water bath at 95 degrees C (Group A) or 80 degrees C (Group B) for 15 minutes and cooled rapidly in an ice bath at 0- 4 degrees C during 15 minutes. Successive dilutions were performed until a final aliquot of 30 to 300 colony-forming units (CFU) was obtained. The inoculums were placed in Petri dishes with culture medium (soy extract, casein agar adapted for spores, melted and cooled to 45-50 degrees C) and incubated at 55 degrees C or 37 degrees C. Statistical analysis of the data was performed. A larger number of spores were found at 48 hours than at 24 hours. However, this finding did not hold true for all the groups. The present results show that monitoring viable spores pre-sterilization would guarantee the accuracy of the data. Total spore counts must be within 50 and 300% of the number of spores indicated in the biological control. The procedure is essential to guarantee the efficacy of the biological control.

  2. Control of Lymantria dispar L. by biological agents

    Institute of Scientific and Technical Information of China (English)

    ZHANGGuo-cai; WANGYue-jie; YANGXiao-guang

    2005-01-01

    The experiment on control of Lymantria dispar L by using different kinds of biological measures, including nuclear polyhedrosis virus (NPV) of Lymantria dispar L., BtMP-342, sex-attractant as well as botanical insecticide, was carried out in the forest regions of Inner Mongolia in 2003. Two concentrations (2.632×106 PIB·ml-1 and 2.632×107 PIB·ml-1) of Lymantria dispar L. NPV were sprayed on the 2rd-instar-larvae of L. dispar and 70% and 77.8% control effect were obtained respectively. BtMP0-342 was applied to the 3rd- and 4th-instar larvae and the control effect was around 80%. The sex-attractant provided by Canada Pacific Forestry Research Center also showed a good result in trapping L. dispar adults. The self-produced botanical insecticide, which was extracted from a kind of poisonous plant distributed in Daxing'an Mountains, China, exhibited a good control result in controlling the larvae of L. dispar, and 82% mortality was observed when spraying primary liquid of the botanical insecticide on the 3rd-5th-instar-larvae in lab.

  3. Biological control via "ecological" damping: An approach that attenuates non-target effects.

    Science.gov (United States)

    Parshad, Rana D; Quansah, Emmanuel; Black, Kelly; Beauregard, Matthew

    2016-03-01

    In this work we develop and analyze a mathematical model of biological control to prevent or attenuate the explosive increase of an invasive species population, that functions as a top predator, in a three-species food chain. We allow for finite time blow-up in the model as a mathematical construct to mimic the explosive increase in population, enabling the species to reach "disastrous", and uncontrollable population levels, in a finite time. We next improve the mathematical model and incorporate controls that are shown to drive down the invasive population growth and, in certain cases, eliminate blow-up. Hence, the population does not reach an uncontrollable level. The controls avoid chemical treatments and/or natural enemy introduction, thus eliminating various non-target effects associated with such classical methods. We refer to these new controls as "ecological damping", as their inclusion dampens the invasive species population growth. Further, we improve prior results on the regularity and Turing instability of the three-species model that were derived in Parshad et al. (2014). Lastly, we confirm the existence of spatiotemporal chaos.

  4. Controlling a Mobile Robot with a Biological Brain

    Directory of Open Access Journals (Sweden)

    Kevin Warwick

    2010-01-01

    Full Text Available The intelligent controlling mechanism of a typical mobile robot is usually a computer system. Some recent research is ongoing in which biological neurons are being cultured and trained to act as the brain of an interactive real world robot–thereby either completely replacing, or operating in a cooperative fashion with, a computer system. Studying such hybrid systems can provide distinct insights into the operation of biological neural structures, and therefore, such research has immediate medical implications as well as enormous potential in robotics. The main aim of the research is to assess the computational and learning capacity of dissociated cultured neuronal networks. A hybrid system incorporating closed-loop control of a mobile robot by a dissociated culture of neurons has been created. The system is flexible and allows for closed-loop operation, either with hardware robot or its software simulation. The paper provides an overview of the problem area, gives an idea of the breadth of present ongoing research, establises a new system architecture and, as an example, reports on the results of conducted experiments with real-life robots.Defence Science Journal, 2010, 60(1, pp.5-14, DOI:http://dx.doi.org/10.14429/dsj.60.11

  5. Reevaluation of the value of autoparasitoids in biological control.

    Directory of Open Access Journals (Sweden)

    Lian-Sheng Zang

    Full Text Available Autoparasitoids with the capacity of consuming primary parasitoids that share the same hosts to produce males are analogous to intraguild predators. The use of autoparasitoids in biological control programs is a controversial matter because there is little evidence to support the view that autoparasitoids do not disrupt and at times may promote suppression of insect pests in combination with primary parasitoids. We found that Encarsia sophia, a facultative autoparasitoid, preferred to use heterospecific hosts as secondary hosts for producing males. The autoparasitoids mated with males originated from heterospecifics may parasitize more hosts than those mated with males from conspecifics. Provided with an adequate number of males, the autoparasitoids killed more hosts than En. formosa, a commonly used parasitoid for biological control of whiteflies. This study supports the view that autoparasitoids in combination with primary parasitoids do not disrupt pest management and may enhance such programs. The demonstrated preference of an autoparasitoid for heterospecifics and improved performance of males from heterospecifics observed in this study suggests these criteria should be considered in strategies that endeavor to mass-produce and utilize autoparasitoids in the future.

  6. New developments in classical microscopy; what can be expected for the official control?

    NARCIS (Netherlands)

    Raamsdonk, van L.W.D.; Pinotti, L.; Veys, P.; Bremer, M.G.E.G.; Hekman, W.E.; Kemmers-Voncken, A.E.M.; Campagnoli, A.; Paltanin, C.; Crespo, C.; Vliege, J.J.M.; Pinckaers, V.G.Z.; Jorgensen, J.S.

    2011-01-01

    The official control of animal proteins in feed is focused on the prevention of Bovine Spongiform Encephalopathy (mad cow disease). The current legislation of the European Union is planned to avoid the feeding of animal by-products to the same species as its origin (ban of cannibalism, or species-to

  7. Biological control of weeds: research by the United States Department of Agriculture-Agricultural Research Service: selected case studies.

    Science.gov (United States)

    Quimby, Paul C; DeLoach, C Jack; Wineriter, Susan A; Goolsby, John A; Sobhian, Rouhollah; Boyette, C Douglas; Abbas, Hamed K

    2003-01-01

    Research by the USDA-Agricultural Research Service (ARS) on biological control of weeds has been practiced for many years because of its inherent ecological and economic advantages. Today, it is further driven by ARS adherence to Presidential Executive Order 13112 (3 February 1999) on invasive species and to USDA-ARS policy toward developing technology in support of sustainable agriculture with reduced dependence on non-renewable petrochemical resources. This paper reports examples or case studies selected to demonstrate the traditional or classical approach for biological control programs using Old World arthropods against Tamarix spp, Melaleuca quinquenervia (Cav) ST Blake and Galium spurium L/G aparine L, and the augmentative approach with a native plant pathogen against Pueraria lobata Ohwi = P montana. The examples illustrated various conflicts of interest with endangered species and ecological complexities of arthropods with associated microbes such as nematodes.

  8. New experimental approaches to the biology of flight control systems.

    Science.gov (United States)

    Taylor, Graham K; Bacic, Marko; Bomphrey, Richard J; Carruthers, Anna C; Gillies, James; Walker, Simon M; Thomas, Adrian L R

    2008-01-01

    Here we consider how new experimental approaches in biomechanics can be used to attain a systems-level understanding of the dynamics of animal flight control. Our aim in this paper is not to provide detailed results and analysis, but rather to tackle several conceptual and methodological issues that have stood in the way of experimentalists in achieving this goal, and to offer tools for overcoming these. We begin by discussing the interplay between analytical and empirical methods, emphasizing that the structure of the models we use to analyse flight control dictates the empirical measurements we must make in order to parameterize them. We then provide a conceptual overview of tethered-flight paradigms, comparing classical ;open-loop' and ;closed-loop' setups, and describe a flight simulator that we have recently developed for making flight dynamics measurements on tethered insects. Next, we provide a conceptual overview of free-flight paradigms, focusing on the need to use system identification techniques in order to analyse the data they provide, and describe two new techniques that we have developed for making flight dynamics measurements on freely flying birds. First, we describe a technique for obtaining inertial measurements of the orientation, angular velocity and acceleration of a steppe eagle Aquila nipalensis in wide-ranging free flight, together with synchronized measurements of wing and tail kinematics using onboard instrumentation and video cameras. Second, we describe a photogrammetric method to measure the 3D wing kinematics of the eagle during take-off and landing. In each case, we provide demonstration data to illustrate the kinds of information available from each method. We conclude by discussing the prospects for systems-level analyses of flight control using these techniques and others like them.

  9. 75 FR 28232 - Availability of an Environmental Assessment for a Biological Control Agent for Hemlock Woolly...

    Science.gov (United States)

    2010-05-20

    ... a biological control agent to reduce the severity of hemlock woolly adelgid infestations. We are... continental United States for use as a biological control agent to reduce the severity of hemlock woolly... releasing an insect, L. osakensis, into the continental United States for use as a biological control...

  10. 75 FR 64984 - Availability of an Environmental Assessment for a Biological Control Agent for Hawkweeds

    Science.gov (United States)

    2010-10-21

    ... Assessment for a Biological Control Agent for Hawkweeds AGENCY: Animal and Plant Health Inspection Service... States as a biological control agent to reduce the severity of infestations of hawkweeds. We are making... subterminalis, into the continental United States for the biological control of hawkweeds (Hieracium...

  11. 76 FR 3076 - Availability of an Environmental Assessment for a Biological Control Agent for Air Potato

    Science.gov (United States)

    2011-01-19

    ..., Lilioceris cheni, into the continental United States for use as a biological control agent to reduce the..., Lilioceris cheni, into the continental United States for use as a biological control agent to reduce the.... cheni, into the continental United States for use as a biological control agent to reduce the...

  12. 75 FR 69396 - Availability of an Environmental Assessment for a Biological Control Agent for Arundo donax

    Science.gov (United States)

    2010-11-12

    ... Assessment for a Biological Control Agent for Arundo donax AGENCY: Animal and Plant Health Inspection Service... a biological control agent to reduce the severity of Arundo donax infestations. We are making the... United States for use as a biological control agent to reduce the severity of Arundo donax...

  13. The effects of vestibular stimulation and fatigue on postural control in classical ballet dancers.

    Science.gov (United States)

    Hopper, Diana M; Grisbrook, Tiffany L; Newnham, Prudence J; Edwards, Dylan J

    2014-01-01

    This study aimed to investigate the effects of ballet-specific vestibular stimulation and fatigue on static postural control in ballet dancers and to establish whether these effects differ across varying levels of ballet training. Dancers were divided into three groups: professional, pre-professional, and recreational. Static postural control of 23 dancers was measured on a force platform at baseline and then immediately, 30 seconds, and 60 seconds after vestibular stimulation (pirouettes) and induction of fatigue (repetitive jumps). The professional dancers' balance was unaffected by both the vestibular stimulation and the fatigue task. The pre-professional and recreational dancers' static sway increased following both perturbations. It is concluded that professional dancers are able to compensate for vestibular and fatiguing perturbations due to a higher level of skill-specific motor training.

  14. Enhancing the effectiveness of biological control programs of invasive species through a more comprehensive pest management approach.

    Science.gov (United States)

    DiTomaso, Joseph M; Van Steenwyk, Robert A; Nowierski, Robert M; Vollmer, Jennifer L; Lane, Eric; Chilton, Earl; Burch, Patrick L; Cowan, Phil E; Zimmerman, Kenneth; Dionigi, Christopher P

    2017-01-01

    Invasive species are one of the greatest economic and ecological threats to agriculture and natural areas in the US and the world. Among the available management tools, biological control provides one of the most economical and long-term effective strategies for managing widespread and damaging invasive species populations of nearly all taxa. However, integrating biological control programs in a more complete integrated pest management approach that utilizes increased information and communication, post-release monitoring, adaptive management practices, long-term stewardship strategies, and new and innovative ecological and genetic technologies can greatly improve the effectiveness of biological control. In addition, expanding partnerships among relevant national, regional, and local agencies, as well as academic scientists and land managers, offers far greater opportunities for long-term success in the suppression of established invasive species. In this paper we direct our recommendations to federal agencies that oversee, fund, conduct research, and develop classical biological control programs for invasive species. By incorporating these recommendations into adaptive management strategies, private and public land managers will have far greater opportunities for long-term success in suppression of established invasive species. © 2016 Society of Chemical Industry.

  15. An application of classical and instrumental methods of analysis in quality control of beer

    OpenAIRE

    Rajković Miloš B.; Sredović-Ignjatović Ivana D.; Ignjatović Ljubiša M.; Nedović Viktor A.; Prijić Slobodan M.

    2015-01-01

    In order to control the quality of beer and raw materials for production of beer in Belgrade Beer Industry (BIP), water is analyzed (city, technological and demineralized water). Measurements of pH values indicated the increased pH values in the sample of tehnological water, which had no impact on wort hopping, since the tested samples of wort, young beer and final product had a pH value within the expected range. After processing city water, a sample of te...

  16. Classics Online.

    Science.gov (United States)

    Clayman, Dee L.

    1995-01-01

    Appraises several databases devoted to classical literature. Thesaurus Linguae Graecae (TLG) contains the entire extant corpus of ancient Greek literature, including works on lexicography and historiography, extending into the 15th century. Other works awaiting completion are the Database of Classical Bibliography and a CD-ROM pictorial dictionary…

  17. Classical integrability

    Science.gov (United States)

    Torrielli, Alessandro

    2016-08-01

    We review some essential aspects of classically integrable systems. The detailed outline of the sections consists of: 1. Introduction and motivation, with historical remarks; 2. Liouville theorem and action-angle variables, with examples (harmonic oscillator, Kepler problem); 3. Algebraic tools: Lax pairs, monodromy and transfer matrices, classical r-matrices and exchange relations, non-ultralocal Poisson brackets, with examples (non-linear Schrödinger model, principal chiral field); 4. Features of classical r-matrices: Belavin-Drinfeld theorems, analyticity properties, and lift of the classical structures to quantum groups; 5. Classical inverse scattering method to solve integrable differential equations: soliton solutions, spectral properties and the Gel’fand-Levitan-Marchenko equation, with examples (KdV equation, Sine-Gordon model). Prepared for the Durham Young Researchers Integrability School, organised by the GATIS network. This is part of a collection of lecture notes.

  18. Structure and Magnetic Property Control of Copper Hydroxide Acetate by Non-Classical Crystallization.

    Science.gov (United States)

    Song, RuiQi; Krasia-Christoforou, Theodora; Debus, Christian; Cölfen, Helmut

    2017-03-01

    Copper hydroxide acetate (CHA), one layered hydroxide compound with tunable magnetism, attracts great interest because of its potential applications in memory devices. However, ferromagnetism for CHA is only demonstrated by means of GPa pressure. Herein, a new method is reported, involving the combination of different crystallization pathways to control crystallization of amorphous CHA toward the formation of CHA/polymer composites with tunable magnetic properties and even a tunability that can be tested at room temperature. By using poly[(ethylene glycol)6 methyl ether methacrylate]-block-poly[2-(acetoacetoxy) ethyl methacrylate] (PEGMA-b-PAEMA) diblock copolymers as additives in combination with a post-treatment process by ultracentrifugation, it is demonstrated that CHA and PEGMA-b-PAEMA form composites exhibiting different magnetic properties, depending on CHA in-plane nanostructures. Analytical characterization reveals that crystallization of CHA is induced by ultracentrifugation, during which CHA nanostructures can be well controlled by changing the degrees of polymerization of the PEGMA and PAEMA blocks and their block length ratios. These findings not only present the first example of using crystallization from polymer stabilized amorphous precursors toward the generation of magnetic nanomaterials with tunable magnetism but also pave the way for the future design of functional composite materials.

  19. A Bayesian framework to assess the potential for controlling classical scrapie in sheep flocks using a live diagnostic test.

    Science.gov (United States)

    Gryspeirt, Aiko; Gubbins, Simon

    2013-09-01

    Current strategies to control classical scrapie remove animals at risk of scrapie rather than those known to be infected with the scrapie agent. Advances in diagnostic tests, however, suggest that a more targeted approach involving the application of a rapid live test may be feasible in future. Here we consider the use of two diagnostic tests: recto-anal mucosa-associated lymphatic tissue (RAMALT) biopsies; and a blood-based assay. To assess their impact we developed a stochastic age- and prion protein (PrP) genotype-structured model for the dynamics of scrapie within a sheep flock. Parameters were estimated in a Bayesian framework to facilitate integration of a number of disparate datasets and to allow parameter uncertainty to be incorporated in model predictions. In small flocks a control strategy based on removal of clinical cases was sufficient to control disease and more stringent measures (including the use of a live diagnostic test) did not significantly reduce outbreak size or duration. In medium or large flocks strategies in which a large proportion of animals are tested with either live diagnostic test significantly reduced outbreak size, but not always duration, compared with removal of clinical cases. However, the current Compulsory Scrapie Flocks Scheme (CSFS) significantly reduced outbreak size and duration compared with both removal of clinical cases and all strategies using a live diagnostic test. Accordingly, under the assumptions made in the present study there is little benefit from implementing a control strategy which makes use of a live diagnostic test.

  20. Endovenous Laser Ablation of Varicose Veins Preserves Biological Properties of Vascular Endothelium and Modulates Proinflammatory Agent Profile More Favorably Than Classic Vein Stripping

    Directory of Open Access Journals (Sweden)

    Paweł Uruski

    2017-01-01

    Full Text Available Here we compared effect of serum from varicose patients undergoing endovenous laser ablation (EVLA and classic vein stripping (CVS on biological properties of endothelial cells and on the local and systemic profiles of proinflammatory agents. Results showed that serum from EVLA patients improved proliferation and reduced senescence and oxidative stress in the endothelial cells, as compared with the serum from CVS patients. These effects were related to a suppressed activity of TGF-β1, the level of which in the serum from the EVLA patients was decreased. Medium generated by the cells subjected to EVLA serum contained decreased amounts of ICAM-1, VCAM-1, and E-selectin and increased amount of uPA, whereas the serum itself contained decreased concentrations of ICAM-1, E-selectin, and P-selectin and increased concentrations of uPA, PAI-1, and TFPI. Both EVLA and CVS resulted in diversified patients’ reaction with respect to a direction of postprocedure changes in proinflammatory factors’ serum level. Analysis of proportions showed that the groups differed remarkably in case of ICAM-1 and ET-1, the level of which declined in a higher fraction of patients treated endovenously. Our findings indicate that EVLA preserves better than CVS the functionality of vascular endothelium and modulates better both local and systemic profile of proinflammatory mediators.

  1. Endovenous Laser Ablation of Varicose Veins Preserves Biological Properties of Vascular Endothelium and Modulates Proinflammatory Agent Profile More Favorably Than Classic Vein Stripping

    Science.gov (United States)

    Uruski, Paweł; Aniukiewicz, Krzysztof; Mikuła-Pietrasik, Justyna; Sosińska, Patrycja; Tykarski, Andrzej; Krasiński, Zbigniew

    2017-01-01

    Here we compared effect of serum from varicose patients undergoing endovenous laser ablation (EVLA) and classic vein stripping (CVS) on biological properties of endothelial cells and on the local and systemic profiles of proinflammatory agents. Results showed that serum from EVLA patients improved proliferation and reduced senescence and oxidative stress in the endothelial cells, as compared with the serum from CVS patients. These effects were related to a suppressed activity of TGF-β1, the level of which in the serum from the EVLA patients was decreased. Medium generated by the cells subjected to EVLA serum contained decreased amounts of ICAM-1, VCAM-1, and E-selectin and increased amount of uPA, whereas the serum itself contained decreased concentrations of ICAM-1, E-selectin, and P-selectin and increased concentrations of uPA, PAI-1, and TFPI. Both EVLA and CVS resulted in diversified patients' reaction with respect to a direction of postprocedure changes in proinflammatory factors' serum level. Analysis of proportions showed that the groups differed remarkably in case of ICAM-1 and ET-1, the level of which declined in a higher fraction of patients treated endovenously. Our findings indicate that EVLA preserves better than CVS the functionality of vascular endothelium and modulates better both local and systemic profile of proinflammatory mediators. PMID:28316983

  2. Comparing the epidemiological and economic effects of control strategies against classical swine fever in Denmark

    DEFF Research Database (Denmark)

    Boklund, Anette; Toft, Nils; Alban, Lis;

    2009-01-01

    and to investigate the effect of extra biosecurity measures on farms. We used InterSpread Plus to model the effect of nine different control strategies: the minimum measures required by the EU plus depopulation of contact herds (EUplus), extra depopulation of neighbouring herds, extra surveillance within...... the protection and surveillance zones, extra biosecurity in SPF herds-or in all herds, vaccination of all pigs in the 1 or 2 km zones using live vaccine as a protective measure (vaccination-to-kill), vaccination of all weaners and finishers in the 1 or 2 km zones using an E2 marker vaccine as a suppressive...... is a nucleus herd. This implies that biosecurity in nucleus herds is extremely important to avoid transmission of CSF to these herds. Simulations showed that a Danish CSF epidemic will be moderate in most cases and will include fewer than 10 cases and last less than 2 weeks on average. However, for some...

  3. Biology and host range of Heterapoderopsis bicallosicollis; a potential biological control agent for Chinese tallow Triadica sebifera

    Science.gov (United States)

    Chinese tallow, Triadica sebifera, is an invasive weed that infests natural and agricultural areas of the southeastern USA. A candidate for biological control of Chinese tallow has been studied under quarantine conditions. The biology and host range of a primitive leaf feeding beetle, Heterapoderops...

  4. Parasites and biological invasions: parallels, interactions, and control.

    Science.gov (United States)

    Dunn, Alison M; Hatcher, Melanie J

    2015-05-01

    Species distributions are changing at an unprecedented rate owing to human activity. We examine how two key processes of redistribution - biological invasion and disease emergence - are interlinked. There are many parallels between invasion and emergence processes, and invasions can drive the spread of new diseases to wildlife. We examine the potential impacts of invasion and disease emergence, and discuss how these threats can be countered, focusing on biosecurity. In contrast with international policy on emerging diseases of humans and managed species, policy on invasive species and parasites of wildlife is fragmented, and the lack of international cooperation encourages individual parties to minimize their input into control. We call for international policy that acknowledges the strong links between emerging diseases and invasion risk.

  5. A Biologically Inspired Cooperative Multi-Robot Control Architecture

    Science.gov (United States)

    Howsman, Tom; Craft, Mike; ONeil, Daniel; Howell, Joe T. (Technical Monitor)

    2002-01-01

    A prototype cooperative multi-robot control architecture suitable for the eventual construction of large space structures has been developed. In nature, there are numerous examples of complex architectures constructed by relatively simple insects, such as termites and wasps, which cooperatively assemble their nests. The prototype control architecture emulates this biological model. Actions of each of the autonomous robotic construction agents are only indirectly coordinated, thus mimicking the distributed construction processes of various social insects. The robotic construction agents perform their primary duties stigmergically i.e., without direct inter-agent communication and without a preprogrammed global blueprint of the final design. Communication and coordination between individual agents occurs indirectly through the sensed modifications that each agent makes to the structure. The global stigmergic building algorithm prototyped during the initial research assumes that the robotic builders only perceive the current state of the structure under construction. Simulation studies have established that an idealized form of the proposed architecture was indeed capable of producing representative large space structures with autonomous robots. This paper will explore the construction simulations in order to illustrate the multi-robot control architecture.

  6. Biological control of biofilms on membranes by metazoans.

    Science.gov (United States)

    Klein, Theresa; Zihlmann, David; Derlon, Nicolas; Isaacson, Carl; Szivak, Ilona; Weissbrodt, David G; Pronk, Wouter

    2016-01-01

    Traditionally, chemical and physical methods have been used to control biofouling on membranes by inactivating and removing the biofouling layer. Alternatively, the permeability can be increased using biological methods while accepting the presence of the biofouling layer. We have investigated two different types of metazoans for this purpose, the oligochaete Aelosoma hemprichi and the nematode Plectus aquatilis. The addition of these grazing metazoans in biofilm-controlled membrane systems resulted in a flux increase of 50% in presence of the oligochaetes (Aelosoma hemprichi), and a flux increase of 119-164% in presence of the nematodes (Plectus aquatilis) in comparison to the control system operated without metazoans. The change in flux resulted from (1) a change in the biofilm structure, from a homogeneous, cake-like biofilm to a more heterogeneous, porous structure and (2) a significant reduction in the thickness of the basal layer. Pyrosequencing data showed that due to the addition of the predators, also the community composition of the biofilm in terms of protists and bacteria was strongly affected. The results have implications for a range of membrane processes, including ultrafiltration for potable water production, membrane bioreactors and reverse osmosis.

  7. An application of classical and instrumental methods of analysis in quality control of beer

    Directory of Open Access Journals (Sweden)

    Rajković Miloš B.

    2015-01-01

    Full Text Available In order to control the quality of beer and raw materials for production of beer in Belgrade Beer Industry (BIP, water is analyzed (city, technological and demineralized water. Measurements of pH values indicated the increased pH values in the sample of tehnological water, which had no impact on wort hopping, since the tested samples of wort, young beer and final product had a pH value within the expected range. After processing city water, a sample of tehnological water was found with increased carbonate hardness, which is caused by the increased content of sodium hydrogen carbonate. Analysing the titration alkalinity, titration acidity and buffering power, it was found that the alkalinity was decreasing which is in accordance with the determination of pH values of wort and beer samples (young beer and final product. Analyzing the content of anions and cations in the examined water samples, it has been shown that the concentration of these examinated anions (Cl-, NO3 -, SO4 2- and PO4 3- and cations (NH4 +, Na+, K+, Ca2+, Mg2+ are within the limits prescribed by the Regulations on hygienic safety of drinking water, and thus by the Regulations of quality and other requirements for beer. The contents of anions in wort and beer samples (young beer and final product were determined by ion chromatography method. The contents of sulphate and nitrate ions were within the recommended limits. The concentration of chloride ions was above 150 mg/dm3, which may have an impact on the sensory properties of beer, while changes in the content of phosphate ions were insignificant. [Projekat Ministarstva nauke Republike Srbije, br. III 43009

  8. Use of rhizobacteria and endophytes for biological control of weeds

    Directory of Open Access Journals (Sweden)

    Trognitz, Friederike

    2014-02-01

    Full Text Available Weeds cause severe yield losses in agriculture, with a maximum estimate of 34% of yield loss worldwide due to competition between the crops and the weeds for nutrition, light and humidity (OERKE, 2006. Invasive plants contribute partially to other problems. The pollen of common ragweed, Ambrosia artemisiifolia L., for example, is five times more allergenic than grass pollen; already ten pollen grains per m3 air can trigger allergy in sensitized patients, including rhinitis, conjunctivitis and asthma. This neophyte from America has extended the season of allergy in European patients to October. Common ragweed is currently most frequent in Hungary, France and Italy. In Austria, ragweed populations along roads have increased dramatically since 2000. The effective means to control this weed of the Asteraceae family are limited; a single plant can produce up to 6000 seeds which stay in the soil for 40 years. Control using selective herbicides is not possible within stands of the Asteraceae member sunflower. Efforts to use herbivore insects as biological control agents also failed due to the unavailability of insects specializing on this ragweed. The use of plant-associated rhizobacteria and endophytes as bio-herbicides offers a novel alternative to conventional methods. By analogy to experiences from other plant-microbe systems, the chances to find microbes of the desired characteristics are highest when isolating and testing specimens directly from ragweed plants. These organisms often have an extremely narrow host range that permits their use for the control of among several even closely related plant species growing together in a field.

  9. Using Biological-Control Research in the Classroom to Promote Scientific Inquiry & Literacy

    Science.gov (United States)

    Richardson, Matthew L.; Richardson, Scott L.; Hall, David G.

    2012-01-01

    Scientists researching biological control should engage in education because translating research programs into classroom activities is a pathway to increase scientific literacy among students. Classroom activities focused on biological control target all levels of biological organization and can be cross-disciplinary by drawing from subject areas…

  10. Biological control of Ascaris suum eggs by Pochonia chlamydosporia fungus.

    Science.gov (United States)

    Ferreira, Sebastião Rodrigo; de Araújo, Jackson Victor; Braga, Fábio Ribeiro; Araujo, Juliana Milani; Frassy, Luiza Neme; Ferreira, Aloízio Soares

    2011-12-01

    Ascaris suum is a gastrointestinal nematode parasite of swines. The aim of this study was to observe Pochonia chlamydosporia fungus on biological control of A. suum eggs after fungus passage through swines gastrointestinal tract. Eighteen pigs, previously dewormed, were randomly divided into three groups: group 1, treated with the fungus isolate VC4; group 2, treated with the fungus isolate VC1 and group 3 did not receive fungus (control). In the treated groups, each animal received a 9 g single dose of mycelium mass containing P. chlamydosporia (VC1 or VC4). Thereafter, animal fecal samples were collected at the following intervals: 8, 12, 24, 36, 48, 72 and 96 h after treatment beginning and these were poured in Petri dishes containing 2% water-agar culture medium. Then, 1,000 A. suum eggs were poured into each dish and kept in an incubator at 26 °C and in the dark for 30 days. After this period, approximately 100 eggs were removed from each Petri dish and morphologically analyzed under light microscopy following the ovicidal activity parameters. The higher percentage observed for isolated VC4 eggs destruction was 57.5% (36 h) after fungus administration and for isolate VC1 this percentage was 45.8% (24 h and 72 h) (p > 0.01). P. chlamydosporia remained viable after passing through the gastrointestinal tract of swines, maintaining its ability of destroying A. suum eggs.

  11. Control of neo-classical double tearing modes by differential poloidal rotation in reversed magnetic shear tokamak plasmas

    Science.gov (United States)

    Wang, Jialei; Wang, Zheng-Xiong; Wei, Lai; Liu, Yue

    2017-04-01

    The control of neo-classical tearing modes (NTMs) by the differential rotation in the reversed magnetic shear (RMS) configuration with different separations Δ {{r}\\text{s}} between two rational surfaces is numerically studied by means of reduced magnetohydrodynamic (MHD) simulations. It is found that the differential rotation with a strong shear at the outer resonant surface can effectively suppress the explosive burst of double tearing modes (DTMs)/NTMs. Critical values of the strength of rotation to suppress the burst are also presented for different bootstrap current fractions {{f}\\text{b}} . Furthermore, a couple of measurable parameters ≤ft(δ, κ \\right) , corresponding respectively to the triangularity and elongation of the magnetic islands at the outer resonant surface, are introduced to characterize the deformation of islands in the nonlinear phase. It is found that the triangularity δ is more likely to precisely predict the onset of burst than the island width w and elongation κ . For a given Δ {{r}\\text{s}} , the critical value of triangularity {δ\\text{crit}} is obtained by scanning different plasma parameters. Establishing such a database of ≤ft(δ,κ \\right) is helpful to effectively control the development of NTMs in the RMS experimental discharges.

  12. Biological agents for whitefly control in Sardinian greenhouse tomatoes.

    Science.gov (United States)

    Nannini, M; Foddi, F; Manca, L; Pisci, R; Sanna, F

    2009-01-01

    To evaluate the effectiveness of alternative options for biocontrol of whiteflies in greenhouse tomatoes, an experiment was carried out during the cropping season 2005-2006 in one of Sardinia's major horticultural districts (S. Margherita di Pula, Cagliari, Italy). Twelve long-cycle and 17 short-cycle tomato crops (8 autumn and 9 spring crops) were surveyed. All of them were treated for insect pest control at the beginning of the growing season, but in 19 out of 29 cases whitefly natural enemies were also released (BCA greenhouses), at least four weeks after the last treatment. The following release programmes were tested: on autumn crops, 1 Macrolophus caliginosus and 12 Eretmocerus mundus/m2; on long-cycle crops, 1 M. caliginosus (released in autumn or spring) and 24 Encarsia formosa/m2 or 48 E. formosa/m2; on spring crops, 1 M. caliginosus and 24 E. formosa/m2 or 48 E. formosa/m2. The cost of each option was fixed at approximately 0.25 Euros/m2. The remaining greenhouses were maintained as controls (no BCA greenhouses). While whitefly and mirid populations were monitored monthly, whitefly species composition and mortality of immature stages were estimated at least twice during the growing season. On short-cycle autumn crops, the release of M. caliginosus and E. mundus produced negligible results in terms of Bemisia tabaci control. On long-cycle and spring crops, even though in June mortality rates in BCA greenhouses were found to be 2- to 3-fold higher than in no-BCA greenhouses, Trialeurodes vaporariorum population growth was not significantly affected by natural enemies. Among the beneficials tested, E. formosa proved to be the most effective; E. mundus and M. caliginosus did not establish well, probably owing to the persistence of insecticide residues, scarce prey availability and intense plant de-leafing. The presence of indigenous natural enemies of whiteflies was observed in most sites, but in general they contributed little to biological control. The

  13. Study Reveals Brain Biology behind Self-Control

    Science.gov (United States)

    Sparks, Sarah D.

    2011-01-01

    A new neuroscience twist on a classic psychology study offers some clues to what makes one student able to buckle down for hours of homework before a test while his classmates party. The study published in the September 2011 edition of "Proceedings of the National Academy of Science," suggests environmental cues may "hijack" the brain's mechanisms…

  14. Biological Control of Meloidogyne hapla Using an Antagonistic Bacterium

    Directory of Open Access Journals (Sweden)

    Jiyeong Park

    2014-09-01

    Full Text Available We examined the efficacy of a bacterium for biocontrol of the root-knot nematode (RKN Meloidogyne hapla in carrot (Daucus carota subsp. sativus and tomato (Solanum lycopersicum. Among 542 bacterial isolates from various soils and plants, the highest nematode mortality was observed for treatments with isolate C1-7, which was identified as Bacillus cereus based on cultural and morphological characteristics, the Biolog program, and 16S rRNA sequencing analyses. The population density and the nematicidal activity of B. cereus C1-7 remained high until the end of culture in brain heart infusion broth, suggesting that it may have sustainable biocontrol potential. In pot experiments, the biocontrol efficacy of B. cereus C1-7 was high, showing complete inhibition of root gall or egg mass formation by RKN in carrot and tomato plants, and subsequently reducing RKN damage and suppressing nematode population growth, respectively. Light microscopy of RKN-infected carrot root tissues treated with C1-7 showed reduced formation of gall cells and fully developed giant cells, while extensive gall cells and fully mature giant cells with prominent cell wall ingrowths formed in the untreated control plants infected with RKNs. These histopathological characteristics may be the result of residual or systemic biocontrol activity of the bacterium, which may coincide with the biocontrol efficacies of nematodes in pots. These results suggest that B. cereus C1-7 can be used as a biocontrol agent for M. hapla.

  15. Changes of trabecular bone under control of biologically mechanical mechanism

    Science.gov (United States)

    Wang, C.; Zhang, C. Q.; Dong, X.; Wu, H.

    2008-10-01

    In this study, a biological process of bone remodeling was considered as a closed loop feedback control system, which enables bone to optimize and renew itself over a lifetime. A novel idea of combining strain-adaptive and damage-induced remodeling algorithms at Basic Multicellular Unit (BMU) level was introduced. In order to make the outcomes get closer to clinical observation, the stochastic occurrence of microdamage was involved and a hypothesis that remodeling activation probability is related to the value of damage rate was assumed. Integrated with Finite Element Analysis (FEA), the changes of trabecular bone in morphology and material properties were simulated in the course of five years. The results suggest that deterioration and anisotropy of trabecluar bone are inevitable with natural aging, and that compression rather than tension can be applied to strengthen the ability of resistance to fracture. This investigation helps to gain more insight the mechanism of bone loss and identify improved treatment and prevention for osteoporosis or stress fracture.

  16. Implications of Plasmodium vivax Biology for Control, Elimination, and Research

    Science.gov (United States)

    Olliaro, Piero L.; Barnwell, John W.; Barry, Alyssa; Mendis, Kamini; Mueller, Ivo; Reeder, John C.; Shanks, G. Dennis; Snounou, Georges; Wongsrichanalai, Chansuda

    2016-01-01

    This paper summarizes our current understanding of the biology of Plasmodium vivax, how it differs from Plasmodium falciparum, and how these differences explain the need for P. vivax-tailored interventions. The article further pinpoints knowledge gaps where investments in research are needed to help identify and develop such specific interventions. The principal obstacles to reduce and eventually eliminate P. vivax reside in 1) its higher vectorial capacity compared with P. falciparum due to its ability to develop at lower temperature and over a shorter sporogonic cycle in the vector, allowing transmission in temperate zones and making it less sensitive to vector control measures that are otherwise effective on P. falciparum; 2) the presence of dormant liver forms (hypnozoites), sustaining multiple relapsing episodes from a single infectious bite that cannot be diagnosed and are not susceptible to any available antimalarial except primaquine, with routine deployment restricted by toxicity; 3) low parasite densities, which are difficult to detect with current diagnostics leading to missed diagnoses and delayed treatments (and protracted transmission), coupled with 4) transmission stages (gametocytes) occurring early in acute infections, before infection is diagnosed. PMID:27799636

  17. Identification of Bacillus strains for biological control of catfish pathogens.

    Directory of Open Access Journals (Sweden)

    Chao Ran

    Full Text Available Bacillus strains isolated from soil or channel catfish intestine were screened for their antagonism against Edwardsiella ictaluri and Aeromonas hydrophila, the causative agents of enteric septicemia of catfish (ESC and motile aeromonad septicaemia (MAS, respectively. Twenty one strains were selected and their antagonistic activity against other aquatic pathogens was also tested. Each of the top 21 strains expressed antagonistic activity against multiple aquatic bacterial pathogens including Edwardsiella tarda, Streptococcus iniae, Yersinia ruckeri, Flavobacterium columnare, and/or the oomycete Saprolegnia ferax. Survival of the 21 Bacillus strains in the intestine of catfish was determined as Bacillus CFU/g of intestinal tissue of catfish after feeding Bacillus spore-supplemented feed for seven days followed by normal feed for three days. Five Bacillus strains that showed good antimicrobial activity and intestinal survival were incorporated into feed in spore form at a dose of 8×10(7 CFU/g and fed to channel catfish for 14 days before they were challenged by E. ictaluri in replicate. Two Bacillus subtilis strains conferred significant benefit in reducing catfish mortality (P<0.05. A similar challenge experiment conducted in Vietnam with four of the five Bacillus strains also showed protective effects against E. ictaluri in striped catfish. Safety of the four strains exhibiting the strongest biological control in vivo was also investigated in terms of whether the strains contain plasmids or express resistance to clinically important antibiotics. The Bacillus strains identified from this study have good potential to mediate disease control as probiotic feed additives for catfish aquaculture.

  18. New knowledge in application of vaccines with Kina(Kstrain in control and curbing of classical swine fever

    Directory of Open Access Journals (Sweden)

    Prodanov Jasna

    2006-01-01

    Full Text Available The program of curbing and outrooting classical swine fever (CSF in our country has for years been based on the vaccination of all categories of swine with the Kina (K strain of the CSF virus, and, after the establishment of the source of infection, with the non-harmful removal of the infected swine herd, as well as on the implementation of all measures prescribed by the valid regulations. However, in spite of the implementation of all the listed measures, CSF still occurs continually. The epizootiological situation in our country in the course of 2005 was extremely unfavorable from the aspect of the number of identified CSF crisis spots, and it can be pointed out at this time that the disease was diagnosed clinically, pathomorphologically and using laboratory methods in 51 farms in a single examined epizootiological district. Under conditions when CSF appears continually throughout the year, vaccination using a modified live vaccine must continue being the basic measure in preventing the appearance, spreading, curbing, and eradication of CSF. With the objective of securing a concept of the most efficient further strategy for control and curbing of this disease, the paper presents the most important aspects regarding efficacy, safety, as well as field experience in applying vaccines which are based on the K strain of the CSF virus. .

  19. Evaluation of a New Biological Control Pathogen for Management of Eurasian Watermilfoil

    Science.gov (United States)

    2013-06-01

    perceived threats to human health and the environment. Biological control has been studied as an option for milfoil management for over 40 years...2008). Combined with glyphosate in an integrated weed management approach, M. verrucaria could control weeds in fields planted to glyphosate ...radicans) controlled under field conditions by a synergistic interaction of the bioherbicide Myrothecium verrucaria, with glyphosate . Weed Biology

  20. Classical Mechanics

    OpenAIRE

    Gallavotti, Giovanni

    2012-01-01

    This is the English version of a friendly graduate course on Classical Mechanics, containing about 80% of the material I covered during the January-June 1999 semester at IFUG in the Mexican city of Leon. For the Spanish version, see physics/9906066

  1. PROTECTING ECOSYSTEMS BY WAY OF BIOLOGICAL CONTROL: CURSORY REFLECTIONS ON THE MAIN REGULATORY INSTRUMENTS FOR BIOLOGICAL CONTROL AGENTS, PRESENT AND FUTURE

    Directory of Open Access Journals (Sweden)

    R Alberts

    2013-06-01

    Full Text Available Although there are numerous threats to ecosystems and the resultant ecosystem services, alien and invasive plants (AIP have been identified as being one of the major causes of ecosystem destruction. In addressing the threat of alien and invasive plants through the use of various mechanisms, the regulatory framework imposed by legislation is key in ensuring that that controlling AIPs does in fact not do more harm than good. One such control mechanism, which has the potential to do wonders or wreak havoc if not adroitly implemented, is that of using biological control agents. This contribution provides a brief overview on the three main regulatory instruments used to control biological control agents in South Africa, namely the Conservation of Agricultural Resources Act 43 of 1983, the Agricultural Pests Act 36 of 1983 and the National Environmental Management: Biodiversity Act 10 of 2004. It also considers possible future developments on the regulation of biological control agents.

  2. Patterns and controls on nitrogen cycling of biological soil crusts

    Science.gov (United States)

    Barger, Nichole N.; Zaady, Eli; Weber, Bettina; Garcia-Pichel, Ferran; Belnap, Jayne

    2016-01-01

    Biocrusts play a significant role in the nitrogen [N ] cycle within arid and semi-arid ecosystems, as they contribute major N inputs via biological fixation and dust capture, harbor internal N transformation processes, and direct N losses via N dissolved, gaseous and erosional loss processes (Fig. 1). Because soil N availability in arid and semi-arid ecosystems is generally low and may limit net primary production (NPP), especially during periods when adequate water is available, understanding the mechanisms and controls of N input and loss pathways in biocrusts is critically important to our broader understanding of N cycling in dryland environments. In particular, N cycling by biocrusts likely regulates short-term soil N availability to support vascular plant growth, as well as long-term N accumulation and maintenance of soil fertility. In this chapter, we review the influence of biocrust nutrient input, internal cycling, and loss pathways across a range of biomes. We examine linkages between N fixation capabilities of biocrust organisms and spatio-temporal patterns of soil N availability that may influence the longer-term productivity of dryland ecosystems. Lastly, biocrust influence on N loss pathways such as N gas loss, leakage of N compounds from biocrusts, and transfer in wind and water erosion are important to understand the maintenance of dryland soil fertility over longer time scales. Although great strides have been made in understanding the influence of biocrusts on ecosystem N cycling, there are important knowledge gaps in our understanding of the influence of biocrusts on ecosystem N cycling that should be the focus of future studies. Because work on the interaction of N cycling and biocrusts was reviewed in Belnap and Lange (2003), this chapter will focus primarily on research findings that have emerged over the last 15 years (2000-2015).

  3. Eicosanoids: Exploiting Insect Immunity to Improve Biological Control Programs

    Directory of Open Access Journals (Sweden)

    David Stanley

    2012-05-01

    Full Text Available Insects, like all invertebrates, express robust innate, but not adaptive, immune reactions to infection and invasion. Insect immunity is usually resolved into three major components. The integument serves as a physical barrier to infections. Within the hemocoel, the circulating hemocytes are the temporal first line of defense, responsible for clearing the majority of infecting bacterial cells from circulation. Specific cellular defenses include phagocytosis, microaggregation of hemocytes with adhering bacteria, nodulation and encapsulation. Infections also stimulate the humoral component of immunity, which involves the induced expression of genes encoding antimicrobial peptides and activation of prophenoloxidase. These peptides appear in the hemolymph of challenged insects 6–12 hours after the challenge. Prostaglandins and other eicosanoids are crucial mediators of innate immune responses. Eicosanoid biosynthesis is stimulated by infection in insects. Inhibition of eicosanoid biosynthesis lethally renders experimental insects unable to clear bacterial infection from hemolymph. Eicosanoids mediate specific cell actions, including phagocytosis, microaggregation, nodulation, hemocyte migration, hemocyte spreading and the release of prophenoloxidase from oenocytoids. Some invaders have evolved mechanisms to suppress insect immunity; a few of them suppress immunity by targeting the first step in the eicosanoid biosynthesis pathways, the enzyme phospholipase A2. We proposed research designed to cripple insect immunity as a technology to improve biological control of insects. We used dsRNA to silence insect genes encoding phospholipase A2, and thereby inhibited the nodulation reaction to infection. The purpose of this article is to place our view of applying dsRNA technologies into the context of eicosanoid actions in insect immunity. The long-term significance of research in this area lies in developing new pest management

  4. Effect of individualized goal-setting on college biology students' locus of control

    Science.gov (United States)

    Schafer, John E.

    This study investigated the effect of Individualized Goal-Setting A-T, relative to Classic A-T, on a student's locus of control (generalized and academic). This study also examined the effect of pretesting, relative to no pretesting, on a student's locus of control. Sixty students in an introductory, Audio-Tutorial, college zoology course were randomly assigned to treatment and control groups. Control groups (Classic A-T) completed the course in the usual manner. Treatment groups (IGS A-T) completed the course in the usual manner with one exception. That is, they used a different format for Optional Minicourse mastery. This new format released greater control to students over means as well as ends of minicourse mastery. Data were collected through use of the Solomon Four-Group design, with two levels of treatment (Classic A-T, IGS A-T) and two levels of pretesting (pretest, no pretest). Instruments included the Rotter I-E and Schafer Academic I-E Locus of Control Scales. Posttest scores were analyzed by a 2 × 2 multivariate analysis of variance (MANOVA).The following conclusions were made (p < 0.10).1IGS A-T, relative to Classic A-T, has no significant effect on a student's locus of control.2Pretesting, relative to no pretesting, has no significant effect on posttest locus of control.

  5. WILD PIGS: BIOLOGY, DAMAGE, CONTROL TECHINQUES AND MANAGEMENT

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, John; Brisbin, I. Lehr

    2009-12-31

    about anything; and, they can live just about anywhere. On top of that, wild pigs are both very difficult to control and, with the possible exception of island ecosystems, almost impossible to eradicate (Dickson et al. 2001, Sweeney et al. 2003). The solution to the wild pig problem has not been readily apparent. The ultimate answer as to how to control these animals has not been found to date. In many ways, wild pigs are America's most successful large invasive species. All of which means that wild pigs are a veritable nightmare for land and resource managers trying to keep the numbers of these animals and the damage that they do under control. Since the more that one knows about an invasive species, the easier it is to deal with and hopefully control. For wild pigs then, it is better to 'know thy enemy' than to not, especially if one expects to be able to successfully control them. In an effort to better 'know thy enemy,' a two-day symposium was held in Augusta, Georgia, on April 21-22, 2004. This symposium was organized and sponsored by U.S.D.A. Forest Service-Savannah River (USFS-SR), U. S. Department of Energy-Savannah River Operations Office (DOE-SR), the Westinghouse Savannah River Company (WSRC), the South Carolina Chapter of the Soil & Water Conservation Society, and the Savannah River Ecology Laboratory (SREL). The goal of this symposium was to assemble researchers and land managers to first address various aspects of the biology and damage of wild pigs, and then review the control techniques and management of this invasive species. The result would then be a collected synopsis of what is known about wild pigs in the United States. Although the focus of the symposium was primarily directed toward federal agencies, presenters also included professionals from academic institutions, and private-sector control contractors and land managers. Most of the organizations associated with implementing this symposium were affiliated with the

  6. WILD PIGS: BIOLOGY, DAMAGE, CONTROL TECHINQUES AND MANAGEMENT

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, John; Brisbin, I. Lehr

    2009-12-31

    about anything; and, they can live just about anywhere. On top of that, wild pigs are both very difficult to control and, with the possible exception of island ecosystems, almost impossible to eradicate (Dickson et al. 2001, Sweeney et al. 2003). The solution to the wild pig problem has not been readily apparent. The ultimate answer as to how to control these animals has not been found to date. In many ways, wild pigs are America's most successful large invasive species. All of which means that wild pigs are a veritable nightmare for land and resource managers trying to keep the numbers of these animals and the damage that they do under control. Since the more that one knows about an invasive species, the easier it is to deal with and hopefully control. For wild pigs then, it is better to 'know thy enemy' than to not, especially if one expects to be able to successfully control them. In an effort to better 'know thy enemy,' a two-day symposium was held in Augusta, Georgia, on April 21-22, 2004. This symposium was organized and sponsored by U.S.D.A. Forest Service-Savannah River (USFS-SR), U. S. Department of Energy-Savannah River Operations Office (DOE-SR), the Westinghouse Savannah River Company (WSRC), the South Carolina Chapter of the Soil & Water Conservation Society, and the Savannah River Ecology Laboratory (SREL). The goal of this symposium was to assemble researchers and land managers to first address various aspects of the biology and damage of wild pigs, and then review the control techniques and management of this invasive species. The result would then be a collected synopsis of what is known about wild pigs in the United States. Although the focus of the symposium was primarily directed toward federal agencies, presenters also included professionals from academic institutions, and private-sector control contractors and land managers. Most of the organizations associated with implementing this symposium were affiliated with the

  7. Phosphorylation of CRTC3 by the salt-inducible kinases controls the interconversion of classically activated and regulatory macrophages.

    Science.gov (United States)

    Clark, Kristopher; MacKenzie, Kirsty F; Petkevicius, Kasparas; Kristariyanto, Yosua; Zhang, Jiazhen; Choi, Hwan Geun; Peggie, Mark; Plater, Lorna; Pedrioli, Patrick G A; McIver, Ed; Gray, Nathanael S; Arthur, J Simon C; Cohen, Philip

    2012-10-16

    Macrophages acquire strikingly different properties that enable them to play key roles during the initiation, propagation, and resolution of inflammation. Classically activated (M1) macrophages produce proinflammatory mediators to combat invading pathogens and respond to tissue damage in the host, whereas regulatory macrophages (M2b) produce high levels of anti-inflammatory molecules, such as IL-10, and low levels of proinflammatory cytokines, like IL-12, and are important for the resolution of inflammatory responses. A central problem in this area is to understand how the formation of regulatory macrophages can be promoted at sites of inflammation to prevent and/or alleviate chronic inflammatory and autoimmune diseases. Here, we demonstrate that the salt-inducible kinases (SIKs) restrict the formation of regulatory macrophages and that their inhibition induces striking increases in many of the characteristic markers of regulatory macrophages, greatly stimulating the production of IL-10 and other anti-inflammatory molecules. We show that SIK inhibitors elevate IL-10 production by inducing the dephosphorylation of cAMP response element-binding protein (CREB)-regulated transcriptional coactivator (CRTC) 3, its dissociation from 14-3-3 proteins and its translocation to the nucleus where it enhances a gene transcription program controlled by CREB. Importantly, the effects of SIK inhibitors on IL-10 production are lost in macrophages that express a drug-resistant mutant of SIK2. These findings identify SIKs as a key molecular switch whose inhibition reprograms macrophages to an anti-inflammatory phenotype. The remarkable effects of SIK inhibitors on macrophage function suggest that drugs that target these protein kinases may have therapeutic potential for the treatment of inflammatory and autoimmune diseases.

  8. Bit by bit control of nonlinear ecological and biological networks using Evolutionary Network Control

    Directory of Open Access Journals (Sweden)

    Alessandro Ferrarini

    2016-06-01

    Full Text Available Evolutionary Network Control (ENC has been first introduced in 2013 to effectively subdue network-like systems. ENC opposes the idea, very common in the scientific literature, that controllability of networks should be based on the identification of the set of driver nodes that can guide the system's dynamics, in other words on the choice of a subset of nodes that should be selected to be permanently controlled. ENC has proven to be effective in the global control (i.e. the focus is on mastery of the final state of network dynamics of linear and nonlinear networks, and in the local (i.e. the focus is on the step-by-step ascendancy of network dynamics control of linear networks. In this work, ENC is applied to the local control of nonlinear networks. Using the Lotka-Volterra model as a case study, I show here that ENC is capable of locally driving nonlinear networks as well, so that also intermediate steps (not only the final state are under our strict control. ENC can be readily applied to any kind of ecological, biological, economic and network-like system.

  9. Indirect ecological effects in invaded landscapes: Spillover and spillback from biological control agents to native analogues

    Science.gov (United States)

    Biological control remains an effective option for managing large-scale weed problems in natural areas. The predation or parasitism of biological control agents by other species present in the introduced range (biotic resistance) is well studied and is often cited as the cause for a lack of establis...

  10. A theoretical framework for biological control of soil-borne plant pathogens: Identifying effective strategies.

    Science.gov (United States)

    Cunniffe, Nik J; Gilligan, Christopher A

    2011-06-07

    We develop and analyse a flexible compartmental model of the interaction between a plant host, a soil-borne pathogen and a microbial antagonist, for use in optimising biological control. By extracting invasion and persistence thresholds of host, pathogen and biological control agent, performing an equilibrium analysis, and numerical investigation of sensitivity to parameters and initial conditions, we determine criteria for successful biological control. We identify conditions for biological control (i) to prevent a pathogen entering a system, (ii) to eradicate a pathogen that is already present and, if that is not possible, (iii) to reduce the density of the pathogen. Control depends upon the epidemiology of the pathogen and how efficiently the antagonist can colonise particular habitats (i.e. healthy tissue, infected tissue and/or soil-borne inoculum). A sharp transition between totally effective control (i.e. eradication of the pathogen) and totally ineffective control can follow slight changes in biologically interpretable parameters or to the initial amounts of pathogen and biological control agent present. Effective biological control requires careful matching of antagonists to pathosystems. For preventative/eradicative control, antagonists must colonise susceptible hosts. However, for reduction in disease prevalence, the range of habitat is less important than the antagonist's bulking-up efficiency.

  11. Biology and host range of Tecmessa elegans (Lepidoptera: Notodontidae), a leaf-feeding moth evaluated as a potential biological control agent for Schinus terebinthifolius (Sapindales: Anacardiaceae) in the United States.

    Science.gov (United States)

    Oleiro, Marina; Mc Kay, Fernando; Wheeler, Gregory S

    2011-06-01

    During surveys for natural enemies that could be used as classical biological control agents of Schinus terebinthifolius Raddi (Brazilian pepper), the caterpillar, Tecmessa elegans Schaus (Lepidoptera: Notodontidae), was recorded feeding on the leaves of the shrub in South America. The biology and larval and adult host range of this species were examined to determine the insect's suitability for biological control of this invasive weed in North America and Hawaii. Biological observations indicate that the larvae have five instars. When disturbed, the late instar larvae emit formic acid from a prothoracic gland that may protect larvae from generalist predators. Larval host range tests conducted both in South and North America indicated that this species feeds and completes development primarily on members of the Anacardiaceae within the tribe Rhoeae. Oviposition tests indicated that when given a choice in large cages the adults will select the target weed over Pistacia spp. However, considering the many valued plant species in its host range, especially several North American natives, this species will not be considered further for biological control of S. terebinthifolius in North America.

  12. Evolutionary game based control for biological systems with applications in drug delivery.

    Science.gov (United States)

    Li, Xiaobo; Lenaghan, Scott C; Zhang, Mingjun

    2013-06-01

    Control engineering and analysis of biological systems have become increasingly important for systems and synthetic biology. Unfortunately, no widely accepted control framework is currently available for these systems, especially at the cell and molecular levels. This is partially due to the lack of appropriate mathematical models to describe the unique dynamics of biological systems, and the lack of implementation techniques, such as ultra-fast and ultra-small devices and corresponding control algorithms. This paper proposes a control framework for biological systems subject to dynamics that exhibit adaptive behavior under evolutionary pressures. The control framework was formulated based on evolutionary game based modeling, which integrates both the internal dynamics and the population dynamics. In the proposed control framework, the adaptive behavior was characterized as an internal dynamic, and the external environment was regarded as an external control input. The proposed open-interface control framework can be integrated with additional control algorithms for control of biological systems. To demonstrate the effectiveness of the proposed framework, an optimal control strategy was developed and validated for drug delivery using the pathogen Giardia lamblia as a test case. In principle, the proposed control framework can be applied to any biological system exhibiting adaptive behavior under evolutionary pressures.

  13. [Classical taxomomies].

    Science.gov (United States)

    Liubarskiĭ, G Iu

    2006-01-01

    The sequence of classic paradigms in taxonomy that partly replaced each other and partly co-exist is given as follows: the theory of "organ and organism similarity", the naturalistic theory, the descriptive theory, and the phylogenetic theory. The naturalistic classics accepted the notion of "the plan of creation". The rejection of appealing to this plan brought forth certain problems in the formulation of the purpose of taxonomy; these problems were differently solved by the descriptive and the phylogenetic classic traditions. The difficulties of the current paradigms arising from the loss of a "strong purpose", a problem to be solved by taxonomists that is to be clear and interesting to a wide range of non-professionals. The paradox of formalization led to the losing of content of the methods due to their formalization. To attract attention to taxonomy, a new "image of the results" of its work that would be interesting to the non-professionals is necessary. The co-existence of different methods of reseach applied to different groups of facts leads to the loss of integrity of the research. It is not only that the taxon becomes a hypothesis and such hypotheses multiply. The comparison of these hypotheses is problematic, because each of them is supported by its own independent scope of facts. Because of the existence of a fundamental meronotaxonomic discrepancy, taxonomic systems based on different groups of characters appear to be incomparable, being rather systems of characters than systems of taxa. Systems of characters are not directly comparable with each other; they can be compared only through appealing to taxa, but taxa themselves exist only in the form of a number of hypotheses. Consequently, each separate taxonomic approach creates its own nature, its own subject of research. Therefore, it is necessary to describe the subject of research correctly (and indicate the purpose of research), as well as to distinguish clearly between results achieved through

  14. Controlling the biological effects of spermine using a synthetic receptor.

    Science.gov (United States)

    Vial, Laurent; Ludlow, R Frederick; Leclaire, Julien; Pérez-Fernandez, Ruth; Otto, Sijbren

    2006-08-09

    Polyamines play an important role in biology, yet their exact function in many processes is poorly understood. Artificial host molecules capable of sequestering polyamines could be useful tools for studying their cellular function. However, designing synthetic receptors with affinities sufficient to compete with biological polyamine receptors remains a huge challenge. Binding affinities of synthetic hosts are typically separated by a gap of several orders of magnitude from those of biomolecules. We now report that a dynamic combinatorial selection approach can deliver a synthetic receptor that bridges this gap. The selected receptor binds spermine with a dissociation constant of 22 nM, sufficient to remove it from its natural host DNA and reverse some of the biological effects of spermine on the nucleic acid. In low concentrations, spermine induces the formation of left-handed DNA, but upon addition of our receptor, the DNA reverts back to its right-handed form. NMR studies and computer simulations suggest that the spermine complex has the form of a pseudo-rotaxane. The spermine receptor is a promising lead for the development of therapeutics or molecular probes for elucidating spermine's role in cell biology.

  15. Controlling the Biological Effects of Spermine Using a Synthetic Receptor

    NARCIS (Netherlands)

    Vial, Laurent; Ludlow, R. Frederick; Leclaire, Julien; Pérez-Fernández, Ruth; Otto, Sijbren

    2006-01-01

    Polyamines play an important role in biology, yet their exact function in many processes is poorly understood. Artificial host molecules capable of sequestering polyamines could be useful tools for studying their cellular function. However, designing synthetic receptors with affinities sufficient to

  16. Biological stability of drinking water: Controlling factors, methods, and challenges

    NARCIS (Netherlands)

    Prest, E.I.E.D.; Hammes, F.; Van Loosdrecht, M.C.M.; Vrouwenvelder, J.S.

    2016-01-01

    Biological stability of drinking water refers to the concept of providing consumers with drinking water of same microbial quality at the tap as produced at the water treatment facility. However, uncontrolled growth of bacteria can occur during distribution in water mains and premise plumbing, and ca

  17. [We control our bodies: the biological and social dialectic].

    Science.gov (United States)

    Giffin, K M

    1991-01-01

    This article aims at reviewing the discussion of biological and social factors in the analysis of women's social condition. With the appearance of a feminist perspective, the dominance of earlier biologically-based explanations was substituted by an emphasis on the social construction of female identity. Even when women's identification with the body and with nature, and their secondary status, were considered universal, biological determinism was rejected. In this process of re-definition of the object of study, the ideological role of science was pointed out, since male dominance in science and society accompanied the historical tendency which relegated "the woman question" to the sphere of natural fact. Although growing awareness of the socially-constructed nature of scientific activity itself is producing a tendency to abandon the biological/social dichotomy at the conceptual level, differences between men and women in the reproductive sphere continue to exist. It is argued that analysis of reproduction requires characterization of the sexes as biosocial entities in relationship, situated in specific historical contexts, and that in modern society women are subject to a double reproductive contradiction.

  18. Control of rugose spiraling whitefly using biological insecticides, 2014

    Science.gov (United States)

    The objective of this study was to evaluate the efficacy of selected biological insecticides against a new invasive whitefly pest, Aleurodicus rugioperculatus Martin, in white bird of paradise under field condition. The trial was conducted at United States Horticultural Research Laboratory in Fort P...

  19. Physical constraints on biological integral control design for homeostasis and sensory adaptation.

    Science.gov (United States)

    Ang, Jordan; McMillen, David R

    2013-01-22

    Synthetic biology includes an effort to use design-based approaches to create novel controllers, biological systems aimed at regulating the output of other biological processes. The design of such controllers can be guided by results from control theory, including the strategy of integral feedback control, which is central to regulation, sensory adaptation, and long-term robustness. Realization of integral control in a synthetic network is an attractive prospect, but the nature of biochemical networks can make the implementation of even basic control structures challenging. Here we present a study of the general challenges and important constraints that will arise in efforts to engineer biological integral feedback controllers or to analyze existing natural systems. Constraints arise from the need to identify target output values that the combined process-plus-controller system can reach, and to ensure that the controller implements a good approximation of integral feedback control. These constraints depend on mild assumptions about the shape of input-output relationships in the biological components, and thus will apply to a variety of biochemical systems. We summarize our results as a set of variable constraints intended to provide guidance for the design or analysis of a working biological integral feedback controller.

  20. The biological control as a strategy to support nontraditional agricultural exports in Peru: An empirical analysis

    Directory of Open Access Journals (Sweden)

    Franklin Duarte Cueva

    2012-12-01

    Full Text Available The study is oriented to explore the general characteristics of agriculture, the biological control as a pest control mechanism and agro export industry. In this context, we try to promote the use of biological control as a strategy to support nontraditional exports related to products such as asparagus and fresh avocados grown in the La Libertad Department (Peru, through an agronomic and management approach. Biological control is the basis of integrated pest management (IPM and contributes to the conservation of agricultural ecosystems allowing to export companies reduce costs, fulfill international phytosanitary measures and supports the preservation of the environment and health. Thus, the Peruvian agro export companies could build a sustainable competitive advantage and seek a positioning as socially responsible firms. We analyze variables such as crop statistics, comparative costs between biological control and chemical control, main destination markets for asparagus and fresh avocados, international standards, among others.

  1. Dynamical Systems and Control Theory Inspired by Molecular Biology

    Science.gov (United States)

    2011-02-20

    is odd) steady states, there never are more than 2n − 1 steady states, that for parameters near the standard Michaelis - Menten quasi-steady state...conditions, there are at most n + 1 steady states and that for parameters far from the standard Michaelis - Menten quasi-steady state conditions, there is at...moments for certain stochastic kinetics : We have recently started research into stochastic aspects in systems biology. Deterministic mod- els

  2. Commercial biological control agents targeted against plant-parasitic root-knot nematodes

    OpenAIRE

    Marie-Stéphane Tranier; Johan Pognant-Gros; Reynaldo De la Cruz Quiroz; Cristóbal Noé Aguilar González; Thierry Mateille; Sevastianos Roussos

    2014-01-01

    International audience; Root-knot nematodes are microscopic round worms, which cause severe agricultural losses. Their attacks affect the productivity by reducing the amount and the caliber of the fruits. Chemical control is widely used, but biological control appears to be a better solution, mainly using microorganisms to reduce the quantity of pests infecting crops. Biological control is developing gradually, and with time, more products are being marketed worldwide. They can be formulated ...

  3. Biological Control of the Invasive Dryocosmus kuriphilus (Hymenoptera: Cynipidae - an Overview and the First Trials in Croatia

    Directory of Open Access Journals (Sweden)

    Dinka Matošević

    2014-06-01

    Full Text Available Background and Purpose: Dryocosmus kuriphilus is a globally invasive insect pest, spreading very quickly in new habitats and making serious damage to sweet chestnut forests in Croatia and in several other European countries. Indigenous parasitoid species trophically associated with oak gallwasps have adapted to this new host but cannot effectively regulate its population density. Classical biological control using parasitoid Torymus sinensis has been proven to be the only effective method of controlling the populations of D. kuriphilus and has been successfully applied in Japan, South Korea, the USA and Italy. The aim of this review paper is to provide overview and up-to date knowledge about biological control of D. kurphilus and to describe first steps of introduction of T. sinensis to sweet chestnut forests in Croatia. Conclusions and Future Prospects: Results presented in this paper show adapted biology and behavioural traits of T. sinensis to its host D. kuriphilus. The history and results of introductions of T. sinensis to Japan, the USA, Italy, France and Hungary are shown. The first report of release of T. sinensis to sweet chestnut forests in Croatia is given with discussion on native parasitoids attacking D. kuriphilus. Possible negative effects of T. sinensis on native parasitoid fauna and risks that could influence the successful establishment of T. sinensis in Croatia are discussed. Previous experiences have shown that T. sinensis can successfully control the population density of D. kuriphilus, slowing down the spread and mitigating negative impact of this invasive chestnut pest and keeping the damage of D. kuriphilus at acceptable level. High specificity of T. sinensis suggests that it has limited potential of exploiting native hosts but further detailed monitoring of native parasitoid and possible interactions with introduced T. sinensis is strongly suggested.

  4. 75 FR 28233 - Availability of an Environmental Assessment for a Biological Control Agent for Asian Citrus Psyllid

    Science.gov (United States)

    2010-05-20

    ... for use as a biological control agent to reduce the severity of Asian citrus psyllid infestations. We... continental United States for use as a biological control agent to reduce the severity of Asian citrus psyllid... include chemical control and the release of an alternative biological control agent, an encyrtid...

  5. 大攻角导弹控制的经典和现代方法比较%Comparisons on Classic and Modern Controls for High AOA Missiles

    Institute of Scientific and Technical Information of China (English)

    宋雪海; 侯明善; 熊飞

    2011-01-01

    Comparisons on precision and robustness of classic and modern controls for high Angle-of-Attack (AOA) are presented. Based on the nonlinear characteristics of the high AOA missile, two kinds of missile longitudinal autopilot are designed using classical three-loops configuration and dynamic inversion embedded pole placement technique respectively. Study on their command tracking precision and robustness have been conducted. It's proved by simulation that classic and modern controls are nearly identical in either rapidity of response or robustness, but modern control can obtain better tracking precision.%比较研究了大攻角导弹的经典和现代控制方法的精度和鲁棒性.基于大攻角非线性弹体动力学模型,根据经典三回路控制系统结构和动态逆双时标极点配置方法分别设计了控制器,研究了两种控制方法的指令跟踪精度和抗弹体气动参数摄动的鲁棒性.结果表明,传统控制方法的鲁棒性和快速性与现代方法基本一致,而现代方法则具有更好的稳态精度.

  6. Classic hallucinogens in the treatment of addictions.

    Science.gov (United States)

    Bogenschutz, Michael P; Johnson, Matthew W

    2016-01-01

    Addictive disorders are very common and have devastating individual and social consequences. Currently available treatment is moderately effective at best. After many years of neglect, there is renewed interest in potential clinical uses for classic hallucinogens in the treatment of addictions and other behavioral health conditions. In this paper we provide a comprehensive review of both historical and recent clinical research on the use of classic hallucinogens in the treatment of addiction, selectively review other relevant research concerning hallucinogens, and suggest directions for future research. Clinical trial data are very limited except for the use of LSD in the treatment of alcoholism, where a meta-analysis of controlled trials has demonstrated a consistent and clinically significant beneficial effect of high-dose LSD. Recent pilot studies of psilocybin-assisted treatment of nicotine and alcohol dependence had strikingly positive outcomes, but controlled trials will be necessary to evaluate the efficacy of these treatments. Although plausible biological mechanisms have been proposed, currently the strongest evidence is for the role of mystical or other meaningful experiences as mediators of therapeutic effects. Classic hallucinogens have an excellent record of safety in the context of clinical research. Given our limited understanding of the clinically relevant effects of classic hallucinogens, there is a wealth of opportunities for research that could contribute important new knowledge and potentially lead to valuable new treatments for addiction.

  7. Biological control through intraguild predation: case studies in pest control, invasive species and range expansion.

    Science.gov (United States)

    Bampfylde, C J; Lewis, M A

    2007-04-01

    Intraguild predation (IGP), the interaction between species that eat each other and compete for shared resources, is ubiquitous in nature. We document its occurrence across a wide range of taxonomic groups and ecosystems with particular reference to non-indigenous species and agricultural pests. The consequences of IGP are complex and difficult to interpret. The purpose of this paper is to provide a modelling framework for the analysis of IGP in a spatial context. We start by considering a spatially homogeneous system and find the conditions for predator and prey to exclude each other, to coexist and for alternative stable states. Management alternatives for the control of invasive or pest species through IGP are presented for the spatially homogeneous system. We extend the model to include movement of predator and prey. In this spatial context, it is possible to switch between alternative stable steady states through local perturbations that give rise to travelling waves of extinction or control. The direction of the travelling wave depends on the details of the nonlinear intraguild interactions, but can be calculated explicitly. This spatial phenomenon suggests means by which invasions succeed or fail, and yields new methods for spatial biological control. Freshwater case studies are used to illustrate the outcomes.

  8. Evaluation of biological control agents for mosquitoes control in artificial breeding places

    Institute of Scientific and Technical Information of China (English)

    Salim Abadi Yaser; Vatandoost Hassan; Rassi Yavar; Abai Mohammad Reza; Sanei Dehkordi Ali Reza; Paksa Azim

    2010-01-01

    Objective:To evaluate the entomological impact of chlorpyrifos-methyl,Bacillus thuringiensis, andGambusia affinis on mosquitoes control in artificial breeding places.Methods:A Latin square design with 4 replicates was performed in order to evaluate the efficacy of chlorpyrifos-methyl,Bacillus thuringiensis, andGambusia affinis on larva. The larvicide was applied at the dosage of 100 mg a.h/ha,Bacillus thuringiensis at the recommended dosage and 10 fishes per m2 were applied at 1í1 m2 artificial breeding sites. The larval densities for both anopheline and culicine were counted according to larvae /10 dippers prior and 24 h after application.Results:All three control agents are effective for mosquito density reduction, and the difference between the three agents and the control is significant (P<0.05). There is also significant difference among chlorpyrifos-methyl,Bacillus thuringiensis andGambusia affinis.Bacillus thuringiensisexhibited more reduction on mosquito larval density than fish and larvicide (P<0.05).Conclusions:Bacillus thuringiensis in comparison with two other agents is the appropriate method for larviciding in the breeding places. Although long term assessing for biological activities as well as monitoring and mapping of resistance is required.

  9. Anaerobic Digestion. Student Manual. Biological Treatment Process Control.

    Science.gov (United States)

    Carnegie, John W., Ed.

    This student manual contains the textual material for a four-lesson unit on anaerobic digestion control. Areas addressed include: (1) anaerobic sludge digestion (considering the nature of raw sludge, purposes of anaerobic digestion, the results of digestion, types of equipment, and other topics); (2) digester process control (considering feeding…

  10. Biological control of wood decay against fungal infection.

    Science.gov (United States)

    Susi, Petri; Aktuganov, Gleb; Himanen, Juha; Korpela, Timo

    2011-07-01

    Wood (timber) is an important raw material for various purposes, and having biological composition it is susceptible to deterioration by various agents. The history of wood protection by impregnation with synthetic chemicals is almost two hundred years old. However, the ever-increasing public concern and the new environmental regulations on the use of chemicals have created the need for the development and the use of alternative methods for wood protection. Biological wood protection by antagonistic microbes alone or in combination with (bio)chemicals, is one of the most promising ways for the environmentally sound wood protection. The most effective biocontrol antagonists belong to genera Trichoderma, Gliocladium, Bacillus, Pseudomonas and Streptomyces. They compete for an ecological niche by consuming available nutrients as well as by secreting a spectrum of biochemicals effective against various fungal pathogens. The biochemicals include cell wall-degrading enzymes, siderophores, chelating iron and a wide variety of volatile and non-volatile antibiotics. In this review, the nature and the function of the antagonistic microbes in wood protection are discussed.

  11. Biological control of greenhouse whitefly (Trialeurodes vaporariorum) with fungal insecticides.

    Science.gov (United States)

    Siongers, C; Coosemans, J

    2003-01-01

    The influence of the biological insecticide Botanigard (Beauveria bassiana) on different developmental stages of the greenhouse whitefly (Trialeurodes vaporariorum) has been tested and compared with the influence of Preferal (Paecilomyces fumosoroseus), also a biological product. Six experiments were set up to test the two products on eggs, which were four and seven days old, on larvae of the first, second/third and fourth stage and to test the effect on egg-deposition. These experiments were all conducted on cucumber. Egg-deposition was limited to a small area on the leaf by using leaf cages. To evaluate these tests the number of eggs or larvae developed to the next stage has been counted and compared to the total amount of eggs or larvae on the leaves. The results revealed that Botanigard has an effect on the larval stages. The first larval stage is most sensitive; the next stages have a decreasing sensitivity. There was no influence on the hatching of the eggs, but a treatment short before the hatching could have a residual effect on the new nymphs. When the treatment with Botanigard is performed shortly before a moult or a fungicide treatment, the efficacy of the product decreases significantly. The influence of Preferal on the greenhouse whitefly is, under the same circumstances, less obvious.

  12. ABT-controllable laser hyperthermia of biological objects

    Science.gov (United States)

    Krotov, Eugene V.; Yakovlev, Ivan V.; Zhadobov, Maxim; Reyman, Alexander M.

    2002-05-01

    The results of experimentally investigated laser heating of optically absorbing inhomogeneities inside the biological objects accompanied with monitoring of internal temperature by acoustical brightness thermometry (ABT) have been presented. One of the urgent problems of modern medicine is to provide organism safety during photodynamic therapy of various neoplasms including malignant ones. In the case when neoplasm differs from normal tissue mainly in optical absorption it seems to be effective to use laser heating for this purpose. In our experiments we used the NIR emission of CW and pulse-periodic Nd:YAG lasers (1064 nm) as well as CW semiconductor laser (800 nm) for heating of tissue- simulating phantom. Optically transparent gelatine with absorbing inhomogeneity inside was used as a phantom. Internal temperature was measured non-invasively by means of multi-channel ABT after long heating of an object by laser radiation. Temperature was also measured independently by contact electronic thermometer. The results of experiments demonstrated high efficiency of ABT application for internal temperature monitoring during PDT and other hyperthermia procedures. Besides that laser radiation can be used for backlighting followed by ABT investigation of internal structure of temperature distribution inside biological tissues. This work was supported by Russian Foundation for Basic Research (Projects # 00-02-16600; 01-02-06417; 01-02- 17645) and 6th competition-expertise of young scientists of Russian Academy of Sciences (Project #399).

  13. Biologically-Plausible Reactive Control of Mobile Robots

    OpenAIRE

    Rene, Zapata; Pascal, Lepinay

    2006-01-01

    This chapter addressed the problem of controlling the reactive behaviours of a mobile robot evolving in unstructured and dynamic environments. We have carried out successful experiments for determining the distance field of a mobile robot using two

  14. IQGAP1 and its binding proteins control diverse biological functions.

    Science.gov (United States)

    White, Colin D; Erdemir, Huseyin H; Sacks, David B

    2012-04-01

    IQGAP proteins have been identified in a wide spectrum of organisms, ranging from yeast to humans. The most extensively studied family member is the ubiquitously expressed scaffold protein IQGAP1, which participates in multiple essential aspects of mammalian biology. IQGAP1 mediates these effects by binding to and regulating the function of numerous interacting proteins. Over ninety proteins have been reported to associate with IQGAP1, either directly or as part of a larger complex. In this review, we summarise those IQGAP1 binding partners that have been identified in the last five years. The molecular mechanisms by which these interactions contribute to the functions of receptors and their signalling cascades, small GTPase function, cytoskeletal dynamics, neuronal regulation and intracellular trafficking are evaluated. The evidence that has accumulated recently validates the role of IQGAP1 as a scaffold protein and expands the repertoire of cellular activities in which it participates.

  15. Marine biological controls on atmospheric CO2 and climate

    Science.gov (United States)

    Mcelroy, M. B.

    1983-01-01

    It is argued that the ocean is losing N gas faster than N is being returned to the ocean, and that replenishment of the N supply in the ocean usually occurs during ice ages. Available N from river and estruarine transport and from rainfall after formation by lightning are shown to be at a rate too low to compensate for the 10,000 yr oceanic lifetime of N. Ice sheets advance and transfer moraine N to the ocean, lower the sea levels, erode the ocean beds, promote greater biological productivity, and reduce CO2. Ice core samples have indicated a variability in the atmospheric N content that could be attributed to the ice age scenario.

  16. Prospects for the use of biological control agents against Anoplophora in Europe

    Science.gov (United States)

    This review summarises the literature on the biological control of Anoplophora spp. (Coleoptera: Cerambycidae) and discusses its potential for use in Europe. Entomopathogenic fungi: Beauveria brongniartii Petch (Hypocreales: Cordycipitaceae) has already been developed into a commercial product in Ja...

  17. Holarchical Systems and Emotional Holons : Biologically-Inspired System Designs for Control of Autonomous Aerial Vehicles

    Science.gov (United States)

    Ippolito, Corey; Plice, Laura; Pisanich, Greg

    2003-01-01

    The BEES (Bio-inspired Engineering for Exploration Systems) for Mars project at NASA Ames Research Center has the goal of developing bio-inspired flight control strategies to enable aerial explorers for Mars scientific investigations. This paper presents a summary of our ongoing research into biologically inspired system designs for control of unmanned autonomous aerial vehicle communities for Mars exploration. First, we present cooperative design considerations for robotic explorers based on the holarchical nature of biological systems and communities. Second, an outline of an architecture for cognitive decision making and control of individual robotic explorers is presented, modeled after the emotional nervous system of cognitive biological systems. Keywords: Holarchy, Biologically Inspired, Emotional UAV Flight Control

  18. Comparative evaluation of two populations of Pseudophilothrips ichini as candidates for biological control of Brazilian peppertree

    Science.gov (United States)

    Brazilian peppertree, Schinus terebinthifolius Raddi (Sapindales: Anacardiaceae) is one of the worst invasive species in Florida. The thrips Pseudophilothrips ichini Hood (Thysanoptera: Phlaeothripidae) is being considered as a potential biological control agent of Brazilian peppertree. Two populati...

  19. Early-season flood enhances native biological control agents in Wisconsin cranberry

    Science.gov (United States)

    Biological control is predicated on the concept that crop plants are protected when predators suppress herbivore populations. However, many factors, including concurrent crop protection strategies, may modify the effectiveness of a predator in a given agroecosystem. In Wisconsin commercial cranberry...

  20. Utilization of an introduced weed biological control agent by a native parasitoid

    Science.gov (United States)

    A native parasitoid, Kalopolynema ema (Schauff and Grissell) (Hymenoptera, Mymaridae), that usually parasitizes the eggs of Megamelus davisi VanDuzee (Hemiptera, Delphacidae), has begun utilizing a new host, Megamelus scutellaris (Berg) (Hemiptera, Delphacidae), the introduced biological control age...

  1. THE DAMAGE, BIOLOGY AND CONTROL OF PINE MISTLETOES (Viscum album ssp. austriacum (Wiesb.) Vollman)

    OpenAIRE

    Yüksel, Beşir; Akbulut, Süleyman; KETEN, Akif

    2009-01-01

    Although mistletoes are known as parasitic plants on coniferous forest of Turkey, their control is still an important problem for Forest Service. In this paper, the information on the characteristics of pine mistletoe (biology, damage, and control methods) were gathered from different sources and observations. Possible control methods and damage ratings of mistletoe were discussed. Keywords: Mistletoes, Parasite plant, Pine

  2. Biological control of banana black Sigatoka disease with Trichoderma

    Directory of Open Access Journals (Sweden)

    Poholl Adan Sagratzki Cavero

    2015-06-01

    Full Text Available Black Sigatoka disease caused by Mycosphaerella fijiensis is the most severe banana disease worldwide. The pathogen is in an invasive phase in Brazil and is already present in most States of the country. The potential of 29 isolates of Trichoderma spp. was studied for the control of black Sigatoka disease under field conditions. Four isolates were able to significantly reduce disease severity and were further tested in a second field experiment. Isolate 2.047 showed the best results in both field experiments and was selected for fungicide sensitivity tests and mass production. This isolate was identified as Trichoderma atroviride by sequencing fragments of the ITS region of the rDNA and tef-1α of the RNA polymerase. Trichoderma atroviride was as effective as the fungicide Azoxystrobin, which is recommended for controlling black Sigatoka. This biocontrol agent has potential to control the disease and may be scaled-up for field applications on rice-based solid fermentation

  3. Biological Control of Mosquito Vectors: Past, Present, and Future

    Science.gov (United States)

    Benelli, Giovanni; Jeffries, Claire L.; Walker, Thomas

    2016-01-01

    Mosquitoes represent the major arthropod vectors of human disease worldwide transmitting malaria, lymphatic filariasis, and arboviruses such as dengue virus and Zika virus. Unfortunately, no treatment (in the form of vaccines or drugs) is available for most of these diseases and vector control is still the main form of prevention. The limitations of traditional insecticide-based strategies, particularly the development of insecticide resistance, have resulted in significant efforts to develop alternative eco-friendly methods. Biocontrol strategies aim to be sustainable and target a range of different mosquito species to reduce the current reliance on insecticide-based mosquito control. In this review, we outline non-insecticide based strategies that have been implemented or are currently being tested. We also highlight the use of mosquito behavioural knowledge that can be exploited for control strategies. PMID:27706105

  4. Novel ESCRT functions in cell biology: spiraling out of control?

    Science.gov (United States)

    Campsteijn, Coen; Vietri, Marina; Stenmark, Harald

    2016-08-01

    The endosomal sorting complex required for transport (ESCRT), originally identified for its role in endosomal protein sorting and biogenesis of multivesicular endosomes (MVEs), has proven to be a versatile machinery for involution and scission of narrow membrane invaginations filled with cytosol. Budding of enveloped viruses and cytokinetic abscission were early described functions for the ESCRT machinery, and recently a number of new ESCRT functions have emerged. These include cytokinetic abscission checkpoint control, plasma membrane repair, exovesicle release, quality control of nuclear pore complexes, neuron pruning, and sealing of the newly formed nuclear envelope. Here we review these novel ESCRT mechanisms and discuss similarities and differences between the various ESCRT-dependent activities.

  5. Potential for widespread application of biological control of stored-product pests

    DEFF Research Database (Denmark)

    Hansen, Lise Stengaard

    2007-01-01

    Biological control of stored product pests has substantial potential in Europe". This is essentially the conclusion of the activities of a European working group funded by the COST system, an intergovernmental networking system. Working group 4 of COST action 842 (2000-2005) focussed on biological......, beetles and moths; (2) Preventative treatment of bulk commodities against weevils (Sitophilus spp.) and storage mites; (3) Preventative application of egg-parasitoids against moths in packaged products. Development of methods for biological control and of mass production of natural enemies...

  6. Anaerobic Digestion. Instructor's Guide. Biological Treatment Process Control.

    Science.gov (United States)

    Carnegie, John W., Ed.

    This instructor's guide contains materials needed to teach a four-lesson unit on anaerobic digestion control. These materials include: (1) unit overview; (2) lesson plans; (3) lecture outlines; (4) student worksheets for each lesson (with answers); and (5) two copies of a final quiz (with and without answers). Lesson 1 is a review of the theory of…

  7. Microbial control of the dark end of the biological pump.

    Science.gov (United States)

    Herndl, Gerhard J; Reinthaler, Thomas

    2013-09-01

    A fraction of the carbon captured by phytoplankton in the sunlit surface ocean sinks to depth as dead organic matter and faecal material. The microbial breakdown of this material in the subsurface ocean generates carbon dioxide. Collectively, this microbially mediated flux of carbon from the atmosphere to the ocean interior is termed the biological pump. In recent decades it has become clear that the composition of the phytoplankton community in the surface ocean largely determines the quantity and quality of organic matter that sinks to depth. This settling organic matter, however, is not sufficient to meet the energy demands of microbes in the dark ocean. Two additional sources of organic matter have been identified: non-sinking organic particles of debated origin that escape capture by sediment traps and exhibit stable concentrations throughout the dark ocean, and microbes that convert inorganic carbon into organic matter. Whether these two sources can together account for the significant mismatch between organic matter consumption and supply in the dark ocean remains to be seen. It is clear, however, that the microbial community of the deep ocean works in a fundamentally different way from surface water communities.

  8. Biological control of harmful algal blooms: A modelling study

    Science.gov (United States)

    Solé, Jordi; Estrada, Marta; Garcia-Ladona, Emilio

    2006-07-01

    A multispecies dynamic simulation model (ERSEM) was used to examine the influence of allelopathic and trophic interactions causing feeding avoidance by predators, on the formation of harmful algal blooms, under environmental scenarios typical of a Mediterranean harbour (Barcelona). The biological state variables of the model included four functional groups of phytoplankton (diatoms, toxic and non-toxic flagellates and picophytoplankton), heterotrophic flagellates, micro- and mesozooplankton and bacteria. The physical-chemical forcing (irradiance, temperature and major nutrient concentrations) was based on an actual series of measurements taken along a year cycle in the Barcelona harbour. In order to evaluate potential effects of advection, some runs were repeated after introducing a biomass loss term. Numerical simulations showed that allelopathic effects of a toxic alga on a non-toxic but otherwise similar competitor did not have appreciable influence on the dynamics of the system. However, induction of avoidance of the toxic alga by predators, which resulted on increased predation pressure on other algal groups had a significant effect on the development of algal and predator populations. The presence of advection overrided the effect of these interactions and only allowed organisms with sufficiently high potential growth rates to thrive.

  9. Allee effects in tritrophic food chains: some insights in pest biological control.

    Science.gov (United States)

    Costa, Michel Iskin da S; Dos Anjos, Lucas

    2016-12-01

    Release of natural enemies to control pest populations is a common strategy in biological control. However, its effectiveness is supposed to be impaired, among other factors, by Allee effects in the biological control agent and by the fact that introduced pest natural enemies interact with some native species of the ecosystem. In this work, we devise a tritrophic food chain model where the assumptions previously raised are proved correct when a hyperpredator attacks the introduced pest natural enemy by a functional response type 2 or 3. Moreover, success of pest control is shown to be related to the release of large amounts (i.e., inundative releases) of natural enemies.

  10. Differences in Kaposi sarcoma-associated herpesvirus-specific and herpesvirus-non-specific immune responses in classic Kaposi sarcoma cases and matched controls in Sicily.

    Science.gov (United States)

    Amodio, Emanuele; Goedert, James J; Barozzi, Patrizia; Riva, Giovanni; Firenze, Alberto; Bonura, Filippa; Viviano, Enza; Romano, Nino; Luppi, Mario

    2011-10-01

    Kaposi sarcoma (KS) might develop because of incompetent immune responses, both non-specifically and specifically against the KS-associated herpesvirus (KSHV). Peripheral blood mononuclear cells from 15 classic (non-AIDS) KS cases, 13 KSHV seropositives (without KS) and 15 KSHV-seronegative controls were tested for interferon-γ T-cell (enzyme-linked immunospot [Elispot]) responses to KSHV-latency-associated nuclear antigen (LANA), KSHV-K8.1 and CMV/Epstein-Barr virus (EBV) peptide pools. The forearm and thigh of each participant was also tested for delayed-type hypersensitivity (DTH) against common recall antigens. Groups were compared with Fisher exact test and multinomial logistic regression to calculate odds ratios (OR) and 95% confidence intervals (CI). A KSHV Elispot response was detected in 10 (67%) classic KS cases, 11 (85%) KSHV seropositives (without KS) and two (13%) seronegative controls. All four cases with KSHV-LANA responses had current KS lesions, whereas five of six cases with KSHV-K8.1 responses had no lesions (P = 0.048). No case responded to both LANA and K8.1. Compared with the seronegative controls, the risk for classic KS was inversely related to DTH in the thigh (OR 0.71, 95% CI 0.55-0.94, P = 0.01), directly associated with DTH in the forearm (OR 1.35, 95% CI 1.02-1.80, P = 0.04) and tended to be increased fivefold per KSHV Elispot response (OR 5.13, 95% CI 0.86-30.77, P = 0.07). Compared with KSHV seropositives (without KS), the risk for classic KS was reduced fivefold (OR 0.20, CI 0.03-0.77, P = 0.04) per KSHV response. The CMV/EBV Elispot responses were irrelevant. Deficiency of both KSHV-specific and KSHV-non-specific immunity is associated with classic KS. This might clarify why Kaposi sarcoma responds to immune reconstitution.

  11. Biological Control of Mosquito Vectors: Past, Present, and Future

    Directory of Open Access Journals (Sweden)

    Giovanni Benelli

    2016-10-01

    Full Text Available Mosquitoes represent the major arthropod vectors of human disease worldwide transmitting malaria, lymphatic filariasis, and arboviruses such as dengue virus and Zika virus. Unfortunately, no treatment (in the form of vaccines or drugs is available for most of these diseases andvectorcontrolisstillthemainformofprevention. Thelimitationsoftraditionalinsecticide-based strategies, particularly the development of insecticide resistance, have resulted in significant efforts to develop alternative eco-friendly methods. Biocontrol strategies aim to be sustainable and target a range of different mosquito species to reduce the current reliance on insecticide-based mosquito control. In thisreview, weoutline non-insecticide basedstrategiesthat havebeenimplemented orare currently being tested. We also highlight the use of mosquito behavioural knowledge that can be exploited for control strategies.

  12. Mechanization and Control Concepts for Biologically Inspired Micro Aerial Vehicles

    Science.gov (United States)

    Raney, David L.; Slominski, Eric C.

    2003-01-01

    It is possible that MAV designs of the future will exploit flapping flight in order to perform missions that require extreme agility, such as rapid flight beneath a forest canopy or within the confines of a building. Many of nature's most agile flyers generate flapping motions through resonant excitation of an aeroelastically tailored structure: muscle tissue is used to excite a vibratory mode of their flexible wing structure that creates propulsion and lift. A number of MAV concepts have been proposed that would operate in a similar fashion. This paper describes an ongoing research activity in which mechanization and control concepts with application to resonant flapping MAVs are being explored. Structural approaches, mechanical design, sensing and wingbeat control concepts inspired by hummingbirds, bats and insects are examined. Experimental results from a testbed capable of generating vibratory wingbeat patterns that approximately match those exhibited by hummingbirds in hover, cruise, and reverse flight are presented.

  13. Exploration for the Biological Control of Flowering Rush, Butomus umbellatus

    Science.gov (United States)

    2015-06-01

    aggressive invader of freshwater systems especially in the midwestern and western states of the USA and western Canada. Since no effective control...ovipositing females had been transferred. We are currently trying different methods in order to further improve rearing success. Nevertheless we were able...ten test plant species offered, none was accepted for egg laying by female weevils, confirming the narrow host range of B. nodulosus. We will continue

  14. The role and control of sludge age in biological nutrient removal activated sludge systems.

    Science.gov (United States)

    Ekama, G A

    2010-01-01

    The sludge age is the most fundamental and important parameter in the design, operation and control of biological nutrient removal (BNR) activated sludge (AS) systems. Generally, the better the effluent and waste sludge quality required from the system, the longer the sludge age, the larger the biological reactor and the more wastewater characteristics need to be known. Controlling the reactor concentration does not control sludge age, only the mass of sludge in the system. When nitrification is a requirement, sludge age control becomes a requirement and the secondary settling tanks can no longer serve the dual purpose of clarifier and waste activated sludge thickeners. The easiest and most practical way to control sludge age is with hydraulic control by wasting a defined proportion of the reactor volume daily. In AS plants with reactor concentration control, nitrification fails first. With hydraulic control of sludge age, nitrification will not fail, rather the plant fails by shedding solids over the secondary settling tank effluent weirs.

  15. Multi-objective evolutionary optimization of biological pest control with impulsive dynamics in soybean crops.

    Science.gov (United States)

    Cardoso, Rodrigo T N; da Cruz, André R; Wanner, Elizabeth F; Takahashi, Ricardo H C

    2009-08-01

    The biological pest control in agriculture, an environment-friendly practice, maintains the density of pests below an economic injury level by releasing a suitable quantity of their natural enemies. This work proposes a multi-objective numerical solution to biological pest control for soybean crops, considering both the cost of application of the control action and the cost of economic damages. The system model is nonlinear with impulsive control dynamics, in order to cope more effectively with the actual control action to be applied, which should be performed in a finite number of discrete time instants. The dynamic optimization problem is solved using the NSGA-II, a fast and trustworthy multi-objective genetic algorithm. The results suggest a dual pest control policy, in which the relative price of control action versus the associated additional harvest yield determines the usage of either a low control action strategy or a higher one.

  16. Controlling disease outbreaks in wildlife using limited culling: modelling classical swine fever incursions in wild pigs in Australia.

    Science.gov (United States)

    Cowled, Brendan D; Garner, M Graeme; Negus, Katherine; Ward, Michael P

    2012-01-16

    Disease modelling is one approach for providing new insights into wildlife disease epidemiology. This paper describes a spatio-temporal, stochastic, susceptible- exposed-infected-recovered process model that simulates the potential spread of classical swine fever through a documented, large and free living wild pig population following a simulated incursion. The study area (300 000 km2) was in northern Australia. Published data on wild pig ecology from Australia, and international Classical Swine Fever data was used to parameterise the model. Sensitivity analyses revealed that herd density (best estimate 1-3 pigs km-2), daily herd movement distances (best estimate approximately 1 km), probability of infection transmission between herds (best estimate 0.75) and disease related herd mortality (best estimate 42%) were highly influential on epidemic size but that extraordinary movements of pigs and the yearly home range size of a pig herd were not. CSF generally established (98% of simulations) following a single point introduction. CSF spread at approximately 9 km2 per day with low incidence rates (wild pig area). The low incidence rate indicates that surveillance for wildlife disease epidemics caused by short lived infections will be most efficient when surveillance is based on detection and investigation of clinical events, although this may not always be practical. Epidemics could be contained and eradicated with culling (aerial shooting) or vaccination when these were adequately implemented. It was apparent that the spatial structure, ecology and behaviour of wild populations must be accounted for during disease management in wildlife. An important finding was that it may only be necessary to cull or vaccinate relatively small proportions of a population to successfully contain and eradicate some wildlife disease epidemics.

  17. Laboratory Study on Biological Control of Ticks (Acari: Ixodidae) by Entomopathogenic Indigenous Fungi (Beauveria bassiana)

    OpenAIRE

    M Abdigoudarzi; Esmaeilnia, K; Shariat, N

    2009-01-01

    Background: Chemical control method using different acaricides as spray, dipping solution or pour-on is routinely used for controlling ticks. Biological control agents are favorable due to their safety for animals and environment. Entomopathogenic fungi such as Beauveria bassiana are well known for controlling ticks. In this study, two Iranian indigenous strains of B. bassiana (B. bassiana 5197 and B. bassiana Evin) were selected and grown on specific me­dia. The pathogenic effects of the...

  18. Investigating Biological Control Agents for Controlling Invasive Populations of the Mealybug Pseudococcus comstocki in France

    Science.gov (United States)

    Malausa, Thibaut; Delaunay, Mathilde; Fleisch, Alexandre; Groussier-Bout, Géraldine; Warot, Sylvie; Crochard, Didier; Guerrieri, Emilio; Delvare, Gérard; Pellizzari, Giuseppina; Kaydan, M. Bora; Al-Khateeb, Nadia; Germain, Jean-François; Brancaccio, Lisa; Le Goff, Isabelle; Bessac, Melissa; Ris, Nicolas; Kreiter, Philippe

    2016-01-01

    Pseudococcus comstocki (Hemiptera: Pseudococcidae) is a mealybug species native to Eastern Asia and present as an invasive pest in northern Italy and southern France since the start of the century. It infests apple and pear trees, grapevines and some ornamental trees. Biocontrol programmes against this pest proved successful in central Asia and North America in the second half of the 20th century. In this study, we investigated possible biocontrol agents against P. comstocki, with the aim of developing a biocontrol programme in France. We carried out systematic DNA-barcoding at each step in the search for a specialist parasitoid. First we characterised the French target populations of P. comstocki. We then identified the parasitoids attacking P. comstocki in France. Finally, we searched for foreign mealybug populations identified a priori as P. comstocki and surveyed their hymenopteran parasitoids. Three mealybug species (P. comstocki, P. viburni and P. cryptus) were identified during the survey, together with at least 16 different parasitoid taxa. We selected candidate biological control agent populations for use against P. comstocki in France, from the species Allotropa burrelli (Hymenoptera: Platygastridae) and Acerophagus malinus (Hymenoptera: Encyrtidae). The coupling of molecular and morphological characterisation for both pests and natural enemies facilitated the programme development and the rejection of unsuitable or generalist parasitoids. PMID:27362639

  19. Investigating Biological Control Agents for Controlling Invasive Populations of the Mealybug Pseudococcus comstocki in France.

    Directory of Open Access Journals (Sweden)

    Thibaut Malausa

    Full Text Available Pseudococcus comstocki (Hemiptera: Pseudococcidae is a mealybug species native to Eastern Asia and present as an invasive pest in northern Italy and southern France since the start of the century. It infests apple and pear trees, grapevines and some ornamental trees. Biocontrol programmes against this pest proved successful in central Asia and North America in the second half of the 20th century. In this study, we investigated possible biocontrol agents against P. comstocki, with the aim of developing a biocontrol programme in France. We carried out systematic DNA-barcoding at each step in the search for a specialist parasitoid. First we characterised the French target populations of P. comstocki. We then identified the parasitoids attacking P. comstocki in France. Finally, we searched for foreign mealybug populations identified a priori as P. comstocki and surveyed their hymenopteran parasitoids. Three mealybug species (P. comstocki, P. viburni and P. cryptus were identified during the survey, together with at least 16 different parasitoid taxa. We selected candidate biological control agent populations for use against P. comstocki in France, from the species Allotropa burrelli (Hymenoptera: Platygastridae and Acerophagus malinus (Hymenoptera: Encyrtidae. The coupling of molecular and morphological characterisation for both pests and natural enemies facilitated the programme development and the rejection of unsuitable or generalist parasitoids.

  20. Agricultural biological reference materials for analytical quality control

    Energy Technology Data Exchange (ETDEWEB)

    Ihnat, M.

    1986-01-01

    Cooperative work is under way at Agriculture Canada, US Department of Agriculture, and US National Bureau of Standards in an attempt to fill some of the gaps in the world repertoire of reference materials and to provide much needed control materials for laboratories' day to day operations. This undertaking involves the preparation and characterization of a number of agricultural and food materials for data quality control for inorganic constituents. Parameters considered in the development of these materials were material selection based on importance in commerce and analysis; techniques of preparation, processing, and packaging; physical and chemical characterization; homogeneity testing and quantitation (certification). A large number of agricultural/food products have been selected to represent a wide range of not only levels of sought-for constituents (elements) but also a wide range of matrix components such as protein, carbohydrate, dietary fiber, fat, and ash. Elements whose concentrations are being certified cover some two dozen major, minor, and trace elements of nutritional, toxicological, and environmental significance.

  1. Identification of Bacillus strains for biological control of catfish pathogens.

    Science.gov (United States)

    Ran, Chao; Carrias, Abel; Williams, Malachi A; Capps, Nancy; Dan, Bui C T; Newton, Joseph C; Kloepper, Joseph W; Ooi, Ei L; Browdy, Craig L; Terhune, Jeffery S; Liles, Mark R

    2012-01-01

    Bacillus strains isolated from soil or channel catfish intestine were screened for their antagonism against Edwardsiella ictaluri and Aeromonas hydrophila, the causative agents of enteric septicemia of catfish (ESC) and motile aeromonad septicaemia (MAS), respectively. Twenty one strains were selected and their antagonistic activity against other aquatic pathogens was also tested. Each of the top 21 strains expressed antagonistic activity against multiple aquatic bacterial pathogens including Edwardsiella tarda, Streptococcus iniae, Yersinia ruckeri, Flavobacterium columnare, and/or the oomycete Saprolegnia ferax. Survival of the 21 Bacillus strains in the intestine of catfish was determined as Bacillus CFU/g of intestinal tissue of catfish after feeding Bacillus spore-supplemented feed for seven days followed by normal feed for three days. Five Bacillus strains that showed good antimicrobial activity and intestinal survival were incorporated into feed in spore form at a dose of 8×10(7) CFU/g and fed to channel catfish for 14 days before they were challenged by E. ictaluri in replicate. Two Bacillus subtilis strains conferred significant benefit in reducing catfish mortality (Pbiological control in vivo was also investigated in terms of whether the strains contain plasmids or express resistance to clinically important antibiotics. The Bacillus strains identified from this study have good potential to mediate disease control as probiotic feed additives for catfish aquaculture.

  2. Predator interference effects on biological control: The "paradox" of the generalist predator revisited

    Science.gov (United States)

    Parshad, Rana D.; Bhowmick, Suman; Quansah, Emmanuel; Basheer, Aladeen; Upadhyay, Ranjit Kumar

    2016-10-01

    An interesting conundrum in biological control questions the efficiency of generalist predators as biological control agents. Theory suggests, generalist predators are poor agents for biological control, primarily due to mutual interference. However field evidence shows they are actually quite effective in regulating pest densities. In this work we provide a plausible answer to this paradox. We analyze a three species model, where a generalist top predator is introduced into an ecosystem as a biological control, to check the population of a middle predator, that in turn is depredating on a prey species. We show that the inclusion of predator interference alone, can cause the solution of the top predator equation to blow-up in finite time, while there is global existence in the no interference case. This result shows that interference could actually cause a population explosion of the top predator, enabling it to control the target species, thus corroborating recent field evidence. Our results might also partially explain the population explosion of certain species, introduced originally for biological control purposes, such as the cane toad (Bufo marinus) in Australia, which now functions as a generalist top predator. We also show both Turing instability and spatio-temporal chaos in the model. Lastly we investigate time delay effects.

  3. Control biológico del entrenamiento de resistencia. Biological control of endurance training.

    Directory of Open Access Journals (Sweden)

    González Gross, Marcela

    2006-01-01

    Full Text Available ResumenLa alta exigencia en los deportistas de elite hace cada vez más necesario controlar el proceso de adaptación al entrenamiento. El objetivo de esta revisión es analizar la información biológica de un análisis de sangre, al objeto de obtener información de la carga de entrenamiento en atletas de resistencia. La mayor parte de los parámetros sanguíneos han sido empleados, más que para determinar el proceso del entrenamiento, precisamente, para lo opuesto: el sobreentrenamiento. La concentración en plasma de sustratos metabólicos (glucosa y ácidos grasos no son parámetros que pueda utilizarse para controlar el entrenamiento, debido a las bajas especificidad y sensibilidad. No obstante, la concentración de determinados enzimas que intervienen en la utilización de los sustratos puede ser importante. Valores de creatín kinasa superiores a 200 U/l en una persona sana sugiere claramente que la carga de entrenamiento total de una determinada sesión ha sido elevada. La concentración en plasma de algún producto de degradación del catabolismo también puede señalar la adaptación del organismo al entrenamiento. La concentración de ácido láctico en plasma es la herramienta más común en la valoración de la carga de entrenamiento. La concentración de urea es un buen marcador biológico de la carga de entrenamiento. Valores superiores a 8 mmol/l en varones y de 6,5 mmol/l en mujeres, indican que el entrenamiento ha sido muy intenso. La determinación de otros productos (amonio o sustratos (glutamina se han utilizado para detectar el sobreentrenamiento.AbstractThe high exigency in the elite sportsmen does more necessary to control the process of training adaptation. The purpose of this review is to analyze the biological information of a blood analysis to obtain data of load training in endurance athletes. Most blood parameters has been used to evaluate the overtraining state instead of determining the training process. The

  4. Compatible biological and chemical control systems for Rhizoctonia solani in potato

    NARCIS (Netherlands)

    Boogert, van den P.H.J.F.; Luttikholt, A.J.G.

    2004-01-01

    A series of chemical and biological control agents were tested for compatibility with the Rhizoctonia-specific biocontrol fungus Verticillium biguttatum aimed at designing novel control strategies for black scurf (Rhizoctonia solani) and other tuber diseases in potato. The efficacy of chemicals, alo

  5. Candidate predators for biological control of the poultry red mite Dermanyssus gallinae

    NARCIS (Netherlands)

    Lesna, Izabela; Wolfs, Peter; Faraji, Farid; Roy, Lise; Komdeur, Jan; Sabelis, Maurice W.

    2009-01-01

    The poultry red mite, Dermanyssus gallinae, is currently a significant pest in the poultry industry in Europe. Biological control by the introduction of predatory mites is one of the various options for controlling poultry red mites. Here, we present the first results of an attempt to identify poten

  6. Controlled light field concentration through turbid biological membrane for phototherapy.

    Science.gov (United States)

    Wang, Fujuan; He, Hexiang; Zhuang, Huichang; Xie, Xiangsheng; Yang, Zhenchong; Cai, Zhigang; Gu, Huaiyu; Zhou, Jianying

    2015-06-01

    Laser propagation through a turbid rat dura mater membrane is shown to be controllable with a wavefront modulation technique. The scattered light field can be refocused into a target area behind the rat dura mater membrane with a 110 times intensity enhancement using a spatial light modulator. The efficient laser intensity concentration system is demonstrated to imitate the phototherapy for human brain tumors. The power density in the target area is enhanced more than 200 times compared with the input power density on the dura mater membrane, thus allowing continued irradiation concentration to the deep lesion without damage to the dura mater. Multibeam inputs along different directions, or at different positions, can be guided to focus to the same spot behind the membrane, hence providing a similar gamma knife function in optical spectral range. Moreover, both the polarization and the phase of the input field can be recovered in the target area, allowing coherent field superposition in comparison with the linear intensity superposition for the gamma knife.

  7. Zika virus: History, emergence, biology, and prospects for control.

    Science.gov (United States)

    Weaver, Scott C; Costa, Federico; Garcia-Blanco, Mariano A; Ko, Albert I; Ribeiro, Guilherme S; Saade, George; Shi, Pei-Yong; Vasilakis, Nikos

    2016-06-01

    Zika virus (ZIKV), a previously obscure flavivirus closely related to dengue, West Nile, Japanese encephalitis and yellow fever viruses, has emerged explosively since 2007 to cause a series of epidemics in Micronesia, the South Pacific, and most recently the Americas. After its putative evolution in sub-Saharan Africa, ZIKV spread in the distant past to Asia and has probably emerged on multiple occasions into urban transmission cycles involving Aedes (Stegomyia) spp. mosquitoes and human amplification hosts, accompanied by a relatively mild dengue-like illness. The unprecedented numbers of people infected during recent outbreaks in the South Pacific and the Americas may have resulted in enough ZIKV infections to notice relatively rare congenital microcephaly and Guillain-Barré syndromes. Another hypothesis is that phenotypic changes in Asian lineage ZIKV strains led to these disease outcomes. Here, we review potential strategies to control the ongoing outbreak through vector-centric approaches as well as the prospects for the development of vaccines and therapeutics.

  8. Cyprinid herpesvirus 3 and its evolutionary future as a biological control agent for carp in Australia

    OpenAIRE

    Kenneth A. McColl; Sunarto, Agus; Holmes, Edward C.

    2016-01-01

    Biological invasions are a major threat to global biodiversity. Australia has experienced many invasive species, with the common carp (Cyprinus carpio L.) a prominent example. Cyprinid herpesvirus 3 (CyHV-3) has been proposed as a biological control (biocontrol) agent for invasive carp in Australia. Safety and efficacy are critical factors in assessing the suitability of biocontrol agents, and extensive host-specificity testing suggests that CyHV-3 is safe. Efficacy depends on the relationshi...

  9. Biological control of invasive Dryocosmus kuriphilus with introduced parasitoid Torymus sinensis in Croatia, Slovenia and Hungary

    OpenAIRE

    2016-01-01

    Background and purpose: Dryocosmus kuriphilus is considered as one of the major pests of sweet chestnut and the effective method of controlling its populations and damage is the biological control with its introduced parasitoid Torymus sinensis. T. sinensis is a univoltine, host specific parasitoid, phenologically synchronized and morphologically adapted to D. kuriphilus. It has a good dispersal ability, it builds up populations quickly and it effectively controls the pest already few years a...

  10. Natural biological control of pest mites in Brazilian sun coffee agroecosystems.

    Science.gov (United States)

    Teodoro, Adenir V; Sarmento, Renato A; Rêgo, Adriano S; da Graça S Maciel, Anilde

    2010-06-01

    Coffee is one of the leading commodities in tropical America. Although plantations are usually established under a canopy of trees in most producing countries in the region, Brazilian coffee is mostly produced under full sun conditions. Such simple, single-crop agroecosystems with intensive agrochemical inputs often suffer with pests like mites. Predatory mites of the family Phytoseiidae are the main natural enemies associated with pest mites in the field. However, these beneficial arthropods struggle to survive in intensive agroecosystems such as coffee monocultures due to unfavorable microclimatic conditions, widespread pesticide use, and lack of alternative food (pollen, nectar). Conservation biological control uses a range of management strategies to sustain and enhance populations of indigenous natural enemies such as predatory mites. We discuss here conservation biological control as a strategy to improve biological control of pest mites by native predatory mites in Brazilian coffee monocultures as well as some related patents.

  11. Global stability and optimisation of a general impulsive biological control model

    CERN Document Server

    Mailleret, Ludovic

    2008-01-01

    An impulsive model of augmentative biological control consisting of a general continuous predator-prey model in ordinary differential equations augmented by a discrete part describing periodic introductions of predators is considered. It is shown that there exists an invariant periodic solution that corresponds to prey eradication and a condition ensuring its global asymptotic stability is given. An optimisation problem related to the preemptive use of augmentative biological control is then considered. It is assumed that the per time unit budget of biological control (i.e. the number of predators to be released) is fixed and the best deployment of this budget is sought after in terms of release frequency. The cost function to be minimised is the time taken to reduce an unforeseen prey (pest) invasion under some harmless level. The analysis shows that the optimisation problem admits a countable infinite number of solutions. An argumentation considering the required robustness of the optimisation result is the...

  12. Comparison of methods for controlling dental caries in the classical medicine and alternative medical practices and future prospects

    Directory of Open Access Journals (Sweden)

    Rabbani Khorasgani Mohammad

    2015-07-01

    Full Text Available Dental caries is a multi-factorial disease and the most common human infection that annually are spent millions dollars to control and treat it. Several methods have been proposed so far to control it. The most important control methods it is now include : dental hygiene, proper nutrition , fluoride therapy , the use of non- cariogenic sweeteners . Also, the use of probiotics , nanomaterials , bacteriophages , antimicrobial peptides and anti- caries vaccines can be considered as new perspective of human in the dental caries control field. In addition, the use of complementary and alternative therapies , especially herbal drug therapy recently has been considered . Demonstrating the efficacy of complementary medicine against dental caries and its use in combination with conventional medicine or trial of new methods for decline of dental caries in the future would be hopeful.

  13. Design of a nanomechanical fluid control valve based on functionalized silicon cantilevers: coupling molecular mechanics with classical engineering design

    OpenAIRE

    Santiago D. Solares; Blanco, Mario; Goddard, William A.

    2004-01-01

    Process engineering design relies on a host of mechanical devices that enable transport phenomena to take place under controlled conditions. These devices include pipes, valves, pumps, chemical reactors, heat exchangers, packed columns, etc. Mass, energy, and momentum transfer will also be essential phenomena in nanoprocess engineering, particularly at the interface between micro- and nanodevices. Control valves are one of the most fundamental components. In this paper we explore the design o...

  14. Biological control of invasive plant species: a reassessment for the Anthropocene.

    Science.gov (United States)

    Seastedt, Timothy R

    2015-01-01

    The science of finding, testing and releasing herbivores and pathogens to control invasive plant species has achieved a level of maturity and success that argues for continued and expanded use of this program. The practice, however, remains unpopular with some conservationists, invasion biologists, and stakeholders. The ecological and economic benefits of controlling densities of problematic plant species using biological control agents can be quantified, but the risks and net benefits of biological control programs are often derived from social or cultural rather than scientific criteria. Management of invasive plants is a 'wicked problem', and local outcomes to wicked problems have both positive and negative consequences differentially affecting various groups of stakeholders. The program has inherent uncertainties; inserting species into communities that are experiencing directional or even transformational changes can produce multiple outcomes due to context-specific factors that are further confounded by environmental change drivers. Despite these uncertainties, biological control could play a larger role in mitigation and adaptation strategies used to maintain biological diversity as well as contribute to human well-being by protecting food and fiber resources.

  15. The inception and evolution of a unique masters program in cancer biology, prevention and control.

    Science.gov (United States)

    Cousin, Carolyn; Blancato, Jan

    2010-09-01

    The University of the District of Columbia (UDC) and the Lombardi Comprehensive Cancer Center (LCCC), Georgetown University Medical Center established a Masters Degree Program in Cancer Biology, Prevention and Control at UDC that is jointly administered and taught by UDC and LCCC faculty. The goal of the Masters Degree Program is to educate students as master-level cancer professionals capable of conducting research and service in cancer biology, prevention, and control or to further advance the education of students to pursue doctoral studies. The Program's unique nature is reflected in its philosophy "the best cancer prevention and control researchers are those with a sound understanding of cancer biology". This program is a full-time, 2-year, 36-credit degree in which students take half of their coursework at UDC and half of their coursework at LCCC. During the second year, students are required to conduct research either at LCCC or UDC. Unlike most cancer biology programs, this unique Program emphasizes both cancer biology and cancer outreach training.

  16. The role of evolutionary biology in research and control of liver flukes in Southeast Asia.

    Science.gov (United States)

    Echaubard, Pierre; Sripa, Banchob; Mallory, Frank F; Wilcox, Bruce A

    2016-09-01

    Stimulated largely by the availability of new technology, biomedical research at the molecular-level and chemical-based control approaches arguably dominate the field of infectious diseases. Along with this, the proximate view of disease etiology predominates to the exclusion of the ultimate, evolutionary biology-based, causation perspective. Yet, historically and up to today, research in evolutionary biology has provided much of the foundation for understanding the mechanisms underlying disease transmission dynamics, virulence, and the design of effective integrated control strategies. Here we review the state of knowledge regarding the biology of Asian liver Fluke-host relationship, parasitology, phylodynamics, drug-based interventions and liver Fluke-related cancer etiology from an evolutionary biology perspective. We consider how evolutionary principles, mechanisms and research methods could help refine our understanding of clinical disease associated with infection by Liver Flukes as well as their transmission dynamics. We identify a series of questions for an evolutionary biology research agenda for the liver Fluke that should contribute to an increased understanding of liver Fluke-associated diseases. Finally, we describe an integrative evolutionary medicine approach to liver Fluke prevention and control highlighting the need to better contextualize interventions within a broader human health and sustainable development framework.

  17. Enhancement of biological control agents for use against forest insect pests and diseases through biotechnology

    Science.gov (United States)

    Slavicek, James M.

    1991-01-01

    Research and development efforts in our research group are focused on the generation of more efficacious biological control agents through the techniques of biotechnology for use against forest insect pests and diseases. Effective biological controls for the gypsy moth and for tree fungal wilt pathogens are under development. The successful use of Gypchek, a formulation of the Lymantria dispar nuclear polyhedrosis virus (LdNPV), in gypsy moth control programs has generated considerable interest in that agent. As a consequence of its specificity, LdPNV has negligible adverse ecological impacts compared to most gypsy moth control agents. However, LdNPV is not competitive with other control agents in terms of cost and efficacy. We are investigating several parameters of LdNPV replication and polyhedra production in order to enhance viral potency and efficacy thus mitigating the current disadvantages of LdNPV for gypsy moth control, and have identified LdNPV variants that will facilitate these efforts. Tree endophytic bacteria that synthesize antifungal compounds were identified and an antibiotic compound from one of these bacteria was characterized. The feasibility of developing tree endophytes as biological control agents for tree vascular fungal pathogens is being investigated.

  18. Understanding the biology and control of the poultry red mite Dermanyssus gallinae: a review.

    Science.gov (United States)

    Pritchard, James; Kuster, Tatiana; Sparagano, Olivier; Tomley, Fiona

    2015-01-01

    Dermanyssus gallinae, the poultry red mite (PRM), is a blood-feeding ectoparasite capable of causing pathology in birds, amongst other animals. It is an increasingly important pathogen in egg layers and is responsible for substantial economic losses to the poultry industry worldwide. Even though PRM poses a serious problem, very little is known about the basic biology of the mite. Here we review the current body of literature describing red mite biology and discuss how this has been, or could be, used to develop methods to control PRM infestations. We focus primarily on the PRM digestive system, salivary glands, nervous system and exoskeleton and also explore areas of PRM biology which have to date received little or no study but have the potential to offer new control targets.

  19. The use of a microcomputer system as an aid to classical and digital control system design and analysis.

    OpenAIRE

    Humphrey, John Douglas

    1983-01-01

    Approved for public release; distribution is unlimited This thesis takes five FORTRAN IV programs from "Computer Programs for Computational Assistance in the Study of Linear Control Theory" by Melsa and Jones and translates them into a microcomputer BASIC language to run on an inexpensive microcomputer system. Three of the five programs are state variable programs. They are BASMAT for basic matrix manipulation, RTRESP for rational time response, and GTRESP for graphica...

  20. Polynomial-Time Algorithm for Controllability Test of a Class of Boolean Biological Networks

    Directory of Open Access Journals (Sweden)

    Koichi Kobayashi

    2010-01-01

    Full Text Available In recent years, Boolean-network-model-based approaches to dynamical analysis of complex biological networks such as gene regulatory networks have been extensively studied. One of the fundamental problems in control theory of such networks is the problem of determining whether a given substance quantity can be arbitrarily controlled by operating the other substance quantities, which we call the controllability problem. This paper proposes a polynomial-time algorithm for solving this problem. Although the algorithm is based on a sufficient condition for controllability, it is easily computable for a wider class of large-scale biological networks compared with the existing approaches. A key to this success in our approach is to give up computing Boolean operations in a rigorous way and to exploit an adjacency matrix of a directed graph induced by a Boolean network. By applying the proposed approach to a neurotransmitter signaling pathway, it is shown that it is effective.

  1. Flower power? Potential benefits and pitfalls of using (flowering) vegetation for conservation biological control

    NARCIS (Netherlands)

    Wackers, F.L.; Rijn, van P.C.J.; Winkler, K.; Olson, D.

    2006-01-01

    Whereas nectar and pollen provision to predators and parasitoids is a main objective in pursuing agricultural biodiversity, we often know little about whether the flowering plant species involved are actually suitable as insect food sources or about their ultimate impact on biological pest control.

  2. Acquired natural enemies of the weed biological control agent Oxyops vitiosa (Coleoptera: Curculionidae)

    Science.gov (United States)

    The Australian curculionid Oxyops vitiosa Pascoe was introduced into Florida during 1997 as a biological control agent of the invasive tree Melaleuca quinquenervia (Cav.) S.T. Blake. Populations of the weevil increased rapidly and became widely distributed throughout much of the invasive tree’s adve...

  3. Biological control of tropical soda apple (Solanaceae) in Florida: Post-release evaluation

    Science.gov (United States)

    The leaf feeding beetle Gratiana boliviana Spaeth (Coleoptera: Chrysomelidae) was released as a biological control agent against tropical soda apple (TSA) (Solanum viarum Dunal (Solanaceae)) in Sumter County, FL in 2006. Evaluation of beetle feeding damage to TSA plants and changes in the beetle po...

  4. Preliminary study on three pathogens with potential biological control in Barnyard grass (Echinochloa crus galli)

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    @@ More than 10 species of pathogenic fungi were isolated from the naturally infected leaves of barnyard grass (Echinochloa crus-galli) in paddy. After preliminary bioassaying, it was found that the Alternaria alternata (Fr.) keissler(AA), Exserohilum monoceras (EM),and "99-10" were three potential agents for biological control of barnyard grass.

  5. Erroneous host identification frustrates systematics and delays implementation of biological control

    NARCIS (Netherlands)

    Bin, F.; Roversi, P.F.; Lenteren, van J.C.

    2012-01-01

    Misidentifications of pests and their natural enemies and misinterpretations of pest-natural enemy associations have led to the failure of a number of biological control projects. In addition to misidentification, more complicated kinds of errors, such as mistakes in establishing host records of par

  6. Host range of the inadvertent biological control agent Caloptilia triadicae: an invasive herbivore of Chinese tallowtree

    Science.gov (United States)

    An inadvertent biological control agent of the invasive weed Chinese tallowtree (Triadica sebifera) first appeared in North America in 2004. Identified as a Caloptilia triadicae, this leaf miner was found damaging T. sebifera saplings. In Gainesville, FL we exposed naturalized populations of C. tria...

  7. Evolutionary interactions between the invasive tallow tree and herbivores: implications for biological control

    Science.gov (United States)

    Understanding interactions between insect agents and host plants is critical for forecasting their impact before the insects are introduced, and for improving our knowledge of the mechanisms driving success or failure in biological weed control. As invasive plants may undergo rapid adaptive evolutio...

  8. Biological control of whitefly on greenhouse tomato in Colombia: Encarsia formosa or Amitus fuscipennis?

    NARCIS (Netherlands)

    Vis, de R.J.

    2001-01-01

    In Colombia, biological control of pests in greenhouse crops is only applied on a very limited scale in ornamentals and as yet non-existent in greenhouse vegetables. Greenhouse production of vegetables - mostly tomatoes- is a recent development, as a result of the high losses of field production due

  9. Agronomic aspects of strip intercropping lettuce with alyssum for biological control of aphids

    Science.gov (United States)

    Organic growers in California typically devote 5 to 10% of the area in lettuce (Lactuca sativa L.) fields to insectary strips of alyssum (Lobularia maritime (L.) Desv.) to attract syrphid flies (Syrphidae) whose larvae provide biological control of aphids. A 2-year study with organic romaine lettuc...

  10. Grape Berry Colonization and Biological Control of Botrytis cinerea by Indigenous Vineyard Yeasts

    Science.gov (United States)

    Botrytis bunch rot, caused by Botrytis cinerea, is the most important disease of grape berries, especially during transportation and storage. Biological control is a potential means of postharvest management of Botrytis bunch rot. The study was aimed at testing the hypothesis that antagonistic yeast...

  11. Evaluation of Puccinia carduorum for biological control of Carduus pycnocephalus in Tunisia

    Science.gov (United States)

    The rust fungus Puccinia carduorum is a candidate for biological control of Carduus pycnocephalus in the USA. In Tunisia, rusted C. pycnocephalus has been found in many fields during surveys conducted in the north of the country. The pathogenicity of Puccinia carduorum was evaluated under greenhou...

  12. Integration of biological control and transgenic insect protection for mitigation of mycotoxins in corn

    Science.gov (United States)

    Biological control is known to be effective in reducing aflatoxin contamination of corn and some transgenic corn hybrids incur greatly reduced damage from corn earworm (Helicoverpa zea). We conducted seven field trials over two years to test the hypothesis that transgenic insect protection and biol...

  13. Biological Control of Olive Fruit Fly in California with a Parasitoid Imported from Guatemala

    Science.gov (United States)

    The parasitoid, Psyttalia cf. concolor (Szépligeti), was imported into California from the USDA-APHIS-PPQ, Moscamed, San Miguel Petapa, Guatemala for biological control of olive fruit fly, Bactrocera oleae (Gmelin), in olives, Olea europaea L. The parasitoid did not develop in the seedhead fly, Cha...

  14. Ex-ante analysis of economic returns from biological control of coconut mite in Tanzania

    NARCIS (Netherlands)

    Oleke, J.M.; Manyong, V.; Mignouna, D.; Isinika, A.; Mutabazi, K.; Hanna, R.; Sabelis, M.

    2013-01-01

    The coconut mite, Aceria guerreronis Keifer, has been identified as one of the pests that pose a threat to the coconut industry in Benin. The study presents the simulation results of the economic benefits of the biological control of coconut mites in Benin using a standard economic surplus model. In

  15. Evaluation of Amitus fuscipennis as biological control agent of Trialeurodes vaporariorum on bean in Colombia

    NARCIS (Netherlands)

    Manzano Martinez, M.R.

    2000-01-01

    The research described in this thesis concerns the study of a natural enemy of whiteflies, Amitus fuscipennis MacGown & Nebeker under Colombian field and laboratory conditions. The general aim of the project was to study whether biological control of Trialeurodes vaporariorum (Westwood) with A. fusc

  16. Biological control of pests and insects. (Latest citations from the NTIS bibliographic database). Published Search

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-04-01

    The bibliography contains citations concerning the use of biological agents to control insects and pests. Radiation, genetic breeding, bacteria, fungi, viruses, and pheromones are discussed as alternatives to pesticidal management. Methods for monitoring the effectiveness and environmental impact of these agents are reviewed. Population control of fruit flies, spruce sawflies, flies, mosquitoes, cockroaches, gypsy moths, and other agriculturally-important insects is also discussed. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  17. Biological control of pests and insects. (Latest citations from the NTIS bibliographic database). Published Search

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-02-01

    The bibliography contains citations concerning the use of biological agents to control insects and pests. Radiation, genetic breeding, bacteria, fungi, viruses, and pheromones are discussed as alternatives to pesticidal management. Methods for monitoring the effectiveness and environmental impact of these agents are reviewed. Population control of fruit flies, spruce sawflies, flies, mosquitoes, cockroaches, gypsy moths, and other agriculturally-important insects is also discussed. (Contains a minimum of 190 citations and includes a subject term index and title list.)

  18. Integrated Pest Management of Aphis spiraecola (Hemiptera: Aphididae) in clementines: enhancing its biological control

    OpenAIRE

    GOMEZ MARCO, FRANCESC

    2016-01-01

    [EN] Aphis spiraecola Patch. (Hemiptera: Aphididae) is a key pest of clementines. Biological control of A. spiraecola is still poorly known and efforts were based on the use and conservation of parasitoids but it did not success. With all this said, the aims of this thesis were: i) to disentangle the reasons behind the low parasitism of A. spiraecola; ii) to determine when and how predators can control A. spiraecola populations; and, finally, iii) to evaluate whether a ground cover of Poaceae...

  19. Do biological-based strategies hold promise to biofouling control in MBRs?

    KAUST Repository

    Malaeb, Lilian

    2013-10-01

    Biofouling in membrane bioreactors (MBRs) remains a primary challenge for their wider application, despite the growing acceptance of MBRs worldwide. Research studies on membrane fouling are extensive in the literature, with more than 200 publications on MBR fouling in the last 3 years; yet, improvements in practice on biofouling control and management have been remarkably slow. Commonly applied cleaning methods are only partially effective and membrane replacement often becomes frequent. The reason for the slow advancement in successful control of biofouling is largely attributed to the complex interactions of involved biological compounds and the lack of representative-for-practice experimental approaches to evaluate potential effective control strategies. Biofouling is driven by microorganisms and their associated extra-cellular polymeric substances (EPS) and microbial products. Microorganisms and their products convene together to form matrices that are commonly treated as a black box in conventional control approaches. Biological-based antifouling strategies seem to be a promising constituent of an effective integrated control approach since they target the essence of biofouling problems. However, biological-based strategies are in their developmental phase and several questions should be addressed to set a roadmap for translating existing and new information into sustainable and effective control techniques. This paper investigates membrane biofouling in MBRs from the microbiological perspective to evaluate the potential of biological-based strategies in offering viable control alternatives. Limitations of available control methods highlight the importance of an integrated anti-fouling approach including biological strategies. Successful development of these strategies requires detailed characterization of microorganisms and EPS through the proper selection of analytical tools and assembly of results. Existing microbiological/EPS studies reveal a number of

  20. Do biological-based strategies hold promise to biofouling control in MBRs?

    Science.gov (United States)

    Malaeb, Lilian; Le-Clech, Pierre; Vrouwenvelder, Johannes S; Ayoub, George M; Saikaly, Pascal E

    2013-10-01

    Biofouling in membrane bioreactors (MBRs) remains a primary challenge for their wider application, despite the growing acceptance of MBRs worldwide. Research studies on membrane fouling are extensive in the literature, with more than 200 publications on MBR fouling in the last 3 years; yet, improvements in practice on biofouling control and management have been remarkably slow. Commonly applied cleaning methods are only partially effective and membrane replacement often becomes frequent. The reason for the slow advancement in successful control of biofouling is largely attributed to the complex interactions of involved biological compounds and the lack of representative-for-practice experimental approaches to evaluate potential effective control strategies. Biofouling is driven by microorganisms and their associated extra-cellular polymeric substances (EPS) and microbial products. Microorganisms and their products convene together to form matrices that are commonly treated as a black box in conventional control approaches. Biological-based antifouling strategies seem to be a promising constituent of an effective integrated control approach since they target the essence of biofouling problems. However, biological-based strategies are in their developmental phase and several questions should be addressed to set a roadmap for translating existing and new information into sustainable and effective control techniques. This paper investigates membrane biofouling in MBRs from the microbiological perspective to evaluate the potential of biological-based strategies in offering viable control alternatives. Limitations of available control methods highlight the importance of an integrated anti-fouling approach including biological strategies. Successful development of these strategies requires detailed characterization of microorganisms and EPS through the proper selection of analytical tools and assembly of results. Existing microbiological/EPS studies reveal a number of

  1. Cardiocladius oliffi (Diptera: Chironomidae as a potential biological control agent against Simulium squamosum (Diptera: Simuliidae

    Directory of Open Access Journals (Sweden)

    Wilson Michael D

    2009-04-01

    Full Text Available Abstract Background The control of onchocerciasis in the African region is currently based mainly on the mass drug administration of ivermectin. Whilst this has been found to limit morbidity, it does not stop transmission. In the absence of a macrofilaricide, there is a need for an integrated approach for disease management, which includes vector control. Vector control using chemical insecticides is expensive to apply, and therefore the use of other measures such as biological control agents is needed. Immature stages of Simulium squamosum, reared in the laboratory from egg masses collected from the field at Boti Falls and Huhunya (River Pawnpawn in Ghana, were observed to be attacked and fed upon by larvae of the chironomid Cardiocladius oliffi Freeman, 1956 (Diptera: Chironomidae. Methods Cardiocladius oliffi was successfully reared in the rearing system developed for S. damnosum s.l. and evaluated for its importance as a biological control agent in the laboratory. Results Even at a ratio of one C. oliffi to five S. squamosum, they caused a significant decrease in the number of adult S. squamosum emerging from the systems (treatments. Predation was confirmed by the amplification of Simulium DNA from C. oliffi observed to have fed on S. squamosum pupae. The study also established that the chironomid flies could successfully complete their development on a fish food diet only. Conclusion Cardiocladius oliffi has been demonstrated as potential biological control agent against S. squamosum.

  2. Imposing early stability to ecological and biological networks through Evolutionary Network Control

    Directory of Open Access Journals (Sweden)

    Alessandro Ferrarini

    2015-03-01

    Full Text Available The stability analysis of the dynamical networks is a well-studied topic, both in ecology and in biology. In this work, I adopt a different perspective: instead of analysing the stability of an arbitrary ecological network, I seek here to impose such stability as soon as possible (or, contrariwise, as late as possible during network dynamics. Evolutionary Network Control (ENC is a theoretical and methodological framework aimed to the control of ecological and biological networks by coupling network dynamics and evolutionary modelling. ENC covers several topics of network control, for instance a the global control from inside and b from outside, c the local (step-by-step control, and the computation of: d control success, e feasibility, and f degree of uncertainty. In this work, I demonstrate that ENC can also be employed to impose early (but, also, late stability to arbitrary ecological and biological networks, and provide an applicative example based on the nonlinear, widely-used, Lotka-Volterra model.

  3. [Testing of the effect of classic conditioning stimuli in human experiment by means of the transfer of control paradigm].

    Science.gov (United States)

    Wolter, J

    1999-01-01

    Pavlovian conditioning in animals is often evaluated by means of transfer of control experiments. With human subjects, however, only very few studies have been conducted and the outcomes were often not in accordance with theoretical explanations based on studies with animals. A theoretical framework is presented that tries to integrate the results of the human conditioning paradigm and the animal conditioning paradigm as well, with reference to the well-known Yerkes-Dodson law. The experimental study with human subjects (N = 24) confirmed the predictions out of this framework, when a procedure similar to animal research is applied.

  4. The classical task

    DEFF Research Database (Denmark)

    Gillis, Steven; Souman, Agnita; Dhollander, Sim

    -year-olds to 9-year-olds. The experiment was also administered with a control group of adults. Procedure: The procedure consists of a classical set-up in which the subjects are shown pictures of objects. On presenting each object, the test leader says: "Here is a X (name of the object)". The next...... articulated: Prediction 1: a global analysis of the plural forms provided by the subjects is expected to show an increase of the correct responses as children grow older. Prediction 2: As to suffix selection, we expect that the plural of nouns selecting a fully predictable suffix will be more readily mastered...

  5. Strengthening cancer biology research, prevention, and control while reducing cancer disparities: student perceptions of a collaborative master's degree program in cancer biology, preventions, and control.

    Science.gov (United States)

    Jillson, I A; Cousin, C E; Blancato, J K

    2013-09-01

    This article provides the findings of a survey of previous and current students in the UDC/GU-LCCC master's degree program. This master's degree program, Cancer Biology, Prevention, and Control is administered and taught jointly by faculty of a Minority Serving Institution, the University of the District of Columbia, and the Lombardi Comprehensive Cancer Center to incorporate the strengths of a community-based school with a research intensive medical center. The program was initiated in 2008 through agreements with both University administrations and funding from the National Cancer Institute. The master's degree program is 36 credits with a focus on coursework in biostatistics, epidemiology, tumor biology, cancer prevention, medical ethics, and cancer outreach program design. For two semesters during the second year, students work full-time with a faculty person on a laboratory or outreach project that is a requirement for graduation. Students are supported and encouraged to transition to a doctoral degree after they obtain the master's and many of them are currently in doctorate programs. Since the inception of the program, 45 students have initiated the course of study, 28 have completed the program, and 13 are currently enrolled in the program. The survey was designed to track the students in their current activities, as well as determine which courses, program enhancements, and research experiences were the least and most useful, and to discern students' perceptions of knowledge acquired on various aspects of Cancer Biology Prevention, and Control Master's Program. Thirty of the 35 individuals to whom email requests were sent responded to the survey, for a response rate of 85.7%. The results of this study will inform the strengthening of the Cancer Biology program by the Education Advisory Committee. They can also be used in the development of comparable collaborative master's degree programs designed to address the significant disparities in prevalence of

  6. An economic evaluation of preclinical testing strategies compared to the compulsory scrapie flock scheme in the control of classical scrapie.

    Science.gov (United States)

    Boden, Lisa; Handel, Ian; Hawkins, Neil; Houston, Fiona; Fryer, Helen; Kao, Rowland

    2012-01-01

    Cost-benefit is rarely combined with nonlinear dynamic models when evaluating control options for infectious diseases. The current strategy for scrapie in Great Britain requires that all genetically susceptible livestock in affected flocks be culled (Compulsory Scrapie Flock Scheme or CSFS). However, this results in the removal of many healthy sheep, and a recently developed pre-clinical test for scrapie now offers a strategy based on disease detection. We explore the flock level cost-effectiveness of scrapie control using a deterministic transmission model and industry estimates of costs associated with genotype testing, pre-clinical tests and the value of a sheep culled. Benefit was measured in terms of the reduction in the number of infected sheep sold on, compared to a baseline strategy of doing nothing, using Incremental Cost Effectiveness analysis to compare across strategies. As market data was not available for pre-clinical testing, a threshold analysis was used to set a unit-cost giving equal costs for CSFS and multiple pre-clinical testing (MT, one test each year for three consecutive years). Assuming a 40% within-flock proportion of susceptible genotypes and a test sensitivity of 90%, a single test (ST) was cheaper but less effective than either the CSFS or MT strategies (30 infected-sales-averted over the lifetime of the average epidemic). The MT strategy was slightly less effective than the CSFS and would be a dominated strategy unless preclinical testing was cheaper than the threshold price of £6.28, but may be appropriate for flocks with particularly valuable livestock. Though the ST is not currently recommended, the proportion of susceptible genotypes in the national flock is likely to continue to decrease; this may eventually make it a cost-effective alternative to the MT or CSFS.

  7. An economic evaluation of preclinical testing strategies compared to the compulsory scrapie flock scheme in the control of classical scrapie.

    Directory of Open Access Journals (Sweden)

    Lisa Boden

    Full Text Available Cost-benefit is rarely combined with nonlinear dynamic models when evaluating control options for infectious diseases. The current strategy for scrapie in Great Britain requires that all genetically susceptible livestock in affected flocks be culled (Compulsory Scrapie Flock Scheme or CSFS. However, this results in the removal of many healthy sheep, and a recently developed pre-clinical test for scrapie now offers a strategy based on disease detection. We explore the flock level cost-effectiveness of scrapie control using a deterministic transmission model and industry estimates of costs associated with genotype testing, pre-clinical tests and the value of a sheep culled. Benefit was measured in terms of the reduction in the number of infected sheep sold on, compared to a baseline strategy of doing nothing, using Incremental Cost Effectiveness analysis to compare across strategies. As market data was not available for pre-clinical testing, a threshold analysis was used to set a unit-cost giving equal costs for CSFS and multiple pre-clinical testing (MT, one test each year for three consecutive years. Assuming a 40% within-flock proportion of susceptible genotypes and a test sensitivity of 90%, a single test (ST was cheaper but less effective than either the CSFS or MT strategies (30 infected-sales-averted over the lifetime of the average epidemic. The MT strategy was slightly less effective than the CSFS and would be a dominated strategy unless preclinical testing was cheaper than the threshold price of £6.28, but may be appropriate for flocks with particularly valuable livestock. Though the ST is not currently recommended, the proportion of susceptible genotypes in the national flock is likely to continue to decrease; this may eventually make it a cost-effective alternative to the MT or CSFS.

  8. Biological control of Ixodes ricinus larvae and nymphs with Metarhizium anisopliae blastospores.

    Science.gov (United States)

    Wassermann, Marion; Selzer, Philipp; Steidle, Johannes L M; Mackenstedt, Ute

    2016-07-01

    The entomopathogenic fungus Metarhizium anisopliae is used as a biological pest control agent against various arthropod species, including ticks. However, the efficacy depends on tick species, tick stage and fungus strain. We studied the effect of M. anisopliae on engorged larvae and nymphs of Ixodes ricinus, the most abundant tick species in Europe, under laboratory and semi-field conditions. A significant reduction of engorged larvae and nymphs could be shown under laboratory as well as under semi-field conditions. Only 3.5% of the larvae treated in the lab and only 18.5% kept under semi-field conditions were able to develop into nymphs compared to the recovered nymphs of the control groups, which were regarded as 100%. Only 7.1% of nymphs were recovered as adult ticks after fungal treatment under semi-field conditions compared to the control (100%). The efficacy of blastospores of M. anisopliae against engorged larvae and nymphs of I. ricinus under semi-field conditions was demonstrated in this study, showing their high potential as a biological control agent of ticks. Further studies will have to investigate the effect of this agent against other stages of I. ricinus as well as other tick species before its value as a biological control agent against ticks can be fully assessed.

  9. Commercial Biological Control Agents Targeted Against Plant-Parasitic Root-knot Nematodes

    Directory of Open Access Journals (Sweden)

    Marie-Stéphane Tranier

    2014-12-01

    Full Text Available Root-knot nematodes are microscopic round worms, which cause severe agricultural losses. Their attacks affect the productivity by reducing the amount and the caliber of the fruits. Chemical control is widely used, but biological control appears to be a better solution, mainly using microorganisms to reduce the quantity of pests infecting crops. Biological control is developing gradually, and with time, more products are being marketed worldwide. They can be formulated with bacteria, viruses or with filamentous fungi, which can destroy and feed on phytoparasitic nematodes. To be used by the farmers, biopesticides must be legalized by the states, which has led to the establishment of a legal framework for their use, devised by various governmental organizations.

  10. The Google matrix controls the stability of structured ecological and biological networks

    Science.gov (United States)

    Stone, Lewi

    2016-09-01

    May's celebrated theoretical work of the 70's contradicted the established paradigm by demonstrating that complexity leads to instability in biological systems. Here May's random-matrix modelling approach is generalized to realistic large-scale webs of species interactions, be they structured by networks of competition, mutualism or both. Simple relationships are found to govern these otherwise intractable models, and control the parameter ranges for which biological systems are stable and feasible. Our analysis of model and real empirical networks is only achievable on introducing a simplifying Google-matrix reduction scheme, which in the process, yields a practical ecological eigenvalue stability index. These results provide an insight into how network topology, especially connectance, influences species stable coexistence. Constraints controlling feasibility (positive equilibrium populations) in these systems are found more restrictive than those controlling stability, helping explain the enigma of why many classes of feasible ecological models are nearly always stable.

  11. What classicality? Decoherence and Bohr's classical concepts

    CERN Document Server

    Schlosshauer, Maximilian

    2010-01-01

    Niels Bohr famously insisted on the indispensability of what he termed "classical concepts." In the context of the decoherence program, on the other hand, it has become fashionable to talk about the "dynamical emergence of classicality" from the quantum formalism alone. Does this mean that decoherence challenges Bohr's dictum and signifies a break with the Copenhagen interpretation-for example, that classical concepts do not need to be assumed but can be derived? In this paper we'll try to shine some light down the murky waters where formalism and philosophy cohabitate. To begin, we'll clarify the notion of classicality in the decoherence description. We'll then discuss Bohr's and Heisenberg's take on the quantum-classical problem and reflect on different meanings of the terms "classicality" and "classical concepts" in the writings of Bohr and his followers. This analysis will allow us to put forward some tentative suggestions for how we may better understand the relation between decoherence-induced classical...

  12. Metarhizium anisopliae as a biological control agent against Hyalomma anatolicum (Acari: Ixodidae).

    Science.gov (United States)

    Suleiman, Elham A; Shigidi, M T; Hassan, S M

    2013-12-15

    In the Sudan, ticks and Tick-borne Diseases (TBDs) with subsequent costs of control and treatment are causing substantial economic loss. Control of ticks is mainly by chemical insecticides. The rising environmental hazards and problem of resistance has motivated research on biological agents as alternative methods of control. The present study aims at controlling livestock ticks using fungi for their unique mode of action besides their ability to adhere to the cuticle, to germinate and penetrate enzymatically. The study was conducted to evaluate the fungus Metarhizium anisopliae for tick control as an alternative mean to chemical acaricides. Pathogenicity of the fungus was tested on different developmental stages of the tick Hyalomma anatolicum. The fungus induced high mortality to flat immature stages. It, also, affected reproductive potential of the females. Egg laid, hatching percent, fertility and moulting percent of immature stages were significantly (p anisopliae to control ticks is discussed.

  13. Classical mechanics approach applied to analysis of genetic oscillators.

    Science.gov (United States)

    Vasylchenkova, Anastasiia; Mraz, Miha; Zimic, Nikolaj; Moskon, Miha

    2016-04-05

    Biological oscillators present a fundamental part of several regulatory mechanisms that control the response of various biological systems. Several analytical approaches for their analysis have been reported recently. They are, however, limited to only specific oscillator topologies and/or to giving only qualitative answers, i.e., is the dynamics of an oscillator given the parameter space oscillatory or not. Here we present a general analytical approach that can be applied to the analysis of biological oscillators. It relies on the projection of biological systems to classical mechanics systems. The approach is able to provide us with relatively accurate results in the meaning of type of behaviour system reflects (i.e. oscillatory or not) and periods of potential oscillations without the necessity to conduct expensive numerical simulations. We demonstrate and verify the proposed approach on three different implementations of amplified negative feedback oscillator.

  14. Is ground cover vegetation an effective biological control enhancement strategy against olive pests?

    Directory of Open Access Journals (Sweden)

    Daniel Paredes

    Full Text Available Ground cover vegetation is often added or allowed to generate to promote conservation biological control, especially in perennial crops. Nevertheless, there is inconsistent evidence of its effectiveness, with studies reporting positive, nil or negative effects on pest control. This might arise from differences between studies at the local scale (e.g. orchard management and land use history, the landscape context (e.g. presence of patches of natural or semi-natural vegetation near the focal orchard, or regional factors, particularly climate in the year of the study. Here we present the findings from a long-term regional monitoring program conducted on four pest species (Bactrocera oleae, Prays oleae, Euphyllura olivina, Saissetia oleae in 2,528 olive groves in Andalusia (Spain from 2006 to 2012. Generalized linear mixed effect models were used to analyze the effect of ground cover on different response variables related to pest abundance, while accounting for variability at the local, landscape and regional scales. There were small and inconsistent effects of ground cover on the abundance of pests whilst local, landscape and regional variability explained a large proportion of the variability in pest response variables. This highlights the importance of local and landscape-related variables in biological control and the potential effects that might emerge from their interaction with practices, such as groundcover vegetation, implemented to promote natural enemy activity. The study points to perennial vegetation close to the focal crop as a promising alternative strategy for conservation biological control that should receive more attention.

  15. Is ground cover vegetation an effective biological control enhancement strategy against olive pests?

    Science.gov (United States)

    Paredes, Daniel; Cayuela, Luis; Gurr, Geoff M; Campos, Mercedes

    2015-01-01

    Ground cover vegetation is often added or allowed to generate to promote conservation biological control, especially in perennial crops. Nevertheless, there is inconsistent evidence of its effectiveness, with studies reporting positive, nil or negative effects on pest control. This might arise from differences between studies at the local scale (e.g. orchard management and land use history), the landscape context (e.g. presence of patches of natural or semi-natural vegetation near the focal orchard), or regional factors, particularly climate in the year of the study. Here we present the findings from a long-term regional monitoring program conducted on four pest species (Bactrocera oleae, Prays oleae, Euphyllura olivina, Saissetia oleae) in 2,528 olive groves in Andalusia (Spain) from 2006 to 2012. Generalized linear mixed effect models were used to analyze the effect of ground cover on different response variables related to pest abundance, while accounting for variability at the local, landscape and regional scales. There were small and inconsistent effects of ground cover on the abundance of pests whilst local, landscape and regional variability explained a large proportion of the variability in pest response variables. This highlights the importance of local and landscape-related variables in biological control and the potential effects that might emerge from their interaction with practices, such as groundcover vegetation, implemented to promote natural enemy activity. The study points to perennial vegetation close to the focal crop as a promising alternative strategy for conservation biological control that should receive more attention.

  16. Conservation biological control of pests in the molecular era: new opportunities to address old constraints

    Directory of Open Access Journals (Sweden)

    Gurr eGeoff

    2016-01-01

    Full Text Available ABSTRACTBiological control has long been considered a potential alternative to pesticidal strategies for pest management but its impact and level of use globally remain modest and inconsistent. A rapidly expanding range of molecular – particularly DNA-related – techniques is currently revolutionizing many life sciences. This review identifies a series of constraints on the development and uptake of conservation biological control and considers the contemporary and likely future influence of molecular methods on these constraints. Molecular approaches are now often used to complement morphological taxonomic methods for the identification and study of biological control agents including microbes. A succession of molecular techniques has been applied to ‘who eats whom’ questions in food-web ecology. Polymerase chain reaction (PCR approaches have largely superseded immunological approaches such as enzyme-linked immunosorbent assay (ELISA and now – in turn – are being overtaken by next generation sequencing (NGS- based approaches that offer unparalleled power at a rapidly diminishing cost. There is scope also to use molecular techniques to manipulate biological control agents, which will be accelerated with the advent of gene editing tools, the CRISPR/Cas9 system in particular. Gene editing tools also offer unparalleled power to both elucidate and manipulate the plant defence mechanisms including those that involve natural enemy attraction to attacked plants. Rapid advances in technology will allow the development of still more novel pest management options for which uptake is likely to be limited chiefly by regulatory hurdles.

  17. Prospects for the use of biological control agents against Anoplophora in Europe.

    Science.gov (United States)

    Brabbs, Thomas; Collins, Debbie; Hérard, Franck; Maspero, Matteo; Eyre, Dominic

    2015-01-01

    This review summarises the literature on the biological control of Anoplophora spp. (Coleoptera: Cerambycidae) and discusses its potential for use in Europe. Entomopathogenic fungi: Beauveria brongniartii Petch (Hypocreales: Cordycipitaceae) has already been developed into a commercial product in Japan, and fungal infection results in high mortality rates. Parasitic nematodes: Steinernema feltiae Filipjev (Rhabditida: Steinernematidae) and Steinernema carpocapsae Weiser have potential for use as biopesticides as an alternative to chemical treatments. Parasitoids: a parasitoid of Anoplophora chinensis Forster, Aprostocetus anoplophorae Delvare (Hymenoptera: Eulophidae), was discovered in Italy in 2002 and has been shown to be capable of parasitising up to 72% of A. chinensis eggs; some native European parasitoid species (e.g. Spathius erythrocephalus) also have potential to be used as biological control agents. Predators: two woodpecker (Piciformis: Picidae) species that are native to Europe, Dendrocopos major Beicki and Picus canus Gmelin, have been shown to be effective at controlling Anoplophora glabripennis Motschulsky in Chinese forests. The removal and destruction of infested and potentially infested trees is the main eradication strategy for Anoplophora spp. in Europe, but biological control agents could be used in the future to complement other management strategies, especially in locations where eradication is no longer possible.

  18. Pathogen variation and urea influence selection and success of Streptomyces mixtures in biological control.

    Science.gov (United States)

    Otto-Hanson, L K; Grabau, Z; Rosen, C; Salomon, C E; Kinkel, L L

    2013-01-01

    Success in biological control of plant diseases remains inconsistent in the field. A collection of well-characterized Streptomyces antagonists (n = 19 isolates) was tested for their capacities to inhibit pathogenic Streptomyces scabies (n = 15 isolates). There was significant variation among antagonists in ability to inhibit pathogen isolates and among pathogens in their susceptibility to inhibition. Only one antagonist could inhibit all pathogens, and antagonist-pathogen interactions were highly specific, highlighting the limitations of single-strain inoculum in biological control. However, the collection of pathogens could be inhibited by several combinations of antagonists, suggesting the potential for successful antagonist mixtures. Urea generally increased effectiveness of antagonists at inhibiting pathogens in vitro (increased mean inhibition zones) but its specific effects varied among antagonist-pathogen combinations. In greenhouse trials, urea enhanced the effectiveness of antagonist mixtures relative to individual antagonists in controlling potato scab. Although antagonist mixtures were frequently antagonistic in the absence of urea, all n= 2 and n = 3 antagonist-isolate combinations were synergistic in the presence of urea. This work provides insights into the efficacy of single- versus multiple-strain inocula in biological control and on the potential for nutrients to influence mixture success.

  19. The effect of temperature on the biology of Phytoseiulus macropilis (Banks (Phytoseiidae in applied biological control program

    Directory of Open Access Journals (Sweden)

    Catiane Dameda

    2016-10-01

    Full Text Available Phytoseiulus macropilis (Banks (Phytoseiidae is a natural enemy of Tetranychus urticae Koch (TSSM, a common pest in several cultures, especially in greenhouses. This research aimed to know the biological parameters of a strain of P. macropilis from Vale do Taquari, State of Rio Grande do Sul, feeding on TSSM at different temperatures. The study was initiated with 30 eggs individualized in arenas under the temperature of 20, 25 and 30 ± 1°C and relative humidity of 80 ± 10%. The average length (T of each generation decreased with the increase of temperature, ranging from 25.71 days at 20°C to 11.14 days at 30°C. The net reproductive rate (Ro ranged from 45.47 at 20°C to 18.25 at 30°C; the innate capacity for increase (rm was 0.15 at 20°C, reaching 0.26 at 30°C and the finite increase rate (λ ranged from 1.41 to 1.82 females day-1 at 20 and 30°C, respectively. In the present study, it was observed that the strain of the evaluated predatory mite from mild climate of South Brazil, might present a good performance to control TSSM when exposed to a temperature range between 20 and 30°C.

  20. 77 FR 46373 - Field Release of Aphelinus glycinis for the Biological Control of the Soybean Aphid in the...

    Science.gov (United States)

    2012-08-03

    ... the Biological Control of the Soybean Aphid in the Continental United States; Availability of an... release of Aphelinus glycinis for the biological control of the soybean aphid, Aphis glycines, in the...-2323. SUPPLEMENTARY INFORMATION: Background The soybean aphid, Aphis glycinis, which is native to...

  1. Development of biological control of Tetranychus urticae (Acari:Tetranychidae) and Phorodon humuli (Hemiptera: Aphididae) in Oregon Hop yards

    Science.gov (United States)

    The temporal development of biological control of arthropod pests in perennial cropping systems is largely unreported. In this study, the development of biological control of twospotted spider mite, Tetranychus urticae Koch and hop aphid, Phorodon humuli (Schrank) in a new planting of hop in Oregon...

  2. The influence of flower morphology and nectar quality on the longevity of a parasitoid biological control agent

    NARCIS (Netherlands)

    Vattala, H.D.; Wratten, S.D.; Phillips, C.B.; Wäckers, F.L.

    2006-01-01

    Conservation biological control aims to enhance the efficacy of arthropod biological control agents, such as parasitoids, partly by providing them with access to floral nectar. However, the suitability of a flower species for providing nectar to a parasitoid is dependent on the morphologies of the p

  3. Climate warming increases biological control agent impact on a non-target species

    Science.gov (United States)

    Lu, Xinmin; Siemann, Evan; He, Minyan; Wei, Hui; Shao, Xu; Ding, Jianqing

    2015-01-01

    Climate change may shift interactions of invasive plants, herbivorous insects and native plants, potentially affecting biological control efficacy and non-target effects on native species. Here, we show how climate warming affects impacts of a multivoltine introduced biocontrol beetle on the non-target native plant Alternanthera sessilis in China. In field surveys across a latitudinal gradient covering their full distributions, we found beetle damage on A. sessilis increased with rising temperature and plant life history changed from perennial to annual. Experiments showed that elevated temperature changed plant life history and increased insect overwintering, damage and impacts on seedling recruitment. These results suggest that warming can shift phenologies, increase non-target effect magnitude and increase non-target effect occurrence by beetle range expansion to additional areas where A. sessilis occurs. This study highlights the importance of understanding how climate change affects species interactions for future biological control of invasive species and conservation of native species. PMID:25376303

  4. Climate warming increases biological control agent impact on a non-target species.

    Science.gov (United States)

    Lu, Xinmin; Siemann, Evan; He, Minyan; Wei, Hui; Shao, Xu; Ding, Jianqing

    2015-01-01

    Climate change may shift interactions of invasive plants, herbivorous insects and native plants, potentially affecting biological control efficacy and non-target effects on native species. Here, we show how climate warming affects impacts of a multivoltine introduced biocontrol beetle on the non-target native plant Alternanthera sessilis in China. In field surveys across a latitudinal gradient covering their full distributions, we found beetle damage on A. sessilis increased with rising temperature and plant life history changed from perennial to annual. Experiments showed that elevated temperature changed plant life history and increased insect overwintering, damage and impacts on seedling recruitment. These results suggest that warming can shift phenologies, increase non-target effect magnitude and increase non-target effect occurrence by beetle range expansion to additional areas where A. sessilis occurs. This study highlights the importance of understanding how climate change affects species interactions for future biological control of invasive species and conservation of native species.

  5. Economic Benefits of Advanced Control Strategies in Biological Nutrient Removal Systems

    DEFF Research Database (Denmark)

    Carstensen, J.; Nielsen, M.K.; Harremoës, Poul

    1994-01-01

    Advances in on-line monitoring of nutrient salt concentrations and computer technology has created a large potential for the implementation of advanced and complex control strategies in biological nutrient removal systems. The majority of wastewater treatment plants today are operated with very...... strategies incorporating information from the grey box models are capable of reducing the total nitrogen discharge as well as energy costs. These results have a major impact on both existing and future plants. In fact, it is expected that future plants can be reduced with 10-20 per cent in size......, and that the complexity in reactor design of biological nutrient removal systems will be substituted by complexity in control in the future....

  6. A simulation benchmark to evaluate the performance of advanced control techniques in biological wastewater treatment plants

    Directory of Open Access Journals (Sweden)

    Sotomayor O.A.Z.

    2001-01-01

    Full Text Available Wastewater treatment plants (WWTP are complex systems that incorporate a large number of biological, physicochemical and biochemical processes. They are large and nonlinear systems subject to great disturbances in incoming loads. The primary goal of a WWTP is to reduce pollutants and the second goal is disturbance rejection, in order to obtain good effluent quality. Modeling and computer simulations are key tools in the achievement of these two goals. They are essential to describe, predict and control the complicated interactions of the processes. Numerous control techniques (algorithms and control strategies (structures have been suggested to regulate WWTP; however, it is difficult to make a discerning performance evaluation due to the nonuniformity of the simulated plants used. The main objective of this paper is to present a benchmark of an entire biological wastewater treatment plant in order to evaluate, through simulations, different control techniques. This benchmark plays the role of an activated sludge process used for removal of organic matter and nitrogen from domestic effluents. The development of this simulator is based on models widely accepted by the international community and is implemented in Matlab/Simulink (The MathWorks, Inc. platform. The benchmark considers plant layout and the effects of influent characteristics. It also includes a test protocol for analyzing the open and closed-loop responses of the plant. Examples of control applications in the benchmark are implemented employing conventional PI controllers. The following common control strategies are tested: dissolved oxygen (DO concentration-based control, respirometry-based control and nitrate concentration-based control.

  7. Effect of non-crop vegetation types on conservation biological control of pests in olive groves

    OpenAIRE

    2013-01-01

    Conservation biological control (CBC) is an environmentally sound potential alternative to the use of chemical insecticides. It involves modifications of the environment to promote natural enemy activity on pests. Despite many CBC studies increasing abundance of natural enemies, there are far fewer demonstrations of reduced pest density and very little work has been conducted in olive crops. In this study we investigated the effects of four forms of non-crop vegetation on the abundance of two...

  8. Protein-polymer nano-machines. Towards synthetic control of biological processes

    Directory of Open Access Journals (Sweden)

    Alexander Cameron

    2004-09-01

    Full Text Available Abstract The exploitation of nature's machinery at length scales below the dimensions of a cell is an exciting challenge for biologists, chemists and physicists, while advances in our understanding of these biological motifs are now providing an opportunity to develop real single molecule devices for technological applications. Single molecule studies are already well advanced and biological molecular motors are being used to guide the design of nano-scale machines. However, controlling the specific functions of these devices in biological systems under changing conditions is difficult. In this review we describe the principles underlying the development of a molecular motor with numerous potential applications in nanotechnology and the use of specific synthetic polymers as prototypic molecular switches for control of the motor function. The molecular motor is a derivative of a TypeI Restriction-Modification (R-M enzyme and the synthetic polymer is drawn from the class of materials that exhibit a temperature-dependent phase transition. The potential exploitation of single molecules as functional devices has been heralded as the dawn of new era in biotechnology and medicine. It is not surprising, therefore, that the efforts of numerous multidisciplinary teams 12. have been focused in attempts to develop these systems. as machines capable of functioning at the low sub-micron and nanometre length-scales 3. However, one of the obstacles for the practical application of single molecule devices is the lack of functional control methods in biological media, under changing conditions. In this review we describe the conceptual basis for a molecular motor (a derivative of a TypeI Restriction-Modification enzyme with numerous potential applications in nanotechnology and the use of specific synthetic polymers as prototypic molecular switches for controlling the motor function 4.

  9. Phosphorus limitation controls rates of biological N2-fixation in boreal peatlands

    Science.gov (United States)

    Dynarski, K. A.; Wieder, R.; Vile, M. A.

    2013-12-01

    N2-fixation, once thought to occur at negligible rates in pristine boreal peatlands, has recently been demonstrated to be the dominant input of nitrogen (N) to these ecosystems. The controls of biological N2-fixation in pristine boreal peatlands are not well understood, but limitation of the nutrients molybdenum (Mo) and phosphorus (P) may play a key role. Because the enzyme nitrogenase requires molybdenum-containing cofactors to function, biological N2-fixation may be limited by the trace metal molybdenum. Recent studies have shown that Mo limits nitrogen fixation rates in tropical soils. P availability may also be important in regulating N2-fixation rates; N2-fixation is a P-intensive process because the nitrogenase enzyme is rich in P, and P is likely to be the most limiting nutrient to boreal peatland productivity, next to N. In this study, we examined the role of Mo and P limitation in controlling rates of biological N2-fixation in boreal peatlands. We applied Mo and P nutrient amendments equivalent to 5 mg m-2 yr-1and 10 kg ha-1 yr-1 respectively, both alone and in combination, to fifteen 0.36 m2 plots in a pristine Alberta fen throughout the summer 2013 growing season. We periodically assessed N2-fixation rates in Sphagnum angustifolium moss samples using the acetylene reduction assay with subsequent calibration using 15N2. We found a significant overall treatment effect (F3,44=15.62, pTukey's HSD indicates that N2-fixation rates were significantly higher in plots receiving P additions relative to control plots. However, Mo additions had no effect on N2-fixation rates. These results indicate that P, not Mo, availability is dominant in controlling rates of biological N2-fixation in boreal peatland ecosystems.

  10. Invasive Species Biology, Control, and Research. Part 2. Multiflora Rose (Rosa multiflora)

    Science.gov (United States)

    2008-11-01

    this agent should be considered in concert with other biological control methods. The dying canes are incapable of asexual reproduction via layering...two, Multiflora Rose seedlings grow inconspicuously, but quickly become well anchored. Multiflora Rose reproduces asexually by suckering and...mowing the remaining topgrowth eliminates any remaining live plant parts that could asexually reproduce. ERDC TR-08-11 8 Table 1. Herbicides that

  11. Recent Advances in Biological Control of Pest Insects by Using Viruses in China

    Institute of Scientific and Technical Information of China (English)

    Xiu-lian SUN; Hui-yin PENG

    2007-01-01

    Insect viruses are attractive as biological control agents and could be a feasible alternative to chemical insecticides in the management of insect infestations. This review describes recent advances in the development of wild-type and genetically modified viruses as insecticides. A new strategy of application of insect viruses in China is reviewed. Also, the assessment of biosafety of genetically modified Helicoverpa armigera Nucleopolyhedovirus (HearNPV) is emphasized as a case-study.

  12. Integration of biological control and botanical pesticides : evaluation in a tritrophic context

    OpenAIRE

    Charleston, D.S.; Dicke, M.; Vet, L.E.M.; Kfir, R.

    2001-01-01

    The plant kingdom is by far the most efficient producer of chemical compounds, synthesising many products that are used in defence against herbivores. Extracts made from some plants, particularly extracts from plants within the Meliaceae (mahogany) family, have been shown to have insecticidal properties. We investigated the potential of these extracts and the possibility of integrating botanical pesticides with biological control of the diamondback moth, Plutella xylostella. Sub-lethal doses ...

  13. Parasites, politics and public science: the promotion of biological control in Western Australia, 1900-1910.

    Science.gov (United States)

    Deveson, Edward

    2016-06-01

    Biological control of arthropods emerged as a scientific enterprise in the late nineteenth century and the orchard industry of California was an early centre of expertise. In 1900, as the Australian colonies prepared for federation, each had a government entomologist attached to its agriculture department. The hiring of George Compere from California by the Western Australian Department of Agriculture began a controversial chapter in the early history of biological control that was linked to a late, local popularization of acclimatization. Compere became known as the 'travelling entomologist' and for a decade brought 'parasites' of pest insects from overseas and released them in Perth. His antagonistic disciplinary rhetoric and inflated claims for the 'parasite theory' created conflict with his counterparts in the eastern states. The resulting inter-state entomological controversy was played out in the press, revealing the political use of science for institutional and even state identity. It is a story of transnational exchanges, chance discoveries and popular public science: popular because of the promise of a simple, natural solution to agricultural insect pests and because of the public nature of the disputes it generated between the experts. This microcosm contributes to the global historiography of acclimatization, biological control, scientific exposition and the professionalization of agricultural science.

  14. Possibility of biological control of primocane fruiting raspberry disease caused by Fusarium sambucinum.

    Science.gov (United States)

    Shternshis, Margarita V; Belyaev, Anatoly A; Matchenko, Nina S; Shpatova, Tatyana V; Lelyak, Anastasya A

    2015-10-01

    Biological control agents are a promising alternative to chemical pesticides for plant disease suppression. The main advantage of the natural biocontrol agents, such as antagonistic bacteria compared with chemicals, includes environmental pollution prevention and a decrease of chemical residues in fruits. This study is aimed to evaluate the impact of three Bacillus strains on disease of primocane fruiting raspberry canes caused by Fusarium sambucinum under controlled infection load and uncontrolled environmental factors. Bacillus subtilis, Bacillus licheniformis, and Bacillus amyloliquefaciens were used for biocontrol of plant disease in 2013 and 2014 which differed by environmental conditions. The test suspensions were 10(5) CFU/ml for each bacterial strain. To estimate the effect of biological agents on Fusarium disease, canes were cut at the end of vegetation, and the area of outer and internal lesions was measured. In addition to antagonistic effect, the strains revealed the ability to induce plant resistance comparable with chitosan-based formulation. Under variable ways of cane treatment by bacterial strains, the more effective were B. subtilis and B. licheniformis demonstrating dual biocontrol effect. However, environmental factors were shown to impact the strain biocontrol ability; changes in air temperature and humidity led to the enhanced activity of B. amyloliquefaciens. For the first time, the possibility of replacing chemicals with environmentally benign biological agents for ecologically safe control of the raspberry primocane fruiting disease was shown.

  15. Herbivore-induced plant volatiles to enhance biological control in agriculture.

    Science.gov (United States)

    Peñaflor, M F G V; Bento, J M S

    2013-08-01

    Plants under herbivore attack synthetize defensive organic compounds that directly or indirectly affect herbivore performance and mediate other interactions with the community. The so-called herbivore-induced plant volatiles (HIPVs) consist of odors released by attacked plants that serve as important cues for parasitoids and predators to locate their host/prey. The understanding that has been gained on the ecological role and mechanisms of HIPV emission opens up paths for developing novel strategies integrated with biological control programs with the aim of enhancing the efficacy of natural enemies in suppressing pest populations in crops. Tactics using synthetic HIPVs or chemically/genetically manipulating plant defenses have been suggested in order to recruit natural enemies to plantations or help guiding them to their host more quickly, working as a "synergistic" agent of biological control. This review discusses strategies using HIPVs to enhance biological control that have been proposed in the literature and were categorized here as: (a) exogenous application of elicitors on plants, (b) use of plant varieties that emit attractive HIPVs to natural enemies, (c) release of synthetic HIPVs, and (d) genetic manipulation targeting genes that optimize HIPV emission. We discuss the feasibility, benefits, and downsides of each strategy by considering not only field studies but also comprehensive laboratory assays that present an applied approach for HIPVs or show the potential of employing them in the field.

  16. Cell biology in neuroscience: Architects in neural circuit design: glia control neuron numbers and connectivity.

    Science.gov (United States)

    Corty, Megan M; Freeman, Marc R

    2013-11-11

    Glia serve many important functions in the mature nervous system. In addition, these diverse cells have emerged as essential participants in nearly all aspects of neural development. Improved techniques to study neurons in the absence of glia, and to visualize and manipulate glia in vivo, have greatly expanded our knowledge of glial biology and neuron-glia interactions during development. Exciting studies in the last decade have begun to identify the cellular and molecular mechanisms by which glia exert control over neuronal circuit formation. Recent findings illustrate the importance of glial cells in shaping the nervous system by controlling the number and connectivity of neurons.

  17. Classical mechanics without determinism

    OpenAIRE

    Nikolic, H.

    2005-01-01

    Classical statistical particle mechanics in the configuration space can be represented by a nonlinear Schrodinger equation. Even without assuming the existence of deterministic particle trajectories, the resulting quantum-like statistical interpretation is sufficient to predict all measurable results of classical mechanics. In the classical case, the wave function that satisfies a linear equation is positive, which is the main source of the fundamental difference between classical and quantum...

  18. Quantum computing classical physics.

    Science.gov (United States)

    Meyer, David A

    2002-03-15

    In the past decade, quantum algorithms have been found which outperform the best classical solutions known for certain classical problems as well as the best classical methods known for simulation of certain quantum systems. This suggests that they may also speed up the simulation of some classical systems. I describe one class of discrete quantum algorithms which do so--quantum lattice-gas automata--and show how to implement them efficiently on standard quantum computers.

  19. Efficacy of Chaetomium Species as Biological Control Agents against Phytophthora nicotianae Root Rot in Citrus.

    Science.gov (United States)

    Hung, Phung Manh; Wattanachai, Pongnak; Kasem, Soytong; Poeaim, Supattra

    2015-09-01

    Thailand is one of the largest citrus producers in Southeast Asia. Pathogenic infection by Phytophthora, however, has become one of major impediments to production. This study identified a pathogenic oomycete isolated from rotted roots of pomelo (Citrus maxima) in Thailand as Phytophthora nicotianae by the internal transcribed spacer ribosomal DNA sequence analysis. Then, we examined the in vitro and in vivo effects of Chaetomium globosum, Chaetomium lucknowense, Chaetomium cupreum and their crude extracts as biological control agents in controlling this P. nicotianae strain. Represent as antagonists in biculture test, the tested Chaetomium species inhibited mycelial growth by 50~56% and parasitized the hyphae, resulting in degradation of P. nicotianae mycelia after 30 days. The crude extracts of these Chaetomium species exhibited antifungal activities against mycelial growth of P. nicotianae, with effective doses of 2.6~101.4 µg/mL. Under greenhouse conditions, application of spores and methanol extracts of these Chaetomium species to pomelo seedlings inoculated with P. nicotianae reduced root rot by 66~71% and increased plant weight by 72~85% compared to that in the control. The method of application of antagonistic spores to control the disease was simple and economical, and it may thus be applicable for large-scale, highly effective biological control of this pathogen.

  20. Biological control of Tetranychus urticae by Phytoseiulus macropilis and Macrolophus pygmaeus in tomato greenhouses.

    Science.gov (United States)

    Gigon, Vincent; Camps, Cédric; Le Corff, Josiane

    2016-01-01

    Biological control against phytophagous arthropods has been widely used under greenhouse conditions. Its success is dependent on a number of factors related to the abiotic conditions and to the interactions between pests and biological control agents. In particular, when multiple predator species are introduced to suppress one pest, competitive interactions might occur, including intraguild predation (IGP). In tomato crops, the spider mite Tetranychus urticae Koch is a very problematic phytophagous mite and its control is not yet satisfactory. In 2012 and 2013, the ability of a potential new predatory mite Phytoseiulus macropilis (Banks) was assessed, alone and in the presence of Macrolophus pygmaeus Rambur. Macrolophus pygmaeus is a polyphagous mirid supposed to predate on P. macropilis. Both years, under greenhouse conditions, the effectiveness of the two predators was compared between the following treatments: T. urticae, T. urticae + P. macropilis, T. urticae + M. pygmaeus, and T. urticae + P. macropilis + M. pygmaeus. The number of arthropods per tomato plant over time indicated that P. macropilis well-controlled the population of T. urticae, whereas M. pygmaeus had a very limited impact. Furthermore, there was no evidence of IGP between the two predators but in the presence of M. pygmaeus, P. macropilis tended to have a more clumped spatial distribution. Further studies should clarify the number and location of inoculation points to optimize the control of T. urticae by P. macropilis.

  1. Integration of plant defense traits with biological control of arthropod pests: challenges and opportunities

    Directory of Open Access Journals (Sweden)

    Julie A Peterson

    2016-11-01

    Full Text Available Crop plants exhibit a wide diversity of defensive traits and strategies to protect themselves from damage by herbivorous pests and disease. These defensive traits may be naturally occurring or artificially selected through crop breeding, including introduction via genetic engineering. While these traits can have obvious and direct impacts on herbivorous pests, many have profound effects on higher trophic levels, including the natural enemies of herbivores. Multi-trophic effects of host plant resistance have the potential to influence, both positively and negatively, biological control. Plant defense traits can influence both the numerical and functional responses of natural enemies; these interactions can be semiochemically-, plant toxin-, plant nutrient-, and/or physically-mediated. Case studies involving predators, parasitoids, and pathogens of crop pests will be presented and discussed. These diverse groups of natural enemies may respond differently to crop plant traits based on their own unique biology and the ecological niches they fill. Genetically modified crop plants that have been engineered to express transgenic products affecting herbivorous pests are an additional consideration. For the most part, transgenic plant incorporated protectant (PIP traits are compatible with biological control due to their selective toxicity to targeted pests and relatively low non-target impacts, although transgenic crops may have indirect effects on higher trophic levels and arthropod communities mediated by lower host or prey number and/or quality. Host plant resistance and biological control are two of the key pillars of integrated pest management; their potential interactions, whether they are synergistic, complementary, or disruptive, are key in understanding and achieving sustainable and effective pest management.

  2. Biological control of white mold by Trichoderma harzianum in common bean under field conditions

    Directory of Open Access Journals (Sweden)

    Daniel Diego Costa Carvalho

    2015-12-01

    Full Text Available Abstract: The objective of this work was to evaluate Trichoderma harzianum isolates for biological control of white mold in common bean (Phaseolus vulgaris. Five isolates were evaluated for biocontrol of white mold in 'Perola' common bean under field conditions, in the 2009 and 2010 crop seasons. A commercial isolate (1306 and a control treatment were included. Foliar applications at 2x109 conidia mL-1 were performed at 42 and 52 days after sowing (DAS, in 2009, and at 52 DAS in 2010. The CEN287, CEN316, and 1306 isolates decreased the number of Sclerotinia sclerotiorum apothecia per square meter in comparison to the control, in both crop seasons. CEN287, CEN316, and 1306 decreased white mold severity during the experimental period, when compared to the control.

  3. Primary Study on Biological Control Potential of Trichoderma harzianum TL-1

    Institute of Scientific and Technical Information of China (English)

    Su; Zhenyu; Xiao; Man; Gao; Xinzheng; Tang; Libo; Li; Li

    2014-01-01

    Trichoderma harzianum is a widely used biocontrol fungus. The growth promoting effect of strain Trichoderma harzianum TL-1 on tomato and pepper and its biological control effects against tomato seedling damping-off and pepper blight were investigated through pot experiments. The results showed that the stain TL-1 had significant promotion effect on growth of pepper and tomato in sterilized and natural soils. With the application dose of 3. 0 and 0. 5g/ pot,their dry weight were increased up to 46% and 150% compared with control,respectively. In addition,TL-1 had good control effects against tomato seedling damping-off and pepper blight. Compared with fungicide treatment,TL-1 treatment could control diseases for long term,without repeat occurrence of diseases.

  4. High-latitude controls of thermocline nutrients and low latitude biological productivity.

    Science.gov (United States)

    Sarmiento, J L; Gruber, N; Brzezinski, M A; Dunne, J P

    2004-01-01

    The ocean's biological pump strips nutrients out of the surface waters and exports them into the thermocline and deep waters. If there were no return path of nutrients from deep waters, the biological pump would eventually deplete the surface waters and thermocline of nutrients; surface biological productivity would plummet. Here we make use of the combined distributions of silicic acid and nitrate to trace the main nutrient return path from deep waters by upwelling in the Southern Ocean and subsequent entrainment into subantarctic mode water. We show that the subantarctic mode water, which spreads throughout the entire Southern Hemisphere and North Atlantic Ocean, is the main source of nutrients for the thermocline. We also find that an additional return path exists in the northwest corner of the Pacific Ocean, where enhanced vertical mixing, perhaps driven by tides, brings abyssal nutrients to the surface and supplies them to the thermocline of the North Pacific. Our analysis has important implications for our understanding of large-scale controls on the nature and magnitude of low-latitude biological productivity and its sensitivity to climate change.

  5. Evidence of a Biological Control over Origin, Growth and End of the Calcite Prisms in the Shells of Pinctada margaritifera (Pelecypod, Pterioidea

    Directory of Open Access Journals (Sweden)

    Jean-Pierre Cuif

    2014-12-01

    Full Text Available Consistently classified among the references for calcite simple prisms, the microstructural units that form the outer layer of the Pinctada margaritifera have been investigated through a series of morphological, crystallographical and biochemical characterizations. It is often said that the polygonal transverse shape of the prisms result from the competition for space between adjacent crystals. In contrast to this classical scheme the Pinctada prisms appear to be composed of four successive developmental stages from the concentrically growing disks on the internal side of the periostracum to the morphological, structural and compositional changes in both envelopes and mineral components at the end of the prisms. These latest structural and compositional changes predate nacre deposition, so that the end of prism growth is not caused by occurrence of nacre, but by metabolic changes in the secretory epithelium. This sequence makes obvious the permanent biological control exerted by the outer cell layer of the mantle in both organic envelopes and mineralizing organic phases.

  6. State-of-the-art exposure chamber for highly controlled and reproducible THz biological effects studies

    Science.gov (United States)

    Cerna, Cesario Z.; Elam, David P.; Echchgadda, Ibtissam; Sloan, Mark A.; Wilmink, Gerald J.

    2014-03-01

    Terahertz (THz) imaging and sensing technologies are increasingly being used at international airports for security screening purposes and at major medical centers for cancer and burn diagnosis. The emergence of new THz applications has directly resulted in an increased interest regarding the biological effects associated with this frequency range. Knowledge of THz biological effects is also desired for the safe use of THz systems, identification of health hazards, and development of empirically-based safety standards. In this study, we developed a state-of-the-art exposure chamber that allowed for highly controlled and reproducible studies of THz biological effects. This innovative system incorporated an industry grade cell incubator system that permitted a highly controlled exposure environment, where temperatures could be maintained at 37 °C +/- 0.1 °C, carbon dioxide (CO2) levels at 5% +/- 0.1%, and relative humidity (RH) levels at 95% +/- 1%. To maximize the THz power transmitted to the cell culture region inside the humid incubator, a secondary custom micro-chamber was fabricated and incorporated into the system. This micro-chamber shields the THz beam from the incubator environment and could be nitrogen-purged to eliminate water absorption effects. Additionally, a microscope that allowed for real-time visualization of the live cells before, during, and after THz exposure was integrated into the exposure system.

  7. Interaction of Ulocladium atrum, a Potential Biological Control Agent, with Botrytis cinerea and Grapevine Plantlets

    Directory of Open Access Journals (Sweden)

    Sébastien Ronseaux

    2013-09-01

    Full Text Available The effectiveness of biological control agent, Ulocladium atrum (isolates U13 and U16 in protecting Vitis vinifera L. cv. Chardonnay against gray mold disease caused by Botrytis cinerea, and simulation of the foliar defense responses was investigated. A degraded mycelium structure during cultural assay on potato dextrose agar revealed that U. atrum isolates U13 and U16 were both antagonistic to B. cinerea, mainly when isolates were inoculated two days before Botrytis. Under in vitro conditions, foliar application of U. atrum protected grapevine leaves against gray mold disease. An increase in chitinase activity was induced by the presence of U. atrum isolates indicating that the biological control agents triggered plant defense mechanisms. Moreover, U13 has the potential to colonize the grapevine plantlets and to improve their growth. The ability of U. atrum isolates to exhibit an antagonistic effect against B. cinerea in addition to their aptitude to induce plant resistance and to promote grapevine growth may explain a part of their biological activity. Hence, this study suggests that U. atrum provides a suitable biocontrol agent against gray mold in grapevines.

  8. Magnetic resonance imaging contribution for diagnosing symptomatic neurovascular contact in classical trigeminal neuralgia: a blinded case-control study and meta-analysis.

    Science.gov (United States)

    Antonini, Giovanni; Di Pasquale, Antonella; Cruccu, Giorgio; Truini, Andrea; Morino, Stefania; Saltelli, Giorgia; Romano, Andrea; Trasimeni, Guido; Vanacore, Nicola; Bozzao, Alessandro

    2014-08-01

    Although classical trigeminal neuralgia (CTN) is frequently caused by neurovascular contact (NVC) at the trigeminal root entry zone (REZ), both anatomical and MRI studies have shown that NVC of the trigeminal nerve frequently occurs in individuals without CTN. To assess the accuracy of MRI in distinguishing symptomatic from asymptomatic trigeminal NVC, we submitted to high-definition MRI the series of CTN patients referred to our outpatient service between June 2011 and January 2013 (n=24), and a similar number of age-matched healthy controls. Two neuroradiologists, blinded to the clinical data, evaluated whether the trigeminal nerve displayed NVC in the REZ or non-REZ, whether it was dislocated by the vessel or displayed atrophy at the contact site, and whether the offending vessel was an artery or a vein. Our data were meta-analyzed with those of all similar studies published from January 1970 to June 2013. In our sample, REZ contact, nerve dislocation and nerve atrophy were independently associated with CTN (P=.027; P=.005; P=.035 respectively). Compared to a rather low sensitivity of each of these items (alone or in combination), their specificity was high. When REZ contact and nerve atrophy coexisted, both specificity and positive predictive value rose to 100%. Meta-analysis showed that REZ NVC was detected in 76% of symptomatic and 17% of asymptomatic nerves (PNVC, as detected by MRI, is highly likely to be symptomatic when it is associated with anatomical nerve changes.

  9. Perspectives on the potential of entomopathogenic fungi in biological control of ticks.

    Science.gov (United States)

    Fernandes, Éverton K K; Bittencourt, Vânia R E P; Roberts, Donald W

    2012-03-01

    Ticks are serious health threats for humans, and both domestic and wild animals. Ticks are controlled mostly by application of chemical products; but these acaricides have several negative side effects, including toxicity to animals, environmental contamination, and induction of chemical resistance in some tick populations. Entomopathogenic fungi infect arthropods in nature and can occur at enzootic or epizootic levels in their host populations. Laboratory studies clearly demonstrate that these fungi can cause high mortality in all developmental stages of several tick species, and also reduce oviposition of infected engorged females. Tick mortality following application of fungi in the field, however, often is less than that suggested by laboratory tests. This is due to many negative biotic and climatic factors. To increase efficacy of fungal agents for biological control of ticks under natural conditions, several points need consideration: (1) select effective isolates (viz., high virulence; and tolerance to high temperature, ultraviolet radiation and desiccation); (2) understand the main factors that affect virulence of fungal isolates to their target arthropods including the role of toxic metabolites of the fungal isolates; and (3) define with more precision the immune response of ticks to infection by entomopathogenic fungi. The current study reviews recent literature on biological control of ticks, and comments on the relevance of these results to advancing the development of fungal biocontrol agents, including improving formulation of fungal spores for use in tick control, and using entomopathogenic fungi in integrated pest (tick) management programs.

  10. Phenotypic charactheristics of fluorescent pseudomonss, biological control agent of lincat disease of temanggung tobacco

    Directory of Open Access Journals (Sweden)

    NINING NURUL AZIZAH

    2007-04-01

    Full Text Available Fluorescent pseudomonass isolated from local plants-rishosphere in temanggung controlled lincat disease of tobacco. This report describe phenotypic charactheristics of the bacteria in order to be used as a base for the development of the bacteria as a biological control agent of lincat disease. Phenotypic charactheristics of six isolates of fluorescent Pseudomonass which controlled lincat disease in the field were determined in the laboratory of Plant Bacteriology, Faculty of Agriculture, Gadjah Mada University. Plant pathogenicity tests were conducted by hypersensitive reaction into tobacco leaf and inoculation to tobacco plants. Antagonism test between fluorescent Pseudomonass and other candidate of biological control agents were also conducted. The results indicated that the bacteria were rod shape, Gram negative, positive reaction in catalase and oxidase tests. Nitrate reduce to nitrite, arginine was hydrolysed, fluorescent pigment were produced on King’s B medium, levan formation positive and all bacteria denitrifiy. The bacteria used urea, tween 80 and amylum were not hydrolised, poly--hydroxybutyrate was not accumulated in the cells. Negative reactions were observed for lysine decarboxylation, indol production, VP/MR reaction, and gelatn liquefation. Some compounds could be used as solely carbon sources. All isolates grew on the medium containing 2% NaCl. The best pH for growth was 6-7 and all isolates grew at 20-41C. Negative result were obtained for hypersensitive reaction and pathogenicity tests.

  11. The role of bacillus-based biological control agents in integrated pest management systems: plant diseases.

    Science.gov (United States)

    Jacobsen, B J; Zidack, N K; Larson, B J

    2004-11-01

    ABSTRACT Bacillus-based biological control agents (BCAs) have great potential in integrated pest management (IPM) systems; however, relatively little work has been published on integration with other IPM management tools. Unfortunately, most research has focused on BCAs as alternatives to synthetic chemical fungicides or bactericides and not as part of an integrated management system. IPM has had many definitions and this review will use the national coalition for IPM definition: "A sustainable approach to managing pests by combining biological, cultural, physical and chemical tools in a way that minimizes economic, health and environmental risks." This review will examine the integrated use of Bacillus-based BCAs with disease management tools, including resistant cultivars, fungicides or bactericides, or other BCAs. This integration is important because the consistency and degree of disease control by Bacillus-based BCAs is rarely equal to the control afforded by the best fungicides or bactericides. In theory, integration of several tools brings stability to disease management programs. Integration of BCAs with other disease management tools often provides broader crop adaptation and both more efficacious and consistent levels of disease control. This review will also discuss the use of Bacillus-based BCAs in fungicide resistance management. Work with Bacillus thuringiensis and insect pest management is the exception to the relative paucity of reports but will not be the focus of this review.

  12. Entanglement in Classical Optics

    CERN Document Server

    Ghose, Partha

    2013-01-01

    The emerging field of entanglement or nonseparability in classical optics is reviewed, and its similarities with and differences from quantum entanglement clearly pointed out through a recapitulation of Hilbert spaces in general, the special restrictions on Hilbert spaces imposed in quantum mechanics and the role of Hilbert spaces in classical polarization optics. The production of Bell-like states in classical polarization optics is discussed, and new theorems are proved to discriminate between separable and nonseparable states in classical wave optics where no discreteness is involved. The influence of the Pancharatnam phase on a classical Bell-like state is deived. Finally, to what extent classical polarization optics can be used to simulate quantum information processing tasks is also discussed. This should be of great practical importance because coherence and entanglement are robust in classical optics but not in quantum systems.

  13. [Biological activities of exogenous polysaccharides via controlling endogenous proteoglycan metabolism in vascular endothelial cells].

    Science.gov (United States)

    Sato, Tomoko; Yamamoto, Chika; Fujiwara, Yasuyuki; Kaji, Toshiyuki

    2008-05-01

    Proteoglycan contains glycosmainoglycans, which are endogenous sulfated polysaccharides, in the molecule. The metabolism of proteoglycans regulates cell behavior and cellular events. It is possible that exogenous polysaccharide-related molecules exhibit their biological activities by two mechanisms. One is the interaction with cells and the other is the interaction with growth factors/cytokines that regulate proteoglycans. In this review, we describe sodium spirulan, a sulfated polysaccharide obtained from a hot-water extract of the blue-green alga Spirulina platensis, as an exogenous polysaccharide that stimulates the release of proteoglycans from vascular endothelial cells. Factors that regulate endothelial proteoglycan metabolism are also being described as possible target molecules of exogenous polysaccharides. Further research is required to obtain exogenous polysaccharide-related molecules that exhibit useful biological activities through controlling endothelial proteoglycan metabolism for protection against vascular lesions such as atheroslcerosis.

  14. The small hive beetle Aethina tumida: A review of its biology and control measures

    Directory of Open Access Journals (Sweden)

    Andrew G. S. CUTHBERTSON et al

    2013-10-01

    Full Text Available The small hive beetle Aethina tumida is an endemic parasitic pest and scavenger of colonies of social bees indigenous to sub-Saharan Africa. In this region this species rarely inflicts severe damage on strong colonies since the bees have develo­­ped strategies to combat them. However, A. tumida has since ‘escaped’ from its native home and has recently invaded areas such as North America and Australia where its economic impact on the apiculture industry has been significant. Small hive beetle, should it become established within Europe, represents a real and live threat to the UK bee keeping industry. Here we review the biology and current pest status of A. tumida and up to-date research in terms of both chemical and biological control used against this honey bee pest [Current Zoology 59 (5: 644–653, 2013].

  15. 猪瘟控制(净化)对母猪分娩率的影响%Influence of Controlling (Eradicating) Classic Swine Fever to Sow Parturition Rate in a Large Scale Pig Farm

    Institute of Scientific and Technical Information of China (English)

    罗才庆

    2014-01-01

    Objective:Investigate and analyze whether the sow parturition rate could be improved by controlling (eradicating) classic swine fever in a large scale pig farm. Method:The antibodies of classic swine fever of sow were detected with Enzyme-linked immunosorbent assay (ELISA) on a large scale pig farm in Longyan city. The sows which the antibodies of classic swine fever were below standard were sifted out controlling (eradicating) classic swine fever. The data of the sow parturition rate were analyzed before controlling (eradicating) classic swine fever and after. Results:The numbers of the sows which showed returning to estrus, abortion and non-pregnancy have reduced and the sow parturition rate was improved obviously by controlling (eradicating) classic swine fever. Con-clusion:Controlling (eradicating) classic swine fever can improve the sow parturition efficiency. It is of a great sig-nificance for a large scale pig farm to control (eradicate) classic swine fever.%目的:通过对某猪场母猪实施猪瘟控制(净化)方案,研究分析能否提高该猪场的母猪分娩率。方法:采用酶联免疫吸附试验(ELISA)对龙岩市某规模化猪场的母猪进行猪瘟抗体检测,对猪瘟抗体检测不合格(阻断率小于40%)且同时满足两条及以上淘汰标准的种猪实行淘汰以达到猪瘟控制(净化)目的,并对猪瘟控制(净化)前后配种分娩结果进行收集、统计。结果:猪瘟控制(净化)后,母猪返情、流产、空胎数量减少,分娩率明显提升。结论:猪瘟控制(净化)可以提高母猪分娩率,实行猪瘟控制(净化)对规模化猪场具有重大意义。

  16. Biologically Based Methods for Control of Fumonisin-Producing Fusarium Species and Reduction of the Fumonisins.

    Science.gov (United States)

    Alberts, Johanna F; van Zyl, Willem H; Gelderblom, Wentzel C A

    2016-01-01

    Infection by the fumonisin-producing Fusarium spp. and subsequent fumonisin contamination of maize adversely affect international trade and economy with deleterious effects on human and animal health. In developed countries high standards of the major food suppliers and retailers are upheld and regulatory controls deter the importation and local marketing of fumonisin-contaminated food products. In developing countries regulatory measures are either lacking or poorly enforced, due to food insecurity, resulting in an increased mycotoxin exposure. The lack and poor accessibility of effective and environmentally safe control methods have led to an increased interest in practical and biological alternatives to reduce fumonisin intake. These include the application of natural resources, including plants, microbial cultures, genetic material thereof, or clay minerals pre- and post-harvest. Pre-harvest approaches include breeding for resistant maize cultivars, introduction of biocontrol microorganisms, application of phenolic plant extracts, and expression of antifungal proteins and fumonisin degrading enzymes in transgenic maize cultivars. Post-harvest approaches include the removal of fumonisins by natural clay adsorbents and enzymatic degradation of fumonisins through decarboxylation and deamination by recombinant carboxylesterase and aminotransferase enzymes. Although, the knowledge base on biological control methods has expanded, only a limited number of authorized decontamination products and methods are commercially available. As many studies detailed the use of natural compounds in vitro, concepts in reducing fumonisin contamination should be developed further for application in planta and in the field pre-harvest, post-harvest, and during storage and food-processing. In developed countries an integrated approach, involving good agricultural management practices, hazard analysis and critical control point (HACCP) production, and storage management, together with

  17. Biologically Based Methods for Control of Fumonisin-producing Fusarium species and Reduction of the Fumonisins

    Directory of Open Access Journals (Sweden)

    Johanna Francina Alberts

    2016-04-01

    Full Text Available Infection by the fumonisin-producing Fusarium spp. and subsequent fumonisin contamination of maize adversely affect international trade and economy with deleterious effects on human and animal health. In developed countries high standards of the major food suppliers and retailers are upheld and regulatory controls deter the importation and local marketing of fumonisin-contaminated food products. In developing countries regulatory measures are either lacking or poorly enforced, due to food insecurity, resulting in an increased mycotoxin exposure. The lack and poor accessibility of effective and environmentally safe control methods have led to an increased interest in practical and biological alternatives to reduce fumonisin intake. These include the application of natural resources, including plants, microbial cultures, genetic material thereof or clay minerals pre- and postharvest. Pre-harvest approaches include breeding for resistant maize cultivars, introduction of biocontrol microorganisms, application of phenolic plant extracts, and expression of antifungal proteins and fumonisin degrading enzymes in transgenic maize cultivars. Postharvest approaches include the removal of fumonisins by natural clay adsorbents and enzymatic degradation of fumonisins through decarboxylation and deamination by recombinant carboxylesterase and aminotransferase enzymes. Although the knowledge base on biological control methods has expanded, only a limited number of authorized decontamination products and methods are commercially available. As many studies detailed the use of natural compounds in vitro, concepts in reducing fumonisin contamination should be developed further for application in planta and in the field pre-harvest, postharvest, and during storage and food-processing. In developed countries an integrated approach, involving good agricultural management practices, hazard analysis and critical control point (HACCP production and storage management

  18. Biological insect control using Metarhizium anisopliae: morphological, molecular, and ecological aspects

    Directory of Open Access Journals (Sweden)

    Patricia Vieira Tiago

    2014-04-01

    Full Text Available Microbial control of insects is based on the rational use of pathogens to maintain environmentally balanced pest population levels, and Metarhizium anisopliae has been the most studied and most utilized fungal species for that purpose. The natural genetic variability of entomopathogenic fungi is considered one of the principal advantages of microbial insect control. The inter- and intraspecific variability and the genetic diversity and population structures of Metarhizium and other entomopathogenic fungi have been examined using ITS-RFLP, ISSR, and ISSP molecular markers. The persistence of M. anisopliae in the soil and its possible effects on the structures of resident microbial communities must be considered when selecting isolates for biological insect control.

  19. A controlled rate freeze/thaw system for cryopreservation of biological materials

    Science.gov (United States)

    Anselmo, V. J.; Harrison, R. G.

    1979-01-01

    A system which allows programmable temperature-time control for a 5 cc sample volume of an arbitrary biological material was constructed. Steady state and dynamic temperature control was obtained by supplying heat to the sample volume through resistive elements constructed as an integral part of the sample container. For cooling purposes, this container was totally immersed into a cold heat sink. Sample volume thermodynamic property data were obtained by measurements of heater power and heat flux through the container walls. Using a mixture of dry ice and alcohol at -79 C, sample volume was controlled from +40 C to -60 C at rates from steady state to + or - 65 C/min. Steady state temperature precision was better than 0.2 C while the dynamic capability depends on the temperature rate of change as well as the thermal mass of the sample and the container.

  20. [Nematophagous fungi used for the biological control of gastrointestinal nematodes in livestock and administration routes].

    Science.gov (United States)

    Sagüés, María Federica; Purslow, Peter; Fernández, Silvina; Fusé, Luis; Iglesias, Lucía; Saumell, Carlos

    2011-01-01

    The control of gastrointestinal nematodes relies at present mostly on antihelmintic treatments using synthetic molecules. This approach, however, has led to the appearance of resistance to some types of antihelmintics which, together with the need to cut down on the use of chemicals, has fostered the development of other control methods, such as biological control, which is the use of living organisms that are naturally antagonistic to an unwanted species. Among the natural enemies of nematode parasitic larvae is the microfungus Duddingtonia flagrans. Research has shown the ability of this fungus to reduce the number of nematode larvae in faeces, the ability of its chlamydospores to survive the passage through the gastrointestinal tract of livestock and, moreover, to keep its germinative ability, thus facilitating the development of formulations. The present review looks at the species currently used and the different ways of administering already tested nematophagous fungi.

  1. Long-term organic farming fosters below and aboveground biota: Implications for soil quality, biological control and productivity

    DEFF Research Database (Denmark)

    Birkhofer, K.; Bezemer, TM; Bloem, J;

    2008-01-01

     Organic farming may contribute substantially to future agricultural production worldwide by improving soil quality and pest control, thereby reducing environmental impacts of conventional farming. We investigated in a comprehensive way soil chemical, as well as below and aboveground biological...... promoting negative environmental impacts of agriculture by reducing internal biological cycles and pest control. On the contrary, organic farming fosters microbial and faunal decomposers and this propagates into the aboveground system via generalist predators thereby increasing conservation biological...... control. However, grain and straw yields were 23% higher in systems receiving mineral fertilizers and herbicides reflecting the trade-off between productivity and environmental responsibility....

  2. Biological and chemical control of the Asiatic garden beetle, Maladera castanea (Coleoptera: Scarabaeidae).

    Science.gov (United States)

    Koppenhöfer, Albrecht M; Fuzy, Eugene M

    2003-08-01

    The efficacy of chemical and biological control agents against larvae of the Asiatic garden beetle, Maladera castanea (Arrow), in turfgrass under laboratory, greenhouse, and field conditions were determined. In field trials where insecticides were applied preventively against eggs and young larvae, the molt-accelerating compound halofenozide and the neonicotinoids imidacloprid and thiamethoxam were ineffective, whereas another neonicotinoid, clothianidin, provided 62-93% control. In greenhouse experiments against third instars in pots, the carbamate insecticide carbaryl was ineffective, whereas the organophosphate trichlorfon provided 71-83% control. In laboratory, greenhouse, and field experiments, the entomopathogenic nematode Heterorhabditis bacteriophora Poinar and Steinernema glaseri Steiner (not tested in the field) were ineffective against third instars, whereas S. scarabaei Stock & Koppenhöfer provided excellent control. In microplot field experiments at a rate of 2.5 x 10(9) infective juveniles per ha, H. bacteriophora provided 12-33% control and S. scarabaei 71-86% control. Combinations of S. scarabaei and imidacloprid did not provide more control of third instars compared with S. scarabaei alone.

  3. Toward Building Hybrid Biological/in silico Neural Networks for Motor Neuroprosthetic Control.

    Science.gov (United States)

    Kocaturk, Mehmet; Gulcur, Halil Ozcan; Canbeyli, Resit

    2015-01-01

    In this article, we introduce the Bioinspired Neuroprosthetic Design Environment (BNDE) as a practical platform for the development of novel brain-machine interface (BMI) controllers, which are based on spiking model neurons. We built the BNDE around a hard real-time system so that it is capable of creating simulated synapses from extracellularly recorded neurons to model neurons. In order to evaluate the practicality of the BNDE for neuroprosthetic control experiments, a novel, adaptive BMI controller was developed and tested using real-time closed-loop simulations. The present controller consists of two in silico medium spiny neurons, which receive simulated synaptic inputs from recorded motor cortical neurons. In the closed-loop simulations, the recordings from the cortical neurons were imitated using an external, hardware-based neural signal synthesizer. By implementing a reward-modulated spike timing-dependent plasticity rule, the controller achieved perfect target reach accuracy for a two-target reaching task in one-dimensional space. The BNDE combines the flexibility of software-based spiking neural network (SNN) simulations with powerful online data visualization tools and is a low-cost, PC-based, and all-in-one solution for developing neurally inspired BMI controllers. We believe that the BNDE is the first implementation, which is capable of creating hybrid biological/in silico neural networks for motor neuroprosthetic control and utilizes multiple CPU cores for computationally intensive real-time SNN simulations.

  4. Use of ryegrass strips to enhance biological control of aphids by ladybirds in wheat fields

    Institute of Scientific and Technical Information of China (English)

    Zhao-Ke Dong; Feng-Juan Gao; Run-Zhi Zhang

    2012-01-01

    Non-crop habitats may play a vital role in conservation biological control.This study tested the effect of ryegrass (Lolium muitiflorum L.) strips on aphid and ladybird populations in adjacent winter wheat fields.The field experiment was conducted in three ryegrass-margin wheat plots and three control plots in 2010 in North China.In spring,the same aphid species,Sitobion miscanthi (Takahashi),was found in both the ryegrass strips and wheat plots.The population density of ladybirds in the ryegrass strips (3.5±0.9/m2) was significantly higher than in the wheat plots (1.5±0.5/m2).We cut the ryegrass,forcing the ladybirds to migrate to the wheat fields.Three and eight days after cutting the ryegrass,the aphid numbers in the ryegrass-margin wheat plots decreased significantly:they were 19.9% and 53.6%,respectively,lower than in control plots.In the early period of ladybird population development,the percentage of larvae was greater in the ryegrass-margin wheat plots than in controls,and the peak number of pupae in the ryegrass-margin wheat plots occurred 5 days earlier than in the control plots.The results suggest that ryegrass strips may promote the development of ladybird populations.Cutting ryegrass can manipulate ladybirds to enhance biological aphid control in wheat fields.The efficiency of this management approach is discussed.

  5. Laboratory Study on Biological Control of Ticks (Acari: Ixodidae by Entomopathogenic Indigenous Fungi (Beauveria bassiana

    Directory of Open Access Journals (Sweden)

    M Abdigoudarzi

    2009-12-01

    Full Text Available Background: Chemical control method using different acaricides as spray, dipping solution or pour-on is routinely used for controlling ticks. Biological control agents are favorable due to their safety for animals and environment. Entomopathogenic fungi such as Beauveria bassiana are well known for controlling ticks. In this study, two Iranian indigenous strains of B. bassiana (B. bassiana 5197 and B. bassiana Evin were selected and grown on specific me­dia. The pathogenic effects of these strains were evaluated on adult stages of two Iranian Ixodidae members (H. anatolicum anatolicum Koch 1844, and H. marginatum Koch 1844 by dipping method."nMethods: Two Iranian strains of Beauveria bassiana (Beauveria bassiana 5197 and Beauveria bassiana Evin were selected and were grown successfully on specific media. The pathogenic effects of these strains were evaluated on adult stages of Iranian Ixodidae members such as, Hyalomma anatolicum anatolicum and H. marginatum by dipping method (these ticks were grown up at laboratory conditions during 2002 up to 2003 and still it is continued ."nResults: There was no effect of strain 5197 on mortality or fecundity rates for ticks. There was acute phase sign of paralysis in test group after dipping ticks in suspension made from Evin strain of B. bassiana. In addition, the test groups were totally died after four months, but the control groups survived for six months."nConclusion: High concentration of fungal spores is needed for inducing fungal infection. Additional study using different strains and fungi on Iranian ticks is proposed.   Keywords: Biological control, fungi, Beauveria bassiana, ticks, Ixodidae, Iran

  6. Quantum teleportation without classical channel

    Science.gov (United States)

    Al Amri, M.; Li, Zheng-Hong; Zubairy, M. Suhail

    2016-11-01

    For the first time, we show how quantum teleportation can be achieved without the assistance of classical channels. Our protocol does not need any pre-established entangled photon pairs beforehand. Just by utilizing quantum Zeno effect and couterfactual communication idea, we can achieve two goals; entangling a photon and an atom and also disentangling them by non-local interaction. Information is completely transferred from atom to photon with controllable disentanglement processes. More importantly, there is no need to confirm teleportation results via classical channels.

  7. Biologically inspired kinematic synergies enable linear balance control of a humanoid robot.

    Science.gov (United States)

    Hauser, Helmut; Neumann, Gerhard; Ijspeert, Auke J; Maass, Wolfgang

    2011-05-01

    Despite many efforts, balance control of humanoid robots in the presence of unforeseen external or internal forces has remained an unsolved problem. The difficulty of this problem is a consequence of the high dimensionality of the action space of a humanoid robot, due to its large number of degrees of freedom (joints), and of non-linearities in its kinematic chains. Biped biological organisms face similar difficulties, but have nevertheless solved this problem. Experimental data reveal that many biological organisms reduce the high dimensionality of their action space by generating movements through linear superposition of a rather small number of stereotypical combinations of simultaneous movements of many joints, to which we refer as kinematic synergies in this paper. We show that by constructing two suitable non-linear kinematic synergies for the lower part of the body of a humanoid robot, balance control can in fact be reduced to a linear control problem, at least in the case of relatively slow movements. We demonstrate for a variety of tasks that the humanoid robot HOAP-2 acquires through this approach the capability to balance dynamically against unforeseen disturbances that may arise from external forces or from manipulating unknown loads.

  8. Biological and chemical treatment of Cedrela fissilis seeds for controlling Rhizoctonia sp.

    Directory of Open Access Journals (Sweden)

    Marília Lazarotto

    2013-03-01

    Full Text Available This research evaluated the effect of a fungicide and a biological product, singly and combined, for the control of pathogens, especially Rhizoctonia sp., in seeds of Cedrela fissilis. Before the seeds treatment, the inoculation of Rhizoctonia sp., isolated from C. fissilis seeds in blotter-test and considered pathogenic for the specie, was done on half of the seeds used. After, the seeds were subjected to treatments with powder organic product based on Trichoderma spp. (singly, powder fungicide Captan (also singly, combination of two products in a maximum dose considered (100% and combination of half dose of both products, besides the control. After the seeds treatments the following tests were done: germination, emergence in vermiculite, with evaluations of seedlings and sanitary by blotter-test. No treatment could eradicate Rhizoctonia sp. inoculated seed, but the treatment with 100% of the dose of both products reduced its incidence. The combination of chemical and biological products can be a viable alternative for the treatment of C. fissililis seeds, especially in the control of Rhizoctonia sp.

  9. Early pest development and loss of biological control are associated with urban warming.

    Science.gov (United States)

    Meineke, Emily K; Dunn, Robert R; Frank, Steven D

    2014-11-01

    Climate warming is predicted to cause many changes in ectotherm communities, one of which is phenological mismatch, wherein one species' development advances relative to an associated species or community. Phenological mismatches already lead to loss of pollination services, and we predict that they also cause loss of biological control. Here, we provide evidence that a pest develops earlier due to urban warming but that phenology of its parasitoid community does not similarly advance. This mismatch is associated with greater egg production that likely leads to more pests on trees.

  10. Entomopathogenic fungi as biological controllers: New insights into their virulence and pathogenicity

    Directory of Open Access Journals (Sweden)

    Shahid Ali Ahmad

    2012-01-01

    Full Text Available Entomopathogenic fungi vary considerably in their mode of action and virulence. Successful infection depends primarily on the adherence and penetration ability of a fungus to the host integuments. A variety of extracellular enzymes is produced during the degradation of insect integument. The attempts to control insects have changed over time from chemicals to natural control methods. This is why the development of natural methods of insect control or biopesticides, is preferred. By the use of fungal entomopathogens, insect pests can be controlled. There is no doubt that insects have been used for many years, but their effective use in the field remains elusive. However, their additional role in nature has also been discovered. Comparison of entomopathogens with conventional chemical pesticides depends on their efficiency and cost. In addition to efficiency, there are advantages in using microbial control agents, such as human safety and other non-target organisms; pesticide residues are minimized in food and biodiversity increased in managed ecosystems. In the present review the pathogenicity and virulence of entomopathogenic fungi and their role as biological control agents using biotechnology will be discussed.

  11. Survey of locomotion control of legged robots inspired by biological concept

    Institute of Scientific and Technical Information of China (English)

    WU QiDi; LIU ChengJu; ZHANG JiaQi; CHEN QiJun

    2009-01-01

    Compared with wheeled mobile robots, legged robots can easily step over obstacles and walk through rugged ground. They have more flexible bodies and therefore, can deal with complex environment. Nev-ertheless, some other issues make the locomotion control of legged robots a much complicated task, such as the redundant degree of freedoms and balance keeping. From literatures, locomotion control has been solved mainly based on programming mechanism. To use this method, walking trajectories for each leg and the gaits have to be designed, and the adaptability to an unknown environment cannot be guaranteed. From another aspect, studying and simulating animals' walking mechanism for engi-neering application is an efficient way to break the bottleneck of locomotion control for legged robots. This has attracted more and more attentions. Inspired by central pattern generator (CPG), a control method has been proved to be a successful attempt within this scope. In this paper, we will review the biological mechanism, the existence evidences, and the network properties of CPG. From the en-gineering perspective, we will introduce the engineering simulation of CPG, the property analysis, and the research progress of CPG inspired control method in locomotion control of legged robots. Then, in our research, we will further discuss on existing problems, hot issues, and future research directions in this field.

  12. Reliability of unstable periodic orbit based control strategies in biological systems

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, Nagender; Singh, Harinder P. [Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India); Hasse, Maria [Institut für Höchstleistungsrechnen, Universität Stuttgart, D-70569 Stuttgart (Germany); Biswal, B. [Cluster Innovation Center, University of Delhi, Delhi 110007 (India); Sri Venkateswara College, University of Delhi, Delhi 110021 (India)

    2015-04-15

    Presence of recurrent and statistically significant unstable periodic orbits (UPOs) in time series obtained from biological systems is now routinely used as evidence for low dimensional chaos. Extracting accurate dynamical information from the detected UPO trajectories is vital for successful control strategies that either aim to stabilize the system near the fixed point or steer the system away from the periodic orbits. A hybrid UPO detection method from return maps that combines topological recurrence criterion, matrix fit algorithm, and stringent criterion for fixed point location gives accurate and statistically significant UPOs even in the presence of significant noise. Geometry of the return map, frequency of UPOs visiting the same trajectory, length of the data set, strength of the noise, and degree of nonstationarity affect the efficacy of the proposed method. Results suggest that establishing determinism from unambiguous UPO detection is often possible in short data sets with significant noise, but derived dynamical properties are rarely accurate and adequate for controlling the dynamics around these UPOs. A repeat chaos control experiment on epileptic hippocampal slices through more stringent control strategy and adaptive UPO tracking is reinterpreted in this context through simulation of similar control experiments on an analogous but stochastic computer model of epileptic brain slices. Reproduction of equivalent results suggests that far more stringent criteria are needed for linking apparent success of control in such experiments with possible determinism in the underlying dynamics.

  13. Reliability of unstable periodic orbit based control strategies in biological systems

    Science.gov (United States)

    Mishra, Nagender; Hasse, Maria; Biswal, B.; Singh, Harinder P.

    2015-04-01

    Presence of recurrent and statistically significant unstable periodic orbits (UPOs) in time series obtained from biological systems is now routinely used as evidence for low dimensional chaos. Extracting accurate dynamical information from the detected UPO trajectories is vital for successful control strategies that either aim to stabilize the system near the fixed point or steer the system away from the periodic orbits. A hybrid UPO detection method from return maps that combines topological recurrence criterion, matrix fit algorithm, and stringent criterion for fixed point location gives accurate and statistically significant UPOs even in the presence of significant noise. Geometry of the return map, frequency of UPOs visiting the same trajectory, length of the data set, strength of the noise, and degree of nonstationarity affect the efficacy of the proposed method. Results suggest that establishing determinism from unambiguous UPO detection is often possible in short data sets with significant noise, but derived dynamical properties are rarely accurate and adequate for controlling the dynamics around these UPOs. A repeat chaos control experiment on epileptic hippocampal slices through more stringent control strategy and adaptive UPO tracking is reinterpreted in this context through simulation of similar control experiments on an analogous but stochastic computer model of epileptic brain slices. Reproduction of equivalent results suggests that far more stringent criteria are needed for linking apparent success of control in such experiments with possible determinism in the underlying dynamics.

  14. Cyprinid herpesvirus 3 and its evolutionary future as a biological control agent for carp in Australia.

    Science.gov (United States)

    McColl, Kenneth A; Sunarto, Agus; Holmes, Edward C

    2016-12-08

    Biological invasions are a major threat to global biodiversity. Australia has experienced many invasive species, with the common carp (Cyprinus carpio L.) a prominent example. Cyprinid herpesvirus 3 (CyHV-3) has been proposed as a biological control (biocontrol) agent for invasive carp in Australia. Safety and efficacy are critical factors in assessing the suitability of biocontrol agents, and extensive host-specificity testing suggests that CyHV-3 is safe. Efficacy depends on the relationship between virus transmissibility and virulence. Based on observations from natural outbreaks, as well as the biology of virus-host interactions, we hypothesize that (i) close contact between carp provides the most efficient transmission of virus, (ii) transmission occurs at regular aggregations of carp that favour recrudescence of latent virus, and (iii) the initially high virulence of CyHV-3 will decline following its release in Australia. We also suggest that the evolution of carp resistance to CyHV-3 will likely necessitate the future release of progressively more virulent strains of CyHV-3, and/or an additional broad-scale measure(s) to complement the effect of the virus. If the release of CyHV-3 does go ahead, longitudinal studies are required to track the evolution of a virus-host relationship from its inception, and particularly the complex interplay between transmission, virulence and host resistance.

  15. Quantifying uncertainty in partially specified biological models: how can optimal control theory help us?

    Science.gov (United States)

    Adamson, M W; Morozov, A Y; Kuzenkov, O A

    2016-09-01

    Mathematical models in biology are highly simplified representations of a complex underlying reality and there is always a high degree of uncertainty with regards to model function specification. This uncertainty becomes critical for models in which the use of different functions fitting the same dataset can yield substantially different predictions-a property known as structural sensitivity. Thus, even if the model is purely deterministic, then the uncertainty in the model functions carries through into uncertainty in model predictions, and new frameworks are required to tackle this fundamental problem. Here, we consider a framework that uses partially specified models in which some functions are not represented by a specific form. The main idea is to project infinite dimensional function space into a low-dimensional space taking into account biological constraints. The key question of how to carry out this projection has so far remained a serious mathematical challenge and hindered the use of partially specified models. Here, we propose and demonstrate a potentially powerful technique to perform such a projection by using optimal control theory to construct functions with the specified global properties. This approach opens up the prospect of a flexible and easy to use method to fulfil uncertainty analysis of biological models.

  16. Decreased functional diversity and biological pest control in conventional compared to organic crop fields.

    Science.gov (United States)

    Krauss, Jochen; Gallenberger, Iris; Steffan-Dewenter, Ingolf

    2011-01-01

    Organic farming is one of the most successful agri-environmental schemes, as humans benefit from high quality food, farmers from higher prices for their products and it often successfully protects biodiversity. However there is little knowledge if organic farming also increases ecosystem services like pest control. We assessed 30 triticale fields (15 organic vs. 15 conventional) and recorded vascular plants, pollinators, aphids and their predators. Further, five conventional fields which were treated with insecticides were compared with 10 non-treated conventional fields. Organic fields had five times higher plant species richness and about twenty times higher pollinator species richness compared to conventional fields. Abundance of pollinators was even more than one-hundred times higher on organic fields. In contrast, the abundance of cereal aphids was five times lower in organic fields, while predator abundances were three times higher and predator-prey ratios twenty times higher in organic fields, indicating a significantly higher potential for biological pest control in organic fields. Insecticide treatment in conventional fields had only a short-term effect on aphid densities while later in the season aphid abundances were even higher and predator abundances lower in treated compared to untreated conventional fields. Our data indicate that insecticide treatment kept aphid predators at low abundances throughout the season, thereby significantly reducing top-down control of aphid populations. Plant and pollinator species richness as well as predator abundances and predator-prey ratios were higher at field edges compared to field centres, highlighting the importance of field edges for ecosystem services. In conclusion organic farming increases biodiversity, including important functional groups like plants, pollinators and predators which enhance natural pest control. Preventative insecticide application in conventional fields has only short-term effects on aphid

  17. Biological and Cultural Control of Olive Fruit Fly in California---Utilization of Parasitoids from USDA-APHIS-PPQ, Guatemala and Cultural Control Methods

    Science.gov (United States)

    The parasitoid Psytallia humilis = P. cf. concolor (Szépligeti) was reared on sterile Mediterranean fruit fly, Ceratitis capitata (Wiedemann), larvae at the USDA, APHIS, PPQ, Moscamed biological control laboratory in San Miguel Petapa, Guatemala and shipped to the USDA, ARS, Parlier, for biological ...

  18. Geomorphic controls on biological soil crust distribution: A conceptual model from the Mojave Desert (USA)

    Science.gov (United States)

    Williams, Amanda J.; Buck, Brenda J.; Soukup, Deborah A.; Merkler, Douglas J.

    2013-08-01

    Biological soil crusts (BSCs) are bio-sedimentary features that play critical geomorphic and ecological roles in arid environments. Extensive mapping, surface characterization, GIS overlays, and statistical analyses explored relationships among BSCs, geomorphology, and soil characteristics in a portion of the Mojave Desert (USA). These results were used to develop a conceptual model that explains the spatial distribution of BSCs. In this model, geologic and geomorphic processes control the ratio of fine sand to rocks, which constrains the development of three surface cover types and biogeomorphic feedbacks across intermontane basins. (1) Cyanobacteria crusts grow where abundant fine sand and negligible rocks form saltating sand sheets. Cyanobacteria facilitate moderate sand sheet activity that reduces growth potential of mosses and lichens. (2) Extensive tall moss-lichen pinnacled crusts are favored on early to late Holocene surfaces composed of mixed rock and fine sand. Moss-lichen crusts induce a dust capture feedback mechanism that promotes further crust propagation and forms biologically-mediated vesicular (Av) horizons. The presence of thick biogenic vesicular horizons supports the interpretation that BSCs are long-lived surface features. (3) Low to moderate density moss-lichen crusts grow on early Holocene and older geomorphic surfaces that display high rock cover and negligible surficial fine sand. Desert pavement processes and abiotic vesicular horizon formation dominate these surfaces and minimize bioturbation potential. The biogeomorphic interactions that sustain these three surface cover trajectories support unique biological communities and soil conditions, thereby sustaining ecological stability. The proposed conceptual model helps predict BSC distribution within intermontane basins to identify biologically sensitive areas, set reference conditions for ecological restoration, and potentially enhance arid landscape models, as scientists address impacts

  19. Long-term organic farming fosters below and aboveground biota: Implications for soil quality, biological control and productivity

    NARCIS (Netherlands)

    Birkhofer, K.; Bezemer, T.M.; Bloem, J.; Bonkowski, M.; Christensen, S.; Dubois, D.; Ekelund, F.; Fliessbach, A.; Gunst, L.; Hedlund, K.; Mäder, P.; Mikola, J.; Robin, C.; Setälä, H.; Tatin-Froux, F.; Putten, van der W.H.; Scheu, S.

    2008-01-01

    Organic farming may contribute substantially to future agricultural production worldwide by improving soil quality and pest control, thereby reducing environmental impacts of conventional farming. We investigated in a comprehensive way soil chemical, as well as below and aboveground biological param

  20. High Host Specificity in Encarsia diaspidicola (Hymenoptera: Aphelinidae), a Biological Control Candidate Against the White Peach Scale in Hawaii

    Science.gov (United States)

    Pre-introductory host specificity tests were performed with Encarsia diaspidicola, a biological control candidate against the invasive white peach scale, Pseudaulacaspis pentagona. False oleander scale, P. cockerelli, coconut scale, Aspidiotus destructor, cycad scale, Aulacaspis yasumatsui, greenh...

  1. Classical, Semi-classical and Quantum Noise

    CERN Document Server

    Poor, H; Scully, Marlan

    2012-01-01

    David Middleton was a towering figure of 20th Century engineering and science and one of the founders of statistical communication theory. During the second World War, the young David Middleton, working with Van Fleck, devised the notion of the matched filter, which is the most basic method used for detecting signals in noise. Over the intervening six decades, the contributions of Middleton have become classics. This collection of essays by leading scientists, engineers and colleagues of David are in his honor and reflect the wide  influence that he has had on many fields. Also included is the introduction by Middleton to his forthcoming book, which gives a wonderful view of the field of communication, its history and his own views on the field that he developed over the past 60 years. Focusing on classical noise modeling and applications, Classical, Semi-Classical and Quantum Noise includes coverage of statistical communication theory, non-stationary noise, molecular footprints, noise suppression, Quantum e...

  2. Generation of a Tunable Environment for the Simulation of Excitonic Transport in Classical Systems

    CERN Document Server

    León-Montiel, R de J; Torres, Juan P

    2014-01-01

    The simulation and modeling of open systems has become an invaluable tool for understanding several processes that take place in physical, chemical and biological systems. An example of paramount importance is photosynthesis, a biological process that involves the transport of energy with a remarkable high efficiency to a reaction center. Recently, it has been shown that classical oscillator systems can be used to model the transport and coherence properties of molecular aggregates, in particular those of light-harvesting complexes. Even though the simulation of coherent evolution of classical oscillator systems can be easily implemented, the question on how to experimentally introduce and control dephasing effects due to a surrounding environment remains open. Here, we put forward a setup that provides an unique tool to generate a tunable environment for classical electrical oscillators. We illustrate the operation of the setup by considering the case of a damped random frequency harmonic oscillator. To demo...

  3. THE ROLE OF HALTICA SP. (COLEOPTERA: HALTICIDAE AS BIOLOGICAL CONTROL AGENT OF POLYGONUM CHINENSE

    Directory of Open Access Journals (Sweden)

    SUN JAY A

    1991-01-01

    Full Text Available The role of Haltica sp. (Coleoptera: Halticidae with emphasis on host specificity and damage potential in controlling Polygonum chinense was evaluated under laboratory condition. Starvation test of the weevil on 33 weeds and 14 crop plant species indicated that only 6 weed species were attacked: Polygonum chinense, P. nepalense, P. barbatum, P. longisetum, Ludwigia octovalvis and L. parennis with P. chinense as the most preferred host plant. Preliminary damage potential test indicated that a population of 0, 1,2 and 3 pairs of adult weevil reduced the percentage of fresh weight increment of P. chinense by 0; 46.2; 74.7 and 75.5% respectively. Field observations indicated that the larvae as well as adult weevils are potential biological control agents of P. chinense. Further studies are, however, on the host-range of this weevil.

  4. Supplemental control of lepidopterous pests on Bt transgenic sweet corn with biologically-based spray treatments.

    Science.gov (United States)

    Farrar, Robert R; Shepard, B Merle; Shapiro, Martin; Hassell, Richard L; Schaffer, Mark L; Smith, Chad M

    2009-01-01

    Biologically-based spray treatments, including nucleopolyhedroviruses, neem, and spinosad, were evaluated as supplemental controls for the fall armyworm, Spodoptera frugiperda (J. E. Smith), and corn earworm, Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae), on transgenic sweet corn, Zea mays (L.) (Poales: Poaceae), expressing a Cry1Ab toxin from Bacillus thuringiensis Berliner (Bacillales: Bacillaceae) (Bt). Overall, transgenic corn supported lower densities of both pests than did nontransgenic corn. Control of the fall armyworm was improved in both whorl-stage and tassel-stage corn by the use of either a nucleopolyhedrovirus or neem, but the greatest improvement was seen with spinosad. Only spinosad consistently reduced damage to ears, which was caused by both pest species. In general, efficacy of the spray materials did not differ greatly between transgenic and nontransgenic corn.

  5. Biological Control beneath the Feet: A Review of Crop Protection against Insect Root Herbivores

    Directory of Open Access Journals (Sweden)

    Alan Kergunteuil

    2016-11-01

    Full Text Available Sustainable agriculture is certainly one of the most important challenges at present, considering both human population demography and evidence showing that crop productivity based on chemical control is plateauing. While the environmental and health threats of conventional agriculture are increasing, ecological research is offering promising solutions for crop protection against herbivore pests. While most research has focused on aboveground systems, several major crop pests are uniquely feeding on roots. We here aim at documenting the current and potential use of several biological control agents, including micro-organisms (viruses, bacteria, fungi, and nematodes and invertebrates included among the macrofauna of soils (arthropods and annelids that are used against root herbivores. In addition, we discuss the synergistic action of different bio-control agents when co-inoculated in soil and how the induction and priming of plant chemical defense could be synergized with the use of the bio-control agents described above to optimize root pest control. Finally, we highlight the gaps in the research for optimizing a more sustainable management of root pests.

  6. Biological Control of Spreading Dayflower (Commelina diffusa with the Fungal Pathogen Phoma commelinicola

    Directory of Open Access Journals (Sweden)

    Clyde D. Boyette

    2015-10-01

    Full Text Available Greenhouse and field experiments showed that conidia of the fungal pathogen, Phoma commelinicola, exhibited bioherbicidal activity against spreading dayflower (Commelina diffusa seedlings when applied at concentrations of 106 to 109 conidia·mL−1. Greenhouse tests determined an optimal temperature for conidial germination of 25 °C–30 °C, and that sporulation occurred on several solid growth media. A dew period of ≥ 12 h was required to achieve 60% control of cotyledonary-first leaf growth stage seedlings when applications of 108 conidia·mL−1 were applied. Maximal control (80% required longer dew periods (21 h and 90% plant dry weight reduction occurred at this dew period duration. More efficacious control occurred on younger plants (cotyledonary-first leaf growth stage than older, larger plants. Mortality and dry weight reduction values in field experiments were ~70% and >80%, respectively, when cotyledonary-third leaf growth stage seedlings were sprayed with 108 or 109 conidia·mL−1. These results indicate that this fungus has potential as a biological control agent for controlling this problematic weed that is tolerant to the herbicide glyphosate.

  7. Laboratory Study on Biological Control of Ticks (Acari: Ixodidae by Entomopathogenic Indigenous Fungi (Beauveria bassiana

    Directory of Open Access Journals (Sweden)

    M Abdigoudarzi

    2009-12-01

    Full Text Available Background: Chemical control method using different acaricides as spray, dipping solution or pour-on is routinely used for controlling ticks. Biological control agents are favorable due to their safety for animals and environment. Entomopathogenic fungi such as Beauveria bassiana are well known for controlling ticks. In this study, two Iranian indigenous strains of B. bassiana (B. bassiana 5197 and B. bassiana Evin were selected and grown on specific me­dia. The pathogenic effects of these strains were evaluated on adult stages of two Iranian Ixodidae members (H. anatolicum anatolicum Koch 1844, and H. marginatum Koch 1844 by dipping method.Methods: Two Iranian strains of Beauveria bassiana (Beauveria bassiana 5197 and Beauveria bassiana Evin were selected and were grown successfully on specific media. The pathogenic effects of these strains were evaluated on adult stages of Iranian Ixodidae members such as, Hyalomma anatolicum anatolicum and H. marginatum by dipping method (these ticks were grown up at laboratory conditions during 2002 up to 2003 and still it is continued .Results: There was no effect of strain 5197 on mortality or fecundity rates for ticks. There was acute phase sign of paralysis in test group after dipping ticks in suspension made from Evin strain of B. bassiana. In addition, the test groups were totally died after four months, but the control groups survived for six months.Conclusion: High concentration of fungal spores is needed for inducing fungal infection. Additional study using different strains and fungi on Iranian ticks is proposed. 

  8. Manipulating the banana rhizosphere microbiome for biological control of Panama disease.

    Science.gov (United States)

    Xue, Chao; Penton, C Ryan; Shen, Zongzhuan; Zhang, Ruifu; Huang, Qiwei; Li, Rong; Ruan, Yunze; Shen, Qirong

    2015-08-05

    Panama disease caused by Fusarium oxysporum f. sp. cubense infection on banana is devastating banana plantations worldwide. Biological control has been proposed to suppress Panama disease, though the stability and survival of bio-control microorganisms in field setting is largely unknown. In order to develop a bio-control strategy for this disease, 16S rRNA gene sequencing was used to assess the microbial community of a disease-suppressive soil. Bacillus was identified as the dominant bacterial group in the suppressive soil. For this reason, B. amyloliquefaciens NJN-6 isolated from the suppressive soil was selected as a potential bio-control agent. A bioorganic fertilizer (BIO), formulated by combining this isolate with compost, was applied in nursery pots to assess the bio-control of Panama disease. Results showed that BIO significantly decreased disease incidence by 68.5%, resulting in a doubled yield. Moreover, bacterial community structure was significantly correlated to disease incidence and yield and Bacillus colonization was negatively correlated with pathogen abundance and disease incidence, but positively correlated to yield. In total, the application of BIO altered the rhizo-bacterial community by establishing beneficial strains that dominated the microbial community and decreased pathogen colonization in the banana rhizosphere, which plays an important role in the management of Panama disease.

  9. Pochonia chlamydosporia in the biological control of Fasciola hepatica in cattle in Southeastern Brazil.

    Science.gov (United States)

    Dias, A S; Araújo, J V; Braga, F R; Puppin, A C; Perboni, W R

    2013-06-01

    Biological control with the use of nematophagous fungi has been described very successfully by many authors and presents itself as a complementary control method, acting on the free-living forms of helminths. The efficacy of a formulation containing the fungus Pochonia chlamydosporia in controlling Fasciola hepatica eggs in faeces was evaluated in an experimental field assay. Two bovine groups (six animals each) were used: A (control) and B (treated with fungus). At 30 days after deworming, the animals were separated into two similar paddocks with flooded areas and were given pellets containing 25 % mycelial mass (group B) or no fungus (group A) at a dose of 1 g/10 kg body weight, twice a week, during 18 months. Faecal samples were harvested fortnightly in the animals of groups A and B and they were submitted at examination of quantitative sedimentation. The mean count of F. hepatica eggs per grams of faeces was significantly higher in group A (1.19) compared with those from group B (0.82) (P control group (A). Every month, faecal samples from paddocks A and B were collected and they were incubated. P. chlamydosporia was identified only in sample source of the paddock B. It can be concluded that the application of this fungical formulation with P. chlamydosporia 25 % mycelial mass was effective in reducing the availability of eggs in the environment and reinfections in calves in natural conditions.

  10. Effect of non-crop vegetation types on conservation biological control of pests in olive groves.

    Science.gov (United States)

    Paredes, Daniel; Cayuela, Luis; Gurr, Geoff M; Campos, Mercedes

    2013-01-01

    Conservation biological control (CBC) is an environmentally sound potential alternative to the use of chemical insecticides. It involves modifications of the environment to promote natural enemy activity on pests. Despite many CBC studies increasing abundance of natural enemies, there are far fewer demonstrations of reduced pest density and very little work has been conducted in olive crops. In this study we investigated the effects of four forms of non-crop vegetation on the abundance of two important pests: the olive psyllid (Euphyllura olivina) and the olive moth (Prays oleae). Areas of herbaceous vegetation and areas of woody vegetation near olive crops, and smaller patches of woody vegetation within olive groves, decreased pest abundance in the crop. Inter-row ground covers that are known to increase the abundance of some predators and parasitoids had no effect on the pests, possibly as a result of lack of synchrony between pests and natural enemies, lack of specificity or intra-guild predation. This study identifies examples of the right types of diversity for use in conservation biological control in olive production systems.

  11. COMPLEMENTARY SEX DETERMINATION IN HYMENOPTERAN PARASITOIDS AND ITS IMPLICATIONS FOR BIOLOGICAL CONTROL

    Institute of Scientific and Technical Information of China (English)

    WUZhishan; KeithR.Hopper; PaulJ.Ode; RogerW.Fuester; CHENJia-hua; GeorgeE.Heimpel

    2003-01-01

    In haplodiploid Hymenoptera, unfertilized eggs produce haploid males while fertilized eggs lead to diploid females under most circumstances. Diploid males can also be produced from fertilization under a system of sex determination known as complementary sex determination (CSD). Under single-locus CSD, sex is determined by multiple alleles at a single sex locus. Individuals heterozygous at the sex locus are female while hemizygous and homozygous individuals develop as haploid and diploid males, respectively. In multiple-locus CSD, two or more loci, each with two or more alleles, determine sex. Diploid individuals are female if one or more sex loci are het-erozygous, while a diploid is male only if homozygous at all sex loci. Diploid males are known to occur in 43 hym-enopteran species and single-locus CSD has been demonstrated in 22 of these species. Diploid males are either developmentally inviable or sterile, so their production constitutes a genetic load. Because diploid male production is more likely under inbreeding, CSD is a form of inbreeding depression. It is crucial to preserve the diversity of sex alleles and reduce the loss of genetic variation in biological control. In the parasitoid species with single-locus CSD, certain precautionary procedures can prevent negative effects of single-locus CSD on biological control.

  12. Chemical Biology Approaches to Genome Editing: Understanding, Controlling, and Delivering Programmable Nucleases.

    Science.gov (United States)

    Hu, Johnny H; Davis, Kevin M; Liu, David R

    2016-01-21

    Programmable DNA nucleases have provided scientists with the unprecedented ability to probe, regulate, and manipulate the human genome. Zinc-finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs), and the clustered regularly interspaced short palindromic repeat-Cas9 system (CRISPR-Cas9) represent a powerful array of tools that can bind to and cleave a specified DNA sequence. In their canonical forms, these nucleases induce double-strand breaks at a DNA locus of interest that can trigger cellular DNA repair processes that disrupt or replace genes. The fusion of these programmable nucleases with a variety of other protein domains has led to a rapidly growing suite of tools for activating, repressing, visualizing, and modifying loci of interest. Maximizing the usefulness and therapeutic relevance of these tools, however, requires precisely controlling their activity and specificity to minimize potentially toxic side effects arising from off-target activities. This need has motivated the application of chemical biology principles and methods to genome-editing proteins, including the engineering of variants of these proteins with improved or altered specificities, and the development of genetic, chemical, optical, and protein delivery methods that control the activity of these agents in cells. Advancing the capabilities, safety, effectiveness, and therapeutic relevance of genome-engineering proteins will continue to rely on chemical biology strategies that manipulate their activity, specificity, and localization.

  13. Effect of non-crop vegetation types on conservation biological control of pests in olive groves

    Directory of Open Access Journals (Sweden)

    Daniel Paredes

    2013-07-01

    Full Text Available Conservation biological control (CBC is an environmentally sound potential alternative to the use of chemical insecticides. It involves modifications of the environment to promote natural enemy activity on pests. Despite many CBC studies increasing abundance of natural enemies, there are far fewer demonstrations of reduced pest density and very little work has been conducted in olive crops. In this study we investigated the effects of four forms of non-crop vegetation on the abundance of two important pests: the olive psyllid (Euphyllura olivina and the olive moth (Prays oleae. Areas of herbaceous vegetation and areas of woody vegetation near olive crops, and smaller patches of woody vegetation within olive groves, decreased pest abundance in the crop. Inter-row ground covers that are known to increase the abundance of some predators and parasitoids had no effect on the pests, possibly as a result of lack of synchrony between pests and natural enemies, lack of specificity or intra-guild predation. This study identifies examples of the right types of diversity for use in conservation biological control in olive production systems.

  14. An intensive search for promising fungal biological control agents of ticks, particularly Rhipicephalus microplus.

    Science.gov (United States)

    Fernandes, Everton K K; Angelo, Isabele C; Rangel, Drauzio E N; Bahiense, Thiago C; Moraes, Aurea M L; Roberts, Donald W; Bittencourt, Vânia R E P

    2011-12-15

    Entomopathogenic fungi have been investigated worldwide as promising biological control agents of the cattle tick Rhipicephalus microplus. The current study evaluates the virulence of several fungal isolates to R. microplus larva in the laboratory as part of an effort to identify isolates with promise for effective biocontrol of R. microplus in the field. Sixty fungal isolates, encompassing 5 Beauveria spp. and 1 Engyodontium albus (=Beauveria alba), were included in this study. In addition to bioassays, the isolates were characterized morphologically and investigated as to their potential for conidial mass production. These findings were correlated with previous reports on the same fungal isolates of their natural UV-B tolerance (Fernandes et al., 2007), thermotolerance and cold activity (Fernandes et al., 2008), and genotypes (Fernandes et al., 2009). R. microplus larvae obtained from artificially infested calves were less susceptible to Beauveria bassiana infection than ticks acquired from naturally infested cattle from a different location. Isolates CG 464, CG 500 and CG 206 were among the most virulent Beauveria isolates tested in this study. All fungal isolates presented morphological features consistent with their species descriptions. Of the 53 B. bassiana isolates, five (CG 481, CG 484, CG 206, CG 235 and CG 487) had characteristics that qualified them as promising candidates for biological control agents of R. microplus, viz., mean LC(50) between 10(7) and 10(8)conidiaml(-1); produced 5000 conidia or more on 60mm(2) surface area of PDAY medium; and, in comparison to untreated (control) conidia, had the best conidial tolerances to UV-B (7.04 kJ m(-2)) and heat (45°C, 2h) of 50% or higher, and conidial cold (5°C, 15d) activity (mycelial growth) higher than 60%. The current study of 60 Beauveria spp. isolates, therefore, singles out a few (five) with high potential for controlling ticks under field conditions.

  15. The QTL within the H2 Complex Involved in the Control of Tuberculosis Infection in Mice Is the Classical Class II H2-Ab1 Gene.

    Science.gov (United States)

    Logunova, Nadezhda; Korotetskaya, Maria; Polshakov, Vladimir; Apt, Alexander

    2015-11-01

    The level of susceptibility to tuberculosis (TB) infection depends upon allelic variations in numerous interacting genes. In our mouse model system, the whole-genome quantitative trait loci (QTLs) scan revealed three QTLs involved in TB control on chromosomes 3, 9, and in the vicinity of the H2 complex on chromosome 17. For the present study, we have established a panel of new congenic, MHC-recombinant mouse strains bearing differential small segments of chromosome 17 transferred from the TB-susceptible I/St (H2j) strain onto the genetic background of TB-resistant C57BL/6 (B6) mice (H2b). This allowed narrowing the QTL interval to 17Ch: 33, 77-34, 34 Mb, containing 36 protein-encoding genes. Cloning and sequencing of the H2j allelic variants of these genes demonstrated profound polymorphic variations compare to the H2b haplotype. In two recombinant strains, B6.I-249.1.15.100 and B6.I-249.1.15.139, recombination breakpoints occurred in different sites of the H2-Aβ 1 gene (beta-chain of the Class II heterodimer H2-A), providing polymorphic variations in the domain β1 of the Aβ-chain. These variations were sufficient to produce different TB-relevant phenotypes: the more susceptible B6.I-249.1.15.100 strain demonstrated shorter survival time, more rapid body weight loss, higher mycobacterial loads in the lungs and more severe lung histopathology compared to the more resistant B6.I-249.1.15.139 strain. CD4+ T cells recognized mycobacterial antigens exclusively in the context of the H2-A Class II molecule, and the level of IFN-γ-producing CD4+ T cells in the lungs was significantly higher in the resistant strain. Thus, we directly demonstrated for the first time that the classical H2- Ab1 Class II gene is involved in TB control. Molecular modeling of the H2-Aj product predicts that amino acid (AA) substitutions in the Aβ-chain modify the motif of the peptide-MHC binding groove. Moreover, unique AA substitutions in both α- and β-chains of the H2-Aj molecule might

  16. The QTL within the H2 Complex Involved in the Control of Tuberculosis Infection in Mice Is the Classical Class II H2-Ab1 Gene.

    Directory of Open Access Journals (Sweden)

    Nadezhda Logunova

    2015-11-01

    Full Text Available The level of susceptibility to tuberculosis (TB infection depends upon allelic variations in numerous interacting genes. In our mouse model system, the whole-genome quantitative trait loci (QTLs scan revealed three QTLs involved in TB control on chromosomes 3, 9, and in the vicinity of the H2 complex on chromosome 17. For the present study, we have established a panel of new congenic, MHC-recombinant mouse strains bearing differential small segments of chromosome 17 transferred from the TB-susceptible I/St (H2j strain onto the genetic background of TB-resistant C57BL/6 (B6 mice (H2b. This allowed narrowing the QTL interval to 17Ch: 33, 77-34, 34 Mb, containing 36 protein-encoding genes. Cloning and sequencing of the H2j allelic variants of these genes demonstrated profound polymorphic variations compare to the H2b haplotype. In two recombinant strains, B6.I-249.1.15.100 and B6.I-249.1.15.139, recombination breakpoints occurred in different sites of the H2-Aβ 1 gene (beta-chain of the Class II heterodimer H2-A, providing polymorphic variations in the domain β1 of the Aβ-chain. These variations were sufficient to produce different TB-relevant phenotypes: the more susceptible B6.I-249.1.15.100 strain demonstrated shorter survival time, more rapid body weight loss, higher mycobacterial loads in the lungs and more severe lung histopathology compared to the more resistant B6.I-249.1.15.139 strain. CD4+ T cells recognized mycobacterial antigens exclusively in the context of the H2-A Class II molecule, and the level of IFN-γ-producing CD4+ T cells in the lungs was significantly higher in the resistant strain. Thus, we directly demonstrated for the first time that the classical H2- Ab1 Class II gene is involved in TB control. Molecular modeling of the H2-Aj product predicts that amino acid (AA substitutions in the Aβ-chain modify the motif of the peptide-MHC binding groove. Moreover, unique AA substitutions in both α- and β-chains of the H2-Aj

  17. Efficacy of a classical antiobesity Unani pharmacopial formulation (Safoof-e-Muhazzil in systolic and diastolic blood pressure: A randomized, open-labeled, controlled clinical study

    Directory of Open Access Journals (Sweden)

    Asim Ali Khan

    2013-01-01

    Full Text Available The aim of this study is to evaluate the efficacy of a Unani formulation in hypertension. A total of 90 patients with total cholesterol level of more than 220 mg/dl with associated conditions were included in this study. A total of 30 patients having a mean systolic blood pressure (BP of 133.86 mmHg comprising Group A received Unani formulation Safoof-e-Muhazzil (SM in its classical powder form in the dose of 5 g twice a day orally. Group B comprising of 30 patients with a mean systolic BP of 133.13 mmHg received same drug, but in compressed tablet form in the same dosage, whereas, 30 patients comprising Group C with a mean systolic BP of 129.45 mmHg, received Atorvastatin 10 mg as a standard control. Patients were evaluated on each follow-up at 2 nd , 4 th and 6 th week. The mean systolic BP in Group A and B before treatment was 133.86 ± 3.028 mmHg and 133.13 ± 2.852 mmHg, which significantly decreased to 119.33 ± 1.922 mmHg (P < 0.001 and 119 ± 1.760 mmHg (P < 0.001 respectively. In the control Group C before treatment BP was 129.45 ± 2.499 mmHg and after treatment it significantly decreased to 124.34 ± 1.794 mmHg (P < 0.01. The percentage change after treatment was 10.85%, 10.61% and 3.94% respectively in each group. Mean diastolic BP in Group A and B before treatment was 85.06 ± 2.11 mmHg and 84.56 ± 1.5 mmHg, which significantly decreased to 79.06 ± 1.56 mmHg (P < 0.001 and 79.96 ± 1.15 mmHg (P < 0.001 respectively, BP before treatment in Group C was 83.23 ± 1.588 mmHg, which was decreased to 124.34 ± 1.794 mmHg (P < 0.01. The study results indicate that the test drug was quite effective in reducing both systolic as well as diastolic BP.

  18. Partitioning the climatic and biological controls on photosynthetic fluxes in Amazonian tropical evergreen forests

    Science.gov (United States)

    Wu, J.; Guan, K.; Albert, L.; Hayek, M.; Restrepo-Coupe, N.; Prohaska, N.; Wiedemann, K. T.; Marostica, S. F.; Stark, S. C.; Smith, M.; Silva, R. D.; Dye, D. G.; Nelson, B. W.; Huete, A. R.; Saleska, S. R.

    2014-12-01

    Understanding the mechanistic controls on tropical forests photosynthetic metabolism is a central problem of ecology and global change biology. We hypothesize two different temporal scales for the mechanisms regulating tropical photosynthesis (Gross Ecosystem Productivity, GEP): (1) at seasonal scales, leaf phenology (changing age and amount of leaves) is the primary control on GEP seasonality; (2) at the hourly scale with a constant phenological stage, climatic variables are the first order controls on GEP. In order to test this hypothesis, we partitioned the sources of GEP variation measured on eddy flux towers in central Amazon forests into biological and climatic components. The biological component (photosynthetic capacity, or PC) was defined as the monthly mean value of GEP extracted under a fixed narrow range of climate conditions, representing phenological changes associated with the amount and age of leaves. The climatic component was extracted via a path analysis of the hourly flux data, conditioned on a given monthly PC, representing the effects of fluctuating climate operating on the given PC. The main climatic variables were PAR, air-temperature, VPD, and Cloudiness Index (CI), the fraction of reduction of incident solar radiance due to clouds and aerosols relative to that expected under clear sky conditions. We found that the variability in monthly GEP arises from both seasonality of PC and that of climate, but despite the strong seasonality of climate, GEP was dominated by PC seasonality (R2=0.92). We found that the variability in hourly GEP (relative to the potential represented by monthly PC) was controlled primarily by PAR and VPD (as modified by the influence of CI). The tradeoff between the positive GEP effects of increased PAR and the negative effects of higher VPD stress indicates that tropical forests are stable in the face of modest climatic variability. For example, a significant reduction in mean cloudiness (of 0.1 CI units, corresponding

  19. Lectures on Classical Integrability

    CERN Document Server

    Torrielli, Alessandro

    2016-01-01

    We review some essential aspects of classically integrable systems. The detailed outline of the lectures consists of: 1. Introduction and motivation, with historical remarks; 2. Liouville theorem and action-angle variables, with examples (harmonic oscillator, Kepler problem); 3. Algebraic tools: Lax pairs, monodromy and transfer matrices, classical r-matrices and exchange relations, non-ultralocal Poisson brackets, with examples (non-linear Schroedinger model, principal chiral field); 4. Features of classical r-matrices: Belavin-Drinfeld theorems, analyticity properties, and lift of the classical structures to quantum groups; 5. Classical inverse scattering method to solve integrable differential equations: soliton solutions, spectral properties and the Gel'fand-Levitan-Marchenko equation, with examples (KdV equation, Sine-Gordon model). Prepared for the Durham Young Researchers Integrability School, organised by the GATIS network. This is part of a collection of lecture notes.

  20. Epidemic Reasons and Recommendations of Prevention and Control about Classical Swine Fever%猪瘟的流行原因及其防控建议

    Institute of Scientific and Technical Information of China (English)

    黄江峰; 江岸林; 杨晓天; 李纪春

    2011-01-01

    @@ 猪瘟(Classical SwiHe fever,CSF)是由猪瘟病毒(Classical swine fever virus,CSFV)引起猪的一种高度接触性、致死性的传染病.高热稽留,便秘与拉稀交替,死亡率高是其主要特征.目前,主要有非典型性猪瘟和繁殖障碍性猪瘟两种类型.

  1. Maneuvering control and configuration adaptation of a biologically inspired morphing aircraft

    Science.gov (United States)

    Abdulrahim, Mujahid

    Natural flight as a source of inspiration for aircraft design was prominent with early aircraft but became marginalized as aircraft became larger and faster. With recent interest in small unmanned air vehicles, biological inspiration is a possible technology to enhance mission performance of aircraft that are dimensionally similar to gliding birds. Serial wing joints, loosely modeling the avian skeletal structure, are used in the current study to allow significant reconfiguration of the wing shape. The wings are reconfigured to optimize aerodynamic performance and maneuvering metrics related to specific mission tasks. Wing shapes for each mission are determined and related to the seagulls, falcons, albatrosses, and non-migratory African swallows on which the aircraft are based. Variable wing geometry changes the vehicle dynamics, affording versatility in flight behavior but also requiring appropriate compensation to maintain stability and controllability. Time-varying compensation is in the form of a baseline controller which adapts to both the variable vehicle dynamics and to the changing mission requirements. Wing shape is adapted in flight to minimize a cost function which represents energy, temporal, and spatial efficiency. An optimal control architecture unifies the control and adaptation tasks.

  2. Molecular biological approaches to the study of vectors in relation to malaria control

    Directory of Open Access Journals (Sweden)

    J. M. Crampton

    1992-01-01

    Full Text Available To a large extent, control of malaria vectors relies on the elimination of breeding sites and the application of chemical agents. There are increasing problems associated with the use of synthetic insecticides for vector control, including the evolution of resistance, the high cost of developing and registering new insecticides and an awareness of pollution from insecticide residues. These factors have stimulated interest in the application of molecular biology to the study of mosquito vectors of malaria; focussing primarily on two aspects. First, the improvement of existing control measures through the development of simplified DNA probe systems suitable for identification of vectors of malaria. The development of synthetic, non-radioactive DNA probes suitable for identification of species in the Anopheles gambiae complex is described with the aim of defining a simplified methodology wich is suitable for entomologist in the field. The second aspect to be considered is the development of completely novel strategies through the development of completely novel strategies through the genetic manipulation of insect vectors of malaria in order to alter their ability to transmit the disease. The major requirements for producing transgenic mosquitoes are outlined together with the progress wich has been made to date and discussed in relation to the prospects which this type of approach has for the future control of malaria.

  3. Control of rRNA Synthesis in Escherichia coli: a Systems Biology Approach†

    Science.gov (United States)

    Dennis, Patrick P.; Ehrenberg, Mans; Bremer, Hans

    2004-01-01

    The first part of this review contains an overview of the various contributions and models relating to the control of rRNA synthesis reported over the last 45 years. The second part describes a systems biology approach to identify the factors and effectors that control the interactions between RNA polymerase and rRNA (rrn) promoters of Escherichia coli bacteria during exponential growth in different media. This analysis is based on measurements of absolute rrn promoter activities as transcripts per minute per promoter in bacterial strains either deficient or proficient in the synthesis of the factor Fis and/or the effector ppGpp. These absolute promoter activities are evaluated in terms of rrn promoter strength (Vmax/Km) and free RNA polymerase concentrations. Three major conclusions emerge from this evaluation. First, the rrn promoters are not saturated with RNA polymerase. As a consequence, changes in the concentration of free RNA polymerase contribute to changes in rrn promoter activities. Second, rrn P2 promoter strength is not specifically regulated during exponential growth at different rates; its activity changes only when the concentration of free RNA polymerase changes. Third, the effector ppGpp reduces the strength of the rrn P1 promoter both directly and indirectly by reducing synthesis of the stimulating factor Fis. This control of rrn P1 promoter strength forms part of a larger feedback loop that adjusts the synthesis of ribosomes to the availability of amino acids via amino acid-dependent control of ppGpp accumulation. PMID:15590778

  4. Supplemental food that supports both predator and pest: a risk for biological control?

    Science.gov (United States)

    Leman, Ada; Messelink, Gerben J

    2015-04-01

    Supplemental food sources to support natural enemies in crops are increasingly being tested and used. This is particularly interesting for generalist predators that can reproduce on these food sources. However, a potential risk for pest control could occur when herbivores also benefit from supplemental food sources. In order to optimize biological control, it may be important to select food sources that support predator populations more than herbivore populations. In this study we evaluated the nutritional quality of four types of supplemental food for the generalist predatory mites Amblyseius swirskii Athias-Henriot and Amblydromalus (Typhlodromalus) limonicus (Garman and McGregor), both important thrips predators, and for the herbivore western flower thrips Frankliniella occidentalis Pergande, by assessing oviposition rates. These tests showed that application of corn pollen, cattail pollen or sterilized eggs of Ephestia kuehniella Zeller to chrysanthemum leaves resulted in three times higher oviposition rates of thrips compared to leaves without additional food. None of the tested food sources promoted predatory mites or western flower thrips exclusively. Decapsulated cysts of Artemia franciscana Kellogg were not suitable, whereas cattail pollen was very suitable for both predatory mites and western flower thrips. In addition, we found that the rate of thrips predation by A. swirskii can be reduced by 50 %, when pollen is present. Nevertheless, application of pollen or Ephestia eggs to a chrysanthemum crop still strongly enhanced the biological control of thrips with A. swirskii, both at low and high release densities of predatory mites through the strong numerical response of the predators. Despite these positive results, application in a crop should be approached with caution, as the results may strongly depend on the initial predator-prey ratio, the nutritional quality of the supplemental food source, the species of predatory mites, the distribution of the

  5. Fungal biological control agents for integrated management of Culicoides spp. (Diptera: Ceratopogonidae of livestock

    Directory of Open Access Journals (Sweden)

    B. W. Narladkar

    2015-02-01

    Full Text Available Aim: Entomopathogenic fungi Metarhizium anisopliae and Beauveria bassiana had wide host range against insects and hence these are being exploited as fungal bio-pesticide on a large scale. Both fungi are proved pesticides against many crop pests and farmers are well acquainted with their use on the field. Thus, research was aimed to explore the potency of these fungal spores against larval and adult Culicoides midges, a pest of livestock. Materials and Methods: In-vitro testing of both fungal biological control agents was undertaken in Petri dishes against field collected Culicoides larvae, while in plastic beakers against field collected blood-engorged female Culicoides midges. In-vivo testing was undertaken by spraying requisite concentration of fungal spores on the drainage channel against larvae and resting sites of adult Culicoides midges in the cattle shed. Lethal concentration 50 (LC50 values and regression equations were drawn by following probit analysis using SPSS statistical computerized program. Results: The results of this study revealed LC50 values of 2692 mg and 3837 mg (108 cfu/g for B. bassiana and M. anisopliae, respectively, against Culicoides spp. larvae. Death of Culicoides larvae due to B. bassiana showed greenish coloration in the middle of the body with head and tail showed intense blackish changes, while infection of M. anisopliae resulted in death of Culicoides larvae with greenish and blackish coloration of body along with total destruction, followed by desquamation of intestinal channel. The death of adult Culicoides midges were caused by both the fungi and after death growth of fungus were very well observed on the dead cadavers proving the efficacy of the fungus. Conclusion: Preliminary trials with both funguses (M. anisopliae, B. bassiana showed encouraging results against larvae and adults of Culicoides spp. Hence, it was ascertained that, these two fungal molecules can form a part of biological control and

  6. Teaching Classical Mechanics using Smartphones

    CERN Document Server

    Chevrier, Joel; Ledenmat, Simon; Bsiesy, Ahmad

    2012-01-01

    Using a personal computer and a smartphone, iMecaProf is a software that provides a complete teaching environment for practicals associated to a Classical Mechanics course. iMecaProf proposes a visual, real time and interactive representation of data transmitted by a smartphone using the formalism of Classical Mechanics. Using smartphones is more than using a set of sensors. iMecaProf shows students that important concepts of physics they here learn, are necessary to control daily life smartphone operations. This is practical introduction to mechanical microsensors that are nowadays a key technology in advanced trajectory control. First version of iMecaProf can be freely downloaded. It will be tested this academic year in Universit\\'e Joseph Fourier (Grenoble, France)

  7. Biological control of mycotoxin-producing molds Controle biológico de fungos de armazenamento produtores de micotoxinas

    Directory of Open Access Journals (Sweden)

    Flávio Henrique Vasconcelos de Medeiros

    2012-10-01

    Full Text Available Mycotoxins are produced by the secondary metabolism of many fungi and can be found in almost 25% of the world's agricultural commodities. These compounds are toxic to humans, animals, and plants and therefore, efforts should be made to avoid mycotoxin contamination in food and feed. Besides, up to 25% of all harvested fruits and vegetables are lost due to storage molds and/or mycotoxin contamination and many methods have been applied to mitigate these issues, but most of them rely on the use of fungicides. Although chemicals are often the first defensive line against mycotoxigenic fungi, the indiscriminate use of fungicides are awakening the public perception due to their noxious effects on the environment and human/animal health. Thus, there is an increasing public pressure for a safer and eco-friendly alternative to control these organisms. In this background, biological control using microbial antagonists such as bacteria, fungi and yeasts have been shown to be a feasible substitute to reduce the use of chemical compounds. Despite of the positive findings using the biocontrol agents only a few products have been registered and are commercially available to control mycotoxin-producing fungi. This review brings about the up-to-date biological control strategies to prevent or reduce harvested commodity damages caused by storage fungi and the contamination of food and feed by mycotoxins.As micotoxinas são produzidas pelo metabolismo secundário de várias espécies de fungos e podem ser encontradas em quase 25% das commodities agrícolas. Esses compostos são tóxicos a humanos, animais e plantas e, portanto, esforços para evitar a contaminação de micotoxinas em alimentos e rações devem ser feitos. Além disso, até 25% das frutas e legumes em pós-colheita são perdidos em decorrência do ataque de fungos de armazenamento e/ou contaminações por micotoxinas. Vários métodos têm sido aplicados para mitigar os problemas de micotoxinas

  8. Application of Bathurin and borax in the biological control of Monomorium pharaonis in housing estates.

    Science.gov (United States)

    Vobrázková, E; Vanková, J; Samsinák, K

    1976-05-01

    Of two apartment houses infested with ants of the species Monomorium pharaonis, one was treated with a biological, the other with a chemical substance. In the first case we used Bathurin in combination with borax at a concentration of 1.3% for both substances. In the first week, borax was added to the bait (minced beef), within the next three weeks, the bait was mixed with Bathurin. The procedure was repeated 5 times. After this period, we achieved complete control of the ants on the infested premises.--Our results obtained with the chemical substance (the insecticide Anthrix) were less successful. This indicates that the first method, although time-consuming and requiring a perfect collaboration with all inhabitants, is safer, because it leads to the complete eradication of ants in the infested premises.

  9. The possible usage of mycoviruses in biological control against tree pathogenic fungi

    Directory of Open Access Journals (Sweden)

    Ayşe Gülden Aday Kaya

    2015-01-01

    Full Text Available Mycoviruses in many organism including plant pathogenic fungi. They are mostly spread intracellularly via asexual and sexual reproduction of the fungi and cause some changes on them. Although many mycoviruses have no clear effect on their hosts, there are also many reports that they cause some phenotypic chances. Especially, they have effect on plant pathogenic fungi by increasing or decreasing their virulence. When they reduce the virulence of the host like in Chestnut canker sample, it is possible to use them in biological control. In this review, mycoviruses detected on some important fungal pathogens of forest trees both in our country and world were introduced and the studies carried out were summarized.

  10. ECOLOGY OF PANTOEA AGGLOMERANS 2066-7 STRAIN: A BIOLOGICAL CONTROL OF BACTERIA ONION DISEASES

    Directory of Open Access Journals (Sweden)

    Soumia Sadik

    2016-06-01

    Full Text Available The growth response of the biocontrol agent Pantoea agglomerans 2066-7 to change in water activity (aw, temperature, and pH was determined in vitro in basic medium. The minimum temperature at which 2066-7 was able to grow was 7°C, and the growth of 2066-7 did not change at varying pH levels (4–10.34. The best growth was obtained at a water activity of 0.98 in all media modified with the four solutes (glucose, glycerol, NaCl and polyethylene glycol. The solute used to reduce water activity had a great influence on bacterial growth, especially at unfavorable conditions (low temperature. This study has defined the range of environmental conditions (aw, pH, and temperature over which the bacteria may be developed for biological control of plant diseases.

  11. Suppressive composts from organic wastes as agents of biological control of fusariosis in Tatartan Republic (Russia)

    Science.gov (United States)

    Gumerova, Raushaniya; Galitskaya, Polina; Beru, Franchesca; Selivanovskaya, Svetlana

    2015-04-01

    Plant diseases are one of the seriously limiting factors of agriculture efficiency around the world. Diseases caused by fungi are the major threat to plants. Crop protection in modern agriculture heavily depends on chemical fungicides. Disadvantages of chemical pesticides soon became apparent as damage to the environment and a hazard to human health. In this regard use of biopesticides becomes an attractive alternative method of plant protection. For biological control of fungal plant diseases, separate bacterial or fungal strains as well as their communities can be used. Biopreparations must consist of microbes that are typical for local climate and soil conditions and therefore are able to survive in environments for a long time. Another option of plant pests' biological control is implementation of suppressive composts made of agricultural or other organic wastes. These composts can not only prevent the development of plant diseases, but also improve the soil fertility. The objective of this work was estimation of potential of composts and strains isolated from these composts as means for biological control of fusariosis that is one of the most widespread plant soil born disease. The composts were made up of the commonly produced agricultural wastes produced in Tatarstan Republic (Russia). Fusarium oxysporum f. sp. radicis-lycopersici was used as a model phytopathogen. Ten types of organic waste (Goat manure (GM), Chicken dung (CD), Chicken dung with straw addition (CS), Rabbit dung (RD), Cow manure (CM), Rerotting pork manure (RPM), Fresh pork manure (FPM), Pork manure with sawdust and straw (PMS), the remains of plants and leaves (PL), the vegetable waste (VW) were sampled in the big farms situated in Tatarstan Republic which is one of the main agricultural regions of Russia. The initial wastes were composted for 150 days. Further, the following characteristics of the composts were assessed: pH, electro conductivity, TOC, DOC, Ntot. On petri dishes with meat

  12. Molecular biological applications in the diagnosis and control of leishmaniasis and parasite identification.

    Science.gov (United States)

    Schallig, Henk D F H; Oskam, Linda

    2002-08-01

    Molecular biology is increasingly relevant to the diagnosis and control of infectious diseases. Information on DNA sequences has been extensively exploited for the development of polymerase chain reaction-based assays for the diagnosis of leishmaniasis and the identification of parasite species. It has also led to the use of cloned antigen for serodiagnosis. It is expected that the sequencing of the Leishmania major genome and the genomes of other Leishmania species will enable important progress in further improving diagnosis and control. The ability to use genome data to clone and sequence genes, which, when expressed, provide antigens for vaccine development, will increase the possibilities for rational vaccine development. Moreover, DNA on its own will provide the basis for the development of DNA vaccines that may overcome some of the problems encountered with protein-based vaccines. One of the greatest threats to parasite control is the development of drug resistance in parasites. Knowing the molecular basis of drug resistance and the ability to monitor its development with sensitive and specific DNA-based assays for 'resistance alleles' may aid maintaining the effectiveness of available anti-Leishmania drugs. Finally, techniques such as microarrays and nucleic acid sequence-based amplification will eventually allow rapid screening for specific parasite genotypes and assist in diagnostic and epidemiological studies.

  13. AMIGO2, a toolbox for dynamic modeling, optimization and control in systems biology

    Science.gov (United States)

    Balsa-Canto, Eva; Henriques, David; Gábor, Attila; Banga, Julio R.

    2016-01-01

    Motivation: Many problems of interest in dynamic modeling and control of biological systems can be posed as non-linear optimization problems subject to algebraic and dynamic constraints. In the context of modeling, this is the case of, e.g. parameter estimation, optimal experimental design and dynamic flux balance analysis. In the context of control, model-based metabolic engineering or drug dose optimization problems can be formulated as (multi-objective) optimal control problems. Finding a solution to those problems is a very challenging task which requires advanced numerical methods. Results: This work presents the AMIGO2 toolbox: the first multiplatform software tool that automatizes the solution of all those problems, offering a suite of state-of-the-art (multi-objective) global optimizers and advanced simulation approaches. Availability and Implementation: The toolbox and its documentation are available at: sites.google.com/site/amigo2toolbox. Contact: ebalsa@iim.csic.es Supplementary information: Supplementary data are available at Bioinformatics online. PMID:27378288

  14. Candidate predators for biological control of the poultry red mite Dermanyssus gallinae.

    Science.gov (United States)

    Lesna, Izabela; Wolfs, Peter; Faraji, Farid; Roy, Lise; Komdeur, Jan; Sabelis, Maurice W

    2009-06-01

    The poultry red mite, Dermanyssus gallinae, is currently a significant pest in the poultry industry in Europe. Biological control by the introduction of predatory mites is one of the various options for controlling poultry red mites. Here, we present the first results of an attempt to identify potential predators by surveying the mite fauna of European starling (Sturnus vulgaris) nests, by assessing their ability to feed on poultry red mites and by testing for their inability to extract blood from bird hosts, i.e., newly hatched, young starlings and chickens. Two genuine predators of poultry red mites are identified: Hypoaspis aculeifer and Androlaelaps casalis. A review of the literature shows that some authors suspected the latter species to parasitize on the blood of birds and mammals, but they did not provide experimental evidence for these feeding habits and/or overlooked published evidence showing the reverse. We advocate careful analysis of the trophic structure of arthropods inhabiting bird nests as a basis for identifying candidate predators for control of poultry red mites.

  15. A biologically inspired meta-control navigation system for the Psikharpax rat robot.

    Science.gov (United States)

    Caluwaerts, K; Staffa, M; N'Guyen, S; Grand, C; Dollé, L; Favre-Félix, A; Girard, B; Khamassi, M

    2012-06-01

    A biologically inspired navigation system for the mobile rat-like robot named Psikharpax is presented, allowing for self-localization and autonomous navigation in an initially unknown environment. The ability of parts of the model (e.g. the strategy selection mechanism) to reproduce rat behavioral data in various maze tasks has been validated before in simulations. But the capacity of the model to work on a real robot platform had not been tested. This paper presents our work on the implementation on the Psikharpax robot of two independent navigation strategies (a place-based planning strategy and a cue-guided taxon strategy) and a strategy selection meta-controller. We show how our robot can memorize which was the optimal strategy in each situation, by means of a reinforcement learning algorithm. Moreover, a context detector enables the controller to quickly adapt to changes in the environment-recognized as new contexts-and to restore previously acquired strategy preferences when a previously experienced context is recognized. This produces adaptivity closer to rat behavioral performance and constitutes a computational proposition of the role of the rat prefrontal cortex in strategy shifting. Moreover, such a brain-inspired meta-controller may provide an advancement for learning architectures in robotics.

  16. Biological control of rice brown spot with native isolates of three Trichoderma species.

    Science.gov (United States)

    Khalili, Elham; Sadravi, Mehdi; Naeimi, Shahram; Khosravi, Vahid

    2012-01-01

    Brown spot caused by Bipolaris oryzae is an important rice disease in Southern coast of Caspian Sea, the major rice growing region in Iran. A total of 45 Trichoderma isolates were obtained from rice paddy fields in Golestan and Mazandaran provinces which belonged to Trichoderma harzianum, T. virens and T. atroviride species. Initially, they were screened against B. oryzae by antagonism tests including dual culture, volatile and nonvolatile metabolites and hyperparasitism. Results showed that Trichoderma isolates can significantly inhibit mycelium growth of pathogen in vitro by producing volatile and nonvolatile metabolites Light microscopic observations showed no evidence of mycoparasitic behaviour of the tested isolates of Trichoderma spp. such as coiling around the B. oryzae. According to in vitro experiments, Trichoderma isolates were selected in order to evaluate their efficacy in controlling brown spot in glasshouse using seed treatment and foliar spray methods. Concerning the glasshouse tests, two strains of T. harzianum significantly controlled the disease and one strain of T. atroviride increased the seedling growth. It is the first time that the biological control of rice brown spot and increase of seedling growth with Trichoderma species have been studied in Iran.

  17. Biological control of mosquitoes in scrap tires in Brownsville, Texas, USA and Matamoros, Tamaulipas, Mexico.

    Science.gov (United States)

    Uejio, Christopher K; Hayden, Mary H; Zielinski-Gutierrez, Emily; Lopez, Jose Luis Robles; Barrera, Roberto; Amador, Manuel; Thompson, Gregory; Waterman, Stephen H

    2014-06-01

    Dengue periodically circulates in southern Texas and neighboring Tamaulipas, Mexico; thus, a closer examination of human and vector ecology at the northern limits of North American transmission may improve prevention activities. Scrap tires produce large mosquito populations and increase the risk of dengue transmission. Some households choose not to pay tire disposal fees, and many tires are illegally dumped in residential areas. Biological control may provide low-cost and environmentally friendly mosquito control. This pilot study evaluated the ability of Mesocyclops longisetus to reduce mosquito populations in existing residential scrap tire piles. Mosquito populations were measured by the number of all mosquito pupae within tires or adult Aedes aegypti and Ae. albopictus near piles. Mesocyclops longisetus treated piles did not significantly reduce total mosquito pupae (P = 0.07) in Matamoros, Mexico. The study also evaluated the efficacy of native Toxorhynchites moctezuma which preferentially colonized tire piles under vegetation cover in Brownsville, TX. Toxorhynchites moctezuma larvae significantly reduced total mosquito pupae, but the strength of control diminished over time.

  18. Biological control of thrips pests (Thysanoptera: Thripidae in a commercial greenhouse in Hungary

    Directory of Open Access Journals (Sweden)

    Farkas Péter

    2016-12-01

    Full Text Available Polyphagous thrips, like western flower thrips Frankliniella occidentalis and onion thrips Thrips tabaci, are major pests in various ornamental and vegetable crops in greenhouses throughout the world. In Hungary, both of these polyphagous thrips species frequently cause severe damage in many greenhouse crops, especially in commercial sweet pepper. Chemical control is not always feasible because of certain ecological characteristics of these thrips species. The commercially available phytoseiid predatory mites like Amblyseius swirskii and anthocorid flower bugs like Orius laevigatus are often used simultaneously for the biological control of severe thrips infestation in sweet pepper cultivation in Hungary. Our observations demonstrated that the polyphagous thrips assemblages were effectively controlled by the combined release of natural enemies, despite the fact that the establishment of O. laevigatus did not seem to be successful in the first year. Overall, the thrips population density remained below the economic threshold in both years. However, the low infestation level of thrips suggests that a single predator release strategy could be applied effectively and still maintain the thrips below the damage threshold in greenhouse sweet pepper.

  19. Fermions from classical statistics

    OpenAIRE

    2010-01-01

    We describe fermions in terms of a classical statistical ensemble. The states $\\tau$ of this ensemble are characterized by a sequence of values one or zero or a corresponding set of two-level observables. Every classical probability distribution can be associated to a quantum state for fermions. If the time evolution of the classical probabilities $p_\\tau$ amounts to a rotation of the wave function $q_\\tau(t)=\\pm \\sqrt{p_\\tau(t)}$, we infer the unitary time evolution of a quantum system of fe...

  20. Davidson and classical pragmatism

    Directory of Open Access Journals (Sweden)

    Paula Rossi

    2007-06-01

    Full Text Available In this paper I wish to trace some connections between Donald Davidson's work (1917-2003 and two major representatives of the classical pragmatist movement: Charles S. Peirce (1839-1914 and William James (1842-1910. I will start with a basic characterization of classical pragmatism; then, I shall examine certain conceptions in Peirce's and James' pragmatism, in order to establish affinities with Davidson´s thought. Finally, and bearing in mind the previous con-nections, I will reflect briefly on the relevance –often unrecognized- of classical pragmatist ideas in the context of contemporary philosophi-cal discussions.

  1. Conservation Biological Control and Pest Performance in Lawn Turf: Does Mowing Height Matter?

    Science.gov (United States)

    Dobbs, Emily K.; Potter, Daniel A.

    2014-03-01

    With >80 million United States households engaged in lawn and gardening activities, increasing sustainability of lawn care is important. Mowing height is an easily manipulated aspect of lawn management. We tested the hypothesis that elevated mowing of tall fescue lawn grass promotes a larger, more diverse community of arthropod natural enemies which in turn provides stronger biological control services, and the corollary hypothesis that doing so also renders the turf itself less suitable for growth of insect pests. Turf-type tall fescue was mowed low (6.4 cm) or high (10.2 cm) for two growing seasons, natural enemy populations were assessed by vacuum sampling, pitfall traps, and ant baits, and predation and parasitism were evaluated with sentinel prey caterpillars, grubs, and eggs. In addition, foliage-feeding caterpillars and root-feeding scarab grubs were confined in the turf to evaluate their performance. Although some predatory groups (e.g., rove beetles and spiders) were more abundant in high-mowed grass, predation rates were uniformly high because ants, the dominant predators, were similarly abundant regardless of mowing height. Lower canopy temperatures in high-mowed grass were associated with slower growth of grass-feeding caterpillars. Higher lawn mowing reduces fuel consumption and yard waste, and promotes a deep, robust root system that reduces need for water and chemical inputs. Although in this study elevated mowing height did not measurably increase the already-high levels of predation, it did suggest additional ways through which bottom-up effects on insect pest growth might interact with natural enemies to facilitate conservation biological control.

  2. Biological weed control with soil fungi? Antagonistic effects of arbuscular mycorrhizal fungi on the growth of weeds

    NARCIS (Netherlands)

    Veiga, R.

    2012-01-01

    Excessive weed growth represents one of the major threats to crop production especially when reliance on herbicides is reduced. Biological weed control is an alternative, environmentally-sound method that, combined with other weed control practices, can contribute to an effective weed management in

  3. Biological control of mealybugs with lacewing larvae is affected by the presence and type of supplemental prey

    NARCIS (Netherlands)

    Messelink, Gerben J.; Vijverberg, Roland; Leman, Ada; Janssen, Arne

    2016-01-01

    The diversity of prey and food sources in crops has a major effect on biological pest control by generalist predators. In this study, we tested if and how supplemental prey or food affects the control of the citrus mealybug Planococcus citri (Risso) by larvae of the green lacewing Chrysoperla luc

  4. Detection and reconstruction of error control codes for engineered and biological regulatory systems.

    Energy Technology Data Exchange (ETDEWEB)

    May, Elebeoba Eni; Rintoul, Mark Daniel; Johnston, Anna Marie; Pryor, Richard J.; Hart, William Eugene; Watson, Jean-Paul

    2003-10-01

    A fundamental challenge for all communication systems, engineered or living, is the problem of achieving efficient, secure, and error-free communication over noisy channels. Information theoretic principals have been used to develop effective coding theory algorithms to successfully transmit information in engineering systems. Living systems also successfully transmit biological information through genetic processes such as replication, transcription, and translation, where the genome of an organism is the contents of the transmission. Decoding of received bit streams is fairly straightforward when the channel encoding algorithms are efficient and known. If the encoding scheme is unknown or part of the data is missing or intercepted, how would one design a viable decoder for the received transmission? For such systems blind reconstruction of the encoding/decoding system would be a vital step in recovering the original message. Communication engineers may not frequently encounter this situation, but for computational biologists and biotechnologist this is an immediate challenge. The goal of this work is to develop methods for detecting and reconstructing the encoder/decoder system for engineered and biological data. Building on Sandia's strengths in discrete mathematics, algorithms, and communication theory, we use linear programming and will use evolutionary computing techniques to construct efficient algorithms for modeling the coding system for minimally errored engineered data stream and genomic regulatory DNA and RNA sequences. The objective for the initial phase of this project is to construct solid parallels between biological literature and fundamental elements of communication theory. In this light, the milestones for FY2003 were focused on defining genetic channel characteristics and providing an initial approximation for key parameters, including coding rate, memory length, and minimum distance values. A secondary objective addressed the question of

  5. The role of transient dynamics in biological pest control: insights from a host-parasitoid community.

    Science.gov (United States)

    Kidd, David; Amarasekare, Priyanga

    2012-01-01

    1. Identifying natural enemies that can maintain pests at low abundances is a priority in biological control. Here, we show that experiments combined with models generate new insights into identifying effective control agents prior to their release in the field. Using a host-parasitoid community (the harlequin bug and its egg parasitoids) as a model system, we report three key findings. 2. The interplay between the host's self-limitation and the parasitoids' saturating functional response causes the long-term (steady-state) outcomes for pest suppression to differ from those of short-term (transient) dynamics. When the bug's self-limitation is moderately strong, the parasitoid with the higher attack rate and conversion efficiency (Ooencyrtus) achieves greater host suppression in the long term, but its longer handling time causes long periods of transient dynamics during which the bug can reach high abundances; when the bug's self-limitation is weak, host fluctuations amplify over time and Ooencyrtus fails at host suppression altogether. In contrast, the parasitoid with the lower attack rate and conversion efficiency but the shorter handling time (Trissolcus) induces only weak transient fluctuations of short duration and can maintain the host at low abundances regardless of the strength of the bug's self-limitation. 3. Release of multiple enemy species can compromise host suppression if an enemy that induces stronger transient fluctuations excludes one that induces weaker fluctuations. For instance, Ooencyrtus excludes Trissolcus despite having a longer handling time because of its higher conversion efficiency. The model correctly predicts the time to exclusion observed in experiments, suggesting that it captures the key biological features of the host-parasitoid interaction. 4. Intraspecific interference reduces long-term pest suppression but improves short-term pest control by reducing the magnitude and duration of transient fluctuations. 5. These results highlight

  6. Using counterfactuals to evaluate the cost-effectiveness of controlling biological invasions.

    Science.gov (United States)

    McConnachie, Matthew M; van Wilgen, Brian W; Ferraro, Paul J; Forsyth, Aurelia T; Richardson, David M; Gaertner, Mirijam; Cowling, Richard M

    2016-03-01

    Prioritizing limited conservation funds for controlling biological invasions requires accurate estimates of the effectiveness of interventions to remove invasive species and their cost-effectiveness (cost per unit area or individual). Despite billions of dollars spent controlling biological invasions worldwide, it is unclear whether those efforts are effective, and cost-effective. The paucity of evidence results from the difficulty in measuring the effect of invasive species removal: a researcher must estimate the difference in outcomes (e.g. invasive species cover) between where the removal program intervened and what might have been observed if the program had not intervened. In the program evaluation literature, this is called a counterfactual analysis, which formally compares what actually happened and what would have happened in the absence of an intervention. When program implementation is not randomized, estimating counterfactual outcomes is especially difficult. We show how a thorough understanding of program implementation, combined with a matching empirical design can improve the way counterfactual outcomes are estimated in nonexperimental contexts. As a practical demonstration, we estimated the cost-effectiveness of South Africa's Working for Water program, arguably the world's most ambitious invasive species control program, in removing invasive alien trees from different land use types, across a large area in the Cape Floristic Region. We estimated that the proportion of the treatment area covered by invasive trees would have been 49% higher (5.5% instead of 2.7% of the grid cells occupied) had the program not intervened. Our estimates of cost per hectare to remove invasive species, however, are three to five times higher than the predictions made when the program was initiated. Had there been no control (counter-factual), invasive trees would have spread on untransformed land, but not on land parcels containing plantations or land transformed by

  7. Advanced classical field theory

    CERN Document Server

    Giachetta, Giovanni; Sardanashvily, Gennadi

    2009-01-01

    Contemporary quantum field theory is mainly developed as quantization of classical fields. Therefore, classical field theory and its BRST extension is the necessary step towards quantum field theory. This book aims to provide a complete mathematical foundation of Lagrangian classical field theory and its BRST extension for the purpose of quantization. Based on the standard geometric formulation of theory of nonlinear differential operators, Lagrangian field theory is treated in a very general setting. Reducible degenerate Lagrangian theories of even and odd fields on an arbitrary smooth manifold are considered. The second Noether theorems generalized to these theories and formulated in the homology terms provide the strict mathematical formulation of BRST extended classical field theory

  8. Systems Cancer Biology and the Controlling Mechanisms for the J-Shaped Cancer Dose Response: Towards Relaxing the LNT Hypothesis

    OpenAIRE

    Lou, In Chio; Zhao, Yuchao; Wu, YingJie; Ricci, Paolo F

    2012-01-01

    The hormesis phenomena or J-shaped dose response have been accepted as a common phenomenon regardless of the involved biological model, endpoint measured and chemical class/physical stressor. This paper first introduced a mathematical dose response model based on systems biology approach. It links molecular-level cell cycle checkpoint control information to clonal growth cancer model to predict the possible shapes of the dose response curves of Ionizing Radiation (IR) induced tumor transforma...

  9. On Noncommutative Classical Mechanics

    CERN Document Server

    Djemai, A E F

    2003-01-01

    In this work, I investigate the noncommutative Poisson algebra of classical observables corresponding to a proposed general Noncommutative Quantum Mechanics, \\cite{1}. I treat some classical systems with various potentials and some Physical interpretations are given concerning the presence of noncommutativity at large scales (Celeste Mechanics) directly tied to the one present at small scales (Quantum Mechanics) and its possible relation with UV/IR mixing.

  10. Between classical and quantum

    OpenAIRE

    2007-01-01

    The relationship between classical and quantum theory is of central importance to the philosophy of physics, and any interpretation of quantum mechanics has to clarify it. Our discussion of this relationship is partly historical and conceptual, but mostly technical and mathematically rigorous, including over 500 references. On the assumption that quantum mechanics is universal and complete, we discuss three ways in which classical physics has so far been believed to emerge from quantum physic...

  11. Quantum and Classic Brackets

    OpenAIRE

    Kisil, Vladimir V.

    2000-01-01

    We describe an $p$-mechanical (see funct-an/9405002 and quant-ph/9610016) brackets which generate quantum (commutator) and classic (Poisson) brackets in corresponding representations of the Heisenberg group. We \\emph{do not} use any kind of semiclassic approximation or limiting procedures for $\\hbar \\to 0$. Harmonic oscillator considered within the approach. Keywords: Classic and quantum mechanics, Hamilton and Heisenberg equations, Poisson brackets, commutator, Heisenberg group.

  12. Biological control of cyathostomin (Nematoda: Cyathostominae) with nematophagous fungus Monacrosporium thaumasium in tropical southeastern Brazil.

    Science.gov (United States)

    Tavela, Alexandre de Oliveira; Araújo, Jackson Victor; Braga, Fábio Ribeiro; Silva, André Ricardo; Carvalho, Rogério Oliva; Araujo, Juliana Milani; Ferreira, Sebastião Rodrigo; Carvalho, Giovanni Ribeiro

    2011-01-10

    Horses are hosts to a wide variety of helminthes; the most important are the cyathostomin, or small strongyles. The viability of a fungal formulation (pellets) using the nematode-trapping fungus Monacrosporium thaumasium was assessed in biological control of horse cyathostomin. Two groups (fungus-treated and control) consisted of six mares in each group, crossbred (ages of 2.5 and 3.5 years), were placed in pastures of Cynodon sp. naturally infected with horse cyathostomin larvae. In the treated group, each animal received 1g/10 kg body weight (0.2g/10 kg live weight of fungus) of pellets of sodium alginate matrix containing the fungus M. thaumasium orally, twice a week for 6 months. In the control group, animals received (1g/10 kg body weight) of pellets without fungus. The egg count per gram of feces showed difference (pcontrol animals during all months of the experiment. The EPG percentage decrease were 87.5%, 89.7%, 68.3%, 58.7%, 52.5% and 35.2% during June, July, August, September, October and November, respectively. In faecal cultures, there was difference (pcontrol animals during all the experiment month, with percentage reduction of 67.5%, 61.4% and 31.8% in September, October and November, respectively. Difference (pcontrol group with a reduction of 60.9% and between 0-20 and 0-40 cm from the faecal pat reduction (pcontrol group pasture. There was no difference (p>0.05) between the average weight gains in both animal groups. The treatment of horses with pellets containing the nematophagous fungus M. thaumasium can be effective in controlling cyathostomin in the tropical region of southeastern Brazil.

  13. Ecological engineering to control bioclogging: an original field study coupling infiltration and biological measurements

    Science.gov (United States)

    Gette-bouvarot, Morgane; Mermillod-Blondin, Florian; Lassabatere, Laurent; Lemoine, Damien; Delolme, Cécile; Volatier, Laurence

    2014-05-01

    Infiltration systems are increasingly used in urban areas for several purposes such as flood prevention and groundwater recharge. However, their functioning is often impacted by clogging that leads to decreases in hydraulic and water treatment performances. These systems are commonly built with sand as infiltration medium, a media subject to rapid clogging by the combined and overlapping processes of pore occlusion by fine particles and biofilm development. In a previous study, we pointed out that the phototrophic component of biofilms developed at the surface layer of infiltration systems (algae, cyanobacteria) could reduce by up to 60-fold the saturated hydraulic conductivity. Consequently, it appears crucial to control biofilm growth to maintain porous infiltration media performances. The present study aimed to test the influence of biotic (addition of animals or macrophytes) and abiotic (light reduction) treatments on biofilm development and associated hydraulic properties in an infiltration device dedicated to aquifer recharge with river water in Lyon Area (France). Twenty-five benthic enclosures were used to test 5 "treatments" on non-manipulated surface layer under field conditions. Three biotic treatments consisted in the introduction of: (i) an invertebrate acting as algae grazer (Viviparus viviparus), (ii) an invertebrate that digs galleries in sediments (Tubifex tubifex), and (iii) a macrophyte that could inhibit benthic biofilm by allelopathic activity (Vallisneria spiralis L). The fourth treatment was designed to simulate shading. The last "treatment" was a control which monitored the evolution of the system during the experiment without manipulation (addition of macro-organisms or shading). Each treatment was replicated five times. The experiment was conducted for 6 weeks, and sampling of the surface layer (0-1 cm) was carried out in each enclosure at the beginning (t0) and the end (tf). We coupled biological characterizations (organic matter, algal

  14. Biological actions of silver nanoparticles embedded in titanium controlled by micro-galvanic effects.

    Science.gov (United States)

    Cao, Huiliang; Liu, Xuanyong; Meng, Fanhao; Chu, Paul K

    2011-01-01

    Titanium embedded with silver nanoparticles (Ag NPs) using a single step silver plasma immersion ion implantation (Ag-PIII) demonstrate micro-galvanic effects that give rise to both controlled antibacterial activity and excellent compatibility with osteoblasts. Scanning electron microscopy (SEM) shows that nanoparticles with average sizes of about 5 nm and 8 nm are formed homogeneously on the titanium surface after undergoing Ag-PIII for 0.5 h and 1 h, respectively. Transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) indicate that those nanoparticles are metallic silver produced on and underneath the titanium surface via a local nucleation process from the solid solution of α-Ti(Ag). The Ag-PIII samples inhibit the growth of both Staphylococcus aureus and Escherichia coli while enhancing proliferation of the osteoblast-like cell line MG63. Electrochemical polarization and Zeta potential measurements demonstrate that the low surface toxicity and good cytocompatibility are related to the micro-galvanic effect between the Ag NPs and titanium matrix. Our results show that the physico-chemical properties of the Ag NPs are important in the control of the cytotoxicity and this study opens a new window for the design of nanostructured surfaces on which the biological actions of the Ag NPs can be accurately tailored.

  15. Biological nitrogen fixation: rates, patterns and ecological controls in terrestrial ecosystems

    Science.gov (United States)

    Vitousek, Peter M.; Menge, Duncan N.L.; Reed, Sasha C.; Cleveland, Cory C.

    2013-01-01

    New techniques have identified a wide range of organisms with the capacity to carry out biological nitrogen fixation (BNF)—greatly expanding our appreciation of the diversity and ubiquity of N fixers—but our understanding of the rates and controls of BNF at ecosystem and global scales has not advanced at the same pace. Nevertheless, determining rates and controls of BNF is crucial to placing anthropogenic changes to the N cycle in context, and to understanding, predicting and managing many aspects of global environmental change. Here, we estimate terrestrial BNF for a pre-industrial world by combining information on N fluxes with 15N relative abundance data for terrestrial ecosystems. Our estimate is that pre-industrial N fixation was 58 (range of 40–100) Tg N fixed yr−1; adding conservative assumptions for geological N reduces our best estimate to 44 Tg N yr−1. This approach yields substantially lower estimates than most recent calculations; it suggests that the magnitude of human alternation of the N cycle is substantially larger than has been assumed.

  16. Nematophagous fungi for biological control of gastrointestinal nematodes in domestic animals.

    Science.gov (United States)

    Braga, Fabio Ribeiro; de Araújo, Jackson Victor

    2014-01-01

    Several studies have been conducted using fungi in the biological control of domestic animals and humans. In this respect, a large amount of research has been undertaken to understand the particularities of each fungus used. These fungi have been demonstrated to act on all classes of helminthes. Therefore, they should not only be called nematophagous but also helmintophagous. Evidence of enzymatic action has also revealed their mechanism of action, as well as potential metabolites that could be synthesized as bioactive molecules. Cultural barriers to the use of fungi should be broken down, since the impact on the environment is minimal. In this context, much is already known about the mechanism of interaction of these organisms with their 'targets'. Recent research has pointed to the search for substances derived from nematophagous fungi that have demonstrated their ovicidal and/or larvicidal activity, thus being a global premise to be studied further. Crude extracts derived from nematophagous fungi of predator and ovicidal groups reduce the amount of larvae of gastrointestinal nematodes and prevent the hatching of their eggs, since they have been demonstrated to act with extracellular proteases and other enzymes. Furthermore, the activity of these enzymes has begun to be explored regarding their possible interaction with the exoskeleton of arthropods, which could emerge as an alternative method of tick control. Finally, it should be clear that nematophagous fungi in general are 'old friends' that are ready to the 'fight with our old enemies', the gastrointestinal helminth parasites harmful to human and animal health.

  17. Gluconic acid: an antifungal agent produced by Pseudomonas species in biological control of take-all.

    Science.gov (United States)

    Kaur, Rajvinder; Macleod, John; Foley, William; Nayudu, Murali

    2006-03-01

    Pseudomonas strain AN5 (Ps. str. AN5), a non-fluorescent Australian bacterial isolate, is an effective biological control (biocontrol) agent of the take-all disease of wheat caused by the fungus Gaeumannomyces graminis var. tritici (Ggt). Ps. str. AN5 controls Ggt by producing an antifungal compound which was purified by thin layer and column chromatography, and identified by NMR and mass spectroscopic analysis to be d-gluconic acid. Commercially bought pure gluconic acid strongly inhibited Ggt. Two different transposon mutants of Ps. str. AN5 which had lost take-all biocontrol did not produce d-gluconic acid. Gluconic acid production was restored, along with take-all biocontrol, when one of these transposon mutants was complemented with the corresponding open reading frame from wild-type genomic DNA. Gluconic acid was detected in the rhizosphere of wheat roots treated with the wild-type Ps. str. AN5, but not in untreated wheat or wheat treated with a transposon mutant strain which had lost biocontrol. The antifungal compounds phenazine-1-carboxylic acid and 2,4-diacetylphloroglucinol, produced by other Pseudomonads and previously shown to be effective in suppressing the take-all disease, were not detected in Ps. str. AN5 extracts. These results suggest that d-gluconic acid is the most significant antifungal agent produced by Ps. str. AN5 in biocontrol of take-all on wheat roots.

  18. [Soil biological activities at maize seedling stage under application of slow/controlled release nitrogen fertilizers].

    Science.gov (United States)

    Li, Dongpo; Wu, Zhijie; Chen, Lijun; Liang, Chenghua; Zhang, Lili; Wang, Weicheng; Yang, Defu

    2006-06-01

    With pot experiment and simulating field ecological environment, this paper studied the effects of different slow/ controlled release N fertilizers on the soil nitrate - reductase and urease activities and microbial biomass C and N at maize seedling stage. The results showed that granular urea amended with dicyandiamide (DCD) and N-(n-bultyl) thiophosphoric triamide (NBPT) induced the highest soil nitrate-reductase activity, granular urea brought about the highest soil urease activity and microbial biomass C and N, while starch acetate (SA)-coated granular urea, SA-coated granular urea amended with DCD, methyl methacrylate (MMA) -coated granular urea amended with DCD, and no N fertilization gave a higher soil urease activity. Soil microbial C and N had a similar variation trend after applying various kinds of test slow/controlled release N fertilizers, and were the lowest after applying SA-coated granular urea amended with DCD and NBPT. Coated granular urea amended with inhibitors had a stronger effect on soil biological activities than coated granular urea, and MMA-coating had a better effect than SA-coating.

  19. Potential nontarget effects of Metarhizium anisopliae (Deuteromycetes) used for biological control of ticks (Acari: Ixodidae)

    Science.gov (United States)

    Ginsberg, Howard S.; LeBrun, Roger A.; Heyer, Klaus; Zhioua, Elyes

    2002-01-01

    The potential for nontarget effects of the entomopathogenic fungus Metarhizium anisopliae (Metschnikoff) Sorokin, when used for biological control of ticks, was assessed in laboratory trials. Fungal pathogenicity was studied against convergent ladybird beetles, Hippodamia convergens Guérin-Méneville, house crickets, Acheta domesticus (L.), and the milkweed bugs Oncopeltus fasciatus (Dallas). Fungal spores applied with a spray tower produced significant mortality in H. convergens and A. domesticus, but effects on O. fasciatus were marginal. Placing treated insects with untreated individuals resulted in mortality from horizontal transmission to untreated beetles and crickets, but not milkweed bugs. Spread of fungal infection in the beetles resulted in mortality on days 4–10 after treatment, while in crickets mortality was on day 2 after treatment, suggesting different levels of pathogenicity and possibly different modes of transmission. Therefore, M. anisopliae varies in pathogenicity to different insects. Inundative applications can potentially affect nontarget species, but M. anisopliae is already widely distributed in North America, so applications for tick control generally would not introduce a novel pathogen into the environment. Pathogenicity in lab trials does not, by itself, demonstrate activity under natural conditions, so field trials are needed to confirm these results and to assess methods to minimize nontarget exposure.

  20. Controversies in modern evolutionary biology: the imperative for error detection and quality control

    Directory of Open Access Journals (Sweden)

    Prosdocimi Francisco

    2012-01-01

    Full Text Available Abstract Background The data from high throughput genomics technologies provide unique opportunities for studies of complex biological systems, but also pose many new challenges. The shift to the genome scale in evolutionary biology, for example, has led to many interesting, but often controversial studies. It has been suggested that part of the conflict may be due to errors in the initial sequences. Most gene sequences are predicted by bioinformatics programs and a number of quality issues have been raised, concerning DNA sequencing errors or badly predicted coding regions, particularly in eukaryotes. Results We investigated the impact of these errors on evolutionary studies and specifically on the identification of important genetic events. We focused on the detection of asymmetric evolution after duplication, which has been the subject of controversy recently. Using the human genome as a reference, we established a reliable set of 688 duplicated genes in 13 complete vertebrate genomes, where significantly different evolutionary rates are observed. We estimated the rates at which protein sequence errors occur and are accumulated in the higher-level analyses. We showed that the majority of the detected events (57% are in fact artifacts due to the putative erroneous sequences and that these artifacts are sufficient to mask the true functional significance of the events. Conclusions Initial errors are accumulated throughout the evolutionary analysis, generating artificially high rates of event predictions and leading to substantial uncertainty in the conclusions. This study emphasizes the urgent need for error detection and quality control strategies in order to efficiently extract knowledge from the new genome data.

  1. Induced Resistance as a Mechanism of Biological Control by Lysobacter enzymogenes Strain C3.

    Science.gov (United States)

    Kilic-Ekici, Ozlem; Yuen, Gary Y

    2003-09-01

    ABSTRACT Induced resistance was found to be a mechanism for biological control of leaf spot, caused by Bipolaris sorokiniana, in tall fescue (Festuca arundinacea) using the bacterium Lysobacter enzymogenes strain C3. Resistance elicited by C3 suppressed germination of B. sorokiniana conidia on the phylloplane in addition to reducing the severity of leaf spot. The pathogen-inhibitory effect could be separated from antibiosis by using heat-inactivated cells of C3 that retained no antifungal activity. Application of live or heat-killed cells to tall fescue leaves resulted only in localized resistance confined to the treated leaf, whereas treatment of roots resulted in systemic resistance expressed in the foliage. The effects of foliar and root applications of C3 were long lasting, as evidenced by suppression of conidial germination and leaf spot development even when pathogen inoculation was delayed 15 days after bacterial treatment. When C3 population levels and germination of pathogen conidia was examined on leaf segments, germination percentage was reduced on all segments from C3-treated leaves compared with segments from non-treated leaves, but no dose-response relationship typical of antagonism was found. Induced resistance by C3 was not host or pathogen specific; foliar application of heat-killed C3 cells controlled B. sorokiniana on wheat and also was effective in reducing the severity of brown patch, caused by Rhizoctonia solani, on tall fescue. Treatments of tall fescue foliage or roots with C3 resulted in significantly elevated peroxidase activity compared with the control.

  2. Rhagoletis cerasi Loew (Diptera: Tephritidae – Biological Characteristics, Harmfulness, and Control

    Directory of Open Access Journals (Sweden)

    Svetomir Stamenković

    2012-01-01

    Full Text Available The European cherry fruit fly, Rhagoletis cerasi Loew (Diptera: Tephritidae, is a highlydestructive pest in sweet and sour cherry orchards with a distribution area throughoutEurope and the temperate regions of Asia. It occurs regularly in all production regions ofthese fruit species in Serbia, damaging up to 10% of cherries in commercial production,while damage can go up to 100% in orchards and on solitary threes unprotected by controlmeasures.In Serbia, European cherry fruit fly most often attacks and damages fruits of the lateripeningcultivars of sweet cherry (Van, Stela, Hedelfinger, Bing, Lambert, Drogan’s Yellow.After a sweet cherry harvest, adults migrate to sour cherry where they continue feedingand ovipositing in half-mature sour cherries (prevailingly the domestic ecotype Oblačinska.During their activity period, larvae damage the fruits, so that they can no longer be consumedeither fresh or processed. The high percentage of sour cherries damaged by R. cerasihas become a factor limiting exports because the intensity of infestation of this fruitexceeds permissible limits. Pesticide use for controlling this pest, especially in integratedproduction, is based on a very poor selection of insecticides which cause problems withresidual ecotoxicity. Consequently, alternative measures for controlling European cherryfruit fly have been intensively studied over the past few years.This work surveys up-to-date results of various studies on the European cherry fruit flyas a very important pest in Serbia and other South and Mid-European countries. The workcontains detailed descriptions of its biological characteristics, flight phenology, infestationintensity and possibilities of fly control in sweet and sour cherry production areas.

  3. Subnuclear organization and trafficking of regulatory proteins: implications for biological control and cancer.

    Science.gov (United States)

    Stein, G S; van Wijnen, A J; Stein, J L; Lian, J B; Montecino, M; Zaidi, K; Javed, A

    2000-01-01

    The regulated and regulatory components that interrelate nuclear structure and function must be experimentally established. A formidable challenge is to define further the control of transcription factor targeting to acceptor sites associated with the nuclear matrix. It will be important to determine whether acceptor proteins are associated with a pre-existing core-filament structural lattice or whether a compositely organized scaffold of regulatory factors is dynamically assembled. An inclusive model for all steps in the targeting of proteins to subnuclear sites cannot yet be proposed. However, this model must account for the apparent diversity of intranuclear targeting signals. It is also important to assess the extent to which regulatory discrimination is mediated by subnuclear domain-specific trafficking signals. Furthermore, the checkpoints that monitor subnuclear distribution of regulatory factors and the sorting steps that ensure both structural and functional fidelity of nuclear domains in which replication and expression of genes occur must be biochemically and mechanistically defined. There is emerging recognition that placement of regulatory components of gene expression must be temporally and spatially coordinated to facilitate biological control. The consequences of breaches in nuclear structure-function relationships are observed in an expanding series of diseases that include cancer [Weis et al., 1994; Rogaia et al., 1997; Yano et al., 1997; Rowley, 1998; Zeng et al., 1998; McNeil et al., 1999; Tao and Levine, 1999a] and neurological disorders [Skinner et al., 1997]. As the repertoire of architecture-associated regulatory factors and cofactors expands, workers in the field are becoming increasingly confident that nuclear organization contributes significantly to control of transcription. To gain increased appreciation for the complexities of subnuclear organization and gene regulation, we must continue to characterize mechanisms that direct

  4. Regional Suppression of Bactrocera Fruit Flies (Diptera: Tephritidae in the Pacific through Biological Control and Prospects for Future Introductions into Other Areas of the World

    Directory of Open Access Journals (Sweden)

    Roger I. Vargas

    2012-08-01

    Full Text Available Bactrocera fruit fly species are economically important throughout the Pacific. The USDA, ARS U.S. Pacific Basin Agricultural Research Center has been a world leader in promoting biological control of Bactrocera spp. that includes classical, augmentative, conservation and IPM approaches. In Hawaii, establishment of Bactrocera cucurbitae (Coquillett in 1895 resulted in the introduction of the most successful parasitoid, Psyttalia fletcheri (Silvestri; similarly, establishment of Bactrocera dorsalis (Hendel in 1945 resulted in the introduction of 32 natural enemies of which Fopius arisanus (Sonan, Diachasmimorpha longicaudata (Ashmead and Fopius vandenboschi (Fullaway were most successful. Hawaii has also been a source of parasitoids for fruit fly control throughout the Pacific region including Australia, Pacific Island Nations, Central and South America, not only for Bactrocera spp. but also for Ceratitis and Anastrepha spp. Most recently, in 2002, F. arisanus was introduced into French Polynesia where B. dorsalis had invaded in 1996. Establishment of D. longicaudata into the new world has been important to augmentative biological control releases against Anastrepha spp. With the rapid expansion of airline travel and global trade there has been an alarming spread of Bactrocera spp. into new areas of the world (i.e., South America and Africa. Results of studies in Hawaii and French Polynesia, support parasitoid introductions into South America and Africa, where B. carambolae and B. invadens, respectively, have become established. In addition, P. fletcheri is a candidate for biological control of B. cucurbitae in Africa. We review past and more

  5. Time optimal control of an additional food provided predator-prey system with applications to pest management and biological conservation.

    Science.gov (United States)

    Srinivasu, P D N; Prasad, B S R V

    2010-04-01

    Use of additional food has been widely recognized by experimental scientists as one of the important tools for biological control such as species conservation and pest management. The quality and quantity of additional food supplied to the predators is known to play a vital role in the controllability of the system. The present study is continuation of a previous work that highlights the importance of quality and quantity of the additional food in the dynamics of a predator-prey system in the context of biological control. In this article the controllability of the predator-prey system is analyzed by considering inverse of quality of the additional food as the control variable. Control strategies are offered to steer the system from a given initial state to a required terminal state in a minimum time by formulating Mayer problem of optimal control. It is observed that an optimal strategy is a combination of bang-bang controls and could involve multiple switches. Properties of optimal paths are derived using necessary conditions for Mayer problem. In the light of the results evolved in this work it is possible to eradicate the prey from the eco-system in the minimum time by providing the predator with high quality additional food, which is relevant in the pest management. In the perspective of biological conservation this study highlights the possibilities to drive the state to an admissible interior equilibrium (irrespective of its stability nature) of the system in a minimum time.

  6. Population structure of the Classic period Maya.

    Science.gov (United States)

    Scherer, Andrew K

    2007-03-01

    This study examines the population structure of Classic period (A.D. 250-900) Maya populations through analysis of odontometric variation of 827 skeletons from 12 archaeological sites in Mexico, Guatemala, Belize, and Honduras. The hypothesis that isolation by distance characterized Classic period Maya population structure is tested using Relethford and Blangero's (Hum Biol 62 (1990) 5-25) approach to R matrix analysis for quantitative traits. These results provide important biological data for understanding ancient Maya population history, particularly the effects of the competing Tikal and Calakmul hegemonies on patterns of lowland Maya site interaction. An overall F(ST) of 0.018 is found for the Maya area, indicating little among-group variation for the Classic Maya sites tested. Principal coordinates plots derived from the R matrix analysis show little regional patterning in the data, though the geographic outliers of Kaminaljuyu and a pooled Pacific Coast sample did not cluster with the lowland Maya sites. Mantel tests comparing the biological distance matrix to a geographic distance matrix found no association between genetic and geographic distance. In the Relethford-Blangero analysis, most sites possess negative or near-zero residuals, indicating minimal extraregional gene flow. The exceptions were Barton Ramie, Kaminaljuyu, and Seibal. A scaled R matrix analysis clarifies that genetic drift is a consideration for understanding Classic Maya population structure. All results indicate that isolation by distance does not describe Classic period Maya population structure.

  7. Classical decoherence in a nanomechanical resonator

    Science.gov (United States)

    Maillet, O.; Vavrek, F.; Fefferman, A. D.; Bourgeois, O.; Collin, E.

    2016-07-01

    Decoherence is an essential mechanism that defines the boundary between classical and quantum behaviours, while imposing technological bounds for quantum devices. Little is known about quantum coherence of mechanical systems, as opposed to electromagnetic degrees of freedom. But decoherence can also be thought of in a purely classical context, as the loss of phase coherence in the classical phase space. Indeed the bridge between quantum and classical physics is under intense investigation, using, in particular, classical nanomechanical analogues of quantum phenomena. In the present work, by separating pure dephasing from dissipation, we quantitatively model the classical decoherence of a mechanical resonator: through the experimental control of frequency fluctuations, we engineer artificial dephasing. Building on the fruitful analogy introduced between spins/quantum bits and nanomechanical modes, we report on the methods available to define pure dephasing in these systems, while demonstrating the intrinsic almost-ideal properties of silicon nitride beams. These experimental and theoretical results, at the boundary between classical nanomechanics and quantum information fields, are prerequisite in the understanding of decoherence processes in mechanical devices, both classical and quantum.

  8. Discrete Classical Electromagnetic Fields

    CERN Document Server

    De Souza, M M

    1997-01-01

    The classical electromagnetic field of a spinless point electron is described in a formalism with extended causality by discrete finite transverse point-vector fields with discrete and localized point interactions. These fields are taken as a classical representation of photons, ``classical photons". They are all transversal photons; there are no scalar nor longitudinal photons as these are definitely eliminated by the gauge condition. The angular distribution of emitted photons coincides with the directions of maximum emission in the standard formalism. The Maxwell formalism and its standard field are retrieved by the replacement of these discrete fields by their space-time averages, and in this process scalar and longitudinal photons are necessarily created and added. Divergences and singularities are by-products of this averaging process. This formalism enlighten the meaning and the origin of the non-physical photons, the ones that violate the Lorentz condition in manifestly covariant quantization methods.

  9. Between classical and quantum

    CERN Document Server

    Landsman, N P

    2005-01-01

    The relationship between classical and quantum theory is of central importance to the philosophy of physics, and any interpretation of quantum mechanics has to clarify it. Our discussion of this relationship is partly historical and conceptual, but mostly technical and mathematically rigorous, including over 500 references. On the assumption that quantum mechanics is universal and complete, we discuss three ways in which classical physics has so far been believed to emerge from quantum physics, namely in the limit h -> 0 of small Planck's constant (in a finite system), in the limit of a large system, and through decoherence and consistent histores. The first limit is closely related to modern quantization theory and microlocal analysis, whereas the second involves methods of C*-algebras and the concepts of superselection sectors and macroscopic observables. In these limits, the classical world does not emerge as a sharply defined objective reality, but rather as an approximate appearance relative to certain "...

  10. Randomness: Quantum versus classical

    Science.gov (United States)

    Khrennikov, Andrei

    2016-05-01

    Recent tremendous development of quantum information theory has led to a number of quantum technological projects, e.g. quantum random generators. This development had stimulated a new wave of interest in quantum foundations. One of the most intriguing problems of quantum foundations is the elaboration of a consistent and commonly accepted interpretation of a quantum state. Closely related problem is the clarification of the notion of quantum randomness and its interrelation with classical randomness. In this short review, we shall discuss basics of classical theory of randomness (which by itself is very complex and characterized by diversity of approaches) and compare it with irreducible quantum randomness. We also discuss briefly “digital philosophy”, its role in physics (classical and quantum) and its coupling to the information interpretation of quantum mechanics (QM).

  11. Classical mechanics with Maxima

    CERN Document Server

    Timberlake, Todd Keene

    2016-01-01

    This book guides undergraduate students in the use of Maxima—a computer algebra system—in solving problems in classical mechanics. It functions well as a supplement to a typical classical mechanics textbook. When it comes to problems that are too difficult to solve by hand, computer algebra systems that can perform symbolic mathematical manipulations are a valuable tool. Maxima is particularly attractive in that it is open-source, multiple-platform software that students can download and install free of charge. Lessons learned and capabilities developed using Maxima are easily transferred to other, proprietary software.

  12. Covariantizing Classical Field Theories

    CERN Document Server

    López, Marco Castrillón

    2010-01-01

    We show how to enlarge the covariance group of any classical field theory in such a way that the resulting "covariantized" theory is 'essentially equivalent' to the original. In particular, our technique will render any classical field theory generally covariant, that is, the covariantized theory will be spacetime diffeomorphism-covariant and free of absolute objects. Our results thus generalize the well-known parametrization technique of Dirac and Kucha\\v{r}. Our constructions apply equally well to internal covariance groups, in which context they produce natural derivations of both the Utiyama minimal coupling and St\\"uckelberg tricks.

  13. Problems in classical mechanics

    CERN Document Server

    Katkar, L N

    2014-01-01

    Problems in classical mechanics presents a lucid treatment of the formulations of Lagrangian, Hamiltonian, and the Principles of Calculus of Variations etc. important for the study of modern physics. The study of classical mechanics prepares students to apply the principles and the mathematical tools to solve real life problems. The book also incorporates and discusses in detail topics such as Central Force Motion, Rigid Body Motion and Canonical Transformations. KEY FEATURES: Around 200 solved examples with complete mathematical theory Around 70 examples given as an exercise to test and develop students understanding The physical interpretation of the Hamiltonian is highlighted

  14. Classic Problems of Probability

    CERN Document Server

    Gorroochurn, Prakash

    2012-01-01

    "A great book, one that I will certainly add to my personal library."—Paul J. Nahin, Professor Emeritus of Electrical Engineering, University of New Hampshire Classic Problems of Probability presents a lively account of the most intriguing aspects of statistics. The book features a large collection of more than thirty classic probability problems which have been carefully selected for their interesting history, the way they have shaped the field, and their counterintuitive nature. From Cardano's 1564 Games of Chance to Jacob Bernoulli's 1713 Golden Theorem to Parrondo's 1996 Perplexin

  15. Classical Holographic Codes

    CERN Document Server

    Brehm, Enrico M

    2016-01-01

    In this work, we introduce classical holographic codes. These can be understood as concatenated probabilistic codes and can be represented as networks uniformly covering hyperbolic space. In particular, classical holographic codes can be interpreted as maps from bulk degrees of freedom to boundary degrees of freedom. Interestingly, they are shown to exhibit features similar to those expected from the AdS/CFT correspondence. Among these are a version of the Ryu-Takayanagi formula and intriguing properties regarding bulk reconstruction and boundary representations of bulk operations. We discuss the relation of our findings with expectations from AdS/CFT and, in particular, with recent results from quantum error correction.

  16. Learning Classical Music Club

    CERN Multimedia

    Learning Classical Music Club

    2010-01-01

    There is a new CERN Club called “Learning Classical Music at CERN”. We are aiming to give classical music lessons for different instruments (see link) for students from 5 to 100 years old. We are now ready to start our activities in the CERN barracks. We are now in the enrollment phase and hope to start lessons very soon ! Club info can be found in the list of CERN Club: http://user.web.cern.ch/user/Communication/SocialLifeActivities/Clubs/Clubs.html Salvatore Buontempo Club President

  17. Improving biological control of stalk borers in sugarcane by applying silicon as a soil amendment

    Directory of Open Access Journals (Sweden)

    Nikpay Amin

    2016-12-01

    Full Text Available The sugarcane stalk borers, Sesamia spp. (Lepidoptera: Noctuidae are the most destructive sugarcane insect pests in Iran. The efficiency of Telenomus busseolae Gahan (Hymenoptera: Scelionidae used alone or in combination with silicon fertilization was investigated for controlling the sugarcane stalk borers under field conditions. The treatments were: a combination of silicon plus multiple releases of 2,500 T. busseolae, and multiple releases of 5,000, 2,500 and 1,250 T. busseolae alone. Plots receiving no soil amendment or parasites were included as the controls. Three weeks after the first application of each treatment, 100 shoots were selected randomly from each plot and the percentage of dead heart was determined. Then, three months after the first application of parasites, the percentage of stalks damaged, the percentage of internodes bored, and the level of parasitism were determined. Finally, at harvest the percentage of stalks damaged, the percentage of internodes bored, and sugarcane quality characteristics were determined. Results indicated that the efficiency of parasitism increased when combined with an application of silicon fertilizer. The release of 2,500 T. busseolae followed by an application of silicon fertilizer decreased dead hearts to 4%, while 12% dead hearts was observed in the control plots. For the combination treatment, the percentages of stalk damage were 1.5% and 17.2%, at 3 weeks and 3 months after time release, respectively. However, the percentages of stalk damage were 35.2% and 51% when no treatment was applied. Cane quality was significantly higher with the application of silicon fertilizer plus the release of 2,500 T. busseolae, followed by releasing 5,000 Hymenoptera. The level of parasitism was also greater when parasites were released in combination with an application of silicon. We conclude that biological control by egg parasitoids can be enhanced with concurrent applications of silicon fertilizer as a soil

  18. Ecological complexity in a coffee agroecosystem: spatial heterogeneity, population persistence and biological control.

    Directory of Open Access Journals (Sweden)

    Heidi Liere

    Full Text Available BACKGROUND: Spatial heterogeneity is essential for the persistence of many inherently unstable systems such as predator-prey and parasitoid-host interactions. Since biological interactions themselves can create heterogeneity in space, the heterogeneity necessary for the persistence of an unstable system could be the result of local interactions involving elements of the unstable system itself. METHODOLOGY/PRINCIPAL FINDINGS: Here we report on a predatory ladybird beetle whose natural history suggests that the beetle requires the patchy distribution of the mutualism between its prey, the green coffee scale, and the arboreal ant, Azteca instabilis. Based on known ecological interactions and the natural history of the system, we constructed a spatially-explicit model and showed that the clustered spatial pattern of ant nests facilitates the persistence of the beetle populations. Furthermore, we show that the dynamics of the beetle consuming the scale insects can cause the clustered distribution of the mutualistic ants in the first place. CONCLUSIONS/SIGNIFICANCE: From a theoretical point of view, our model represents a novel situation in which a predator indirectly causes a spatial pattern of an organism other than its prey, and in doing so facilitates its own persistence. From a practical point of view, it is noteworthy that one of the elements in the system is a persistent pest of coffee, an important world commodity. This pest, we argue, is kept within limits of control through a complex web of ecological interactions that involves the emergent spatial pattern.

  19. Control of Root-knot Nematodes on Tomato in Stone Wool Substrate with Biological Nematicides

    Science.gov (United States)

    López-Pérez, Jose Antonio; Edwards, Scott

    2011-01-01

    The efficacy of four biological nematicides on root-galling, root-knot nematode (Meloidogyne incognita) reproduction, and shoot weight of tomato (Solanum lycopersicum) grown in stone wool substrate or in pots with sandy soil was compared to an oxamyl treatment and a non-treated control. In stone wool grown tomato, Avid® (a.i. abamectin) was highly effective when applied as a drench at time of nematode inoculation. It strongly reduced root-galling and nematode reproduction, and prevented a reduction in tomato shoot weight. However, applying the product one week before, or two weeks after nematode inoculation was largely ineffective. This shows that Avid® has short-lived, non-systemic activity. The effects of Avid® on nematode symptoms and reproduction on soil-grown tomato were only very minor, probably due to the known strong adsorption of the active ingredient abamectin to soil particles. The neem derived product Ornazin® strongly reduced tomato root-galling and nematode reproduction only in stone wool and only when applied as a drench one week prior to nematode inoculation, suggesting a local systemic activity or modification of the root system, rendering them less suitable host for the nematodes. This application however also had some phytotoxic effect, reducing tomato shoot weights. The other two products, Nema-Q™ and DiTera®, did not result in strong or consistent effects on nematode symptoms or reproduction. PMID:22791920

  20. Potential of Chitinolytic Serratia marcescens Strain JPP1 for Biological Control of Aspergillus parasiticus and Aflatoxin

    Directory of Open Access Journals (Sweden)

    Kai Wang

    2013-01-01

    Full Text Available Serratia marcescens strain JPP1 was isolated from peanut hulls in Huai'an city, Jiangsu Province, China. Its potential to inhibit the mycelial growth of Aspergillus parasiticus and the subsequent aflatoxin production was evaluated. The strain JPP1 could produce chitinase to degrade fungal cell walls, which was the main mechanism of strain JPP1 for biocontrol. Scanning electron microscopy of fungi treated with the crude chitinase revealed abnormal morphological changes. While the strain was grown in the peanut hulls-based medium, the chitinase activity reached 7.39 units. RT-PCR analysis showed that the crude chitinase repressed the transcription of genes involved in the aflatoxin gene cluster, such as aflR, aflC (pksL1, and aflO (dmtA genes. By visual agar plate assay and tip culture method, the strain JPP1 exhibited remarkable inhibitory effect on mycelia growth (antifungal ratio >95% and subsequent aflatoxin production (antiaflatoxigenic ratio >98%. An in vitro assay with seed coating agent of bacterial suspension showed that strain JPP1 effectively reduced fungal growth and subsequent aflatoxin production on peanut seeds, and its antagonistic effect was superior to the common agricultural fungicide of carbendazim. These characteristics suggest that S. marcescens JPP1 strain could potentially be utilized for the biological control of phytopathogenic fungi and aflatoxin in Chinese peanut main producing areas.

  1. Potential of chitinolytic Serratia marcescens strain JPP1 for biological control of Aspergillus parasiticus and aflatoxin.

    Science.gov (United States)

    Wang, Kai; Yan, Pei-Sheng; Cao, Li-Xin; Ding, Qing-Long; Shao, Chi; Zhao, Teng-Fei

    2013-01-01

    Serratia marcescens strain JPP1 was isolated from peanut hulls in Huai'an city, Jiangsu Province, China. Its potential to inhibit the mycelial growth of Aspergillus parasiticus and the subsequent aflatoxin production was evaluated. The strain JPP1 could produce chitinase to degrade fungal cell walls, which was the main mechanism of strain JPP1 for biocontrol. Scanning electron microscopy of fungi treated with the crude chitinase revealed abnormal morphological changes. While the strain was grown in the peanut hulls-based medium, the chitinase activity reached 7.39 units. RT-PCR analysis showed that the crude chitinase repressed the transcription of genes involved in the aflatoxin gene cluster, such as aflR, aflC (pksL1), and aflO (dmtA) genes. By visual agar plate assay and tip culture method, the strain JPP1 exhibited remarkable inhibitory effect on mycelia growth (antifungal ratio >95%) and subsequent aflatoxin production (antiaflatoxigenic ratio >98%). An in vitro assay with seed coating agent of bacterial suspension showed that strain JPP1 effectively reduced fungal growth and subsequent aflatoxin production on peanut seeds, and its antagonistic effect was superior to the common agricultural fungicide of carbendazim. These characteristics suggest that S. marcescens JPP1 strain could potentially be utilized for the biological control of phytopathogenic fungi and aflatoxin in Chinese peanut main producing areas.

  2. Identification and Characterization of Lysobacter enzymogenes as a Biological Control Agent Against Some Fungal Pathogens

    Institute of Scientific and Technical Information of China (English)

    QIAN Guo-liang; HU Bai-shi; JIANG Ying-hua; LIU Feng-quan

    2009-01-01

    Strain OH11, a Gram-negative, nonspore forming, rod-shaped bacterium with powerful antagonistic activity, was isolated from rhizosphere of green pepper in Jiangsu Academy of Agricultural Sciences of China and characterized to determine its taxonomic position. 16S rRNA gene sequence analysis revealed that strain OH11 belongs to the Gammaproteobacteria and had the highest degree of sequence similarity to Lysobacter enzymogenes strain C3 (AY074793) (99%), Lysobacter enzyrnogenes strain N4-7 (U89965) (99%), Lysobacter antibioticus strain (AB019582) (97%), and Lysobacter gummosus strain (AB16136) (97%). Chemotaxonomic data revealed that strain OH11 possesses a quinine system with Q-8 as the predominant compound and C15:0 iso,C17:1 iso w9c as the predominant iso-branched fatty acids,all of which corroborated the assignment of strain OH11 to the genus Lysobacter. Results of DNA-DNA hybridization and physiological and biochemical tests clearly showed that strain OH11 was classified as Lysobacter enzymogenes. Strain OH11 could produce protease, chitinase, and β-1,3-glucanase. It showed strong in vitro antifungal activity against Rhizoctonia solani, Sclerotinia scletotiorum, and several other phytopathogenic fungi. This is the first report of identification and characterization of Lysobacter enzymogenes as a biological control agent of plant diseases in China.

  3. Studies on potential biological control agents of immature mosquitoes in sewage wastewater in southern California.

    Science.gov (United States)

    Mian, L S; Mulla, M S; Wilson, B A

    1986-09-01

    Three biological control agents, a copepod, Mesocyclops leuckarti pilosa, and two fish, Cyprinodon macularius and Poecilia reticulata, were evaluated for their survival in secondary sewage effluent (SSE) and predation potential on mosquito larvae. Results showed that the survival of M. l. pilosa was not significantly affected in SSE or SSE diluted (50%) with water. In predation tests, the copepod consumed from 50 to 90% of the 1st-instar larvae of Culex quinquefasciatus in 24 to 72 hr and P. reticulata fed on almost all stages (egg to pupa) of the test mosquitoes. Survivorship of P. reticulata and C. macularius in SSE was not significantly affected by SSE under both greenhouse and sewage aquaculture conditions. Poecilia reticulata was distributed towards the influent end and C. macularius towards the effluent end of the aquaculture ponds, indicating the former species can tolerate higher levels of pollution which exists at the influent end of the pond. However, low water temperature and dissolved oxygen may be detrimental to these fish species in sewage aquacultural systems.

  4. Control of root-knot nematodes on tomato in stone wool substrate with biological nematicides.

    Science.gov (United States)

    López-Pérez, Jose Antonio; Edwards, Scott; Ploeg, Antoon

    2011-06-01

    The efficacy of four biological nematicides on root-galling, root-knot nematode (Meloidogyne incognita) reproduction, and shoot weight of tomato (Solanum lycopersicum) grown in stone wool substrate or in pots with sandy soil was compared to an oxamyl treatment and a non-treated control. In stone wool grown tomato, Avid® (a.i. abamectin) was highly effective when applied as a drench at time of nematode inoculation. It strongly reduced root-galling and nematode reproduction, and prevented a reduction in tomato shoot weight. However, applying the product one week before, or two weeks after nematode inoculation was largely ineffective. This shows that Avid® has short-lived, non-systemic activity. The effects of Avid® on nematode symptoms and reproduction on soil-grown tomato were only very minor, probably due to the known strong adsorption of the active ingredient abamectin to soil particles. The neem derived product Ornazin® strongly reduced tomato root-galling and nematode reproduction only in stone wool and only when applied as a drench one week prior to nematode inoculation, suggesting a local systemic activity or modification of the root system, rendering them less suitable host for the nematodes. This application however also had some phytotoxic effect, reducing tomato shoot weights. The other two products, Nema-Q™ and DiTera®, did not result in strong or consistent effects on nematode symptoms or reproduction.

  5. Biological control of phytophagous arthropods in the physic nut tree Jatropha curcas L. in Brazil

    Directory of Open Access Journals (Sweden)

    Flávio Lemes Fernandes

    2014-11-01

    Full Text Available Jatropha curcas has a high biofuel oil content, which could replace polluting fuels, and has great potential for large scale monoculture cultivation in the conventional system. We explored the occurrence, spatial distribution and the functional response of the main phytophagous species of this plant and their natural enemies to explore the potential for conservative biological control. We began sampling phytophagous species and predators when J. curcas plants were six months old. The most common species of phytophagous insects were nymphs and adults of Empoasca kraemeri, followed by Frankliniella schultzei and Myzus persicae. Among the predators, Ricoseius loxocheles, Iphiseioides zuluagai, Araneidae, larvae and adults of Psyllobora vigintimaculata and Anthicus sp. were the most frequently encountered. The most common parasitoids were the families Encyrtidae and Braconidae. The highest densities of E. kraemeri and F. schultzei on the edges of the J. curcas crop follow spatial patterns similar to those of their natural enemies I. zuluagai and Anthicus sp. These arthropods can be considered efficient predators of immature stages of E. kraemeri and F. schultzei on J. curcas.

  6. Isolation, Characterization, and Identification of Biological Control Agent for Potato Soft Rot in Bangladesh

    Directory of Open Access Journals (Sweden)

    M. M. Rahman

    2012-01-01

    Full Text Available A total of 91 isolates of probable antagonistic bacteria of potato soft rot bacterium Erwinia carotovora subsp. carotovora (Ecc were extracted from rhizospheres and endophytes of various crop plants, different soil varieties, and atmospheres in the potato farming areas of Bangladesh. Antibacterial activity of the isolated probable antagonistic bacteria was tested in vitro against the previously identified most common and most virulent soft rot causing bacterial strain Ecc P-138. Only two isolates E-45 and E-65 significantly inhibited the in vitro growth of Ecc P-138. Physiological, biochemical, and carbon source utilization tests identified isolate E-65 as a member of the genus Bacillus and the isolate E-45 as Lactobacillus sp. The stronger antagonistic activity against Ecc P-138 was found in E-65 in vitro screening and storage potatoes. E-65 reduced the soft rot infection to 22-week storage potatoes of different varieties by 32.5–62.5% in model experiment, demonstrating its strong potential to be used as an effective biological control agent for the major pectolytic bacteria Ecc. The highest (62.5% antagonistic effect of E-65 was observed in the Granola and the lowest (32.7% of that was found in the Cardinal varieties of the Bangladeshi potatoes. The findings suggest that isolate E-65 could be exploited as a biocontrol agent for potato tubers.

  7. Biology, etiology, and control of virus diseases of banana and plantain.

    Science.gov (United States)

    Kumar, P Lava; Selvarajan, Ramasamy; Iskra-Caruana, Marie-Line; Chabannes, Matthieu; Hanna, Rachid

    2015-01-01

    Banana and plantain (Musa spp.), produced in 10.3 million ha in the tropics, are among the world's top 10 food crops. They are vegetatively propagated using suckers or tissue culture plants and grown almost as perennial plantations. These are prone to the accumulation of pests and pathogens, especially viruses which contribute to yield reduction and are also barriers to the international exchange of germplasm. The most economically important viruses of banana and plantain are Banana bunchy top virus (BBTV), a complex of banana streak viruses (BSVs) and Banana bract mosaic virus (BBrMV). BBTV is known to cause the most serious economic losses in the "Old World," contributing to a yield reduction of up to 100% and responsible for a dramatic reduction in cropping area. The BSVs exist as episomal and endogenous forms are known to be worldwide in distribution. In India and the Philippines, BBrMV is known to be economically important but recently the virus was discovered in Colombia and Costa Rica, thus signaling its spread into the "New World." Banana and plantain are also known to be susceptible to five other viruses of minor significance, such as Abaca mosaic virus, Abaca bunchy top virus, Banana mild mosaic virus, Banana virus X, and Cucumber mosaic virus. Studies over the past 100 years have contributed to important knowledge on disease biology, distribution, and spread. Research during the last 25 years have led to a better understanding of the virus-vector-host interactions, virus diversity, disease etiology, and epidemiology. In addition, new diagnostic tools were developed which were used for surveillance and the certification of planting material. Due to a lack of durable host resistance in the Musa spp., phytosanitary measures and the use of virus-free planting material are the major methods of virus control. The state of knowledge on BBTV, BBrMV, and BSVs, and other minor viruses, disease spread, and control are summarized in this review.

  8. Biological Control of Rice Bakanae by an Endophytic Bacillus oryzicola YC7007

    Directory of Open Access Journals (Sweden)

    Mohammad Tofajjal Hossain

    2016-06-01

    Full Text Available In our previous study, we reported that a novel endophytic bacterium Bacillus oryzicola YC7007 has suppressed bacterial diseases of rice via induced systemic resistance and antibiotic production. This endophytic strain, B. oryzicola YC7007 was used as a biological control agent against bakanae disease of rice caused by Fusarium fujikuroi, and its mechanism of interaction with the pathogen and the rice was further elucidated. Root drenching with B. oryzicola YC7007 suspension reduced the disease severity of bakanae significantly when compared with the untreated controls. The treatments of B. oryzicola YC7007 suspension (2.0 × 10⁷ cfu/ml to the rice rhizosphere reduced bakanae severity by 46–78% in pots and nursery box tests containing autoclaved and non-autoclaved soils. Moreover, in the detached rice leaves bioassay, the development of necrotic lesion and mycelial expansion of F. fujikuroi were inhibited significantly by spraying the culture filtrate of B. oryzicola YC7007. Drenching of ethyl acetate extracts of the culture filtrate to the rhizosphere of rice seedlings also reduced the bakanae disease severity in the plant culture dish tests. With the root drenching of B. oryzicola YC7007 suspension, the accumulation of hydrogen peroxide was observed at an early stage of rice seedlings, and a hormonal defense was elicited with and without pathogen inoculation. Our results showed that the strain B. oryzicola YC7007 had a good biocontrol activity against the bakanae disease of rice by direct inhibition, and was also capable of inducing systemic resistance against the pathogen via primed induction of the jasmonic acid pathway.

  9. Disease control by chemical and biological fungicides in cultivated mushrooms: button mushroom, oyster mushroom and shiitake

    Directory of Open Access Journals (Sweden)

    Ivana Potočnik

    2015-12-01

    Full Text Available The most commonly cultivated basidiomycetes worldwide and in Serbia are button mushroom (Agaricus bisporus, oyster mushroom (Pleurotus sp. and shiitake (Lentinus edodes. Production of their fruiting bodies is severely afflicted by fungal, bacterial, and viral pathogens that are able to cause diseases which affect yield and quality. Major A. bisporus fungal pathogens include Mycogone perniciosa, Lecanicillium fungicola, and Cladobotryum spp., the causal agents of dry bubble, wet bubble, and cobweb disease, respectively. Various Trichoderma species, the causal agents of green mould, also affect all three kinds of edible mushrooms. Over the past two decades, green mould caused by T. aggressivum has been the most serious disease of button mushroom. Oyster mushroom is susceptible to T. pleurotum and shiitake to T. harzianum. The bacterial brawn blotch disease, caused by Pseudomonas tolaasii, is distributed globally. Disease control on mushroom farms worldwide is commonly based on the use of fungicides. However, evolution of pathogen resistance to fungicides after frequent application, and host sensitivity to fungicides are serious problems. Only a few fungicides are officially recommended in mushroom production: chlorothalonil and thiabendazol in North America and prochloraz in the EU and some other countries. Even though decreased sensitivity levels of L. fungicola and Cladobotryum mycophilum to prochloraz have been detected, disease control is still mainly provided by that chemical fungicide. Considering such resistance evolution, harmful impact to the environment and human health, special attention should be focused on biofungicides, both microbiological products based on Bacillus species and various natural substances of biological origin, together with good programs of hygiene. Introduction of biofungicides has created new possibilities for crop protection with reduced application of chemicals.

  10. Climatic and Grazing Controls on Biological Soil Crust Nitrogen Fixation in Semi-arid Ecosystems

    Science.gov (United States)

    Schwabedissen, S. G.; Reed, S.; Lohse, K. A.; Magnuson, T. S.

    2014-12-01

    Nitrogen, next to water, is believed to be the main limiting resource in arid and semi-arid ecosystems. Biological soil crusts (biocrusts) -a surface community of mosses, lichens and cyanobacteria-have been found to be the main influx of "new" nitrogen (N) into many dryland ecosystems. Controls on biocrust N fixation rates include climate (temperature and moisture), phosphorus availability, and disturbance factors such as trampling, yet a systematic examination of climatic and disturbance controls on biocrusts communities is lacking. Biocrust samples were collected along an elevation gradient in the Reynolds Creek Experimental Watershed near Murphy, Idaho. Four sites were selected from a sagebrush steppe ecosystem with precipitation ranging from ≤250mm/yr to ≥1100mm/yr. Each site included 5 grazed plots and one historic exclosure plot that has been free from grazing for more than 40 years. Five samples each were collected from under plants and from interplant spaces from the grazed plots and exclosures and analyzed for potential N fixation using an acetylene reduction assay. We hypothesized that N fixation rates would be the highest in the exclosures of the two middle sites along the elevation gradient, due to the lack of disturbance and optimal temperature and moisture, respectively. As predicted, results showed higher rates of potential N fixation in exclosures than non-exclosures at a mid-elevation 8.4 ± 3.1 kg N/ha/yr in the exclosures compared to 1.8 ± 1.5 kg N/ha/yr indicating that grazing may reduce N fixation activity. Interestingly, rates were 2-5 times lower under plant canopies compared to interplant spaces at all but the highest elevation site. Findings from our study suggest that biocrust N fixation may be a dominant input of N into theses dryland systems and, in line with our hypotheses, that climate, location within the landscape, and disturbance may interact to regulate the rates of this fundamental ecosystem process.

  11. Invading freshwater snails and biological control in Martinique Island, French West Indies

    Directory of Open Access Journals (Sweden)

    Jean-Pierre Pointier

    2001-09-01

    Full Text Available Eight alien freshwater snail species were introduced into Martinique Island during the last 50 years. The introduced snails include four planorbids (Biomphalaria straminea, Helisoma duryi, Amerianna carinata and Gyraulus sp., three thiarids (Melanoides tuberculata, M. amabilis and Tarebia granifera and one ampullarid (Marisa cornuarietis. Four of these species rapidly colonized the whole Martinican hydrographic system whereas the other four remained restricted to some particular sites. The invasion processes were documented during the last 20 years and showed (i a rapid invasion of the island by several morphs of M. tuberculata at the beginning of the 80's; (ii the introduction of T. granifera in 1991 and M. amabilis in 1997; and (iii the rapid spread of these last two species throughout the island. In the years following its introduction, M. tuberculata was used in biological control experiments against the snail hosts of schistosomiasis, B. glabrata and B. straminea. Experiments were conducted with success in several groups of water-cress beds which constituted the latest transmission sites for schistosomiasis at the beginning of the 80's. A malacological survey carried out in 2000 all over the island showed the absence of B. glabrata but the presence of some residual populations of B. straminea. Long-term studies carried out in Martinique have shown that the thiarids are able to maintain relatively stable populations over a long period of time, thus preventing recolonization by the snail hosts. Within this context the invasion of the hydrographic system of Martinique by thiarid snails has resulted in an efficient and sustainable control of the intermediate hosts of schistosomiasis.

  12. Autonomous Biological Control of Dactylopius opuntiae (Hemiptera: Dactyliiopidae) in a Prickly Pear Plantation With Ecological Management.

    Science.gov (United States)

    Cruz-Rodríguez, J A; González-Machorro, E; Villegas González, A A; Rodríguez Ramírez, M L; Mejía Lara, F

    2016-04-07

    It is broadly known that the conservation of biological diversity in agricultural ecosystems contributes to pest control. This process was studied in a prickly pear plantation (Opuntia megacanthaandOpuntia ficus-indica) located in central Mexico. No insecticides have been used on this plantation since 2000, and local farmers believe that the presence of different species of insects limits the growth of the wild cochineal (Dactylopius opuntiaeCockerell), which is one of the main pests in this crop. From August 2012 to November 2013, we estimated the number of cochineal per stem in the plantation and determined its spatial distribution pattern. In order to identify signs of population regulation, we obtained histograms of the frequency distribution of the size of the clusters and determined if distribution is adjusted to a power function (power law). We identified the cochineal predators and determined the correlation in their abundances. The greater abundance of cochineal occurred between summer and autumn while the minimum value was recorded in spring. The frequency distribution of the cochineal clusters had a high level of adjustment to a power function, suggesting the presence of population regulation processes. Six species that prey on cochineal were identified.Laetilia coccidivoraandHyperaspis trifurcatawere the most active and their abundance was significantly correlated with the abundance of cochineal. We found that the probability of extinction of these insects in a cladode increases with its density, since the density and predator activity also increased. It is likely that, under these conditions, the cochineal have established an autonomous control.

  13. Ein Klassiker der Padagogik in Evolutionarer Perspektive: Eduard Sprangers "Lebensformen" im Lichte der Modernen Biologie (A Classic of Pedagogics from an Evolutionary Perspective: Edward Spranger's "Forms of Life" in the Light of Modern Biology).

    Science.gov (United States)

    Neumann, Dieter

    2002-01-01

    Interprets Edward Spranger's "Forms of Life" against the background of the findings of modern biology. Shows how far Spranger's diagnosis of different human types, which are not affected by external influences on characteristics, conform with research hypotheses of modern biological sciences. (CAJ)

  14. Construction of biological control strain of Trichoderma viride and study of their ability to induce plant disease resistance

    Institute of Scientific and Technical Information of China (English)

    LIU Shi-wang; GUO Ze-jian

    2004-01-01

    @@ Plant diseases heavily affct plant growth and crop yield even in modern agriculture. Control its difficult because pathogens mutate frequently, and this leads in frequent breaking of disease resistance in commercial cultivars. The excessive application of chemical pesticides is not only producing pesticideresistant pathogens, but it is harming the environment threatening the health of human beings.Therefore, the use of biological control agents (BCA) may provide an environmental friendly alternative to chemicals for plant disease control. Hypersensitive response (HR) and systemic acquired resistance (SAR) are the typical expressions of plant defense reactions. Once SAR is established,, the plants exhibits a broad-spectrum of disease resistance against pathogen attack. Researchers have identified elicitor proteins, such as elicitins and harpins, which activate plant defense reactions. It would be useful to explore the possibility of using biological control agents to induce a status of SAR in crop plants.

  15. 78 FR 74218 - Imposition of Additional Sanctions on Syria Under the Chemical and Biological Weapons Control and...

    Science.gov (United States)

    2013-12-10

    ... Imposition of Additional Sanctions on Syria Under the Chemical and Biological Weapons Control and Warfare.... ACTION: Notice. SUMMARY: On August 2, 2013, a determination was made that the Government of Syria used... Notice 8460. That determination resulted in sanctions against the Government of Syria. Section 307(b)...

  16. Whole-Genome Sequence of Pseudomonas graminis Strain UASWS1507, a Potential Biological Control Agent and Biofertilizer Isolated in Switzerland

    Science.gov (United States)

    Crovadore, Julien; Calmin, Gautier; Chablais, Romain; Cochard, Bastien; Schulz, Torsten

    2016-01-01

    We report here the whole-genome shotgun sequence of the strain UASWS1507 of the species Pseudomonas graminis, isolated in Switzerland from an apple tree. This is the first genome registered for this species, which is considered as a potential and valuable resource of biological control agents and biofertilizers for agriculture.

  17. Modelling biological control with wild-type and genetically modified baculoviruses in the Helicoverpa armigera-cotton system

    NARCIS (Netherlands)

    Sun, X.; Werf, van der W.; Bianchi, F.J.J.A.; Hu, Z.; Vlak, J.M.

    2006-01-01

    A comprehensive model was developed to simulate virus epizootics in a stage structured insect population and analyse scenarios for the biological control of cotton bollworm (CBW), Helicoverpa armigera, in cotton, using wild-type or genetically modified baculoviruses. In simulations on dosage and tim

  18. Phenology and temperature-dependent development of Ceutorhynchus assimilis, a potential biological control agent for Lepidium draba

    Science.gov (United States)

    Heart-podded hoary cress (Lepidium draba) is an alien weed that has invaded rangeland in the northwestern USA. A host race (i;e; host-specific biotype) of the weevil, Ceutorhynchus assimilis, is being evaluated as a prospective biological control agent. This biotype is only known from southern Eur...

  19. Differential performance of tropical soda apple and its biological control agent Gratiana boliviana (Coleoptera: Chrysomelidae) in open and shaded habitats

    Science.gov (United States)

    The leaf feeding beetle Gratiana boliviana Spaeth has been released since 2003 in the southeastern United States for biological control of tropical soda apple, Solanum viarum Dunal. In Florida, G. boliviana can be found on tropical soda apple growing in open pastures as well as in shady wooded areas...

  20. Biological and Cultural Control of Olive Fruit Fly in California---Utilization of Parasitoids from USDA-APHIS-PPQ, Guatemala

    Science.gov (United States)

    The parasitoid Psytallia cf. concolor (Szépligeti) was reared on sterile Mediterranean fruit fly larvae at the USDA-APHIS-PPQ, Petapa Quarantine Laboratory in Guatemala and shipped to the USDA-ARS, Parlier, for wide-spread release and biological control of olive fruit fly in California. As many as 3...