Academic literature on the topic 'Parasitic component'
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Journal articles on the topic "Parasitic component"
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Vasjanov, Aleksandr, and Vaidotas Barzdenas. "A Methodology Improving Off-Chip, Lumped RF Impedance Matching Network Response Accuracy." Electronics 7, no. 9 (September 10, 2018): 188. http://dx.doi.org/10.3390/electronics7090188.
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Impedance matching is concurrent with any radio frequency (RF) circuit design and is essential for maximizing the gain and efficiency while minimizing the noise of high-frequency amplifiers as well as some mixer topologies. The main impedance matching network components are capacitors, inductors, and RF transformers all of which contain parasitic parameters that influence the matching response S11 curve. After calculating matching network component values using classical matching techniques, the measured and simulated response curves differ depending on the target frequency. This results in multiple calculations and measurement cycles in order to precisely match the source and load at the desired frequency. This article proposes an algorithm and methodology of estimating component parasitic parameters and taking them into account when calculating the main component parameters (capacitance and inductance). The proposed algorithm has been implemented as a toolbox in Cadence Virtuoso and verified through simulation and measurements. Measurement results show, that at 500 MHz 10% tolerance components with parasitics included and values based on classical theory provide a 3.2–9.8% offset from the target frequency. In the same conditions, matching networks with compensated (according to the proposed algorithm) values provide 0.1–8.8% target frequency offset. At 1500 MHz 10% components provided 4–12.3% (non-compensated) and 1–8.7% (compensated) target frequency offset ranges. At 3000 MHz. The frequency offset range of using compensated matching network component values is reduced from 5.5–15.1% to 1.3–8.1%.
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Tritten, Lucienne, Cristina Ballesteros, Robin Beech, Timothy G. Geary, and Yovany Moreno. "Mining nematode protein secretomes to explain lifestyle and host specificity." PLOS Neglected Tropical Diseases 15, no. 9 (September 29, 2021): e0009828. http://dx.doi.org/10.1371/journal.pntd.0009828.
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Parasitic nematodes are highly successful pathogens, inflicting disease on humans, animals and plants. Despite great differences in their life cycles, host preference and transmission modes, these parasites share a common capacity to manipulate their host’s immune system. This is at least partly achieved through the release of excretory/secretory proteins, the most well-characterized component of nematode secretomes, that are comprised of functionally diverse molecules. In this work, we analyzed published protein secretomes of parasitic nematodes to identify common patterns as well as species-specific traits. The 20 selected organisms span 4 nematode clades, including plant pathogens, animal parasites, and the free-living species Caenorhabditis elegans. Transthyretin-like proteins were the only component common to all adult secretomes; many other protein classes overlapped across multiple datasets. The glycolytic enzymes aldolase and enolase were present in all parasitic species, but missing from C. elegans. Secretomes from larval stages showed less overlap between species. Although comparison of secretome composition across species and life-cycle stages is challenged by the use of different methods and depths of sequencing among studies, our workflow enabled the identification of conserved protein families and pinpointed elements that may have evolved as to enable parasitism. This strategy, extended to more secretomes, may be exploited to prioritize therapeutic targets in the future.
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Lee, Hyeonjin, and Tae-Hong Kim. "Wideband Square Loop Antenna with Parasitic Loop Component." Microwave and Optical Technology Letters 55, no. 10 (July 26, 2013): 2302–4. http://dx.doi.org/10.1002/mop.27826.
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Fadeeva, Galina Anatolievna, and Elena Evgenievna Boryakova. "Assessment of the stability of bat ectoparasite communities using a Principal Component Analysis (PCA) method." Samara Journal of Science 8, no. 1 (February 28, 2019): 119–24. http://dx.doi.org/10.17816/snv201981121.
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The paper deals with a research of epiparasite communities in native karst caves in the South of Nizhny Novgorod Region. Six species of bats such as Daubentons water bat, Brandts bat, whiskered bat, pond bat, northern bat and long-eared bat were examined. A Principal Component Analysis was used to identify factors influencing the composition of ectoparasites as well as the number and distribution of mites in mixed colonies of bats. As the cave and its inhabitants can be considered as a microbiotope, it is obvious that there are specific relations between inhabitants in caves. Special habitat conditions indirectly influence the parasitic systems developing there which are characterized by certain stability. Mann-Whitney U-test was used to estimate the difference between samples of animals from different habitats. Methods of nonparametric statistics didnt find significant distinctions by the hosts, years and biotopes, the bat colony and their ectoparasites can be estimated as a single complexly organized system, existing long in space and time. From all possible factorial space four factors have significant effect on systems. The contribution of the first and second factors is equal to 65% of variance (specificity of parasites to hosts and a factor of dominant species presence). In parasite communities of bats interrelations which cause successful existence of all types without the expressed competition are observed. Our results indicate a complex relationship between the parasites in the community on the one hand, and long-term existence of the community on the other hand. Each member of parasitic system has a position in factorial space. In parasite communities of bats we met only one factor-dependent species ( Spinturnix acuminatus, Sp. plecotinus, Leptotrombidium russicum ). Species that show moderate and positive, moderate and negative correlation dependence with several factors are found. For example, Spinturnix myoti , Sp. kolenatii , Macronyssus heteromorphus , etc. Heterogeneity of environmental impact on the parasitic systems which are formed in natural caves provides stability of bat parasite communities in general.
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Short, Erica E., Cyril Caminade, and Bolaji N. Thomas. "Climate Change Contribution to the Emergence or Re-Emergence of Parasitic Diseases." Infectious Diseases: Research and Treatment 10 (January 1, 2017): 117863361773229. http://dx.doi.org/10.1177/1178633617732296.
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The connection between our environment and parasitic diseases may not always be straightforward, but it exists nonetheless. This article highlights how climate as a component of our environment, or more specifically climate change, has the capability to drive parasitic disease incidence and prevalence worldwide. There are both direct and indirect implications of climate change on the scope and distribution of parasitic organisms and their associated vectors and host species. We aim to encompass a large body of literature to demonstrate how a changing climate will perpetuate, or perhaps exacerbate, public health issues and economic stagnation due to parasitic diseases. The diseases examined include those caused by ingested protozoa and soil helminths, malaria, lymphatic filariasis, Chagas disease, human African trypanosomiasis, leishmaniasis, babesiosis, schistosomiasis, and echinococcus, as well as parasites affecting livestock. It is our goal to impress on the scientific community the magnitude a changing climate can have on public health in relation to parasitic disease burden. Once impending climate changes are now upon us, and as we see these events unfold, it is critical to create management plans that will protect the health and quality of life of the people living in the communities that will be significantly affected.
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Kwon, Hyuk Min, Sung Kyu Kwon, Woon Il Choi, Seung Yong Sung, Jong Kwan Shin, Chang Yong Kang, Raj Jammy, and Hi Deok Lee. "RF Characteristics of SiO2/HfO2/SiO2 MIM Capacitor." Advanced Materials Research 658 (January 2013): 112–15. http://dx.doi.org/10.4028/www.scientific.net/amr.658.112.
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RF characteristics of metal-insulator-metal (MIM) capacitors with SiO2/HfO2/SiO2 (SHS) were investigated using an equivalent circuit model that is associated with the main impedance ZMIM.cap and the substrate-related conductance Ysub. However, the parasitic capacitance in Ysub was lower than that of another element component in ZMIM.cap, which makes difficult for accurate RF modeling because the parasitic component was dominant at high frequency regions. As low parasitic component is eliminated from the modeling, the extracted capacitance for SHS MIM capacitor was stable up to 20 GHz. The Q-factor and resonant frequency (fr) point of SHS structure are 23.9 at 1 GHz and 9.76 GHz, respectively.
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Betantya Nugroho, Azli Yahya, Abd Rahim Mat Sidek, and Trias Andromeda. "MATLAB Modeling of Component in Electrical Discharge Machining (EDM) Pulses." Media Journal of General Computer Science 1, no. 1 (December 9, 2023): 1–6. http://dx.doi.org/10.62205/mjgcs.v1i1.6.
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Electrical Discharge Machining (EDM), is a machining technique for working with conductive materials. During the EDM process, electrical discharge energy is transformed into thermal energy, leading to the erosion of the workpiece. The energy utilized by the EDM process is represented by the time-dependent current, which determines the energy density employed for workpiece erosion. Ideally, during a discharge event, the current pulse should exhibit a square wave shape. However, in practice, EDM circuits often incorporate parasitic components that lead to non-square waveforms or transient currents. In this paper, we describe the simulation of parasitic components using MATLAB, revealing that these components alter the signal waveform and affect the achievement of a square pulse wave in MRR. The presence of parasitic components results in transient current patterns during the discharge phase and, consequently, a reduction in MRR. The implementation of a square wave current, however, enhances the MRR value and increases the efficiency of the EDM process
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Polyaeva, Kseniya Viktorovna, Gennady Nikolaevich Dorovskikh, and Yuliya Konstantinovna Chugunova. "Species composition and structure of parasites component communities of tugun Coregonus tugun (Pallas, 1814) from the Khatanga and Yenisei Rivers." Samara Journal of Science 8, no. 3 (August 5, 2019): 72–80. http://dx.doi.org/10.17816/snv201983112.
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Tugun Coregonus tugun (Pallas, 1814) is an endemic of Siberia. Information about the species composition and structure of tugun parasite community on the stage of spawning migration is described in this paper. We carried out ichtioparasitologic studies in the Yenisey and the Khatanga Rivers in 2011-2014. Tugun parasite complex from the Khatanga River remains statistically identical in species composition, number of individuals and biomass and differs from those of the Yeniseis tugun over the entire study period. Apparently two different stocks of tugun were investigated in the Yenisei River. One of them lives in the Yeniseis streambed, the other one lives in the Podkamennaya Tunguska River. The composition of the parasitic fauna of tugun from two rivers is formed by generalist species. Tugun parasites component communities from all material collection stations have high values of the Shannon index and two dominant species (by numbers of parasites and by biomass). We found out that the species biomasses differ significantly on the graphic community structure. The description of tugun parasite communities corresponds to characteristic of a climax community on the stage of destruction except the graphic structure. In the analyzed parasitic communities the processes of egg laying and larval appearance, the death of parasites of previous year generation and infection with this year parasites occur simultaneously. The stages of formation and destruction of the community overlap. The described state of tugun parasites communities has an adaptive value. The load on the host body is reduced which ensures the long-term existence of parasites.
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Maruszewska-Cheruiyot, Marta, Katarzyna Donskow-Łysoniewska, and Maria Doligalska. "Helminth therapy – local and systemic activity, on example of inflammatory bowel diseases and multiple sclerosis." Postępy Higieny i Medycyny Doświadczalnej 73 (December 2, 2019): 645–53. http://dx.doi.org/10.5604/01.3001.0013.6092.
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Autoimmunological diseases are an increasing problem nowadays in societies. Due to complex etiology, effective therapy against immune disorders is still needed. A promising alternative for the current methods of treatment can be helminthic therapy. Series of tests on animal models as well as clinical studies indicates that parasitic infection can inhibit inflammation in inflammatory bowel diseases and multiple sclerosis. Effectiveness of therapy with helminths, mainly gut nematodes depends on the activity of many compounds released during infection. Despite hopeful results, mechanisms activated by nematodes aren’t explained yet, besides, therapeutically use of live parasites is controversial. Most of studies are focused on searching parasitic factors. The use of this compound in autoimmunological diseases could be an alternative for current medicaments. The aim of current study is summarizing and discussing helminth therapy of autoimmunological disorder on multiple sclerosis and inflammatory bowel diseases examples as well as using parasitic compounds as a potential pharmaceutical component.
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Lassois, Ludivine, M. Haïssam Jijakli, Marc Chillet, and Luc de Lapeyre de Bellaire. "Crown Rot of Bananas: Preharvest Factors Involved in Postharvest Disease Development and Integrated Control Methods." Plant Disease 94, no. 6 (June 2010): 648–58. http://dx.doi.org/10.1094/pdis-94-6-0648.
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Crown rot is a complex disease that affects export bananas in all banana-producing countries. Usually invisible when the fruits are packed for transportation from tropical countries to distant destinations, disease symptoms occur during shipment, ripening, and storage. This disease, characterized by rot and necrosis, affects tissues joining the fingers with each other, called the crown. It may reach the pedicel and even the banana pulp when crown rot is severe. Losses from 10 to 86% have been recorded for treated and untreated bananas, respectively. In this paper, we summarize the current knowledge on crown rot disease and associated control measures that must be considered throughout the production channel in order to be effective. We suggest a new approach to this postharvest disease of bananas: that of considering fruit quality potential in the field. This new concept of preharvest quality potential is a key factor to understanding crown rot development. Fruit quality potential depends on both a physiological and a parasitic component, both of which depend on agrotechnic and pedoclimatic factors of the crop production area. The physiological component is defined as the sensitivity of the fruits to crown rot, and the parasitic component reflects the capacity of the parasitic complex to induce a level of disease. The content of this review is divided into two parts. First, the fruit quality potential at field level is addressed, with special emphasis on its physiological and parasitic components. Second, the control methods are examined at different steps of the channel, in order to give an overview of a possible integrated control strategy.
Dissertations / Theses on the topic "Parasitic component"
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Sitter, Nicholas James. "Two-wire, low component count soil temperature sensor." Thesis, University of Iowa, 2011. https://ir.uiowa.edu/etd/1081.
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A two-wire, low component count soil temperature sensor was developed. The sensor uses one wire for ground and the other wire is used for both power and communication. Pulse width modulation is used to send temperature measurements to the master, where the duty cycle is proportional to the temperature. The sensor parasitically powers itself from the bidirectional data line. In order to reduce the number of components necessary, a microcontroller with an internal temperature sensor is used. Finally, the sensor can receive data from the master on the bidirectional communication line, which is used for calibrating the sensor.
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Valentino, Eric. "The Design of Passive Networks with Full-Wave Component Models." Scholar Commons, 2019. https://scholarcommons.usf.edu/etd/7979.
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In this thesis, the design of passive networks with the aid of full-wave simulation software and geometry-based models of lumped elements is investigated. This is done by examining the results of a number of simulation examples, as well as measured data from manufactured designs to compare against simulated equivalents. One such example is a chip antenna evaluation board design, in which the PCB, antenna, matching components and connector are all modeled. When measured, the simulation agreed with the board’s best matched frequency of 5.5 GHz to within 20 MHz. In another, a new antenna layout is generated from an existing evaluation design which, produced a match of about -15 dB at the design frequency with a similar bandwidth to that shown on the antenna datasheet on the first attempt at manufacture. Additionally, a statistical experiment was conducted in order to provide insight into the phenomenon of coupling between lumped components, and to define clearly when it starts to become an important effect to consider. For both chip capacitors and inductors, a behavioral model of how much crosstalk is present in a prospective circuit was developed which takes into account angle and distance between components, as well as case size. Finally, a simple discrete gradient descent was implemented in a commercial full-wave simulation software in order to assist in the refinement of designs containing 3-D geometry-defined component models.
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Zasada, Inga Anne. "Chemical components of the Brassicaceae that suppress plant-parasitic nematodes /." For electronic version search Digital dissertations database. Restricted to UC campuses. Access is free to UC campus dissertations, 2002. http://uclibs.org/PID/11984.
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Capwell, John. "Characterization and Modeling of Planar Spiral Inductors and Pad Stack Parasitic Effects." [Tampa, Fla.] : University of South Florida, 2003. http://purl.fcla.edu/fcla/etd/SFE0000144.
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Duong, Viet-Son. "Étude de l'intégration d'une protection par fusible dans les convertisseurs à IGBT." Grenoble INPG, 1997. http://www.theses.fr/1997INPG0081.
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Les progrès technologiques réalisés en matière d'interrupteurs semiconducteurs de puissance, ont conduit au début des années 80, à l'apparition du transistor bipolaire à grille isolée, plus couramment désigné sous l'abréviation IGBT. Etant donnés les niveaux de puissance que ces composants sont aujourd'hui aptes à commuter, une protection contre les défauts devient nécessaire. Un fusible rapide associé au composant permet d'éviter l'explosion du boîtier en cas de court-circuit, et ainsi de garantir la sécurité des personnes et des divers composants à proximité. Une étude du comportement de l'IGBT en régime de court-circuit a été entreprise afin d'évaluer une valeur caractéristique de l'explosion, et de dimensionner précisément le calibre du fusible. L'intégration d'un fusible dans un convertisseur à IGBT passe en premier lieu par l'étude des perturbations générées par le convertisseur sur le fusible. Ces perturbations, associées aux effets de proximité, se traduisent par une répartition déséquilibrée des courants entre des fusibles en parallèle ou même entre les éléments fusibles. Ainsi, nous nous sommes attachés à élaborer un modèle électrothermique du fusible permettant de calculer la répartition des courants et la température des éléments fusibles. Ce modèle permet de définir des abaques, en liaison avec un critère thermique de bon fonctionnement des fusibles. En second lieu, nous avons analysé les perturbations engendrées par le fusible sur le convertisseur. Celles-ci se traduisent principalement par l'introduction d'une inductance supplémentaire dans le circuit, laquelle pouvant être néfaste au fonctionnement du convertisseur. Nous avons proposé quelques règles de conception permettant de réduire l'inductance rajoutéeTechnology advancement in power semiconductor devices has led to the achievement of the insulated gate bipolar transistor (IGBT). Considering the power switched by these components, protection against fauIts is necessary. A fast fuse in series with the device can prevent the explosion of the case if a short circuit occurs, and consequently ensures people and equipment safety. An investigation on the short circuit behaviour ofIGBT has been carried out to select the ideal fuse rating. KEYWORDS Disturbances created by converters on the fuse have to be taken into account when integrating the fuse in the converter. These disturbances can be attributed to proximity effects, a consequence of which is an unbalance between fuses in parallel or even between fuse elements inside a fuselink. Consequently, an electrothermal model of the fuse is elaborated for the calculation of the distribution of current and temperature of fuse elements. This model helps us to obtain abacus associated to a thermal criterion ensuring the good working conditions of fuses. Perturbation created by the fuse on the converter is mainly characterised by an inductance added in the circuit. This inductance can be harmful to the working of the converter. Sorne rules of conception are proposed to reduce this supplementary inductance
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Toledo, Gislayne de Melo [UNESP]. "Biodiversidade de helmintos parasitas de anuros procedentes de diferentes fitofisionomias no Peru." Universidade Estadual Paulista (UNESP), 2017. http://hdl.handle.net/11449/150449.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Diversas características ecológicas do hospedeiro e a sua distribuição geográfica são fatores que influenciam na composição e estrutura das comunidades de parasitas. O inventário da diversidade parasitária é considerado de grande importância para o conhecimento da relação parasita-hospedeiro e também da conservação e preservação de ecossistemas. No entanto, poucos estudos sobre comunidade de parasitas associadas a comunidades de hospedeiros tem sido realizados. Assim, os objetivos deste estudo foram: descrever e caracterizar a composição e estrutura das comunidades componentes de helmintos associados aos anuros hospedeiros do Peru; avaliar a riqueza e diversidade das comunidades componentes de helmintos para a comunidade de hospedeiros para cada área estudada; avaliar a similaridade das comunidades componentes de parasitas entre os ambientes estudados; avaliar a influência dos fatores bióticos dos hospedeiros sobre a fauna parasitária; e em que extensão as estratégias de vida dos hospedeiros podem influenciar esta especificidade. Um total de 279 espécimes de 12 espécies de anuros foi analisado quanto a presença de parasitas: Allobates ornatus, Rhinella marina, Rhinella spinulosa, Ameerega trivittata, Dendropsophus rhodopeplus, Hypsiboas lanciformis, Hypsiboas punctatus, Scinax garbei, Adenomera andreae, Leptodactylus discodactylus, Leptodactylus pentadactylus e Leptodactylus wagneri. Foram registrados 36 taxa de helmintos: 23 nematoides, 7 trematódeos, 3 acantocéfalos, 2 cestoides e 1 monogenético. Rhinella marina apresentou a maior abundância média (184,3 ± 670,9) e a maior riqueza (S = 19). Rhinella marina de Tarapoto, apresentou riqueza e diversidade parasitária similares entre as áreas antropizada e preservada (p > 0,05), porém algumas espécies de parasitas apresentaram diferenças nos valores de prevalência, abundância e importância relativa entre as duas infracomunidades. Assim, a composição e estrutura da comunidade de helmintos de Tarapoto pode esta sofrendo influência das características dos habitats nesta espécie de anuro. Está influência também é observada quando comparamos as comunidades de helmintos das quatro localidades do Peru: Huanuco, Iquitos, Tarapoto e Tingo Maria. O acantocéfalo, Pseudoacanthocephalus lutzi,foi encontrado com alta prevalência parasitária em R. marina de Huanuco. No entanto, o tamanho do hospedeiro e do parasita não tiveram correlação significativa com a abundância parasitária (p > 0,05), então, a comunidade deste acantocéfalo em Huanuco não esta sofrendo influência das características do hospedeiro. Este estudo também registrou vários novos registros de hospedeiros e localidade para espécies de helmintos, contribuindo para o conhecimento da fauna de parasitas de anfíbios na região Neotropical.
Several ecological characteristics of the host and its geographical distribution are factors that influence the composition and structure of the parasite communities. The inventory of parasite diversity is considered of great importance for the knowledge of the parasite-host relationship and also for the conservation and preservation of ecosystems. However, few studies on parasite community associated with host communities have been conducted. Thus, the objectives of this study were: to describe and to characterize the composition and structure of the helminth component communities associated with the anurans of Peru; to evaluate the richness and diversity of the helminth component communities for the host community for each studied area; to evaluate the similarity of the parasite component communities among the studied environments; to evaluate the influence of host biotic factors on parasitic fauna; and to what extent host life strategies can influence the specificity. A total of 279 specimens of 12 species of anurans was analyzed for the presence of parasites: Allobates ornatus, Rhinella marina, Rhinella spinulosa, Ameerega trivittata, Dendropsophus rhodopeplus, Hypsiboas lanciformis, Hypsiboas punctatus, Scinax garbei, Adenomera andreae, Leptodactylus discodactylus, Leptodactylus pentadactylus, and Leptodactylus wagneri. Thirty-six helminth taxa were recorded, as follow: 23 nematodes, seven trematodes, three acanthocephals, two cestodes, and one monogenean. Rhinella marina showed the highest mean abundance (184.3 ± 670.9) and the highest richness (S = 19). Rhinella marina of Tarapoto, presented parasitic richness and diversity similar between anthropic and preserved areas (p > 0.05), but some parasite species showed differences in prevalence, abundance, and relative importance between the two infracommunities. Thus, the composition and structure of the helminth community of Tarapoto may be influenced by the characteristics of the habitats in this anuran species. This influence is also observed when we compare the helminth communities of the four locations of Peru: Huanuco, Iquitos, Tarapoto, and Tingo Maria. The acanthocephalus, Pseudoacanthocephalus lutzi, was found with high parasitic prevalence in R. marina of Huanuco. However, host and parasite size did not correlate significantly with abundance of parasites (p > 0,05), then, the community this acanthocephalan in Huanuco is not influenced by characteristics of the host. This study also recorded several new host and local records for species of helminths, contributing to the knowledge of the fauna of amphibian parasites in the Neotropical region.
CNPq: 140301/2013-5
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Toledo, Gislayne de Melo. "Biodiversidade de helmintos parasitas de anuros procedentes de diferentes fitofisionomias no Peru." Botucatu, 2017. http://hdl.handle.net/11449/150449.
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Orientador: Reinaldo José da SilvaResumo: Diversas características ecológicas do hospedeiro e a sua distribuição geográfica são fatores que influenciam na composição e estrutura das comunidades de parasitas. O inventário da diversidade parasitária é considerado de grande importância para o conhecimento da relação parasita-hospedeiro e também da conservação e preservação de ecossistemas. No entanto, poucos estudos sobre comunidade de parasitas associadas a comunidades de hospedeiros tem sido realizados. Assim, os objetivos deste estudo foram: descrever e caracterizar a composição e estrutura das comunidades componentes de helmintos associados aos anuros hospedeiros do Peru; avaliar a riqueza e diversidade das comunidades componentes de helmintos para a comunidade de hospedeiros para cada área estudada; avaliar a similaridade das comunidades componentes de parasitas entre os ambientes estudados; avaliar a influência dos fatores bióticos dos hospedeiros sobre a fauna parasitária; e em que extensão as estratégias de vida dos hospedeiros podem influenciar esta especificidade. Um total de 279 espécimes de 12 espécies de anuros foi analisado quanto a presença de parasitas: Allobates ornatus, Rhinella marina, Rhinella spinulosa, Ameerega trivittata, Dendropsophus rhodopeplus, Hypsiboas lanciformis, Hypsiboas punctatus, Scinax garbei, Adenomera andreae, Leptodactylus discodactylus, Leptodactylus pentadactylus e Leptodactylus wagneri. Foram registrados 36 taxa de helmintos: 23 nematoides, 7 trematódeos, 3 acan... (Resumo completo, clicar acesso eletrônico abaixo)
Doutor
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Joshi, Kanchan A. "Upper thermal limits differ among component species in a host-parasitoid-hyperparasitoid system." VCU Scholars Compass, 2016. http://scholarscompass.vcu.edu/etd/4454.
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Among the predicted impacts associated with global climate change, warming is of special interest because the rates of physiological processes are temperature-dependent. Insects and other ectotherms are likely to be affected due to their limited ability to control body temperature. In this study, I measured the tolerance to extreme high temperatures, i.e., critical thermal maximum (CTmax), of component species in a tri-trophic system, including an herbivore (Manduca sexta), a primary larval parasitoid (Cotesia congregata) and a hyperparasitoid (genus Silochalcis). For wild insects, the parasitoid had the lowest CTmax, the hyperparasitoid had the highest, and the herbivore was intermediate. For laboratory insects, the parasitoid had a lower CTmax than the herbivore. Results suggest that laboratory colonies can be used to predict relative thermal performance of interacting species in the field. Variations in tolerance to high temperature among component species could disrupt the outcome of interactions in multi-trophic systems.
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Tan, Wenhua. "Modélisation et Conception des Composants Passifs Planar pour Filtres CEM." Phd thesis, Ecole Centrale de Lille, 2012. http://tel.archives-ouvertes.fr/tel-00776515.
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Les composants magnétiques en technologie planar répondent aux exigences actuelles de l'Electronique de Puissance (EP), à savoir la montée en fréquence de commutation des structures d'EP et la réduction du volume des convertisseurs. La première tendance impose des contraintes fortes en termes de compatibilité électromagnétique (CEM) des équipements. Ces dernières doivent être prises en compte par les ingénieurs dès la phase conception des convertisseurs en se basant sur des modèles fiables, peu développés pour les composants planar dans la littérature scientifique. Ce travail de thèse porte ainsi sur la modélisation des composants planar pour applications aux filtres CEM. Différentes méthodes sont développées au cours de cette thèse pour arriver à évaluer de manière fine les éléments parasites des inductances planar de mode commun : capacités parasites et inductances de fuite. Une partie du travail a porté sur la modélisation par circuits équivalents du comportement fréquentiel des inductances de MC. Une approche automatisée, basée sur un algorithme de fitting a ainsi été développée pour élaborer des circuits équivalents fiables et robustes. Des approches analytiques (Décomposition du Champ Electrique) et semi-analytiques (Fonctions de Green) ont aussi été proposées pour évaluer les valeurs des éléments parasites. La dernière partie de la thèse est plus orientée conception, avec la réalisation de deux structures de composants innovantes, la première se basant sur une technique de compensation des capacités parasites à l'aide d'éléments parasites structuraux et la seconde sur l'association de deux noyaux magnétiques, possédant matériaux et géométries différentes
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Nott, Lucy. "Analysis of multi-component resistance to the downy mildew Peronospora parasitica revealed by natural variation in Arabidopsis." Thesis, University of Birmingham, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.289729.
Full textBooks on the topic "Parasitic component"
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E, Brecher Mark, and American Association of Blood Banks., eds. Bacterial and parasitic contamination of blood components. Bethesda, Md: AABB Press, 2003.
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Nott, Lucinda Mary. Analysis of multi-component resistance to the downy mildew Peronospora parasitica revealed by natural variation in Arabidopsis. Birmingham: University of Birmingham, 2002.
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Symposium on Integrated Pest Management Control Component (1992 Bogor, Indonesia). Proceedings of the Symposium on Integrated Pest Management Control Component, Bogor, Indonesia, 21-23 January 1992. Edited by Watson Alan K, Banpot Napompeth, and Dharmaputra Okky Setyawati. Bogor, Indonesia: Southeast Asian Regional Centre for Tropical Biology, 1993.
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Martyn, Amanda. Changes in host and parasite-derived cellular and extracellular matrix components in developing cysts of Myxobolus pendula (Myxozoa). Ottawa: National Library of Canada, 2002.
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Ajzensztejn, Daniel. Cancers related to infection. Edited by Patrick Davey and David Sprigings. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780199568741.003.0321.
Full textAbstract:
The development of a cancer is often complex and multifactorial. Environmental factors such as smoking, diet, asbestos exposure, and sun exposure are important causes of cancer, with smoking alone responsible for 25%–30% of cancers. Up to 10% of cancers have a genetic component. Infectious agents are implicated in the development of approximately 15% of cancers. Viruses, bacteria, and parasites can all cause cancers. Cervical and hepatocellular carcinoma are the two commonest cancers related to infections.
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Boswell, Carl A. Immunological perspectives of a host-parasite system: Studies on the humoral and cellular components of Biomphalaria glabrata, New World host for Schistosoma mansoni. 1985.
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Miguel, Eve, Florence Fournet, Serge Yerbanga, Nicolas Moiroux, Franck Yao, Timothée Vergne, Bernard Cazelles, Roch K. Dabiré, Frédéric Simard, and Benjamin Roche. Optimizing public health strategies in low-income countries: epidemiology, ecology and evolution for the control of malaria. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780198789833.003.0016.
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During the 20th century, health inequalities among countries have increased. Several factors explain this pattern, such as immunization and massive antibiotherapy, but nutrition, housing and hygiene are key parameters for health improvement. This heterogeneity among countries is well illustrated by malaria, although disappeared from many high-income countries, is still endemic and prevalent in low- and middle-income countries. We question these differences and detail the recommendations proposed by the World Health Organization to tackle malaria. We investigate the optimal combination of actions to deploy in resource-limited countries and the best spatio-temporal window to target. We propose a new framework for health program management based on evolutionary biology approaches to tailor global programs, to improve their local efficiency and avoid resistance. Thus, we explore all components of the ecological niche of the parasite (human, vector and environment) and consider the magnitude of actions to deploy to reach its local.
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McLeod, Rima, Kelsey Wheeler, Pauline Levigne, and Kenneth Boyer. Toxoplasma gondii. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780190604813.003.0017.
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Mother-to-child transmission (MTCT) of the parasite Toxoplasma gondii can result in congenital toxoplasmosis. Untreated congenital toxoplasmosis presents considerable potential risks to patients and costs for society, with manifestations recurring throughout life. Infection with T. gondii, acquired at any time during pregnancy can damage the fetus, but especially during early gestation. Fetal infection with T. gondii can cause fetal loss, intrauterine growth retardation, and damage to organs (especially the brain and eyes). Treatment with pyrimethamine and sulfadiazine improves manifestations of active infection in the fetus, congenital infection in infants, and recurrent disease when manifested later in life in those congenitally infected. Key components of the prevention and treatment of congenital toxoplasmosis include prompt, correct diagnosis and treatment with effective anti–T. gondii medications. Several countries have gestational screening programs to detect newly acquired T. gondii infections. In the future, development of new medications, including those for chronic infection, and vaccines for prevention will be important.
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Eljaafari, Assia, and Pierre Miossec. Cellular side of acquired immunity (T cells). Oxford University Press, 2013. http://dx.doi.org/10.1093/med/9780199642489.003.0049.
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The adaptive T-cell response represents the most sophisticated component of the immune response. Foreign invaders are recognized first by cells of the innate immune system. This leads to a rapid and non-specific inflammatory response, followed by induction of the adaptive and specific immune response. Different adaptive responses can be promoted, depending on the predominant effector cells that are involved, which themselves depend on the microbial/antigen stimuli. As examples, Th1 cells contribute to cell-mediated immunity against intracellular pathogens, Th2 cells protect against parasites, and Th17 cells act against extracellular bacteria and fungi that are not cleared by Th1 and Th2 cells. Among the new subsets, Th22 cells protect against disruption of epithelial layers secondary to invading pathogens. Finally these effector subsets are regulated by regulatory T cells. These T helper subsets counteract each other to maintain the homeostasis of the immune system, but this balance can be easily disrupted, leading to chronic inflammation or autoimmune diseases. The challenge is to detect early changes in this balance, prior to its clinical expression. New molecular tools such as microarrays could be used to determine the predominant profile of the immune effector cells involved in a disease process. Such understanding should provide better therapeutic tools to counteract deregulated effector cells.
Book chapters on the topic "Parasitic component"
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Dhameniya, Harshit Kumar, Ramesh Kumar Verma, Dheeraj Tripathi, and Shadab Azam Siddique. "Impact of Parasitic Component on Bandwidth of Printed Dipole Antenna." In Lecture Notes in Electrical Engineering, 431–43. Singapore: Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-0312-0_43.
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Subbotin, Sergei A. "Molecular identification of nematodes using polymerase chain reaction (PCR)." In Techniques for work with plant and soil nematodes, 218–39. Wallingford: CABI, 2021. http://dx.doi.org/10.1079/9781786391759.0218.
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Abstract Molecular diagnostics are a vital component of the management of economically important pests, including plant-parasitic nematodes. Various molecular techniques for diagnostics have been introduced to nematology during last decades, but the most popular is Polymerase Chain Reaction (PCR) based. This chapter presents procedures for DNA extraction, PCR techniques, cloning and DNA sequencing of nematodes.
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Subbotin, Sergei A. "Molecular identification of nematodes using polymerase chain reaction (PCR)." In Techniques for work with plant and soil nematodes, 218–39. Wallingford: CABI, 2021. http://dx.doi.org/10.1079/9781786391759.0012a.
Full textAbstract:
Abstract Molecular diagnostics are a vital component of the management of economically important pests, including plant-parasitic nematodes. Various molecular techniques for diagnostics have been introduced to nematology during last decades, but the most popular is Polymerase Chain Reaction (PCR) based. This chapter presents procedures for DNA extraction, PCR techniques, cloning and DNA sequencing of nematodes.
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Zhou, Jiaxu, Zhifei Fang, and Huichao Deng. "Effect of Fan Parameters on Forced-Convection Open-Cathode Proton Exchange Membrane Fuel Cells." In Proceedings of the 10th Hydrogen Technology Convention, Volume 1, 429–34. Singapore: Springer Nature Singapore, 2024. http://dx.doi.org/10.1007/978-981-99-8631-6_42.
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AbstractForced-convection open-cathode proton exchange membrane fuel cells have attracted much attention due to simple structure. The fan, as an important component of the stack, significantly influences the mass density and performance of the stack. Therefore, it is crucial to select the appropriate fan. In this study, the performance of stacks with different fans is compared and the optimal duty ratio and temperature of stacks under different load currents are determined. The experimental results show that excessive air volume reduces the performance of the stack, and the parasitic power should be taken into consideration. Additionally, the weight of the fan is is a significant factor that needs to be considered. Furthermore, the experimental results show that under the condition of sufficient air supply, the appropriate temperature rise is conducive to the improvement of stack performance. In order to reduce the weight of the stack, it is necessary to choose a reasonable fan.
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Sangwine, S. J. "Parasitic electrical and electromagnetic effects." In Electronic Components and Technology, 115–41. Boston, MA: Springer US, 1994. http://dx.doi.org/10.1007/978-1-4899-6934-7_8.
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Esch, Gerald W., and Jacqueline C. Fernández. "Component and compound communities." In A Functional Biology of Parasitism, 172–89. Dordrecht: Springer Netherlands, 1993. http://dx.doi.org/10.1007/978-94-011-2352-5_7.
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Athanasiadou, Spiridoula, and Jos G. M. Houdijk. "Nutrition and Immunity in Animal Disease: Lessons from Parasitic Gastroenteritis." In Dietary Components and Immune Function, 63–74. Totowa, NJ: Humana Press, 2010. http://dx.doi.org/10.1007/978-1-60761-061-8_4.
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Wake, Akira, and Herbert R. Morgan. "The Nonspecific Humoral Components." In Host-Parasite Relationships and the Yersinia Model, 115–30. Berlin, Heidelberg: Springer Berlin Heidelberg, 1986. http://dx.doi.org/10.1007/978-3-642-71344-6_13.
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Wake, Akira, and Herbert R. Morgan. "Specific Humoral Components: Immunoglobulins." In Host-Parasite Relationships and the Yersinia Model, 131–37. Berlin, Heidelberg: Springer Berlin Heidelberg, 1986. http://dx.doi.org/10.1007/978-3-642-71344-6_14.
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Jensen, Scott, J. Clair Batty, and David McLain. "Reduction of Parasitic Heat Loads to Cryogenically Cooled Components." In Cryocoolers 9, 773–82. Boston, MA: Springer US, 1997. http://dx.doi.org/10.1007/978-1-4615-5869-9_88.
Full textConference papers on the topic "Parasitic component"
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Stein, Aaron L. F., Phyo Aung Kyaw, Jesse Feldman-Stein, and Charles R. Sullivan. "Scaling of parasitic capacitance with magnetic component physical size." In 2018 IEEE 19th Workshop on Control and Modeling for Power Electronics (COMPEL). IEEE, 2018. http://dx.doi.org/10.1109/compel.2018.8460011.
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Axelrod, Allan M., Hassan A. Kingravi, and Girish V. Chowdhary. "Gaussian process based subsumption of a parasitic control component." In 2015 American Control Conference (ACC). IEEE, 2015. http://dx.doi.org/10.1109/acc.2015.7171173.
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Kravchenko, V. M., G. A. Kravchenko, and G. S. Itin. "DIROFILARIASIS DIAGNOSTICS IN DOGS." In THEORY AND PRACTICE OF PARASITIC DISEASE CONTROL. All-Russian Scientific Research Institute for Fundamental and Applied Parasitology of Animals and Plant – a branch of the Federal State Budget Scientific Institution “Federal Scientific Centre VIEV”, 2023. http://dx.doi.org/10.31016/978-5-6048555-6-0.2023.24.225-228.
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As a result of our own long-term research, a comparative analysis of clinical
signs, and laboratory, immunological and instrumental methods for diagnosing
dirofilariasis of dogs in the North-Western Caucasus was carried out. As a result
of the study, it was found that only a comprehensive diagnosis performed in stages
allows us not only to diagnose most accurately both mature nematodes and their
microfilariae but also to significantly reduce the economic component. Therefore,
when diagnosing dirofilariasis in dogs, it is necessary to take into account only the
most specific clinical signs. Laboratory methods should combine both simple express
methods and more complex, time-consuming ones. When choosing immunological
test systems, it is necessary to take into account not only their economic feasibility,
but also the qualitative component, since the main principle of test system operation
is the reaction to Dirofilaria antigens contained in the blood of an infected dog. They
can be used for both individual and group research. When choosing instrumental
diagnostic methods such as CT, MRI, ultrasound, etc., which are aimed at detecting
sexually mature nematodes, and due to their high cost and complexity, it is necessary
to take into account their expediency based on predicting the disease outcome.
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Aijun Song, Han Lei, and Han-Xiong Li. "Experimental identification of parasitic vibrations on ultrasonic bonding transducer." In Conference on High Density Microsystem Design and Packaging and Component Failure Analysis, 2006. HDP'06. IEEE, 2006. http://dx.doi.org/10.1109/hdp.2006.1707569.
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Vasilevich, F. I., S. A. Shemyakova, and N. V. Esaulova. "VETERINARY AND MEDICAL SIGNIFICANCE OF HORSEFLY (TABANIDAE). REVIEW." In THEORY AND PRACTICE OF PARASITIC DISEASE CONTROL. All-Russian Scientific Research Institute for Fundamental and Applied Parasitology of Animals and Plant – a branch of the Federal State Budget Scientific Institution “Federal Scientific Centre VIEV”, 2023. http://dx.doi.org/10.31016/978-5-6048555-6-0.2023.24.133-137.
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The article provides information on the harmful effect of horseflies (Diptera,
Tabanidae) as a midge component and a vector (carrier) transmitting pathogens
of infectious and parasitic diseases including zoonosis. Horseflies are harmful
to animals and humans in places of their abundance. Horseflies cause significant
economic losses to livestock. With an intense attack of horseflies, individual areas
of the skin of animals represent a continuous bleeding surface. Horsefly saliva
inserted into a wound at the time of the bite is very toxic and allergenic causing a
local inflammatory process and general intoxication of the body. The insects are
of particular danger as vectors transmitting pathogens of animals and humans. The
role of horseflies in the transmission of tularemia in natural foci of this infection has
been proven. The sources of horsefly infection are primarily various small mammals
including water rats. Horseflies are equally important as carriers of the anthrax
pathogen. Causative agents of Coxiella burnetti infection, blackleg, pasteurellosis,
and other infections have been isolated from horseflies. Horseflies are involved in the
transmission of Trypanosoma evansi in horses and camels, anaplasmosis in cattle,
Theileria cervi in reindeer, and equine infectious anemia virus.
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Nam, Bu-il, Jayang Yoon, Kyunghea Lee, Sol Kim, Junhong Park, Chi-Weon Yoon, and Eunkyoung Kim. "Integrated Circuit to Compensate Parasitic Leakage Component for WL Leakage Current in NAND Flash Memory." In 2023 IEEE Asian Solid-State Circuits Conference (A-SSCC). IEEE, 2023. http://dx.doi.org/10.1109/a-sscc58667.2023.10347919.
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Nakano, Y., and Y. H. Taguchi. "Feature extraction for discriminance of symbiotic/parasitic bacterial type III effector protein using principal component analysis." In 2011 IEEE International Conference on Bioinformatics and Biomedicine Workshops (BIBMW). IEEE, 2011. http://dx.doi.org/10.1109/bibmw.2011.6112521.
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Xingjian Kinger Cai, Ke Wang, and Neffody E. Kraskoff. "Effectively compensating parasitic capacitance of ESD component for high-speed differential channel in high density routing platform." In 2010 Asia-Pacific International Symposium on Electromagnetic Compatibility. IEEE, 2010. http://dx.doi.org/10.1109/apemc.2010.5475743.
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Fonseca, Nuno, Galin Tahchiev, Sébastien Fouques, Carl Trygve Stansberg, and José Miguel Rodrigues. "Model Tests and Numerical Prediction of the Low Frequency Motions of a Moored Ship in Shallow Water With a Wave Splitting Method." In ASME 2020 39th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/omae2020-18806.
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Abstract Prediction of shallow water low frequency (LF) motions of vessels in the context of mooring analysis is challenging. Model tests are often performed to calibrate and validate numerical models and, in this way, reduce the uncertainty. Model tests are part of the positioning system qualifying process. However, model tests also present challenges and uncertainties related to parasitic low frequency wave systems which are unavoidable in shallow water ocean basin conditions. The paper presents model tests with a ship moored in shallow water (20 m), the analysis and discussion of the test data and comparisons with numerical predictions. The focus is on the low frequency motions and related wave drift forces. The tests have been performed in harmonic waves, bi-harmonic waves and irregular seastates, including conditions with and without current. The first part of the study consists of analysing the wave field measured by a long array of wave sensors distributed along the ocean basin. The analysis provides split wave systems, namely the low frequency components including the bound wave, the incoming free parasitic wave, the reflected component and additional very long waves. The second part proposes a method to calibrate and validate mooring analysis numerical models, based on comparisons with model test data which includes the unavoidable effects from parasitic waves. Simulations of LF motions with the calibrated model show a good agreement with the measurements.
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Kapo, Naida, Jasmin Omeragić, Šejla Goletić, Adis Softić, Emina Šabić, and Teufik Goletić. "Phenotypic and Genotypic Analysis of Anthelmintic Resistance." In Socratic Lectures 8. University of Lubljana Press, 2023. http://dx.doi.org/10.55295/psl.2023.i3.
Full textAbstract:
A growing issue on a global scale is the emergence of helminth species and populations that are resistant to one or more anthelmintics. The majority of currently available anthelmintics used to control parasitic nematodes of cattle and sheep belong to only three main groups, benzimidazoles, imidazothiazoles and avermectins/milbemycins. The availability of reliable and precise techniques for its identification and monitoring is a critical component of the success of helminth control programs intended to prevent the spread of resistance in nematode populations. In vivo method like fecal egg count reduction test and in vitro methods such as egg hatch assays, larval motility test, larval development test and polymerase chain reaction (PCR) can be used for the detection of anthelmintic resistance although each has some reliability, repeatability, sensitivity, and ease of interpretation issues. The genetic basis of resistance to the majority of anthelmintics are still not well understood. Thanks to recent developments in high-throughput sequencing, it is now possible to define features such as drug resistance using genome-wide techniques. Keywords: Anthelmintics; Helminths; Resistance; Detection assays; Molecular diagnostics; Parasite control
Reports on the topic "Parasitic component"
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Kapulnik, Yoram, Maria J. Harrison, Hinanit Koltai, and Joseph Hershenhorn. Targeting of Strigolacatones Associated Pathways for Conferring Orobanche Resistant Traits in Tomato and Medicago. United States Department of Agriculture, July 2011. http://dx.doi.org/10.32747/2011.7593399.bard.
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This proposal is focused on examination of two plant interactions: parasitic with Orobanche, and symbiosis with arbuscular mycorrhiza fungi (AMF), and the involvement of a newly define plant hormones, strigolactones (SLs), in these plant interactions. In addition to strigolactones role in regulation of above-ground plant architecture, they are also known to be secreted from roots, and to be a signal for seed germination of the parasitic plants Orobanche. Moreover, secreted strigolactones were recognized as inducers of AMFhyphae branching. The present work was aimed at Generation of RNAi mutants of both tomato and Medicago, targeting multiple genes that may be involved in strigolactone production, carotenoid biosynthesis pathway, Pi signaling or other metabolic pathways, and hence affect AMF colonization and/or Orobanche resistance. Following the newly formed and existing RNAi mutants were examined for AMF colonization and Orobanche resistance. At the first phase of this project Orobanche seed germination assays and AMF colonization were examined in intact plants. These assays were shown to be effective and resulted with enhancement of Orobanche seed germination and AMF colonization in WT tomato plants, whereas roots of strigolactones impaired lines did not result with Orobanche seed germination and mycorrhiza colonization. Unexpectedly, root organ cultures (ROC) that were produced from the same wild type (WT) and mutant lines did not induce the Orobanche seed germination and AMFhyphal branching. This implies that under in vitro conditions ROC cultures are missing an important component for induction of Orobanche seed germination and AMFhyphal branching. In another line of experiments we have tested transgenic lines of Medicagotruncatula for AMFhuyphal branching and Orobanche seed germination assays. These lines included lines silenced for a GRAS transcription factor (RNAi 1845), an NBS-LRR type resistance gene (RNAi 1847), a kinase (RNAi 2403) and a protein of unknown function (RNAi 2417). In all cases, five independent transgenic root lines showed altered AMFphenotypes with reduced or aberrant colonization patterns. Following, we transformed tomato plants with the M. truncatulaTC 127050 PhosphoinositidekinaseRNAi construct. Transgenic lines that contained GUS constructs were used as control. All transgenic lines showed reduced level of Orobanche seed germination, masking any strigoalctones-specific effect. The research demonstrated that SLs production may not be examined in ROC –based bioassays. It was shown by the 3 independent assays employed in this project that none of the recognized characters of SLs may be reflected in these bioassays. However, when the whole plant root exudates were examined, SLs activity in root exudates was demonstrated. Hence, it can be concluded that the presence of an intact shoot, and possibly, shoot factors, may be necessary for production of SLs in roots. Another point of interest that rises from these results is that the presence of SLs is not necessary for AMF completion of life cycle. Hence, it may be concluded that SLs are important for AMFhyphal branching, before symbiosis, but not essential for AMF colonization and life cycle completion under ROC system conditions.
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McClure, Michael A., Yitzhak Spiegel, David M. Bird, R. Salomon, and R. H. C. Curtis. Functional Analysis of Root-Knot Nematode Surface Coat Proteins to Develop Rational Targets for Plantibodies. United States Department of Agriculture, October 2001. http://dx.doi.org/10.32747/2001.7575284.bard.
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The goal of this research was to provide a better understanding of the interface between root-knot nematodes, Meloidogyne spp., and their host in order to develop rational targets for plantibodies and other novel methods of nematode control directed against the nematode surface coat (SC). Specific objectives were: 1. To produce additional monoclonal SC antibodies for use in Objectives 2, 3, and 4 and as candidates for development of plantibodies. 2. To determine the production and distribution of SC proteins during the infection process. 3. To use biochemical and immunological methods to perturbate the root-knot nematode SC in order to identify SC components that will serve as targets for rationally designed plantibodies. 4. To develop SC-mutant nematodes as additional tools for defining the role of the SC during infection. The external cuticular layer of nematodes is the epicuticle. In many nematodes, it is covered by a fuzzy material termed "surface coat" (SC). Since the SC is the outermost layer, it may playa role in the interaction between the nematode and its surroundings during all life stages in soil and during pathogenesis. The SC is composed mainly of proteins, carbohydrates (which can be part of glycoproteins), and lipids. SC proteins and glycoproteins have been labeled and extracted from preparasitic second-stage juveniles and adult females of Meloidogyne and specific antibodies have been raised against surface antigens. Antibodies can be used to gain more information about surface function and to isolate genes encoding for surface antigens. Characterization of surface antigens and their roles in different life-stages may be an important step towards the development of alternative control. Nevertheless, the role of the plant- parasitic nematode's surface in plant-nematode interaction is still not understood. Carbohydrates or carbohydrate-recognition domains (CROs) on the nematode surface may interact with CROs or carbohydrate molecules, on root surfaces or exudates, or be active after the nematode has penetrated into the root. Surface antigens undoubtedly play an important role in interactions with microorganisms that adhere to the nematodes. Polyclonal (PC) and monoclonal (MC) antibodies raised against Meloidogyne javanica, M. incognita and other plant-parasitic nematodes, were used to characterize the surface coat and secreted-excreted products of M. javanica and M. incognita. Some of the MC and PC antibodies raised against M. incognita showed cross-reactivity with the surface coat of M. javanica. Further characterization, in planta, of the epitopes recognized by the antibodies, showed that they were present in the parasitic juvenile stages and that the surface coat is shed during root penetration by the nematode and its migration between root cells. At the molecular level, we have followed two lines of experimentation. The first has been to identify genes encoding surface coat (SC) molecules, and we have isolated and characterized a small family of mucin genes from M. incognita. Our second approach has been to study host genes that respond to the nematode, and in particular, to the SC. Our previous work has identified a large suite of genes expressed in Lycopersicon esculentum giant cells, including the partial cDNA clone DB#131, which encodes a serine/threonine protein kinase. Isolation and predicted translation of the mature cDNA revealed a frame shift mutation in the translated region of nematode sensitive plants. By using primers homologous to conserved region of DB#131 we have identified the orthologues from three (nematode-resistant) Lycopersicon peruvianum strains and found that these plants lacked the mutation.
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Houck, Marilyn, Uri Gerson, and Robert Luck. Two Predator Model Systems for the Biological Control of Diaspidid Scale Insects. United States Department of Agriculture, June 1994. http://dx.doi.org/10.32747/1994.7570554.bard.
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Hemisarcoptes (Acari: Hamisarcoptidae) is a parasite of scale insects (Diaspididae), tenacious pests of vascular plants. Hemisarcoptes also has a stenoxenic phoretic (dispersal) relationship with Chilocorus (Coleoptera: Coccinellidae). Chilocorus feeds on diaspidids, transports mites as they feed, and has been applied to the control of scales, with limited success. U.S.-Israeli cooperation focused on this mite-beetle interaction so that a two-component system could be applied to the control of scale insects effectively. Life history patterns of Hemisarcoptes were investigated in response to host plant type and physical parameters. Field and lab data indicated that mites attack all host stages of scales tested, but preferred adult females. Scale species and host plant species influenced the bionomics of Hemisarcoptes. Beetle diet also influenced survival of phoretic mites. Mites use a ventral sucker plate to extract material from Chilocorus, that is essential for development. Seven alkaloids were found in the hemolymph of Chilocorus and three were characterized. Examination of the subelytral surface of Chilocorus indicated that microsetae play a role in the number and distribution of mites a beetle transports. While Hemisarcoptes can be innoculatd into agroecosystems using various indigenous or imported Chilocorus species, the following are preferred: C. bipustulatus, C. cacti, C. distigma, C. fraternus, C. orbus, and C. tristis.
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Oron, Gideon, Raphi Mandelbaum, Carlos E. Enriquez, Robert Armon, Yoseph Manor, L. Gillerman, A. Alum, and Charles P. Gerba. Optimization of Secondary Wastewater Reuse to Minimize Environmental Risks. United States Department of Agriculture, December 1999. http://dx.doi.org/10.32747/1999.7573077.bard.
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The main purpose of the research was to examine approaches and to evaluate methods for minimizing the risks during applying treated domestic wastewater for agricultural irrigation. This general purpose consisted of examining under field conditions the possibilities when implementing different application technologies for minimizing health and environmental risks. It was assumed that Subsurface Drip Irrigation (SDI) will provide adequate conditions for safe effluent reuse. Controlled field experiments where conducted in commercial fields to evaluate the alternatives. Main efforts where conducted in Israel in the grape vineyard in Arad heights, in the field crops in Kibbutz Chafets Chaim and in Arizona in fields adjacent to the University campus. The complementary part was to examine the behavior of the various pathogens in the effluent-soil-plant system. The analysis is based on controlled experiments, primarily in greenhouse along with field experiments. Molecular biology methods were used to identify the behavior of the pathogens in the components of the system. The project included as well examining the effluent quality in various sites, primarily those in which treated wastewater is reused for agricultural irrigation. The monitoring included conventional parameters however, also parasites such as Giardia and Cryptosporidium. The results obtained indicate the prominent advantages of using Subsurface Drip Irrigation (SDI) method for minimizing health and environmental risks during application of secondary effluent. A theoretical model for assessing the risks while applying treated wastewater was completed as well. The management model shows the risks during various scenarios of wastewater quality, application technology and related human exposure.
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Hernandez Arenas, Diana Paola. Parásitos en la salud pública. Universidad Nacional Abierta y a Distancia, September 2023. http://dx.doi.org/10.22490/notas.6621.
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La parasitología, estudia la relación existente entre los organismos parásitos y sus huéspedes, pudiendo o no causar daños a su hospedador. Al igual que los parásitos, los sistemas de producción se desarrollan en un medio físico, biológico y social; y es en este último en donde suele influir de manera significativa para la salud pública de las regiones y poblaciones consolidándose como un factor importante en la presentación de enfermedades zoonóticas parasitarias y por ende causal del detrimento sanitario de las poblaciones que se ven afectadas. Por ello, la parasitología tomada desde el punto de vista de la salud pública, proporciona herramientas que permiten conocer y fortalecer la prevención y el control de los agentes parasitarios que afectan la población humana y animal debido a su carácter zoonótico, ayudando a reducir el impacto que ocasionan dichas zoonosis parasitarias en la salud pública; Sin embargo, es poco frecuente hallar bibliografía actualizada que logre demostrarlo claramente. Teniendo en cuenta lo anterior, la parasitología se instaura dentro del proceso académico de los estudiantes de Zootecnia como un eje encaminado a la comprensión no solo del ciclo de vida del parasito, sino también de las consecuencias que pueden traer para las explotaciones productivas y la población, por tanto, la presente nota de campus tiene como finalidad dar a conocer al estudiante las generalidades de las zoonosis vistas desde la salud pública, dando a conocer algunos aspectos concernientes con el impacto de la parasitología en esta, así como algunos de los parásitos zoonóticos más frecuentes. Inicialmente, se presenta el concepto de zoonosis parasitarias, los factores asociados a su transmisión y otros conceptos fundamentales que enmarca la temática, la cual se desglosa en cada uno de los capítulos que incluye el documento. Dicho contenido que puede ser usado como apoyo en el curso de Parasitología, el cual hace parte del componente disciplinar de la malla curricular de los programas de Zootecnia y Tecnología en Producción Animal.
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McElwain, Terry, Eugene Pipano, Guy Palmer, Varda Shkap, Stephen Hines, and Douglas Jasmer. Protection of Cattle Against Babesiosis: Immunization with Recombinant DNA Derived Apical Complex Antigens of Babesia bovis. United States Department of Agriculture, June 1995. http://dx.doi.org/10.32747/1995.7612835.bard.
Full textAbstract:
Bovine babesiosis caused by Babesia bovis continues to be a significant deterrent to global livestock production. Current control methods have both biological and technical drawbacks that have stimulated research on improved methods of vaccination. This BARD project has focused on characterization of candidate Babesia bovis vaccine antigens located in the apical complex, a unique group of subcellular organelles - including rhoptries, micronemes, and spherical bodies - involved in the invation of erythrocytes. Spherical bodies and rhoptries were partially purified and their contents characterized using monoclonal antibodies. Existing and newly developed monoclonal antibodies bound to antigens in the spherical body, rhoptry, merozoite membrane, and infected erythrocyte membrane. In an initial immunization study using biologically cloned strains, it was demonstrated that strain-common epitopes are important for inducing immune protection against heterologous challenge. Rhoptry-associated antigen 1 (RAP-1) had been demonstrated previously to induce partial immune protection, fulfilled criteria of broad interstrain B and T cell epitope conservation, and thus was further characterized. The RAP-1 gene family consists of at least two gene copies, is homologous to the RAP-1 gene family in B. bigemina, and contains significant sequence similarity to other erythroparasitic protozoan candidate vaccine antigens, including the apical membrane antigen of Plasmodium falciparum. A new RAP-1 monoclonal antibody was developed that inhibits merozoite growth in vitro, demonstrating the presence of a RAP-1 neutralization sensitive domain. Based on these observations, cattle were immunized with Mo7 (Mexico) strain recombinant RAP-1 representing one of the two gene copies. All cattle responded with variable levels of serum antibodies inhibitory to heterologous Israel strain merozoite growth in vitro, and RAP-1 specific T lymphocytes that proliferated when stimulated with either homologous or heterologous native parasite antigen. Minimal protection from clinical disease was present after virulent Israel (heterologous) strain B. bovis challenge. In total, the results support the continued development of RAP-1 as a vaccine antigen, but indicate that additional information about the native structure and function of both RAP-1 gene copies, including the relationship of conserved and polymorphic sequences to B and T cell lepitopes relevant for protection, is necessary for optimization of RAP-1 as a vaccine component.
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McElwain, Terry F., Eugene Pipano, Guy H. Palmer, Varda Shkap, Stephn A. Hines, and Wendy C. Brown. Protection of Cattle against Babesiosis: Immunization against Babesia bovis with an Optimized RAP-1/Apical Complex Construct. United States Department of Agriculture, September 1999. http://dx.doi.org/10.32747/1999.7573063.bard.
Full textAbstract:
Previous research and current efforts at control of babesiosis fall short of meeting the needs of countries where the disease is endemic, such as Israel, as well as the needs of exporting countries and countries bordering on endemic areas, such as the U.S. Our long-term goal is to develop improved methods of immunization against bovine babesiosis based on an understanding of the molecular mechanisms of immune protection and parasite targets of a protective immune response. In our previous BARD project, we established the basis for focusing on rhoptry antigens as components of a subunit vaccine against bovine babesiosis, and for additional research to better characterize rhoptry associated protein-1 (RAP-1) as a target of protective immunity. In this continuation BARD project, our objectives were to [1] optimize the immune response against RAP-1, and [2] identify additional rhoptry candidate vaccine antigens. The entire locus encoding B. bovis RAP-1 was sequenced, and the rap-1 open reading frame compared among several strains. Unlike B. bigemina, in which multiple gene copies with variant domains encode RAP-1, the B. bovis RAP-1 locus contains only two identical genes which are conserved among strains. Through testing of multiple truncated constructs of rRAP-1, one or more immunodominant T cell epitopes were mapped to the amino terminal half of RAP-1. At least one linear and one conformational B cell epitope have been demonstrated in the same amino terminal construct, which in B. bigemina RAP-1 also contains an epitope recognized by neutralizing antibody. The amine terminal half of the molecule represents the most highly conserved part of the gene family and contains motifs conserved broadly among the apicomplexa. In contrast, the carboxy terminal half of B. bovis RAP-1 is less well conserved and contains multiple repeats encoding a linear B cell epitope potentially capable of inducing an ineffective, T cell independent, type 2 immune response. Therefore, we are testing an amino terminal fragment of RAP-1 (RAP-1N) in an immunization trial in cattle. Cattle have beer immunized with RAP-1N or control antigen, and IL-12 with Ribi adjuvant. Evaluation of the immune response is ongoing, and challenge with virulent B. bovis will occur in the near future. While no new rhoptry antigens were identified, our studies did identify and characterize a new spherical body antigen (SBP3), and several heat shock proteins (HSP's). The SBP3 and HSP21 antigens stimulate T cells from immune cattle and are considered new vaccine candidates worthy of further testing. Overall, we conclude that a single RAP-1 vaccine construct representing the conserved amino terminal region of the molecule should be sufficient for immunization against all strains of B. bovis. While results of the ongoing immunization trial will direct our next research steps, results at this time are consistent with our long term goal of designing a subunit vaccine which contains only the epitopes relevant to induction of protective immunity. Parallel studies are defining the mechanisms of protective immunity. Apicomplexan protozoa, including babesiosis and malaria, cause persistent diseases for which control is inadequate. The apical organelles are defining features of these complex protozoa, and have been conserved through the evolutionary process, Past and current BARD projects on babesiosis have established the validity and potential of exploiting these conserved organelles in developing improved control methods applicable to all apicomplexan diseases.