Academic literature on the topic 'Interfering methods'
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Journal articles on the topic "Interfering methods"
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Gholamy, Shabanali, Abdolrahim Javaherian, and Abdolreza Ghods. "Automatic detection of interfering seismic wavelets using fractal methods." Journal of Geophysics and Engineering 5, no. 3 (August 8, 2008): 338–47. http://dx.doi.org/10.1088/1742-2132/5/3/009.
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Shen, Tao, Ming Qing Xiao, and Qing Chun Kong. "The Methods of Laser Guided Signal Information Identification." Advanced Materials Research 457-458 (January 2012): 192–95. http://dx.doi.org/10.4028/www.scientific.net/amr.457-458.192.
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The aim of laser guided weapons adopting laser code and decode is to resolve the mutual interference of multiple irradiator in the same war zone. As an effective interfering means, active interference makes the laser guided weapons lose the right object information to protect the important objects in the attack phase by sending much interfering signal. But how to intercept, capture, analyze and identify the laser guided signal code information real-time is the first task in the laser countwork. Based on analyzing the characters of existed laser coding and wave gate, combining the time-correlation character of laser guided signal, this paper proposes the technique of laser guided signal information autocorrelation identification, and it is studied deeply by simulation and experiment. The result shows that the technique resolved the difficult problem of copying the enemy laser signal in short time effectively. The technique wins the time for the laser countwork, and it is feasible and takes on military application value.
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Zhang, Sheng Yuan, Wen Jie Yang, and Tao Zou. "Design on Electromagnetic Compatibility of Electrical Driving System Controller Based on Computer Control." Advanced Materials Research 466-467 (February 2012): 804–8. http://dx.doi.org/10.4028/www.scientific.net/amr.466-467.804.
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This article analyses the electromagnetic interfering sources and its transmitting ways inside electric driving system controller and expounds the anti-disturbing methods in designing the electromagnetic compatibility of electric driving system controller. Among that the interfering sources are the rectifiers and inverse transformer in the AC frequency converter and the interference signals from electric network, the transmitting ways of the electromagnetic interfering signals include transmitting in electric wires, radiating and coupling through space, and the anti-disturbing methods have (a) separating interference sources with the system or devices, (b) connecting filters in the output ends of interfering sources and the input ends of the devices easily to be interfered, (c) shielding the interfering sources, (d) grounding correctly and reliably, (e) adding circuit power filters. The experimental results demonstrated that the anti-disturbing methods mentioned above are very effective for the electric driving system controller based on computer control.
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Kubiak, Ireneusz. "Digital processing methods of images and signals in electromagnetic infiltration process." Image Processing & Communications 18, no. 1 (March 1, 2013): 5–14. http://dx.doi.org/10.2478/v10248-012-0070-7.
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Abstract The article contains information about the capabilities of electromagnetic infiltration process in case of occurrence of strong interfering signals. As a methods supporting infiltration process used method of digital processing of signals and images in the form of histogram transformations, global and local thresholding of signal amplitudes and logical filters. The material presented in the article shows that risk can arise if the uncontrolled use of the computer. Risks that could decide our safety and security of our data. obtained images. Manipulation of histograms, threshold amplitudes of the emission signal correlated with the classified signals or logical filters highlight the weakness of the security used at the source. The presence of strong interfering signals such as vertical and horizontal synchronization signals blocking measurement receivers, do not prevent the reproduction of classified information. Opportunities of the electromagnetic infiltration in situations of weak compromising emissions occurs are presented in the article.
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Ananenkov, Andrey, Pavel Sokolov, Vladimir Nuzhdin, and Dmitry Marin. "Detection methods of low-speed small objects for panoramic ultrashort pulsed radar." ITM Web of Conferences 30 (2019): 15017. http://dx.doi.org/10.1051/itmconf/20193015017.
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The article discusses ways to improve the detection efficiency of small and low-speed objects in conditions of intense background reflections. The properties of the ultrashort pulse echo signals are investigated. The phenomenon of interfering visibility is investigated.
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Homich, Dmitro. "A study and systematization of methods of thefts of natural gas are by interference with work of device of account." Law Review of Kyiv University of Law, no. 1 (April 15, 2020): 336–39. http://dx.doi.org/10.36695/2219-5521.1.2020.67.
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The results of the study of different ways to commit abduction of natural gas by interfering with the work appliance are considered in the article. A special attention is paid to the abduction of natural gas by interfering with manipulation of a gas meter. The study has revealed that these ways include training actions, committing and hiding of criminological traces of such crimes. The ways to commit abduction of natural gas depend on the following factors: professional skills of the offender, construction of gas network, methods of direct impact on gas meters and their components. Results of studying given problem make it possible to systematize the actions of criminals aimed at direct abduction of natural gas by interfering with manipulation of a gas meter: by exposure time (regular and one-off), by form of influence (mechanic and magnetic methods). A way of committing a crime manifested itself in committing certain actions and left certain trace picture changing the environment. These changes reflected the ways of committing the crime, disclosed the professional and criminal skills of the offender. The techniques of committing crimes that were investigated were repeated. This pattern is objective in the investigation technique of the abduction of natural gas by interfering with manipulation of a gas meter. The key finding of the study shows that the repetitive nature of such crimes is explained by the repetition of objective and subjective factors. It gives us reason to talk about similarity in the commission of crimes caused by a coincidence of species traits. The ways to commit abduction of natural gas by interfering with the work appliance includes acts that are naturally associated with the commission of a crime and aimed at preparing and hiding them.
Therefore, to prevent the abduction of natural gas by interfering with manipulation of a gas meter the study focused on revealing the ways of committing such crimes because they are of great use in their investigation. A list of ways to steal natural gas is not complete, new ways of abduction of natural gas will appear that will be characterized by greater level of concealment.
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May, W., D. Wu, C. Eastman, P. Bourdoux, and G. Maberly. "Evaluation of automated urinary iodine methods: problems of interfering substances identified." Clinical Chemistry 36, no. 6 (June 1, 1990): 865–69. http://dx.doi.org/10.1093/clinchem/36.6.865.
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Abstract We evaluated automated methods for measurement of urinary iodine (UI) over a range expected in iodine-replete and iodine-deficient populations. Results obtained with Technicon AutoAnalyzer II systems, based on either dialysis or acid digestion, were compared with those obtained by a manual alkaline ashing technique. Results of automated dialysis were consistently higher than those obtained by the other methods. The apparently higher concentrations of UI we measured were due to interfering substances crossing the dialysis membrane and participating in the catalytic reaction. Thiocyanate (SCN) was one endogenous substance contributing to the increased measurement of UI. For urinary SCN concentrations of 5 to 15 mg/L, the amount of overestimation in the UI measurement attributable to SCN ranged from 21.8 to 61 micrograms/L. However, SCN may account for only 40-50% of the apparent increase in UI. In samples with lower UI (less than 50 micrograms/L), interfering substances produced a 100% error in results. We conclude that the automated dialysis system should not be used to assess iodine-deficient populations. This leaves a major dilemma for researchers wanting to assess the iodine status of populations, because the automated digestion method is no longer commercially available.
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Duman-Scheel, Molly. "Saccharomyces cerevisiae (Baker’s Yeast) as an Interfering RNA Expression and Delivery System." Current Drug Targets 20, no. 9 (June 11, 2019): 942–52. http://dx.doi.org/10.2174/1389450120666181126123538.
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The broad application of RNA interference for disease prevention is dependent upon the production of dsRNA in an economically feasible, scalable, and sustainable fashion, as well as the identification of safe and effective methods for RNA delivery. Current research has sparked interest in the use of Saccharomyces cerevisiae for these applications. This review examines the potential for commercial development of yeast interfering RNA expression and delivery systems. S. cerevisiae is a genetic model organism that lacks a functional RNA interference system, which may make it an ideal system for expression and accumulation of high levels of recombinant interfering RNA. Moreover, recent studies in a variety of eukaryotic species suggest that this microbe may be an excellent and safe system for interfering RNA delivery. Key areas for further research and development include optimization of interfering RNA expression in S. cerevisiae, industrial-sized scaling of recombinant yeast cultures in which interfering RNA molecules are expressed, the development of methods for largescale drying of yeast that preserve interfering RNA integrity, and identification of encapsulating agents that promote yeast stability in various environmental conditions. The genetic tractability of S. cerevisiae and a long history of using this microbe in both the food and pharmaceutical industry will facilitate further development of this promising new technology, which has many potential applications of medical importance.
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García Campaña, A. M., L. Cuadros Rodríguez, C. Jiménez Linares, F. Alés Barrero, and M. Román Ceba. "Estimation of the Tolerance Level of Interfering Substances in Instrumental Analytical Methods." Analytical Letters 28, no. 2 (January 1995): 369–80. http://dx.doi.org/10.1080/00032719508000329.
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Bandurko, V. "PROBLEM ASPECTS ON DETERMINING THE INTERFERING FACTORS IN STUDIED SIGNATURES PERFORMED BY MANUSCRIPTED METHOD." Criminalistics and Forensics, no. 64 (May 7, 2019): 441–46. http://dx.doi.org/10.33994/kndise.2019.64.39.
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The article is devoted to the consideration of problematic situations that may arise when determining interfering factors (natural, artificial) when in the investigated signature their combined effect manifests itself or the presence of the same information content under the influence of various interfering factors is found. Considering the possibility of such complex cases arising from the ambiguity of the origin of interfering factors, with insufficient information content of the signature, an insignificant number of free samples identifying features that prevailed over others, the ability to explain the differences and the lack of full confidence in the categorical expert is a probable form of conclusion. To sum up it can be concluded that handwriting experts obtain scientific research on the identification of interfering factors affecting the signer. The level of knowledge and experience of the expert, the perfection of research methods, etc. will play an important role. Key words: signature, interfering factors, natural, artificial.
Dissertations / Theses on the topic "Interfering methods"
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Kok, Kin-hang, and 郭健恆. "Development of small interfering RNA-based methods for blocking gene expression in vertebrate cells." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2002. http://hub.hku.hk/bib/B31970576.
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Kok, Kin-hang. "Development of small interfering RNA-based methods for blocking gene expression in vertebrate cells." Hong Kong : University of Hong Kong, 2002. http://sunzi.lib.hku.hk/hkuto/record.jsp?
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Santana, Filho Eduardo Bentes. "Avaliação da concentração de Interferon-gama em pacientes com Tuberculose pulmonar e contatos diretos, por Quantiferon TB Gold (In tube method)." Universidade Federal do Amazonas, 2012. http://tede.ufam.edu.br/handle/tede/2620.
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Previous issue date: 2012-05-17Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Tuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis complex species, which infect the exposed individuals, initiate an immune response with production of several cytokines, among them interferon-gamma (IFN-gamma), which is crucial for activation of cellular immune response against TB bacillus. This cytokine has been extensively studied as a possible biomarker for diagnosis of TB. In this work, we analyzed the levels of IFN-gamma in response to in vitro stimulation with ESAT-6, CFP10 and TB7.7, by QuantiFERON ®-TB Gold (In-tube method) (QTF-IT) in 155 participants: 47 patients confirmed pulmonary TB (patient group), 49 direct contacts (group contact), and 59 individuals without history or contact with TB (control group). The levels of IFN-gamma were different among the groups (p=0.0001); the highest level was observed in the patients group (median=1.43 IU/mL). In contacts group, 20/49 (40.8%) subjects were positive for the QTF-IT (median = 0.26 IU / mL), and among these positive contacts 14/20 (70.0%) exhibited high levels of IFN-gamma, (≥ 1.05 IU/mL). The performance testing of TB patients versus controls, resulted in 80.9% sensitivity (95% CI = 69.6% to 92.1%) and 93.2% specificity (95% CI = 86.8 % to 99.6%), but when the results of contacts and control group were combined, the specificity decreased to 77.8% (95% CI = 69.9% to 85.6%). Thus, according to our data, there is a distinctive profile of IFN-gamma, with higher levels in the patients group. The QTF-IT positive in contacts, especially those with high levels of IFN-gamma, should be monitored, especially those with high levels of IFN-gamma. This result may be a risk factor for developing TB disease. In addition, the QTF-IT, properly executed, can be useful in endemic areas for the diagnosis of latent and active TB (infection) when evaluated with other routine tests.
A Tuberculose (TB) é uma doença infecciosa causada por espécies do complexo Mycobacterium tuberculosis, que ao infectar os indivíduos expostos, iniciam uma resposta imunológica com produção de várias citocinas, dentre elas o Interferon-gama (IFN-gama), que é crucial para ativação da resposta imune celular contra o bacilo da TB. Esta citocina tem sido amplamente estudada como um possível biomarcador para auxiliar no diagnóstico da TB. Neste trabalho foram analisados as concentrações de IFN-gama em resposta a estímulos in vitro com ESAT-6, CFP10 e TB7.7, utilizando o QuantiFERON®-TB Gold (In-tube method) (QTF-IT), em 155 participantes, sendo: 47 pacientes com TB pulmonar confirmada (grupo paciente), 49 contatos de pacientes com TB pulmonar (grupo contato), e 59 indivíduos sem história e/ou contato com TB (grupo controle). As concentrações de IFN-gama foram diferentes entre os grupos avaliados (p=0,0001), sendo mais elevado nos pacientes com TB (Mediana = 1.43 UI/mL). Dos contatos diretos, 20/49 (40,8%) foram positivos para o QTF-IT (Mediana=0,26 UI/mL), e destes 14/20 (70,0%) apresentaram níveis elevados de IFN-gama, superior à 1,05 UI/mL. O desempenho do teste relacionando os pacientes de TB como os doentes e os controles como sadios, resultou em 80,9% de sensibilidade (IC 95% = 69,6% a 92,1%) e 93,2% de especificidade (IC 95% = 86,8% a 99,6%), mas quando os resultados dos contatos diretos foram adicionados aos controles, a especificidade reduziu para 77,8% (IC 95% = 69,9% a 85,6%). Concluiu-se que há um perfil diferenciado na produção de IFN-gama, com níveis mais elevados nos pacientes de TB ativa, e que os contatos positivos para o QTF-IT, principalmente, aqueles com altas concentrações de IFN-gama, devem ser monitorados, considerando que o perfil ou concentração elevado desta citocina, pode ser um fator de risco para o desenvolvimento da TB doença. Além disso, o QTF-IT, executado corretamente, pode ser útil em áreas endêmicas para auxiliar no diagnóstico da TB latente (infecção) e ativa, quando avaliados com outros exames de rotina.
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Rosenblatt, Marcus [Verfasser], and Jens [Akademischer Betreuer] Timmer. "From steady states to dynamics : : methods for mechanistic modeling of biological systems with applications to interferon apha signaling." Freiburg : Universität, 2021. http://d-nb.info/1233966510/34.
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Stewart, Claire Emma. "Viruses and the interferon (IFN) response : methods to improve production and to rapidly select IFN-sensitive viruses for vaccine development." Thesis, University of St Andrews, 2017. http://hdl.handle.net/10023/11346.
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Manipulation of a virus's capacity to circumvent the interferon (IFN) response aids both fundamental studies as well as many practical applications including the design of live-attenuated vaccines. However, these IFN-sensitive viruses are often difficult to grow to high titer in cells that produce and respond to IFN. In the first part of this study we further characterised the use of the IFN inhibitor, Ruxolitinib (Rux) for its ability to block the IFN response and subsequently enhance replication of IFN-sensitive viruses. This study has shown that i) Rux could provide a more rapid and therefore more efficient alternative for the growth of IFN-sensitive viruses than the current default option, growth in Vero cells and ii) addition of Rux can increase growth of multiple viruses in numerous cell-lines. These results indicate that as well as aiding fundamental studies the addition of Rux could become a valuable technique in a number of virological applications including live attenuated vaccine production and techniques to isolate newly emerging viruses. In the second part of this study we developed a novel method to isolate IFN-sensitive viruses from Paramyxoviruses, using PIV5 (Parainfluenza virus 5) as an experimental model system to obtain selection parameters. We successfully isolated three mutant viruses (rPIV5mCh-α, rPIV5mCh-β and PIV5 W3-γ) that each contain mutations within the IFN antagonist V protein and the P protein which is essential for RNA replication. Subsequently, both rPIV5mCh-α and PIV5 W3-γ were shown to contain non- functional V proteins and exhibit IFN-sensitivity. Ultimately, this study is the first step towards creating a general method to isolate various types of IFN-sensitive viruses that as well as aiding fundamental studies, may be further developed as attenuated vaccines for clinically important viruses lacking vaccines.
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Leung, Chieh-wing Jervis, and 梁倢榮. "Development of a real-time PCR-based method for the measurement of neutralizing antibody to interferon-beta in multiple sclerosis patients." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2014. http://hdl.handle.net/10722/206488.
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Background Multiple sclerosis (MS) is a chronic inflammatory demyelinating disorder of the central nervous system (CNS). In Hong Kong, the prevalence rates of MS is 4.8/100,000. First line disease modifying agent (DMA) type 1 interferon β (IFN-β) is the most commonly use therapy for relapsing and remitting MS(RRMS). Depending on the administration type and route of IFN-β, up to 80% of patients develop harmless binding antibody (BAb),which binds to IFN molecules but not necessary interfere its bioactivity. When IFN-β therapy continues, maturation of BAb response can lead to the formation of high affinity neutralizing antibody (NAb). About 45% of MS patients develop NAb against IFN-β in one year of IFN-β treatment. NAb shows a loss of IFN-β clinical effect by increasing MRI activity and disease progression. As the clinical effect of NAb is lagging behind the initial appearance of NAb in the body, it is suggested to develop a NAb assay to predict treatment failure and advice switching therapy for patients when NAb is present.
Aim The aim of this study was:
I. To develop and evaluate a qPCR-based method for the measurement of NAb to IFN-β in MS patient.
II. To establish the normal reference range of NAb in Chinese population.
III. To seek the possibility of using anti-IFN-β BAb assay and in vivo MxA gene expression assay as a screening test for NAb
IV. To compare the performance between MxA induction qPCR, ELISA, WB assay and luciferase IFN-β reporter gene assay
Materials and methods23Chinese RRMS patients who treated with IFN-β-1a therapy for a minimum of12 months were recruited in this study. Serum and PBMC were collected12 hours after the IFN-β-1a injection. MxA, IFNAR1 and IFNAR2 mRNA from PBMC were tested byin vivo MxA gene expression assay. NAb containing serum was tested by anti-IFN-β BAb assay, IFN-β reporter gene assay, in vitro MxA induction WB, ELISA and qPCR assay. In addition, blood samples from 3 Chinese volunteers without any known autoimmune disease history were collected to evaluate the baseline of NAb titer and MxA expression.
Result The experimental condition of MxA induction qPCR assay was optimized by using 2.5×105A549 cells plating density, 10% FCS concentration,5 hours IFN-β stimulation time and GAPDH normalization. Assay accuracy was validated by reference anti-IFN-β antibody. Starting from 2.5 TRU, linear relationship could be observed (r2= 0.9873). The lower limit of quantification (LLOQ) was 0.02 LU/mL, the upper limit of quantification (ULOQ) was 16LU/mL and the limit of detection (LOD) was 0.002 LU/mL. The reproducibility of the assay was measured, the intra-and inter-assay imprecision(%CV)for high value were 5.95% and 7.17% respectively, while the intra-and inter-assay impression were8.31% and 15.95%respectively.Results of the qPCR-based method were concurring with that of luciferase IFN-β reporter gene assay. The upper limit of the NAb reference range in Chinese population was 40.3 TRU (n=3, 95% CI = 31.7-48.8). The performance observed in MxA induction ELISA assay swas unsatisfactory. The correlation of anti-IFN-β BAb assay and in vivoMxA gene expression assay results with NAb status indicated both tests were sensitive enough for NAb screening.
Conclusion A normal range of NAb titer in Chinese population was established in this study. Anti-IFN-β BAb assay and in vivo MxA gene expression assay were proved suitable for NAb screening. The performance of the developed MxA induction qPCR assay was superior to MxA induction ELISA, WB assay and comparable to luciferase IFN-β reporter gene assay. By using MxA induction qPCR assay, actual efficacy of IFN-β therapy could be measured and monitored. Any treatment failure could be predicted earlier.published_or_final_version
Pathology
Master
Master of Medical Sciences
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Lisboa, Filho Normando da Silva. "Desenvolvimento e validação de método analítico para determinação de interferentes endócrinos: aplicação em amostras da água da Baía de Todos os Santos, Ba." reponame:Repositório Institucional da UFBA, 2012. http://www.repositorio.ufba.br/ri/handle/ri/11723.
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CAPES
O objetivo deste trabalho foi o desenvolvimento de um procedimento analítico empregado Cromatografia Líquida Ultra Rápida acoplada a Detector de Fluorescência (UFLC-FLU) para determinação de interferentes endócrinos (IEs; bisfenol A (BPA), 4n-nonilfenol (4NP), 4-octifenol (4OP), 4-t-octifenol (4TOP), estriol (E3), estrona (E1), 17β- estradiol (E2) e 17α-etinilestradiol (EE2)) em água do mar. Foi utilizado um sistema de pré-concentração em fase solida (cartucho SPE com fase estácionária C18) para extração e pré-concentração dos IE em as amostras de água do mar. A separação foi otimizada e realizada em um tempo total de corrida de 10 min, em uma coluna cromatográfica Shim-pack XR-ODS C-18 (2,0 mm ID x 50 mm), com a fase móvel de acetonitrila e água ultra pura com gradiente de eluição. A vazão foi de 0,12 mL min-1, a temperatura da coluna foi mantida em 60°C e os comprimentos de onda de emissão e excitação foram de 306 nm e 280 nm, respectivamente. O método validado foi aplicado em amostras de água coletadas na Baia de Todos os Santos, Bahia, Brasil. As amostras foram coletadas na Baía da Ribeira, Feira do São Joaquim, Santo Amaro da Purificação, São Francisco do Conde, Cachoeira e Acupe. As recuperações para o IE variaram entre 84,9% (para o composto 4nOP) e 104% (para o composto 4nNP), e a repetibilidade foi adequada (RSD < 4,5%). Os limites de detecção e quantificação encontrados para os compostos estudados variaram de 4 a 27 µg L-1 e de 19 a 185 µg L-1, respectivamente para o método cromatográfico. Considerando o fator de concentração de 2000 vezes, o LD e LQ variaram de 2 a 23 ng L-1 e de 9 a 96 ng L-1, respectivamente quando calculados para amostra real. Foi observada a ocorrência dos seguintes IE nas amostras reais: bisfenol A (BPA), 17β-estradiol (E2), estriol (E3) e 4n-octifenol (4NOP) em concentrações que variaram de 5 ng L-1 em Santo Amaro a 18,3 ng L-1 em Cachoeira para o E2, 20 ng L-1 do 4NOP na Ribeira a 135 ng L-1 no estuario do Rio Subaé (Santo Amaro), sendo o 4NOP o contaminante onipresente nas amostras analisadas. A concentração de 38 ng L-1 de E3 foi encontrada apenas nas amostras da Ribeira. A presença de BPA foi detectada em quase todas as amostras (o BPA não foi detectado na Ribeira), em níveis entre 13 ng L-1 no estuário do rio Paraguaçu em Cachoeira e aproximadamente 77 ng L-1 no estuário do rio Subaé. Os resultados sugerem que as regiões estudadas encontram-se possivelmente impactadas em relação os IE estudados e que as concentrações encontradas poderiam indicar possíveis danos ao ecossistema marinho local. O método analítico empregando SPE e UFLC-FLU se mostrou eficiente na determinação dos oito compostos de interesse usando um volume de amostra de 4 litros.
Salvador
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Hoberg, Emilia. "Metodverifiering av reagens med förhöjt tröskelvärde för biotininterferens för biomarkörerna NT-proBNP, prokalcitonin och prostataspecifikt antigen på Roche Cobas® e801." Thesis, Linnéuniversitetet, Institutionen för kemi och biomedicin (KOB), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-96861.
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Biotin är ett vitamin som finns naturligt i livsmedel och det dagliga intaget nås via födan. Höga doser biotintillskott samt höga doser biotin i läkemedel, kan leda till biotininterferens i kliniska immunokemiska analyser. Roche Diagnostics® vill införa nya reagens med högre tröskel för biotininterferens för att minska risken för biotininterferens vid analys av patientplasma. Därför var syftet med studien att metodverifiera fyra nya reagens från Roche Diagnostics® som används vid diagnostisering och behandling av hjärtsvikt, sepsis, och prostatacancer. De fyra reagensen, Elecsys® proBNP II, Elecsys® BRAHMS PCT, Elecsys® total PSA samt Elecsys® free PSA metodverifierades för att användas på Cobas® e801. Studiematerialet bestod av 20 patientprover av litiumheparinplasma per reagens (totalt 80 patientprover). Resultatet av verifieringen av Elecsys® proBNP II visade en korrelation till det befintliga reagenset på r = 0,9998 och Bland-Altman analys visade en spridning av resultaten på < 10 %; inomserieprecisionsstudien gav CV 1,56 %. Elecsys® BRAHMS PCT hade en korrelation på r = 0,9997 och Bland-Altman analysen visade en spridning på > 10 %; inomserieprecisionsstudien gav CV 1,70 %. För Elecsys® total PSA och free PSA fanns korrelationen till det befintliga reagenset på r = 1 respektive 0,9997 och Bland- Altman analysen visade en spridning på < 10 % hos båda reagensen. Inomserieprecisionsstudien gav CV 0,44 % respektive CV 2,67 %. Resultaten för samtliga reagens uppvisar god korrelation till det befintliga reagenset och en hög mätnoggrannhet vilket talar för att de fyra nya reagensen kan tas i bruk.Biotin is naturally found in foods, and we obtain this vitamin through our daily diet. Biotin supplements as well as high doses of biotin in drugs can lead to biotin interference in clinical immunochemical analyzes. Therefore, the purpose of this study was to methodically verify four new reagents from Roche Diagnostics® with a higher threshold for biotin interference, used in the diagnosis and treatment of heart faliure, sepsis and prostate cancer. The four reagents, Elecsys® proBNP II, Elecsys® BRAHMS PCT, Elecsys® total PSA and Elecsys® free PSA were method-verified for use on Cobas® e801. The study material consisted of 20 patient samples of lithium heparin plasma per reagent. In total 80 samples were analyzed.The result of the verification of Elecsys® proBNP II showed a correlation to the existing reagent of r = 0.9998 and Bland-Altman analysis showed a distribution of the results of <10 %. The withinseries precision study yielded CV 1.56 %. Elecsys® BRAHMS PCT had a correlation of r = 0.9997 and the Bland-Altman analysis showed a distribution of > 10 %. The withinseries precision study gave CV 1.70 %. For Elecsys® total PSA and free PSA, the correlation to the existing reagent was r = 1 and 0.9997, respectively, and the Bland-Altman analysis showed a distribution of <10 % in both reagents. The withinseries precision study yielded CV 0.44 % and CV 2.67 % respectively.The results for all reagents show a good correlation to the existing reagent and a high accuracy of measurement, which indicates that the four new reagents can be used.
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Rivière, Isabelle. "Construction et expression de vecteurs rétroviraux portant l'ADNc du gène de l'adénosine déaminase (ADA) humaine et l'ADNc du gène de l'IFN-beta murin pour le développement et l'amélioration de stratégies de thérapies géniques." Paris 11, 1993. http://www.theses.fr/1993PA112035.
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Des stratégies de thérapie génique sont en cours d'étude pour le traitement de maladies humaines. Ce type de thérapie s'adresse en premier lieu aux anomalies héréditaires récessives causées par la déficience en un gène unique dont le traitement nécessite l'addition du gène normal, mais pourrait être utilise également pour le traitement de cancers, de leucémies ou de maladies infectieuses. Le recours aux modèles animaux est indispensable pour : 1) juger directement de l'efficacité du transfert de gènes in vivo; 2) explorer les effets biologiques et potentiellement thérapeutiques de molécules exprimées à des niveaux physiologiques ou non physiologiques; 3) améliorer la méthodologie qui sera finalement appliquée à l'homme. Nos travaux s'inscrivent précisément dans le cadre du développement et de l'amélioration de modèles animaux murins. Étant donné les propriétés antivirales de l'interféron (IFN), nous développons une approche de thérapie génique basée sur l'expression constitutive de l'IFN dans les cellules hématopoïétiques et dirigée contre les maladies virales fatales à évolution lente et chronique comme le sida. D'autre part, nous nous intéressons à une maladie génétique héréditaire causée par la déficience en un gène unique codant pour l'adénosine déaminase (ADA); le dysfonctionnement de ce gène entraine une immunodéficience combinée sévère (SCID) chez l'homme. Aussi, la seconde partie de nos travaux concerne l'amélioration de la technologie relative à l'expression du gène codant pour l'ADA humaine dans les cellules hématopoïétiques in vivo, dans un modèle murin. L’approche commune à ces deux projets repose sur l'expression des ADNc (ADN complémentaires) des gènes codant pour l'IFN-beta murin et l'ADA humaine dans les cellules hématopoïétiques par l'intermédiaire de vecteurs rétroviraux.
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Chen, Yung-sheng, and 陳永盛. "On the study of measuring methods and interfering factors in the determination of atmospheric aerosol carbons." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/76285246177692195196.
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碩士國立中央大學
環境工程研究所
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The thermal-optical method is widely used for measuring atmospheric aerosol carbons. In this method, pyrolyzed carbon correction can be split into thermal optical reflectance (TOR) and thermal optical transmittance (TOT). This study compares the differences due to different temperature protocols and pyrolyzed carbon corrections. Meanwhile, the interferences of volatile organic carbons (VOCs) on aerosol carbon analysis for filter samples are also studied. Moreover, the effects of NaCl on EC fractionization in the coastal area are evaluated. Finally, the monitoring data of aerosol black carbon (BC) and elemental carbon (EC) from North aerosol supersite are adopted to conduct a linear regression analysis. The slope resulted from this analysis is considered to be the best BC absorption cross section (σ) and the influencing factors of σ values are also disussed. The results show that TOR tends to underestimate pyrolyzed carbon correction when atmospheric carbon concentration is increased and thus the depth of particle deposition on a filter. Under the influence of vehicle exhausts and ambient temperature, VOCs adsorption by quartz fiber filter will be increased when using the filter in aerosol collection. Meanwhile, organic carbon evaporation from deposited particles is severer. The interference of Na+ on EC fractionization is significant when Na+ concentration reaches 3 - 6 μg m-3 based on the observation at the Shimen site on the coastline of Taipei County. In this study, 17,000 hourly data from North aerosol supersite were used to obtain the correction value of σ. The variation of σ is within the range of 20 - 40 m2 g-1 during this time period. Meanwhile, the value of σ is found to increase with higher aerosol nitrate, higher ozone concentration, higher atmospheric relative humidity above 90%, and the duration of raining event. In the diurnal variation of σ, σ value is found to enhance in the traffic peak hours. The diurnal variations of σ value are also agreed well with that of PM2.5, PAH, and OC. It indicates that the increase of atmospheric aerosols and aerosol organic fractions will affect σ values. The best σ value in the greater Taipei metropolis is recommended to change from the manufacturer’s 16.6 to 24.5 m2 g-1 for AE31 Aethalometer in measuring BC at 880 nm wavelength.
Books on the topic "Interfering methods"
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Siomi, Mikiko C. PIWI-interacting RNAs: Methods and protocols. New York: Humana Press, 2014.
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MicroRNAs and the immune system: Methods and protocols. New York, NY: Humana Press, 2010.
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RNAi and plant gene function analysis: Methods and protocols. New York: Springer, 2011.
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Antiviral RNAi: Concepts, methods, and applications. New York: Humana Press/Springer Science, 2011.
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Next-generation MicroRNA expression profiling technology: Methods and protocols. New York: Humana Press, 2012.
Find full textBook chapters on the topic "Interfering methods"
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Bramsen, Jesper B., and Jørgen Kjems. "Engineering Small Interfering RNAs by Strategic Chemical Modification." In Methods in Molecular Biology, 87–109. Totowa, NJ: Humana Press, 2012. http://dx.doi.org/10.1007/978-1-62703-119-6_5.
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Uroz, Stéphane, and Phil M. Oger. "Screening for N-AHSL-Based-Signaling Interfering Enzymes." In Methods in Molecular Biology, 271–86. New York, NY: Springer New York, 2016. http://dx.doi.org/10.1007/978-1-4939-6691-2_18.
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Oger, Phil M., and Stéphane Uroz. "Screening for N-AHSL-Based-Signaling Interfering Enzymes." In Methods in Molecular Biology, 203–17. Totowa, NJ: Humana Press, 2010. http://dx.doi.org/10.1007/978-1-60761-823-2_14.
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Gaida, Annette, Urs B. Hagemann, Dinah Mattay, Christina Räuber, Kristian M. Müller, and Katja M. Arndt. "Selection of Peptides Interfering with Protein–Protein Interaction." In Methods in Molecular Biology, 263–91. Totowa, NJ: Humana Press, 2009. http://dx.doi.org/10.1007/978-1-59745-557-2_16.
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Hamil, Alexander S., and Steven F. Dowdy. "Synthesis and Conjugation of Small Interfering Ribonucleic Neutral SiRNNs." In Methods in Molecular Biology, 1–9. New York, NY: Springer New York, 2016. http://dx.doi.org/10.1007/978-1-4939-3112-5_1.
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Wahlgren, Jessica, Luisa Statello, Gabriel Skogberg, Esbjörn Telemo, and Hadi Valadi. "Delivery of Small Interfering RNAs to Cells via Exosomes." In Methods in Molecular Biology, 105–25. New York, NY: Springer New York, 2016. http://dx.doi.org/10.1007/978-1-4939-3112-5_10.
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Wang, Hong, Qingqing Yuan, Minghui Niu, Liping Wen, Hongyong Fu, Fan Zhou, Weihui Zhang, and Zuping He. "Gene Silencing of Human Sertoli Cells Utilizing Small Interfering RNAs." In Methods in Molecular Biology, 191–202. New York, NY: Springer New York, 2018. http://dx.doi.org/10.1007/978-1-4939-7698-0_14.
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Contreras, Fernanda, and Jaime Andrés Rivas-Pardo. "Interfering with the Folding of Group A Streptococcal pili Proteins." In Methods in Molecular Biology, 347–64. New York, NY: Springer US, 2020. http://dx.doi.org/10.1007/978-1-0716-0467-0_28.
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Chernolovskaya, Elena L., and Marina A. Zenkova. "Design of Nuclease-Resistant Fork-Like Small Interfering RNA (fsiRNA)." In Methods in Molecular Biology, 153–68. Totowa, NJ: Humana Press, 2012. http://dx.doi.org/10.1007/978-1-62703-119-6_8.
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Yin, Hongwei, Chris Sereduk, and Nanyun Tang. "Establishing an Infrastructure for High-Throughput Short-Interfering RNA Screening." In Methods in Molecular Biology, 1–13. New York, NY: Springer New York, 2016. http://dx.doi.org/10.1007/978-1-4939-6337-9_1.
Full textConference papers on the topic "Interfering methods"
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Anderson, Christian C., Michal Pakula, Mark R. Holland, Pascal Laugier, James G. Miller, G. Larry Bretthorst, Paul M. Goggans, and Chun-Yong Chan. "DECOMPOSITION OF INTERFERING ULTRASONIC WAVES IN BONE AND BONE-MIMICKING MATERIALS." In BAYESIAN INFERENCE AND MAXIMUM ENTROPY METHODS IN SCIENCE AND ENGINEERING: The 29th International Workshop on Bayesian Inference and Maximum Entropy Methods in Science and Engineering. AIP, 2009. http://dx.doi.org/10.1063/1.3275629.
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Gholamy, Shabanali, Abdolrahim Javaherian, and Abdolreza Ghods. "Automatic detection of wavelets interfering in seismic sections using fractal methods." In Proceedings of the 8th SEGJ International Symposium. Society of Exploration Geophysicists of Japan, 2006. http://dx.doi.org/10.1190/segj082006-001.61.
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Park, Haewook, Seok-Hwan Park, Hakjea Sung, and Inkyu Lee. "Scheduling Methods with MIMO Interference Alignment for Mutually Interfering Broadcast Channels." In GLOBECOM 2010 - 2010 IEEE Global Communications Conference. IEEE, 2010. http://dx.doi.org/10.1109/glocom.2010.5683466.
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Shakir, Ressol R., and Akram Aqar Altaweel. "Yield of different methods of analytic studies for interfering of shallow foundations." In PROCEEDINGS OF THE 2020 2ND INTERNATIONAL CONFERENCE ON SUSTAINABLE MANUFACTURING, MATERIALS AND TECHNOLOGIES. AIP Publishing, 2020. http://dx.doi.org/10.1063/5.0030568.
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Haug, Edward J., Frederick A. Adkins, Chi-Mei Luh, and Jia-Yi Wang. "Domains of Interference Between Working Bodies in Mechanisms and Manipulators." In ASME 1995 Design Engineering Technical Conferences collocated with the ASME 1995 15th International Computers in Engineering Conference and the ASME 1995 9th Annual Engineering Database Symposium. American Society of Mechanical Engineers, 1995. http://dx.doi.org/10.1115/detc1995-0085.
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Abstract Criteria for the set of all points in a pair of working bodies in a mechanism or manipulator that can coincide for any kinematically admissible configuration of the underlying mechanism, called the domain of interference between the bodies, are formulated. Kinematic equations for the mechanism and parameterizations of the domains of the working bodies are used to derive analytical criteria for domains of interference. Three complementary problems are formulated and analyzed to characterize (1) the set of points in one of the interfering bodies that are occupied by any point in the second body, (2) the set of points in one of the interfering bodies that are occupied by any point on the boundary of the second body, and (3) the set of all points in space that are simultaneously occupied by points in the interfering bodies; each condition occurring for any kinematically admissible configuration of the mechanism. Analytical criteria for the boundaries of domains of interference for each of the three problems arc derived, based on row-rank deficiency of a sub-Jacobian matrix associated with the kinematic equations for each of the problems. Numerical methods for mapping boundaries of domains of interference are presented and illustrated for planar Stewart platforms with domes attached that are characteristic of flight or ground vehicle simulators.
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Razminia, Kambiz, and Alain C. Gringarten. "Restoring Erroneous or Missing Rates in Interfering Wells Using Multiwell Deconvolution." In SPE Europec featured at 82nd EAGE Conference and Exhibition. SPE, 2021. http://dx.doi.org/10.2118/205160-ms.
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Abstract Objectives/Scope Single well deconvolution (von Schroeter et al., 2001) has been added to the well test interpretation toolbox nearly twenty years ago. In recent years, the single well deconvolution algorithm has been extended to multiple interfering wells (Cumming et al., 2013), and further improved with the additions of constraints to account for existing a-priory knowledge on the reservoir (constrained multiwell deconvolution, Cumming et al., 2019). The main objective of multiwell deconvolution is to identify the signatures of all wells involved and the interference signals between wells, from which information can be extracted about the reservoir that may not be obtainable otherwise, e.g. heterogeneities, boundaries and compartmentalization. The single well deconvolution algorithm has also been shown to be capable of restoring erroneous or missing rates (Gringarten, 2010). As shown in this paper, the same is true with multiwell deconvolution, which is able to restore erroneous or missing rates in all the wells involved. Methods, Procedures, Process Starting with arbitrary initial guesses for the missing rates in the various wells involved, we use multiwell deconvolution to estimate these missing flow rates or correct for erroneous ones. Two methods are presented: (1) we use unconstrained multiwell deconvolution as a first step to estimate the missing/erroneous rates, then use constrained multiwell deconvolution with these rates to estimate deconvolved derivatives; and (2) we restore/correct the flow rates and derive deconvolved derivatives simultaneously using constrained multiwell deconvolution. We show that the first approach is more accurate than the second one. In both approaches, we only obtain rates that are proportional to the true flow rates. To obtain the true flow rates, we need to know either one of the actual flow rates in each well, or the corresponding permeabilities. Results, Observations, Conclusions We prove the ability of multiwell deconvolution to estimate rates on synthetic oil reservoirs and gas reservoirs with moderate average reservoir pressure depletion, that include non-interfering wells. We then apply to oil and gas field examples and compare restored vs. actually measured rates. In all cases, the agreement is very good. Novel/Additive Information Using only measured pressure data, constrained multiwell deconvolution can be used to restore unknown flow rates and/or correct for erroneous rates, in addition to estimating deconvolved derivatives of all wells. This is particularly useful in the case of allocated rates or when rates are missing in some of the interfering wells.
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Smith, D. C., and D. J. Nelson. "A comparison of two methods for demodulating a target AIS signal through a collision with an interfering AIS signal." In SPIE Optical Engineering + Applications, edited by Mark S. Schmalz, Gerhard X. Ritter, Junior Barrera, Jaakko T. Astola, and Franklin T. Luk. SPIE, 2009. http://dx.doi.org/10.1117/12.825383.
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Kornev, A. A., V. V. Vysochinskaya, N. A. Knyazev, A. K. Emel'yanov, and A. A. Bogdanov. "Transfection of human peripheral blood T-lymphocytes with synthetic small interfering RNAs: selection of an effective technique." In Global science. Development and novelty. L-Journal, 2020. http://dx.doi.org/10.18411/gsdn-25-12-2020-04.
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It has been shown that the state of the human immune system and its activity determines the development, course and prognosis of many oncological diseases. To date, various immunotherapeutic approaches have been developed, of which the most promising is adoptive cell therapy (ACT). An increase in the effectiveness of this type of therapy could be achieved by using synthetic small interfering RNAs (siRNAs) to suppress the expression of key immune checkpoint (ICI) genes (PD1, CTL4) in T-lymphocytes, which are involved in cellular immunosuppression. However, there is a problem of selecting an effective method for delivering such siRNAs to T-lymphocytes. In the present study, we developed a synthetic siRNA specific to the mRNA sequence of the PD1 gene and evaluated the efficiency of its delivery to activated human T-lymphocytes using chemically modified siRNA, histone H1, – 18 – Global science. Development and novelty and the liposomal agent HiperFect. Ex vivo activated T-lymphocytes from healthy donors were used. The efficiency of siRNA transfection into cells and its confirmation was assessed using flow cytofluorometry and confocal microscopy. As a result of the study, a high (51%) efficiency of transfection into these cells using chemically modified "self-delivering" siRNA was shown. For other methods of delivery of miRNA to T-lymphocytes, low efficiency is shown. Thus, our data suggest that of the three approaches used in this work for miRNAs delivery to activated T-lymphocytes, the most effective is the use of “self-delivering” chemically modified cholesterol miRNA.
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Parker, Gordon W. "New Electromagnetic Methods to Locate and Assess Buried CP Problems." In 2002 4th International Pipeline Conference. ASMEDC, 2002. http://dx.doi.org/10.1115/ipc2002-27266.
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In this era of increased market competitiveness and the need for cost reduction strategies, natural gas pipeline and local distribution companies are now able to control the growth of their cathodic protection (CP) pipeline maintenance costs with the emergence of several new tools and related methods for diagnosing CP problems. In the early 1990’s, corrosion control engineers at the Southern California Gas Company (SoCal) were encouraged to find new methods to reduce maintenance costs associated with the company’s approximately 173 million feet of cathodically protected pipelines, mains and services. Mindful of how the maintenance problems in their CP systems were typically being resolved, an intriguing concept was conceived that could potentially reduce these costs and increase productivity by at least 40%. Driven to become more cost efficient, SoCal and the Pacific Gas and Electric Company (PG&E) in conjunction with the Gas Research Institute, now Gas Technology Institute (GTI) partnered with Radiodetection Corporation in the mid-90’s to research and design a more efficient way of troubleshooting and fault finding on CP systems. Radiodetections experience with electromagnetic detection equipment resulted in a family of non-invasive and cost-effective techniques to evaluate coating quality and to detect and record the flow of desired and interfering CP currents. The productivity gains and cost savings produced by this technology are significant. Additionally, problems that may have been difficult or impossible to detect now can be found allowing proactive and preventative maintenance. A history of these developments is discussed along with a brief review of the instruments technical aspects and capabilities. Typical field case studies are shown that demonstrate the improved corrosion control troubleshooting efficiencies available with these new technologies.
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Jangale, Vilas, Alexei Saveliev, Serguei Zelepouga, Vitaly Gnatenko, and John Pratapas. "A Real-Time Method for Determining the Composition and Heating Value of Opportunity Fuel Blends." In ASME 2012 Internal Combustion Engine Division Spring Technical Conference. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/ices2012-81111.
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Engine manufacturers and researchers in the United States are finding growing interest among customers in the use of opportunity fuels such as syngas from the gasification and pyrolysis of biomass and biogas from anaerobic digestion of biomass. Once adequately cleaned, the most challenging issue in utilizing these opportunity fuels in engines is that their compositions can vary from site to site and with time depending on feedstock and process parameters. At present, there are no identified methods that can measure the composition and heating value in real-time. Key fuel properties of interest to the engine designer/researcher such as heating value, laminar flame speed, stoichiometric air to fuel ratio and Methane Number can then be determined. This paper reports on research aimed at developing a real-time method for determining the composition of a variety of opportunity fuels and blends with natural gas. Interfering signals from multiple measurement sources are processed collectively using multivariate regression methods, such as, the principal components regression and partial least squares regression to predict the composition and energy content of the fuel blends. The accuracy of the method is comparable to gas chromatography.
Reports on the topic "Interfering methods"
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Joyce, Christine, and Deidre Mountain. Optimization of Liposomal Encapsulation Efficiency. University of Tennessee Health Science Center, 2021. http://dx.doi.org/10.21007/com.lsp.2018.0002.
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Introduction: My project was a continuation of the Vascular Research Lab’s (VRL) ongoing research at the University of Tennessee Medical Center Knoxville (UTMCK) aimed at optimizing liposomal encapsulation efficiency of small interfering RNA (siRNA) which can be used to silence genes to prevent a variety of disease pathologies. Methods: Assay siRNA loading capacity of liposomes based on lipid concentration Development of a method for liposome purification: HPLC & HiTRAP Column Results & Conclusion: siRNA loading capacity Higher lipid:siRNA resulted in increased encapsulation efficiency HPLC – did not work as expected HiTRAP Column – currently being optimized to be used as part of standard operating procedures
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Whitham, Steven A., Amit Gal-On, and Victor Gaba. Post-transcriptional Regulation of Host Genes Involved with Symptom Expression in Potyviral Infections. United States Department of Agriculture, June 2012. http://dx.doi.org/10.32747/2012.7593391.bard.
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Understanding how RNA viruses cause disease symptoms in their hosts is expected to provide information that can be exploited to enhance modern agriculture. The helper component-proteinase (HC-Pro) protein of potyviruses has been implicated in symptom development. Previously, we demonstrated that symptom expression is associated with binding of duplex small-interfering-RNA (duplex-siRNA) to a highly conserved FRNK amino acid motif in the HC-Pro of Zucchini yellow mosaic virus (ZYMV). This binding activity also alters host microRNA (miRNA) profiles. In Turnip mosaic virus (TuMV), which infects the model plant Arabidopsis, mutation of the FRNK motif to FINK was lethal providing further indication of the importance of this motif to HC-Pro function. In this continuation project, our goal was to further investigate how ZYMV and TuMV cause the mis-expression of genes in cucurbits and Arabidopsis, respectively, and to correlate altered gene expression with disease symptoms. Objective 1 was to examine the roles of aromatic and positively charged residues F164RNH and K215RLF adjacent to FR180NK in small RNA binding. Objective 2 was to determine the target genes of the miRNAs which change during HC-Pro expression in infected tissues and transgenic cucumber. Objective 3 was to characterize RNA silencing mechanisms underlying differential expression of host genes. Objective 4 was to analyze the function of miRNA target genes and differentially expressed genes in potyvirus-infected tissues. We found that the charged K/R amino acid residues in the FKNH and KRLF motifs are essential for virus viability. Replacement of K to I in FKNH disrupted duplex-siRNA binding and virus infectivity, while in KRLF mutants duplex-siRNA binding was maintained and virus infectivity was limited: symptomless following a recovery phenomenon. These findings expanded the duplex-siRNA binding activity of HC-Pro to include the adjacent FRNK and FRNH sites. ZYMV causes many squash miRNAs to hyper-accumulate such as miR166, miR390, mir168, and many others. Screening of mir target genes showed that only INCURVATA-4 and PHAVOLUTA were significantly upregulated following ZYMVFRNK infection. Supporting this finding, we found similar developmental symptoms in transgenic Arabidopsis overexpressing P1-HC-Pro of a range of potyviruses to those observed in miR166 mutants. We characterized increased transcription of AGO1 in response to infection with both ZYMV strains. Differences in viral siRNA profiles and accumulation between mild and severe virus infections were characterized by Illumina sequencing, probably due to the differences in HC-Pro binding activity. We determined that the TuMV FINK mutant could accumulate and cause symptoms in dcl2 dcl4 or dcl2 dcl3 dcl4 mutants similar to TuMV FRNK in wild type Arabidopsis plants. These dcl mutant plants are defective in antiviral defenses, and the results show that factors other than HC-ProFRNK motif can induce symptoms in virus-infected plants. As a result of this work, we have a better understanding of the FRNK and FKNH amino acid motifs of HC-Pro and their contributions to the duplex-siRNA binding functions. We have identified plant genes that potentially contribute to infectivity and symptoms of virus infected plants when they are mis-expressed during potyviral infections. The results establish that there are multiple underlying molecular mechanisms that lead viral pathogenicity, some dependent on HC-Pro. The potential benefits include the development of novel strategies for controlling diseases caused by viruses, methods to ensure stable expression of transgenes in genetically improved crops, and improved potyvirus vectors for expression of proteins or peptides in plants.
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Davidson, Irit, Hsing-Jien Kung, and Richard L. Witter. Molecular Interactions between Herpes and Retroviruses in Dually Infected Chickens and Turkeys. United States Department of Agriculture, January 2002. http://dx.doi.org/10.32747/2002.7575275.bard.
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Tumors in commercial poultry are caused mainly by infection with avian herpes and retroviruses, the herpesvirus Marek's disease virus (MDV) and the retroviruses, reticuloendotheliosis (REV), lymphoid leukosis, subgroups A-I and J (ALV and ALV-J) in chickens, or Iymphoprolipherative disease (LPDV) in turkeys. Infection with one virus aggravates the clinical outcome of birds that are already infected by another oncogenic virus. As these viruses do not interfere for infection, MDV and one or more retroviruses can infect the same flock, the same bird and the same cell. While infecting the same cell, herpes and retroviruses might interact in at least three ways: a) Integration of retrovirus genomes, or genomic fragments (mainly the LTR) into MDV;b) alteration of LTR-driven expression of retroviral genes by MDV immediate- early genes, and c) by herpesvirus induced cellular transcriptional factors. The first type of molecular interaction have been demonstrated to happen efficiently in vitro by Dr. Kung, in cases multiple infection of cell cultures with MDV and REV or MDV and ALV. Moreover, Dr. Witter showed that an in vitro-created recombinant, RM1, had altered in vitro replication and in vivo biological properties. A more comprehensive characterization of RM1 was carried out in the present project. We sought to highlight whether events of such integrations occur also in the bird, in vivo. For that, we had first to determine the prevalence of dually-infected individual birds in commercial flocks, as no systematic survey has been yet reported. Surprisingly, about 25% of the commercial flocks infected with avian oncogenic viruses had a multiple virus infection and 5% of the total samples ana lysed had multiple virus sequences. Then, we aimed to evaluate and characterize biologically and molecularly the resulting recombinants, if formed, and to analyse the factors that affect these events (virus strains, type and age of birds and time interval between the infection with both viruses). The perception of retrovirus insertions into herpesviruses in vivo is not banal, as the in vivo and in vitro systems differ in the viral-target cells, lymphocytes or fibroblasts, in the MDV-replicative type, transforming or productive, and the immune system presence. We realized that previous methods employed to study in vitro created recombinant viruses were not adequate for the study of samples taken directly from the bird. Therefore, the Hot Spot-combined PCR was developed based on the molecularly known RM1 virus. Also, the PFGE that was used for tissue cultured-MDV separation was inefficient for separating MDV from organs, but useful with feather tips as a source of bird original MDV. Much attention was dedicated now to feathers, because if a recombinant virus would be formed in vivo, its biological significance would be evident by horizontal dissemination through the feathers. Major findings were: a) not only in vitro, but also in vivo MDV and retrovirus co-infections lead to LTR integrations into MDV. That was shown by the detection of chimeric molecules. These appeared in low quantities and as quasispecies, thus interfering with sequence analysis of cloned gel-purified chimeric molecules. Mainly inserts were located in the repeat long MDV fragments. In field birds chimeric molecules were detected at a lower frequency (2.5%) than in experimentally infected birds (30-50%). These could be transmitted experimentally to another birds by inoculation with chimeric molecules containing blood. Several types of chimeric molecules were formed, and same types were detected in birds infected by a second round. To reproduce viral integrations, in vivo infection trials were done with field inoculate that contained both viruses, but the chimeric molecule yield was undetectable.
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Whitham, Steven A., Amit Gal-On, and Tzahi Arazi. Functional analysis of virus and host components that mediate potyvirus-induced diseases. United States Department of Agriculture, March 2008. http://dx.doi.org/10.32747/2008.7591732.bard.
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The mechanisms underlying the development of symptoms in response to virus infection remain to be discovered in plants. Insight into symptoms induced by potyviruses comes from evidence implicating the potyviral HC-Pro protein in symptom development. In particular, recent studies link the development of symptoms in infected plants to HC-Pro's ability to interfere with small RNA metabolism and function in plant hosts. Moreover, mutation of the highly conserved FRNK amino acid motif to FINK in the HC-Pro of Zucchini yellow mosaic virus (ZYMV) converts a severe strain into an asymptomatic strain, but does not affect virus accumulation in cucurbit hosts. The ability of this FINK mutation to uncouple symptoms from virus accumulation creates a unique opportunity to study symptom etiology, which is usually confounded by simultaneous attenuation of both symptoms and virus accumulation. Our goal was to determine how mutations in the conserved FRNK motif affect host responses to potyvirus infection in cucurbits and Arabidopsis thaliana. Our first objective was to define those amino acids in the FRNK motif that are required for symptoms by mutating the FRNK motif in ZYMV and Turnip mosaic virus (TuMV). Symptom expression and accumulation of resulting mutant viruses in cucurbits and Arabidopsis was determined. Our second objective was to identify plant genes associated with virus disease symptoms by profiling gene expression in cucurbits and Arabidopsis in response to mutant and wild type ZYMV and TuMV, respectively. Genes from the two host species that are differentially expressed led us to focus on a subset of genes that are expected to be involved in symptom expression. Our third objective was to determine the functions of small RNA species in response to mutant and wild type HC-Pro protein expression by monitoring the accumulation of small RNAs and their targets in Arabidopsis and cucurbit plants infected with wild type and mutant TuMV and ZYMV, respectively. We have found that the maintenance of the charge of the amino acids in the FRNK motif of HC-Pro is required for symptom expression. Reduced charge (FRNA, FRNL) lessen virus symptoms, and maintain the suppression of RNA silencing. The FRNK motif is involved in binding of small RNA species including microRNAs (miRNA) and short interfering RNAs (siRNA). This binding activity mediated by the FRNK motif has a role in protecting the viral genome from degradation by the host RNA silencing system. However, it also provides a mechanism by which the FRNK motif participates in inducing the symptoms of viral infection. Small RNA species, such as miRNA and siRNA, can regulate the functions of plant genes that affect plant growth and development. Thus, this binding activity suggests a mechanism by which ZYMVHC-Pro can interfere with plant development resulting in disease symptoms. Because the host genes regulated by small RNAs are known, we have identified candidate host genes that are expected to play a role in symptoms when their regulation is disrupted during viral infections. As a result of this work, we have a better understanding of the FRNK amino acid motif of HC-Pro and its contribution to the functions of HC-Pro, and we have identified plant genes that potentially contribute to symptoms of virus infected plants when their expression becomes misregulated during potyviral infections. The results set the stage to establish the roles of specific host genes in viral pathogenicity. The potential benefits include the development of novel strategies for controlling diseases caused by viruses, methods to ensure stable expression of transgenes in genetically improved crops, and improved potyvirus vectors for expression of proteins or peptides in plants.
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Jander, Georg, and Daniel Chamovitz. Investigation of growth regulation by maize benzoxazinoid breakdown products. United States Department of Agriculture, January 2015. http://dx.doi.org/10.32747/2015.7600031.bard.
Full textAbstract:
Introduction Previous research had suggested that benzoxazinoids, a class of defensive metabolites found in maize, wheat, rye, and wild barley, are not only direct insect deterrents, but also influence other areas of plant metabolism. In particular, the benzoxazinoid 2,4-dihydroxy-7-methoxy-2H-1,4-benzoxa- zin-3(4H)- one (DIMBOA) was implicated in: (i) altering plant growth by interfering with auxin signaling, and (ii) leading to the induction of gene expression changes and secondary plant defense responses. The overall goal of this proposal was to identify mechanisms by which benzoxazinoids influence other aspects of plant growth and defense. Specifically, the following hypotheses were proposed to be tested as part of an approved BARD proposal: Benzoxazinoid breakdown products directly interfere with auxin perception Global changes in maize and barley gene expression are induced by benzoxazinoid activation. There is natural variation in the maize photomorphogenic response to benzoxazinoids. Although the initial proposal included experiments with both maize and barley, there were some technical difficulties with the proposed transgenic barley experiments and most of the experimental results were generated with maize. Summary of major findings Previous research by other labs, involving both maize and other plant species, had suggested that DIMBOA alters plant growth by interfering with auxin signaling. However, experiments conducted in both the Chamovitz and the Jander labs using Arabidopsis and maize, respectively, were unable to confirm previously published reports of exogenously added DIMBOA effects on auxin signaling. Nevertheless, analysis of bx1 and bx2 maize mutant lines, which have almost no detectable benzoxazinoids, showed altered responses to blue light signaling. Transcriptomic analysis of maize mutant lines, variation in inbred lines, and responses to exogenously added DIMBOA showed alteration in the transcription of a blue light receptor, which is required for plant growth responses. This finding provides a novel mechanistic explanation of the trade-off between growth and defense that is often observed in plants. Experiments by the Jander lab and others had demonstrated that DIMBOA not only has direct toxicity against insect pests and microbial pathogens, but also induces the formation of callose in both maize and wheat. In the current project, non-targeted metabolomic assays of wildtype maize and mutants with defects in benzoxazinoid biosynthesis were used to identify unrelated metabolites that are regulated in a benzoxazinoid-dependent manner. Further investigation identified a subset of these DIMBOA-responsive compounds as catechol, as well as its glycosylated and acetylated derivatives. Analysis of co-expression data identified indole-3-glycerol phosphate synthase (IGPS) as a possible regulator of benzoxazinoid biosynthesis in maize. In the current project, enzymatic activity of three predicted maize IGPS genes was confirmed by heterologous expression. Transposon knockout mutations confirmed the function of the maize genes in benzoxazinoid biosynthesis. Sub-cellular localization studies showed that the three maize IGPS proteins are co-localized in the plastids, together with BX1 and BX2, two previously known enzymes of the benzoxazinoid biosynthesis pathway. Implications Benzoxazinoids are among the most abundant and effective defensive metabolites in maize, wheat, and rye. Although there is considerable with-in species variation in benzoxazinoid content, very little is known about the regulation of this variation and the specific effects on plant growth and defense. The results of this research provide further insight into the complex functions of maize benzoxazinoids, which are not only toxic to pests and pathogens, but also regulate plant growth and other defense responses. Knowledge gained through the current project will make it possible to engineer benzoxazinoid biosynthesis in a more targeted manner to produce pest-tolerant crops without negative effects on growth and yield.