Articoli di riviste: "Vector control"

1

Rajagopalan, P. K. "Aspects of Vector Borne Disease Control". Journal of Communicable Diseases 50, n. 01 (29 marzo 2018): 28–31. http://dx.doi.org/10.24321/0019.5138.201806.

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Sharma, SN. "Scrub Typhus: Vector Surveillance and its Control". Journal of Communicable Diseases 51, n. 03 (22 ottobre 2019): 55–61. http://dx.doi.org/10.24321/0019.5138.201927.

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Ross, Perran A., e Ary A. Hoffmann. "Vector control: Discovery of Wolbachia in malaria vectors". Current Biology 31, n. 11 (giugno 2021): R738—R740. http://dx.doi.org/10.1016/j.cub.2021.04.038.

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Meredith, S. E. O., e A. A. James. "Biotechnology as applied to vectors and vector control". Annales de Parasitologie Humaine et Comparée 65 (1990): 113–18. http://dx.doi.org/10.1051/parasite/1990651113.

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Iwaszkiewicz, Jan, e Adam Muc. "Vector control strategy of the five-phase VSI". Renewable Energy and Power Quality Journal 19 (settembre 2021): 641–46. http://dx.doi.org/10.24084/repqj19.370.

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The paper describes an example of the vector control strategy applied to five-phase two-level inverters. Two base methods are discussed. The first one is based on the standard space vector transformation, while the other uses state vectors which enable the definition of the basic physical quantities of the inverter. The proposed notation system offers an universal simplification of vector identification. It comprises a standardized proposal of notation and vector marking. This tool may be really useful for the description of inverter states and makes it possible to reach correlation between state and space vectors. All vectors are defined by use of the same digits. The proposed mathematical tool has been verified during simulation tests performed with the use of the PLECS program.

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Lobo, Neil F., Nicole L. Achee, John Greico e Frank H. Collins. "Modern Vector Control". Cold Spring Harbor Perspectives in Medicine 8, n. 1 (15 maggio 2017): a025643. http://dx.doi.org/10.1101/cshperspect.a025643.

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Kay, Brian H. "Dengue vector control". Pathology 25 (1993): 19. http://dx.doi.org/10.1016/s0031-3025(16)35774-9.

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Aïkpon, R. "Malaria vector control". International Journal of Infectious Diseases 21 (aprile 2014): 142. http://dx.doi.org/10.1016/j.ijid.2014.03.720.

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Kamal, Shaukat. "Standardisation of Units for Assessment of Adult Disease Vector Density under Vector Control Programmes in India". Journal of Communicable Diseases 54, n. 4 (31 dicembre 2022): 69–73. http://dx.doi.org/10.24321/0019.5138.2022105.

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Vector density is one of the most frequently used monitoring parameters of entomological surveillance under any vector control programme. Vector control applications are guided by the density of vectors or their abundance in different seasons and settings. The vectors of different common vector-borne diseases viz. malaria, filaria, kala-azar, dengue, chikungunya, Zika and Japanese Encephalitis (JE) have different bionomics. Scientists, researchers, and public health entomologists of various research institutes and programmes are engaged in studying vector bionomics through vector surveillance activities. The most common parameter used to estimate the density of vector and non-vector species of both mosquitoes and flies is the collection of species in a given unit of time. In the malaria control programme, it started as a collection of resting vector mosquitoes at a specified time of dawn and dusk. These are expressed in a number of forms viz. ‘per man hour’, ‘per ten man hour’ and ‘ten man hour’ to ascertain the level of vector population and its increasing or decreasing trend with climatic factors which may be correlated with the active transmission of the disease. The minimum level of density at which active transmission was evidenced has been termed as ‘critical density’. Various vector species have different critical densities. Many other parameters are used to estimate vector or non-vector populations but such different units may often lead to confusion among the field functionaries. This article describes the significance of ‘per man-hour density’, the methodology which has been in practice for ages and the statistical method for its calculation. To avoid misconception, it should be understood that the density expressed for a particular species is the ‘differential density’ and not the absolute density.

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Ekawasti, Fitrine, e Eny Martindah. "Vector Control of Zoonotic Arbovirus Disease in Indonesia". Indonesian Bulletin of Animal and Veterinary Sciences 26, n. 4 (17 maggio 2017): 151. http://dx.doi.org/10.14334/wartazoa.v26i4.1402.

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Zoonotic Arbovirus diseases which are caused by the genus of Flavivirus, Alphavirus, and Bunyavirus, are transmitted through potential vectors. These diseases are commonly occurred, especially in tropical countries, including Indonesia. They can affect the economic development because of the high morbidity and mortality. This paper describes the incidence of zoonotic Arbovirus in Indonesia and the strategy to control its vector. Factors that support the occurrence of zoonotic Arbovirus diseases are environmental, demographic and behavioral changes, as well as advanced technology, transportation and global trade. These diseases would not occur without the role of vectors. Vector control can be carried out effectively through longitudinal surveillance to identify types of potential vectors in the area. Therefore to prevent the increased incidence of the diseases, controlling the vector is necessary.

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Yuan, Jie, Dingdou Wen e Yang Zhang. "Model Predictive Current Control Strategy with Reduced Computation Burden". Mathematical Problems in Engineering 2021 (4 febbraio 2021): 1–10. http://dx.doi.org/10.1155/2021/6677543.

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In this paper, three model predictive current control (MPCC) schemes for permanent magnet synchronous motors (PMSM) are studied. The first control scheme is the traditional optimal duty cycle model predictive current control (ODC-MPCC). In this scheme, according to the principle of minimizing the cost function, the optimal voltage vector is selected from the six basic voltage vectors which are optimized simultaneously with the duty, and then, the optimal voltage vector and its duty are applied to the inverter. In order to reduce the computational burden of ODC-MPCC, a second control scheme is proposed. This scheme optimizes the voltage vector control set, reducing the number of candidate voltage vectors from 6 to 2. Finally, according to the principle of minimizing the cost function, the optimal voltage vector is found from the two voltage vectors, and the optimal voltage vector and its duty cycle are applied to the inverter. In addition, in order to further improve the steady-state performance, another vector selection method is introduced. In the combination of voltage vectors, the third control scheme extends the combination of voltage vectors in the second control scheme. The simulation results show that the second control scheme not only reduces the computational burden of the first control scheme but also obtains steady-state performance and dynamic performance equivalent to the first control scheme. The third control scheme obtains better steady-state performance without significantly increasing the computational burden and has dynamic performance comparable to the first and second control schemes.

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Nie, Danyue, Jiaqiao Li, Qinghua Xie, Lele Ai, Changqiang Zhu, Yifan Wu, Qiyuan Gui, Lingling Zhang e Weilong Tan. "Nanoparticles: A Potential and Effective Method to Control Insect-Borne Diseases". Bioinorganic Chemistry and Applications 2023 (11 maggio 2023): 1–13. http://dx.doi.org/10.1155/2023/5898160.

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Insects act as vectors to carry a wide range of bacteria and viruses that can cause multiple vector-borne diseases in humans. Diseases such as dengue fever, epidemic encephalitis B, and epidemic typhus, which pose serious risks to humans, can be transmitted by insects. Due to the absence of effective vaccines for most arbovirus, insect control was the main strategy for vector-borne diseases control. However, the rise of drug resistance in the vectors brings a great challenge to the prevention and control of vector-borne diseases. Therefore, finding an eco-friendly method for vector control is essential to combat vector-borne diseases. Nanomaterials with the ability to resist insects and deliver drugs offer new opportunities to increase agent efficacy compared with traditional agents, and the application of nanoagents has expanded the field of vector-borne disease control. Up to now, the reviews of nanomaterials mainly focus on biomedicines, and the control of insect-borne diseases has always been a neglected field. In this study, we analyzed 425 works of the literature about different nanoparticles applied on vectors in PubMed around keywords, such as“nanoparticles against insect,” “NPs against insect,” and “metal nanoparticles against insect.” Through these articles, we focus on the application and development of nanoparticles (NPs) for vector control, discussing the lethal mechanism of NPs to vectors, which can explore the prospect of applying nanotechnology in the prevention and control of vectors.

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Jin, Ningzhi, Chao Wang, Dongyang Sun, Zelin Li e Kai Zhou. "MTPA control of permanent magnet synchronous motor based on dual-vector model predictive control". PLOS ONE 17, n. 1 (21 gennaio 2022): e0262135. http://dx.doi.org/10.1371/journal.pone.0262135.

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The vector control of the permanent magnet synchronous motor (PMSM) is affected by cross-coupling, output delay, parameter mismatch, and other factors; thus, resulting in its poor steady-state and insufficient dynamic performance. To address these problems, the design proposed in this study adopts a model predictive current control strategy. In the traditional model predictive control, the absolute value of the difference between the predicted output current of the inverter and the reference current is used as the cost function instead of the minimum value of the valence function, i.e., the optimal solution of the system, and the best switching state is outputted. The design proposed in this study adopts the dual-vector model to predict the current control. Firstly, the reference voltage vector was predicted on basis of the deadbeat idea, which reduced the calculation burden of processor. Next, in order to further improve the stability of the system, a two-vectors duty cycle calculation method was introduced. Then, simplifies the selection range of the two voltage vectors. While ensuring the accuracy of the voltage vector, the control is reduced. Reduce the amount of calculation in the system, thereby improving its robustness. Finally, based on the principle of current vector tracking error minimization, the duration of the selected voltage vector was determined. Last but not the least, the control strategy is applied to the MTPA control to increase the operating efficiency of the control motor. The improved control strategy can effectively reduce the torque ripple and improve the dynamic and steady-state performance of the system. Simulation results verify the feasibility and effectiveness of the proposed control algorithm.

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Wang, De Cheng, Er Hao Liu e Hui Lin. "One Approach for Direct Torque Control Switching Voltage Vector Selection". Applied Mechanics and Materials 246-247 (dicembre 2012): 867–71. http://dx.doi.org/10.4028/www.scientific.net/amm.246-247.867.

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Direct torque control selected switching voltage vector according to torque hysteresis comparator output, flux hysteresis comparator output, and sector. One switching voltage vector selection approach was proposed. It used support vector regression machine to carry out direct torque control switching voltage vector selection. The selection of eight switching voltage vectors was an eight classification problem. This classification problem was changed into regression problem by support vector regression machine. The nonlinear function used for switching voltage vector selection was gained by support vector regression machine training. Asynchronous motor direct torque control simulation result shows feasibility and effectivity of proposed method.

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Sharma, SN. "Kyasanur Forest Disease: Vector Surveillance and its Control". Journal of Communicable Diseases 51, n. 02 (28 agosto 2019): 38–44. http://dx.doi.org/10.24321/0019.5138.201915.

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Wilson, Anne L., Marleen Boelaert, Immo Kleinschmidt, Margaret Pinder, Thomas W. Scott, Lucy S. Tusting e Steve W. Lindsay. "Evidence-based vector control? Improving the quality of vector control trials". Trends in Parasitology 31, n. 8 (agosto 2015): 380–90. http://dx.doi.org/10.1016/j.pt.2015.04.015.

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17

Kauffman, Elizabeth B., e Laura D. Kramer. "Zika Virus Mosquito Vectors: Competence, Biology, and Vector Control". Journal of Infectious Diseases 216, suppl_10 (15 dicembre 2017): S976—S990. http://dx.doi.org/10.1093/infdis/jix405.

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Li, Hong, Yang Liu, Rende Qi e Yu Ding. "A Novel Multi-vector Model Predictive Current Control of Three-Phase Active Power Filter". European Journal of Electrical Engineering 23, n. 1 (28 febbraio 2021): 71–78. http://dx.doi.org/10.18280/ejee.230109.

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This paper proposes the application of a novel finite control set model predictive control (FCS-MPC) strategy in active power filter (APF). In the process of APF compensating harmonic and reactive power, the traditional single vector model predictive current control (MPCC) has low tracking accuracy to harmonic current, while the multi-vector MPCC has the problems of complex calculation and long calculation time, a new multi-vector MPCC control method has proposed in this paper. Firstly, the harmonic reference value is transformed into d-q coordinate system, according to the sector, the slope is calculated and the action time is obtained. Six new expected vectors are synthesized from six effective vectors and zero vectors. The value function is established to loop and calculate the optimal virtual vector, which is applied to APF. Compared with single vector control and traditional multi-vector control, it has a wider vector action area and faster calculation speed. The compensation results and dynamic performance are improved. The simulation results show that the total harmonic distortion (THD) is low.

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Gu, Xin, Wenyuan Xu, Guozheng Zhang, Wei Chen e Xuefeng Jin. "Three-Level Inverter-PMSM Model Predictive Current Control Based on the Extended Control Set". Electronics 12, n. 3 (21 gennaio 2023): 557. http://dx.doi.org/10.3390/electronics12030557.

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In the neutral point clamped (NPC) three-level inverter-permanent magnet synchronous motor system, traditional model predictive current control (MPCC) uses the system predictive model to traverse the 27 basic voltage vectors, to achieve the d-q axis current component and neutral point voltage of the multi-objective optimal control. Finite control set model predictive control predicts the state change of the control target at future moments based on a finite number of switching states of the inverter. The control principle of this method is simple and easy to implement, but the control effectiveness of this control strategy is limited because only one basic vector can be selected as the optimum output per control period. In this paper, a model predictive current control strategy based on an extended control set (ECS-MPCC) is proposed, which can improve the control performance of the system by extending the control set to select multiple vectors in a single control period compared to the traditional strategy. In addition, to address the disadvantage of extending virtual space vectors leading to an increase in computation, this paper proposes a fast search method for optimal vector based on region reduction. The proposed method avoids the optimization process traversing all virtual space vectors, thus enabling a fast search for the optimal vector. The experimental results show that the proposed control strategy has good steady-state and dynamic performance.

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Xu, Yan, Tingna Shi, Yan Yan e Xin Gu. "Dual-Vector Predictive Torque Control of Permanent Magnet Synchronous Motors Based on a Candidate Vector Table". Energies 12, n. 1 (4 gennaio 2019): 163. http://dx.doi.org/10.3390/en12010163.

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In order to reduce the torque ripple of permanent magnet synchronous motors (PMSMs), this paper proposes a dual-vector predictive torque control strategy based on a candidate vector table. The main feature of this strategy is that two vectors are acted in a control period to form a vector combination, and the vector combination can be either an effective-zero combination or an effective-effective combination. In the process of establishing the vector combinations, the switching frequency is also taken into account, therefore avoiding a high switching frequency, while effectively reducing the motor torque ripple. The candidate vector table is constructed offline, and three sets of candidate vectors and their duty cycles can be determined by looking up the table. Then the cost function is used to screen the action vectors from the three sets candidate vectors, so the two vectors acted in one control period and their duty cycles can be obtained simultaneously. Finally, the feasibility and effectiveness of the proposed method are verified on a 5.2 kW two-level inverter-fed PMSM drive system.

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Michalakis, Yannis, e François Renaud. "Evolution in vector control". Nature 462, n. 7271 (novembre 2009): 298–300. http://dx.doi.org/10.1038/462298a.

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Beaty, Barry. "139 Dengue vector control". JAIDS Journal of Acquired Immune Deficiency Syndromes 65 (aprile 2014): 58. http://dx.doi.org/10.1097/01.qai.0000446719.52800.4e.

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23

Lam, F. C. "Vector control is important". BMJ 339, dec09 2 (9 dicembre 2009): b5332. http://dx.doi.org/10.1136/bmj.b5332.

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24

Matthews, G. A. "Pest and vector control". Crop Protection 23, n. 12 (dicembre 2004): 1265. http://dx.doi.org/10.1016/j.cropro.2004.06.001.

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25

Curtis, Chris. "Equipment for vector control". Parasitology Today 7, n. 5 (gennaio 1991): 126. http://dx.doi.org/10.1016/0169-4758(91)90178-q.

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Cox, F. E. G. "Vector control: Making predictions". Parasitology Today 7, n. 9 (gennaio 1991): 223. http://dx.doi.org/10.1016/0169-4758(91)90230-l.

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27

Danasekaran, Raja, Kalaivani Annadurai e Geetha Mani. "National Vector Borne Disease Control Programme: Current Updates". Journal of Comprehensive Health 3, n. 1 (24 ottobre 2020): 9–16. http://dx.doi.org/10.53553/jch.v03i01.002.

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Vector-borne diseases are a group of communicable diseases transmitted by mosquitoes and other vectors. National Vector Borne Disease Control Programme is the programme for prevention & control of these diseases. Many new initiatives have been undertaken in the programme which includes National Programme for Prevention & Control of JE/AES, Strategic Plan for Malaria control in India (2012-2017), National Drug Policy on Malaria-2013, Environmental Codes of Practice, etc. in order to make India free from vector borne diseases with equitable access to quality health care.

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Dong, Hongliang, e Yi Zhang. "A Low-Complexity Double Vector Model Predictive Current Control for Permanent Magnet Synchronous Motors". Energies 17, n. 1 (27 dicembre 2023): 147. http://dx.doi.org/10.3390/en17010147.

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Compared to the conventional finite control set model predictive control (FCS-MPC), the double vector model predictive current control (DVMPCC) for permanent magnet synchronous motors (PMSMs) has a better steady-state performance without significantly increasing the switching frequency. However, determining optimal vectors with their dwell times requires a high computational burden. A low-complexity DVMPCC in the steady state was proposed in this study to address this problem. Firstly, the operating state of the motor was judged according to the speed error. During steady-state operation, the first optimal active vector was selected from three candidate vectors adjacent or identical to the active vector applied in the previous control period, reducing the number of comparisons by half. Next, the second optimal vector was selected from the other two active vectors, and the zero vector, the second optimal vector with the duty cycle, was determined according to the deadbeat condition of the q-axis current and cost function minimization. Finally, simulation and experimental results proved that the proposed low-complexity DVMPCC for surface-mounted permanent magnet synchronous motors is practical and feasible.

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Abhisubesh Vijayakumar, Sahadiya Mandodan, Hemaladkshmi Padmanaban, Bhagyashree Bora, Manikandan Sivaprakasam, Kakhuangailiu Gangmei, Jibi Lukose et al. "A review of vectors, vector borne diseases, vector control and their impact on public health". World Journal of Advanced Science and Technology 2, n. 2 (30 ottobre 2022): 001–11. http://dx.doi.org/10.53346/wjast.2022.2.2.0046.

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Mosquitoes are most important insect vectors for human disease transmission. Dengue, yellow fever, chikungunya, and zika are all spread by Aedes mosquitoes in many parts of the world. The primary vector of human malaria transmission is Anopheles. Culex is responsible for the transmission of Japanese encephalitis, lymphatic filariasis and West Nile virus fever. Synthetic pesticides have been successfully utilized in mosquito-control programmes for several decades. However, there are a number of disadvantages to the chemical method. As a result, there has been a rise in concern in the usage of biological agents for mosquito control in recent years. Because of their highly effective mosquitocidal activity, Bacillus sphaericus and Bacillus thuringiensis israelensis have been utilized extensively. While insecticide-based interventions have successfully reduced mosquito populations for a number of years, the reliance on a few number of insecticides has now led to the evolution of resistance. So there is a need to search for novel mosquitocidal bacteria for control the mosquito species. Since soil is one of the world's most diversified environments in which bacteria and fungi are abundant, screening of soil samples for isolation of novel mosquitocidal bacteria is attempted.

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Vassiliou, P. C. G., A. C. Georgiou e N. Tsantas. "Control of asymptotic variability in non-homogeneous Markov systems". Journal of Applied Probability 27, n. 4 (dicembre 1990): 756–66. http://dx.doi.org/10.2307/3214820.

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In this paper we provide two basic results. First, we find the set of all the limiting vectors of expectations, variances and covariances in an NHMS which are possible provided that we control the limit vector of the sequence of vectors of input probabilities. Secondly, under certain conditions easily met in practice we find the distribution of the limiting vector of expectations, variances and covariances to be multinomial with probabilities the corresponding limiting expected populations in the various states of the NHMS.

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Vassiliou, P. C. G., A. C. Georgiou e N. Tsantas. "Control of asymptotic variability in non-homogeneous Markov systems". Journal of Applied Probability 27, n. 04 (dicembre 1990): 756–66. http://dx.doi.org/10.1017/s0021900200027947.

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In this paper we provide two basic results. First, we find the set of all the limiting vectors of expectations, variances and covariances in an NHMS which are possible provided that we control the limit vector of the sequence of vectors of input probabilities. Secondly, under certain conditions easily met in practice we find the distribution of the limiting vector of expectations, variances and covariances to be multinomial with probabilities the corresponding limiting expected populations in the various states of the NHMS.

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Bonsall, Michael B., Laith Yakob, Nina Alphey e Luke Alphey. "Transgenic Control of Vectors: The Effects of Interspecific Interactions". Israel Journal of Ecology and Evolution 56, n. 3-4 (6 maggio 2010): 353–70. http://dx.doi.org/10.1560/ijee.56.3-4.353.

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The control of insect vectors through conventional sterile insect or transgenic technologies (e.g., RIDL®) is an intense focus of research in the combat against vector-borne disease. While the population dynamic implications of these control strategies are reasonably well-established, the effects of interspecific competition between different vectors and control strategies have not previously been explored. Different control intervention methods can affect the interaction and potential coexistence of vector species. By altering the shape of the zero net growth isoclines, conventional and transgenic control can affect patterns of vector coexistence and/or exclusion through Allee effects and transient dynamics. Further, transgenic control methods can mediate coexistence between target and non-target species and this can have important consequences for the persistence of disease and community ecological interactions.

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Tereshkin, Vladimir M., Dmitriy A. Grishin, Sergey P. Balandin e Vyacheslav V. Tereshkin. "Options of Shaping a Symmetrical Seven-Phase Output Voltage of a Valve Converter". Vestnik MEI, n. 1 (2022): 85–93. http://dx.doi.org/10.24160/1993-6982-2022-1-85-93.

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A seven-phase bridge converter has 128 logical states. When a seven-phase symmetric winding is connected to the converter, each logical state produces a spatial-temporal resulting voltage vector. In total, the converter can produce 126 active vectors and 2 zero vectors. The aim of the work is to study and classify the vector space in implementing the converter control algorithms performing spatial-vector modulation of the voltage by a seven-phase symmetric winding. It has been determined that there are nine control algorithms that form a symmetrical seven-phase voltage with various phase voltage waveforms. Each waveform corresponds to a certain value of the phase voltage fundamental harmonic component. The fundamental harmonic amplitude corresponds to the modulus of the generalized spatial-temporal voltage vector of discrete states. The vector spaces of phase voltage vectors corresponding to the converter logical states and shaping the resulting vectors, and also the vector spaces of generalized voltage vectors are investigated. The numerical values of the resulting and generalized voltage vectors are obtained. In carrying out the study, the vector analysis methods and methods of expanding functions into Fourier series were used. The theoretical studies have been tested experimentally. The experiments were carried out on a bench intended for studying the spatial-vector modulation of multiphase motors using a prototype seven-phase motor. The results can be used to implement nonlinear vector control systems for a seven-phase motor.

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Luan, Tianjiao, Zhichao Wang, Yang Long, Zhen Zhang, Qi Li, Zhihao Zhu e Chunhua Liu. "Multi-Virtual-Vector Model Predictive Current Control for Dual Three-Phase PMSM". Energies 14, n. 21 (3 novembre 2021): 7292. http://dx.doi.org/10.3390/en14217292.

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This paper proposes a multi-virtual-vector model predictive control (MPC) for a dual three-phase permanent magnet synchronous machine (DTP-PMSM), which aims to regulate the currents in both fundamental and harmonic subspace. Apart from the fundamental α-β subspace, the harmonic subspace termed x-y is decoupled in multiphase PMSM according to vector space decomposition (VSD). Hence, the regulation of x-y currents is of paramount importance to improve control performance. In order to take into account both fundamental and harmonic subspaces, this paper presents a multi-virtual-vector model predictive control (MVV-MPC) scheme to significantly improve the steady performance without affecting the dynamic response. In this way, virtual vectors are pre-synthesized to eliminate the components in the x-y subspace and then a vector with adjustable phase and amplitude is composed of two effective virtual vectors and a zero vector. As a result, an enhanced current tracking ability is acquired due to the expanded output range of the voltage vector. Lastly, both simulation and experimental results are given to confirm the feasibility of the proposed MVV-MPC for DTP-PMSM.

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Bouscayrol, Alain, Maria Pietrzak-David e Bernard de Fornel. "Comparison of cartesian vector control and polar vector control for induction motor drives". Mathematics and Computers in Simulation 46, n. 3-4 (maggio 1998): 325–37. http://dx.doi.org/10.1016/s0378-4754(97)00145-6.

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Touré, Y. T. "4. Vector study and vector control in the control of malaria and babesiosis". Transactions of the Royal Society of Tropical Medicine and Hygiene 83 (gennaio 1989): 39–41. http://dx.doi.org/10.1016/0035-9203(89)90602-0.

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Valipour, Khalil, e Reza Najafi. "Performance Evaluation of Doubly-Fed Induction Generator Using Combined Vector Control and Direct Power Control Method". Indonesian Journal of Electrical Engineering and Computer Science 3, n. 1 (1 luglio 2016): 49. http://dx.doi.org/10.11591/ijeecs.v3.i1.pp49-58.

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<p>This paper presents the performance evaluation of Doubly-Fed Induction Generator Using Combined Vector Control and Direct Power Control Method. Combined vector and direct power control (CVDPC) is used for the rotor side converter (RSC) of double-fed induction generators (DFIGs). The control system is according a direct current control by selecting suitable voltage vectors from a switching table. Actually, the proposed CVDPC encompass the benefits of vector control (VC) and direct power control (DPC) in a compact control system. Its benefits compare with VC contains rapid dynamic response, Stability against the machine parameters Changes, less computation, and naive implementation. On the other hand, it has benefits compared with DPC, contains less harmonic distortion and lower power ripple. This technique is to improve the dynamic performance of the DFIG driven by the wind-energy conversion system.</p>

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Kaur, Navneet, Daniel K. Hasegawa, Kai-Shu Ling e William M. Wintermantel. "Application of Genomics for Understanding Plant Virus-Insect Vector Interactions and Insect Vector Control". Phytopathology® 106, n. 10 (ottobre 2016): 1213–22. http://dx.doi.org/10.1094/phyto-02-16-0111-fi.

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The relationships between plant viruses and their vectors have evolved over the millennia, and yet, studies on viruses began <150 years ago and investigations into the virus and vector interactions even more recently. The advent of next generation sequencing, including rapid genome and transcriptome analysis, methods for evaluation of small RNAs, and the related disciplines of proteomics and metabolomics offer a significant shift in the ability to elucidate molecular mechanisms involved in virus infection and transmission by insect vectors. Genomic technologies offer an unprecedented opportunity to examine the response of insect vectors to the presence of ingested viruses through gene expression changes and altered biochemical pathways. This review focuses on the interactions between viruses and their whitefly or thrips vectors and on potential applications of genomics-driven control of the insect vectors. Recent studies have evaluated gene expression in vectors during feeding on plants infected with begomoviruses, criniviruses, and tospoviruses, which exhibit very different types of virus-vector interactions. These studies demonstrate the advantages of genomics and the potential complementary studies that rapidly advance our understanding of the biology of virus transmission by insect vectors and offer additional opportunities to design novel genetic strategies to manage insect vectors and the viruses they transmit.

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Luo, Yumei, e Detu Zhu. "Combinatorial Control of Transgene Expression by Hypoxia-Responsive Promoter and MicroRNA Regulation for Neural Stem Cell-Based Cancer Therapy". BioMed Research International 2014 (2014): 1–9. http://dx.doi.org/10.1155/2014/751397.

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Owing to their strong migratory capacity, tumor tropism, and tumor inhibitory effect, neural stem cells (NSCs) have recently emerged as one of the most attractive gene delivery vectors for cancer therapy. However, further animal studies found that proportional NSC vectors were distributed to nontarget organs after intravenous injection and the nonspecific transgene expression led to significant cytotoxic effects in these organs. Hence, an expression cassette that controls the transgene expression within NSC vectors in a tumor site-specific manner is desired. Considering hypoxia as a hallmark of tumor microenvironment, we have developed a novel NSC vector platform coupling transcriptional targeting with microRNA (miRNA) regulation for tumor hypoxia targeting. This combinatorial vector employed a hypoxia-responsive promoter and repeated targeting sequences of an miRNA that is enriched in NSCs but downregulated upon hypoxia induction to control the transgene expression. This resulted in significantly improved hypoxic selectivity over the use of a control vector without miRNA regulation. Thus, incorporating miRNA regulation into a transcriptional targeting vector adds an extra layer of security to prevent off-target transgene expression and should be useful for the development of NSC vectors with high targeting specifcity for cancer therapy.

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Kowolik, Claudia M., Jun Hu e Jiing-Kuan Yee. "Locus Control Region of the Human CD2Gene in a Lentivirus Vector Confers Position-Independent Transgene Expression". Journal of Virology 75, n. 10 (15 maggio 2001): 4641–48. http://dx.doi.org/10.1128/jvi.75.10.4641-4648.2001.

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ABSTRACT Vectors derived from murine leukemia virus (MLV) have been used in many human gene therapy clinical trials. However, insertion of the locus control regions (LCRs) derived from the β-globin gene locus or the CD2 gene into MLV vectors frequently led to vector rearrangement. Since the human immunodeficiency virus (HIV) sequence diverges significantly from the MLV sequence, we tested whether the LCR sequence is more stable in the context of an HIV vector. Clones derived from human fibrosarcoma line HT1080 cells transduced with an HIV vector containing the T-cell-specific CD2 LCR exhibit the same wide range of transgene expression as clones lacking the LCR. In contrast, Jurkat and primary T-cell clones derived from the transduction of the LCR-containing vector show, on average, a three- to fourfold increase in transgene expression relative to that of the control vector. This is consistent with previous observations that the CD2 LCR contains a T-cell-specific enhancer. In addition, the clones derived from the LCR-containing vector have a much lower clonal variation in transgene expression than those derived from the control vector. We also demonstrate that the level of transgene expression is proportional to the vector copy number. These results suggest that the human CD2 LCR sequence is compatible with HIV vector sequences and confers enhanced integration site-independent and copy number-dependent expression of the transgene. Thus, HIV vectors may represent the ideal vehicle to deliver genes controlled by various cis-acting elements such as LCRs.

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Zhang, Qingyue. "Vector-Stability of Univariate Refinable Vectors". Numerical Functional Analysis and Optimization 37, n. 7 (26 maggio 2016): 913–25. http://dx.doi.org/10.1080/01630563.2016.1180629.

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42

Zheng, Hai-bo, Jiang-tao Huang, Cheng-jun He, Bin Wu e Chao Gao. "A novel thrust vector nozzle with conical surface based on Coanda effect". Journal of Physics: Conference Series 2472, n. 1 (1 maggio 2023): 012002. http://dx.doi.org/10.1088/1742-6596/2472/1/012002.

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Abstract In this paper, a novel thrust vector control method based on Coanda effect is proposed for conical surface. The effect of thrust vector control is studied by computation fluid dynamic (CFD) numerical simulation. When there is no side plate on both sides of Coanda surface, there are large vortex structures on both sides of nozzle wake, and the vector control cannot be realized. After adding the side plate, the comprehensive control of the pitch and yaw thrust vectors was realized. When the nozzle pressure ratio (NPR) is 2~2.4, the pitch and yaw vector angles decreased with the increase of NPR, and the maximum pitch vector angle is 8°. And the yaw vector angle is 8°.

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Киселёва, О. А., С. А. Винокуров e Д. Д. Киселёва. "Local-optimal control in an electromechanical system with a contactless DC motor". МОДЕЛИРОВАНИЕ, ОПТИМИЗАЦИЯ И ИНФОРМАЦИОННЫЕ ТЕХНОЛОГИИ 9, n. 1(32) (31 gennaio 2021): 16–17. http://dx.doi.org/10.26102/2310-6018/2021.32.1.016.

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В работе проводится анализ возможности локально-оптимального управления в электромеханической системе на базе бесконтактного двигателя постоянного тока, который позволяет определить требуемые параметры импульса напряжения не только в регулируемом сигнальном секторе, но и в следующем секторе при переключении базовых векторов в процессе регулирования. Управление выходной координатой (состоянием системы) происходит за счет переключения базовых векторов и пульсации каждого импульса времени. Процессы управления пульсациями базового вектора (широтно-импульсная модуляция) аналогичны для каждого вектора, только эти вектора могут быть смещены в пространстве на определенный угол. Угол смещения данных векторов обратно пропорционален произведению числа пар полюсов и фаз. Процессы пульсации становятся периодическими, причем происходит чередование базового вектора и нулевого. В зависимости от частоты вращения ротора и периода пульсаций, число пульсаций одного базового вектора (без переключения его в пространстве) может достигать нескольких десятков. Если считать, что процессы, которые протекают при переключении только базовых векторов, идентичны по всем параметрам, кроме расположения в пространстве, то при расчете можно перемещать начало координат в новую точку пространства (расположение базового вектора) и получать периодические процессы для создания электромагнитного момента. Для синтеза алгоритма управления электромеханической системой с бесконтактным двигателем постоянного тока можно использовать метод прогнозирующего управления – Model predictive control (MPC). Целью данного исследования является оценка возможности применения локально-оптимального управления при каждом переключении базовых векторов с учетом особенностей построения бесконтактного двигателя постоянного тока. Оно направлено на формирование управляемых параметров одного базового вектора в сочетании с нулевым вектором, который определен как пространственно, так и начальными условиями исходным базовым вектором. Показано, что состояние системы будет зависеть также от скорости рассеивания в нулевом векторе накопленной электромагнитной энергии за время существования базового вектора. The paper analyses the possibility of local-optimal control in an electromechanical system based on a contactless DC motor, which allows the required voltage pulse parameters to be determined, not only in the regulated signal sector but also in the next sector during the switching of the base vectors of the control process. The output coordinate (system state) control is accounted for by the reference vectors switching and each time pulse ripple. The base vector pulsation control processes (pulse width modulation) are similar for each vector. Only these vectors can be shifted in space by a certain angle. The angle at which these vectors are shifted is inversely proportional to the product of the number of pole and phase pairs. The pulsation processes become periodic, with the base vector and zero vector alternating. Depending on rotor speed and pulsation period, the number of pulsations of one base vector (without switching it in space) can reach several dozens. Providing that processes occurring at switching of base vectors only are identical in all parameters except for location in space, we can move the origin of coordinates to a new position (location of the base vector) and get periodical processes for the creation of electromagnetic momentum during calculation. To synthesize an electromechanical control system with a contactless DC engine, you can use the predictive control method - Model predictive control (MPC). The purpose of this study is to assess the feasibility of locally optimal control every time the base vectors are switched, considering the features of building a DC contactless engine. Aimed at forming the controlled parameters of one base vector combined with a zero vector, which is defined by both spatial and initial conditions of the original base vector. It is demonstrated that the system status will also depend on the rate of dispersal in the zero vector of accumulated electromagnetic energy during the existence of the base vector control in an electromechanical system with a contactless DC motor.

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Wang, Zhengqi, Haoyu Zhou, Qunhai Huo e Sipeng Hao. "Three-Vector-Based Low Complexity Model Predictive Control for Soft Open Point". Mathematical Problems in Engineering 2022 (5 gennaio 2022): 1–12. http://dx.doi.org/10.1155/2022/1526676.

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Soft open point (SOP) can improve the flexibility and reliability of power supplies; thus, they are widely used in distribution network systems. Traditional single-vector model predictive control (SV-MPC) can quickly and flexibly control the power and current at both ports of the SOP. However, SV-MPC can only select one voltage vector in a sampling time, producing large current ripples, and power fluctuations. In order to solve the above problems, this paper proposes a three-vector-based low complexity model predictive control (TV-MPC). In the proposed control method, two effective voltage vectors and one zero voltage vector are selected in a sampling time. For the two-port SOP, methods are given to judge the sectors on both sides and select the voltage vectors. Furthermore, the calculation method of the distribution time is proposed as well. Finally, the effectiveness of the proposed method is verified by steady-state and dynamic-state simulation results compared with the SV-MPC.

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Pei, Yuanxin, Pengfei Zhi, Haifeng Wei e Yi Zhang. "Direct power control of dual three-phase permanent magnet synchronous motor based on multiple vectors". Journal of Physics: Conference Series 2758, n. 1 (1 aprile 2024): 012008. http://dx.doi.org/10.1088/1742-6596/2758/1/012008.

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Abstract In response to the traditional mode of dual three-phase permanent magnet synchronous generator switch form vector direct power control (DPC), the current harmonics are large, the active (P) and reactive (Q) harmonic oscillations are large, and the unstable losses of each phase current are large. A virtual voltage vector direct power control method based on duty cycle modulation is proposed. This method compares and synthesizes the two vectors of the outermost and second layers of the PWM rectifier, as well as three large vector synthesis methods, to obtain 12 new virtual voltage vectors. Then, the combined voltage vector is directly modulated into the deadbeat switching table, and the optimal predicted vector value is calculated based on the principle of the deadbeat formula, further suppressing the problem of large fluctuations in active and reactive power. Results show that the proposed multi-vector composite odd even quadrant DPC can effectively reduce current harmonics and power ripple, make the phase current more stable, reduce motor operating losses, and significantly improve the motor.

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Mwansat, Georgina Samuel. "Biodiversity of Insect Vectors and Parasites: Prospects and Challenges in the 21st Century". Nigerian Journal of Entomology 36, n. 1 (1 settembre 2020): 11–21. http://dx.doi.org/10.36108/nje/0202/63.01.20.

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This paper examines diversity of insect vectors and parasites/vector-borne diseases also the successes and challenges in vector control in the 21st century and the way forward suggested. The generally accepted insect biodiversity is estimated to be 5.5 million worldwide with only about 1.5 million described. Generally, four insect orders: Coloeptera, Lepidopera, Hymenoptera and Odonata have been well studied and broadly described. Majority of insect species are known to be beneficial to man and the environment however, insect vectors which are fewer have been identified as causes of morbidity. Mosquitoes which are hematophagous insect vectors are known to be the leading vector for human infectious agents. Insecticides majorly dichloro-diphenyl-trichloroethane (DDT) were therefore used for the control of insect vectors. This succeeded only for a short while in the 19th century due to insect vector resistance and the widely condemned ecological disadvantages. This led to the development of safer and more effective insecticides such as the pyrethriods although also plagued with the tendencies of insect vector resistance. However, it has been strongly indicated that there are links between drivers of global biodiversity modification and vector-borne diseases. This is identified as the strongest reason for control programs that are all encompassing, engaging different fields and institutions, communities and individuals. The Integrated Vector Management (IVM) is therefore, advocated as the way forward for control of insect vector in the 21st century. It is encouraged to be practised putting the basic principles of biodiversity conservation which are ensuring biological diversity, ecological integrity and resilience in proper perspective.

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Njoroge, Teresia Muthoni, Majidah Hamid-Adiamoh e Molly Duman-Scheel. "Maximizing the Potential of Attractive Targeted Sugar Baits (ATSBs) for Integrated Vector Management". Insects 14, n. 7 (28 giugno 2023): 585. http://dx.doi.org/10.3390/insects14070585.

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Due to the limitations of the human therapeutics and vaccines available to treat and prevent mosquito-borne diseases, the primary strategy for disease mitigation is through vector control. However, the current tools and approaches used for mosquito control have proven insufficient to prevent malaria and arboviral infections, such as dengue, Zika, and lymphatic filariasis, and hence, these diseases remain a global public health threat. The proven ability of mosquito vectors to adapt to various control strategies through insecticide resistance, invasive potential, and behavioral changes from indoor to outdoor biting, combined with human failures to comply with vector control requirements, challenge sustained malaria and arboviral disease control worldwide. To address these concerns, increased efforts to explore more varied and integrated control strategies have emerged. These include approaches that involve the behavioral management of vectors. Attractive targeted sugar baits (ATSBs) are a vector control approach that manipulates and exploits mosquito sugar-feeding behavior to deploy insecticides. Although traditional approaches have been effective in controlling malaria vectors indoors, preventing mosquito bites outdoors and around human dwellings is challenging. ATSBs, which can be used to curb outdoor biting mosquitoes, have the potential to reduce mosquito densities and clinical malaria incidence when used in conjunction with existing vector control strategies. This review examines the available literature regarding the utility of ATSBs for mosquito control, providing an overview of ATSB active ingredients (toxicants), attractants, modes of deployment, target organisms, and the potential for integrating ATSBs with existing vector control interventions.

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Rachmawati, Kartika Diyah, Rusmiati e Khambali. "IMPLEMENTASI METODE CIPP PADA EVALUASI PROGRAM PENGENDALIAN VEKTOR DI RUMAH SAKIT UNTUK MENURUNKAN RISIKO PENULARAN PENYAKIT". Gema Lingkungan Kesehatan 20, n. 1 (31 gennaio 2022): 42–48. http://dx.doi.org/10.36568/gelinkes.v20i1.4.

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Vector control is part of efforts to control vector-borne diseases directly or indirectly which aims to reduce the presence of vectors by implementing preventive measures so that disease transmission does not occur. The vector-borne and zoonotic disease control programs carried out include reduction, elimination, and eradication. The number of vectors at the Royal Surabaya Hospital in 2018 contained 52.5% mosquito vectors, 27.5% cockroach vectors, 57.5% ants, and 30% rats. Density increased in 2019, namely mosquito vectors as much as 87.9%, cockroach vectors 30.3%, ants 57.6%, and mice 60.6%. However, it did not experience a significant decrease in 2020 with the number of mosquito vectors as much as 84.6%, cockroach vectors 15.4%, ants 46.2%, and rats 38.5%. The purpose of this study was to evaluate the vector control program using the CIPP method (Context, Input, Process and Product). This research is a descriptive study with an exploratory approach. The sample in this study were 32 heads of the room. Data collection was obtained by conducting interviews using questionnaires and observations at the Royal Surabaya Hospital. The data that has been collected is analyzed descriptively. The result of this research is that the CIPP method can be used to evaluate vector and pest control programs. Context, input, and process evaluations got good categories, while in product evaluation there were still cockroaches, flies, mice, and cats. From this research, it is recommended to close all access to vectors and nuisance animals, to maintain cleanliness, especially in waste management and sewerage, to coordinate with the head of the room, partners and all employees to participate in reducing the presence of vectors.

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Blaustein, Leon, Richard S. Ostfeld e Robert D. Holt. "A Community-Ecology Framework for Understanding Vector and Vector-Borne Disease Dynamics". Israel Journal of Ecology and Evolution 56, n. 3-4 (6 maggio 2010): 251–62. http://dx.doi.org/10.1560/ijee.56.3-4.251.

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The integration of community ecology into the understanding and management of vectors and vector-borne diseases has largely occurred only recently. This compendium examines a variety of community interactions that can affect vector or vector-borne disease dynamics. They include: the importance of risk of predation, risk of ectoparasatism, competition, interactions of competition with transgenic control, apparent competition mediated through vectors, indirect effects of pesticides, vector diversity, and parasite diversity within a vector. In this paper, we summarize these studies and introduce several additional important questions in need of further exploration.

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Zolotukhin, Yu N., K. Yu Kotov, A. S. Mal’tsev, A. A. Nesterov e A. P. Yan. "VELOCITY VECTOR CONTROL OF AIRCRAFT". Автометрия 57, n. 4 (2021): 3–9. http://dx.doi.org/10.15372/aut20210401.

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