scholarly journals The State-Dependent Impulsive Model with Action Threshold Depending on the Pest Density and Its Changing Rate

Complexity ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Ihsan Ullah Khan ◽  
Sanyi Tang ◽  
Biao Tang
Keyword(s):  
Periodic Solutions ◽  
Integrated Control ◽  
Dynamical Behavior ◽  
Analytical Techniques ◽  
The State ◽  
Control Measures ◽  
Lambert W Function ◽  
Action Threshold ◽  
Pest Density ◽  
Changing Rate

Whether the integrated control measures are applied or not depends not only on the current density of pest population, but also on its current growth rate, and this undoubtedly brings challenges and new ideas to the state control measures that only rely on the pest density. To address this, utilizing the tactics of IPM, we constructed a Lotka-Volterra predator-prey system with action threshold depending on the pest density and its changing rate and examined its dynamical behavior. We present new criteria guaranteeing the existence, uniqueness, and global stability of periodic solutions. With the help of Lambert W function, the Poincaré map is constructed for the phase set, which can help us to provide the satisfactory conditions for the existence and stability of the semitrivial periodic solution and interior order-1 periodic solutions. Furthermore, the existence of order-2 and nonexistence of order-k(k≥3) periodic solutions are discussed. The idea of action threshold depending on the pest density and its changing rate is more general and can generate new remarkable directions as well compared with those represented in earlier studies. The analytical techniques developed in this paper can play a significant role in analyzing the impulsive models with complex phase set or impulsive set.

scholarly journals The Impulsive Model with Pest Density and Its Change Rate Dependent Feedback Control

2020 ◽  
Vol 2020 ◽  
pp. 1-20 ◽  
Author(s):  
Ihsan Ullah Khan ◽  
Sanyi Tang
Keyword(s):  
Feedback Control ◽  
Periodic Solutions ◽  
Poincaré Map ◽  
Dynamical Behavior ◽  
Sufficient Conditions ◽  
Control Measures ◽  
Poincare Map ◽  
Change Rate ◽  
Action Threshold ◽  
Pest Density

The idea of action threshold depends on the pest density and its change rate is more general and furthermore can produce new modelling techniques related to integrated pest management (IPM) as compared with those that appeared in earlier studies, which definitely bring challenges to analytical analysis and generate new ideas to the state control measures. Keeping this in mind, using the strategies of IPM, we develop a prey-predator system with action threshold depending on the pest density and its change rate, and study its dynamical behavior. We develop new criteria guaranteeing the existence, uniqueness, local and global stability of order-1 periodic solutions. Applying the properties of Lambert W function, the Poincaré map is portrayed for the exact phase set, which is helpful to provide the sufficient conditions for the existence and stability of the interior order-1 periodic solutions and boundary order-1 periodic solution, also confirmed by numerical simulations. It is studied in detail that how and under what conditions the fixed point of Poincaré map and its stability are affected by the newly introduced action threshold. The analytical methods developed in this paper will be very beneficial to study other generalized models with state-dependent feedback control.

BIFURCATION ANALYSIS OF CURRENT COUPLED BVP OSCILLATORS

2007 ◽  
Vol 17 (03) ◽  
pp. 837-850 ◽  
Author(s):  
SHIGEKI TSUJI ◽  
TETSUSHI UETA ◽  
HIROSHI KAWAKAMI
Keyword(s):  
Periodic Solutions ◽  
Poincaré Map ◽  
Dynamical Behavior ◽  
Coupled Systems ◽  
Poincare Map ◽  
Circuit Implementation ◽  
Coupling Structure ◽  
Bifurcation Phenomena ◽  
Junctional Coupling ◽  
Current Coupling

The Bonhöffer–van der Pol (BVP) oscillator is a simple circuit implementation describing neuronal dynamics. Lately the diffusive coupling structure of neurons attracts much attention since the existence of the gap-junctional coupling has been confirmed in the brain. Such coupling is easily realized by linear resistors for the circuit implementation, however, there are not enough investigations about diffusively coupled BVP oscillators, even a couple of BVP oscillators. We have considered several types of coupling structure between two BVP oscillators, and discussed their dynamical behavior in preceding works. In this paper, we treat a simple structure called current coupling and study their dynamical properties by the bifurcation theory. We investigate various bifurcation phenomena by computing some bifurcation diagrams in two cases, symmetrically and asymmetrically coupled systems. In symmetrically coupled systems, although all internal elements of two oscillators are the same, we obtain in-phase, anti-phase solution and some chaotic attractors. Moreover, we show that two quasi-periodic solutions disappear simultaneously by the homoclinic bifurcation on the Poincaré map, and that a large quasi-periodic solution is generated by the coalescence of these quasi-periodic solutions, but it disappears by the heteroclinic bifurcation on the Poincaré map. In the other case, we confirm the existence a conspicuous chaotic attractor in the laboratory experiments.

The effect of organic compost of Caryocar brasiliense waste against Meloidogyne javanica in two vegetable crops

Nematology ◽  
2021 ◽  
pp. 1-8
Author(s):  
Fabíola de J. Silva ◽  
Regina C.F. Ribeiro ◽  
Adelica A. Xavier ◽  
Vanessa A. Gomes ◽  
Paulo V.M. Pacheco ◽  
...  
Keyword(s):  
Integrated Control ◽  
Meloidogyne Javanica ◽  
Control Measures ◽  
Vegetable Crops ◽  
Root Knot Nematode ◽  
Second Stage ◽  
Tomato Roots ◽  
Crop Development ◽  
Caryocar Brasiliense ◽  
Organic Compost

Summary Root-knot nematodes (Meloidogyne spp.) are responsible for various significant crop losses, which require taking integrated control measures. The present study aimed to identify a possible sustainable approach to the management of Meloidogyne javanica in vegetable crops using an organic compound based on pequi (Caryocar brasiliense) fruit residues. A pot experiment was conducted using cultivars of tomato and lettuce susceptible to M. javanica, with three amendments including inorganic fertiliser, cattle manure and five doses of organic compost with pequi residues. All treatments were inoculated with second-stage juveniles of M. javanica to simulate the root-knot nematode disease in field conditions. Increasing doses of organic compost with pequi residues from 5 kg m−3 to 30 kg m−3 promoted a significant decrease in the nematode population in both cultures evaluated. Organic compost (30 kg m−3) reduced the numbers of galls and eggs of M. javanica by 41.6 and 46.5% in tomato roots, and by 80.3 and 59.2% in lettuce roots, respectively, compared with non-treated control. Organic compost also increased crop development considerably. In general, there was a 43.0% increase in plant development compared to non-treated control. Hence, organic compost of pequi residues could be an alternative to toxic chemical nematicides and recommended as eco-friendly management of M. javanica in vegetable crops.

Perspective on control options forEchinococcus multiloculariswith particular reference to Japan

Parasitology ◽  
2003 ◽  
Vol 127 (S1) ◽  
pp. S159-S172 ◽  
Author(s):  
A. ITO ◽  
T. ROMIG ◽  
K. TAKAHASHI
Keyword(s):  
Close Contact ◽  
Integrated Control ◽  
Risk Behaviour ◽  
Control Measures ◽  
Domestic Dogs ◽  
Western China ◽  
Preventive Strategies ◽  
Preventive Chemotherapy ◽  
Information Campaigns ◽  
Control Options

Following a brief introduction of recent advances in molecular and immunological technology for detection of persons and animals infected withEchinococcus multilocularisand an overview of the current situation of alveolar echinococcosis (AE) in Japan, perspectives on control options are discussed with reference to different epidemiological situations. AE is considered the most serious parasitic zoonosis in temperate and arctic regions of the northern hemisphere. The number of human cases differs drastically among regions. While high numbers of patients are apparently associated with highE. multilocularisprevalence in domestic dogs, e.g. in parts of Alaska and western China, the number of cases is moderate or low in areas where the parasite is mainly transmitted by wild canid species (e.g. in central Europe or temperate North America). However, the severity of the disease, the absence of curative treatment for most cases, the high cost of long-term chemotherapy and the anxiety caused for the population in highly endemic areas call for the development of preventive strategies even in regions where human AE is rare. Furthermore, in view of (1) drastically increasing numbers and infection rates of foxes involved in transmission ofE. multilocularis, and (2) increasingly close contact between humans and foxes e.g. in Europe and Japan, there is considerable concern that AE incidences may in future increase in these regions. Control options depend on a variety of factors including the species of canid principally responsible for transmission and the socio-economic situation in the region. Where domestic dogs (stray or owned) are the principal hosts forE. multilocularis, control options can include those applicable toE. granulosus, i.e. reduction of the number of stray dogs, registration and regular preventive chemotherapy of owned dogs, and information campaigns for the population promoting low-risk behaviour for man and dogs. WhereE. multilocularisis mainly transmitted by wild canids, the situation is far more difficult with preventive strategies still being in trial stage. Integrated control measures could include prevention information campaigns, restricting access of pet animals (dogs and cats) to rodents, chemotherapy of foxes on local or regional scales, and strategies to minimize contacts between people and foxes.

scholarly journals Mycoplasma agalactiae in Dairy Goat Flocks Bred in State of Ceará in Association with Caprine Arthritis Encephalitis Virus

2018 ◽  
Vol 46 (1) ◽  
pp. 7
Author(s):  
Renato Mesquita Peixoto ◽  
Alice Andrioli ◽  
Raymundo Rizaldo Pinheiro ◽  
Francisco Selmo Fernandes Alves ◽  
Vanderlan Warlington Souza Dos Santos ◽  
...  
Keyword(s):  
Milk Production ◽  
Clinical Signs ◽  
Small Ruminants ◽  
The State ◽  
Encephalitis Virus ◽  
Control Measures ◽  
Dairy Goat ◽  
Economic Losses ◽  
Caprine Arthritis Encephalitis Virus ◽  
Mycoplasma Agalactiae

Background: Contagious agalactia is an infectious disease caused by Mycoplasma agalactiae (M. agalactiae) that occurs in small ruminants leading to productive and economic losses. Due to the similarity of clinical signs presented in Caprine Arthritis Encephalitis (CAE), which is a viral disease, a differential diagnosis is important. Therefore, this study aimed to investigate the presence of anti-Mycoplasma agalactiae antibodies in dairy goat flocks in Ceará State and possible correlation with CAE.Materials, Methods & Results: The research was performed in four mesoregions in Ceará State (Metropolitan Region of Fortaleza-MRF; Northeast Ceará - NeC; North Ceará - NC; Sertões in Ceará - SC), from which 16 productions located in 10 cities with the highest representativeness for goat milk production within the State or mesoregion were sampled. A total of 417 females and 69 males (486 animals) of breeds with dairy production aptitude, pure or crossbreed, maintained in semi-intensive or intensive systems, were tested. Blood serum was obtained by venipuncture of the jugular vein with vacuum pressure syringe followed by centrifugation at 1,500 g for 10min. Antibodies against the caprine arthritis encephalitis virus (CAEV) were detected with micro technique of agarose gel immunodiffusion (AGID) and Western Blot (WB). The anti-Mycoplasma agalactiae antibodies were detected with commercial kit of enzymatic immunoassay (IDEXX Laboratories™). Seroprevalence of M. agalactiae in dairy goat flocks in Ceará State was 0.62% (3/486). From the total of 16 visited productions, 18.75% (3/16) had seropositive animals for M. agalactiae located in MRF, NC and SC mesoregions. CAE was diagnosed in 56.25% (9/16) of productions with AGID and in 81.25% (13/16) with WB. In addition, 5.2% (25/486) of animals were seropositive for CAE with AGID and 16.6% (80/486) with WB. Animals that reacted positive for M. agalactiae were all females of pure breed with milk production aptitude in distinct mesoregions submitted to intensive rearing system. None of these animals was positive in neither test (AGID or WB) for CAE. Therefore, no correlation of results obtained in diagnosis of M. agalactiae by ELISA and CAEV by AGID or WB (P < 0.05) was identified. However, two out of three productions that were positive for M. agalactiae presented positive results for CAEV with frequencies of 10% and 20%.Discussion: Seroprevalence of M. agalactiae in Ceará State was low in comparison with other Brazilian states and even other countries. However, the presence of the pathogen in more than one mesoregion indicates that the disease occurs in different locations within the State. Therefore, flocks in Ceará are susceptible to the infection, which may be favored by uncontrolled commerce that occurs with deficient surveillance, associated with the importation of animals to improve flock genetic quality. The presence of the pathogen in dairy goats may contribute to significant losses in the local production. On the other hand, CAE was diagnosedin nearly all productions proving the dissemination of this lentivirus infection among dairy goat flocks in Ceará State. Although an association between these diseases was not identified, the presence of a retrovirus in the organism may favor co-infection with another micro-organism, promoting the deficiency in the immune system of the host. In conclusion, M. agalactiae is present in different mesoregions of the Ceará State and control measures should be adopted in short term to prevent pathogen dissemination and, consequently reduce economic and productive losses in the local dairy goat production. No correlation was identified between the prevalence of infection by CAEV and M. agalactiae in this study.Keywords: correlation, diagnosis, caprine lentivirus, mycoplasmosis.

scholarly journals Mathematical Modelling and Analysis of Corruption of Morals amongst Adolescents with Control Measures in Kenya

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Nathan Oigo Mokaya ◽  
Haileyesus Tessema Alemmeh ◽  
Cyrus Gitonga Ngari ◽  
Grace Gakii Muthuri
Keyword(s):  
Integrated Control ◽  
Equilibrium Points ◽  
Endemic Equilibrium ◽  
Control Measures ◽  
Asymptotically Stable ◽  
Globally Asymptotically Stable ◽  
Age Appropriate ◽  
Manifold Theory ◽  
Necessary And Sufficient ◽  
Well Posed

In the present paper, we formulate a new mathematical model for the dynamics of moral corruption with comprehensive age-appropriate sexual information and provision of guidance and counselling. The population is subdivided into three (3) different compartments according to their level of information on sexual matters. The model is proved to be both epidemiologically and mathematically well posed. The existence of unique morally corrupt-free and endemic equilibrium points is investigated. The basic reproduction number with respect to morally corrupt-free equilibrium is obtained using next generation matrix approach to monitor the dynamics of corrupt morals and ascertain its level in order to suggest effective intervention strategies to control this problem. The local as well as global asymptotic stability of these equilibrium points is studied. The analysis reveals a globally asymptotically stable morally corrupt-free equilibrium whenever ℛ 0 ≤ 1 and a globally asymptotically stable endemic equilibrium if otherwise. Further analysis, using center manifold theory, shows that the model exhibits forward bifurcation insinuating that the classical epidemiological requirement of ℛ 0 ≤ 1 is necessary and sufficient for elimination of moral corruption. A brief discussion on the graphical results using the available numerical procedures is shown. From numerical simulations, it was ascertain that integrated control strategy is the best approach to fight against moral corruption transmission. Lastly, some key parameters that show significance in the moral corruption elimination from the society are also exploited.

scholarly journals A Critical Assessment on the Indonesian Free Visa Policy: a Neorealist Perspective

2020 ◽  
Vol 22 (1) ◽  
pp. 54
Author(s):  
Andry Indrady
Keyword(s):  
Public Perception ◽  
Economic Benefits ◽  
Critical Assessment ◽  
The State ◽  
Control Measures ◽  
The Other ◽  
Immigration Control ◽  
Other Hand ◽  
Visa Policy ◽  
The Ideal

This paper discusses the implementation of free visa policy in Indonesia from a neorealist perspective. By utilizing the perspective of interdependence sovereignty and domestic sovereignty, this paper critically assesses the implementation of the free visa policy in Indonesia. From the interdependence sovereignty perspective, which elaborates the economic benefits, reciprocal and security approaches the paper finds that the free visa policy in Indonesia has yet to formulate a rational and objective policy that would lead to potential security – order threat. On the other hand, from the domestic sovereignty perspective the paper finds that although the state performs its immigration control capabilities effectively, however the said immigration control measures are implemented at a rather repressive level, instead of at the ideal prevention level. In the end, the paper suggests further research that fills the gap from findings on the specific methods to enhance the state’s capability in managing challenges posed by the free visa policy in more detail, as well as providing a method to measure public perception on the performance of immigration control.

DYNAMICS OF A PREY-DEPENDENT DIGESTIVE MODEL WITH STATE-DEPENDENT IMPULSIVE CONTROL

2012 ◽  
Vol 22 (04) ◽  
pp. 1250092 ◽  
Author(s):  
LINNING QIAN ◽  
QISHAO LU ◽  
JIARU BAI ◽  
ZHAOSHENG FENG
Keyword(s):  
Numerical Simulations ◽  
Analytical Method ◽  
Impulsive Control ◽  
Dynamical Behavior ◽  
Sufficient Conditions ◽  
Period Doubling ◽  
Lambert W Function ◽  
Impulsive Effect ◽  
State Dependent ◽  
Theoretical Results

In this paper, we study the dynamical behavior of a prey-dependent digestive model with a state-dependent impulsive effect. Using the Poincaré map and the Lambert W-function, we find the analytical expression of discrete mapping. Sufficient conditions are established for transcritical bifurcation and period-doubling bifurcation through an analytical method. Exact locations of these bifurcations are explored. Numerical simulations of an example are illustrated which agree well with our theoretical results.

Graphical Hopf Bifurcation of a Filippov HTLV-1 Model With Delay in Cytotoxic T Cells Response

2018 ◽  
Vol 140 (9) ◽  
Author(s):  
Elham Shamsara ◽  
Zahra Afsharnezhad ◽  
Elham Javidmanesh
Keyword(s):  
T Cells ◽  
Hopf Bifurcation ◽  
Periodic Solutions ◽  
Bifurcation Theory ◽  
Cytotoxic T Cells ◽  
Dynamical Behavior ◽  
Bifurcation Theorem ◽  
Nyquist Criterion ◽  
The Stability ◽  
Frequency Domain Approach

In this paper, we present a discontinuous cytotoxic T cells (CTLs) response for HTLV-1. Moreover, a delay parameter for the activation of CTLs is considered. In fact, a system of differential equation with discontinuous right-hand side with delay is defined for HTLV-1. For analyzing the dynamical behavior of the system, graphical Hopf bifurcation is used. In general, Hopf bifurcation theory will help to obtain the periodic solutions of a system as parameter varies. Therefore, by applying the frequency domain approach and analyzing the associated characteristic equation, the existence of Hopf bifurcation by using delay immune response as a bifurcation parameter is determined. The stability of Hopf bifurcation periodic solutions is obtained by the Nyquist criterion and the graphical Hopf bifurcation theorem. At the end, numerical simulations demonstrated our results for the system of HTLV-1.

Rabies Ecology in Bauchi State, Nigeria

2019 ◽  
Vol 2 (1) ◽  
pp. 5-12
Author(s):  
Bolajoko Muhammad-Bashir ◽  
Yakubu Joel Atuman
Keyword(s):  
Risk Factors ◽  
Cost Effective ◽  
The State ◽  
Control Measures ◽  
P Value ◽  
Public Health Implication ◽  
Factors Associated ◽  
Canine Rabies ◽  
Dog Ownership ◽  
Dog Owners

Despite availability of safer and cost-effective treatments and vaccines, rabies is still considered among the most fatal viral zoonotic disease worldwide. The epidemiology of rabies is directly associated with the ecology of the reservoirs which needs better understanding to underpin appropriate control measures. There are only few reported attempts made towards understanding the ecology of dog and rabies cases in Nigeria. Although dogs are tolerated and kept in Bauchi State, the risk factors associated with dog ownership in the state, remain to be studied. This study is aimed at determining the risk factors associated with dog ownership in Bauchi state and to evaluate the degree with which the presence or absence of the identified factors can increase or decrease risk of rabies cases in the state. A questionnaire-based survey was conducted amongst dog owners across the state. Basic descriptive analyses were carried out in Microsoft Excel 2016 and IBM SPSS 21 was used to determine the relative risk (RR) of rabies occurrence in households across the state when exposed to each of the identified risk factors where P-value was set at 0.05. A total of 80 questionnaires were completed and received from the respondents. The calculated RR, revealed that the practice of extensive system of management increases the risk of canine rabies amongst dogs of the state by 80% and knowledge of dog owners about canine rabies reduces the risk of canine rabies by 27%. This study confirmed that dogs are owned and tolerated but poorly managed under extensive management system in Bauchi state with increasing risks of rabies spread due to low vaccination coverage and lack of practical application of knowledge on the dangers of rabies amongst the populace. The public health implication of this situation and the need for concerted efforts for sustainable control of rabies in the state is discussed

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