scholarly journals Environment as a Complex System: the Malaria Decrease in the Legal Amazonia (LA) Case

2018 ◽  
pp. 569-584
Author(s):  
Arlindo Kamimura ◽  
Geraldo Burani ◽  
Ildo Sauer

In Brazil, malaria is an endemic disease present mainly in the Legal Amazon (LA), which accounts for more than 99% of the country´s cases. In 2000 the number of new cases of malaria in LA was 613.3 thousand, decreasing to 265.4 thousand cases in 2011, thus dropping by 56.7%. The malaria system behavior depends on many interrelated variables and environmental factors, constituting itself in a complex, non-linear dynamical living system, whose resulting dynamics have as main characteristics the unpredictability and the extreme sensitivity to the initial conditions. This paper is an investigation of a possible additional cause for the huge decrease in cases of malaria in the states of LA, in addition to the already recognized governmental effort to malaria disease control. The hypothesis adopted is that all domestic animals (exception fowls) compete with the man in the position of hosts feeding of the mosquito Anopheles, vector-borne of the disease.

2018 ◽  
Vol 4 (4) ◽  
pp. 513
Author(s):  
Rakhshan .

Mosquitoes are vectors of many pathogens which causes serious human diseases like Malaria, Filariasis, Japanese encephalitis, Dengue fever, Chikungunya, Yellow fever and Zika virus which constitute a major public health problem globally. Mosquito borne diseases cause high level of economic impact all over the world and result in millions of death every year. They infect around 700,000,000 people annually worldwide and 40,000,000 only in India. The continuous use of synthetic pesticides to control vector mosquitoes has caused physiological resistance, toxic effect on human health, environmental pollution and addition to these, its adverse effects can be observed on non-target organisms. Synthetic chemical pesticides have been proved to be effective, but overall in last 5 decades indiscriminate use of synthetic pesticides against vector borne disease control have originated several ecological issues due to their residual accumulation and development of resistance in target vectors and their chronic effects.


2021 ◽  
Vol 11 (13) ◽  
pp. 5944
Author(s):  
Gunwoo Lee ◽  
Jongpil Jeong

Semiconductor equipment consists of a complex system in which numerous components are organically connected and controlled by many controllers. EventLog records all the information available during system processes. Because the EventLog records system runtime information so developers and engineers can understand system behavior and identify possible problems, it is essential for engineers to troubleshoot and maintain it. However, because the EventLog is text-based, complex to view, and stores a large quantity of information, the file size is very large. For long processes, the log file comprises several files, and engineers must look through many files, which makes it difficult to find the cause of the problem and therefore, a long time is required for the analysis. In addition, if the file size of the EventLog becomes large, the EventLog cannot be saved for a prolonged period because it uses a large amount of hard disk space on the CTC computer. In this paper, we propose a method to reduce the size of existing text-based log files. Our proposed method saves and visualizes text-based EventLogs in DB, making it easier to approach problems than the existing text-based analysis. We will confirm the possibility and propose a method that makes it easier for engineers to analyze log files.


2001 ◽  
Vol 08 (02) ◽  
pp. 137-146 ◽  
Author(s):  
Janusz Szczepański ◽  
Zbigniew Kotulski

Pseudorandom number generators are used in many areas of contemporary technology such as modern communication systems and engineering applications. In recent years a new approach to secure transmission of information based on the application of the theory of chaotic dynamical systems has been developed. In this paper we present a method of generating pseudorandom numbers applying discrete chaotic dynamical systems. The idea of construction of chaotic pseudorandom number generators (CPRNG) intrinsically exploits the property of extreme sensitivity of trajectories to small changes of initial conditions, since the generated bits are associated with trajectories in an appropriate way. To ensure good statistical properties of the CPRBG (which determine its quality) we assume that the dynamical systems used are also ergodic or preferably mixing. Finally, since chaotic systems often appear in realistic physical situations, we suggest a physical model of CPRNG.


PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0257958
Author(s):  
Miguel Navascués ◽  
Costantino Budroni ◽  
Yelena Guryanova

In the context of epidemiology, policies for disease control are often devised through a mixture of intuition and brute-force, whereby the set of logically conceivable policies is narrowed down to a small family described by a few parameters, following which linearization or grid search is used to identify the optimal policy within the set. This scheme runs the risk of leaving out more complex (and perhaps counter-intuitive) policies for disease control that could tackle the disease more efficiently. In this article, we use techniques from convex optimization theory and machine learning to conduct optimizations over disease policies described by hundreds of parameters. In contrast to past approaches for policy optimization based on control theory, our framework can deal with arbitrary uncertainties on the initial conditions and model parameters controlling the spread of the disease, and stochastic models. In addition, our methods allow for optimization over policies which remain constant over weekly periods, specified by either continuous or discrete (e.g.: lockdown on/off) government measures. We illustrate our approach by minimizing the total time required to eradicate COVID-19 within the Susceptible-Exposed-Infected-Recovered (SEIR) model proposed by Kissler et al. (March, 2020).


2021 ◽  
Vol 53 (5) ◽  
Author(s):  
Hend H. A. M. Abdullah ◽  
Mohamed K. Elbayoumy ◽  
Ahmad M. Allam ◽  
Heba M. Ashry ◽  
Sobhy Abdel-Shafy

Mathematics ◽  
2019 ◽  
Vol 7 (7) ◽  
pp. 602
Author(s):  
Bruno Carbonaro ◽  
Marco Menale

The paper deals with the problem of continuous dependence on initial data of solutions to the equation describing the evolution of a complex system in the presence of an external force acting on the system and of a thermostat, simply identified with the condition that the second order moment of the activity variable (see Section 1) is a constant. We are able to prove that these solutions are stable with respect to the initial conditions in the Hadamard’s sense. In this connection, two remarks spontaneously arise and must be carefully considered: first, one could complain the lack of information about the “distance” between solutions at any time t ∈ [ 0 , + ∞ ) ; next, one cannot expect any more complete information without taking into account the possible distribution of the transition probabiliy densities and the interaction rates (see Section 1 again). This work must be viewed as a first step of a research which will require many more steps to give a sufficiently complete picture of the relations between solutions (see Section 5).


2019 ◽  
Vol 29 (Supplement_4) ◽  
Author(s):  
A Hounsa ◽  
D Yao ◽  
A R Attia ◽  
M Gokpéya ◽  
K J Sackou ◽  
...  

Abstract Background In malaria-endemic areas, asymptomatic carriers are a reservoir of parasites that contribue to the persistence of malaria transmission. In Côte d’Ivoire, this situation is poorly documented. The objective of our study was to assess the frequency and socio-environmental factors associated with asymptomatic malaria in the town of Assuefry, located in the northeast of Côte d’Ivoire, a region where malaria prevalence remains high. Methods A cross-sectional study in two stages was conducted from October to December 2018, first at the Urban Health Center (UHC) in Assuefry and then in the households. The sample size calculated for patients was 162 extrapolated to 201 people. All persons received at the CSU who had clinical symptoms of malaria and a positive Rapid Diagnostic Test (RDT) were included. In the households of these index subjects, a follow-up survey allowed active RDT screening for malaria among all household members with no clinical signs of malaria. The socio-environmental factors taken into account were: the area of residence (urban or peri-urban), domestic animals husbandry, water storage at home, nearby garbage dump, wastewater collection and disposal system, type of housing and number of people in the household. Results The frequency of asymptomatic malaria was 341 (38.8%) out of 879 household members visited. Both female and male gender was concerned (51% vs. 49%). The 5 to 25 years old group concentrated nearly 82% of all cases. Only domestic animals husbandry was associated with asymptomatic malaria at the household level (p = 0.021). Conclusions The high frequency of asymptomatic malaria found in this study is a challenge for the National Malaria Control Program in Côte d’Ivoire. This should be taken into account while organizing control strategies. Key messages The frequency of asymptomatic malaria in Côte d’Ivoire is high. Control strategies must take into account in the guidelines the challenges of detecting and treating asymptomatic malaria. For the judicious use of antimalarial drugs, any subject with a positive RDT without clinical signs of malaria should receive a ‘Drop - Thick’ before treatment.


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