scholarly journals Analysis of a mosquito life cycle model

2021 ◽  
Vol Volume 34 - 2020 - Special... ◽  
Author(s):  
Albert Kouchéré ◽  
Hamadjam Abboubakar ◽  
Irepran Damakoa
Keyword(s):  
Life Cycle ◽  
Sterile Insect Technique ◽  
Deterministic Model ◽  
Communicable Disease ◽  
Control Measures ◽  
Reproductive Number ◽  
Gonotrophic Cycle ◽  
Complete Life Cycle ◽  
Trivial Equilibrium ◽  
International Audience

International audience The gonotrophic cycle of mosquitoes conditions the frequency of mosquito-human contacts. The knowledge of this important phenomenon in the mosquito life cycle is a fundamental element in the epidemiological analysis of a communicable disease such as mosquito-borne diseases.In this work, we analyze a deterministic model of the complete life cycle of mosquitoes which takes into account the principal phases of female mosquitoes' gonotrophic cycle, and the Sterile Insect technique combined with the use of insecticide as control measures to fight the proliferation of mosquitoes. We compute the corresponding mosquito reproductive number N ∗ and prove the global asymptotic stability of trivial equilibrium. We prove that the model admits two non-trivial equilibria whenever N^{∗} is greater than another threshold, N_c, which the total number of sterile mosquitoes depends on. Numerical simulations, using mosquito parameters of the Aedes species, are carried out to illustrate our analytical results and permit to show that the strategy which consists in combining the sterile insect technique with adulticides, when it is well done, effectively combats the proliferation of mosquitoes.

scholarly journals Dynamics of Tuberculosis (TB) with Drug Resistance to First-Line Treatment and Leaky Vaccination: A Deterministic Modelling Perspective

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Dominic Otoo ◽  
Shaibu Osman ◽  
Stephen Atta Poku ◽  
Elvis Kobina Donkoh
Keyword(s):  
Drug Resistance ◽  
Deterministic Model ◽  
Control Measure ◽  
Equilibrium Points ◽  
Control Measures ◽  
Basic Reproductive Number ◽  
Reproductive Number ◽  
First Line ◽  
Susceptible Population ◽  
Deterministic Modelling

A deterministic model was formulated and employed in the analysis of the dynamics of tuberculosis with a keen emphasis on vaccination and drug resistance as the first line of treatment. It was assumed that some of the susceptible population were vaccinated but with temporal immunity. This is due to the fact that vaccines do not confer permanent immunity. Moreover, part of the infected individual after treatment grows resistance to the drug. Infective immigrants were also considered to be part of the population. The basic reproductive number for the model is estimated using the next-generation matrix method. The equilibrium points of the TB model and their local and global stability were determined. It was established that if the basic reproductive number was less than unity R 0 < 1 , then the disease free equilibrium is stable and unstable if R 0 > 1 . Furthermore, we investigated the optimal prevention, treatment, and vaccination as control measures for the disease. As the objective functional was optimised, there have been a significant reduction in the number of infections and an increase in the number of recovery. The best control measure in combating tuberculosis infections is prevention and vaccination of the susceptible population.

scholarly journals Liquid materials for biomedical research: a highly IT-integrated and automated biobanking solution

2019 ◽  
Vol 43 (6) ◽  
pp. 347-354 ◽  
Author(s):  
Daniela Popp ◽  
Romanus Diekmann ◽  
Lutz Binder ◽  
Abdul R. Asif ◽  
Sara Y. Nussbeck
Keyword(s):  
Life Cycle ◽  
Medical Center ◽  
Research Results ◽  
Long Term Storage ◽  
Medical Centers ◽  
It Systems ◽  
Complete Life Cycle ◽  
The University ◽  
Term Storage

Abstract Various information technology (IT) infrastructures for biobanking, networks of biobanks and biomaterial management are described in the literature. As pre-analytical variables play a major role in the downstream interpretation of clinical as well as research results, their documentation is essential. A description for mainly automated documentation of the complete life-cycle of each biospecimen is lacking so far. Here, the example taken is from the University Medical Center Göttingen (UMG), where the workflow of liquid biomaterials is standardized between the central laboratory and the central biobank. The workflow of liquid biomaterials from sample withdrawal to long-term storage in a biobank was analyzed. Essential data such as time and temperature for processing and freezing can be automatically collected. The proposed solution involves only one major interface between the main IT systems of the laboratory and the biobank. It is key to talk to all the involved stakeholders to ensure a functional and accepted solution. Although IT components differ widely between clinics, the proposed way of documenting the complete life-cycle of each biospecimen can be transferred to other university medical centers. The complete documentation of the life-cycle of each biospecimen ensures a good interpretability of downstream routine as well as research results.

scholarly journals Parameter-dependent transmission dynamics and optimal control of foot and mouth disease in a contaminated environment

2019 ◽  
Vol 27 (1) ◽  
Author(s):  
Francis Mugabi ◽  
Joseph Mugisha ◽  
Betty Nannyonga ◽  
Henry Kasumba ◽  
Margaret Tusiime
Keyword(s):  
Optimal Control ◽  
Deterministic Model ◽  
Foot And Mouth Disease ◽  
Decay Rates ◽  
Mouth Disease ◽  
Control Measures ◽  
Transmission Dynamics ◽  
Optimality System ◽  
Foot And Mouth ◽  
Environmental Decontamination

AbstractThe problem of foot and mouth disease (FMD) is of serious concern to the livestock sector in most nations, especially in developing countries. This paper presents the formulation and analysis of a deterministic model for the transmission dynamics of FMD through a contaminated environment. It is shown that the key parameters that drive the transmission of FMD in a contaminated environment are the shedding, transmission, and decay rates of the virus. Using numerical results, it is depicted that the host-to-host route is more severe than the environmental-to-host route. The model is then transformed into an optimal control problem. Using the Pontryagin’s Maximum Principle, the optimality system is determined. Utilizing a gradient type algorithm with projection, the optimality system is solved for three control strategies: optimal use of vaccination, environmental decontamination, and a combination of vaccination and environmental decontamination. Results show that a combination of vaccination and environmental decontamination is the most optimal strategy. These results indicate that if vaccination and environmental decontamination are used optimally during an outbreak, then FMD transmission can be controlled. Future studies focusing on the control measures for the transmission of FMD in a contaminated environment should aim at reducing the transmission and the shedding rates, while increasing the decay rate.

On the relevance of genotoxicity for fish populations II: genotoxic effects in zebrafish (Danio rerio) exposed to 4-nitroquinoline-1-oxide in a complete life-cycle test

2004 ◽  
Vol 68 (1) ◽  
pp. 27-37 ◽  
Author(s):  
Markus Diekmann ◽  
Petra Waldmann ◽  
Andreas Schnurstein ◽  
Tamara Grummt ◽  
Thomas Braunbeck ◽  
...  
Keyword(s):  
Life Cycle ◽  
Danio Rerio ◽  
Fish Populations ◽  
Genotoxic Effects ◽  
Complete Life Cycle

The cattle lice of Great Britain Part I. Biology, with special reference to Haematopinus eurysternus

Parasitology ◽  
1941 ◽  
Vol 33 (3) ◽  
pp. 331-342 ◽  
Author(s):  
H. J. Craufurd-Benson
Keyword(s):  
Life Cycle ◽  
Great Britain ◽  
Special Reference ◽  
Incubation Period ◽  
Air Temperature ◽  
Average Length ◽  
Starvation Period ◽  
Complete Life Cycle ◽  
Threshold Of Development ◽  
Minimum Air Temperature

1. The geographical distribution of cattle lice in Britain is recorded in detail. Bovicola bovis is the commonest and most widely distributed species in Britain.2. The incubation period for the eggs was found to be: Haematopinus eurysternus, 9–19 days (av. 12); Bovicola bovis, 7–10 days (av. 8); Linognathus vitula, 10–13 days; Solenopotes capillatus, 10–13 days. With eggs of H. eurysternus it was found that the higher the minimum air temperature the shorter was the incubation period.3. In H. eurysternus the average length of the instars was: 1st, 4 days; 2nd, 4 days; 3rd, 4 days; pre-oviposition period, 3–4 days. The average time for the complete life cycle, egg to egg, was 28 days.4. The maximum longevity of H. eurysternus on the host was: males, 10 days; females, 16 days. No males or females of H. eurysternus survived a starvation period of 72 hr. at 20° C. and R.H. 70 or 0–10° C. and R.H. 70–85; but some nymphs survived this period at 20° C. and R.H. 70, but none survived 96 hr. starvation.5. The maximum number of eggs recorded for one female was 24; and eggs were laid at the rate of 1–4 a day.6. The threshold of development of the eggs of H. eurysternus appears to be about 27·5° C.

Public Health Control Measures in Response to Global Pandemics and Drug Resistance

2015 ◽  
Vol 43 (S2) ◽  
pp. 49-56
Author(s):  
Polly J. Price
Keyword(s):  
Public Health ◽  
Communicable Disease ◽  
International Health ◽  
Control Measures ◽  
World Health ◽  
Legal Authority ◽  
List Type ◽  
Resistant Disease ◽  
Global Pandemic ◽  
Health Organization

These teaching materials explore the specific powers of governments to implement control measures in response to communicable disease, in two different contexts:The first context concerns global pandemic diseases. Relevant legal authority includes international law, World Health Organization governance and the International Health Regulations, and regulatory authority of nations.The second context is centered on U.S. law and concerns control measures for drug-resistant disease, using tuberculosis as an example. In both contexts, international and domestic, the point is to understand legal authority to address public health emergencies.

MODELING THE IMPACT OF VOLUNTARY TESTING AND TREATMENT ON TUBERCULOSIS TRANSMISSION DYNAMICS

2012 ◽  
Vol 05 (04) ◽  
pp. 1250029 ◽  
Author(s):  
S. MUSHAYABASA ◽  
C. P. BHUNU
Keyword(s):  
Deterministic Model ◽  
Reproduction Number ◽  
Positive Impact ◽  
Transmission Dynamics ◽  
Effective Control ◽  
Reproductive Number ◽  
Voluntary Testing ◽  
Manifold Theory ◽  
The Impact ◽  
Disease Free

A deterministic model for evaluating the impact of voluntary testing and treatment on the transmission dynamics of tuberculosis is formulated and analyzed. The epidemiological threshold, known as the reproduction number is derived and qualitatively used to investigate the existence and stability of the associated equilibrium of the model system. The disease-free equilibrium is shown to be locally-asymptotically stable when the reproductive number is less than unity, and unstable if this threshold parameter exceeds unity. It is shown, using the Centre Manifold theory, that the model undergoes the phenomenon of backward bifurcation where the stable disease-free equilibrium co-exists with a stable endemic equilibrium when the associated reproduction number is less than unity. The analysis of the reproduction number suggests that voluntary tuberculosis testing and treatment may lead to effective control of tuberculosis. Furthermore, numerical simulations support the fact that an increase voluntary tuberculosis testing and treatment have a positive impact in controlling the spread of tuberculosis in the community.

scholarly journals Environmental Sustainability of Building Retrofit through Vertical Greening Systems: A Life-Cycle Approach

2021 ◽  
Vol 13 (9) ◽  
pp. 4886
Author(s):  
Katia Perini ◽  
Fabio Magrassi ◽  
Andrea Giachetta ◽  
Luca Moreschi ◽  
Michela Gallo ◽  
...  
Keyword(s):  
Life Cycle ◽  
Energy Consumption ◽  
Environmental Sustainability ◽  
Urban Areas ◽  
Baseline Scenario ◽  
Life Cycle Approach ◽  
Complete Life Cycle ◽  
Wide Range ◽  
Use Phase ◽  
Vertical Greening

Urban greening provides a wide range of ecosystem services to address the main challenges of urban areas, e.g., carbon sequestration, evapotranspiration and shade, thermal insulation, and pollution control. This study evaluates the environmental sustainability of a vertical greening system (VGS) built in 2014 in Italy, for which extensive monitoring activities were implemented. The life-cycle assessment methodology was applied to quantify the water–energy–climate nexus of the VGS for 1 m2 of the building’s wall surface. Six different scenarios were modelled according to three different end-of-life scenarios and two different useful lifetime scenarios (10 and 25 years). The environmental impact of global-warming potential and generated energy consumption during the use phase in the VGS scenarios were reduced by 56% in relation to the baseline scenario (wall without VGS), and showed improved environmental performance throughout the complete life cycle. However, the water-scarcity index (WSI) of the VGS scenarios increased by 42%. This study confirms that the installation of VGSs offers a relevant environmental benefit in terms of greenhouse-gas emissions and energy consumption; however, increased water consumption in the use phase may limit the large-scale application of VGSs.

Environmental Assessment of Products over the Complete Life Cycle

2021 ◽  
Vol 41 (8) ◽  
pp. 772-774
Author(s):  
S. I. Gorbachev ◽  
A. E. Sorokin ◽  
S. N. Bulychev
Keyword(s):  
Life Cycle ◽  
Environmental Assessment ◽  
Complete Life Cycle
Sign in / Sign up

Export Citation Format

Share Document