scholarly journals Dynamical Models of Interactions between Herds Forage and Water Resources in Sahelian Region

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Jean Jules Tewa ◽  
Alassane Bah ◽  
Suares Clovis Oukouomi Noutchie
Keyword(s):  
Drinking Water ◽  
Water Resources ◽  
Mathematical Models ◽  
Optimal Foraging ◽  
Consumer Behaviour ◽  
High Variability ◽  
Dynamical Models ◽  
Predator Prey ◽  
Abrupt Changes ◽  
Predator Prey Models

Optimal foraging is one of the capital topics nowadays in Sahelian region. The vast majority of feed consumed by ruminants in Sahelian region is still formed by natural pastures. Pastoral constraints are the high variability of available forage and drinking water in space and especially in time (highly seasonal, interannual variability) and the scarcity of water resources. The mobility is the main functional and opportunistic adaptation to these constraints. Our goal in this paper is to formalize two dynamical models for interactions between a herd of domesticate animals, forage resources, and water resources inside a given Sahelian area, in order to confirm, explain, and predict by mathematical models some observations about pastoralism in Sahelian region. These models in some contexts can be similar to predator-prey models as forage and water resources can be considered as preys and herd’s animals as predators. These models exhibit very rich dynamics, since it predicts abrupt changes in consumer behaviour and disponibility of forage or water resources. The dynamics exhibits a possible coexistence between herd, resources, and water with alternative peaks in their trajectories.

Drinking water quality and protection of resources

2010 ◽  
Vol 1 (1-2) ◽  
pp. 51-54
Author(s):  
J. Fettig
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Water Resources ◽  
River Water ◽  
Spring Water ◽  
Public Water Supply ◽  
Legal Requirements ◽  
Reservoir Water ◽  
Water Lake ◽  
Treatment Step

Abstract The structure of public water supply in Germany and the water resources used are briefly described. An overview over the legal requirements for drinking water is given, and the sources for contaminants are outlined. Then the multiple-barrier approach is discussed with respect to the resources groundwater and spring water, lake and reservoir water, and river water. Examples for treatment schemes are given and the principle of subsurface transport of river water as a first treatment step is described.

The global dynamics of stochastic Holling type II predator-prey models with non constant mortality rate

Filomat ◽  
2017 ◽  
Vol 31 (18) ◽  
pp. 5811-5825
Author(s):  
Xinhong Zhang
Keyword(s):  
Mortality Rate ◽  
Stochastic Model ◽  
Sufficient Conditions ◽  
Positive Periodic Solution ◽  
Global Dynamics ◽  
Type Ii ◽  
Predator Prey ◽  
Persistence In The Mean ◽  
The Mean ◽  
Predator Prey Models

In this paper we study the global dynamics of stochastic predator-prey models with non constant mortality rate and Holling type II response. Concretely, we establish sufficient conditions for the extinction and persistence in the mean of autonomous stochastic model and obtain a critical value between them. Then by constructing appropriate Lyapunov functions, we prove that there is a nontrivial positive periodic solution to the non-autonomous stochastic model. Finally, numerical examples are introduced to illustrate the results developed.

Plugging Space into Predator-Prey Models: An Empirical Approach

2006 ◽  
Vol 167 (2) ◽  
pp. 246
Author(s):  
Bergström ◽  
Englund ◽  
Leonardsson
Keyword(s):  
Empirical Approach ◽  
Predator Prey ◽  
Predator Prey Models

scholarly journals Technologies Developing in Heavy Metals’ Removal from Water

Water ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 860
Author(s):  
Konstantinos Simeonidis ◽  
Manassis Mitrakas
Keyword(s):  
Heavy Metals ◽  
Drinking Water ◽  
Water Resources ◽  
Human Health ◽  
Urban Wastewater ◽  
Heavy Metals Removal ◽  
Metals Removal ◽  
Drinking Water Resources

Elevated concentrations of heavy metals in drinking water resources and industrial or urban wastewater pose a serious threat to human health and the equilibrium of ecosystems [...]

Ensuring access to water in an emergency context: Towards an overexploitation and contamination of water resources?

2021 ◽  
pp. 096466392110316
Author(s):  
Chloé Nicolas-Artero
Keyword(s):  
Drinking Water ◽  
Water Resources ◽  
Qualitative Methods ◽  
Water Scarcity ◽  
Water Rights ◽  
Environmental Crisis ◽  
Supply Network ◽  
Mining Pollution ◽  
Access To Water

This article shows how geo-legal devices created to deal with environmental crisis situations make access to drinking water precarious and contribute to the overexploitation and contamination of water resources. It relies on qualitative methods (interviews, observations, archive work) to identify and analyse two geo-legal devices applied in the case study of the Elqui Valley in Chile. The first device, generated by the Declaration of Water Scarcity, allows private sanitation companies to concentrate water rights and extend their supply network, thus producing an overexploitation of water resources. In the context of mining pollution, the second device is structured around the implementation of the Rural Drinking Water Programme and the distribution of water by tankers, which has made access to drinking water more precarious for the population and does nothing to prevent pollution.

scholarly journals Functional genomics study of Pseudomonas putida to determine traits associated with avoidance of a myxobacterial predator

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shukria Akbar ◽  
D. Cole Stevens
Keyword(s):  
Pseudomonas Putida ◽  
Bacterial Communities ◽  
Predator Avoidance ◽  
Phenotypic Diversity ◽  
Myxococcus Xanthus ◽  
Predator Prey ◽  
Mucoid Conversion ◽  
Small Colony ◽  
Predator Prey Models ◽  
Insight Into

AbstractPredation contributes to the structure and diversity of microbial communities. Predatory myxobacteria are ubiquitous to a variety of microbial habitats and capably consume a broad diversity of microbial prey. Predator–prey experiments utilizing myxobacteria have provided details into predatory mechanisms and features that facilitate consumption of prey. However, prey resistance to myxobacterial predation remains underexplored, and prey resistances have been observed exclusively from predator–prey experiments that included the model myxobacterium Myxococcus xanthus. Utilizing a predator–prey pairing that instead included the myxobacterium, Cystobacter ferrugineus, with Pseudomonas putida as prey, we observed surviving phenotypes capable of eluding predation. Comparative transcriptomics between P. putida unexposed to C. ferrugineus and the survivor phenotype suggested that increased expression of efflux pumps, genes associated with mucoid conversion, and various membrane features contribute to predator avoidance. Unique features observed from the survivor phenotype when compared to the parent P. putida include small colony variation, efflux-mediated antibiotic resistance, phenazine-1-carboxylic acid production, and increased mucoid conversion. These results demonstrate the utility of myxobacterial predator–prey models and provide insight into prey resistances in response to predatory stress that might contribute to the phenotypic diversity and structure of bacterial communities.

scholarly journals Applying predator-prey theory to modelling immune-mediated, within-host interspecific parasite interactions

Parasitology ◽  
2010 ◽  
Vol 137 (6) ◽  
pp. 1027-1038 ◽  
Author(s):  
ANDY FENTON ◽  
SARAH E. PERKINS
Keyword(s):  
Functional Response ◽  
Interspecific Interactions ◽  
Parasite Load ◽  
Multiple Infections ◽  
Functional Responses ◽  
Predator Prey ◽  
Immune Activity ◽  
Parasite Communities ◽  
Immune Mediated ◽  
Predator Prey Models

SUMMARYPredator-prey models are often applied to the interactions between host immunity and parasite growth. A key component of these models is the immune system's functional response, the relationship between immune activity and parasite load. Typically, models assume a simple, linear functional response. However, based on the mechanistic interactions between parasites and immunity we argue that alternative forms are more likely, resulting in very different predictions, ranging from parasite exclusion to chronic infection. By extending this framework to consider multiple infections we show that combinations of parasites eliciting different functional responses greatly affect community stability. Indeed, some parasites may stabilize other species that would be unstable if infecting alone. Therefore hosts' immune systems may have adapted to tolerate certain parasites, rather than clear them and risk erratic parasite dynamics. We urge for more detailed empirical information relating immune activity to parasite load to enable better predictions of the dynamic consequences of immune-mediated interspecific interactions within parasite communities.

scholarly journals Evaluation of Human Enteric Viruses in Surface Water and Drinking Water Resources in Southern Ghana

2011 ◽  
Vol 84 (1) ◽  
pp. 20-29 ◽  
Author(s):  
Kristen E. Gibson ◽  
Yayi Guo ◽  
James T. Schissler ◽  
Melissa C. Opryszko ◽  
Kellogg J. Schwab
Keyword(s):  
Drinking Water ◽  
Surface Water ◽  
Water Resources ◽  
Enteric Viruses ◽  
Drinking Water Resources ◽  
Human Enteric Viruses ◽  
Southern Ghana
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