scholarly journals Resource-Driven Encounters and the Induction of Disease Among Consumers

2016 ◽  
Author(s):  
Rebecca K. Borchering ◽  
Steve E. Bellan ◽  
Jason M. Flynn ◽  
Juliet R.C. Pulliam ◽  
Scott A. McKinley
Keyword(s):  
National Park ◽  
Interaction Model ◽  
Spatially Explicit ◽  
Encounter Rate ◽  
Model Parameters ◽  
Expected Number ◽  
Spatially Explicit Model ◽  
Consumer Population ◽  
Using Data ◽  
The Relationship

AbstractSubmitted Manuscript 2016. Territorial animals share a variety of common resources, which can be a major driver of conspecific encounter rates. We examine how changes in resource availability influence the rate of encounters among individuals in a consumer population by implementing a spatially explicit model for resource visitation behavior by consumers. Using data from 2009 and 2010 in Etosha National Park, we verify our model's prediction that there is a saturation effect in the expected number of jackals that visit a given carcass site as carcasses become abundant. However, this does not directly imply that the overall resource-driven encounter rate among jackals decreases. This is because the increase in available carcasses is accompanied by an increase in the number of jackals that detect and potentially visit carcasses. Using simulations and mathematical analysis of our consumer-resource interaction model, we characterize key features of the relationship between resource-driven encounter rate and model parameters. These results are used to investigate a standing hypothesis that the outbreak of a fatal disease among zebras can potentially lead to an outbreak of an entirely different disease in the jackal population, a process we refer to as indirect induction of disease.

scholarly journals Spatial interplay of plant competition and consumer foraging mediate plant coexistence and drive the invasion ratchet

2010 ◽  
Vol 277 (1698) ◽  
pp. 3307-3315 ◽  
Author(s):  
John L. Orrock ◽  
Marissa L. Baskett ◽  
Robert D. Holt
Keyword(s):  
Plant Communities ◽  
Consumer Behaviour ◽  
Stable Equilibrium ◽  
Plant Competition ◽  
Apparent Competition ◽  
Spatially Explicit ◽  
Initial Population ◽  
Spatially Explicit Model ◽  
The Relationship ◽  
Plant Coexistence

Indirect effects may play an important role in structuring plant communities. Using a spatially explicit model of consumer foraging and plant competition, we demonstrate how the relationship between the spatial area over which plants compete and the spatial scale of consumer behaviour can determine the outcome of competition when one plant species provides a refuge for mobile consumers (i.e. refuge-mediated apparent competition). Once an initial population of the invader is established, complete invasion may be inevitable because of an ever-advancing invasion front ratchets forward driven by a feeding front of mobile consumers. Because the spatial extent of apparent competition determines the area available for colonization, consumers may also dictate the rate at which an invasion occurs. We find that, as long as refuge-mediated apparent competition is sufficiently localized, invasion is possible even in systems characterized by low overall levels of consumer pressure. Moreover, we show that a stable equilibrium can result in which both resident and invading plants coexist, suggesting that spatial heterogeneity created by refuge-mediated apparent competition may be important in mediating coexistence in plant communities. The spatial interplay of consumer behaviour and plant competition may be an underappreciated mechanism affecting the composition, diversity and spatial pattern of plant communities.

scholarly journals Resource-driven encounters among consumers and implications for the spread of infectious disease

2017 ◽  
Vol 14 (135) ◽  
pp. 20170555 ◽  
Author(s):  
Rebecca K. Borchering ◽  
Steve E. Bellan ◽  
Jason M. Flynn ◽  
Juliet R. C. Pulliam ◽  
Scott A. McKinley
Keyword(s):  
Resource Availability ◽  
Food Resource ◽  
Maximum Distance ◽  
Spatially Explicit ◽  
Encounter Rate ◽  
Supplemental Food ◽  
Resource Density ◽  
Critical Resource ◽  
The Relationship ◽  
Theoretical Results

Animals share a variety of common resources, which can be a major driver of conspecific encounter rates. In this work, we implement a spatially explicit mathematical model for resource visitation behaviour in order to examine how changes in resource availability can influence the rate of encounters among consumers. Using simulations and asymptotic analysis, we demonstrate that, under a reasonable set of assumptions, the relationship between resource availability and consumer conspecific encounters is not monotonic. We characterize how the maximum encounter rate and associated critical resource density depend on system parameters like consumer density and the maximum distance from which consumers can detect and respond to resources. The assumptions underlying our theoretical model and analysis are motivated by observations of large aggregations of black-backed jackals at carcasses generated by seasonal outbreaks of anthrax among herbivores in Etosha National Park, Namibia. As non-obligate scavengers, black-backed jackals use carcasses as a supplemental food resource when they are available. While jackals do not appear to acquire disease from ingesting anthrax carcasses, changes in their movement patterns in response to changes in carcass abundance do alter jackals' conspecific encounter rate in ways that may affect the transmission dynamics of other diseases, such as rabies. Our theoretical results provide a method to quantify and analyse the hypothesis that the outbreak of a fatal disease among herbivores can potentially facilitate outbreaks of an entirely different disease among jackals. By analysing carcass visitation data, we find support for our model's prediction that the number of conspecific encounters at resource sites decreases with additional increases in resource availability. Whether or not this site-dependent effect translates to an overall decrease in encounters depends, unexpectedly, on the relationship between the maximum distance of detection and the resource density.

Factors affecting gray wolf (Canis lupus) encounter rate with elk (Cervus elaphus) in Yellowstone National Park

2018 ◽  
Vol 96 (9) ◽  
pp. 1032-1042 ◽  
Author(s):  
H.W. Martin ◽  
L.D. Mech ◽  
J. Fieberg ◽  
M.C. Metz ◽  
D.R. MacNulty ◽  
...  
Keyword(s):  
Cervus Elaphus ◽  
Canis Lupus ◽  
Yellowstone National Park ◽  
Snow Depth ◽  
National Park ◽  
Encounter Rate ◽  
Encounter Rates ◽  
Hunting Success ◽  
Kill Rate ◽  
The Relationship

Despite encounter rates being a key component of kill rate, few studies of large carnivore predation have quantified encounter rates with prey, the factors that influence them, and the relationship between encounter rate and kill rate. The study’s primary motivation was to determine the relationship between prey density and encounter rate in understanding the mechanism behind the functional response. Elk (Cervus elaphus Linnaeus, 1758) population decline and variable weather in northern Yellowstone National Park provided an opportunity to examine how these factors influenced wolf (Canis lupus Linnaeus, 1758) encounter rates with elk. We explored how factors associated with wolf kill rate and encounter rate in other systems (season, elk density, elk group density, average elk group size, snow depth, wolf pack size, and territory size) influenced wolf–elk encounter rate in Yellowstone National Park. Elk density was the only factor significantly correlated with wolf–elk encounter rate, and we found a nonlinear density-dependent relationship that may be a mechanism for a functional response in this system. Encounter rate was correlated with number of elk killed during early winter but not late winter. Weak effects of snow depth and elk group size on encounter rate suggest that these factors influence kill rate via hunting success because kill rate is the product of hunting success and encounter rate.

A spatially explicit model of leaf litter fall in hemlock–hardwood forests

1996 ◽  
Vol 26 (11) ◽  
pp. 1905-1913 ◽  
Author(s):  
James B. Ferrari ◽  
Shinya Sugita
Keyword(s):  
Leaf Litter ◽  
Hardwood Forests ◽  
Likelihood Method ◽  
Spatially Explicit ◽  
Model Parameters ◽  
Leaf Fall ◽  
Litter Fall ◽  
Explicit Model ◽  
Spatially Explicit Model ◽  
Isolated Trees

A spatially explicit model of leaf litter fall was developed for hemlock–hardwood forests using litter-trap data from mapped forest plots and from isolated trees. The model assumes that litter declines exponentially with distance, as shown by the litter traps from isolated trees, and that a variable allometric equation describes the relationship of DBH to foliage biomass. Model parameters were estimated by a maximum likelihood method using field data from one mapped plot and then tested on a second plot. Predicted leaf fall of sugar maple (Acersaccharum Marsh.), yellow birch (Betulaalleghaniensis Britton), basswood (Tiliaamericana L.), and eastern hemlock (Tsugacanadensis (L.) Carrière) was consistent with the leaf fall measured in 20 traps (r = 0.86, 0.77, 0.95, 0.92, respectively). Data from 100 paired litter traps show the similarity of litter fall at sites 2.7 m apart; trap contents in two successive autumns were also comparable. The model results show that hemlock has the narrowest leaf-fall shadow, while basswood has the broadest. The average radius within which 90% of the leaf litter fall to a trap originates is 17.1 m. A litter fall model can be used to predict nutrient inputs to the forest floor based on a stem map, and strengthens links between population and ecosystem ecology.

Accent Policy and Accent Modification Enterprises as Potential Indicators of Intercultural Power Relations: A Call for an Updated Research Agenda

2013 ◽  
Vol 3 (1) ◽  
pp. 22-33 ◽  
Author(s):  
Brynne D. Ovalle ◽  
Rahul Chakraborty
Keyword(s):  
International Relations ◽  
Identity Construction ◽  
Social Theory ◽  
Power Relations ◽  
Linguistic Diversity ◽  
Cultural Organization ◽  
Using Data ◽  
The Individual ◽  
The Impact ◽  
The Relationship

This article has two purposes: (a) to examine the relationship between intercultural power relations and the widespread practice of accent discrimination and (b) to underscore the ramifications of accent discrimination both for the individual and for global society as a whole. First, authors review social theory regarding language and group identity construction, and then go on to integrate more current studies linking accent bias to sociocultural variables. Authors discuss three examples of intercultural accent discrimination in order to illustrate how this link manifests itself in the broader context of international relations (i.e., how accent discrimination is generated in situations of unequal power) and, using a review of current research, assess the consequences of accent discrimination for the individual. Finally, the article highlights the impact that linguistic discrimination is having on linguistic diversity globally, partially using data from the United Nations Educational, Scientific and Cultural Organization (UNESCO) and partially by offering a potential context for interpreting the emergence of practices that seek to reduce or modify speaker accents.

Workplace Ostracism and Its Negative Outcomes

2016 ◽  
Vol 15 (4) ◽  
pp. 143-151 ◽  
Author(s):  
Xiaoming Zheng ◽  
Jun Yang ◽  
Hang-Yue Ngo ◽  
Xiao-Yu Liu ◽  
Wengjuan Jiao
Keyword(s):  
Affective Commitment ◽  
Psychological Capital ◽  
Intention To Leave ◽  
Future Research ◽  
Conservation Of Resources ◽  
Negative Consequences ◽  
Negative Outcomes ◽  
Workplace Ostracism ◽  
Using Data ◽  
The Relationship

Abstract. Workplace ostracism, conceived as to being ignored or excluded by others, has attracted the attention of researchers in recent years. One essential topic in this area is how to reduce or even eliminate the negative consequences of workplace ostracism. Based on conservation of resources (COR) theory, the current study assesses the relationship between workplace ostracism and its negative outcomes, as well as the moderating role played by psychological capital, using data collected from 256 employees in three companies in the northern part of China. The study yields two important findings: (1) workplace ostracism is positively related to intention to leave and (2) psychological capital moderates the effect of workplace ostracism on affective commitment and intention to leave. This paper concludes by discussing the implications of these findings for organizations and employees, along with recommendations for future research.

Editor’s Pick: Regulatory and Ethical Issues in the New Era of Radiomics and Radiogenomics

EMJ Radiology ◽  
2020 ◽  
Author(s):  
Filippo Pesapane
Keyword(s):  
Ethical Issues ◽  
Medical Images ◽  
Practical Significance ◽  
Innovative Technology ◽  
New Era ◽  
Naked Eye ◽  
Disease Characteristics ◽  
The Future ◽  
Using Data ◽  
The Relationship

Radiomics is a science that investigates a large number of features from medical images using data-characterisation algorithms, with the aim to analyse disease characteristics that are indistinguishable to the naked eye. Radiogenomics attempts to establish and examine the relationship between tumour genomic characteristics and their radiologic appearance. Although there is certainly a lot to learn from these relationships, one could ask the question: what is the practical significance of radiogenomic discoveries? This increasing interest in such applications inevitably raises numerous legal and ethical questions. In an environment such as the technology field, which changes quickly and unpredictably, regulations need to be timely in order to be relevant.  In this paper, issues that must be solved to make the future applications of this innovative technology safe and useful are analysed.

Electricity consumption and economic growth in ASEAN

2017 ◽  
Vol 5 (2) ◽  
pp. 16
Author(s):  
Ahmad Ghazali Ismail ◽  
Arlinah Abd Rashid ◽  
Azlina Hanif
Keyword(s):  
Economic Growth ◽  
Energy Use ◽  
Electricity Consumption ◽  
Panel Estimation ◽  
Real Gdp ◽  
Long Run ◽  
Bidirectional Relationship ◽  
Short Run ◽  
Using Data ◽  
The Relationship

The relationship and causality direction between electricity consumption and economic growth is an important issue in the fields of energy economics and policies towards energy use. Extensive literatures has discussed the issue, but the array of findings provides anything but consensus on either the existence of relations or direction of causality between the variables. This study extends research in this area by studying the long-run and causal relations between economic growth, electricity consumption, labour and capital based on the neo-classical one sector aggregate production technology mode using data of electricity consumption and real GDP for ASEAN from the year 1983 to 2012. The analysis is conducted using advanced panel estimation approaches and found no causality in the short run while in the long-run, the results indicate that there are bidirectional relationship among variables. This study provides supplementary evidences of relationship between electricity consumption and economic growth in ASEAN.

Gender Ideology and Fertility: Evidence for a Curvilinear Hypothesis

2020 ◽  
Author(s):  
Serena Stefani ◽  
Gabriele Prati
Keyword(s):  
Gender Ideology ◽  
Two Dimensions ◽  
Curvilinear Relationship ◽  
World Population ◽  
Fertility Rates ◽  
The World ◽  
And Gender ◽  
Using Data ◽  
National Analysis ◽  
The Relationship

Research on the relationship between fertility and gender ideology revealed inconsistent results. In the present study, we argue that inconsistencies may be due to the fact that such relationship may be nonlinear. We hypothesize a U- shaped relationship between two dimensions of gender ideology (i.e. primacy of breadwinner role and acceptance of male privilege) and fertility rates. We conducted a cross-national analysis of 60 countries using data from the World Values Survey as well as the World Population Prospects 2019. Controlling for gross domestic product, we found support for a U-shaped relationship between gender ideology and fertility. Higher levels of fertility rates were found at lower and especially higher levels of traditional gender ideology, while a medium level of gender ideology was associated with the lowest fertility rate. This curvilinear relationship is in agreement with the phase of the gender revolution in which the country is located. Traditional beliefs are linked to a complementary division of private versus public sphere between sexes, while egalitarian attitudes are associated with a more equitable division. Both conditions strengthen fertility. Instead, as in the transition phase, intermediate levels of gender ideology’s support are associated with an overload and a difficult reconciliation of the roles that women have to embody (i.e. working and nurturing) so reducing fertility. The present study has contributed to the literature by addressing the inconsistencies of prior research by demonstrating that the relationship between gender ideology and fertility rates is curvilinear rather than linear.

Openness and Self-enhancement are predictors of cultural and economic beliefs: an analysis of European countries across 15 years

2019 ◽  
Author(s):  
Gabriela Czarnek ◽  
Małgorzata Kossowska
Keyword(s):  
Cultural Context ◽  
Cultural Beliefs ◽  
European Social Survey ◽  
European Countries ◽  
Political Beliefs ◽  
Economic Beliefs ◽  
Nationally Representative ◽  
Self Transcendence ◽  
Using Data ◽  
The Relationship

In this study, we investigate the relationship between values and political beliefs and how it varies as a function of cultural context and time. In particular, we analyzed the effects of Conservation vs. Openness to change and Self-transcendence vs. Self-enhancement for cultural and economic political beliefs using data from nationally representative samples of citizens from 34 European countries from eight rounds of the European Social Survey (data spans the 2002–2016 period). We found that the effects of values on political beliefs are moderated by the Western vs. Eastern cultural context and that there is a modest round-to-round variation in the effects of values on beliefs. The relationship between Openness and cultural beliefs was negative and largely consistent across the Western and Eastern countries. Similarly, the effects of Self-enhancement were positive across these Western and Eastern countries. In contrast, the effects of Openness on economic beliefs were positive for the Eastern countries but largely weak and inconsistent for the Western countries. Finally, the effects of Self-enhancement on cultural beliefs are weak for both cultural contexts.

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