scholarly journals Navigating Deeply Uncertain Tradeoffs in Harvested Predator-Prey Systems

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-18 ◽  
Author(s):  
Antonia Hadjimichael ◽  
Patrick M. Reed ◽  
Julianne D. Quinn
Keyword(s):  
Dynamic Properties ◽  
Management Strategies ◽  
Basins Of Attraction ◽  
Economic Benefits ◽  
Ecological Interactions ◽  
Management Options ◽  
Predator Prey ◽  
Ecological Criteria ◽  
Nonlinear Dynamic Properties ◽  
Ecological Objectives

Multiple fisheries have collapsed as a result of overfishing and strong limitations in our knowledge of system conditions and consequential ecological interactions. Fishery managers need to establish harvesting strategies that balance economic benefits against ecological objectives, including avoiding unintended catastrophic consequences. Our results show that classical assumptions for fisheries management can yield severe instabilities in our quantified views of socioecological tradeoffs, making their ability to inform stakeholder preferences questionable. The complex ecological interactions implied by different parameterizations of such systems yield highly complex and nonlinear dynamic properties with multiple distinct basins of attraction. We show that small changes in our deeply uncertain representations of predator-prey systems can fundamentally shift their dynamics and the validity of candidate management strategies for harvest. Insights from this study highlight the importance of ensuring models capture deep uncertainties, as well as a breadth of financial and ecological criteria when searching for robust management options for resilient fisheries.

State-shifts of lion prey selection in the Kruger National Park

2017 ◽  
Vol 44 (1) ◽  
pp. 28 ◽  
Author(s):  
N. T. Maruping-Mzileni ◽  
P. J. Funston ◽  
S. M. Ferreira
Keyword(s):  
National Park ◽  
Prey Selection ◽  
Management Strategies ◽  
Stable State ◽  
Kruger National Park ◽  
Ecological Processes ◽  
Policy Makers ◽  
Predator Prey ◽  
Key Indicator ◽  
Management Interventions

Aims Indicators of pending state-shifts carry value for policy makers. Predator–prey relations reflect key ecological processes that shape ecosystems. Variance in predator–prey relations may serve as a key indicator of future state-shifts. Methods Lion (Panthera leo) diet in the Kruger National Park was evaluated as such an indicator. Over the three-decade time span reviewed, variance in diet in relation to rainfall, prey abundance, management strategies and disease emergence were reviewed. Key results Rainfall patterns, both seasonal and cyclical, were identified as key drivers of predator–prey selection. However, the intensity of management in the form of artificial waterpoints overrode and confounded natural process. The results suggest that savanna systems are stable and punctuated by climatic events in the form of extreme above-average rainfall that temporarily destabilises the system. However, droughts are a cyclical part of the savanna system. Conclusion Lion prey selection did fluctuate with changing environmental conditions. Abrupt state shifts did occur; however, the ecosystem returned to a stable state. Implications State shifts in ecosystems pose key challenges to conservation managers. State shifts appear to be primarily associated with management interventions and environmental factors.

Modeling Habitat Suitability and Management Options for Maintaining Round Whitefish (Prosopium cylindraceum) in Adirondack Ponds

2021 ◽  
Author(s):  
Amy Kathleen Conley ◽  
Matthew D. Schlesinger ◽  
James G. Daley ◽  
Lisa K. Holst ◽  
Timothy G. Howard
Keyword(s):  
Species Distribution Model ◽  
Management Strategies ◽  
Distribution Model ◽  
Nonnative Species ◽  
Simulated Population ◽  
Management Options ◽  
The Past ◽  
Almost All ◽  
Reintroduction Success ◽  
Maximum Air Temperature

Habitat loss, acid precipitation, and nonnative species have drastically reduced the number of Adirondack waterbodies occupied by round whitefish (Prosopium cylindraceum). The goal of this study was to 1) increase the probability of reintroduction success by modeling the suitability of ponds for reintroduction and 2) better understand the effects of different rates of pond reclamation. We created a species distribution model that identified 70 waterbodies that were physically similar to occupied ponds. The most influential variables for describing round whitefish habitat included trophic, temperature, and alkalinity classes; waterbody maximum depth; maximum air temperature; and surrounding soil texture and impervious surface. Next, we simulated population dynamics under a variety of treatment scenarios and compared the probability of complete extirpation using a modified Markov model. Under almost all management strategies, and under pressure from nonnative competitors like that observed in the past 30 years, the number of occupied ponds will decline over the next 100 years. However, restoring one pond every 3 years would result in a 99% chance of round whitefish persistence after 100 years.

Nonlinear Dynamic Properties of the Pancreas and Liver

1973 ◽  
Vol 6 (4) ◽  
pp. 503-508
Author(s):  
Richard N. Bergman ◽  
Richard J. Bucolo
Keyword(s):  
Nonlinear Dynamic ◽  
Dynamic Properties ◽  
Nonlinear Dynamic Properties

scholarly journals Impacts of Whale-Watching on the Short-Term Behavior of Fin Whales (Balaenoptera physalus) in a Marine Protected Area in the Southeastern Pacific

2021 ◽  
Vol 8 ◽  
Author(s):  
Macarena Santos-Carvallo ◽  
Fernanda Barilari ◽  
María José Pérez-Alvarez ◽  
Laura Gutiérrez ◽  
Guido Pavez ◽  
...  
Keyword(s):  
Marine Protected Area ◽  
Management Strategies ◽  
Movement Patterns ◽  
Economic Benefits ◽  
Observation Point ◽  
Behavioral Patterns ◽  
Whale Watching ◽  
Balaenoptera Physalus ◽  
Fin Whales ◽  
Response Variables

Whale-watching (WW) is an activity which has been increasing worldwide due to the great interest of tourists and the economic benefits it provides to local communities. However, it has been reported that this activity affects the behavioral patterns of some cetaceans, although for some species such as the fin whale (Balaenoptera physalus) this has not been extensively studied. To identify the effects of WW on the behavioral patterns of this species, we studied its traveling and resting behaviors in a locality of north-central Chile from 2015 to 2018. Using a theodolite, we calculated the response variables of swim speed, directness index, and reorientation for each behavior. We used the number of WW boats and the WW scenarios of “before”, “during”, and “after” the presence of boats as possible factors to explain the differences in the response variables of the whales, along with the factors of year, month, group size, and distance from the observation point. Reorientation increased significantly and the directness index decreased significantly for both traveling and resting behaviors from “before” to “during” WW scenarios, indicating more erratic and sinuous movements in the presence of boats. These changes in movement patterns are a commonly reported evasion response of cetaceans to the presence of WW boats. For traveling behavior, the swimming speed significantly increased, and trends showed increased reorientation and a decrease in the directness index in the “after” WW scenario, which suggests perturbation of the whales potentially associated with the speed and the direction in which the boats left. During resting behavior, the trajectories of the fin whales became straighter (decrease in reorientation) as the number of boats increased, thus evasion (more erratic and sinuous movements) is a behavior used less by fin whales as the number of boats increases. Notwithstanding the fact that tourism development in the study area is small in scale, we found that WW generates adverse effects that are reflected in changes in the whales’ movement patterns. This kind of information is valuable to the adjustment and/or design of management strategies for the species, which is fundamental for WW to continue to be a sustainable activity.

scholarly journals Tiered healthcare in South Africa exposes deficiencies in management and more patients with infectious etiology of primary adrenal insufficiency

PLoS ONE ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. e0241845
Author(s):  
Thabiso Rafaki Petrus Mofokeng ◽  
Kwazi Celani Zwakele Ndlovu ◽  
Salem A. Beshyah ◽  
Ian L. Ross
Keyword(s):  
South Africa ◽  
Adrenal Insufficiency ◽  
Online Survey ◽  
Management Strategies ◽  
Adrenal Crisis ◽  
Public Healthcare ◽  
Antibody Testing ◽  
Management Options ◽  
Primary Adrenal Insufficiency ◽  
The Public

Objective We wished to determine the prevalence, etiology, presentation, and available management strategies for primary adrenal insufficiency (PAI) in South Africa (SA), hypothesizing a prevalence greater than the described 3.1 per million. There is great inequity in healthcare allocation, as two parallel healthcare systems exist, potentially modifying PAI patients’ clinical profiles, private being better resourced than public healthcare. Methods An online survey of physicians’ experience relating to PAI. Results The physicians were managing 811 patients, equal to a prevalence of 14.2 per million. Likely causes of PAI in public/ academic vs private settings included: AIDS-related [304 (44.8%) vs 5 (3.8%); p<0.001], tuberculosis [288 (42.5%) vs 8 (6.0%); p<0.001], autoimmune disease [50 (7.4%) vs 88 (66.2%); p<0.001], malignancy [27 (4.0%) vs 7 (5.3%); p = 0.500], genetic including adrenoleukodystrophy (ALD) [5 (0.7%) vs 16 (12.0%); p<0.001], respectively. Overall, more patients presented with nausea [101 (74.3%) and vomiting 89 (65.9%), than diarrhoea 76 (58.9%); p = 0.008 and 126 (15.5%) in adrenal crisis. Features suggestive of a crisis were hypoglycaemia [40 (78.4%) vs 42 (48.8%); p = 0.001], shock [36 (67.9%) vs 31(36.9%); p<0.001], and loss of consciousness [25 (52.1%) vs 27 (32.9%); p = 0.031]. Greater unavailability of antibody testing in the public vs. the private sector [32 (66.7%) vs 30 (32.1%); p = 0.001], [serum-ACTH 25 (52.1%) vs 16 (19.5%); p<0.001] and glucocorticoids were [26 (54.2%) vs 33 (40.2%); p = 0.015]. Many patients, 389(66.7%) were not using identification, indicating that they need steroids in an emergency. Conclusion A survey of South African physicians suggests a higher prevalence than previously reported. Patients presented with typical symptoms, and 15.5% presented in adrenal crisis. Significant disparities in the availability of physicians’ expertise, diagnostic resources, and management options were noted in the public versus private settings. Greater awareness among health practitioners to timeously diagnose PAI is required to prevent a life-threatening outcome.

scholarly journals Semi-Automated Procedure to Estimate Nonlinear Kinematic Hardening Model to Simulate the Nonlinear Dynamic Properties of Soil and Rock

2021 ◽  
Vol 11 (18) ◽  
pp. 8611
Author(s):  
Van-Linh Ngo ◽  
Changho Lee ◽  
Eun-haeng Lee ◽  
Jae-Min Kim
Keyword(s):  
Dynamic Properties ◽  
Kinematic Hardening ◽  
Back Stress ◽  
Good Match ◽  
Nonlinear Properties ◽  
Backbone Curves ◽  
Nonlinear Dynamic Properties ◽  
Strain Dependent ◽  
Fitting Parameters ◽  
Properties Of Soil

The strain-dependent nonlinear properties of ground materials, such as shear modulus degradation (G/Gmax) and damping, are of significant importance in seismic-related analyses. However, the ABAQUS program lacks a comprehensive procedure to estimate parameters for a built-in model. In this study, a nonlinear kinematic hardening (NKH) model with three back-stress values was used, which allows better fitting to the backbone curves compared to the simplified nonlinear kinematic hardening (SNKH) model previously proposed. Instead of modeling in ABAQUS, a semi-automated procedure was implemented in MATLAB, which can predict shear stress–shear strain hysteretic loops, to find the fitting parameters to the target G/Gmax and/or damping curves. The procedure was applied for three soil and two rock samples, and the results indicate a good match between model and target backbone curves, which proves the application of the procedure and the NKH model in simulating the nonlinear properties of ground materials.

Zooming in on mechanistic predator–prey ecology: Integrating camera traps with experimental methods to reveal the drivers of ecological interactions

2020 ◽  
Vol 89 (9) ◽  
pp. 1997-2012 ◽  
Author(s):  
Justine A. Smith ◽  
Justin P. Suraci ◽  
Jennifer S. Hunter ◽  
Kaitlyn M. Gaynor ◽  
Carson B. Keller ◽  
...  
Keyword(s):  
Experimental Methods ◽  
Camera Traps ◽  
Ecological Interactions ◽  
Predator Prey

scholarly journals An Application of the A’WOT Analysis for the Management of Cultural Heritage Assets: The Case of the Historical Farmhouses in the Aglié Castle (Turin)

2020 ◽  
Vol 12 (3) ◽  
pp. 1071 ◽  
Author(s):  
Marta Bottero ◽  
Chiara D’Alpaos ◽  
Alessia Marello
Keyword(s):  
Cultural Heritage ◽  
Management Strategies ◽  
Economic Benefits ◽  
Unesco World Heritage ◽  
World Heritage Sites ◽  
Heritage Sites ◽  
Decision Aiding ◽  
Design And Implementation ◽  
Trade Offs ◽  
Real Estate Assets

In recent years, governments, public institutions, and local communities have devoted growing attention to the identification of promising strategies for the preservation and valorization of cultural heritage assets. Decisions on the management of cultural heritage assets based on multiple, often conflicting, criteria and on the stakes of various, and potentially non-consensual actors and stakeholders. In this context, in which the trade-offs between the preservation of assets historical symbolic values and the adaptation to alternative and economically profitable uses play a key role in investment decisions, multi-criteria analyses provide robust theoretical and methodological frameworks to support decision-makers in the design and implementation of adaptive reuse strategies for cultural heritage and public real estate assets. In this paper, we provide a multi-criteria decision aiding approach for ranking valorization strategies of cultural heritage assets aimed at promoting their restoration and conservation, as well as at creating cultural and economic benefits. In detail, we present a novel application of the A’WOT analysis to support the design and implementation of alternative management strategies of abandoned cultural heritage assets. The paper focuses on the potential reuse and management of four historical farmhouses (Cascina Mandria, Cascina Lavanderia, Cascina Gozzani, and Cascina Ortovalle) located in the Agliè Castle estate, one of the Residences of the Royal House of Savoy, currently listed in the UNESCO World Heritage Sites.

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