Responding to spatial and temporal variations in predation risk: space use of a game species in a changing landscape of fear

2009 ◽  
Vol 87 (12) ◽  
pp. 1129-1137 ◽  
Author(s):  
V. Tolon ◽  
S. Dray ◽  
A. Loison ◽  
A. Zeileis ◽  
C. Fischer ◽  
...  
Keyword(s):  
Temporal Variations ◽  
Low Risk ◽  
Home Ranges ◽  
Hunting Season ◽  
Landscape Of Fear ◽  
Individual Level ◽  
Risk Of Predation ◽  
Increased Risk ◽  
Changes In Risk ◽  
The Individual

Predators generate a “landscape of fear” within which prey can minimize the risk of predation by selecting low-risk areas. Depending on the spatial structure of this “landscape”, i.e., whether it is coarse- or fine-grained, prey may respond to increased risk by shifting their home ranges or by fine-scale redistributions within these ranges, respectively. We studied how wild boar ( Sus scrofa L., 1758) responded to temporal changes in risk in hunted areas (risky habitat) surrounding a nature reserve (refuge habitat). Animals with home ranges “in contact” with the reserve during the low-risk season were the only ones to shift toward the refuge when the risk increased. These shifts occurred at two temporal scales in response to the increased risk during the daytime and during the hunting season. Whereas animals not influenced by the reserve found food and shelter in forest during the hunting season, shifts to the refuge area were detrimental to the rather scarce forest areas in the reserve. This confirms that spatiotemporal changes in risk are major drivers of animal distribution when predation strongly limits their fitness. Their response is, however, scale-dependent and reflects at the individual level the perceived structure of their “landscape of fear”.

scholarly journals Late-Life Vascular Risk Score in Association With Postmortem Cerebrovascular Disease Brain Pathologies

Stroke ◽  
2021 ◽  
Author(s):  
Shahram Oveisgharan ◽  
Lei Yu ◽  
Ana Capuano ◽  
Zoe Arvanitakis ◽  
Lisa L. Barnes ◽  
...  
Keyword(s):  
Cerebrovascular Disease ◽  
Cerebral Amyloid Angiopathy ◽  
Risk Score ◽  
Odds Ratio ◽  
Amyloid Angiopathy ◽  
Individual Level ◽  
Framingham Risk ◽  
Increased Risk ◽  
Cerebral Amyloid ◽  
The Individual

Background and Purpose: The general cardiovascular Framingham risk score (FRS) identifies adults at increased risk for stroke. We tested the hypothesis that baseline FRS is associated with the presence of postmortem cerebrovascular disease (CVD) pathologies. Methods: We studied the brains of 1672 older decedents with baseline FRS and measured CVD pathologies including macroinfarcts, microinfarcts, atherosclerosis, arteriolosclerosis, and cerebral amyloid angiopathy. We employed a series of logistic regressions to examine the association of baseline FRS with each of the 5 CVD pathologies. Results: Average age at baseline was 80.5±7.0 years and average age at death was 89.2±6.7 years. A higher baseline FRS was associated with higher odds of macroinfarcts (odds ratio, 1.10 [95% CI, 1.07–1.13], P <0.001), microinfarcts (odds ratio, 1.04 [95% CI, 1.01–1.07], P =0.009), atherosclerosis (odds ratio, 1.07 [95% CI, 1.04–1.11], P <0.001), and arteriolosclerosis (odds ratio, 1.04 [95% CI, 1.01–1.07], P =0.005). C statistics for these models ranged from 0.537 to 0.595 indicating low accuracy for predicting CVD pathologies. FRS was not associated with the presence of cerebral amyloid angiopathy. Conclusions: A higher FRS score in older adults is associated with higher odds of some, but not all, CVD pathologies, with low discrimination at the individual level. Further work is needed to develop a more robust risk score to identify adults at risk for accumulating CVD pathologies.

Suitability of a young deciduous-dominated forest for American marten and the effects of forest removal

2004 ◽  
Vol 82 (3) ◽  
pp. 423-435 ◽  
Author(s):  
Kim G Poole ◽  
Aswea D Porter ◽  
Andrew de Vries ◽  
Chris Maundrell ◽  
Scott D Grindal ◽  
...  
Keyword(s):  
Populus Tremuloides ◽  
Forest Cover ◽  
Agricultural Land ◽  
Prey Availability ◽  
Population Level ◽  
Home Ranges ◽  
American Marten ◽  
Individual Level ◽  
The Individual

American marten (Martes americana (Turton, 1806)) are generally considered to be reliant upon and most successful in continuous late-successional coniferous forests. By contrast, young seral forests and deciduous-dominated forests are assumed to provide low-quality marten habitat, primarily as a result of insufficient structure, overhead cover, and prey. This study examined a moderate-density population of marten in northeastern British Columbia in what appeared to be comparatively low-quality, deciduous-dominated habitat, overgrown agricultural land primarily consisting of 30- to 40-year-old stands of regenerating trembling aspen (Populus tremuloides Michx.). Over 4 years, we monitored 52 radio-collared marten. The population appeared to be stable, as indicated by large numbers of adults, relatively constant densities, long-term residency of many individuals, low mortality rates, and older age structure. Relatively small home ranges (males, 3.3 km2; females, 2.0 km2) implied good habitat quality and prey availability. Shearing (removal of immature forest cover) of 17% of the study area resulted in home range shifts at the individual level but no detectable impact at the population level. Categorically, marten avoided nonforested cover types and preferred mature coniferous (>25% conifer) stands (7% of the study area) but otherwise appeared to use all forested stands relative to their availability, including extensive use of deciduous-dominated stands and deciduous stands <40 years of age. Thus, these young deciduous forests appeared to have sufficient structure, overhead cover, and prey to maintain moderate densities of resident marten on a long-term basis.

scholarly journals Who Is Purged? Determinants of Elite Purges in North Korea

2021 ◽  
Vol 54 (3) ◽  
pp. 73-96
Author(s):  
Taekbin Kim
Keyword(s):  
Survival Analysis ◽  
North Korea ◽  
Career Path ◽  
Educational Background ◽  
Low Risk ◽  
Individual Factors ◽  
Individual Level ◽  
Studying Abroad ◽  
Military Background ◽  
The Individual

The existing literature on elite purges in dictatorships claims that the risk of coups to replace dictators is the main cause of the dictator’s choice of purge strategy. Why then do elite purges occur even in well-established dictatorships with a consistently low risk of coups? This article argues that elite purges in consolidated dictatorships have a different purpose and logic. Dictators, who have consolidated their position, seek to maximize the efficiency of rule by making the elite obedient through purges. For this purpose, dictators carefully select the purge target by considering various factors. To test this theory, the article examines the pattern of elite purges in North Korea based on an original individual-level dataset, which contains the personal background of 367 North Korean elites and their purge records between 1948 and 2019. The result of survival analysis shows that the purge risk of the elite is not significantly associated with their military background but is associated with the characteristics of the institution to which the individual elite member belongs. Other individual factors, including the elite’s educational background, the experience of studying abroad, and the career path, are also significantly related to the probability of being purged. The finding suggests that coup-proofing is not the only purpose of elite purges but that ensuring the leader’s political superiority is another purpose of elite purges in consolidated dictatorships.

Community Ecology of Stream Fishes: Concepts, Approaches, and Techniques

2010 ◽  
Keyword(s):  
Spatial Scales ◽  
Distribution Patterns ◽  
Home Ranges ◽  
Stream Fishes ◽  
Ecological Processes ◽  
Individual Level ◽  
Population Spread ◽  
Heavy Tailed ◽  
Resource Patches ◽  
The Individual

<em>Abstract</em>.—Long-distance dispersal (LDD; relatively infrequent displacements occupying the tails of the dispersal kernel) and habitat connectivity (the degree to which the landscape facilitates or impedes movement among resource patches) influence many important ecological processes. These processes include population spread and redistribution, regulation of local and regional population dynamics, colonization of newly available habitats, maintenance of diversity in variable environments, and transfer of energy and nutrients. Field studies have shown that both LDD and instream barriers can have marked effects on the distribution patterns and demographic isolation of stream fishes at various spatial scales. Traditional summary measures of spatial use at the individual level, such as home ranges, have limited utility for examining the effects of connectivity in the presence of LDD or instream barriers; however, simple models can be tailored to extract and synthesize this information efficiently. This study presents a modeling framework for quantifying LDD of marked fish as well as their movements in the presence of barriers of differing porosity or permeability. Simulations are used to illustrate the feasibility of the modeling approach and explore sample size and spatial scale requirements. Comparison of model parameters across systems, species, and time periods should provide insights into the contribution of movement to structuring fish communities in riverine landscapes. The proposed framework can help improve on methods currently used (e.g., to quantify characteristic scales of habitat use by using median displacements or other appropriate percentile measures instead of home ranges and to relate fish movements to environmental or individual predictors by robust analyses based on heavy-tailed rather than simple normal distributions).

Individual- and School-Level Factors Contributing to Disproportionate Suspension Rates: A Multilevel Analysis of One State

2018 ◽  
Vol 27 (4) ◽  
pp. 209-220 ◽  
Author(s):  
Kristine A. Camacho ◽  
Michael P. Krezmien
Keyword(s):  
High Schools ◽  
Students With Disabilities ◽  
Multilevel Model ◽  
English Language ◽  
School Enrollment ◽  
School Level ◽  
Highly Qualified ◽  
Individual Level ◽  
Increased Risk ◽  
The Individual

Data from middle schools ( n = 219), high schools ( n = 200), and combined middle and high schools ( n = 20) were used to examine individual- and school-level factors within a multilevel model associated with an increased risk of suspension for minority students and students with disabilities. Results indicate that the individual-level variables of race and disability status were associated with an increased risk of suspension. Multiple school-level factors were also found to be associated with an increased risk of suspension including school enrollment, attendance, mobility, the percent of highly qualified teachers, the percent of students receiving free and reduced priced meals, the percent of students receiving special education services, the school’s Title I status, the student-to-teacher ratio, English Language Arts state exam scores, and the percent of White students in the school. In both analyses, the majority of variance was associated with the multilevel model which indicates the importance of examining individual factors within the context of school-level factors when trying to understand and respond to disproportionate suspension practices.

scholarly journals Socioeconomic position and SARS-CoV-2 infections: seroepidemiological findings from a German nationwide dynamic cohort

2021 ◽  
Author(s):  
Jens Hoebel ◽  
Markus M Grabka ◽  
Carsten Schroeder ◽  
Sebastian Haller ◽  
Hannelore Neuhauser ◽  
...  
Keyword(s):  
Socioeconomic Position ◽  
Adult Population ◽  
Individual Level ◽  
Highly Educated ◽  
Increased Risk ◽  
Pandemic Planning ◽  
Nasal Swabs ◽  
The Individual ◽  
Low Educated ◽  
The Relationship

Background: Evidence on the relationship between socioeconomic position (SEP) and infections with the SARS-CoV-2 coronavirus is still limited as most of the available studies are ecological in nature. This is the first German nationwide study to examine differences in the risk of SARS-CoV-2 infections according to SEP at the individual level. Methods: The 'CORONA-MONITORING bundesweit' (RKI-SOEP) study is a seroepidemiological survey among a dynamic cohort of the German adult population (n=15,122; October 2020 to February 2021). Dried blood samples were tested for SARS-CoV-2 antibodies and oral-nasal swabs for viral RNA. SEP was measured by education and income. Robust logistic regression was used to examine adjusted associations of SARS-CoV-2 infections with SEP. Results: 288 participants were seropositive, PCR-positive, or self-reported a previous laboratory-confirmed SARS-CoV-2 infection. The adjusted odds of SARS-CoV-2 infection were 1.87-fold (95% confidence interval [CI]=1.06–3.29) higher among low-educated than highly educated adults. Evidence was weaker for income differences in infections (odds ratio=1.65; 95% CI=0.89–3.05). Highly educated adults had lower odds of undetected infection. Conclusions: The results indicate an increased risk of SARS-CoV-2 infection in low-educated groups. To promote health equity in the pandemic and beyond, social determinants should be addressed more in infection protection and pandemic planning.

scholarly journals Professional resilience in GPs working in areas of socioeconomic deprivation: a qualitative study in primary care

2018 ◽  
Vol 68 (677) ◽  
pp. e819-e825 ◽  
Author(s):  
Eleanor Eley ◽  
Ben Jackson ◽  
Chris Burton ◽  
Elizabeth Walton
Keyword(s):  
Primary Care ◽  
Qualitative Study ◽  
Personal Characteristic ◽  
Socioeconomic Deprivation ◽  
Individual Level ◽  
Trade Offs ◽  
Increased Risk ◽  
Framework Approach ◽  
Data Saturation ◽  
The Individual

BackgroundGPs working in areas of high socioeconomic deprivation face particular challenges, and are at increased risk of professional burnout. Understanding how GPs working in such areas perceive professional resilience is important in order to recruit and retain a GP workforce in these areas.AimTo understand how GPs working in areas of high socioeconomic deprivation consider professional resilience.Design and settingA qualitative study of GPs practising in deprived areas within one primary care region of England.MethodIn total, 14 individual interviews and one focus group of eight participants were undertaken, with sampling to data saturation. A framework approach was used for data analysis.ResultsParticipants described three key themes relating to resilience. First, resilience was seen as involving flexibility and adaptability. This involved making trade-offs in order to keep going, even if this was imperfect. Second, resilience was enacted through teams rather than through individual strength. Third, resilience required the integration of personal and professional values rather than keeping the two separate. This dynamic adaptive view, with an emphasis on the importance of individuals within teams rather than in isolation, contrasts with the discourse of resilience as a personal characteristic, which should be strengthened at the individual level.ConclusionProfessional resilience is about more than individual strength. Policies to promote professional resilience, particularly in settings such as areas of high socioeconomic deprivation, must recognise the importance of flexibility, adaptability, working as teams, and successful integration between work and personal values.

scholarly journals Spatial and temporal variability across life's hierarchies in the terrestrial Antarctic

2007 ◽  
Vol 362 (1488) ◽  
pp. 2307-2331 ◽  
Author(s):  
Steven L Chown ◽  
Peter Convey
Keyword(s):  
Climate Change ◽  
Species Interactions ◽  
Life Histories ◽  
Temporal Variations ◽  
Spatial And Temporal Variability ◽  
Individual Level ◽  
The Individual ◽  
Terrestrial Biodiversity ◽  
Available Information ◽  
The Antarctic

Antarctica and its surrounding islands lie at one extreme of global variation in diversity. Typically, these regions are characterized as being species poor and having simple food webs. Here, we show that terrestrial systems in the region are nonetheless characterized by substantial spatial and temporal variations at virtually all of the levels of the genealogical and ecological hierarchies which have been thoroughly investigated. Spatial variation at the individual and population levels has been documented in a variety of genetic studies, and in mosses it appears that UV-B radiation might be responsible for within-clump mutagenesis. At the species level, modern molecular methods have revealed considerable endemism of the Antarctic biota, questioning ideas that small organisms are likely to be ubiquitous and the taxa to which they belong species poor. At the biogeographic level, much of the relatively small ice-free area of Antarctica remains unsurveyed making analyses difficult. Nonetheless, it is clear that a major biogeographic discontinuity separates the Antarctic Peninsula and continental Antarctica, here named the ‘Gressitt Line’. Across the Southern Ocean islands, patterns are clearer, and energy availability is an important correlate of indigenous and exotic species richness, while human visitor numbers explain much of the variation in the latter too. Temporal variation at the individual level has much to do with phenotypic plasticity, and considerable life-history and physiological plasticity seems to be a characteristic of Antarctic terrestrial species. Environmental unpredictability is an important driver of this trait and has significantly influenced life histories across the region and probably throughout much of the temperate Southern Hemisphere. Rapid climate change-related alterations in the range and abundance of several Antarctic and sub-Antarctic populations have taken place over the past several decades. In many sub-Antarctic locations, these have been exacerbated by direct and indirect effects of invasive alien species. Interactions between climate change and invasion seem set to become one of the most significant conservation problems in the Antarctic. We conclude that despite the substantial body of work on the terrestrial biodiversity of the Antarctic, investigations of interactions between hierarchical levels remain scarce. Moreover, little of the available information is being integrated into terrestrial conservation planning, which lags far behind in this region by comparison with most others.

scholarly journals O6E.2 Exposure assessment for a study of cognitive impairment in former professional footballers in england

2019 ◽  
Vol 76 (Suppl 1) ◽  
pp. A59.2-A59
Author(s):  
Damien Mcelvenny ◽  
Ioannis Basinas ◽  
Richard Graveling ◽  
John Cherrie ◽  
Valeintina Gallo ◽  
...  
Keyword(s):  
Exposure Assessment ◽  
Study Cohort ◽  
List Type ◽  
Head Impacts ◽  
Individual Level ◽  
Video Footage ◽  
Predictive Variables ◽  
Increased Risk ◽  
The Individual ◽  
And Training

Evidence is accumulating on the possible increased risks of neurodegenerative disease in former (professional) sportspersons. This study will assess the associations between a history of repetitive low-level head trauma and general and neurological health in retired professional footballers aged 50+in England. The main exposure measures are concussions and cumulative lifetime repeated sub-concussive head impacts (RSHIs), either from heading footballs or other forces applied to the head. Information on factors associated with concussions and RSHIs will be collected via a structured questionnaire during face-to-face interviews.Our approach will include:Literature search to identify potentially important proxy measures of RSHI during training and matches;Developing a model of cumulative RSHIs, based on the more strongly predictive variables, which may include playing position, the frequency of heading, the number of games played and training sessions attended, decade of play and the type of ball used.The model will be developed from analyses of head contacts from video footage of matches and training, at the individual level and in general, and from statistics on playing career. We will also consult a panel of former professional footballers on the exposure assessment.The exposure data will be crucial to assess whether those with higher exposure within the study cohort are at increased risk compared to those with lower exposure.

scholarly journals Bayesian Analysis of Population Health Data

Mathematics ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 577
Author(s):  
Dorota Młynarczyk ◽  
Carmen Armero ◽  
Virgilio Gómez-Rubio ◽  
Pedro Puig
Keyword(s):  
Ischemic Stroke ◽  
Random Effects ◽  
Drug Prescription ◽  
Temporal Variations ◽  
Survival Models ◽  
Stroke Event ◽  
Stroke Incidence ◽  
Individual Level ◽  
Different Types ◽  
The Individual

The analysis of population-wide datasets can provide insight on the health status of large populations so that public health officials can make data-driven decisions. The analysis of such datasets often requires highly parameterized models with different types of fixed and random effects to account for risk factors, spatial and temporal variations, multilevel effects and other sources on uncertainty. To illustrate the potential of Bayesian hierarchical models, a dataset of about 500,000 inhabitants released by the Polish National Health Fund containing information about ischemic stroke incidence for a 2-year period is analyzed using different types of models. Spatial logistic regression and survival models are considered for analyzing the individual probabilities of stroke and the times to the occurrence of an ischemic stroke event. Demographic and socioeconomic variables as well as drug prescription information are available at an individual level. Spatial variation is considered by means of region-level random effects.

Sign in / Sign up

Export Citation Format

Share Document