Search results for "Empirical data"
showing 10 items of 77 documents
Understanding the long-term effects of species invasions
2006
We describe here the ecological and evolutionary processes that modulate the effects of invasive species over time, and argue that such processes are so widespread and important that ecologists should adopt a long-term perspective on the effects of invasive species. These processes (including evolution, shifts in species composition, accumulation of materials and interactions with abiotic variables) can increase, decrease, or qualitatively change the impacts of an invader through time. However, most studies of the effects of invasive species have been brief and lack a temporal context; 40% of recent studies did not even state the amount of time that had passed since the invasion. Ecologists…
Examining nonstationarity in the recruitment dynamics of fishes using Bayesian change point analysis
2017
Marine ecosystems can undergo regime shifts, which result in nonstationarity in the dynamics of the fish populations inhabiting them. The assumption of time-invariant parameters in stock–recruitment models can lead to severe errors when forecasting renewal ability of stocks that experience shifts in their recruitment dynamics. We present a novel method for fitting stock–recruitment models using the Bayesian online change point detection algorithm, which is able to cope with sudden changes in the model parameters. We validate our method using simulations and apply it to empirical data of four demersal fishes in the southern Gulf of St. Lawrence. We show that all of the stocks have experience…
Multiple‐batch spawning as a bet‐hedging strategy in highly stochastic environments: An exploratory analysis of Atlantic cod
2021
Stochastic environments shape life‐history traits and can promote selection for risk‐spreading strategies, such as bet‐hedging. Although the strategy has often been hypothesised to exist for various species, empirical tests providing firm evidence have been rare, mainly due to the challenge in tracking fitness across generations. Here, we take a ‘proof of principle’ approach to explore whether the reproductive strategy of multiple‐batch spawning constitutes a bet‐hedging. We used Atlantic cod (Gadus morhua) as the study species and parameterised an eco‐evolutionary model, using empirical data on size‐related reproductive and survival traits. To evaluate the fitness benefits of multiple‐batc…
Mechanisms of reciprocity and diversity in social networks: a modeling and comparative approach
2018
Individual-based computer models show that different mechanisms, proximity-based or emotional bookkeeping, can lead to reciprocation. By comparing social networks from different computer models with those of empirical data, we show that the models’ social networks bear limited resemblance with some features of the observed social networks. This indicates that additional social processes (third-party awareness) may be needed in these models to represent more accurately the social behavior and interaction patterns observed in group-living animals.
The Importance of Cerebellar Connectivity on Simulated Brain Dynamics
2020
The brain shows a complex multiscale organization that prevents a direct understanding of how structure, function and dynamics are correlated. To date, advances in neural modeling offer a unique opportunity for simulating global brain dynamics by embedding empirical data on different scales in a mathematical framework. The Virtual Brain (TVB) is an advanced data-driven model allowing to simulate brain dynamics starting from individual subjects' structural and functional connectivity obtained, for example, from magnetic resonance imaging (MRI). The use of TVB has been limited so far to cerebral connectivity but here, for the first time, we have introduced cerebellar nodes and interconnecting…
Channel Choice Complications
2019
In spite of massive investment and increased adoption of digital services, citizens continue to use traditional channels to interact with public organizations. The channel choice (CC) field of research tries to understand citizens’ interactions with public authorities to make the interaction more efficient and increase citizen satisfaction. However, most studies have been conducted either as surveys of hypothetical services or in experimental settings, leading to a lack of empirical data from actual use contexts. Therefore, we present the results of a sequential mixed methods study which combines observations of citizen-caseworker interaction in a call center, contextual interviews with cal…
Brain activity during intra- and cross-modal priming: new empirical data and review of the literature
2003
A positron emission tomography (PET) study was conducted to investigate the neurofunctional correlate of auditory within-modality and auditory-to-visual cross-modality stem completion priming. Compared to the auditory-to-auditory priming condition, cross-modality priming was associated with a significantly larger regional cerebral blood flow (rCBF) decrease at the boundary between left inferior temporal and fusiform gyri, brain regions previously associated with modality independent lexical retrieval and reading. Instead, within-modality auditory priming was associated with a bilateral pattern of prefrontal rCBF increase. This was likely the expression of more efficient access to output lex…
Emotional Self-Regulation Therapy for Smoking Reduction: Description and Initial Empirical Data
1995
Abstract Self-regulation therapy (Amigoo, 1992) is a set of procedures derived from cognitive skill training programs for increasing hypnotizability. First, experiences are generated by actual stimuli. Clients are then asked to associate those experiences with various cues. They are then requested to generate the experiences in response to the cues, but without the actual stimuli. When they are able to do so quickly and easily, therapeutic suggestions are given. Studies of self-regulation therapy indicate that it can be used successfully to treat smoking.
Household Expenditure on Leisure: a Comparative Study of Italian Households with Children from Y- and Z-Generation
2019
The intrinsic complexity of post-materialist society makes it challenging to investigate the connection between social changes and generations. However, the study of consumption might help in the analysis of such a connection. In this paper, we analyse empirical data of consumption on leisure of Italian households, and focus on families at a very precise stage of family life-cycle, that is, couples with teenager children. We look at consumption of households at different points in time, 2001, 2007, and 2012, in order to investigate the impact of both social change and generation of children–Y-generation in 2001 and 2007, and Z-generation in 2012–on the leisure expenditure patterns of famili…
Innovativeness as a determinant of entrepreneurial orientation: analysis of the hotel sector
2019
This paper analyses entrepreneurial orientation as a composite formed of innovation, proactiveness and risk-taking. The empirical data for this study were gathered from a survey sent to hotel managers. The fieldwork was carried out between January and June 2018. The process provided 102 valid questionnaires. Two methods were used: structural equation modelling (PLS-SEM) and fuzzy-set qualitative comparative analysis (fsQCA). This study makes six key contributions and findings. First, the use of these two methods provides robust and reliable results. Second, reliability and validity values for innovativeness, proactiveness and risk-taking are satisfactory. Third, the operationalisation of en…