Search results for "Spatial"
showing 10 items of 2121 documents
Data from: Predator encounters have spatially extensive impacts on parental behaviour in a breeding bird community
2016
Predation risk has negative indirect effects on prey fitness, partly mediated through changes in behaviour. Evidence that individuals gather social information from other members of the population suggests that events in a community may impact the behaviour of distant individuals. However, spatially wide-ranging impacts on individual behaviour caused by a predator encounter elsewhere in a community have not been documented before. We investigated the effect of a predator encounter (hawk model presented at a focal nest) on the parental behaviour of pied flycatchers (Ficedula hypoleuca), both at the focal nest and at nearby nests different distances from the predator encounter. We show that n…
Data from: Large birds travel farther in homogeneous environments
2019
Aim: Animal movement is an important determinant of individual survival, population dynamics, and ecosystem structure and function. Yet it is still unclear how local movements are related to resource availability and the spatial arrangement of resources. Using resident bird species and migratory bird species outside of the migratory period, we examined how the distribution of resources affect the movement patterns of both large terrestrial birds (e.g., raptors, bustards, hornbills) and waterbirds (e.g., cranes, storks, ducks, geese, flamingos). Location: Global Time Period: 2003 - 2015 Major taxa studied: Birds Methods: We compiled GPS tracking data for 386 individuals across 36 bird specie…
Data from: Fine-scale population dynamics in a marine fish species inferred from dynamic state-space models
2018
Identifying the spatial scale of population structuring is critical for the conservation of natural populations and for drawing accurate ecological inferences. However, population studies often use spatially aggregated data to draw inferences about population trends and drivers, potentially masking ecologically relevant population sub-structure and dynamics. The goals of this study were to investigate how population dynamics models with and without spatial structure affect inferences on population trends and the identification of intrinsic drivers of population dynamics (e.g. density dependence). Specifically, we developed dynamic, age-structured, state-space models to test different hypoth…
Data from: Colour polymorphism torn apart by opposing positive frequency-dependent selection, yet maintained in space
2016
1. Polymorphic warning signals in aposematic species are enigmatic because predator learning and discrimination should select for the most common coloration, resulting in positive frequency-dependent survival selection. 2. Here, we investigated whether differential mating success could create sufficiently strong negative frequency-dependent selection for rare morphs to explain polymorphic (white and yellow) warning coloration in male wood tiger moths (Parasemia plantaginis). 3. We conducted an experiment in semi-natural conditions where we estimated mating success for both white and yellow male moths under three different morph frequencies. 4. Contrary to expectations, mating success was po…
Data from: Oxygen and carbon isoscapes for the Baltic Sea: testing their applicability in fish migration studies
2018
Conventional tags applied to individuals have been used to investigate animal movement, but these methods require tagged individuals be recaptured. Maps of regional isotopic variability known as “isoscapes” offer potential for various applications in migration research without tagging wherein isotope values of tissues are compared to environmental isotope values. In this study, we present the spatial variability in oxygen (math formula) and dissolved inorganic carbon (δ13CDIC) isotope values of Baltic Sea water. We also provide an example of how these isoscapes can reveal locations of individual animal via spatial probability surface maps, using the high-resolution salmon otolith isotope da…
Evaluation of MRI and cannabinoid type 1 receptor PET templates constructed using DARTEL for spatial normalization of rat brains
2015
Purpose: Image registration is one prerequisite for the analysis of brain regions in magnetic-resonance-imaging (MRI) or positron-emission-tomography (PET) studies. Diffeomorphic anatomical registration through exponentiated Lie algebra (DARTEL) is a nonlinear, diffeomorphic algorithm for image registration and construction of image templates. The goal of this small animal study was (1) the evaluation of a MRI and calculation of several cannabinoid type 1 (CB1) receptor PET templates constructed using DARTEL and (2) the analysis of the image registration accuracy of MR and PET images to their DARTEL templates with reference to analytical and iterative PET reconstruction algorithms. Methods:…
Suppression of phase ambiguity in digital holography by using partial coherence or specimen rotation
2008
In this paper we present two approaches for extracting the surface profile as well as obtaining 3D imaging of near field objects by usage of partial coherence and digital holography. In the first approach a light source with given temporal partial coherence is used to illuminate a near field object. The reflected light is interfered with the reference source. By computing the local contrast of the generated fringes one may estimate the 3D topography and the profile of the object. This approach extracts the 3D information from a single image, and its accuracy does not depend on triangulation angle like in fringe projection methods. The second approach is tomography based. There we illuminate…
Single-trial-based Temporal Principal Component Analysis on Extracting Event-related Potentials of Interest for an Individual Subject
2021
Abstract Temporal principal component analysis (t-PCA) has been widely used to extract event-related potentials (ERPs) at the group level of multiple subjects’ ERP data. The key assumption of group t-PCA analysis is that desired ERPs of all subjects share the same waveforms (i.e., temporal components), whereas waveforms of different subjects’ ERPs can be variant in phases, peak latencies and so on, to some extent. Additionally, several PCA-extracted components coming from the same ERP dataset failed to be statistically analysed simultaneously because their polarities and amplitudes were indeterminate. To fill these gaps, a novel technique was proposed and employed to extract desired ERP fro…
Second to fourth digit ratio (2D:4D) of the right hand is associated with nociception and augmenting-reducing
2008
The ratio of the length of the second and fourth fingers (2D:4D) represents an individual difference variable putatively related to prenatal testosterone exposure. Previous research found significant associations between this variable and sexually dimorphic and other sex-hormone mediated traits like fertility, masculinity, spatial ability and sensation seeking. The present study aimed to relate digit ratio to pain perception using electric pain stimuli. 131 volunteers (69 females) participated. Two electric stimuli of different intensity were applied to the forearm. Digit ratio was obtained from the left and right hands and pain tolerance was assessed by means of visual analog scales. Addit…
The Covid-19 containment effects of public health measures - A spatial difference-in-differences approach
2020
AbstractSince mid-March 2020 the Federal and state governments in Germany agreed on comprehensive public health measures to curb the spread of SARS-CoV-2 infections leading to the Covid-19 disease. We study the containment effects of these policy interventions on the progression of the pandemic in the first containment phase in spring 2020 before the easing of restrictions may become effective by the end of April. To exploit both the temporal and spatial dimension in the dissemination of the virus, we conduct a spatial panel data analysis for German NUTS-3 regions. Specifically, we employ a spatial difference-in-differences approach to identify the effects of six compound sets of public hea…