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Sample records for modeling animal movement

  1. Stochastic modelling of animal movement

    PubMed Central

    Smouse, Peter E.; Focardi, Stefano; Moorcroft, Paul R.; Kie, John G.; Forester, James D.; Morales, Juan M.

    2010-01-01

    Modern animal movement modelling derives from two traditions. Lagrangian models, based on random walk behaviour, are useful for multi-step trajectories of single animals. Continuous Eulerian models describe expected behaviour, averaged over stochastic realizations, and are usefully applied to ensembles of individuals. We illustrate three modern research arenas. (i) Models of home-range formation describe the process of an animal ‘settling down’, accomplished by including one or more focal points that attract the animal's movements. (ii) Memory-based models are used to predict how accumulated experience translates into biased movement choices, employing reinforced random walk behaviour, with previous visitation increasing or decreasing the probability of repetition. (iii) Lévy movement involves a step-length distribution that is over-dispersed, relative to standard probability distributions, and adaptive in exploring new environments or searching for rare targets. Each of these modelling arenas implies more detail in the movement pattern than general models of movement can accommodate, but realistic empiric evaluation of their predictions requires dense locational data, both in time and space, only available with modern GPS telemetry. PMID:20566497

  2. Modeling interdependent animal movement in continuous time.

    PubMed

    Niu, Mu; Blackwell, Paul G; Skarin, Anna

    2016-06-01

    This article presents a new approach to modeling group animal movement in continuous time. The movement of a group of animals is modeled as a multivariate Ornstein Uhlenbeck diffusion process in a high-dimensional space. Each individual of the group is attracted to a leading point which is generally unobserved, and the movement of the leading point is also an Ornstein Uhlenbeck process attracted to an unknown attractor. The Ornstein Uhlenbeck bridge is applied to reconstruct the location of the leading point. All movement parameters are estimated using Markov chain Monte Carlo sampling, specifically a Metropolis Hastings algorithm. We apply the method to a small group of simultaneously tracked reindeer, Rangifer tarandus tarandus, showing that the method detects dependency in movement between individuals. PMID:26812666

  3. Continuous-time discrete-space models for animal movement

    USGS Publications Warehouse

    Hanks, Ephraim M.; Hooten, Mevin B.; Alldredge, Mat W.

    2015-01-01

    The processes influencing animal movement and resource selection are complex and varied. Past efforts to model behavioral changes over time used Bayesian statistical models with variable parameter space, such as reversible-jump Markov chain Monte Carlo approaches, which are computationally demanding and inaccessible to many practitioners. We present a continuous-time discrete-space (CTDS) model of animal movement that can be fit using standard generalized linear modeling (GLM) methods. This CTDS approach allows for the joint modeling of location-based as well as directional drivers of movement. Changing behavior over time is modeled using a varying-coefficient framework which maintains the computational simplicity of a GLM approach, and variable selection is accomplished using a group lasso penalty. We apply our approach to a study of two mountain lions (Puma concolor) in Colorado, USA.

  4. On modeling animal movements using Brownian motion with measurement error.

    PubMed

    Pozdnyakov, Vladimir; Meyer, Thomas; Wang, Yu-Bo; Yan, Jun

    2014-02-01

    Modeling animal movements with Brownian motion (or more generally by a Gaussian process) has a long tradition in ecological studies. The recent Brownian bridge movement model (BBMM), which incorporates measurement errors, has been quickly adopted by ecologists because of its simplicity and tractability. We discuss some nontrivial properties of the discrete-time stochastic process that results from observing a Brownian motion with added normal noise at discrete times. In particular, we demonstrate that the observed sequence of random variables is not Markov. Consequently the expected occupation time between two successively observed locations does not depend on just those two observations; the whole path must be taken into account. Nonetheless, the exact likelihood function of the observed time series remains tractable; it requires only sparse matrix computations. The likelihood-based estimation procedure is described in detail and compared to the BBMM estimation.

  5. A dynamic Brownian bridge movement model to estimate utilization distributions for heterogeneous animal movement.

    PubMed

    Kranstauber, Bart; Kays, Roland; Lapoint, Scott D; Wikelski, Martin; Safi, Kamran

    2012-07-01

    1. The recently developed Brownian bridge movement model (BBMM) has advantages over traditional methods because it quantifies the utilization distribution of an animal based on its movement path rather than individual points and accounts for temporal autocorrelation and high data volumes. However, the BBMM assumes unrealistic homogeneous movement behaviour across all data. 2. Accurate quantification of the utilization distribution is important for identifying the way animals use the landscape. 3. We improve the BBMM by allowing for changes in behaviour, using likelihood statistics to determine change points along the animal's movement path. 4. This novel extension, outperforms the current BBMM as indicated by simulations and examples of a territorial mammal and a migratory bird. The unique ability of our model to work with tracks that are not sampled regularly is especially important for GPS tags that have frequent failed fixes or dynamic sampling schedules. Moreover, our model extension provides a useful one-dimensional measure of behavioural change along animal tracks. 5. This new method provides a more accurate utilization distribution that better describes the space use of realistic, behaviourally heterogeneous tracks.

  6. Spatial memory and animal movement.

    PubMed

    Fagan, William F; Lewis, Mark A; Auger-Méthé, Marie; Avgar, Tal; Benhamou, Simon; Breed, Greg; LaDage, Lara; Schlägel, Ulrike E; Tang, Wen-wu; Papastamatiou, Yannis P; Forester, James; Mueller, Thomas

    2013-10-01

    Memory is critical to understanding animal movement but has proven challenging to study. Advances in animal tracking technology, theoretical movement models and cognitive sciences have facilitated research in each of these fields, but also created a need for synthetic examination of the linkages between memory and animal movement. Here, we draw together research from several disciplines to understand the relationship between animal memory and movement processes. First, we frame the problem in terms of the characteristics, costs and benefits of memory as outlined in psychology and neuroscience. Next, we provide an overview of the theories and conceptual frameworks that have emerged from behavioural ecology and animal cognition. Third, we turn to movement ecology and summarise recent, rapid developments in the types and quantities of available movement data, and in the statistical measures applicable to such data. Fourth, we discuss the advantages and interrelationships of diverse modelling approaches that have been used to explore the memory-movement interface. Finally, we outline key research challenges for the memory and movement communities, focusing on data needs and mathematical and computational challenges. We conclude with a roadmap for future work in this area, outlining axes along which focused research should yield rapid progress.

  7. Mapping behavioral landscapes for animal movement: a finite mixture modeling approach

    USGS Publications Warehouse

    Tracey, Jeff A.; Zhu, Jun; Boydston, Erin E.; Lyren, Lisa M.; Fisher, Robert N.; Crooks, Kevin R.

    2013-01-01

    Because of its role in many ecological processes, movement of animals in response to landscape features is an important subject in ecology and conservation biology. In this paper, we develop models of animal movement in relation to objects or fields in a landscape. We take a finite mixture modeling approach in which the component densities are conceptually related to different choices for movement in response to a landscape feature, and the mixing proportions are related to the probability of selecting each response as a function of one or more covariates. We combine particle swarm optimization and an Expectation-Maximization (EM) algorithm to obtain maximum likelihood estimates of the model parameters. We use this approach to analyze data for movement of three bobcats in relation to urban areas in southern California, USA. A behavioral interpretation of the models revealed similarities and differences in bobcat movement response to urbanization. All three bobcats avoided urbanization by moving either parallel to urban boundaries or toward less urban areas as the proportion of urban land cover in the surrounding area increased. However, one bobcat, a male with a dispersal-like large-scale movement pattern, avoided urbanization at lower densities and responded strictly by moving parallel to the urban edge. The other two bobcats, which were both residents and occupied similar geographic areas, avoided urban areas using a combination of movements parallel to the urban edge and movement toward areas of less urbanization. However, the resident female appeared to exhibit greater repulsion at lower levels of urbanization than the resident male, consistent with empirical observations of bobcats in southern California. Using the parameterized finite mixture models, we mapped behavioral states to geographic space, creating a representation of a behavioral landscape. This approach can provide guidance for conservation planning based on analysis of animal movement data using

  8. Spontaneously hypertensive rats: possible animal model of sleep-related movement disorders.

    PubMed

    Esteves, Andrea M; Lopes, Cleide; Frussa-Filho, Roberto; Frank, Miriam K; Cavagnolli, Daniel; Arida, Ricardo M; Tufik, Sergio; de Mello, Marco Tulio

    2013-01-01

    Clinical experience suggests that restless legs syndrome (RLS), periodic leg movement (PLM), and attention-deficit hyperactivity disorder (ADHD) may co-occur in both children and adults. The purpose of the present study was to provide an electrocorticography and electromyography evaluation of the spontaneously hypertensive rat (SHR) to investigate the potential of this rat strain as an animal model of RLS-PLM. Initial work focused on evaluating sleep patterns and limb movements during sleep in SHR, having normotensive Wistar rats (NWR) as control, followed by comparison of two treatments (pharmacological-dopaminergic agonist treatment and nonpharmacological-chronic physical exercise), known to be clinically beneficial for sleep-related movement disorders. The captured data strengthen the association between SHR and RLS-PLM, revealing a significant reduction on sleep efficiency and slow wave sleep and an increase on wakefulness and limb movements for the SHR group during the dark period, as compared to the NWR group, effects that have characteristics that are strikingly consistent with RLS-PLM. The pharmacological and nonpharmacological manipulations validated these results. The present findings suggest that the SHR may be a useful putative animal model to study sleep-related movement disorders mechanisms. PMID:24079375

  9. a Geo-Visual Analytics Approach to Biological Shepherding: Modelling Animal Movements and Impacts

    NASA Astrophysics Data System (ADS)

    Benke, K. K.; Sheth, F.; Betteridge, K.; Pettit, C. J.; Aurambout, J.-P.

    2012-07-01

    The lamb industry in Victoria is a significant component of the state economy with annual exports in the vicinity of 1 billion. GPS and visualisation tools can be used to monitor grazing animal movements at the farm scale and observe interactions with the environment. Modelling the spatial-temporal movements of grazing animals in response to environmental conditions provides input for the design of paddocks with the aim of improving management procedures, animal performance and animal welfare. The term "biological shepherding" is associated with the re-design of environmental conditions and the analysis of responses from grazing animals. The combination of biological shepherding with geo-visual analytics (geo-spatial data analysis with visualisation) provides a framework for improving landscape design and supports research in grazing behaviour in variable landscapes, heat stress avoidance behaviour during summer months, and modelling excreta distributions (with respect to nitrogen emissions and nitrogen return for fertilising the paddock). Nitrogen losses due to excreta are mainly in the form of gaseous emissions to the atmosphere and leaching into the groundwater. In this study, background and context are provided in the case of biological shepherding and tracking animal movements. Examples are provided of recent applications in regional Australia and New Zealand. Based on experimental data and computer simulation, and using data visualisation and feature extraction, it was demonstrated that livestock excreta are not always randomly located, but concentrated around localised gathering points, sometimes separated by the nature of the excretion. Farmers require information on the nitrogen losses in order to reduce emissions to meet local and international nitrogen leaching and greenhouse gas targets and to improve the efficiency of nutrient management.

  10. Effects of temporal resolution on an inferential model of animal movement.

    PubMed

    Postlethwaite, Claire M; Dennis, Todd E

    2013-01-01

    Recently, there has been much interest in describing the behaviour of animals by fitting various movement models to tracking data. Despite this interest, little is known about how the temporal 'grain' of movement trajectories affects the outputs of such models, and how behaviours classified at one timescale may differ from those classified at other scales. Here, we present a study in which random-walk state-space models were fit both to nightly geospatial lifelines of common brushtail possums (Trichosurus vulpecula) and synthetic trajectories parameterised from empirical observations. Observed trajectories recorded by GPS collars at 5-min intervals were sub-sampled at periods varying between 10 and 60 min, to approximate the effect of collecting data at lower sampling frequencies. Markov-Chain Monte-Carlo fitting techniques, using information about movement rates and turning angles between sequential fixes, were employed using a Bayesian framework to assign distinct behavioural states to individual location estimates. We found that in trajectories with higher temporal granularities behaviours could be clearly differentiated into 'slow-area-restricted' and 'fast-transiting' states, but for trajectories with longer inter-fix intervals this distinction was markedly less obvious. Specifically, turning-angle distributions varied from being highly peaked around either 0° or 180° at fine temporal scales, to being uniform across all angles at low sampling intervals. Our results highlight the difficulty of comparing model results amongst tracking-data sets that vary substantially in temporal grain, and demonstrate the importance of matching the observed temporal resolution of tracking devices to the timescales of behaviours of interest, otherwise inter-individual comparisons of inferred behaviours may be invalid, or important biological information may be obscured.

  11. Integrative modelling of animal movement: incorporating in situ habitat and behavioural information for a migratory marine predator.

    PubMed

    Bestley, Sophie; Jonsen, Ian D; Hindell, Mark A; Guinet, Christophe; Charrassin, Jean-Benoît

    2013-01-01

    A fundamental goal in animal ecology is to quantify how environmental (and other) factors influence individual movement, as this is key to understanding responsiveness of populations to future change. However, quantitative interpretation of individual-based telemetry data is hampered by the complexity of, and error within, these multi-dimensional data. Here, we present an integrative hierarchical Bayesian state-space modelling approach where, for the first time, the mechanistic process model for the movement state of animals directly incorporates both environmental and other behavioural information, and observation and process model parameters are estimated within a single model. When applied to a migratory marine predator, the southern elephant seal (Mirounga leonina), we find the switch from directed to resident movement state was associated with colder water temperatures, relatively short dive bottom time and rapid descent rates. The approach presented here can have widespread utility for quantifying movement-behaviour (diving or other)-environment relationships across species and systems. PMID:23135676

  12. Analyzing animal movements using Brownian bridges.

    PubMed

    Horne, Jon S; Garton, Edward O; Krone, Stephen M; Lewis, Jesse S

    2007-09-01

    By studying animal movements, researchers can gain insight into many of the ecological characteristics and processes important for understanding population-level dynamics. We developed a Brownian bridge movement model (BBMM) for estimating the expected movement path of an animal, using discrete location data obtained at relatively short time intervals. The BBMM is based on the properties of a conditional random walk between successive pairs of locations, dependent on the time between locations, the distance between locations, and the Brownian motion variance that is related to the animal's mobility. We describe two critical developments that enable widespread use of the BBMM, including a derivation of the model when location data are measured with error and a maximum likelihood approach for estimating the Brownian motion variance. After the BBMM is fitted to location data, an estimate of the animal's probability of occurrence can be generated for an area during the time of observation. To illustrate potential applications, we provide three examples: estimating animal home ranges, estimating animal migration routes, and evaluating the influence of fine-scale resource selection on animal movement patterns.

  13. How Relevant Are Imaging Findings in Animal Models of Movement Disorders to Human Disease?

    PubMed

    Bannon, Darryl; Landau, Anne M; Doudet, Doris J

    2015-08-01

    The combination of novel imaging techniques with the use of small animal models of disease is often used in attempt to understand disease mechanisms, design potential clinical biomarkers and therapeutic interventions, and develop novel methods with translatability to human clinical conditions. However, it is clear that most animal models are deficient when compared to the complexity of human diseases: they cannot sufficiently replicate all the features of multisystem disorders. Furthermore, some practical differences may affect the use or interpretation of animal imaging to model human conditions such as the use of anesthesia, various species differences, and limitations of methodological tools. Nevertheless, imaging animal models allows us to dissect, in interpretable bits, the effects of one system upon another, the consequences of variable neuronal losses or overactive systems, the results of experimental treatments, and we can develop and validate new methods. In this review, we focus on imaging modalities that are easily used in both human subjects and animal models such as positron emission and magnetic resonance imaging and discuss aging and Parkinson's disease as prototypical examples of preclinical imaging studies.

  14. Combining High-Speed Cameras and Stop-Motion Animation Software to Support Students' Modeling of Human Body Movement

    NASA Astrophysics Data System (ADS)

    Lee, Victor R.

    2015-04-01

    Biomechanics, and specifically the biomechanics associated with human movement, is a potentially rich backdrop against which educators can design innovative science teaching and learning activities. Moreover, the use of technologies associated with biomechanics research, such as high-speed cameras that can produce high-quality slow-motion video, can be deployed in such a way to support students' participation in practices of scientific modeling. As participants in classroom design experiment, fifteen fifth-grade students worked with high-speed cameras and stop-motion animation software (SAM Animation) over several days to produce dynamic models of motion and body movement. The designed series of learning activities involved iterative cycles of animation creation and critique and use of various depictive materials. Subsequent analysis of flipbooks of human jumping movements created by the students at the beginning and end of the unit revealed a significant improvement in both the epistemic fidelity of students' representations. Excerpts from classroom observations highlight the role that the teacher plays in supporting students' thoughtful reflection of and attention to slow-motion video. In total, this design and research intervention demonstrates that the combination of technologies, activities, and teacher support can lead to improvements in some of the foundations associated with students' modeling.

  15. Maximum-entropy description of animal movement.

    PubMed

    Fleming, Chris H; Subaşı, Yiğit; Calabrese, Justin M

    2015-03-01

    We introduce a class of maximum-entropy states that naturally includes within it all of the major continuous-time stochastic processes that have been applied to animal movement, including Brownian motion, Ornstein-Uhlenbeck motion, integrated Ornstein-Uhlenbeck motion, a recently discovered hybrid of the previous models, and a new model that describes central-place foraging. We are also able to predict a further hierarchy of new models that will emerge as data quality improves to better resolve the underlying continuity of animal movement. Finally, we also show that Langevin equations must obey a fluctuation-dissipation theorem to generate processes that fall from this class of maximum-entropy distributions when the constraints are purely kinematic.

  16. Can physical exercise have a protective effect in an animal model of sleep-related movement disorder?

    PubMed

    Esteves, Andrea M; Lopes, Cleide; Frank, Miriam K; Arida, Ricardo M; Frussa-Filho, Roberto; Tufik, Sergio; de Mello, Marco Túlio

    2016-05-15

    The purpose of the present study was to determine whether physical exercise (PE) has a protective effect in an experimental animal model of sleep-related movement disorder (A11 dopaminergic nuclei lesions with 6-OHDA). Rats were divided into four groups (Control PE-CTRL/PE, SHAM/PE, A11 lesion/NPE, A11 lesion/PE). Two experiments were performed: (1) the rats underwent PE before (2 weeks) and after (4 weeks) the A11 lesion; and (2) the rats underwent PE only after (4 weeks) the A11 lesion. Electrode insertion surgery was performed and sleep analyses were conducted over a period of 24h (baseline and after PE) and analyzed in 6 blocks of 4h. The results demonstrated that the A11 lesion produced an increased percentage of wakefulness in the final block of the dark period (3-7am) and a significant enhancement of the number of limb movements (LM) throughout the day. Four weeks of PE was important for reducing the number of LMs in the A11 lesion group in the rats that performed PE before and after the A11 lesion. However, in the analysis of the protective effect of PE on LM, the results showed that the number of LMs was lower at baseline in the group that had performed 2 weeks of PE prior to the A11 lesion than in the group that had not previously performed PE. In conclusion, these findings consistently demonstrate that non-pharmacological manipulations had a beneficial effect on the symptoms of sleep-related movement disorder.

  17. Movement of regulatory RNA between animal cells.

    PubMed

    Jose, Antony M

    2015-07-01

    Recent studies suggest that RNA can move from one cell to another and regulate genes through specific base-pairing. Mechanisms that modify or select RNA for secretion from a cell are unclear. Secreted RNA can be stable enough to be detected in the extracellular environment and can enter the cytosol of distant cells to regulate genes. Mechanisms that import RNA into the cytosol of an animal cell can enable uptake of RNA from many sources including other organisms. This role of RNA is akin to that of steroid hormones, which cross cell membranes to regulate genes. The potential diagnostic use of RNA in human extracellular fluids has ignited interest in understanding mechanisms that enable the movement of RNA between animal cells. Genetic model systems will be essential to gain more confidence in proposed mechanisms of RNA transport and to connect an extracellular RNA with a specific biological function. Studies in the worm C. elegans and in other animals have begun to reveal parts of this novel mechanism of cell-to-cell communication. Here, I summarize the current state of this nascent field, highlight the many unknowns, and suggest future directions.

  18. Movement of regulatory RNA between animal cells

    PubMed Central

    Jose, Antony M.

    2015-01-01

    Summary Recent studies suggest that RNA can move from one cell to another and regulate genes through specific base-pairing. Mechanisms that modify or select RNA for secretion from a cell are unclear. Secreted RNA can be stable enough to be detected in the extracellular environment and can enter the cytosol of distant cells to regulate genes. Mechanisms that import RNA into the cytosol of an animal cell can enable uptake of RNA from many sources including other organisms. This role of RNA is akin to that of steroid hormones, which cross cell membranes to regulate genes. The potential diagnostic use of RNA in human extracellular fluids has ignited interest in understanding mechanisms that enable the movement of RNA between animal cells. Genetic model systems will be essential to gain more confidence in proposed mechanisms of RNA transport and to connect an extracellular RNA with a specific biological function. Studies in the worm C. elegans and in other animals have begun to reveal parts of this novel mechanism of cell-to-cell communication. Here, I summarize the current state of this nascent field, highlight the many unknowns, and suggest future directions. PMID:26138457

  19. Building the bridge between animal movement and population dynamics.

    PubMed

    Morales, Juan M; Moorcroft, Paul R; Matthiopoulos, Jason; Frair, Jacqueline L; Kie, John G; Powell, Roger A; Merrill, Evelyn H; Haydon, Daniel T

    2010-07-27

    While the mechanistic links between animal movement and population dynamics are ecologically obvious, it is much less clear when knowledge of animal movement is a prerequisite for understanding and predicting population dynamics. GPS and other technologies enable detailed tracking of animal location concurrently with acquisition of landscape data and information on individual physiology. These tools can be used to refine our understanding of the mechanistic links between behaviour and individual condition through 'spatially informed' movement models where time allocation to different behaviours affects individual survival and reproduction. For some species, socially informed models that address the movements and average fitness of differently sized groups and how they are affected by fission-fusion processes at relevant temporal scales are required. Furthermore, as most animals revisit some places and avoid others based on their previous experiences, we foresee the incorporation of long-term memory and intention in movement models. The way animals move has important consequences for the degree of mixing that we expect to find both within a population and between individuals of different species. The mixing rate dictates the level of detail required by models to capture the influence of heterogeneity and the dynamics of intra- and interspecific interaction.

  20. Building the bridge between animal movement and population dynamics

    PubMed Central

    Morales, Juan M.; Moorcroft, Paul R.; Matthiopoulos, Jason; Frair, Jacqueline L.; Kie, John G.; Powell, Roger A.; Merrill, Evelyn H.; Haydon, Daniel T.

    2010-01-01

    While the mechanistic links between animal movement and population dynamics are ecologically obvious, it is much less clear when knowledge of animal movement is a prerequisite for understanding and predicting population dynamics. GPS and other technologies enable detailed tracking of animal location concurrently with acquisition of landscape data and information on individual physiology. These tools can be used to refine our understanding of the mechanistic links between behaviour and individual condition through ‘spatially informed’ movement models where time allocation to different behaviours affects individual survival and reproduction. For some species, socially informed models that address the movements and average fitness of differently sized groups and how they are affected by fission–fusion processes at relevant temporal scales are required. Furthermore, as most animals revisit some places and avoid others based on their previous experiences, we foresee the incorporation of long-term memory and intention in movement models. The way animals move has important consequences for the degree of mixing that we expect to find both within a population and between individuals of different species. The mixing rate dictates the level of detail required by models to capture the influence of heterogeneity and the dynamics of intra- and interspecific interaction. PMID:20566505

  1. Comparative study between two animal models of extrapyramidal movement disorders: prevention and reversion by pecan nut shell aqueous extract.

    PubMed

    Trevizol, Fabiola; Benvegnú, Dalila M; Barcelos, Raquel C S; Pase, Camila S; Segat, Hecson J; Dias, Verônica Tironi; Dolci, Geisa S; Boufleur, Nardeli; Reckziegel, Patrícia; Bürger, Marilise E

    2011-08-01

    Acute reserpine and subchronic haloperidol are animal models of extrapyramidal disorders often used to study parkinsonism, akinesia and tardive dyskinesia. In humans, these usually irreversible and disabling extrapyramidal disorders are developed by typical antipsychotic treatment, whose pathophysiology has been related to oxidative damages development. So far, there is no treatment to prevent these problems of the psychiatric clinic, and therefore further studies are needed. Here we used the animal models of extrapyramidal disorders cited above, which were performed in two distinct experiments: orofacial dyskinesia (OD)/catalepsy induced by acute reserpine and subchronic haloperidol after (experiment 1) and before (experiment 2) oral treatment with pecan shell aqueous extract (AE), a natural and promissory antioxidant. When administered previously (exp.1), the AE prevented OD and catalepsy induced by both reserpine and haloperidol. When reserpine and haloperidol were administered before the extract (exp.2), the animals developed OD and catalepsy all the same. However, the orofacial parameter (but not catalepsy) in both animal models was reversed after 7 and 14 days of AE treatment. These results indicate that, acute reserpine and subchronic haloperidol administrations induced similar motor disorders, although through different mechanisms, and therefore are important animal models to study the physiopathology of extrapyramidal disorders. Comparatively, the pecan shell AE was able to both prevent and reverse OD but only to prevent catalepsy. These results reinforce the role of oxidative stress and validate the two animal models used here. Our findings also favor the idea of prevention of extrapyramidal disorders, rather than their reversal. PMID:21356248

  2. Understanding the dynamical control of animal movement

    NASA Astrophysics Data System (ADS)

    Edwards, Donald

    2008-03-01

    Over the last 50 years, neurophysiologists have described many neural circuits that transform sensory input into motor commands, while biomechanicians and behavioral biologists have described many patterns of animal movement that occur in response to sensory input. Attempts to link these two have been frustrated by our technical inability to record from the necessary neurons in a freely behaving animal. As a result, we don't know how these neural circuits function in the closed loop context of free behavior, where the sensory and motor context changes on a millisecond time-scale. To address this problem, we have developed a software package, AnimatLab (www.AnimatLab.com), that enables users to reconstruct an animal's body and its relevant neural circuits, to link them at the sensory and motor ends, and through simulation, to test their ability to reproduce appropriate patterns of the animal's movements in a simulated Newtonian world. A Windows-based program, AnimatLab consists of a neural editor, a body editor, a world editor, stimulus and recording facilities, neural and physics engines, and an interactive 3-D graphical display. We have used AnimatLab to study three patterns of behavior: the grasshopper jump, crayfish escape, and crayfish leg movements used in postural control, walking, reaching and grasping. In each instance, the simulation helped identify constraints on both nervous function and biomechanical performance that have provided the basis for new experiments. Colleagues elsewhere have begun to use AnimatLab to study control of paw movements in cats and postural control in humans. We have also used AnimatLab simulations to guide the development of an autonomous hexapod robot in which the neural control circuitry is downloaded to the robot from the test computer.

  3. Combining High-Speed Cameras and Stop-Motion Animation Software to Support Students' Modeling of Human Body Movement

    ERIC Educational Resources Information Center

    Lee, Victor R.

    2015-01-01

    Biomechanics, and specifically the biomechanics associated with human movement, is a potentially rich backdrop against which educators can design innovative science teaching and learning activities. Moreover, the use of technologies associated with biomechanics research, such as high-speed cameras that can produce high-quality slow-motion video,…

  4. Memory Effects on Movement Behavior in Animal Foraging

    PubMed Central

    Bracis, Chloe; Gurarie, Eliezer; Van Moorter, Bram; Goodwin, R. Andrew

    2015-01-01

    An individual’s choices are shaped by its experience, a fundamental property of behavior important to understanding complex processes. Learning and memory are observed across many taxa and can drive behaviors, including foraging behavior. To explore the conditions under which memory provides an advantage, we present a continuous-space, continuous-time model of animal movement that incorporates learning and memory. Using simulation models, we evaluate the benefit memory provides across several types of landscapes with variable-quality resources and compare the memory model within a nested hierarchy of simpler models (behavioral switching and random walk). We find that memory almost always leads to improved foraging success, but that this effect is most marked in landscapes containing sparse, contiguous patches of high-value resources that regenerate relatively fast and are located in an otherwise devoid landscape. In these cases, there is a large payoff for finding a resource patch, due to size, value, or locational difficulty. While memory-informed search is difficult to differentiate from other factors using solely movement data, our results suggest that disproportionate spatial use of higher value areas, higher consumption rates, and consumption variability all point to memory influencing the movement direction of animals in certain ecosystems. PMID:26288228

  5. When to be discrete: The importance of time formulation in understanding animal movement

    USGS Publications Warehouse

    McClintock, Brett T.; Johnson, Devin S.; Hooten, Mevin B.; Ver Hoef, Jay M.; Morales, Juan M.

    2014-01-01

    Animal movement is essential to our understanding of population dynamics, animal behavior, and the impacts of global change. Coupled with high-resolution biotelemetry data, exciting new inferences about animal movement have been facilitated by various specifications of contemporary models. These approaches differ, but most share common themes. One key distinction is whether the underlying movement process is conceptualized in discrete or continuous time. This is perhaps the greatest source of confusion among practitioners, both in terms of implementation and biological interpretation. In general, animal movement occurs in continuous time but we observe it at fixed discrete-time intervals. Thus, continuous time is conceptually and theoretically appealing, but in practice it is perhaps more intuitive to interpret movement in discrete intervals. With an emphasis on state-space models, we explore the differences and similarities between continuous and discrete versions of mechanistic movement models, establish some common terminology, and indicate under which circumstances one form might be preferred over another. Counter to the overly simplistic view that discrete- and continuous-time conceptualizations are merely different means to the same end, we present novel mathematical results revealing hitherto unappreciated consequences of model formulation on inferences about animal movement. Notably, the speed and direction of movement are intrinsically linked in current continuous-time random walk formulations, and this can have important implications when interpreting animal behavior. We illustrate these concepts in the context of state-space models with multiple movement behavior states using northern fur seal (Callorhinus ursinus) biotelemetry data.

  6. When to be discrete: the importance of time formulation in understanding animal movement.

    PubMed

    McClintock, Brett T; Johnson, Devin S; Hooten, Mevin B; Ver Hoef, Jay M; Morales, Juan M

    2014-01-01

    Animal movement is essential to our understanding of population dynamics, animal behavior, and the impacts of global change. Coupled with high-resolution biotelemetry data, exciting new inferences about animal movement have been facilitated by various specifications of contemporary models. These approaches differ, but most share common themes. One key distinction is whether the underlying movement process is conceptualized in discrete or continuous time. This is perhaps the greatest source of confusion among practitioners, both in terms of implementation and biological interpretation. In general, animal movement occurs in continuous time but we observe it at fixed discrete-time intervals. Thus, continuous time is conceptually and theoretically appealing, but in practice it is perhaps more intuitive to interpret movement in discrete intervals. With an emphasis on state-space models, we explore the differences and similarities between continuous and discrete versions of mechanistic movement models, establish some common terminology, and indicate under which circumstances one form might be preferred over another. Counter to the overly simplistic view that discrete- and continuous-time conceptualizations are merely different means to the same end, we present novel mathematical results revealing hitherto unappreciated consequences of model formulation on inferences about animal movement. Notably, the speed and direction of movement are intrinsically linked in current continuous-time random walk formulations, and this can have important implications when interpreting animal behavior. We illustrate these concepts in the context of state-space models with multiple movement behavior states using northern fur seal (Callorhinus ursinus) biotelemetry data.

  7. When to be discrete: the importance of time formulation in understanding animal movement.

    PubMed

    McClintock, Brett T; Johnson, Devin S; Hooten, Mevin B; Ver Hoef, Jay M; Morales, Juan M

    2014-01-01

    Animal movement is essential to our understanding of population dynamics, animal behavior, and the impacts of global change. Coupled with high-resolution biotelemetry data, exciting new inferences about animal movement have been facilitated by various specifications of contemporary models. These approaches differ, but most share common themes. One key distinction is whether the underlying movement process is conceptualized in discrete or continuous time. This is perhaps the greatest source of confusion among practitioners, both in terms of implementation and biological interpretation. In general, animal movement occurs in continuous time but we observe it at fixed discrete-time intervals. Thus, continuous time is conceptually and theoretically appealing, but in practice it is perhaps more intuitive to interpret movement in discrete intervals. With an emphasis on state-space models, we explore the differences and similarities between continuous and discrete versions of mechanistic movement models, establish some common terminology, and indicate under which circumstances one form might be preferred over another. Counter to the overly simplistic view that discrete- and continuous-time conceptualizations are merely different means to the same end, we present novel mathematical results revealing hitherto unappreciated consequences of model formulation on inferences about animal movement. Notably, the speed and direction of movement are intrinsically linked in current continuous-time random walk formulations, and this can have important implications when interpreting animal behavior. We illustrate these concepts in the context of state-space models with multiple movement behavior states using northern fur seal (Callorhinus ursinus) biotelemetry data. PMID:25709830

  8. Predicting the Movement Speeds of Animals in Natural Environments.

    PubMed

    Wilson, Robbie S; Husak, Jerry F; Halsey, Lewis G; Clemente, Christofer J

    2015-12-01

    An animal's movement speed affects all behaviors and underlies the intensity of an activity, the time it takes to complete it, and the probability of successfully completing it, but which factors determine how fast or slow an animal chooses to move? Despite the critical importance of an animal's choice of speed (hereafter designated as "speed-choice"), we still lack a framework for understanding and predicting how fast animals should move in nature. In this article, we develop a framework for predicting speed that is applicable to any animal-including humans-performing any behavior where choice of speed occurs. To inspire new research in this area, we (1) detail the main factors likely to affect speed-choice, including organismal constraints (i.e., energetic, physiological, and biomechanical) and environmental constraints (i.e., predation intensity and abiotic factors); (2) discuss the value of optimal foraging theory in developing models of speed-choice; and (3) describe how optimality models might be integrated with the range of potential organismal and environmental constraints to predict speed. We show that by utilizing optimality theory it is possible to provide quantitative predictions of optimal speeds across different ecological contexts. However, the usefulness of any predictive models is still entirely dependent on being able to provide relevant mathematical functions to insert into such models. We still lack basic knowledge about how an animal's speed affects its motor control, maneuverability, observational skills, and vulnerability to predators. Studies exploring these gaps in knowledge will help facilitate the field of optimal performance and allow us to adequately parameterize models predicting the speed-choice of animals, which represents one of the most basic of all behavioral decisions.

  9. Predicting oscillatory dynamics in the movement of territorial animals.

    PubMed

    Giuggioli, L; Potts, J R; Harris, S

    2012-07-01

    Understanding ecological processes relies upon the knowledge of the dynamics of each individual component. In the context of animal population ecology, the way animals move and interact is of fundamental importance in explaining a variety of observed patterns. Here, we present a theoretical investigation on the movement dynamics of interacting scent-marking animals. We study how the movement statistics of territorial animals is responsible for the appearance of damped oscillations in the mean square displacement (MSD) of the animals. This non-monotonicity is shown to depend on one dimensionless parameter, given by the ratio of the correlation distance between successive steps to the size of the territory. As that parameter increases, the time dependence of the animal's MSD displays a transition from monotonic, characteristic of Brownian walks, to non-monotonic, characteristic of highly correlated walks. The results presented here represent a novel way of determining the degree of persistence in animal movement processes within confined regions.

  10. Predicting oscillatory dynamics in the movement of territorial animals

    PubMed Central

    Giuggioli, L.; Potts, J. R.; Harris, S.

    2012-01-01

    Understanding ecological processes relies upon the knowledge of the dynamics of each individual component. In the context of animal population ecology, the way animals move and interact is of fundamental importance in explaining a variety of observed patterns. Here, we present a theoretical investigation on the movement dynamics of interacting scent-marking animals. We study how the movement statistics of territorial animals is responsible for the appearance of damped oscillations in the mean square displacement (MSD) of the animals. This non-monotonicity is shown to depend on one dimensionless parameter, given by the ratio of the correlation distance between successive steps to the size of the territory. As that parameter increases, the time dependence of the animal's MSD displays a transition from monotonic, characteristic of Brownian walks, to non-monotonic, characteristic of highly correlated walks. The results presented here represent a novel way of determining the degree of persistence in animal movement processes within confined regions. PMID:22262814

  11. Art In Movement: New Directions in Animation.

    ERIC Educational Resources Information Center

    Halas, John; Manvell, Roger

    Thanks to film, graphic artists can now create over time as well as in space. An essay discusses the influence of cinema on still paintings (e.g., Duchamp's "Nude Descending a Staircase" and the increasing combination of animation and live action in films. New techniques that are available in animation and in special visual effects are explained,…

  12. Hierarchical patch dynamics and animal movement pattern.

    PubMed

    Fauchald, Per; Tveraa, Torkild

    2006-09-01

    In hierarchical patch systems, small-scale patches of high density are nested within large-scale patches of low density. The organization of multiple-scale hierarchical systems makes non-random strategies for dispersal and movement particularly important. Here, we apply a new method based on first-passage time on the pathway of a foraging seabird, the Antarctic petrel (Thalassoica antarctica), to quantify its foraging pattern and the spatial dynamics of its foraging areas. Our results suggest that Antarctic petrels used a nested search strategy to track a highly dynamic hierarchical patch system where small-scale patches were congregated within patches at larger scales. The birds searched for large-scale patches by traveling fast and over long distances. Once within a large-scale patch, the birds concentrated their search to find smaller scale patches. By comparing the pathway of different birds we were able to quantify the spatial scale and turnover of their foraging areas. On the largest scale we found foraging areas with a characteristic scale of about 400 km. Nested within these areas we found foraging areas with a characteristic scale of about 100 km. The large-scale areas disappeared or moved within a time frame of weeks while the nested small-scale areas disappeared or moved within days. Antarctic krill (Euphausia superba) is the dominant food item of Antarctic petrels and we suggest that our findings reflect the spatial dynamics of krill in the area. PMID:16794832

  13. Crossing regimes of temperature dependence in animal movement.

    PubMed

    Gibert, Jean P; Chelini, Marie-Claire; Rosenthal, Malcolm F; DeLong, John P

    2016-05-01

    A pressing challenge in ecology is to understand the effects of changing global temperatures on food web structure and dynamics. The stability of these complex ecological networks largely depends on how predator-prey interactions may respond to temperature changes. Because predators and prey rely on their velocities to catch food or avoid being eaten, understanding how temperatures may affect animal movement is central to this quest. Despite our efforts, we still lack a mechanistic understanding of how the effect of temperature on metabolic processes scales up to animal movement and beyond. Here, we merge a biomechanical approach, the Metabolic Theory of Ecology and empirical data to show that animal movement displays multiple regimes of temperature dependence. We also show that crossing these regimes has important consequences for population dynamics and stability, which depend on the parameters controlling predator-prey interactions. We argue that this dependence upon interaction parameters may help explain why experimental work on the temperature dependence of interaction strengths has so far yielded conflicting results. More importantly, these changes in the temperature dependence of animal movement can have consequences that go well beyond ecological interactions and affect, for example, animal communication, mating, sensory detection, and any behavioral modality dependent on the movement of limbs. Finally, by not taking into account the changes in temperature dependence reported here we might not be able to properly forecast the impact of global warming on ecological processes and propose appropriate mitigation action when needed. PMID:26854767

  14. Toward a mechanistic understanding of animal migration: incorporating physiological measurements in the study of animal movement

    PubMed Central

    Jachowski, David S.; Singh, Navinder J.

    2015-01-01

    Movements are a consequence of an individual's motion and navigational capacity, internal state variables and the influence of external environmental conditions. Although substantial advancements have been made in methods of measuring and quantifying variation in motion capacity, navigational capacity and external environmental parameters in recent decades, the role of internal state in animal migration (and in movement in general) is comparatively little studied. Recent studies of animal movement in the wild illustrate how direct physiological measurements can improve our understanding of the mechanisms underlying movement decisions. In this review, we synthesize and provide examples of how recent technical advances in the physiology-related fields of energetics, nutrition, endocrinology, immunology and ecotoxicology provide opportunities for direct measurements of physiological state in the study of animal movement. We then propose a framework for practitioners to enable better integration of studies of physiological state into animal movement ecology by assessing the mechanistic role played by physiology as both a driver and a modulator of movement. Finally, we highlight the current limitations and research priorities for better integration of direct measurements of animal physiological state into the study of animal movement. PMID:27293720

  15. Toward a mechanistic understanding of animal migration: incorporating physiological measurements in the study of animal movement.

    PubMed

    Jachowski, David S; Singh, Navinder J

    2015-01-01

    Movements are a consequence of an individual's motion and navigational capacity, internal state variables and the influence of external environmental conditions. Although substantial advancements have been made in methods of measuring and quantifying variation in motion capacity, navigational capacity and external environmental parameters in recent decades, the role of internal state in animal migration (and in movement in general) is comparatively little studied. Recent studies of animal movement in the wild illustrate how direct physiological measurements can improve our understanding of the mechanisms underlying movement decisions. In this review, we synthesize and provide examples of how recent technical advances in the physiology-related fields of energetics, nutrition, endocrinology, immunology and ecotoxicology provide opportunities for direct measurements of physiological state in the study of animal movement. We then propose a framework for practitioners to enable better integration of studies of physiological state into animal movement ecology by assessing the mechanistic role played by physiology as both a driver and a modulator of movement. Finally, we highlight the current limitations and research priorities for better integration of direct measurements of animal physiological state into the study of animal movement.

  16. Combining animal movements and behavioural data to detect behavioural states.

    PubMed

    Nams, Vilis O

    2014-10-01

    Animal movement paths show variation in space caused by qualitative shifts in behaviours. I present a method that (1) uses both movement path data and ancillary sensor data to detect natural breakpoints in animal behaviour and (2) groups these segments into different behavioural states. The method can also combine analyses of different path segments or paths from different individuals. It does not assume any underlying movement mechanism. I give an example with simulated data. I also show the effects of random variation, # of states and # of segments on this method. I present a case study of a fisher movement path spanning 8 days, which shows four distinct behavioural states divided into 28 path segments when only turning angles and speed were considered. When accelerometer data were added, the analysis shows seven distinct behavioural states divided into 41 path segments. PMID:25040789

  17. A passive integrated transponder system for tracking animal movements

    USGS Publications Warehouse

    Boarman, W.I.; Beigel, M.L.; Goodlett, G.C.; Sazaki, M.

    1999-01-01

    We describe an automated system that uses passive integrated transponder (PIT) tags to track movements of animals past specific locations. The system was designed to operate maintenance free for several months, be secure from vandalism and environmental damage, and record the identity, date, and time of passage of animals past a 2.4-m wide area. We used the system to monitor effectively the movements of 172 desert tortoises (Gopherus agassizii) through 2 storm drain culverts that pass beneath a state highway in the Mojave Desert, California. Four tortoises entered or passed through the culverts on 60 occasions. The system can be easily adapted to other species.

  18. First passage time analysis of animal movement and insights into the functional response.

    PubMed

    McKenzie, Hannah W; Lewis, Mark A; Merrill, Evelyn H

    2009-01-01

    Movement plays a role in structuring the interactions between individuals, their environment, and other species. Although movement models coupled with empirical data are widely used to study animal distribution, they have seldom been used to study search time. This paper proposes first passage time as a novel approach for understanding the effect of the landscape on animal movement and search time. In the context of animal movement, first passage time is the time taken for an animal to reach a specified site for the first time. We synthesize current first passage time theory and derive a general first passage time equation for animal movement. This equation is related to the Fokker-Planck equation, which is used to describe the distribution of animals in the landscape. We illustrate the first passage time method by analyzing the effect of territorial behavior on the time required for a red fox to locate prey throughout its home range. Using first passage time to compute search times, we consider the effect of two different searching modes on a functional response. We show that random searching leads to a Holling type III functional response. First passage time analysis provides a new tool for studying how animal movement may influence ecological processes. PMID:18825463

  19. Modelling Farm Animal Welfare

    PubMed Central

    Collins, Lisa M.; Part, Chérie E.

    2013-01-01

    Simple Summary In this review paper we discuss the different modeling techniques that have been used in animal welfare research to date. We look at what questions they have been used to answer, the advantages and pitfalls of the methods, and how future research can best use these approaches to answer some of the most important upcoming questions in farm animal welfare. Abstract The use of models in the life sciences has greatly expanded in scope and advanced in technique in recent decades. However, the range, type and complexity of models used in farm animal welfare is comparatively poor, despite the great scope for use of modeling in this field of research. In this paper, we review the different modeling approaches used in farm animal welfare science to date, discussing the types of questions they have been used to answer, the merits and problems associated with the method, and possible future applications of each technique. We find that the most frequently published types of model used in farm animal welfare are conceptual and assessment models; two types of model that are frequently (though not exclusively) based on expert opinion. Simulation, optimization, scenario, and systems modeling approaches are rarer in animal welfare, despite being commonly used in other related fields. Finally, common issues such as a lack of quantitative data to parameterize models, and model selection and validation are discussed throughout the review, with possible solutions and alternative approaches suggested. PMID:26487411

  20. Animal models of scoliosis.

    PubMed

    Bobyn, Justin D; Little, David G; Gray, Randolph; Schindeler, Aaron

    2015-04-01

    Multiple techniques designed to induce scoliotic deformity have been applied across many animal species. We have undertaken a review of the literature regarding experimental models of scoliosis in animals to discuss their utility in comprehending disease aetiology and treatment. Models of scoliosis in animals can be broadly divided into quadrupedal and bipedal experiments. Quadrupedal models, in the absence of axial gravitation force, depend upon development of a mechanical asymmetry along the spine to initiate a scoliotic deformity. Bipedal models more accurately mimic human posture and consequently are subject to similar forces due to gravity, which have been long appreciated to be a contributing factor to the development of scoliosis. Many effective models of scoliosis in smaller animals have not been successfully translated to primates and humans. Though these models may not clarify the aetiology of human scoliosis, by providing a reliable and reproducible deformity in the spine they are a useful means with which to test interventions designed to correct and prevent deformity.

  1. Discovering loose group movement patterns from animal trajectories

    USGS Publications Warehouse

    Wang, Yuwei; Luo, Ze; Xiong, Yan; Prosser, Diann J.; Newman, Scott H.; Takekawa, John Y.; Yan, Baoping

    2015-01-01

    The technical advances of positioning technologies enable us to track animal movements at finer spatial and temporal scales, and further help to discover a variety of complex interactive relationships. In this paper, considering the loose gathering characteristics of the real-life groups' members during the movements, we propose two kinds of loose group movement patterns and corresponding discovery algorithms. Firstly, we propose the weakly consistent group movement pattern which allows the gathering of a part of the members and individual temporary leave from the whole during the movements. To tolerate the high dispersion of the group at some moments (i.e. to adapt the discontinuity of the group's gatherings), we further scheme the weakly consistent and continuous group movement pattern. The extensive experimental analysis and comparison with the real and synthetic data shows that the group pattern discovery algorithms proposed in this paper are similar to the the real-life frequent divergences of the members during the movements, can discover more complete memberships, and have considerable performance.

  2. Equivalence between Step Selection Functions and Biased Correlated Random Walks for Statistical Inference on Animal Movement

    PubMed Central

    Duchesne, Thierry; Fortin, Daniel; Rivest, Louis-Paul

    2015-01-01

    Animal movement has a fundamental impact on population and community structure and dynamics. Biased correlated random walks (BCRW) and step selection functions (SSF) are commonly used to study movements. Because no studies have contrasted the parameters and the statistical properties of their estimators for models constructed under these two Lagrangian approaches, it remains unclear whether or not they allow for similar inference. First, we used the Weak Law of Large Numbers to demonstrate that the log-likelihood function for estimating the parameters of BCRW models can be approximated by the log-likelihood of SSFs. Second, we illustrated the link between the two approaches by fitting BCRW with maximum likelihood and with SSF to simulated movement data in virtual environments and to the trajectory of bison (Bison bison L.) trails in natural landscapes. Using simulated and empirical data, we found that the parameters of a BCRW estimated directly from maximum likelihood and by fitting an SSF were remarkably similar. Movement analysis is increasingly used as a tool for understanding the influence of landscape properties on animal distribution. In the rapidly developing field of movement ecology, management and conservation biologists must decide which method they should implement to accurately assess the determinants of animal movement. We showed that BCRW and SSF can provide similar insights into the environmental features influencing animal movements. Both techniques have advantages. BCRW has already been extended to allow for multi-state modeling. Unlike BCRW, however, SSF can be estimated using most statistical packages, it can simultaneously evaluate habitat selection and movement biases, and can easily integrate a large number of movement taxes at multiple scales. SSF thus offers a simple, yet effective, statistical technique to identify movement taxis. PMID:25898019

  3. 9 CFR 71.16 - Inspection and certification of poultry or other animals for interstate movement.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... poultry or other animals for interstate movement. 71.16 Section 71.16 Animals and Animal Products ANIMAL... (INCLUDING POULTRY) AND ANIMAL PRODUCTS GENERAL PROVISIONS § 71.16 Inspection and certification of poultry or other animals for interstate movement. (a) Assistance and facilities. When poultry or other animals...

  4. 9 CFR 71.16 - Inspection and certification of poultry or other animals for interstate movement.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... poultry or other animals for interstate movement. 71.16 Section 71.16 Animals and Animal Products ANIMAL... (INCLUDING POULTRY) AND ANIMAL PRODUCTS GENERAL PROVISIONS § 71.16 Inspection and certification of poultry or other animals for interstate movement. (a) Assistance and facilities. When poultry or other animals...

  5. 9 CFR 71.16 - Inspection and certification of poultry or other animals for interstate movement.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... poultry or other animals for interstate movement. 71.16 Section 71.16 Animals and Animal Products ANIMAL... (INCLUDING POULTRY) AND ANIMAL PRODUCTS GENERAL PROVISIONS § 71.16 Inspection and certification of poultry or other animals for interstate movement. (a) Assistance and facilities. When poultry or other animals...

  6. 9 CFR 71.16 - Inspection and certification of poultry or other animals for interstate movement.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... poultry or other animals for interstate movement. 71.16 Section 71.16 Animals and Animal Products ANIMAL... (INCLUDING POULTRY) AND ANIMAL PRODUCTS GENERAL PROVISIONS § 71.16 Inspection and certification of poultry or other animals for interstate movement. (a) Assistance and facilities. When poultry or other animals...

  7. 9 CFR 71.16 - Inspection and certification of poultry or other animals for interstate movement.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... poultry or other animals for interstate movement. 71.16 Section 71.16 Animals and Animal Products ANIMAL... (INCLUDING POULTRY) AND ANIMAL PRODUCTS GENERAL PROVISIONS § 71.16 Inspection and certification of poultry or other animals for interstate movement. (a) Assistance and facilities. When poultry or other animals...

  8. Animal models for osteoporosis

    NASA Technical Reports Server (NTRS)

    Turner, R. T.; Maran, A.; Lotinun, S.; Hefferan, T.; Evans, G. L.; Zhang, M.; Sibonga, J. D.

    2001-01-01

    Animal models will continue to be important tools in the quest to understand the contribution of specific genes to establishment of peak bone mass and optimal bone architecture, as well as the genetic basis for a predisposition toward accelerated bone loss in the presence of co-morbidity factors such as estrogen deficiency. Existing animal models will continue to be useful for modeling changes in bone metabolism and architecture induced by well-defined local and systemic factors. However, there is a critical unfulfilled need to develop and validate better animal models to allow fruitful investigation of the interaction of the multitude of factors which precipitate senile osteoporosis. Well characterized and validated animal models that can be recommended for investigation of the etiology, prevention and treatment of several forms of osteoporosis have been listed in Table 1. Also listed are models which are provisionally recommended. These latter models have potential but are inadequately characterized, deviate significantly from the human response, require careful choice of strain or age, or are not practical for most investigators to adopt. It cannot be stressed strongly enough that the enormous potential of laboratory animals as models for osteoporosis can only be realized if great care is taken in the choice of an appropriate species, age, experimental design, and measurements. Poor choices will results in misinterpretation of results which ultimately can bring harm to patients who suffer from osteoporosis by delaying advancement of knowledge.

  9. Animal Density and Track Counts: Understanding the Nature of Observations Based on Animal Movements

    PubMed Central

    Keeping, Derek; Pelletier, Rick

    2014-01-01

    Counting animals to estimate their population sizes is often essential for their management and conservation. Since practitioners frequently rely on indirect observations of animals, it is important to better understand the relationship between such indirect indices and animal abundance. The Formozov-Malyshev-Pereleshin (FMP) formula provides a theoretical foundation for understanding the relationship between animal track counts and the true density of species. Although this analytical method potentially has universal applicability wherever animals are readily detectable by their tracks, it has long been unique to Russia and remains widely underappreciated. In this paper, we provide a test of the FMP formula by isolating the influence of animal travel path tortuosity (i.e., convolutedness) on track counts. We employed simulations using virtual and empirical data, in addition to a field test comparing FMP estimates with independent estimates from line transect distance sampling. We verify that track counts (total intersections between animals and transects) are determined entirely by density and daily movement distances. Hence, the FMP estimator is theoretically robust against potential biases from specific shapes or patterns of animal movement paths if transects are randomly situated with respect to those movements (i.e., the transects do not influence animals’ movements). However, detectability (the detection probability of individual animals) is not determined simply by daily travel distance but also by tortuosity, so ensuring that all intersections with transects are counted regardless of the number of individual animals that made them becomes critical for an accurate density estimate. Additionally, although tortuosity has no bearing on mean track encounter rates, it does affect encounter rate variance and therefore estimate precision. We discuss how these fundamental principles made explicit by the FMP formula have widespread implications for methods of

  10. Dissemination of parasites by animal movements in small ruminant farms.

    PubMed

    Vasileiou, N G C; Fthenakis, G C; Papadopoulos, E

    2015-09-30

    The present paper discusses the spread of parasites by animal movements in small ruminant farms; it focuses in dissemination of parasitic forms that would lead to subsequent infection of sheep or goats. Systems of small ruminant production involve a component of animal movement (e.g., grazing) as part of routine husbandry, which favors spread of parasitic forms; that refers mainly to parasites of the digestive system (nematodes, trematodes, cestodes, protozoa), as well as helminthes of the respiratory system, although dissemination of the various parasitic forms in the environment would not always result to subsequent infection; external parasites may also be disseminated during movements, e.g., to inhabit wooden poles used in fencing. New livestock into a farm constitutes a biosecurity hazard and the most common means to introducing new parasitic pathogens into a farm; in contemporary small ruminant health management, this contributes in dissemination of anthelmintic resistant parasitic strains; other parasitic disease agents (e.g., mange mites, ticks) may also be spread into a farm that way. Often, especially in small scale farming, visits of rams or bucks take place from one farm to another during the mating season; in such cases, ectoparasites (e.g., mange mites) can be disseminated through direct contact of animals, as well other pathogens (e.g., Toxoplasma gondii, Neospora caninum) via the semen. During transportation of sheep/goats, parasitic forms can also spread, as well as during movement of sheep or goats to slaughterhouses, in which case dogs present in these places would contribute to their dissemination. Spread of life forms of various parasites can also occur from animal species present in the environment of sheep or goats; these include animals present within a farm, stray dogs roaming around a farm (e.g., for spread of Multiceps multiceps, Echinococcus granulosus, Taenia hydatigena, N. caninum), cats commanding the environment of a farm (e.g., for

  11. Animal models of tinnitus.

    PubMed

    Brozoski, Thomas J; Bauer, Carol A

    2016-08-01

    Presented is a thematic review of animal tinnitus models from a functional perspective. Chronic tinnitus is a persistent subjective sound sensation, emergent typically after hearing loss. Although the sensation is experientially simple, it appears to have central a nervous system substrate of unexpected complexity that includes areas outside of those classically defined as auditory. Over the past 27 years animal models have significantly contributed to understanding tinnitus' complex neurophysiology. In that time, a diversity of models have been developed, each with its own strengths and limitations. None has clearly become a standard. Animal models trace their origin to the 1988 experiments of Jastreboff and colleagues. All subsequent models derive some of their features from those experiments. Common features include behavior-dependent psychophysical determination, acoustic conditions that contrast objective sound and silence, and inclusion of at least one normal-hearing control group. In the present review, animal models have been categorized as either interrogative or reflexive. Interrogative models use emitted behavior under voluntary control to indicate hearing. An example would be pressing a lever to obtain food in the presence of a particular sound. In this type of model animals are interrogated about their auditory sensations, analogous to asking a patient, "What do you hear?" These models require at least some training and motivation management, and reflect the perception of tinnitus. Reflexive models, in contrast, employ acoustic modulation of an auditory reflex, such as the acoustic startle response. An unexpected loud sound will elicit a reflexive motor response from many species, including humans. Although involuntary, acoustic startle can be modified by a lower-level preceding event, including a silent sound gap. Sound-gap modulation of acoustic startle appears to discriminate tinnitus in animals as well as humans, and requires no training or

  12. Spatiotemporal Variation in Distance Dependent Animal Movement Contacts: One Size Doesn’t Fit All

    PubMed Central

    Brommesson, Peter; Wennergren, Uno; Lindström, Tom

    2016-01-01

    The structure of contacts that mediate transmission has a pronounced effect on the outbreak dynamics of infectious disease and simulation models are powerful tools to inform policy decisions. Most simulation models of livestock disease spread rely to some degree on predictions of animal movement between holdings. Typically, movements are more common between nearby farms than between those located far away from each other. Here, we assessed spatiotemporal variation in such distance dependence of animal movement contacts from an epidemiological perspective. We evaluated and compared nine statistical models, applied to Swedish movement data from 2008. The models differed in at what level (if at all), they accounted for regional and/or seasonal heterogeneities in the distance dependence of the contacts. Using a kernel approach to describe how probability of contacts between farms changes with distance, we developed a hierarchical Bayesian framework and estimated parameters by using Markov Chain Monte Carlo techniques. We evaluated models by three different approaches of model selection. First, we used Deviance Information Criterion to evaluate their performance relative to each other. Secondly, we estimated the log predictive posterior distribution, this was also used to evaluate their relative performance. Thirdly, we performed posterior predictive checks by simulating movements with each of the parameterized models and evaluated their ability to recapture relevant summary statistics. Independent of selection criteria, we found that accounting for regional heterogeneity improved model accuracy. We also found that accounting for seasonal heterogeneity was beneficial, in terms of model accuracy, according to two of three methods used for model selection. Our results have important implications for livestock disease spread models where movement is an important risk factor for between farm transmission. We argue that modelers should refrain from using methods to simulate

  13. A new method for discovering behavior patterns among animal movements

    USGS Publications Warehouse

    Wang, Y.; Luo, Ze; Takekawa, J.; Prosser, Diann J.; Xiong, Y.; Newman, S.; Xiao, X.; Batbayar, N.; Spragens, Kyle A; Balachandran, S.; Yan, B.

    2016-01-01

    Advanced satellite tracking technologies enable biologists to track animal movements at fine spatial and temporal scales. The resultant data present opportunities and challenges for understanding animal behavioral mechanisms. In this paper, we develop a new method to elucidate animal movement patterns from tracking data. Here, we propose the notion of continuous behavior patterns as a concise representation of popular migration routes and underlying sequential behaviors during migration. Each stage in the pattern is characterized in terms of space (i.e., the places traversed during movements) and time (i.e. the time spent in those places); that is, the behavioral state corresponding to a stage is inferred according to the spatiotemporal and sequential context. Hence, the pattern may be interpreted predictably. We develop a candidate generation and refinement framework to derive all continuous behavior patterns from raw trajectories. In the framework, we first define the representative spots to denote the underlying potential behavioral states that are extracted from individual trajectories according to the similarity of relaxed continuous locations in certain distinct time intervals. We determine the common behaviors of multiple individuals according to the spatiotemporal proximity of representative spots and apply a projection-based extension approach to generate candidate sequential behavior sequences as candidate patterns. Finally, the candidate generation procedure is combined with a refinement procedure to derive continuous behavior patterns. We apply an ordered processing strategy to accelerate candidate refinement. The proposed patterns and discovery framework are evaluated through conceptual experiments on both real GPS-tracking and large synthetic datasets.

  14. A new method for discovering behavior patterns among animal movements

    PubMed Central

    Wang, Yuwei; Luo, Ze; Takekawa, John; Prosser, Diann; Xiong, Yan; Newman, Scott; Xiao, Xiangming; Batbayar, Nyambayar; Spragens, Kyle; Balachandran, Sivananinthaperumal; Yan, Baoping

    2016-01-01

    Advanced satellite tracking technologies enable biologists to track animal movements at fine spatial and temporal scales. The resultant data present opportunities and challenges for understanding animal behavioral mechanisms. In this paper, we develop a new method to elucidate animal movement patterns from tracking data. Here, we propose the notion of continuous behavior patterns as a concise representation of popular migration routes and underlying sequential behaviors during migration. Each stage in the pattern is characterized in terms of space (i.e., the places traversed during movements) and time (i.e. the time spent in those places); that is, the behavioral state corresponding to a stage is inferred according to the spatiotemporal and sequential context. Hence, the pattern may be interpreted predictably. We develop a candidate generation and refinement framework to derive all continuous behavior patterns from raw trajectories. In the framework, we first define the representative spots to denote the underlying potential behavioral states that are extracted from individual trajectories according to the similarity of relaxed continuous locations in certain distinct time intervals. We determine the common behaviors of multiple individuals according to the spatiotemporal proximity of representative spots and apply a projection-based extension approach to generate candidate sequential behavior sequences as candidate patterns. Finally, the candidate generation procedure is combined with a refinement procedure to derive continuous behavior patterns. We apply an ordered processing strategy to accelerate candidate refinement. The proposed patterns and discovery framework are evaluated through conceptual experiments on both real GPS-tracking and large synthetic datasets. PMID:27217810

  15. Animal movement constraints improve resource selection inference in the presence of telemetry error

    USGS Publications Warehouse

    Brost, Brian M.; Hooten, Mevin B.; Hanks, Ephraim M.; Small, Robert J.

    2016-01-01

    Multiple factors complicate the analysis of animal telemetry location data. Recent advancements address issues such as temporal autocorrelation and telemetry measurement error, but additional challenges remain. Difficulties introduced by complicated error structures or barriers to animal movement can weaken inference. We propose an approach for obtaining resource selection inference from animal location data that accounts for complicated error structures, movement constraints, and temporally autocorrelated observations. We specify a model for telemetry data observed with error conditional on unobserved true locations that reflects prior knowledge about constraints in the animal movement process. The observed telemetry data are modeled using a flexible distribution that accommodates extreme errors and complicated error structures. Although constraints to movement are often viewed as a nuisance, we use constraints to simultaneously estimate and account for telemetry error. We apply the model to simulated data, showing that it outperforms common ad hoc approaches used when confronted with measurement error and movement constraints. We then apply our framework to an Argos satellite telemetry data set on harbor seals (Phoca vitulina) in the Gulf of Alaska, a species that is constrained to move within the marine environment and adjacent coastlines.

  16. Animal movement constraints improve resource selection inference in the presence of telemetry error.

    PubMed

    Brost, Brian M; Hooten, Mevin B; Hanks, Ephraim M; Small, Robert J

    2015-10-01

    Multiple factors complicate the analysis of animal telemetry location data. Recent advancements address issues such as temporal autocorrelation and telemetry measurement error, but additional challenges remain. Difficulties introduced by complicated error structures or barriers to animal movement can weaken inference. We propose an approach for obtaining resource selection inference from animal location data that accounts for complicated error structures, movement constraints, and temporally autocorrelated observations. We specify a model for telemetry data observed with error conditional on unobserved true locations that reflects prior knowledge about constraints in the animal movement process. The observed telemetry data are modeled using a flexible distribution that accommodates extreme errors and complicated error structures. Although constraints to movement are often viewed as a nuisance, we use constraints to simultaneously estimate and account for telemetry error. We apply the model to simulated data, showing that it outperforms common ad hoc approaches used when confronted with measurement error and movement constraints. We then apply our framework to an Argos satellite telemetry data set on harbor seals (Phoca vitulina) in the Gulf of Alaska, a species that is constrained to move within the marine environment and adjacent coastlines. PMID:26649380

  17. Joint estimation over multiple individuals improves behavioural state inference from animal movement data

    PubMed Central

    Jonsen, Ian

    2016-01-01

    State-space models provide a powerful way to scale up inference of movement behaviours from individuals to populations when the inference is made across multiple individuals. Here, I show how a joint estimation approach that assumes individuals share identical movement parameters can lead to improved inference of behavioural states associated with different movement processes. I use simulated movement paths with known behavioural states to compare estimation error between nonhierarchical and joint estimation formulations of an otherwise identical state-space model. Behavioural state estimation error was strongly affected by the degree of similarity between movement patterns characterising the behavioural states, with less error when movements were strongly dissimilar between states. The joint estimation model improved behavioural state estimation relative to the nonhierarchical model for simulated data with heavy-tailed Argos location errors. When applied to Argos telemetry datasets from 10 Weddell seals, the nonhierarchical model estimated highly uncertain behavioural state switching probabilities for most individuals whereas the joint estimation model yielded substantially less uncertainty. The joint estimation model better resolved the behavioural state sequences across all seals. Hierarchical or joint estimation models should be the preferred choice for estimating behavioural states from animal movement data, especially when location data are error-prone. PMID:26853261

  18. Animal models of sepsis

    PubMed Central

    Fink, Mitchell P

    2014-01-01

    Sepsis remains a common, serious, and heterogeneous clinical entity that is difficult to define adequately. Despite its importance as a public health problem, efforts to develop and gain regulatory approval for a specific therapeutic agent for the adjuvant treatment of sepsis have been remarkably unsuccessful. One step in the critical pathway for the development of a new agent for adjuvant treatment of sepsis is evaluation in an appropriate animal model of the human condition. Unfortunately, the animal models that have been used for this purpose have often yielded misleading findings. It is likely that there are multiple reasons for the discrepancies between the results obtained in tests of pharmacological agents in animal models of sepsis and the outcomes of human clinical trials. One of important reason may be that the changes in gene expression, which are triggered by trauma or infection, are different in mice, a commonly used species for preclinical testing, and humans. Additionally, many species, including mice and baboons, are remarkably resistant to the toxic effects of bacterial lipopolysaccharide, whereas humans are exquisitely sensitive. New approaches toward the use of animals for sepsis research are being investigated. But, at present, results from preclinical studies of new therapeutic agents for sepsis must be viewed with a degree of skepticism. PMID:24022070

  19. Animal Models of Atherosclerosis

    PubMed Central

    Getz, Godfrey S.; Reardon, Catherine A.

    2012-01-01

    Atherosclerosis is a chronic inflammatory disorder that is the underlying cause of most cardiovascular disease. Both cells of the vessel wall and cells of the immune system participate in atherogenesis. This process is heavily influenced by plasma lipoproteins, genetics and the hemodynamics of the blood flow in the artery. A variety of small and large animal models have been used to study the atherogenic process. No model is ideal as each has its own advantages and limitations with respect to manipulation of the atherogenic process and modeling human atherosclerosis or lipoprotein profile. Useful large animal models include pigs, rabbits and non-human primates. Due in large part to the relative ease of genetic manipulation and the relatively short time frame for the development of atherosclerosis, murine models are currently the most extensively used. While not all aspects of murine atherosclerosis are identical to humans, studies using murine models have suggested potential biological processes and interactions that underlie this process. As it becomes clear that different factors may influence different stages of lesion development, the use of mouse models with the ability to turn on or delete proteins or cells in tissue specific and temporal manner will be very valuable. PMID:22383700

  20. Agent Based Model of Livestock Movements

    NASA Astrophysics Data System (ADS)

    Miron, D. J.; Emelyanova, I. V.; Donald, G. E.; Garner, G. M.

    The modelling of livestock movements within Australia is of national importance for the purposes of the management and control of exotic disease spread, infrastructure development and the economic forecasting of livestock markets. In this paper an agent based model for the forecasting of livestock movements is presented. This models livestock movements from farm to farm through a saleyard. The decision of farmers to sell or buy cattle is often complex and involves many factors such as climate forecast, commodity prices, the type of farm enterprise, the number of animals available and associated off-shore effects. In this model the farm agent's intelligence is implemented using a fuzzy decision tree that utilises two of these factors. These two factors are the livestock price fetched at the last sale and the number of stock on the farm. On each iteration of the model farms choose either to buy, sell or abstain from the market thus creating an artificial supply and demand. The buyers and sellers then congregate at the saleyard where livestock are auctioned using a second price sealed bid. The price time series output by the model exhibits properties similar to those found in real livestock markets.

  1. 9 CFR 72.1 - Interstate movement of infested or exposed animals prohibited.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Interstate movement of infested or exposed animals prohibited. 72.1 Section 72.1 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE INTERSTATE TRANSPORTATION OF ANIMALS (INCLUDING POULTRY)...

  2. 9 CFR 94.15 - Animal products and materials; movement and handling.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Animal products and materials; movement and handling. 94.15 Section 94.15 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE EXPORTATION AND IMPORTATION OF ANIMALS (INCLUDING POULTRY) AND...

  3. 9 CFR 94.15 - Animal products and materials; movement and handling.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Animal products and materials; movement and handling. 94.15 Section 94.15 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE EXPORTATION AND IMPORTATION OF ANIMALS (INCLUDING POULTRY) AND...

  4. 9 CFR 94.15 - Animal products and materials; movement and handling.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Animal products and materials; movement and handling. 94.15 Section 94.15 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE EXPORTATION AND IMPORTATION OF ANIMALS (INCLUDING POULTRY) AND...

  5. 9 CFR 94.15 - Animal products and materials; movement and handling.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Animal products and materials; movement and handling. 94.15 Section 94.15 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE EXPORTATION AND IMPORTATION OF ANIMALS (INCLUDING POULTRY) AND...

  6. Modeling animal landscapes.

    PubMed

    Porter, W P; Ostrowski, S; Williams, J B

    2010-01-01

    There is an increasing need to assess the effects of climate and land-use change on habitat quality, ideally from a mechanistic basis. The symposium "Molecules to Migration: Pressures of Life" at the Fourth International Conference in Africa for Comparative Physiology and Biochemistry, Maasai Mara National Reserve, Kenya, 2008, illustrated how the principles of biophysical ecology can capture the mechanistic links between organisms, climate, and other habitat features. These principles provide spatially explicit assessments of habitat quality from a physiological perspective (i.e., "animal landscapes") that can be validated independently of the data used to derive and parameterize them. The contents of this symposium showcased how the modeling of animal landscapes can be used to assess key issues in applied and theoretical ecology. The presentations included applications to amphibians, reptiles, birds, and mammals. The rare Arabian oryx on the Arabian Peninsula is used as an example for energetic calculations and their implications for behavior on the landscape. PMID:20670170

  7. Animal models of candidiasis.

    PubMed

    Clancy, Cornelius J; Cheng, Shaoji; Nguyen, Minh Hong

    2009-01-01

    Animal models are powerful tools to study the pathogenesis of diverse types of candidiasis. Murine models are particularly attractive because of cost, ease of handling, technical feasibility, and experience with their use. In this chapter, we describe methods for two of the most popular murine models of disease caused by Candida albicans. In an intravenously disseminated candidiasis (DC) model, immunocompetent mice are infected by lateral tail vein injections of a C. albicans suspension. Endpoints include mortality, tissue burdens of infection (most importantly in the kidneys, although spleens and livers are sometimes also assessed), and histopathology of infected organs. In a model of oral/esophageal candidiasis, mice are immunosuppressed with cortisone acetate and inoculated in the oral cavities using swabs saturated with a C. albicans suspension. Since mice do not die from oral candidiasis in this model, endpoints are tissue burden of infection and histopathology. The DC and oral/esophageal models are most commonly used for studies of C. albicans virulence, in which the disease-causing ability of a mutant strain is compared with an isogenic parent strain. Nevertheless, the basic techniques we describe are also applicable to models adapted to investigate other aspects of pathogenesis, such as spatiotemporal patterns of gene expression, specific aspects of host immune response and assessment of antifungal agents, immunomodulatory strategies, and vaccines.

  8. Can orchards help connect Mediterranean ecosystems? Animal movement data alter conservation priorities

    USGS Publications Warehouse

    Nogeire, Theresa M.; Davis, Frank W.; Crooks, Kevin R.; McRae, Brad H.; Lyren, Lisa M.; Boydston, Erin E.

    2015-01-01

    As natural habitats become fragmented by human activities, animals must increasingly move through human-dominated systems, particularly agricultural landscapes. Mapping areas important for animal movement has therefore become a key part of conservation planning. Models of landscape connectivity are often parameterized using expert opinion and seldom distinguish between the risks and barriers presented by different crop types. Recent research, however, suggests different crop types, such as row crops and orchards, differ in the degree to which they facilitate or impede species movements. Like many mammalian carnivores, bobcats (Lynx rufus) are sensitive to fragmentation and loss of connectivity between habitat patches. We investigated how distinguishing between different agricultural land covers might change conclusions about the relative conservation importance of different land uses in a Mediterranean ecosystem. Bobcats moved relatively quickly in row crops but relatively slowly in orchards, at rates similar to those in natural habitats of woodlands and scrub. We found that parameterizing a connectivity model using empirical data on bobcat movements in agricultural lands and other land covers, instead of parameterizing the model using habitat suitability indices based on expert opinion, altered locations of predicted animal movement routes. These results emphasize that differentiating between types of agriculture can alter conservation planning outcomes.

  9. Animal Models in Osteosarcoma

    PubMed Central

    Guijarro, Maria V.; Ghivizzani, Steven C.; Gibbs, C. Parker

    2014-01-01

    Osteosarcoma (OS) is the most common non-hematologic primary tumor of bone in children and adults. High-dose cytotoxic chemotherapy and surgical resection have improved prognosis, with long-term survival for non-metastatic disease approaching 70%. However, most OS tumors are high grade and tend to rapidly develop pulmonary metastases. Despite clinical advances, patients with metastatic disease or relapse have a poor prognosis. Toward a better understanding of the molecular pathogenesis of human OS, several genetically modified OS mouse models have been developed and will be reviewed here. However, better animal models that more accurately recapitulate the natural progression of the disease are needed for the development of improved prognostic and diagnostic markers as well as targeted therapies for both primary and metastatic OS. PMID:25101245

  10. Computer-generated animal model stimuli.

    PubMed

    Woo, Kevin L

    2007-01-01

    Communication between animals is diverse and complex. Animals may communicate using auditory, seismic, chemosensory, electrical, or visual signals. In particular, understanding the constraints on visual signal design for communication has been of great interest. Traditional methods for investigating animal interactions have used basic observational techniques, staged encounters, or physical manipulation of morphology. Less intrusive methods have tried to simulate conspecifics using crude playback tools, such as mirrors, still images, or models. As technology has become more advanced, video playback has emerged as another tool in which to examine visual communication (Rosenthal, 2000). However, to move one step further, the application of computer-animation now allows researchers to specifically isolate critical components necessary to elicit social responses from conspecifics, and manipulate these features to control interactions. Here, I provide detail on how to create an animation using the Jacky dragon as a model, but this process may be adaptable for other species. In building the animation, I elected to use Lightwave 3D to alter object morphology, add texture, install bones, and provide comparable weight shading that prevents exaggerated movement. The animation is then matched to select motor patterns to replicate critical movement features. Finally, the sequence must rendered into an individual clip for presentation. Although there are other adaptable techniques, this particular method had been demonstrated to be effective in eliciting both conspicuous and social responses in staged interactions.

  11. Introduction to the Symposium: Towards a General Framework for Predicting Animal Movement Speeds in Nature.

    PubMed

    Wilson, Robbie S; Husak, Jerry F

    2015-12-01

    Speed of movement is fundamental to animal behavior-defining the intensity of a task, the time needed to complete it, and the likelihood of success-but how does an animal decide how fast to move? Most studies of animal performance measure maximum capabilities, but animals rarely move at their maximum in the wild. It was the goal of our symposium to develop a conceptual framework to explore the choices of speed in nature. A major difference between our approach and previous work is our move toward understanding optimal rather than maximal speeds. In the following series of papers, we provide a starting point for future work on animal movement speeds, including a conceptual framework, a simple optimality model, an evolutionary context, and an exploration of the various biomechanical and energetic constraints on speed. By applying a cross-disciplinary approach to the study of the choice of speed-as we have done here-we can reveal much about the way animals use habitats, interact with conspecifics, avoid predators, obtain food, and negotiate human-modified landscapes. PMID:26493610

  12. The effect of animal movement on line transect estimates of abundance.

    PubMed

    Glennie, Richard; Buckland, Stephen T; Thomas, Len

    2015-01-01

    Line transect sampling is a distance sampling method for estimating the abundance of wild animal populations. One key assumption of this method is that all animals are detected at their initial location. Animal movement independent of the transect and observer can thus cause substantial bias. We present an analytic expression for this bias when detection within the transect is certain (strip transect sampling) and use simulation to quantify bias when detection falls off with distance from the line (line transect sampling). We also explore the non-linear relationship between bias, detection, and animal movement by varying detectability and movement type. We consider animals that move in randomly orientated straight lines, which provides an upper bound on bias, and animals that are constrained to a home range of random radius. We find that bias is reduced when animal movement is constrained, and bias is considerably smaller in line transect sampling than strip transect sampling provided that mean animal speed is less than observer speed. By contrast, when mean animal speed exceeds observer speed the bias in line transect sampling becomes comparable with, and may exceed, that of strip transect sampling. Bias from independent animal movement is reduced by the observer searching further perpendicular to the transect, searching a shorter distance ahead and by ignoring animals that may overtake the observer from behind. However, when animals move in response to the observer, the standard practice of searching further ahead should continue as the bias from responsive movement is often greater than that from independent movement.

  13. Statistical tests for analysing directed movement of self-organising animal groups.

    PubMed

    Merrifield, A; Myerscough, Mary R; Weber, N

    2006-09-01

    We discuss some theory concerning directional data and introduce a suite of statistical tools that researchers interested in the directional movement of animal groups can use to analyse results from their models. We illustrate these tools by analysing the results of a model of groups moving under the duress of certain informed indistinguishable individuals, that arises in the context of honeybee (Apis mellifera) swarming behaviour. We modify an existing model of collective motion, based on inter-individual social interactions, allowing knowledgeable individuals to guide group members to the goal by travelling through the group in a direct line aligned with the goal direction.

  14. 9 CFR 78.2 - Handling of certificates, permits, and “S” brand permits for interstate movement of animals.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... âSâ brand permits for interstate movement of animals. 78.2 Section 78.2 Animals and Animal Products... certificates, permits, and “S” brand permits for interstate movement of animals. (a) Any certificate, permit, or “S” brand permit required by this part for the interstate movement of animals shall be...

  15. 9 CFR 78.2 - Handling of certificates, permits, and “S” brand permits for interstate movement of animals.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... âSâ brand permits for interstate movement of animals. 78.2 Section 78.2 Animals and Animal Products... certificates, permits, and “S” brand permits for interstate movement of animals. (a) Any certificate, permit, or “S” brand permit required by this part for the interstate movement of animals shall be...

  16. Apparent power-law distributions in animal movements can arise from intraspecific interactions

    PubMed Central

    Breed, Greg A.; Severns, Paul M.; Edwards, Andrew M.

    2015-01-01

    Lévy flights have gained prominence for analysis of animal movement. In a Lévy flight, step-lengths are drawn from a heavy-tailed distribution such as a power law (PL), and a large number of empirical demonstrations have been published. Others, however, have suggested that animal movement is ill fit by PL distributions or contend a state-switching process better explains apparent Lévy flight movement patterns. We used a mix of direct behavioural observations and GPS tracking to understand step-length patterns in females of two related butterflies. We initially found movement in one species (Euphydryas editha taylori) was best fit by a bounded PL, evidence of a Lévy flight, while the other (Euphydryas phaeton) was best fit by an exponential distribution. Subsequent analyses introduced additional candidate models and used behavioural observations to sort steps based on intraspecific interactions (interactions were rare in E. phaeton but common in E. e. taylori). These analyses showed a mixed-exponential is favoured over the bounded PL for E. e. taylori and that when step-lengths were sorted into states based on the influence of harassing conspecific males, both states were best fit by simple exponential distributions. The direct behavioural observations allowed us to infer the underlying behavioural mechanism is a state-switching process driven by intraspecific interactions rather than a Lévy flight. PMID:25519992

  17. 9 CFR 80.3 - Movement of domestic animals that are positive to an official Johne's disease test.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... positive to an official Johne's disease test. 80.3 Section 80.3 Animals and Animal Products ANIMAL AND... (INCLUDING POULTRY) AND ANIMAL PRODUCTS JOHNE'S DISEASE IN DOMESTIC ANIMALS § 80.3 Movement of domestic animals that are positive to an official Johne's disease test. (a) Movement of domestic animals...

  18. 9 CFR 80.4 - Segregation of animals positive to an official Johne's disease test during interstate movement.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... official Johne's disease test during interstate movement. 80.4 Section 80.4 Animals and Animal Products... ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS JOHNE'S DISEASE IN DOMESTIC ANIMALS § 80.4 Segregation of animals positive to an official Johne's disease test during interstate movement. Animals that are...

  19. 9 CFR 80.3 - Movement of domestic animals that are positive to an official Johne's disease test.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... positive to an official Johne's disease test. 80.3 Section 80.3 Animals and Animal Products ANIMAL AND... (INCLUDING POULTRY) AND ANIMAL PRODUCTS JOHNE'S DISEASE IN DOMESTIC ANIMALS § 80.3 Movement of domestic animals that are positive to an official Johne's disease test. (a) Movement of domestic animals...

  20. 9 CFR 80.3 - Movement of domestic animals that are positive to an official Johne's disease test.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... positive to an official Johne's disease test. 80.3 Section 80.3 Animals and Animal Products ANIMAL AND... (INCLUDING POULTRY) AND ANIMAL PRODUCTS JOHNE'S DISEASE IN DOMESTIC ANIMALS § 80.3 Movement of domestic animals that are positive to an official Johne's disease test. (a) Movement of domestic animals...

  1. 9 CFR 80.4 - Segregation of animals positive to an official Johne's disease test during interstate movement.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... official Johne's disease test during interstate movement. 80.4 Section 80.4 Animals and Animal Products... ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS JOHNE'S DISEASE IN DOMESTIC ANIMALS § 80.4 Segregation of animals positive to an official Johne's disease test during interstate movement. Animals that are...

  2. 9 CFR 80.4 - Segregation of animals positive to an official Johne's disease test during interstate movement.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... official Johne's disease test during interstate movement. 80.4 Section 80.4 Animals and Animal Products... ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS JOHNE'S DISEASE IN DOMESTIC ANIMALS § 80.4 Segregation of animals positive to an official Johne's disease test during interstate movement. Animals that are...

  3. 9 CFR 80.3 - Movement of domestic animals that are positive to an official Johne's disease test.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... positive to an official Johne's disease test. 80.3 Section 80.3 Animals and Animal Products ANIMAL AND... (INCLUDING POULTRY) AND ANIMAL PRODUCTS JOHNE'S DISEASE IN DOMESTIC ANIMALS § 80.3 Movement of domestic animals that are positive to an official Johne's disease test. (a) Movement of domestic animals...

  4. 9 CFR 80.4 - Segregation of animals positive to an official Johne's disease test during interstate movement.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... official Johne's disease test during interstate movement. 80.4 Section 80.4 Animals and Animal Products... ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS JOHNE'S DISEASE IN DOMESTIC ANIMALS § 80.4 Segregation of animals positive to an official Johne's disease test during interstate movement. Animals that are...

  5. 9 CFR 80.4 - Segregation of animals positive to an official Johne's disease test during interstate movement.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... official Johne's disease test during interstate movement. 80.4 Section 80.4 Animals and Animal Products... ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS JOHNE'S DISEASE IN DOMESTIC ANIMALS § 80.4 Segregation of animals positive to an official Johne's disease test during interstate movement. Animals that are...

  6. 9 CFR 80.3 - Movement of domestic animals that are positive to an official Johne's disease test.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... positive to an official Johne's disease test. 80.3 Section 80.3 Animals and Animal Products ANIMAL AND... (INCLUDING POULTRY) AND ANIMAL PRODUCTS JOHNE'S DISEASE IN DOMESTIC ANIMALS § 80.3 Movement of domestic animals that are positive to an official Johne's disease test. (a) Movement of domestic animals...

  7. Eye Movements in Reading: Models and Data

    PubMed Central

    Rayner, Keith

    2010-01-01

    Models of eye movement control in reading and their impact on the field are discussed. Differences between the E-Z Reader model and the SWIFT model are reviewed, as are benchmark data that need to be accounted for by any model of eye movement control. Predictions made by the models and how models can sometimes account for counterintuitive findings are also discussed. Finally, the role of models and data in further understanding the reading process is considered. PMID:20664810

  8. ANIMAL MODELS FOR IMMUNOTOXICITY

    EPA Science Inventory

    Greater susceptibility to infection is a hallmark of compromised immune function in humans and animals, and is often considered the benchmark against which the predictive value of immune function tests are compared. This focus of this paper is resistance to infection with the pa...

  9. Animal Models of Colorectal Cancer

    PubMed Central

    Johnson, Robert L.; Fleet, James C.

    2012-01-01

    Colorectal cancer is a heterogeneous disease that afflicts a large number of people in the United States. The use of animal models has the potential to increase our understanding of carcinogenesis, tumor biology, and the impact of specific molecular events on colon biology. In addition, animal models with features of specific human colorectal cancers can be used to test strategies for cancer prevention and treatment. In this review we provide an overview of the mechanisms driving human cancer, we discuss the approaches one can take to model colon cancer in animals, and we describe a number of specific animal models that have been developed for the study of colon cancer. We believe that there are many valuable animal models to study various aspects of human colorectal cancer. However, opportunities for improving upon these models exist. PMID:23076650

  10. Animal models of colorectal cancer.

    PubMed

    Johnson, Robert L; Fleet, James C

    2013-06-01

    Colorectal cancer is a heterogeneous disease that afflicts a large number of people in the USA. The use of animal models has the potential to increase our understanding of carcinogenesis, tumor biology, and the impact of specific molecular events on colon biology. In addition, animal models with features of specific human colorectal cancers can be used to test strategies for cancer prevention and treatment. In this review, we provide an overview of the mechanisms driving human cancer, we discuss the approaches one can take to model colon cancer in animals, and we describe a number of specific animal models that have been developed for the study of colon cancer. We believe that there are many valuable animal models to study various aspects of human colorectal cancer. However, opportunities for improving upon these models exist.

  11. Model of Emotional Expressions in Movements

    ERIC Educational Resources Information Center

    Rozaliev, Vladimir L.; Orlova, Yulia A.

    2013-01-01

    This paper presents a new approach to automated identification of human emotions based on analysis of body movements, a recognition of gestures and poses. Methodology, models and automated system for emotion identification are considered. To characterize the person emotions in the model, body movements are described with linguistic variables and a…

  12. Animated Randomness, Avatars, Movement, and Personalization in Risk Graphics

    PubMed Central

    Fuhrel-Forbis, Andrea; Wijeysundera, Harindra C; Exe, Nicole; Dickson, Mark; Holtzman, Lisa; Kahn, Valerie C; Zikmund-Fisher, Brian J

    2014-01-01

    Background Risk communication involves conveying two inherently difficult concepts about the nature of risk: the underlying random distribution of outcomes and how a population-based proportion applies to an individual. Objective The objective of this study was to test whether 4 design factors in icon arrays—animated random dispersal of risk events, avatars to represent an individual, personalization (operationalized as choosing the avatar’s color), and a moving avatar—might help convey randomness and how a given risk applies to an individual, thereby better aligning risk perceptions with risk estimates. Methods A diverse sample of 3630 adults with no previous heart disease or stroke completed an online nested factorial experiment in which they entered personal health data into a risk calculator that estimated 10-year risk of cardiovascular disease based on a robust and validated model. We randomly assigned them to view their results in 1 of 10 risk graphics that used different combinations of the 4 design factors. We measured participants’ risk perceptions as our primary outcome, as well as behavioral intentions and recall of the risk estimate. We also assessed subjective numeracy, whether or not participants knew anyone who had died of cardiovascular causes, and whether or not they knew their blood pressure and cholesterol as potential moderators. Results Animated randomness was associated with better alignment between risk estimates and risk perceptions (F 1,3576=6.12, P=.01); however, it also led to lower scores on healthy lifestyle intentions (F 1,3572=11.1, P<.001). Using an avatar increased risk perceptions overall (F 1,3576=4.61, P=.03) and most significantly increased risk perceptions among those who did not know a particular person who had experienced the grave outcomes of cardiovascular disease (F 1,3576=5.88, P=.02). Using an avatar also better aligned actual risk estimates with intentions to see a doctor (F 1,3556=6.38, P=.01). No design

  13. Uncertainty in spatially explicit animal dispersal models

    USGS Publications Warehouse

    Mooij, Wolf M.; DeAngelis, Donald L.

    2003-01-01

    Uncertainty in estimates of survival of dispersing animals is a vexing difficulty in conservation biology. The current notion is that this uncertainty decreases the usefulness of spatially explicit population models in particular. We examined this problem by comparing dispersal models of three levels of complexity: (1) an event-based binomial model that considers only the occurrence of mortality or arrival, (2) a temporally explicit exponential model that employs mortality and arrival rates, and (3) a spatially explicit grid-walk model that simulates the movement of animals through an artificial landscape. Each model was fitted to the same set of field data. A first objective of the paper is to illustrate how the maximum-likelihood method can be used in all three cases to estimate the means and confidence limits for the relevant model parameters, given a particular set of data on dispersal survival. Using this framework we show that the structure of the uncertainty for all three models is strikingly similar. In fact, the results of our unified approach imply that spatially explicit dispersal models, which take advantage of information on landscape details, suffer less from uncertainly than do simpler models. Moreover, we show that the proposed strategy of model development safeguards one from error propagation in these more complex models. Finally, our approach shows that all models related to animal dispersal, ranging from simple to complex, can be related in a hierarchical fashion, so that the various approaches to modeling such dispersal can be viewed from a unified perspective.

  14. How animals move along? Exactly solvable model of superdiffusive spread resulting from animal's decision making.

    PubMed

    Tilles, Paulo F C; Petrovskii, Sergei V

    2016-07-01

    Patterns of individual animal movement have been a focus of considerable attention recently. Of particular interest is a question how different macroscopic properties of animal dispersal result from the stochastic processes occurring on the microscale of the individual behavior. In this paper, we perform a comprehensive analytical study of a model where the animal changes the movement velocity as a result of its behavioral response to environmental stochasticity. The stochasticity is assumed to manifest itself through certain signals, and the animal modifies its velocity as a response to the signals. We consider two different cases, i.e. where the change in the velocity is or is not correlated to its current value. We show that in both cases the early, transient stage of the animal movement is super-diffusive, i.e. ballistic. The large-time asymptotic behavior appears to be diffusive in the uncorrelated case but super-ballistic in the correlated case. We also calculate analytically the dispersal kernel of the movement and show that, whilst it converge to a normal distribution in the large-time limit, it possesses a fatter tail during the transient stage, i.e. at early and intermediate time. Since the transients are known to be highly relevant in ecology, our findings may indicate that the fat tails and superdiffusive spread that are sometimes observed in the movement data may be a feature of the transitional dynamics rather than an inherent property of the animal movement. PMID:26650504

  15. Modeling moisture movement in rice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice is one of the leading food crops in the world. At harvest, rice normally has higher moisture content than the moisture content considered safe for its storage, which creates the necessity for a drying process before its storage. In addition to drying, moisture movement within the rice kernels a...

  16. Animal models of erectile dysfunction.

    PubMed

    Kapoor, Mandeep Singh; Khan, Samsroz Ahmad; Gupta, Sanjay Kumar; Choudhary, Rajesh; Bodakhe, Surendra H

    2015-01-01

    Erectile dysfunction (ED) is a prevalent male sexual dysfunction with profound adverse effects on the physical and the psychosocial health of men and, subsequently, on their partners. The expanded use of various types of rodent models has produced some advances in the study of ED, and neurophysiological studies using various animal models have provided important insights into human sexual dysfunction. At present, animal models play a key role in exploring and screening novel drugs designed to treat ED.

  17. Animal models of systemic sclerosis.

    PubMed

    Morin, Florence; Kavian, Niloufar; Batteux, Frederic

    2015-01-01

    Systemic sclerosis is a systemic connective tissue disorder characterized by the fibrosis of the skin and certain visceral organs, vasculopathy, and immunological abnormalities. Several genetic and inducible animal models of SSc have been developed and are available for research studies. The purpose of this review is to summarize the various animal models of systemic sclerosis and describe the various contributions of these models in terms of understanding the pathophysiology of the condition and searching for new therapeutic strategies for this incurable disease.

  18. Spatial scaling: Its analysis and effects on animal movements in semiarid landscape mosaics

    SciTech Connect

    Wiens, J.A.

    1992-09-01

    The research conducted under this agreement focused in general on the effects of envirorunental heterogeneity on movements of animals and materials in semiarid grassland landscapes, on the form of scale-dependency of ecological patterns and processes, and on approaches to extrapolating among spatial scales. The findings are summarized in a series of published and unpublished papers that are included as the main body of this report. We demonstrated the value of experimental model systems'' employing observations and experiments conducted in small-scale microlandscapes to test concepts relating to flows of individuals and materials through complex, heterogeneous mosaics. We used fractal analysis extensively in this research, and showed how fractal measures can produce insights and lead,to questions that do not emerge from more traditional scale-dependent measures. We developed new concepts and theory to deal with scale-dependency in ecological systems and with integrating individual movement patterns into considerations of population and ecosystem dynamics.

  19. The modelling cycle for collective animal behaviour

    PubMed Central

    Sumpter, David J. T.; Mann, Richard P.; Perna, Andrea

    2012-01-01

    Collective animal behaviour is the study of how interactions between individuals produce group level patterns, and why these interactions have evolved. This study has proved itself uniquely interdisciplinary, involving physicists, mathematicians, engineers as well as biologists. Almost all experimental work in this area is related directly or indirectly to mathematical models, with regular movement back and forth between models, experimental data and statistical fitting. In this paper, we describe how the modelling cycle works in the study of collective animal behaviour. We classify studies as addressing questions at different levels or linking different levels, i.e. as local, local to global, global to local or global. We also describe three distinct approaches—theory-driven, data-driven and model selection—to these questions. We show, with reference to our own research on species across different taxa, how we move between these different levels of description and how these various approaches can be applied to link levels together. PMID:23173077

  20. Animal models of cerebral ischemia

    NASA Astrophysics Data System (ADS)

    Khodanovich, M. Yu.; Kisel, A. A.

    2015-11-01

    Cerebral ischemia remains one of the most frequent causes of death and disability worldwide. Animal models are necessary to understand complex molecular mechanisms of brain damage as well as for the development of new therapies for stroke. This review considers a certain range of animal models of cerebral ischemia, including several types of focal and global ischemia. Since animal models vary in specificity for the human disease which they reproduce, the complexity of surgery, infarct size, reliability of reproduction for statistical analysis, and adequate models need to be chosen according to the aim of a study. The reproduction of a particular animal model needs to be evaluated using appropriate tools, including the behavioral assessment of injury and non-invasive and post-mortem control of brain damage. These problems also have been summarized in the review.

  1. Animal Models in Burn Research

    PubMed Central

    Abdullahi, A.; Amini-Nik, S.; Jeschke, M.G

    2014-01-01

    Burn injury is a severe form of trauma affecting more than two million people in North America each year. Burn trauma is not a single pathophysiological event but a devastating injury that causes structural and functional deficits in numerous organ systems. Due to its complexity and the involvement of multiple organs, in vitro experiments cannot capture this complexity nor address the pathophysiology. In the past two decades, a number of burn animal models have been developed to replicate the various aspects of burn injury; to elucidate the pathophysiology and explore potential treatment interventions. Understanding the advantages and limitations of these animal models is essential for the design and development of treatments that are clinically relevant to humans. This review paper aims to highlight the common animal models of burn injury in order to provide investigators with a better understanding of the benefits and limitations of these models for translational applications. While many animal models of burn exist, we limit our discussion to the skin healing of mouse, rat, and pig. Additionally, we briefly explain hypermetabolic characteristics of burn injury and the animal model utilized to study this phenomena. Finally, we discuss the economic costs associated with each of these models in order to guide decisions of choosing the appropriate animal model for burn research. PMID:24714880

  2. Taking animal tracking to new depths: synthesizing horizontal--vertical movement relationships for four marine predators.

    PubMed

    Bestley, Sophie; Jonsen, Ian D; Hindell, Mark A; Harcourt, Robert G; Gales, Nicholas J

    2015-02-01

    In animal ecology, a question of key interest for aquatic species is how changes in movement behavior are related in the horizontal and vertical dimensions when individuals forage. Alternative theoretical models and inconsistent empirical findings mean that this question remains unresolved. Here we tested expectations by incorporating the vertical dimension (dive information) when predicting switching between movement states ("resident" or "directed") within a state-space model. We integrated telemetry-based tracking and diving data available for four seal species (southern elephant, Weddell, antarctic fur, and crabeater) in East Antarctica. Where possible, we included dive variables derived from the relationships between (1) dive duration and depth (as a measure of effort), and (2) dive duration and the postdive surface interval (as a physiological measure of cost). Our results varied within and across species, but there was a general tendency for the probability of switching into "resident" state to be positively associated with shorter dive durations (for a given depth) and longer postdive surface intervals (for a given dive duration). Our results add to a growing body of literature suggesting that simplistic interpretations of optimal foraging theory based only on horizontal movements do not directly translate into the vertical dimension in dynamic marine environments. Analyses that incorporate at least two dimensions can test more sophisticated models of foraging behavior. PMID:26240863

  3. Animal models for candidiasis.

    PubMed

    Conti, Heather R; Huppler, Anna R; Whibley, Natasha; Gaffen, Sarah L

    2014-04-02

    Multiple forms of candidiasis are clinically important in humans. Established murine models of disseminated, oropharyngeal, vaginal, and cutaneous candidiasis caused by Candida albicans are described in this unit. Detailed materials and methods for C. albicans growth and detection are also described.

  4. Animal models of portal hypertension

    PubMed Central

    Abraldes, Juan G; Pasarín, Marcos; García-Pagán, Juan Carlos

    2006-01-01

    Animal models have allowed detailed study of hemodynamic alterations typical of portal hypertension and the molecular mechanisms involved in abnormalities in splanchnic and systemic circulation associated with this syndrome. Models of prehepatic portal hypertension can be used to study alterations in the splanchnic circulation and the pathophysiology of the hyperdynamic circulation. Models of cirrhosis allow study of the alterations in intrahepatic microcirculation that lead to increased resistance to portal flow. This review summarizes the currently available literature on animal models of portal hypertension and analyzes their relative utility. The criteria for choosing a particular model, depending on the specific objectives of the study, are also discussed. PMID:17075968

  5. Animal models for human diseases.

    PubMed

    Rust, J H

    1982-01-01

    The use of animal models for the study of human disease is, for the most part, a recent development. This discussion of the use of animal models for human diseases directs attention to the sterile period, early advances, some personal experiences, the human as the model, biological oddities among common laboratory animals, malignancies in laboratory animals, problems created by federal regulations, cancer tests with animals, and what the future holds in terms of the use of animal models as an aid to understanding human disease. In terms of early use of animal models, there was a school of rabbis, some of whom were also physicians, in Babylon who studied and wrote extensively on ritual slaughter and the suitability of birds and beasts for food. Considerable detailed information on animal pathology, physiology, anatomy, and medicine in general can be found in the Soncino Babylonian Talmudic Translations. The 1906 edition of the "Jewish Encyclopedia," has been a rich resource. Although it has not been possible to establish what diseases of animals were studied and their relationship to the diseases of humans, there are fascinating clues to pursue, despite the fact that these were sterile years for research in medicine. The quotation from the Talmud is of interest: "The medical knowledge of the Talmudist was based upon tradition, the dissection of human bodies, observation of disease and experiments upon animals." A bright light in the lackluster years of medical research was provided by Galen, considered the originator of research in physiology and anatomy. His dissection of animals and work on apes and other lower animals were models for human anatomy and physiology and the bases for many treatises. Yet, Galen never seemed to suggest that animals could serve as models for human diseases. Most early physicians who can be considered to have been students of disease developed their medical knowledge by observing the sick under their care. 1 early medical investigator

  6. 9 CFR 71.2 - Secretary to issue rule governing quarantine and interstate movement of diseased animals...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... quarantine and interstate movement of diseased animals, including poultry. 71.2 Section 71.2 Animals and... TRANSPORTATION OF ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS GENERAL PROVISIONS § 71.2 Secretary to issue rule governing quarantine and interstate movement of diseased animals, including poultry. When...

  7. 9 CFR 71.2 - Secretary to issue rule governing quarantine and interstate movement of diseased animals...

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... quarantine and interstate movement of diseased animals, including poultry. 71.2 Section 71.2 Animals and... TRANSPORTATION OF ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS GENERAL PROVISIONS § 71.2 Secretary to issue rule governing quarantine and interstate movement of diseased animals, including poultry. When...

  8. 9 CFR 71.2 - Secretary to issue rule governing quarantine and interstate movement of diseased animals...

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... quarantine and interstate movement of diseased animals, including poultry. 71.2 Section 71.2 Animals and... TRANSPORTATION OF ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS GENERAL PROVISIONS § 71.2 Secretary to issue rule governing quarantine and interstate movement of diseased animals, including poultry. When...

  9. 9 CFR 71.2 - Secretary to issue rule governing quarantine and interstate movement of diseased animals...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... quarantine and interstate movement of diseased animals, including poultry. 71.2 Section 71.2 Animals and... TRANSPORTATION OF ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS GENERAL PROVISIONS § 71.2 Secretary to issue rule governing quarantine and interstate movement of diseased animals, including poultry. When...

  10. 9 CFR 71.2 - Secretary to issue rule governing quarantine and interstate movement of diseased animals...

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... quarantine and interstate movement of diseased animals, including poultry. 71.2 Section 71.2 Animals and... TRANSPORTATION OF ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS GENERAL PROVISIONS § 71.2 Secretary to issue rule governing quarantine and interstate movement of diseased animals, including poultry. When...

  11. Animal models in myopia research.

    PubMed

    Schaeffel, Frank; Feldkaemper, Marita

    2015-11-01

    Our current understanding of the development of refractive errors, in particular myopia, would be substantially limited had Wiesel and Raviola not discovered by accident that monkeys develop axial myopia as a result of deprivation of form vision. Similarly, if Josh Wallman and colleagues had not found that simple plastic goggles attached to the chicken eye generate large amounts of myopia, the chicken model would perhaps not have become such an important animal model. Contrary to previous assumptions about the mechanisms of myopia, these animal models suggested that eye growth is visually controlled locally by the retina, that an afferent connection to the brain is not essential and that emmetropisation uses more sophisticated cues than just the magnitude of retinal blur. While animal models have shown that the retina can determine the sign of defocus, the underlying mechanism is still not entirely clear. Animal models have also provided knowledge about the biochemical nature of the signal cascade converting the output of retinal image processing to changes in choroidal thickness and scleral growth; however, a critical question was, and still is, can the results from animal models be applied to myopia in children? While the basic findings from chickens appear applicable to monkeys, some fundamental questions remain. If eye growth is guided by visual feedback, why is myopic development not self-limiting? Why does undercorrection not arrest myopic progression even though positive lenses induce myopic defocus, which leads to the development of hyperopia in emmetropic animals? Why do some spectacle or contact lens designs reduce myopic progression and others not? It appears that some major differences exist between animals reared with imposed defocus and children treated with various optical corrections, although without the basic knowledge obtained from animal models, we would be lost in an abundance of untestable hypotheses concerning human myopia. PMID:26769177

  12. Velocity-based movement modeling for individual and population level inference

    USGS Publications Warehouse

    Hanks, Ephraim M.; Hooten, Mevin B.; Johnson, Devin S.; Sterling, Jeremy T.

    2011-01-01

    Understanding animal movement and resource selection provides important information about the ecology of the animal, but an animal's movement and behavior are not typically constant in time. We present a velocity-based approach for modeling animal movement in space and time that allows for temporal heterogeneity in an animal's response to the environment, allows for temporal irregularity in telemetry data, and accounts for the uncertainty in the location information. Population-level inference on movement patterns and resource selection can then be made through cluster analysis of the parameters related to movement and behavior. We illustrate this approach through a study of northern fur seal (Callorhinus ursinus) movement in the Bering Sea, Alaska, USA. Results show sex differentiation, with female northern fur seals exhibiting stronger response to environmental variables.

  13. Velocity-Based Movement Modeling for Individual and Population Level Inference

    PubMed Central

    Hanks, Ephraim M.; Hooten, Mevin B.; Johnson, Devin S.; Sterling, Jeremy T.

    2011-01-01

    Understanding animal movement and resource selection provides important information about the ecology of the animal, but an animal's movement and behavior are not typically constant in time. We present a velocity-based approach for modeling animal movement in space and time that allows for temporal heterogeneity in an animal's response to the environment, allows for temporal irregularity in telemetry data, and accounts for the uncertainty in the location information. Population-level inference on movement patterns and resource selection can then be made through cluster analysis of the parameters related to movement and behavior. We illustrate this approach through a study of northern fur seal (Callorhinus ursinus) movement in the Bering Sea, Alaska, USA. Results show sex differentiation, with female northern fur seals exhibiting stronger response to environmental variables. PMID:21931584

  14. Animal Models of Bone Metastasis.

    PubMed

    Simmons, J K; Hildreth, B E; Supsavhad, W; Elshafae, S M; Hassan, B B; Dirksen, W P; Toribio, R E; Rosol, T J

    2015-09-01

    Bone is one of the most common sites of cancer metastasis in humans and is a significant source of morbidity and mortality. Bone metastases are considered incurable and result in pain, pathologic fracture, and decreased quality of life. Animal models of skeletal metastases are essential to improve the understanding of the molecular pathways of cancer metastasis and growth in bone and to develop new therapies to inhibit and prevent bone metastases. The ideal animal model should be clinically relevant, reproducible, and representative of human disease. Currently, an ideal model does not exist; however, understanding the strengths and weaknesses of the available models will lead to proper study design and successful cancer research. This review provides an overview of the current in vivo animal models used in the study of skeletal metastases or local tumor invasion into bone and focuses on mammary and prostate cancer, lymphoma, multiple myeloma, head and neck squamous cell carcinoma, and miscellaneous tumors that metastasize to bone.

  15. Animal Models of Bone Metastasis

    PubMed Central

    Simmons, J. K.; Hildreth, B. E.; Supsavhad, W.; Elshafae, S. M.; Hassan, B. B.; Dirksen, W. P.; Toribio, R. E.; Rosol, T. J.

    2015-01-01

    Bone is one of the most common sites of cancer metastasis in humans and is a significant source of morbidity and mortality. Bone metastases are considered incurable and result in pain, pathologic fracture, and decreased quality of life. Animal models of skeletal metastases are essential to improve the understanding of the molecular pathways of cancer metastasis and growth in bone and to develop new therapies to inhibit and prevent bone metastases. The ideal animal model should be clinically relevant, reproducible, and representative of human disease. Currently, an ideal model does not exist; however, understanding the strengths and weaknesses of the available models will lead to proper study design and successful cancer research. This review provides an overview of the current in vivo animal models used in the study of skeletal metastases or local tumor invasion into bone and focuses on mammary and prostate cancer, lymphoma, multiple myeloma, head and neck squamous cell carcinoma, and miscellaneous tumors that metastasize to bone. PMID:26021553

  16. Modelling larval movement data from individual bioassays.

    PubMed

    McLellan, Chris R; Worton, Bruce J; Deasy, William; Birch, A Nicholas E

    2015-05-01

    We consider modelling the movements of larvae using individual bioassays in which data are collected at a high-frequency rate of five observations per second. The aim is to characterize the behaviour of the larvae when exposed to attractant and repellent compounds. Mixtures of diffusion processes, as well as Hidden Markov models, are proposed as models of larval movement. These models account for directed and localized movements, and successfully distinguish between the behaviour of larvae exposed to attractant and repellent compounds. A simulation study illustrates the advantage of using a Hidden Markov model rather than a simpler mixture model. Practical aspects of model estimation and inference are considered on extensive data collected in a study of novel approaches for the management of cabbage root fly. PMID:25764283

  17. Modelling larval movement data from individual bioassays.

    PubMed

    McLellan, Chris R; Worton, Bruce J; Deasy, William; Birch, A Nicholas E

    2015-05-01

    We consider modelling the movements of larvae using individual bioassays in which data are collected at a high-frequency rate of five observations per second. The aim is to characterize the behaviour of the larvae when exposed to attractant and repellent compounds. Mixtures of diffusion processes, as well as Hidden Markov models, are proposed as models of larval movement. These models account for directed and localized movements, and successfully distinguish between the behaviour of larvae exposed to attractant and repellent compounds. A simulation study illustrates the advantage of using a Hidden Markov model rather than a simpler mixture model. Practical aspects of model estimation and inference are considered on extensive data collected in a study of novel approaches for the management of cabbage root fly.

  18. Dystonia and Paroxysmal Dyskinesias: Under-Recognized Movement Disorders in Domestic Animals? A Comparison with Human Dystonia/Paroxysmal Dyskinesias

    PubMed Central

    Richter, Angelika; Hamann, Melanie; Wissel, Jörg; Volk, Holger A.

    2015-01-01

    Dystonia is defined as a neurological syndrome characterized by involuntary sustained or intermittent muscle contractions causing twisting, often repetitive movements, and postures. Paroxysmal dyskinesias are episodic movement disorders encompassing dystonia, chorea, athetosis, and ballism in conscious individuals. Several decades of research have enhanced the understanding of the etiology of human dystonia and dyskinesias that are associated with dystonia, but the pathophysiology remains largely unknown. The spontaneous occurrence of hereditary dystonia and paroxysmal dyskinesia is well documented in rodents used as animal models in basic dystonia research. Several hyperkinetic movement disorders, described in dogs, horses and cattle, show similarities to these human movement disorders. Although dystonia is regarded as the third most common movement disorder in humans, it is often misdiagnosed because of the heterogeneity of etiology and clinical presentation. Since these conditions are poorly known in veterinary practice, their prevalence may be underestimated in veterinary medicine. In order to attract attention to these movement disorders, i.e., dystonia and paroxysmal dyskinesias associated with dystonia, and to enhance interest in translational research, this review gives a brief overview of the current literature regarding dystonia/paroxysmal dyskinesia in humans and summarizes similar hereditary movement disorders reported in domestic animals. PMID:26664992

  19. Animal Models of Head Trauma

    PubMed Central

    Cernak, Ibolja

    2005-01-01

    Summary: Animal models of traumatic brain injury (TBI) are used to elucidate primary and secondary sequelae underlying human head injury in an effort to identify potential neuroprotective therapies for developing and adult brains. The choice of experimental model depends upon both the research goal and underlying objectives. The intrinsic ability to study injury-induced changes in behavior, physiology, metabolism, the blood/tissue interface, the blood brain barrier, and/or inflammatory- and immune-mediated responses, makes in vivo TBI models essential for neurotrauma research. Whereas human TBI is a highly complex multifactorial disorder, animal trauma models tend to replicate only single factors involved in the pathobiology of head injury using genetically well-defined inbred animals of a single sex. Although such an experimental approach is helpful to delineate key injury mechanisms, the simplicity and hence inability of animal models to reflect the complexity of clinical head injury may underlie the discrepancy between preclinical and clinical trials of neuroprotective therapeutics. Thus, a search continues for new animal models, which would more closely mimic the highly heterogeneous nature of human TBI, and address key factors in treatment optimization. PMID:16389305

  20. Optogenetics in psychiatric animal models.

    PubMed

    Wentz, Christian T; Oettl, Lars-Lennart; Kelsch, Wolfgang

    2013-10-01

    Optogenetics is the optical control of neuronal excitability by genetically delivered light-activated channels and pumps and represents a promising tool to fuel the study of circuit function in psychiatric animal models. This review highlights three developments. First, we examine the application of optogenetics in one of the neuromodulators central to the pathophysiology of many psychiatric disorders, the dopaminergic system. We then discuss recent work in translating functional magnetic resonance imaging in small animals (in which optogenetics can be employed to reveal physiological mechanisms underlying disease-related alterations in brain circuits) to patients. Finally, we describe emerging technological developments for circuit manipulation in freely behaving animals.

  1. Animal welfare and use of silkworm as a model animal.

    PubMed

    Sekimizu, N; Paudel, A; Hamamoto, H

    2012-08-01

    Sacrificing model animals is required for developing effective drugs before being used in human beings. In Japan today, at least 4,210,000 mice and other mammals are sacrificed to a total of 6,140,000 per year for the purpose of medical studies. All the animals treated in Japan, including test animals, are managed under control of "Act on Welfare and Management of Animals". Under the principle of this Act, no person shall kill, injure, or inflict cruelty on animals without due cause. "Animal" addressed in the Act can be defined as a "vertebrate animal". If we can make use of invertebrate animals in testing instead of vertebrate ones, that would be a remarkable solution for the issue of animal welfare. Furthermore, there are numerous advantages of using invertebrate animal models: less space and small equipment are enough for taking care of a large number of animals and thus are cost-effective, they can be easily handled, and many biological processes and genes are conserved between mammals and invertebrates. Today, many invertebrates have been used as animal models, but silkworms have many beneficial traits compared to mammals as well as other insects. In a Genome Pharmaceutical Institute's study, we were able to achieve a lot making use of silkworms as model animals. We would like to suggest that pharmaceutical companies and institutes consider the use of the silkworm as a model animal which is efficacious both for financial value by cost cutting and ethical aspects in animals' welfare.

  2. Animal models of pituitary neoplasia

    PubMed Central

    Lines, K.E.; Stevenson, M.; Thakker, R.V.

    2016-01-01

    Pituitary neoplasias can occur as part of a complex inherited disorder, or more commonly as sporadic (non-familial) disease. Studies of the molecular and genetic mechanisms causing such pituitary tumours have identified dysregulation of >35 genes, with many revealed by studies in mice, rats and zebrafish. Strategies used to generate these animal models have included gene knockout, gene knockin and transgenic over-expression, as well as chemical mutagenesis and drug induction. These animal models provide an important resource for investigation of tissue-specific tumourigenic mechanisms, and evaluations of novel therapies, illustrated by studies into multiple endocrine neoplasia type 1 (MEN1), a hereditary syndrome in which ∼30% of patients develop pituitary adenomas. This review describes animal models of pituitary neoplasia that have been generated, together with some recent advances in gene editing technologies, and an illustration of the use of the Men1 mouse as a pre clinical model for evaluating novel therapies. PMID:26320859

  3. An information maximization model of eye movements

    NASA Technical Reports Server (NTRS)

    Renninger, Laura Walker; Coughlan, James; Verghese, Preeti; Malik, Jitendra

    2005-01-01

    We propose a sequential information maximization model as a general strategy for programming eye movements. The model reconstructs high-resolution visual information from a sequence of fixations, taking into account the fall-off in resolution from the fovea to the periphery. From this framework we get a simple rule for predicting fixation sequences: after each fixation, fixate next at the location that minimizes uncertainty (maximizes information) about the stimulus. By comparing our model performance to human eye movement data and to predictions from a saliency and random model, we demonstrate that our model is best at predicting fixation locations. Modeling additional biological constraints will improve the prediction of fixation sequences. Our results suggest that information maximization is a useful principle for programming eye movements.

  4. ANIMAL MODELS FOR FOOD ALLERGY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Animal models have been used to provide insight into the complex immunological and pathophysioligical mechanisms of human Type 1 allergic diseases. Research efforts that include mechanistic studies in search of new therapies and screening models for hazard identification of potential allergens in a...

  5. From moonlight to movement and synchronized randomness: Fourier and wavelet analyses of animal location time series data.

    PubMed

    Polansky, Leo; Wittemyer, George; Cross, Paul C; Tambling, Craig J; Getz, Wayne M

    2010-05-01

    High-resolution animal location data are increasingly available, requiring analytical approaches and statistical tools that can accommodate the temporal structure and transient dynamics (non-stationarity) inherent in natural systems. Traditional analyses often assume uncorrelated or weakly correlated temporal structure in the velocity (net displacement) time series constructed using sequential location data. We propose that frequency and time-frequency domain methods, embodied by Fourier and wavelet transforms, can serve as useful probes in early investigations of animal movement data, stimulating new ecological insight and questions. We introduce a novel movement model with time-varying parameters to study these methods in an animal movement context. Simulation studies show that the spectral signature given by these methods provides a useful approach for statistically detecting and characterizing temporal dependency in animal movement data. In addition, our simulations provide a connection between the spectral signatures observed in empirical data with null hypotheses about expected animal activity. Our analyses also show that there is not a specific one-to-one relationship between the spectral signatures and behavior type and that departures from the anticipated signatures are also informative. Box plots of net displacement arranged by time of day and conditioned on common spectral properties can help interpret the spectral signatures of empirical data. The first case study is based on the movement trajectory of a lion (Panthera leo) that shows several characteristic daily activity sequences, including an active-rest cycle that is correlated with moonlight brightness. A second example based on six pairs of African buffalo (Syncerus caffer) illustrates the use of wavelet coherency to show that their movements synchronize when they are within approximately 1 km of each other, even when individual movement was best described as an uncorrelated random walk, providing

  6. Animal models of eating disorders

    PubMed Central

    Kim, Sangwon F.

    2012-01-01

    Feeding is a fundamental process for basic survival, and is influenced by genetics and environmental stressors. Recent advances in our understanding of behavioral genetics have provided a profound insight on several components regulating eating patterns. However, our understanding of eating disorders such as anorexia nervosa, bulimia nervosa, and binge eating is still poor. The animal model is an essential tool in the investigation of eating behaviors and their pathological forms, yet development of an appropriate animal model for eating disorders still remains challenging due to our limited knowledge and some of the more ambiguous clinical diagnostic measures. Therefore, this review will serve to focus on the basic clinical features of eating disorders and the current advances in animal models of eating disorders. PMID:22465439

  7. Animal models of cardiac cachexia.

    PubMed

    Molinari, Francesca; Malara, Natalia; Mollace, Vincenzo; Rosano, Giuseppe; Ferraro, Elisabetta

    2016-09-15

    Cachexia is the loss of body weight associated with several chronic diseases including chronic heart failure (CHF). The cachectic condition is mainly due to loss of skeletal muscle mass and adipose tissue depletion. The majority of experimental in vivo studies on cachexia rely on animal models of cancer cachexia while a reliable and appropriate model for cardiac cachexia has not yet been established. A critical issue in generating a cardiac cachexia model is that genetic modifications or pharmacological treatments impairing the heart functionality and used to obtain the heart failure model might likely impair the skeletal muscle, this also being a striated muscle and sharing with the myocardium several molecular and physiological mechanisms. On the other hand, often, the induction of heart damage in the several existing models of heart failure does not necessarily lead to skeletal muscle loss and cachexia. Here we describe the main features of cardiac cachexia and illustrate some animal models proposed for cardiac cachexia studies; they include the genetic calsequestrin and Dahl salt-sensitive models, the monocrotaline model and the surgical models obtained by left anterior descending (LAD) ligation, transverse aortic constriction (TAC) and ascending aortic banding. The availability of a specific animal model for cardiac cachexia is a crucial issue since, besides the common aspects of cachexia in the different syndromes, each disease has some peculiarities in its etiology and pathophysiology leading to cachexia. Such peculiarities need to be unraveled in order to find new targets for effective therapies. PMID:27317993

  8. Animal models of cardiac cachexia.

    PubMed

    Molinari, Francesca; Malara, Natalia; Mollace, Vincenzo; Rosano, Giuseppe; Ferraro, Elisabetta

    2016-09-15

    Cachexia is the loss of body weight associated with several chronic diseases including chronic heart failure (CHF). The cachectic condition is mainly due to loss of skeletal muscle mass and adipose tissue depletion. The majority of experimental in vivo studies on cachexia rely on animal models of cancer cachexia while a reliable and appropriate model for cardiac cachexia has not yet been established. A critical issue in generating a cardiac cachexia model is that genetic modifications or pharmacological treatments impairing the heart functionality and used to obtain the heart failure model might likely impair the skeletal muscle, this also being a striated muscle and sharing with the myocardium several molecular and physiological mechanisms. On the other hand, often, the induction of heart damage in the several existing models of heart failure does not necessarily lead to skeletal muscle loss and cachexia. Here we describe the main features of cardiac cachexia and illustrate some animal models proposed for cardiac cachexia studies; they include the genetic calsequestrin and Dahl salt-sensitive models, the monocrotaline model and the surgical models obtained by left anterior descending (LAD) ligation, transverse aortic constriction (TAC) and ascending aortic banding. The availability of a specific animal model for cardiac cachexia is a crucial issue since, besides the common aspects of cachexia in the different syndromes, each disease has some peculiarities in its etiology and pathophysiology leading to cachexia. Such peculiarities need to be unraveled in order to find new targets for effective therapies.

  9. Animal models of cardiovascular diseases.

    PubMed

    Zaragoza, Carlos; Gomez-Guerrero, Carmen; Martin-Ventura, Jose Luis; Blanco-Colio, Luis; Lavin, Begoña; Mallavia, Beñat; Tarin, Carlos; Mas, Sebastian; Ortiz, Alberto; Egido, Jesus

    2011-01-01

    Cardiovascular diseases are the first leading cause of death and morbidity in developed countries. The use of animal models have contributed to increase our knowledge, providing new approaches focused to improve the diagnostic and the treatment of these pathologies. Several models have been developed to address cardiovascular complications, including atherothrombotic and cardiac diseases, and the same pathology have been successfully recreated in different species, including small and big animal models of disease. However, genetic and environmental factors play a significant role in cardiovascular pathophysiology, making difficult to match a particular disease, with a single experimental model. Therefore, no exclusive method perfectly recreates the human complication, and depending on the model, additional considerations of cost, infrastructure, and the requirement for specialized personnel, should also have in mind. Considering all these facts, and depending on the budgets available, models should be selected that best reproduce the disease being investigated. Here we will describe models of atherothrombotic diseases, including expanding and occlusive animal models, as well as models of heart failure. Given the wide range of models available, today it is possible to devise the best strategy, which may help us to find more efficient and reliable solutions against human cardiovascular diseases. PMID:21403831

  10. Terrestrial movement energetics: current knowledge and its application to the optimising animal.

    PubMed

    Halsey, Lewis G

    2016-05-15

    The energetic cost of locomotion can be a substantial proportion of an animal's daily energy budget and thus key to its ecology. Studies on myriad species have added to our knowledge about the general cost of animal movement, including the effects of variations in the environment such as terrain angle. However, further such studies might provide diminishing returns on the development of a deeper understanding of how animals trade-off the cost of movement with other energy costs, and other ecological currencies such as time. Here, I propose the 'individual energy landscape' as an approach to conceptualising the choices facing the optimising animal. In this Commentary, first I outline previous broad findings about animal walking and running locomotion, focusing in particular on the use of net cost of transport as a metric of comparison between species, and then considering the effects of environmental perturbations and other extrinsic factors on movement costs. I then introduce and explore the idea that these factors combine with the behaviour of the animal in seeking short-term optimality to create that animal's individual energy landscape - the result of the geographical landscape and environmental factors combined with the animal's selected trade-offs. Considering an animal's locomotion energy expenditure within this context enables hard-won empirical data on transport costs to be applied to questions about how an animal can and does move through its environment to maximise its fitness, and the relative importance, or otherwise, of locomotion energy economy. PMID:27207950

  11. Animal Models of Ricin Toxicosis

    PubMed Central

    Song, Kejing; Sivasubramani, Satheesh K.; Gardner, Donald J.; Pincus, Seth H.

    2015-01-01

    Animal models of ricin toxicosis are necessary for testing the efficacy of therapeutic measures, as well studying the mechanisms by which ricin exerts its toxicity in intact animals. Because ricin can serve as a particularly well-characterized model of tissue damage, and the host response to that damage, studies of the mechanisms of ricin toxicity may have more general applicability. For example, our studies of the molecular mechanisms underlying the development of ricin-induced hypoglycemia may help elucidate the relationship of type II diabetes, insulin resistance, and inflammation. Studies in non-human primates are most relevant for testing and developing agents having clinical utility. But these animals are expensive and limited in quantity, and so rodents are used for most mechanistic studies. PMID:21956160

  12. Tortuosity entropy: a measure of spatial complexity of behavioral changes in animal movement.

    PubMed

    Liu, Xiaofeng; Xu, Ning; Jiang, Aimin

    2015-01-01

    The goal of animal movement analysis is to understand how organisms explore and exploit complex and varying environments. Animals usually exhibit varied and complicated movements, from apparently deterministic behaviours to highly random behaviours. It has been a common method to assess movement efficiency and foraging strategies by means of quantifying and analyzing movement trajectories. Here we introduce a tortuosity entropy (TorEn), a simple measure for quantifying the behavioral change in animal movement data. In our approach, the differences between pairwise successive track points are transformed into symbolic sequences, then we map these symbols into a group of pattern vectors and calculate the information entropy of pattern vectors. We test the algorithm on both simulated trajectories and real trajectories to show that it can accurately identify not only the mixed segments in simulated data, but also the different phases in real movement data. Tortuosity entropy can be easily applied to arbitrary real-world data, whether deterministic or stochastic, stationary or non-stationary. It could be a promising tool to reveal behavioral mechanism in movement data.

  13. Animal models of polymicrobial pneumonia

    PubMed Central

    Hraiech, Sami; Papazian, Laurent; Rolain, Jean-Marc; Bregeon, Fabienne

    2015-01-01

    Pneumonia is one of the leading causes of severe and occasionally life-threatening infections. The physiopathology of pneumonia has been extensively studied, providing information for the development of new treatments for this condition. In addition to in vitro research, animal models have been largely used in the field of pneumonia. Several models have been described and have provided a better understanding of pneumonia under different settings and with various pathogens. However, the concept of one pathogen leading to one infection has been challenged, and recent flu epidemics suggest that some pathogens exhibit highly virulent potential. Although “two hits” animal models have been used to study infectious diseases, few of these models have been described in pneumonia. Therefore the aims of this review were to provide an overview of the available literature in this field, to describe well-studied and uncommon pathogen associations, and to summarize the major insights obtained from this information. PMID:26170617

  14. Movement to curtail animal dissections in zoology curriculum: review of the Indian experience.

    PubMed

    Akbarsha, Mohammad Abdulkader

    2007-01-01

    Animal dissections have been dropped from the curriculum in several developed countries, and virtual laboratories are taking their place, or at least the concept of the "three R's" is becoming accepted. Yet, the scenario in the developing countries in this regard has been dismal. However, recently, a movement has started in India in this area, thanks to the aggressive approach of PfA, I-CARE and InterNICHE, supported by a few zoology educators and policy makers, who joined this movement as freelancers. The aggressive campaigners against animal dissections put up convincing arguments to the orthodox zoology educators and higher education planners with such veracity that the arguments cannot be ignored. The arguments, to be presented in detail at the conference, and the campaign have been rewarded with success such that a few universities and autonomous colleges have revamped their zoology curricula so as to dispense with or reduce animal dissections. The Bharathidasan University, Tiruchirappalli, Tamil Nadu, India, has been the trendsetter, evolving what is known as the "Bharathidasan University Model". A memorandum from I-CARE and PfA to the University Grants Commission, Government of India, New Delhi, was sent out by the UGC to the universities with a request to consider the points positively. However, there is still a need to bring about an attitudinal change in the zoology educators and higher education planners such that they participate willingly in this endeavour. The role-players at all levels are identified and approached with a language that is understandable to each and are adequately supported by hands-on training in the alternative methods. Ultimately, the responsibility in this regard lies with the educators themselves, since they are the ones who, working in the academic committees that design the curricula, can cut down on the requirement for dissections.

  15. Animal Models of Subjective Tinnitus

    PubMed Central

    2014-01-01

    Tinnitus is one of the major audiological diseases, affecting a significant portion of the ageing society. Despite its huge personal and presumed economic impact there are only limited therapeutic options available. The reason for this deficiency lies in the very nature of the disease as it is deeply connected to elementary plasticity of auditory processing in the central nervous system. Understanding these mechanisms is essential for developing a therapy that reverses the plastic changes underlying the pathogenesis of tinnitus. This requires experiments that address individual neurons and small networks, something usually not feasible in human patients. However, in animals such invasive experiments on the level of single neurons with high spatial and temporal resolution are possible. Therefore, animal models are a very critical element in the combined efforts for engineering new therapies. This review provides an overview over the most important features of animal models of tinnitus: which laboratory species are suitable, how to induce tinnitus, and how to characterize the perceived tinnitus by behavioral means. In particular, these aspects of tinnitus animal models are discussed in the light of transferability to the human patients. PMID:24829805

  16. Animal models of subjective tinnitus.

    PubMed

    von der Behrens, Wolfger

    2014-01-01

    Tinnitus is one of the major audiological diseases, affecting a significant portion of the ageing society. Despite its huge personal and presumed economic impact there are only limited therapeutic options available. The reason for this deficiency lies in the very nature of the disease as it is deeply connected to elementary plasticity of auditory processing in the central nervous system. Understanding these mechanisms is essential for developing a therapy that reverses the plastic changes underlying the pathogenesis of tinnitus. This requires experiments that address individual neurons and small networks, something usually not feasible in human patients. However, in animals such invasive experiments on the level of single neurons with high spatial and temporal resolution are possible. Therefore, animal models are a very critical element in the combined efforts for engineering new therapies. This review provides an overview over the most important features of animal models of tinnitus: which laboratory species are suitable, how to induce tinnitus, and how to characterize the perceived tinnitus by behavioral means. In particular, these aspects of tinnitus animal models are discussed in the light of transferability to the human patients.

  17. Predicting the continuum between corridors and barriers to animal movements using Step Selection Functions and Randomized Shortest Paths.

    PubMed

    Panzacchi, Manuela; Van Moorter, Bram; Strand, Olav; Saerens, Marco; Kivimäki, Ilkka; St Clair, Colleen C; Herfindal, Ivar; Boitani, Luigi

    2016-01-01

    The loss, fragmentation and degradation of habitat everywhere on Earth prompts increasing attention to identifying landscape features that support animal movement (corridors) or impedes it (barriers). Most algorithms used to predict corridors assume that animals move through preferred habitat either optimally (e.g. least cost path) or as random walkers (e.g. current models), but neither extreme is realistic. We propose that corridors and barriers are two sides of the same coin and that animals experience landscapes as spatiotemporally dynamic corridor-barrier continua connecting (separating) functional areas where individuals fulfil specific ecological processes. Based on this conceptual framework, we propose a novel methodological approach that uses high-resolution individual-based movement data to predict corridor-barrier continua with increased realism. Our approach consists of two innovations. First, we use step selection functions (SSF) to predict friction maps quantifying corridor-barrier continua for tactical steps between consecutive locations. Secondly, we introduce to movement ecology the randomized shortest path algorithm (RSP) which operates on friction maps to predict the corridor-barrier continuum for strategic movements between functional areas. By modulating the parameter Ѳ, which controls the trade-off between exploration and optimal exploitation of the environment, RSP bridges the gap between algorithms assuming optimal movements (when Ѳ approaches infinity, RSP is equivalent to LCP) or random walk (when Ѳ → 0, RSP → current models). Using this approach, we identify migration corridors for GPS-monitored wild reindeer (Rangifer t. tarandus) in Norway. We demonstrate that reindeer movement is best predicted by an intermediate value of Ѳ, indicative of a movement trade-off between optimization and exploration. Model calibration allows identification of a corridor-barrier continuum that closely fits empirical data and demonstrates that RSP

  18. Infectious disease surveillance in animal movement networks: An approach based on the friendship paradox.

    PubMed

    Amaku, Marcos; Grisi-Filho, José Henrique de Hildebrand; Negreiros, Rísia Lopes; Dias, Ricardo Augusto; Ferreira, Fernando; Ferreira Neto, José Soares; Cipullo, Rafael Ishibashi; Marques, Fernando Silveira; Ossada, Raul

    2015-10-01

    The network of animal movements among livestock premises is an important topological structure for the spread of infectious diseases. The central focus of this study was to analyze strategies for selecting premises based on the friendship paradox ("your friends have more friends than you do") - in which premises that neighbor randomly selected premises are sampled for surveillance or control - to determine whether these strategies are viable alternatives for the surveillance and control of diseases in scenarios with insufficient data on animal movement. To test the effectiveness of these strategies, we performed three sets of simulations. In the first set, we examined the risk of spreading an infectious disease using the cattle movement network of the state of Mato Grosso, Brazil. All tested strategies based on the friendship paradox have comparable performance to the hub control strategy (controlling premises that sold more animals) and superior performance to random sampling in terms of both reducing the risk of purchasing infected animals and the number of premises that need to be controlled. In the second and third sets of simulations, we observed that the friendship paradox strategies were more sensitive than the random sampling strategy to detect cases and disease, respectively. The survey of the entire animal movement network to identify animal premises with a key role in trade is not always possible, either because the data are insufficient or because informal trade is significant. If surveying the network is not possible, all approaches based on knowledge of the network become useless. As an alternative, knowing that there is a hidden movement network that follows rules inherent to all networks, such as the friendship paradox, can be used to our advantage. Strategies based on the friendship paradox do not assume knowledge of the animal movement network and therefore may be viable alternatives for the surveillance or control of infectious diseases in the

  19. Animal Models of Sleep Disorders

    PubMed Central

    Toth, Linda A; Bhargava, Pavan

    2013-01-01

    Problems with sleep affect a large part of the general population, with more than half of all people in the United States reporting difficulties with sleep or insufficient sleep at various times and about 40 million affected chronically. Sleep is a complex physiologic process that is influenced by many internal and environmental factors, and problems with sleep are often related to specific personal circumstances or are based on subjective reports from the affected person. Although human subjects are used widely in the study of sleep and sleep disorders, the study of animals has been invaluable in developing our understanding about the physiology of sleep and the underlying mechanisms of sleep disorders. Historically, the use of animals for the study of sleep disorders has arguably been most fruitful for the condition of narcolepsy, in which studies of dogs and mice revealed previously unsuspected mechanisms for this condition. The current overview considers animal models that have been used to study 4 of the most common human sleep disorders—insomnia, narcolepsy, restless legs syndrome, and sleep apnea—and summarizes considerations relevant to the use of animals for the study of sleep and sleep disorders. Animal-based research has been vital to the elucidation of mechanisms that underlie sleep, its regulation, and its disorders and undoubtedly will remain crucial for discovering and validating sleep mechanisms and testing interventions for sleep disorders. PMID:23582416

  20. Construction of energy landscapes can clarify the movement and distribution of foraging animals

    PubMed Central

    Wilson, Rory P.; Quintana, Flavio; Hobson, Victoria J.

    2012-01-01

    Variation in the physical characteristics of the environment should impact the movement energetics of animals. Although cognizance of this may help interpret movement ecology, determination of the landscape-dependent energy expenditure of wild animals is problematic. We used accelerometers in animal-attached tags to derive energy expenditure in 54 free-living imperial cormorants Phalacrocorax atriceps and construct an energy landscape of the area around a breeding colony. Examination of the space use of a further 74 birds over 4 years showed that foraging areas selected varied considerably in distance from the colony and water depth, but were characterized by minimal power requirements compared with other areas in the available landscape. This accords with classic optimal foraging concepts, which state that animals should maximize net energy gain by minimizing costs where possible and show how deriving energy landscapes can help understand how and why animals distribute themselves in space. PMID:21900327

  1. Construction of energy landscapes can clarify the movement and distribution of foraging animals.

    PubMed

    Wilson, Rory P; Quintana, Flavio; Hobson, Victoria J

    2012-03-01

    Variation in the physical characteristics of the environment should impact the movement energetics of animals. Although cognizance of this may help interpret movement ecology, determination of the landscape-dependent energy expenditure of wild animals is problematic. We used accelerometers in animal-attached tags to derive energy expenditure in 54 free-living imperial cormorants Phalacrocorax atriceps and construct an energy landscape of the area around a breeding colony. Examination of the space use of a further 74 birds over 4 years showed that foraging areas selected varied considerably in distance from the colony and water depth, but were characterized by minimal power requirements compared with other areas in the available landscape. This accords with classic optimal foraging concepts, which state that animals should maximize net energy gain by minimizing costs where possible and show how deriving energy landscapes can help understand how and why animals distribute themselves in space. PMID:21900327

  2. Animal models of source memory.

    PubMed

    Crystal, Jonathon D

    2016-01-01

    Source memory is the aspect of episodic memory that encodes the origin (i.e., source) of information acquired in the past. Episodic memory (i.e., our memories for unique personal past events) typically involves source memory because those memories focus on the origin of previous events. Source memory is at work when, for example, someone tells a favorite joke to a person while avoiding retelling the joke to the friend who originally shared the joke. Importantly, source memory permits differentiation of one episodic memory from another because source memory includes features that were present when the different memories were formed. This article reviews recent efforts to develop an animal model of source memory using rats. Experiments are reviewed which suggest that source memory is dissociated from other forms of memory. The review highlights strengths and weaknesses of a number of animal models of episodic memory. Animal models of source memory may be used to probe the biological bases of memory. Moreover, these models can be combined with genetic models of Alzheimer's disease to evaluate pharmacotherapies that ultimately have the potential to improve memory.

  3. The Effect of Map Boundary on Estimates of Landscape Resistance to Animal Movement

    PubMed Central

    Koen, Erin L.; Garroway, Colin J.; Wilson, Paul J.; Bowman, Jeff

    2010-01-01

    Background Artificial boundaries on a map occur when the map extent does not cover the entire area of study; edges on the map do not exist on the ground. These artificial boundaries might bias the results of animal dispersal models by creating artificial barriers to movement for model organisms where there are no barriers for real organisms. Here, we characterize the effects of artificial boundaries on calculations of landscape resistance to movement using circuit theory. We then propose and test a solution to artificially inflated resistance values whereby we place a buffer around the artificial boundary as a substitute for the true, but unknown, habitat. Methodology/Principal Findings We randomly assigned landscape resistance values to map cells in the buffer in proportion to their occurrence in the known map area. We used circuit theory to estimate landscape resistance to organism movement and gene flow, and compared the output across several scenarios: a habitat-quality map with artificial boundaries and no buffer, a map with a buffer composed of randomized habitat quality data, and a map with a buffer composed of the true habitat quality data. We tested the sensitivity of the randomized buffer to the possibility that the composition of the real but unknown buffer is biased toward high or low quality. We found that artificial boundaries result in an overestimate of landscape resistance. Conclusions/Significance Artificial map boundaries overestimate resistance values. We recommend the use of a buffer composed of randomized habitat data as a solution to this problem. We found that resistance estimated using the randomized buffer did not differ from estimates using the real data, even when the composition of the real data was varied. Our results may be relevant to those interested in employing Circuitscape software in landscape connectivity and landscape genetics studies. PMID:20668690

  4. Animal models of Kennedy disease.

    PubMed

    Merry, Diane E

    2005-07-01

    Since the identification of the polyglutamine repeat expansion responsible for Kennedy disease (KD) more than a decade ago, several laboratories have created animal models for KD. The slowly progressive nature of KD, its X-linked dominant mode of inheritance, and its recently elucidated hormone dependence have made the modeling of this lower motor neuron disease uniquely challenging. Several models have been generated in which variations in specificity, age of onset, and rate of progression have been achieved. Animal models that precisely reproduce the motor neuron specificity, delayed onset, and slow progression of disease may not support preclinical therapeutics testing, whereas models with rapidly progressing symptoms may preclude the ability to fully elucidate pathogenic pathways. Drosophila models of KD provide unique opportunities to use the power of genetics to identify pathogenic pathways at work in KD. This paper reviews the new wealth of transgenic mouse and Drosophila models for KD. Whereas differences, primarily in neuropathological findings, exist in these models, these differences may be exploited to begin to elucidate the most relevant pathological features of KD.

  5. An accurate and portable eye movement detector for studying sleep in small animals.

    PubMed

    Sánchez-López, Álvaro; Escudero, Miguel

    2015-08-01

    Although eye movements are a highly valuable variable in attempts to precisely identify different periods of the sleep-wake cycle, their indirect measurement by electrooculography is not good enough. The present article describes an accurate and portable scleral search coil that allows the detection of tonic and phasic characteristics of eye movements in free-moving animals. Six adult Wistar rats were prepared for chronic recording of electroencephalography, electromyography and eye movements using the scleral search coil technique. We developed a miniature magnetic field generator made with two coils, consisting of 35 turns and 15 mm diameter of insulated 0.2 mm cooper wire, mounted in a frame of carbon fibre. This portable scleral search coil was fixed on the head of the animal, with each magnetic coil parallel to the eye coil and at 5 mm from each eye. Eye movements detected by the portable scleral search coil were compared with those measured by a commercial scleral search coil requiring immobilizing the head of the animal. No qualitative differences were found between the two scleral search coil systems in their capabilities to detect eye movements. This innovative portable scleral search coil system is an essential tool to detect slow changes in eye position and miniature rapid eye movements during sleep. The portable scleral search coil is much more suitable for detecting eye movements than any previously available system because of its precision and simplicity, and because it does not require immobilization of the animal's head. PMID:25590417

  6. Software Validation via Model Animation

    NASA Technical Reports Server (NTRS)

    Dutle, Aaron M.; Munoz, Cesar A.; Narkawicz, Anthony J.; Butler, Ricky W.

    2015-01-01

    This paper explores a new approach to validating software implementations that have been produced from formally-verified algorithms. Although visual inspection gives some confidence that the implementations faithfully reflect the formal models, it does not provide complete assurance that the software is correct. The proposed approach, which is based on animation of formal specifications, compares the outputs computed by the software implementations on a given suite of input values to the outputs computed by the formal models on the same inputs, and determines if they are equal up to a given tolerance. The approach is illustrated on a prototype air traffic management system that computes simple kinematic trajectories for aircraft. Proofs for the mathematical models of the system's algorithms are carried out in the Prototype Verification System (PVS). The animation tool PVSio is used to evaluate the formal models on a set of randomly generated test cases. Output values computed by PVSio are compared against output values computed by the actual software. This comparison improves the assurance that the translation from formal models to code is faithful and that, for example, floating point errors do not greatly affect correctness and safety properties.

  7. Modeling the biomechanics of fetal movements.

    PubMed

    Verbruggen, Stefaan W; Loo, Jessica H W; Hayat, Tayyib T A; Hajnal, Joseph V; Rutherford, Mary A; Phillips, Andrew T M; Nowlan, Niamh C

    2016-08-01

    Fetal movements in the uterus are a natural part of development and are known to play an important role in normal musculoskeletal development. However, very little is known about the biomechanical stimuli that arise during movements in utero, despite these stimuli being crucial to normal bone and joint formation. Therefore, the objective of this study was to create a series of computational steps by which the forces generated during a kick in utero could be predicted from clinically observed fetal movements using novel cine-MRI data of three fetuses, aged 20-22 weeks. A custom tracking software was designed to characterize the movements of joints in utero, and average uterus deflection of [Formula: see text] mm due to kicking was calculated. These observed displacements provided boundary conditions for a finite element model of the uterine environment, predicting an average reaction force of [Formula: see text] N generated by a kick against the uterine wall. Finally, these data were applied as inputs for a musculoskeletal model of a fetal kick, resulting in predicted maximum forces in the muscles surrounding the hip joint of approximately 8 N, while higher maximum forces of approximately 21 N were predicted for the muscles surrounding the knee joint. This study provides a novel insight into the closed mechanical environment of the uterus, with an innovative method allowing elucidation of the biomechanical interaction of the developing fetus with its surroundings. PMID:26534772

  8. Model for bidirectional movement of cytoplasmic dynein.

    PubMed

    Sumathy, S; Satyanarayana, S V M

    2015-09-01

    Cytoplasmic dynein exhibits a directional processive movement on microtubule filaments and is known to move in steps of varying length based on the number of ATP molecules bound to it and the load that it carries. It is experimentally observed that dynein takes occasional backward steps and the frequency of such backward steps increases as the load approaches the stall force. Using a stochastic process model, we investigate the bidirectional movement of single head of a dynein motor. The probability for backward step is implemented based on fluctuation theorem of non-equilibrium statistical mechanics. We find that the movement of dynein motor is characterized with negative velocity implying backward motion beyond stall force. We observe that the motor moves backward for super stall forces by hydrolyzing the ATP exactly the same way as it does while moving forward for sub-stall forces. Movement of dynein is also simulated using a kinetic Monte Carlo method and the simulated velocities are in good agreement with velocities obtained using a stochastic rate equation model.

  9. [Animal models of cardiovascular disease].

    PubMed

    Chorro, Francisco J; Such-Belenguer, Luis; López-Merino, Vicente

    2009-01-01

    The use of animal models to study cardiovascular disease has made a substantial contribution to increasing our understanding of disease pathogenesis, has led to the development of diagnostic techniques, and has made it possible to verify the effectiveness of different preventative and therapeutic approaches, whether pharmacological or interventional. The main limitations stem from differences between human and experimentally induced pathology, in terms of both genetic regulatory mechanisms and factors that influence cardiovascular function. The experimental models and preparations used in cardiovascular research include those based on isolated cells or tissues or structures immersed in organ baths. The Langendorff system enables isolated perfused hearts to be studied directly under conditions of either no load or controlled loading. In small mammals, a number of models have been developed of cardiovascular conditions that result from spontaneous genetic mutations or, alternatively, that may be induced by specific genomic modification. One of the techniques employed is gene transfer, which can involve the controlled induction of mutations that result in the expression of abnormalities associated with the development of a broad range of different types of cardiovascular disease. Larger animals are used in experimental models in which it is important that physiological regulatory and homeostatic mechanisms are present.

  10. Animal models of erectile dysfunction

    PubMed Central

    Gajbhiye, Snehlata V.; Jadhav, Kshitij S.; Marathe, Padmaja A.; Pawar, Dattatray B.

    2015-01-01

    Animal models have contributed to a great extent to understanding and advancement in the field of sexual medicine. Many current medical and surgical therapies in sexual medicine have been tried based on these animal models. Extensive literature search revealed that the compiled information is limited. In this review, we describe various experimental models of erectile dysfunction (ED) encompassing their procedures, variables of assessment, advantages and disadvantages. The search strategy consisted of review of PubMed based articles. We included original research work and certain review articles available in PubMed database. The search terms used were “ED and experimental models,” “ED and nervous stimulation,” “ED and cavernous nerve stimulation,” “ED and central stimulation,” “ED and diabetes mellitus,” “ED and ageing,” “ED and hypercholesteremia,” “ED and Peyronie's disease,” “radiation induced ED,” “telemetric recording,” “ED and mating test” and “ED and non-contact erection test.” PMID:25624570

  11. Urban landscape features influencing rodent control and animal movement in two urban areas of California

    EPA Science Inventory

    “Pest” control of both native (e.g., gophers) and exotic (e.g., black rats, house mice) species may impact populations of non-target species inadvertently. We evaluated relationships among animal movement, rodent control, and landscape features in two urban locations in Californ...

  12. Landscape features influencing residential rodent control and animal movement in two urban areas of California

    EPA Science Inventory

    Residential “pest” control of both native (e.g., gophers, rabbits) and exotic (e.g., black and Norway rats, house mice) species may impact populations of non-target species inadvertently. We evaluated relationships among animal movement, rodent control, and landscape features in...

  13. Animal models of skin regeneration.

    PubMed

    Gawronska-Kozak, Barbara; Grabowska, Anna; Kopcewicz, Marta; Kur, Anna

    2014-03-01

    Cutaneous injury in the majority of vertebrate animals results in the formation of a scar in the post-injured area. Scar tissues, although beneficial for maintaining integrity of the post-wounded region often interferes with full recovery of injured tissues. The goal of wound-healing studies is to identify mechanisms to redirect reparative pathways from debilitating scar formation to regenerative pathways that lead to normal functionality. To perform such studies models of regeneration, which are rare in mammals, are required. In this review we discussed skin regenerative capabilities present in lower vertebrates and in models of skin scar-free healing in mammals, e.g. mammalian fetuses. However, we especially focused on the attributes of two unusual models of skin scar-free healing capabilities that occur in adult mammals, that is, those associated with nude, FOXN1-deficient mice and in wild-type African spiny mice.

  14. Animal movements in the Kenya Rift and evidence for the earliest ambush hunting by hominins

    NASA Astrophysics Data System (ADS)

    Kübler, Simon; Owenga, Peter; Reynolds, Sally C.; Rucina, Stephen M.; King, Geoffrey C. P.

    2015-09-01

    Animal movements in the Kenya Rift Valley today are influenced by a combination of topography and trace nutrient distribution. These patterns would have been the same in the past when hominins inhabited the area. We use this approach to create a landscape reconstruction of Olorgesailie, a key site in the East African Rift with abundant evidence of large-mammal butchery between ~1.2 and ~0.5 Ma BP. The site location in relation to limited animal routes through the area show that hominins were aware of animal movements and used the location for ambush hunting during the Lower to Middle Pleistocene. These features explain the importance of Olorgesailie as a preferred location of repeated hominin activity through multiple changes in climate and local environmental conditions, and provide insights into the cognitive and hunting abilities of Homo erectus while indicating that their activities at the site were aimed at hunting, rather than scavenging.

  15. Animal movements in the Kenya Rift and evidence for the earliest ambush hunting by hominins

    PubMed Central

    Kübler, Simon; Owenga, Peter; Reynolds, Sally C.; Rucina, Stephen M.; King, Geoffrey C. P.

    2015-01-01

    Animal movements in the Kenya Rift Valley today are influenced by a combination of topography and trace nutrient distribution. These patterns would have been the same in the past when hominins inhabited the area. We use this approach to create a landscape reconstruction of Olorgesailie, a key site in the East African Rift with abundant evidence of large-mammal butchery between ~1.2 and ~0.5 Ma BP. The site location in relation to limited animal routes through the area show that hominins were aware of animal movements and used the location for ambush hunting during the Lower to Middle Pleistocene. These features explain the importance of Olorgesailie as a preferred location of repeated hominin activity through multiple changes in climate and local environmental conditions, and provide insights into the cognitive and hunting abilities of Homo erectus while indicating that their activities at the site were aimed at hunting, rather than scavenging. PMID:26369499

  16. Animal movements in the Kenya Rift and evidence for the earliest ambush hunting by hominins.

    PubMed

    Kübler, Simon; Owenga, Peter; Reynolds, Sally C; Rucina, Stephen M; King, Geoffrey C P

    2015-01-01

    Animal movements in the Kenya Rift Valley today are influenced by a combination of topography and trace nutrient distribution. These patterns would have been the same in the past when hominins inhabited the area. We use this approach to create a landscape reconstruction of Olorgesailie, a key site in the East African Rift with abundant evidence of large-mammal butchery between ~1.2 and ~0.5 Ma BP. The site location in relation to limited animal routes through the area show that hominins were aware of animal movements and used the location for ambush hunting during the Lower to Middle Pleistocene. These features explain the importance of Olorgesailie as a preferred location of repeated hominin activity through multiple changes in climate and local environmental conditions, and provide insights into the cognitive and hunting abilities of Homo erectus while indicating that their activities at the site were aimed at hunting, rather than scavenging. PMID:26369499

  17. Animal movements in the Kenya Rift and evidence for the earliest ambush hunting by hominins.

    PubMed

    Kübler, Simon; Owenga, Peter; Reynolds, Sally C; Rucina, Stephen M; King, Geoffrey C P

    2015-01-01

    Animal movements in the Kenya Rift Valley today are influenced by a combination of topography and trace nutrient distribution. These patterns would have been the same in the past when hominins inhabited the area. We use this approach to create a landscape reconstruction of Olorgesailie, a key site in the East African Rift with abundant evidence of large-mammal butchery between ~1.2 and ~0.5 Ma BP. The site location in relation to limited animal routes through the area show that hominins were aware of animal movements and used the location for ambush hunting during the Lower to Middle Pleistocene. These features explain the importance of Olorgesailie as a preferred location of repeated hominin activity through multiple changes in climate and local environmental conditions, and provide insights into the cognitive and hunting abilities of Homo erectus while indicating that their activities at the site were aimed at hunting, rather than scavenging.

  18. Animal models of cartilage repair

    PubMed Central

    Cook, J. L.; Hung, C. T.; Kuroki, K.; Stoker, A. M.; Cook, C. R.; Pfeiffer, F. M.; Sherman, S. L.; Stannard, J. P.

    2014-01-01

    Cartilage repair in terms of replacement, or regeneration of damaged or diseased articular cartilage with functional tissue, is the ‘holy grail’ of joint surgery. A wide spectrum of strategies for cartilage repair currently exists and several of these techniques have been reported to be associated with successful clinical outcomes for appropriately selected indications. However, based on respective advantages, disadvantages, and limitations, no single strategy, or even combination of strategies, provides surgeons with viable options for attaining successful long-term outcomes in the majority of patients. As such, development of novel techniques and optimisation of current techniques need to be, and are, the focus of a great deal of research from the basic science level to clinical trials. Translational research that bridges scientific discoveries to clinical application involves the use of animal models in order to assess safety and efficacy for regulatory approval for human use. This review article provides an overview of animal models for cartilage repair. Cite this article: Bone Joint Res 2014;4:89–94. PMID:24695750

  19. An animal model of fetishism.

    PubMed

    Köksal, Falih; Domjan, Michael; Kurt, Adnan; Sertel, Ozlem; Orüng, Sabiha; Bowers, Rob; Kumru, Gulsen

    2004-12-01

    An animal model of sexual fetishism was developed with male Japanese quail based on persistence of conditioned sexual responding during extinction to an inanimate object made of terrycloth (Experiments 1 and 3). This persistent responding occurred only in subjects that came to copulate with the terrycloth object, suggesting that the copulatory behavior served to maintain the fetishistic behavior. Sexual conditioning was carried out by pairing a conditioned stimulus (CS) with the opportunity to copulate with a female (the unconditioned stimulus or US). Copulation with the CS object and persistent responding did not develop if the CS was a light (Experiment 1) or if conditioning was carried out with a food US (Experiment 2). In addition, subjects that showed persistence in responding to the terrycloth CS did not persist in their responding to a light CS (Experiment 3). The results are consistent with the hypothesis that conditioned copulatory behavior creates a form of self-maintenance that leads to persistent responding to an inanimate object. The development of an animal model of such fetishistic behavior should facilitate experimental analysis of the phenomenon. PMID:15500813

  20. Animal models and conserved processes

    PubMed Central

    2012-01-01

    Background The concept of conserved processes presents unique opportunities for using nonhuman animal models in biomedical research. However, the concept must be examined in the context that humans and nonhuman animals are evolved, complex, adaptive systems. Given that nonhuman animals are examples of living systems that are differently complex from humans, what does the existence of a conserved gene or process imply for inter-species extrapolation? Methods We surveyed the literature including philosophy of science, biological complexity, conserved processes, evolutionary biology, comparative medicine, anti-neoplastic agents, inhalational anesthetics, and drug development journals in order to determine the value of nonhuman animal models when studying conserved processes. Results Evolution through natural selection has employed components and processes both to produce the same outcomes among species but also to generate different functions and traits. Many genes and processes are conserved, but new combinations of these processes or different regulation of the genes involved in these processes have resulted in unique organisms. Further, there is a hierarchy of organization in complex living systems. At some levels, the components are simple systems that can be analyzed by mathematics or the physical sciences, while at other levels the system cannot be fully analyzed by reducing it to a physical system. The study of complex living systems must alternate between focusing on the parts and examining the intact whole organism while taking into account the connections between the two. Systems biology aims for this holism. We examined the actions of inhalational anesthetic agents and anti-neoplastic agents in order to address what the characteristics of complex living systems imply for inter-species extrapolation of traits and responses related to conserved processes. Conclusion We conclude that even the presence of conserved processes is insufficient for inter

  1. Generation of animation sequences of three dimensional models

    NASA Technical Reports Server (NTRS)

    Poi, Sharon (Inventor); Bell, Brad N. (Inventor)

    1990-01-01

    The invention is directed toward a method and apparatus for generating an animated sequence through the movement of three-dimensional graphical models. A plurality of pre-defined graphical models are stored and manipulated in response to interactive commands or by means of a pre-defined command file. The models may be combined as part of a hierarchical structure to represent physical systems without need to create a separate model which represents the combined system. System motion is simulated through the introduction of translation, rotation and scaling parameters upon a model within the system. The motion is then transmitted down through the system hierarchy of models in accordance with hierarchical definitions and joint movement limitations. The present invention also calls for a method of editing hierarchical structure in response to interactive commands or a command file such that a model may be included, deleted, copied or moved within multiple system model hierarchies. The present invention also calls for the definition of multiple viewpoints or cameras which may exist as part of a system hierarchy or as an independent camera. The simulated movement of the models and systems is graphically displayed on a monitor and a frame is recorded by means of a video controller. Multiple movement and hierarchy manipulations are then recorded as a sequence of frames which may be played back as an animation sequence on a video cassette recorder.

  2. Parathyroid diseases and animal models.

    PubMed

    Imanishi, Yasuo; Nagata, Yuki; Inaba, Masaaki

    2012-01-01

    CIRCULATING CALCIUM AND PHOSPHATE ARE TIGHTLY REGULATED BY THREE HORMONES: the active form of vitamin D (1,25-dihydroxyvitamin D), fibroblast growth factor (FGF)-23, and parathyroid hormone (PTH). PTH acts to stimulate a rapid increment in serum calcium and has a crucial role in calcium homeostasis. Major target organs of PTH are kidney and bone. The oversecretion of the hormone results in hypercalcemia, caused by increased intestinal calcium absorption, reduced renal calcium clearance, and mobilization of calcium from bone in primary hyperparathyroidism. In chronic kidney disease, secondary hyperparathyroidism of uremia is observed in its early stages, and this finally develops into the autonomous secretion of PTH during maintenance hemodialysis. Receptors in parathyroid cells, such as the calcium-sensing receptor, vitamin D receptor, and FGF receptor (FGFR)-Klotho complex have crucial roles in the regulation of PTH secretion. Genes such as Cyclin D1, RET, MEN1, HRPT2, and CDKN1B have been identified in parathyroid diseases. Genetically engineered animals with these receptors and the associated genes have provided us with valuable information on the patho-physiology of parathyroid diseases. The application of these animal models is significant for the development of new therapies.

  3. Effects of number of animals monitored on representations of cattle group movement characteristics and spatial occupancy.

    PubMed

    Liu, Tong; Green, Angela R; Rodríguez, Luis F; Ramirez, Brett C; Shike, Daniel W

    2015-01-01

    The number of animals required to represent the collective characteristics of a group remains a concern in animal movement monitoring with GPS. Monitoring a subset of animals from a group instead of all animals can reduce costs and labor; however, incomplete data may cause information losses and inaccuracy in subsequent data analyses. In cattle studies, little work has been conducted to determine the number of cattle within a group needed to be instrumented considering subsequent analyses. Two different groups of cattle (a mixed group of 24 beef cows and heifers, and another group of 8 beef cows) were monitored with GPS collars at 4 min intervals on intensively managed pastures and corn residue fields in 2011. The effects of subset group size on cattle movement characterization and spatial occupancy analysis were evaluated by comparing the results between subset groups and the entire group for a variety of summarization parameters. As expected, more animals yield better results for all parameters. Results show the average group travel speed and daily travel distances are overestimated as subset group size decreases, while the average group radius is underestimated. Accuracy of group centroid locations and group radii are improved linearly as subset group size increases. A kernel density estimation was performed to quantify the spatial occupancy by cattle via GPS location data. Results show animals among the group had high similarity of spatial occupancy. Decisions regarding choosing an appropriate subset group size for monitoring depend on the specific use of data for subsequent analysis: a small subset group may be adequate for identifying areas visited by cattle; larger subset group size (e.g. subset group containing more than 75% of animals) is recommended to achieve better accuracy of group movement characteristics and spatial occupancy for the use of correlating cattle locations with other environmental factors.

  4. Effects of Number of Animals Monitored on Representations of Cattle Group Movement Characteristics and Spatial Occupancy

    PubMed Central

    Liu, Tong; Green, Angela R.; Rodríguez, Luis F.; Ramirez, Brett C.; Shike, Daniel W.

    2015-01-01

    The number of animals required to represent the collective characteristics of a group remains a concern in animal movement monitoring with GPS. Monitoring a subset of animals from a group instead of all animals can reduce costs and labor; however, incomplete data may cause information losses and inaccuracy in subsequent data analyses. In cattle studies, little work has been conducted to determine the number of cattle within a group needed to be instrumented considering subsequent analyses. Two different groups of cattle (a mixed group of 24 beef cows and heifers, and another group of 8 beef cows) were monitored with GPS collars at 4 min intervals on intensively managed pastures and corn residue fields in 2011. The effects of subset group size on cattle movement characterization and spatial occupancy analysis were evaluated by comparing the results between subset groups and the entire group for a variety of summarization parameters. As expected, more animals yield better results for all parameters. Results show the average group travel speed and daily travel distances are overestimated as subset group size decreases, while the average group radius is underestimated. Accuracy of group centroid locations and group radii are improved linearly as subset group size increases. A kernel density estimation was performed to quantify the spatial occupancy by cattle via GPS location data. Results show animals among the group had high similarity of spatial occupancy. Decisions regarding choosing an appropriate subset group size for monitoring depend on the specific use of data for subsequent analysis: a small subset group may be adequate for identifying areas visited by cattle; larger subset group size (e.g. subset group containing more than 75% of animals) is recommended to achieve better accuracy of group movement characteristics and spatial occupancy for the use of correlating cattle locations with other environmental factors. PMID:25647571

  5. Effects of number of animals monitored on representations of cattle group movement characteristics and spatial occupancy.

    PubMed

    Liu, Tong; Green, Angela R; Rodríguez, Luis F; Ramirez, Brett C; Shike, Daniel W

    2015-01-01

    The number of animals required to represent the collective characteristics of a group remains a concern in animal movement monitoring with GPS. Monitoring a subset of animals from a group instead of all animals can reduce costs and labor; however, incomplete data may cause information losses and inaccuracy in subsequent data analyses. In cattle studies, little work has been conducted to determine the number of cattle within a group needed to be instrumented considering subsequent analyses. Two different groups of cattle (a mixed group of 24 beef cows and heifers, and another group of 8 beef cows) were monitored with GPS collars at 4 min intervals on intensively managed pastures and corn residue fields in 2011. The effects of subset group size on cattle movement characterization and spatial occupancy analysis were evaluated by comparing the results between subset groups and the entire group for a variety of summarization parameters. As expected, more animals yield better results for all parameters. Results show the average group travel speed and daily travel distances are overestimated as subset group size decreases, while the average group radius is underestimated. Accuracy of group centroid locations and group radii are improved linearly as subset group size increases. A kernel density estimation was performed to quantify the spatial occupancy by cattle via GPS location data. Results show animals among the group had high similarity of spatial occupancy. Decisions regarding choosing an appropriate subset group size for monitoring depend on the specific use of data for subsequent analysis: a small subset group may be adequate for identifying areas visited by cattle; larger subset group size (e.g. subset group containing more than 75% of animals) is recommended to achieve better accuracy of group movement characteristics and spatial occupancy for the use of correlating cattle locations with other environmental factors. PMID:25647571

  6. Path segmentation for beginners: an overview of current methods for detecting changes in animal movement patterns.

    PubMed

    Edelhoff, Hendrik; Signer, Johannes; Balkenhol, Niko

    2016-01-01

    Increased availability of high-resolution movement data has led to the development of numerous methods for studying changes in animal movement behavior. Path segmentation methods provide basics for detecting movement changes and the behavioral mechanisms driving them. However, available path segmentation methods differ vastly with respect to underlying statistical assumptions and output produced. Consequently, it is currently difficult for researchers new to path segmentation to gain an overview of the different methods, and choose one that is appropriate for their data and research questions. Here, we provide an overview of different methods for segmenting movement paths according to potential changes in underlying behavior. To structure our overview, we outline three broad types of research questions that are commonly addressed through path segmentation: 1) the quantitative description of movement patterns, 2) the detection of significant change-points, and 3) the identification of underlying processes or 'hidden states'. We discuss advantages and limitations of different approaches for addressing these research questions using path-level movement data, and present general guidelines for choosing methods based on data characteristics and questions. Our overview illustrates the large diversity of available path segmentation approaches, highlights the need for studies that compare the utility of different methods, and identifies opportunities for future developments in path-level data analysis.

  7. Path segmentation for beginners: an overview of current methods for detecting changes in animal movement patterns.

    PubMed

    Edelhoff, Hendrik; Signer, Johannes; Balkenhol, Niko

    2016-01-01

    Increased availability of high-resolution movement data has led to the development of numerous methods for studying changes in animal movement behavior. Path segmentation methods provide basics for detecting movement changes and the behavioral mechanisms driving them. However, available path segmentation methods differ vastly with respect to underlying statistical assumptions and output produced. Consequently, it is currently difficult for researchers new to path segmentation to gain an overview of the different methods, and choose one that is appropriate for their data and research questions. Here, we provide an overview of different methods for segmenting movement paths according to potential changes in underlying behavior. To structure our overview, we outline three broad types of research questions that are commonly addressed through path segmentation: 1) the quantitative description of movement patterns, 2) the detection of significant change-points, and 3) the identification of underlying processes or 'hidden states'. We discuss advantages and limitations of different approaches for addressing these research questions using path-level movement data, and present general guidelines for choosing methods based on data characteristics and questions. Our overview illustrates the large diversity of available path segmentation approaches, highlights the need for studies that compare the utility of different methods, and identifies opportunities for future developments in path-level data analysis. PMID:27595001

  8. Mechanics, modulation and modelling: how muscles actuate and control movement

    PubMed Central

    Higham, Timothy E.; Biewener, Andrew A.; Delp, Scott L.

    2011-01-01

    Animal movement is often complex, unsteady and variable. The critical role of muscles in animal movement has captivated scientists for over 300 years. Despite this, emerging techniques and ideas are still shaping and advancing the field. For example, sonomicrometry and ultrasound techniques have enhanced our ability to quantify muscle length changes under in vivo conditions. Robotics and musculoskeletal models have benefited from improved computational tools and have enhanced our ability to understand muscle function in relation to movement by allowing one to simulate muscle–tendon dynamics under realistic conditions. The past decade, in particular, has seen a rapid advancement in technology and shifts in paradigms related to muscle function. In addition, there has been an increased focus on muscle function in relation to the complex locomotor behaviours, rather than relatively simple (and steady) behaviours. Thus, this Theme Issue will explore integrative aspects of muscle function in relation to diverse locomotor behaviours such as swimming, jumping, hopping, running, flying, moving over obstacles and transitioning between environments. Studies of walking and running have particular relevance to clinical aspects of human movement and sport. This Theme Issue includes contributions from scientists working on diverse taxa, ranging from humans to insects. In addition to contributions addressing locomotion in various taxa, several manuscripts will focus on recent advances in neuromuscular control and modulation during complex behaviours. Finally, some of the contributions address recent advances in biomechanical modelling and powered prostheses. We hope that our comprehensive and integrative Theme Issue will form the foundation for future work in the fields of neuromuscular mechanics and locomotion. PMID:21502117

  9. Polycystic ovarian disease: animal models.

    PubMed

    Mahajan, D K

    1988-12-01

    The reproductive systems of human beings and other vertebrates are grossly similar. In the ovary particularly, the biochemical and physiologic processes are identical not only in the formation of germ cells, the development of primordial follicles and their subsequent growth to Graafian follicles, and eventual ovulation but also in anatomic structure. In a noncarcinogenic human ovary, hypersecretion of androgen causes PCOD. Such hypersecretion may result from a nonpulsatile, constant elevated level of circulating LH or a disturbance in the action of neurotransmitters in the hypothalamus. In studying the pathophysiology of PCOD in humans, one must be aware of the limitations for manipulating the hypothalamic-pituitary axis. Although the rat is a polytocous rodent, the female has a regular ovarian cyclicity of 4 or 5 days, with distinct proestrus, estrus, and diestrus phases. Inasmuch as PCOD can be experimentally produced in the rat, that species is a good model for studying the pathophysiology of human PCOD. These PCOD models and their validity have been described: (1) estradiol-valerate, (2) DHA, (3) constant-light (LL), and (4) neonatally androgenized. Among these, the LL model is noninvasive and seems superior to the others for study of the pathophysiology of PCOD. The production of the polycystic ovarian condition in the rat by the injection of estrogens or androgens in neonate animals, or estradiol or DHA in adult rats, or the administration of antigonadotropins to these animals all cause a sudden appearance of the persistent estrus state by disturbing the metabolic and physiologic processes, whereas exposure of the adult rat to LL causes polycystic ovaries gradually, similar to what is seen in human idiopathic PCOD. After about 50 days of LL, the rat becomes anovulatory and the ovaries contain thickened tunica albuginea and many atretic follicles, and the tertiary follicles are considerably distended and cystic. The granulosa and theca cells appear normal

  10. Opportunities for the application of advanced remotely-sensed data in ecological studies of terrestrial animal movement.

    PubMed

    Neumann, Wiebke; Martinuzzi, Sebastian; Estes, Anna B; Pidgeon, Anna M; Dettki, Holger; Ericsson, Göran; Radeloff, Volker C

    2015-01-01

    Animal movement patterns in space and time are a central aspect of animal ecology. Remotely-sensed environmental indices can play a key role in understanding movement patterns by providing contiguous, relatively fine-scale data that link animal movements to their environment. Still, implementation of newly available remotely-sensed data is often delayed in studies of animal movement, calling for a better flow of information to researchers less familiar with remotely-sensed data applications. Here, we reviewed the application of remotely-sensed environmental indices to infer movement patterns of animals in terrestrial systems in studies published between 2002 and 2013. Next, we introduced newly available remotely-sensed products, and discussed their opportunities for animal movement studies. Studies of coarse-scale movement mostly relied on satellite data representing plant phenology or climate and weather. Studies of small-scale movement frequently used land cover data based on Landsat imagery or aerial photographs. Greater documentation of the type and resolution of remotely-sensed products in ecological movement studies would enhance their usefulness. Recent advancements in remote sensing technology improve assessments of temporal dynamics of landscapes and the three-dimensional structures of habitats, enabling near real-time environmental assessment. Online movement databases that now integrate remotely-sensed data facilitate access to remotely-sensed products for movement ecologists. We recommend that animal movement studies incorporate remotely-sensed products that provide time series of environmental response variables. This would facilitate wildlife management and conservation efforts, as well as the predictive ability of movement analyses. Closer collaboration between ecologists and remote sensing experts could considerably alleviate the implementation gap. Ecologists should not expect that indices derived from remotely-sensed data will be directly

  11. Expanding Panjabi's stability model to express movement: a theoretical model.

    PubMed

    Hoffman, J; Gabel, P

    2013-06-01

    Novel theoretical models of movement have historically inspired the creation of new methods for the application of human movement. The landmark theoretical model of spinal stability by Panjabi in 1992 led to the creation of an exercise approach to spinal stability. This approach however was later challenged, most significantly due to a lack of favourable clinical effect. The concepts explored in this paper address and consider the deficiencies of Panjabi's model then propose an evolution and expansion from a special model of stability to a general one of movement. It is proposed that two body-wide symbiotic elements are present within all movement systems, stability and mobility. The justification for this is derived from the observable clinical environment. It is clinically recognised that these two elements are present and identifiable throughout the body in different joints and muscles, and the neural conduction system. In order to generalise the Panjabi model of stability to include and illustrate movement, a matching parallel mobility system with the same subsystems was conceptually created. In this expanded theoretical model, the new mobility system is placed beside the existing stability system and subsystems. The ability of both stability and mobility systems to work in harmony will subsequently determine the quality of movement. Conversely, malfunction of either system, or their subsystems, will deleteriously affect all other subsystems and consequently overall movement quality. For this reason, in the rehabilitation exercise environment, focus should be placed on the simultaneous involvement of both the stability and mobility systems. It is suggested that the individual's relevant functional harmonious movements should be challenged at the highest possible level without pain or discomfort. It is anticipated that this conceptual expansion of the theoretical model of stability to one with the symbiotic inclusion of mobility, will provide new understandings

  12. Disease Spread through Animal Movements: A Static and Temporal Network Analysis of Pig Trade in Germany

    PubMed Central

    Lentz, Hartmut H. K.; Koher, Andreas; Hövel, Philipp; Gethmann, Jörn; Sauter-Louis, Carola; Selhorst, Thomas; Conraths, Franz J.

    2016-01-01

    Background Animal trade plays an important role for the spread of infectious diseases in livestock populations. The central question of this work is how infectious diseases can potentially spread via trade in such a livestock population. We address this question by analyzing the underlying network of animal movements. In particular, we consider pig trade in Germany, where trade actors (agricultural premises) form a complex network. Methodology The considered pig trade dataset spans several years and is analyzed with respect to its potential to spread infectious diseases. Focusing on measurements of network-topological properties, we avoid the usage of external parameters, since these properties are independent of specific pathogens. They are on the contrary of great importance for understanding any general spreading process on this particular network. We analyze the system using different network models, which include varying amounts of information: (i) static network, (ii) network as a time series of uncorrelated snapshots, (iii) temporal network, where causality is explicitly taken into account. Findings We find that a static network view captures many relevant aspects of the trade system, and premises can be classified into two clearly defined risk classes. Moreover, our results allow for an efficient allocation strategy for intervention measures using centrality measures. Data on trade volume do barely alter the results and is therefore of secondary importance. Although a static network description yields useful results, the temporal resolution of data plays an outstanding role for an in-depth understanding of spreading processes. This applies in particular for an accurate calculation of the maximum outbreak size. PMID:27152712

  13. Optimal orientation in flows: providing a benchmark for animal movement strategies.

    PubMed

    McLaren, James D; Shamoun-Baranes, Judy; Dokter, Adriaan M; Klaassen, Raymond H G; Bouten, Willem

    2014-10-01

    Animal movements in air and water can be strongly affected by experienced flow. While various flow-orientation strategies have been proposed and observed, their performance in variable flow conditions remains unclear. We apply control theory to establish a benchmark for time-minimizing (optimal) orientation. We then define optimal orientation for movement in steady flow patterns and, using dynamic wind data, for short-distance mass movements of thrushes (Turdus sp.) and 6000 km non-stop migratory flights by great snipes, Gallinago media. Relative to the optimal benchmark, we assess the efficiency (travel speed) and reliability (success rate) of three generic orientation strategies: full compensation for lateral drift, vector orientation (single-heading movement) and goal orientation (continually heading towards the goal). Optimal orientation is characterized by detours to regions of high flow support, especially when flow speeds approach and exceed the animal's self-propelled speed. In strong predictable flow (short distance thrush flights), vector orientation adjusted to flow on departure is nearly optimal, whereas for unpredictable flow (inter-continental snipe flights), only goal orientation was near-optimally reliable and efficient. Optimal orientation provides a benchmark for assessing efficiency of responses to complex flow conditions, thereby offering insight into adaptive flow-orientation across taxa in the light of flow strength, predictability and navigation capacity. PMID:25056213

  14. Optimal orientation in flows: providing a benchmark for animal movement strategies.

    PubMed

    McLaren, James D; Shamoun-Baranes, Judy; Dokter, Adriaan M; Klaassen, Raymond H G; Bouten, Willem

    2014-10-01

    Animal movements in air and water can be strongly affected by experienced flow. While various flow-orientation strategies have been proposed and observed, their performance in variable flow conditions remains unclear. We apply control theory to establish a benchmark for time-minimizing (optimal) orientation. We then define optimal orientation for movement in steady flow patterns and, using dynamic wind data, for short-distance mass movements of thrushes (Turdus sp.) and 6000 km non-stop migratory flights by great snipes, Gallinago media. Relative to the optimal benchmark, we assess the efficiency (travel speed) and reliability (success rate) of three generic orientation strategies: full compensation for lateral drift, vector orientation (single-heading movement) and goal orientation (continually heading towards the goal). Optimal orientation is characterized by detours to regions of high flow support, especially when flow speeds approach and exceed the animal's self-propelled speed. In strong predictable flow (short distance thrush flights), vector orientation adjusted to flow on departure is nearly optimal, whereas for unpredictable flow (inter-continental snipe flights), only goal orientation was near-optimally reliable and efficient. Optimal orientation provides a benchmark for assessing efficiency of responses to complex flow conditions, thereby offering insight into adaptive flow-orientation across taxa in the light of flow strength, predictability and navigation capacity.

  15. Optimal orientation in flows: providing a benchmark for animal movement strategies

    PubMed Central

    McLaren, James D.; Shamoun-Baranes, Judy; Dokter, Adriaan M.; Klaassen, Raymond H. G.; Bouten, Willem

    2014-01-01

    Animal movements in air and water can be strongly affected by experienced flow. While various flow-orientation strategies have been proposed and observed, their performance in variable flow conditions remains unclear. We apply control theory to establish a benchmark for time-minimizing (optimal) orientation. We then define optimal orientation for movement in steady flow patterns and, using dynamic wind data, for short-distance mass movements of thrushes (Turdus sp.) and 6000 km non-stop migratory flights by great snipes, Gallinago media. Relative to the optimal benchmark, we assess the efficiency (travel speed) and reliability (success rate) of three generic orientation strategies: full compensation for lateral drift, vector orientation (single-heading movement) and goal orientation (continually heading towards the goal). Optimal orientation is characterized by detours to regions of high flow support, especially when flow speeds approach and exceed the animal's self-propelled speed. In strong predictable flow (short distance thrush flights), vector orientation adjusted to flow on departure is nearly optimal, whereas for unpredictable flow (inter-continental snipe flights), only goal orientation was near-optimally reliable and efficient. Optimal orientation provides a benchmark for assessing efficiency of responses to complex flow conditions, thereby offering insight into adaptive flow-orientation across taxa in the light of flow strength, predictability and navigation capacity. PMID:25056213

  16. Animal models in today's translational medicine world.

    PubMed

    Choudhary, Abhishek; Ibdah, Jamal A

    2013-01-01

    Translational medicine drives progress of research along the continuum from basic biomedical research findings into clinical practice. Animal models play a central role in the above continuum. The recent explosion in molecular biology and generation of human physiological system in animals has led to an increasing use of in vivo animal models in today's translational medicine.

  17. Animal models to evaluate bacterial biofilm development.

    PubMed

    Thomsen, Kim; Trøstrup, Hannah; Moser, Claus

    2014-01-01

    Medical biofilms have attracted substantial attention especially in the past decade. Animal models are contributing significantly to understand the pathogenesis of medical biofilms. In addition, animal models are an essential tool in testing the hypothesis generated from clinical observations in patients and preclinical testing of agents showing in vitro antibiofilm effect. Here, we describe three animal models - two non-foreign body Pseudomonas aeruginosa biofilm models and a foreign body Staphylococcus aureus model.

  18. Potency of Animal Models in KANSEI Engineering

    NASA Astrophysics Data System (ADS)

    Ozaki, Shigeru; Hisano, Setsuji; Iwamoto, Yoshiki

    Various species of animals have been used as animal models for neuroscience and provided critical information about the brain functions. Although it seems difficult to elucidate a highly advanced function of the human brain, animal models have potency to clarify the fundamental mechanisms of emotion, decision-making and social behavior. In this review, we will pick up common animal models and point to both the merits and demerits caused by the characteristics. We will also mention that wide-ranging approaches from animal models are advantageous to understand KANSEI as well as mind in humans.

  19. Energy efficiency and allometry of movement of swimming and flying animals

    PubMed Central

    Bale, Rahul; Hao, Max; Bhalla, Amneet Pal Singh; Patankar, Neelesh A.

    2014-01-01

    Which animals use their energy better during movement? One metric to answer this question is the energy cost per unit distance per unit weight. Prior data show that this metric decreases with mass, which is considered to imply that massive animals are more efficient. Although useful, this metric also implies that two dynamically equivalent animals of different sizes will not be considered equally efficient. We resolve this longstanding issue by first determining the scaling of energy cost per unit distance traveled. The scale is found to be M2/3 or M1/2, where M is the animal mass. Second, we introduce an energy-consumption coefficient (CE) defined as energy per unit distance traveled divided by this scale. CE is a measure of efficiency of swimming and flying, analogous to how drag coefficient quantifies aerodynamic drag on vehicles. Derivation of the energy-cost scale reveals that the assumption that undulatory swimmers spend energy to overcome drag in the direction of swimming is inappropriate. We derive allometric scalings that capture trends in data of swimming and flying animals over 10–20 orders of magnitude by mass. The energy-consumption coefficient reveals that swimmers beyond a critical mass, and most fliers are almost equally efficient as if they are dynamically equivalent; increasingly massive animals are not more efficient according to the proposed metric. Distinct allometric scalings are discovered for large and small swimmers. Flying animals are found to require relatively more energy compared with swimmers. PMID:24821764

  20. Energy efficiency and allometry of movement of swimming and flying animals.

    PubMed

    Bale, Rahul; Hao, Max; Bhalla, Amneet Pal Singh; Patankar, Neelesh A

    2014-05-27

    Which animals use their energy better during movement? One metric to answer this question is the energy cost per unit distance per unit weight. Prior data show that this metric decreases with mass, which is considered to imply that massive animals are more efficient. Although useful, this metric also implies that two dynamically equivalent animals of different sizes will not be considered equally efficient. We resolve this longstanding issue by first determining the scaling of energy cost per unit distance traveled. The scale is found to be M(2/3) or M(1/2), where M is the animal mass. Second, we introduce an energy-consumption coefficient (CE) defined as energy per unit distance traveled divided by this scale. CE is a measure of efficiency of swimming and flying, analogous to how drag coefficient quantifies aerodynamic drag on vehicles. Derivation of the energy-cost scale reveals that the assumption that undulatory swimmers spend energy to overcome drag in the direction of swimming is inappropriate. We derive allometric scalings that capture trends in data of swimming and flying animals over 10-20 orders of magnitude by mass. The energy-consumption coefficient reveals that swimmers beyond a critical mass, and most fliers are almost equally efficient as if they are dynamically equivalent; increasingly massive animals are not more efficient according to the proposed metric. Distinct allometric scalings are discovered for large and small swimmers. Flying animals are found to require relatively more energy compared with swimmers.

  1. Energy efficiency and allometry of movement of swimming and flying animals.

    PubMed

    Bale, Rahul; Hao, Max; Bhalla, Amneet Pal Singh; Patankar, Neelesh A

    2014-05-27

    Which animals use their energy better during movement? One metric to answer this question is the energy cost per unit distance per unit weight. Prior data show that this metric decreases with mass, which is considered to imply that massive animals are more efficient. Although useful, this metric also implies that two dynamically equivalent animals of different sizes will not be considered equally efficient. We resolve this longstanding issue by first determining the scaling of energy cost per unit distance traveled. The scale is found to be M(2/3) or M(1/2), where M is the animal mass. Second, we introduce an energy-consumption coefficient (CE) defined as energy per unit distance traveled divided by this scale. CE is a measure of efficiency of swimming and flying, analogous to how drag coefficient quantifies aerodynamic drag on vehicles. Derivation of the energy-cost scale reveals that the assumption that undulatory swimmers spend energy to overcome drag in the direction of swimming is inappropriate. We derive allometric scalings that capture trends in data of swimming and flying animals over 10-20 orders of magnitude by mass. The energy-consumption coefficient reveals that swimmers beyond a critical mass, and most fliers are almost equally efficient as if they are dynamically equivalent; increasingly massive animals are not more efficient according to the proposed metric. Distinct allometric scalings are discovered for large and small swimmers. Flying animals are found to require relatively more energy compared with swimmers. PMID:24821764

  2. Chronobiology of ethanol: animal models.

    PubMed

    Rosenwasser, Alan M

    2015-06-01

    Clinical and epidemiological observations have revealed that alcohol abuse and alcoholism are associated with widespread disruptions in sleep and other circadian biological rhythms. As with other psychiatric disorders, animal models have been very useful in efforts to better understand the cause and effect relationships underlying the largely correlative human data. This review summarizes the experimental findings indicating bidirectional interactions between alcohol (ethanol) consumption and the circadian timing system, emphasizing behavioral studies conducted in the author's laboratory. Together with convergent evidence from multiple laboratories, the work summarized here establishes that ethanol intake (or administration) alters fundamental properties of the underlying circadian pacemaker. In turn, circadian disruption induced by either environmental or genetic manipulations can alter voluntary ethanol intake. These reciprocal interactions may create a vicious cycle that contributes to the downward spiral of alcohol and drug addiction. In the future, such studies may lead to the development of chronobiologically based interventions to prevent relapse and effectively mitigate some of the societal burden associated with such disorders.

  3. Animal models and integrated nested Laplace approximations.

    PubMed

    Holand, Anna Marie; Steinsland, Ingelin; Martino, Sara; Jensen, Henrik

    2013-08-07

    Animal models are generalized linear mixed models used in evolutionary biology and animal breeding to identify the genetic part of traits. Integrated Nested Laplace Approximation (INLA) is a methodology for making fast, nonsampling-based Bayesian inference for hierarchical Gaussian Markov models. In this article, we demonstrate that the INLA methodology can be used for many versions of Bayesian animal models. We analyze animal models for both synthetic case studies and house sparrow (Passer domesticus) population case studies with Gaussian, binomial, and Poisson likelihoods using INLA. Inference results are compared with results using Markov Chain Monte Carlo methods. For model choice we use difference in deviance information criteria (DIC). We suggest and show how to evaluate differences in DIC by comparing them with sampling results from simulation studies. We also introduce an R package, AnimalINLA, for easy and fast inference for Bayesian Animal models using INLA.

  4. A Heterogeneous Wireless Identification Network for the Localization of Animals Based on Stochastic Movements

    PubMed Central

    Gutiérrez, Álvaro; González, Carlos; Jiménez-Leube, Javier; Zazo, Santiago; Dopico, Nelson; Raos, Ivana

    2009-01-01

    The improvement in the transmission range in wireless applications without the use of batteries remains a significant challenge in identification applications. In this paper, we describe a heterogeneous wireless identification network mostly powered by kinetic energy, which allows the localization of animals in open environments. The system relies on radio communications and a global positioning system. It is made up of primary and secondary nodes. Secondary nodes are kinetic-powered and take advantage of animal movements to activate the node and transmit a specific identifier, reducing the number of batteries of the system. Primary nodes are battery-powered and gather secondary-node transmitted information to provide it, along with position and time data, to a final base station in charge of the animal monitoring. The system allows tracking based on contextual information obtained from statistical data. PMID:22412344

  5. Relevance of animal models to human tardive dyskinesia

    PubMed Central

    2012-01-01

    Tardive dyskinesia remains an elusive and significant clinical entity that can possibly be understood via experimentation with animal models. We conducted a literature review on tardive dyskinesia modeling. Subchronic antipsychotic drug exposure is a standard approach to model tardive dyskinesia in rodents. Vacuous chewing movements constitute the most common pattern of expression of purposeless oral movements and represent an impermanent response, with individual and strain susceptibility differences. Transgenic mice are also used to address the contribution of adaptive and maladaptive signals induced during antipsychotic drug exposure. An emphasis on non-human primate modeling is proposed, and past experimental observations reviewed in various monkey species. Rodent and primate models are complementary, but the non-human primate model appears more convincingly similar to the human condition and better suited to address therapeutic issues against tardive dyskinesia. PMID:22404856

  6. Minimally Invasive Techniques to Accelerate the Orthodontic Tooth Movement: A Systematic Review of Animal Studies

    PubMed Central

    Qamruddin, Irfan; Alam, Mohammad Khursheed; Khamis, Mohd Fadhli; Husein, Adam

    2015-01-01

    Objective. To evaluate various noninvasive and minimally invasive procedures for the enhancement of orthodontic tooth movement in animals. Materials and Methods. Literature was searched using NCBI (PubMed, PubMed Central, and PubMed Health), MedPilot (Medline, Catalogue ZB MED, Catalogue Medicine Health, and Excerpta Medica Database (EMBASE)), and Google Scholar from January 2009 till 31 December 2014. We included original articles related to noninvasive and minimally invasive procedures to enhance orthodontic tooth movement in animals. Extraction of data and quality assessments were carried out by two observers independently. Results. The total number of hits was 9195 out of which just 11 fulfilled the inclusion criteria. Nine articles were good and 5 articles were moderate in quality. Low level laser therapy (LLLT) was among the most common noninvasive techniques whereas flapless corticision using various instruments was among the commonest minimally invasive procedures to enhance velocity of tooth movement. Conclusions. LLLT, low intensity pulsed ultrasound (LIPUS), mechanical vibration, and flapless corticision are emerging noninvasive and minimally invasive techniques which need further researches to establish protocols to use them clinically with conviction. PMID:26881201

  7. Computer Model Predicts the Movement of Dust

    NASA Technical Reports Server (NTRS)

    2002-01-01

    A new computer model of the atmosphere can now actually pinpoint where global dust events come from, and can project where they're going. The model may help scientists better evaluate the impact of dust on human health, climate, ocean carbon cycles, ecosystems, and atmospheric chemistry. Also, by seeing where dust originates and where it blows people with respiratory problems can get advanced warning of approaching dust clouds. 'The model is physically more realistic than previous ones,' said Mian Chin, a co-author of the study and an Earth and atmospheric scientist at Georgia Tech and the Goddard Space Flight Center (GSFC) in Greenbelt, Md. 'It is able to reproduce the short term day-to-day variations and long term inter-annual variations of dust concentrations and distributions that are measured from field experiments and observed from satellites.' The above images show both aerosols measured from space (left) and the movement of aerosols predicted by computer model for the same date (right). For more information, read New Computer Model Tracks and Predicts Paths Of Earth's Dust Images courtesy Paul Giroux, Georgia Tech/NASA Goddard Space Flight Center

  8. MOAB: a spatially explicit, individual-based expert system for creating animal foraging models

    USGS Publications Warehouse

    Carter, J.; Finn, John T.

    1999-01-01

    We describe the development, structure, and corroboration process of a simulation model of animal behavior (MOAB). MOAB can create spatially explicit, individual-based animal foraging models. Users can create or replicate heterogeneous landscape patterns, and place resources and individual animals of a goven species on that landscape to simultaneously simulate the foraging behavior of multiple species. The heuristic rules for animal behavior are maintained in a user-modifiable expert system. MOAB can be used to explore hypotheses concerning the influence of landscape patttern on animal movement and foraging behavior. A red fox (Vulpes vulpes L.) foraging and nest predation model was created to test MOAB's capabilities. Foxes were simulated for 30-day periods using both expert system and random movement rules. Home range size, territory formation and other available simulation studies. A striped skunk (Mephitis mephitis L.) model also was developed. The expert system model proved superior to stochastic in respect to territory formation, general movement patterns and home range size.

  9. The mathematics of movement

    USGS Publications Warehouse

    Johnson, D.H.

    1999-01-01

    Review of: Quantitative Analysis of Movement: Measuring and Modeling Population Redistribution in Animals and Plants. Peter Turchin. 1998. Sinauer Associates, Sunderland, MA. 306 pages. $38.95 (paper).

  10. Space-use behaviour of woodland caribou based on a cognitive movement model.

    PubMed

    Avgar, Tal; Baker, James A; Brown, Glen S; Hagens, Jevon S; Kittle, Andrew M; Mallon, Erin E; McGreer, Madeleine T; Mosser, Anna; Newmaster, Steven G; Patterson, Brent R; Reid, Douglas E B; Rodgers, Art R; Shuter, Jennifer; Street, Garrett M; Thompson, Ian; Turetsky, Merritt J; Wiebe, Philip A; Fryxell, John M

    2015-07-01

    Movement patterns offer a rich source of information on animal behaviour and the ecological significance of landscape attributes. This is especially useful for species occupying remote landscapes where direct behavioural observations are limited. In this study, we fit a mechanistic model of animal cognition and movement to GPS positional data of woodland caribou (Rangifer tarandus caribou; Gmelin 1788) collected over a wide range of ecological conditions. The model explicitly tracks individual animal informational state over space and time, with resulting parameter estimates that have direct cognitive and ecological meaning. Three biotic landscape attributes were hypothesized to motivate caribou movement: forage abundance (dietary digestible biomass), wolf (Canis lupus; Linnaeus, 1758) density and moose (Alces alces; Linnaeus, 1758) habitat. Wolves are the main predator of caribou in this system and moose are their primary prey. Resulting parameter estimates clearly indicated that forage abundance is an important driver of caribou movement patterns, with predator and moose avoidance often having a strong effect, but not for all individuals. From the cognitive perspective, our results support the notion that caribou rely on limited sensory inputs from their surroundings, as well as on long-term spatial memory, to make informed movement decisions. Our study demonstrates how sensory, memory and motion capacities may interact with ecological fitness covariates to influence movement decisions by free-ranging animals. PMID:25714592

  11. Space-use behaviour of woodland caribou based on a cognitive movement model.

    PubMed

    Avgar, Tal; Baker, James A; Brown, Glen S; Hagens, Jevon S; Kittle, Andrew M; Mallon, Erin E; McGreer, Madeleine T; Mosser, Anna; Newmaster, Steven G; Patterson, Brent R; Reid, Douglas E B; Rodgers, Art R; Shuter, Jennifer; Street, Garrett M; Thompson, Ian; Turetsky, Merritt J; Wiebe, Philip A; Fryxell, John M

    2015-07-01

    Movement patterns offer a rich source of information on animal behaviour and the ecological significance of landscape attributes. This is especially useful for species occupying remote landscapes where direct behavioural observations are limited. In this study, we fit a mechanistic model of animal cognition and movement to GPS positional data of woodland caribou (Rangifer tarandus caribou; Gmelin 1788) collected over a wide range of ecological conditions. The model explicitly tracks individual animal informational state over space and time, with resulting parameter estimates that have direct cognitive and ecological meaning. Three biotic landscape attributes were hypothesized to motivate caribou movement: forage abundance (dietary digestible biomass), wolf (Canis lupus; Linnaeus, 1758) density and moose (Alces alces; Linnaeus, 1758) habitat. Wolves are the main predator of caribou in this system and moose are their primary prey. Resulting parameter estimates clearly indicated that forage abundance is an important driver of caribou movement patterns, with predator and moose avoidance often having a strong effect, but not for all individuals. From the cognitive perspective, our results support the notion that caribou rely on limited sensory inputs from their surroundings, as well as on long-term spatial memory, to make informed movement decisions. Our study demonstrates how sensory, memory and motion capacities may interact with ecological fitness covariates to influence movement decisions by free-ranging animals.

  12. Hidden Markov Models: The Best Models for Forager Movements?

    PubMed Central

    Joo, Rocio; Bertrand, Sophie; Tam, Jorge; Fablet, Ronan

    2013-01-01

    One major challenge in the emerging field of movement ecology is the inference of behavioural modes from movement patterns. This has been mainly addressed through Hidden Markov models (HMMs). We propose here to evaluate two sets of alternative and state-of-the-art modelling approaches. First, we consider hidden semi-Markov models (HSMMs). They may better represent the behavioural dynamics of foragers since they explicitly model the duration of the behavioural modes. Second, we consider discriminative models which state the inference of behavioural modes as a classification issue, and may take better advantage of multivariate and non linear combinations of movement pattern descriptors. For this work, we use a dataset of >200 trips from human foragers, Peruvian fishermen targeting anchovy. Their movements were recorded through a Vessel Monitoring System (∼1 record per hour), while their behavioural modes (fishing, searching and cruising) were reported by on-board observers. We compare the efficiency of hidden Markov, hidden semi-Markov, and three discriminative models (random forests, artificial neural networks and support vector machines) for inferring the fishermen behavioural modes, using a cross-validation procedure. HSMMs show the highest accuracy (80%), significantly outperforming HMMs and discriminative models. Simulations show that data with higher temporal resolution, HSMMs reach nearly 100% of accuracy. Our results demonstrate to what extent the sequential nature of movement is critical for accurately inferring behavioural modes from a trajectory and we strongly recommend the use of HSMMs for such purpose. In addition, this work opens perspectives on the use of hybrid HSMM-discriminative models, where a discriminative setting for the observation process of HSMMs could greatly improve inference performance. PMID:24058400

  13. Impact of Bisphosphonate on Orthodontic tooth movement and osteoclastic count: An Animal Study

    PubMed Central

    Venkataramana, V; Chidambaram, S; Reddy, B Vishnuvardhan; Goud, E V Soma Shekara; Arafath, Mohammed; Krishnan, Santhana

    2014-01-01

    Background : The aim of the current study is to examine the effect of systemically administered BP-Pamidronate, on Orthodontic Tooth Movement (OTM) along with osteoclastic quantification in New Zealand white rabbits. Materials & Methods : Twenty rabbits used in the study, were equally divided into 2 groups ; Group-1 as Control & Group-2 as Experimental. A sentalloy NITI closed coil spring (GAC International, USA) of 100 gram force, ligated between the lower first molar and the anterior most incisors of the rabbit has served as orthodontic force element. The BP- Pamidronate was administered at the dosage of 1.5 mg/kg body intra-peritonially, on the 1st, 7th and 14th day of the experiment. On the 21st day both group of animals were sacrificed, mandibles were dissected. The formed diastema between the 1st and 2nd molar was measured on the dissected mandibles using standard metric scale, which is considered as the OTM in the mesial direction. Next, the alveolar bone regions along with intact mesial surfaces were processed for histological investigation (osteoclastic count). Results : The student ‘t’ test has been done to compare the mean values of molar tooth movement and osteoclastic count. Parameter :1 molar tooth movement has shown a significant difference between the control (3.750 ± 0.548 mm) and the experimental group (3.050 ± 0.556 mm) with calculated ‘p’ value (p-value <0.05) is significant at 0.0110 level. Parameter : 2 osteoclastic count has shown a significant difference between the control (13.335000 ± 0.735856 per square mm.) and the experimental group (11.426900 ± 1.49369 per square mm) calculated ‘p’ value (p-value <0.05) is significant at 0.003 level. Conclusion : The molar tooth movement and the osteoclastic count were significantly reduced in BP – Pamidronate administered animals than non-drug recipients. How to cite the article: Venkataramana V, Chidambaram S, Reddy BV, Goud EV, Arafath M, Krishnan S. Impact of Bisphosphonate on

  14. Measurement error causes scale-dependent threshold erosion of biological signals in animal movement data.

    PubMed

    Bradshaw, Corey J A; Sims, David W; Hays, Graeme C

    2007-03-01

    Recent advances in telemetry technology have created a wealth of tracking data available for many animal species moving over spatial scales from tens of meters to tens of thousands of kilometers. Increasingly, such data sets are being used for quantitative movement analyses aimed at extracting fundamental biological signals such as optimal searching behavior and scale-dependent foraging decisions. We show here that the location error inherent in various tracking technologies reduces the ability to detect patterns of behavior within movements. Our analyses endeavored to set out a series of initial ground rules for ecologists to help ensure that sampling noise is not misinterpreted as a real biological signal. We simulated animal movement tracks using specialized random walks known as Lévy flights at three spatial scales of investigation: 100-km, 10-km, and 1-km maximum daily step lengths. The locations generated in the simulations were then blurred using known error distributions associated with commonly applied tracking methods: the Global Positioning System (GPS), Argos polar-orbiting satellites, and light-level geolocation. Deviations from the idealized Lévy flight pattern were assessed for each track after incrementing levels of location error were applied at each spatial scale, with additional assessments of the effect of error on scale-dependent movement patterns measured using fractal mean dimension and first-passage time (FPT) analyses. The accuracy of parameter estimation (Lévy mu, fractal mean D, and variance in FPT) declined precipitously at threshold errors relative to each spatial scale. At 100-km maximum daily step lengths, error standard deviations of > or = 10 km seriously eroded the biological patterns evident in the simulated tracks, with analogous thresholds at the 10-km and 1-km scales (error SD > or = 1.3 km and 0.07 km, respectively). Temporal subsampling of the simulated tracks maintained some elements of the biological signals depending on

  15. Measurement error causes scale-dependent threshold erosion of biological signals in animal movement data.

    PubMed

    Bradshaw, Corey J A; Sims, David W; Hays, Graeme C

    2007-03-01

    Recent advances in telemetry technology have created a wealth of tracking data available for many animal species moving over spatial scales from tens of meters to tens of thousands of kilometers. Increasingly, such data sets are being used for quantitative movement analyses aimed at extracting fundamental biological signals such as optimal searching behavior and scale-dependent foraging decisions. We show here that the location error inherent in various tracking technologies reduces the ability to detect patterns of behavior within movements. Our analyses endeavored to set out a series of initial ground rules for ecologists to help ensure that sampling noise is not misinterpreted as a real biological signal. We simulated animal movement tracks using specialized random walks known as Lévy flights at three spatial scales of investigation: 100-km, 10-km, and 1-km maximum daily step lengths. The locations generated in the simulations were then blurred using known error distributions associated with commonly applied tracking methods: the Global Positioning System (GPS), Argos polar-orbiting satellites, and light-level geolocation. Deviations from the idealized Lévy flight pattern were assessed for each track after incrementing levels of location error were applied at each spatial scale, with additional assessments of the effect of error on scale-dependent movement patterns measured using fractal mean dimension and first-passage time (FPT) analyses. The accuracy of parameter estimation (Lévy mu, fractal mean D, and variance in FPT) declined precipitously at threshold errors relative to each spatial scale. At 100-km maximum daily step lengths, error standard deviations of > or = 10 km seriously eroded the biological patterns evident in the simulated tracks, with analogous thresholds at the 10-km and 1-km scales (error SD > or = 1.3 km and 0.07 km, respectively). Temporal subsampling of the simulated tracks maintained some elements of the biological signals depending on

  16. Homogenization of Large-Scale Movement Models in Ecology

    USGS Publications Warehouse

    Garlick, M.J.; Powell, J.A.; Hooten, M.B.; McFarlane, L.R.

    2011-01-01

    A difficulty in using diffusion models to predict large scale animal population dispersal is that individuals move differently based on local information (as opposed to gradients) in differing habitat types. This can be accommodated by using ecological diffusion. However, real environments are often spatially complex, limiting application of a direct approach. Homogenization for partial differential equations has long been applied to Fickian diffusion (in which average individual movement is organized along gradients of habitat and population density). We derive a homogenization procedure for ecological diffusion and apply it to a simple model for chronic wasting disease in mule deer. Homogenization allows us to determine the impact of small scale (10-100 m) habitat variability on large scale (10-100 km) movement. The procedure generates asymptotic equations for solutions on the large scale with parameters defined by small-scale variation. The simplicity of this homogenization procedure is striking when compared to the multi-dimensional homogenization procedure for Fickian diffusion,and the method will be equally straightforward for more complex models. ?? 2010 Society for Mathematical Biology.

  17. Animal models of anxiety in mice.

    PubMed

    Bourin, Michel; Petit-Demoulière, Benoit; Dhonnchadha, Brid Nic; Hascöet, Martine

    2007-12-01

    Among the multiple possibilities to study human pathologies, animal models remain one of the most used pathways. They allow to access to unavailable answers in human patients and to learn about mechanisms of action of drugs. Primarily developed with rats, animal models in anxiety have been adapted with a mixed success for mice, an easy-to-use mammal with better genetic possibilities than rats. In this review, we have focused on the most used animal models in anxiety in mice. Both conditioned and unconditioned models are described, to represent all types of animal models of anxiety. Behavioural studies require strong care for variable parameters, linked to environment, handling or paradigm; we have discussed about this topic. Finally, we focused on the consequences of re-exposure to the apparatus. Test-retest procedures can bring in new answers, but should be deeply studied, to revalidate the whole paradigm as an animal model of anxiety.

  18. PARTICLE TRACKING ANALYSIS & ANIMATIONS DEPICTING MOVEMENT OF THE CARBON TETRACHLORIDE PLUME REPORT

    SciTech Connect

    MCMAHON, W.J.; ROHAY, V.J.

    2006-11-02

    The purpose of the hydraulic particle tracking animation files is to show where carbon tetrachloride that reached groundwater from the known discharge facilities would have been likely to travel fin the groundwater, and from where carbon tetrachloride presently observed in the aquifer likely would have started. These analyses support the 200-PW-1 Operable Unit activity to identify sources of carbon tetrachloride currently observed in groundwater or locations where carbon tetrachloride may have entered the groundwater. The animation files show travel paths (both forward and backward in time) for hypothetical particles of carbon tetrachloride carried in the groundwater. The travel paths represent the movement of the carbon tetrachloride at the average groundwater velocity. The particles only represent an estimation of where the carbon tetrachloride would be expected to be (or have come from) and do not indicate or imply what the concentration in the groundwater would be.

  19. Evaluation of spinal cord injury animal models

    PubMed Central

    Zhang, Ning; Fang, Marong; Chen, Haohao; Gou, Fangming; Ding, Mingxing

    2014-01-01

    Because there is no curative treatment for spinal cord injury, establishing an ideal animal model is important to identify injury mechanisms and develop therapies for individuals suffering from spinal cord injuries. In this article, we systematically review and analyze various kinds of animal models of spinal cord injury and assess their advantages and disadvantages for further studies. PMID:25598784

  20. Animal models of gastrointestinal and liver diseases. Animal models of acute and chronic pancreatitis.

    PubMed

    Zhan, Xianbao; Wang, Fan; Bi, Yan; Ji, Baoan

    2016-09-01

    Animal models of pancreatitis are useful for elucidating the pathogenesis of pancreatitis and developing and testing novel interventions. In this review, we aim to summarize the most commonly used animal models, overview their pathophysiology, and discuss their strengths and limitations. We will also briefly describe common animal study procedures and refer readers to more detailed protocols in the literature. Although animal models include pigs, dogs, opossums, and other animals, we will mainly focus on rodent models because of their popularity. Autoimmune pancreatitis and genetically engineered animal models will be reviewed elsewhere. PMID:27418683

  1. Experimental Animal Models in Periodontology: A Review

    PubMed Central

    Struillou, Xavier; Boutigny, Hervé; Soueidan, Assem; Layrolle, Pierre

    2010-01-01

    In periodontal research, animal studies are complementary to in vitro experiments prior to testing new treatments. Animal models should make possible the validation of hypotheses and prove the safety and efficacy of new regenerating approaches using biomaterials, growth factors or stem cells. A review of the literature was carried out by using electronic databases (PubMed, ISI Web of Science). Numerous animal models in different species such as rats, hamsters, rabbits, ferrets, canines and primates have been used for modeling human periodontal diseases and treatments. However, both the anatomy and physiopathology of animals are different from those of humans, making difficult the evaluation of new therapies. Experimental models have been developed in order to reproduce major periodontal diseases (gingivitis, periodontitis), their pathogenesis and to investigate new surgical techniques. The aim of this review is to define the most pertinent animal models for periodontal research depending on the hypothesis and expected results. PMID:20556202

  2. Novel animal models of affective disorders.

    PubMed

    Redei, E E; Ahmadiyeh, N; Baum, A E; Sasso, D A; Slone, J L; Solberg, L C; Will, C C; Volenec, A

    2001-01-01

    Is there an appropriate animal model for human affective disorders? The traditional difficulties in accepting animal models for psychopathology stem from the argument that there is no evidence for concluding that what occurs in the brain of the animal is equivalent to what occurs in the brain of a human. However, if one models any or some core aspects of affective disorder, this model can become an invaluable tool in the analysis of the multitude of causes, genetic, environmental, or pharmacological, that can bring about symptoms homologous to those of patients with affective disorders. Animal models can also allow the study of the mechanisms of specific behaviors, their pathophysiology, and can aid in developing and predicting therapeutic responses to pharmacologic agents. Although animals exhibit complex and varied social and emotional behaviors for which well-validated and standardized measures exist, an understanding that a precise replica of human affective disorders cannot be expected in a single animal model is crucial. Instead, a good animal model of a human disorder should fulfill as many of the four main criteria as possible: (1) strong behavioral similarities, (2) common cause, (3) similar pathophysiology, and (4) common treatment. An animal model fulfilling any or most of these criteria can be used to elucidate the mechanisms of the specific aspect of the model that is homologous to the human disorder. A wide range of animal models of affective disorders, primarily depression, has been developed to date. They include models in which "depressive behavior" is the result of genetic selection or manipulation, environmental stressors during development or in adulthood, or pharmacologic treatments. The assessment of these animal models is based either on behavioral tests measuring traits that are homologous to symptoms of the human disorder they model, or behavioral tests responsive to appropriate pharmacologic treatments. The goal of this review is to focus

  3. Animal models for the study of tendinopathy

    PubMed Central

    Warden, S J

    2007-01-01

    Tendinopathy is a common and significant clinical problem characterised by activity‐related pain, focal tendon tenderness and intratendinous imaging changes. Recent histopathological studies have indicated the underlying pathology to be one of tendinosis (degeneration) as opposed to tendinitis (inflammation). Relatively little is known about tendinosis and its pathogenesis. Contributing to this is an absence of validated animal models of the pathology. Animal models of tendinosis represent potential efficient and effective means of furthering our understanding of human tendinopathy and its underlying pathology. By selecting an appropriate species and introducing known risk factors for tendinopathy in humans, it is possible to develop tendon changes in animal models that are consistent with the human condition. This paper overviews the role of animal models in tendinopathy research by discussing the benefits and development of animal models of tendinosis, highlighting potential outcome measures that may be used in animal tendon research, and reviewing current animal models of tendinosis. It is hoped that with further development of animal models of tendinosis, new strategies for the prevention and treatment of tendinopathy in humans will be generated. PMID:17127722

  4. Use of animal models in musculoskeletal research.

    PubMed Central

    Neyt, J. G.; Buckwalter, J. A.; Carroll, N. C.

    1998-01-01

    Understanding of the human musculoskeletal system and common clinical disorders of bones, joints and soft tissues has been enhanced by the use of experimental animal models. Articles reporting on the results of these biomedical experiments frequently include conclusions that are based on the assumption that the biology of the animal model is similar to that of a human being for the disease process under investigation. The purpose of this investigation was to study the criteria and the considerations for selection of an animal model in musculoskeletal research. Selected journals from the musculoskeletal literature published between January 1991 and November 1995 were scrutinized for the use of animal models, and several criteria used in the selection of the various animal models were investigated. The selection criteria analyzed in this study included the biologic characteristics of the model, budget issues, the reproducibility of a musculoskeletal disease, and animal handling factors. A computer-assisted search of the musculoskeletal literature published from 1965 to 1995 was also performed to screen for reports comparing mammals used as animal models in terms of these selection criteria. Our findings imply that the selection of animal models in research of the musculoskeletal system is based partly on non-standardized criteria that are not necessarily based on the biology of the disease process being studied. In addition, there are limited comparative data on the selection and use of different animals for musculoskeletal research. We believe the selection of models should be more standardized based on both biological and non-biological criteria. Researchers would then be able to put in a more meaningful perspective the results of research using animal models and their clinical implications. PMID:9807717

  5. DynAOI: a tool for matching eye-movement data with dynamic areas of interest in animations and movies.

    PubMed

    Papenmeier, Frank; Huff, Markus

    2010-02-01

    Analyzing gaze behavior with dynamic stimulus material is of growing importance in experimental psychology; however, there is still a lack of efficient analysis tools that are able to handle dynamically changing areas of interest. In this article, we present DynAOI, an open-source tool that allows for the definition of dynamic areas of interest. It works automatically with animations that are based on virtual three-dimensional models. When one is working with videos of real-world scenes, a three-dimensional model of the relevant content needs to be created first. The recorded eye-movement data are matched with the static and dynamic objects in the model underlying the video content, thus creating static and dynamic areas of interest. A validation study asking participants to track particular objects demonstrated that DynAOI is an efficient tool for handling dynamic areas of interest. PMID:20160298

  6. Animal Models in Studying Cerebral Arteriovenous Malformation

    PubMed Central

    Xu, Ming; Xu, Hongzhi; Qin, Zhiyong

    2015-01-01

    Brain arteriovenous malformation (AVM) is an important cause of hemorrhagic stroke. The etiology is largely unknown and the therapeutics are controversial. A review of AVM-associated animal models may be helpful in order to understand the up-to-date knowledge and promote further research about the disease. We searched PubMed till December 31, 2014, with the term “arteriovenous malformation,” limiting results to animals and English language. Publications that described creations of AVM animal models or investigated AVM-related mechanisms and treatments using these models were reviewed. More than 100 articles fulfilling our inclusion criteria were identified, and from them eight different types of the original models were summarized. The backgrounds and procedures of these models, their applications, and research findings were demonstrated. Animal models are useful in studying the pathogenesis of AVM formation, growth, and rupture, as well as in developing and testing new treatments. Creations of preferable models are expected. PMID:26649296

  7. A method to quantify movement activity of groups of animals using automated image analysis

    NASA Astrophysics Data System (ADS)

    Xu, Jianyu; Yu, Haizhen; Liu, Ying

    2009-07-01

    Most physiological and environmental changes are capable of inducing variations in animal behavior. The behavioral parameters have the possibility to be measured continuously in-situ by a non-invasive and non-contact approach, and have the potential to be used in the actual productions to predict stress conditions. Most vertebrates tend to live in groups, herds, flocks, shoals, bands, packs of conspecific individuals. Under culture conditions, the livestock or fish are in groups and interact on each other, so the aggregate behavior of the group should be studied rather than that of individuals. This paper presents a method to calculate the movement speed of a group of animal in a enclosure or a tank denoted by body length speed that correspond to group activity using computer vision technique. Frame sequences captured at special time interval were subtracted in pairs after image segmentation and identification. By labeling components caused by object movement in difference frame, the projected area caused by the movement of every object in the capture interval was calculated; this projected area was divided by the projected area of every object in the later frame to get body length moving distance of each object, and further could obtain the relative body length speed. The average speed of all object can well respond to the activity of the group. The group activity of a tilapia (Oreochromis niloticus) school to high (2.65 mg/L) levels of unionized ammonia (UIA) concentration were quantified based on these methods. High UIA level condition elicited a marked increase in school activity at the first hour (P<0.05) exhibiting an avoidance reaction (trying to flee from high UIA condition), and then decreased gradually.

  8. 9 CFR 71.17 - Interstate movement of dead poultry or other animals prohibited in same car with live poultry or...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Interstate movement of dead poultry or other animals prohibited in same car with live poultry or other animals. 71.17 Section 71.17 Animals and... TRANSPORTATION OF ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS GENERAL PROVISIONS § 71.17 Interstate...

  9. 9 CFR 71.17 - Interstate movement of dead poultry or other animals prohibited in same car with live poultry or...

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Interstate movement of dead poultry or other animals prohibited in same car with live poultry or other animals. 71.17 Section 71.17 Animals and... TRANSPORTATION OF ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS GENERAL PROVISIONS § 71.17 Interstate...

  10. 9 CFR 71.17 - Interstate movement of dead poultry or other animals prohibited in same car with live poultry or...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Interstate movement of dead poultry or other animals prohibited in same car with live poultry or other animals. 71.17 Section 71.17 Animals and... TRANSPORTATION OF ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS GENERAL PROVISIONS § 71.17 Interstate...

  11. 9 CFR 71.17 - Interstate movement of dead poultry or other animals prohibited in same car with live poultry or...

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Interstate movement of dead poultry or other animals prohibited in same car with live poultry or other animals. 71.17 Section 71.17 Animals and... TRANSPORTATION OF ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS GENERAL PROVISIONS § 71.17 Interstate...

  12. 9 CFR 71.17 - Interstate movement of dead poultry or other animals prohibited in same car with live poultry or...

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Interstate movement of dead poultry or other animals prohibited in same car with live poultry or other animals. 71.17 Section 71.17 Animals and... TRANSPORTATION OF ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS GENERAL PROVISIONS § 71.17 Interstate...

  13. Engineering large animal models of human disease.

    PubMed

    Whitelaw, C Bruce A; Sheets, Timothy P; Lillico, Simon G; Telugu, Bhanu P

    2016-01-01

    The recent development of gene editing tools and methodology for use in livestock enables the production of new animal disease models. These tools facilitate site-specific mutation of the genome, allowing animals carrying known human disease mutations to be produced. In this review, we describe the various gene editing tools and how they can be used for a range of large animal models of diseases. This genomic technology is in its infancy but the expectation is that through the use of gene editing tools we will see a dramatic increase in animal model resources available for both the study of human disease and the translation of this knowledge into the clinic. Comparative pathology will be central to the productive use of these animal models and the successful translation of new therapeutic strategies.

  14. Animal Models of Corneal Injury

    PubMed Central

    Chan, Matilda F.; Werb, Zena

    2015-01-01

    The cornea is an excellent model system to use for the analysis of wound repair because of its accessibility, lack of vascularization, and simple anatomy. Corneal injuries may involve only the superficial epithelial layer or may penetrate deeper to involve both the epithelial and stromal layers. Here we describe two well-established in vivo corneal wound models: a mechanical wound model that allows for the study of re-epithelialization and a chemical wound model that may be used to study stromal activation in response to injury (Stepp et al., 2014; Carlson et al., 2003). PMID:26191536

  15. Modelling Fine Scale Movement Corridors for the Tricarinate Hill Turtle

    NASA Astrophysics Data System (ADS)

    Mondal, I.; Kumar, R. S.; Habib, B.; Talukdar, G.

    2016-06-01

    Habitat loss and the destruction of habitat connectivity can lead to species extinction by isolation of population. Identifying important habitat corridors to enhance habitat connectivity is imperative for species conservation by preserving dispersal pattern to maintain genetic diversity. Circuit theory is a novel tool to model habitat connectivity as it considers habitat as an electronic circuit board and species movement as a certain amount of current moving around through different resistors in the circuit. Most studies involving circuit theory have been carried out at small scales on large ranging animals like wolves or pumas, and more recently on tigers. This calls for a study that tests circuit theory at a large scale to model micro-scale habitat connectivity. The present study on a small South-Asian geoemydid, the Tricarinate Hill-turtle (Melanochelys tricarinata), focuses on habitat connectivity at a very fine scale. The Tricarinate has a small body size (carapace length: 127-175 mm) and home range (8000-15000 m2), with very specific habitat requirements and movement patterns. We used very high resolution Worldview satellite data and extensive field observations to derive a model of landscape permeability at 1 : 2,000 scale to suit the target species. Circuit theory was applied to model potential corridors between core habitat patches for the Tricarinate Hill-turtle. The modelled corridors were validated by extensive ground tracking data collected using thread spool technique and found to be functional. Therefore, circuit theory is a promising tool for accurately identifying corridors, to aid in habitat studies of small species.

  16. Tracking animal movement by comparing trace element signatures in claws to spatial variability of elements in soils.

    PubMed

    Ethier, Danielle M; Kyle, Christopher J; Nocera, Joseph J

    2014-01-15

    Biogeochemical markers in ecology have provided a useful means for indicating geographic origin and movement patterns of species on various temporal and spatial scales. We used trace element analysis to resolve spatial and habitat-specific environmental gradients in elemental distributions that could be used to infer geographic origin and habitat association in a model terrestrial carnivore: American badger (Taxidea taxus jacksoni). To accomplish this, we generated element base-maps using spatial principal component analysis, and assessed habitat-specific signatures using multivariate statistics from soil element concentrations in southwestern Ontario, Canada. Using canonical correlation analysis (CCA) we also test whether element variability in the claw keratin of a terrestrial carnivore could be explained by the chemical variability in the soils of the local environment. Results demonstrated that trace element signatures in soils vary locally with land use practices and soil texture type and broadly with the underlying geology. CCA results suggest that chemical profiles in claws can be linked to the surrounding chemical environment, providing evidence that geographic patterns in mammalian movement can be discerned on the basis of claw chemistry. From this, we conclude that geographic assignment of individuals based on element profiles in their tissues and referenced against soil elemental distributions would be coarse (at a spatial scale of 100-1000 km, depending on the chemical heterogeneity of the landscape), but could be used to assess origin of highly mobile animals or habitat association of individuals. Compared to stable isotope analysis, the assessment of trace elements can provide a much greater level of detail in backcasting animal movement pathways.

  17. Stem cells, regenerative medicine, and animal models of disease.

    PubMed

    Steindler, Dennis A

    2007-01-01

    The field of stem cell biology and regenerative medicine is rapidly moving toward translation to clinical practice, and in doing so has become even more dependent on animal donors and hosts for generating cellular reagents and assaying their potential therapeutic efficacy in models of human disease. Advances in cell culture technologies have revealed a remarkable plasticity of stem cells from embryonic and adult tissues, and transplantation models are now needed to test the ability of these cells to protect at-risk cells and replace cells lost to injury or disease. With such a mandate, issues related to acceptable sources and controversial (e.g., chimeric) models have challenged the field to provide justification of their potential efficacy before the passage of new restrictions that may curb anticipated breakthroughs. Progress from the use of both in vitro and in vivo regenerative medicine models already offers hope both for the facilitation of stem cell phenotyping in recursive gene expression profile models and for the use of stem cells as powerful new therapeutic reagents for cancer, stroke, Parkinson's, and other challenging human diseases that result in movement disorders. This article describes research in support of the following three objectives: (1) To discover the best stem or progenitor cell in vitro protocols for isolating, expanding, and priming these cells to facilitate their massive propagation into just the right type of neuronal precursor cell for protection or replacement protocols for brain injury or disease, including those that affect movement such as Parkinson's disease and stroke; (2) To discover biogenic factors--compounds that affect stem/progenitor cells (e.g., from high-throughput screening and other bioassay approaches)--that will encourage reactive cell genesis, survival, selected differentiation, and restoration of connectivity in central nervous system movement and other disorders; and (3) To establish the best animal models of human

  18. A likelihood-based biostatistical model for analyzing consumer movement in simultaneous choice experiments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Measures of animal movement versus consumption rates can provide valuable, ecologically relevant information on feeding preference, specifically estimates of attraction rate, leaving rate, tenure time, or measures of flight/walking path. Here, we develop a simple biostatistical model to analyze repe...

  19. Rethinking animal models and human obesity.

    PubMed

    Joyner, Michael J

    2014-11-01

    Human obesity is a complex phenomenon where economic, cultural, behavioral, and biological factors intersect in the physiological space. Developing animal models that capture several elements of the many potential interactions between these factors will only increase their translational value.

  20. Hidden semi-Markov models reveal multiphasic movement of the endangered Florida panther.

    PubMed

    van de Kerk, Madelon; Onorato, David P; Criffield, Marc A; Bolker, Benjamin M; Augustine, Ben C; McKinley, Scott A; Oli, Madan K

    2015-03-01

    Animals must move to find food and mates, and to avoid predators; movement thus influences survival and reproduction, and ultimately determines fitness. Precise description of movement and understanding of spatial and temporal patterns as well as relationships with intrinsic and extrinsic factors is important both for theoretical and applied reasons. We applied hidden semi-Markov models (HSMM) to hourly geographic positioning system (GPS) location data to understand movement patterns of the endangered Florida panther (Puma concolor coryi) and to discern factors influencing these patterns. Three distinct movement modes were identified: (1) Resting mode, characterized by short step lengths and turning angles around 180(o); (2) Moderately active (or intermediate) mode characterized by intermediate step lengths and variable turning angles, and (3) Traveling mode, characterized by long step lengths and turning angles around 0(o). Males and females, and females with and without kittens, exhibited distinctly different movement patterns. Using the Viterbi algorithm, we show that differences in movement patterns of male and female Florida panthers were a consequence of sex-specific differences in diurnal patterns of state occupancy and sex-specific differences in state-specific movement parameters, whereas the differences between females with and without dependent kittens were caused solely by variation in state occupancy. Our study demonstrates the use of HSMM methodology to precisely describe movement and to dissect differences in movement patterns according to sex, and reproductive status. PMID:25251870

  1. Hidden semi-Markov models reveal multiphasic movement of the endangered Florida panther.

    PubMed

    van de Kerk, Madelon; Onorato, David P; Criffield, Marc A; Bolker, Benjamin M; Augustine, Ben C; McKinley, Scott A; Oli, Madan K

    2015-03-01

    Animals must move to find food and mates, and to avoid predators; movement thus influences survival and reproduction, and ultimately determines fitness. Precise description of movement and understanding of spatial and temporal patterns as well as relationships with intrinsic and extrinsic factors is important both for theoretical and applied reasons. We applied hidden semi-Markov models (HSMM) to hourly geographic positioning system (GPS) location data to understand movement patterns of the endangered Florida panther (Puma concolor coryi) and to discern factors influencing these patterns. Three distinct movement modes were identified: (1) Resting mode, characterized by short step lengths and turning angles around 180(o); (2) Moderately active (or intermediate) mode characterized by intermediate step lengths and variable turning angles, and (3) Traveling mode, characterized by long step lengths and turning angles around 0(o). Males and females, and females with and without kittens, exhibited distinctly different movement patterns. Using the Viterbi algorithm, we show that differences in movement patterns of male and female Florida panthers were a consequence of sex-specific differences in diurnal patterns of state occupancy and sex-specific differences in state-specific movement parameters, whereas the differences between females with and without dependent kittens were caused solely by variation in state occupancy. Our study demonstrates the use of HSMM methodology to precisely describe movement and to dissect differences in movement patterns according to sex, and reproductive status.

  2. [Animal models of Peyronie's disease: An update].

    PubMed

    Li, Jin-hong; Yuan, Jiu-hong

    2016-05-01

    Peyronie's disease is characterized by local fibrosis of the tunica albuginea and relatively rare clinically. Few relevant basic researches could be retrieved, which might be attributed to the absence of a robust animal model of the disease as well as to its rareness. At present, some animal models available for Peyronie's disease have their own merits and demerits. TGF-β1-induced and Fibrin-induced models are lack of penile curvature and calcification/ossification. A surgical model might be established for the acute phase of the disease. The characteristic of a widespread fibrotic process involving many organs in the spontaneous model is quite different from that of human Peyronie's disease. Therefore, choosing the right model is essential for researches. This paper presents an overview of the animal models of Peyronie's disease, meant to provide some reference for the basic research of the disease. PMID:27416671

  3. Coarse-grained dynamics of alignment in animal group models

    NASA Astrophysics Data System (ADS)

    Moon, Sung Joon; Levin, Simon; Kevrekidis, Yannis

    2006-03-01

    Coordinated motion in animal groups, such as bird flocks and fish schools, and their models gives rise to remarkable coherent structures. Using equation-free computational tools we explore the coarse-grained dynamics of a model for the orientational movement decision in animal groups, consisting of a small number of informed "leaders" and a large number of uninformed, nonidentical ``followers.'' The direction in which each group member is headed is characterized by a phase angle of a limit-cycle oscillator, whose dynamics are nonlinearly coupled with those of all the other group members. We identify a small number of proper coarse-grained variables (using uncertainty quantification methods) that describe the collective dynamics, and perform coarse projective integration and equation-free bifurcation analysis of the coarse-grained model behavior in these variables.

  4. Development of osteoporosis animal model using micropigs.

    PubMed

    Kim, Sang-Woo; Kim, Kyoung-Shim; Solis, Chester D; Lee, Myeong-Seop; Hyun, Byung-Hwa

    2013-09-01

    Osteoporosis is a known major health problem and a serious disease of the bone, there has been a great need to develop more and newer animal models for this disease. Among animal models used for testing drug efficacy, the minipig model has become useful and effective due to its close similarity with humans (validity), particularly with the pharmacokinetics of compounds via subcutaneous administration, the structure and function of the organs, the morphology of bone and the overall metabolic nature. Based on these advantages, we sought to develop a new animal model of osteoporosis using micropig, which differs from other miniature pigs in the genetic background. Female micropigs were used for the induction of a moderate osteoporosis model by bilateral ovariectomy (OVX) and compared with shamoperated animals. For osteoporosis evaluation, clinical biomarkers such as blood osteocalcin (OSC) and parathyroid hormone (PTH) levels were measured, as well as bone mineral density (BMD) using micro-computed tomography (micro-CT). Compared to sham, OVX animals have decreased blood OSC level, while the blood PTH level increased in blood sera. In addition, we observed the significantly decreased BMDs of tibia region in OVX animals. Based on these results, we report that the micropig model developed in this study can be used to develop a new and effective medical method for diagnosis and treatment of osteoporosis.

  5. Assessing the Permeability of Landscape Features to Animal Movement: Using Genetic Structure to Infer Functional Connectivity

    PubMed Central

    Anderson, Sara J.; Kierepka, Elizabeth M.; Swihart, Robert K.; Latch, Emily K.; Rhodes, Olin E.

    2015-01-01

    Human-altered environments often challenge native species with a complex spatial distribution of resources. Hostile landscape features can inhibit animal movement (i.e., genetic exchange), while other landscape attributes facilitate gene flow. The genetic attributes of organisms inhabiting such complex environments can reveal the legacy of their movements through the landscape. Thus, by evaluating landscape attributes within the context of genetic connectivity of organisms within the landscape, we can elucidate how a species has coped with the enhanced complexity of human altered environments. In this research, we utilized genetic data from eastern chipmunks (Tamias striatus) in conjunction with spatially explicit habitat attribute data to evaluate the realized permeability of various landscape elements in a fragmented agricultural ecosystem. To accomplish this we 1) used logistic regression to evaluate whether land cover attributes were most often associated with the matrix between or habitat within genetically identified populations across the landscape, and 2) utilized spatially explicit habitat attribute data to predict genetically-derived Bayesian probabilities of population membership of individual chipmunks in an agricultural ecosystem. Consistency between the results of the two approaches with regard to facilitators and inhibitors of gene flow in the landscape indicate that this is a promising new way to utilize both landscape and genetic data to gain a deeper understanding of human-altered ecosystems. PMID:25719366

  6. Animal models of orthopedic implant infection.

    PubMed

    An, Y H; Friedman, R J

    1998-01-01

    Prosthetic infection following total joint replacement can have catastrophic results both physically and psychologically for patients, leading to complete failure of the arthroplasty, possible amputation, prolonged hospitalization, and even death. Although with the use of prophylactic antibiotics and greatly improved operating room techniques the infection rate has decreased markedly during the years, challenges still remain for better preventive and therapeutic measures. In this review the in vivo experimental methods for studies of prosthetic infection are discussed, concentrating on (1) the animal models that have been established and the use of these animal models for studies of pathogenesis of bacteria, behavior of biofilm, effect of biomaterials on prosthetic infection rate, and the effect of infection on biomaterial surfaces, and (2) how to design and conduct an animal model of orthopedic prosthetic infection including animal selection, implant fabrication, bacterial inoculation, surgical technique, and the methods for evaluating the results.

  7. Animal models for SARS and MERS coronaviruses

    PubMed Central

    Gretebeck, Lisa M; Subbarao, Kanta

    2015-01-01

    The emergence of Severe Acute Respiratory Syndrome coronavirus (SARS-CoV) and Middle East Respiratory Syndrome coronavirus (MERS-CoV), two strains of animal coronaviruses that crossed the species barrier to infect and cause severe respiratory infections in humans within the last 12 years, have taught us that coronaviruses represent a global threat that does not recognize international borders. We can expect to see other novel coronaviruses emerge in the future. An ideal animal model should reflect the clinical signs, viral replication and pathology seen in humans. In this review, we present factors to consider in establishing an animal model for the study of novel coronaviruses and compare the different animal models that have been employed to study SARS-CoV and MERS-CoV. PMID:26184451

  8. Progress With Nonhuman Animal Models of Addiction.

    PubMed

    Crabbe, John C

    2016-09-01

    Nonhuman animals have been major contributors to the science of the genetics of addiction. Given the explosion of interest in genetics, it is fair to ask, are we making reasonable progress toward our goals with animal models? I will argue that our goals are changing and that overall progress has been steady and seems likely to continue apace. Genetics tools have developed almost incredibly rapidly, enabling both more reductionist and more synthetic or integrative approaches. I believe that these approaches to making progress have been unbalanced in biomedical science, favoring reductionism, particularly in animal genetics. I argue that substantial, novel progress is also likely to come in the other direction, toward synthesis and abstraction. Another area in which future progress with genetic animal models seems poised to contribute more is the reconciliation of human and animal phenotypes, or consilience. The inherent power of the genetic animal models could be more profitably exploited. In the end, animal research has continued to provide novel insights about how genes influence individual differences in addiction risk and consequences. The rules of the genetics game are changing so fast that it is hard to remember how comparatively little we knew even a generation ago. Rather than worry about whether we have been wasting time and resources asking the questions we have been, we should look to the future and see if we can come up with some new ones. The valuable findings from the past will endure, and the sidetracks will be forgotten. PMID:27588527

  9. Genetic animal models of dystonia: common features and diversities.

    PubMed

    Richter, Franziska; Richter, Angelika

    2014-10-01

    Animal models are pivotal for studies of pathogenesis and treatment of disorders of the central nervous system which in its complexity cannot yet be modeled in vitro or using computer simulations. The choice of a specific model to test novel therapeutic strategies for a human disease should be based on validity of the model for the approach: does the model reflect symptoms, pathogenesis and treatment response present in human patients? In the movement disorder dystonia, prior to the availability of genetically engineered mice, spontaneous mutants were chosen based on expression of dystonic features, including abnormal muscle contraction, movements and postures. Recent discovery of a number of genes and gene products involved in dystonia initiated research on pathogenesis of the disorder, and the creation of novel models based on gene mutations. Here we present a review of current models of dystonia, with a focus on genetic rodent models, which will likely be first choice in the future either for pathophysiological or for preclinical drug testing or both. In order to help selection of a model depending on expression of a specific feature of dystonia, this review is organized by symptoms and current knowledge of pathogenesis of dystonia. We conclude that albeit there is increasing need for research on pathogenesis of the disease and development of improved models, current models do replicate features of dystonia and are useful tools to develop urgently demanded treatment for this debilitating disorder.

  10. Animal models of monogenic migraine.

    PubMed

    Chen, Shih-Pin; Tolner, Else A; Eikermann-Haerter, Katharina

    2016-06-01

    Migraine is a highly prevalent and disabling neurological disorder with a strong genetic component. Rare monogenic forms of migraine, or syndromes in which migraine frequently occurs, help scientists to unravel pathogenetic mechanisms of migraine and its comorbidities. Transgenic mouse models for rare monogenic mutations causing familial hemiplegic migraine (FHM), cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), and familial advanced sleep-phase syndrome (FASPS), have been created. Here, we review the current state of research using these mutant mice. We also discuss how currently available experimental approaches, including epigenetic studies, biomolecular analysis and optogenetic technologies, can be used for characterization of migraine genes to further unravel the functional and molecular pathways involved in migraine. PMID:27154999

  11. Animal models in motion sickness research

    NASA Technical Reports Server (NTRS)

    Daunton, Nancy G.

    1990-01-01

    Practical information on candidate animal models for motion sickness research and on methods used to elicit and detect motion sickness in these models is provided. Four good potential models for use in motion sickness experiments include the dog, cat, squirrel monkey, and rat. It is concluded that the appropriate use of the animal models, combined with exploitation of state-of-the-art biomedical techniques, should generate a great step forward in the understanding of motion sickness mechanisms and in the development of efficient and effective approaches to its prevention and treatment in humans.

  12. Animal models of human disease: inflammation.

    PubMed

    Webb, David R

    2014-01-01

    Animals have been used as models to study inflammation and autoimmunity for more than 80 years. During that time it has been understood that although the use of such models is an important and necessary part of understanding human disease, they inevitably display significant differences from the human disease state. Since our understanding of human inflammation and autoimmunity is necessarily incomplete, it may be concluded that the animal models will also be reflective of the state of knowledge regarding such diseases. Nevertheless, animal models of rheumatoid arthritis, inflammatory bowel disease and multiple sclerosis have been successfully used to enhance the understanding of the human disease and have made significant contributions to the development of powerful new therapies. However, there are exceptions. One of the most persistent has been the study of sepsis where the animal models have been woefully inadequate in uncovering targets for drug discovery and have led to repeated clinical failures. As will be explained, only by using newly developed genomics tools has it been possible to uncover the differences between sepsis in mice and sepsis in man. It is concluded that approaches using the newer genomic and proteomic data derived from human tissues, will make possible the development of animal models with more predictive power as aids to drug discovery.

  13. Animal Eye Models for Uveal Melanoma

    PubMed Central

    Cao, Jinfeng; Jager, Martine J.

    2015-01-01

    Animal models play an important role in understanding tumor growth and may be used to develop novel therapies against human malignancies. The significance of the results from animal experiments depends on the selection of the proper model. Many attempts have been made to create appropriate animal models for uveal melanoma and its characteristic metastatic behavior. One approach is to use transgenic animal models or to implant tumor cells. A variety of tumor types have been used for this purpose: tumor cells, such as Greene melanoma, murine B16 melanoma, and human uveal melanoma cells, may be implanted in the eyes of hamsters, rats, rabbits, and mice, among others. Various inoculation routes, including into the anterior chamber and posterior compartment, and retro-orbitally, have been applied to obtain tumor growth mimicking ocular uveal melanoma. However, when we choose animal models, we must be conscious of many disadvantages, such as variable tumor growth, or the need for immunosuppression in xenogeneic grafts. In this paper, we will discuss the various eye models. PMID:27172424

  14. Animal Eye Models for Uveal Melanoma.

    PubMed

    Cao, Jinfeng; Jager, Martine J

    2015-04-01

    Animal models play an important role in understanding tumor growth and may be used to develop novel therapies against human malignancies. The significance of the results from animal experiments depends on the selection of the proper model. Many attempts have been made to create appropriate animal models for uveal melanoma and its characteristic metastatic behavior. One approach is to use transgenic animal models or to implant tumor cells. A variety of tumor types have been used for this purpose: tumor cells, such as Greene melanoma, murine B16 melanoma, and human uveal melanoma cells, may be implanted in the eyes of hamsters, rats, rabbits, and mice, among others. Various inoculation routes, including into the anterior chamber and posterior compartment, and retro-orbitally, have been applied to obtain tumor growth mimicking ocular uveal melanoma. However, when we choose animal models, we must be conscious of many disadvantages, such as variable tumor growth, or the need for immunosuppression in xenogeneic grafts. In this paper, we will discuss the various eye models. PMID:27172424

  15. Animal models of human response to dioxins.

    PubMed Central

    Grassman, J A; Masten, S A; Walker, N J; Lucier, G W

    1998-01-01

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is the most potent member of a class of chlorinated hydrocarbons that interact with the aryl hydrocarbon receptor (AhR). TCDD and dioxinlike compounds are environmentally and biologically stable and as a result, human exposure is chronic and widespread. Studies of highly exposed human populations show that dioxins produce developmental effects, chloracne, and an increase in all cancers and suggest that they may also alter immune and endocrine function. In contrast, the health effects of low-level environmental exposure have not been established. Experimental animal models can enhance the understanding of the effects of low-level dioxin exposure, particularly when there is evidence that humans respond similarly to the animal models. Although there are species differences in pharmacokinetics, experimental animal models demonstrate AhR-dependent health effects that are similar to those found in exposed human populations. Comparisons of biochemical changes show that humans and animal models have similar degrees of sensitivity to dioxin-induced effects. The information gained from animal models is important for developing mechanistic models of dioxin toxicity and critical for assessing the risks to human populations under different circumstances of exposure. PMID:9599728

  16. Animal Models for Viral Hemorrhagic Fever.

    PubMed

    Falzarano, Darryl; Bente, Dennis A

    2014-04-01

    Viral hemorrhagic fever can be caused by one of a diverse group of viruses that come from four different families of RNA viruses. Disease severity can vary from mild self-limiting febrile illness to severe disease characterized by high fever, high-level viremia, increased vascular permeability that can progress to shock, multi-organ failure, and death. Despite the urgent need, effective treatments and preventative vaccines are currently lacking for the majority of these viruses. A number of factors preclude the effective study of these diseases in humans including the high virulence of the agents involved, the sporadic nature of outbreaks of these viruses which are typically in geographically isolated areas with underserviced diagnostic capabilities, and the requirements for high level bio-containment. As a result, animal models that accurately mimic human disease are essential for advancing our understanding of the pathogenesis of viral hemorrhagic fevers. Moreover, animal models for viral hemorrhagic fevers are necessary to test vaccines and therapeutic intervention strategies. Here, we present an overview of the animal models that have been established for each of the hemorrhagic fever viruses and identify which aspects of human disease are modeled. Furthermore, we discuss how experimental design considerations, such as choice of species and virus strain as well as route and dose of inoculation, have an influence on animal model development. We also bring attention to some of the pitfalls that need to be avoided when extrapolating results from animal models. This article is protected by copyright. All rights reserved.

  17. Pharmacokinetic modeling in aquatic animals. 1. Models and concepts

    USGS Publications Warehouse

    Barron, M.G.; Stehly, Guy R.; Hayton, W.L.

    1990-01-01

    While clinical and toxicological applications of pharmacokinetics have continued to evolve both conceptually and experimentally, pharmacokinetics modeling in aquatic animals has not progressed accordingly. In this paper we present methods and concepts of pharmacokinetic modeling in aquatic animals using multicompartmental, clearance-based, non-compartmental and physiologically-based pharmacokinetic models. These models should be considered as alternatives to traditional approaches, which assume that the animal acts as a single homogeneous compartment based on apparent monoexponential elimination.

  18. Current status: Animal models of nausea

    NASA Technical Reports Server (NTRS)

    Fox, Robert A.

    1991-01-01

    The advantages, and possible benefits of a valid, reliable animal model for nausea are discussed, and difficulties inherent to the development of a model are considered. A principle problem for developing models arises because nausea is a subjective sensation that can be identified only in humans. Several putative measures of nausea in animals are considered, with more detailed consideration directed to variation in cardiac rate, levels of vasopressin, and conditioned taste aversion. Demonstration that putative measures are associated with reported nausea in humans is proposed as a requirement for validating measures to be used in animal models. The necessity for a 'real-time' measure of nausea is proposed as an important factor for future research; and the need for improved understanding of the neuroanatomy underlying the emetic syndrome is discussed.

  19. Animal models of human granulocyte diseases.

    PubMed

    Schäffer, Alejandro A; Klein, Christoph

    2013-02-01

    In vivo animal models have proven very useful to the understanding of basic biologic pathways of the immune system, a prerequisite for the development of innovate therapies. This article addresses currently available models for defined human monogenetic defects of neutrophil granulocytes, including murine, zebrafish, and larger mammalian species. Strengths and weaknesses of each system are summarized, and clinical investigators may thus be inspired to develop further lines of research to improve diagnosis and therapy by use of the appropriate animal model system. PMID:23351993

  20. Retinal Cell Degeneration in Animal Models

    PubMed Central

    Niwa, Masayuki; Aoki, Hitomi; Hirata, Akihiro; Tomita, Hiroyuki; Green, Paul G.; Hara, Akira

    2016-01-01

    The aim of this review is to provide an overview of various retinal cell degeneration models in animal induced by chemicals (N-methyl-d-aspartate- and CoCl2-induced), autoimmune (experimental autoimmune encephalomyelitis), mechanical stress (optic nerve crush-induced, light-induced) and ischemia (transient retinal ischemia-induced). The target regions, pathology and proposed mechanism of each model are described in a comparative fashion. Animal models of retinal cell degeneration provide insight into the underlying mechanisms of the disease, and will facilitate the development of novel effective therapeutic drugs to treat retinal cell damage. PMID:26784179

  1. Optogenetics in animal model of alcohol addiction

    NASA Astrophysics Data System (ADS)

    Nalberczak, Maria; Radwanska, Kasia

    2014-11-01

    Our understanding of the neuronal and molecular basis of alcohol addiction is still not satisfactory. As a consequence we still miss successful therapy of alcoholism. One of the reasons for such state is the lack of appropriate animal models which would allow in-depth analysis of biological basis of addiction. Here we will present our efforts to create the animal model of alcohol addiction in the automated learning device, the IntelliCage setup. Applying this model to optogenetically modified mice with remotely controlled regulation of selected neuronal populations by light may lead to very precise identification of neuronal circuits involved in coding addiction-related behaviors.

  2. Role of Animal Models in Coronary Stenting.

    PubMed

    Iqbal, Javaid; Chamberlain, Janet; Francis, Sheila E; Gunn, Julian

    2016-02-01

    Coronary angioplasty initially employed balloon dilatation only. This technique revolutionized the treatment of coronary artery disease, although outcomes were compromised by acute vessel closure, late constrictive remodeling, and restenosis due to neointimal proliferation. These processes were studied in animal models, which contributed to understanding the biology of endovascular arterial injury. Coronary stents overcome acute recoil, with improvements in the design and metallurgy since then, leading to the development of drug-eluting stents and bioresorbable scaffolds. These devices now undergo computer modeling and benchtop and animal testing before evaluation in clinical trials. Animal models, including rabbit, sheep, dog and pig are available, all with individual benefits and limitations. In smaller mammals, such as mouse and rabbit, the target for stenting is generally the aorta; whereas in larger animals, such as the pig, it is generally the coronary artery. The pig coronary stenting model is a gold-standard for evaluating safety; but insights into biomechanical properties, the biology of stenting, and efficacy in controlling neointimal proliferation can also be gained. Intra-coronary imaging modalities such as intravascular ultrasound and optical coherence tomography allow precise serial evaluation in vivo, and recent developments in genetically modified animal models of atherosclerosis provide realistic test beds for future stents and scaffolds.

  3. Animal Models for HIV Cure Research.

    PubMed

    Policicchio, Benjamin B; Pandrea, Ivona; Apetrei, Cristian

    2016-01-01

    The HIV-1/AIDS pandemic continues to spread unabated worldwide, and no vaccine exists within our grasp. Effective antiretroviral therapy (ART) has been developed, but ART cannot clear the virus from the infected patient. A cure for HIV-1 is badly needed to stop both the spread of the virus in human populations and disease progression in infected individuals. A safe and effective cure strategy for human immunodeficiency virus (HIV) infection will require multiple tools, and appropriate animal models are tools that are central to cure research. An ideal animal model should recapitulate the essential aspects of HIV pathogenesis and associated immune responses, while permitting invasive studies, thus allowing a thorough evaluation of strategies aimed at reducing the size of the reservoir (functional cure) or eliminating the reservoir altogether (sterilizing cure). Since there is no perfect animal model for cure research, multiple models have been tailored and tested to address specific quintessential questions of virus persistence and eradication. The development of new non-human primate and mouse models, along with a certain interest in the feline model, has the potential to fuel cure research. In this review, we highlight the major animal models currently utilized for cure research and the contributions of each model to this goal.

  4. Animal Models for HIV Cure Research

    PubMed Central

    Policicchio, Benjamin B.; Pandrea, Ivona; Apetrei, Cristian

    2016-01-01

    The HIV-1/AIDS pandemic continues to spread unabated worldwide, and no vaccine exists within our grasp. Effective antiretroviral therapy (ART) has been developed, but ART cannot clear the virus from the infected patient. A cure for HIV-1 is badly needed to stop both the spread of the virus in human populations and disease progression in infected individuals. A safe and effective cure strategy for human immunodeficiency virus (HIV) infection will require multiple tools, and appropriate animal models are tools that are central to cure research. An ideal animal model should recapitulate the essential aspects of HIV pathogenesis and associated immune responses, while permitting invasive studies, thus allowing a thorough evaluation of strategies aimed at reducing the size of the reservoir (functional cure) or eliminating the reservoir altogether (sterilizing cure). Since there is no perfect animal model for cure research, multiple models have been tailored and tested to address specific quintessential questions of virus persistence and eradication. The development of new non-human primate and mouse models, along with a certain interest in the feline model, has the potential to fuel cure research. In this review, we highlight the major animal models currently utilized for cure research and the contributions of each model to this goal. PMID:26858716

  5. Lessons from Animal Models of Arterial Aneurysm

    PubMed Central

    Gertz, S. David; Mintz, Yoav; Beeri, Ronen; Rubinstein, Chen; Gilon, Dan; Gavish, Leah; Berlatzky, Yacov; Appelbaum, Liat; Gavish, Lilach

    2013-01-01

    We review the results from the most common animal models of arterial aneurysm, including recent findings from our novel, laparoscopy-based pig model of abdominal aortic aneurysm, that contribute important insights into early pathogenesis. We emphasize the relevance of these findings for evaluation of treatment protocols and novel device prototypes for mechanism-based prevention of progression and rupture. PMID:26798701

  6. Large animal models for stem cell therapy.

    PubMed

    Harding, John; Roberts, R Michael; Mirochnitchenko, Oleg

    2013-03-28

    The field of regenerative medicine is approaching translation to clinical practice, and significant safety concerns and knowledge gaps have become clear as clinical practitioners are considering the potential risks and benefits of cell-based therapy. It is necessary to understand the full spectrum of stem cell actions and preclinical evidence for safety and therapeutic efficacy. The role of animal models for gaining this information has increased substantially. There is an urgent need for novel animal models to expand the range of current studies, most of which have been conducted in rodents. Extant models are providing important information but have limitations for a variety of disease categories and can have different size and physiology relative to humans. These differences can preclude the ability to reproduce the results of animal-based preclinical studies in human trials. Larger animal species, such as rabbits, dogs, pigs, sheep, goats, and non-human primates, are better predictors of responses in humans than are rodents, but in each case it will be necessary to choose the best model for a specific application. There is a wide spectrum of potential stem cell-based products that can be used for regenerative medicine, including embryonic and induced pluripotent stem cells, somatic stem cells, and differentiated cellular progeny. The state of knowledge and availability of these cells from large animals vary among species. In most cases, significant effort is required for establishing and characterizing cell lines, comparing behavior to human analogs, and testing potential applications. Stem cell-based therapies present significant safety challenges, which cannot be addressed by traditional procedures and require the development of new protocols and test systems, for which the rigorous use of larger animal species more closely resembling human behavior will be required. In this article, we discuss the current status and challenges of and several major directions

  7. Large animal models for stem cell therapy

    PubMed Central

    2013-01-01

    The field of regenerative medicine is approaching translation to clinical practice, and significant safety concerns and knowledge gaps have become clear as clinical practitioners are considering the potential risks and benefits of cell-based therapy. It is necessary to understand the full spectrum of stem cell actions and preclinical evidence for safety and therapeutic efficacy. The role of animal models for gaining this information has increased substantially. There is an urgent need for novel animal models to expand the range of current studies, most of which have been conducted in rodents. Extant models are providing important information but have limitations for a variety of disease categories and can have different size and physiology relative to humans. These differences can preclude the ability to reproduce the results of animal-based preclinical studies in human trials. Larger animal species, such as rabbits, dogs, pigs, sheep, goats, and non-human primates, are better predictors of responses in humans than are rodents, but in each case it will be necessary to choose the best model for a specific application. There is a wide spectrum of potential stem cell-based products that can be used for regenerative medicine, including embryonic and induced pluripotent stem cells, somatic stem cells, and differentiated cellular progeny. The state of knowledge and availability of these cells from large animals vary among species. In most cases, significant effort is required for establishing and characterizing cell lines, comparing behavior to human analogs, and testing potential applications. Stem cell-based therapies present significant safety challenges, which cannot be addressed by traditional procedures and require the development of new protocols and test systems, for which the rigorous use of larger animal species more closely resembling human behavior will be required. In this article, we discuss the current status and challenges of and several major directions

  8. Social network models predict movement and connectivity in ecological landscapes.

    PubMed

    Fletcher, Robert J; Acevedo, Miguel A; Reichert, Brian E; Pias, Kyle E; Kitchens, Wiley M

    2011-11-29

    Network analysis is on the rise across scientific disciplines because of its ability to reveal complex, and often emergent, patterns and dynamics. Nonetheless, a growing concern in network analysis is the use of limited data for constructing networks. This concern is strikingly relevant to ecology and conservation biology, where network analysis is used to infer connectivity across landscapes. In this context, movement among patches is the crucial parameter for interpreting connectivity but because of the difficulty of collecting reliable movement data, most network analysis proceeds with only indirect information on movement across landscapes rather than using observed movement to construct networks. Statistical models developed for social networks provide promising alternatives for landscape network construction because they can leverage limited movement information to predict linkages. Using two mark-recapture datasets on individual movement and connectivity across landscapes, we test whether commonly used network constructions for interpreting connectivity can predict actual linkages and network structure, and we contrast these approaches to social network models. We find that currently applied network constructions for assessing connectivity consistently, and substantially, overpredict actual connectivity, resulting in considerable overestimation of metapopulation lifetime. Furthermore, social network models provide accurate predictions of network structure, and can do so with remarkably limited data on movement. Social network models offer a flexible and powerful way for not only understanding the factors influencing connectivity but also for providing more reliable estimates of connectivity and metapopulation persistence in the face of limited data. PMID:22084081

  9. Social network models predict movement and connectivity in ecological landscapes

    USGS Publications Warehouse

    Fletcher, Robert J.; Acevedo, M.A.; Reichert, Brian E.; Pias, Kyle E.; Kitchens, Wiley M.

    2011-01-01

    Network analysis is on the rise across scientific disciplines because of its ability to reveal complex, and often emergent, patterns and dynamics. Nonetheless, a growing concern in network analysis is the use of limited data for constructing networks. This concern is strikingly relevant to ecology and conservation biology, where network analysis is used to infer connectivity across landscapes. In this context, movement among patches is the crucial parameter for interpreting connectivity but because of the difficulty of collecting reliable movement data, most network analysis proceeds with only indirect information on movement across landscapes rather than using observed movement to construct networks. Statistical models developed for social networks provide promising alternatives for landscape network construction because they can leverage limited movement information to predict linkages. Using two mark-recapture datasets on individual movement and connectivity across landscapes, we test whether commonly used network constructions for interpreting connectivity can predict actual linkages and network structure, and we contrast these approaches to social network models. We find that currently applied network constructions for assessing connectivity consistently, and substantially, overpredict actual connectivity, resulting in considerable overestimation of metapopulation lifetime. Furthermore, social network models provide accurate predictions of network structure, and can do so with remarkably limited data on movement. Social network models offer a flexible and powerful way for not only understanding the factors influencing connectivity but also for providing more reliable estimates of connectivity and metapopulation persistence in the face of limited data.

  10. Standardization of A Physiologic Hypoparathyroidism Animal Model

    PubMed Central

    Jung, Soo Yeon; Kim, Ha Yeong; Park, Hae Sang; Yin, Xiang Yun; Chung, Sung Min; Kim, Han Su

    2016-01-01

    Ideal hypoparathyroidism animal models are a prerequisite to developing new treatment modalities for this disorder. The purpose of this study was to evaluate the feasibility of a model whereby rats were parathyroidectomized (PTX) using a fluorescent-identification method and the ideal calcium content of the diet was determined. Thirty male rats were divided into surgical sham (SHAM, n = 5) and PTX plus 0, 0.5, and 2% calcium diet groups (PTX-FC (n = 5), PTX-NC (n = 10), and PTX-HC (n = 10), respectively). Serum parathyroid hormone levels decreased to non-detectable levels in all PTX groups. All animals in the PTX—FC group died within 4 days after the operation. All animals survived when supplied calcium in the diet. However, serum calcium levels were higher in the PTX-HC than the SHAM group. The PTX-NC group demonstrated the most representative modeling of primary hypothyroidism. Serum calcium levels decreased and phosphorus levels increased, and bone volume was increased. All animals survived without further treatment and did not show nephrotoxicity including calcium deposits. These findings demonstrate that PTX animal models produced by using the fluorescent-identification method, and fed a 0.5% calcium diet, are appropriate for hypoparathyroidism treatment studies. PMID:27695051

  11. Animal models of traumatic brain injury

    PubMed Central

    Xiong, Ye; Mahmood, Asim; Chopp, Michael

    2014-01-01

    Traumatic brain injury (TBI) is a leading cause of mortality and morbidity in both civilian life and the battlefield worldwide. Survivors of TBI frequently experience long-term disabling changes in cognition, sensorimotor function and personality. Over the past three decades, animal models have been developed to replicate the various aspects of human TBI, to better understand the underlying pathophysiology and to explore potential treatments. Nevertheless, promising neuroprotective drugs, which were identified to be effective in animal TBI models, have all failed in phase II or phase III clinical trials. This failure in clinical translation of preclinical studies highlights a compelling need to revisit the current status of animal models of TBI and therapeutic strategies. PMID:23329160

  12. Low relative error in consumer-grade GPS units make them ideal for measuring small-scale animal movement patterns

    PubMed Central

    Severns, Paul M.

    2015-01-01

    Consumer-grade GPS units are a staple of modern field ecology, but the relatively large error radii reported by manufacturers (up to 10 m) ostensibly precludes their utility in measuring fine-scale movement of small animals such as insects. Here we demonstrate that for data collected at fine spatio-temporal scales, these devices can produce exceptionally accurate data on step-length and movement patterns of small animals. With an understanding of the properties of GPS error and how it arises, it is possible, using a simple field protocol, to use consumer grade GPS units to collect step-length data for the movement of small animals that introduces a median error as small as 11 cm. These small error rates were measured in controlled observations of real butterfly movement. Similar conclusions were reached using a ground-truth test track prepared with a field tape and compass and subsequently measured 20 times using the same methodology as the butterfly tracking. Median error in the ground-truth track was slightly higher than the field data, mostly between 20 and 30 cm, but even for the smallest ground-truth step (70 cm), this is still a signal-to-noise ratio of 3:1, and for steps of 3 m or more, the ratio is greater than 10:1. Such small errors relative to the movements being measured make these inexpensive units useful for measuring insect and other small animal movements on small to intermediate scales with budgets orders of magnitude lower than survey-grade units used in past studies. As an additional advantage, these units are simpler to operate, and insect or other small animal trackways can be collected more quickly than either survey-grade units or more traditional ruler/gird approaches. PMID:26312190

  13. Simplification of the kinematic model of human movement

    NASA Astrophysics Data System (ADS)

    Dusza, Jacek J.; Wawrzyniak, Zbigniew M.; del Prado Martinez, David

    2013-10-01

    The paper presents a methods of simplification of the human gait model. The experimental data were obtained in the laboratory of the group SATI in the Electronics Engineering Department of the University of Valencia. As a result of the Mean Double Step (MDS) procedure, the human motion were described by a matrix containing the Cartesian coordinates of 26 markers placed on the human body recorded in the 100 time points. With these data it has been possible to develop an software application which performs a wide diversity of tasks like array simplification, mask calculation for the simplification, error calculation as well as tools for signals comparison and movement animation of the markers. Simplifications were made by the spectral analysis of signals and calculating the standard deviation of the differences between the signal and its approximation. Using this method the signals of displacement could be written as the time series limited to a small number of harmonic signals. This approach allows us for a high degree of data compression. The model presented in this work can be applied into the context of medical diagnostics or rehabilitation because for a given approximation error and a large number of harmonics may demonstrate some abnormalities (of orthopaedic symptoms) in the gait cycle analysis.

  14. An indexing and price movement model for managing pension funds.

    PubMed

    Freeman, H R

    1994-10-01

    A model for the investment of pension funds has been created that combines passive and active portfolio management strategies. The model uses a passive index fund to reduce the amount spent in transaction costs. It applies a percentage band that identifies the portion of the portfolio that should be committed to equity investments at various stages of the market movement cycle. Finally, it uses price movement trigger points to dictate when pension funds should be moved into and withdrawn from stock market investments.

  15. Animal and cellular models of Friedreich ataxia.

    PubMed

    Perdomini, Morgane; Hick, Aurore; Puccio, Hélène; Pook, Mark A

    2013-08-01

    The development and use of animal and cellular models of Friedreich ataxia (FRDA) are essential requirements for the understanding of FRDA disease mechanisms and the investigation of potential FRDA therapeutic strategies. Although animal and cellular models of lower organisms have provided valuable information on certain aspects of FRDA disease and therapy, it is intuitive that the most useful models are those of mammals and mammalian cells, which are the closest in physiological terms to FRDA patients. To date, there have been considerable efforts put into the development of several different FRDA mouse models and relevant FRDA mouse and human cell line systems. We summarize the principal mammalian FRDA models, discuss the pros and cons of each system, and describe the ways in which such models have been used to address two of the fundamental, as yet unanswered, questions regarding FRDA. Namely, what is the exact pathophysiology of FRDA and what is the detailed genetic and epigenetic basis of FRDA?

  16. Pathophysiology and animal modeling of underactive bladder.

    PubMed

    Tyagi, Pradeep; Smith, Phillip P; Kuchel, George A; de Groat, William C; Birder, Lori A; Chermansky, Christopher J; Adam, Rosalyn M; Tse, Vincent; Chancellor, Michael B; Yoshimura, Naoki

    2014-09-01

    While the symptomology of underactive bladder (UAB) may imply a primary dysfunction of the detrusor muscle, insights into pathophysiology indicate that both myogenic and neurogenic mechanisms need to be considered. Due to lack of proper animal models, the current understanding of the UAB pathophysiology is limited, and much of what is known about the clinical etiology of the condition has been derived from epidemiological data. We hereby review current state of the art in the understanding of the pathophysiology of and animal models used to study the UAB.

  17. Modeling white sturgeon movement in a reservoir: The effect of water quality and sturgeon density

    USGS Publications Warehouse

    Sullivan, A.B.; Jager, H.I.; Myers, R.

    2003-01-01

    We developed a movement model to examine the distribution and survival of white sturgeon (Acipenser transmontanus) in a reservoir subject to large spatial and temporal variation in dissolved oxygen and temperature. Temperature and dissolved oxygen were simulated by a CE-QUAL-W2 model of Brownlee Reservoir, Idaho for a typical wet, normal, and dry hydrologic year. We compared current water quality conditions to scenarios with reduced nutrient inputs to the reservoir. White sturgeon habitat quality was modeled as a function of temperature, dissolved oxygen and, in some cases, suitability for foraging and depth. We assigned a quality index to each cell along the bottom of the reservoir. The model simulated two aspects of daily movement. Advective movement simulated the tendency for animals to move toward areas with high habitat quality, and diffusion simulated density dependent movement away from areas with high sturgeon density in areas with non-lethal habitat conditions. Mortality resulted when sturgeon were unable to leave areas with lethal temperature or dissolved oxygen conditions. Water quality was highest in winter and early spring and lowest in mid to late summer. Limiting nutrient inputs reduced the area of Brownlee Reservoir with lethal conditions for sturgeon and raised the average habitat suitability throughout the reservoir. Without movement, simulated white sturgeon survival ranged between 45 and 89%. Allowing movement raised the predicted survival of sturgeon under all conditions to above 90% as sturgeon avoided areas with low habitat quality. ?? 2003 Elsevier B.V. All rights reserved.

  18. Understanding eye movements in face recognition using hidden Markov models.

    PubMed

    Chuk, Tim; Chan, Antoni B; Hsiao, Janet H

    2014-09-16

    We use a hidden Markov model (HMM) based approach to analyze eye movement data in face recognition. HMMs are statistical models that are specialized in handling time-series data. We conducted a face recognition task with Asian participants, and model each participant's eye movement pattern with an HMM, which summarized the participant's scan paths in face recognition with both regions of interest and the transition probabilities among them. By clustering these HMMs, we showed that participants' eye movements could be categorized into holistic or analytic patterns, demonstrating significant individual differences even within the same culture. Participants with the analytic pattern had longer response times, but did not differ significantly in recognition accuracy from those with the holistic pattern. We also found that correct and wrong recognitions were associated with distinctive eye movement patterns; the difference between the two patterns lies in the transitions rather than locations of the fixations alone.

  19. Animal models of anorexia and cachexia

    PubMed Central

    DeBoer, Mark Daniel

    2009-01-01

    Background Cachexia is a devastating syndrome of body wasting that worsens quality of life and survival for patients suffering from diseases such as cancer, chronic kidney disease and chronic heart failure. Successful treatments have been elusive in humans, leaving a clear need for the development of new treatment compounds. Animal models of cachexia are able to recapitulate the clinical findings from human disease and have provided a much-needed means of testing the efficacy of prospective therapies. Objective This review focuses on animal models of cachexia caused by cancer, chronic heart failure and chronic kidney disease, including the features of these models, their implementation, and commonly-followed outcome measures. Conclusion Given a dire clinical need for effective treatments of cachexia, animal models will continue a vital role in assessing the efficacy and safety of potential treatments prior to testing in humans. Also important in the future will be the use of animal models to assess the durability of effect from anti-cachexia treatments and their effect on prognosis of the underlying disease states. PMID:20160874

  20. [Diabetes mellitus and its animal models].

    PubMed

    Duhault, J; Koenig-Berard, E

    1997-01-01

    This review presents the major animal models usually used for the study of the pathological processes related to insulin-dependent diabetes mellitus (IDDM), non-insulin-dependent diabetes mellitus (NIDDM) and to the main diabetic complications. These models can be observed spontaneously or can be obtained by selective cross-breeding or toxic exposure (chemical or viral), as well as genetically induced. They reproduce some aspects of the human pathology without combining them all in a single model. Consequently, a pertinent pharmacological approach may compare the results obtained with several models. The examination of the recent results obtained with transgenesis does not allow these animal models to replace more classical ones but they may constitute a future challenge for gene therapy despite the multifactorial aspect of diabetic disease. PMID:9501560

  1. Are animal models predictive for humans?

    PubMed Central

    2009-01-01

    It is one of the central aims of the philosophy of science to elucidate the meanings of scientific terms and also to think critically about their application. The focus of this essay is the scientific term predict and whether there is credible evidence that animal models, especially in toxicology and pathophysiology, can be used to predict human outcomes. Whether animals can be used to predict human response to drugs and other chemicals is apparently a contentious issue. However, when one empirically analyzes animal models using scientific tools they fall far short of being able to predict human responses. This is not surprising considering what we have learned from fields such evolutionary and developmental biology, gene regulation and expression, epigenetics, complexity theory, and comparative genomics. PMID:19146696

  2. Measuring Animal Movements in a Natural Ecosystem: A Mark-Recapture Investigation Using Stream-Dwelling Snails

    ERIC Educational Resources Information Center

    Stewart, Timothy W.

    2007-01-01

    In this investigation, students measure and describe movements of animals in a natural ecosystem. Students mark stream-dwelling snails with nail polish, then search for these snails 1-7 days later. Distances and directions moved by recaptured snails are recorded. Simple statistical techniques are used to answer specific research questions and…

  3. Animal models for photodynamic therapy (PDT)

    PubMed Central

    Silva, Zenildo Santos; Bussadori, Sandra Kalil; Fernandes, Kristianne Porta Santos; Huang, Ying-Ying; Hamblin, Michael R.

    2015-01-01

    Photodynamic therapy (PDT) employs non-toxic dyes called photosensitizers (PSs), which absorb visible light to give the excited singlet state, followed by the long-lived triplet state that can undergo photochemistry. In the presence of ambient oxygen, reactive oxygen species (ROS), such as singlet oxygen and hydroxyl radicals are formed that are able to kill cancer cells, inactivate microbial pathogens and destroy unwanted tissue. Although there are already several clinically approved PSs for various disease indications, many studies around the world are using animal models to investigate the further utility of PDT. The present review will cover the main groups of animal models that have been described in the literature. Cancer comprises the single biggest group of models including syngeneic mouse/rat tumours that can either be subcutaneous or orthotopic and allow the study of anti-tumour immune response; human tumours that need to be implanted in immunosuppressed hosts; carcinogen-induced tumours; and mice that have been genetically engineered to develop cancer (often by pathways similar to those in patients). Infections are the second biggest class of animal models and the anatomical sites include wounds, burns, oral cavity, ears, eyes, nose etc. Responsible pathogens can include Gram-positive and Gram-negative bacteria, fungi, viruses and parasites. A smaller and diverse group of miscellaneous animal models have been reported that allow PDT to be tested in ophthalmology, atherosclerosis, atrial fibrillation, dermatology and wound healing. Successful studies using animal models of PDT are blazing the trail for tomorrow's clinical approvals. PMID:26415497

  4. Animal models for photodynamic therapy (PDT).

    PubMed

    Silva, Zenildo Santos; Bussadori, Sandra Kalil; Fernandes, Kristianne Porta Santos; Huang, Ying-Ying; Hamblin, Michael R

    2015-01-01

    Photodynamic therapy (PDT) employs non-toxic dyes called photosensitizers (PSs), which absorb visible light to give the excited singlet state, followed by the long-lived triplet state that can undergo photochemistry. In the presence of ambient oxygen, reactive oxygen species (ROS), such as singlet oxygen and hydroxyl radicals are formed that are able to kill cancer cells, inactivate microbial pathogens and destroy unwanted tissue. Although there are already several clinically approved PSs for various disease indications, many studies around the world are using animal models to investigate the further utility of PDT. The present review will cover the main groups of animal models that have been described in the literature. Cancer comprises the single biggest group of models including syngeneic mouse/rat tumours that can either be subcutaneous or orthotopic and allow the study of anti-tumour immune response; human tumours that need to be implanted in immunosuppressed hosts; carcinogen-induced tumours; and mice that have been genetically engineered to develop cancer (often by pathways similar to those in patients). Infections are the second biggest class of animal models and the anatomical sites include wounds, burns, oral cavity, ears, eyes, nose etc. Responsible pathogens can include Gram-positive and Gram-negative bacteria, fungi, viruses and parasites. A smaller and diverse group of miscellaneous animal models have been reported that allow PDT to be tested in ophthalmology, atherosclerosis, atrial fibrillation, dermatology and wound healing. Successful studies using animal models of PDT are blazing the trail for tomorrow's clinical approvals. PMID:26415497

  5. Animation of finite element models and results

    NASA Technical Reports Server (NTRS)

    Lipman, Robert R.

    1992-01-01

    This is not intended as a complete review of computer hardware and software that can be used for animation of finite element models and results, but is instead a demonstration of the benefits of visualization using selected hardware and software. The role of raw computational power, graphics speed, and the use of videotape are discussed.

  6. Animal models for genetic neuromuscular diseases.

    PubMed

    Vainzof, Mariz; Ayub-Guerrieri, Danielle; Onofre, Paula C G; Martins, Poliana C M; Lopes, Vanessa F; Zilberztajn, Dinorah; Maia, Lucas S; Sell, Karen; Yamamoto, Lydia U

    2008-03-01

    The neuromuscular disorders are a heterogeneous group of genetic diseases, caused by mutations in genes coding sarcolemmal, sarcomeric, and citosolic muscle proteins. Deficiencies or loss of function of these proteins leads to variable degree of progressive loss of motor ability. Several animal models, manifesting phenotypes observed in neuromuscular diseases, have been identified in nature or generated in laboratory. These models generally present physiological alterations observed in human patients and can be used as important tools for genetic, clinic, and histopathological studies. The mdx mouse is the most widely used animal model for Duchenne muscular dystrophy (DMD). Although it is a good genetic and biochemical model, presenting total deficiency of the protein dystrophin in the muscle, this mouse is not useful for clinical trials because of its very mild phenotype. The canine golden retriever MD model represents a more clinically similar model of DMD due to its larger size and significant muscle weakness. Autosomal recessive limb-girdle MD forms models include the SJL/J mice, which develop a spontaneous myopathy resulting from a mutation in the Dysferlin gene, being a model for LGMD2B. For the human sarcoglycanopahties (SG), the BIO14.6 hamster is the spontaneous animal model for delta-SG deficiency, whereas some canine models with deficiency of SG proteins have also been identified. More recently, using the homologous recombination technique in embryonic stem cell, several mouse models have been developed with null mutations in each one of the four SG genes. All sarcoglycan-null animals display a progressive muscular dystrophy of variable severity and share the property of a significant secondary reduction in the expression of the other members of the sarcoglycan subcomplex and other components of the Dystrophin-glycoprotein complex. Mouse models for congenital MD include the dy/dy (dystrophia-muscularis) mouse and the allelic mutant dy(2J)/dy(2J) mouse

  7. Animal models of chronic obstructive pulmonary disease.

    PubMed

    Pérez-Rial, Sandra; Girón-Martínez, Álvaro; Peces-Barba, Germán

    2015-03-01

    Animal models of disease have always been welcomed by the scientific community because they provide an approach to the investigation of certain aspects of the disease in question. Animal models of COPD cannot reproduce the heterogeneity of the disease and usually only manage to represent the disease in its milder stages. Moreover, airflow obstruction, the variable that determines patient diagnosis, not always taken into account in the models. For this reason, models have focused on the development of emphysema, easily detectable by lung morphometry, and have disregarded other components of the disease, such as airway injury or associated vascular changes. Continuous, long-term exposure to cigarette smoke is considered the main risk factor for this disease, justifying the fact that the cigarette smoke exposure model is the most widely used. Some variations on this basic model, related to exposure time, the association of other inducers or inhibitors, exacerbations or the use of transgenic animals to facilitate the identification of pathogenic pathways have been developed. Some variations or heterogeneity of this disease, then, can be reproduced and models can be designed for resolving researchers' questions on disease identification or treatment responses. PMID:25201221

  8. Animal models of chronic obstructive pulmonary disease.

    PubMed

    Pérez-Rial, Sandra; Girón-Martínez, Álvaro; Peces-Barba, Germán

    2015-03-01

    Animal models of disease have always been welcomed by the scientific community because they provide an approach to the investigation of certain aspects of the disease in question. Animal models of COPD cannot reproduce the heterogeneity of the disease and usually only manage to represent the disease in its milder stages. Moreover, airflow obstruction, the variable that determines patient diagnosis, not always taken into account in the models. For this reason, models have focused on the development of emphysema, easily detectable by lung morphometry, and have disregarded other components of the disease, such as airway injury or associated vascular changes. Continuous, long-term exposure to cigarette smoke is considered the main risk factor for this disease, justifying the fact that the cigarette smoke exposure model is the most widely used. Some variations on this basic model, related to exposure time, the association of other inducers or inhibitors, exacerbations or the use of transgenic animals to facilitate the identification of pathogenic pathways have been developed. Some variations or heterogeneity of this disease, then, can be reproduced and models can be designed for resolving researchers' questions on disease identification or treatment responses.

  9. Overturning conclusions of Lévy flight movement patterns by fishing boats and foraging animals.

    PubMed

    Edwards, Andrew M

    2011-06-01

    A surprisingly diverse variety of foragers have previously been concluded to exhibit movement patterns known as Lévy flights, a special type of random walk. These foragers range in size from microzooplankton in experiments to fishermen in the Pacific Ocean and the North Sea. The Lévy flight conclusion implies that all the foragers have similar scale-free movement patterns that can be described by a single dimensionless parameter, the exponent micro of a power-law (Pareto) distribution. However, the previous conclusions have been made using methods that have since been shown to be problematic: inaccurate techniques were used to estimate micro, and the power-law distribution was usually assumed to hold without testing any alternative hypotheses. Therefore, I address the open question of whether the previous data still support the Lévy flight hypothesis, and thus determine whether Lévy flights really are so ubiquitous in ecology. I present a comprehensive reanalysis of 17 data sets from seven previous studies for which Lévy flight behavior had been concluded, covering marine, terrestrial, and experimental systems from four continents. I use the modern likelihood and Akaike weights approach to test whether simple alternative models are more supported by the data than Lévy flights. The previously estimated values of the power-law exponent micro do not match those calculated here using the accurate likelihood approach, and almost all of them lie outside of the likelihood-based 95% confidence intervals. Furthermore, the original power-law Lévy flight model is overwhelmingly rejected for 16 out of the 17 data sets when tested against three other simple models. For one data set, the data are consistent with coming from a bounded power-law distribution (a truncated Lévy flight). For three other data sets, an exponential distribution corresponding to a simple Poisson process is suitable. Thus, Lévy flight movement patterns are not the common phenomena that was once

  10. Overturning conclusions of Lévy flight movement patterns by fishing boats and foraging animals.

    PubMed

    Edwards, Andrew M

    2011-06-01

    A surprisingly diverse variety of foragers have previously been concluded to exhibit movement patterns known as Lévy flights, a special type of random walk. These foragers range in size from microzooplankton in experiments to fishermen in the Pacific Ocean and the North Sea. The Lévy flight conclusion implies that all the foragers have similar scale-free movement patterns that can be described by a single dimensionless parameter, the exponent micro of a power-law (Pareto) distribution. However, the previous conclusions have been made using methods that have since been shown to be problematic: inaccurate techniques were used to estimate micro, and the power-law distribution was usually assumed to hold without testing any alternative hypotheses. Therefore, I address the open question of whether the previous data still support the Lévy flight hypothesis, and thus determine whether Lévy flights really are so ubiquitous in ecology. I present a comprehensive reanalysis of 17 data sets from seven previous studies for which Lévy flight behavior had been concluded, covering marine, terrestrial, and experimental systems from four continents. I use the modern likelihood and Akaike weights approach to test whether simple alternative models are more supported by the data than Lévy flights. The previously estimated values of the power-law exponent micro do not match those calculated here using the accurate likelihood approach, and almost all of them lie outside of the likelihood-based 95% confidence intervals. Furthermore, the original power-law Lévy flight model is overwhelmingly rejected for 16 out of the 17 data sets when tested against three other simple models. For one data set, the data are consistent with coming from a bounded power-law distribution (a truncated Lévy flight). For three other data sets, an exponential distribution corresponding to a simple Poisson process is suitable. Thus, Lévy flight movement patterns are not the common phenomena that was once

  11. Small mammalian animal models of heart disease

    PubMed Central

    Camacho, Paula; Fan, Huimin; Liu, Zhongmin; He, Jia-Qiang

    2016-01-01

    There is an urgent clinical need to develop new therapeutic approaches for treating cardiovascular disease, but the biology of cardiovascular regeneration is complex. Model systems are required to advance our understanding of the pathogenesis, progression, and mechanisms underlying cardiovascular disease as well as to test therapeutic approaches to regenerate tissue and restore cardiac function following injury. An ideal model system should be inexpensive, easily manipulated, reproducible, physiologically representative of human disease, and ethically sound. The choice of animal model needs to be considered carefully since it affects experimental outcomes and whether findings of the study can be reasonably translated to humans. This review presents a guideline for the commonly used small animal models (mice, rats, rabbits, and cats) used in cardiac research as an effort to standardize the most relevant procedures and obtain translatable and reproducible results.

  12. Animal models for meniscus repair and regeneration.

    PubMed

    Deponti, Daniela; Di Giancamillo, Alessia; Scotti, Celeste; Peretti, Giuseppe M; Martin, Ivan

    2015-05-01

    The meniscus plays an important role in knee function and mechanics. Meniscal lesions, however, are common phenomena and this tissue is not able to achieve spontaneous successful repair, particularly in the inner avascular zone. Several animal models have been studied and proposed for testing different reparative approaches, as well as for studying regenerative methods aiming to restore the original shape and function of this structure. This review summarizes the gross anatomy, function, ultrastructure and biochemical composition of the knee meniscus in several animal models in comparison with the human meniscus. The relevance of the models is discussed from the point of view of basic research as well as of clinical translation for meniscal repair, substitution and regeneration. Finally, the advantages and disadvantages of each model for various research directions are critically discussed.

  13. Animal models for HIV/AIDS research.

    PubMed

    Hatziioannou, Theodora; Evans, David T

    2012-12-01

    The AIDS pandemic continues to present us with unique scientific and public health challenges. Although the development of effective antiretroviral therapy has been a major triumph, the emergence of drug resistance requires active management of treatment regimens and the continued development of new antiretroviral drugs. Moreover, despite nearly 30 years of intensive investigation, we still lack the basic scientific knowledge necessary to produce a safe and effective vaccine against HIV-1. Animal models offer obvious advantages in the study of HIV/AIDS, allowing for a more invasive investigation of the disease and for preclinical testing of drugs and vaccines. Advances in humanized mouse models, non-human primate immunogenetics and recombinant challenge viruses have greatly increased the number and sophistication of available mouse and simian models. Understanding the advantages and limitations of each of these models is essential for the design of animal studies to guide the development of vaccines and antiretroviral therapies for the prevention and treatment of HIV-1 infection.

  14. Traumatic Brain Injury Models in Animals.

    PubMed

    Rostami, Elham

    2016-01-01

    Traumatic brain injury (TBI) is the leading cause of death in young adults in industrialized nations and in the developing world the WHO considers TBI a silent epidemic caused by an increasing number of traffic accidents. Despite the major improvement of TBI outcome in the acute setting in the past 20 years, the assessment, therapeutic interventions, and prevention of long-term complications remain a challenge. In order to get a deeper insight into the pathology of TBI and advancement of medical understanding and clinical progress experimental animal models are an essential requirement. This chapter provides an overview of most commonly used experimental animal TBI models and the pathobiological findings based on current data. In addition, limitations and advantages of each TBI model are mentioned. This will hopefully give an insight into the possibilities of each model and be of value in choosing one when designing a study. PMID:27604712

  15. Small mammalian animal models of heart disease.

    PubMed

    Camacho, Paula; Fan, Huimin; Liu, Zhongmin; He, Jia-Qiang

    2016-01-01

    There is an urgent clinical need to develop new therapeutic approaches for treating cardiovascular disease, but the biology of cardiovascular regeneration is complex. Model systems are required to advance our understanding of the pathogenesis, progression, and mechanisms underlying cardiovascular disease as well as to test therapeutic approaches to regenerate tissue and restore cardiac function following injury. An ideal model system should be inexpensive, easily manipulated, reproducible, physiologically representative of human disease, and ethically sound. The choice of animal model needs to be considered carefully since it affects experimental outcomes and whether findings of the study can be reasonably translated to humans. This review presents a guideline for the commonly used small animal models (mice, rats, rabbits, and cats) used in cardiac research as an effort to standardize the most relevant procedures and obtain translatable and reproducible results. PMID:27679742

  16. Small mammalian animal models of heart disease

    PubMed Central

    Camacho, Paula; Fan, Huimin; Liu, Zhongmin; He, Jia-Qiang

    2016-01-01

    There is an urgent clinical need to develop new therapeutic approaches for treating cardiovascular disease, but the biology of cardiovascular regeneration is complex. Model systems are required to advance our understanding of the pathogenesis, progression, and mechanisms underlying cardiovascular disease as well as to test therapeutic approaches to regenerate tissue and restore cardiac function following injury. An ideal model system should be inexpensive, easily manipulated, reproducible, physiologically representative of human disease, and ethically sound. The choice of animal model needs to be considered carefully since it affects experimental outcomes and whether findings of the study can be reasonably translated to humans. This review presents a guideline for the commonly used small animal models (mice, rats, rabbits, and cats) used in cardiac research as an effort to standardize the most relevant procedures and obtain translatable and reproducible results. PMID:27679742

  17. Animal models for the study of HCV

    PubMed Central

    Vercauteren, Koen; de Jong, Ype P.; Meuleman, Philip

    2015-01-01

    1 Summary The development and evaluation of effective therapies and vaccines for the hepatitis C virus (HCV) and the study of its interactions with the mammalian host have been hindered for a long time by the absence of suitable small animal models. Immune compromised mouse models that recapitulate the complete HCV life cycle have been useful to investigate many aspects of the HCV life cycle including antiviral interventions. However, HCV has a high propensity to establish persistence and associated histopathological manifestations such as steatosis, fibrosis, cirrhosis and hepatocellular carcinoma (HCC). Better understanding of these processes requires the development of a permissive and fully immunocompetent small animal model. In this review we summarize the in vivo models that are available for the study of HCV. PMID:26304554

  18. Modeling short-term dynamics and variability for realistic interactive facial animation.

    PubMed

    Stoiber, Nicolas; Breton, Gaspard; Seguier, Renaud

    2010-01-01

    Modern modeling and rendering techniques have produced nearly photorealistic face models, but truly expressive digital faces also require natural-looking movements. Virtual characters in today's applications often display unrealistic facial expressions. Indeed, facial animation with traditional schemes such as keyframing and motion capture demands expertise. Moreover, the traditional schemes aren't adapted to interactive applications that require the real-time generation of context-dependent movements. A new animation system produces realistic expressive facial motion at interactive speed. The system relies on a set of motion models controlling facial-expression dynamics. The models are fitted on captured motion data and therefore retain the dynamic signature of human facial expressions. They also contain a nondeterministic component that ensures the variety of the long-term visual behavior. This system can efficiently animate any synthetic face. The video illustrates interactive use of a system that generates facial-animation sequences.

  19. Modeling short-term dynamics and variability for realistic interactive facial animation.

    PubMed

    Stoiber, Nicolas; Breton, Gaspard; Seguier, Renaud

    2010-01-01

    Modern modeling and rendering techniques have produced nearly photorealistic face models, but truly expressive digital faces also require natural-looking movements. Virtual characters in today's applications often display unrealistic facial expressions. Indeed, facial animation with traditional schemes such as keyframing and motion capture demands expertise. Moreover, the traditional schemes aren't adapted to interactive applications that require the real-time generation of context-dependent movements. A new animation system produces realistic expressive facial motion at interactive speed. The system relies on a set of motion models controlling facial-expression dynamics. The models are fitted on captured motion data and therefore retain the dynamic signature of human facial expressions. They also contain a nondeterministic component that ensures the variety of the long-term visual behavior. This system can efficiently animate any synthetic face. The video illustrates interactive use of a system that generates facial-animation sequences. PMID:20650728

  20. Modeling of human movement monitoring using Bluetooth Low Energy technology.

    PubMed

    Mokhtari, G; Zhang, Q; Karunanithi, M

    2015-01-01

    Bluetooth Low Energy (BLE) is a wireless communication technology which can be used to monitor human movements. In this monitoring system, a BLE signal scanner scans signal strength of BLE tags carried by people, to thus infer human movement patterns within its monitoring zone. However to the extent of our knowledge one main aspect of this monitoring system which has not yet been thoroughly investigated in literature is how to build a sound theoretical model, based on tunable BLE communication parameters such as scanning time interval and advertising time interval, to enable the study and design of effective and efficient movement monitoring systems. In this paper, we proposed and developed a statistical model based on Monte-Carlo simulation, which can be utilized to assess impacts of BLE technology parameters in terms of latency and efficiency, on a movement monitoring system, and can thus benefit a more efficient system design.

  1. Modeling of human movement monitoring using Bluetooth Low Energy technology.

    PubMed

    Mokhtari, G; Zhang, Q; Karunanithi, M

    2015-01-01

    Bluetooth Low Energy (BLE) is a wireless communication technology which can be used to monitor human movements. In this monitoring system, a BLE signal scanner scans signal strength of BLE tags carried by people, to thus infer human movement patterns within its monitoring zone. However to the extent of our knowledge one main aspect of this monitoring system which has not yet been thoroughly investigated in literature is how to build a sound theoretical model, based on tunable BLE communication parameters such as scanning time interval and advertising time interval, to enable the study and design of effective and efficient movement monitoring systems. In this paper, we proposed and developed a statistical model based on Monte-Carlo simulation, which can be utilized to assess impacts of BLE technology parameters in terms of latency and efficiency, on a movement monitoring system, and can thus benefit a more efficient system design. PMID:26737430

  2. State-Space Modelling of the Drivers of Movement Behaviour in Sympatric Species

    PubMed Central

    Pérez-Barbería, F. J.; Small, M.; Hooper, R. J.; Aldezabal, A.; Soriguer-Escofet, R.; Bakken, G. S.; Gordon, I. J.

    2015-01-01

    Understanding animal movement behaviour is key to furthering our knowledge on intra- and inter-specific competition, group cohesion, energy expenditure, habitat use, the spread of zoonotic diseases or species management. We used a radial basis function surface approximation subject to minimum description length constraint to uncover the state-space dynamical systems from time series data. This approximation allowed us to infer structure from a mathematical model of the movement behaviour of sheep and red deer, and the effect of density, thermal stress and vegetation type. Animal movement was recorded using GPS collars deployed in sheep and deer grazing a large experimental plot in winter and summer. Information on the thermal stress to which animals were exposed was estimated using the power consumption of mechanical heated models and meteorological records of a network of stations in the plot. Thermal stress was higher in deer than in sheep, with less differences between species in summer. Deer travelled more distance than sheep, and both species travelled more in summer than in winter; deer travel distance showed less seasonal differences than sheep. Animal movement was better predicted in deer than in sheep and in winter than in summer; both species showed a swarming behaviour in group cohesion, stronger in deer. At shorter separation distances swarming repulsion was stronger between species than within species. At longer separation distances inter-specific attraction was weaker than intra-specific; there was a positive density-dependent effect on swarming, and stronger in deer than in sheep. There was not clear evidence which species attracted or repelled the other; attraction between deer at long separation distances was stronger when the model accounted for thermal stress, but in general the dynamic movement behaviour was hardly affected by the thermal stress. Vegetation type affected intra-species interactions but had little effect on inter

  3. State-Space Modelling of the Drivers of Movement Behaviour in Sympatric Species.

    PubMed

    Pérez-Barbería, F J; Small, M; Hooper, R J; Aldezabal, A; Soriguer-Escofet, R; Bakken, G S; Gordon, I J

    2015-01-01

    Understanding animal movement behaviour is key to furthering our knowledge on intra- and inter-specific competition, group cohesion, energy expenditure, habitat use, the spread of zoonotic diseases or species management. We used a radial basis function surface approximation subject to minimum description length constraint to uncover the state-space dynamical systems from time series data. This approximation allowed us to infer structure from a mathematical model of the movement behaviour of sheep and red deer, and the effect of density, thermal stress and vegetation type. Animal movement was recorded using GPS collars deployed in sheep and deer grazing a large experimental plot in winter and summer. Information on the thermal stress to which animals were exposed was estimated using the power consumption of mechanical heated models and meteorological records of a network of stations in the plot. Thermal stress was higher in deer than in sheep, with less differences between species in summer. Deer travelled more distance than sheep, and both species travelled more in summer than in winter; deer travel distance showed less seasonal differences than sheep. Animal movement was better predicted in deer than in sheep and in winter than in summer; both species showed a swarming behaviour in group cohesion, stronger in deer. At shorter separation distances swarming repulsion was stronger between species than within species. At longer separation distances inter-specific attraction was weaker than intra-specific; there was a positive density-dependent effect on swarming, and stronger in deer than in sheep. There was not clear evidence which species attracted or repelled the other; attraction between deer at long separation distances was stronger when the model accounted for thermal stress, but in general the dynamic movement behaviour was hardly affected by the thermal stress. Vegetation type affected intra-species interactions but had little effect on inter

  4. State-Space Modelling of the Drivers of Movement Behaviour in Sympatric Species.

    PubMed

    Pérez-Barbería, F J; Small, M; Hooper, R J; Aldezabal, A; Soriguer-Escofet, R; Bakken, G S; Gordon, I J

    2015-01-01

    Understanding animal movement behaviour is key to furthering our knowledge on intra- and inter-specific competition, group cohesion, energy expenditure, habitat use, the spread of zoonotic diseases or species management. We used a radial basis function surface approximation subject to minimum description length constraint to uncover the state-space dynamical systems from time series data. This approximation allowed us to infer structure from a mathematical model of the movement behaviour of sheep and red deer, and the effect of density, thermal stress and vegetation type. Animal movement was recorded using GPS collars deployed in sheep and deer grazing a large experimental plot in winter and summer. Information on the thermal stress to which animals were exposed was estimated using the power consumption of mechanical heated models and meteorological records of a network of stations in the plot. Thermal stress was higher in deer than in sheep, with less differences between species in summer. Deer travelled more distance than sheep, and both species travelled more in summer than in winter; deer travel distance showed less seasonal differences than sheep. Animal movement was better predicted in deer than in sheep and in winter than in summer; both species showed a swarming behaviour in group cohesion, stronger in deer. At shorter separation distances swarming repulsion was stronger between species than within species. At longer separation distances inter-specific attraction was weaker than intra-specific; there was a positive density-dependent effect on swarming, and stronger in deer than in sheep. There was not clear evidence which species attracted or repelled the other; attraction between deer at long separation distances was stronger when the model accounted for thermal stress, but in general the dynamic movement behaviour was hardly affected by the thermal stress. Vegetation type affected intra-species interactions but had little effect on inter

  5. Cholestasis: human disease and experimental animal models.

    PubMed

    Rodríguez-Garay, Emilio Alberto

    2003-01-01

    Cholestasis may result from a failure in bile secretion in hepatocytes or ductular cells, or from a blockade to the free bile flow. Human cholestasis may be induced by many drugs, being antibiotics the more common. Other types of cholestasis seen in humans are a group of familial cholestatic disorders, obstructive cholestasis, primary biliary cirrhosis, extrahepatic biliary atresia, primary sclerosing cholangitis, cholestasis of pregnancy, oral contraceptive-induced cholestasis, and sepsis-induced cholestasis. Experimental animal models allow the understanding of pathophysiological mechanisms involved and their clinical correlates. The most common experimental models of intrahepatic cholestasis are estrogen-induced, endotoxin-induced and drug-induced cholestasis. A well known model of extrahepatic biliary obstruction is common bile duct ligation. Drug-induced cholestasis were described using different drugs. On this regard, alpha naphthylisothiocyanate treatment has been extensively used, permitting to describe not only cholestatic alterations but also compensatory mechanisms. Congenital defficiency of transport proteins also were studied in natural rat models of cholestasis. The experimental animal models allow to define down-regulated alterations of hepatocyte transport proteins, and up-regulated ones acting as compensatory mechanisms. In conclusion, animal model and transport protein studies are necessary for the progressive understanding of congenital and acquired human cholestasis, and regulatory mechanisms that operate on liver cells.

  6. Evaluation of Surrogate Animal Models of Melioidosis

    PubMed Central

    Warawa, Jonathan Mark

    2010-01-01

    Burkholderia pseudomallei is the Gram-negative bacterial pathogen responsible for the disease melioidosis. B. pseudomallei establishes disease in susceptible individuals through multiple routes of infection, all of which may proceed to a septicemic disease associated with a high mortality rate. B. pseudomallei opportunistically infects humans and a wide range of animals directly from the environment, and modeling of experimental melioidosis has been conducted in numerous biologically relevant models including mammalian and invertebrate hosts. This review seeks to summarize published findings related to established animal models of melioidosis, with an aim to compare and contrast the virulence of B. pseudomallei in these models. The effect of the route of delivery on disease is also discussed for intravenous, intraperitoneal, subcutaneous, intranasal, aerosol, oral, and intratracheal infection methodologies, with a particular focus on how they relate to modeling clinical melioidosis. The importance of the translational validity of the animal models used in B. pseudomallei research is highlighted as these studies have become increasingly therapeutic in nature. PMID:21772830

  7. Potential animal models of seasonal affective disorder.

    PubMed

    Workman, Joanna L; Nelson, Randy J

    2011-01-01

    Seasonal affective disorder (SAD) is characterized by depressive episodes during winter that are alleviated during summer and by morning bright light treatment. Currently, there is no animal model of SAD. However, it may be possible to use rodents that respond to day length (photoperiod) to understand how photoperiod can shape the brain and behavior in humans. As nights lengthen in the autumn, the duration of the nightly elevation of melatonin increase; seasonally breeding animals use this information to orchestrate seasonal changes in physiology and behavior. SAD may originate from the extended duration of nightly melatonin secretion during fall and winter. These similarities between humans and rodents in melatonin secretion allows for comparisons with rodents that express more depressive-like responses when exposed to short day lengths. For instance, Siberian hamsters, fat sand rats, Nile grass rats, and Wistar rats display a depressive-like phenotype when exposed to short days. Current research in depression and animal models of depression suggests that hippocampal plasticity may underlie the symptoms of depression and depressive-like behaviors, respectively. It is also possible that day length induces structural changes in human brains. Many seasonally breeding rodents undergo changes in whole brain and hippocampal volume in short days. Based on strict validity criteria, there is no animal model of SAD, but rodents that respond to reduced day lengths may be useful to approximate the neurobiological phenomena that occur in people with SAD, leading to greater understanding of the etiology of the disorder as well as novel therapeutic interventions.

  8. Three-dimensional temporomandibular joint modeling and animation.

    PubMed

    Cascone, Piero; Rinaldi, Fabrizio; Pagnoni, Mario; Marianetti, Tito Matteo; Tedaldi, Massimiliano

    2008-11-01

    The three-dimensional (3D) temporomandibular joint (TMJ) model derives from a study of the cranium by 3D virtual reality and mandibular function animation. The starting point of the project is high-fidelity digital acquisition of a human dry skull. The cooperation between the maxillofacial surgeon and the cartoonist enables the reconstruction of the fibroconnective components of the TMJ that are the keystone for comprehension of the anatomic and functional features of the mandible. The skeletal model is customized with the apposition of the temporomandibular ligament, the articular disk, the retrodiskal tissue, and the medial and the lateral ligament of the disk. The simulation of TMJ movement is the result of the integration of up-to-date data on the biomechanical restrictions. The 3D TMJ model is an easy-to-use application that may be run on a personal computer for the study of the TMJ and its biomechanics. PMID:19098544

  9. Large genetic animal models of Huntington's Disease.

    PubMed

    Morton, A Jennifer; Howland, David S

    2013-01-01

    The dominant nature of the Huntington's disease gene mutation has allowed genetic models to be developed in multiple species, with the mutation causing an abnormal neurological phenotype in all animals in which it is expressed. Many different rodent models have been generated. The most widely used of these, the transgenic R6/2 mouse, carries the mutation in a fragment of the human huntingtin gene and has a rapidly progressive and fatal neurological phenotype with many relevant pathological changes. Nevertheless, their rapid decline has been frequently questioned in the context of a disease that takes years to manifest in humans, and strenuous efforts have been made to make rodent models that are genetically more 'relevant' to the human condition, including full length huntingtin gene transgenic and knock-in mice. While there is no doubt that we have learned, and continue to learn much from rodent models, their usefulness is limited by two species constraints. First, the brains of rodents differ significantly from humans in both their small size and their neuroanatomical organization. Second, rodents have much shorter lifespans than humans. Here, we review new approaches taken to these challenges in the development of models of Huntington's disease in large brained, long-lived animals. We discuss the need for such models, and how they might be used to fill specific niches in preclinical Huntington's disease research, particularly in testing gene-based therapeutics. We discuss the advantages and disadvantages of animals in which the prodromal period of disease extends over a long time span. We suggest that there is considerable 'value added' for large animal models in preclinical Huntington's disease research.

  10. Animal models of enteroaggregative Escherichia coli infection

    PubMed Central

    Philipson, Casandra W.; Bassaganya-Riera, Josep; Hontecillas, Raquel

    2013-01-01

    Enteroaggregative Escherichia coli (EAEC) has been acknowledged as an emerging cause of gastroenteritis worldwide for over two decades. Epidemiologists are revealing the role of EAEC in diarrheal outbreaks as a more common occurrence than ever suggested before. EAEC induced diarrhea is most commonly associated with travelers, children and immunocompromised individuals however its afflictions are not limited to any particular demographic. Many attributes have been discovered and characterized surrounding the capability of EAEC to provoke a potent pro-inflammatory immune response, however cellular and molecular mechanisms underlying initiation, progression and outcomes are largely unknown. This limited understanding can be attributed to heterogeneity in strains and the lack of adequate animal models. This review aims to summarize current knowledge about EAEC etiology, pathogenesis and clinical manifestation. Additionally, current animal models and their limitations will be discussed along with the value of applying systems-wide approaches such as computational modeling to study host-EAEC interactions. PMID:23680797

  11. Animal models of antimuscle specific kinase myasthenia

    PubMed Central

    Richman, David P.; Nishi, Kayoko; Ferns, Michael J.; Schnier, Joachim; Pytel, Peter; Maselli, Ricardo A.; Agius, Mark A.

    2014-01-01

    Antimuscle specific kinase (anti-MuSK) myasthenia (AMM) differs from antiacetylcholine receptor myasthenia gravis in exhibiting more focal muscle involvement (neck, shoulder, facial, and bulbar muscles) with wasting of the involved, primarily axial, muscles. AMM is not associated with thymic hyperplasia and responds poorly to anticholinesterase treatment. Animal models of AMM have been induced in rabbits, mice, and rats by immunization with purified xenogeneic MuSK ectodomain, and by passive transfer of large quantities of purified serum IgG from AMM patients into mice. The models have confirmed the pathogenic role of the MuSK antibodies in AMM and have demonstrated the involvement of both the presynaptic and postsynaptic components of the neuromuscular junction. The observations in this human disease and its animal models demonstrate the role of MuSK not only in the formation of this synapse but also in its maintenance. PMID:23252909

  12. Animal models of HIV peripheral neuropathy

    PubMed Central

    Burdo, Tricia H; Miller, Andrew D

    2014-01-01

    The use of animal models in the study of HIV and AIDS has advanced our understanding of the underlying pathophysiologic mechanisms of infection. Of the multitude of HIV disease manifestations, peripheral neuropathy remains one of the most common long-term side effects. Several of the most important causes of peripheral neuropathy in AIDS patients include direct association with HIV infection with or without antiretroviral medication and infection with opportunistic agents. Because the pathogeneses of these diseases are difficult to study in human patients, animal models have allowed for significant advancement in the understanding of the role of viral infection and the immune system in disease genesis. This review focuses on rodent, rabbit, feline and rhesus models used to study HIV-associated peripheral neuropathies, focusing specifically on sensory neuropathy and antiretroviral-associated neuropathies. PMID:25214880

  13. Animal models of anxiety disorders and stress.

    PubMed

    Campos, Alline C; Fogaça, Manoela V; Aguiar, Daniele C; Guimarães, Francisco S

    2013-01-01

    Anxiety and stress-related disorders are severe psychiatric conditions that affect performance in daily tasks and represent a high cost to public health. The initial observation of Charles Darwin that animals and human beings share similar characteristics in the expression of emotion raise the possibility of studying the mechanisms of psychiatric disorders in other mammals (mainly rodents). The development of animal models of anxiety and stress has helped to identify the pharmacological mechanisms and potential clinical effects of several drugs. Animal models of anxiety are based on conflict situations that can generate opposite motivational states induced by approach-avoidance situations. The present review revisited the main rodent models of anxiety and stress responses used worldwide. Here we defined as "ethological" the tests that assess unlearned/unpunished responses (such as the elevated plus maze, light-dark box, and open field), whereas models that involve learned/punished responses are referred to as "conditioned operant conflict tests" (such as the Vogel conflict test). We also discussed models that involve mainly classical conditioning tests (fear conditioning). Finally, we addressed the main protocols used to induce stress responses in rodents, including psychosocial (social defeat and neonatal isolation stress), physical (restraint stress), and chronic unpredictable stress.

  14. System identification of perilymphatic fistula in an animal model

    NASA Technical Reports Server (NTRS)

    Wall, C. 3rd; Casselbrant, M. L.

    1992-01-01

    An acute animal model has been developed in the chinchilla for the study of perilymphatic fistulas. Micropunctures were made in three sites to simulate bony, round window, and oval window fistulas. The eye movements in response to pressure applied to the external auditory canal were recorded after micropuncture induction and in preoperative controls. The main pressure stimulus was a pseudorandom binary sequence (PRBS) that rapidly changed between plus and minus 200 mm of water. The PRBS stimulus, with its wide frequency bandwidth, produced responses clearly above the preoperative baseline in 78 percent of the runs. The response was better between 0.5 and 3.3 Hz than it was below 0.5 Hz. The direction of horizontal eye movement was toward the side of the fistula with positive pressure applied in 92 percent of the runs. Vertical eye movements were also observed. The ratio of vertical eye displacement to horizontal eye displacement depended upon the site of the micropuncture induction. Thus, such a ratio measurement may be clinically useful in the noninvasive localization of perilymphatic fistulas in humans.

  15. Fantastic animals as an experimental model to teach animal adaptation

    PubMed Central

    Guidetti, Roberto; Baraldi, Laura; Calzolai, Caterina; Pini, Lorenza; Veronesi, Paola; Pederzoli, Aurora

    2007-01-01

    Background Science curricula and teachers should emphasize evolution in a manner commensurate with its importance as a unifying concept in science. The concept of adaptation represents a first step to understand the results of natural selection. We settled an experimental project of alternative didactic to improve knowledge of organism adaptation. Students were involved and stimulated in learning processes by creative activities. To set adaptation in a historic frame, fossil records as evidence of past life and evolution were considered. Results The experimental project is schematized in nine phases: review of previous knowledge; lesson on fossils; lesson on fantastic animals; planning an imaginary world; creation of an imaginary animal; revision of the imaginary animals; adaptations of real animals; adaptations of fossil animals; and public exposition. A rubric to evaluate the student's performances is reported. The project involved professors and students of the University of Modena and Reggio Emilia and of the "G. Marconi" Secondary School of First Degree (Modena, Italy). Conclusion The educational objectives of the project are in line with the National Indications of the Italian Ministry of Public Instruction: knowledge of the characteristics of living beings, the meanings of the term "adaptation", the meaning of fossils, the definition of ecosystem, and the particularity of the different biomes. At the end of the project, students will be able to grasp particular adaptations of real organisms and to deduce information about the environment in which the organism evolved. This project allows students to review previous knowledge and to form their personalities. PMID:17767729

  16. Automated Tracking of Animal Posture and Movement during Exploration and Sensory Orientation Behaviors

    PubMed Central

    Gomez-Marin, Alex; Partoune, Nicolas; Stephens, Greg J.; Louis, Matthieu

    2012-01-01

    Background The nervous functions of an organism are primarily reflected in the behavior it is capable of. Measuring behavior quantitatively, at high-resolution and in an automated fashion provides valuable information about the underlying neural circuit computation. Accordingly, computer-vision applications for animal tracking are becoming a key complementary toolkit to genetic, molecular and electrophysiological characterization in systems neuroscience. Methodology/Principal Findings We present Sensory Orientation Software (SOS) to measure behavior and infer sensory experience correlates. SOS is a simple and versatile system to track body posture and motion of single animals in two-dimensional environments. In the presence of a sensory landscape, tracking the trajectory of the animal's sensors and its postural evolution provides a quantitative framework to study sensorimotor integration. To illustrate the utility of SOS, we examine the orientation behavior of fruit fly larvae in response to odor, temperature and light gradients. We show that SOS is suitable to carry out high-resolution behavioral tracking for a wide range of organisms including flatworms, fishes and mice. Conclusions/Significance Our work contributes to the growing repertoire of behavioral analysis tools for collecting rich and fine-grained data to draw and test hypothesis about the functioning of the nervous system. By providing open-access to our code and documenting the software design, we aim to encourage the adaptation of SOS by a wide community of non-specialists to their particular model organism and questions of interest. PMID:22912674

  17. Animal Models of Depression: Molecular Perspectives

    PubMed Central

    Krishnan, Vaishnav; Nestler, Eric J.

    2012-01-01

    Much of the current understanding about the pathogenesis of altered mood, impaired concentration and neurovegetative symptoms in major depression has come from animal models. However, because of the unique and complex features of human depression, the generation of valid and insightful depression models has been less straightforward than modeling other disabling diseases like cancer or autoimmune conditions. Today’s popular depression models creatively merge ethologically valid behavioral assays with the latest technological advances in molecular biology and automated video-tracking. This chapter reviews depression assays involving acute stress (e.g., forced swim test), models consisting of prolonged physical or social stress (e.g., social defeat), models of secondary depression, genetic models, and experiments designed to elucidate the mechanisms of antidepressant action. These paradigms are critically evaluated in relation to their ease, validity and replicability, the molecular insights that they have provided, and their capacity to offer the next generation of therapeutics for depression. PMID:21225412

  18. A model of loggerhead sea turtle (Caretta caretta) habitat and movement in the oceanic North Pacific.

    PubMed

    Abecassis, Melanie; Senina, Inna; Lehodey, Patrick; Gaspar, Philippe; Parker, Denise; Balazs, George; Polovina, Jeffrey

    2013-01-01

    Habitat preferences for juvenile loggerhead turtles in the North Pacific were investigated with data from two several-year long tagging programs, using 224 satellite transmitters deployed on wild and captive-reared turtles. Animals ranged between 23 and 81 cm in straight carapace length. Tracks were used to investigate changes in temperature preferences and speed of the animals with size. Average sea surface temperatures along the tracks ranged from 18 to 23 °C. Bigger turtles generally experienced larger temperature ranges and were encountered in warmer surface waters. Seasonal differences between small and big turtles suggest that the larger ones dive deeper than the mixed layer and subsequently target warmer surface waters to rewarm. Average swimming speeds were under 1 km/h and increased with size for turtles bigger than 30 cm. However, when expressed in body lengths per second (bl s(-1)), smaller turtles showed much higher swimming speeds (>1 bl s (-1) ) than bigger ones (0.5 bl s(-1)). Temperature and speed values at size estimated from the tracks were used to parameterize a habitat-based Eulerian model to predict areas of highest probability of presence in the North Pacific. The model-generated habitat index generally matched the tracks closely, capturing the north-south movements of tracked animals, but the model failed to replicate observed east-west movements, suggesting temperature and foraging preferences are not the only factors driving large-scale loggerhead movements. Model outputs could inform potential bycatch reduction strategies.

  19. A Model of Loggerhead Sea Turtle (Caretta caretta) Habitat and Movement in the Oceanic North Pacific

    PubMed Central

    Abecassis, Melanie; Senina, Inna; Lehodey, Patrick; Gaspar, Philippe; Parker, Denise; Balazs, George; Polovina, Jeffrey

    2013-01-01

    Habitat preferences for juvenile loggerhead turtles in the North Pacific were investigated with data from two several-year long tagging programs, using 224 satellite transmitters deployed on wild and captive-reared turtles. Animals ranged between 23 and 81 cm in straight carapace length. Tracks were used to investigate changes in temperature preferences and speed of the animals with size. Average sea surface temperatures along the tracks ranged from 18 to 23 °C. Bigger turtles generally experienced larger temperature ranges and were encountered in warmer surface waters. Seasonal differences between small and big turtles suggest that the larger ones dive deeper than the mixed layer and subsequently target warmer surface waters to rewarm. Average swimming speeds were under 1 km/h and increased with size for turtles bigger than 30 cm. However, when expressed in body lengths per second (bl s−1), smaller turtles showed much higher swimming speeds (>1 bl s−1) than bigger ones (0.5 bl s−1). Temperature and speed values at size estimated from the tracks were used to parameterize a habitat-based Eulerian model to predict areas of highest probability of presence in the North Pacific. The model-generated habitat index generally matched the tracks closely, capturing the north-south movements of tracked animals, but the model failed to replicate observed east-west movements, suggesting temperature and foraging preferences are not the only factors driving large-scale loggerhead movements. Model outputs could inform potential bycatch reduction strategies. PMID:24039901

  20. Pharmacological animal models of tic disorders.

    PubMed

    McCairn, Kevin W; Isoda, Masaki

    2013-01-01

    This review summarizes animal models of Tourette syndrome (TS) and associated tic disorders that have been developed through pharmacological manipulation. These models provide a useful platform to explore the pathophysiology and the therapeutic interventions available for these disorders. The current pharmacological models, primarily using rodents and nonhuman primates, are classified in this review into two major categories depending on the methodology used for administration, that is, systemic and focal (intracerebral) injection protocols. The systemic protocol primarily targets monoamines such as dopamine and serotonin, whereas the focal protocol mainly manipulates local transmission of gamma-aminobutyric acid (GABA). Each category is capable of inducing behavioral abnormalities that are characteristic of TS spectrum disorders, ranging from sensorimotor to cognitive and emotional symptoms to various degrees. Among a variety of pharmacological models, focal microinjection of GABA antagonists into the sensorimotor striatum has helped identify abnormal neural discharge in the global networks which underlie tourettism, including not only the cerebral cortex and basal ganglia but also the cerebellum, consistent with recent neuroimaging studies for TS subjects. This unique model also provides the opportunity to clarify the effect and mechanisms of therapeutic deep brain stimulation. Continuing efforts to incorporate cutting-edge knowledge into the existing models, as well as to combine different model platforms, will allow further refinement of animal models, thereby leading to a greater understanding of TS and associated tic disorders.

  1. Modelling the Constraints of Spatial Environment in Fauna Movement Simulations: Comparison of a Boundaries Accurate Function and a Cost Function

    NASA Astrophysics Data System (ADS)

    Jolivet, L.; Cohen, M.; Ruas, A.

    2015-08-01

    Landscape influences fauna movement at different levels, from habitat selection to choices of movements' direction. Our goal is to provide a development frame in order to test simulation functions for animal's movement. We describe our approach for such simulations and we compare two types of functions to calculate trajectories. To do so, we first modelled the role of landscape elements to differentiate between elements that facilitate movements and the ones being hindrances. Different influences are identified depending on landscape elements and on animal species. Knowledge were gathered from ecologists, literature and observation datasets. Second, we analysed the description of animal movement recorded with GPS at fine scale, corresponding to high temporal frequency and good location accuracy. Analysing this type of data provides information on the relation between landscape features and movements. We implemented an agent-based simulation approach to calculate potential trajectories constrained by the spatial environment and individual's behaviour. We tested two functions that consider space differently: one function takes into account the geometry and the types of landscape elements and one cost function sums up the spatial surroundings of an individual. Results highlight the fact that the cost function exaggerates the distances travelled by an individual and simplifies movement patterns. The geometry accurate function represents a good bottom-up approach for discovering interesting areas or obstacles for movements.

  2. Animal models of Diamond Blackfan Anemia

    PubMed Central

    McGowan, Kelly A.; Mason, Philip J.

    2011-01-01

    Diamond Blackfan anemia is a genetic syndrome characterized by red blood cell aplasiain association with developmental abnormalities such as growth retardation, orofacial, hand or limb malformations, urogenital anomalies and heart defects. The only known cause is heterozygosity for mutations in genes encoding ribosomal proteins. Understanding how defective ribosome biogenesis and function, important for all cells, causes defects in erythropoiesis and tissue-specific phenotypes during development is paramount to the evolution of effective treatment protocols. Here, we discuss how animal models based on mammals, insects and fish replicate genetic or developmental aspects of DBA and have led to the identification of pathways and candidate molecules that are important in the pathogenesis of the disease. A recurring theme in many of these models suggests that defective ribosome biogenesis induces a p53-dependent cell cycle checkpoint in cells that require high levels of ribosome production and leads to cell type-specific, whole animal phenotypes. PMID:21435507

  3. Standardised animal models of host microbial mutualism

    PubMed Central

    Macpherson, A J; McCoy, K D

    2015-01-01

    An appreciation of the importance of interactions between microbes and multicellular organisms is currently driving research in biology and biomedicine. Many human diseases involve interactions between the host and the microbiota, so investigating the mechanisms involved is important for human health. Although microbial ecology measurements capture considerable diversity of the communities between individuals, this diversity is highly problematic for reproducible experimental animal models that seek to establish the mechanistic basis for interactions within the overall host-microbial superorganism. Conflicting experimental results may be explained away through unknown differences in the microbiota composition between vivaria or between the microenvironment of different isolated cages. In this position paper, we propose standardised criteria for stabilised and defined experimental animal microbiotas to generate reproducible models of human disease that are suitable for systematic experimentation and are reproducible across different institutions. PMID:25492472

  4. Pediatric Epileptic Encephalopathies: Pathophysiology and Animal Models.

    PubMed

    Shao, Li-Rong; Stafstrom, Carl E

    2016-05-01

    Epileptic encephalopathies are syndromes in which seizures or interictal epileptiform activity contribute to or exacerbate brain function, beyond that caused by the underlying pathology. These severe epilepsies begin early in life, are associated with poor lifelong outcome, and are resistant to most treatments. Therefore, they represent an immense challenge for families and the medical care system. Furthermore, the pathogenic mechanisms underlying the epileptic encephalopathies are poorly understood, hampering attempts to devise novel treatments. This article reviews animal models of the three classic epileptic encephalopathies-West syndrome (infantile spasms), Lennox-Gastaut syndrome, and continuous spike waves during sleep or Landau-Kleffner syndrome-with discussion of how animal models are revealing underlying pathophysiological mechanisms that might be amenable to targeted therapy. PMID:27544466

  5. Animal models of age related macular degeneration

    PubMed Central

    Pennesi, Mark E.; Neuringer, Martha; Courtney, Robert J.

    2013-01-01

    Age related macular degeneration (AMD) is the leading cause of vision loss of those over the age of 65 in the industrialized world. The prevalence and need to develop effective treatments for AMD has lead to the development of multiple animal models. AMD is a complex and heterogeneous disease that involves the interaction of both genetic and environmental factors with the unique anatomy of the human macula. Models in mice, rats, rabbits, pigs and non-human primates have recreated many of the histological features of AMD and provided much insight into the underlying pathological mechanisms of this disease. In spite of the large number of models developed, no one model yet recapitulates all of the features of human AMD. However, these models have helped reveal the roles of chronic oxidative damage, inflammation and immune dysregulation, and lipid metabolism in the development of AMD. Models for induced choroidal neovascularization have served as the backbone for testing new therapies. This article will review the diversity of animal models that exist for AMD as well as their strengths and limitations. PMID:22705444

  6. Experimental Diabetes Mellitus in Different Animal Models.

    PubMed

    Al-Awar, Amin; Kupai, Krisztina; Veszelka, Médea; Szűcs, Gergő; Attieh, Zouhair; Murlasits, Zsolt; Török, Szilvia; Pósa, Anikó; Varga, Csaba

    2016-01-01

    Animal models have historically played a critical role in the exploration and characterization of disease pathophysiology and target identification and in the evaluation of novel therapeutic agents and treatments in vivo. Diabetes mellitus disease, commonly known as diabetes, is a group of metabolic disorders characterized by high blood glucose levels for a prolonged time. To avoid late complications of diabetes and related costs, primary prevention and early treatment are therefore necessary. Due to its chronic symptoms, new treatment strategies need to be developed, because of the limited effectiveness of the current therapies. We overviewed the pathophysiological features of diabetes in relation to its complications in type 1 and type 2 mice along with rat models, including Zucker Diabetic Fatty (ZDF) rats, BB rats, LEW 1AR1/-iddm rats, Goto-Kakizaki rats, chemically induced diabetic models, and Nonobese Diabetic mouse, and Akita mice model. The advantages and disadvantages that these models comprise were also addressed in this review. This paper briefly reviews the wide pathophysiological and molecular mechanisms associated with type 1 and type 2 diabetes, particularly focusing on the challenges associated with the evaluation and predictive validation of these models as ideal animal models for preclinical assessments and discovering new drugs and therapeutic agents for translational application in humans. PMID:27595114

  7. Experimental Diabetes Mellitus in Different Animal Models

    PubMed Central

    Al-awar, Amin; Veszelka, Médea; Szűcs, Gergő; Attieh, Zouhair; Murlasits, Zsolt; Török, Szilvia; Pósa, Anikó; Varga, Csaba

    2016-01-01

    Animal models have historically played a critical role in the exploration and characterization of disease pathophysiology and target identification and in the evaluation of novel therapeutic agents and treatments in vivo. Diabetes mellitus disease, commonly known as diabetes, is a group of metabolic disorders characterized by high blood glucose levels for a prolonged time. To avoid late complications of diabetes and related costs, primary prevention and early treatment are therefore necessary. Due to its chronic symptoms, new treatment strategies need to be developed, because of the limited effectiveness of the current therapies. We overviewed the pathophysiological features of diabetes in relation to its complications in type 1 and type 2 mice along with rat models, including Zucker Diabetic Fatty (ZDF) rats, BB rats, LEW 1AR1/-iddm rats, Goto-Kakizaki rats, chemically induced diabetic models, and Nonobese Diabetic mouse, and Akita mice model. The advantages and disadvantages that these models comprise were also addressed in this review. This paper briefly reviews the wide pathophysiological and molecular mechanisms associated with type 1 and type 2 diabetes, particularly focusing on the challenges associated with the evaluation and predictive validation of these models as ideal animal models for preclinical assessments and discovering new drugs and therapeutic agents for translational application in humans.

  8. Experimental Diabetes Mellitus in Different Animal Models

    PubMed Central

    Al-awar, Amin; Veszelka, Médea; Szűcs, Gergő; Attieh, Zouhair; Murlasits, Zsolt; Török, Szilvia; Pósa, Anikó; Varga, Csaba

    2016-01-01

    Animal models have historically played a critical role in the exploration and characterization of disease pathophysiology and target identification and in the evaluation of novel therapeutic agents and treatments in vivo. Diabetes mellitus disease, commonly known as diabetes, is a group of metabolic disorders characterized by high blood glucose levels for a prolonged time. To avoid late complications of diabetes and related costs, primary prevention and early treatment are therefore necessary. Due to its chronic symptoms, new treatment strategies need to be developed, because of the limited effectiveness of the current therapies. We overviewed the pathophysiological features of diabetes in relation to its complications in type 1 and type 2 mice along with rat models, including Zucker Diabetic Fatty (ZDF) rats, BB rats, LEW 1AR1/-iddm rats, Goto-Kakizaki rats, chemically induced diabetic models, and Nonobese Diabetic mouse, and Akita mice model. The advantages and disadvantages that these models comprise were also addressed in this review. This paper briefly reviews the wide pathophysiological and molecular mechanisms associated with type 1 and type 2 diabetes, particularly focusing on the challenges associated with the evaluation and predictive validation of these models as ideal animal models for preclinical assessments and discovering new drugs and therapeutic agents for translational application in humans. PMID:27595114

  9. Diabetic Retinopathy: Animal Models, Therapies, and Perspectives

    PubMed Central

    Cai, Xue; McGinnis, James F.

    2016-01-01

    Diabetic retinopathy (DR) is one of the major complications of diabetes. Although great efforts have been made to uncover the mechanisms underlying the pathology of DR, the exact causes of DR remain largely unknown. Because of multifactor involvement in DR etiology, currently no effective therapeutic treatments for DR are available. In this paper, we review the pathology of DR, commonly used animal models, and novel therapeutic approaches. Perspectives and future directions for DR treatment are discussed. PMID:26881246

  10. Diabetic Retinopathy: Animal Models, Therapies, and Perspectives.

    PubMed

    Cai, Xue; McGinnis, James F

    2016-01-01

    Diabetic retinopathy (DR) is one of the major complications of diabetes. Although great efforts have been made to uncover the mechanisms underlying the pathology of DR, the exact causes of DR remain largely unknown. Because of multifactor involvement in DR etiology, currently no effective therapeutic treatments for DR are available. In this paper, we review the pathology of DR, commonly used animal models, and novel therapeutic approaches. Perspectives and future directions for DR treatment are discussed. PMID:26881246

  11. Animal Models of Compulsive Eating Behavior

    PubMed Central

    Di Segni, Matteo; Patrono, Enrico; Patella, Loris; Puglisi-Allegra, Stefano; Ventura, Rossella

    2014-01-01

    Eating disorders are multifactorial conditions that can involve a combination of genetic, metabolic, environmental, and behavioral factors. Studies in humans and laboratory animals show that eating can also be regulated by factors unrelated to metabolic control. Several studies suggest a link between stress, access to highly palatable food, and eating disorders. Eating “comfort foods” in response to a negative emotional state, for example, suggests that some individuals overeat to self-medicate. Clinical data suggest that some individuals may develop addiction-like behaviors from consuming palatable foods. Based on this observation, “food addiction” has emerged as an area of intense scientific research. A growing body of evidence suggests that some aspects of food addiction, such as compulsive eating behavior, can be modeled in animals. Moreover, several areas of the brain, including various neurotransmitter systems, are involved in the reinforcement effects of both food and drugs, suggesting that natural and pharmacological stimuli activate similar neural systems. In addition, several recent studies have identified a putative connection between neural circuits activated in the seeking and intake of both palatable food and drugs. The development of well-characterized animal models will increase our understanding of the etiological factors of food addiction and will help identify the neural substrates involved in eating disorders such as compulsive overeating. Such models will facilitate the development and validation of targeted pharmacological therapies. PMID:25340369

  12. Animal models of tic disorders: A translational perspective

    PubMed Central

    Godar, Sean C.; Mosher, Laura J.; Di Giovanni, Giuseppe; Bortolato, Marco

    2014-01-01

    Tics are repetitive, sudden movements and/or vocalizations, typically enacted as maladaptive responses to intrusive premonitory urges. The most severe tic disorder, Tourette syndrome (TS), is a childhood-onset condition featuring multiple motor and at least one phonic tic for a duration longer than 1 year. The pharmacological treatment of TS is mainly based on antipsychotic agents; while these drugs are often effective in reducing tic severity and frequency, their therapeutic compliance is limited by serious motor and cognitive side effects. The identification of novel therapeutic targets and development of better treatments for tic disorders is conditional on the development of animal models with high translational validity. In addition, these experimental tools can prove extremely useful to test hypotheses on the etiology and neurobiological bases of TS and related conditions. In recent years, the translational value of these animal models has been enhanced, thanks to a significant re-organization of our conceptual framework of neuropsychiatric disorders, with a greater focus on endophenotypes and quantitative indices, rather than qualitative descriptors. Given the complex and multifactorial nature of TS and other tic disorders, the selection of animal models that can appropriately capture specific symptomatic aspects of these conditions can pose significant theoretical and methodological challenges. In this article, we will review the state of the art on the available animal models of tic disorders, based on genetic mutations, environmental interventions as well as pharmacological manipulations. Furthermore, we will outline emerging lines of translational research showing how some of these experimental preparations have led to significant progress in the identification of novel therapeutic targets for tic disorders. PMID:25244952

  13. Animal models of tic disorders: a translational perspective.

    PubMed

    Godar, Sean C; Mosher, Laura J; Di Giovanni, Giuseppe; Bortolato, Marco

    2014-12-30

    Tics are repetitive, sudden movements and/or vocalizations, typically enacted as maladaptive responses to intrusive premonitory urges. The most severe tic disorder, Tourette syndrome (TS), is a childhood-onset condition featuring multiple motor and at least one phonic tic for a duration longer than 1 year. The pharmacological treatment of TS is mainly based on antipsychotic agents; while these drugs are often effective in reducing tic severity and frequency, their therapeutic compliance is limited by serious motor and cognitive side effects. The identification of novel therapeutic targets and development of better treatments for tic disorders is conditional on the development of animal models with high translational validity. In addition, these experimental tools can prove extremely useful to test hypotheses on the etiology and neurobiological bases of TS and related conditions. In recent years, the translational value of these animal models has been enhanced, thanks to a significant re-organization of our conceptual framework of neuropsychiatric disorders, with a greater focus on endophenotypes and quantitative indices, rather than qualitative descriptors. Given the complex and multifactorial nature of TS and other tic disorders, the selection of animal models that can appropriately capture specific symptomatic aspects of these conditions can pose significant theoretical and methodological challenges. In this article, we will review the state of the art on the available animal models of tic disorders, based on genetic mutations, environmental interventions as well as pharmacological manipulations. Furthermore, we will outline emerging lines of translational research showing how some of these experimental preparations have led to significant progress in the identification of novel therapeutic targets for tic disorders.

  14. Humanized animal exercise model for clinical implication.

    PubMed

    Seo, Dae Yun; Lee, Sung Ryul; Kim, Nari; Ko, Kyung Soo; Rhee, Byoung Doo; Han, Jin

    2014-09-01

    Exercise and physical activity function as a patho-physiological process that can prevent, manage, and regulate numerous chronic conditions, including metabolic syndrome and age-related sarcopenia. Because of research ethics and technical difficulties in humans, exercise models using animals are requisite for the future development of exercise mimetics to treat such abnormalities. Moreover, the beneficial or adverse outcomes of a new regime or exercise intervention in the treatment of a specific condition should be tested prior to implementation in a clinical setting. In rodents, treadmill running (or swimming) and ladder climbing are widely used as aerobic and anaerobic exercise models, respectively. However, exercise models are not limited to these types. Indeed, there are no golden standard exercise modes or protocols for managing or improving health status since the types (aerobic vs. anaerobic), time (morning vs. evening), and duration (continuous vs. acute bouts) of exercise are the critical determinants for achieving expected beneficial effects. To provide insight into the understanding of exercise and exercise physiology, we have summarized current animal exercise models largely based on aerobic and anaerobic criteria. Additionally, specialized exercise models that have been developed for testing the effect of exercise on specific physiological conditions are presented. Finally, we provide suggestions and/or considerations for developing a new regime for an exercise model.

  15. Animal models in drug development for MRSA.

    PubMed

    Marra, Andrea

    2014-01-01

    One of the foremost challenges of drug discovery in any therapeutic area is that of solidifying the correlation between in vitro activity and clinical efficacy. Between these is the confirmation that affecting a particular target in vivo will lead to a therapeutic benefit. In antibacterial drug discovery, there is a key advantage from the start, since the targets are bacteria-therefore, it is simple to ascertain in vitro whether a drug has the desired effect, i.e., bacterial cell inhibition or killing, and to understand the mechanism by which that occurs. The downstream criteria, whether a compound reaches the infection site and achieves appropriately high levels to affect bacterial viability, can be evaluated in animal models of infection. In this way animal models of infection can be a highly valuable and predictive bridge between in vitro drug discovery and early clinical evaluation.The Gram-positive pathogen Staphylococcus aureus causes a wide variety of infections in humans (Archer, Clin Infect Dis 26:1179-1181, 1998) and has been said to be able to infect every tissue type. Fortunately, over the years a great deal of effort has been expended toward developing infection models in rodents using this organism, with good success. This chapter will describe the advantages, methods, and outcome measurements of the rodent models most used in drug discovery for S. aureus. Mouse models will be the focus of this chapter, as they are the most economical and thus most commonly used, but a rat infection model is included as well.

  16. Proliferative retinopathies: animal models and therapeutic opportunities.

    PubMed

    Villacampa, Pilar; Haurigot, Virginia; Bosch, Fatima

    2015-01-01

    Proliferative retinopathies are the leading causes of blindness in Western societies. The development of new, more efficacious treatments that take advantage of recent advances in the fields of gene and cell therapy requires further investigations on the mechanisms underlying disease onset and progression, and adequate animal models that recapitulate the pathogenesis of human proliferative retinopathy and allow evaluation of the long-term therapeutic benefits that these therapies can offer. Unfortunately, most models of retinal neovascularization have short-term evolution and diabetic rodents show a very mild retinal phenotype, limited to non-proliferative changes, and do not develop proliferative retinopathy at all. Transgenic mice overexpressing Insulin-like Growth Factor-I (IGF-I) in the retina (TgIGF-I) constitute the only rodent model currently available that develops most of the retinal alterations observed in diabetic eyes, with a temporal evolution that resembles that of the human disease. TgIGF-I have retinal vascular alterations that progress as animals age from non-proliferative to proliferative disease, making these mice an excellent model of proliferative retinopathy that, due to its slow progression, allows long-term evaluation of novel antiangiogenic therapies. At the molecular level, transgenic retinas recapitulate a variety of changes that are also observed in diabetic retinas, which reinforces the validity of this model. In addition to vascular and glial alterations, Tg-IGF-I mice show progressive neurodegeneration that leads to blindness in old animals. Thus, TgIGF-I are a useful model for testing the long-term efficacy and safety of innovative antiangiogenic, glial-modulating and neuroprotective therapies for the treatment of diabetic retinopathy and other retinal proliferative disorders.

  17. Animating Event B Models by Formal Data Models

    NASA Astrophysics Data System (ADS)

    Ait-Sadoune, Idir; Ait-Ameur, Yamine

    We present a formal approach allowing to animate event B formal models. Invariants, deadlock freeness properties are expressed and proved on these models. This paper presents an approach that suggests to complete the proof activity in the event B method by animation activity. The obtained animator may be used to check if the event B models obtained fulfill user requirements, or to provide a help to the developer when describing its formal event B models and particularly in defining event B invariants and guards. More precisely, event B models are translated into data models expressed in the EXPRESS formal data modeling technique. The obtained data models are instantiated and provide an animation of the original B models. Following this approach, it becomes possible to trigger event B models, which themselves trigger entity instantiation on the EXPRESS side. As a further step, we show that the B models can be used as a monitoring system raising alarms in case of incorrect systems behavior. The proposed approach is operationally implemented in the B2EXPRESS tool which handles animation of event B models. It has been experimented for the validation of multimodal human interfaces in the context of VERBATIM project.

  18. Animal infection models and ethics -- the perfect infection model.

    PubMed

    Zak, Oto; O'Reilly, Terence

    1993-05-01

    Experimental infection models have long been recognized as an essential part of testing anti-infective therapies. A perfect animal model would be a model that satisfied not only scientific criteria, but ethical criteria as well. In the design and execution of such experiments, scientific and ethical considerations are not mutually exclusive, but should be convergent and therefore result in the optimal model.

  19. Animal models of chronic liver diseases.

    PubMed

    Liu, Yan; Meyer, Christoph; Xu, Chengfu; Weng, Honglei; Hellerbrand, Claus; ten Dijke, Peter; Dooley, Steven

    2013-03-01

    Chronic liver diseases are frequent and potentially life threatening for humans. The underlying etiologies are diverse, ranging from viral infections, autoimmune disorders, and intoxications (including alcohol abuse) to imbalanced diets. Although at early stages of disease the liver regenerates in the absence of the insult, advanced stages cannot be healed and may require organ transplantation. A better understanding of underlying mechanisms is mandatory for the design of new drugs to be used in clinic. Therefore, rodent models are being developed to mimic human liver disease. However, no model to date can completely recapitulate the "corresponding" human disorder. Limiting factors are the time frame required in humans to establish a certain liver disease and the fact that rodents possess a distinct immune system compared with humans and have different metabolic rates affecting liver homeostasis. These features account for the difficulties in developing adequate rodent models for studying disease progression and for testing new pharmaceuticals to be translated into the clinic. Nevertheless, traditional and new promising animal models that mimic certain attributes of chronic liver diseases are established and being used to deepen our understanding in the underlying mechanisms of distinct liver diseases. This review aims at providing a comprehensive overview of recent advances in animal models recapitulating different features and etiologies of human liver diseases. PMID:23275613

  20. Hormones and autoimmunity: animal models of arthritis.

    PubMed

    Wilder, R L

    1996-05-01

    Hormones, particularly those involved in the hypothalamic-pituitary-gonadal and -adrenal axes (HPG and HPA), play important roles in various animal models of autoimmunity such as systemic lupus erythematosus in mice and collagen-induced arthritis (CIA) in mice and rats, and the streptococcal cell wall, adjuvant and avridine arthritis models in rats. Intimately linked to the subject of hormones and autoimmunity are gender, sex chromosomes and age. The importance of these factors in the various animal models is emphasized in this chapter. Several major themes are apparent. First, oestrogens promote B-cell dependent immune-complex mediated disease (e.g. lupus nephritis) but suppress T-cell dependent pathology (CIA in mice and rats), and vice versa. Second, testosterone's effects are complicated and depend on species and disease model. In rats, testosterone suppresses both T-cell and B-cell immunity. In mice, the effects are complex and difficult to interpret, e.g. they tend to enhance CIA arthritis and suppress lupus. Sex chromosome/sex hormone interactions are clearly involved in generating these complicated effects. Third, studies in Lewis and Fischer F344 rats exemplify the importance of corticosteroids, corticotrophin releasing hormone and the HPA axis in the regulation of inflammation and the predisposition to autoimmune diseases. Fourth, the HPA axis is intimately linked to the HPG axis and is sexually dimorphic. Oestrogens stimulate higher corticosteroid responses in females. The animal model data have major implications for understanding autoimmunity in humans. In particular, adrenal and gonadal hormone deficiency is likely to facilitate T-cell dependent diseases like rheumatoid arthritis, while high oestrogen levels or effects, relative to testosterone, are likely to promote B-cell dependent immune-complex-mediated diseases such as lupus nephritis.

  1. Animal models of depression: are there any?

    PubMed

    O'Neil, Michael F; Moore, Nicholas A

    2003-06-01

    Simple tests for antidepressant-like activity, such as 5-HTP-induced syndrome or reserpine-induced hypomotility, are often mechanism-based tests, pharmacologically specific for certain known classes of therapeutically successful antidepressant agents. Many of these behavioural assays have been superseded by neurochemical techniques such as in vivo microdialysis. In contrast to these mechanistic-based models, investigators have also endeavoured to reproduce in the laboratory, factors that are believed to precipitate depression in people. It is a strong assumption in this approach that depression is a response to stress. This strategy profiles the consequences of chronic stress particularly psychosocial stress or early life events, in order to reproduce in animals the behavioural signs and pathologies associated with depression. The advances in the social psychological, clinical pathological and new areas such as neuroimaging research offer the possibility of establishing more sophisticated models for depression in animals with a broader range of biomarkers from the immunological and endocrinological to neurochemical and behavioural. Combining these novel insights with more traditional tests of depression may not only increase our understanding of the neurobiology of depression but also afford more precise and predictive preclinical models of depression. The responsiveness of different strains or genetically modified animals to stress is likely to be a key area of study. Furthermore we must look to individual differences in subjects, even within the same strain, to more fully understand why some individuals show pathological responses to stress whereas others appear unaffected. Conversely in validating our models using currently available treatments we must include the concept of non-responders so as not to disregard models that may extend therapeutic possibilities in these patients. PMID:12766928

  2. Realistic avatar eye and head animation using a neurobiological model of visual attention

    NASA Astrophysics Data System (ADS)

    Itti, Laurent; Dhavale, Nitin; Pighin, Frederic

    2004-01-01

    We describe a neurobiological model of visual attention and eye/head movements in primates, and its application to the automatic animation of a realistic virtual human head watching an unconstrained variety of visual inputs. The bottom-up (image-based) attention model is based on the known neurophysiology of visual processing along the occipito-parietal pathway of the primate brain, while the eye/head movement model is derived from recordings in freely behaving Rhesus monkeys. The system is successful at autonomously saccading towards and tracking salient targets in a variety of video clips, including synthetic stimuli, real outdoors scenes and gaming console outputs. The resulting virtual human eye/head animation yields realistic rendering of the simulation results, both suggesting applicability of this approach to avatar animation and reinforcing the plausibility of the neural model.

  3. Modeling movement and fidelity of American black ducks

    USGS Publications Warehouse

    Zimpfer, N.L.; Conroy, M.J.

    2006-01-01

    Spatial relationships among stocks of breeding waterfowl can be an important component of harvest management. Prediction and optimal harvest management under adaptive harvest management (AHM) requires information on the spatial relationships among breeding populations (fidelity and inter-year exchange), as well as rates of movements from breeding to harvest regions. We used band-recovery data to develop a model to estimate probabilities of movement for American black ducks (Anas rubripes) among 3 Canadian breeding strata and 6 harvest regions (3 in Canada, and 3 in the United States) over the period 1965-1998. Model selection criteria suggested that models containing area-, year-, and age-specific recovery rates with area- and sex-specific movement rates were the best for modeling movement. Movement by males to southern harvest areas was variable depending on the originating area. Males from the western breeding area predominantly moved to the Mississippi Flyway or southern Atlantic Flyway (??ij = 0.353, SE = 0.0187 and ??ij = 0.473, SE = 0.037, respectively), whereas males that originated in the eastern and central breeding strata moved to the northern Atlantic flyway (??ij = 0.842, SE = 0.010 and ??ij = 0.578, SE = 0.0222, respectively). We used combined recoveries and recaptures in Program MARK to estimate fidelity to the 3 Canadian breeding strata. Information criteria identified a model containing sex- and age-specific fidelity for black ducks. Estimates of fidelity were 0.9695 (SE = 0.0249) and 0.9554 (SE = 0.0434) for adult males and females, respectively. Estimates of fidelity for juveniles were slightly lower at 0.9210 (SE = 0.0931) and 0.8870 (SE = 0.0475) for males and females, respectively. These models have application to the development of spatially stratified black duck harvest management models for use in AHM.

  4. Biomedical Research and the Animal Rights Movement: A Contrast in Values.

    ERIC Educational Resources Information Center

    Morrison, Adrian R.

    1993-01-01

    This article explains how animals are used in research in an effort to counteract animal rights literature. Reveals how medical professionals and others trained in scholarship have misquoted the scientific literature to bolster their claims against the utility of animal research. (PR)

  5. Using Computational and Mechanical Models to Study Animal Locomotion

    PubMed Central

    Miller, Laura A.; Goldman, Daniel I.; Hedrick, Tyson L.; Tytell, Eric D.; Wang, Z. Jane; Yen, Jeannette; Alben, Silas

    2012-01-01

    Recent advances in computational methods have made realistic large-scale simulations of animal locomotion possible. This has resulted in numerous mathematical and computational studies of animal movement through fluids and over substrates with the purpose of better understanding organisms’ performance and improving the design of vehicles moving through air and water and on land. This work has also motivated the development of improved numerical methods and modeling techniques for animal locomotion that is characterized by the interactions of fluids, substrates, and structures. Despite the large body of recent work in this area, the application of mathematical and numerical methods to improve our understanding of organisms in the context of their environment and physiology has remained relatively unexplored. Nature has evolved a wide variety of fascinating mechanisms of locomotion that exploit the properties of complex materials and fluids, but only recently are the mathematical, computational, and robotic tools available to rigorously compare the relative advantages and disadvantages of different methods of locomotion in variable environments. Similarly, advances in computational physiology have only recently allowed investigators to explore how changes at the molecular, cellular, and tissue levels might lead to changes in performance at the organismal level. In this article, we highlight recent examples of how computational, mathematical, and experimental tools can be combined to ultimately answer the questions posed in one of the grand challenges in organismal biology: “Integrating living and physical systems.” PMID:22988026

  6. Piperidine, pyridine alkaloid inhibition of fetal movement in a day 40 pregnant goat model.

    PubMed

    Green, Benedict T; Lee, Stephen T; Welch, Kevin D; Pfister, James A; Panter, Kip E

    2013-08-01

    Inhibition of fetal movement is one mechanism behind the development of multiple congenital contracture-type defects in developing fetuses of humans and animals. We tested the alkaloids anabasine, lobeline, and myosmine for agonist actions, and sensitivity to alpha conotoxins EI and GI blockade at fetal muscle-type nicotinic acetylcholine receptors (nAChR) expressed by TE-671 cells. We also determined if the alkaloids decreased fetal movement in an IV dosed, day 40 pregnant goat model. In TE-671 cells, all three alkaloids elicited concentration-dependent changes in membrane potential sensing dye fluorescence. 1.0 μM alpha conotoxin GI shifted the concentration-effect curves of anabasine and myosmine to the right, and decreased maximal responses. Neither of the conotoxins blocked the actions of lobeline in TE-671 cells. In the day 40 pregnant goats, 0.8 mg/kg anabasine abolished fetal movement at 30 and 60 min after dosing and fetal movement was reduced by lobeline and myosmine. The blockade of anabasine and myosmine actions in TE-671 cells by alpha conotoxin GI indicates that they are agonists at fetal muscle-type nAChR. All three alkaloids did significantly decrease fetal movement in the day 40 pregnant goat model suggesting a potential for these alkaloids to cause multiple congenital contracture-type defects in developing fetuses.

  7. Forward Models and State Estimation in Compensatory Eye Movements

    PubMed Central

    Frens, Maarten A.; Donchin, Opher

    2009-01-01

    The compensatory eye movement (CEM) system maintains a stable retinal image, integrating information from different sensory modalities to compensate for head movements. Inspired by recent models of the physiology of limb movements, we suggest that CEM can be modeled as a control system with three essential building blocks: a forward model that predicts the effects of motor commands; a state estimator that integrates sensory feedback into this prediction; and, a feedback controller that translates a state estimate into motor commands. We propose a specific mapping of nuclei within the CEM system onto these control functions. Specifically, we suggest that the Flocculus is responsible for generating the forward model prediction and that the Vestibular Nuclei integrate sensory feedback to generate an estimate of current state. Finally, the brainstem motor nuclei – in the case of horizontal compensation this means the Abducens Nucleus and the Nucleus Prepositus Hypoglossi – implement a feedback controller, translating state into motor commands. While these efforts to understand the physiological control system as a feedback control system are in their infancy, there is the intriguing possibility that CEM and targeted voluntary movements use the same cerebellar circuitry in fundamentally different ways. PMID:19956563

  8. Domestic animals as models for biomedical research

    PubMed Central

    Andersson, Leif

    2016-01-01

    Domestic animals are unique models for biomedical research due to their long history (thousands of years) of strong phenotypic selection. This process has enriched for novel mutations that have contributed to phenotype evolution in domestic animals. The characterization of such mutations provides insights in gene function and biological mechanisms. This review summarizes genetic dissection of about 50 genetic variants affecting pigmentation, behaviour, metabolic regulation, and the pattern of locomotion. The variants are controlled by mutations in about 30 different genes, and for 10 of these our group was the first to report an association between the gene and a phenotype. Almost half of the reported mutations occur in non-coding sequences, suggesting that this is the most common type of polymorphism underlying phenotypic variation since this is a biased list where the proportion of coding mutations are inflated as they are easier to find. The review documents that structural changes (duplications, deletions, and inversions) have contributed significantly to the evolution of phenotypic diversity in domestic animals. Finally, we describe five examples of evolution of alleles, which means that alleles have evolved by the accumulation of several consecutive mutations affecting the function of the same gene. PMID:26479863

  9. Animal models of glucocorticoid-induced glaucoma.

    PubMed

    Overby, Darryl R; Clark, Abbot F

    2015-12-01

    Glucocorticoid (GC) therapy is widely used to treat a variety of inflammatory diseases and conditions. While unmatched in their anti-inflammatory and immunosuppressive activities, GC therapy is often associated with the significant ocular side effect of GC-induced ocular hypertension (OHT) and iatrogenic open-angle glaucoma. Investigators have generated GC-induced OHT and glaucoma in at least 8 different species besides man. These models mimic many features of this condition in man and provide morphologic and molecular insights into the pathogenesis of GC-OHT. In addition, there are many clinical, morphological, and molecular similarities between GC-induced glaucoma and primary open-angle glaucoma (POAG), making animals models of GC-induced OHT and glaucoma attractive models in which to study specific aspects of POAG.

  10. Macrophages and Uveitis in Experimental Animal Models

    PubMed Central

    Mérida, Salvador; Palacios, Elena; Bosch-Morell, Francisco

    2015-01-01

    Resident and infiltrated macrophages play relevant roles in uveitis as effectors of innate immunity and inductors of acquired immunity. They are major effectors of tissue damage in uveitis and are also considered to be potent antigen-presenting cells. In the last few years, experimental animal models of uveitis have enabled us to enhance our understanding of the leading role of macrophages in eye inflammation processes, including macrophage polarization in experimental autoimmune uveoretinitis and the major role of Toll-like receptor 4 in endotoxin-induced uveitis. This improved knowledge should guide advantageous iterative research to establish mechanisms and possible therapeutic targets for human uveitis resolution. PMID:26078494

  11. Movement Activity Based Classification of Animal Behaviour with an Application to Data from Cheetah (Acinonyx jubatus)

    PubMed Central

    Grünewälder, Steffen; Broekhuis, Femke; Macdonald, David Whyte; Wilson, Alan Martin; McNutt, John Weldon; Shawe-Taylor, John; Hailes, Stephen

    2012-01-01

    We propose a new method, based on machine learning techniques, for the analysis of a combination of continuous data from dataloggers and a sampling of contemporaneous behaviour observations. This data combination provides an opportunity for biologists to study behaviour at a previously unknown level of detail and accuracy; however, continuously recorded data are of little use unless the resulting large volumes of raw data can be reliably translated into actual behaviour. We address this problem by applying a Support Vector Machine and a Hidden-Markov Model that allows us to classify an animal's behaviour using a small set of field observations to calibrate continuously recorded activity data. Such classified data can be applied quantitatively to the behaviour of animals over extended periods and at times during which observation is difficult or impossible. We demonstrate the usefulness of the method by applying it to data from six cheetah (Acinonyx jubatus) in the Okavango Delta, Botswana. Cumulative activity data scores were recorded every five minutes by accelerometers embedded in GPS radio-collars for around one year on average. Direct behaviour sampling of each of the six cheetah were collected in the field for comparatively short periods. Using this approach we are able to classify each five minute activity score into a set of three key behaviour (feeding, mobile and stationary), creating a continuous behavioural sequence for the entire period for which the collars were deployed. Evaluation of our classifier with cross-validation shows the accuracy to be , but that the accuracy for individual classes is reduced with decreasing sample size of direct observations. We demonstrate how these processed data can be used to study behaviour identifying seasonal and gender differences in daily activity and feeding times. Results given here are unlike any that could be obtained using traditional approaches in both accuracy and detail. PMID:23185301

  12. Movement activity based classification of animal behaviour with an application to data from cheetah (Acinonyx jubatus).

    PubMed

    Grünewälder, Steffen; Broekhuis, Femke; Macdonald, David Whyte; Wilson, Alan Martin; McNutt, John Weldon; Shawe-Taylor, John; Hailes, Stephen

    2012-01-01

    We propose a new method, based on machine learning techniques, for the analysis of a combination of continuous data from dataloggers and a sampling of contemporaneous behaviour observations. This data combination provides an opportunity for biologists to study behaviour at a previously unknown level of detail and accuracy; however, continuously recorded data are of little use unless the resulting large volumes of raw data can be reliably translated into actual behaviour. We address this problem by applying a Support Vector Machine and a Hidden-Markov Model that allows us to classify an animal's behaviour using a small set of field observations to calibrate continuously recorded activity data. Such classified data can be applied quantitatively to the behaviour of animals over extended periods and at times during which observation is difficult or impossible. We demonstrate the usefulness of the method by applying it to data from six cheetah (Acinonyx jubatus) in the Okavango Delta, Botswana. Cumulative activity data scores were recorded every five minutes by accelerometers embedded in GPS radio-collars for around one year on average. Direct behaviour sampling of each of the six cheetah were collected in the field for comparatively short periods. Using this approach we are able to classify each five minute activity score into a set of three key behaviour (feeding, mobile and stationary), creating a continuous behavioural sequence for the entire period for which the collars were deployed. Evaluation of our classifier with cross-validation shows the accuracy to be 83%-94%, but that the accuracy for individual classes is reduced with decreasing sample size of direct observations. We demonstrate how these processed data can be used to study behaviour identifying seasonal and gender differences in daily activity and feeding times. Results given here are unlike any that could be obtained using traditional approaches in both accuracy and detail.

  13. Multi-quadric collocation model of horizontal crustal movement

    NASA Astrophysics Data System (ADS)

    Chen, Gang; Zeng, Anmin; Ming, Feng; Jing, Yifan

    2016-05-01

    To establish the horizontal crustal movement velocity field of the Chinese mainland, a Hardy multi-quadric fitting model and collocation are usually used. However, the kernel function, nodes, and smoothing factor are difficult to determine in the Hardy function interpolation. Furthermore, the covariance function of the stochastic signal must be carefully constructed in the collocation model, which is not trivial. In this paper, a new combined estimation method for establishing the velocity field, based on collocation and multi-quadric equation interpolation, is presented. The crustal movement estimation simultaneously takes into consideration an Euler vector as the crustal movement trend and the local distortions as the stochastic signals, and a kernel function of the multi-quadric fitting model substitutes for the covariance function of collocation. The velocities of a set of 1070 reference stations were obtained from the Crustal Movement Observation Network of China, and the corresponding velocity field was established using the new combined estimation method. A total of 85 reference stations were used as checkpoints, and the precision in the north and east component was 1.25 and 0.80 mm yr-1, respectively. The result obtained by the new method corresponds with the collocation method and multi-quadric interpolation without requiring the covariance equation for the signals.

  14. Models for extracting vertical crustal movements from leveling data

    NASA Technical Reports Server (NTRS)

    Holdahl, S. H.

    1978-01-01

    Various adjustment strategies are being used in North America to obtain vertical crustal movements from repeated leveling. The more successful models utilize polynomials or multiquadric analysis to describe elevation change with a velocity surface. Other features permit determination of nonlinear motions, motions associated with earthquakes or episodes, and vertical motions of blocks where boundaries are prespecified. The preferred models for estimating crustal motions permit the use of detached segments of releveling to govern the shape of a velocity surface and allow for input from nonleveling sources such as tide gages and paired lake gages. Some models for extracting vertical crustal movements from releveling data are also excellent for adjusting leveling networks, and permit mixing old and new data in areas exhibiting vertical motion. The new adjustment techniques are more general than older static models and will undoubtedly be used routinely in the future as the constitution of level networks becomes mainly relevelings.

  15. Spatial scaling: Its analysis and effects on animal movements in semiarid landscape mosaics. Final report, 1 September 1988--31 May 1992

    SciTech Connect

    Wiens, J.A.

    1992-09-01

    The research conducted under this agreement focused in general on the effects of envirorunental heterogeneity on movements of animals and materials in semiarid grassland landscapes, on the form of scale-dependency of ecological patterns and processes, and on approaches to extrapolating among spatial scales. The findings are summarized in a series of published and unpublished papers that are included as the main body of this report. We demonstrated the value of ``experimental model systems`` employing observations and experiments conducted in small-scale microlandscapes to test concepts relating to flows of individuals and materials through complex, heterogeneous mosaics. We used fractal analysis extensively in this research, and showed how fractal measures can produce insights and lead,to questions that do not emerge from more traditional scale-dependent measures. We developed new concepts and theory to deal with scale-dependency in ecological systems and with integrating individual movement patterns into considerations of population and ecosystem dynamics.

  16. Animal model of neuropathic tachycardia syndrome

    NASA Technical Reports Server (NTRS)

    Carson, R. P.; Appalsamy, M.; Diedrich, A.; Davis, T. L.; Robertson, D.

    2001-01-01

    Clinically relevant autonomic dysfunction can result from either complete or partial loss of sympathetic outflow to effector organs. Reported animal models of autonomic neuropathy have aimed to achieve complete lesions of sympathetic nerves, but incomplete lesions might be more relevant to certain clinical entities. We hypothesized that loss of sympathetic innervation would result in a predicted decrease in arterial pressure and a compensatory increase in heart rate. Increased heart rate due to loss of sympathetic innervation is seemingly paradoxical, but it provides a mechanistic explanation for clinical autonomic syndromes such as neuropathic postural tachycardia syndrome. Partially dysautonomic animals were generated by selectively lesioning postganglionic sympathetic neurons with 150 mg/kg 6-hydroxydopamine hydrobromide in male Sprague-Dawley rats. Blood pressure and heart rate were monitored using radiotelemetry. Systolic blood pressure decreased within hours postlesion (Delta>20 mm Hg). Within 4 days postlesion, heart rate rose and remained elevated above control levels. The severity of the lesion was determined functionally and pharmacologically by spectral analysis and responsiveness to tyramine. Low-frequency spectral power of systolic blood pressure was reduced postlesion and correlated with the diminished tyramine responsiveness (r=0.9572, P=0.0053). The tachycardia was abolished by treatment with the beta-antagonist propranolol, demonstrating that it was mediated by catecholamines acting on cardiac beta-receptors. Partial lesions of the autonomic nervous system have been hypothesized to underlie many disorders, including neuropathic postural tachycardia syndrome. This animal model may help us better understand the pathophysiology of autonomic dysfunction and lead to development of therapeutic interventions.

  17. A model for the assessment of the animal disease risks associated with the importation of animals and animal products.

    PubMed

    Morley, R S

    1993-12-01

    A simple mathematical model to assess the disease risks associated with the importation of animals and animal products is presented. This model is dependent on the animal health and disease statistics reported by the Member Countries of the Office International des Epizooties (OIE), and provides a structured approach to using information about a particular importation. The model can incorporate any number of determinants; these may be related to the animal health status of the exporting country, the commodity (whether animal or animal product), the properties of the disease agent and the epidemiology of the disease. All disease risks can be considered. Examples illustrate the model with respect to the importation of cattle, swine and related products. PMID:8312611

  18. Integrating population- and individual-level information in a movement model of Yellowstone bison.

    PubMed

    Geremia, C; White, P J; Hoeting, J A; Wallen, R L; Watson, F G R; Blanton, D; Hobbs, N T

    2014-03-01

    Throughout the world, fragmentation of landscapes by human activities has constrained the opportunity for large herbivores to migrate. Conflict between people and wildlife results when migrating animals transmit disease to livestock, damage property, and threaten human safety. Mitigating this conflict requires understanding the forces that shape migration patterns. Bison Bos bison migrating from Yellowstone National Park into the state of Montana during winter and spring concern ranchers on lands surrounding the park because bison can transmit brucellosis (Brucella abortus) to cattle. Migrations have been constrained, with bison being lethally removed or moved back into the park. We developed a state-space model to support decisions on bison management aimed at mitigating conflict with landowners outside the park. The model integrated recent GPS observations with 22 years (1990-2012) of aerial counts to forecast monthly distributions and identify factors driving migration. Wintering areas were located along decreasing elevation gradients, and bison accumulated in wintering areas prior to moving to areas progressively lower in elevation. Bison movements were affected by time since the onset of snowpack, snowpack magnitude, standing crop, and herd size. Migration pathways were increasingly used over time, suggesting that experience or learning influenced movements. To support adaptive management of Yellowstone bison, we forecast future movements to evaluate alternatives. Our approach of developing models capable of making explicit probabilistic forecasts of large herbivore movements and seasonal distributions is applicable to managing the migratory movements of large herbivores worldwide. These forecasts allow managers to develop and refine strategies in advance, and promote sound decision-making that reduces conflict as migratory animals come into contact with people.

  19. Assessing the impact of a cattle risk-based trading scheme on the movement of bovine tuberculosis infected animals in England and Wales.

    PubMed

    Adkin, A; Brouwer, A; Downs, S H; Kelly, L

    2016-01-01

    The adoption of bovine tuberculosis (bTB) risk-based trading (RBT) schemes has the potential to reduce the risk of bTB spread. However, any scheme will have cost implications that need to be balanced against its likely success in reducing bTB. This paper describes the first stochastic quantitative model assessing the impact of the implementation of a cattle risk-based trading scheme to inform policy makers and contribute to cost-benefit analyses. A risk assessment for England and Wales was developed to estimate the number of infected cattle traded using historic movement data recorded between July 2010 and June 2011. Three scenarios were implemented: cattle traded with no RBT scheme in place, voluntary provision of the score and a compulsory, statutory scheme applying a bTB risk score to each farm. For each scenario, changes in trade were estimated due to provision of the risk score to potential purchasers. An estimated mean of 3981 bTB infected animals were sold to purchasers with no RBT scheme in place in one year, with 90% confidence the true value was between 2775 and 5288. This result is dependent on the estimated between herd prevalence used in the risk assessment which is uncertain. With the voluntary provision of the risk score by farmers, on average, 17% of movements was affected (purchaser did not wish to buy once the risk score was available), with a reduction of 23% in infected animals being purchased initially. The compulsory provision of the risk score in a statutory scheme resulted in an estimated mean change to 26% of movements, with a reduction of 37% in infected animals being purchased initially, increasing to a 53% reduction in infected movements from higher risk sellers (score 4 and 5). The estimated mean reduction in infected animals being purchased could be improved to 45% given a 10% reduction in risky purchase behaviour by farmers which may be achieved through education programmes, or to an estimated mean of 49% if a rule was implemented

  20. Immune-mediated animal models of Tourette syndrome

    PubMed Central

    Hornig, Mady; Lipkin, W. Ian

    2014-01-01

    An autoimmune diathesis has been proposed in Tourette syndrome (TS) and related neuropsychiatric disorders such as obsessive-compulsive disorder, attention-deficit/hyperactivity disorder, autism and anorexia nervosa. Environmental triggers including infection and xenobiotics are hypothesized to lead to the production of brain-directed autoantibodies in a subset of genetically susceptible individuals. Although much work has focused on Group A Streptococcus (GAS), the role of this common childhood infection remains controversial. Animal model studies based on immune and autoantibody findings in TS have demonstrated immunoglobulin (Ig) deposits and stereotypic movements and related behavioral disturbances reminiscent of TS following exposure to GAS and other activators of host anti-microbial responses, soluble immune mediators and anti-GAS or anti-neuronal antibodies. Demonstration of the ability to recreate these abnormalities through passive transfer of serum IgG from GAS-immunized mice into naïve mice and abrogation of this activity through depletion of IgG has provided compelling evidence in support of the autoimmune hypothesis. Immunologically-based animal models of TS are a potent tool for dissecting the pathogenesis of this serious neuropsychiatric syndrome. PMID:23313649

  1. An Intermediate Animal Model of Spinal Cord Stimulation

    PubMed Central

    Guiho, Thomas; Coste, Christine Azevedo; Delleci, Claire; Chenu, Jean-Patrick; Vignes, Jean-Rodolphe; Bauchet, Luc; Guiraud, David

    2016-01-01

    Spinal cord injuries (SCI) result in the loss of movement and sensory feedback as well as organs dysfunctions. For example, nearly all SCI subjects loose their bladder control and are prone to kidney failure if they do not proceed to intermittent (self-) catheterization. Electrical stimulation of the sacral spinal roots with an implantable neuroprosthesis is a promising approach, with commercialized products, to restore continence and control micturition. However, many persons do not ask for this intervention since a surgical deafferentation is needed and the loss of sensory functions and reflexes become serious side effects of this procedure. Recent results renewed interest in spinal cord stimulation. Stimulation of existing pre-cabled neural networks involved in physiological processes regulation is suspected to enable synergic recruitment of spinal fibers. The development of direct spinal stimulation strategies aiming at bladder and bowel functions restoration would therefore appear as a credible alternative to existent solutions. However, a lack of suitable large animal model complicates these kinds of studies. In this article, we propose a new animal model of spinal stimulation -pig- and will briefly introduce results from one first acute experimental validation session. PMID:27478570

  2. Animal models in obesity and hypertension.

    PubMed

    Segal-Lieberman, Gabriella; Rosenthal, Talma

    2013-06-01

    Although obesity is a well-known risk factor for hypertension, the mechanisms by which hypertension develops in obese patients are not entirely clear. Animal models of obesity and their different susceptibilities to develop hypertension have revealed some of the mechanisms linking obesity and hypertension. Adipose tissue is an endocrine organ secreting hormones that impact blood pressure, such as elements of the renin-angiotensin system whose role in hypertension have been established. In addition, the appetite-suppressing adipokine leptin activates the sympathetic nervous system via the melanocortin system, and this activation, especially in the kidney, increases blood pressure. Leptin secretion from adipocytes is increased in most models of obesity due to leptin resistance, although the resistance is often selective to the anorexigenic effect, while the susceptibility to the hypertensive effect remains intact. Understanding the pathways by which obesity contributes to increased blood pressure will hopefully pave the way to and better define the appropriate treatment for obesity-induced hypertension.

  3. A model for nonexercising hindlimb muscles in exercising animals.

    PubMed

    Bonen, A; Blewett, C; McDermott, J C; Elder, G C

    1990-07-01

    Nonexercising muscles appear to be metabolically active during exercise. Animal models for this purpose have not been established. However, we have been able to teach animals to run on their forelimbs while their hindlimbs are suspended above the treadmill with no visible limb movement. To document that indeed this mode of exercise does not provoke additional muscle activity, we have compared the levels of neural activation of the soleus and plantaris muscles using a computer analysis of the electromyographic interference pattern, recorded from bipolar fine wire electrodes implanted across each muscle. Via computer analyses of the electromyographic interference patterns the frequencies and amplitudes of motor unit action potentials were obtained. The data were sampled during 20 s of every minute of observation. Comparisons were made in four conditions: (i) resting on the treadmill while bearing weight on the hindlimbs (normal rest), (ii) running on the treadmill (15 m/min, 8% grade) on all four limbs (normal exercise), (iii) resting while the hindlimbs were suspended in a harness above the treadmill (suspended rest), and (iv) exercising with the forelimbs (15 m/min, 8% grade) while the hindlimbs were suspended above the treadmill (suspended exercise). All four experimental conditions were carried out for 90 min each and were performed by each animal. The results clearly show that muscle activities (frequencies and amplitudes), when the hindlimbs are suspended above the treadmill, at rest or during exercise, are lower than the activities in these same muscles when the animals are at rest, supporting only their body weight. Activities in the same muscles during exercise were from 300 to 2000% greater than during hindlimb suspension.(ABSTRACT TRUNCATED AT 250 WORDS)

  4. A Simulation Model for Intra-Urban Movements

    PubMed Central

    Serok, Nimrod; Blumenfeld-Lieberthal, Efrat

    2015-01-01

    Human mobility patterns (HMP) have become of interest to a variety of disciplines. The increasing availability of empirical data enables researchers to analyze patterns of people’s movements. Recent work suggested that HMP follow a Levy-flight distribution and present regularity. Here, we present an innovative agent-based model that simulates HMP for various purposes. It is based on the combination of regular movements with spatial considerations, represented by an expanded gravitation model. The agents in this model have different attributes that affect their choice of destination and the duration they stay in each location. Thus, their movement mimics real-life situations. This is a stochastic, bottom-up model, yet it yields HMP that qualitatively fit HMP empirical data in terms of individuals, as well as the entire population. Our results also correspond to real-life phenomena in terms of urban spatial dynamics, that is, the emergence of popular locations in the city due to bottom-up behavior of people. Our model is novel in being based on the assumption that HMP are space-dependent as well as follow high regularity. To our knowledge, we are the first to succeed in simulating HMP not only at the inter-city scale but also at the intra-urban one. PMID:26161640

  5. Animal models of anxiety and benzodiazepine actions.

    PubMed

    Iversen, S D

    1980-01-01

    If rats trained to press a lever for food, then receive a shock to the feet following every response, their behavioural output is severely depressed. This procedure is termed immediately punishment and it was used by Geller and Seifter in the task devised to demonstrate the anxiolytic effect of benzodiazepines. These drugs and a number of others with anxiolytic activity (e. g. barbiturates, ethanol) reverse the suppression induced by the presentation of a highly aversive stimulus, like electric shock. The Geller-Seifter procedure has figured prominently in behavioural studies of benzodiazepines and in the efforts to determine the neuropharmacological basis of their anxiolytic action. Experiments involving the manipulation of brain noradrenaline (NA) and 5-hydroxytryptamine (5-HT) levels with drugs or lesions are discussed. The Geller-Seifter procedure is, however, a time consuming and difficult behavioural baseline to work with. It is important, therefore, to devise equally specific but simpler animal models of anxiety. Electric shock, as the anxiety-inducing event has dominated the tasks devised by behavioural psychologists. It is essential to search for more biologically relevant events with which to control the level of anxiety in experimental animals. Tests involving the manipulation of novelty and uncertainty will be presented and their responsiveness to anxiolytic drugs and neuropharmacological manipulation discussed. Recent advances in defining the biochemical and pharmacological properties of benzodiazepine receptors and particularly of their differential distribution in brain, makes it likely that simple reliable animal tests of anxiety would serve neuropharmacology well and be of great value in understanding the functional importance of the benzodiazepine receptors of brain.

  6. Bronze baby syndrome: an animal model.

    PubMed

    Jori, G; Reddi, E; Rubaltelli, F F

    1990-01-01

    We evaluated the appropriateness of an animal model for the bronze baby syndrome. Ligation of the common bile duct in adult Wistar rats induces an accumulation of porphyrins and copper in the liver and a 20% conversion of protoporphyrin IX into (Cu(II)-protoporphyrin IX. Upon irradiation of these animals with super-blue lamps, the plasma content of Cu(II)-protoporphyrin increases by about 30%. Cholestasis also increases the recovery of porphyrins in the urine, although light treatment of ligated rats further increases urinary porphyrin excretion. The spectroscopic changes induced by irradiation of sera of ligated rats are consistent with the formation of products that have the typical spectrum found in bronze baby syndrome patients, i.e. a reduced absorbance in the visible region and an increased absorption in near-UV and red spectral regions. The products responsible for the brown discoloration found in bronze baby syndrome seem to result from phototransformation of copper-porphyrins subsequent to an electron transfer between photoexcited bilirubin and the copper ion.

  7. Animal models for investigating chronic pancreatitis

    PubMed Central

    2011-01-01

    Chronic pancreatitis is defined as a continuous or recurrent inflammatory disease of the pancreas characterized by progressive and irreversible morphological changes. It typically causes pain and permanent impairment of pancreatic function. In chronic pancreatitis areas of focal necrosis are followed by perilobular and intralobular fibrosis of the parenchyma, by stone formation in the pancreatic duct, calcifications in the parenchyma as well as the formation of pseudocysts. Late in the course of the disease a progressive loss of endocrine and exocrine function occurs. Despite advances in understanding the pathogenesis no causal treatment for chronic pancreatitis is presently available. Thus, there is a need for well characterized animal models for further investigations that allow translation to the human situation. This review summarizes existing experimental models and distinguishes them according to the type of pathological stimulus used for induction of pancreatitis. There is a special focus on pancreatic duct ligation, repetitive overstimulation with caerulein and chronic alcohol feeding. Secondly, attention is drawn to genetic models that have recently been generated and which mimic features of chronic pancreatitis in man. Each technique will be supplemented with data on the pathophysiological background of the model and their limitations will be discussed. PMID:22133269

  8. Elucidating the significance of spatial memory on movement decisions by African savannah elephants using state–space models

    PubMed Central

    Polansky, Leo; Kilian, Werner; Wittemyer, George

    2015-01-01

    Spatial memory facilitates resource acquisition where resources are patchy, but how it influences movement behaviour of wide-ranging species remains to be resolved. We examined African elephant spatial memory reflected in movement decisions regarding access to perennial waterholes. State–space models of movement data revealed a rapid, highly directional movement behaviour almost exclusively associated with visiting perennial water. Behavioural change point (BCP) analyses demonstrated that these goal-oriented movements were initiated on average 4.59 km, and up to 49.97 km, from the visited waterhole, with the closest waterhole accessed 90% of the time. Distances of decision points increased when switching to different waterholes, during the dry season, or for female groups relative to males, while selection of the closest waterhole decreased when switching. Overall, our analyses indicated detailed spatial knowledge over large scales, enabling elephants to minimize travel distance through highly directional movement when accessing water. We discuss the likely cognitive and socioecological mechanisms driving these spatially precise movements that are most consistent with our findings. By applying modern analytic techniques to high-resolution movement data, this study illustrates emerging approaches for studying how cognition structures animal movement behaviour in different ecological and social contexts. PMID:25808888

  9. Elucidating the significance of spatial memory on movement decisions by African savannah elephants using state-space models.

    PubMed

    Polansky, Leo; Kilian, Werner; Wittemyer, George

    2015-04-22

    Spatial memory facilitates resource acquisition where resources are patchy, but how it influences movement behaviour of wide-ranging species remains to be resolved. We examined African elephant spatial memory reflected in movement decisions regarding access to perennial waterholes. State-space models of movement data revealed a rapid, highly directional movement behaviour almost exclusively associated with visiting perennial water. Behavioural change point (BCP) analyses demonstrated that these goal-oriented movements were initiated on average 4.59 km, and up to 49.97 km, from the visited waterhole, with the closest waterhole accessed 90% of the time. Distances of decision points increased when switching to different waterholes, during the dry season, or for female groups relative to males, while selection of the closest waterhole decreased when switching. Overall, our analyses indicated detailed spatial knowledge over large scales, enabling elephants to minimize travel distance through highly directional movement when accessing water. We discuss the likely cognitive and socioecological mechanisms driving these spatially precise movements that are most consistent with our findings. By applying modern analytic techniques to high-resolution movement data, this study illustrates emerging approaches for studying how cognition structures animal movement behaviour in different ecological and social contexts.

  10. Modeling basal ganglia for understanding Parkinsonian reaching movements.

    PubMed

    Magdoom, K N; Subramanian, D; Chakravarthy, V S; Ravindran, B; Amari, Shun-Ichi; Meenakshisundaram, N

    2011-02-01

    We present a computational model that highlights the role of basal ganglia (BG) in generating simple reaching movements. The model is cast within the reinforcement learning (RL) framework with correspondence between RL components and neuroanatomy as follows: dopamine signal of substantia nigra pars compacta as the temporal difference error, striatum as the substrate for the critic, and the motor cortex as the actor. A key feature of this neurobiological interpretation is our hypothesis that the indirect pathway is the explorer. Chaotic activity, originating from the indirect pathway part of the model, drives the wandering, exploratory movements of the arm. Thus, the direct pathway subserves exploitation, while the indirect pathway subserves exploration. The motor cortex becomes more and more independent of the corrective influence of BG as training progresses. Reaching trajectories show diminishing variability with training. Reaching movements associated with Parkinson's disease (PD) are simulated by reducing dopamine and degrading the complexity of indirect pathway dynamics by switching it from chaotic to periodic behavior. Under the simulated PD conditions, the arm exhibits PD motor symptoms like tremor, bradykinesia and undershooting. The model echoes the notion that PD is a dynamical disease. PMID:21105828

  11. Animal models for prenatal gene therapy: choosing the right model.

    PubMed

    Mehta, Vedanta; Peebles, Donald; David, Anna L

    2012-01-01

    Testing in animal models is an essential requirement during development of prenatal gene therapy for -clinical application. Some information can be derived from cell lines or cultured fetal cells, such as the efficiency of gene transfer and the vector dose that might be required. Fetal tissues can also be maintained in culture for short periods of time and transduced ex vivo. Ultimately, however, the use of animals is unavoidable since in vivo experiments allow the length and level of transgene expression to be measured, and provide an assessment of the effect of the delivery procedure and the gene therapy on fetal and neonatal development. The choice of animal model is determined by the nature of the disease and characteristics of the animal, such as its size, lifespan, and immunology, the number of fetuses and their development, parturition, and the length of gestation and the placentation. The availability of a disease model is also critical. In this chapter, we discuss the various animal models that can be used and consider how their characteristics can affect the results obtained. The projection to human application and the regulatory hurdles are also presented.

  12. Modeling of aquifer movement due to seismic and hydraulic forces

    NASA Astrophysics Data System (ADS)

    Xu, Aiguo

    A mathematical description of aquifer movement due to inertial and viscous forces is formulated by applying fundamental physical principles such as mass balance and momentum balance to a saturated aquifer system. An explicit interaction term in the momentum balance equation for the water phase sharing the same mathematical space with the solid phase introduced in the derivation of the governing equation system of aquifer movement distinguishes the development in this study from those of others such as Li's and that of Zienkiewicz and Bettess. The solid matrix is assumed to be a Helm-Li material which deforms as a highly non-linear viscous fluid rather than as the conventional poroelastic material. The finite element method is applied to solve three simplified situations: (a) negligible relative acceleration; (b) negligible acceleration of water; and (c) negligible bulk acceleration. Helm's bulk flux concept is applied in the simplifications. A computer code called Aquivis3d is developed in order to calculate the velocity and displacement of aquifer movement due to both inertial and viscous forces. Evaluation of the numerical model is accomplished by applying the code to different cases which include: standard laboratory consolidation tests; one dimensional radial movement of a Theis-Thiem aquifer; and a disturbance propagation. Simulation results favorably fit laboratory measurements for selected consolidation tests. Simulation results of one dimensional radial movement of a Theis-Thiem aquifer based in this study on poroviscosity are similar in general features to Helm's analytical results based on poroelasticity. Frequency dispersion and intensity attenuation of a disturbance propagation are fully simulated without any additional ad hoc damping assumption for dynamic aquifer movement. Sensitivity analyses are made for the viscous constitutive parameters and the hydraulic parameters in the consolidation and the one dimensional radial movement of a Theis

  13. Mousepox, a small animal model of smallpox.

    PubMed

    Esteban, David; Parker, Scott; Schriewer, Jill; Hartzler, Hollyce; Buller, R Mark

    2012-01-01

    Ectromelia virus infections in the laboratory mouse have emerged as a valuable model to investigate human orthopoxvirus infections to understand the progression of disease, to discover and characterize antiviral treatments, and to study the host-pathogen relationship as it relates to pathogenesis and the immune response. Here we describe how to safely work with the virus and protocols for common procedures for the study of ectromelia virus in the laboratory mouse including the preparation of virus stocks, the use of various routes of inoculation, and collection of blood and tissue from infected animals. In addition, several procedures are described for assessing the host response to infection: for example, measurement of virus-specific CD8 T cells and the use of ELISA and neutralization assays to measure orthopoxvirus-specific antibody titers.

  14. Eye-movement models for arithmetic and reading performance.

    PubMed

    Suppes, P

    1990-01-01

    Three stochastic eye-movement models for arithmetic and reading performance have been proposed, one for arithmetic and two for reading. Each model characterizes a real-time stochastic process in terms of fixation durations and saccadic movement, but only direction and length of saccades are considered, not acceleration or velocity. Aspects of the models that are emphasized, partly because of their general neglect in the literature, are the probability distribution of fixation durations and the random walk of saccade directions. The distributions of fixation duration are approximately exponential, but systematic deviations can be accounted for in the models, even though the fit to data is not perfect. In the case of the arithmetic algorithms of addition and subtraction, the random walk of the normative model has only two possible moves. Data are also presented on backtracking, skipping and wandering eye movements, each of which has a significant relative frequency. The first reading model is called a minimal control model, because it does not take account of the effects of many local variables, e.g., word length, that have been extensively studied. The axioms on fixation duration for the minimal control model are the same as for the arithmetic model. Abstracting from the different arrangement of stimuli in arithmetic algorithms and in linear text, the axioms on saccadic motion for the two models are also essentially identical. The stochastic nature of both models is strongly supported by data on the independence of fixation durations from previous fixation durations. Additional detailed evidence is presented for the arithmetic model. To better account for a great variety of experimental results concerning significant effects on eye movements in reading, a text-dependent probabilistic model of reading is introduced. Significant local effects fall into three classes, identified as line, word and grammatical variables. The revised axioms embody five features of text

  15. A framework for analyzing the robustness of movement models to variable step discretization.

    PubMed

    Schlägel, Ulrike E; Lewis, Mark A

    2016-10-01

    When sampling animal movement paths, the frequency at which location measurements are attempted is a critical feature for data analysis. Important quantities derived from raw data, e.g. travel distance or sinuosity, can differ largely based on the temporal resolution of the data. Likewise, when movement models are fitted to data, parameter estimates have been demonstrated to vary with sampling rate. Thus, biological statements derived from such analyses can only be made with respect to the resolution of the underlying data, limiting extrapolation of results and comparison between studies. To address this problem, we investigate whether there are models that are robust against changes in temporal resolution. First, we propose a mathematically rigorous framework, in which we formally define robustness as a model property. We then use the framework for a thorough assessment of a range of basic random walk models, in which we also show how robustness relates to other probabilistic concepts. While we found robustness to be a strong condition met by few models only, we suggest a new method to extend models so as to make them robust. Our framework provides a new systematic, mathematically founded approach to the question if, and how, sampling rate of movement paths affects statistical inference.

  16. Inverse Modelling to Obtain Head Movement Controller Signal

    NASA Technical Reports Server (NTRS)

    Kim, W. S.; Lee, S. H.; Hannaford, B.; Stark, L.

    1984-01-01

    Experimentally obtained dynamics of time-optimal, horizontal head rotations have previously been simulated by a sixth order, nonlinear model driven by rectangular control signals. Electromyography (EMG) recordings have spects which differ in detail from the theoretical rectangular pulsed control signal. Control signals for time-optimal as well as sub-optimal horizontal head rotations were obtained by means of an inverse modelling procedures. With experimentally measured dynamical data serving as the input, this procedure inverts the model to produce the neurological control signals driving muscles and plant. The relationships between these controller signals, and EMG records should contribute to the understanding of the neurological control of movements.

  17. Peroxisome deficient invertebrate and vertebrate animal models

    PubMed Central

    Van Veldhoven, Paul P.; Baes, Myriam

    2013-01-01

    Although peroxisomes are ubiquitous organelles in all animal species, their importance for the functioning of tissues and organs remains largely unresolved. Because peroxins are essential for the biogenesis of peroxisomes, an obvious approach to investigate their physiological role is to inactivate a Pex gene or to suppress its translation. This has been performed in mice but also in more primitive organisms including D. melanogaster, C. elegans, and D. rerio, and the major findings and abnormalities in these models will be highlighted. Although peroxisomes are generally not essential for embryonic development and organogenesis, a generalized inactivity of peroxisomes affects lifespan and posthatching/postnatal growth, proving that peroxisomal metabolism is necessary for the normal maturation of these organisms. Strikingly, despite the wide variety of model organisms, corresponding tissues are affected including the central nervous system and the testis. By inactivating peroxisomes in a cell type selective way in the brain of mice, it was also demonstrated that peroxisomes are necessary to prevent neurodegeneration. As these peroxisome deficient model organisms recapitulate pathologies of patients affected with peroxisomal diseases, their further analysis will contribute to the elucidation of still elusive pathogenic mechanisms. PMID:24319432

  18. Animal models of tumorigenic herpesviruses--an update.

    PubMed

    Dittmer, Dirk P; Damania, Blossom; Sin, Sang-Hoon

    2015-10-01

    Any one model system, be it culture or animal, only recapitulates one aspect of the viral life cycle in the human host. By providing recent examples of animal models for Epstein-Barr virus and Kaposi sarcoma-associated herpesvirus, we would argue that multiple animal models are needed to gain a comprehensive understanding of the pathogenesis associated with human oncogenic herpesviruses. Transgenic mice, homologous animal herpesviruses, and tumorgraft and humanized mouse models all complement each other in the study of viral pathogenesis. The use of animal model systems facilitates the exploration of novel anti-viral and anti-cancer treatment modalities for diseases associated with oncogenic herpesviruses. PMID:26476352

  19. Animal Model of Acute Deep Vein Thrombosis

    SciTech Connect

    Roy, Sumit; Laerum, Frode; Brosstad, Frank; Kvernebo, Knut; Sakariassen, Kjell S.

    1998-07-15

    Purpose: To develop an animal model of acute deep vein thrombosis (DVT). Methods: In part I of the study nine juvenile domestic pigs were used. Each external iliac vein was transluminally occluded with a balloon catheter. Thrombin was infused through a microcatheter in one leg according to one of the following protocols: (1) intraarterial (IA): 1250 U at 25 U/min in the common femoral artery (n= 3); (2) intravenous (IV): 5000 U in the popliteal vein at 500 U/min (n= 3), or at 100 U/min (n= 3). Saline was administered in the opposite leg. After the animals were killed, the mass of thrombus in the iliofemoral veins was measured. The pudendoepiploic (PEV), profunda femoris (PF), and popliteal veins (PV) were examined. Thrombosis in the tributaries of the superficial femoral vein (SFVt) was graded according to a three-point scale (0, +, ++). In part II of the study IV administration was further investigated in nine pigs using the following three regimens with 1000 U at 25 U/min serving as the control: (1) 1000 U at 100 U/min, (2) 250 U at 25 U/min, (3) 250 U at 6.25 U/min. Results: All animals survived. In part I median thrombus mass in the test limbs was 1.40 g as compared with 0.25 g in the controls (p= 0.01). PEV, PFV and PV were thrombosed in all limbs infused with thrombin. IV infusion was more effective in inducing thrombosis in both the parent veins (mass 1.32-1.78 g) and SVFt (++ in 4 of 6 legs), as compared with IA infusion (mass 0.0-1.16 g; SFVt ++ in 1 of 3 legs). In part II thrombus mass in axial veins ranged from 1.23 to 2.86 g, and showed no relationship with the dose of thrombin or the rate of infusion. Tributary thrombosis was less extensive with 250 U at 25 U/min than with the other regimens. Conclusion: Slow distal intravenous thrombin infusion in the hind legs of pigs combined with proximal venous occlusion induces thrombosis in the leg veins that closely resembles clinical DVT in distribution.

  20. RASopathies: unraveling mechanisms with animal models

    PubMed Central

    Jindal, Granton A.; Goyal, Yogesh; Burdine, Rebecca D.; Rauen, Katherine A.; Shvartsman, Stanislav Y.

    2015-01-01

    ABSTRACT RASopathies are developmental disorders caused by germline mutations in the Ras-MAPK pathway, and are characterized by a broad spectrum of functional and morphological abnormalities. The high incidence of these disorders (∼1/1000 births) motivates the development of systematic approaches for their efficient diagnosis and potential treatment. Recent advances in genome sequencing have greatly facilitated the genotyping and discovery of mutations in affected individuals, but establishing the causal relationships between molecules and disease phenotypes is non-trivial and presents both technical and conceptual challenges. Here, we discuss how these challenges could be addressed using genetically modified model organisms that have been instrumental in delineating the Ras-MAPK pathway and its roles during development. Focusing on studies in mice, zebrafish and Drosophila, we provide an up-to-date review of animal models of RASopathies at the molecular and functional level. We also discuss how increasingly sophisticated techniques of genetic engineering can be used to rigorously connect changes in specific components of the Ras-MAPK pathway with observed functional and morphological phenotypes. Establishing these connections is essential for advancing our understanding of RASopathies and for devising rational strategies for their management and treatment. PMID:26203125

  1. Instrumental learning: an animal model for sleep dependent memory enhancement.

    PubMed

    Leenaars, Cathalijn H C; Girardi, Carlos E N; Joosten, Ruud N J M A; Lako, Irene M; Ruimschotel, Emma; Hanegraaf, Maaike A J; Dematteis, Maurice; Feenstra, Matthijs G P; Van Someren, Eus J W

    2013-07-15

    The relationship between learning and sleep is multifaceted; learning influences subsequent sleep characteristics, which may in turn influence subsequent memory. Studies in humans indicate that sleep may not only prevent degradation of acquired memories, but even enhance performance without further practice. In a rodent instrumental learning task, individual differences occur in how fast rats learn to associate lever pressing with food reward. Rats habitually sleep between learning sessions, and may differ in this respect. The current study assessed if the instrumental leaning paradigm could serve as a model to study sleep-dependent memory enhancement. Male Wistar rats performed 2 sessions of instrumental learning per day for 1-3 days. Electroencephalography was recorded both before and after the sessions. Sleep deprivation (3 h) was applied between the first and second session in a subgroup of rats. Measurements comprised the number of lever presses in each session, slow wave sleep (SWS) duration, Rapid Eye Movement Sleep (REMS) duration and sleep spindles. Baseline sleep parameters were similar for fast and slow learning rats. Task-exposure increased REMS-duration. The increase in REMS-duration was observed specifically after sessions in which learning occurred, but not after a later session. Sleep deprivation during the 3h period between the initial two sessions interfered with performance enhancement, but did not prevent this in all rats. Our considered movement control protocol induced partial sleep deprivation and also interfered with performance enhancement. The classic instrumental learning task provides a practical model for animal studies on sleep-dependent memory enhancement.

  2. A quantitative release assessment for the noncommercial movement of companion animals: risk of rabies reintroduction to the United kingdom.

    PubMed

    Goddard, A D; Donaldson, N M; Horton, D L; Kosmider, R; Kelly, L A; Sayers, A R; Breed, A C; Freuling, C M; Müller, T; Shaw, S E; Hallgren, G; Fooks, A R; Snary, E L

    2012-10-01

    In 2004, the European Union (EU) implemented a pet movement policy (referred to here as the EUPMP) under EU regulation 998/2003. The United Kingdom (UK) was granted a temporary derogation from the policy until December 2011 and instead has in place its own Pet Movement Policy (Pet Travel Scheme (PETS)). A quantitative risk assessment (QRA) was developed to estimate the risk of rabies introduction to the UK under both schemes to quantify any change in the risk of rabies introduction should the UK harmonize with the EU policy. Assuming 100 % compliance with the regulations, moving to the EUPMP was predicted to increase the annual risk of rabies introduction to the UK by approximately 60-fold, from 7.79 × 10(-5) (5.90 × 10(-5), 1.06 × 10(-4)) under the current scheme to 4.79 × 10(-3) (4.05 × 10(-3), 5.65 × 10(-3)) under the EUPMP. This corresponds to a decrease from 13,272 (9,408, 16,940) to 211 (177, 247) years between rabies introductions. The risks associated with both the schemes were predicted to increase when less than 100 % compliance was assumed, with the current scheme of PETS and quarantine being shown to be particularly sensitive to noncompliance. The results of this risk assessment, along with other evidence, formed a scientific evidence base to inform policy decision with respect to companion animal movement.

  3. Goats as an osteopenic animal model.

    PubMed

    Leung, K S; Siu, W S; Cheung, N M; Lui, P Y; Chow, D H; James, A; Qin, L

    2001-12-01

    A large osteopenic animal model that resembles human osteoporotic changes is essential for osteoporosis research. This study aimed at establishing a large osteopenic animal model in goats. Twenty-five Chinese mountain goats were used in which they were either ovariectomized (OVX) and fed with a low-calcium diet (n = 16) or sham-operated (SHAM; n = 9). Monthly photodensitometric analysis on proximal tibial metaphysis and calcaneus was performed. Two iliac crest biopsy specimens obtained before and 6 months after OVX were used for bone mineral density (BMD) measurement with peripheral quantitative computed tomography (pQCT). Lumbar vertebrae (L2 and L7), humeral heads, and calcanei were collected for BMD measurement after euthanasia. The humeral heads and calcanei were used in biomechanical indentation test. BMD measurement showed a significant 25.0% (p = 0.006) decrease in BMD of the iliac crest biopsy specimens 6 months after OVX. It also was statistically significant when compared with the SHAM (p = 0.028). BMD at L2, L7, calcaneus, and humeral head reduced by 24-33% (p ranged from 0.001 to 0.011) when compared with the SHAM. Photodensitometry showed a continuous decrease in bone density after OVX. There were significant decreases of 18.9% in proximal tibial metaphysis (p = 0.003) and 21.8% in calcaneus (p = 0.023) in the OVX group 6 months postoperatively. Indentation test on the humeral head and calcaneus showed a significant decrease 52% (p = 0.006) and 54% (p = 0.001), respectively, in energy required for displacement of 3 mm in the OVX group compared with the SHAM group. The decreases correlated significantly to the decrease in BMD of the corresponding specimens (r2 = 0.439 and 0.581; p < 0.001 for both). In conclusion, this study showed that OVX plus a low-calcium diet could induce significant osteopenia and deterioration of mechanical properties of the cancellous bone in goats.

  4. 9 CFR 94.15 - Animal products and materials; movement and handling.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... FEVER, SWINE VESICULAR DISEASE, AND BOVINE SPONGIFORM ENCEPHALOPATHY: PROHIBITED AND RESTRICTED... Act (7 U.S.C. 8301 et seq.). (d) Meat and other products of ruminants or swine from regions listed in... part are met. (e) Any meat or other animal products not otherwise eligible for entry into the...

  5. Biology Notes: How the Skeleton Functions in the Movement of Animals

    ERIC Educational Resources Information Center

    Worsley, C. J.

    1972-01-01

    Argues that the term skeleton is not a word denoting a structure but a word denoting a function--that of allowing animals the freedom of self-motivated purposive local motion. Indeed a skeleton is a necessary prerequisite for there to be locomotion at all.'' (Author/AL)

  6. Quantifying the risk of localised animal movement bans for foot-and-mouth disease.

    PubMed

    Schley, David; Gubbins, Simon; Paton, David J

    2009-01-01

    The maintenance of disease-free status from Foot-and-Mouth Disease is of significant socio-economic importance to countries such as the UK. The imposition of bans on the movement of susceptible livestock following the discovery of an outbreak is deemed necessary to prevent the spread of what is a highly contagious disease, but has a significant economic impact on the agricultural community in itself. Here we consider the risk of applying movement restrictions only in localised zones around outbreaks in order to help evaluate how quickly nation-wide restrictions could be lifted after notification. We show, with reference to the 2001 and 2007 UK outbreaks, that it would be practical to implement such a policy provided the basic reproduction ratio of known infected premises can be estimated. It is ultimately up to policy makers and stakeholders to determine the acceptable level of risk, involving a cost benefit analysis of the potential outcomes, but quantifying the risk of spread from different sized zones is a prerequisite for this. The approach outlined is relevant to the determination of control zones and vaccination policies and has the potential to be applied to future outbreaks of other diseases.

  7. Modeling rapid mass movements using the shallow water equations

    NASA Astrophysics Data System (ADS)

    Hergarten, S.; Robl, J.

    2014-11-01

    We propose a new method to model rapid mass movements on complex topography using the shallow water equations in Cartesian coordinates. These equations are the widely used standard approximation for the flow of water in rivers and shallow lakes, but the main prerequisite for their application - an almost horizontal fluid table - is in general not satisfied for avalanches and debris flows in steep terrain. Therefore, we have developed appropriate correction terms for large topographic gradients. In this study we present the mathematical formulation of these correction terms and their implementation in the open source flow solver GERRIS. This novel approach is evaluated by simulating avalanches on synthetic and finally natural topographies and the widely used Voellmy flow resistance law. The results are tested against analytical solutions and the commercial avalanche model RAMMS. The overall results are in excellent agreement with the reference system RAMMS, and the deviations between the different models are far below the uncertainties in the determination of the relevant fluid parameters and involved avalanche volumes in reality. As this code is freely available and open source, it can be easily extended by additional fluid models or source areas, making this model suitable for simulating several types of rapid mass movements. It therefore provides a valuable tool assisting regional scale natural hazard studies.

  8. A highly predictable animal model of retinoblastoma.

    PubMed

    Kobayashi, M; Mukai, N; Solish, S P; Pomeroy, M E

    1982-01-01

    A new animal model of retinoblastoma was developed in newborn inbred CDF rats by intravitreous inoculation of retinal tumor cells (5 X 10(4)/5 microliter) derived from the cultured tumor cell line EXP-5. The retinal tumor from which the cell line originated was induced by a single intravitreous inoculation of human adenovirus serotype 12 (5 microliter of 10(8) TCID 50/0.1 ml) in syngeneic rats. Within 1 month after intravitreous inoculation of EXP-5 cells, a clinically recognizable ocular tumor was obtained in all 39 rats. Ad 12-specific T-antigens were demonstrated in the cultured tumor cells using immunofluorescent techniques. Morphologically these tumor cells closely resembled retinoblastoma, with poorly differentiated intracytoplasmic organelles, solitary cilia with a 9 + 0 tubule pattern, and abnormal nuclear membrane associated with a set of basal bodies. The significance of this highly manipulable retinal tumor cell line is the capability of providing a full-fledged intravitreous tumor in 1-month-old CDF rats, whose actual life span is known to be 42 months. Transplantable retinal tumors described to date are reviewed briefly and compared with the presently reported cell line.

  9. Animal model of Mycoplasma fermentans respiratory infection

    PubMed Central

    2013-01-01

    Background Mycoplasma fermentans has been associated with respiratory, genitourinary tract infections and rheumatoid diseases but its role as pathogen is controversial. The purpose of this study was to probe that Mycoplasma fermentans is able to produce respiratory tract infection and migrate to several organs on an experimental infection model in hamsters. One hundred and twenty six hamsters were divided in six groups (A-F) of 21 hamsters each. Animals of groups A, B, C were intratracheally injected with one of the mycoplasma strains: Mycoplasma fermentans P 140 (wild strain), Mycoplasma fermentans PG 18 (type strain) or Mycoplasma pneumoniae Eaton strain. Groups D, E, F were the negative, media, and sham controls. Fragments of trachea, lungs, kidney, heart, brain and spleen were cultured and used for the histopathological study. U frequency test was used to compare recovery of mycoplasmas from organs. Results Mycoplasmas were detected by culture and PCR. The three mycoplasma strains induced an interstitial pneumonia; they also migrated to several organs and persisted there for at least 50 days. Mycoplasma fermentans P 140 induced a more severe damage in lungs than Mycoplasma fermentans PG 18. Mycoplasma pneumoniae produced severe damage in lungs and renal damage. Conclusions Mycoplasma fermentans induced a respiratory tract infection and persisted in different organs for several weeks in hamsters. This finding may help to explain the ability of Mycoplasma fermentans to induce pneumonia and chronic infectious diseases in humans. PMID:23298636

  10. The maternal deprivation animal model revisited.

    PubMed

    Marco, Eva M; Llorente, Ricardo; López-Gallardo, Meritxell; Mela, Virginia; Llorente-Berzal, Álvaro; Prada, Carmen; Viveros, María-Paz

    2015-04-01

    Early life stress, in the form of MD (24h at pnd 9), interferes with brain developmental trajectories modifying both behavioral and neurobiochemical parameters. MD has been reported to enhance neuroendocrine responses to stress, to affect emotional behavior and to impair cognitive function. More recently, changes in body weight gain, metabolic parameters and immunological responding have also been described. Present data give support to the fact that neuronal degeneration and/or astrocyte proliferation are present in specific brain regions, mainly hippocampus, prefrontal cortex and hypothalamus, which are particularly vulnerable to the effects of neonatal stress. The MD animal model arises as a valuable tool for the investigation of the brain processes occurring at the narrow time window comprised between pnd 9 and 10 that are critical for the establishment of brain circuitries critical for the regulation of behavior, metabolism and energy homeostasis. In the present review we will discuss three possible mechanisms that might be crucial for the effects of MD, namely, the rapid increase in glucocorticoids, the lack of the neonatal leptin surge, and the enhanced endocannabinoid signaling during the specific critical period of MD. A better understanding of the mechanisms underlying the detrimental consequences of MD is a concern for public health and may provide new insights into mental health prevention strategies and into novel therapeutic approaches in neuropsychiatry. PMID:25616179

  11. The maternal deprivation animal model revisited.

    PubMed

    Marco, Eva M; Llorente, Ricardo; López-Gallardo, Meritxell; Mela, Virginia; Llorente-Berzal, Álvaro; Prada, Carmen; Viveros, María-Paz

    2015-04-01

    Early life stress, in the form of MD (24h at pnd 9), interferes with brain developmental trajectories modifying both behavioral and neurobiochemical parameters. MD has been reported to enhance neuroendocrine responses to stress, to affect emotional behavior and to impair cognitive function. More recently, changes in body weight gain, metabolic parameters and immunological responding have also been described. Present data give support to the fact that neuronal degeneration and/or astrocyte proliferation are present in specific brain regions, mainly hippocampus, prefrontal cortex and hypothalamus, which are particularly vulnerable to the effects of neonatal stress. The MD animal model arises as a valuable tool for the investigation of the brain processes occurring at the narrow time window comprised between pnd 9 and 10 that are critical for the establishment of brain circuitries critical for the regulation of behavior, metabolism and energy homeostasis. In the present review we will discuss three possible mechanisms that might be crucial for the effects of MD, namely, the rapid increase in glucocorticoids, the lack of the neonatal leptin surge, and the enhanced endocannabinoid signaling during the specific critical period of MD. A better understanding of the mechanisms underlying the detrimental consequences of MD is a concern for public health and may provide new insights into mental health prevention strategies and into novel therapeutic approaches in neuropsychiatry.

  12. Varicocele-Induced Infertility in Animal Models

    PubMed Central

    Razi, Mazdak; Malekinejad, Hassan

    2015-01-01

    Varicocele is characterized by abnormal tortuosity and dilation of the veins of the pampiniform plexus within the spermatic cord. Although several reports show the mechanisms by which the varicocele exerts its infertility impact, the exact pathophysiology for varicocele-induced inflammation and its relationship with testicular endocrine disruption remain largely unknown. This review article will update previous findings by discussing the pathophysiology of long term-induced varicocele in rats. Testicular endocrine disruption in experimentally-induced varicocele, new findings related to biochemical alterations in germinal epithelium, and sperm cells apoptosis are highlighted. Recent observations show that varicocele down-regulates first and second maturation divisions, results in Leydig and Sertoli cell inflammation, and increases immune cell infiltration in the testes of the rat as an animal model. Ultimately, previous findings of our laboratory have revealed that varicocele decreased sperm motility, viability and severe DNA damage. Damage in sperm significantly lowers the animal’s fertility potential. Varicocele not only exerts its pathologic impact by lowering the testicular antioxidant capacity but it also down-regulates first and second maturation divisions by exerting biochemical alterations such as reducing the intracytoplasmic carbohydrate ratio in germinal epithelium. PMID:26246871

  13. What future for Lévy walks in animal movement research?. Comment on "Liberating Lévy walk research from the shackles of optimal foraging", by A.M. Reynolds

    NASA Astrophysics Data System (ADS)

    Boyer, Denis

    2015-09-01

    Due to the apparent erratic nature of animal trajectories, the standard random walk, including variants like the correlated random walk (CRW), represents a natural framework for modeling animal movement [1]. The complexity of movement decisions is reduced to a stochastic noise for the sake of simplicity. This approach can be further simplified thanks to the Markov hypothesis, which is very popular. Namely, if one also assumes that successive displacements are independent, or if memory decays sufficiently fast over time like in the CRW, the theory of random walks becomes relatively friendly and easy to apply. Not less relevant to animal mobility are non-Markovian processes, though, in particular self-repulsing and self-attracting random walks, which commonly model ants and bacteria movements [2]. These stochastic processes, arguably more realistic in many situations and with rich emerging properties, have not found their place (yet?) in the dominant animal movement paradigm. More because of their formidable mathematical complexity than their lack of relevance, probably.

  14. Predicting local and non-local effects of resources on animal space use using a mechanistic step selection model

    PubMed Central

    Potts, Jonathan R; Bastille-Rousseau, Guillaume; Murray, Dennis L; Schaefer, James A; Lewis, Mark A

    2014-01-01

    Predicting space use patterns of animals from their interactions with the environment is fundamental for understanding the effect of habitat changes on ecosystem functioning. Recent attempts to address this problem have sought to unify resource selection analysis, where animal space use is derived from available habitat quality, and mechanistic movement models, where detailed movement processes of an animal are used to predict its emergent utilization distribution. Such models bias the animal's movement towards patches that are easily available and resource-rich, and the result is a predicted probability density at a given position being a function of the habitat quality at that position. However, in reality, the probability that an animal will use a patch of the terrain tends to be a function of the resource quality in both that patch and the surrounding habitat. We propose a mechanistic model where this non-local effect of resources naturally emerges from the local movement processes, by taking into account the relative utility of both the habitat where the animal currently resides and that of where it is moving. We give statistical techniques to parametrize the model from location data and demonstrate application of these techniques to GPS location data of caribou (Rangifer tarandus) in Newfoundland. Steady-state animal probability distributions arising from the model have complex patterns that cannot be expressed simply as a function of the local quality of the habitat. In particular, large areas of good habitat are used more intensively than smaller patches of equal quality habitat, whereas isolated patches are used less frequently. Both of these are real aspects of animal space use missing from previous mechanistic resource selection models. Whilst we focus on habitats in this study, our modelling framework can be readily used with any environmental covariates and therefore represents a unification of mechanistic modelling and step selection approaches to

  15. Zebrafish: A complete animal model to enumerate the nanoparticle toxicity.

    PubMed

    Chakraborty, Chiranjib; Sharma, Ashish Ranjan; Sharma, Garima; Lee, Sang-Soo

    2016-01-01

    Presently, nanotechnology is a multi-trillion dollar business sector that covers a wide range of industries, such as medicine, electronics and chemistry. In the current era, the commercial transition of nanotechnology from research level to industrial level is stimulating the world's total economic growth. However, commercialization of nanoparticles might offer possible risks once they are liberated in the environment. In recent years, the use of zebrafish (Danio rerio) as an established animal model system for nanoparticle toxicity assay is growing exponentially. In the current in-depth review, we discuss the recent research approaches employing adult zebrafish and their embryos for nanoparticle toxicity assessment. Different types of parameters are being discussed here which are used to evaluate nanoparticle toxicity such as hatching achievement rate, developmental malformation of organs, damage in gill and skin, abnormal behavior (movement impairment), immunotoxicity, genotoxicity or gene expression, neurotoxicity, endocrine system disruption, reproduction toxicity and finally mortality. Furthermore, we have also highlighted the toxic effect of different nanoparticles such as silver nanoparticle, gold nanoparticle, and metal oxide nanoparticles (TiO2, Al2O3, CuO, NiO and ZnO). At the end, future directions of zebrafish model and relevant assays to study nanoparticle toxicity have also been argued. PMID:27544212

  16. Systematic Review of Traumatic Brain Injury Animal Models.

    PubMed

    Phipps, Helen W

    2016-01-01

    The goals of this chapter are to provide an introduction into the variety of animal models available for studying traumatic brain injury (TBI) and to provide a concise systematic review of the general materials and methods involved in each model. Materials and methods were obtained from a literature search of relevant peer-reviewed articles. Strengths and weaknesses of each animal choice were presented to include relative cost, anatomical and physiological features, and mechanism of injury desired. Further, a variety of homologous, isomorphic/induced, and predictive animal models were defined, described, and compared with respect to their relative ease of use, characteristics, range, adjustability (e.g., amplitude, duration, mass/size, velocity, and pressure), and rough order of magnitude cost. Just as the primary mechanism of action of TBI is limitless, so are the animal models available to study TBI. With such a wide variety of available animals, types of injury models, along with the research needs, there exists no single "gold standard" model of TBI rendering cross-comparison of data extremely difficult. Therefore, this chapter reflects a representative sampling of the TBI animal models available and is not an exhaustive comparison of every possible model and associated parameters. Throughout this chapter, special considerations for animal choice and TBI animal model classification are discussed. Criteria central to choosing appropriate animal models of TBI include ethics, funding, complexity (ease of use, safety, and controlled access requirements), type of model, model characteristics, and range of control (scope). PMID:27604713

  17. Animal models of rheumatoid arthritis: How informative are they?

    PubMed

    McNamee, Kay; Williams, Richard; Seed, Michael

    2015-07-15

    Animal models of arthritis are widely used to de-convolute disease pathways and to identify novel drug targets and therapeutic approaches. However, the high attrition rates of drugs in Phase II/III rates means that a relatively small number of drugs reach the market, despite showing efficacy in pre-clinical models. There is also increasing awareness of the ethical issues surrounding the use of animal models of disease and it is timely, therefore, to review the relevance and translatability of animal models of arthritis. In this paper we review the most commonly used animal models in terms of their pathological similarities to human rheumatoid arthritis as well as their response to drug therapy. In general, the ability of animal models to predict efficacy of biologics in man has been good. However, the predictive power of animal models for small molecules has been variable, probably because of differences in the levels of target knockdown achievable in vivo.

  18. Animal models in virus research: their utility and limitations.

    PubMed

    Louz, Derrick; Bergmans, Hans E; Loos, Birgit P; Hoeben, Rob C

    2013-11-01

    Viral diseases are important threats to public health worldwide. With the number of emerging viral diseases increasing the last decades, there is a growing need for appropriate animal models for virus studies. The relevance of animal models can be limited in terms of mimicking human pathophysiology. In this review, we discuss the utility of animal models for studies of influenza A viruses, HIV and SARS-CoV in light of viral emergence, assessment of infection and transmission risks, and regulatory decision making. We address their relevance and limitations. The susceptibility, immune responses, pathogenesis, and pharmacokinetics may differ between the various animal models. These complexities may thwart translating results from animal experiments to the humans. Within these constraints, animal models are very informative for studying virus immunopathology and transmission modes and for translation of virus research into clinical benefit. Insight in the limitations of the various models may facilitate further improvements of the models.

  19. Modeling loggerhead turtle movement in the Mediterranean: importance of body size and oceanography.

    PubMed

    Eckert, Scott A; Moore, Jeffrey E; Dunn, Daniel C; van Buiten, Ricardo Sagarminaga; Eckert, Karen L; Halpin, Patrick N

    2008-03-01

    Adapting state-space models (SSMs) to telemetry data has been helpful for dealing with location error and for modeling animal movements. We used a combination of two hierarchical Bayesian SSMs to estimate movement pathways from Argos satellite-tag data for 15 juvenile loggerhead turtles (Caretta caretta) in the western Mediterranean Sea, and to probabilistically assign locations to one of two behavioral movement types and relate those behaviors to environmental features. A Monte Carlo procedure helped propagate location uncertainty from the first SSM into the estimation of behavioral states and environment--behavior relationships in the second SSM. Turtles using oceanic habitats of the Balearic Sea (n = 9 turtles) within the western Mediterranean were more likely to exhibit "intensive search" behavior as might occur during foraging, but only larger turtles responded to variations in sea-surface height. This suggests that they were better able than smaller turtles to cue on environmental features that concentrate prey resources or were more dependent on high-quality feeding areas. These findings stress the importance of individual heterogeneity in the analysis of movement behavior and, taken in concert with descriptive studies of Pacific loggerheads, suggest that directed movements toward patchy ephemeral resources may be a general property of larger juvenile loggerheads in different populations. We discovered size-based variation in loggerhead distribution and documented use of the western Mediterranean Sea by turtles larger than previously thought to occur there. With one exception, only individuals > 57 cm curved carapace length used the most westerly basin in the Mediterranean (western Alborán Sea). These observations shed new light on loggerhead migration phenology.

  20. A bayesian approach for modeling cattle movements in the United States: scaling up a partially observed network.

    PubMed

    Lindström, Tom; Grear, Daniel A; Buhnerkempe, Michael; Webb, Colleen T; Miller, Ryan S; Portacci, Katie; Wennergren, Uno

    2013-01-01

    Networks are rarely completely observed and prediction of unobserved edges is an important problem, especially in disease spread modeling where networks are used to represent the pattern of contacts. We focus on a partially observed cattle movement network in the U.S. and present a method for scaling up to a full network based on bayesian inference, with the aim of informing epidemic disease spread models in the United States. The observed network is a 10% state stratified sample of Interstate Certificates of Veterinary Inspection that are required for interstate movement; describing approximately 20,000 movements from 47 of the contiguous states, with origins and destinations aggregated at the county level. We address how to scale up the 10% sample and predict unobserved intrastate movements based on observed movement distances. Edge prediction based on a distance kernel is not straightforward because the probability of movement does not always decline monotonically with distance due to underlying industry infrastructure. Hence, we propose a spatially explicit model where the probability of movement depends on distance, number of premises per county and historical imports of animals. Our model performs well in recapturing overall metrics of the observed network at the node level (U.S. counties), including degree centrality and betweenness; and performs better compared to randomized networks. Kernel generated movement networks also recapture observed global network metrics, including network size, transitivity, reciprocity, and assortativity better than randomized networks. In addition, predicted movements are similar to observed when aggregated at the state level (a broader geographic level relevant for policy) and are concentrated around states where key infrastructures, such as feedlots, are common. We conclude that the method generally performs well in predicting both coarse geographical patterns and network structure and is a promising method to generate full

  1. Modeling individual animal histories with multistate capture–recapture models

    USGS Publications Warehouse

    Lebreton, Jean-Dominique; Nichols, James D.; Barker, Richard J.; Pradel, Roger; Spendelow, Jeffrey A.

    2009-01-01

    Many fields of science begin with a phase of exploration and description, followed by investigations of the processes that account for observed patterns. The science of ecology is no exception, and recent decades have seen a focus on understanding key processes underlying the dynamics of ecological systems. In population ecology, emphasis has shifted from the state variable of population size to the demographic processes responsible for changes in this state variable: birth, death, immigration, and emigration. In evolutionary ecology, some of these same demographic processes, rates of birth and death, are also the determinants of fitness. In animal population ecology, the estimation of state variables and their associated vital rates is especially problematic because of the difficulties in sampling such populations and detecting individual animals. Indeed, early capture–recapture models were developed for the purpose of estimating population size, given the reality that all animals are not caught or detected at any sampling occasion. More recently, capture–recapture models for open populations were developed to draw inferences about survival in the face of these same sampling problems. The focus of this paper is on multi‐state mark–recapture models (MSMR), which first appeared in the 1970s but have undergone substantial development in the last 15 years. These models were developed to deal explicitly with biological variation, in that animals in different “states” (classes defined by location, physiology, behavior, reproductive status, etc.) may have different probabilities of survival and detection. Animal transitions between states are also stochastic and themselves of interest. These general models have proven to be extremely useful and provide a way of thinking about a remarkably wide range of important ecological processes. These methods are now at a stage of refinement and sophistication where they can readily be used by biologists to tackle a wide

  2. A Mathematical Model of the Cervical Spine Movement

    NASA Astrophysics Data System (ADS)

    Toth-Tascau, Mirela; Pater, Flavius; Stoia, Dan Ioan; Menyhardt, Karoly; Rosu, Serban; Rusu, Lucian; Vigaru, Cosmina

    2011-09-01

    The general purpose of this study was to develop a valid and reliable laboratory tool to evaluate the cervical spine mobility in normal conditions. The paper proposes an approximation function to model the variation in time of movement angles and angular velocities. The measurements have been performed using a Zebris ultrasound-based measuring system in Motion Laboratory of the "Politehnica" University of Timisoara. The approximation functions were compared with the recorded data series and graphically plotted as both time and phase diagram representation.

  3. An animal model for chorioamnionitis at term

    PubMed Central

    Dell'Ovo, Valeria; Rosenzweig, Jason; Burd, Irina; Merabova, Nana; Darbinian, Nune; Goetzl, Laura

    2016-01-01

    OBJECTIVE The purpose of this study was to develop an animal model for intrapartum inflammation at term to investigate the interactions between maternal and fetal inflammatory responses and adverse neurologic outcome. STUDY DESIGN Lipopolysaccharide (160, 320, or 640 μg/kg) was administered intraperitoneally to day 20 term-pregnant Sprague Dawley rat dams 2, 4, and 6 hours before sample collection. Maternal outcomes included dam core temperature and plasma interleukin 6 (IL-6). Fetal outcomes included plasma IL-6, brain IL-6 messenger RNA expression, and brain IL-6 protein expression. Primary cortical cell cultures were prepared to examine neuronal morphologic condition. Neurite counts were obtained with the use of automated Sholl analysis. RESULTS Maternal plasma IL-6 levels peaked 2 hours after lipopolysaccharide stimulus and rapidly resolved, except for an observed low level persistence at 6 hours with 640 μg/kg. Fetal plasma and placental IL-6 expression also peaked rapidly but only persisted in placental samples. Fetal brain IL-6 RNA and protein expression was significantly higher than control litters at 6 hours after the exposure to both 320 μg/kg (P ≤ .05) and 640 μg/kg (P ≤ .01). Cortical cells from fetuses that were exposed for 6 hours to maternal systemic inflammation showed reduced neurite number and neurite length (P < .001) with increasing lipopolysaccharide dose. CONCLUSION Our results demonstrate that fetal brain injury follows isolated systemic maternal inflammation and that fetal brain inflammation lags after maternal stimulus, which creates a potential 4-hour clinical window for therapeutic intervention. PMID:25979619

  4. A model for evaluating friction during orthodontic tooth movement.

    PubMed

    Loftus, B P; Artum, J

    2001-06-01

    Orthodontic forces for sliding tooth movement during space closure are applied at a distance from the centre of resistance of the teeth. For this reason, the teeth will tip until contacts are established between the archwire and diagonally opposite corners of the bracket wings. They will also rotate until the wire contacts opposite corners of the ligature tie or the buccal shield with self-ligating brackets, and the base of the slot. Frictional forces measured with models that do not enable such movements may therefore not be representative of the clinical condition. To test this hypothesis, a dentoalveolar model that allowed accurate reproduction of the width of a material of similar elastic properties as the periodontal ligament (PDL) was fabricated. In addition, a device was designed that allowed accurate adjustment of the bracket slot in all three planes of space during mounting of the model in an Instron machine. Frictional forces during sliding of ceramic brackets with 0.022 x 0.028-inch bracket slots along 0.019 x 0.025-inch stainless steel wires were tested using models with simulated PDL widths of 0.00, 0.33, 0.67, and 1.00 mm. ANOVA detected a significant effect of PDL width on mean frictional force (P < 0.001). Pairwise comparisons at 0.05 significance level indicated no differences between the models without PDL and those with a width of 0.33 mm, and between models with PDL widths of 0.67 and 1.00 mm. However, the two models with smaller widths produced significantly lower frictional forces. PMID:11471268

  5. Animal models to evaluate anti-atherosclerotic drugs.

    PubMed

    Priyadharsini, Raman P

    2015-08-01

    Atherosclerosis is a multifactorial condition characterized by endothelial injury, fatty streak deposition, and stiffening of the blood vessels. The pathogenesis is complex and mediated by adhesion molecules, inflammatory cells, and smooth muscle cells. Statins have been the major drugs in treating hypercholesterolemia for the past two decades despite little efficacy. There is an urgent need for new drugs that can replace statins or combined with statins. The preclinical studies evaluating atherosclerosis require an ideal animal model which resembles the disease condition, but there is no single animal model which mimics the disease. The animal models used are rabbits, rats, mice, hamsters, mini pigs, etc. Each animal model has its own advantages and disadvantages. The method of induction of atherosclerosis includes diet, chemical induction, mechanically induced injuries, and genetically manipulated animal models. This review mainly focuses on the various animal models, method of induction, the advantages, disadvantages, and the current perspectives with regard to preclinical studies on atherosclerosis.

  6. How interactions between animal movement and landscape processes modify range dynamics and extinction risk

    EPA Science Inventory

    Range dynamics models now incorporate many of the mechanisms and interactions that drive species distributions. However, connectivity continues to be studied using overly simple distance-based dispersal models with little consideration of how the individual behavior of dispersin...

  7. The Importance of Animal Models in Tuberculosis Vaccine Development

    PubMed Central

    Acosta, Armando; Norazmi, Mohd Nor; Hernandez-Pando, Rogelio; Alvarez, Nadine; Borrero, Reinier; Infante, Juan F; Sarmiento, Maria E

    2011-01-01

    Research, development, and production of vaccines are still highly dependent on the use of animal models in the various evaluation steps. Despite this fact, there are strong interests and ongoing efforts to reduce the use of animals in vaccine development. Tuberculosis vaccine development is one important example of the complexities involved in the use of animal models for the production of new vaccines. This review summarises some of the general aspects related with the use of animals in vaccine research and production, as well as achievements and challenges towards the rational use of animals, particularly in the case of tuberculosis vaccine development. PMID:22589668

  8. Modelling and monitoring of passive control structures in human movement

    NASA Astrophysics Data System (ADS)

    Hemami, Hooshang; Hemami, Mahmoud

    2014-09-01

    Passive tissues, ligaments and cartilage are vital to human movement. Their contribution to stability, joint function and joint integrity is essential. The articulation of their functions and quantitative assessment of what they do in a healthy or injured state are important in athletics, orthopaedics, medicine and health. In this paper, the role of cartilage and ligaments in stability of natural contacts, connections and joints is articulated by including them in two very simple skeletal systems: one- and three-link rigid body systems. Based on the Newton-Euler equations, a state space presentation of the dynamics is discussed that allows inclusion of ligament and cartilage structures in the model, and allows for Lyapunov stability studies for the original and reduced systems. The connection constraints may be holonomic and non-holonomic depending on the structure of the passive elements. The development is pertinent to the eventual design of a computational framework for the study of human movement that involves computer models of all the relevant skeletal, neural and physiological elements of the central nervous system (CNS). Such a structure also permits testing of different hypotheses about the functional neuroanatomy of the CNS, and the study of the effects and dynamics of disease, deterioration, aging and injuries. The formulation here is applied to one- and three-link systems. Digital computer simulations of a two rigid body system are presented to demonstrate the feasibility and effectiveness of the approach and the methods.

  9. Animal models of bronchopulmonary dysplasia. The term rat models.

    PubMed

    O'Reilly, Megan; Thébaud, Bernard

    2014-12-15

    Bronchopulmonary dysplasia (BPD) is the chronic lung disease of prematurity that affects very preterm infants. Although advances in perinatal care have enabled the survival of infants born as early as 23-24 wk of gestation, the challenge of promoting lung growth while protecting the ever more immature lung from injury is now bigger. Consequently, BPD remains one of the most common complications of extreme prematurity and still lacks specific treatments. Progress in our understanding of BPD and the potential of developing therapeutic strategies have arisen from large (baboons, sheep, and pigs) and small (rabbits, rats, and mice) animal models. This review focuses specifically on the use of the rat to model BPD and summarizes how the model is used in various research studies and the advantages and limitations of this particular model, and it highlights recent therapeutic advances in BPD by using this rat model.

  10. Animal models of bronchopulmonary dysplasia. The term rat models.

    PubMed

    O'Reilly, Megan; Thébaud, Bernard

    2014-12-15

    Bronchopulmonary dysplasia (BPD) is the chronic lung disease of prematurity that affects very preterm infants. Although advances in perinatal care have enabled the survival of infants born as early as 23-24 wk of gestation, the challenge of promoting lung growth while protecting the ever more immature lung from injury is now bigger. Consequently, BPD remains one of the most common complications of extreme prematurity and still lacks specific treatments. Progress in our understanding of BPD and the potential of developing therapeutic strategies have arisen from large (baboons, sheep, and pigs) and small (rabbits, rats, and mice) animal models. This review focuses specifically on the use of the rat to model BPD and summarizes how the model is used in various research studies and the advantages and limitations of this particular model, and it highlights recent therapeutic advances in BPD by using this rat model. PMID:25305248

  11. Extending the E-Z Reader Model of Eye Movement Control to Chinese Readers

    ERIC Educational Resources Information Center

    Rayner, Keith; Li, Xingshan; Pollatsek, Alexander

    2007-01-01

    Chinese readers' eye movements were simulated in the context of the E-Z Reader model, which was developed to account for the eye movements of readers of English. Despite obvious differences between English and Chinese, the model did a fairly good job of simulating the eye movements of Chinese readers. The successful simulation suggests that the…

  12. The utility of modeling word identification from visual input within models of eye movements in reading.

    PubMed

    Bicknell, Klinton; Levy, Roger

    2012-04-01

    Decades of empirical work have shown that a range of eye movement phenomena in reading are sensitive to the details of the process of word identification. Despite this, major models of eye movement control in reading do not explicitly model word identification from visual input. This paper presents a argument for developing models of eye movements that do include detailed models of word identification. Specifically, we argue that insights into eye movement behavior can be gained by understanding which phenomena naturally arise from an account in which the eyes move for efficient word identification, and that one important use of such models is to test which eye movement phenomena can be understood this way. As an extended case study, we present evidence from an extension of a previous model of eye movement control in reading that does explicitly model word identification from visual input, Mr. Chips (Legge, Klitz, & Tjan, 1997), to test two proposals for the effect of using linguistic context on reading efficiency.

  13. Animation of natural scene by virtual eye-movements evokes high precision and low noise in V1 neurons.

    PubMed

    Baudot, Pierre; Levy, Manuel; Marre, Olivier; Monier, Cyril; Pananceau, Marc; Frégnac, Yves

    2013-01-01

    Synaptic noise is thought to be a limiting factor for computational efficiency in the brain. In visual cortex (V1), ongoing activity is present in vivo, and spiking responses to simple stimuli are highly unreliable across trials. Stimulus statistics used to plot receptive fields, however, are quite different from those experienced during natural visuomotor exploration. We recorded V1 neurons intracellularly in the anaesthetized and paralyzed cat and compared their spiking and synaptic responses to full field natural images animated by simulated eye-movements to those evoked by simpler (grating) or higher dimensionality statistics (dense noise). In most cells, natural scene animation was the only condition where high temporal precision (in the 10-20 ms range) was maintained during sparse and reliable activity. At the subthreshold level, irregular but highly reproducible membrane potential dynamics were observed, even during long (several 100 ms) "spike-less" periods. We showed that both the spatial structure of natural scenes and the temporal dynamics of eye-movements increase the signal-to-noise ratio by a non-linear amplification of the signal combined with a reduction of the subthreshold contextual noise. These data support the view that the sparsening and the time precision of the neural code in V1 may depend primarily on three factors: (1) broadband input spectrum: the bandwidth must be rich enough for recruiting optimally the diversity of spatial and time constants during recurrent processing; (2) tight temporal interplay of excitation and inhibition: conductance measurements demonstrate that natural scene statistics narrow selectively the duration of the spiking opportunity window during which the balance between excitation and inhibition changes transiently and reversibly; (3) signal energy in the lower frequency band: a minimal level of power is needed below 10 Hz to reach consistently the spiking threshold, a situation rarely reached with visual dense

  14. An extensible simulation environment and movement metrics for testing walking behavior in agent-based models

    SciTech Connect

    Paul M. Torrens; Atsushi Nara; Xun Li; Haojie Zhu; William A. Griffin; Scott B. Brown

    2012-01-01

    Human movement is a significant ingredient of many social, environmental, and technical systems, yet the importance of movement is often discounted in considering systems complexity. Movement is commonly abstracted in agent-based modeling (which is perhaps the methodological vehicle for modeling complex systems), despite the influence of movement upon information exchange and adaptation in a system. In particular, agent-based models of urban pedestrians often treat movement in proxy form at the expense of faithfully treating movement behavior with realistic agency. There exists little consensus about which method is appropriate for representing movement in agent-based schemes. In this paper, we examine popularly-used methods to drive movement in agent-based models, first by introducing a methodology that can flexibly handle many representations of movement at many different scales and second, introducing a suite of tools to benchmark agent movement between models and against real-world trajectory data. We find that most popular movement schemes do a relatively poor job of representing movement, but that some schemes may well be 'good enough' for some applications. We also discuss potential avenues for improving the representation of movement in agent-based frameworks.

  15. Is that really my movement? - Students' experiences of a video-supported interactive learning model for movement awareness.

    PubMed

    Backåberg, Sofia; Gummesson, Christina; Brunt, David; Rask, Mikael

    2015-01-01

    Healthcare staff and students have a great risk of developing musculoskeletal symptoms. One cause of this is heavy load related work activities such as manual handling, in which the quality of individual work technique may play a major role. Preventive interventions and well-defined educational strategies to support movement awareness and long-lasting movement changes need to be developed. The aim of the present study was to explore nursing students' experiences of a newly developed interactive learning model for movement awareness. The learning model, which is based on a life-world perspective with focus on interpersonal interaction, has been used with 11 undergraduate students from the second and final year. Each student participated in three individual video sessions with a facilitator. Two individual interviews were carried out with each student during the learning process and one interview 12-18 months after the last session. The interviews were audio-recorded and transcribed verbatim, and a phenomenological hermeneutic method inspired by Paul Ricoeur and described by Lindseth and Norberg was used to interpret the interviews and diary notes. The interpretation resulted in three key themes and nine subthemes. The key themes were; "Obtaining better preconditions for bodily awareness," "Experiencing changes in one's own movement," and "Experiencing challenges in the learning process." The interactive learning model entails a powerful and challenging experience that develops movement awareness. The experience of meaningfulness and usefulness emerges increasingly and alternates with a feeling of discomfort. The learning model may contribute to the body of knowledge of well-defined educational strategies in movement awareness and learning in, for example, preventive interventions and ergonomic education. It may also be valuable in other practical learning situations where movement awareness is required. PMID:26274385

  16. Is that really my movement?—Students' experiences of a video-supported interactive learning model for movement awareness

    PubMed Central

    Backåberg, Sofia; Gummesson, Christina; Brunt, David; Rask, Mikael

    2015-01-01

    Healthcare staff and students have a great risk of developing musculoskeletal symptoms. One cause of this is heavy load related work activities such as manual handling, in which the quality of individual work technique may play a major role. Preventive interventions and well-defined educational strategies to support movement awareness and long-lasting movement changes need to be developed. The aim of the present study was to explore nursing students’ experiences of a newly developed interactive learning model for movement awareness. The learning model, which is based on a life-world perspective with focus on interpersonal interaction, has been used with 11 undergraduate students from the second and final year. Each student participated in three individual video sessions with a facilitator. Two individual interviews were carried out with each student during the learning process and one interview 12–18 months after the last session. The interviews were audio-recorded and transcribed verbatim, and a phenomenological hermeneutic method inspired by Paul Ricoeur and described by Lindseth and Norberg was used to interpret the interviews and diary notes. The interpretation resulted in three key themes and nine subthemes. The key themes were; “Obtaining better preconditions for bodily awareness,” “Experiencing changes in one's own movement,” and “Experiencing challenges in the learning process.” The interactive learning model entails a powerful and challenging experience that develops movement awareness. The experience of meaningfulness and usefulness emerges increasingly and alternates with a feeling of discomfort. The learning model may contribute to the body of knowledge of well-defined educational strategies in movement awareness and learning in, for example, preventive interventions and ergonomic education. It may also be valuable in other practical learning situations where movement awareness is required. PMID:26274385

  17. ANIMAL MODELS OF CHRONIC PESTICIDE NEUROTOXICITY.

    EPA Science Inventory

    There is a wealth of literature on neurotoxicological outcomes of acute and short-term exposure to pesticides in laboratory animals, but there are relatively few studies of- long-term exposure. Many reports in the literature describing ;chronic' exposures to pesticides are, in fa...

  18. ANIMAL MODELS OF CHRONIC PESTICIDE NEUROTOXICITY.

    EPA Science Inventory

    There is a wealth of literature on neurotoxicological outcomes of acute and short-term exposure to pesticides in laboratory animals, but there are relatively few reports of long-term exposure. Reports in the literature describing "chronic" exposures to pesticides are, in fact, a...

  19. Institutional Animal Care and Use Committee Considerations for Animal Models of Peripheral Neuropathy

    PubMed Central

    Brabb, Thea; Carbone, Larry; Snyder, Jessica; Phillips, Nona

    2014-01-01

    Peripheral neuropathy and neuropathic pain are debilitating, life-altering conditions that affect a significant proportion of the human population. Animal models, used to study basic disease mechanisms and treatment modalities, are diverse and provide many challenges for institutional animal care and use committee (IACUC) review and postapproval monitoring. Items to consider include regulatory and ethical imperatives in animal models that may be designed to study pain, the basic mechanism of neurodegeneration, and different disease processes for which neuropathic pain is a side effect. Neuropathic pain can be difficult to detect or quantify in many models, and pain management is often unsuccessful in both humans and animals, inspiring the need for more research. Design of humane endpoints requires clear communication of potential adverse outcomes and solutions. Communication with the IACUC, researchers, and veterinary staff is also key for successful postapproval monitoring of these challenging models. PMID:24615447

  20. COLLECTIVE VORTEX BEHAVIORS: DIVERSITY, PROXIMATE, AND ULTIMATE CAUSES OF CIRCULAR ANIMAL GROUP MOVEMENTS.

    PubMed

    Delcourt, Johann; Bode, Nikolai W F; Denoël, Mathieu

    2016-03-01

    Ant mill, caterpillar circle, bat doughnut, amphibian vortex, duck swirl, and fish torus are different names for rotating circular animal formations, where individuals turn around a common center. These "collective vortex behaviors" occur at different group sizes from pairs to several million individuals and have been reported in a large number of organisms, from bacteria to vertebrates, including humans. However, to date, no comprehensive review and synthesis of the literature on vortex behaviors has been conducted. Here, we review the state of the art of the proximate and ultimate causes of vortex behaviors. The ubiquity of this behavioral phenomenon could suggest common causes or fundamental underlying principles across contexts. However, we find that a variety of proximate mechanisms give rise to vortex behaviors. We highlight the potential benefits of collective vortex behaviors to individuals involved in them. For example, in some species, vortices increase feeding efficiency and could give protection against predators. It has also been argued that vortices could improve collective decision-making and information transfer. We highlight gaps in our understanding of these ubiquitous behavioral phenomena and discuss future directions for research in vortex studies. PMID:27192777

  1. How interactions between animal movement and landscape processes modify local range dynamics and extinction risk

    PubMed Central

    Fordham, Damien A.; Shoemaker, Kevin T.; Schumaker, Nathan H.; Akçakaya, H. Reşit; Clisby, Nathan; Brook, Barry W.

    2014-01-01

    Forecasts of range dynamics now incorporate many of the mechanisms and interactions that drive species distributions. However, connectivity continues to be simulated using overly simple distance-based dispersal models with little consideration of how the individual behaviour of dispersing organisms interacts with landscape structure (functional connectivity). Here, we link an individual-based model to a niche-population model to test the implications of this omission. We apply this novel approach to a turtle species inhabiting wetlands which are patchily distributed across a tropical savannah, and whose persistence is threatened by two important synergistic drivers of global change: predation by invasive species and overexploitation. We show that projections of local range dynamics in this study system change substantially when functional connectivity is modelled explicitly. Accounting for functional connectivity in model simulations causes the estimate of extinction risk to increase, and predictions of range contraction to slow. We conclude that models of range dynamics that simulate functional connectivity can reduce an important source of bias in predictions of shifts in species distributions and abundances, especially for organisms whose dispersal behaviours are strongly affected by landscape structure. PMID:24806426

  2. How interactions between animal movement and landscape processes modify local range dynamics and extinction risk.

    PubMed

    Fordham, Damien A; Shoemaker, Kevin T; Schumaker, Nathan H; Akçakaya, H Reşit; Clisby, Nathan; Brook, Barry W

    2014-05-01

    Forecasts of range dynamics now incorporate many of the mechanisms and interactions that drive species distributions. However, connectivity continues to be simulated using overly simple distance-based dispersal models with little consideration of how the individual behaviour of dispersing organisms interacts with landscape structure (functional connectivity). Here, we link an individual-based model to a niche-population model to test the implications of this omission. We apply this novel approach to a turtle species inhabiting wetlands which are patchily distributed across a tropical savannah, and whose persistence is threatened by two important synergistic drivers of global change: predation by invasive species and overexploitation. We show that projections of local range dynamics in this study system change substantially when functional connectivity is modelled explicitly. Accounting for functional connectivity in model simulations causes the estimate of extinction risk to increase, and predictions of range contraction to slow. We conclude that models of range dynamics that simulate functional connectivity can reduce an important source of bias in predictions of shifts in species distributions and abundances, especially for organisms whose dispersal behaviours are strongly affected by landscape structure. PMID:24806426

  3. Animal Models of Ischemic Stroke. Part One: Modeling Risk Factors

    PubMed Central

    Bacigaluppi, Marco; Comi, Giancarlo; Hermann, Dirk M.

    2010-01-01

    Ischemic stroke is one of the leading causes of long-term disability and death in developed and developing countries. As emerging disease, stroke related mortality and morbidity is going to step up in the next decades. This is both due to the poor identification of risk factors and persistence of unhealthy habits, as well as to the aging of the population. To counteract the estimated increase in stroke incidence, it is of primary importance to identify risk factors, study their effects, to promote primary and secondary prevention, and to extend the therapeutic repertoire that is currently limited to the very first hours after stroke. While epidemiologic studies in the human population are essential to identify emerging risk factors, adequate animal models represent a fundamental tool to dissect stroke risk factors to their molecular mechanism and to find efficacious therapeutic strategies for this complex multi- factorial disorder. The present review is organized into two parts: the first part deals with the animal models that have been developed to study stroke and its related risk factors and the second part analyzes the specific stroke models. These models represent an indispensable tool to investigate the mechanisms of cerebral injury and to develop novel therapies. PMID:20802809

  4. Do the eyes scan dream images during rapid eye movement sleep? Evidence from the rapid eye movement sleep behaviour disorder model.

    PubMed

    Leclair-Visonneau, Laurène; Oudiette, Delphine; Gaymard, Bertrand; Leu-Semenescu, Smaranda; Arnulf, Isabelle

    2010-06-01

    Rapid eye movements and complex visual dreams are salient features of human rapid eye movement sleep. However, it remains to be elucidated whether the eyes scan dream images, despite studies that have retrospectively compared the direction of rapid eye movements to the dream recall recorded after having awakened the sleeper. We used the model of rapid eye movement sleep behaviour disorder (when patients enact their dreams by persistence of muscle tone) to determine directly whether the eyes move in the same directions as the head and limbs. In 56 patients with rapid eye movement sleep behaviour disorder and 17 healthy matched controls, the eye movements were monitored by electrooculography in four (right, left, up and down) directions, calibrated with a target and synchronized with video and sleep monitoring. The rapid eye movement sleep behaviour disorder-associated behaviours occurred 2.1 times more frequently during rapid eye movement sleep with than without rapid eye movements, and more often during or after rapid eye movements than before. Rapid eye movement density, index and complexity were similar in patients with rapid eye movement sleep behaviour disorder and controls. When rapid eye movements accompanied goal-oriented motor behaviour during rapid eye movement sleep behaviour disorder (e.g. grabbing a fictive object, hand greetings, climbing a ladder), which happened in 19 sequences, 82% were directed towards the action of the patient (same plane and direction). When restricted to the determinant rapid eye movements, the concordance increased to 90%. Rapid eye movements were absent in 38-42% of behaviours. This directional coherence between limbs, head and eye movements during rapid eye movement sleep behaviour disorder suggests that, when present, rapid eye movements imitate the scanning of the dream scene. Since the rapid eye movements are similar in subjects with and without rapid eye movement sleep behaviour disorder, this concordance can be extended

  5. Reaction time in ankle movements: a diffusion model analysis

    PubMed Central

    Michmizos, Konstantinos P.; Krebs, Hermano Igo

    2015-01-01

    Reaction time (RT) is one of the most commonly used measures of neurological function and dysfunction. Despite the extensive studies on it, no study has ever examined the RT in the ankle. Twenty-two subjects were recruited to perform simple, 2- and 4-choice RT tasks by visually guiding a cursor inside a rectangular target with their ankle. RT did not change with spatial accuracy constraints imposed by different target widths in the direction of the movement. RT increased as a linear function of potential target stimuli, as would be predicted by Hick–Hyman law. Although the slopes of the regressions were similar, the intercept in dorsal–plantar (DP) direction was significantly smaller than the intercept in inversion–eversion (IE) direction. To explain this difference, we used a hierarchical Bayesian estimation of the Ratcliff's (Psychol Rev 85:59, 1978) diffusion model parameters and divided processing time into cognitive components. The model gave a good account of RTs, their distribution and accuracy values, and hence provided a testimony that the non-decision processing time (overlap of posterior distributions between DP and IE < 0.045), the boundary separation (overlap of the posterior distributions < 0.1) and the evidence accumulation rate (overlap of the posterior distributions < 0.01) components of the RT accounted for the intercept difference between DP and IE. The model also proposed that there was no systematic change in non-decision processing time or drift rate when spatial accuracy constraints were altered. The results were in agreement with the memory drum hypothesis and could be further justified neurophysiologically by the larger innervation of the muscles controlling DP movements. This study might contribute to assessing deficits in sensorimotor control of the ankle and enlighten a possible target for correction in the framework of our on-going effort to develop robotic therapeutic interventions to the ankle of children with cerebral palsy

  6. Overview of Vertebrate Animal Models of Fungal Infection

    PubMed Central

    Hohl, Tobias M.

    2014-01-01

    Fungi represent emerging infectious threats to human populations worldwide. Mice and other laboratory animals have proved invaluable in modeling clinical syndromes associated with superficial and life-threatening invasive mycoses. This review outlines salient features of common vertebrate animal model systems to study fungal pathogenesis, host antifungal immune responses, and antifungal compounds. PMID:24709390

  7. The Various Roles of Animal Models in Understanding Human Development

    ERIC Educational Resources Information Center

    Gottlieb, Gilbert; Lickliter, Robert

    2004-01-01

    In this article, the authors take a very conservative view of the contribution of animal models to an understanding of human development. We do not think that homologies can be readily documented with even our most closely related relatives' behavior and psychological functioning. The major contribution of animal models is their provision of food…

  8. Are animal models as good as we think?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Models have been a tool of science at least since the 18th century and serve a variety of purposes from focusing abstract thoughts to representing scaled down version of things for study. Generally, animal models are needed when it is impractical or unethical to study the target animal. Biologists...

  9. Edaphics, active tectonics and animal movements in the Kenyan Rift - implications for early human evolution and dispersal

    NASA Astrophysics Data System (ADS)

    Kübler, Simon; Owenga, Peter; Rucina, Stephen; King, Geoffrey C. P.

    2014-05-01

    The quality of soils (edaphics) and the associated vegetation strongly controls the health of grazing animals. Until now, this has hardly been appreciated by paleo-anthropologists who only take into account the availability of water and vegetation in landscape reconstruction attempts. A lack of understanding the importance of the edaphics of a region greatly limits interpretations of the relation between our ancestors and animals over the last few million years. If a region lacks vital trace elements then wild grazing and browsing animals will avoid it and go to considerable length and take major risks to seek out better pasture. As a consequence animals must move around the landscape at different times of the year. In complex landscapes, such as tectonically active rifts, hominins can use advanced group behaviour to gain strategic advantage for hunting. Our study in the southern Kenya rift in the Lake Magadi region shows that the edaphics and active rift structures play a key role in present day animal movements as well as the for the location of an early hominin site at Mt. Olorgesailie. We carried out field analysis based on studying the relationship between the geology and soil development as well as the tectonic geomorphology to identify 'good' and 'bad' regions both in terms of edaphics and accessibility for grazing animals. We further sampled different soils that developed on the volcanic bedrock and sediment sources of the region and interviewed the local Maasai shepherds to learn about present-day good and bad grazing sites. At the Olorgesailie site the rift valley floor is covered with flood trachytes; basalts only occur at Mt. Olorgesailie and farther east up the rift flank. The hominin site is located in lacustrine sediments at the southern edge of a playa that extends north and northwest of Mt. Olorgesailie. The lakebeds are now tilted and eroded by motion on two north-south striking faults. The lake was trapped by basalt flows from Mt. Olorgesailie

  10. Animal models of human respiratory syncytial virus disease

    PubMed Central

    Domachowske, Joseph B.; Rosenberg, Helene F.

    2011-01-01

    Infection with the human pneumovirus pathogen, respiratory syncytial virus (hRSV), causes a wide spectrum of respiratory disease, notably among infants and the elderly. Laboratory animal studies permit detailed experimental modeling of hRSV disease and are therefore indispensable in the search for novel therapies and preventative strategies. Present animal models include several target species for hRSV, including chimpanzees, cattle, sheep, cotton rats, and mice, as well as alternative animal pneumovirus models, such as bovine RSV and pneumonia virus of mice. These diverse animal models reproduce different features of hRSV disease, and their utilization should therefore be based on the scientific hypothesis under investigation. The purpose of this review is to summarize the strengths and limitations of each of these animal models. Our intent is to provide a resource for investigators and an impetus for future research. PMID:21571908

  11. Translational research challenges: finding the right animal models.

    PubMed

    Prabhakar, Sharma

    2012-12-01

    Translation of scientific discoveries into meaningful human applications, particularly novel therapies of human diseases, requires development of suitable animal models. Experimental approaches to test new drugs in preclinical phases often necessitated animal models that not only replicate human disease in etiopathogenesis and pathobiology but also biomarkers development and toxicity prediction. Whereas the transgenic and knockout techniques have revolutionized manipulation of rodents and other species to get greater insights into human disease pathogenesis, we are far from generating ideal animal models of most human disease states. The challenges in using the currently available animal models for translational research, particularly for developing potentially new drugs for human disease, coupled with the difficulties in toxicity prediction have led some researchers to develop a scoring system for translatability. These aspects and the challenges in selecting an animal model among those that are available to study human disease pathobiology and drug development are the topics covered in this detailed review.

  12. Serotonin in animal models of alcoholism.

    PubMed

    Compagnon, P; Ernouf, D; Narcisse, G; Daoust, M

    1993-01-01

    Ethanol naive alcohol preferring rodents have low serotonin transmission. Both pharmacological, biochemical and behavioral studies show that increased serotonin transmission influence reduces ethanol consumption in animals. This paper develops the role of serotonin in different lines of ethanol preferring rats and mice, and shows a regulation of 5-HT1A receptors in alcoholised dependent mice. Different sensitivities to ethanol observed between ethanol-preferring and non-preferring rats or mice seems to be at the root of the maintenance of alcohol intake.

  13. Animal models of oral candidiasis. A review.

    PubMed

    Allen, C M

    1994-08-01

    Candida albicans is the most common fungal infection of the human oral mucosa, yet much remains to be understood with respect to the pathogenesis of the disease. Numerous difficulties are inherent in designing studies that use human beings as subjects. The use of various animal species in experimental contexts has helped to provide insight with respect to this condition. A variety of manipulations of the system can be performed, including altering the host immune response, the mucosal environment, or the systemic environment. In addition, organism-related factors can be examined in a more controlled setting. The information obtained from such studies could not be obtained in an in vitro situation.

  14. Animal Models of Tourette Syndrome—From Proliferation to Standardization

    PubMed Central

    Yael, Dorin; Israelashvili, Michal; Bar-Gad, Izhar

    2016-01-01

    Tourette syndrome (TS) is a childhood onset disorder characterized by motor and vocal tics and associated with multiple comorbid symptoms. Over the last decade, the accumulation of findings from TS patients and the emergence of new technologies have led to the development of novel animal models with high construct validity. In addition, animal models which were previously associated with other disorders were recently attributed to TS. The proliferation of TS animal models has accelerated TS research and provided a better understanding of the mechanism underlying the disorder. This newfound success generates novel challenges, since the conclusions that can be drawn from TS animal model studies are constrained by the considerable variation across models. Typically, each animal model examines a specific subset of deficits and centers on one field of research (physiology/genetics/pharmacology/etc.). Moreover, different studies do not use a standard lexicon to characterize different properties of the model. These factors hinder the evaluation of individual model validity as well as the comparison across models, leading to a formation of a fuzzy, segregated landscape of TS pathophysiology. Here, we call for a standardization process in the study of TS animal models as the next logical step. We believe that a generation of standard examination criteria will improve the utility of these models and enable their consolidation into a general framework. This should lead to a better understanding of these models and their relationship to TS, thereby improving the research of the mechanism underlying this disorder and aiding the development of new treatments. PMID:27065791

  15. Naturally occurring animal models of human hepatitis E virus infection.

    PubMed

    Yugo, Danielle M; Cossaboom, Caitlin M; Meng, Xiang-Jin

    2014-01-01

    Hepatitis E virus (HEV) is a single-stranded, positive-sense RNA virus in the family Hepeviridae. Hepatitis E caused by HEV is a clinically important global disease. There are currently four well-characterized genotypes of HEV in mammalian species, although numerous novel strains of HEV likely belonging to either new genotypes or species have recently been identified from several other animal species. HEV genotypes 1 and 2 are limited to infection in humans, whereas genotypes 3 and 4 infect an expanding host range of animal species and are zoonotic to humans. Historical animal models include various species of nonhuman primates, which have been indispensable for the discovery of human HEV and for understanding its pathogenesis and course of infection. With the genetic identification and characterization of animal strains of HEV, a number of naturally occurring animal models such as swine, chicken, and rabbit have recently been developed for various aspects of HEV research, including vaccine trials, pathogenicity, cross-species infection, mechanism of virus replication, and molecular biology studies. Unfortunately, the current available animal models for HEV are still inadequate for certain aspects of HEV research. For instance, an animal model is still lacking to study the underlying mechanism of severe and fulminant hepatitis E during pregnancy. Also, an animal model that can mimic chronic HEV infection is critically needed to study the mechanism leading to chronicity in immunocompromised individuals. Genetic identification of additional novel animal strains of HEV may lead to the development of better naturally occurring animal models for HEV. This article reviews the current understanding of animal models of HEV infection in both natural and experimental infection settings and identifies key research needs and limitations.

  16. Animal Models for Salmonellosis: Applications in Vaccine Research.

    PubMed

    Higginson, Ellen E; Simon, Raphael; Tennant, Sharon M

    2016-09-01

    Salmonellosis remains an important cause of human disease worldwide. While there are several licensed vaccines for Salmonella enterica serovar Typhi, these vaccines are generally ineffective against other Salmonella serovars. Vaccines that target paratyphoid and nontyphoidal Salmonella serovars are very much in need. Preclinical evaluation of candidate vaccines is highly dependent on the availability of appropriate scientific tools, particularly animal models. Many different animal models exist for various Salmonella serovars, from whole-animal models to smaller models, such as those recently established in insects. Here, we discuss various mouse, rat, rabbit, calf, primate, and insect models for Salmonella infection, all of which have their place in research. However, choosing the right model is imperative in selecting the best vaccine candidates for further clinical testing. In this minireview, we summarize the various animal models that are used to assess salmonellosis, highlight some of the advantages and disadvantages of each, and discuss their value in vaccine development.

  17. Animal Models for Salmonellosis: Applications in Vaccine Research.

    PubMed

    Higginson, Ellen E; Simon, Raphael; Tennant, Sharon M

    2016-09-01

    Salmonellosis remains an important cause of human disease worldwide. While there are several licensed vaccines for Salmonella enterica serovar Typhi, these vaccines are generally ineffective against other Salmonella serovars. Vaccines that target paratyphoid and nontyphoidal Salmonella serovars are very much in need. Preclinical evaluation of candidate vaccines is highly dependent on the availability of appropriate scientific tools, particularly animal models. Many different animal models exist for various Salmonella serovars, from whole-animal models to smaller models, such as those recently established in insects. Here, we discuss various mouse, rat, rabbit, calf, primate, and insect models for Salmonella infection, all of which have their place in research. However, choosing the right model is imperative in selecting the best vaccine candidates for further clinical testing. In this minireview, we summarize the various animal models that are used to assess salmonellosis, highlight some of the advantages and disadvantages of each, and discuss their value in vaccine development. PMID:27413068

  18. Systematic Reviews of Animal Models: Methodology versus Epistemology

    PubMed Central

    Greek, Ray; Menache, Andre

    2013-01-01

    Systematic reviews are currently favored methods of evaluating research in order to reach conclusions regarding medical practice. The need for such reviews is necessitated by the fact that no research is perfect and experts are prone to bias. By combining many studies that fulfill specific criteria, one hopes that the strengths can be multiplied and thus reliable conclusions attained. Potential flaws in this process include the assumptions that underlie the research under examination. If the assumptions, or axioms, upon which the research studies are based, are untenable either scientifically or logically, then the results must be highly suspect regardless of the otherwise high quality of the studies or the systematic reviews. We outline recent criticisms of animal-based research, namely that animal models are failing to predict human responses. It is this failure that is purportedly being corrected via systematic reviews. We then examine the assumption that animal models can predict human outcomes to perturbations such as disease or drugs, even under the best of circumstances. We examine the use of animal models in light of empirical evidence comparing human outcomes to those from animal models, complexity theory, and evolutionary biology. We conclude that even if legitimate criticisms of animal models were addressed, through standardization of protocols and systematic reviews, the animal model would still fail as a predictive modality for human response to drugs and disease. Therefore, systematic reviews and meta-analyses of animal-based research are poor tools for attempting to reach conclusions regarding human interventions. PMID:23372426

  19. Systematic reviews of animal models: methodology versus epistemology.

    PubMed

    Greek, Ray; Menache, Andre

    2013-01-01

    Systematic reviews are currently favored methods of evaluating research in order to reach conclusions regarding medical practice. The need for such reviews is necessitated by the fact that no research is perfect and experts are prone to bias. By combining many studies that fulfill specific criteria, one hopes that the strengths can be multiplied and thus reliable conclusions attained. Potential flaws in this process include the assumptions that underlie the research under examination. If the assumptions, or axioms, upon which the research studies are based, are untenable either scientifically or logically, then the results must be highly suspect regardless of the otherwise high quality of the studies or the systematic reviews. We outline recent criticisms of animal-based research, namely that animal models are failing to predict human responses. It is this failure that is purportedly being corrected via systematic reviews. We then examine the assumption that animal models can predict human outcomes to perturbations such as disease or drugs, even under the best of circumstances. We examine the use of animal models in light of empirical evidence comparing human outcomes to those from animal models, complexity theory, and evolutionary biology. We conclude that even if legitimate criticisms of animal models were addressed, through standardization of protocols and systematic reviews, the animal model would still fail as a predictive modality for human response to drugs and disease. Therefore, systematic reviews and meta-analyses of animal-based research are poor tools for attempting to reach conclusions regarding human interventions.

  20. A Statistical Quality Model for Data-Driven Speech Animation.

    PubMed

    Ma, Xiaohan; Deng, Zhigang

    2012-11-01

    In recent years, data-driven speech animation approaches have achieved significant successes in terms of animation quality. However, how to automatically evaluate the realism of novel synthesized speech animations has been an important yet unsolved research problem. In this paper, we propose a novel statistical model (called SAQP) to automatically predict the quality of on-the-fly synthesized speech animations by various data-driven techniques. Its essential idea is to construct a phoneme-based, Speech Animation Trajectory Fitting (SATF) metric to describe speech animation synthesis errors and then build a statistical regression model to learn the association between the obtained SATF metric and the objective speech animation synthesis quality. Through delicately designed user studies, we evaluate the effectiveness and robustness of the proposed SAQP model. To the best of our knowledge, this work is the first-of-its-kind, quantitative quality model for data-driven speech animation. We believe it is the important first step to remove a critical technical barrier for applying data-driven speech animation techniques to numerous online or interactive talking avatar applications.

  1. Modeling Caribou Movements: Seasonal Ranges and Migration Routes of the Central Arctic Herd.

    PubMed

    Nicholson, Kerry L; Arthur, Stephen M; Horne, Jon S; Garton, Edward O; Del Vecchio, Patricia A

    2016-01-01

    Migration is an important component of the life history of many animals, but persistence of large-scale terrestrial migrations is being challenged by environmental changes that fragment habitats and create obstacles to animal movements. In northern Alaska, the Central Arctic herd (CAH) of barren-ground caribou (Rangifer tarandus granti) is known to migrate over large distances, but the herd's seasonal distributions and migratory movements are not well documented. From 2003-2007, we used GPS radio-collars to determine seasonal ranges and migration routes of 54 female caribou from the CAH. We calculated Brownian bridges to model fall and spring migrations for each year and used the mean of these over all 4 years to identify areas that were used repeatedly. Annual estimates of sizes of seasonal ranges determined by 90% fixed kernel utilization distributions were similar between summer and winter (X̅ = 27,929 SE = 1,064 and X̅ = 26,585 SE = 4912 km2, respectively). Overlap between consecutive summer and winter ranges varied from 3.3-18.3%. Percent overlap between summer ranges used during consecutive years (X̅ = 62.4% SE = 3.7%) was higher than for winter ranges (X̅ = 42.8% SE = 5.9%). Caribou used multiple migration routes each year, but some areas were used by caribou during all years, suggesting that these areas should be managed to allow for continued utilization by caribou. Restoring migration routes after they have been disturbed or fragmented is challenging. However, prior knowledge of movements and threats may facilitate maintenance of migratory paths and seasonal ranges necessary for long-term persistence of migratory species.

  2. Modeling Caribou Movements: Seasonal Ranges and Migration Routes of the Central Arctic Herd

    PubMed Central

    Nicholson, Kerry L.; Arthur, Stephen M.; Horne, Jon S.; Garton, Edward O.; Del Vecchio, Patricia A.

    2016-01-01

    Migration is an important component of the life history of many animals, but persistence of large-scale terrestrial migrations is being challenged by environmental changes that fragment habitats and create obstacles to animal movements. In northern Alaska, the Central Arctic herd (CAH) of barren-ground caribou (Rangifer tarandus granti) is known to migrate over large distances, but the herd’s seasonal distributions and migratory movements are not well documented. From 2003–2007, we used GPS radio-collars to determine seasonal ranges and migration routes of 54 female caribou from the CAH. We calculated Brownian bridges to model fall and spring migrations for each year and used the mean of these over all 4 years to identify areas that were used repeatedly. Annual estimates of sizes of seasonal ranges determined by 90% fixed kernel utilization distributions were similar between summer and winter (X̅ = 27,929 SE = 1,064 and X̅ = 26,585 SE = 4912 km2, respectively). Overlap between consecutive summer and winter ranges varied from 3.3–18.3%. Percent overlap between summer ranges used during consecutive years (X̅ = 62.4% SE = 3.7%) was higher than for winter ranges (X̅ = 42.8% SE = 5.9%). Caribou used multiple migration routes each year, but some areas were used by caribou during all years, suggesting that these areas should be managed to allow for continued utilization by caribou. Restoring migration routes after they have been disturbed or fragmented is challenging. However, prior knowledge of movements and threats may facilitate maintenance of migratory paths and seasonal ranges necessary for long-term persistence of migratory species. PMID:27045587

  3. Modeling Caribou Movements: Seasonal Ranges and Migration Routes of the Central Arctic Herd.

    PubMed

    Nicholson, Kerry L; Arthur, Stephen M; Horne, Jon S; Garton, Edward O; Del Vecchio, Patricia A

    2016-01-01

    Migration is an important component of the life history of many animals, but persistence of large-scale terrestrial migrations is being challenged by environmental changes that fragment habitats and create obstacles to animal movements. In northern Alaska, the Central Arctic herd (CAH) of barren-ground caribou (Rangifer tarandus granti) is known to migrate over large distances, but the herd's seasonal distributions and migratory movements are not well documented. From 2003-2007, we used GPS radio-collars to determine seasonal ranges and migration routes of 54 female caribou from the CAH. We calculated Brownian bridges to model fall and spring migrations for each year and used the mean of these over all 4 years to identify areas that were used repeatedly. Annual estimates of sizes of seasonal ranges determined by 90% fixed kernel utilization distributions were similar between summer and winter (X̅ = 27,929 SE = 1,064 and X̅ = 26,585 SE = 4912 km2, respectively). Overlap between consecutive summer and winter ranges varied from 3.3-18.3%. Percent overlap between summer ranges used during consecutive years (X̅ = 62.4% SE = 3.7%) was higher than for winter ranges (X̅ = 42.8% SE = 5.9%). Caribou used multiple migration routes each year, but some areas were used by caribou during all years, suggesting that these areas should be managed to allow for continued utilization by caribou. Restoring migration routes after they have been disturbed or fragmented is challenging. However, prior knowledge of movements and threats may facilitate maintenance of migratory paths and seasonal ranges necessary for long-term persistence of migratory species. PMID:27045587

  4. Mathematical models of behavior of individual animals.

    PubMed

    Tsibulsky, Vladimir L; Norman, Andrew B

    2007-01-01

    This review is focused on mathematical modeling of behaviors of a whole organism with special emphasis on models with a clearly scientific approach to the problem that helps to understand the mechanisms underlying behavior. The aim is to provide an overview of old and contemporary mathematical models without complex mathematical details. Only deterministic and stochastic, but not statistical models are reviewed. All mathematical models of behavior can be divided into two main classes. First, models that are based on the principle of teleological determinism assume that subjects choose the behavior that will lead them to a better payoff in the future. Examples are game theories and operant behavior models both of which are based on the matching law. The second class of models are based on the principle of causal determinism, which assume that subjects do not choose from a set of possibilities but rather are compelled to perform a predetermined behavior in response to specific stimuli. Examples are perception and discrimination models, drug effects models and individual-based population models. A brief overview of the utility of each mathematical model is provided for each section.

  5. Dynamical movement primitives: learning attractor models for motor behaviors.

    PubMed

    Ijspeert, Auke Jan; Nakanishi, Jun; Hoffmann, Heiko; Pastor, Peter; Schaal, Stefan

    2013-02-01

    Nonlinear dynamical systems have been used in many disciplines to model complex behaviors, including biological motor control, robotics, perception, economics, traffic prediction, and neuroscience. While often the unexpected emergent behavior of nonlinear systems is the focus of investigations, it is of equal importance to create goal-directed behavior (e.g., stable locomotion from a system of coupled oscillators under perceptual guidance). Modeling goal-directed behavior with nonlinear systems is, however, rather difficult due to the parameter sensitivity of these systems, their complex phase transitions in response to subtle parameter changes, and the difficulty of analyzing and predicting their long-term behavior; intuition and time-consuming parameter tuning play a major role. This letter presents and reviews dynamical movement primitives, a line of research for modeling attractor behaviors of autonomous nonlinear dynamical systems with the help of statistical learning techniques. The essence of our approach is to start with a simple dynamical system, such as a set of linear differential equations, and transform those into a weakly nonlinear system with prescribed attractor dynamics by means of a learnable autonomous forcing term. Both point attractors and limit cycle attractors of almost arbitrary complexity can be generated. We explain the design principle of our approach and evaluate its properties in several example applications in motor control and robotics.

  6. Model of solute and water movement in the kidney.

    PubMed

    Stephenson, J L; Mejia, R; Tewarson, R P

    1976-01-01

    Finite difference equations describing salt and water movement in a model of the mammalian kidney have been solved numerically by an extension of the Newton-Raphson method used for the medullary counterflow system. The method permits both steady-state and transient solutions. It has been possible to simulate behavior of the whole kidney as a function of hydrostatic pressures in renal artery, vein, and pelvis; protein and other solute concentrations in arterial blood; and phenomenological equations describing transport of solute and water across nephron and capillary walls. With the model it has been possible to compute concentrations, flows, and hydrostatic pressures in the various nephron segments and in cortical and medullary capillaries and interstitium. In a general way, calculations on the model have met intuitive expectations. In addition, they have reemphasized the critical dependence of renal function on the hydraulic and solute permeabilities of glomerular, postglomerular, and medullary capillaries. These studies provide additional support for our thesis that the functional unit of the kidney is not the single nephron, but a nephrovascular unit consisting of a group of nephrons and their tightly coupled vasculature.

  7. A new CDF model for data movement based on SRM

    SciTech Connect

    Jha, Manoj Kumar; Compostella, Gabriele; Lucchesi, Donatella; Griso, Simone P.; Benjamin, Doug; /Duke U.

    2010-01-01

    Being a large international collaboration established well before the full development of the Grid as the main computing tool for High Energy Physics, CDF has recently changed and improved its computing model, decentralizing some parts of it in order to be able to exploit the rising number of distributed resources available nowadays. Despite those efforts, while the large majority of CDF Monte Carlo production has moved to the Grid, data processing is still mainly performed in dedicated farms hosted at FNAL, requiring a centralized management of data and Monte Carlo samples needed for physics analysis. This rises the question on how to manage the transfer of produced Monte Carlo samples from remote Grid sites to FNAL in an efficient way; up to now CDF has relied on a non scalable centralized solution based on dedicated data servers accessed through rcp protocol, which has proven to be unsatisfactory. A new data transfer model has been designed that uses SRMs as local caches for remote Monte Carlo production sites, interfaces them with SAM, the experiment data catalog, and finally realizes the file movement exploiting the features provided by the data catalog transfer layer. We describe here the model and its integration within the current CDF computing architecture.

  8. Animal Models of Diabetic Neuropathy: Progress Since 1960s

    PubMed Central

    Islam, Md. Shahidul

    2013-01-01

    Diabetic or peripheral diabetic neuropathy (PDN) is one of the major complications among some other diabetic complications such as diabetic nephropathy, diabetic retinopathy, and diabetic cardiomyopathy. The use of animal models in the research of diabetes and diabetic complications is very common when rats and mice are most commonly used for many reasons. A numbers of animal models of diabetic and PDN have been developed in the last several decades such as streptozotocin-induced diabetic rat models, conventional or genetically modified or high-fat diet-fed C57BL/Ks (db/db) mice models, streptozotocin-induced C57BL6/J and ddY mice models, Chinese hamster neuropathic model, rhesus monkey PDN model, spontaneously diabetic WBN/Kob rat model, L-fucose-induced neropathic rat model, partial sciatic nerve ligated rat model, nonobese diabetic (NOD) mice model, spontaneously induced Ins2 Akita mice model, leptin-deficient (ob/ob) mice model, Otsuka Long-Evans Tokushima Fatty (OLETF) rat model, surgically-induced neuropathic model, and genetically modified Spontaneously Diabetic Torii (SDT) rat model, none of which are without limitations. An animal model of diabetic or PDN should mimic the all major pathogeneses of human diabetic neuropathy. Hence, this review comparatively evaluates the animal models of diabetic and PDN which are developed since 1960s with their advantages and disadvantages to help diabetic research groups in order to more accurately choose an appropriate model to meet their specific research objectives. PMID:23984428

  9. Animal models of attention-deficit hyperactivity disorder

    PubMed Central

    Russell, Vivienne A; Sagvolden, Terje; Johansen, Espen Borgå

    2005-01-01

    Although animals cannot be used to study complex human behaviour such as language, they do have similar basic functions. In fact, human disorders that have animal models are better understood than disorders that do not. ADHD is a heterogeneous disorder. The relatively simple nervous systems of rodent models have enabled identification of neurobiological changes that underlie certain aspects of ADHD behaviour. Several animal models of ADHD suggest that the dopaminergic system is functionally impaired. Some animal models have decreased extracellular dopamine concentrations and upregulated postsynaptic dopamine D1 receptors (DRD1) while others have increased extracellular dopamine concentrations. In the latter case, dopamine pathways are suggested to be hyperactive. However, stimulus-evoked release of dopamine is often decreased in these models, which is consistent with impaired dopamine transmission. It is possible that the behavioural characteristics of ADHD result from impaired dopamine modulation of neurotransmission in cortico-striato-thalamo-cortical circuits. There is considerable evidence to suggest that the noradrenergic system is poorly controlled by hypofunctional α2-autoreceptors in some models, giving rise to inappropriately increased release of norepinephrine. Aspects of ADHD behaviour may result from an imbalance between increased noradrenergic and decreased dopaminergic regulation of neural circuits that involve the prefrontal cortex. Animal models of ADHD also suggest that neural circuits may be altered in the brains of children with ADHD. It is therefore of particular importance to study animal models of the disorder and not normal animals. Evidence obtained from animal models suggests that psychostimulants may not be acting on the dopamine transporter to produce the expected increase in extracellular dopamine concentration in ADHD. There is evidence to suggest that psychostimulants may decrease motor activity by increasing serotonin levels. In

  10. Recording Lifetime Behavior and Movement in an Invertebrate Model

    PubMed Central

    Zou, Sige; Liedo, Pablo; Altamirano-Robles, Leopoldo; Cruz-Enriquez, Janeth; Morice, Amy; Ingram, Donald K.; Kaub, Kevin; Papadopoulos, Nikos; Carey, James R.

    2011-01-01

    Characterization of lifetime behavioral changes is essential for understanding aging and aging-related diseases. However, such studies are scarce partly due to the lack of efficient tools. Here we describe and provide proof of concept for a stereo vision system that classifies and sequentially records at an extremely fine scale six different behaviors (resting, micro-movement, walking, flying, feeding and drinking) and the within-cage (3D) location of individual tephritid fruit flies by time-of-day throughout their lives. Using flies fed on two different diets, full sugar-yeast and sugar-only diets, we report for the first time their behavioral changes throughout their lives at a high resolution. We have found that the daily activity peaks at the age of 15–20 days and then gradually declines with age for flies on both diets. However, the overall daily activity is higher for flies on sugar-only diet than those on the full diet. Flies on sugar-only diet show a stronger diurnal localization pattern with higher preference to staying on the top of the cage during the period of light-off when compared to flies on the full diet. Clustering analyses of age-specific behavior patterns reveal three distinct young, middle-aged and old clusters for flies on each of the two diets. The middle-aged groups for flies on sugar-only diet consist of much younger age groups when compared to flies on full diet. This technology provides research opportunities for using a behavioral informatics approach for understanding different ways in which behavior, movement, and aging in model organisms are mutually affecting. PMID:21559058

  11. Large animal models for vaccine development and testing.

    PubMed

    Gerdts, Volker; Wilson, Heather L; Meurens, Francois; van Drunen Littel-van den Hurk, Sylvia; Wilson, Don; Walker, Stewart; Wheler, Colette; Townsend, Hugh; Potter, Andrew A

    2015-01-01

    The development of human vaccines continues to rely on the use of animals for research. Regulatory authorities require novel vaccine candidates to undergo preclinical assessment in animal models before being permitted to enter the clinical phase in human subjects. Substantial progress has been made in recent years in reducing and replacing the number of animals used for preclinical vaccine research through the use of bioinformatics and computational biology to design new vaccine candidates. However, the ultimate goal of a new vaccine is to instruct the immune system to elicit an effective immune response against the pathogen of interest, and no alternatives to live animal use currently exist for evaluation of this response. Studies identifying the mechanisms of immune protection; determining the optimal route and formulation of vaccines; establishing the duration and onset of immunity, as well as the safety and efficacy of new vaccines, must be performed in a living system. Importantly, no single animal model provides all the information required for advancing a new vaccine through the preclinical stage, and research over the last two decades has highlighted that large animals more accurately predict vaccine outcome in humans than do other models. Here we review the advantages and disadvantages of large animal models for human vaccine development and demonstrate that much of the success in bringing a new vaccine to market depends on choosing the most appropriate animal model for preclinical testing.

  12. Using animal models to develop new treatments for tuberculosis.

    PubMed

    Nuermberger, Eric

    2008-10-01

    Animal models have an important role in the preclinical evaluation of new antituberculosis drug candidates. Although it does not recapitulate the clinicopathological manifestations of tuberculosis in humans, the mouse remains the best characterized and most economical animal model for experimental chemotherapy. Provided care is taken to optimize the experimental conditions, the mouse has produced reliable data on the bactericidal and sterilizing activity of existing antituberculosis drugs and informed numerous clinical trials. Still, other animal models, especially the guinea pig, may have utility as confirmatory, or even alternative, models under certain circumstances. This chapter reviews some of the important considerations when selecting an animal model and presents a model for the sequential evaluation of a new compound with promising antituberculosis activity.

  13. Implementing a modeling software for animated protein-complex interactions using a physics simulation library.

    PubMed

    Ueno, Yutaka; Ito, Shuntaro; Konagaya, Akihiko

    2014-12-01

    To better understand the behaviors and structural dynamics of proteins within a cell, novel software tools are being developed that can create molecular animations based on the findings of structural biology. This study proposes our method developed based on our prototypes to detect collisions and examine the soft-body dynamics of molecular models. The code was implemented with a software development toolkit for rigid-body dynamics simulation and a three-dimensional graphics library. The essential functions of the target software system included the basic molecular modeling environment, collision detection in the molecular models, and physical simulations of the movement of the model. Taking advantage of recent software technologies such as physics simulation modules and interpreted scripting language, the functions required for accurate and meaningful molecular animation were implemented efficiently.

  14. Large animal model for development of functional restoration paradigms using epidural and intraspinal stimulation.

    PubMed

    Hachmann, Jan T; Jeong, Ju Ho; Grahn, Peter J; Mallory, Grant W; Evertz, Loribeth Q; Bieber, Allan J; Lobel, Darlene A; Bennet, Kevin E; Lee, Kendall H; Lujan, J Luis

    2013-01-01

    Restoration of movement following spinal cord injury (SCI) has been achieved using electrical stimulation of peripheral nerves and skeletal muscles. However, practical limitations such as the rapid onset of muscle fatigue hinder clinical application of these technologies. Recently, direct stimulation of alpha motor neurons has shown promise for evoking graded, controlled, and sustained muscle contractions in rodent and feline animal models while overcoming some of these limitations. However, small animal models are not optimal for the development of clinical spinal stimulation techniques for functional restoration of movement. Furthermore, variance in surgical procedure, targeting, and electrode implantation techniques can compromise therapeutic outcomes and impede comparison of results across studies. Herein, we present a protocol and large animal model that allow standardized development, testing, and optimization of novel clinical strategies for restoring motor function following spinal cord injury. We tested this protocol using both epidural and intraspinal stimulation in a porcine model of spinal cord injury, but the protocol is suitable for the development of other novel therapeutic strategies. This protocol will help characterize spinal circuits vital for selective activation of motor neuron pools. In turn, this will expedite the development and validation of high-precision therapeutic targeting strategies and stimulation technologies for optimal restoration of motor function in humans. PMID:24339929

  15. Animal models of gastrointestinal and liver diseases. Animal models of cystic fibrosis: gastrointestinal, pancreatic, and hepatobiliary disease and pathophysiology

    PubMed Central

    Olivier, Alicia K.; Gibson-Corley, Katherine N.

    2015-01-01

    Multiple organ systems, including the gastrointestinal tract, pancreas, and hepatobiliary systems, are affected by cystic fibrosis (CF). Many of these changes begin early in life and are difficult to study in young CF patients. Recent development of novel CF animal models has expanded opportunities in the field to better understand CF pathogenesis and evaluate traditional and innovative therapeutics. In this review, we discuss manifestations of CF disease in gastrointestinal, pancreatic, and hepatobiliary systems of humans and animal models. We also compare the similarities and limitations of animal models and discuss future directions for modeling CF. PMID:25591863

  16. Animal models of gastrointestinal and liver diseases. Animal models of cystic fibrosis: gastrointestinal, pancreatic, and hepatobiliary disease and pathophysiology.

    PubMed

    Olivier, Alicia K; Gibson-Corley, Katherine N; Meyerholz, David K

    2015-03-15

    Multiple organ systems, including the gastrointestinal tract, pancreas, and hepatobiliary systems, are affected by cystic fibrosis (CF). Many of these changes begin early in life and are difficult to study in young CF patients. Recent development of novel CF animal models has expanded opportunities in the field to better understand CF pathogenesis and evaluate traditional and innovative therapeutics. In this review, we discuss manifestations of CF disease in gastrointestinal, pancreatic, and hepatobiliary systems of humans and animal models. We also compare the similarities and limitations of animal models and discuss future directions for modeling CF.

  17. Nutraceuticals in joint health: animal models as instrumental tools.

    PubMed

    Mével, Elsa; Monfoulet, Laurent-Emmanuel; Merceron, Christophe; Coxam, Véronique; Wittrant, Yohann; Beck, Laurent; Guicheux, Jérôme

    2014-10-01

    Osteoarthritis (OA) is a degenerative joint disease with no curative treatments. Many studies have begun to demonstrate the efficacy of nutraceuticals for slowing down OA. Animal models are utilized as a compulsory step in demonstrating the protective potential of these compounds on joint health. Nevertheless, there exist a wide variety of available OA models and selecting a suitable system for evaluating the effects of a specific compound remains difficult. Here, we discuss animal studies that have investigated nutraceutical effects on OA. In particular, we highlight the large spectrum of animal models that are currently accepted for examining the OA-related effects of nutraceuticals, giving recommendations for their use. PMID:24955836

  18. Animator

    ERIC Educational Resources Information Center

    Tech Directions, 2008

    2008-01-01

    Art and animation work is the most significant part of electronic game development, but is also found in television commercials, computer programs, the Internet, comic books, and in just about every visual media imaginable. It is the part of the project that makes an abstract design idea concrete and visible. Animators create the motion of life in…

  19. A systematic review of animal models for Staphylococcus aureus osteomyelitis

    PubMed Central

    Reizner, W.; Hunter, J.G.; O’Malley, N.T.; Southgate, R.D.; Schwarz, E.M.; Kates, S.L.

    2015-01-01

    Staphylococcus aureus (S. aureus) osteomyelitis is a significant complication for orthopaedic patients undergoing surgery, particularly with fracture fixation and arthroplasty. Given the difficulty in studying S. aureus infections in human subjects, animal models serve an integral role in exploring the pathogenesis of osteomyelitis, and aid in determining the efficacy of prophylactic and therapeutic treatments. Animal models should mimic the clinical scenarios seen in patients as closely as possible to permit the experimental results to be translated to the corresponding clinical care. To help understand existing animal models of S. aureus, we conducted a systematic search of PubMed & Ovid MEDLINE to identify in vivo animal experiments that have investigated the management of S. aureus osteomyelitis in the context of fractures and metallic implants. In this review, experimental studies are categorized by animal species and are further classified by the setting of the infection. Study methods are summarized and the relevant advantages and disadvantages of each species and model are discussed. While no ideal animal model exists, the understanding of a model’s strengths and limitations should assist clinicians and researchers to appropriately select an animal model to translate the conclusions to the clinical setting. PMID:24668594

  20. Atherosclerosis and Thrombosis: Insights from Large Animal Models

    PubMed Central

    Vilahur, Gemma; Padro, Teresa; Badimon, Lina

    2011-01-01

    Atherosclerosis and its thrombotic complications are responsible for remarkably high numbers of deaths. The combination of in vitro, ex vivo, and in vivo experimental approaches has largely contributed to a better understanding of the mechanisms underlying the atherothrombotic process. Indeed, different animal models have been implemented in atherosclerosis and thrombosis research in order to provide new insights into the mechanisms that have already been outlined in isolated cells and protein studies. Yet, although no model completely mimics the human pathology, large animal models have demonstrated better suitability for translation to humans. Indeed, direct translation from mice to humans should be taken with caution because of the well-reported species-related differences. This paper provides an overview of the available atherothrombotic-like animal models, with a particular focus on large animal models of thrombosis and atherosclerosis, and examines their applicability for translational research purposes as well as highlights species-related differences with humans. PMID:21274431

  1. Animal Models of Psychosis: Current State and Future Directions

    PubMed Central

    Forrest, Alexandra D.; Coto, Carlos A.; Siegel, Steven J.

    2014-01-01

    Psychosis is an abnormal mental state characterized by disorganization, delusions and hallucinations. Animal models have become an increasingly important research tool in the effort to understand both the underlying pathophysiology and treatment of psychosis. There are multiple animal models for psychosis, with each formed by the coupling of a manipulation and a measurement. In this manuscript we do not address the diseases of which psychosis is a prominent comorbidity. Instead, we summarize the current state of affairs and future directions for animal models of psychosis. To accomplish this, our manuscript will first discuss relevant behavioral and electrophysiological measurements. We then provide an overview of the different manipulations that are combined with these measurements to produce animal models. The strengths and limitations of each model will be addressed in order to evaluate its cross-species comparability. PMID:25215267

  2. Animal models are reliably mimicking human diseases? A morphological study that compares animal with human NAFLD.

    PubMed

    Solinas, Paola; Isola, Michela; Lilliu, Maria Alberta; Conti, Gabriele; Civolani, Alberto; Demelia, Luigi; Loy, Francesco; Isola, Raffaella

    2014-10-01

    Non-alcoholic fatty liver disease (NAFLD) is a clinical-pathological syndrome that includes a wide spectrum of morphological alterations. In research, animal models are crucial in evaluating not only the pathogenesis of NAFLD and its progression, but also the therapeutic effects of various agents. Investigations on the ultrastructural features of NAFLD in humans are not copious, due to the difficulty to obtain human samples and to the long time of NAFLD to evolve. Translational comparative studies on the reliability of animal models in representing the histopathologic picture as seen in humans are missing. To overcome this lack of investigations, we compared the ultrastructural NAFLD features of an animal model versus human. Sprague-Dawley rats were fed with a high fat diet (HFD) for 1-4 weeks, while control rats were fed with a standard diet. Human specimens were collected from patients with diagnosed fatty liver disease, undergoing liver biopsies or surgery. Rat and human samples were examined by light microscopy and by transmission and high resolution scanning electron microscopy. The present work demonstrated that NAFLD in animal model and in human, share overlapping ultrastructural features. In conclusion, animal HFD represent an appropriate tool in studying the pathogenesis of NAFLD.

  3. Animal models for testing anti-prion drugs.

    PubMed

    Fernández-Borges, Natalia; Elezgarai, Saioa R; Eraña, Hasier; Castilla, Joaquín

    2013-01-01

    Prion diseases belong to a group of fatal infectious diseases with no effective therapies available. Throughout the last 35 years, less than 50 different drugs have been tested in different experimental animal models without hopeful results. An important limitation when searching for new drugs is the existence of appropriate models of the disease. The three different possible origins of prion diseases require the existence of different animal models for testing anti-prion compounds. Wild type, over-expressing transgenic mice and other more sophisticated animal models have been used to evaluate a diversity of compounds which some of them were previously tested in different in vitro experimental models. The complexity of prion diseases will require more pre-screening studies, reliable sporadic (or spontaneous) animal models and accurate chemical modifications of the selected compounds before having an effective therapy against human prion diseases. This review is intended to put on display the more relevant animal models that have been used in the search of new antiprion therapies and describe some possible procedures when handling chemical compounds presumed to have anti-prion activity prior to testing them in animal models.

  4. Emerging preclinical animal models for FSHD.

    PubMed

    Lek, Angela; Rahimov, Fedik; Jones, Peter L; Kunkel, Louis M

    2015-05-01

    Facioscapulohumeral dystrophy (FSHD) is a unique and complex genetic disease that is not entirely solved. Recent advances in the field have led to a consensus genetic premise for the disorder, enabling researchers to now pursue the design of preclinical models. In this review we explore all available FSHD models (DUX4-dependent and -independent) for their utility in therapeutic discovery and potential to yield novel disease insights. Owing to the complex nature of FSHD, there is currently no single model that accurately recapitulates the genetic and pathophysiological spectrum of the disorder. Existing models emphasize only specific aspects of the disease, highlighting the need for more collaborative research and novel paradigms to advance the translational research space of FSHD. PMID:25801126

  5. Exploring the Validity of Valproic Acid Animal Model of Autism

    PubMed Central

    Mabunga, Darine Froy N.; Gonzales, Edson Luck T.; Kim, Ji-woon; Kim, Ki Chan

    2015-01-01

    The valproic acid (VPA) animal model of autism spectrum disorder (ASD) is one of the most widely used animal model in the field. Like any other disease models, it can't model the totality of the features seen in autism. Then, is it valid to model autism? This model demonstrates many of the structural and behavioral features that can be observed in individuals with autism. These similarities enable the model to define relevant pathways of developmental dysregulation resulting from environmental manipulation. The uncovering of these complex pathways resulted to the growing pool of potential therapeutic candidates addressing the core symptoms of ASD. Here, we summarize the validity points of VPA that may or may not qualify it as a valid animal model of ASD. PMID:26713077

  6. Animal Models of Posttraumatic Seizures and Epilepsy.

    PubMed

    Glushakov, Alexander V; Glushakova, Olena Y; Doré, Sylvain; Carney, Paul R; Hayes, Ronald L

    2016-01-01

    Posttraumatic epilepsy (PTE) is one of the most common and devastating complications of traumatic brain injury (TBI). Currently, the etiopathology and mechanisms of PTE are poorly understood and as a result, there is no effective treatment or means to prevent it. Antiepileptic drugs remain common preventive strategies in the management of TBI to control acute posttraumatic seizures and to prevent the development of PTE, although their efficacy in the latter case is disputed. Different strategies of PTE prophylaxis have been showing promise in preclinical models, but their translation to the clinic still remains elusive due in part to the variability of these models and the fact they do not recapitulate all complex pathologies associated with human TBI. TBI is a multifaceted disorder reflected in several potentially epileptogenic alterations in the brain, including mechanical neuronal and vascular damage, parenchymal and subarachnoid hemorrhage, subsequent toxicity caused by iron-rich hemoglobin breakdown products, and energy disruption resulting in secondary injuries, including excitotoxicity, gliosis, and neuroinflammation, often coexisting to a different degree. Several in vivo models have been developed to reproduce the acute TBI cascade of events, to reflect its anatomical pathologies, and to replicate neurological deficits. Although acute and chronic recurrent posttraumatic seizures are well-recognized phenomena in these models, there is only a limited number of studies focused on PTE. The most used mechanical TBI models with documented electroencephalographic and behavioral seizures with remote epileptogenesis include fluid percussion, controlled cortical impact, and weight-drop. This chapter describes the most popular models of PTE-induced TBI models, focusing on the controlled cortical impact and the fluid percussion injury models, the methods of behavioral and electroencephalogram seizure assessments, and other approaches to detect epileptogenic properties

  7. Sex differences in animal models of psychiatric disorders.

    PubMed

    Kokras, N; Dalla, C

    2014-10-01

    Psychiatric disorders are characterized by sex differences in their prevalence, symptomatology and treatment response. Animal models have been widely employed for the investigation of the neurobiology of such disorders and the discovery of new treatments. However, mostly male animals have been used in preclinical pharmacological studies. In this review, we highlight the need for the inclusion of both male and female animals in experimental studies aiming at gender-oriented prevention, diagnosis and treatment of psychiatric disorders. We present behavioural findings on sex differences from animal models of depression, anxiety, post-traumatic stress disorder, substance-related disorders, obsessive-compulsive disorder, schizophrenia, bipolar disorder and autism. Moreover, when available, we include studies conducted across different stages of the oestrous cycle. By inspection of the relevant literature, it is obvious that robust sex differences exist in models of all psychiatric disorders. However, many times results are conflicting, and no clear conclusion regarding the direction of sex differences and the effect of the oestrous cycle is drawn. Moreover, there is a lack of considerable amount of studies using psychiatric drugs in both male and female animals, in order to evaluate the differential response between the two sexes. Notably, while in most cases animal models successfully mimic drug response in both sexes, test parameters and treatment-sensitive behavioural indices are not always the same for male and female rodents. Thus, there is an increasing need to validate animal models for both sexes and use standard procedures across different laboratories. PMID:24697577

  8. GHRH treatment: studies in an animal model.

    PubMed

    Shakutsui, S; Abe, H; Chihara, K

    1989-01-01

    This study examined the effects of chronic deletion of circulating growth hormone-releasing (GHRH) and/or somatostatin (SRIF) on normal growing male rats, as well as the effects of exogenous GHRH (1-29)NH2 and/or SMS 201-995 administration on the growth of rats with hypothalamic ablation. Passive immunization with anti-rat GHRH goat gamma-globulin (GHRH-Ab) for 3 weeks caused a marked decrease in the levels of pituitary GH mRNA and severe growth failure. Treatment with anti-SRIF goat gamma-globulin (SRIF-Ab) for 3 weeks produced a more modest decrease in GH mRNA levels in the pituitary and a slight but significant inhibition of normal somatic growth. Hypothalamic ablation produced a marked decrease in the level of mRNA in the pituitary. Chronic continuous administration of GHRH (1-29)NH2 stimulated pituitary GH synthesis, elevated serum levels of insulin-like growth factor I and increased body weight gain in rats with hypothalamic ablation treated with replacement doses of cortisone, testosterone and L-thyroxine. Combined treatment with GHRH (1-29)NH2 and SMS 201-995 appeared to promote the effect of GHRH on pituitary GH release and somatic growth in these animals. The results suggest that continuous administration of GHRH will be useful in the treatment of children with growth retardation resulting from hypothalamic disorders. In children with combined GHRH and somatostatin deficiencies, the addition of somatostatin to a GHRH treatment regimen may produce better results. PMID:2568726

  9. Stimulation of circus movement by activin, bFGF and TGF-beta 2 in isolated animal cap cells of Xenopus laevis.

    PubMed

    Minoura, I; Nakamura, H; Tashiro, K; Shiokawa, K

    1995-01-01

    Lobopodium is a hyaline cytoplasmic protrusion which rotates circumferencially around a cell. This movement is called circus movement, which is seen in dissociated cells of amphibian embryos. Relative abundance of the lobopodia-forming cells changes temporally and spatially within Xenopus embryos, reflecting stage-dependent difference of morphogenetic movements. The lobopodia-forming activity of dissociated animal cap cells was stimulated strongly by activin and bFGF, and weakly by TGF-beta 2. In addition, activin A was found to stimulate cellular attachment to the substratum when the cultivation lasted long. Thus, mesoderm-inducing growth factors stimulate lobopodia formation and cellular movements which may be necessary for gastrulation and neurulation in Xenopus early embryos.

  10. Tracking boundary movement and exterior shape modelling in lung EIT imaging.

    PubMed

    Biguri, A; Grychtol, B; Adler, A; Soleimani, M

    2015-06-01

    Electrical impedance tomography (EIT) has shown significant promise for lung imaging. One key challenge for EIT in this application is the movement of electrodes during breathing, which introduces artefacts in reconstructed images. Various approaches have been proposed to compensate for electrode movement, but no comparison of these approaches is available. This paper analyses boundary model mismatch and electrode movement in lung EIT. The aim is to evaluate the extent to which various algorithms tolerate movement, and to determine if a patient specific model is required for EIT lung imaging. Movement data are simulated from a CT-based model, and image analysis is performed using quantitative figures of merit. The electrode movement is modelled based on expected values of chest movement and an extended Jacobian method is proposed to make use of exterior boundary tracking. Results show that a dynamical boundary tracking is the most robust method against any movement, but is computationally more expensive. Simultaneous electrode movement and conductivity reconstruction algorithms show increased robustness compared to only conductivity reconstruction. The results of this comparative study can help develop a better understanding of the impact of shape model mismatch and electrode movement in lung EIT.

  11. How do animal territories form and change? Lessons from 20 years of mechanistic modelling.

    PubMed

    Potts, Jonathan R; Lewis, Mark A

    2014-06-01

    Territory formation is ubiquitous throughout the animal kingdom. At the individual level, various behaviours attempt to exclude conspecifics from regions of space. At the population level, animals often segregate into distinct territorial areas. Consequently, it should be possible to derive territorial patterns from the underlying behavioural processes of animal movements and interactions. Such derivations are an important element in the development of an ecological theory that can predict the effects of changing conditions on territorial populations. Here, we review the approaches developed over the past 20 years or so, which go under the umbrella of 'mechanistic territorial models'. We detail the two main strands to this research: partial differential equations and individual-based approaches, showing what each has offered to our understanding of territoriality and how they can be unified. We explain how they are related to other approaches to studying territories and home ranges, and point towards possible future directions. PMID:24741017

  12. Animal models for screening anxiolytic-like drugs: a perspective.

    PubMed

    Bourin, Michel

    2015-09-01

    Contemporary biological psychiatry uses experimental animal models to increase our understanding of affective disorder pathogenesis. Modern anxiolytic drug discovery mainly targets specific pathways and molecular determinants within a single phenotypic domain. However, greater understanding of the mechanisms of action is possible through animal models. Primarily developed with rats, animal models in anxiety have been adapted with mixed success for mice, easy-to-use mammals with better genetic possibilities than rats. In this review, we focus on the three most common animal models of anxiety in mice used in the screening of anxiolytics. Both conditioned and unconditioned models are described, in order to represent all types of animal models of anxiety. Behavioral studies require careful attention to variable parameters linked to environment, handling, or paradigms; this is also discussed. Finally, we focus on the consequences of re-exposure to the apparatus. Test-retest procedures can provide new answers, but should be intensively studied in order to revalidate the entire paradigm as an animal model of anxiety.

  13. Animal Models in Cardiovascular Research: Hypertension and Atherosclerosis

    PubMed Central

    Ng, Chun-Yi; Jaarin, Kamsiah

    2015-01-01

    Hypertension and atherosclerosis are among the most common causes of mortality in both developed and developing countries. Experimental animal models of hypertension and atherosclerosis have become a valuable tool for providing information on etiology, pathophysiology, and complications of the disease and on the efficacy and mechanism of action of various drugs and compounds used in treatment. An animal model has been developed to study hypertension and atherosclerosis for several reasons. Compared to human models, an animal model is easily manageable, as compounding effects of dietary and environmental factors can be controlled. Blood vessels and cardiac tissue samples can be taken for detailed experimental and biomolecular examination. Choice of animal model is often determined by the research aim, as well as financial and technical factors. A thorough understanding of the animal models used and complete analysis must be validated so that the data can be extrapolated to humans. In conclusion, animal models for hypertension and atherosclerosis are invaluable in improving our understanding of cardiovascular disease and developing new pharmacological therapies. PMID:26064920

  14. Animal models for screening anxiolytic-like drugs: a perspective

    PubMed Central

    Bourin, Michel

    2015-01-01

    Contemporary biological psychiatry uses experimental animal models to increase our understanding of affective disorder pathogenesis. Modern anxiolytic drug discovery mainly targets specific pathways and molecular determinants within a single phenotypic domain. However, greater understanding of the mechanisms of action is possible through animal models. Primarily developed with rats, animal models in anxiety have been adapted with mixed success for mice, easy-to-use mammals with better genetic possibilities than rats. In this review, we focus on the three most common animal models of anxiety in mice used in the screening of anxiolytics. Both conditioned and unconditioned models are described, in order to represent all types of animal models of anxiety. Behavioral studies require careful attention to variable parameters linked to environment, handling, or paradigms; this is also discussed. Finally, we focus on the consequences of re-exposure to the apparatus. Test-retest procedures can provide new answers, but should be intensively studied in order to revalidate the entire paradigm as an animal model of anxiety. PMID:26487810

  15. Animal models for arthritis: innovative tools for prevention and treatment.

    PubMed

    Kollias, George; Papadaki, Piyi; Apparailly, Florence; Vervoordeldonk, Margriet J; Holmdahl, Rikard; Baumans, Vera; Desaintes, Christian; Di Santo, James; Distler, Jörg; Garside, Paul; Hegen, Martin; Huizinga, Tom W J; Jüngel, Astrid; Klareskog, Lars; McInnes, Iain; Ragoussis, Ioannis; Schett, Georg; Hart, Bert 't; Tak, Paul P; Toes, Rene; van den Berg, Wim; Wurst, Wolfgang; Gay, Steffen

    2011-08-01

    The development of novel treatments for rheumatoid arthritis (RA) requires the interplay between clinical observations and studies in animal models. Given the complex molecular pathogenesis and highly heterogeneous clinical picture of RA, there is an urgent need to dissect its multifactorial nature and to propose new strategies for preventive, early and curative treatments. Research on animal models has generated new knowledge on RA pathophysiology and aetiology and has provided highly successful paradigms for innovative drug development. Recent focus has shifted towards the discovery of novel biomarkers, with emphasis on presymptomatic and emerging stages of human RA, and towards addressing the pathophysiological mechanisms and subsequent efficacy of interventions that underlie different disease variants. Shifts in the current paradigms underlying RA pathogenesis have also led to increased demand for new (including humanised) animal models. There is therefore an urgent need to integrate the knowledge on human and animal models with the ultimate goal of creating a comprehensive 'pathogenesis map' that will guide alignment of existing and new animal models to the subset of disease they mimic. This requires full and standardised characterisation of all models at the genotypic, phenotypic and biomarker level, exploiting recent technological developments in 'omics' profiling and computational biology as well as state of the art bioimaging. Efficient integration and dissemination of information and resources as well as outreach to the public will be necessary to manage the plethora of data accumulated and to increase community awareness and support for innovative animal model research in rheumatology.

  16. ASSESSMENT OF VENOUS THROMBOSIS IN ANIMAL MODELS

    PubMed Central

    SP, Grover; CE, Evans; AS, Patel; B, Modarai; P, Saha; A, Smith

    2016-01-01

    Deep vein thrombosis and common complications, including pulmonary embolism and post thrombotic syndrome, represent a major source of morbidity and mortality worldwide. Experimental models of venous thrombosis have provided considerable insight into the cellular and molecular mechanisms that regulate thrombus formation and subsequent resolution. Here we critically appraise the ex vivo and in vivo techniques used to assess venous thrombosis in these models. Particular attention is paid to imaging modalities, including magnetic resonance imaging, micro computed tomography and high frequency ultrasound that facilitate longitudinal assessment of thrombus size and composition. PMID:26681755

  17. Assessment of Venous Thrombosis in Animal Models.

    PubMed

    Grover, Steven P; Evans, Colin E; Patel, Ashish S; Modarai, Bijan; Saha, Prakash; Smith, Alberto

    2016-02-01

    Deep vein thrombosis and common complications, including pulmonary embolism and post-thrombotic syndrome, represent a major source of morbidity and mortality worldwide. Experimental models of venous thrombosis have provided considerable insight into the cellular and molecular mechanisms that regulate thrombus formation and subsequent resolution. Here, we critically appraise the ex vivo and in vivo techniques used to assess venous thrombosis in these models. Particular attention is paid to imaging modalities, including magnetic resonance imaging, micro-computed tomography, and high-frequency ultrasound that facilitate longitudinal assessment of thrombus size and composition.

  18. Animal Models of Uveal Melanoma: Methods, Applicability, and Limitations.

    PubMed

    Stei, Marta M; Loeffler, Karin U; Holz, Frank G; Herwig, Martina C

    2016-01-01

    Animal models serve as powerful tools for investigating the pathobiology of cancer, identifying relevant pathways, and developing novel therapeutic agents. They have facilitated rapid scientific progress in many tumor entities. However, for establishing a powerful animal model of uveal melanoma fundamental challenges remain. To date, no animal model offers specific genetic attributes as well as histologic, immunologic, and metastatic features of uveal melanoma. Syngeneic models with intraocular injection of cutaneous melanoma cells may suit best for investigating immunologic/tumor biology aspects. However, differences between cutaneous and uveal melanoma regarding genetics and metastasis remain problematic. Human xenograft models are widely used for evaluating novel therapeutics but require immunosuppression to allow tumor growth. New approaches aim to establish transgenic mouse models of spontaneous uveal melanoma which recently provided preliminary promising results. Each model provides certain benefits and may render them suitable for answering a respective scientific question. However, all existing models also exhibit relevant limitations which may have led to delayed research progress. Despite refined therapeutic options for the primary ocular tumor, patients' prognosis has not improved since the 1970s. Basic research needs to further focus on a refinement of a potent animal model which mimics uveal melanoma specific mechanisms of progression and metastasis. This review will summarise and interpret existing animal models of uveal melanoma including recent advances in the field. PMID:27366747

  19. Animal Models of Uveal Melanoma: Methods, Applicability, and Limitations

    PubMed Central

    Stei, Marta M.; Loeffler, Karin U.; Holz, Frank G.; Herwig, Martina C.

    2016-01-01

    Animal models serve as powerful tools for investigating the pathobiology of cancer, identifying relevant pathways, and developing novel therapeutic agents. They have facilitated rapid scientific progress in many tumor entities. However, for establishing a powerful animal model of uveal melanoma fundamental challenges remain. To date, no animal model offers specific genetic attributes as well as histologic, immunologic, and metastatic features of uveal melanoma. Syngeneic models with intraocular injection of cutaneous melanoma cells may suit best for investigating immunologic/tumor biology aspects. However, differences between cutaneous and uveal melanoma regarding genetics and metastasis remain problematic. Human xenograft models are widely used for evaluating novel therapeutics but require immunosuppression to allow tumor growth. New approaches aim to establish transgenic mouse models of spontaneous uveal melanoma which recently provided preliminary promising results. Each model provides certain benefits and may render them suitable for answering a respective scientific question. However, all existing models also exhibit relevant limitations which may have led to delayed research progress. Despite refined therapeutic options for the primary ocular tumor, patients' prognosis has not improved since the 1970s. Basic research needs to further focus on a refinement of a potent animal model which mimics uveal melanoma specific mechanisms of progression and metastasis. This review will summarise and interpret existing animal models of uveal melanoma including recent advances in the field. PMID:27366747

  20. Animal models of gastrointestinal and liver diseases. Animal models of visceral pain: pathophysiology, translational relevance, and challenges.

    PubMed

    Greenwood-Van Meerveld, Beverley; Prusator, Dawn K; Johnson, Anthony C

    2015-06-01

    Visceral pain describes pain emanating from the thoracic, pelvic, or abdominal organs. In contrast to somatic pain, visceral pain is generally vague, poorly localized, and characterized by hypersensitivity to a stimulus such as organ distension. Animal models have played a pivotal role in our understanding of the mechanisms underlying the pathophysiology of visceral pain. This review focuses on animal models of visceral pain and their translational relevance. In addition, the challenges of using animal models to develop novel therapeutic approaches to treat visceral pain will be discussed.

  1. Mathematical modelling of animate and intentional motion.

    PubMed Central

    Rittscher, Jens; Blake, Andrew; Hoogs, Anthony; Stein, Gees

    2003-01-01

    Our aim is to enable a machine to observe and interpret the behaviour of others. Mathematical models are employed to describe certain biological motions. The main challenge is to design models that are both tractable and meaningful. In the first part we will describe how computer vision techniques, in particular visual tracking, can be applied to recognize a small vocabulary of human actions in a constrained scenario. Mainly the problems of viewpoint and scale invariance need to be overcome to formalize a general framework. Hence the second part of the article is devoted to the question whether a particular human action should be captured in a single complex model or whether it is more promising to make extensive use of semantic knowledge and a collection of low-level models that encode certain motion primitives. Scene context plays a crucial role if we intend to give a higher-level interpretation rather than a low-level physical description of the observed motion. A semantic knowledge base is used to establish the scene context. This approach consists of three main components: visual analysis, the mapping from vision to language and the search of the semantic database. A small number of robust visual detectors is used to generate a higher-level description of the scene. The approach together with a number of results is presented in the third part of this article. PMID:12689374

  2. Retinal degeneration in animal models with a defective visual cycle

    PubMed Central

    Maeda, Akiko; Palczewski, Krzysztof

    2014-01-01

    Continuous generation of visual chromophore through the visual (retinoid) cycle is essential to maintain eyesight and retinal heath. Impairments in this cycle and related pathways adversely affect vision. In this review, we summarize the chemical reactions of vitamin A metabolites involved in the retinoid cycle and describe animal models of associated human diseases. Development of potential therapies for retinal disorders in these animal models is also introduced. PMID:25210527

  3. Proteomics in farm animals models of human diseases.

    PubMed

    Ceciliani, Fabrizio; Restelli, Laura; Lecchi, Cristina

    2014-10-01

    The need to provide in vivo complex environments to understand human diseases strongly relies on the use of animal models, which traditionally include small rodents and rabbits. It is becoming increasingly evident that the few species utilised to date cannot be regarded as universal. There is a great need for new animal species that are naturally endowed with specific features relevant to human diseases. Farm animals, including pigs, cows, sheep and horses, represent a valid alternative to commonly utilised rodent models. There is an ample scope for the application of proteomic techniques in farm animals, and the establishment of several proteomic maps of plasma and tissue has clearly demonstrated that farm animals provide a disease environment that closely resembles that of human diseases. The present review offers a snapshot of how proteomic techniques have been applied to farm animals to improve their use as biomedical models. Focus will be on specific topics of biomedical research in which farm animal models have been characterised through the application of proteomic techniques.

  4. Current and new cytomegalovirus antivirals and novel animal model strategies.

    PubMed

    McGregor, Alistair

    2010-09-01

    Cytomegalovirus (CMV) is a significant health problem among immunosuppressed individuals. In particular, transplant and AIDS patients and the developing fetus in utero are highly susceptible to CMV. In these vulnerable populations, infection leads to life threatening end organ viral disease or in surviving newborn babies to deafness or to mental retardation. Currently, the most effective way to control CMV infection, given the lack of an effective vaccine, is by antiviral therapy. However, available antivirals suffer from complications associated with prolonged use, such as drug toxicity as well as the emergence of resistant strains of virus. Additionally, since CMV has multiple complex immune evasion strategies, to avoid innate and adaptive immune responses, there is a need for new antiviral development. Any antiviral should be tested in a controlled animal model but species specificity of HCMV precludes the direct study of the virus in an animal model. Consequently, animal CMV in their respective animal host are used to study intervention strategies. In this review, both current and new antiviral strategies are discussed as are the various animal models and strategies to improve existing antiviral animal models by humanizing animal CMV.

  5. The FAO/NACA Asia Regional Technical Guidelines on Health Management for the Responsible Movement of Live Aquatic Animals: lessons learned from their development and implementation.

    PubMed

    Subasinghe, R P; Bondad-Reantaso, M G

    2008-04-01

    Aquaculture is the fastest growing food producing sector in the world and it is expected to produce significant quantities of fish in the coming years to meet the growing global demand for aquatic animal products. The expansion and diversification of the sector, along with globalisation and trade liberalisation have resulted in aquatic animals and animal products moving around the world rapidly, causing serious disease outbreaks stemming from incursions of pathogens through unregulated transboundary movements. It has become necessary to develop appropriate guidelines for establishing national regulatory frameworks to improve responsibility in transboundary movement of live aquatic animals. In 2000, the Food and Agriculture Organization of the United Nations (FAO), in collaboration with the Network of Aquaculture Centres in Asia-Pacific (NACA) and in partnership with 21 Asian countries, developed the Asia Regional Technical Guidelines on Health Management for the Responsible Movement of Live Aquatic Animals. The present article outlines the development process of the guidelines, the lessons learned from their implementation at national level and the way forward. PMID:18666478

  6. The FAO/NACA Asia Regional Technical Guidelines on Health Management for the Responsible Movement of Live Aquatic Animals: lessons learned from their development and implementation.

    PubMed

    Subasinghe, R P; Bondad-Reantaso, M G

    2008-04-01

    Aquaculture is the fastest growing food producing sector in the world and it is expected to produce significant quantities of fish in the coming years to meet the growing global demand for aquatic animal products. The expansion and diversification of the sector, along with globalisation and trade liberalisation have resulted in aquatic animals and animal products moving around the world rapidly, causing serious disease outbreaks stemming from incursions of pathogens through unregulated transboundary movements. It has become necessary to develop appropriate guidelines for establishing national regulatory frameworks to improve responsibility in transboundary movement of live aquatic animals. In 2000, the Food and Agriculture Organization of the United Nations (FAO), in collaboration with the Network of Aquaculture Centres in Asia-Pacific (NACA) and in partnership with 21 Asian countries, developed the Asia Regional Technical Guidelines on Health Management for the Responsible Movement of Live Aquatic Animals. The present article outlines the development process of the guidelines, the lessons learned from their implementation at national level and the way forward.

  7. Chimeric animal models in human stem cell biology.

    PubMed

    Glover, Joel C; Boulland, Jean-Luc; Halasi, Gabor; Kasumacic, Nedim

    2009-01-01

    The clinical use of stem cells for regenerative medicine is critically dependent on preclinical studies in animal models. In this review we examine some of the key issues and challenges in the use of animal models to study human stem cell biology-experimental standardization, body size, immunological barriers, cell survival factors, fusion of host and donor cells, and in vivo imaging and tracking. We focus particular attention on the various imaging modalities that can be used to track cells in living animals, comparing their strengths and weaknesses and describing technical developments that are likely to lead to new opportunities for the dynamic assessment of stem cell behavior in vivo. We then provide an overview of some of the most commonly used animal models, their advantages and disadvantages, and examples of their use for xenotypic transplantation of human stem cells, with separate reviews of models involving rodents, ungulates, nonhuman primates, and the chicken embryo. As the use of human somatic, embryonic, and induced pluripotent stem cells increases, so too will the range of applications for these animal models. It is likely that increasingly sophisticated uses of human/animal chimeric models will be developed through advances in genetic manipulation, cell delivery, and in vivo imaging.

  8. Origins of systems biology in William Harvey's masterpiece on the movement of the heart and the blood in animals.

    PubMed

    Auffray, Charles; Noble, Denis

    2009-04-17

    In this article we continue our exploration of the historical roots of systems biology by considering the work of William Harvey. Central arguments in his work on the movement of the heart and the circulation of the blood can be shown to presage the concepts and methods of integrative systems biology. These include: (a) the analysis of the level of biological organization at which a function (e.g. cardiac rhythm) can be said to occur; (b) the use of quantitative mathematical modelling to generate testable hypotheses and deduce a fundamental physiological principle (the circulation of the blood) and (c) the iterative submission of his predictions to an experimental test. This article is the result of a tri-lingual study: as Harvey's masterpiece was published in Latin in 1628, we have checked the original edition and compared it with and between the English and French translations, some of which are given as notes to inform the reader of differences in interpretation.

  9. The Use of Animal Models for Stroke Research: A Review

    PubMed Central

    Casals, Juliana B; Pieri, Naira CG; Feitosa, Matheus LT; Ercolin, Anna CM; Roballo, Kelly CS; Barreto, Rodrigo SN; Bressan, Fabiana F; Martins, Daniele S; Miglino, Maria A; Ambrósio, Carlos E

    2011-01-01

    Stroke has been identified as the second leading cause of death worldwide. Stroke is a focal neurologic deficit caused by a change in cerebral circulation. The use of animal models in recent years has improved our understanding of the physiopathology of this disease. Rats and mice are the most commonly used stroke models, but the demand for larger models, such as rabbits and even nonhuman primates, is increasing so as to better understand the disease and its treatment. Although the basic mechanisms of stroke are nearly identical among mammals, we here discuss the differences between the human encephalon and various animals. In addition, we compare common surgical techniques used to induce animal models of stroke. A more complete anatomic knowledge of the cerebral vessels of various model species is needed to develop more reliable models for objective results that improve knowledge of the pathology of stroke in both human and veterinary medicine. PMID:22330245

  10. The Fuzzy Model for Diagnosis of Animal Disease

    NASA Astrophysics Data System (ADS)

    Jianhua, Xiao; Luyi, Shi; Yu, Zhang; Li, Gao; Honggang, Fan; Haikun, Ma; Hongbin, Wang

    The knowledge of animal disease diagnosis was fuzzy; the fuzzy model can imitate the character of clinical diagnosis for veterinary. The fuzzy model of disease, the methods for class the disease group of differential diagnosis and the fuzzy diagnosis model were discussed in this paper.

  11. Microcosm Experiments and Modeling of Microbial Movement Under Unsaturated Conditions

    SciTech Connect

    Brockman, F.J.; Kapadia, N.; Williams, G.; Rockhold, M.

    2006-04-05

    Colonization of bacteria in porous media has been studied primarily in saturated systems. In this study we examine how microbial colonization in unsaturated porous media is controlled by water content and particle size. This is important for understanding the feasibility and success of bioremediation via nutrient delivery when contaminant degraders are at low densities and when total microbial populations are sparse and spatially discontinuous. The study design used 4 different sand sizes, each at 4 different water contents; experiments were run with and without acetate as the sole carbon source. All experiments were run in duplicate columns and used the motile organism Pseudomonas stutzeri strain KC, a carbon tetrachloride degrader. At a given sand size, bacteria traveled further with increasing volumetric water content. At a given volumetric water content, bacteria generally traveled further with increasing sand size. Water redistribution, solute transport, gas diffusion, and bacterial colonization dynamics were simulated using a numerical finite-difference model. Solute and bacterial transport were modeled using advection-dispersion equations, with reaction rate source/sink terms to account for bacterial growth and substrate utilization, represented using dual Monod-type kinetics. Oxygen transport and diffusion was modeled accounting for equilibrium partitioning between the aqueous and gas phases. The movement of bacteria in the aqueous phase was modeled using a linear impedance model in which the term D{sub m} is a coefficient, as used by Barton and Ford (1995), representing random motility. The unsaturated random motility coefficients we obtained (1.4 x 10{sup -6} to 2.8 x 10{sup -5} cm{sup 2}/sec) are in the same range as those found by others for saturated systems (3.5 x 10{sup -6} to 3.5 x 10{sup -5} cm{sup 2}/sec). The results show that some bacteria can rapidly migrate in well sorted unsaturated sands (and perhaps in relatively high porosity, poorly

  12. Contaminant plume configuration and movement: an experimental model

    NASA Astrophysics Data System (ADS)

    Alencoao, A.; Reis, A.; Pereira, M. G.; Liberato, M. L. R.; Caramelo, L.; Amraoui, M.; Amorim, V.

    2009-04-01

    The relevance of Science and Technology in our daily routines makes it compulsory to educate citizens who have both scientific literacy and scientific knowledge. These will allow them to be intervening citizens in a constantly changing society. Thus, physical and natural sciences are included in school curricula, both in primary and secondary education, with the fundamental aim of developing in the students the skills, attitudes and knowledge needed for the understanding of the planet Earth and its real problems. On the other hand, teaching in Geosciences is more and more based on practical methodologies which use didactic material, sustaining teachers' pedagogical practices and facilitating students' learning tasks suggested on the syllabus defined for each school level. Themes related to exploring the different components of the Hydrological Cycle and themes related to natural environment protection and preservation, namely water resources and soil contamination by industrial and urban sewage are examples of subject matters included on the Portuguese syllabus. These topics motivated the conception and construction of experimental models for the study of the propagation of pollutants on a porous medium. The experimental models allow inducing a horizontal flux of water though different kinds of permeable substances (e.g. sand, silt), with contamination spots on its surface. These experimental activities facilitate the student to understand the flow path of contaminating substances on the saturated zone and to observe the contaminant plume configuration and movement. The activities are explored in a teaching and learning process perspective where the student builds its own knowledge through real question- problem based learning which relate Science, Technology and Society. These activities have been developed in the framework of project ‘Water in the Environment' (CV/PVI/0854) of the POCTI Program (Programa Operacional "Ciência, Tecnologia, Inovação") financed

  13. Modeling crawling cell movement on soft engineered substrates

    NASA Astrophysics Data System (ADS)

    Aronson, Igor

    2014-03-01

    Self-propelled motion, emerging spontaneously or in response to external cues, is a hallmark of living organisms. Systems of self-propelled synthetic particles are also relevant for multiple applications, from targeted drug delivery to the design of self-healing materials. Self-propulsion relies on the force transfer to the surrounding. While self-propelled swimming in the bulk of liquids is fairly well characterized, many open questions remain in our understanding of self-propelled motion along substrates, such as in the case of crawling cells or related biomimetic objects. How is the force transfer organized and how does it interplay with the deformability of the moving object and the substrate? How do the spatially dependent traction distribution and adhesion dynamics give rise to complex cell behavior? How can we engineer a specific cell response on synthetic compliant substrates? Here we present a phase-field model for a crawling cell by incorporating locally resolved traction forces and substrate deformations. The model captures the generic structure of the traction force distribution and faithfully reproduces experimental observations, like the response of a cell on a gradient in substrate elasticity (durotaxis). It also exhibits complex modes of cell movement such as ``bipedal'' motion. Our work may guide experiments on cell traction force microscopy and substrate-based cell sorting and can be helpful for the design of biomimetic ``crawlers'' and active and reconfigurable self-healing materials. This work was supported by the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Materials Science and Engineering, under Contract DE-AC02-06CH11357.

  14. Animal Models of Cystic Fibrosis Pathology: Phenotypic Parallels and Divergences.

    PubMed

    Lavelle, Gillian M; White, Michelle M; Browne, Niall; McElvaney, Noel G; Reeves, Emer P

    2016-01-01

    Cystic fibrosis (CF) is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. The resultant characteristic ion transport defect results in decreased mucociliary clearance, bacterial colonisation, and chronic neutrophil-dominated inflammation. Much knowledge surrounding the pathophysiology of the disease has been gained through the generation of animal models, despite inherent limitations in each. The failure of certain mouse models to recapitulate the phenotypic manifestations of human disease has initiated the generation of larger animals in which to study CF, including the pig and the ferret. This review will summarise the basic phenotypes of three animal models and describe the contributions of such animal studies to our current understanding of CF. PMID:27340661

  15. Animal Models of Cystic Fibrosis Pathology: Phenotypic Parallels and Divergences

    PubMed Central

    McElvaney, Noel G.

    2016-01-01

    Cystic fibrosis (CF) is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. The resultant characteristic ion transport defect results in decreased mucociliary clearance, bacterial colonisation, and chronic neutrophil-dominated inflammation. Much knowledge surrounding the pathophysiology of the disease has been gained through the generation of animal models, despite inherent limitations in each. The failure of certain mouse models to recapitulate the phenotypic manifestations of human disease has initiated the generation of larger animals in which to study CF, including the pig and the ferret. This review will summarise the basic phenotypes of three animal models and describe the contributions of such animal studies to our current understanding of CF. PMID:27340661

  16. Are animal models relevant to key aspects of human parturition?

    PubMed

    Mitchell, Bryan F; Taggart, Michael J

    2009-09-01

    Preterm birth remains the most serious complication of pregnancy and is associated with increased rates of infant death or permanent neurodevelopmental disability. Our understanding of the regulation of parturition remains inadequate. The scientific literature, largely derived from rodent animal models, suggests two major mechanisms regulating the timing of parturition: the withdrawal of the steroid hormone progesterone and a proinflammatory response by the immune system. However, available evidence strongly suggests that parturition in the human has significantly different regulators and mediators from those in most of the animal models. Our objectives are to critically review the data and concepts that have arisen from use of animal models for parturition and to rationalize the use of a new model. Many animal models have contributed to advances in our understanding of the regulation of parturition. However, we suggest that those animals dependent on progesterone withdrawal to initiate parturition clearly have a limitation to their translation to the human. In such models, a linear sequence of events (e.g., luteolysis, progesterone withdrawal, uterine activation, parturition) gives rise to the concept of a "trigger" mechanism. Conversely, we propose that human parturition may arise from the concomitant maturation of several systems in parallel. We have termed this novel concept "modular accumulation of physiological systems" (MAPS). We also emphasize the urgency to determine the precise role of the immune system in the process of parturition in situations other than intrauterine infection. Finally, we accentuate the need to develop a nonprimate animal model whose physiology is more relevant to human parturition. We suggest that the guinea pig displays several key physiological characteristics of gestation that more closely resemble human pregnancy than do currently favored animal models. We conclude that the application of novel concepts and new models are

  17. Animal models for prion-like diseases.

    PubMed

    Fernández-Borges, Natalia; Eraña, Hasier; Venegas, Vanesa; Elezgarai, Saioa R; Harrathi, Chafik; Castilla, Joaquín

    2015-09-01

    Prion diseases or Transmissible Spongiform Encephalopathies (TSEs) are a group of fatal neurodegenerative disorders affecting several mammalian species being Creutzfeldt-Jacob Disease (CJD) the most representative in human beings, scrapie in ovine, Bovine Spongiform Encephalopathy (BSE) in bovine and Chronic Wasting Disease (CWD) in cervids. As stated by the "protein-only hypothesis", the causal agent of TSEs is a self-propagating aberrant form of the prion protein (PrP) that through a misfolding event acquires a β-sheet rich conformation known as PrP(Sc) (from scrapie). This isoform is neurotoxic, aggregation prone and induces misfolding of native cellular PrP. Compelling evidence indicates that disease-specific protein misfolding in amyloid deposits could be shared by other disorders showing aberrant protein aggregates such as Alzheimer's Disease (AD), Parkinson's Disease (PD), Amyotrophic lateral sclerosis (ALS) and systemic Amyloid A amyloidosis (AA amyloidosis). Evidences of shared mechanisms of the proteins related to each disease with prions will be reviewed through the available in vivo models. Taking prion research as reference, typical prion-like features such as seeding and propagation ability, neurotoxic species causing disease, infectivity, transmission barrier and strain evidences will be analyzed for other protein-related diseases. Thus, prion-like features of amyloid β peptide and tau present in AD, α-synuclein in PD, SOD-1, TDP-43 and others in ALS and serum α-amyloid (SAA) in systemic AA amyloidosis will be reviewed through models available for each disease. PMID:25907990

  18. [Animal models in urological laparoscopic training].

    PubMed

    Usón Gargallo, J; Sánchez Margallo, F M; Díaz-Güemes Martín-Portugués, I; Loscertales Martín de Agar, B; Soria Gálvez, F; Pascual Sánchez-Gijón, S

    2006-05-01

    We present the experience of the Minimally Invasive Surgery Centre (MISC) in the development of a modular training model in laparoscopic surgery. The experience analysis includes the description of the training objectives, the learning process of simple and advance laparoscopic urologic techniques, as well as some current and future considerations before applying the laparoscopic techniques. This learning program pretends to optimize the knowledge of the surgeon and the clinical practice of these surgical techniques. The phases of the learning process have been classified in four levels, which include different modules and models and whose application will depend on the experience and surgical skills. This pyramidal training system permits the student to advance step by step through each level depending on her surgical skills. We have presented our experience in twelve courses about laparoscopic urology and four courses of laparoscopic radical prostatectomy, in which more than 300 urologists have assisted. Furthermore, some Spanish Urology Units have been developing special experimental training programs on laparoscopic radical prostatectomy, partial nephrectomy or laparoscopic dismembered pyeloplasty with Anderson-Hynes technique. It has been previously described that laparoscopic modular learning constitutes a very useful concept to avoid problems related to an incomplete and incorrect learning process. Also it seems clear that the laparoscopic training reduces the learning curve in laparoscopic urologic techniques.

  19. The utility of animal models in developing immunosuppressive agents.

    PubMed

    McDaid, James; Scott, Christopher J; Kissenpfennig, Adrien; Chen, Huifang; Martins, Paulo N

    2015-07-15

    The immune system comprises an integrated network of cellular interactions. Some responses are predictable, while others are more stochastic. While in vitro the outcome of stimulating a single type of cell may be stereotyped and reproducible, in vivo this is often not the case. This phenomenon often merits the use of animal models in predicting the impact of immunosuppressant drugs. A heavy burden of responsibility lies on the shoulders of the investigator when using animal models to study immunosuppressive agents. The principles of the three R׳s: refine (less suffering,), reduce (lower animal numbers) and replace (alternative in vitro assays) must be applied, as described elsewhere in this issue. Well designed animal model experiments have allowed us to develop all the immunosuppressive agents currently available for treating autoimmune disease and transplant recipients. In this review, we examine the common animal models used in developing immunosuppressive agents, focusing on drugs used in transplant surgery. Autoimmune diseases, such as multiple sclerosis, are covered elsewhere in this issue. We look at the utility and limitations of small and large animal models in measuring potency and toxicity of immunosuppressive therapies.

  20. Cytomegalovirus Antivirals and Development of Improved Animal Models

    PubMed Central

    McGregor, Alistair; Choi, K. Yeon

    2015-01-01

    Introduction Cytomegalovirus (CMV) is a ubiquitous pathogen that establishes a life long asymptomatic infection in healthy individuals. Infection of immunesuppressed individuals causes serious illness. Transplant and AIDS patients are highly susceptible to CMV leading to life threatening end organ disease. Another vulnerable population is the developing fetus in utero, where congenital infection can result in surviving newborns with long term developmental problems. There is no vaccine licensed for CMV and current antivirals suffer from complications associated with prolonged treatment. These include drug toxicity and emergence of resistant strains. There is an obvious need for new antivirals. Candidate intervention strategies are tested in controlled pre-clinical animal models but species specificity of HCMV precludes the direct study of the virus in an animal model. Areas covered This review explores the current status of CMV antivirals and development of new drugs. This includes the use of animal models and the development of new improved models such as humanized animal CMV and bioluminescent imaging of virus in animals in real time. Expert Opinion Various new CMV antivirals are in development, some with greater spectrum of activity against other viruses. Although the greatest need is in the setting of transplant patients there remains an unmet need for a safe antiviral strategy against congenital CMV. This is especially important since an effective CMV vaccine remains an elusive goal. In this capacity greater emphasis should be placed on suitable pre-clinical animal models and greater collaboration between industry and academia. PMID:21883024

  1. Noninvasive fluorescence imaging in animal models of stroke.

    PubMed

    Stemmer, N; Mehnert, J; Steinbrink, J; Wunder, A

    2012-01-01

    Noninvasive fluorescence imaging (NFI) is a powerful tool to study physiology and pathophysiology in animal disease models. NFI has been successfully applied in a number of animal disease models including cancer, arthritis, and stroke. Furthermore, several applications in humans have been described. NFI is widely available in research laboratories because it has a number of advantages: It uses non-ionizing radiation and requires comparably simple, inexpensive instrumentation, and easy to handle. Fluorochromes can be detected with high sensitivity, and image acquisition time is relatively short. Furthermore, a plethora of fluorescent imaging agents is available including unspecific, target-specific, and activatable imaging probes. With these probes, biological processes such as inflammation, cell death or enzyme activity, and many others can be visualized in living animals. This review offers an overview of current approaches in NFI of stroke pathophysiology in animal models of cerebral ischemia. First, the instrumentation and the different types of imaging agents for NFI are described. Second, a short introduction to animal models of stroke is provided. Third, examples for NFI in animal models of stroke are given. Finally, the use of NFI in human stroke is critically discussed.

  2. Sex differences in animal models of psychiatric disorders

    PubMed Central

    Kokras, N; Dalla, C

    2014-01-01

    Psychiatric disorders are characterized by sex differences in their prevalence, symptomatology and treatment response. Animal models have been widely employed for the investigation of the neurobiology of such disorders and the discovery of new treatments. However, mostly male animals have been used in preclinical pharmacological studies. In this review, we highlight the need for the inclusion of both male and female animals in experimental studies aiming at gender-oriented prevention, diagnosis and treatment of psychiatric disorders. We present behavioural findings on sex differences from animal models of depression, anxiety, post-traumatic stress disorder, substance-related disorders, obsessive–compulsive disorder, schizophrenia, bipolar disorder and autism. Moreover, when available, we include studies conducted across different stages of the oestrous cycle. By inspection of the relevant literature, it is obvious that robust sex differences exist in models of all psychiatric disorders. However, many times results are conflicting, and no clear conclusion regarding the direction of sex differences and the effect of the oestrous cycle is drawn. Moreover, there is a lack of considerable amount of studies using psychiatric drugs in both male and female animals, in order to evaluate the differential response between the two sexes. Notably, while in most cases animal models successfully mimic drug response in both sexes, test parameters and treatment-sensitive behavioural indices are not always the same for male and female rodents. Thus, there is an increasing need to validate animal models for both sexes and use standard procedures across different laboratories. Linked Articles This article is part of a themed section on Animal Models in Psychiatry Research. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2014.171.issue-20 PMID:24697577

  3. [Efficient and rapid liquid reduction animal model].

    PubMed

    Han, Bing; Kou, Shu-ming; Chen, Biao; Peng, Yao-zong; Wang, Yue; Han, Yu-long; Ye, Xiao-li; Li, Xue-gang

    2015-11-01

    To investigate the practicability of establishing zebrafish lipid-lowering drug screening model and the effect of berberine (BBR) on hyperlipidemic zebrafish. Three-month-old zebrafishes were fed with 4% cholesterol for 0, 2, 4, 8, 14, 20, 25, 30 days, and the level of total cholesterol in serum was measured. Zebrafish were randomly divided into four groups: the control group, the high cholesterol diet group, the 0.01% simvastatin-treated group, the 0.1% berberine-treated group and the 0.2% berberine-treated group. The levels of total cholesterol (TC), triglyceride (TC), low density lipoprotein cholesterol (LDL-c) and high-density lipoprotein cholesterol (HDL-c) in serum were measured; the expression of hepatic HMGCR, LDLR and CYP7A1a mRNA expressions were detected by real time PCR. Oil red O staining was performed to observe the changes in fat content in the liver. According to the result, the level of serum TC in the 4% cholesterol diet group significantly was higher than that of the normal control group in a time-dependent manner and reached a stable level at the 20th day. The BBR group showed significant decreases in the levels of TC, TG and LDL-c, HMGCR mRNA expression and fat content and increases in LDLR and CYP7A1a mRNA. The hyperlipidemia zebrafish model was successfully established by feeding with 4% cholesterol for 20 days. The findings lay a foundation for further screenings on lipid-lowering drugs.

  4. Utilizing Gaussian Markov random field properties of Bayesian animal models.

    PubMed

    Steinsland, Ingelin; Jensen, Henrik

    2010-09-01

    In this article, we demonstrate how Gaussian Markov random field properties give large computational benefits and new opportunities for the Bayesian animal model. We make inference by computing the posteriors for important quantitative genetic variables. For the single-trait animal model, a nonsampling-based approximation is presented. For the multitrait model, we set up a robust and fast Markov chain Monte Carlo algorithm. The proposed methodology was used to analyze quantitative genetic properties of morphological traits of a wild house sparrow population. Results for single- and multitrait models were compared.

  5. Animal models for studying dengue pathogenesis and therapy.

    PubMed

    Chan, Kitti Wing Ki; Watanabe, Satoru; Kavishna, Ranmali; Alonso, Sylvie; Vasudevan, Subhash G

    2015-11-01

    Development of a suitable animal model for dengue virus disease is critical for understanding pathogenesis and for preclinical testing of antiviral drugs and vaccines. Many laboratory animal models of dengue virus infection have been investigated, but the challenges of recapitulating the complete disease still remain. In this review, we provide a comprehensive coverage of existing models, from man to mouse, with a specific focus on recent advances in mouse models for addressing the mechanistic aspects of severe dengue in humans. This article forms part of a symposium in Antiviral Research on flavivirus drug discovery. PMID:26304704

  6. Animal models for studying dengue pathogenesis and therapy.

    PubMed

    Chan, Kitti Wing Ki; Watanabe, Satoru; Kavishna, Ranmali; Alonso, Sylvie; Vasudevan, Subhash G

    2015-11-01

    Development of a suitable animal model for dengue virus disease is critical for understanding pathogenesis and for preclinical testing of antiviral drugs and vaccines. Many laboratory animal models of dengue virus infection have been investigated, but the challenges of recapitulating the complete disease still remain. In this review, we provide a comprehensive coverage of existing models, from man to mouse, with a specific focus on recent advances in mouse models for addressing the mechanistic aspects of severe dengue in humans. This article forms part of a symposium in Antiviral Research on flavivirus drug discovery.

  7. Animal models of obsessive-compulsive disorder: utility and limitations.

    PubMed

    Alonso, Pino; López-Solà, Clara; Real, Eva; Segalàs, Cinto; Menchón, José Manuel

    2015-01-01

    Obsessive-compulsive disorder (OCD) is a disabling and common neuropsychiatric condition of poorly known etiology. Many attempts have been made in the last few years to develop animal models of OCD with the aim of clarifying the genetic, neurochemical, and neuroanatomical basis of the disorder, as well as of developing novel pharmacological and neurosurgical treatments that may help to improve the prognosis of the illness. The latter goal is particularly important given that around 40% of patients with OCD do not respond to currently available therapies. This article summarizes strengths and limitations of the leading animal models of OCD including genetic, pharmacologically induced, behavioral manipulation-based, and neurodevelopmental models according to their face, construct, and predictive validity. On the basis of this evaluation, we discuss that currently labeled "animal models of OCD" should be regarded not as models of OCD but, rather, as animal models of different psychopathological processes, such as compulsivity, stereotypy, or perseverance, that are present not only in OCD but also in other psychiatric or neurological disorders. Animal models might constitute a challenging approach to study the neural and genetic mechanism of these phenomena from a trans-diagnostic perspective. Animal models are also of particular interest as tools for developing new therapeutic options for OCD, with the greatest convergence focusing on the glutamatergic system, the role of ovarian and related hormones, and the exploration of new potential targets for deep brain stimulation. Finally, future research on neurocognitive deficits associated with OCD through the use of analogous animal tasks could also provide a genuine opportunity to disentangle the complex etiology of the disorder. PMID:26346234

  8. Animal models of obsessive–compulsive disorder: utility and limitations

    PubMed Central

    Alonso, Pino; López-Solà, Clara; Real, Eva; Segalàs, Cinto; Menchón, José Manuel

    2015-01-01

    Obsessive–compulsive disorder (OCD) is a disabling and common neuropsychiatric condition of poorly known etiology. Many attempts have been made in the last few years to develop animal models of OCD with the aim of clarifying the genetic, neurochemical, and neuroanatomical basis of the disorder, as well as of developing novel pharmacological and neurosurgical treatments that may help to improve the prognosis of the illness. The latter goal is particularly important given that around 40% of patients with OCD do not respond to currently available therapies. This article summarizes strengths and limitations of the leading animal models of OCD including genetic, pharmacologically induced, behavioral manipulation-based, and neurodevelopmental models according to their face, construct, and predictive validity. On the basis of this evaluation, we discuss that currently labeled “animal models of OCD” should be regarded not as models of OCD but, rather, as animal models of different psychopathological processes, such as compulsivity, stereotypy, or perseverance, that are present not only in OCD but also in other psychiatric or neurological disorders. Animal models might constitute a challenging approach to study the neural and genetic mechanism of these phenomena from a trans-diagnostic perspective. Animal models are also of particular interest as tools for developing new therapeutic options for OCD, with the greatest convergence focusing on the glutamatergic system, the role of ovarian and related hormones, and the exploration of new potential targets for deep brain stimulation. Finally, future research on neurocognitive deficits associated with OCD through the use of analogous animal tasks could also provide a genuine opportunity to disentangle the compl