Characterizing Width Uniformity by Wave Propagation

This work describes a novel image analysis approach to characterize the uniformity of objects in agglomerates by using the propagation of normal wavefronts. The problem of width uniformity is discussed and its importance for the characterization of composite structures normally found in physics and biology highlighted. The methodology involves identifying each cluster (i.e. connected component) of interest, which can correspond to objects or voids, and estimating the respective medial axes by using a recently proposed wavefront propagation approach, which is briefly reviewed. The distance values along such axes are identified and their mean and standard deviation values obtained. As illustrated with respect to synthetic and real objects (in vitro cultures of neuronal cells), the combined use of these two features provide a powerful description of the uniformity of the separation between the objects, presenting potential for several applications in material sciences and biology.Comment: 14 pages, 23 figures, 1 table, 1 referenc

Towards Computational Models and Applications of Insect Visual Systems for Motion Perception: A Review

Motion perception is a critical capability determining a variety of aspects of insects' life, including avoiding predators, foraging and so forth. A good number of motion detectors have been identified in the insects' visual pathways. Computational modelling of these motion detectors has not only been providing effective solutions to artificial intelligence, but also benefiting the understanding of complicated biological visual systems. These biological mechanisms through millions of years of evolutionary development will have formed solid modules for constructing dynamic vision systems for future intelligent machines. This article reviews the computational motion perception models originating from biological research of insects' visual systems in the literature. These motion perception models or neural networks comprise the looming sensitive neuronal models of lobula giant movement detectors (LGMDs) in locusts, the translation sensitive neural systems of direction selective neurons (DSNs) in fruit flies, bees and locusts, as well as the small target motion detectors (STMDs) in dragonflies and hover flies. We also review the applications of these models to robots and vehicles. Through these modelling studies, we summarise the methodologies that generate different direction and size selectivity in motion perception. At last, we discuss about multiple systems integration and hardware realisation of these bio-inspired motion perception models

Towards a Dynamic Vision System - Computational Modelling of Insect Motion Sensitive Neural Systems

For motion perception, vision plays an irreplaceable role, which can extract more abundant useful movement features from an unpredictable dynamic environment compared to other sensing modalities. Nowadays, building a dynamic vision system for motion perception in a both reliable and efficient manner is still an open challenge. Millions of years of evolutionary development has provided, in nature, animals that possess robust vision systems capable of motion perception to deal with a variety of aspects of life. Insects, in particular, have a relatively smaller number of visual neurons compared to vertebrates and humans, but can still navigate smartly through visually cluttered and dynamic environments. Understanding the insects' visual processing pathways and methods thus are not only attractive to neural system modellers but also critical in providing effective solutions for future intelligent machines. Originated from biological researches in insect visual systems, this thesis investigates computational modelling of motion sensitive neural systems and potential applications to robotics. This proposes novel modelling of the locust and fly visual systems for sensing looming and translating stimuli. Specifically, the proposed models comprise collision selective neural networks of two lobula giant movement detectors (LGMD1 and LGMD2) in locusts, and translating sensitive neural networks of direction selective neurons (DSNs) in flies, as well as hybrid visual neural systems of their combinations. In all these proposed models, the functionality of ON and OFF pathways is highlighted, which separate visual processing into parallel computation. This works effectively to realise neural characteristics of both the LGMD1 and the LGMD2 in locusts and plays crucial roles in separating the different looming selectivity between the two visual neurons. Such a biologically plausible structure can also implement the fly DSNs for translational movements perception and guide fast motion tracking with a behavioural response to visual fixation. The effectiveness and flexibility of the proposed motion sensitive neural systems have been validated by systematic and comparative experiments ranging from off-line synthetic and real-world tests to on-line bio-robotic tests. The underlying characteristics and functionality of the locust LGMDs and the fly DSNs have been achieved by the proposed models. All the proposed visual models have been successfully realised on the embedded system in a vision-based ground mobile robot. The robot tests have verified the computational simplicity and efficiency of proposed bio-inspired methodologies, which hit at great potential of building neuromorphic sensors in autonomous machines for motion perception in a fast, reliable and low-energy manner

Sex-Specific Effects of Ancestral Stress on Brain Health and Disease Across the Lifespan

Early life stress alters fetal brain development with lifetime consequences on individuals exposed and future generations. This thesis investigated the effects of ancestral stress on behaviour, brain aging, and disease incidence of the F1-F4 generation offspring. Two types of ancestral stress offspring were examined: transgenerational stress, where only great-great grandma was stressed and mutigenerational stress where four consecutive F0-F3 generations were stressed during pregnancy. Here were report three main findings: 1) ancestral stress induced sex-specific anxiety-like behaviour and brain plasticity through altered epigenetic regulation; 2) the effects of ancestral stress persisted across the lifespan, altered physical and mental health and increased risk of disease; and 3) social isolation stress altered stress and immune systems and contributed to sex-specific cognitive impairments. These findings contribute to the overall understanding of the perinatal origins of healthy brain aging and disease, and address the urgent need of recommendations to support healthy aging worldwide.Natural Sciences and Engineering Research Council (NSERC) PGS Canadian Institutes of Health Research (CIHR

STABLE ADAPTIVE STRATEGY of HOMO SAPIENS and EVOLUTIONARY RISK of HIGH TECH. Transdisciplinary essay

The co-evolutionary concept of Three-modal stable evolutionary strategy of Homo sapiens is developed. The concept based on the principle of evolutionary complementarity of anthropogenesis: value of evolutionary risk and evolutionary path of human evolution are defined by descriptive (evolutionary efficiency) and creative-teleological (evolutionary correctly) parameters simultaneously, that cannot be instrumental reduced to others ones. Resulting volume of both parameters define the trends of biological, social, cultural and techno-rationalistic human evolution by two gear mechanism ˗ gene-cultural co-evolution and techno- humanitarian balance. The resultant each of them can estimated by the ratio of socio-psychological predispositions of humanization/dehumanization in mentality. Explanatory model and methodology of evaluation of creatively teleological evolutionary risk component of NBIC technological complex is proposed. Integral part of the model is evolutionary semantics (time-varying semantic code, the compliance of the biological, socio-cultural and techno-rationalist adaptive modules of human stable evolutionary strategy)

Biological model representation and analysis

In this thesis, we discuss solutions of phenotype description based on the microscopy image analysis to deal with biological problems both in 2D and 3D space. Our description of patterns goes beyond conventional features and helps to visualize the unseen in feature dataset. These solutions share several common processes which are based on similar principles. Furthermore, we notice that advanced features and classier strategies can help us improve the performance of the solutions. The biological problems that we have studied include the endocytosis routing using high-throughput screening in 2D and time and 3D geometrical representation from biological structures.China Scholarship CouncilComputer Systems, Imagery and Medi

Neuroplasticity, neural reuse, and the language module

What conception of mental architecture can survive the evidence of neuroplasticity and neural reuse in the human brain? In particular, what sorts of modules are compatible with this evidence? I aim to show how developmental and adult neuroplasticity, as well as evidence of pervasive neural reuse, forces us to revise the standard conception of modularity and spells the end of a hardwired and dedicated language module. I argue from principles of both neural reuse and neural redundancy that language is facilitated by a composite of modules (or module-like entities), few if any of which are likely to be linguistically special, and that neuroplasticity provides evidence that (in key respects and to an appreciable extent) few if any of them ought to be considered developmentally robust, though their development does seem to be constrained by features intrinsic to particular regions of cortex (manifesting as domain-specific predispositions or acquisition biases). In the course of doing so I articulate a schematically and neurobiologically precise framework for understanding modules and their supramodular interactions

Smooth Pursuit and Antisaccade Eye Movements as Endophenotypes in Schizophrenia Spectrum Research

Smooth pursuit eye movement (SPEM) and antisaccade deficits have been proposed as schizophrenia spectrum endophenotypes. An endophenotype is a behavioural or biological deficit thought to represent, more closely than the disease phenotype, the effects of an underlying disease gene. Oculomotor endophenotypes possess phenotypic homogeneity, well-understood neural correlates and objective assessment and may thus be used as phenotypes in linkage studies. This thesis investigated a number of issues concerning the reliability and validity of the SPEM and antisaccade tasks as schizophrenia spectrum endophenotypes (and two tasks thought to be unimpaired in the schizophrenia spectrum, visual fixation and prosaccades). The schizophrenia spectrum encompasses not only people with schizophrenia but any population with an increased frequency of schizophrenia-related phenotypes or genotypes, such as schizotypal individuals or first-degree relatives of schizophrenia patients. A valid endophenotype should thus be detected in these populations. Study I investigated reliability, namely internal consistency and temporal stability, of eye movements in healthy individuals. Study II utilised first-episode psychosis patients and healthy controls, aiming to detect behavioural oculomotor deficits in the absence of secondary confounds that may be encountered in chronic schizophrenia. Study III assessed performance in siblings discordant for schizophrenia. Study IV explored the relationship between psychometric schizotypy and oculomotor performance. Study V examined possible state effects of procyclidine, an anticholinergic compound often administered to schizophrenia patients, on performance in a patient group. The results generally confirmed the validity of the SPEM and antisaccade deficits as schizophrenia spectrum endophenotypes: Oculomotor performance was mostly stable both within and between assessments. SPEM and antisaccade impairments were observed in first­episode psychosis patients and schizophrenia patients and their healthy siblings. Antisaccade, but not SPEM, impairments were associated with high levels of schizotypy. State effects of procyclidine on SPEM and antisaccade performance were observed, suggesting the need to consider the influence of pharmacological treatment in future patient studies. These findings suggest that SPEM and antisaccade deficits may be studied profitably as endophenotypes in schizophrenia spectrum research

Immunohistochemical and electrophysiological investigation of E/I balance alterations in animal models of frontotemporal dementia

Behavioural variant frontotemporal dementia (bvFTD) is a neurodegenerative disease characterised by changes in behaviour. Apathy, behavioural disinhibition and stereotyped behaviours are the first symptoms to appear and all have a basis in reward and pleasure deficits. The ventral striatum and ventral regions of the globus pallidus are involved in reward and pleasure. It is therefore reasonable to suggest alterations in these regions may underpin bvFTD. One postulated contributory factor is alteration in E/I balance in striatal regions. GABAergic interneurons play a role in E/I balance, acting as local inhibitory brakes, they are therefore a rational target for research investigating early biological predictors of bvFTD. To investigate this, we will carry out immunohistochemical staining for GABAergic interneurons (parvalbumin and neuronal nitric oxide synthase) in striatal regions of brains taken from CHMP2B mice, a validated animal model of bvFTD. We hypothesise that there will be fewer GABAergic interneurons in the striatum which may lead to ‘reward-seeking’ behaviour in bvFTD. This will also enable us to investigate any preclinical alterations in interneuron expression within this region. Results will be analysed using a mixed ANOVA and if significant, post hoc t-tests will be used. The second part of our study will involve extracellular recordings from CHMP2B mouse brains using a multi-electrode array (MEA). This will enable us to determine if there are alterations in local field potentials (LFP) in preclinical and symptomatic animals. We will also be able to see if neuromodulators such as serotonin and dopamine effect LFPs after bath application. We will develop slice preparations to preserve pathways between the ventral tegmental area and the ventral pallidum, an output structure of the striatum, and the dorsal raphe nucleus and the VP. Using the MEA we will stimulate an endogenous release of dopamine and serotonin using the slice preparations as described above. This will enable us to see if there are any changes in LFPs after endogenous release of neuromodulators. We hypothesise there will be an increase in LFPs due to loss of GABAergic interneurons

Current Air Quality Issues

Air pollution is thus far one of the key environmental issues in urban areas. Comprehensive air quality plans are required to manage air pollution for a particular area. Consequently, air should be continuously sampled, monitored, and modeled to examine different action plans. Reviews and research papers describe air pollution in five main contexts: Monitoring, Modeling, Risk Assessment, Health, and Indoor Air Pollution. The book is recommended to experts interested in health and air pollution issues