124 research outputs found

    Critical fluctuations and coupling of stochastic neural mass models

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    Cotton seedling diseases : answers to frequently asked questions (1994)

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    New March 25, 1994

    Critical fluctuations in cortical models near instability

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    Australian Research Council, the National Health and Medical Research Council, the Brain Network Recovery Group Grant JSMF22002082, and Netherlands Organization for Scientific Research (NWO #451–10-030

    Gone with the Wind: International Migration

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    This paper adds to the literature on the determinants of international migration. First, we offer a joint analysis of the driving forces of migration capturing year-to-year variations and long-run effects. Second, we analyze the dynamic response of migration to shocks to its determinants. We start by presenting a theoretical model that allows us to model migration as an augmented gravity equation. We then construct a rich panel data set with 16 destination and 198 origin countries between 1980 and 2014. Most importantly, we find that climate change is a more important driver than income and political freedom together. Our results imply that a large time dimension is key to understand the effects of climate change. We then estimate a panel vectorautoregressive model showing that the dynamic response of migration is very different across shocks to different driving forces. Our findings carry implications for national and international immigration policies

    Children's Oncology Group's 2013 blueprint for research: Nursing discipline

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    Integration of the nursing discipline within cooperative groups conducting pediatric oncology clinical trials provides unique opportunities to maximize nursing's contribution to clinical care, and to pursue research questions that extend beyond cure of disease to address important gaps in knowledge surrounding the illness experience. Key areas of importance to the advancement of the nursing discipline's scientific knowledge are understanding the effective delivery of patient/family education, and reducing illness‐related distress, both of which are integral to facilitating parental/child coping with the diagnosis and treatment of childhood cancer, and to promoting resilience and well‐being of pediatric oncology patients and their families. Pediatr Blood Cancer 2013; 60: 1031–1036. © 2012 Wiley Periodicals, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/97507/1/24415_ftp.pd

    The Parkinsonian subthalamic network: measures of power, linear, and non-linear synchronization and their relationship to L-DOPA treatment and OFF state motor severity

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    In this paper we investigated the dopaminergic modulation of neuronal interactions occurring in the subthalamic nucleus (STN) during Parkinson's disease (PD). We utilized linear measures of local and long range synchrony such as power and coherence, as well as Detrended Fluctuation Analysis for Phase Synchrony (DFA-PS)- a recently developed non-linear method that computes the extent of long tailed autocorrelations present in the phase interactions between two coupled signals. Through analysis of local field potentials (LFPs) taken from the STN we seek to determine changes in the neurodynamics that may underpin the pathophysiology of PD in a group of 12 patients who had undergone surgery for deep brain stimulation. We demonstrate up modulation of alpha-theta (5–12 Hz) band power in response to L-DOPA treatment, whilst low beta band power (15–20 Hz) band-power is suppressed. We also find evidence for significant local connectivity within the region surrounding STN although there was evidence for its modulation via administration of L-DOPA. Further to this we present evidence for a positive correlation between the phase ordering of bilateral STN interactions and the severity of bradykinetic and rigidity symptoms in PD. Although, the ability of non-linear measures to predict clinical state did not exceed standard measures such as beta power, these measures may help identify the connections which play a role in pathological dynamics

    Levels of resilience and delivery of HIV care in response to urban violence and crime

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    Aims To understand the impact of urban violence and crime on HIV care delivery. Background Urban violence and crime can put pressure on the health care system and on nursing staff. Whilst the impact this has at the individual level has been researched, there is less research that places this within the context of the overall social eco system. Design A qualitative design using inductive thematic analysis. Methods Between July 2016 February 2017, in‐depth interviews were conducted with 10 nurses working in two neighbourhoods with high levels of violence in Cape Town, South Africa. Results The effects of crime and violence were evident at multiple levels resulting in participants feeling ‘safe and unsafe’ in a context where crime is viewed as endemic. Resilience emerged as a key concept in the findings. Resilience was apparent at individual, community and organizational levels and enabled continued delivery of HIV care. Conclusion The findings demonstrate the potential role of resilience within the social eco‐health system required to sustain delivery of HIV care in the midst of urban violence and gangsterism. Impact This study examined the impact of and response to urban violence on HIV care delivery. The findings indicate that resilience manifests at all levels of the social eco‐system. Understanding the mechanisms employed to cope with endemic violence helps to address these challenges in the study setting, but also has a much wider application to other areas with endemic urban violence and crime

    Inference of Brain Networks with Approximate Bayesian Computation– assessing face validity with an example application in Parkinsonism

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    This paper describes and validates a novel framework using the Approximate Bayesian Computation (ABC) algorithm for parameter estimation and model selection in models of mesoscale brain network activity. We provide a proof of principle, first pass validation of this framework using a set of neural mass models of the cortico-basal ganglia thalamic circuit inverted upon spectral features from experimental in vivo recordings. This optimization scheme relaxes an assumption of fixed-form posteriors (i.e. the Laplace approximation) taken in previous approaches to inverse modelling of spectral features. This enables the exploration of model dynamics beyond that approximated from local linearity assumptions and so fit to explicit, numerical solutions of the underlying non-linear system of equations. In this first paper, we establish a face validation of the optimization procedures in terms of: (i) the ability to approximate posterior densities over parameters that are plausible given the known causes of the data; (ii) the ability of the model comparison procedures to yield posterior model probabilities that can identify the model structure known to generate the data; and (iii) the robustness of these procedures to local minima in the face of different starting conditions. Finally, as an illustrative application we show (iv) that model comparison can yield plausible conclusions given the known neurobiology of the cortico-basal ganglia-thalamic circuit in Parkinsonism. These results lay the groundwork for future studies utilizing highly nonlinear or brittle models that can explain time dependent dynamics, such as oscillatory bursts, in terms of the underlying neural circuits

    A critical review and development of a conceptual model of exclusion from social relations for older people

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    Social exclusion is complex and dynamic, and it leads to the non-realization of social, economic, political or cultural rights or participation within a society. This critical review takes stock of the literature on exclusion of social relations. Social relations are defined as comprising social resources, social connections and social networks. An evidence review group undertook a critical review which integrates, interprets and synthesizes information across studies to develop a conceptual model of exclusion from social relations. The resulting model is a subjective interpretation of the literature and is intended to be the starting point for further evaluations. The conceptual model identifies individual risks for exclusion from social relations (personal attributes, biological and neurological risk, retirement, socio-economic status, exclusion from material resources and migration). It incorporates the evaluation of social relations, and the influence of psychosocial resources and socioemotional processes, sociocultural, social-structural, environmental and policy contextual influences on exclusion from social relations. It includes distal outcomes of exclusion from social relations, that is, individual well-being, health and functioning, social opportunities and social cohesion. The dynamic relationships between elements of the model are also reported. We conclude that the model provides a subjective interpretation of the data and an excellent starting point for further phases of conceptual development and systematic evaluation(s). Future research needs to consider the use of sophisticated analytical tools and an interdisciplinary approach in order to understand the underlying biological and ecopsychosocial associations that contribute to individual and dynamic differences in the experience of exclusion from social relation

    The dilemma of aural skills within year eleven music programmes in the New Zealand curriculum.

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    This thesis investigates a perceived dilemma, music teachers and students have about the significance and value aural and listening skills have in relation to Year 11 Music under the National Certificate in Educational Achievement (NCEA). The study considers four teachers’ approaches to the teaching and learning of aural and listening skills, which are based on their own contextual experiences. These experiences have assisted the teachers in the construction of their own knowledge on which they base their own beliefs and pedagogical approaches. The teachers involved in this research collectively agreed that there were three important domains of musical activity, those of performing, composing and listening. Without the ability to ‘listen’, the other two musical activities become pointless. Aural training has been developed over time as a means of promoting critical listening and the ability to perceptively respond to aural stimuli. While there is dissent on the value music educationalists place on one aural skill over the other, it is generally agreed that a unified approach between aural recall and aural notation is the best approach. An area of contention that has emerged from this research is the dichotomy between the performance practices of students focusing on the performance of classical and contemporary music. The discrepancy between students’ understanding of traditional music notation is one of the biggest tensions teachers face. With the perceived emphasis on traditional western notation, some teachers in this research believe that NCEA music assessment focuses on the teaching of traditional classical music notation and theory. Other teachers involved, dispute this fact and strategically decide not to enter students for the external aural examination. For these teachers, their approach is focused on the development of general musicianship skills as a means of further enhancing student performance work. This thesis is practitioner research and developed from a teaching inquiry in an attempt to bring meaning and insight to an area of work that is believed to be critical to the holistic musical development of students
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