396 research outputs found

    Correlation of coastal water turbidity and circulation with ERTS-1 and Skylab imagery

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    There are no author-identified significant results in this report

    Rett Syndrome: Crossing the Threshold to Clinical Translation

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    Lying at the intersection between neurobiology and epigenetics, Rett syndrome (RTT) has garnered intense interest in recent years, not only from a broad range of academic scientists, but also from the pharmaceutical and biotechnology industries. In addition to the critical need for treatments for this devastating disorder, optimism for developing RTT treatments derives from a unique convergence of factors, including a known monogenic cause, reversibility of symptoms in preclinical models, a strong clinical research infrastructure highlighted by an NIH-funded natural history study and well-established clinics with significant patient populations. Here, we review recent advances in understanding the biology of RTT, particularly promising preclinical findings, lessons from past clinical trials, and critical elements of trial design for rare disorders

    Pinceau Organization in the Cerebellum Requires Distinct Functions of Neurofascin in Purkinje and Basket Neurons during Postnatal Development

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    Basket axon collaterals synapse onto the Purkinje soma/axon initial segment (AIS) area to form specialized structures, the pinceau, which are critical for normal cerebellar function. Mechanistic details of how the pinceau become organized during cerebellar development are poorly understood. Loss of cytoskeletal adaptor protein Ankyrin G (AnkG) results in mislocalization of the cell adhesion molecule Neurofascin (Nfasc) at the Purkinje AIS and abnormal organization of the pinceau. Loss of Nfasc in adult Purkinje neurons leads to slow disorganization of the Purkinje AIS and pinceau morphology. Here we utilized mouse conditional knockout techniques to show that selective loss of Nfasc specifically in Purkinje neurons during early development prevented maturation of the AIS and resulted in loss of Purkinje neuron spontaneous activity and pinceau disorganization. Loss of Nfasc in both Purkinje and basket neurons caused abnormal basket axon collateral branching and targeting to Purkinje soma/AIS, leading to extensive pinceau disorganization, Purkinje neuron degeneration and severe ataxia. Our studies reveal that the Purkinje Nfasc is required for AIS maturation and for maintaining stable contacts between basket axon terminals and the Purkinje AIS during pinceau organization, while the basket neuron Nfasc in combination with Purkinje Nfasc is required for proper basket axon collateral outgrowth and targeting to Purkinje soma/AIS. Thus, cerebellar pinceau organization requires coordinated mechanisms involving specific Nfasc functions in both Purkinje and basket neurons

    Angelman syndrome: insights into genomic imprinting and neurodevelopmental phenotypes

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    Angelman syndrome (AS) is a severe genetic disorder caused by mutations or deletions of the maternally inherited UBE3A gene. UBE3A encodes an E3 ubiquitin ligase that is expressed biallelically in most tissues but is maternally expressed in almost all neurons. In this review, we describe recent advances in understanding the expression and function of UBE3A in the brain and the etiology of AS. We highlight current AS model systems, epigenetic mechanisms of UBE3A regulation, and the identification of potential UBE3A substrates in the brain. In the process, we identify major gaps in our knowledge that, if bridged, could move us closer to identifying treatments for this debilitating neurodevelopmental disorder

    Loss of UBE3A from TH-expressing neurons suppresses GABA co-release and enhances VTA-NAc optical self-stimulation

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    Motivated reward-seeking behaviours are governed by dopaminergic ventral tegmental area projections to the nucleus accumbens. In addition to dopamine, these mesoaccumbal terminals co-release other neurotransmitters including glutamate and GABA, whose roles in regulating motivated behaviours are currently being investigated. Here we demonstrate that loss of the E3-ubiquitin ligase, UBE3A, from tyrosine hydroxylase-expressing neurons impairs mesoaccumbal, non-canonical GABA co-release and enhances reward-seeking behaviour measured by optical self-stimulation

    Decreased Axon Caliber Underlies Loss of Fiber Tract Integrity, Disproportional Reductions in White Matter Volume, and Microcephaly in Angelman Syndrome Model Mice

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    Angelman syndrome (AS) is a debilitating neurodevelopmental disorder caused by loss of function of the maternally inherited UBE3A allele. It is currently unclear how the consequences of this genetic insult unfold to impair neurodevelopment. We reasoned that by elucidating the basis of microcephaly in AS, a highly penetrant syndromic feature with early postnatal onset, we would gain new insights into the mechanisms by which maternal UBE3A loss derails neurotypical brain growth and function. Detailed anatomical analysis of both male and female maternal Ube3a-null mice reveals that microcephaly in the AS mouse model is primarily driven by deficits in the growth of white matter tracts, which by adulthood are characterized by densely packed axons of disproportionately small caliber. Our results implicate impaired axon growth in the pathogenesis of AS and identify noninvasive structural neuroimaging as a potentially valuable tool for gauging therapeutic efficacy in the disorder

    GABAergic Neuron-Specific Loss of Ube3a Causes Angelman Syndrome-Like EEG Abnormalities and Enhances Seizure Susceptibility

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    Loss of maternal UBE3A causes Angelman syndrome (AS), a neurodevelopmental disorder associated with severe epilepsy. We previously implicated GABAergic deficits onto layer (L) 2/3 pyramidal neurons in the pathogenesis of neocortical hyperexcitability, and perhaps epilepsy, in AS model mice. Here we investigate consequences of selective Ube3a loss from either GABAergic or glutamatergic neurons, focusing on the development of hyperexcitability within L2/3 neocortex and in broader circuit and behavioral contexts. We find that GABAergic Ube3a loss causes AS-like increases in neocortical EEG delta power, enhances seizure susceptibility, and leads to presynaptic accumulation of clathrin-coated vesicles (CCVs) – all without decreasing GABAergic inhibition onto L2/3 pyramidal neurons. Conversely, glutamatergic Ube3a loss fails to yield EEG abnormalities, seizures, or associated CCV phenotypes, despite impairing tonic inhibition onto L2/3 pyramidal neurons. These results substantiate GABAergic Ube3a loss as the principal cause of circuit hyperexcitability in AS mice, lending insight into ictogenic mechanisms in AS

    The behaviours that dementia care home staff in South Africa find challenging:An exploratory study

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    Background: Behavioural and psychological symptoms of dementia are often the reasons for moving to a care home. Care staff, often with limited dementia training, may have to support residents with distressed behaviour on a daily basis. Evidence about the support of residents with distressed or challenging behaviour in the South African context is lacking. This exploratory study aimed to gain an understanding of what care home staff perceived to be distressed behaviour, their coping strategies and how they learned to work with residents with behavioural symptoms of dementia. Methods: An exploratory study was conducted among 17 participants working in four care homes in the Western Cape province of South Africa in 2014. Semi-structured interviews were audio-recorded. Data were analysed thematically. Findings: Findings reflected the literature with regard to examples of behavioural symptoms of people with dementia that staff find challenging to manage. Overall, the majority of staff reported holding positive feelings about working with people with dementia. All preferred interpersonal approaches to manage distressed behaviour above medication although a small minority noted the use of medication in some cases. Dementia training was considered by most participants as an unmet need. Conclusion: This exploratory study identified care home workers’ desires for training about dementia and their preferences for interpersonal as opposed to pharmacological approaches to managing residents’ distressed behaviour. The legacy of race and cultural perspectives in South Africa appears to still influence care practice and provision. Staff commitment, their interest in advancing their practice and their aspirations to offer more person-centred care were evident. Dementia training was identified as potentially helpful to care home staff who manage residents’ distressed behaviour. Training should be developed in South Africa to promote good practice

    Using systems thinking and open innovation to strengthen aquaculture policy for the United Nations Sustainable Development Goals

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    In a world of nine billion people and a widening income gap between the rich and poor, it is time to rethink how aquaculture can strengthen its contribution to the second UN Sustainable Development Goal (SDG) of zero hunger in our generation. The disparity in the level of sustainable aquaculture development at present, between and within countries, especially regarding human access to farmed aquatic food remains highly variable across the globe. This paper offers a fresh look at the opportunities from using systems thinking and new open innovation measuring tools to grow sustainable aquaculture. Political will in many nations is the main constraint to aquaculture in realising its potential as an: accessible source of micronutrients and nutritious protein; aid to meeting conservation goals; economic prosperity generator where benefits extend to locals and provider of indirect social benefits such as access to education and well‐being, among others. Resources to enable strong partnerships (SDG 17) between academia, civic society, government and industry should be prioritised by governments to build a sustainable aquatic food system, accessible to all, forever
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