234 research outputs found

    The Creative Economy in Maine

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    In the Margaret Chase Smith Essay, Evan Dobelle reflects on Maine’s emerging creative economy. He notes the collaboration with the state’s universities and colleges, and points to the importance of developing “creative clusters.

    Free versus purchased mosquito net ownership and use in Budondo sub-county, Uganda.

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    BACKGROUND: While the distribution of mosquito bed nets is a widely adopted approach for malaria prevention, studies exploring how the usage of a net may be influenced by its source and other factors remain sparse. METHODS: A standardized questionnaire and home-visit observations were used to collect data from 9 villages in Budondo sub-county, Uganda in 2016. Household- and individual-level data were collected, such as bed net ownership (at least one net versus none), acquirement source (free versus purchased), demographics, as well as knowledge of malaria and preventative measures. Net-level data, including alternative uses, and bed net quantity and integrity, were also collected. Mixed effects logistic regression models were performed to identify the key determinants of bed net use. RESULTS: Overall, the proportion of households with at least one bed net was 40%, while bed net availability was only reported among 27% of all household members. Awareness of the benefits of bed net use was statistically significantly associated with ownership of at least one net (OR = 1.72, 95% CI 1.11-2.68, p = 0.02). Among those who own net(s), the odds of a bed net being correctly used (i.e., to sleep under) after adjusting for potential confounders were significantly lower for nets that were obtained free compared to nets that were purchased by the owners themselves (OR = 0.33, 95% CI 0.21-0.51, p < 0.01), resulting in an alternative use of the net. Other factors such as female gender, children ≤ 5 years old, and pregnancy status were also significantly associated with having a net to sleep under (all p < 0.01). CONCLUSION: Understanding inter- and intra-household net-use factors will help malaria control programmes more effectively direct their efforts to increase public health impact. Future studies may additionally consider socioeconomic status and track the lifetime of the net

    Perceived intensity of somatosensory cortical electrical stimulation

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    Artificial sensations can be produced by direct brain stimulation of sensory areas through implanted microelectrodes, but the perceptual psychophysics of such artificial sensations are not well understood. Based on prior work in cortical stimulation, we hypothesized that perceived intensity of electrical stimulation may be explained by the population response of the neurons affected by the stimulus train. To explore this hypothesis, we modeled perceived intensity of a stimulation pulse train with a leaky neural integrator. We then conducted a series of two-alternative forced choice behavioral experiments in which we systematically tested the ability of rats to discriminate frequency, amplitude, and duration of electrical pulse trains delivered to the whisker barrel somatosensory cortex. We found that the model was able to predict the performance of the animals, supporting the notion that perceived intensity can be largely accounted for by spatiotemporal integration of the action potentials evoked by the stimulus train

    Implantable CMOS Biomedical Devices

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    The results of recent research on our implantable CMOS biomedical devices are reviewed. Topics include retinal prosthesis devices and deep-brain implantation devices for small animals. Fundamental device structures and characteristics as well as in vivo experiments are presented

    The effects of denervation and stimulation upon synaptic ultrastructure

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    Quantitative studies of synaptic ultrastructure were made in the upper layers of cat cerebral cortex. Tissues were from intact cortex and from long-term (chronic) undercut cortex with or without electrical stimulation. The synaptic effects of chronic electrical stimulation of denervated cortex are most readily understood as growth and remodeling of synaptic elements. Associated with chronic stimulation were increases in: symmetric membrane contacts; areas of round and flat vesicle containing terminals; dendritic shaft contacts; and synaptic contact lengths. Even without stimulation there were indications of synaptic plasticity in denervated cortex; compared with intact cortex, synapses having symmetric membrane contacts showed an increase in bouton area and an increase in synaptic contacts on dendritic shafts. These data are consistent with the observations of others in which axonal terminal growth occurred after deafferentation. But it appears that chronic electrical stimulation in the adult nervous system promotes significantly more plasticity than occurs without stimulation. In a functional sense stimulation in the present experiments produced effective inhibition which did not occur with denervation alone. Thus the plasticity observed with stimulation had both structural and functional components.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/50005/1/901780107_ftp.pd

    The application of Graphene as a sample support in Transmission Electron Microscopy

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    Transmission electron microscopy has witnessed rampant development and surging point resolution over the past few years. The improved imaging performance of modern electron microscopes shifts the bottleneck for image contrast and resolution to sample preparation. Hence, it is increasingly being realized that the full potential of electron microscopy will only be realized with the optimization of current sample preparation techniques. Perhaps the most recognized issues are background signal and noise contributed by sample supports, sample charging and instability. Graphene provides supports of single atom thickness, extreme physical stability, periodic structure, and ballistic electrical conductivity. As an increasing number of applications adapting graphene to their benefit emerge, we discuss the unique capabilities afforded by the use of graphene as a sample support for electron microscopy.Comment: Review, to appear in solid state communication
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