2,024 research outputs found

    Development of a Functional In Vitro 3D Model of the Peripheral Nerve

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    Peripheral neuropathies, affect approximately 20 million people in the United States and are often a complication of conditions such as diabetes that can result in amputation of affected areas such as the feet and toes. In vitro methodologies to facilitate the understanding and treatment of these disorders often lack the cellular and functional complexity required to accurately model peripheral neuropathies. In particular, they are often 2-D and functional readouts, such as electrical activity, are limited to cell bodies thereby limiting the understanding of axonopathy which often characterizes these disorders. We have developed a functional 3-D model of peripheral nerves using a capillary alginate gel (Capgelâ„¢), as a scaffold. We hypothesize that: 1) The unique microcapillary structure of Capgelâ„¢ allows for the modeling of the 3-D microstructure of the peripheral nerve, and 2) That axon bundling in the capillary allows for the detection of axonal electrical activity. In our initial studies, we demonstrate that culturing embryonic dorsal root ganglia (DRG) within the Capgelâ„¢ environment allows for the separation of cell bodies from axons and recreates many of the features of an in vivo peripheral nerve fascicle including myelinated axons and the formation of a rudimentary perineurium. To develop functionality for this model we have integrated the DRG Capgelâ„¢ culture with a microelectrode array to examine spontaneous activity in axon bundles, which we find demonstrates superiority to other widely used 2-D models of the same tissue. Furthermore, by analyzing the activity on individual electrodes, we were able to record action potentials from multiple axons within the same bundle indicating a functional complexity comparable to that observed in fascicles in vivo. This 3D model of the peripheral nerve can be used to study the functional complexities of peripheral neuropathies and nerve regeneration as well as being utilized in the development of novel therapeutics

    Beyond reason: revising the place of literature in theories of the uncanny

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    The psychoanalytic fixation in seeking to validate 'the real' has long overlooked various key components in theories of the uncanny as they relate to literature. The goal of the present study is to reaffirm the roles of uncertainty, ambiguity, and the purposeful lack of closure in the experience of the uncanny, features which will come to form an integral part of a new theory

    Sensing via signal analysis, analytics, and cyberbiometric patterns

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    Includes bibliographical references.2022 Fall.Internet-connected, or Internet of Things (IoT), sensor technologies have been increasingly incorporated into everyday technology and processes. Their functions are situationally dependent and have been used for vital recordings such as electrocardiograms, gait analysis and step counting, fall detection, and environmental analysis. For instance, environmental sensors, which exist through various technologies, are used to monitor numerous domains, including but not limited to pollution, water quality, and the presence of biota, among others. Past research into IoT sensors has varied depending on the technology. For instance, previous environmental gas sensor IoT research has focused on (i) the development of these sensors for increased sensitivity and increased lifetimes, (ii) integration of these sensors into sensor arrays to combat cross-sensitivity and background interferences, and (iii) sensor network development, including communication between widely dispersed sensors in a large-scale environment. IoT inertial measurement units (IMU's), such as accelerometers and gyroscopes, have been previously researched for gait analysis, movement detection, and gesture recognition, which are often related to human-computer interface (HCI). Methods of IoT Device feature-based pattern recognition for machine learning (ML) and artificial intelligence (AI) are frequently investigated as well, including primitive classification methods and deep learning techniques. The result of this research gives insight into each of these topics individually, i.e., using a specific sensor technology to detect carbon monoxide in an indoor environment, or using accelerometer readings for gesture recognition. Less research has been performed on analyzing the systems aspects of the IoT sensors themselves. However, an important part of attaining overall situational awareness is authenticating the surroundings, which in the case of IoT means the individual sensors, humans interacting with the sensors, and other elements of the surroundings. There is a clear opportunity for the systematic evaluation of the identity and performance of an IoT sensor/sensor array within a system that is to be utilized for "full situational awareness". This awareness may include (i) non-invasive diagnostics (i.e., what is occurring inside the body), (ii) exposure analysis (i.e., what has gone into the body through both respiratory and eating/drinking pathways), and (iii) potential risk of exposure (i.e., what the body is exposed to environmentally). Simultaneously, the system has the capability to harbor security measures through the same situational assessment in the form of multiple levels of biometrics. Through the interconnective abilities of the IoT sensors, it is possible to integrate these capabilities into one portable, hand-held system. The system will exist within a "magic wand", which will be used to collect the various data needed to assess the environment of the user, both inside and outside of their bodies. The device can also be used to authenticate the user, as well as the system components, to discover potential deception within the system. This research introduces levels of biometrics for various scenarios through the investigation of challenge-based biometrics; that is, biometrics based upon how the sensor, user, or subject of study responds to a challenge. These will be applied to multiple facets surrounding "situational awareness" for living beings, non-human beings, and non-living items or objects (which we have termed "abiometrics"). Gesture recognition for intent of sensing was first investigated as a means of deliberate activation of sensors/sensor arrays for situational awareness while providing a level of user authentication through biometrics. Equine gait analysis was examined next, and the level of injury in the lame limbs of the horse was quantitatively measured and classified using data from IoT sensors. Finally, a method of evaluating the identity and health of a sensor/sensory array was examined through different challenges to their environments

    Design, Construction, and Validation of the AFIT Small Scale Combustion Facility and Section Model of the Ultra-Compact Combustor

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    The AFIT small-scale combustion facility is complete and its first experiment designed and built. Beginning with the partially built facility, detailed designs have been developed to complete the laboratory in order to run small-scale combustion experiments at atmospheric pressure. A sectional model of the Ultra-Compact Combustor has also been designed and built. Although the lab\u27s specific design intent was to study the UCC\u27s cavity-vane interaction, facility flexibility has also been maintained for future work. The design enabled the completion of liquid fuel and air delivery systems, power and control systems, and test equipment. The design includes failsafe operation, remote control, and adherence to SAE ARP 1256 testing standards. Construction of the laboratory has forced design changes as new obstacles arose. As system construction has been completed validation and troubleshooting have been undertaken. The AFIT facility can now deliver air in two separately controlled air lines at up to 530 K (500 deg F), at delivery rates of 0.12 kg/s (200 SCFM) for the main line and 0.03 kg/s (60 SCFM) for the secondary. A continuous dual syringe pump can deliver liquid fuel at up to 5.67 mL/s for JP-8 equivalence ratios up to 4. Safe, remote ignition and shutdown are in place and all test equipment fundamental to combustion is installed. The addition of an advanced laser combustion diagnostics system adds more unique capability to the laboratory. The laser system will provide instantaneous Raman and Raman spectroscopy, Coherent Anti-Stokes Raman Scattering, Planar Laser-Induced Fluorescence, Laser-Induced Incandescence and Planar Imaging Velocimetry diagnostic techniques

    HABITAT UTILIZATION BY THE TEXAS HORNED LIZARD (PHRYNOSOMA CORNUTUM) FROM TWO SITES IN CENTRAL TEXAS

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    The Texas Horned Lizard (Phrynosoma cornutum) is found in a variety of habitats. Although several studies have been conducted on habitat use by this species, none have been performed in central Texas, a more mesic habitat than most of those previously studied. This area is of special interest because horned lizard populations have been experiencing sharp declines in central Texas over the last approximately 50 years. We collected habitat data at two sites in central Texas, Camp Bowie and Blue Mountain Peak Ranch. Microhabitat data included canopy cover and ground cover from digitized photographs of Daubenmire quadrats; macrohabitat variables included vegetation height and length, cactus height, soil penetrability, woody plant species richness, tree density, tree diameter at breast height (DBH), and density of ant mounds collected along 100-m by 2-m transects. Similar patterns of habitat use were observed between the two sites. At Blue Mountain Peak Ranch, lizards appeared to be located in areas with a diversity of ground cover types, as observed in previous studies. At Camp Bowie, vegetation encroachment limited lizards in some areas to the use of roads and road margins. Implementation of prescribed burns or other vegetation management could create the preferred ground cover mosaic at such sites

    Discovering and visualizing patterns in EEG data

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    pre-printBrain activity data is often collected through the use of electroen-cephalography (EEG). In this data acquisition modality, the electric fields generated by neurons are measured at the scalp. Although this technology is capable of measuring activity from a group of neurons, recent efforts provide evidence that these small neuronal collections communicate with other, distant assemblies in the brain's cortex. These collaborative neural assemblies are often found by examining the EEG record to find shared activity patterns. In this paper, we present a system that focuses on extracting and visualizing potential neural activity patterns directly from EEG data. Using our system, neuroscientists may investigate the spectral dynamics of signals generated by individual electrodes or groups of sensors. Additionally, users may interactively generate queries which are processed to reveal which areas of the brain may exhibit common activation patterns across time and frequency. The utility of this system is highlighted in a case study in which it is used to analyze EEG data collected during a working memory experiment

    Neuregulin-1 attenuates mortality associated with experimental cerebral malaria.

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    BackgroundCerebral Malaria (CM) is a diffuse encephalopathy caused by Plasmodium falciparum infection. Despite availability of antimalarial drugs, CM-associated mortality remains high at approximately 30% and a subset of survivors develop neurological and cognitive disabilities. While antimalarials are effective at clearing Plasmodium parasites they do little to protect against CM pathophysiology and parasite-induced brain inflammation that leads to seizures, coma and long-term neurological sequelae in CM patients. Thus, there is urgent need to explore therapeutics that can reduce or prevent CM pathogenesis and associated brain inflammation to improve survival. Neuregulin-1 (NRG-1) is a neurotrophic growth factor shown to protect against brain injury associated with acute ischemic stroke (AIS) and neurotoxin exposure. However, this drug has not been tested against CM-associated brain injury. Since CM-associated brain injuries and AIS share similar pathophysiological features, we hypothesized that NRG-1 will reduce or prevent neuroinflammation and brain damage as well as improve survival in mice with late-stage experimental cerebral malaria (ECM).MethodsWe tested the effects of NRG-1 on ECM-associated brain inflammation and mortality in P. berghei ANKA (PbA)-infected mice and compared to artemether (ARM) treatment; an antimalarial currently used in various combination therapies against malaria.ResultsTreatment with ARM (25 mg/kg/day) effectively cleared parasites and reduced mortality in PbA-infected mice by 82%. Remarkably, NRG-1 therapy (1.25 ng/kg/day) significantly improved survival against ECM by 73% despite increase in parasite burden within NRG-1-treated mice. Additionally, NRG-1 therapy reduced systemic and brain pro-inflammatory factors TNFalpha, IL-6, IL-1alpha and CXCL10 and enhanced anti-inflammatory factors, IL-5 and IL-13 while decreasing leukocyte accumulation in brain microvessels.ConclusionsThis study suggests that NRG-1 attenuates ECM-associated brain inflammation and injuries and may represent a novel supportive therapy for the management of CM

    A importância das redes sociais como ferramenta para reter informações sobre o comportamento dos consumidores

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    This work consists of a research about the importance of social networks as a communication and advertising tool on organizations. The main objective was to carry out a survey on how this type of tool reaches its users, in relation to advertising companies. This research characterized as quantitative, spanning variables that influence consumer buying behavior. The data collection method was a questionnaire. The research variables consisted on, which tools these users use, what is the importance of these tools, and the degree of influence that undergo these cycles. According to the survey, the use of these media shows, efficiency, as this new type of advertising reaches a large number of users.NenhumaEste trabalho consiste numa pesquisa sobre a importância das redes sociais como ferramenta de comunicação e publicidade das organizações. O objetivo principal foi realizar uma pesquisa sobre como esse tipo de ferramenta atinge seus usuários, em relação à publicidade das empresas. A presente pesquisa caracterizou se como quantitativa, abrangendo variáveis que influenciam o comportamento de compra dos consumidores. O método de coleta de dados foi um questionário. Entre as variáveis analisadas, pesquisamos quais ferramentas esses usuários utilizam, qual a importância dessas ferramentas, e o grau de influência a quem se submete a esses ciclos sociais. De acordo com a pesquisa realizada os índices de utilização desses meios mostram de forma eficiente como esse novo tipo de publicidade atinge uma grande quantidade de usuários
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