101 research outputs found

    Navigational Heads-Up Display

    Get PDF
    One problem drivers face is distraction from looking at their mobile device while navigating rather than watching the road. This problem can be solved with a heads-up display placed directly on the driver’s windshield. By using a mobile device with a custom GPS application, the following design will be able to send GPS data to a device that will display navigational information on a car windshield. The design includes two primary components, a mobile device and a System Unit, where the System Unit is composed of a portable power supply, a single board computer, and a display. For the design, the mobile device is an android device, the portable power supply is a battery, and the display is a small projector. The design has a very strong software focus, and the main intention of the design is to produce a fully functional Android mobile application that pairs along with prototype hardware elements. In final implementation, the mobile application sends data in the JSON format over a Bluetooth connection. The key features of the project are as follows: • A custom GPS Android Application that can generate routes from the user’s current location to destinations entered by the user. • A System Unit, which is a device that has the capability to be mounted on a vehicle’s dashboard, connect to the user’s mobile device, and generate a display that contains navigation information. • A projected display that is shown on the vehicle’s windshield

    Coherent Cancellation of Photothermal Noise in GaAs/Al0.92_{0.92}Ga0.08_{0.08}As Bragg Mirrors

    Get PDF
    Thermal noise is a limiting factor in many high-precision optical experiments. A search is underway for novel optical materials with reduced thermal noise. One such pair of materials, gallium arsenide and aluminum-alloyed gallium arsenide (collectively referred to as AlGaAs), shows promise for its low Brownian noise when compared to conventional materials such as silica and tantala. However, AlGaAs has the potential to produce a high level of thermo-optic noise. We have fabricated a set of AlGaAs crystalline coatings, transferred to fused silica substrates, whose layer structure has been optimized to reduce thermo-optic noise by inducing coherent cancellation of the thermoelastic and thermorefractive effects. By measuring the photothermal transfer function of these mirrors, we find evidence that this optimization has been successful.Comment: 10 pages, 7 figure

    Hepatic Energy Metabolism under the Local Control of the Thyroid Hormone System

    Get PDF
    The energy homeostasis of the organism is orchestrated by a complex interplay of energy substrate shuttling, breakdown, storage, and distribution. Many of these processes are interconnected via the liver. Thyroid hormones (TH) are well known to provide signals for the regulation of energy homeostasis through direct gene regulation via their nuclear receptors acting as transcription factors. In this comprehensive review, we summarize the effects of nutritional intervention like fasting and diets on the TH system. In parallel, we detail direct effects of TH in liver metabolic pathways with regards to glucose, lipid, and cholesterol metabolism. This overview on hepatic effects of TH provides the basis for understanding the complex regulatory network and its translational potential with regards to currently discussed treatment options of non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) involving TH mimetics

    Alzheimer’s disease progression by geographical region in a clinical trial setting

    Get PDF
    INTRODUCTION: To facilitate enrollment and meet local registration requirements, sponsors have increasingly implemented multi-national Alzheimer's disease (AD) studies. Geographic regions vary on many dimensions that may affect disease progression or its measurement. To aid researchers designing and implementing Phase 3 AD trials, we assessed disease progression across geographic regions using placebo data from four large, multi-national clinical trials of investigational compounds developed to target AD pathophysiology. METHODS: Four similarly-designed 76 to 80 week, randomized, double-blind placebo-controlled trials with nearly identical entry criteria enrolled patients aged ≥55 years with mild or moderate NINCDS/ADRDA probable AD. Descriptive analyses were performed for observed mean score and observed mean change in score from baseline at each scheduled visit. Data included in the analyses were pooled from the intent-to-treat placebo-assigned overall (mild and moderate) AD dementia populations from all four studies. Disease progression was assessed as change from baseline for each of 5 scales - the AD Assessment Scale-cognitive subscale (ADAS-cog11), the AD Cooperative Study- Activities of Daily Living Scale (ADCS-ADL), Mini-Mental State Examination (MMSE), the Clinical Dementia Rating scored by the sum of boxes method (CDR-SB), and the Neuropsychiatric Inventory (NPI). RESULTS: Regions were heterogeneous at baseline. At baseline, disease severity as measured by ADAS-cog11, ADCS-ADL, and CDR-SB was numerically worse for Eastern Europe/Russia compared with other regions. Of all regional populations, Eastern Europe/Russia showed the greatest cognitive and functional decline from baseline; Japan, Asia and/or S. America/Mexico showed the least cognitive and functional decline. CONCLUSIONS: These data suggest that in multi-national clinical trials, AD progression or its measurement may differ across geographic regions; this may be in part due to heterogeneity across populations at baseline. The observed differences in AD progression between outcome measures across geographic regions may generalize to 'real-world' clinic populations, where heterogeneity is the norm

    Photo-physics and electronic structure of lateral graphene/MoS2 and metal/MoS2 junctions

    Full text link
    Integration of semiconducting transition metal dichalcogenides (TMDs) into functional optoelectronic circuitries requires an understanding of the charge transfer across the interface between the TMD and the contacting material. Here, we use spatially resolved photocurrent microscopy to demonstrate electronic uniformity at the epitaxial graphene/molybdenum disulfide (EG/MoS2) interface. A 10x larger photocurrent is extracted at the EG/MoS2 interface when compared to metal (Ti/Au) /MoS2 interface. This is supported by semi-local density-functional theory (DFT), which predicts the Schottky barrier at the EG/MoS2 interface to be ~2x lower than Ti/MoS2. We provide a direct visualization of a 2D material Schottky barrier through combination of angle resolved photoemission spectroscopy with spatial resolution selected to be ~300 nm (nano-ARPES) and DFT calculations. A bending of ~500 meV over a length scale of ~2-3 micrometer in the valence band maximum of MoS2 is observed via nano-ARPES. We explicate a correlation between experimental demonstration and theoretical predictions of barriers at graphene/TMD interfaces. Spatially resolved photocurrent mapping allows for directly visualizing the uniformity of built-in electric fields at heterostructure interfaces, providing a guide for microscopic engineering of charge transport across heterointerfaces. This simple probe-based technique also speaks directly to the 2D synthesis community to elucidate electronic uniformity at domain boundaries alongside morphological uniformity over large areas

    Leveraging high-resolution 7-tesla MRI to derive quantitative metrics for the trigeminal nerve and subnuclei of limbic structures in trigeminal neuralgia

    Full text link
    Background: Trigeminal Neuralgia (TN) is a chronic neurological disease that is strongly associated with neurovascular compression (NVC) of the trigeminal nerve near its root entry zone. The trigeminal nerve at the site of NVC has been extensively studied but limbic structures that are potentially involved in TN have not been adequately characterized. Specifically, the hippocampus is a stress-sensitive region which may be structurally impacted by chronic TN pain. As the center of the emotion-related network, the amygdala is closely related to stress regulation and may be associated with TN pain as well. The thalamus, which is involved in the trigeminal sensory pathway and nociception, may play a role in pain processing of TN. The objective of this study was to assess structural alterations in the trigeminal nerve and subregions of the hippocampus, amygdala, and thalamus in TN patients using ultra-high field MRI and examine quantitative differences in these structures compared with healthy controls. Methods: Thirteen TN patients and 13 matched controls were scanned at 7-Tesla MRI with high resolution, T1- weighted imaging. Nerve cross sectional area (CSA) was measured and an automated algorithm was used to segment hippocampal, amygdaloid, and thalamic subregions. Nerve CSA and limbic structure subnuclei volumes were compared between TN patients and controls. Results: CSA of the posterior cisternal nerve on the symptomatic side was smaller in patients (3.75mm2) compared with side-matched controls (5.77mm2, p = 0.006). In TN patients, basal subnucleus amygdala volume (0.347mm3) was reduced on the symptomatic side compared with controls (0.401mm3, p = 0.025) and the paralaminar subnucleus volume (0.04mm3) was also reduced on the symptomatic side compared with controls (0.05mm3, p = 0.009). The central lateral thalamic subnucleus was larger in TN patients on both the symptomatic side (0.033mm3) and asymptomatic side (0.035mm3), compared with the corresponding sides in controls (0.025mm3 on both sides, p = 0.048 and p = 0.003 respectively). The inferior and lateral pulvinar thalamic subnuclei were both reduced in TN patients on the symptomatic side (0.2mm3 and 0.17mm3 respectively) compared to controls (0.23mm3, p = 0.04 and 0.18 mm3, p = 0.04 respectively). No significant findings were found in the hippocampal subfields analyzed. Conclusions: These findings, generated through a highly sensitive 7 T MRI protocol, provide compelling support for the theory that TN neurobiology is a complex amalgamation of local structural changes within the trigeminal nerve and structural alterations in subnuclei of limbic structures directly and indirectly involved in nociception and pain processing

    Using Population Genetic Theory and DNA Sequences for Species Detection and Identification in Asexual Organisms

    Get PDF
    It is widely agreed that species are fundamental units of biology, but there is little agreement on a definition of species or on an operational criterion for delimiting species that is applicable to all organisms.We focus on asexual eukaryotes as the simplest case for investigating species and speciation. We describe a model of speciation in asexual organisms based on basic principles of population and evolutionary genetics. The resulting species are independently evolving populations as described by the evolutionary species concept or the general lineage species concept. Based on this model, we describe a procedure for using gene sequences from small samples of individuals to assign them to the same or different species. Using this method of species delimitation, we demonstrate the existence of species as independent evolutionary units in seven groups of invertebrates, fungi, and protists that reproduce asexually most or all of the time.This wide evolutionary sampling establishes the general existence of species and speciation in asexual organisms. The method is well suited for measuring species diversity when phenotypic data are insufficient to distinguish species, or are not available, as in DNA barcoding and environmental sequencing. We argue that it is also widely applicable to sexual organisms

    The unruptured intracranial aneurysm treatment score A multidisciplinary consensus

    Get PDF
    Objective: We endeavored to develop an unruptured intracranial aneurysm (UIA) treatment score (UIATS) model that includes and quantifies key factors involved in clinical decision-making in the management of UIAs and to assess agreement for this model among specialists in UIA management and research. Methods: An international multidisciplinary (neurosurgery, neuroradiology, neurology, clinical epidemiology) group of 69 specialists was convened to develop and validate the UIATS model using a Delphi consensus. For internal (39 panel members involved in identification of relevant features) and external validation (30 independent external reviewers), 30 selected UIA cases were used to analyze agreement with UIATS management recommendations based on a 5-point Likert scale (5 indicating strong agreement). Interrater agreement (IRA) was assessed with standardized coefficients of dispersion (v(r)*) (v(r)* 5 0 indicating excellent agreement and v(r)* = 1 indicating poor agreement). Results: The UIATS accounts for 29 key factors in UIA management. Agreement with UIATS (mean Likert scores) was 4.2 (95% confidence interval [CI] 4.1-4.3) per reviewer for both reviewer cohorts; agreement per case was 4.3 (95% CI 4.1-4.4) for panel members and 4.5 (95% CI 4.3-4.6) for external reviewers (p = 0.017). Mean Likert scores were 4.2 (95% CI 4.1-4.3) for interventional reviewers (n = 56) and 4.1 (95% CI 3.9-4.4) for noninterventional reviewers (n = 12) (p = 0.290). Overall IRA (v(r)*) for both cohorts was 0.026 (95% CI 0.019-0.033). Conclusions: This novel UIA decision guidance study captures an excellent consensus among highly informed individuals on UIA management, irrespective of their underlying specialty. Clinicians can use the UIATS as a comprehensive mechanism for indicating how a large group of specialists might manage an individual patient with a UIA.Peer reviewe
    • …
    corecore