903 research outputs found

    Investigations of Balloon and Aeroplane Fabrics

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    Report presents the experimental results of fabrics used for balloons and aeroplanes. Tensile properties, surface roughness, skin friction, flammability, permeability, and water absorption were tested for different combinations of materials

    Conditional Quantum Walk and Iterated Quantum Games

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    Iterated bipartite quantum games are implemented in terms of the discrete-time quantum walk on the line. Our proposal allows for conditional strategies, as two rational agents make a choice from a restricted set of two-qubit unitary operations. Several frequently used classical strategies give rise to families of corresponding quantum strategies. A quantum version of the Prisoner's Dilemma in which both players use mixed strategies is presented as a specific example. Since there are now quantum walk physical implementations at a proof-of principle stage, this connection may represent a step towards the experimental realization of quantum games.Comment: Revtex 4, 6 pages, 3 figures. Expanded version with one more figure and updated references. Abstract was rewritte

    The Vehicle, Spring 1976

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    Table of Contents PhotoJim Painterpage 1 The City is the Black Man\u27s LandCharles (Omar) Davispage 2 NIGGER!Sibyl Burrellpage 2 EssayEl-Edrisi Assibaipage 3 PhotoTom Tieffenbacherpage 3 The Gypsy GhostBill Vermillionpage 4 PhotoTom Tieffenbacherpage 5 PhotoTom Tieffenbacherpage 6 e.e.,H.M. (Wendy) Smithpage 7 Fair LovingGary Thomaspage 7 PhotoTom Tieffenbacherpage 7 Night and Summer in Two WorldsBarry Smithpage 8https://thekeep.eiu.edu/vehicle/1034/thumbnail.jp

    Non-linear relationships of cerebrospinal fluid biomarker levels with cognitive function: an observational study

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    INTRODUCTION: Levels of cerebrospinal fluid (CSF) Ī²-amyloid (AĪ²) and Tau proteins change in Alzheimer's disease (AD). We tested if the relationships of these biomarkers with cognitive impairment are linear or non-linear. METHODS: We assessed cognitive function and assayed CSF AĪ² and Tau biomarkers in 95 non-demented volunteers and 97 AD patients. We then tested non-linearities in their inter-relations. RESULTS: CSF biomarkers related to cognitive function in the non-demented range of cognition, but these relations were weak or absent in the patient range; AĪ²1-40's relationship was biphasic. CONCLUSIONS: Major biomarker changes precede clinical AD and index cognitive impairment in AD poorly, if at all

    A Pilot Study: Attention Deficit Hyperactivity Disorder, Sensation Seeking, and Pubertal Changes

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    This study was designed to examine the relationship of pubertal changes and sensation seeking (SS) in adolescents with Attention Deficit Hyperactivity Disorder (ADHD). Patients with current or past histories of uncomplicated stimulant medication use for ADHD between the ages of 11 and 15 (13 Ā± 1.5) were recruited from a Child Psychiatry and a General Pediatric Clinic. SS was measured using the SS Scale for Children. Pubertal development was measured using Tanner staging, free testosterone, and DHEAS. Subjects and their parent were interviewed with the Diagnostic Interview Schedule for Children (DISC). SS total score was correlated with Tanner stage, free testosterone, and DHEAS (p ā‰¤ 0.01). The combined parent and child reports of symptoms of Oppositional Defiant Disorder from the DISC were inversely related to age (p ā‰¤ 0.05). Understanding SS in ADHD adolescents as they move through puberty will aid clinicians in monitoring ADHD adolescents and their trajectory into high-risk behaviors

    Coping Strategies of Jordanian Adolescents With Cancer: An Interpretive Phenomenological Analysis Study

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    Interpretive phenomenological analysis methodology was used to explore coping strategies used by hospitalized Jordanian adolescents with cancer. In-depth face-to-face interviews were conducted with 10 Jordanian adolescents, aged 13 to18 years, who were receiving chemotherapy for cancer. During treatment, participants were confronted with physical, psychosocial, and emotional distresses resulting from the disease process, the treatment, and its associated side-effects. To cope with the impact of their illness, participants utilized 4 coping strategies: "Strengthening spiritual convictions," "Being optimistic and rebuilding hope," "Enhancing appearance," and "Finding self again." The findings of this study can assist health team members to promote positive psychological care to Arab Muslim adolescents with cancer in a supportive and therapeutic treatment environment

    Reducing Departure Delays for Adjacent Center Airports using Time-Based Flow Management Scheduler: Checkbox On or Off?

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    The Federal Aviation Administration (FAA) has enhanced the Time-Based Flow Management (TBFM) scheduling tool with a "Checkbox ON" vs. "OFF" function which allows Traffic Management Coordinators (TMCs) to make room in a crowded arrival stream for a departure. When scheduling a departure, having the checkbox ON can delay the Scheduled Times of Arrivals (STAs) of the airborne flights upstream of the TBFM freeze horizons and can compress these flights to their minimum required spacing, thereby creating a slot for a departure. Hence, having the checkbox ON can reduce the frequent ground delays of aircraft departing near high volume airports but can increase delays for airborne arrivals. A Human-in-the-Loop (HITL) simulation compared arrival and departure delays to Newark Airport (EWR) with the checkbox ON vs. OFF as the default position. Three other conditions in this HITL involved various National Airspace System (NAS)-wide approaches for timely delivery of aircraft to the TBFM region. These conditions were: Baseline, using current Mile-in-Trail (MIT) spacing restrictions; Integrated Demand Management (IDM), where all aircraft were given departure times (Expect Departure Clearance Times, or EDCTs), ultimately based on the EWR Airport Arrival Rate; and IDM plus Required Time of Arrival (RTA), a flight deck tool which allowed some aircraft to meet a controlled time of arrival to the TBFM area more precisely. Results showed that the checkbox tool was powerful: with the checkbox ON, departure delays decreased and airborne delays increased, as predicted. However, assuming that the cost ratio of a minute of airborne delay to a minute of departure delay is in the range of 1.2 to 3, as commonly indicated by the literature, checkbox ON and checkbox OFF conditions showed approximately equal total delay costs, i.e., the cost of delays in the air balanced the cost of the delay on the ground. The three scheduling conditions also had approximately equal total delay costs, although a simulation artifact may have reduced the delays in the Baseline condition. In the debrief following the simulation, the TMCs concluded that the checkbox should be used flexibly depending on the current delay situation, and suggested modifications to the checkbox tool which would help them use it in this way, along with enhanced training. The relatively similar total cost of both checkbox default options in this simulation indicates that this might be a fruitful approach, and replace the necessity to have the checkbox rigidly set to either ON or OFF

    The Genetic Structure and History of Africans and African Americans.

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    Africa is the source of all modern humans, but characterization of genetic variation and of relationships among populations across the continent has been enigmatic. We studied 121 African populations, four African American populations, and 60 non-African populations for patterns of variation at 1327 nuclear microsatellite and insertion/deletion markers. We identified 14 ancestral population clusters in Africa that correlate with self-described ethnicity and shared cultural and/or linguistic properties. We observed high levels of mixed ancestry in most populations, reflecting historical migration events across the continent. Our data also provide evidence for shared ancestry among geographically diverse hunter-gatherer populations (Khoesan speakers and Pygmies). The ancestry of African Americans is predominantly from Niger-Kordofanian (approximately 71%), European (approximately 13%), and other African (approximately 8%) populations, although admixture levels varied considerably among individuals. This study helps tease apart the complex evolutionary history of Africans and African Americans, aiding both anthropological and genetic epidemiologic studies

    GAMBE: Thermal neutron detection system based on a sandwich configuration of silicon semiconductor detector coupled with neutron reactive material

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    Ā© 2019 Elsevier Ltd Silicon semiconductor detectors are used efficiently for neutron detection when coated with a suitable material. They detect secondary reaction products resulting from the interaction of thermal neutrons with a neutron sensitive material such as 6 LiF. In the present work, the efficiency of the thermal neutron detector system, GAMBE, is discussed. This detector system based on two silicon sensors of 1 cm 2 active area and a layer of 6 LiF (1.5Ā±0.6) mg/cm 2 thick in a sandwich configuration. This arrangement achieves total and coincidence detection efficiency of (4.1Ā±0.5)% and (0.9Ā±0.3)% respectively. The coincidence method defines a true neutron hit by the simultaneous signal recorded by the two sensors facing the conversion film. This coincidence methodology is applied to enhance the rejection factor of fake hits due to high gamma background conditions up to 10 8 as discussed in previous work. Geant simulation indicates that total and coincidence detection efficiency up to 55% and 18% are possible using an advanced design of stacked detectors
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