586 research outputs found

    Citizenship and Ethnic Politics in Latin America

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    human development, culture

    Design of Autonomous Medical Response Agent (AMRA) Aggregate Information Dashboard (AID)

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    Future astronauts in deep space missions will rely on tools and technologies empowering them to self-diagnose and self-treat medical conditions. Given communications delays and limited bandwidth in future long-duration exploration missions (LDEMs), medical decision support technologies must empower the crew to manage routine medical activities, acute medical incidents, as well as emergency medical scenarios independently from ground support.The Autonomous Medical Response Agent (AMRA) is envisioned as a digital tool enabling crew to issue medical complaints and interact with a medical decision support algorithm which develops a differential diagnosis and recommends a treatment protocol for the condition. AMRA will draw from individual crew medical history in addition to crew symptoms to more efficiently identify high-risk medical conditions. A new symptom could be indicative of a chronic condition or a normal adaptation to long-duration spaceflight, but could just as easily be indicative of an adverse vehicle condition affecting the entire crew.While real-time communication with a flight surgeon may not possible, the crew will nonetheless require a means to communicate and document both routine and emergency medical incidents to ground support. Conversely, flight surgeons and medical specialists on the ground will need to understand information such as crew vitals or responses to medical check-ups and examinations within the larger context of crew schedule, mission activities, and vehicle performance. A user interface which establishes communication protocols between an individual crew member and AMRA, as well as ground support to the crew is a significant area of research demanding input and consideration.The design of AMRA AID is intended to: a) represent routine medical activities as well as new (unplanned) medical incidents within the larger context of crew schedule and mission activities, and b) increase confidence between ground support and crew members over the course of LDEMs. Maintaining situation awareness of unplanned medical incidents between ground and crew will be a critical element within LDEMs. Two medical incidents headache and difficulty breathing are being explored within a user interface prototype which captures communications protocols between crew members and mission control, human health monitoring, vehicle or environmental monitoring, as well as crew schedule and mission activities holistically

    Interventional Treatment Options for Trigeminal Neuralgia

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    Trigeminal neuralgia is characterized by sudden and severe shock-like episodes of transient unilateral pain in the trigeminal nerve distribution. Most cases are idiopathic and are known to respond favorably to anticonvulsants. For patients who fail at least three drug trials or experience intolerable side effects, surgery may be warranted. First, a diagnostic block at the trigeminal nerve or Gasserian ganglion to confirm clinical diagnosis is performed. Surgical intervention can be either ablative or nonablative, each with its respective indications, contraindications, and risk-benefit profile. Most common are the percutaneous rhizotomies: conventional and pulsed radiofrequency ablation (RFA), chemical glycerol injections, and mechanical balloon compression. Stereotactic or gamma knife radiosurgery (GKRS) is the least invasive with only a moderate duration of pain relief, whereas microvascular decompression (VMD) is the most invasive, but associated with greatest long-term benefit. RFA has consistently shown favorable results and is the only modality with evidence of pain relief in ≥50% of patients treated 20 years postoperatively. Auxiliary interventional options such as peripheral neurectomy, botulinum toxin type-A (BTX-A) injections, and cryotherapy are available for those with contraindications to rhizotomies, radiosurgery, or neurosurgery. Ultimately, physicians must tailor their management of trigeminal neuralgia to the needs of the patient

    Trade-time based measures of liquidity

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    Dramatic microstructure changes in equity markets have made standard liquidity measures less accurate proxies for trading costs. We develop trade-time liquidity measures that reflect per-dollar price impacts of fixed-dollar volumes. Our measures better capture institutional trading costs and better explain the cross-section of returns than do standard measures, especially in recent years. Despite improvements in measures of market quality, expected trading costs have explanatory power for the cross-section of expected returns: we obtain monthly liquidity premium estimates of 5.3 bp for expected returns and 2.4 bp for risk-adjusted returns. Estimated premiums rise after the financial crisis and remain high thereafter

    Comparison between using longitudinal and shear waves in ultrasonic stress measurement to investigate the effect of post-weld heat-treatment on welding residual stresses

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    ABSTARCT: Fusion welding is a joining process widely used in the industry. However, undesired residual stresses are produced once the welding process is completed. Post-weld heat-treatment (PWHT) is extensively employed in order to relieve the welding residual stresses. In this study, effect of PWHT time and temperature on the residual stresses of a ferritic stainless steel is investigated. Residual stress distributions in eight welded specimens were measured by using an ultrasonic method. Ultrasonic stress measurement is a nondestructive method based on acoustoelasticity law, which correlates mechanical stresses with velocity of an ultrasonic wave propagating within the subject material. The ultrasonic wave employed could be longitudinal or shear wave produced by the longitudinal (normal) or transverse (shear) transducers, respectively. Ultrasonic stress measurements based on longitudinal waves use longitudinal critically refracted (LCR) waves in this direction, while shear wave methods use an ultrasonic birefringence phenomenon. The results show that the effect of PWHT can be successfully inferred by both longitudinal and shear wave methods, but the former is found to be more sensitive to stress variation. Furthermore, the distribution of subsurface residual stresses is found to be more distinguishable when the LCR method is employed

    The Universe is not statistically isotropic

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    The standard cosmological model predicts statistically isotropic cosmic microwave background (CMB) fluctuations. However, several summary statistics of CMB isotropy have anomalous values, including: the low level of large-angle temperature correlations, S1/2S_{1/2}; the excess power in odd versus even low-ℓ\ell multipoles, RTTR^{TT}; the (low) variance of large-scale temperature anisotropies in the ecliptic north, but not the south, σ162\sigma^2_{16}; and the alignment and planarity of the quadrupole and octopole of temperature, SQOS_{QO}. Individually, their low pp-values are weak evidence for violation of statistical isotropy. The correlations of the tail values of these statistics have not to this point been studied. We show that the joint probability of all four of these happening by chance in Λ\LambdaCDM is likely ≤3×10−8\leq3\times10^{-8}. This constitutes more than 5σ5\sigma evidence for violation of statistical isotropy.Comment: 6 page
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