1,061 research outputs found

    Delta nitrogen tetroxide fueling operations

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    The development of the Delta second stage nitrogen tetroxide fueling system is briefly summarized. The nitrogen tetroxide fueling system and the equipment used to protect the spacecraft environment from the toxic nitrogen tetroxide fumes are described. Topics covered include: the nitrogen tetroxide transfer system; loading operations; safety precautions; and chemical treatment of all toxic vapors

    Information Optimization in Coupled Audio-Visual Cortical Maps

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    Barn owls hunt in the dark by using cues from both sight and sound to locate their prey. This task is facilitated by topographic maps of the external space formed by neurons (e.g., in the optic tectum) that respond to visual or aural signals from a specific direction. Plasticity of these maps has been studied in owls forced to wear prismatic spectacles that shift their visual field. Adaptive behavior in young owls is accompanied by a compensating shift in the response of (mapped) neurons to auditory signals. We model the receptive fields of such neurons by linear filters that sample correlated audio-visual signals, and search for filters that maximize the gathered information, while subject to the costs of rewiring neurons. Assuming a higher fidelity of visual information, we find that the corresponding receptive fields are robust and unchanged by artificial shifts. The shape of the aural receptive field, however, is controlled by correlations between sight and sound. In response to prismatic glasses, the aural receptive fields shift in the compensating direction, although their shape is modified due to the costs of rewiring.Comment: 7 pages, 1 figur

    Validity and reliability of the Structured Clinical Interview for Depersonalization-Derealization Spectrum (SCI-DER).

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    This study evaluates the validity and reliability of a new instrument developed to assess symptoms of depresonalization: the Structured Clinical Interview for the Depersonalization-Derealization Spectrum (SCI-DER). The instrument is based on a spectrum model that emphasizes soft-signs, sub-threshold syndromes as well as clinical and subsyndromal manifestations. Items of the interview include, in addition to DSM-IV criteria for depersonalization, a number of features derived from clinical experience and from a review of phenomenological descriptions. Study participants included 258 consecutive patients with mood and anxiety disorders, 16.7% bipolar I disorder, 18.6% bipolar II disorder, 32.9% major depression, 22.1% panic disorder, 4.7% obsessive compulsive disorder, and 1.5% generalized anxiety disorder; 2.7% patients were also diagnosed with depersonalization disorder. A comparison group of 42 unselected controls was enrolled at the same site. The SCI-DER showed excellent reliability and good concurrent validity with the Dissociative Experiences Scale. It significantly discriminated subjects with any diagnosis of mood and anxiety disorders from controls and subjects with depersonalization disorder from controls. The hypothesized structure of the instrument was confirmed empirically

    Risk adjustment for inter-hospital comparison of caesarean delivery rates in low-risk deliveries

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    BACKGROUND: Caesarean delivery (CD) rates have been frequently used as quality measures for maternity service comparisons. More recently, primary CD rates (CD in women without previous CD) or CD rates within selected categories such as nulliparous, term, cephalic singleton deliveries (NTCS) have been used. The objective of this study is to determine the extent to which risk adjustment for clinical and socio-demographic variables is needed for inter-hospital comparisons of CD rates in women without previous CD and in NTCS deliveries. METHODS: Hospital discharge records of women who delivered in Emilia-Romagna Region (Italy) from January, 2007 to June 2009 and in Tuscany Region for year 2009 were linked with birth certificates. Adjusted RRs of CD in women without a previous Caesarean and NTCS were estimated using Poisson regression. Percentage differences in RR before and after adjustment were calculated and hospital rankings, based on crude and adjusted RRs, were examined. RESULTS: Adjusted RR differed substantially from crude RR in women without a previous Caesarean and only marginally in NTCS group. Hospital ranking was markedly affected by adjustment in women without a previous CD, but less in NTCS. CONCLUSION: Risk adjustment is warranted for inter-hospital comparisons of primary CD rates but not for NTCS CD rates. Crude NTCS CD rates are a reliable estimate of adjusted NTCS CD

    INFN What Next: Ultra-relativistic Heavy-Ion Collisions

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    This document was prepared by the community that is active in Italy, within INFN (Istituto Nazionale di Fisica Nucleare), in the field of ultra-relativistic heavy-ion collisions. The experimental study of the phase diagram of strongly-interacting matter and of the Quark-Gluon Plasma (QGP) deconfined state will proceed, in the next 10-15 years, along two directions: the high-energy regime at RHIC and at the LHC, and the low-energy regime at FAIR, NICA, SPS and RHIC. The Italian community is strongly involved in the present and future programme of the ALICE experiment, the upgrade of which will open, in the 2020s, a new phase of high-precision characterisation of the QGP properties at the LHC. As a complement of this main activity, there is a growing interest in a possible future experiment at the SPS, which would target the search for the onset of deconfinement using dimuon measurements. On a longer timescale, the community looks with interest at the ongoing studies and discussions on a possible fixed-target programme using the LHC ion beams and on the Future Circular Collider.Comment: 99 pages, 56 figure

    Implementation of a Quiet-Time Protocol on a Post-Surgical Spine Unit

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    BACKGROUND: Rest is essential for healing the body, especially after spine surgery. While in the hospital, the patient’s sleep is interrupted by noise and staff coming in and out of the room throughout the day and night. These sleep disturbances can negatively affect the patient. LOCAL PROBLEM: The project setting is a 23-bed post-surgical spine unit at a level-one trauma hospital, which is recognized for providing high-quality spine surgery care and an outstanding patient experience. The quiet score on the spine unit is 52%, lower than the national average of 62.0%. METHODS: The Evidence-based Practice Improvement Model (EBPI) is valuable in helping achieve quality improvement goals and was used as the framework for this project. This allowed the use of plan-do-study-act (PDSA) cycles to improve clinical implementation. Pre and post-implementation data of Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) scores were collected to evaluate the effectiveness of a quiet time protocol on quiet scores in the spine unit. INTERVENTIONS: A quiet time protocol was implemented for patients that fit the stakeholders\u27 criteria. The protocol involved fewer interruptions throughout the night, reducing environmental stimuli, and keeping voices and noises low. RESULTS: The quiet time protocol was implemented on 37% of patients seen for spine surgery. Quiet HCAHPS scores increased by 10% following implementation, improving to 61.54%. CONCLUSIONS: Implementing a quiet time protocol on patients following spine surgery was not statistically significant; however, scores for quiet time increased between pre- and post-implementation, which indicates clinical significance. The sustainability of a quiet time protocol involves more stakeholder involvement and continuing staff education

    Gauge-invariant screening masses and static quark free energies in Nf=2+1 QCD at nonzero baryon density

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    We discuss the extension of gauge-invariant electric and magnetic screening masses in the quark-gluon plasma to the case of a finite baryon density, defining them in terms of a matrix of Polyakov loop correlators. We present lattice results for Nf=2+1 QCD with physical quark masses, obtained using the imaginary chemical potential approach, which indicate that the screening masses increase as a function of μB. A separate analysis is carried out for the theoretically interesting case μB/T=3iπ, where charge conjugation is not explicitly broken and the usual definition of the screening masses can be used for temperatures below the Roberge-Weiss transition. Finally, we investigate the dependence of the static quark free energy on the baryon chemical potential, showing that it is a decreasing function of μB, which displays a peculiar behavior as the pseudocritical transition temperature at μB=0 is approached

    Thymus transplantation for complete DiGeorge syndrome: European experience

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    Background: Thymus transplantation is a promising strategy for the treatment of athymic complete DiGeorge syndrome (cDGS). Methods: Twelve patients with cDGS were transplanted with allogeneic cultured thymus. Objective: To confirm and extend the results previously obtained in a single centre. Results: Two patients died of pre-existing viral infections without developing thymopoeisis and one late death occurred from autoimmune thrombocytopaenia. One infant suffered septic shock shortly after transplant resulting in graft loss and the need for a second transplant. Evidence of thymopoeisis developed from 5-6 months after transplantation in ten patients. The median (range) of circulating naïve CD4 counts (x10663 /L) were 44(11-440) and 200(5-310) at twelve and twenty-four months post-transplant and T-cell receptor excision circles were 2238 (320-8807) and 4184 (1582 -24596) per106 65 T-cells. Counts did not usually reach normal levels for age but patients were able to clear pre-existing and later acquired infections. At a median of 49 months (22-80), eight have ceased prophylactic antimicrobials and five immunoglobulin replacement. Histological confirmation of thymopoeisis was seen in seven of eleven patients undergoing biopsy of transplanted tissue including five showing full maturation through to the terminal stage of Hassall body formation. Autoimmune regulator (AIRE) expression was also demonstrated. Autoimmune complications were seen in 7/12 patients. In two, early transient autoimmune haemolysis settled after treatment and did not recur. The other five suffered ongoing autoimmune problems including: thyroiditis (3); haemolysis (1), thrombocytopaenia (4) and neutropenia (1). Conclusions: This study confirms the previous reports that thymus transplantation can reconstitute T cells in cDGS but with frequent autoimmune complications in survivors

    A full non-parametric approach for SAR Coherent Change Detection

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    Synthetic Aperture Radar (SAR) is widely used in heterogeneous fields with aims strictly dependent on the objectives of the application. One of the most common is the exploitation of the Interferometric-SAR (InSAR) to measure millimeter movements on the Earth's surface, aiming to monitor failures or measure infrastructures' health state. In this context, developing algorithms to detect temporal and spatial changes in the radar targets becomes very important. This paper focuses on the temporal change detection framework, proposing a non-parametric Coherent Change Detection (CCD) algorithm called Permutational Change Detection (PCD). The PCD estimates the temporal Change Points (CPs) of a radar target recognizing blocks structure in the coherence matrix without making any assumptions. The performance analysis on simulated data is accomplished, considering a realistic scenario where the geometrical and temporal decorrelation are properly modeled. Finally, the PCD is compared with a parametric CCD algorithm based on the Generalized Likelihood Ratio Test (GLRT)
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