2,023 research outputs found
NASA aviation safety reporting system
The origins and development of the NASA Aviation Safety Reporting System (ASRS) are briefly reviewed. The results of the first quarter's activity are summarized and discussed. Examples are given of bulletins describing potential air safety hazards, and the disposition of these bulletins. During the first quarter of operation, the ASRS received 1464 reports; 1407 provided data relevant to air safety. All reports are being processed for entry into the ASRS data base. During the reporting period, 130 alert bulletins describing possible problems in the aviation system were generated and disseminated. Responses were received from FAA and others regarding 108 of the alert bulletins. Action was being taken with respect to 70 of the 108 responses received. Further studies are planned of a number of areas, including human factors problems related to automation of the ground and airborne portions of the national aviation system
Inducers of Friend leukaemic cell differentiation in vitro--effects of in vivo administration.
Studies were conducted of the in vivo therapeutic potential of compounds which induce the differentiation of Friend leukaemia cells (FLC) in vitro. DBA2/J mice were inoculated with Friend leukaemia cells grown in tissue culture and at various times thereafter were treated with either N-methylacetamide, dimethylacetamide, or tetramethylurea. While survival was only occasionally prolonged, in every study these agents significantly inhibited leukaemia cell proliferation in the spleen and to a lesser extent in the marrow. These agents had no effect on the rate of proliferation of FLC growing subcutaneously nor on the proliferation of myeloid leukaemia in RFMS mice. These studies indicate that the administration of inducing agents to mice bearing Friend leukaemia can alter the proliferation characteristics of the leukaemia cells and hence suggest that these agents may have therapeutic potential
Galactic microwave emission at degree angular scales
We cross-correlate the Saskatoon Ka and Q-Band Cosmic Microwave Background
(CMB) data with different maps to quantify possible foreground contamination.
We detect a marginal correlation (2 sigma) with the Diffuse Infrared Background
Experiment (DIRBE) 240, 140 and 100 microm maps, but we find no significant
correlation with point sources, with the Haslam 408 MHz map or with the Reich
and Reich 1420 MHz map. The rms amplitude of the component correlated with
DIRBE is about 20% of the CMB signal. Interpreting this component as free-free
emission, this normalization agrees with that of Kogut et al. (1996a; 1996b)
and supports the hypothesis that the spatial correlation between dust and warm
ionized gas observed on large angular scales persists to smaller angular
scales. Subtracting this contribution from the CMB data reduces the
normalization of the Saskatoon power spectrum by only a few percent.Comment: Minor revisions to match published version. 14 pages, with 2 figures
included. Color figure and links at
http://www.sns.ias.edu/~angelica/foreground.htm
Quality of survival: a new concept framework to assess the quality of prolonged life in cancer
Background: Improved cancer care means that more patients are surviving longer, but there is a need to examine how well patients survive. We conducted an exploratory analysis of a new conceptual framework termed âquality of survivalâ (QoS) that delineates the quality of patientsâ experience.
Methods: This project included an electronic database search to investigate the survivorship landscape and to create a visual QoS map and semi-structured interviews with patients (n = 35), clinicians (n = 40), and payers (n = 7) to support the QoS map. QoS was discussed in the context of two tumor types, metastatic non-small cell lung cancer and metastatic melanoma.
Results: Despite increased long-term survival, no specific definition of QoS exists. Patients reported many impacts that affect QoS, clinicians viewed QoS as relevant to treatment decisions, and payers felt it could help communicate different aspects relevant to the patient. Four interconnected QoS dimensions were developed (quality of life, survival, side effects, and economic impact), which vary in importance along the care continuum.
Conclusion: QoS is a patient-centric concept that could help decision-making and patient communication. The QoS map could provide a framework to monitor patient experience and help patients frame what treatment attribute is most important to them at any point in the cancer continuum
The effect of discrete vs. continuous-valued ratings on reputation and ranking systems
When users rate objects, a sophisticated algorithm that takes into account
ability or reputation may produce a fairer or more accurate aggregation of
ratings than the straightforward arithmetic average. Recently a number of
authors have proposed different co-determination algorithms where estimates of
user and object reputation are refined iteratively together, permitting
accurate measures of both to be derived directly from the rating data. However,
simulations demonstrating these methods' efficacy assumed a continuum of rating
values, consistent with typical physical modelling practice, whereas in most
actual rating systems only a limited range of discrete values (such as a 5-star
system) is employed. We perform a comparative test of several co-determination
algorithms with different scales of discrete ratings and show that this
seemingly minor modification in fact has a significant impact on algorithms'
performance. Paradoxically, where rating resolution is low, increased noise in
users' ratings may even improve the overall performance of the system.Comment: 6 pages, 2 figure
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