12,002 research outputs found
Orbital Characteristics of the Subdwarf-B and F V Star Binary EC~20117-4014(=V4640 Sgr)
Among the competing evolution theories for subdwarf-B (sdB) stars is the
binary evolution scenario. EC~20117-4014 (=V4640~Sgr) is a spectroscopic binary
system consisting of a pulsating sdB star and a late F main-sequence companion
(O'Donoghue et al. 1997), however the period and the orbit semi-major axes have
not been precisely determined. This paper presents orbital characteristics of
the EC 20117-4014 binary system using 20 years of photometric data. Periodic
Observed minus Calculated (O-C) variations were detected in the two highest
amplitude pulsations identified in the EC 20117-4014 power spectrum, indicating
the binary system's precise orbital period (P = 792.3 days) and the
light-travel time amplitude (A = 468.9 s). This binary shows no significant
orbital eccentricity and the upper limit of the eccentricity is 0.025 (using 3
as an upper limit). This upper limit of the eccentricity is the lowest
among all wide sdB binaries with known orbital parameters. This analysis
indicated that the sdB is likely to have lost its hydrogen envelope through
stable Roche lobe overflow, thus supporting hypotheses for the origin of sdB
stars. In addition to those results, the underlying pulsation period change
obtained from the photometric data was = 5.4 (0.7)
d d, which shows that the sdB is just before the end of the
core helium-burning phase
Innovation flow through social networks: Productivity distribution
A detailed empirical analysis of the productivity of non financial firms
across several countries and years shows that productivity follows a
non-Gaussian distribution with power law tails. We demonstrate that these
empirical findings can be interpreted as consequence of a mechanism of
exchanges in a social network where firms improve their productivity by direct
innovation or/and by imitation of other firm's technological and organizational
solutions. The type of network-connectivity determines how fast and how
efficiently information can diffuse and how quickly innovation will permeate or
behaviors will be imitated. From a model for innovation flow through a complex
network we obtain that the expectation values of the productivity level are
proportional to the connectivity of the network of links between firms. The
comparison with the empirical distributions reveals that such a network must be
of a scale-free type with a power-law degree distribution in the large
connectivity range.Comment: 14 pages, 4 figures, submitted to Phys. Rev.
Medical Escort of Critical Care Patients in the Pre-Hospital Setting
Introduction: Pre-hospital emergency cases include the patient’s transportation to the hospital, with an adequate escort, when indicated.
In Portugal, secondary transport’s escort is guided by an escort score published by the Portuguese Medical Association’s Guidelines on the Critical Care Patient’s Transport (2008). This score (TS) defines three levels of escort: no medical escort (level A), doctor or nurse escort (level B), doctor and nurse escort (level C).
There is no published data on this score’s application to the pre-hospital setting. Such use could improve resource management in the pre-hospital emergency medical services, as it could support the need to involve a doctor and/or nurse in the patient’s escort to the hospital.
Our study’s aim is the evaluate the TS application to the pre-hospital context.
Study Methods: We gathered data from primary transports’ escorts between January 2015 and January 2017. We recorded whether the patient was taken to hospital or not, and if yes, the transport’s escort (Doctor, Doctor and Nurse, or only emergency technicians). Posteriorly, we calculated the TS for each of those transport records. Any records with incomplete escort data or where the score could not be calculated were excluded.
Using this data, we calculated Sensibility (Ss), Specificity (Sp), positive predicitive value (PPV) and negative predictive value (NPV) of the TS for the following situations: Escort by emergency technicians only (level A), escort by doctor or nurse (level B) or escort by doctor and nurse (level C)
Results and discussion: We found complete data regarding 556 primary transports 141 patients were escorted by emergency technicians only, 269 by doctor or nurse only, and 146 by a doctor and nurse.
TS level A was found to have Ss 85,78%, Sp 70,92%, PPV 89,67% and NPV 62,89% regarding escort by emergency technicians only. These values support the decision of taking no medical escort in a primary transport in the pre-hospital setting when TS is level A. On the other hand, TS level C has Ss 78,08%, Sp 59,72%, PPV 40,57% and NPV 88,36% regarding escort by both a doctor and nurse. These numbers are less clear regarding a decision to take a medical escort.
Conclusions: TS appears to be an indicator with enough Ss and Sp to help the pre-hospital team choose whether or not to escort the patient to the hospital with only emergency technicians or with a more differentiated escort, especially when the score’s result is Level A. But it cannot differentiate between doctor or nurse or both doctor and nurse when the result is level B or C.
More figures are needed to understand if this score can be implemented as a decision tool regarding the kind of medical escort a patient needs in a primary transport.info:eu-repo/semantics/publishedVersio
Zoneamento agrÃcola do algodão herbáceo no Nordeste brasileiro safra 2006/2007 ? Estado de Sergipe.
bitstream/CNPA/18378/1/COMTEC285.pd
Zoneamento de riscos climáticos da cultura da mamoneira no Estado de Sergipe, referente ao ano safra de 2006/2007.
bitstream/CNPA/18400/1/COMTEC294.pd
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