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Most animals live in seasonal environments and experience very different conditions throughout the year. Behavioral strategies like migration, hibernation, and a life cycle adapted to the local seasonality help to cope with fluctuations in environmental conditions. Thus, how an individual utilizes the environment depends both on the current availability of habitat and the behavioral prerequisites of the individual at that time. While the increasing availability and richness of animal movement data has facilitated the development of algorithms that classify behavior by movement geometry, changes in the environmental correlates of animal movement have so far not been exploited for a behavioral annotation. Here, we suggest a method that uses these changes in individual–environment associations to divide animal location data into segments of higher ecological coherence, which we term niche segmentation. We use time series of random forest models to evaluate the transferability of habitat use over time to cluster observational data accordingly. We show that our method is able to identify relevant changes in habitat use corresponding to both changes in the availability of habitat and how it was used using simulated data, and apply our method to a tracking data set of common teal (Anas crecca). The niche segmentation proved to be robust, and segmented habitat suitability outperformed models neglecting the temporal dynamics of habitat use. Overall, we show that it is possible to classify animal trajectories based on changes of habitat use similar to geometric segmentation algorithms. We conclude that such an environmentally informed classification of animal trajectories can provide new insights into an individuals' behavior and enables us to make sensible predictions of how suitable areas might be connected by movement in space and time.
Background
Precise and complete documentation of in-hospital cardiopulmonary resuscitations is important but data quality can be poor. In the present study, we investigated the effect of a tablet-based application for real-time resuscitation documentation used by the emergency team leader on documentation quality and clinical performance of the emergency team.
Methods
Senior anaesthesiologists either used the tablet-based application during the simulated resuscitation for documentation and also used the application for the final documentation or conducted the full documentation at the end of the scenario using the local hospital information system. The latter procedure represents the current local documentation method. All scenarios were video recorded. To assess the documentation, we compared the precision of intervention delivery times, documentation completeness, and final documentation time. To assess clinical performance, we compared adherence to guidelines for defibrillation and adrenaline administration, the no-flow fraction, and the time to first defibrillation.
Results
The results showed significant benefits for the tablet-based application compared to the hospital information system for precision of the intervention delivery times, the final documentation time, and the no-flow fraction. We observed no differences between the groups for documentation completeness, adherence to guidelines for defibrillation and adrenaline administration, and the time to first defibrillation.
Discussion
In the presented study, we observed that a tablet-based application can improve documentation data quality. Furthermore, we demonstrated that a well-designed application can be used in real-time by a member of the emergency team with possible beneficial effects on clinical performance.
Conclusion
The present evaluation confirms the advantage of tablet-based documentation tools and also shows that the application can be used by an active member of an emergency team without compromising clinical performance.
Classical novae are thermonuclear explosions occurring on the surface of white dwarfs.
When co-existing in a binary system with a main sequence or more evolved star, mass
accretion from the companion star to the white dwarf can take place if the companion
overflows its Roche lobe. The envelope of hydrogen-rich matter which builds on
top of the white dwarf eventually ignites under degenerate conditions, leading to
a thermonuclear runaway and an explosion in the order of 1046 erg, while leaving
the white dwarf intact. Spectral analyses from the debris indicate an abundance of
isotopes that are tracers of nuclear burning via the hot CNO cycle, which in turn
reveal some sort of mixing between the envelope and the white dwarf underneath.
The exact mechanism is still a matter of debate.
The convection and deflagration in novae develop in the low Mach number regime.
We used the Seven League Hydro code (SLH ), which employs numerical schemes
designed to correctly simulate low Mach number flows, to perform two and three-
dimensional simulations of classical novae. Based on a spherically-symmetric model
created with aid of a stellar evolution code, we developed our own nova model and
tested it on a variety of numerical grids and boundary conditions for validation. We
focused on the evolution of temperature, density and nuclear energy generation rate at
the layers between white dwarf and envelope, where most of the energy is generated,
to understand the structure of the transition region, and its effect on the nuclear
burning. We analyzed the resulting dredge-up efficiency stemming from the convective
motions in the envelope. Our models yield similar results to the literature, but seem
to depend very strongly on the numerical resolution. We followed the evolution of
the nuclear species involved in the CNO cycle and concluded that the thermonuclear
reactions primarily taking place are those of the cold and not the hot CNO cycle.
The reason behind this could be that under the conditions generally assumed for
multi-dimensional simulations, the envelope is in fact not degenerate. We performed
initial tests for 3D simulations and realized that alternative boundary conditions are
needed.