122 resultados para extended quasi-liklihood

em QUB Research Portal - Research Directory and Institutional Repository for Queen's University Belfast


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Background:
Internationally, nurse-directed protocolised-weaning has been evaluated by measuring its impact on patient outcomes. The impact on nurses’ views and perceptions has been largely ignored.

Aim:
To determine the change in intensive care nurses’ perceptions, satisfaction, knowledge and attitudes following the introduction of nurse-directed weaning. Additionally, views were obtained on how useful protocolised-weaning was to practice.

Methods:
The sample comprised nurses working in general intensive care units in three university-affiliated hospitals. Nurse-directed protocolised-weaning was implemented in one unit (intervention group); two ICUs continued with usual doctor-led practice (control group). Nurses’ perceptions, satisfaction, knowledge and attitudes were measured by self-completed questionnaires before (Phase I) and after the implementation of nurse-directed weaning (Phase II) in all units.

Results:
Response rates were 79% (n=140n=140) for Phase 1 and 62% (n=132n=132) for Phase II. Regression-based analyses showed that changes from Phase I to Phase II were not significantly different between the intervention and control groups. Sixty-nine nurses responded to both Phase I and II questionnaires. In the intervention group, these nurses scored their mean perceived level of knowledge higher in Phase II (6.39 vs 7.17, p=0.01p=0.01). In the control group, role perception (4.41 vs 4.22, p=0.01p=0.01) was lower and, perceived knowledge (6.03 vs 6.63, p=0.04p=0.04), awareness of weaning plans (6.09 vs 7.06, p=0.01p=0.01) and satisfaction with communication (5.28 vs 6.19, p=0.01p=0.01) were higher in Phase II. The intervention group found protocolised weaning useful in their practice (75%): this was scored significantly higher by junior and senior nurses than middle grade nurses (p=0.02p=0.02).

Conclusion

We conclude that nurse-directed protocolised-weaning had no effect on nurses’ views and perceptions due to the high level of satisfaction which encouraged nurses’ participation in weaning throughout. Control group changes are attributed to a ‘reactive effect’ from being study participants. Weaning protocols provide a uniform method of weaning practice and are particularly beneficial in providing safe guidance for junior staff.

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Objective To evaluate participants' perceptions of the impact on them of an additional six months' training beyond the standard 12 month general practice vocational training scheme. Design Qualitative study using focus groups. Setting General practice vocational training in Northern Ireland. Participants 13 general practitioner registrars, six of whom participated in the additional six months' training, and four trainers involved in the additional six months' training. Main outcome measures: Participants' views about their experiences in 18 month and 12 month courses. Results Participants reported that the 12 month course was generally positive but was too pressurised and focused on examinations, and also that it had a negative impact on self care. The nature of the learning and assessment was reported to have left participants feeling averse to further continuing education and lacking in confidence. In contrast, the extended six month component was reported to have restimulated learning by focusing more on patient care and promoting self directed learning. It developed confidence, promoted teamwork, and gave experience of two practice contexts, and was reported as valuable by both ex-registrars and trainers. However, both the 12 and 18 month courses left participants feeling underprepared for practice management and self care. Conclusions 12 months' training in general practice does not provide doctors with the necessary competencies and confidence to enter independent practice. The extended period was reported to promote greater professional development, critical evaluation skills, and orientation to lifelong learning but does not fill all the gaps.

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This paper theoretically analysis the recently proposed "Extended Partial Least Squares" (EPLS) algorithm. After pointing out some conceptual deficiencies, a revised algorithm is introduced that covers the middle ground between Partial Least Squares and Principal Component Analysis. It maximises a covariance criterion between a cause and an effect variable set (partial least squares) and allows a complete reconstruction of the recorded data (principal component analysis). The new and conceptually simpler EPLS algorithm has successfully been applied in detecting and diagnosing various fault conditions, where the original EPLS algorithm did only offer fault detection.

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High-precision correlation of palaeoclimatic and palaeoenvironmental records is crucial for testing hypotheses of synchronous change. Although radiocarbon is the traditional method for dating late Quaternary sedimentary sequences, particularly during the last glacial–interglacial transition (LGIT; 15–9?ka), there are inherent problems with the method, particularly during periods of climate change which are often accompanied by major perturbations in atmospheric radiocarbon content. An alternative method is the use of tephras that act as time-parallel marker horizons. Within Europe, numerous volcanic centres are known to have erupted during the LGIT, providing considerable potential for high-precision correlation independent of past radiocarbon fluctuations. Here we report the first identification of the Vedde Ash and Askja Tephra in Ireland, significantly extending the known provenance of these events. We have also identified two new horizons (the Roddans Port Tephras A and B) and tentatively recognise an additional horizon from Vallensgård Mose (Denmark) that provide crucial additional chronological control for the LGIT. Two phases of the Laacher See Tephra (LST) are reported, the lower Laacher See Tephra (LLST) and probably the C2 phase of the Middle Laacher See Tephra (MLST-C2) indicating a more northeasterly distribution of this fan than reported previously.

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The interaction between supernova ejecta and circumstellar matter, arising from previous episodes of mass loss, provides us with a means of constraining the progenitors of supernovae. Radio observations of a number of supernovae show quasi-periodic deviations from a strict power-law decline at late times. Although several possibilities have been put forward to explain these modulations, no single explanation has proven to be entirely satisfactory. Here we suggest that Luminous blue variables undergoing S-Doradus type variations give rise to enhanced phases of mass loss that are imprinted on the immediate environment of the exploding star as a series of density enhancements. The variations in mass loss arise from changes in the ionization balance of Fe, the dominant ion that drives the wind. With this idea, we find that both the recurrence timescale of the variability and the amplitude of the modulations are in line with the observations. Our scenario thus provides a natural, single-star explanation for the observed behaviour that is, in fact, expected on theoretical grounds.

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Course Scheduling consists of assigning lecture events to a limited set of specific timeslots and rooms. The objective is to satisfy as many soft constraints as possible, while maintaining a feasible solution timetable. The most successful techniques to date require a compute-intensive examination of the solution neighbourhood to direct searches to an optimum solution. Although they may require fewer neighbourhood moves than more exhaustive techniques to gain comparable results, they can take considerably longer to achieve success. This paper introduces an extended version of the Great Deluge Algorithm for the Course Timetabling problem which, while avoiding the problem of getting trapped in local optima, uses simple Neighbourhood search heuristics to obtain solutions in a relatively short amount of time. The paper presents results based on a standard set of benchmark datasets, beating over half of the currently published best results with in some cases up to 60% of an improvement.

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Extreme states of matter such as Warm Dense Matter “WDM” and Dense Strongly Coupled Plasmas “DSCP” play a key role in many high energy density experiments, however creating WDM and DSCP in a manner that can be quantified is not readily feasible. In this paper, isochoric heating of matter by intense heavy ion beams in spherical symmetry is investigated for WDM and DSCP research: The heating times are long (100 ns), the samples are macroscopically large (mm-size) and the symmetry is advantageous for diagnostic purposes. A dynamic confinement scheme in spherical symmetry is proposed which allows even ion beam heating times that are long on the hydrodynamic time scale of the target response. A particular selection of low Z-target tamper and x-ray probe radiation parameters allows to identify the x-ray scattering from the target material and use it for independent charge state measurements Z* of the material under study.

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A complex number lambda is called an extended eigenvalue of a bounded linear operator T on a Banach space B if there exists a non-zero bounded linear operator X acting on B such that XT = lambda TX. We show that there are compact quasinilpotent operators on a separable Hilbert space, for which the set of extended eigenvalues is the one-point set {1}.

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We present new general methods to obtain spectral decompositions of dynamical systems in rigged Hilbert spaces and investigate the existence of resonances and the completeness of the associated eigenfunctions. The results are illustrated explicitly for the simplest chaotic endomorphism, namely the Renyi map.