12 research outputs found
Identité de l'image de sport
L'image de sport et le mouvement depuis les premières chronophotographies. Les mises en scène du sport et le public. L'image de sport, un objet d'étude en devenir. Propositions d'outils d'analyse
Moral counselling: a method in development
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93626.pdf (publisher's version ) (Open Access
Reflection Positivity in Heisenberg and Ice-Type Models
This thesis gives a thorough description of the mathematical tool called reflection positivity, which can be used to prove the occurrence of phase transitions in physical models. A major result, although already known, is a theorem that gives tractable conditions on the Hamiltonian such that the Boltzmann functional is reflection positive. In this thesis, the theorem is used to give conditions on free parameters in four different models, such that the model is reflection positive with respect to certain chosen reflections. The evaluated models are (a) the antiferromagnetic quantum Heisenberg model; (b) the spin ice model; (c) the 6-vertex model and (d) the 16-vertex model. For the Heisenberg model we found that for reflections in a reflection plane there are certain parameter values such that the Boltzmann functional is reflection positive, this is an already known and published result. For the spin ice model we found that for the spin invariant reflection there is no symmetry that yields a reflection positive Boltzmann functional, this is a new result. For both the 6-vertex and 16-vertex model we showed that, for certain energy values, the Boltzmann functional is reflection positive with respect to reflections in the diagonal, which are also new results. In the case of the 16-vertex model, this boils down to checking whether or not a matrix is positive semidefinite. Using this result we showed that energy values that allow for the existence of magnetic monopoles do not yield a reflection positive Boltzmann functional. A topic for further research is investigating the occurrence of phase transitions in the models that are shown to be reflection positive, for which chessboard estimates seem to be a promising approach. Furthermore, in this thesis it was not rigorously proved that the spin ice model with a spin inverting reflection gives a reflection positive Boltzmann functional for rotational symmetry or symmetry in a reflection plane. This is believed to be true, but does require further investigation.Applied Mathematics | Applied Physic
Request for organ donation without donor registration
In the Netherlands, consent from relatives is obligatory for post mortal donation. This study explored the perspectives of relatives regarding the request for consent for donation in cases without donor registration. The dataset contains the Secondary analysis of data of a group of relatives of eligible brain dead organ donors.
Results
Relatives of unregistered, brain-dead patients usually refuse consent for donation, even if they harbour pro-donation attitudes themselves, or knew that the deceased favoured organ donation. Half of those who refused consent for donation mentioned afterwards that it could have been an option. The decision not to consent to donation is attributed to contextual factors, such as feeling overwhelmed by the notification of death immediately followed by the request; not being accustomed to speaking about death; inadequate support from other relatives or healthcare professionals , and lengthy procedures
A stepped strategy that aims at the nationwide implementation of the Enhanced Recovery After Surgery programme in major gynaecological surgery: study protocol of a cluster randomised controlled trial
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152306.pdf (publisher's version ) (Open Access)BACKGROUND: Enhanced Recovery After Surgery (ERAS) programmes aim at an early recovery after surgical trauma and consequently at a reduced length of hospitalisation. This paper presents the protocol for a study that focuses on large-scale implementation of the ERAS programme in major gynaecological surgery in the Netherlands. The trial will evaluate effectiveness and costs of a stepped implementation approach that is characterised by tailoring the intensity of implementation activities to the needs of organisations and local barriers for change, in comparison with the generic breakthrough strategy that is usually applied in large-scale improvement projects in the Netherlands. METHODS: All Dutch hospitals authorised to perform major abdominal surgery in gynaecological oncology patients are eligible for inclusion in this cluster randomised controlled trial. The hospitals that already fully implemented the ERAS programme in their local perioperative management or those who predominantly admit gynaecological surgery patients to an external hospital replacement care facility will be excluded. Cluster randomisation will be applied at the hospital level and will be stratified based on tertiary status. Hospitals will be randomly assigned to the stepped implementation strategy or the breakthrough strategy. The control group will receive the traditional breakthrough strategy with three educational sessions and the use of plan-do-study-act cycles for planning and executing local improvement activities. The intervention group will receive an innovative stepped strategy comprising four levels of intensity of support. Implementation starts with generic low-cost activities and may build up to the highest level of tailored and labour-intensive activities. The decision for a stepwise increase in intensive support will be based on the success of implementation so far. Both implementation strategies will be completed within 1 year and evaluated on effect, process, and cost-effectiveness. The primary outcome is length of postoperative hospital stay. Additional outcome measures are length of recovery, guideline adherence, and mean implementation costs per patient. DISCUSSION: This study takes up the challenge to evaluate an efficient strategy for large-scale implementation. Comparing effectiveness and costs of two different approaches, this study will help to define a preferred strategy for nationwide dissemination of best practices. TRIAL REGISTRATION: Dutch Trial Register NTR4058
Intensive care staff, the donation request and relatives' satisfaction with the decision: a focus group study
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138323.pdf (publisher's version ) (Open Access)BACKGROUND: Effectiveness of the donation request is generally measured by consent rates, rather than by relatives' satisfaction with their decision. Our aim was to elicit Dutch ICU staffs' views and experiences with the donation request, to investigate their awareness of (dis)satisfaction with donation decisions by relatives, specifically in the case of refusal, and to collect advice that may leave more relatives satisfied with their decision. METHODS: Five focus groups with a total of 32 participants (IC physicians, IC nurses and transplant coordinators) from five university hospitals in the Netherlands. Transcripts were examined using standard qualitative methods. RESULTS: Four themes (donation request perceived by ICU staff from the perspective of relatives; donation request perceived by ICU staff from their own perspective; aftercare; donation in society) divided into 14 categories were identified. According to ICU staff, relatives mentioned their own values more frequently than values of the potential donor as important for the decision. ICU staff observed this imbalance, but reacted empathically to the relatives' point of view. ICU staff rarely suggested reconsideration of refusal and did not ask relatives for arguments. ICU staff did not always feel comfortable with a request in the delicate context of brain death. Sometimes the interests of patient, relatives and those on the waiting list were irreconcilable. ICU staff were mostly unaware of relatives' regret following their decisions. Aftercare did not provide this type of information. Donation request by IC physicians was influenced by the way organ donation has been regulated in society (law, donor register, education, media). CONCLUSIONS: Our findings lead to the hypothesis that giving relatives more time and inviting them to reconsider their initial refusal will lead to a more stable decision and possibly more consent
Axial mercury segregation in direct current operated low-pressure argon-mercury gas discharge: Part I. Experimental
Due to cataphoresis, axial segregation of mercury will occur when the gas discharge of a fluorescent lamp is operated by means of a direct current. A consequence of this is a non-uniform axial luminance distribution along the lamp. To determine the degree of axial mercury segregation experimentally, axial luminance distributions have been measured which are converted into axial mercury vapour pressure distributions by an appropriate calibration method. The mercury segregation has been investigated for variations in lamp tube radius (3.6–4.8 mm), argon buffer gas pressure (200–600 Pa) and lamp current (100–250 mA) at mercury vapour pressures set at the anode in the range from 0.2 to 9.0 Pa. From the experiments it has been concluded that the mercury vapour pressure gradient at any axial position for a certain lamp tube diameter, argon pressure and lamp current depends on the local mercury vapour pressure. This observation is in contrast to assumptions made in earlier modelling publications in which one mercury vapour pressure gradient is used for all axial positions. By applying a full factorial design, an empirical relation of the mercury segregation is found for any set of parameters inside the investigated parameter ranges
Longitudinal follow-up of blood lymphocyte subpopulations from birth to 1 year of age.
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87144.pdf (publisher's version ) (Closed access)1 oktober 199
Metabolic, thermoregulatory, and perceptual responses during exercise after lower vs. whole body precooling
BACKGROUND: This article is part of a study to gain insight into the decision-making process by looking at the views of the relatives of potential brain dead donors. Alongside a literature review, focus interviews were held with healthcare professionals about their role in the request and decision-making process when post-mortal donation is at stake. This article describes the perspectives of the relatives. METHODS: A content-analysis of 22 semi-structured in-depth interviews with relatives involved in an organ donation decision. RESULTS: Three themes were identified: 'conditions', 'ethical considerations' and 'look back'. Conditions were: 'sense of urgency', 'incompetence to decide' and 'agreement between relatives'. Ethical considerations result in a dilemma for non-donor families: aiding people or protecting the deceased's body, especially when they do not know his/her preference. Donor families respect the deceased's last will, generally confirmed in the National Donor Register. Looking back, the majority of non-donor families resolved their dilemma by justifying their decision with external arguments (lack of time, information etc.). Some non-donor families would like to be supported during decision-making. DISCUSSION: The discrepancy between general willingness to donate and the actual refusal of a donation request can be explained by multiple factors, with a cumulative effect. Firstly, half of the participants (most non-donor families) stated that they felt that they were not competent to decide in such a crisis and they seem to struggle with utilitarian considerations against their wish to protect the body. Secondly, non-donor families refused telling that they did not know the deceased's wishes or contesting posthumous autonomy of the eligible. Thirdly, the findings emphasise the importance of Donor Registration, because it seems to prevent dilemmas in decision-making, at least for donor families. CONCLUSION: Discrepancies between willingness to consent to donate and refusal at the bedside can be attributed to an unresolved dilemma: aiding people or protect the body of the deceased. Non-donor families felt incompetent to decide. They refused consent for donation, since their deceased had not given any directive. When ethical considerations do not lead to an unambiguous answer, situational factors were pivotal. Relatives of unregistered eligible donors are more prone to unstable decisions. To overcome ambivalence, coaching during decision-making is worth investigation