Die rol van Christelike waardes en opvoeding in Verkeersveiligheidsopvoeding

The role of Christian values and education in Traffic Safety EducationTraffic safety is one of the more important issues in South Africa today, since traffic accidents cause thousands o f unnecessary deaths each year, particularly among the youth. The key variable of traffic safety is to be found in principled education emphasizing religious and life values. A child need to learn that life, also his/her own, is sacred to God and must be safeguarded by following traffic safety rules and regulations. Since traffic safety is dependent on, inter alia, attitudes and religious-cultural values, children must be taught positive attitudes at home and at school. This point o f departure implies that teachers need to have positive attitudes towards Traffic Safety Education, which, in turn, implies Traffic Safety Education as a prerequisite fo r teacher education

Quantum Fluctuations Driven Orientational Disordering: A Finite-Size Scaling Study

The orientational ordering transition is investigated in the quantum generalization of the anisotropic-planar-rotor model in the low temperature regime. The phase diagram of the model is first analyzed within the mean-field approximation. This predicts at $T=0$ a phase transition from the ordered to the disordered state when the strength of quantum fluctuations, characterized by the rotational constant $\Theta$, exceeds a critical value $\Theta_{\rm c}^{MF}$. As a function of temperature, mean-field theory predicts a range of values of $\Theta$ where the system develops long-range order upon cooling, but enters again into a disordered state at sufficiently low temperatures (reentrance). The model is further studied by means of path integral Monte Carlo simulations in combination with finite-size scaling techniques, concentrating on the region of parameter space where reentrance is predicted to occur. The phase diagram determined from the simulations does not seem to exhibit reentrant behavior; at intermediate temperatures a pronounced increase of short-range order is observed rather than a genuine long-range order.Comment: 27 pages, 8 figures, RevTe

Generalized feedback vertex set problems on bounded-treewidth graphs: chordality is the key to single-exponential parameterised algorithms

It has long been known that Feedback Vertex Set can be solved in time 2^O(w log w)n^O(1) on graphs of treewidth w, but it was only recently that this running time was improved to 2^O(w)n^O(1), that is, to single-exponential parameterized by treewidth. We investigate which generalizations of Feedback Vertex Set can be solved in a similar running time. Formally, for a class of graphs P, Bounded P-Block Vertex Deletion asks, given a graph G on n vertices and positive integers k and d, whether G contains a set S of at most k vertices such that each block of G-S has at most d vertices and is in P. Assuming that P is recognizable in polynomial time and satisfies a certain natural hereditary condition, we give a sharp characterization of when single-exponential parameterized algorithms are possible for fixed values of d: - if P consists only of chordal graphs, then the problem can be solved in time 2^O(wd^2) n^{O}(1), - if P contains a graph with an induced cycle of length ell>= 4, then the problem is not solvable in time 2^{o(w log w)} n^O(1)} even for fixed d=ell, unless the ETH fails. We also study a similar problem, called Bounded P-Component Vertex Deletion, where the target graphs have connected components of small size instead of having blocks of small size, and present analogous results

Parameterized Approximation Schemes using Graph Widths

Combining the techniques of approximation algorithms and parameterized complexity has long been considered a promising research area, but relatively few results are currently known. In this paper we study the parameterized approximability of a number of problems which are known to be hard to solve exactly when parameterized by treewidth or clique-width. Our main contribution is to present a natural randomized rounding technique that extends well-known ideas and can be used for both of these widths. Applying this very generic technique we obtain approximation schemes for a number of problems, evading both polynomial-time inapproximability and parameterized intractability bounds

Individualized Pain Plans for Pediatric Sickle Cell Patients

Background: Vaso-occlusive (VOC) pain crisis in sickle cell pediatric patients is a hallmark symptom, and both unpredictable and crippling. There is a lack of evidence as to what is best practice to avoid a VOC pain crisis in pediatric sickle cell patients. Individualized Pain Plans were created and trialed based off the format asthma action plans with goals to improve overall pain management and to prevent or decrease emergency department visits and hospitalizations. Aims: This is a cross-sectional and quality improvement study designed to evaluate the effectiveness of previously implemented Individualized Sickle Cell Pain Plans in a midwestern children’s hospital. The primary aim was to evaluate the physical and psychosocial risk factors related to the pain experiences in the post implementation timeline of receiving their individualized pain plan. The second aim was to evaluate the satisfaction and use by both parent and child of the pain plans. Methods: Evaluation of outcomes of these plans were done by survey using the Pediatric Pain Screening Tool (PPST), satisfaction questionnaires, and chart audits of Emergency Department (ED) visits due to pain crisis pre and post implementation administered by the Hematology/Oncology (H/O) team. Settings: This study was conducted at a midwestern children’s hospital and associated H/O clinic. Participants/Subjects: Sample population included pediatric patients, aged four to 18 years old, who are diagnosed with sickle cell disease who have an individualized pain plan created by their Hematology provider, and their parent(s) and/or caregivers. Each patient/parent/caregiver gave verbal consent to participate. Design: The data was collected at a routine follow up appointment at the H/O clinic. Surveys were administered at the appointments including the PPST, demographics, and a satisfaction/use survey for the patient and parent. A chart audit of ED visits due to pain crisis pre and post pain plan implementation was also performed. Results: A total of eleven patients and eleven parents were captured in this study that qualified based on the inclusion criteria. 73% of responses being mostly satisfied and very satisfied with the pain plans, 27% of responses were sometimes satisfied and satisfied, and one response with no satisfaction. Eleven parents were asked how often the pain plans were being used and/or referenced, 18% said they were not using it and needed help with how to use it better, 9% use it when their child cannot sleep at night due to pain, 45% use it when their child cannot play or go to school due to pain, and 27% said they use it when their child tells them they have pain. Six patients were then asked how often they were using the pain plans, one said they do not use it because he lost it, one said they do not know how to use the pain plan, one said they use it when they cannot play, and three (50%) say they use it when an adult tells them to. When compared, the number of ED and inpatient hospital admissions (IHA) for each patient pre and post pain plan implementation, it was found that ED visits increased from pre (16 of 74 patients) to post (29 of 74 patients). Conclusions: Individualized pain plans provide guidance for patients and families when a pain crisis begins. It is recommended that these pain plans be implemented at other pediatric hospitals across the nation to support patients with sickle cell disease and their families. It would be recommended that the clinic continue to collect data indefinitely due to the small sample population of this study as this could provide stronger evidence for the use of the individualized pain plans

Parameterized Inapproximability of Target Set Selection and Generalizations

In this paper, we consider the Target Set Selection problem: given a graph and a threshold value $thr(v)$ for any vertex $v$ of the graph, find a minimum size vertex-subset to "activate" s.t. all the vertices of the graph are activated at the end of the propagation process. A vertex $v$ is activated during the propagation process if at least $thr(v)$ of its neighbors are activated. This problem models several practical issues like faults in distributed networks or word-to-mouth recommendations in social networks. We show that for any functions $f$ and $\rho$ this problem cannot be approximated within a factor of $\rho(k)$ in $f(k) \cdot n^{O(1)}$ time, unless FPT = W[P], even for restricted thresholds (namely constant and majority thresholds). We also study the cardinality constraint maximization and minimization versions of the problem for which we prove similar hardness results

Late recurrent ischaemia in infarct patients with a normal predischarge exercise test after thrombolysis

We investigated the prognostic value of normal predischarge exercise test in 109 patients after myocardial infarction treated with i. v. thrombolysis within 4 h. In 29 of these 109 patients, elective PTCA or bypass surgery was performed for prognostic reasons after coronary angiography; 80 patients were treated conservatively with drug therapy. Recurrent postinfarct angina early after hospital discharge was the reason in 4 of 80 for PTCA or bypass surgery. Twenty-three of the remaining 76 conservatively treated patients developed recurrent ischaemia during long-term follow-up of 12.0 ± 6.2 months, including one patient with reinfarction. Late recurrent ischaemia during long-term follow-up was observed in one third of the conservatively treated patients with a normal predischarge exercise test, although a high percentage (30%) of patients in this subgroup had been treated with PTCA or bypass surgery mainly for prognostic reasons. Predischarge exercise test is therefore of limited value for detection of still viable myocardium at risk of further ischaemic events after acute myocardial infarction and thrombolysi