867 resultados para empirical research and normative assumptions


Relevância:

100.00% 100.00%

Publicador:

Resumo:

PURPOSE: This study (EORTC 30891) attempted to demonstrate equivalent overall survival in patients with localized prostate cancer not suitable for local curative treatment treated with immediate or deferred androgen ablation. PATIENTS AND METHODS: We randomly assigned 985 patients with newly diagnosed prostate cancer T0-4 N0-2 M0 to receive androgen deprivation either immediately (n = 493) or on symptomatic disease progression or occurrence of serious complications (n = 492). RESULTS: Baseline characteristics were well balanced in the two groups. Median age was 73 years (range, 52 to 81). At a median follow-up of 7.8 years, 541 of 985 patients had died, mostly of prostate cancer (n = 193) or cardiovascular disease (n = 185). The overall survival hazard ratio was 1.25 (95% CI, 1.05 to 1.48; noninferiority P > .1) favoring immediate treatment, seemingly due to fewer deaths of nonprostatic cancer causes (P = .06). The time from randomization to progression of hormone refractory disease did not differ significantly, nor did prostate-cancer specific survival. The median time to the start of deferred treatment after study entry was 7 years. In this group 126 patients (25.6%) died without ever needing treatment (44% of the deaths in this arm). CONCLUSION: Immediate androgen deprivation resulted in a modest but statistically significant increase in overall survival but no significant difference in prostate cancer mortality or symptom-free survival. This must be weighed on an individual basis against the adverse effects of life-long androgen deprivation, which may be avoided in a substantial number of patients with a deferred treatment policy.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This phase III trial compared the efficacy and safety of gemcitabine (Gem) plus capecitabine (GemCap) versus single-agent Gem in advanced/metastatic pancreatic cancer.

Relevância:

100.00% 100.00%

Publicador:

Relevância:

100.00% 100.00%

Publicador:

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Teaching is a dynamic activity. It can be very effective, if its impact is constantly monitored and adjusted to the demands of changing social contexts and needs of learners. This implies that teachers need to be aware about teaching and learning processes. Moreover, they should constantly question their didactical methods and the learning resources, which they provide to their students. They should reflect if their actions are suitable, and they should regulate their teaching, e.g., by updating learning materials based on new knowledge about learners, or by motivating learners to engage in further learning activities. In the last years, a rising interest in ‘learning analytics’ is observable. This interest is motivated by the availability of massive amounts of educational data. Also, the continuously increasing processing power, and a strong motivation for discovering new information from these pools of educational data, is pushing further developments within the learning analytics research field. Learning analytics could be a method for reflective teaching practice that enables and guides teachers to investigate and evaluate their work in future learning scenarios. However, this potentially positive impact has not yet been sufficiently verified by learning analytics research. Another method that pursues these goals is ‘action research’. Learning analytics promises to initiate action research processes because it facilitates awareness, reflection and regulation of teaching activities analogous to action research. Therefore, this thesis joins both concepts, in order to improve the design of learning analytics tools. Central research question of this thesis are: What are the dimensions of learning analytics in relation to action research, which need to be considered when designing a learning analytics tool? How does a learning analytics dashboard impact the teachers of technology-enhanced university lectures regarding ‘awareness’, ‘reflection’ and ‘action’? Does it initiate action research? Which are central requirements for a learning analytics tool, which pursues such effects? This project followed design-based research principles, in order to answer these research questions. The main contributions are: a theoretical reference model that connects action research and learning analytics, the conceptualization and implementation of a learning analytics tool, a requirements catalogue for useful and usable learning analytics design based on evaluations, a tested procedure for impact analysis, and guidelines for the introduction of learning analytics into higher education.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Three-dimensional (3D) immersive virtual worlds have been touted as being capable of facilitating highly interactive, engaging, multimodal learning experiences. Much of the evidence gathered to support these claims has been anecdotal but the potential that these environments hold to solve traditional problems in online and technology-mediated education—primarily learner isolation and student disengagement—has resulted in considerable investments in virtual world platforms like Second Life, OpenSimulator, and Open Wonderland by both professors and institutions. To justify this ongoing and sustained investment, institutions and proponents of simulated learning environments must assemble a robust body of evidence that illustrates the most effective use of this powerful learning tool. In this authoritative collection, a team of international experts outline the emerging trends and developments in the use of 3D virtual worlds for teaching and learning. They explore aspects of learner interaction with virtual worlds, such as user wayfinding in Second Life, communication modes and perceived presence, and accessibility issues for elderly or disabled learners. They also examine advanced technologies that hold potential for the enhancement of learner immersion and discuss best practices in the design and implementation of virtual world-based learning interventions and tasks. By evaluating and documenting different methods, approaches, and strategies, the contributors to Learning in Virtual Worlds offer important information and insight to both scholars and practitioners in the field. AU Press is an open access publisher and the book is available for free in PDF format as well as for purchase on our website: http://bit.ly/1W4yTRA

Relevância:

100.00% 100.00%

Publicador:

Resumo:

In September 1995, 225 spring-born calves were weaned on pasture at the McNay Memorial Research and Demonstration Farm to explore procedures necessary to conduct a successful pasture-weaning program. In the two to three week post-weaning period, average daily gains (ADG) for the two groups weaned that year were 1.06 and 3.06 pounds; there were no health problems. In 1996, a research trial utilizing 242 spring-born calves was conducted to compare pastureweaned and feedlot-weaned calves. Half of the calves were weaned on pasture for three weeks and then placed in a feedlot for three more weeks. The other half of the calves were weaned directly into the feedlot for the six week post-weaning period. ADGs during the three week post-weaning period were 1.24 and 2.42 for the pastureweaned and feedlot-weaned calves. For the entire six week trial, ADGs were 1.83 and 2.40 for the pastureweaned and feedlot-weaned calves. There was no sickness in either weaning treatment during the six week trial. Initial experience indicates pasture-weaning is a feasible method of getting calves through a stressful procedure.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Background: Statistical shape models are widely used in biomedical research. They are routinely implemented for automatic image segmentation or object identification in medical images. In these fields, however, the acquisition of the large training datasets, required to develop these models, is usually a time-consuming process. Even after this effort, the collections of datasets are often lost or mishandled resulting in replication of work. Objective: To solve these problems, the Virtual Skeleton Database (VSD) is proposed as a centralized storage system where the data necessary to build statistical shape models can be stored and shared. Methods: The VSD provides an online repository system tailored to the needs of the medical research community. The processing of the most common image file types, a statistical shape model framework, and an ontology-based search provide the generic tools to store, exchange, and retrieve digital medical datasets. The hosted data are accessible to the community, and collaborative research catalyzes their productivity. Results: To illustrate the need for an online repository for medical research, three exemplary projects of the VSD are presented: (1) an international collaboration to achieve improvement in cochlear surgery and implant optimization, (2) a population-based analysis of femoral fracture risk between genders, and (3) an online application developed for the evaluation and comparison of the segmentation of brain tumors. Conclusions: The VSD is a novel system for scientific collaboration for the medical image community with a data-centric concept and semantically driven search option for anatomical structures. The repository has been proven to be a useful tool for collaborative model building, as a resource for biomechanical population studies, or to enhance segmentation algorithms.

Relevância:

100.00% 100.00%

Publicador:

Relevância:

100.00% 100.00%

Publicador:

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The following is a commentary on an article discussing physical activity in Latino children. It is clear that research is needed to determine the causes of inactivity and develop effective strategies for promoting physical activity in this population. Approaches involving numerous community entities (faith-based, businesses) and the implementation of policies that enhance physical activity participation appear very promising.