173 research outputs found
An Analysis of Reduced Error Pruning
Top-down induction of decision trees has been observed to suffer from the
inadequate functioning of the pruning phase. In particular, it is known that
the size of the resulting tree grows linearly with the sample size, even though
the accuracy of the tree does not improve. Reduced Error Pruning is an
algorithm that has been used as a representative technique in attempts to
explain the problems of decision tree learning. In this paper we present
analyses of Reduced Error Pruning in three different settings. First we study
the basic algorithmic properties of the method, properties that hold
independent of the input decision tree and pruning examples. Then we examine a
situation that intuitively should lead to the subtree under consideration to be
replaced by a leaf node, one in which the class label and attribute values of
the pruning examples are independent of each other. This analysis is conducted
under two different assumptions. The general analysis shows that the pruning
probability of a node fitting pure noise is bounded by a function that
decreases exponentially as the size of the tree grows. In a specific analysis
we assume that the examples are distributed uniformly to the tree. This
assumption lets us approximate the number of subtrees that are pruned because
they do not receive any pruning examples. This paper clarifies the different
variants of the Reduced Error Pruning algorithm, brings new insight to its
algorithmic properties, analyses the algorithm with less imposed assumptions
than before, and includes the previously overlooked empty subtrees to the
analysis
Learning object relationships which determine the outcome of actions
Peer reviewedPublisher PD
Health and Social Care Educators' Competence in Digital Collaborative Learning: A Cross-Sectional Survey
The ongoing change from traditional pedagogy to digital collaborative learning requires a new mode of teaching, learning, and educators' responsibilities. For competence in digitally mediated teaching, educators need understanding of how to provide appropriate digital environment to learn collectively and individually. The aim of this study was to describe and explore health and social care educators' perceptions of their current level of competence in digital collaborative learning and identify distinct educators' profiles. Data were collected via cross-sectional survey from educators in 21 universities of applied science and eight vocational colleges in Finland using an instrument covering two subdimensions: educators' competence in fostering construction of knowledge in digital collaborative learning, and supporting students in individualized collaborative learning. The data were analyzed by statistical methods. Three significantly differing clusters of educators' profiles were identified, and a significant association between type of current work organization and their self-reported competence in digital collaborative learning was found. The vocational college educators rated their competence in fostering construction of knowledge in digital collaborative learning as significantly lower than higher education educators. There were also remarkable differences in competence in supporting students' individual collaborative learning. To provide such support, sufficient competence in teaching in digital learning environment is essential, and our study highlights clear needs to enhance this competence
Radium-223 dichloride treatment in metastatic castration-resistant prostate cancer in Finland: A real-world evidence multicenter study
Background: Radium-233 dichloride is an alpha emitter that specifically targets bone metastases in prostate cancer. Results of a previously reported phase III randomized trial showed survival benefit for radium-223 compared to best supportive care in castration-resistant prostate cancer (CRPC) with bone metastases. However, real-world data are also needed with wider inclusion criteria.Methods: We report results of a retrospective multicenter study including all patients with metastatic CRPC treated with radium-223 in all five university hospitals in Finland since the introduction of the treatment. We identified 160 patients who had received radium-223 in Finland in 2014-2019.Results: The median overall survival (OS) was 13.8 months (range 0.5-57 months), and the median real-world progression-free survival (rwPFS) was 4.9 months (range 0.5-29.8 months). Alkaline phosphatase (ALP) values within the normal range before and during the radium-223 treatment or the reduction of elevated ALP to normal range during treatment were associated with better OS when compared to elevated ALP values before and during treatment (p Conclusion: Radium-223 was well tolerated in routine clinical practice, and most patients achieved pain relief. Pain relief, ALP normalization, lower baseline PSA, and PSA decrease during radium-223 treatment were prognostic for better survival. The efficacy of radium-223 in mCRPC as estimated using OS was comparable to earlier randomized trial in this retrospective real-world study. Our results support using radium-223 for mCRPC patients with symptomatic bone metastases even in the era of new-generation androgen receptor-targeted agents.</p
Rapid, Specific Detection of Alphaviruses from Tissue Cultures Using a Replicon-Defective Reporter Gene Assay
We established a rapid, specific technique for detecting alphaviruses using a replicon-defective reporter gene assay derived from the Sindbis virus XJ-160. The pVaXJ expression vector containing the XJ-160 genome was engineered to form the expression vectors pVaXJ-EGFP expressing enhanced green fluorescence protein (EGFP) or pVaXJ-GLuc expressing Gaussia luciferase (GLuc). The replicon-defective reporter plasmids pVaXJ-EGFPΔnsp4 and pVaXJ-GLucΔnsp4 were constructed by deleting 1139 bp in the non-structural protein 4 (nsP4) gene. The deletion in the nsP4 gene prevented the defective replicons from replicating and expressing reporter genes in transfected BHK-21 cells. However, when these transfected cells were infected with an alphavirus, the non-structural proteins expressed by the alphavirus could act on the defective replicons in trans and induce the expression of the reporter genes. The replicon-defective plasmids were used to visualize the presence of alphavirus qualitatively or detect it quantitatively. Specificity tests showed that this assay could detect a variety of alphaviruses from tissue cultures, while other RNA viruses, such as Japanese encephalitis virus and Tahyna virus, gave negative results with this system. Sensitivity tests showed that the limit of detection (LOD) of this replicon-defective assay is between 1 and 10 PFU for Sindbis viruses. These results indicate that, with the help of the replicon-defective alphavirus detection technique, we can specifically, sensitively, and rapidly detect alphaviruses in tissue cultures. The detection technique constructed here may be well suited for use in clinical examination and epidemiological surveillance, as well as for rapid screening of potential viral biological warfare agents
Using a 3D virtual muscle model to link gene expression changes during myogenesis to protein spatial location in muscle
Background: Myogenesis is an ordered process whereby mononucleated muscle precursor cells (myoblasts) fuse into multinucleated myotubes that eventually differentiate into myofibres, involving substantial changes in gene expression and the organisation of structural components of the cells. To gain further insight into the orchestration of these structural changes we have overlaid the spatial organisation of the protein components of a muscle cell with their gene expression changes during differentiation using a new 3D visualisation tool: the Virtual Muscle 3D (VMus3D)
A systematic review of interventions to improve knowledge and self-management skills concerning contraception, pregnancy and breastfeeding in people with rheumatoid arthritis
This systematic review aimed to determine the effectiveness of interventions for improving knowledge and/or self-management skills concerning contraception, pregnancy and breastfeeding in people with rheumatoid arthritis (RA). We searched four databases (MEDLINE, CINAHL, Cochrane Trials, PsycINFO) using a comprehensive search strategy. Studies were eligible if they were prospective, published in English from 2004 to 2015, included participants with RA and tested an intervention designed to improve knowledge and/or self-management skills relating to family planning, pregnancy or breastfeeding. As no studies met the latter criterion, the search strategy was expanded to include all prospective studies evaluating RA educational and/or self-management interventions. Data on study characteristics, participant characteristics and programme content were extracted to summarise the evidence base for interventions to support people with RA during their reproductive years. Expanded literature searches identified 2290 papers, of which 68 were eligible. Of these, nine papers (13 %) specifically excluded pregnant women/breastfeeding mothers or recruited only older people.Only one study (1 %) explicitly evaluated pregnancy-focused education via a motherhood decision aid, while eight studies (12 %) incorporated relevant (albeit minor) components within broader RA educational or self-management interventions. Of these, three studies provided methotrexate education in relation to conception/pregnancy/breastfeeding; three incorporated discussions on RA and relationships, impact of RA on the family or sexual advice; one provided information regarding contraception and fertility; and one issued a warning regarding use of biologic therapy in pregnancy/breastfeeding. In conclusion, information regarding family planning, pregnancy or breastfeeding represents a negligible part of published RA educational interventions, with scope to develop targeted resources
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