Using taxonomic indexing trees to efficiently retrieve SCORM-compliant documents in e-learning grids

[[abstract]]With the flourishing development of e-Learning, more and more SCORM-compliant teaching materials are developed by institutes and individuals in different sites. In addition, the e-Learning grid is emerging as an infrastructure to enhance traditional e-Learning systems. Therefore, information retrieval schemes supporting SCORM-compliant documents on grid environments are gaining its importance. To minimize the query processing time and content transmission time, our idea is to use a bottom-up approach to reorganize documents in these sites based on their metadata, and to manage these contents in a centralized manner. In this paper, we design an indexing structure named Taxonomic Indexing Trees (TI-trees). A TI-tree is a taxonomic structure and has two novel features: 1) reorganizing documents according to the Classification metadata such that queries by classes can be processed efficiently and 2) indexing dispersedly stored documents in a centralized manner which is suitable for common grid middleware. This approach is composed of a Construction phase and a Search phase. In the former, a local TI-tree is built from each Learning Object Repository. Then, all local TI-trees are merged into a global TI-tree. In the latter, a Grid Portal processes queries and presents results with estimated transmission time to users. Experimental results show that the proposed approach can efficiently retrieve SCORM-compliant documents with good scalability

A Knowledge-based Approach to Retrieving Teaching Materials for Context-aware Learning

[[abstract]]With the rapid development of wireless communication and sensor technologies, ubiquitous learning has become a promising solution to educational problems. In context-aware ubiquitous learning environments, it is required that learning content is retrieved according to environmental contexts, such as learners' location. Also, a learning content retrieval scheme should be able to work with various instructional strategies for different learning activities. To solve the context-aware learning content retrieval problem, we propose a strategy-driven approach to derive content retrieval strategies from instructional strategies. Moreover, we construct a knowledge-based system to expand query keywords based on the derived strategies and then select relevant keywords according to geographical distance between entities of concept and learners. This system is composed of four components: knowledge transformation, query expansion, content retrieval and user interface. Besides, ontology construction algorithms, designed for teachers to easily build up ontology from course outlines, are applied to generate the rules of query expansion and the taxonomic index of learning object repository. The experimental results indicate that the proposed approach can increase the learning performance of students

Pregnancy in multiple system atrophy: a case report

<p>Abstract</p> <p>Introduction</p> <p>Multiple system atrophy is a late, adult-onset α-synucleinopathy with no data on the effect of pregnancy on the disease course. Early stage multiple system atrophy can be difficult to distinguish from Parkinson's disease.</p> <p>Case presentation</p> <p>We describe the case of an Irish woman with parkinsonism starting at age 31, initially diagnosed as having dopa-responsive, idiopathic Parkinson's disease, who successfully delivered a full-term child at age 35. Her pregnancy was complicated by severe orthostatic hypotension and motor fluctuations. Two years post-partum, she underwent bilateral subthalamic nuclei deep brain stimulation for intractable motor fluctuations and disabling dyskinesia. After this treatment course she experienced deterioration of motor symptoms and death eight years after disease onset. Post-mortem neuropathological examination revealed striatonigral degeneration and α-synuclein-positive glial cytoplasmic inclusions in brain stem nuclei, basal ganglia and white matter tracts, consistent with a neuropathological diagnosis of multiple system atrophy.</p> <p>Conclusions</p> <p>Multiple system atrophy can affect women of child-bearing age and pregnancy may be associated with marked disease progression.</p

Community-acquired Klebsiella pneumoniae meningitis in an alcoholic patient with an infected pancreatic pseudocyst; a case report and review of literature

We report a case of a 49-year-old male with a history of chronic alcoholism and evidence of a pancreatic pseudocyst on CT scanning. He presented with a 3-days history of fever, loss of appetite and upper abdominal pain. Blood cultures grew Klebsiella pneumoniae and he improved clinically with a seven-day course of intravenous co-amoxiclav and metronidazole. Two weeks later he was readmitted to hospital with impaired consciousness and septic shock, and died three days later in intensive care. Post mortem examination revealed bacterial meningitis and an infected pancreatic pseudocyst. Klebsiella pneumoniae was isolated from the pancreas and meninges

Expression of the RNA helicase DDX3 and the hypoxia response in breast cancer

&lt;p&gt;Aims: DDX3 is an RNA helicase that has antiapoptotic properties, and promotes proliferation and transformation. In addition, DDX3 was shown to be a direct downstream target of HIF-1α (the master regulatory of the hypoxia response) in breast cancer cell lines. However, the relation between DDX3 and hypoxia has not been addressed in human tumors. In this paper, we studied the relation between DDX3 and the hypoxic responsive proteins in human breast cancer.&lt;/p&gt; &lt;p&gt;Methods and Results: DDX3 expression was investigated by immunohistochemistry in breast cancer in comparison with hypoxia related proteins HIF-1α, GLUT1, CAIX, EGFR, HER2, Akt1, FOXO4, p53, ERα, COMMD1, FER kinase, PIN1, E-cadherin, p21, p27, Transferrin receptor, FOXO3A, c-Met and Notch1. DDX3 was overexpressed in 127 of 366 breast cancer patients, and was correlated with overexpression of HIF-1α and its downstream genes CAIX and GLUT1. Moreover, DDX3 expression correlated with hypoxia-related proteins EGFR, HER2, FOXO4, ERα and c-Met in a HIF-1α dependent fashion, and with COMMD1, FER kinase, Akt1, E-cadherin, TfR and FOXO3A independent of HIF-1α.&lt;/p&gt; &lt;p&gt;Conclusions: In invasive breast cancer, expression of DDX3 was correlated with overexpression of HIF-1α and many other hypoxia related proteins, pointing to a distinct role for DDX3 under hypoxic conditions and supporting the oncogenic role of DDX3 which could have clinical implication for current development of DDX3 inhibitors.&lt;/p&gt

Screen for Localized Proteins in Caulobacter crescentus

Precise localization of individual proteins is required for processes such as motility, chemotaxis, cell-cycle progression, and cell division in bacteria, but the number of proteins that are localized in bacterial species is not known. A screen based on transposon mutagenesis and fluorescence activated cell sorting was devised to identify large numbers of localized proteins, and employed in Caulobacter crescentus. From a sample of the clones isolated in the screen, eleven proteins with no previously characterized localization in C. crescentus were identified, including six hypothetical proteins. The localized hypothetical proteins included one protein that was localized in a helix-like structure, and two proteins for which the localization changed as a function of the cell cycle, suggesting that complex three-dimensional patterns and cell cycle-dependent localization are likely to be common in bacteria. Other mutants produced localized fusion proteins even though the transposon has inserted near the 5′ end of a gene, demonstrating that short peptides can contain sufficient information to localize bacterial proteins. The screen described here could be used in most bacterial species

Effects of an irregular bedtime schedule on sleep quality, daytime sleepiness, and fatigue among university students in Taiwan

<p>Abstract</p> <p>Background</p> <p>An irregular bedtime schedule is a prevalent problem in young adults, and could be a factor detrimentally affecting sleep quality. The goal of the present study was to explore the association between an irregular bedtime schedule and sleep quality, daytime sleepiness, and fatigue among undergraduate students in Taiwan.</p> <p>Methods</p> <p>A total of 160 students underwent a semi-structured interview and completed a survey comprising 4 parts: Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS), Fatigue Severity Scale (FSS), and a rating of irregular bedtime frequency. Participants were grouped into 3 groups in terms of irregular bedtime frequency: low, intermediate, or high according to their 2-week sleep log. To screen for psychological disorders or distress that may have affected responses on the sleep assessment measures, the Chinese health questionnaire-12 (CHQ-12) was also administered.</p> <p>Results</p> <p>We found an increase in bedtime schedule irregularity to be significantly associated with a decrease in average sleep time per day (Spearman r = -0.22, p = 0.05). Multivariate regression analysis revealed that irregular bedtime frequency and average sleep time per day were correlated with PSQI scores, but not with ESS or FSS scores. A significant positive correlation between irregular bedtime frequency and PSQI scores was evident in the intermediate (partial r = 0.18, p = 0.02) and high (partial r = 0.15, p = 0.05) frequency groups as compared to low frequency group.</p> <p>Conclusion</p> <p>The results of our study suggest a high prevalence of both an irregular bedtime schedule and insufficient sleep among university students in Taiwan. Students with an irregular bedtime schedule may experience poor sleep quality. We suggest further research that explores the mechanisms involved in an irregular bedtime schedule and the effectiveness of interventions for improving this condition.</p

Detection and Alignment of 3D Domain Swapping Proteins Using Angle-Distance Image-Based Secondary Structural Matching Techniques

This work presents a novel detection method for three-dimensional domain swapping (DS), a mechanism for forming protein quaternary structures that can be visualized as if monomers had “opened” their “closed” structures and exchanged the opened portion to form intertwined oligomers. Since the first report of DS in the mid 1990s, an increasing number of identified cases has led to the postulation that DS might occur in a protein with an unconstrained terminus under appropriate conditions. DS may play important roles in the molecular evolution and functional regulation of proteins and the formation of depositions in Alzheimer's and prion diseases. Moreover, it is promising for designing auto-assembling biomaterials. Despite the increasing interest in DS, related bioinformatics methods are rarely available. Owing to a dramatic conformational difference between the monomeric/closed and oligomeric/open forms, conventional structural comparison methods are inadequate for detecting DS. Hence, there is also a lack of comprehensive datasets for studying DS. Based on angle-distance (A-D) image transformations of secondary structural elements (SSEs), specific patterns within A-D images can be recognized and classified for structural similarities. In this work, a matching algorithm to extract corresponding SSE pairs from A-D images and a novel DS score have been designed and demonstrated to be applicable to the detection of DS relationships. The Matthews correlation coefficient (MCC) and sensitivity of the proposed DS-detecting method were higher than 0.81 even when the sequence identities of the proteins examined were lower than 10%. On average, the alignment percentage and root-mean-square distance (RMSD) computed by the proposed method were 90% and 1.8Å for a set of 1,211 DS-related pairs of proteins. The performances of structural alignments remain high and stable for DS-related homologs with less than 10% sequence identities. In addition, the quality of its hinge loop determination is comparable to that of manual inspection. This method has been implemented as a web-based tool, which requires two protein structures as the input and then the type and/or existence of DS relationships between the input structures are determined according to the A-D image-based structural alignments and the DS score. The proposed method is expected to trigger large-scale studies of this interesting structural phenomenon and facilitate related applications

Anion gap, anion gap corrected for albumin, base deficit and unmeasured anions in critically ill patients: implications on the assessment of metabolic acidosis and the diagnosis of hyperlactatemia

Abstract Background Base deficit (BD), anion gap (AG), and albumin corrected anion gap (ACAG) are used by clinicians to assess the presence or absence of hyperlactatemia (HL). We set out to determine if these tools can diagnose the presence of HL using cotemporaneous samples. Methods We conducted a chart review of ICU patients who had cotemporaneous arterial blood gas, serum chemistry, serum albumin (Alb) and lactate(Lac) levels measured from the same sample. We assessed the capacity of AG, BD, and ACAG to diagnose HL and severe hyperlactatemia (SHL). HL was defined as Lac > 2.5 mmol/L. SHL was defined as a Lac of > 4.0 mmol/L. Results From 143 patients we identified 497 series of lab values that met our study criteria. Mean age was 62.2 ± 15.7 years. Mean Lac was 2.11 ± 2.6 mmol/L, mean AG was 9.0 ± 5.1, mean ACAG was 14.1 ± 3.8, mean BD was 1.50 ± 5.4. The area under the curve for the ROC for BD, AG, and ACAG to diagnose HL were 0.79, 0.70, and 0.72, respectively. Conclusion AG and BD failed to reliably detect the presence of clinically significant hyperlactatemia. Under idealized conditions, ACAG has the capacity to rule out the presence of hyperlactatemia. Lac levels should be obtained routinely in all patients admitted to the ICU in whom the possibility of shock/hypoperfusion is being considered. If an AG assessment is required in the ICU, it must be corrected for albumin for there to be sufficient diagnostic utility.</p