Virtual Reference for Video Collections: System Infrastructure, User Interface and Pilot User Study

A new video-based Virtual Reference (VR) tool called VideoHelp was designed and developed to support video navigation escorting, a function that enables librarians to co-navigate a digital video with patrons in the web-based environment. A client/server infrastructure was adopted for the VideoHelp system and timestamps were used to achieve the video synchronization between the librarians and patrons. A pilot usability study of using VideoHelp prototype in video seeking was conducted and the preliminary results demonstrated that the system is easy to learn and use, and real-time assistance from virtual librarians in video navigation is desirable on a conditional basis

A novel method for blood vessel detection from retinal images

<p>Abstract</p> <p>Background</p> <p>The morphological changes of the retinal blood vessels in retinal images are important indicators for diseases like diabetes, hypertension and glaucoma. Thus the accurate segmentation of blood vessel is of diagnostic value.</p> <p>Methods</p> <p>In this paper, we present a novel method to segment retinal blood vessels to overcome the variations in contrast of large and thin vessels. This method uses adaptive local thresholding to produce a binary image then extract large connected components as large vessels. The residual fragments in the binary image including some thin vessel segments (or pixels), are classified by Support Vector Machine (SVM). The tracking growth is applied to the thin vessel segments to form the whole vascular network.</p> <p>Results</p> <p>The proposed algorithm is tested on DRIVE database, and the average sensitivity is over 77% while the average accuracy reaches 93.2%.</p> <p>Conclusions</p> <p>In this paper, we distinguish large vessels by adaptive local thresholding for their good contrast. Then identify some thin vessel segments with bad contrast by SVM, which can be lengthened by tracking. This proposed method can avoid heavy computation and manual intervention.</p

A Simulation-free Group Sequential Design with Max-combo Tests in the Presence of Non-proportional Hazards

Non-proportional hazards (NPH) have been observed recently in many immuno-oncology clinical trials. Weighted log-rank tests (WLRT) with suitably chosen weights can be used to improve the power of detecting the difference of the two survival curves in the presence of NPH. However, it is not easy to choose a proper WLRT in practice when both robustness and efficiency are considered. A versatile maxcombo test was proposed to achieve the balance of robustness and efficiency and has received increasing attentions in both methodology development and application. However, survival trials often warrant interim analyses due to its high cost and long duration. The integration and application of maxcombo tests in interim analyses often require extensive simulation studies. In this paper, we propose a simulation-free approach for group sequential design with maxcombo test in survival trials. The simulation results support that the proposed approaches successfully control both the type I error rate and offer great accuracy and flexibility in estimating sample sizes, at the expense of light computation burden. Notably, our methods display a strong robustness towards various model misspecifications, and have been implemented in an R package for free access online

Towards sustaining professional development: identification of essential competencies and effective training techniques for chat reference services

This dissertation seeks to determine the essential chat reference competencies and the effective training techniques to deliver them. Two survey studies were conducted to examine chat reference practitioners’ perceptions of competencies and training techniques reported in the literature. As a result, prioritized lists of chat reference competencies and training techniques were produced, respectively. The examined competencies could be broken down into four categories: 1). Media-independent core reference competencies; 2). Reference competencies highlighted in the context of chat reference; 3). Reference competencies specific to chat reference; and 4). Reference competencies not as important in chat reference. In terms of training techniques that could deliver the essential competencies, the most effective ones are those enabling practice-based learning. Findings from the dissertation study can be used as the basis to design and implement training and education programs to professionally prepare chat reference librarians and eventually lead to better performance of the service and better fulfillment of users information needs

Gamma globulin improves pulmonary function and increases C3 and C4 serum levels of septic children in pediatric intensive care unit

Purpose: To probe into the effects of gamma globulin on the pulmonary functions, and C3 and C4 serum levels of septic children in pediatric intensive care unit (PICU). Methods: Sixty-seven children with sepsis were retrospectively analyzed and assigned into study group (SG, n = 36) and control group (CG, n = 31) based on treatment modalities. The children in CG received conventional sepsis treatment, while children in SG were treated with gamma globulin. Differences in pulmonary function as well as C3 and C4 serum levels were compared in both groups before and after treatment. Children in SG were assigned into mild group (n = 21) and severe group (n = 15) in based on the severity of their conditions. Results: After treatment, SG showed higher forced vital capacity (FVC) and peak expiratory flow (PEF) than CG (p &lt; 0.05). SG also showed higher C3 and C4 serum levels than CG after treatment (p &lt; 0.05). Conclusion: Administration of gamma globulin to children in PICU significantly improves lung function and increases their serum C3 and C4 levels. C3 and C4 serum levels of septic children in PICU correlate with prognosis. Hence, C3 and C4 can be regarded as indicators for the diagnosis, evaluation and prognosis of septic children in PICU

Gamma globulin improves pulmonary function and increases C3 and C4 serum levels of septic children in pediatric intensive care unit

Purpose: To probe into the effects of gamma globulin on the pulmonary functions, and C3 and C4 serum levels of septic children in pediatric intensive care unit (PICU). Methods: Sixty-seven children with sepsis were retrospectively analyzed and assigned into study group (SG, n = 36) and control group (CG, n = 31) based on treatment modalities. The children in CG received conventional sepsis treatment, while children in SG were treated with gamma globulin. Differences in pulmonary function as well as C3 and C4 serum levels were compared in both groups before and after treatment. Children in SG were assigned into mild group (n = 21) and severe group (n = 15) in based on the severity of their conditions. Results: After treatment, SG showed higher forced vital capacity (FVC) and peak expiratory flow (PEF) than CG (p &lt; 0.05). SG also showed higher C3 and C4 serum levels than CG after treatment (p &lt; 0.05). Conclusion: Administration of gamma globulin to children in PICU significantly improves lung function and increases their serum C3 and C4 levels. C3 and C4 serum levels of septic children in PICU correlate with prognosis. Hence, C3 and C4 can be regarded as indicators for the diagnosis, evaluation and prognosis of septic children in PICU