Repairing Multiple Failures in the Suh-Ramchandran Regenerating Codes

Using the idea of interference alignment, Suh and Ramchandran constructed a class of minimum-storage regenerating codes which can repair one systematic or one parity-check node with optimal repair bandwidth. With the same code structure, we show that in addition to single node failure, double node failures can be repaired collaboratively with optimal repair bandwidth as well. We give an example of how to repair double failures in the Suh-Ramchandran regenerating code with six nodes, and give the proof for the general case.Comment: IEEE Int. Symp. Inf. Theory, 201

The causality and simultaneity between price and trading intensity in existing home markets

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Urban Studies and Planning, 1997.Includes bibliographical references (leaf 21).by Junyu Chen.M.S

Novel biomarkers in regulating human dense connective tissue repair

Painful and degenerative disorders of the musculoskeletal system pose a tremendous burden on the healthcare system. One main reason is the limited knowledge of the underlying key factors and pathways responsible for the suboptimal and often varying healing outcomes of dense connective tissues (CTs), such as tendons, ligaments and knee meniscus, which have vital supportive, protective and force transmitting roles in the human body. The overall aim of this thesis was to identify novel biomarkers of dense CT healing. The thesis was designed to explore for biomarkers during the inflammatory- and proliferative healing phases in tissue biopsies and micro-dialysate, respectively, after Achilles tendon rupture (ATR) as a model of dense CT healing. Using quantitative RT-PCR and immunohistochemistry of ATR tissue biopsies from the inflammatory healing phase the presence of potential biomarkers (Col I, Col III, FGF, FN, MMP-9) was identified. The gene expression of fibroblast growth factor (FGF) was positively associated with improved 1-year patient-reported- and functional outcomes. Higher Col III mRNA expression was associated with more perceived tendon strength at 1 year. Proteomic profiling using quantitative mass spectrometry of ATR biopsies from the inflammatory healing phase disclosed 769 proteins, including 51 differentially expressed proteins among patients with good- versus poor 1-year outcome. Among them a novel biomarker, elongation factor-2 (eEF2), was identified as being strongly prognostic of the 1-year clinical outcome. Experimental exploration revealed that eEF2 regulated autophagy, cell proliferation and migration, as well as reduced cell death and apoptosis in dense CT healing. Utilizing the proteomic profile from the inflammatory healing phase together with weighted co-expression network analysis a biomarker, inter-alpha-trypsin inhibitor heavy chain (ITIH4), associated with improved 1-year healing outcomes was discovered. Experimental explorations identified ITIH4 to stimulate collagen I production mediated by PPARγ signaling pathways. Further proteomic profiling of micro-dialysate from the proliferative healing phase discovered 1288 unique proteins, whereof 9 upregulated, and 23 downregulated proteins in patients with good- versus poor 1-year outcome. Upregulated proteins were related mainly to extracellular matrix organization, while downregulated pathways were associated with functions such as thrombosis formation. The most reliable predictive biomarker was the downregulated pro-inflammatory complement factor D (CFD). Expanded characterization of CFD demonstrated higher expression during inflammatory- and lower expression during proliferative healing phases in the good outcome patients. Further experimental explorations demonstrated that CFD improved repair by enhancing cell migration and collagen type I (Col1a1) production during inflammation, while exerting the opposite effects during proliferative healing. The results of this thesis have established biomarkers eEF2, FGF, ITIH4 during the inflammatory healing phase and CFD mainly during the proliferative healing phase, all prognostic of improved patient outcome in tendon repair, presumably reflective of dense CT healing in general. These findings may lead to improved individualized treatment decisions, as well as accelerate the development of improved therapies to promote good long-term clinical healing outcomes

Evolution of anthropogenic air pollutant emissions in Guangdong Province, China, from 2006 to 2015

Guangdong Province (GD), one of the most prosperous and populous regions in China, still experiences haze events and growing ozone pollution in spite of the substantial air-quality improvement in recent years. Integrated control of fine particulate matter (PM2.5) and ozone in GD calls for a systematic review of historical emissions. In this study, emission trends, spatial variations, source-contribution variations, and reduction potentials of sulfur dioxide (SO2), nitrogen oxides (NO), PM2.5, inhalable particles (PM10), carbon monoxide (CO), ammonia (NH3), and volatile organic compounds (VOCs) in GD from 2006 to 2015 were first examined using a dynamic methodology, taking into account economic development, technology penetration, and emission controls. The relative change rates of anthropogenic emissions in GD during 2006-2015 are -48% for SO2, -0.5% for NO, -16% for PM2.5, -22% for PM10, 13% for CO, 3% for NH3, and 13% for VOCs. The declines of SO2, NO, PM2.5, and PM10 emissions in the whole province mainly resulted from the stringent emission control in the Pearl River delta (PRD) region, where most previous control measures were focused, especially on power plants (SO2 and NO), industrial combustion (SO2, PM2.5, PM10), on-road mobile sources (NO), and dust sources (PM2.5 and PM10). Emissions from other areas (non-PRD, NPRD), nevertheless, remain relatively stable due to the lax control measures and rapidly growing energy consumption. In addition, emission leaks of SO2 and NO from industries are observed from PRD to NPRD in 2010 and 2011. As a result, emissions in NPRD are increasingly important in GD, particularly those from industrial combustion. The contribution of NPRD to the total SO2 emissions in GD, for example, increased from 27% in 2006 to 48% in 2015. On-road mobile sources and solvent use are the two key sources that should receive more effective control measures in GD. Current control-driven emission reductions from on-road mobile sources are neutralized by the substantial growth of the vehicle population, while VOC emissions in GD steadily increase due to the growth of solvent use and the absence of effective control measures. Besides, future work could focus on power plants and industrial combustion in GD and industrial process sources in NPRD, which still have large emission reduction potentials. The historical emission inventory developed in this study not only helps to understand the emission evolution in GD, but also provides robust data to quantify the impact of emission and meteorology variations on air quality and unveil the primary cause of significant air-quality change in GD in the recent decade

Challenges of Employing VoiceThread to Enhance U.S. Collegiate Chinese Language Learners’ Oral Proficiency

The digital age in education inspires Chinese teachers to integrate Web 2.0 technologies into Chinese as a second language (CSL) curricula to enhance teaching effects. However, few studies examine the challenges that teachers face when integrating Web 2.0 technologies to improve student oral proficiency in Chinese. This study aims to investigate students’ perceptions of the effectiveness of the Web 2.0 technology VoiceThread (VT). It examines the challenges of integrating VT to enhance student oral proficiency. The authors conducted two studies with 31 students responding to a questionnaire in Study 1 and 48 students responding to the same questionnaire in Study 2. All students are beginner-level CSL learners. Three results were obtained. Result 1 shows that documents and articles report VT as popular and easy to use, however, few teachers employed VT in their teaching practices. Result 2 indicates another discrepancy. Although students highly evaluated the usefulness of the VT-facilitated activities, they were reluctant to perform these activities. By comparing Study 1 and Study 2, the authors obtained Result 3: Students in Study 2 evaluated VT-integrated teaching practices consistently higher than those in Study 1. Teachers’ using experiences primarily led these perception differences. This study provides CSL teachers with a vision of the opportunities and challenges that may occur when they integrate Web 2.0 technologies into curricular to improve CSL oral proficiency