Quasistatic computing environments

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1996.Includes bibliographical references (p. 55-57).by Ian S. Eslick.M.Eng

Searching for commonsense

Thesis (S.M.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2006.Includes bibliographical references (leaves 97-101).Acquiring and representing the large body of "common sense" knowledge underlying ordinary human reasoning and communication is a long standing problem in the field of artificial intelligence. This thesis will address the question whether a significant quantity of this knowledge may be acquired by mining natural language content on the Web. Specifically, this thesis emphasizes the representation of knowledge in the form of binary semantic relationships, such as cause, effect, intent, and time, among natural language phrases. The central hypothesis is that seed knowledge collected from volunteers enables automated acquisition of this knowledge from a large, unannotated, general corpus like the Web. A text mining system, ConceptMiner, was developed to evaluate this hypothesis. ConceptMiner leverages web search engines, Information Extraction techniques and the ConceptNet toolkit to analyze Web content for textual evidence indicating common sense relationships.(cont.) Experiments are reported for three semantic relation classes: desire, effect, and capability. A Pointwise Mutual Infomation measure computed from Web hit counts is demonstrated to filter general common sense from instance knowledge true only in specific circumstances. A semantic distance metric is introduced which significantly reduces negative instances from the extracted hypotheses. The results confirm that significant relational common sense knowledge exists on the Web and provides evidence that the algorithms employed by ConceptMiner can extract this knowledge with a precision approaching that provided by human subjects.by Ian Scott Eslick.S.M

GraphStep: A System Architecture for Sparse-Graph Algorithms

Many important applications are organized around long-lived, irregular sparse graphs (e.g., data and knowledge bases, CAD optimization, numerical problems, simulations). The graph structures are large, and the applications need regular access to a large, data-dependent portion of the graph for each operation (e.g., the algorithm may need to walk the graph, visiting all nodes, or propagate changes through many nodes in the graph). On conventional microprocessors, the graph structures exceed on-chip cache capacities, making main-memory bandwidth and latency the key performance limiters. To avoid this “memory wall,” we introduce a concurrent system architecture for sparse graph algorithms that places graph nodes in small distributed memories paired with specialized graph processing nodes interconnected by a lightweight network. This gives us a scalable way to map these applications so that they can exploit the high-bandwidth and low-latency capabilities of embedded memories (e.g., FPGA Block RAMs). On typical spreading activation queries on the ConceptNet Knowledge Base, a sample application, this translates into an order of magnitude speedup per FPGA compared to a state-of-the-art Pentium processor

Technology-Enabled Health Care Collaboration in Pediatric Chronic Illness: Pre-post Interventional Study for Feasibility, Acceptability, and Clinical Impact of an Electronic Health Record–Linked Platform for Patient-Clinician Partnership

Background: Mobile health (mHealth) technology has the potential to support the Chronic Care Model\u27s vision of closed feedback loops and patient-clinician partnerships. Objective: This study aims to evaluate the feasibility, acceptability, and short-term impact of an electronic health record-linked mHealth platform (Orchestra) supporting patient and clinician collaboration through real-time, bidirectional data sharing. Methods: We conducted a 6-month prospective, pre-post, proof-of-concept study of Orchestra among patients and parents in the Cincinnati Children\u27s Hospital inflammatory bowel disease (IBD) and cystic fibrosis (CF) clinics. Participants and clinicians used Orchestra during and between visits to complete and view patient-reported outcome (PRO) measures and previsit plans. Surveys completed at baseline and at 3- and 6-month follow-up visits plus data from the platform were used to assess outcomes including PRO completion rates, weekly platform use, disease self-efficacy, and impact on care. Analyses included descriptive statistics; pre-post comparisons; Pearson correlations; and, if applicable, effect sizes. Results: We enrolled 92 participants (CF: n = 52 and IBD: n = 40), and 73% (67/92) completed the study. Average PRO completion was 61%, and average weekly platform use was 80%. Participants reported improvement in self-efficacy from baseline to 6 months (7.90 to 8.44; P = .006). At 6 months, most participants reported that the platform was useful (36/40, 90%) and had a positive impact on their care, including improved visit quality (33/40, 83%), visit collaboration (35/40, 88%), and visit preparation (31/40, 78%). PRO completion was positively associated with multiple indicators of care impact at 3 and 6 months. Conclusions: Use of an mHealth tool to support closed feedback loops through real-time data sharing and patient-clinician collaboration is feasible and shows indications of acceptability and promise as a strategy for improving pediatric chronic illness management

Australian clinical practice guidelines for the diagnosis and management of Barrett's esophagus and early esophageal adenocarcinoma

Author version made available following 12 month embargo from date of publication according to publisher copyright policy.Barrett's esophagus (BE), a common condition, is the only known precursor to esophageal adenocarcinoma (EAC). There is uncertainty about the best way to manage BE as most people with BE never develop EAC and most patients diagnosed with EAC have no preceding diagnosis of BE. Moreover, there have been recent advances in knowledge and practice about the management of BE and early EAC. To aid clinical decision making in this rapidly moving field, Cancer Council Australia convened an expert working party to identify pertinent clinical questions. The questions covered a wide range of topics including endoscopic and histological definitions of BE and early EAC; prevalence, incidence, natural history, and risk factors for BE; and methods for managing BE and early EAC. The latter considered modification of lifestyle factors; screening and surveillance strategies; and medical, endoscopic, and surgical interventions. To answer each question, the working party systematically reviewed the literature and developed a set of recommendations through consensus. Evidence underpinning each recommendation was rated according to quality and applicability

C5b-9 membrane attack complex formation and extracellular vesicle shedding in Barrett's esophagus and esophageal adenocarcinoma

The early complement components have emerged as mediators of pro-oncogenic inflammation, classically inferred to cause terminal complement activation, but there are limited data on the activity of terminal complement in cancer. We previously reported elevated serum and tissue C9, the terminal complement component, in esophageal adenocarcinoma (EAC) compared to the precursor condition Barrett’s Esophagus (BE) and healthy controls. Here, we investigate the level and cellular fates of the terminal complement complex C5b-9, also known as the membrane attack complex. Punctate C5b-9 staining and diffuse C9 staining was detected in BE and EAC by multiplex immunohistofluorescence without corresponding increase of C9 mRNA transcript. Increased C9 and C5b-9 staining were observed in the sequence normal squamous epithelium, BE, low- and high-grade dysplasia, EAC. C5b-9 positive esophageal cells were morphologically intact, indicative of sublytic or complement-evasion mechanisms. To investigate this at a cellular level, we exposed non-dysplastic BE (BAR-T and CP-A), high-grade dysplastic BE (CP-B and CP-D) and EAC (FLO-1 and OE-33) cell lines to the same sublytic dose of immunopurified human C9 (3 µg/ml) in the presence of C9-depleted human serum. Cellular C5b-9 was visualized by immunofluorescence confocal microscopy. Shed C5b-9 in the form of extracellular vesicles (EV) was measured in collected conditioned medium using recently described microfluidic immunoassay with capture by a mixture of three tetraspanin antibodies (CD9/CD63/CD81) and detection by surface-enhanced Raman scattering (SERS) after EV labelling with C5b-9 or C9 antibody conjugated SERS nanotags. Following C9 exposure, all examined cell lines formed C5b-9, internalized C5b-9, and shed C5b-9+ and C9+ EVs, albeit at varying levels despite receiving the same C9 dose. In conclusion, these results confirm increased esophageal C5b-9 formation during EAC development and demonstrate capability and heterogeneity in C5b-9 formation and shedding in BE and EAC cell lines following sublytic C9 exposure. Future work may explore the molecular mechanisms and pathogenic implications of the shed C5b-9+ EV

ScratchTalk and Social Computation: Towards a natural language scripting model

Natural Language interfaces have been proposed as a solution to make application functionality more accessible to end users. Practical implementation of such systems has been hampered by both semantic and knowledge-engineering challenges. This paper introduces Social Computation, a theoretical model targeting both challenges. The model employs natural language in a planning framework to enable communities of end-users to collaborate, explicitly and implicitly, in the development of new functionality. The model intrinsically supports the acquisition of user goals and natural language semantics in the context of the application domain. ScratchTalk is a prototype of the natural language planning component of the model applied to the Scratch programming environment. This serves to ground the framework and provide insights into the space of applications likely to be addressable by the Social Computation model

Langutils: A natural language toolkit for common lisp

In recent years, Natural Language Processing (NLP) has emerged as an important capability in many applications and areas of research. Natural language can be both the domain of application and an important component in the human-computer interface. This paper describes the design and implementation of "langutils, ” a highperformance natural language toolkit for Common Lisp. We introduce the techniques of real-world NLP and explore tradeoffs in the representation and implementation of tokenization, part-of-speech tagging, and parsing. The paper concludes with a discussion of the use of the toolkit in two natural language applications

Anecdotes to aggregated self-experiments

Thesis: Ph. D., Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2013.Cataloged from PDF version of thesis.Includes bibliographical references (pages 305-315).Nearly one quarter of US adults read patient-generated health information found on blogs, forums and social media; many say they use this information to influence everyday health decisions. Topics of discussion in online forums are often poorly-addressed by existing, clinical research, so a patient's reported experiences are the only evidence. No rigorous methods exist to help patients leverage anecdotal evidence to make better decisions. This dissertation reports on multiple prototype systems that help patients augment anecdote with data to improve individual decision making, optimize healthcare delivery, and accelerate research. The web-based systems were developed through a multi-year collaboration with individuals, advocacy organizations, healthcare providers, and biomedical researchers. The result of this work is a new scientific model for crowdsourcing health insights: Aggregated Self-Experiments. The self-experiment, a type of single-subject (n-of-1) trial, formally validates the effectiveness of an intervention on a single person. Aggregated Personal Experiments enables user communities to translate anecdotal correlations into repeatable trials that can validate efficacy in the context of their daily lives. Aggregating the outcomes of multiple trials improves the efficiency of future trials and enables users to prioritize trials for a given condition. Successful outcomes from many patients provide evidence to motivate future clinical research. The model, and the design principles that support it were evaluated through a set of focused user studies, secondary data analyses, and experience with real-world deployments.by Ian Scott Eslick.Ph. D

The role of left ventrolateral prefrontal cortex during episodic decisions : semantic elaboration or resolution of episodic interference?

Context memory retrieval tasks often implicate the left ventrolateral pFC (LVPFC) during functional imaging. Although this region has been linked to controlled semantic processing of materials, it may also play a more general role in selecting among competing episodic representations during demanding retrieval tasks. Thus, the LVPFC response during context memory retrieval may reflect either semantic processing of memoranda or adjudication of interfering episodic memories evoked by memoranda. To distinguish between these hypotheses, we contrasted context and item memory retrieval tasks for meaningful and nonmeaningful memoranda using fMRI. Increased LVPFC activation during context compared with item memory only occurred for meaningful memory probes. In contrast, even demanding context retrieval for nonmeaningful materials failed to engage LVPFC. These data demonstrate that the activation previously seen during episodic tasks likely reflects semantic processing of the probes during episodic retrieval attempt, not the selection among competing elicited episodic representations. Posterior middle temporal gyrus and the body/head of the caudate demonstrated the same selective response as LVPFC, although resting state functional connectivity analyses suggested that these two regions likely shared separate functional relationships with the LVPFC.Publisher PDFPeer reviewe