Film dynamics and lubricant depletion by droplets moving on lubricated surfaces

Lubricated surfaces have shown promise in numerous applications where impinging foreign droplets must be removed easily; however, before they can be widely adopted, the problem of lubricant depletion, which eventually leads to decreased performance, must be solved. Despite recent progress, a quantitative mechanistic explanation for lubricant depletion is still lacking. Here, we first explained the shape of a droplet on a lubricated surface by balancing the Laplace pressures across interfaces. We then showed that the lubricant film thicknesses beneath, behind, and wrapping around a moving droplet change dynamically with droplet's speed---analogous to the classical Landau-Levich-Derjaguin problem. The interconnected lubricant dynamics results in the growth of the wetting ridge around the droplet, which is the dominant source of lubricant depletion. We then developed an analytic expression for the maximum amount of lubricant that can be depleted by a single droplet. Counter-intuitively, faster moving droplets subjected to higher driving forces deplete less lubricant than their slower moving counterparts. The insights developed in this work will inform future work and the design of longer-lasting lubricated surfaces

Exploring affect-context dependencies for adaptive system development

We use χ2 to investigate the context dependency of student affect in our computer tutoring dialogues, targeting uncertainty in student answers in 3 automatically monitorable contexts. Our results show significant dependencies between uncertain answers and specific contexts. Identification and analysis of these dependencies is our first step in developing an adaptive version of our dialogue system.

Type and Timing of Rehabilitation Following Acute and Subacute Spinal Cord Injury: A Systematic Review

Objectives: The objective of this study was to conduct a systematic review of the literature to address the following clinical questions: In adult patients with acute and subacute complete or incomplete traumatic SCI, (1) does the time interval between injury and commencing rehabilitation affect outcome?; (2) what is the comparative effectiveness of different rehabilitation strategies, including different intensities and durations of treatment?; (3) are there patient or injury characteristics that affect the efficacy of rehabilitation?; and (4) what is the cost-effectiveness of various rehabilitation strategies? Methods: A systematic search was conducted for literature published through March 31, 2015 that evaluated rehabilitation strategies in adults with acute or subacute traumatic SCI at any level. Studies were critically appraised individually and the overall strength of evidence was evaluated using methods proposed by the GRADE (Grades of Recommendation Assessment, Development and Evaluation) working group. Results: The search strategy yielded 384 articles, 19 of which met our inclusion criteria. Based on our results, there was no difference between body weight–supported treadmill training and conventional rehabilitation with respect to improvements in Functional Independence Measure (FIM) Locomotor score, Lower Extremity Motor Scores, the distance walked in 6 minutes or gait velocity over 15.2 m. Functional electrical therapy resulted in slightly better FIM Motor, FIM Self-Care, and Spinal Cord Independence Measure Self-Care subscores compared with conventional occupational therapy. Comparisons using the Toronto Rehabilitation Institute Hand Function Test demonstrated no differences between groups in 7 of 9 domains. There were no clinically important differences in Maximal Lean Test, Maximal Sidewards Reach Test, T-shirt Test, or the Canadian Occupational Performance Measure between unsupported sitting training and standard in-patient rehabilitation. Conclusion: The current evidence base for rehabilitation following acute and subacute spinal cord injury is limited. Methodological challenges have contributed to this and further research is still needed. © 2017, © The Author(s) 2017

Impact of Baseline Magnetic Resonance Imaging on Neurologic, Functional, and Safety Outcomes in Patients With Acute Traumatic Spinal Cord Injury

Study Design: Systematic review. Objective: To perform a systematic review to evaluate the utility of magnetic resonance imaging (MRI) in patients with acute spinal cord injury (SCI). Methods: An electronic search of Medline, EMBASE, the Cochrane Collaboration Library, and Google Scholar was conducted for literature published through May 12, 2015, to answer key questions associated with the use of MRI in patients with acute SCI. Results: The literature search yielded 796 potentially relevant citations, 8 of which were included in this review. One study used MRI in a protocol to decide on early surgical decompression. The MRI-protocol group showed improved outcomes; however, the quality of evidence was deemed very low due to selection bias. Seven studies reported MRI predictors of neurologic or functional outcomes. There was moderate-quality evidence that longer intramedullary hemorrhage (2 studies) and low-quality evidence that smaller spinal canal diameter at the location of maximal spinal cord compression and the presence of cord swelling are associated with poor neurologic recovery. There was moderate-quality evidence that clinical outcomes are not predicted by SCI lesion length and the presence of cord edema. Conclusions: Certain MRI characteristics appear to be predictive of outcomes in acute SCI, including length of intramedullary hemorrhage (moderate-quality evidence), canal diameter at maximal spinal cord compression (low-quality evidence), and spinal cord swelling (low-quality evidence). Other imaging features were either inconsistently (presence of hemorrhage, maximal canal compromise, and edema length) or not associated with outcomes. The paucity of literature highlights the need for well-designed prospective studies. © 2017, © The Author(s) 2017

Using system and user performance features to improve emotion detection in spoken tutoring dialogs

In this study, we incorporate automatically obtained system/user performance features into machine learning experiments to detect student emotion in computer tutoring dialogs. Our results show a relative improvement of 2.7% on classification accuracy and 8.08% on Kappa over using standard lexical, prosodie, sequential, and identification features. This level of improvement is comparable to the performance improvement shown in previous studies by applying dialog acts or lexical/prosodic-/discourse- level contextual features

Efficacy, Safety, and Timing of Anticoagulant Thromboprophylaxis for the Prevention of Venous Thromboembolism in Patients With Acute Spinal Cord Injury: A Systematic Review

Study Design: Systematic review. Objectives: The objective of this study was to answer 5 key questions: What is the comparative effectiveness and safety of (1a) anticoagulant thromboprophylaxis compared to no prophylaxis, placebo, or another anticoagulant strategy for preventing deep vein thrombosis (DVT) and pulmonary embolism (PE) after acute spinal cord injury (SCI)? (1b) Mechanical prophylaxis strategies alone or in combination with other strategies for preventing DVT and PE after acute SCI? (1c) Prophylactic inferior vena cava filter insertion alone or in combination with other strategies for preventing DVT and PE after acute SCI? (2) What is the optimal timing to initiate and/or discontinue anticoagulant, mechanical, and/or prophylactic inferior vena cava filter following acute SCI? (3) What is the cost-effectiveness of these treatment options? Methods: A systematic literature search was conducted to identify studies published through February 28, 2015. We sought randomized controlled trials evaluating efficacy and safety of antithrombotic strategies. Strength of evidence was evaluated using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system. Results: Nine studies satisfied inclusion criteria. We found a trend toward lower risk of DVT in patients treated with enoxaparin. There were no significant differences in rates of DVT, PE, bleeding, and mortality between patients treated with different types of low-molecular-weight heparin or between low-molecular-weight heparin and unfractionated heparin. Combined anticoagulant and mechanical prophylaxis initiated within 72 hours of SCI resulted in lower risk of DVT than treatment commenced after 72 hours of injury. Conclusion: Prophylactic treatments can be used to lower the risk of venous thromboembolic events in patients with acute SCI, without significant increase in risk of bleeding and mortality and should be initiated within 72 hours. © 2017, © The Author(s) 2017

The need for clinical practice guidelines in assessing and managing perioperative neurologic deficit: results from a survey of the AOSpine international community

Objectives: There is no standardized approach to assess and manage perioperative neurologic deficit (PND) in patients undergoing spinal surgery. This survey aimed to evaluate the awareness and usage of clinical practice guidelines (CPGs) as well as investigate how surgeons performing spine surgeries feel about and manage PND, and how they perceive the value of developing CPGs for the management of PND. Methods: An invitation to participate was sent to the AOSpine International community. Questions were related to the awareness, usage of CPGs and demographics. Results from the entire sample and subgroups were analyzed. Results: Of 770 respondents, 659 (85.6%) reported being aware of the existence of guideline(s), and among those, 578 (87.7%) acknowledged using guideline(s). Overall, 58.8% of surgeons reported not feeling comfortable managing a patient who wakes up quadriplegic after an uneventful multilevel posterior cervical decompression with instrumented fusion. While 22.9% would consider an immediate return to the operating room, the other 77.1% favored conducting some kind of investigation/medical intervention first, such as obtaining a MRI (85.9%), administrating high-dose corticosteroids (50.2%) or increasing the MAP (44.7%). Overall, 90.6% of surgeons believed that CPGs for the management of PND would be useful and 94.4% would be either likely or extremely likely to use these CPGs in their clinical practice. Conclusions: The majority of respondents are aware and routinely use CPGs in their practice. Most surgeons performing spine surgeries reported not feeling comfortable managing PND. However, they highly value the creation and are likely to use CPGs in its management

Feasibility of High-Throughput Genome-Wide Genotyping using DNA from Stored Buccal Cell Samples

It is unclear if buccal cell samples contain sufficient human DNA with adequately sized fragments for high throughput genetic bioassays. Yet buccal cell sample collection is an attractive alternative to gathering blood samples for genetic epidemiologists engaged in large-scale genetic biomarker studies. We assessed the genotyping efficiency (GE) and genotyping concordance (GC) of buccal cell DNA samples compared to corresponding blood DNA samples, from 32 Nurses’ Health Study (NHS) participants using the Illumina Infinium 660W-Quad platform. We also assessed how GE and GC accuracy varied as a function of DNA concentration using serial dilutions of buccal DNA samples. Finally we determined the nature and genomic distribution of discordant genotypes in buccal DNA samples. The mean GE of undiluted buccal cell DNA samples was high (99.32%), as was the GC between the paired buccal and blood samples (99.29%). GC between the dilutions versus the undiluted buccal DNA was also very high (greater than 97%), though both GE and GC notably declined at DNA concentrations less than 5 ng/μl. Most (greater than 95%) genotype determinations in buccal cell samples were of the “missing call” variety (as opposed to the “alternative genotype call” variety) across the spectrum of buccal DNA concentrations studied. Finally, for buccal DNA concentration above 1.7 ng/ul, discordant genotyping calls did not cluster in any particular chromosome. Buccal cell-derived DNA represents a viable alternative to blood DNA for genotyping on a high-density platform

Feasibility of High-Throughput Genome-Wide Genotyping using DNA from Stored Buccal Cell Samples

It is unclear if buccal cell samples contain sufficient human DNA with adequately sized fragments for high throughput genetic bioassays. Yet buccal cell sample collection is an attractive alternative to gathering blood samples for genetic epidemiologists engaged in large-scale genetic biomarker studies. We assessed the genotyping efficiency (GE) and genotyping concordance (GC) of buccal cell DNA samples compared to corresponding blood DNA samples, from 32 Nurses’ Health Study (NHS) participants using the Illumina Infinium 660W-Quad platform. We also assessed how GE and GC accuracy varied as a function of DNA concentration using serial dilutions of buccal DNA samples. Finally we determined the nature and genomic distribution of discordant genotypes in buccal DNA samples. The mean GE of undiluted buccal cell DNA samples was high (99.32%), as was the GC between the paired buccal and blood samples (99.29%). GC between the dilutions versus the undiluted buccal DNA was also very high (>97%), though both GE and GC notably declined at DNA concentrations less than 5 ng/μl. Most (>95%) genotype determinations in buccal cell samples were of the “missing call” variety (as opposed to the “alternative genotype call” variety) across the spectrum of buccal DNA concentrations studied. Finally, for buccal DNA concentration above 1.7 ng/ul, discordant genotyping calls did not cluster in any particular chromosome. Buccal cell-derived DNA represents a viable alternative to blood DNA for genotyping on a high-density platform

Healthcare designers’ use of prescriptive and performance-based approaches

In the UK, healthcare built environment design is guided by a series of long-established design standards and guidance issued by the Department of Health. More recently, healthcare design focus has broadened to encompass new approaches, supported by large bodies of credible research evidence. It is therefore timely to rethink how healthcare design standards and guidance should be best expressed to suit ‘designerly ways’ of using evidence, to improve their use and effectiveness in practice. This research explored how designers use performance and prescriptive approaches during the healthcare design process. Three in-depth healthcare built environment case studies were used to explore how designers employed such approaches during the design of selected exemplar design elements. Results show that design elements in the pre and conceptual design phases significantly employed performance-based approaches, and due to project-unique circumstances, prescriptive solutions were often significantly modified based on performance criteria. For design elements in the detailed and technical design phases, there was a significant use of solutions based on prescriptive approaches, whilst performance-based criteria were used to evaluate design solutions. This research proposes a performance-based, specification-driven healthcare design with supplementary prescriptive specifications provided for optimum healthcare environment design