Use of Mechanical Turk as a MapReduce Framework for Macular OCT Segmentation

PURPOSE: To evaluate the feasibility of using Mechanical Turk as a massively parallel platform to perform manual segmentations of macular spectral domain optical coherence tomography (SD-OCT) images using a MapReduce framework. METHODS: A macular SD-OCT volume of 61 slice images was map-distributed to Amazon Mechanical Turk. Each Human Intelligence Task was set to 0.01 and required the user to draw five lines to outline the sublayers of the retinal OCT image after being shown example images. Each image was submitted twice for segmentation, and interrater reliability was calculated. The interface was created using custom HTML5 and JavaScript code, and data analysis was performed using R. An automated pipeline was developed to handle the map and reduce steps of the framework. RESULTS: More than 93,500 data points were collected using this framework for the 61 images submitted. Pearson’s correlation of interrater reliability was 0.995 () and coefficient of determination was 0.991. The cost of segmenting the macular volume was 1.21. A total of 22 individual Mechanical Turk users provided segmentations, each completing an average of 5.5 HITs. Each HIT was completed in an average of 4.43 minutes. CONCLUSIONS: Amazon Mechanical Turk provides a cost-effective, scalable, high-availability infrastructure for manual segmentation of OCT images

The archaeological contribution of forensic craniofacial reconstruction to a portrait drawing of a Korean historical figure

Craniofacial reconstruction (CFR) is a technique used to rebuild the living facial appearance onto a skull in order to recognise or identify an individual. This technique is primarily employed in forensic investigation, but also utilised in archaeological research to recreate the faces of paleontological and archaeological humans. In this study, the face of a 17th century historical figure from Korea was reconstructed utilising computerized tomography from the mummified remains. A geographic surface comparison programme was employed to evaluate the accuracy of the CFR produced using a three-dimensional computerized modelling system. Analysis of the facial tissue depth discrepancies demonstrated that the CFR may have acceptable resemblance to the living face of the historical individual. Using computerised graphic technology, the CFR outcome, along with the archaeological information about the hair style, ornaments, and dress discovered in the tomb, a portrait-styled in the typical drawing trend from the era was created. The research suggests that current CFR techniques can provide an accurate portrait drawing of historical figures in Korea

A systematic review on the anxiolytic effects of aromatherapy in people with anxiety symptoms

Purpose: We reviewed studies from 1990 to 2010 on using aromatherapy for people with anxiety or anxiety symptoms and examined their clinical effects. Methods: The review was conducted on available electronic databases to extract journal articles that evaluated the anxiolytic effects of aromatherapy for people with anxiety symptoms. Results: The results were based on 16 randomized controlled trials examining the anxiolytic effects of aromatherapy among people with anxiety symptoms. Most of the studies indicated positive effects to quell anxiety. No adverse events were reported. Conclusions: It is recommended that aromatherapy could be applied as a complementary therapy for people with anxiety symptoms. Further studies with better quality on methodology should be conducted to identify its clinical effects and the underlying biologic mechanisms. © 2011, Mary Ann Liebert, Inc.published_or_final_versio

Cost-effectiveness of age-related macular degeneration study supplements in the UK: combined trial and real-world outcomes data

Aims To evaluate the cost-effectiveness of Age-Related Eye Disease Study (AREDS) 1 & 2 supplements in patients with either bilateral intermediate age-related macular degeneration, AREDS category 3, or unilateral neovascular age-related macular degeneration AMD (nAMD), AREDS category 4. Methods A patient-level health state transition model based on levels of visual acuity in the better-seeing eye was constructed to simulate the costs and consequences of patients taking AREDS vitamin supplements. Setting: UK National Health Service (NHS). The model was populated with data from AREDS and real-world outcomes and resource use from a prospective multicentre national nAMD database study containing 92 976 ranibizumab treatment episodes. Interventions Two treatment approaches were compared: immediate intervention with AREDS supplements or no supplements. Main outcome measures: quality-adjusted life years (QALYs) and healthcare costs were accrued for each strategy, and incremental costs and QALYs were calculated for the lifetime of the patient. One-way and probabilistic sensitivity analyses were employed to test the uncertainty of the model. Results For AREDS category 3, the incremental cost-effectiveness ratio was £30 197. For AREDS category 4 compared with no intervention, AREDS supplements are more effective (10.59 vs 10.43 QALYs) and less costly (£52 074 vs 54 900) over the lifetime of the patient. Conclusions The recommendation to publicly fund AREDS supplements to category 3 patients would depend on the healthcare system willingness to pay. In contrast, initiating AREDS supplements in AREDS category 4 patients is both cost saving and more effective than no supplement use and should therefore be considered in public health policy

Cathodal Transcranial Direct Current Stimulation Over Left Dorsolateral Prefrontal Cortex Area Promotes Implicit Motor Learning in a Golf Putting Task.

© 2015 Elsevier Inc. All rights reserved. Background Implicit motor learning is characterized by low dependence on working memory and stable performance despite stress, fatigue, or multi-tasking. However, current paradigms for implicit motor learning are based on behavioral interventions that are often task-specific and limited when applied in practice. Objective To investigate whether cathodal transcranial direct current stimulation (tDCS) over the left dorsolateral prefrontal cortex (DLPFC) area during motor learning suppressed working memory activity and reduced explicit verbal-analytical involvement in movement control, thereby promoting implicit motor learning. Methods Twenty-seven healthy individuals practiced a golf putting task during a Training Phase while receiving either real cathodal tDCS stimulation over the left DLPFC area or sham stimulation. Their performance was assessed during a Test phase on another day. Verbal working memory capacity was assessed before and after the Training Phase, and before the Test Phase. Results Compared to sham stimulation, real stimulation suppressed verbal working memory activity after the Training Phase, but enhanced golf putting performance during the Training Phase and the Test Phase, especially when participants were required to multi-task. Conclusion Cathodal tDCS over the left DLPFC may foster implicit motor learning and performance in complex real-life motor tasks that occur during sports, surgery or motor rehabilitation

Sensor Fabrication Method for in Situ Temperature and Humidity Monitoring of Light Emitting Diodes

In this work micro temperature and humidity sensors are fabricated to measure the junction temperature and humidity of light emitting diodes (LED). The junction temperature is frequently measured using thermal resistance measurement technology. The weakness of this method is that the timing of data capture is not regulated by any standard. This investigation develops a device that can stably and continually measure temperature and humidity. The device is light-weight and can monitor junction temperature and humidity in real time. Using micro-electro-mechanical systems (MEMS), this study minimizes the size of the micro temperature and humidity sensors, which are constructed on a stainless steel foil substrate (40 μm-thick SS-304). The micro temperature and humidity sensors can be fixed between the LED chip and frame. The sensitivities of the micro temperature and humidity sensors are 0.06 ± 0.005 (Ω/°C) and 0.033 pF/%RH, respectively

Escort Evolutionary Game Theory

A family of replicator-like dynamics, called the escort replicator equation, is constructed using information-geometric concepts and generalized information entropies and diverenges from statistical thermodynamics. Lyapunov functions and escort generalizations of basic concepts and constructions in evolutionary game theory are given, such as an escorted Fisher's Fundamental theorem and generalizations of the Shahshahani geometry.Comment: Minor typo correctio

Sequence Variations of Full-Length Hepatitis B Virus Genomes in Chinese Patients with HBsAg-Negative Hepatitis B Infection

BACKGROUND: The underlying mechanism of HBsAg-negative hepatitis B virus (HBV) infection is notoriously difficult to elucidate because of the extremely low DNA levels which define the condition. We used a highly efficient amplification method to overcome this obstacle and achieved our aim which was to identify specific mutations or sequence variations associated with this entity. METHODS: A total of 185 sera and 60 liver biopsies from HBsAg-negative, HBV DNA-positive subjects or known chronic hepatitis B (CHB) subjects with HBsAg seroclearance were amplified by rolling circle amplification followed by full-length HBV genome sequencing. Eleven HBsAg-positive CHB subjects were included as controls. The effects of pivotal mutations identified on regulatory regions on promoter activities were analyzed. RESULTS: 22 and 11 full-length HBV genomes were amplified from HBsAg-negative and control subjects respectively. HBV genotype C was the dominant strain. A higher mutation frequency was observed in HBsAg-negative subjects than controls, irrespective of genotype. The nucleotide diversity over the entire HBV genome was significantly higher in HBsAg-negative subjects compared with controls (p = 0.008) and compared with 49 reference sequences from CHB patients (p = 0.025). In addition, HBsAg-negative subjects had significantly higher amino acid substitutions in the four viral genes than controls (all p<0.001). Many mutations were uniquely found in HBsAg-negative subjects, including deletions in promoter regions (13.6%), abolishment of pre-S2/S start codon (18.2%), disruption of pre-S2/S mRNA splicing site (4.5%), nucleotide duplications (9.1%), and missense mutations in "alpha" determinant region, contributing to defects in HBsAg production. CONCLUSIONS: These data suggest an accumulation of multiple mutations constraining viral transcriptional activities contribute to HBsAg-negativity in HBV infection.published_or_final_versio

Extended RDF: Computability and Complexity Issues

ERDF stable model semantics is a recently proposed semantics for ERDF ontologies and a faithful extension of RDFS semantics on RDF graphs. In this paper, we elaborate on the computability and complexity issues of the ERDF stable model semantics. Based on the undecidability result of ERDF stable model semantics, decidability under this semantics cannot be achieved, unless ERDF ontologies of restricted syntax are considered. Therefore, we propose a slightly modified semantics for ERDF ontologies, called ERDF #n- stable model semantics. We show that entailment under this semantics is, in general, decidable and also extends RDFS entailment. Equivalence statements between the two semantics are provided. Additionally, we provide algorithms that compute the ERDF #n-stable models of syntax-restricted and general ERDF ontologies. Further, we provide complexity results for the ERDF #nstable model semantics on syntax-restricted and general ERDF ontologies. Finally, we provide complexity results for the ERDF stable model semantics on syntax-restricted ERDF ontologies