LLukas22/scidocs huggingface dataset:
Inducing High-Level Behaviors from Problem-Solving Traces Using Machine-Learning Tools

Many researchers consider interactive learning environments to be interesting solutions for overcoming the limits of classical one-to-many teaching methods. However, these environments should incorporate accurate representations of student knowledge to provide relevant guidance. In a problem-solving environment, one way to build and update this student model is model tracing, or using a detailed representation of cognitive skills to precisely follow what the student is doing. Some model-tracing tutors such as PAT (Personal Algebra Tutor) contain rules that the system can use to solve the problem and assess the student's solution.
Automation in Aviation

An aircraft landed safely is the result of a huge organizational effort required to cope with a complex system made up of humans, technology and the environment. The aviation safety record has improved dramatically over the years to reach an unprecedented low in terms of accidents per million take-offs, without ever achieving the “zero accident” target. The introduction of automation on board airplanes must be acknowledged as one of the driving forces behind the decline in the accident rate down to the current level.
Flow : The Psychology of Optimal Experience

BOOK REVIEW: Csikszentmihalyi, M. (2008). Flow: The Psychology of Optimal Experience. New York, NY: HarperCollins. 336 pp. ISBN 978-0-06-133920-2.
Biomarkers of body iron stores and risk of developing type 2 diabetes.

AIM
Iron may contribute to the pathogenesis of type 2 diabetes mellitus (DM) by inducing oxidative stress and interfering with insulin secretion. Elevated ferritin levels are associated with increased DM risk among healthy individuals. However, it is yet unknown if ferritin predicts DM incidence among high-risk individuals with impaired glucose tolerance (IGT). Furthermore, the association between soluble transferrin receptors (sTfR), a novel marker of iron status, and DM risk has not yet been prospectively investigated in these individuals. We conducted this study to evaluate the association between baseline levels of ferritin and sTfR and the risk of developing DM among overweight and obese individuals at high risk of DM.


METHODS
This nested case-control study (280 cases and 280 matched controls) was conducted within the placebo arm of the Diabetes Prevention Program, is a clinical trial conducted among overweight/obese individuals with IGT. Ferritin and sTfR levels were measured by immunoturbidimetric assays. Incident DM was ascertained by annual 75-g oral glucose tolerance test and semi-annual fasting glucose.


RESULTS
Compared with controls, cases had higher sTfR levels (3.50 +/- 0.07 vs. 3.30 +/- 0.06 mg/l; p = 0.03), but ferritin levels were not statistically different. The multivariable odds ratios (OR) and 95% confidence intervals (95% CI) for DM incidence comparing highest with the lowest quartiles of sTfR was 2.26 (1.37-4.01) (p-trend: 0.008).


CONCLUSIONS
Modestly elevated sTfR levels are associated with increased DM risk among overweight and obese individuals with IGT. Future studies should evaluate factors determining sTfR levels and examine if interventions that lower body iron stores reduce DM incidence.
Shape Deformation in Two-Dimensional Electrical Impedance Tomography

Electrical impedance tomography (EIT) uses measurements from surface electrodes to reconstruct an image of the conductivity of the contained medium. However, changes in measurements result from both changes in internal conductivity and changes in the shape of the medium relative to the electrode positions. Failure to account for shape changes results in a conductivity image with significant artifacts. Previous work to address shape changes in EIT has shown that in some cases boundary shape and electrode location can be uniquely determined for isotropic conductivities; however, for geometrically conformal changes, this is not possible. This prior work has shown that the shape change problem can be partially addressed. In this paper, we explore the limits of compensation for boundary movement in EIT using three approaches. First, a theoretical model was developed to separate a deformation vector field into conformal and non-conformal components, from which the reconstruction limits may be determined. Next, finite element models were used to simulate EIT measurements from a domain whose boundary has been deformed. Finally, an experimental phantom was constructed from which boundary deformation measurements were acquired. Results, both in simulation and with experimental data, suggest that some electrode movement and boundary distortions can be reconstructed based on conductivity changes alone while reducing image artifacts in the process.
Liver transplantation in the Nordic countries – An intention to treat and post-transplant analysis from The Nordic Liver Transplant Registry 1982–2013

AIM AND BACKGROUND
The Nordic Liver Transplant Registry (NLTR) accounts for all liver transplants performed in the Nordic countries since the start of the transplant program in 1982. Due to short waiting times, donor liver allocation has been made without considerations of the model of end-stage liver disease (MELD) score. We aimed to summarize key outcome measures and developments for the activity up to December 2013.


MATERIALS AND METHODS
The registry is integrated with the operational waiting-list and liver allocation system of Scandiatransplant (www.scandiatransplant.org) and accounted at the end of 2013 for 6019 patients out of whom 5198 were transplanted. Data for recipient and donor characteristics and relevant end-points retransplantation and death are manually curated on an annual basis to allow for statistical analysis and the annual report.


RESULTS
Primary sclerosing cholangitis, acute hepatic failure, alcoholic liver disease, primary biliary cirrhosis and hepatocellular carcinoma are the five most frequent diagnoses (accounting for 15.3%, 10.8%, 10.6%, 9.3% and 9.0% of all transplants, respectively). Median waiting time for non-urgent liver transplantation during the last 10-year period was 39 days. Outcome has improved over time, and for patients transplanted during 2004-2013, overall one-, five- and 10-year survival rates were 91%, 80% and 71%, respectively. In an intention-to-treat analysis, corresponding numbers during the same time period were 87%, 75% and 66%, respectively.


CONCLUSION
The liver transplant program in the Nordic countries provides comparable outcomes to programs with a MELD-based donor liver allocation system. Unique features comprise the diagnostic spectrum, waiting times and the availability of an integrated waiting list and transplant registry (NLTR).
Antenatal magnesium sulfate exposure and acute cardiorespiratory events in preterm infants.

OBJECTIVE
Antenatal magnesium (anteMg) is used for various obstetric indications including fetal neuroprotection. Infants exposed to anteMg may be at risk for respiratory depression and delivery room (DR) resuscitation. The study objective was to compare the risk of acute cardiorespiratory events among preterm infants who were and were not exposed to anteMg.


STUDY DESIGN
This was a retrospective analysis of prospective data collected in the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network's Generic Database from April 1, 2011, through March 31, 2012. The primary outcome was DR intubation or respiratory support at birth or on day 1 of life. Secondary outcomes were invasive mechanical ventilation, hypotension treatment, neonatal morbidities, and mortality. Logistic regression analysis evaluated the risk of primary outcome after adjustment for covariates.


RESULTS
We evaluated 1544 infants <29 weeks' gestational age (1091 in anteMg group and 453 in nonexposed group). Mothers in the anteMg group were more likely to have higher education, pregnancy-induced hypertension, and antenatal corticosteroids, while their infants were younger in gestation and weighed less (P < .05). The primary outcome (odds ratio [OR], 1.2; 95% confidence interval [CI], 0.88-1.65) was similar between groups. Hypotension treatment (OR, 0.70; 95% CI, 0.51-0.97) and invasive mechanical ventilation (OR, 0.54; 95% CI, 0.41-0.72) were significantly less in the anteMg group.


CONCLUSION
Among preterm infants age <29 weeks' gestation, anteMg exposure was not associated with an increase in cardiorespiratory events in the early newborn period. The safety of anteMg as measured by the need for DR intubation or respiratory support on day 1 of life was comparable between groups.
Learning multi-label scene classification

In classic pattern recognition problems, classes are mutually exclusive by de"nition. Classi"cation errors occur when the classes overlap in the feature space. We examine a di5erent situation, occurring when the classes are, by de"nition, not mutually exclusive. Such problems arise in semantic scene and document classi"cation and in medical diagnosis. We present a framework to handle such problems and apply it to the problem of semantic scene classi"cation, where a natural scene may contain multiple objects such that the scene can be described by multiple class labels (e.g., a "eld scene with a mountain in the background). Such a problem poses challenges to the classic pattern recognition paradigm and demands a di5erent treatment. We discuss approaches for training and testing in this scenario and introduce new metrics for evaluating individual examples, class recall and precision, and overall accuracy. Experiments show that our methods are suitable for scene classi"cation; furthermore, our work appears to generalize to other classi"cation problems of the same nature. ? 2004 Pattern Recognition Society. Published by Elsevier Ltd. All rights reserved.
Transfer learning in heterogeneous collaborative filtering domains

Article history: Received 6 December 2010 Received in revised form 6 December 2012 Accepted 12 January 2013 Available online 11 February 2013
Data Mining in Library Reader Management

Data mining technology has been applied to library management. In this paper, Boustead College Library Information Management System in the history of circulation records, the reader information and collections as a data source, using the Microsoft SQL Server 2005 as a data mining tool, applying data mining algorithm as cluster, association rules and time series to identify characteristics of the reader to borrow in order to achieve individual service.
Modelling of gyro in an IR seeker for real-time simulation

The target tracking system of an IR (InfraRed) guided missile is constantly subjected to disturbances due to the linear and angular motion of the missile. To diminish these LOS (Line Of Sight) disturbances the seeker of the missile can be built from a free gyroscope mounted in a very low friction suspension. The ability of the spinning gyroscope to maintain its direction relative to an inertial frame is used to stabilize the seeker LOS while tracking a target. The tracking velocity of the seeker, i.e. its angular velocity, is controlled by a feedback control unit where the signal from the IR detector is used as input. The electrical driven actuator consists of a set of coils and a magnet on the gyroscope. The purpose of this thesis is to develop a real-time model of the seeker gyroscope in an existing IR MANPAD (MAN Portable Air Defense) missile. The aim is a model that is able to simulate the real system with consideration to the tracking velocity. The model should also be integrated into a hybrid simulator environment. With relatively good knowledge of the system and its subsystems an initial physical modelling approach was used where elementary equations and accepted relations were assembled to describe the mechanism of the subsystems. This formed the framework of the model and gave a good foundation for further modelling. By using experimentation and more detailed system knowledge the initial approach could be developed and modified. Necessary approximations were made and unknown parameters were determined through system identification methods. The model was implemented in MATLAB Simulink . To make it suitable for realtime operation Real-Time Workshop was used. The model design was evaluated in simulations where the tracking performance could be tested for different positions of the gyroscope. The results where satisfying and showed that the model was able to reproduce the output of the system well considering the speed of the model and the approximations made. One important reason that good results can be achieved with a relatively simple model is that the seeker is limited to small rotations. The model can be tuned to operate in a smaller range and the complexity can be kept low. A weakness of the model is that the output error increases for wide angles.
Transition to Agile Development - Rediscovery of Important Requirements Engineering Practices

Many organizations have started to use agile development processes to speed up the development cycle and to improve the ability of the company in reacting to changing requirements. Adopting agile practices may happen as a revolution where all old practices are removed or as a more gradual process. In this paper, we discuss lessons learnt in two agile transition processes. Based on our experience, agile processes can be used in embedded software development for products. The challenges include the varying size of user requirements, the role of system requirements, and architecturally significant requirements. It is difficult for large organizations to be agile. Work allocation for a large number of different teams with different competencies tends to decrease speed, and increase the role of design and management. We conclude that agile development in this context needs very skilled developers and has to be a combination of new and old practices.
Percutaneous Transluminal Angioplasty and Drug-Eluting Stents for Infrapopliteal Lesions in Critical Limb Ischemia (PADI) Trial

BACKGROUND
Endovascular infrapopliteal treatment of patients with critical limb ischemia using percutaneous transluminal angioplasty (PTA) and bail-out bare metal stenting (BMS) is hampered by restenosis. In interventional cardiology, drug-eluting stents (DES) have shown better patency rates and are standard practice nowadays. An investigator-initiated, multicenter, randomized trial was conducted to assess whether DES also improve patency and clinical outcome of infrapopliteal lesions.


METHODS AND RESULTS
Adults with critical limb ischemia (Rutherford category ≥4) and infrapopliteal lesions were randomized to receive PTA±BMS or DES with paclitaxel. Primary end point was 6-month primary binary patency of treated lesions, defined as ≤50% stenosis on computed tomographic angiography. Stenosis >50%, retreatment, major amputation, and critical limb ischemia-related death were regarded as treatment failure. Severity of failure was assessed with an ordinal score, ranging from vessel stenosis through occlusion to the clinical failures. Seventy-four limbs (73 patients) were treated with DES and 66 limbs (64 patients) received PTA±BMS. Six-month patency rates were 48.0% for DES and 35.1% for PTA±BMS (P=0.096) in the modified-intention-to-treat and 51.9% and 35.1% (P=0.037) in the per-protocol analysis. The ordinal score showed significantly worse treatment failure for PTA±BMS versus DES (P=0.041). The observed major amputation rate remained lower in the DES group until 2 years post-treatment, with a trend toward significance (P=0.066). Less minor amputations occurred after DES until 6 months post-treatment (P=0.03).


CONCLUSIONS
In patients with critical limb ischemia caused by infrapopliteal lesions, DES provide better 6-month patency rates and less amputations after 6 and 12 months compared with PTA±BMS.


CLINICAL TRIAL REGISTRATION
URL: http://www.clinicaltrials.gov. Unique identifier: NCT00471289.
Closed Form Valuation of American Barrier Options

Closed form formulae for European barrier options are well known from the literature. This is not the case for American barrier options, for which no closed form formulae have been published. One has therefore had to resort to numerical methods. Using lattice models like a binomial or a trinomial tree for valuation of barrier options is known to converge extremely slowly, compared to plain vanilla options. Methods for improving the algorithms have been described by several authors. However, these are still numerical methods that are quite computer intensive. In this paper we show how American barrier options can be valued analytically in a very simple way. This speeds up the valuation dramatically as well as give new insight into barrier option valuation. 1 Analytical valuation of American barrier options Closed form solutions and valuation techniques for standard European barrier options are well known from the literature, see for instance (Merton 1973, Reiner and Rubinstein 1991, Rich 1994, Haug 1997). No closed form solution for American barrier options exists in the extant literature. The technique used to value American barrier options have therefore been numerical methods. Lattice models have been especially popular. Without doing any adjustments lattice models have been shown to convergence extremely slowly. Several methods have been published to improve on the technique (Boyle and Lau 1994, Ritchken 1994, Derman, Bardhan, Ergener, and Kani 1995), but the method is still quite computer intensive. In the present paper we suggest an analytical solution. This o ers both to speed up the valuation process and it gives new insight into the valuation of barrier options. We limit ourselves to assume that the underlying asset follows a geometric Brownian motion without drift in the risk adjusted economy (i.e., we consider the process after an appropriate change of probability measure). Futures and forwards contracts are examples of underlying securities that satisfy this restriction.
Associative learning predicts intelligence above and beyond working memory and processing speed

Article history: Received 25 April 2008 Received in revised form 16 February 2009 Accepted 16 March 2009 Available online 9 April 2009 Recent evidence suggests the existence of multiple cognitive mechanisms that support the general cognitive ability factor (g). Working memory and processing speed are the two best established candidate mechanisms. Relatively little attention has been given to the possibility that associative learning is an additional mechanism contributing to g. The present study tested the hypothesis that associative learning ability, as assessed by psychometrically sound associative learning tasks, would predict variance in g above and beyond the variance predicted byworkingmemory capacity and processing speed. This hypothesis was confirmed in a sample of 169 adolescents, using structural equation modeling. Associative learning, working memory, and processing speed all contributed significant unique variance to g, indicating not only that multiple elementary cognitive processes underlie intelligence, but also the novel finding that associative learning is one such process. © 2009 Elsevier Inc. All rights reserved.
Radon release from underground strata to the surface and uniaxial compressive test of rock samples

The mechanism and critical conditions of rock failure in underground coal mining processes have attracted great attention. Based on the origin and properties of radon gas, we propose that radon release from underground strata to the surface occurs in two stages, i.e., the formation of free radon and the migration of radon gas. Due to its optimal combination of efficiency and low background measurements, the α-ray measurement was employed to measure radon gas from rock fracturing. The uniaxial compression of rock samples and the concentrations of radon emanating from the loaded samples were experimentally investigated. The results revealed that radon concentrations are negatively related to uniaxial loads and elastic deformations, provided compressive failures are not observed. As the loads increase, the stabilization duration and internal porosity of rock samples get decrease, which result in reduced radon emanation. When the load gets more than the limit strength of rock samples, the radon concentrations increase significantly and eventually reach the maximum value, and then slightly decrease and approximately tend to be stable. Finally, a preliminary correlation between the complete stressstrain process of uniaxial loaded rock samples and the concentration of radon emanated was presented, which needs further experimental validations. Even so, we believe that the failure mechanisms of mining-induced overburdens could be investigated based on radon gas concentrations. ARTICLE INFO
Grading Aortic Stenosis With Mean Gradient and Aortic Valve Area: A Comparison Between Preoperative Transthoracic and Precardiopulmonary Bypass Transesophageal Echocardiography.

OBJECTIVE
The authors hypothesized that average precardiopulmonary bypass (pre-CPB) transesophageal echocardiographic (TEE) mean gradient (PGm) and aortic valve area (AVA) values would be significantly different from preoperative transthoracic (TTE) values in the same patients and that these changes would affect pre-CPB TEE grading of aortic stenosis (AS).


DESIGN
Retrospective, observational design.


SETTING
Single university hospital.


PARTICIPANTS
The study comprised 92 patients who underwent aortic valve replacement with or without coronary artery bypass grafting between 2000 and 2012 at Duke University Hospital and who had PGm and AVA values recorded in both pre-CPB TEE and preoperative TTE reporting databases.


INTERVENTIONS
None.


MEASUREMENTS AND MAIN RESULTS
PGm with pre-CPB TEE was lower by 6.6 mmHg (95% confidence interval, -4.0 to -9.3 mmHg; p<0.001), whereas AVA was higher by 0.10 cm(2) (95% confidence interval, 0.04 to 0.15 cm(2); p<0.001), compared with preoperative TTE values. When using PGm, pre-CPB TEE generated an AS severity 1 grade lower 39.1% of the time and revealed no difference 55.4% of the time compared to preoperative TTE. When using AVA by continuity, pre-CPB TEE generated an AS severity 1 grade lower 14.1% of the time and revealed no difference 81.5% of the time compared to preoperative TTE. When using either PGm or AVA, preoperative TTE exhibited moderate or severe AS for all study patients, whereas, pre-CPB TEE demonstrated mild AS in 5.4% (n = 92) of patients.


CONCLUSIONS
The authors confirmed their hypothesis that pre-CPB TEE generates different PGm and AVA values compared with preoperative TTE. These differences often underestimate AS severity. Hemodynamic standardizations or adjustments of pre-CPB TEE PGm and AVA values may be necessary in anesthetized patients before assigning an AS grade using these parameters.