Enhancing the learning experience- Use of video game technology for teaching Japanese language

The Japanese language is challenging to learn, especially for native speakers of Indo- European languages. The three components of written Japanese -- Hiragana, Katakana, and Kanji – include 2,136 Kanji characters, and 46 each for Katakana and Hiragana. Teaching Japanese – generally through repetition – can lead to student boredom and affect success. Research shows that video games can at least provide a more enjoyable learning experience. Despite this fact, there are a lack of video games for teaching Japanese characters. Using the Unity game engine and the C# programming language, a video game for enhancing the learning of students studying Japanese as a second language was created. Users must identify the Japanese characters as they trickle from top to bottom on the screen. The more times the user identifies a particular Japanese character, the less that character will appear. The reverse applies to incorrect answers – the character will appear more often. This is a key learning technique as the user is forced to repeat those characters he/she does not know. This project demonstrates that the dearth of available, effective video games to complement foreign language learning can be overcome. Basic programming skills combined with some creative design, and a strong desire to help others learn, can result in simple but effective video games. The interactive experience will certainly improve students’ ability to learn this challenging language

Closed-loop CFD Model of the Self-Powered Fontan Circulation for the Hypoplastic Left Heart Syndrome

The Fontan operation is the definitive step in creating a compatible circulation in SV patients. This type of procedure may fail due to the known decrease survival rate, and the inability of the systemic venous blood to pass through the lungs, which leads to further complications in the patient. To improve the Fontan circulation an injection jet shunt (IJS) from the single ventricle to the Fontan pulmonary arteries, is incorporated into the closed-loop circulation model to determine if the energy and momentum will effectively be transferred to the pulmonary artery circulation. Using ANSYS Fluent two models, a baseline and an IJS model, were compared in a steady state solution to determine the effectiveness of the IJS velocity outflow and energy transfer. After the analysis was performed it was determined that a vacuum pressure is created at the exit of the IJS, and that indeed the energy and momentum transfer to the pulmonary arteries, improves the Fontan circulation

Characteristics of patients surviving more than ten years after cardiac transplantation

AbstractThe clinical status and quality of life of 40 patients who lived or are still alive more than 10 years after transplantation at our institution were reviewed with the use of our transplant database, prospective patient examinations, cardiac catheterization, and exercise testing. Patient-perceived health status was determined with use of the Nottingham Health Profile and General Well Being examinations. Factors associated with longevity were determined by a Cox proportional hazards model. Twenty-six patients are alive and 14 have died. The mean age at transplant was 32.4 ± 12 years and the current age (or age at death) is 46.1 ± 12.8 years. Actuarial freedom from rejection was similar to that of patients surviving less than 10 years (p = 0.8), but freedom from all types of infection was less (p = 0.005). Immunosuppressive drugs include cyclosporine (11/26 patients), azathioprine (24/26), and prednisone (26/26, mean dose 12.7 mg/day). Catheterization hemodynamic data show well-preserved graft function at a mean follow-up of 11.7 ± 3.3 years. Graft coronary artery disease prevalence is 51.0% ± 8%. Exercise test results are as follows: duration 8.7 ± 3.5 minutes (range 2 to 16 minutes), maximum heart rate/expected rate 77.3% ± 11% (50% to 92%), maximum systolic blood pressure 171 ± 23 mm Hg (140 to 208 mm Hg), and metabolic equivalents 9.2 ± 2.3 units (5.5 to 12.9 units), or about 84% of predicted. Mean score on the General Well Being examination was 75.3 ± 21.6 (normal). Nottingham Health Profile scores were nearly normal, except for in the 50- to 64-year-old age group in categories of mobility, pain, sleep quality, and energy level. Causes of death were coronary artery disease in 7 of 14, infection in 4 of 14, lymphoma in 1 of 14, and nonlymphoid cancer in 2 of 14. In the Cox regression, variables most associated with survival t > 2.0, multivariate p = 0.0005) were age at transplantation (t = 3.26), preoperative duration of illness (t = 3.57), postoperative cytomegalovirus infection ( t = 2.16), and ejection fraction at 12 months after operation (t = -2.62). We conclude that cardiac transplantation can provide patients with end-stage cardiac failure an acceptable general medical condition, functional status, and perceived quality of life well into the second decade after operation. (J T HORAC C ARDIOVASC S URG 1995;109:1103-15

Computational Fluid Dynamics in Congenital Heart Disease

Computational fluid dynamics has been applied to the design, refinement, and assessment of surgical procedures and medical devices. This tool calculates flow patterns and pressure changes within a virtual model of the cardiovascular system. In the field of paediatric cardiac surgery, computational fluid dynamics is being used to elucidate the optimal approach to staged reconstruction of specific defects and study the haemodynamics of the resulting anatomical configurations after reconstructive or palliative surgery. In this paper, we review the techniques and principal findings of computational fluid dynamics studies as applied to a few representative forms of congenital heart disease

Interpretation of Binary Pulsar Observations

The nature, dynamics and evolution of the three known radio pulsar binaries are discussed. The system containing 1913+16 appears to comprise two ~1.4 M⊙ components, and to undergo orbital decay as predicted by general relativity. It is proposed that 1913+16 has a neutron star companion and that 0655+64 and 0820+02 have white dwarf companions which should be observable optically

Evaluation of Stent and Baffle Deformation in Hybrid Comprehensive Stage II Procedure

Introduction: Hypoplastic Left Heart Syndrome (HLHS) is a Congenital Heart Disease (CHD) that leads to a single ventricle circulation (SV). The existing three-stage palliative operation leads to 50% survival rates. To reduce the morbidity and mortality rate associated with the procedure, an alternative technique called Hybrid Comprehensive Stage II (HCSII) featuring the inclusion of a stent and baffle in the left and right pulmonary arteries shown is proposed. The included stent included has the potential to become fractured as a result of oscillatory asymmetric external loads. Materials and Methods: A dynamically-scaled mock flow loop (MFL) study of HCSII shows the effects of fluid pressure on the stent and baffle to infer long term complications validated with numerical simulations. The MFL includes a patient-specific 3D printed model of the reconstructed anatomy, incorporating an intra-pulmonary baffle graft and a stent. Through the inclusion of the digital video otoscope DE500, videos of the stent and baffle are captured and post-processed to determine baffle displacement during the systolic and diastolic phases. Stent deformation is quantified using Scanning Electron Microscope (SEM).Experimental results are cross-validated, using finite element analysis done in Abaqus. Results and Discussion: The displacement of the baffle is tracked in three different locations throughout the cycles. Between peak systole to peak diastole, the computed baffle displacement for each tracked location, based on the processed image data, is 38, 4 and 6 pixels respectively. Conclusions: For 10 cycles, the stent and the baffle deformations are small. Results indicate the left and right pulmonary flow remain unobstructed despite cyclic deformation of the baffle, hence the likelihood of patient death due to total pulmonary obstruction following stent collapse is low

Core Formation in Giant Gaseous Protoplanets

Sedimentation rates of silicate grains in gas giant protoplanets formed by disk instability are calculated for protoplanetary masses between 1 M_Saturn to 10 M_Jupiter. Giant protoplanets with masses of 5 M_Jupiter or larger are found to be too hot for grain sedimentation to form a silicate core. Smaller protoplanets are cold enough to allow grain settling and core formation. Grain sedimentation and core formation occur in the low mass protoplanets because of their slow contraction rate and low internal temperature. It is predicted that massive giant planets will not have cores, while smaller planets will have small rocky cores whose masses depend on the planetary mass, the amount of solids within the body, and the disk environment. The protoplanets are found to be too hot to allow the existence of icy grains, and therefore the cores are predicted not to contain any ices. It is suggested that the atmospheres of low mass giant planets are depleted in refractory elements compared with the atmospheres of more massive planets. These predictions provide a test of the disk instability model of gas giant planet formation. The core masses of Jupiter and Saturn were found to be ~0.25 M_Earth and ~0.5 M_Earth, respectively. The core masses of Jupiter and Saturn can be substantially larger if planetesimal accretion is included. The final core mass will depend on planetesimal size, the time at which planetesimals are formed, and the size distribution of the material added to the protoplanet. Jupiter's core mass can vary from 2 to 12 M_Earth. Saturn's core mass is found to be ~8 M_Earth.Comment: Accepted for publication in Icaru

Metallicity of the Massive Protoplanets Around HR 8799 If Formed by Gravitational Instability

The final composition of giant planets formed as a result of gravitational instability in the disk gas depends on their ability to capture solid material (planetesimals) during their 'pre-collapse' stage, when they are extended and cold, and contracting quasi-statically. The duration of the pre-collapse stage is inversely proportional roughly to the square of the planetary mass, so massive protoplanets have shorter pre-collapse timescales and therefore limited opportunity for planetesimal capture. The available accretion time for protoplanets with masses of 3, 5, 7, and 10 Jupiter masses is found to be 7.82E4, 2.62E4, 1.17E4 and 5.67E3 years, respectively. The total mass that can be captured by the protoplanets depends on the planetary mass, planetesimal size, the radial distance of the protoplanet from the parent star, and the local solid surface density. We consider three radial distances, 24, 38, and 68 AU, similar to the radial distances of the planets in the system HR 8799, and estimate the mass of heavy elements that can be accreted. We find that for the planetary masses usually adopted for the HR 8799 system, the amount of heavy elements accreted by the planets is small, leaving them with nearly stellar compositions.Comment: accepted for publication in Icaru

Computational Analysis of Hybrid Norwood Circulation with Distal Aortic Arch Obstruction and Reverse Blalock-Taussig Shunt

BACKGROUND: The hemodynamics characteristics of the hybrid Norwood (HN) procedure differ from those of the conventional Norwood and are not fully understood. We present a multi-scale model of HN circulation to understand local hemodynamics and effects of aortic arch stenosis and a reverse Blalock-Taussig shunt (RBTS) on coronary and carotid perfusion. METHODS: Four 3-dimensional models of four HN anatomic variants were developed, with and without 90% distal preductal arch stenosis and with and without a 4-mm RBTS. A lumped parameter model of the circulation was coupled to a local 3-dimensional computational fluid dynamics model. Outputs from the lumped parameter model provided waveform boundary conditions for the computational fluid dynamics model. RESULTS: A 90% distal arch stenosis reduced pressure and net flow-rate through the coronary and carotid arteries by 30%. Addition of the RBTS completely restored pressure and flow rate to baseline in these vessels. Zones of flow stagnation, flow reversal, and recirculation in the presence of stenosis were rendered more orderly by addition of the RBTS. In the absence of stenosis, presence of the shunt resulted in extensive zones of disturbed flow within the RBTS and arch. CONCLUSIONS: We found that a 4-mm × 21-mm RBTS completely compensated for the effects of a 90% discrete stenosis of the distal aortic arch in the HN. Placed preventatively, the RBTS and arch displayed zones with thrombogenic potential showing recirculation and stagnation that persist for a substantial fraction of the cardiac cycle, indicating that anticoagulation should be considered with a prophylactic RBTS

Emission-line profile modelling of structured T Tauri magnetospheres

We present hydrogen emission line profile models of magnetospheric accretion onto Classical T Tauri stars. The models are computed under the Sobolev approximation using the three-dimensional Monte Carlo radiative-transfer code TORUS. We have calculated four illustrative models in which the accretion flows are confined to azimuthal curtains - a geometry predicted by magneto-hydrodynamical simulations. Properties of the line profile variability of our models are discussed, with reference to dynamic spectra and cross-correlation images. We find that some gross characteristics of observed line profile variability are reproduced by our models, although in general the level of variability predicted is larger than that observed. We conclude that this excessive variability probably excludes dynamical simulations that predict accretion flows with low degrees of axisymmetry.Comment: 14 pages, 12 figures. Published in MNRA