Examination of the Monoamine Oxidase a Gene Promoter on Motivation to Exercise and Levels of Voluntary Physical Activity

Purpose: Monoamine oxidase A (MAO-A) is an enzyme that causes inactivation of monoamine neurotransmitters, such as dopamine. Polymorphisms in the promoter region of the MAO-A gene can change transcriptional activity and the amount of MAO-A produced, leading to alterations in available dopamine levels. MAO-A polymorphisms have been associated with physical activity level. This study examined whether motivation to exercise, and levels of voluntary physical activity are associated with MAO-A gene polymorphisms. Methods: Seventy-one participants (18-24 years, 13 males & 58 females) completed the Behavioral Regulation in Exercise Questionaire-2 (BREQ-2) to assess their motivation to exercise and the International Physical Activity Questionnaire (IPAQ) to assess their level of physical activity. DNA was isolated from a cheek cell sample. MAO-A 3/3 and 4/4 genotype individuals were used for analysis. Results: External motivation to exercise was significantly higher (p \u3c 0.01) in the high transcription 4/4 genotype (ave 1.17 ± 0.7) compared to the low transcription 3/3 genotype (ave 0.42 ± 0.5). Internal motivation to exercise, body mass index, and weekly MET minutes were comparable between genotypes. Conclusion: The results suggest a polymorphism in this monoamine pathway may play a role in increasing sensitivity to external factors that motivate individuals to exercise

Predicting the outcome of renal transplantation

ObjectiveRenal transplantation has dramatically improved the survival rate of hemodialysis patients. However, with a growing proportion of marginal organs and improved immunosuppression, it is necessary to verify that the established allocation system, mostly based on human leukocyte antigen matching, still meets today's needs. The authors turn to machine-learning techniques to predict, from donor-recipient data, the estimated glomerular filtration rate (eGFR) of the recipient 1 year after transplantation.DesignThe patient's eGFR was predicted using donor-recipient characteristics available at the time of transplantation. Donors' data were obtained from Eurotransplant's database, while recipients' details were retrieved from Charite Campus Virchow-Klinikum's database. A total of 707 renal transplantations from cadaveric donors were included.MeasurementsTwo separate datasets were created, taking features with <10% missing values for one and <50% missing values for the other. Four established regressors were run on both datasets, with and without feature selection.ResultsThe authors obtained a Pearson correlation coefficient between predicted and real eGFR (COR) of 0.48. The best model for the dataset was a Gaussian support vector machine with recursive feature elimination on the more inclusive dataset. All results are available at http://transplant.molgen.mpg.de/.LimitationsFor now, missing values in the data must be predicted and filled in. The performance is not as high as hoped, but the dataset seems to be the main cause.ConclusionsPredicting the outcome is possible with the dataset at hand (COR=0.48). Valuable features include age and creatinine levels of the donor, as well as sex and weight of the recipient

Three-dimensional simulation of cavitating flow in real journal bearing geometry

This paper was presented at the 4th Micro and Nano Flows Conference (MNF2014), which was held at University College, London, UK. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute, ASME Press, LCN London Centre for Nanotechnology, UCL University College London, UCL Engineering, the International NanoScience Community, www.nanopaprika.eu.Hydrodynamic journal bearings are commonly used in many technical applications because they provide low friction and minimal wear. In general, flow simulation during the engineering design process is carried out by means of the Reynolds equation. The Reynolds equation is a non-linear two-dimensional differential equation, which is based on the pressure and the gap between shaft and bushing in relation to bearing clearance, eccentricity, bushing deformation and load. However, due its two-dimensional nature it is inaccurate where the lubricant flow inside the bearing becomes three-dimensional e.g., in the vicinity of feed holes or grooves. The work on hand presents the numerical approach and the cavitation model based on the Rayleigh-Plesset equation. Moreover, a bearing flow experiment was designed and constructed with the goal to validate numerical results. Finally, the validated 3D simulation model is applied on a real bearing, which was subject to an experimental investigation targeting cavitation. The numerical results include images of complex three-dimensional flow structures, vortices and vapor distributions. In comparison of 2D and 3D simulation, the two-dimensional approach gives wrong information in 2 out of 6 critical regions pertaining cavitation failing in both, over- and under-prediction of cavitation. In summary, a new numerical model expands the scope for the numerical simulation of the lubricant flow in hydrodynamic journal bearings and improves the prediction of cavitation

Coupled opto-electronic simulation of organic bulk-heterojunction solar cells: parameter extraction and sensitivity analysis

A general problem arising in computer simulations is the number of material and device parameters, which have to be determined by dedicated experiments and simulation-based parameter extraction. In this study we analyze measurements of the short-circuit current dependence on the active layer thickness and current-voltage curves in poly(3-hexylthiophene):[6,6]-phenyl-C61-butyric acid methyl ester (P3HT:PCBM) based solar cells. We have identified a set of parameter values including dissociation parameters that describe the experimental data. The overall agreement of our model with experiment is good, however a discrepancy in the thickness dependence of the current-voltage curve questions the influence of the electric field in the dissociation process. In addition transient simulations are analyzed which show that a measurement of the turn-off photocurrent can be useful for estimating charge carrier mobilities.Comment: 10 pages, 12 figures, 2 tables, Accepted for publication in Journal of Applied Physic

Global Perspectives in the Core: Student Attitudes and Instructor Performance

Global learning and global citizenship education (GCE) continue to be integrated as co-curricular and curricular components in US higher education. Many institutions have linked their mission and values statements to global learning. However, their efforts fail to reflect a single shared understanding or philosophy of global learning or GCE. While scholars continue to discuss and debate the substance of these frameworks, few studies have analyzed perspectives of curricular global learning and GCE requirements. Three hundred fifty-four undergraduate students attending a university in the Southern US completed questionnaires assessing their attitudes towards global learning, international issues, and global citizenship, as well as their attitudes toward the college’s required global perspectives curriculum. Results indicate that students feel generally positive towards global learning and issues, believe global learning should be required at this and other institutions, and have high perceptions of faculty performance