248 research outputs found
Evaluation of Hungarian Wines for Resveratrol by Overpressured Layer Chromatography
A method, including solid phase extraction sample preparation, overpressured layer chromatographic separation and subsequent densitometric evaluation, was developed for measurement of total resveratrol (cis- and trans-isomers) content of wine. The amount of resveratrol was determined in wine samples from different winemaking regions of Hungary. The total resveratrol was high in Hungarian red wines (3.6–11 mg/L), and much lower in white ones (0.04–1.5 mg/L)
The Trail Making test : a study of its ability to predict falls in the acute neurological in-patient population
Objective:
To determine whether tests of cognitive function and patient-reported outcome measures of motor function can be used to create a machine learning-based predictive tool for falls.
Design:
Prospective cohort study.
Setting:
Tertiary neurological and neurosurgical center.
Subjects:
In all, 337 in-patients receiving neurosurgical, neurological, or neurorehabilitation-based care.
Main Measures:
Binary (Y/N) for falling during the in-patient episode, the Trail Making Test (a measure of attention and executive function) and the Walk-12 (a patient-reported measure of physical function).
Results:
The principal outcome was a fall during the in-patient stay (n = 54). The Trail test was identified as the best predictor of falls. Moreover, addition of other variables, did not improve the prediction (Wilcoxon signed-rank P < 0.001). Classical linear statistical modeling methods were then compared with more recent machine learning based strategies, for example, random forests, neural networks, support vector machines. The random forest was the best modeling strategy when utilizing just the Trail Making Test data (Wilcoxon signed-rank P < 0.001) with 68% (± 7.7) sensitivity, and 90% (± 2.3) specificity.
Conclusion:
This study identifies a simple yet powerful machine learning (Random Forest) based predictive model for an in-patient neurological population, utilizing a single neuropsychological test of cognitive function, the Trail Making test
Dynamical masses, absolute radii and 3D orbits of the triply eclipsing star HD 181068 from Kepler photometry
HD 181068 is the brighter of the two known triply eclipsing hierarchical triple stars in the
Kepler field. It has been continuously observed for more than 2 yr with the Kepler space
telescope. Of the nine quarters of the data, three have been obtained in short-cadence mode,
that is one point per 58.9 s. Here we analyse this unique data set to determine absolute physical
parameters (most importantly the masses and radii) and full orbital configuration using a
sophisticated novel approach. We measure eclipse timing variations (ETVs), which are then
combined with the single-lined radial velocity measurements to yield masses in a manner
equivalent to double-lined spectroscopic binaries. We have also developed a new light-curve
synthesis code that is used to model the triple, mutual eclipses and the effects of the changing
tidal field on the stellar surface and the relativistic Doppler beaming. By combining the stellar
masses from the ETV study with the simultaneous light-curve analysis we determine the
absolute radii of the three stars. Our results indicate that the close and the wide subsystems
revolve in almost exactly coplanar and prograde orbits. The newly determined parameters
draw a consistent picture of the system with such details that have been beyond reach before
A transdisciplinary and community-driven database to unravel subduction zone initiation
Subduction zones are pivotal for the recycling of Earth’s outer layer into its interior. However, the conditions under which new subduction zones initiate are enigmatic. Here, we constructed a transdisciplinary database featuring detailed analysis of more than a dozen documented subduction zone initiation events from the last hundred million years. Our initial findings reveal that horizontally forced subduction zone initiation is dominant over the last 100 Ma, and that most initiation events are proximal to pre-existing subduction zones. The SZI Database is expandable to facilitate access to the most current understanding of subduction zone initiation as research progresses, providing a community platform that establishes a common language to sharpen discussion across the Earth Science community
Problematic social media use: results from a large-scale nationally representative adolescent sample
Despite social media use being one of the most popular activities among adolescents, prevalence estimates among teenage samples of social media (problematic) use are lacking in the field. The present study surveyed a nationally representative Hungarian sample comprising 5,961 adolescents as part of the European School Survey Project on Alcohol and Other Drugs (ESPAD). Using the Bergen Social Media Addiction Scale (BSMAS) and based on latent profile analysis, 4.5% of the adolescents belonged to the at-risk group, and reported low self-esteem, high level of depression symptoms, and elevated social media use. Results also demonstrated that BSMAS has appropriate psychometric properties. It is concluded that adolescents at-risk of problematic social media use should be targeted by school-based prevention and intervention programs
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