Ultra-precise diamond turning is the method of choice for manufacturing freeform optics. Analyzing surface errors in different spatial frequency ranges has mainly been performed in a one-dimensional representation of the power spectral density function. However, the advanced machine dynamics at the fabrication of freeform mirrors result in highly anisotropic surfaces with regular ripples in different orientations. To properly analyze the entire surface in the frequency regime, a new way of representing the two-dimensional power spectral density is introduced in this paper. This novel tool is utilized for the evaluation of an example freeform mirror.
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http://dx.doi.org/10.1364/AO.57.008692 | DOI Listing |
BMC Psychiatry
January 2025
Department of Neurology, Shenzhen People's Hospital (The Second Clinical Medical College, Jinan University; The First Affiliated Hospital, Southern University of Science and Technology), Shenzhen, Guangdong, China.
Background: The neurasthenia-depression controversy has lasted for several decades. It is challenging to solve the argument by symptoms alone for syndrome-based disease classification. Our aim was to identify objective electroencephalography (EEG) measures that can differentiate neurasthenia from major depressive disorder (MDD).
View Article and Find Full Text PDFSci Rep
January 2025
Department of Biophysics, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal, Karnataka, 576104, India.
Rice (Oryza sativa) is a vital food crop and staple diet for most of the world's population. Poor dietary choices have had a significant role in the development of type-2 diabetes in the population that relies on rice and rice-starch-based foods. Hence, our study investigated the in vitro digestion and glycemic indices of certain indigenous rice cultivars and the factors influencing these indices.
View Article and Find Full Text PDFPLoS One
January 2025
Dept. of Psychiatry, Harvard Medical School, McLean Hospital, Belmont, Massachusetts, United States of America.
Opioid dependence is defined by an aversive withdrawal syndrome upon drug cessation that can motivate continued drug-taking, development of opioid use disorder, and precipitate relapse. An understudied but common opioid withdrawal symptom is disrupted sleep, reported as both insomnia and daytime sleepiness. Despite the prevalence and severity of sleep disturbances during opioid withdrawal, there is a gap in our understanding of their interactions.
View Article and Find Full Text PDFGeroscience
January 2025
Keldysh Institute of Applied Mathematics, Russian Academy of Sciences, Moscow, 125047, Russia.
Age-related dependencies of electric and spectral powers in conventional frequency bands were studied by the newly proposed method of detailed spectral analysis. The magnetic encephalograms (MEG) and magnetic resonance images (MRI) of the head were obtained from the open archive Cam-CAN. The spatial distributions of elementary spectral components (MEG-based functional tomograms) were reconstructed from MEG for 501 subjects (248 males and 253 females, ages 18-88 years, mean age 54.
View Article and Find Full Text PDFPLoS One
January 2025
Computer Engineering, CCSIT, King Faisal University, Al Hufuf, Kingdom of Saudi Arabia.
The health of poultry flock is crucial in sustainable farming. Recent advances in machine learning and speech analysis have opened up opportunities for real-time monitoring of the behavior and health of flock. However, there has been little research on using Tiny Machine Learning (Tiny ML) for continuous vocalization monitoring in poultry.
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