103 research outputs found
Vortex detection in atomic Bose-Einstein condensates using neural networks trained on synthetic images
Quantum vortices in atomic Bose-Einstein condensates (BECs) are topological
defects characterized by quantized circulation of particles around them. In
experimental studies, vortices are commonly detected by time-of-flight imaging,
where their density-depleted cores are enlarged. In this work, we describe a
machine learning-based method for detecting vortices in experimental BEC
images, particularly focusing on turbulent condensates containing irregularly
distributed vortices. Our approach employs a convolutional neural network (CNN)
trained solely on synthetic simulated images, eliminating the need for manual
labeling of the vortex positions as ground truth. We find that the CNN achieves
accurate vortex detection in real experimental images, thereby facilitating
analysis of large experimental datasets without being constrained by specific
experimental conditions. This novel approach represents a significant
advancement in studying quantum vortex dynamics and streamlines the analysis
process in the investigation of turbulent BECs.Comment: 10 pages, 6 figure
Experiences and perspectives on patient-centered education of medical students in Korea
Purpose This study analyzed the current status of and correlations between Korean medical studentsâ experiences and perspectives surrounding patient-centered medical education (PCME). Methods A structured PCME questionnaire composed of three categories, understanding patients within social and cultural contexts, understanding patientsâ individual health contexts through communication, and placement of patients at the center of medical education, was used. The students were stratified into pre-medical (Pre-med), medical (Med), and policlinic (PK) groups because of curriculum differences by grade. The Ï2 test was applied to analyze the association between studentsâ experiences with and perspectives on PCME. A Cramerâs V of 0.200 was considered a large effect size for any association between experiences with and perspectives on PCME. Results Among the respondents, 50.6% answered that they did not know about patient-centered medicine before the survey. With increasing school years went up from Pre-med to PK, fewer students agreed that PCME should be added to pre-clinical medicine curricula (p<0.001), that patients should be in the center throughout medical education (p=0.011), and that patientsâ personal histories, values, and objectives are important PCME (p=0.001). Students who said they learned PCME for each category were more likely to consider PCME important (Cramerâs V was 0.219 and 0.271 for âwith,â and âfor the patientsâ respectively, p<0.001 for âabout/with/for the patientsâ). Students in all groups chose clinical practice as the best method for PCME (p=0.021). Med group chose the lectures as the most effective tool to learn about the importance of communication (p<0.001). Conclusion Students who experienced PCME were likely to perceive PCME as important and it showed that experiences of PCME had positive effects on PCME perceptions. Despite studentsâ preferences for clinical practice as the best method for PCME, PK reported that they did not learn PCME, and regarded PCME as less important compared to students at earlier stages of their medical education. Therefore, more intensive and holistic PCME curricula rather than only clinical practice exposure may be necessary
Magneto-Mechanical Transmitters for Ultra-Low Frequency Near-field Communication
Electromagnetic signals in the ultra-low frequency (ULF) range below 3 kHz
are well suited for underwater and underground wireless communication thanks to
low signal attenuation and high penetration depth. However, it is challenging
to design ULF transmitters that are simultaneously compact and energy efficient
using traditional approaches, e.g., using coils or dipole antennas. Recent
works have considered magneto-mechanical alternatives, in which ULF magnetic
fields are generated using the motion of permanent magnets, since they enable
extremely compact ULF transmitters that can operate with low energy consumption
and are suitable for human-portable applications. Here we explore the design
and operating principles of resonant magneto-mechanical transmitters (MMT) that
operate over frequencies spanning a few 10's of Hz up to 1 kHz. We
experimentally demonstrate two types of MMT designs using both single-rotor and
multi-rotor architectures. We study the nonlinear electro-mechanical dynamics
of MMTs using point dipole approximation and magneto-static simulations. We
further experimentally explore techniques to control the operation frequency
and demonstrate amplitude modulation up to 10 bits-per-second.Comment: 10 pages, 9 figure
Adapting to the projected epidemics of Fusarium head blight of wheat in Korea under climate change scenarios
Fusarium head blight (FHB) of wheat, mainly caused by Fusarium graminearum Schwabe, is an emerging threat to wheat production in Korea under a changing climate. The disease occurrence and accumulation of associated trichothecene mycotoxins in wheat kernels strongly coincide with warm and wet environments during flowering. Recently, the International Panel for Climate Change released the 6th Coupled Model Intercomparison Project (CMIP6) climate change scenarios with shared socioeconomic pathways (SSPs). In this study, we adopted GIBSIM, an existing mechanistic model developed in Brazil to estimate the risk infection index of wheat FHB, to simulate the potential FHB epidemics in Korea using the SSP245 and SSP585 scenarios of CMIP6. The GIBSIM model simulates FHB infection risk from airborne inoculum density and infection frequency using temperature, precipitation, and relative humidity during the flowering period. First, wheat heading dates, during which GIBSIM runs, were predicted over suitable areas of winter wheat cultivation using a crop development rate model for wheat phenology and downscaled SSP scenarios. Second, an integrated model combining all results of wheat suitability, heading dates, and FHB infection risks from the SSP scenarios showed a gradual increase in FHB epidemics towards 2100, with different temporal and spatial patterns of varying magnitudes depending on the scenarios. These results indicate that proactive management strategies need to be seriously considered in the near future to minimize the potential impacts of the FHB epidemic under climate change in Korea. Therefore, available wheat cultivars with early or late heading dates were used in the model simulations as a realistic adaptation measure. As a result, wheat cultivars with early heading dates showed significant decreases in FHB epidemics in future periods, emphasizing the importance of effective adaptation measures against the projected increase in FHB epidemics in Korea under climate change
The Responses of Tissues from the Brain, Heart, Kidney, and Liver to Resuscitation following Prolonged Cardiac Arrest by Examining Mitochondrial Respiration in Rats
Cardiac arrest induces whole-body ischemia, which causes damage to multiple organs. Understanding how each organ responds to ischemia/reperfusion is important to develop better resuscitation strategies. Because direct measurement of organ function is not practicable in most animal models, we attempt to use mitochondrial respiration to test efficacy of resuscitation on the brain, heart, kidney, and liver following prolonged cardiac arrest. Male Sprague-Dawley rats are subjected to asphyxia-induced cardiac arrest for 30âmin or 45âmin, or 30âmin cardiac arrest followed by 60âmin cardiopulmonary bypass resuscitation. Mitochondria are isolated from brain, heart, kidney, and liver tissues and examined for respiration activity. Following cardiac arrest, a time-dependent decrease in state-3 respiration is observed in mitochondria from all four tissues. Following 60âmin resuscitation, the respiration activity of brain mitochondria varies greatly in different animals. The activity after resuscitation remains the same in heart mitochondria and significantly increases in kidney and liver mitochondria. The result shows that inhibition of state-3 respiration is a good marker to evaluate the efficacy of resuscitation for each organ. The resulting state-3 respiration of brain and heart mitochondria following resuscitation reenforces the need for developing better strategies to resuscitate these critical organs following prolonged cardiac arrest
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Additional manuscript. The contents include methods and results of "Estimated Blood Levels of IL-6 during CVVH Operation", "Blood Gas Analysis", "Table E1. Basal characteristics and resuscitation data of randomized animals" and "Table E2. Efficacy of hemofilter on IL-6 removal from circulating blood". (DOCX 305 kb
Improved Mitochondrial Function with Diet-Induced Increase in Either Docosahexaenoic Acid or Arachidonic Acid in Membrane Phospholipids
Mitochondria can depolarize and trigger cell death through the opening of the mitochondrial permeability transition pore (MPTP). We recently showed that an increase in the long chain n3 polyunsaturated fatty acids (PUFA) docosahexaenoic acid (DHA; 22:6n3) and depletion of the n6 PUFA arachidonic acid (ARA; 20:4n6) in mitochondrial membranes is associated with a greater Ca2+ load required to induce MPTP opening. Here we manipulated mitochondrial phospholipid composition by supplementing the diet with DHA, ARA or combined DHA+ARA in rats for 10 weeks. There were no effects on cardiac function, or respiration of isolated mitochondria. Analysis of mitochondrial phospholipids showed DHA supplementation increased DHA and displaced ARA in mitochondrial membranes, while supplementation with ARA or DHA+ARA increased ARA and depleted linoleic acid (18:2n6). Phospholipid analysis revealed a similar pattern, particularly in cardiolipin. Tetralinoleoyl cardiolipin was depleted by 80% with ARA or DHA+ARA supplementation, with linoleic acid side chains replaced by ARA. Both the DHA and ARA groups had delayed Ca2+-induced MPTP opening, but the DHA+ARA group was similar to the control diet. In conclusion, alterations in mitochondria membrane phospholipid fatty acid composition caused by dietary DHA or ARA was associated with a greater cumulative Ca2+ load required to induced MPTP opening. Further, high levels of tetralinoleoyl cardiolipin were not essential for normal mitochondrial function if replaced with very-long chain n3 or n6 PUFAs
Microsphere-based interferometric optical probe
Fluorescent optical probes have rapidly transformed our understanding of complex biological
systems by providing specific information on biological targets in the natural living state.
However, their utility is often limited by insufficient brightness, photostability, and multiplexing capacity. Here, we report a conceptually new optical probe, termed âreflectophoreâ,
which is based on the spectral interference from a dielectric microsphere. Reflectophores are
orders-of-magnitudes brighter than conventional fluorophores and are free from photobleaching,
enabling practically unlimited readout at high fidelity. They also offer high-degree
multiplexing, encoded in their optical size, which can be readily decoded through interferometric detection with nanoscale accuracy, even in turbid biological media. Furthermore, we
showcase their biological applications in cellular barcoding and microenvironmental sensing
of a target protein and local electric field. © The Author(s) 201
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