Over the past few years, the light-gated cation channel Channelrhodopsin-2 (ChR2) has seen a remarkable diversity of applications in neuroscience. However, commonly used wide-field illumination provides poor spatial selectivity for cell stimulation. We explored the potential of focal laser illumination to map photocurrents of individual neurons in sparsely transfected hippocampal slice cultures. Interestingly, the best spatial resolution of photocurrent induction was obtained at the lowest laser power. By adjusting the light intensity to a neuron's spike threshold, we were able to trigger action potentials with a spatial selectivity of less than 30 microm. Experiments with dissociated hippocampal cells suggested that the main factor limiting the spatial resolution was ChR2 current density rather than scattering of the excitation light. We conclude that subcellular resolution can be achieved only in cells with a high ChR2 expression level and that future improved variants of ChR2 are likely to extend the spatial resolution of photocurrent induction to the level of single dendrites.
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Environ Health Perspect
January 2025
Centre for Environment, Fisheries and Aquaculture Science (CEFAS), Weymouth, UK.
Background: Environmental change in coastal areas can drive marine bacteria and resulting infections, such as those caused by , with both foodborne and nonfoodborne exposure routes and high mortality. Although ecological drivers of in the environment have been well-characterized, fewer models have been able to apply this to human infection risk due to limited surveillance.
Objectives: The Cholera and Other Illness Surveillance (COVIS) system database has reported infections in the United States since 1988, offering a unique opportunity to both explore the forecasting capabilities machine learning could provide and to characterize complex environmental drivers of infections.
Science
January 2025
School of Informatics, Computing and Cyber Systems, Northern Arizona University, Flagstaff, AZ, USA.
ACS Nano
January 2025
Department of Mechanical Engineering, University of California at Riverside, Riverside, California 92521, United States.
Sensing light's polarization and wavefront direction enables surface curvature assessment, material identification, shadow differentiation, and improved image quality in turbid environments. Traditional polarization cameras utilize multiple sensor measurements per pixel and polarization-filtering optics, which result in reduced image resolution. We propose a nanophotonic pipeline that enables compressive sensing and reduces the sampling requirements with a low-refractive-index, self-assembled optical encoder.
View Article and Find Full Text PDFMed Biol Eng Comput
January 2025
Artificial Intelligence Lab, School of Computer and Information Sciences, University of Hyderabad, Hyderabad, 500046, India.
The generalization of deep learning (DL) models is critical for accurate lesion segmentation in breast ultrasound (BUS) images. Traditional DL models often struggle to generalize well due to the high frequency and scale variations inherent in BUS images. Moreover, conventional loss functions used in these models frequently result in imbalanced optimization, either prioritizing region overlap or boundary accuracy, which leads to suboptimal segmentation performance.
View Article and Find Full Text PDFJ Acoust Soc Am
January 2025
Department of Informatics, University of Oslo, 0316 Oslo, Norway.
In adaptive beamforming, the array signal processing adjusts its sensor delays and weights based on the incoming data. In conventional beamforming, these parameters are instead given from a predefined model. Adaptive beamformers can improve measurement precision by dynamically rejecting spatial interference.
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