An open environment CT-US fusion for tissue segmentation during interventional guidance.

Therapeutic ultrasound (US) can be noninvasively focused to activate drugs, ablate tumors and deliver drugs beyond the blood brain barrier. However, well-controlled guidance of US therapy requires fusion with a navigational modality, such as magnetic resonance imaging (MRI) or X-ray computed tomography (CT). Here, we developed and validated tissue characterization using a fusion between US and CT. The performance of the CT/US fusion was quantified by the calibration error, target registration error and fiducial registration error. Met-1 tumors in the fat pads of 12 female FVB mice provided a model of developing breast cancer with which to evaluate CT-based tissue segmentation. Hounsfield units (HU) within the tumor and surrounding fat pad were quantified, validated with histology and segmented for parametric analysis (fat: -300 to 0 HU, protein-rich: 1 to 300 HU, and bone: HU>300). Our open source CT/US fusion system differentiated soft tissue, bone and fat with a spatial accuracy of ∼1 mm. Region of interest (ROI) analysis of the tumor and surrounding fat pad using a 1 mm(2) ROI resulted in mean HU of 68±44 within the tumor and -97±52 within the fat pad adjacent to the tumor (p<0.005). The tumor area measured by CT and histology was correlated (r(2) = 0.92), while the area designated as fat decreased with increasing tumor size (r(2) = 0.51). Analysis of CT and histology images of the tumor and surrounding fat pad revealed an average percentage of fat of 65.3% vs. 75.2%, 36.5% vs. 48.4%, and 31.6% vs. 38.5% for tumors <75 mm(3), 75-150 mm(3) and >150 mm(3), respectively. Further, CT mapped bone-soft tissue interfaces near the acoustic beam during real-time imaging. Combined CT/US is a feasible method for guiding interventions by tracking the acoustic focus within a pre-acquired CT image volume and characterizing tissues proximal to and surrounding the acoustic focus

Classical Phase Space Crystals in Open Environment

It was recently discovered that a crystalline many-body state can exist in the phase space of a closed dynamical system. Phase space crystal can be anomalous Chern insulator that supports chiral topological transport without breaking physical time-reversal symmetry [L. Guo et al., Phys. Rev. B 105, 094301 (2022)]. In this work, we further study the effects of open dissipative environment with thermal noise, and identify the existence condition of classical phase space crystals in realistic scenarios. By defining a crystal order parameter, we plot the phase diagram in the parameter space of dissipation rate, interaction and temperature. Our present work paves the way to realise phase space crystals and explore anomalous chiral transport in experiments.Comment: 11 pages, 5 figure

Experimental Investigation of Savonius Wind Rotors in Open and Bounded Flows

The common practice of operating a Savonius rotor 1s m an open environment; however there are times when the rotor is fixed in a bounded environment and there might be changes in the performance of the rotor. The project aims to investigate the possible changes in the performance of the rotor. Three different rotors models are design in this project. The project is conducted experimentally to compare the performance of the Rotors in bounded environment against open environment. The different environments that are tested namely partially bounded environment, li.!lly bounded environment and open environment. Rotors are found to have better starting capabilities when operated in bounded environment, Rotor I starts at 1.7m/s and 2m/s in partially bounded environment and fully bounded environment as compared to 2.7m/s in open environment. Rotor 2 starts at approximately 3.4 m/s for both partially and fully bounded environment as compared to open environment. Rotor 3 starts at 2m/s and 1.8m/s for partially bounded and fully bounded environment as compared to 3m/s for open environment. Apmt from that, all rotors manage to achieve higher power coefficient at a higher TSR as compare to open environment and better torque coei1icient as well in bounded environment as compare to open environment

OEBench: Investigating Open Environment Challenges in Real-World Relational Data Streams

How to get insights from relational data streams in a timely manner is a hot research topic. This type of data stream can present unique challenges, such as distribution drifts, outliers, emerging classes, and changing features, which have recently been described as open environment challenges for machine learning. While existing studies have been done on incremental learning for data streams, their evaluations are mostly conducted with manually partitioned datasets. Thus, a natural question is how those open environment challenges look like in real-world relational data streams and how existing incremental learning algorithms perform on real datasets. To fill this gap, we develop an Open Environment Benchmark named OEBench to evaluate open environment challenges in relational data streams. Specifically, we investigate 55 real-world relational data streams and establish that open environment scenarios are indeed widespread in real-world datasets, which presents significant challenges for stream learning algorithms. Through benchmarks with existing incremental learning algorithms, we find that increased data quantity may not consistently enhance the model accuracy when applied in open environment scenarios, where machine learning models can be significantly compromised by missing values, distribution shifts, or anomalies in real-world data streams. The current techniques are insufficient in effectively mitigating these challenges posed by open environments. More researches are needed to address real-world open environment challenges. All datasets and code are open-sourced in https://github.com/sjtudyq/OEBench

Patterns in surface distribution of human exposure to solar ultraviolet

[Abstract]: A method for the three dimensional representation of erythemally effective ultraviolet radiation (UVery) incident to the human body has been developed from a series of polysulphone dosimeter (PS) measurements to the face, neck, arms, legs and hands of a manikin model. The technique has been used to represent a series of human UVery exposure patterns in the solar zenith angle (SZA) range 30o-50o measured in an open environment in Toowoomba, Australia (27.5oS 151.9oE). The human body representations of exposure presented here improve upon existing techniques to represent the UVery exposure to complex body shape topography, providing for the first time, estimates of exposure that take whole body shading effects into account from high density PS dosimeter measurements