16 research outputs found

    Automated Assessment of Cardiothoracic Ratios on Chest Radiographs Using Deep Learning

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    Introduction: The cardiothoracic ratio (CTR) is a quantitative measure of cardiac size that can measured from chest radiography (CXR). Although radiologists using digital workstations possess the ability to calculate CTR, clinical demands prevent calculation for every case. In this study, the efficacy of a deep convolutional neural network (dCNN) to assess CTR was evaluated. Methods: 611 HIPAA-compliant de-identified CXRs were obtained from [institution blinded] and public databases. Using ImageJ, a board-certified radiologist (reader #1) and a medical student (reader #2), measured the CTR by marking four pixels on all CXRs: the right- and left-most chest wall, the right- and left-most heart border. The Tensorflow framework (v2.0, Google LLC, Mountain View, CA) and the Keras library (v2.3, https://keras.io) were used to train the dCNN. The images were split into training (511 images), validation (50 images), and test (50 images). U-Net network architecture with an Intersection over Union loss function was employed to predict oval masks on new CXRs and calculate the CTR. Results: 45 test cases were analyzed. The mean absolute difference in the calculated CTR was 0.026 (stdev: 0.039) for reader 1 vs dCNN, 0.024 (stdev: 0.039) for reader 2 vs. dCNN, and 0.022 (stdev: 0.024) for reader 1 vs. reader 2. The intra-class correlation coefficient was 0.84 (95% CI: 0.73-0.91), 0.84 (95% CI: 0.72-0.91), 0.92 (95% CI: 0.822-0.958) for reader 1 vs. dCNN, reader 2 vs. dCNN, and reader 1 vs. reader 2, respectively. Discussion: The dCNN trained in this study outputted similar CTR measurements to the human readers with the dCNN achieving good reliability with the human readers and the human readers achieving excellent reliability among themselves. This study proves the feasibility of using a dCNN to perform automated CTR assessment from CXR. Future improvements to the algorithm can allow the dCNN to closely approach the expected limits of inter-observer human agreement

    Effect of Photoperiodicity on Co2 Fixation by Chlorella Vulgaris Buitenzorg in Bubble Column Photobioreactor for Food Supplement Production

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    To reduce the level of CO2 content in air, effort on converting CO2 to useful products is required. One of thealternatives includes CO2 fixation to produce biomass using Chlorella vulgaris Buitenzorg. Chlorella vulgarisBuitenzorg is applied for production of food supplement. Chlorella vulgaris Buitenzorg is also easy to handle due to itssuperior adaptation. Currently, Chlorella vulgaris Buitenzorg has been analyzed by some experts for its cellularcomposition, its ability to produce high quality biomass and the content of essential nutrition. A series of experimentswas conducted by culturing Chlorella vulgaris Buitenzorg using Beneck medium in bubbling column photobioreactor.The main variation in this experiment was photoperiodicity, where growth of Chlorella vulgaris Buitenzorg wasexamined during photoperiodicity condition. The difference between CO2 gas concentration of inlet and outlet of thereactor during operational period, was compared to the same experiment under continuous illumination. Underphotoperiodicity of 8 and 9 h/d, the culture cell densities (N) were approximately 40 % higher than under continuousillumination. Final biomass density of Chlorella vulgaris Buitenzorg at 9 h/d illumination was 1.43 g/dm3, around 46%higher than under continuous illumination. Specific carbon dioxide transfer rate (qCO2) in photoperiodicity was 50-80%higher than under continuous illumination. These experiments showed that photoperiodicity affects the growth ofChlorella vulgaris Buitenzorg The specific growth rate (μ) by photoperiodicity was higher than that by continuousilumination while the growth period was two times longer. Based on the experiments, it can be concluded thatphotoperiodicity might save light energy consumption. The prediction of kinetic model under continuous illuminationas well as under photoperiodicity illumination showed that Haldane model became the fitted kinetic model

    Categorical versus continuous circulating tumor cell enumeration as early surrogate marker for therapy response and prognosis during docetaxel therapy in metastatic prostate cancer patients

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    Background: Circulating tumor cell (CTCs) counts might serve as early surrogate marker for treatment efficacy in metastatic castration-resistant prostate cancer (mCRPC) patients. We prospectively assessed categorical and continuous CTC-counts for their utility in early prediction of radiographic response, progression-free (PFS) and overall survival (OS) in mCRPC patients treated with docetaxel. Methods: CTC-counts were assessed in 122 serial samples, as continuous or categorical (= 5 CTCs) variables, at baseline (q0) and after 1 (q1),4 (q4) and 10 (q10) cycles of docetaxel (3-weekly, 75 mg/m2) in 33 mCRPC patients. Treatment response (TR) was defined as non-progressive (non-PD) and progressive disease (PD),by morphologic RECIST or clinical criteria at q4 and q10. Binary logistic and Cox proportional hazards regression analyses were used as statistical methods. Results: Categorical CTC-count status predicted PD at q4 already after one cycle (q1) and after 4 cycles (q4) of chemotherapy with an odds ratio (OR) of 14.9 (p = 0.02) and 18.0 (p = 0.01). Continuous CTC-values predicted PD only at q4 (OR 1.04, p = 0.048). Regarding PFS, categorical CTC-counts at q1 were independent prognostic markers with a hazard ratio (HR) of 3.85 (95 % CI 1.1-13.8, p = 0.04) whereas early continuous CTC-values at q1 failed significance (HR 1.02, 95 % CI 0.99-1.05, p = 0.14). For OS early categorical and continuous CTC-counts were independent prognostic markers at q1 with a HR of 3.0 (95 % CI 1.6-15.7, p = 0.007) and 1.02 (95 % CI 1.0-1.040, p = 0.04). Conclusions: Categorical CTC-count status is an early independent predictor for TR, PFS and OS only 3 weeks following treatment initiation with docetaxel whereas continuous CTC-counts were an inconsistent surrogate marker in mCRPC patients. For clinical practice, categorical CTC-counts may provide complementary information towards individualized treatment strategies with early prediction of treatment efficacy and optimized sequential treatment

    Conserving Marine Wildlife Through World Trade Law

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    Part I of this Essay marshals the evidence that fisheries around the world are in peril from destructive fishing practices. Part II argues that most fisheries management regimes are ineffective at counteracting the political pressures and economic incentives that lead to unsustainable fishing. Part III makes the case that government subsidies are major enablers of overfishing. The fourth and final Part discusses the continuing efforts to use international trade regulation to eliminate overfishing subsidies and halt the collapse of the world\u27s marine fish populations

    Conserving Marine Wildlife Through World Trade Law

    Get PDF
    Part I of this Essay marshals the evidence that fisheries around the world are in peril from destructive fishing practices. Part II argues that most fisheries management regimes are ineffective at counteracting the political pressures and economic incentives that lead to unsustainable fishing. Part III makes the case that government subsidies are major enablers of overfishing. The fourth and final Part discusses the continuing efforts to use international trade regulation to eliminate overfishing subsidies and halt the collapse of the world\u27s marine fish populations

    EFFECT OF PHOTOPERIODICITY ON CO2 FIXATION BY Chlorella vulgaris Buitenzorg IN BUBBLE COLUMN PHOTOBIOREACTOR FOR FOOD SUPPLEMENT PRODUCTION

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    To reduce the level of CO2 content in air, effort on converting CO2 to useful products is required. One of thealternatives includes CO2 fixation to produce biomass using Chlorella vulgaris Buitenzorg. Chlorella vulgarisBuitenzorg is applied for production of food supplement. Chlorella vulgaris Buitenzorg is also easy to handle due to itssuperior adaptation. Currently, Chlorella vulgaris Buitenzorg has been analyzed by some experts for its cellularcomposition, its ability to produce high quality biomass and the content of essential nutrition. A series of experimentswas conducted by culturing Chlorella vulgaris Buitenzorg using Beneck medium in bubbling column photobioreactor.The main variation in this experiment was photoperiodicity, where growth of Chlorella vulgaris Buitenzorg wasexamined during photoperiodicity condition. The difference between CO2 gas concentration of inlet and outlet of thereactor during operational period, was compared to the same experiment under continuous illumination. Underphotoperiodicity of 8 and 9 h/d, the culture cell densities (N) were approximately 40 % higher than under continuousillumination. Final biomass density of Chlorella vulgaris Buitenzorg at 9 h/d illumination was 1.43 g/dm3, around 46%higher than under continuous illumination. Specific carbon dioxide transfer rate (qCO2) in photoperiodicity was 50-80%higher than under continuous illumination. These experiments showed that photoperiodicity affects the growth ofChlorella vulgaris Buitenzorg The specific growth rate (μ) by photoperiodicity was higher than that by continuousilumination while the growth period was two times longer. Based on the experiments, it can be concluded thatphotoperiodicity might save light energy consumption. The prediction of kinetic model under continuous illuminationas well as under photoperiodicity illumination showed that Haldane model became the fitted kinetic model.Keywords: photoperiodicity, Chlorella vulgaris Buitenzorg, food supplement, CO2 fixation, Haldane model
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