516 research outputs found

    A combined convolutional and recurrent neural network for enhanced glaucoma detection.

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    Glaucoma, a leading cause of blindness, is a multifaceted disease with several patho-physiological features manifesting in single fundus images (e.g., optic nerve cupping) as well as fundus videos (e.g., vascular pulsatility index). Current convolutional neural networks (CNNs) developed to detect glaucoma are all based on spatial features embedded in an image. We developed a combined CNN and recurrent neural network (RNN) that not only extracts the spatial features in a fundus image but also the temporal features embedded in a fundus video (i.e., sequential images). A total of 1810 fundus images and 295 fundus videos were used to train a CNN and a combined CNN and Long Short-Term Memory RNN. The combined CNN/RNN model reached an average F-measure of 96.2% in separating glaucoma from healthy eyes. In contrast, the base CNN model reached an average F-measure of only 79.2%. This proof-of-concept study demonstrates that extracting spatial and temporal features from fundus videos using a combined CNN and RNN, can markedly enhance the accuracy of glaucoma detection

    Influence of Ba[Mg2Al2N4]Eu2+ phosphor particle size on optical properties of the 6000K CPW-LEDs

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    In this paper, we consider the red phosphor Ba[Mg2Al2N4]Eu2+ as the novel recommendation for improving the optical properties of the 6000K conformal packaging WLEDs (CPW-LEDs). For this purpose, we investigate the influence of the Ba[Mg2Al2N4]Eu2+ particle size on the optical properties in terms of CCT, CQS, CRI, and LO using the Light Tools and Mat Lab software. From the research results, it can be observed that the optical properties of the 6000K CPW-LEDs are significantly influenced by the size of the Ba[Mg2Al2N4]Eu2+ particle. The CRI and CQS increase from 65 to 67 and 64 to 68 while the size of the Ba[Mg2Al2N4]Eu2+ particle varies from 1 μm to 10 μm, respectively. This research can provide a novel recommendation for LEDs industry at this time

    A collaborative care pathway for patients with suspected angle closure glaucoma spectrum disease

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    Background: Currently, no specific collaborative care pathway exists that distinguishes open angle glaucoma from narrow angle or angle closure disease. This study evaluates a newly developed referral and collaborative care pathway specifically for patients with angle closure spectrum disease. Methods: The medical records of consecutive patients referred to the Centre for Eye Health for glaucoma assessment were examined, six months before (Pre Suite) and after (Post Suite) the introduction of a novel referral pathway for anterior chamber angle assessment (Angle Suite). Patient demographic and clinical data, the referral letter and practitioner characteristics were extracted. Results: Angle Suite (n = 77) patients had an appointment much sooner compared to Pre (n = 383) and Post Suite (n = 425) patients (p < 0.0001). Following the introduction of Angle Suites, there was a reduction of incidental angle closure disease found in routine, non-angle closure glaucoma assessment. Onward referral was required by 36.4 per cent of patients referred for suspected angle closure disease, while the rest could be discharged back into the community (13.0 per cent) or reviewed at the Centre for Eye Health (50.6 per cent). Multinomial logistic regression found that the presence of an angle description in the referral letter improved the true positive rate for angle closure disease (p < 0.0001). Conclusions: The clinical pathway may reduce the number of incidental angle closure patients and improved the timeliness of appropriate clinical care delivered to a subset of patients who may benefit from prompt medical attention. This pathway provides an opportunity for appropriately staffed and equipped collaborative care clinics to reduce the burden on tertiary level ophthalmic facilities

    Some kinds of the controllable problems for fuzzy control dynamic systems

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    In this work, we have discussed the fuzzy solutions for fuzzy controllable problem, fuzzy feedback problem, and fuzzy global controllable (GC) problems. We use the method of successive approximations under the generalized Lipschitz condition for the local existence and furthermore, we have described the contraction principle under suitable conditions for global existence and uniqueness of fuzzy solutions. We have too the GC results for fuzzy systems. Some examples and computer simulation illustrating our approach are also given for these controllable problems

    Leveraging Static Analysis Tools for Improving Usability of Memory Error Sanitization Compilers

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    Memory errors such as buffer overruns are notorious security vulnerabilities. There has been considerable interest in having a compiler to ensure the safety of compiled code either through static verification or through instrumented runtime checks. While certifying compilation has shown much promise, it has not been practical, leaving code instrumentation as the next best strategy for compilation. We term such compilers Memory Error Sanitization Compilers (MESCs). MESCs are available as part of GCC, LLVM and MSVC suites. Due to practical limitations, MESCs typically apply instrumentation indiscriminately to every memory access, and are consequently prohibitively expensive and practical to only small code bases. This work proposes a methodology that applies state-of-the-art static analysis techniques to eliminate unnecessary runtime checks, resulting in more efficient and scalable defenses. The methodology was implemented on LLVM\u27s Safecode, Integer Overflow, and Address Sanitizer passes, using static analysis of Frama-C and Codesurfer. The benchmarks demonstrate an improvement in runtime performance that makes incorporation of runtime checks a viable option for defenses

    Generalizability assessment of AI models across hospitals in a low-middle and high income country

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    The integration of artificial intelligence (AI) into healthcare systems within low-middle income countries (LMICs) has emerged as a central focus for various initiatives aiming to improve healthcare access and delivery quality. In contrast to high-income countries (HICs), which often possess the resources and infrastructure to adopt innovative healthcare technologies, LMICs confront resource limitations such as insufficient funding, outdated infrastructure, limited digital data, and a shortage of technical expertise. Consequently, many algorithms initially trained on data from non-LMIC settings are now being employed in LMIC contexts. However, the effectiveness of these systems in LMICs can be compromised when the unique local contexts and requirements are not adequately considered. In this study, we evaluate the feasibility of utilizing models developed in the United Kingdom (a HIC) within hospitals in Vietnam (a LMIC). Consequently, we present and discuss practical methodologies aimed at improving model performance, emphasizing the critical importance of tailoring solutions to the distinct healthcare systems found in LMICs. Our findings emphasize the necessity for collaborative initiatives and solutions that are sensitive to the local context in order to effectively tackle the healthcare challenges that are unique to these regions

    A Retrospective Analysis of the Haemodynamic and Metabolic Effects of Fluid Resuscitation in Vietnamese Adults with Severe Falciparum Malaria

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    BACKGROUND: Optimising the fluid resuscitation of patients with severe malaria is a simple and potentially cost-effective intervention. Current WHO guidelines recommend central venous pressure (CVP) guided, crystalloid based, resuscitation in adults. METHODS: Prospectively collected haemodynamic data from intervention trials in Vietnamese adults with severe malaria were analysed retrospectively to assess the responses to fluid resuscitation. RESULTS: 43 patients were studied of whom 24 received a fluid load. The fluid load resulted in an increase in cardiac index (mean increase: 0.75 L/min/m(2) (95% Confidence interval (CI): 0.41 to 1.1)), but no significant change in acid-base status post resuscitation (mean increase base deficit 0.6 mmol/L (95% CI: -0.1 to 1.3). The CVP and PAoP (pulmonary artery occlusion pressure) were highly inter-correlated (r(s) = 0.7, p<0.0001), but neither were correlated with acid-base status (arterial pH, serum bicarbonate, base deficit) or respiratory status (PaO(2)/FiO(2) ratio). There was no correlation between the oxygen delivery (DO(2)) and base deficit at the 63 time-points where they were assessed simultaneously (r(s) = -0.09, p = 0.46). CONCLUSIONS: In adults with severe falciparum malaria there was no observed improvement in patient outcomes or acid-base status with fluid loading. Neither CVP nor PAoP correlated with markers of end-organ perfusion or respiratory status, suggesting these measures are poor predictors of their fluid resuscitation needs

    Coordination of frontline defense mechanisms under severe oxidative stress

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    Inference of an environmental and gene regulatory influence network (EGRINOS) by integrating transcriptional responses to H2O2 and paraquat (PQ) has revealed a multi-tiered oxidative stress (OS)-management program to transcriptionally coordinate three peroxidase/catalase enzymes, two superoxide dismutases, production of rhodopsins, carotenoids and gas vesicles, metal trafficking, and various other aspects of metabolism.ChIP-chip, microarray, and survival assays have validated important architectural aspects of this network, identified novel defense mechanisms (including two evolutionarily distant peroxidase enxymes), and showed that general transcription factors of the transcription factor B family have an important function in coordinating the OS response (OSR) despite their inability to directly sense ROS.A comparison of transcriptional responses to sub-lethal doses of H2O2 and PQ with predictions of these responses made by an EGRIN model generated earlier from responses to other environmental factors has confirmed that a significant fraction of the OSR is made up of a generalized component that is also observed in response to other stressors.Analysis of active regulons within environment and gene regulatory influence network for OS (EGRINOS) across diverse environmental conditions has identified the specialized component of oxidative stress response (OSR) that is triggered by sub-lethal OS, but not by other stressors, including sub-inhibitory levels of redox-active metals, extreme changes in oxygen tension, and a sub-lethal dose of γ rays

    The 1994 international transatlantic two-way satellite time and frequency transfer experiment: Preliminary results

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    The international transatlantic time and frequency transfer experiment was designed by participating laboratories and has been implemented during 1994 to test the international communications path involving a large number of transmitting stations. This paper will present empirically determined clock and time scale differences, time and frequency domain instabilities, and a representative power spectral density analysis. The experiments by the method of co-location which will allow absolute calibration of the participating laboratories have been performed. Absolute time differences and accuracy levels of this experiment will be assessed in the near future
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