Weakly-supervised localization of diabetic retinopathy lesions in retinal fundus images

Convolutional neural networks (CNNs) show impressive performance for image classification and detection, extending heavily to the medical image domain. Nevertheless, medical experts are sceptical in these predictions as the nonlinear multilayer structure resulting in a classification outcome is not directly graspable. Recently, approaches have been shown which help the user to understand the discriminative regions within an image which are decisive for the CNN to conclude to a certain class. Although these approaches could help to build trust in the CNNs predictions, they are only slightly shown to work with medical image data which often poses a challenge as the decision for a class relies on different lesion areas scattered around the entire image. Using the DiaretDB1 dataset, we show that on retina images different lesion areas fundamental for diabetic retinopathy are detected on an image level with high accuracy, comparable or exceeding supervised methods. On lesion level, we achieve few false positives with high sensitivity, though, the network is solely trained on image-level labels which do not include information about existing lesions. Classifying between diseased and healthy images, we achieve an AUC of 0.954 on the DiaretDB1.Comment: Accepted in Proc. IEEE International Conference on Image Processing (ICIP), 201

Titanium Plasma Spectroscopy Studies under Double Pulse Laser Excitation

Laser-induced breakdown spectroscopy (LIBS) was applied for parametric studies of titanium (Ti) plasma using single and double pulsed laser excitation scheme. Here a pulsed Nd:YAG laser was employed for generation of laser produced plasma from solid Ti target at ambient pressure. Several ionized titanium lines were recorded in the 312-334 nm UV region. The temporal evolution of plasma parameters such as excitation temperature and electron number density was evaluated. The effect of incident laser irradiance, position of the laser beam focal point with respect to the surface of illumination, single and double laser pulse effect on plasma parameters were also investigated. This study contributes to a better understanding of the LIBS plasma dynamics of the double laser pulse effect on the temporal evolution of various Ti emission lines, the detection sensitivity and the optimal dynamics of plasma for ionized states of Ti. The results demonstrate a faster decay of the continuum and spectral lines and a shorter plasma life time for the double pulse excitation scheme as compared with single laser pulse excitation. For double pulse excitation technique, the emissions of Ti lines intensities are enhanced by a factor of five which could help in the improvement of analytical performance of LIBS technique. In addition, this study proved that to avoid inhomogeneous effects in the laser produced plasma under high laser intensities, short delay times between the incident laser pulse and ICCD gate are required

LASER INDUCED BREAKDOWN SPECTROSCOPY OF GEOLOGICAL SAMPLES

A highly sensitive laser-based spectroscopic technique, the laser induced breakdown spectroscopy (LIBS), for trace element detection has been developed at our laboratory. This method is based on the study of plasma resulting from interaction of intense laser radiation with sample medium. This technique is demonstrated to be able to detect all the significant major and trace elements including Ni, Cu, Mg, Mo, Cr, K, Na, Ca and Fe, present in the rock samples collected from different parts of the Arabian shield. Atomic emission spectra of different trace elements contained in the rock samples have been recorded in the 300 –700 nm region. The 308 nm (XeCl) laser radiation from a Lambda Physik Model EMG 203 excimer laser at an irradiance of 7.6 × 10 10 W. cm –2 has been used. The atomic emission lines were recorded using grating monochromator and detected with photomultiplier. The electrical signal generated by photomultiplier was fed into Box-car averager and processed by signal processor. The observed spectral lines have been assigned to transitions in the neutral charge state of the corresponding atoms of the material under investigation

Synovitis, acne, pustulosis, hyperostosis, osteitis (SAPHO): an interesting clinical syndrome

Synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome is a rare disorder that classically involves the musculoskeletal system, i.e. bone, joint and skin. The exact pathogenesis of this syndrome is unknown. However, autoimmunity, infections, immune malfunction and genetic factors are attributed to its pathophysiology. Bone and joint involvements are the hallmark of SAPHO syndrome and not necessarily require cutaneous involvement at the time of diagnosis. X-ray of the affected joints could show osteitis with sclerosis. Anterior chest wall involvement particularly ''bullhead appearance'' seen on bone scan is a striking feature of the syndrome. Erythrocyte sedimentation rate (ESR) is usually elevated amongst the majority of patients. Diagnosis of SAPHO is always challenging and often delayed because of a multitude of symptoms. The mainstay of treatment is control of pain and inflammation with both non-steroidal anti-inflammatory drugs (NSAIDs) and rescue courses of systemic steroids. If failed to control symptoms with first-line agents and in those with severe disease, disease-modifying anti-inflammatory drugs (DMARDs) may be needed eventually. Despite a chronic inflammatory condition, it remains stable in the majority of cases. Here in this case report, we reiterate the importance of early recognition, timely diagnosis and prompt treatment initiation

An interesting case of cellulitis caused by Shewanella

Shewanella species are opportunistically pathogenic, gram-negative bacilli that are part of marine microflora. Infection caused by Shewanella species in humans is rare and mostly acquired after direct contact with seawater or ingestion of raw seafood. The exact pathogenesis remains unclear. Cutaneous infections are among the most common manifestation with underlying skin diseases and immune-compromised states; however, bacteremia from lungs, abdominal, and biliary sepsis has also been reported. These infections are difficult to diagnose due to limited physicians' experience and scarce microbiological data available. Hence, delayed diagnosis and treatment could be fatal and may result in sepsis with multi-organ failure. Our case report reiterates the fact that careful attention should be devoted to unusual circumstances in history and atypical pathogens on cultures if there is no or minimal clinical improvement after antibiotics

Geochemical Signature of Mesozoic Volcanic and Granitic Rocks in Madina Regency Area, North Sumatra, Indonesia, and Its Tectonic Implication

Http://dx.doi.org/10.17014/ijog.vol4no2.20094Five samples consisting of two Permian-Triassic basalts, two Triassic-Jurassic granitic rocks, and a Miocene andesite were collected from the Madina Regency area in North Sumatra that is regionally situated on the West Sumatra Block. Previous authors have proposed three different scenarios for the geological setting of West Sumatra Permian Plutonic-Volcanic Belt, namely an island-arc, subduction related continental margin arc, and continental break-up. Petrographic analysis of the Mesozoic basaltic samples indicates that they are island-arcs in origin; however their trace element spider diagram patterns (Rock/MORB ratio) also show the character of back-arc marginal basin, besides the island-arc. Furthermore, their REE spider diagram patterns (Rock/ Chondrite ratio) clearly reveal that they were actually generated in a back-arc marginal basin tectonic setting. Meanwhile, the two Mesozoic granitic rocks and the Miocene andesite reflect the character of an active continental margin. Their spider diagram patterns show a significant enrichment on incompat- ible elements, usually derived from fluids of the subducted slab beneath the subduction zone. The high enrichment on Th makes their plots on Ta/Yb versus Th/Yb diagram are shifted to outside the active continental margin field. Although the volcanic-plutonic products represent different ages, their La/Ce ratio leads to a probability that they have been derived from the same magma sources. This study offers another different scenario for the geological setting of West Sumatra Permian Plutonic-Volcanic Belt, where the magmatic activities started in a back-arc marginal basin tectonic setting during the Permian-Triassic time and changed to an active continental margin during Triassic to Miocene. The data are collected through petrographic and chemical analyses for major, trace, and REE includ- ing literature studies

ON-LINE MEASUREMENTS OF OXIDATION OF CARBON USING VISIBLE SPECTROSCOPY

We have identified four different band heads belonging to the B1 Σ-A1 Π bands of the Angstrom system of the CO spectrum in the visible region at λ = 561.0, 519.8, 451.1 and 439.3 nm, for on-line monitoring of conversion of carbon to carbon monoxide in the ‘de-coking’ process of a ‘coked’ catalyst. A low-power glow discharge in oxygen gas was used as a source for oxidizing carbon from a ‘coked’ zeolite catalyst. Evolution of CO as a function of time was systematically monitored using the 451.1 nm band head since there is no overlap with any possible impurities including oxygen, nitrogen or water vapor. An interesting observation is an exponential increase in the evolution of CO typically after about 10 minutes from the initiation of the discharge. The results may be of particular interest in monitoring catalyst regeneration on-line as well as environmental monitoring of CO