Heterogeneous Computing for Data Stream Mining

Graphical Processing Units are de-facto standard for acceleration of data parallel tasks in high performance computing. They are widely used to accelerate batch machine learning algorithms. High-end discrete GPUs are characterized by a very high number of cores (thousands), high bandwidth memory optimized for the stream access and high power requirements. Integrated GPUs are characterized by a medium number of cores (hundreds), medium bandwidth memory shared with CPU optimized for the random access and low power requirements. Data stream processing applications are often required to provide response within the limited time frame, operate on data in relatively small increments and have strict power requirements if deployed on the embedded devices. This work evaluates performance of integrated and discrete GPUs belonging to the same chip family on several variants of k-nearest neighbours algorithm over sliding window and stochastic gradient descent using OpenCL and novel Heterogeneous System Architecture platforms. We conclude that integrated GPUs provide a niche solution catering for to small work sizes that offers better power efficiency and simplicity of deployment

A rare case of Ewing's sarcoma in a 4-year-old child treated by tumor endoprosthetics using 3D printing

Orthopedic oncology surgery often requires, by its very nature, precise and often extensive resections of bone and soft tissue involved in or near the tumor mass. One of the most recent and promising innovations is represented by 3D printing technology, whose main advantage in this field of application is patient specificity, which is essential in an operation that requires high precision and maximum respect for the individuality of his bones and soft tissues. Material and methods: In the present report, we present a 4-year-old boy diagnosed with Ewing's sarcoma involving ¾ of the right tibia. In another medical facility, he was offered amputation. Our team decided to use the "3D printed tumor megaendoprosthesis, double growing, from the Czech company Prospon. For reinsertion of the muscle groups to the endoprosthesis, we used a LARS textile tube that was attached to the femoral and tibial components of the endoprosthesis. A vascular surgeon also participated in the team. The patellar ligament was reinserted to the tibial component, and myoplasty was additionally performed with the medial head of the m. gastrocnemius. Intraoperatively, we lengthened the lower limb by 1.5 cm to delay the upcoming staged lengthening. Results: The postoperative period was uneventful, with sutures removed on the 12th postoperative day. For 3 weeks, a tutor orthosis was placed. Active physiotherapy was started after removal of the orthosis 21 days after surgery. Conclusion: Our goal is to perform a total revision at the end of skeletal growth if possible and replace the current implant with a non-growing tumor megaendoprosthesis in the absence of near or distant metastases and long-term patient survival. Future expectations are that non-invasive lengthening mechanisms or a biological approach will be able to meet the special needs of this population

Two Cases of Use of Cement Augmented Screws for Osteosynthesis of the Spine

With this report we decided to present the initial experience with the use of cement augmented screws in Cotrel-Dubousset fixation in cases of patients with degenerative spines in combination with severe osteoporosis. We present two patients who underwent treatment at UMHAT "Sv. Georgi ”, Plovdiv. The first is a 75-year-old woman who underwent right hip arthroplasty in 2002 with a Muller prosthesis. 14 years later (in 2016) due to implant ablation, a revision of the joint with a cementless, revision modular endoprosthesis of Metrimed was performed. In 2022, due to secondary degenerative scoliosis, the patient began to complain of pain in the lumbar spine, which required decompression and posterior fixation with cement augmented screws. The second patient was a 72 years old female and in September 2021 suffered an osteoporotic fracture at L4 level. Balloon kyphoplasty was performed at the same level. However, due to leakage of cement into the vertebral canal, it was necessary to decompress the canal and apply again the mentioned fixation system. The visual analog scale (VAS) was used to assess the effect of response to therapy. Both patients had no symptoms of nerve compression. Fenestrated screws were used in both cases.

Initial experience with peroral endoscopic myotomy in Bulgaria: case series

Achalasia is a rare motility disorder with unknown etiology that results in failure of relaxation of the lower esophageal sphincter (LES). As there is no etiological treatment, different pharmacological agents and invasive techniques have been used for relieving the symptoms. For the past decade, peroral endoscopic myotomy (POEM) has proven to have excellent results.We present a retrospective study of five patients that underwent POEM for primary achalasia. We used anterior approach for the submucosal tunneling. The procedure showed immediate results and no severe short- or long-term adverse events. We have been following the patients up for more than 3 years now.Since its invention more than ten years ago, the POEM procedure and its advantages and disadvantages compared to the pneumatic dilatation and the Heller myotomy have been extensively studied. There is still no universal opinion on which procedure should be the first line treatment

Analysis and use of neural networks as a tool for a rapid non-invasive estimation

Water deficit is one of the most important environmental factors limiting sustainable crop yields and it requires a reliable tool for fast and precise quantification. In this work we use simultaneously recorded signals of photoinduced prompt fluorescence (PF) and delayed fluorescence (DF) as well as modulated reflection (MR) of light at 820 nm for analysis of the changes in the photosynthetic activity in detached bean leaves during drying. Depending on the severity of the water deficit we identify different changes in the primary photosynthetic processes. When the relative water content (RWC) is decreased to 60% there is a parallel decrease in the ratio between the rate of excitation trapping in the Photosystem (PS) II reaction center and the rate of reoxidation of reduced PSII acceptors. A further decrease of RWC to 20% suppresses the electron transfer from the reduced plastoquinone pool to the PSI reaction center. At RWC below values 15%, the reoxidation of the photoreduced primary quinone acceptor of PSII, QA–, is inhibited and at less than 5%, the primary photochemical reactions in PSI and II are inactivated. Using the collected sets of PF, DF and MR signals, we construct and train an artificial neural network, capable of recognizing the RWC in a series of “unknown” samples with a correlation between calculated and gravimetrically determined RWC values of about R2 ≈ 0.98. Our results demonstrate that this is a reliable method for determination of RWC in detached leaves and after further development it could be used for quantifying of drought stress of crop plants in situ. This article is part of a Special Issue entitled: Photosynthesis Research for Sustainability: from Natural to Artificial

An Abrupt Drowning of the Black Sea Shelf at 7.5 KYR BP

During latest Quaternary glaciation, the Black Sea became a giant freshwater lake. The surface of this lake drew down to levels more than 100m below its outlet. When the Mediterranean rose to the Bosporus sill at 7.5 kyr BP, saltwater poured through this spillway to refill the and submerge in less than a year, more than 100,000km2 of its exposed continental shelf

Drought-induced modifications of photosynthetic electron transport in intact leaves: Analysis and use of neural networks as a tool for a rapid non-invasive estimation

AbstractWater deficit is one of the most important environmental factors limiting sustainable crop yields and it requires a reliable tool for fast and precise quantification. In this work we use simultaneously recorded signals of photoinduced prompt fluorescence (PF) and delayed fluorescence (DF) as well as modulated reflection (MR) of light at 820nm for analysis of the changes in the photosynthetic activity in detached bean leaves during drying. Depending on the severity of the water deficit we identify different changes in the primary photosynthetic processes. When the relative water content (RWC) is decreased to 60% there is a parallel decrease in the ratio between the rate of excitation trapping in the Photosystem (PS) II reaction center and the rate of reoxidation of reduced PSII acceptors. A further decrease of RWC to 20% suppresses the electron transfer from the reduced plastoquinone pool to the PSI reaction center. At RWC below values 15%, the reoxidation of the photoreduced primary quinone acceptor of PSII, QA–, is inhibited and at less than 5%, the primary photochemical reactions in PSI and II are inactivated. Using the collected sets of PF, DF and MR signals, we construct and train an artificial neural network, capable of recognizing the RWC in a series of “unknown” samples with a correlation between calculated and gravimetrically determined RWC values of about R2≈0.98. Our results demonstrate that this is a reliable method for determination of RWC in detached leaves and after further development it could be used for quantifying of drought stress of crop plants in situ. This article is part of a Special Issue entitled: Photosynthesis Research for Sustainability: from Natural to Artificial

Two Cases of Use of Cement Augmented Screws for Osteosynthesis of the Spine

With this report we decided to present the initial experience with the use of cement augmented screws in Cotrel-Dubousset fixation in cases of patients with degenerative spines in combination with severe osteoporosis. We present two patients who underwent treatment at UMHAT "Sv. Georgi ”, Plovdiv. The first is a 75-year-old woman who underwent right hip arthroplasty in 2002 with a Muller prosthesis. 14 years later (in 2016) due to implant ablation, a revision of the joint with a cementless, revision modular endoprosthesis of Metrimed was performed. In 2022, due to secondary degenerative scoliosis, the patient began to complain of pain in the lumbar spine, which required decompression and posterior fixation with cement augmented screws. The second patient was a 72 years old female and in September 2021 suffered an osteoporotic fracture at L4 level. Balloon kyphoplasty was performed at the same level. However, due to leakage of cement into the vertebral canal, it was necessary to decompress the canal and apply again the mentioned fixation system. The visual analog scale (VAS) was used to assess the effect of response to therapy. Both patients had no symptoms of nerve compression. Fenestrated screws were used in both cases.

A case of tumor megaendoprosthesis for sarcoma of the proximal part of tibia

Our aim was to present a rare case of tumor megaendoprosthetic replacement with restitution of the extensor mechanism of the knee via reattachment of the patellar tendon to the prosthesis and myoplasty with the medial head of gastrocnemius muscle